Search

Point clouds captured using laser scanners mounted on mobile platforms contain errors at the centimetre to decimetre level due to motion distortion. In applications such as lidar odometry or SLAM, this motion distortion is often ignored. However, in applications such as HD mapping or precise vehicle localisation, it is necessary to correct the effect of motion distortion or ‘deskew’ the point clouds before using them. Existing methods for deskewing point clouds mostly rely on high frequency IMU, which may not always be available. In this paper, we propose a straightforward approach that uses the registration of consecutive point clouds to estimate the motion of the scanner and deskew the point clouds. We introduce a novel surface‐based evaluation method to evaluate the performance of the proposed deskewing method. Furthermore, we develop a lidar simulator using the reverse of the proposed deskewing method which can produce synthetic point clouds with realistic motion distortion. [ABSTRACT FROM AUTHOR]

The dynamics of milling circuits, particularly those involving Semi-Autogenous Grinding (SAG) mills, are not adequately studied, despite their critical importance in mineral processing. This paper aims to investigate the dynamic behavior of an SAG mill pebble recycling circuit under varying feed ore conditions, focusing on both uncontrollable parameters (such as ore hardness) and controllable parameters (including circuit layout and pebble crusher configurations). The study is carried out with Simulink dynamic simulations. Our findings reveal several key insights. Firstly, plant designs based solely on static simulations may not be adequate for large or complex circuits, as they fail to account for the dynamic nature of milling processes. Second, incorporating stockpiles after pebble crushing can effectively mitigate the impact of dynamic fluctuations, leading to more stable circuit performance. Third, different circuit layouts can facilitate easier maintenance and operational flexibility. Notably, finer pebble crushing can enhance circuit throughput by 5% to 10%. [ABSTRACT FROM AUTHOR]

Background and Objectives: When a haematopoietic stem cell registry size is constrained by limits on recruiting, as in Canada, identifying the right person to recruit is a critical determinant of effectiveness. The aim of this study was to evaluate the impact of changes to donor recruitment effort, within ethnic groups, on the matching effectiveness of the Canadian registry as it evolves over time. Materials and Methods: Simulation methods are applied to create a cohort of donor recruits and patients over a 10‐year time horizon. New recruits are added to the registry each year, while some existing donors 'age‐out' upon reaching their 36th birthday. In a similar fashion, simulated patient lists are created. At the end of each simulated year, simulated patients are matched against the simulated registry. Results: There are increased matches in non‐White populations when diverse registrants are preferentially recruited, but there are larger decreases in the number of matches for Caucasian patients. Additionally, ethnic communities that have limited registrants in the Canadian registry in 2021 do not benefit from increased recruiting efforts as much as communities with a larger initial number of registrants. Conclusion: Preferentially recruiting from non‐Caucasian populations reduces the number of matches from Canadian sources because increases in non‐Caucasian populations will not fully counterbalance decreases to Caucasian patient matches. Nevertheless, more than 80% of all matches are for Caucasian patients, regardless of the donor recruiting effort within ethnic groups. [ABSTRACT FROM AUTHOR]

The presented article deals with the issue of inventory management optimization through modelling and simulation in the software Tecnomatix Plant Simulation. Based on an in-depth analysis of the supply chain with an emphasis on inventory management, a simulation model was developed. It was optimized using the inventory theory methodology in combination with a discrete-event simulation approach. Dynamic simulation made it possible to perform experiments and optimize the existing state. The solution to the problem is elaborated on a case study to achieve the efficiency of the supply process of a specific operation of a clothing retail chain, which is struggling with the problems of excessive and inaccurate supply. [ABSTRACT FROM AUTHOR]

Educational buildings are public buildings where highly dense pedestrian traffic is seen during the daytime. Although stairs are mainly used in vertical circulation, the presence of an elevator is also required by the regulations. However, when the relevant standards and regulations are observed, a comprehensive analysis method or agenda procedure detailed to determine the number and capacity of the elevator/s for the education building has not been noticed. With the research, elevator design, which is an important design problem, is examined in terms of elevator traffic analysis according to the literature review findings and is also hypothetically evaluated through the schools listed in the building catalog of the Ministry of National Education (MNE). According to both the traditional -based on mathematical calculations- and the modern method -with the help of dynamic simulation program-, elevator traffic analyzes are carried out based on different user profiles, and the carrying capacity of the elevators are tested in the buildings selected. The results of the analysis are evaluated in terms of the Average Waiting Time (AWT), which is considered important for elevator traffic, so that the limits of the system/s are determined. Based on the traffic analysis results of the hypothetical scenarios examined within the scope of the study; it has been observed that the minimum requirements in the legislation/s are determined only by considering the use of elevators due to disabled users, while the possibility of using elevators of the others is not evaluated. It is noticed that the number of elevators prescribed in the regulations for educational buildings and their capacities are examined with disabled users in mind. There was no evidence that a detailed elevator traffic analysis of all users was conducted. [ABSTRACT FROM AUTHOR]

The aim of the work was to develop a multi-body model that can simulate the Impact between the vehicle wheel and a pothole. The model consists of the vehicle wheel together with front McPherson suspension assembly and a potholed road surface. Therefore the kinematics of the suspension when the vehicle hits a pothole can be simulated. The model was first predetermined by an analytical calculation and then successfully validated by an experimental test performed with the same parameters as the virtual model. The results were very similar and therefore allow the model to be used to simulate different scenarios in terms of wheel dynamics and behavior when impacting potholes with different depths. [ABSTRACT FROM AUTHOR]

Understanding of the human body's internal processes to maintain balance is fundamental to simulate postural control behaviour. The body uses multiple sensory systems' information to obtain a reliable estimate about the current body state. This information is used to control the reactive behaviour to maintain balance. To predict a certain motion behaviour with knowledge of the muscle forces, forward dynamic simulations of biomechanical human models can be utilized. We aim to use predictive postural control simulations to give therapy recommendations to patients suffering from postural disorders in the future. It is important to know which types of modelling approaches already exist to apply such predictive forward dynamic simulations. Current literature provides different models that aim to simulate human postural control. We conducted a systematic literature research to identify the different approaches of postural control models. The different approaches are discussed regarding their applied biomechanical models, sensory representation, sensory integration, and control methods in standing and gait simulations. We searched on Scopus, Web of Science and PubMed using a search string, scanned 1253 records, and found 102 studies to be eligible for inclusion. The included studies use different ways for sensory representation and integration, although underlying neural processes still remain unclear. We found that for postural control optimal control methods like linear quadratic regulators and model predictive control methods are used less, when models' level of details is increasing, and nonlinearities become more important. Considering musculoskeletal models, reflex-based and PD controllers are mainly applied and show promising results, as they aim to create human-like motion behaviour considering physiological processes. [ABSTRACT FROM AUTHOR]

Coastal aquaculture is an important economic activity in India dominated majorly by shrimp culture, which involves a range of interconnected processes that are challenging to analyse and optimise without a systematic approach. System dynamics modelling is a useful tool for understanding and predicting the behavior of complex coastal aquaculture systems. here, we review the status of dynamic simulation modelling works undertaken in aquaculture, which can provide directives for various researchers working on developing simulation models for shrimp aquaculture. There is a need to assess the impact of dynamic forces on the animals during the culture period which could be addressed through these models. System dynamic models assist decision-makers to augment potential measures for aquaculture-related problems under different possible scenarios. System dynamic models developed in aquaculture were related to feeding, water quality parameters, nitrogen dynamics, growth, etc. The strengths and limitations of software packages used in developing the simulation models are discussed. Considering the economic potential of shrimp aquaculture, it is important to develop an integrated dynamic model for predicting all the sub-processes of shrimp aquaculture. [ABSTRACT FROM AUTHOR]

• Conversion of a DHN to diversified and decentralized renewable supply. • Fully physical digital twin of real DHN used to compare five renewable scenarios. • Implementation of up to 11 different generation and storage technologies at once. • Thermal energy storages with high charging/discharging power are essential. • Results show that at least 98 % renewable supply is possible. Due to the tremendous effects of climate change, the goal of a climate-friendly energy supply has developed into the main task of the energy sector. Today climate neutrality is a central issue at social, political and economic levels. It is a sector coupling issue, requiring renewable energies in electricity, mobility and heat supply. While the heat sector contributes the largest share to final energy demand of German municipalities, it is also the sector for which the path towards climate neutrality will be most challenging. This study presents pathways for large cities for the transition from fossil to renewable heat supply based on the example of Rostock. A detailed, fully-physical simulation model for Rostock's district heating was developed considering different potential heat sources including heat pumps, industrial and process heat, incineration of sewage sludge, waste and solid biomass as well as geothermal and solar thermal plants. Additionally, thermal energy storages have been integrated into the model. The study highlights the importance of simulation models in evaluating the feasibility of energy systems and emphasizes the need for incorporating detailed information in these models to obtain accurate results. Multiple scenarios have been investigated in order to analyse the interplay of heat generation, storage and the annual course of heat consumption. Five final concepts were derived meeting the requirement of climate-neutral heat supply. Although the results show that each variant has advantages and disadvantages, heat generators that make technical and economic sense in all cases were identified. The implementation of these is recommended. [ABSTRACT FROM AUTHOR]

Background Breast reconstruction (BR) using autologous free flaps has been shown to have numerous psychosocial and quality-of-life benefits. Unfortunately, the microsurgical learning curve is quite steep due to some unique operative challenges. Currently, there is no realistic simulation model that captures real-life respiratory excursion and the depth of internal mammary vessels within the compact recipient site. The purpose of this study was to delineate intraoperative measurements of depth and motion, describe the resulting simulation model, and conduct a pilot study evaluating the simulator as an educational resource. Methods This is a single-center, ethics-approved study. For the intraoperative measurements, all consecutive patients undergoing free flap BR using internal mammary vessels as recipients were recruited. Patient and intraoperative factors as well as intraoperative measurements were recorded. A dynamic model was developed based on intraoperative parameters. For the pilot study, plastic and reconstructive surgery trainees were recruited to complete a hand-sewn internal mammary artery (IMA) anastomosis using the new simulator and completed objective questionnaires pre- and postsimulation. Subjective feedback was recorded and themes determined. Results Fifteen operative sites were analyzed. Flap pocket was found to be between 4 and 5 cm in depth with vertical excursion of 3.7 ± 1.0mm and a respiratory rate of 9 to 14 breaths/minute. Previous radiation, rib space, body mass index (BMI), blood pressure, heart rate, tidal volume, and respiratory rate showed no correlation to vessel depth/excursion. Laterality, rib space, BMI, radiation, vitals, and tidal volume had no correlation with vessel movement. Twenty-two trainees were included in the pilot. An increase in confidence and mixed results for anxiety was reported. Conclusion This study reports a novel microsurgical simulation model that provides a realistic deep inferior epigastric perforator free flap BR IMA anastomosis experience. It replicates movement of vessels in situ with real-time respiratory excursion and similar physical structures of the internal mammary system. This model shows promising results for increased use in microsurgical education. [ABSTRACT FROM AUTHOR]

Dynamic behavior of agricultural implements has always been a challenging topic for researchers. In precision farming, precise control of the agricultural implements is a very important task. To study the dynamics of agricultural implements, Researchers conduct field experiments as well as laboratory tests. These methods are very costly and the measurements are usually associated with some errors. Providing well-controlled experimental conditions in practice is very difficult, if not impossible. In this article, the capability of the SolidWorks in simulation and predicting the dynamic behavior of a conventional sprayer boom is discussed. To validate the results, field tests were conducted using a conventional sprayer boom. The results showed that there was no significant difference at 95% confidence level between results from computer simulation and those obtained from the field test of conventional sprayer boom. [ABSTRACT FROM AUTHOR]

Since existing energy system models often represent storage behavior in a simplified way, in this work, a tool chain for deriving consistent storage model parameters for optimization models is developed. The aim of our research work is to identify what are non-negligible influences on the the technical characteristics and dynamic behavior of the storage, to quantify the effect of these influences, and represent these effects in the model. This paper describes the developed tool chain and presents its application using an example. The tool chain consists of the steps "parameter screening", "dynamic simulation", "regression analysis" and "refining optimization model". It is investigated which parameters have an influence on the storage system (here pumped hydroelectric energy storage (PHES)), how the storage behavior is modeled, which influencing factors have a measurable effect on the system, and how these findings can be integrated into optimization models. The main finding is that in the case of PHES, the dependency of the charging and discharging efficiency on the power is significant, but no further influencing factor has to be considered for accurate modeling (0.946 ≤ R2 ≤ 0.988) of the efficiency. It is concluded that the presented toolchain is suitable for other storage technologies as well, including the analysis of aging behavior. [ABSTRACT FROM AUTHOR]

Learning about human eye movements broadens our comprehension of the visuomotor system and aids in the effective management of strabismus. One's clinical practice is improved by a dynamic simulation of human eye movements using physical models of the extraocular muscles (EOMs). We use our eyeball model to teach the basics of strabismus to undergraduate students and ophthalmology residents. In Listing's plane, extraocular movements of each muscle and the angle demonstration are being used to familiarize students with their knowledge. The degree of the residents' understanding of strabismus is significantly influenced by the eyeball strabismus simulator. This model is an inexpensive, Do It Yourself (DIY) model that is simple to build. [ABSTRACT FROM AUTHOR]

The spring finger collection mechanism is a core component of balers. It is usually used to collect soft straw crops (corn straw, wheat straw, green forage), and rarely used for hard stem crops (such as branch pruning residues). Due to different biophysical characteristics of hard stem crops and soft straw crops, the collection mechanisms are also different. In China, branch pruning residues in apple orchards are collected manually. It is a heavy labor task. To this end, this article uses an improved spring finger mechanism to collect pruning residues in apple orchard branches, effectively replacing manual collection operations. A dynamic motion trajectory simulation platform is developed by analyzing each action using pitchforks or other agricultural tools throughout the entire collection process, and combined with the structure of the spring finger collection mechanism. The platform of the spring finger collection mechanism is improved to collect orchard branches, and redesign and manufacture the core components of the collection mechanism. In addition, comparative tests were performed on4 different placement orientation sunder the conditions of R=40±2 r/min and V=0.9-1.1 m/s. That is, 1) messy, 2) transverse, 3) portrait orientation (the treetop firstly contacts the collection device), and 4) portrait orientation (the thick stems of the branches first touch the collection device). The results indicate that 1) and 2) have similar success rates in picking branches, while 3) and 4) have lower success rates, especially with 4) being the lowest). The analysis found that some branches were directly inserted into the spring finger gap and moved under the machine, resulting in a large amount of losses. This study aims to improve the success rate of picking branches in the bundling machine and verify the relationship between different placement directions and the success rate of picking branches. [ABSTRACT FROM AUTHOR]

The interest to ensure thermal comfort becomes one of the major challenges in the building sector, not only for the quality of interior ambiences, but also to minimize the energy rate consumed for heating and cooling systems. This paper presents the advantage of using the adaptive approach and numerical simulation to assess the level of thermal comfort of dwellings of different architectural typology in hot climate. For this purpose, the method is based on in situ measurements effected on two samples of traditional and contemporary typology; using anemometer instrument, where the climatic parameters measured inside and outside samples are: ambient temperature, relative humidity rate and air velocity. The simulation work is performed by Energy-Plus software; consequently experimental tests are realized on the local material in order to know their physical and thermal characteristics. The results obtained demonstrate the efficiency of the traditional passive devices, which are able to provide a comfortable thermal ambience without referring to the air conditioning system, with an operating temperature of 30.5ºC and a satisfaction rate of 80%. [ABSTRACT FROM AUTHOR]

Emergency materials transportation, both economic and societal, is one of the most important parts of unconventional emergency management. In the present study, we built a quantitative simulation model underlying the mechanism of emergency materials transportation specifically regarding typhoon disasters. We then explored the internal influence factors and association mechanisms of the dynamic model as they relate to the effective control and guidance of emergency materials transportation. Using system dynamic model, this paper conducts the simulation study to identify the key influencing factors for the speed of emergency materials transportation. The relationships between influencing factors and the emergency capability were analyzed qualitatively. On this basis, SD flow chart was built. A typhoon disaster event in Leizhou Peninsula, China, is used as an example to validate the effectiveness and feasibility of the proposed model, as well as to simulate different emergency management strategies. Results of governmental emergency materials transportation are key factors in process of emergency formulating the policy to improve the speed and efficiency for emergency materials transportation during the emergency management process. [ABSTRACT FROM AUTHOR]

The use of temperature rise inhibitors (TRIs) holds significant promise in mitigating thermal cracking issues in modern concrete by controlling the precipitation of C-S-H gel, the main product of cement hydration. However, the complexity of their interaction with the non-classical nucleation process of C-S-H remains unclear. This study systematically investigated the influence of a sorbitol-based liquid-type temperature rise inhibitor (L-TRI) on the hydration kinetics of cement suspension using a combination of methods, including conductivity testing, pore solution analysis, and molecular dynamic simulations. It is revealed that the admixture-to-water ratio, rather than admixture-to-cement ratio, governs the effect of L-TRI on cement hydration. The disturbance of L-TRI molecules in the pore solution, mainly calcium complexation and water stabilization, plays a decisive role in inhibiting the secondary nucleation of C-S-H and decelerating the following growth. In contrast, L-TRI has a negligible influence on cement dissolution and the formation of C-S-H precursor. • Non-adsorbed L-TRI polymer impacts cement hydration through pore solution disturbance. • L-TRI barely affects cement dissolution and primary nucleation of C-S-H. • L-TRI inhibits the secondary nucleation of C-S-H by calcium complexation. • L-TRI decelerates the growth of C-S-H by calcium complexation and water stabilization. [ABSTRACT FROM AUTHOR]

Aztreonam is a Gram-negative bacteria-targeting synthetic monobactam antibiotic. Human serum albumin (HSA) plays an important role in the transference of pharmaceuticals, hormones, and fatty acids, along with other compounds, determining their biodistribution and physiological fate. Using several biophysical and in silico approaches, we studied the interaction of aztreonam with HSA under physiological environments in this study. Results confirm the formation of HSA-aztreonam complex where aztreonam showed moderate affinity towards HSA. A static mode of quenching was confirmed from the steady state fluorescence data. FRET findings also showed that there was a significant feasibility of energy transfer between HSA and aztreonam. Site marker displacement experimental conclusion suggested the binding site of aztreonam was the sub-domain IB of HSA. Circular dichroic spectroscopic analysis suggested that aztreonam interaction decreases the α-helical content of HSA. Changes in microenvironment were studied through synchronous fluorescence data. According to molecular docking results, the HSA-aztreonam complex is mostly maintained by non-covalent forces, with a binding energy of 7.7 kcal mol−1. The presence of a hydrogen bond, van der Waal interaction, and pi-anion interaction in the binding process, as well as conformational changes in HSA after binding with aztreonam, are all confirmed by molecular dynamic simulation. [ABSTRACT FROM AUTHOR]

In order to increase the efficiency of the order-picking process, warehouses are forced to find ways to adopt to constantly intensifying changes in the assortment and quantities of stored products. Accordingly, we present a methodology that deals with such a problem at a tactical level by defining the optimal size and an allocation of products within the order-picking area of the most typical order-picking setting. The methodology combined two methods, dynamic programming and simulation modelling, with the aim of taking advantages of their positive features. In that sense, the optimal allocation of products for different sizes of the order-picking zone were obtained by the dynamic programming approach. Afterwards, the influence of a demand's seasonality and variations were treated by the simulation model, so that the more realistic performances of the system were captured for the optimal allocation of products. The methodology was tested on the retailer data with significant week seasonality. The obtained results confirmed the practical applicability of the methodology in real systems, while the sensitivity analysis of results showed that special attention and effort should be given to the determination of costs related to the engagement of order-pikers, storage equipment and unit replenishment during a planning period. [ABSTRACT FROM AUTHOR]

Angiotensin converting enzyme (ACE) is a key enzyme and mediator in the aetiology of high blood pressure (HBP) and hypertension. As one of the leading cause of untimely death worldwide, there is a lot of research and studies on the management and treatment of hypertension. The usage of medicinal plants in the management of hypertension as alternative to synthetic allopathic drugs is a common practice in folkloric and traditional medicine. Therefore, this study was aimed to investigate the ACE inhibitory activity of some medicinal plants which are commonly used in the treatment of HBP in southwestern part of Nigeria using extensive in-silico approach. Compounds identified in the plants through GC–MS technique, together with Lisinopril were docked against ACE protein. It was observed that only 40 of the compounds had binding affinity ≥ − 6.8 kcal/mol which was demonstrated by the standard drug (lisinopril). Interaction between the compounds and ACE was via conventional hydrogen, carbon hydrogen, alkyl, pi-alkyl, pi-carbon, and Van Der Wall bonds among others. Most of these compounds exhibited drug like properties, without violating majority of the physicochemical descriptors and Lipinski rule of 5. The ADMET evaluation revealed that only 2 compounds (cyclopentadecanone and oxacycloheptadecan-2-one) which were identified in Bacopa florinbunda plant were predicted non-toxic and thus were subjected to molecular dynamics and simulation with ACE. From the molecular dynamics and mechanics analysis, both cyclopentadecanone and oxacycloheptadecan-2-one showed high stability and inhibitory potentials when bound to ACE. Oxacycloheptadecan-2-one was more stable than lisinopril and cyclopentadecanone in the ligand–ACE complex; we therefore suggested its experimental and clinical validation as drug candidates for the treatment of hypertension. [ABSTRACT FROM AUTHOR]

Knowledge about factors affecting the dynamic response process is crucial for development of mixed-potential gas sensor for various applications such as hydrogen detection. Based on a double layer capacitor model and the Butler-Volmer equation, the present work studied the dynamic hydrogen sensing process by numerical simulation in combination with experimental assessment. Simulation shows that both response and recovery times are jointly determined by the decrease rate of the net reaction current and the magnitude of response. Increase of standard reaction rate constants, transfer coefficients, standard equilibrium potential, or gas concentrations accelerates both the response and recovery processes, while double layer capacitance has a reverse effect. A power-law concentration dependence of the response/recovery time is obtained under Tafel kinetics. The simulated response curves and behavior agree quite well with the experimental results. These findings shed lights on the sensing kinetics of the mixed-potential hydrogen sensor, and may help guide the sensor design. • Theoretical and experimental study of dynamic mixed-potential gas sensing process. • Factors function via tuning decrease rate of net reaction current and response value. • Materials of high electrochemical activities favor the sensing dynamics. • Power-law concentration dependence of response time under Tafel kinetics. [ABSTRACT FROM AUTHOR]

The present work shows the design of two simulations using free dynamic software that allows efficient modeling of the reflection, refraction and polarization of light. Specifically, the objective of the designed simulations is to verify computationally the laws of Snell and Malus, evaluating each one of the phenomena in an ideal way. These simulations were developed in GeoGebra computer software which allows the generation of dynamic designs referring to the nature and propagation of light. As a result, the numerical verification of each of the physical phenomena under study is shown, thus generating validity and reliability in the design of the simulations. [ABSTRACT FROM AUTHOR]

[Display omitted] Large-scale freezing and thawing experiments of monoclonal antibody (mAb) solutions are time and material consuming. Computational Fluid Dynamic (CFD) modeling of temperature, solute composition as well as the stress time, defined as the time between start of freezing and reaching T g ' at any point in the container, could be a promising approach to ease and speed up process development. Temperature profiles at six positions were recorded during freezing and thawing of a 2 L rectangular bottle and compared to CFD simulations via OpenFOAM. Furthermore, cryoconcentration upon freezing and concentration gradients upon thawing of a mAb solution were predicted and the stress time calculated. Temperature profiles during freezing were accurately matched by the CFD simulation. Thawing time was only 45 min to 60 min longer in the model. The macroscopic cryoconcentration of the mAb was also matched by the simulation; only a highly concentrated region in the top and a diluted core in the geometrical centre of the 2 L bottle were not well reflected in the simulation. The concentration gradient after thawing obtained by simulation as well agreed with the experimental result. In addition, CFD simulations allowed to extract the global temperature distribution, the formation of ice, and thus the distribution of stress in the freezing liquid. CFD simulations via OpenFOAM are a promising tool to describe large-scale freezing and thawing of mAb solutions and can help to generate a deeper understanding and to improve testing of the robustness of the processes. [ABSTRACT FROM AUTHOR]

Corrective osteotomy of malunion of both forearm bones is a challenging procedure because it needs accurate angular and rotational correction of both bones. Recent advances in three-dimensional (3D) printing techniques have shown promising results in the correction of complex deformities. We report a patient with malunion of both bones of the forearm in whom we determined site and degree of correction required based on the computed tomography images of the affected side and mirrored images of the contralateral healthy side. We then created 3D printed sawbones and simulated osteotomy to confirm stable dynamic forearm rotation. This method enabled satisfactory restoration of anatomical and functional outcomes. Preoperative dynamic motion simulation using 3D printed anatomic bone model is helpful for complex corrective osteotomy of forearm fracture malunion. Level of Evidence: Level V (Therapeutic) [ABSTRACT FROM AUTHOR]

SDTrimSP is a popular simulation program to compute several effects of the interaction between an impinging ion and a solid, such as ion implantation ranges, damage formation or sputtering of surface atoms. We now introduce a graphical user interface for SDTrimSP to make its operation more accessible for a broad group of users. It is written as a separate Python program and is not restricted to any specific operating system. The interface allows a quick and easy start as well as the direct evaluation of SDTrimSP simulations. Its capabilities are demonstrated here in the form of several example cases, including the dynamic simulations with SDTrimSP, where ion-induced target changes are taken into account. The presented graphical user interface is made freely available to support a large number of users in performing simulations of ion–solid interaction. [ABSTRACT FROM AUTHOR]

Layer-by-layer self-assembly of polyelectrolytes is one of the most promising methods for preparing nanofiltration membranes. Here poly (sodium 4-styrenesulfonate) (PSS) and poly (diallyldim-ethylammonium chloride) (PDADMAC) were chosen to prepare polyelectrolyte multilayer (PEM) membrane. The effects of background salt concentration, PSS concentration, background salt types, the number of layers and the outermost functional groups on the separation performance of the PEM were investigated systematically. Molecular dynamic simulation was employed to simulate the influence of background salt on the diffusion of PDADMAC. The simulation results agree well with the experimental results. The optimized (PSS/PDADMAC) 4.5 membrane with Na 2 SO 4 as background salt shows permeance of 15.9 LMH/bar, Na 2 SO 4 rejection of 98.2 %, and an excellent stability. Our study provides both theoretical and experimental supports for the preparation of PEM membranes using LBL method. [Display omitted] • Affecting factors were systematically investigated for polyelectrolyte membrane prepared by layer-by-layer self-assembly. • MD simulation results show that different ions influence the diffusion rate of polyelectrolyte. • The obtained membrane shows excellent separation performance for corresponding salts. [ABSTRACT FROM AUTHOR]

With the development of photovoltaic industry, the demand for silicon materials increases, and the competition in monocrystalline silicon manufacturing is becoming increasingly fierce. To improve efficiency and reduce cost, single crystal furnace operating under a driving system with high stability and reliability is of importance. This paper aims to design and optimize the driving system of the single crystal furnace. The driving system of NVT-HG2000-V1 silicon single crystal growth furnace was taken as the research object. The virtual assembly with SolidWorks 3D modeling was realized, and its dynamic simulation model with ADAMS was established. Then the motion process of the driving system was simulated. Using single variable method, the influence of the fit clearance between copper sleeve and lifting shaft as well as the screw parameters on the driving force and torque was quantitatively analyzed. The results show that when the fit clearance between copper sleeve and lifting shaft reaches 0. 071 mm, the driving torque required for the operation of the driving system can effectively reduces. The increase of lead screw inclination, thread pitch and friction coefficient between threads will lead to a significant increase in the torque required for the operation of the driving system. Reasonable technical suggestions have been proposed based on the research. [ABSTRACT FROM AUTHOR]

Due to the rapid depletion of water resources, more interest is paid for the efficient desalination process in recent years. MoS2 membrane aroused attention due to its high mechanical stability and electronic properties, which can sustain extra-large strains. In this study, the electronic properties and water desalination performance of TiO2/MoS2-hexagonal, and TiO2/MoS2-rhombohedral nanocomposites bilayer membranes were studied and simulated for the first time. The effect of TiO2 in the performance of MoS2 was observed in water desalination under the defined applied pressure ranging from 50 to 250 MPa with a 6.4 Å pore diameter. The membrane structure is created and optimized. The energy minimized for TiO2 from − 19,596.4282 kcal/mol for the initial structure to − 19,605.1611 kcal/mol for the final structure. For TiO2/MoS2-hexagonal, the energy minimized from − 4955.54271 eV) to − 4955.62091 eV and TiO2/MoS2-rhombohedral from − 6042.26925 eV to − 6046.91835 eV. A molecular dynamic (MD) simulation was performed using Material Studio 2019 to study the electronic properties under 0–1 eV electric field using the CASTEP code. The results showed a better photocatalytic performance under the external electric field. The effect of external electric field significantly intensifies absorption in the visible range and achieved a high photocatalytic activity on TiO2/MoS2. TiO2, TiO2/MoS2-hexagonal and TiO2/MoS2-rhombohedral nanocomposites bilayer membranes are simulated and evaluated for the water desalination using ReaxFF software. Both MoS2 phases with TiO2 have achieved a high salt rejection up to 97% (P-value = 0.0036, R2 = 0.958), while TiO2/MoS2-rhombohedral achieved the highest permeability (6.0*10−8 mm g cm−2 s−1 bar−1) (P-value = 0.000296, R2 = 0.972) under 250 MPa applied pressure. [ABSTRACT FROM AUTHOR]

Increasing competition and globalization that encompasses all dealings in the world of business compel SMEs to seek more successful organizational and management modes and approaches. This paper presents a simulation model for the application of Lean methods and tools in SMEs and their impact on the improvement of production processes and product sustainability. The Lean concept can be used to achieve more efficient production whilst manufacturing lower-cost products including shorter manufacturing cycle, high quality, and added value. Research results show the usefulness of the application of dynamic simulations in the detection of critical places in processes and the usefulness of the application of relevant Lean methods and Lean tools for process improvement. Simulation results underline better performance of product manufacturing through the use of Lean tools with the aim to eliminate any waste. Reengineering the assembly line focuses on the following aspects, namely reducing waste, internal logistics, redesigning workplaces, and changing the workplace layout. [ABSTRACT FROM AUTHOR]

Purpose: Global economic growth provides new opportunities for the development of clothing enterprises, but at the same time, the rapid growth of clothing customization demand and the gradual increase of clothing costs also pose new challenges for the development of clothing enterprises. In this context, 3D printing technology is injecting new vitality and providing a new development direction for the vigorous development of clothing enterprises. However, with the application of 3D printing technology, more and more clothing enterprises are facing the problem of business model innovation. In view of the lack of relevant research, it is necessary to carry out exploratory research on this issue. Design/methodology/approach: The business model canvas method was adopted to design business model for clothing enterprises using 3D printing. The simulation model of the designed business model was constructed by a system dynamics method, and the application of the designed business model was analysed by a scenario simulation. Findings: Mass selective customization-centralized manufacturing (MSC-CM) business model was constructed for clothing enterprises using 3D printing, and a static display was carried out using the BMC method. A dynamic simulation model of the MSC-CM business model was constructed. The future scenario of clothing enterprises using 3D printing was developed, and a simulated enterprise was analysed. The results show that the MSC-CM business model has a good application value. The simulation model of the MSC-CM business model performs the function of a business strategy experiment platform and also has a good practical application value. Research limitations/implications: The MSC-CM business model is only a typical business model for clothing enterprises using 3D printing. It is necessary to further develop other business models, and some elements of the MSC-CM business model need to be further improved. In addition, the MSC-CM business model simulation uses a general model, which is not suitable for all clothing enterprises using 3D printing. When the model is applied, the relevant enterprises can further adjust and optimize it, thereby improving the validity of the simulation model. Originality/value: To the best of the authors' knowledge, this is the first paper on the MSC-CM business model for garment enterprises using 3D printing. Secondly, it is the first time that the business model of clothing enterprises using 3D printing has been simulated. In particular, the proposed business model simulation provides the possibility for testing the business strategy of clothing enterprises using 3D printing. In addition, a positive attempt has been made in the collaborative research of using both a static display business model and a dynamic simulation business model. [ABSTRACT FROM AUTHOR]

Purpose: Circular economy (CE) principles have evolved in response to natural resource depletion as a set of guidelines for eliminating the linear take-use-dispose model of product consumption. The consequences of shifting from a linear to a circular supply chain are difficult to visualize in the long term. This study aims to design a methodology for building a simulation model to implement CE strategies in any small and medium-sized enterprise SME to prove policies before implementing them in the real world. This paper applied the methodology in a biological cycle case study: a confectionery factory in Mexico. Design/methodology/approach: This study evaluated service-dominant logic, ecosystem services, system dynamics, and agent-based modeling to design the proposed methodology. A series of interviews with stakeholders were performed to assess the simulation model during the development phase. The circular economy indicator prototype (CEIP) was used as a circular maturity measure of the confectionery factory. The simulator was executed in Netlogo software, implementing a four-scenario analysis based on two CE policies for the caramel recycling process. Five state variables were proposed in this analysis: confectionery waste, recycled glucose, recycling utilization, costs of recycled glucose, and profit. Findings: The CEIP score of the confectionery factory was 52%, rated as a "good" product. Regarding scenario analysis, the first scenario had the highest profit improvement. Practical implications: The simulator allowed stakeholders to understand the operation of the recycling process and visualize all variables involved in the system. Originality/value: In the CE literature, little attention has been paid to proposing a methodology for designing a simulation model to implement CE strategies in any industry. Thus, this study implements a nine-step methodology based on services context and dynamic simulation tools to design a platform to evaluate and visualize the consequences of CE strategies implementation in the long term. [ABSTRACT FROM AUTHOR]

Purpose: Physicians utilize cerebral perfusion maps (e.g., cerebral blood flow, cerebral blood volume, transit time) to prescribe the plan of care for stroke patients. Variability in scanning techniques and post‐processing software can result in differences between these perfusion maps. To determine which techniques are acceptable for clinical care, it is important to validate the accuracy and reproducibility of the perfusion maps. Validation using clinical data is challenging due to the lack of a gold standard to assess cerebral perfusion and the impracticality of scanning patients multiple times with different scanning techniques. In contrast, simulated data from a realistic digital phantom of the cerebral perfusion in acute stroke patients would enable studies to optimize and validate the scanning and post‐processing techniques. Methods: We describe a complete framework to simulate CT perfusion studies for stroke assessment. We begin by expanding the XCAT brain phantom to enable spatially varying contrast agent dynamics and incorporate a realistic model of the dynamics in the cerebral vasculature derived from first principles. A dynamic CT simulator utilizes the time–concentration curves to define the contrast agent concentration in the object at each time point and generates CT perfusion images compatible with commercially available post‐processing software. We also generate ground truth perfusion maps to which the maps generated by post‐processing software can be compared. Results: We demonstrate a dynamic CT perfusion study of a simulated patient with an ischemic stroke and the resulting perfusion maps generated by post‐processing software. We include a visual comparison between the computer‐generated perfusion maps and the ground truth perfusion maps. The framework is highly tunable; users can modify the perfusion properties (e.g., occlusion location, CBF, CBV, and MTT), scanner specifications (e.g., focal spot size and detector configuration), scanning protocol (e.g., kVp and mAs), and reconstruction parameters (e.g., slice thickness and reconstruction filter). Conclusions: This framework provides realistic test data with the underlying ground truth that enables a robust assessment of CT perfusion techniques and post‐processing methods for stroke assessment. [ABSTRACT FROM AUTHOR]

Using the computational fluid dynamic numerical simulation method, the gas, liquid, and solid three-phase hydrodynamic behavior in a self-made aeration fluidized bed reactor was simulated numerically. The influence of gas inlet velocity and solid phase volume on gas holdup, solid holdup, and liquid circulation velocity in the reactor were studied. Treatment of Cd2+ wastewater by the self-made fluidized bed showed that when inlet velocity was 0.3 m/s and adsorbent dosage was 9.5%, the adsorption effect was the best, and the adsorption rate was 63.5%. Simulation results verified the experimental conclusions and clarified the interaction of the three phases of gas, liquid, and solid in the fluidized bed treatment of wastewater. The higher the air inlet speed, the lower was the solid content rate and the greater was the liquid circulation speed; at the same air inlet speed, the larger the solid phase volume, the higher was the solid content rate, the smaller was the solid phase volume, the greater was the liquid circulation speed, the higher was the gas holdup rate, and the higher was the utilization rate. [ABSTRACT FROM AUTHOR]

This study aimed towards an essential subject in the field of solar energy. The sun is a free clean energy source. This research presents the modeling and simulating of forced circulation solar thermal system for domestic hot water production in Iraq. The TRNSYS dynamic simulation program was chosen as the primary research tool. The TRNSYS model comprises component (collectors, controls, storage tanks, circulation pump, solar radiation processor, printer, equations, and integrators). The study was conducted in two different regions in Iraq (Baghdad and Basrah). The model investigated in many aspects, such as provide the demand of hot water for a family (ten persons) by using 10 m² of flat plate collector, stratification effect in a storage tank on the collector's thermal efficiency, and effect of hot domestic water different consumption on solar thermal system performance. Results present that the system could provide hot water demand in Baghdad (67-81% and 39-62%) and Basrah (69-82% and 49-66%) in summer and winter, respectively, by using solar energy. The maximum auxiliary energy was used during the cold months are (2980 MJ/month) in Baghdad and (2607 MJ/month) in Basrah. There was an increase in the isothermal layers in the storage tank due to a rise in collector efficiency. There was a higher performance of forced circulation solar thermal systems (SDHW) when the domestic hot water consumption is lower. [ABSTRACT FROM AUTHOR]

This article applies the Dynamic Simulation (DS) technique to the dynamic input-output model (DS/IO) designed by Johnson (1985 and 1986). The model is a generalization of the static input-output model (Leontief, 1941), with an additional emphasis on economic imbalance. The DS/IO consists of a system of 4n differential equations and 2n constraints. Therefore, attempts to model analytically are likely to be unsuccessful without numerical simulation. The DS/IO used data from the Mexican economy for calibration and validation. It was found that the dynamic multipliers are greater than the static multipliers due to the accelerator effect. The simulation of the DS/IO is also validated by the fact that the adjustment between current values and production projections from 2013 to 2019 is plausible. [ABSTRACT FROM AUTHOR]

This paper deals with a model builder for Hybrid Dynamic Systems (HDS), where technological components including sensors in an iconic format can be automatically dragged from a database and interconnected to produce the overall HDS, following industrial technological schemes. Once the model has been created, its consistency can be checked, and a block diagram simulation can be performed. The theory behind the software is based on Hybrid Bond Graphs (HBG), whose structural and causal properties will be exploited for the automatic generation of the diagnosis algorithms, which will be implemented online. Compared with developed programs for automated modeling of HDS, the presented methodology is valid for continuous and hybrid systems, and the HBG is used not only for block diagram simulation builders but also for the generation of Fault Detection and Isolation algorithms. The theory is illustrated by an industrial application that consists of the pneumo-electrical control of metro rolling stock. [ABSTRACT FROM AUTHOR]

A wheel flat is a common fault in railway vehicles that may develop after incorrect brake application, or localised wheel-rail adhesion reduction. Operators detect wheel flats using wayside systems that are not capable of delivering real-time alarms. A wheel flat defect was modelled and introduced to a railway wagon multibody dynamic simulation to study the vehicle dynamic behaviour triggered by such wheel tread defect. Bogie-based and car body-based wheel flat detection was evaluated to determine eventual hardware robustness and signal processing requirements for on-board wheel flat detection devices. Various vehicle operating conditionds and wheel flat defects were simulated to analyse the wheel flat impact propagation throughout the railway vehicle bodies. Wheel defect detectability was assessed using detectability indicators (DIs) based on envelope power spectrum analysis, crest factor and RMS. It was found that bogie and car body-based wheel flat detectability is highly dependent on the track characteristics. The wheel flat signature was reduced in the wheelset-bogie and bogie-car body interfaces, indicating that advanced signal processing techniques are required for bogie-based and car body-based wheel flat detection systems. The DIs showed clear differences between healthy and faulty wheelset and bogie frame acceleration signals, which is promising for eventual on-board wheel flat detection systems. [ABSTRACT FROM AUTHOR]

Purpose: With the explosive growth of the Internet, online travel agents (OTAs) have gained an increasing market share in the online booking market. However, OTAs are facing fierce competition from hotels' direct booking channels, as well as competition among themselves. Therefore, there is a need for an understanding of the evolution of the OTA market from a dynamic perspective. The purpose of this study is to investigate the long-term effect of OTAs on the hospitality industry and to find whether an equilibrium of this effect exists in the context of e-commerce. Design/methodology/approach: To gain a better understanding of the OTA market process, a mathematical framework is constructed on the basis of four assumptions. NetLogo 5.1.0 is used to perform a series of numerical simulations. Findings: The results indicate the following: (1) the development of the OTA market helps to improve net social welfare, but hotels (especially economy hotels) have suffered as a result; (2) clever exploitation of both online and offline channels that are based on hotels' historical data may improve hotels' performance; (3) a scale-priority strategy can be more helpful than a profit-priority strategy for enabling OTAs to maintain their long-term competitiveness; (4) the timing of participation in online-channel competition is a crucial factor in determining whether OTAs can achieve business success. Social implications: In this study, it is shown how consumer habits have changed since the development of OTAs. The online channels provided by OTAs create a convenient, low-cost user experience, and they consequently improve the net welfare of customers. OTAs should be encouraged appropriately, although some economy hotels may suffer from the rise of OTAs. Originality/value: In this empirical study, a mathematical framework is developed to describe the process of evolution in the OTA market, and it uses simulations as a means to validate prior research findings. Unlike previous studies, a dynamic perspective is used in this investigation to interpret the emergence of OTAs and to analyze their enormous impact on the hospitality industry. Thus, the findings of this study capture the competitive characteristics of online and offline channels in a network context and indicate potential strategies for the development of OTAs and which hotels may use OTAs to achieve better performance. In addition, the study findings could be easily extended to explain many of the classical economic phenomena regarding firms with intangible products. [ABSTRACT FROM AUTHOR]

This paper presents a rigorous analysis of a promising bi-modal multirotor vehicle that can roll and fly. This class of vehicle provides energetic and locomotive advantages over traditional unimodal vehicles. Despite superficial similarities to traditional multirotor vehicles, the dynamics of the vehicle analyzed herein differ substantially. This paper is the first to offer a complete and rigorous derivation, simulation, and validation of the vehicle's terrestrial rolling dynamics. Variational mechanics is used to develop a six degrees-of-freedom dynamic model of the vehicle subject to kinematic rolling constraints and various nonconservative forces. The resulting dynamic system is determined to be differentially flat and the flat outputs of the vehicle are derived. A functional hardware embodiment of the vehicle is constructed, from which empirical motion data are obtained via odometry and inertial sensing. A numerical simulation of the dynamic model is executed, which accurately predicts complex dynamic phenomena observed in the empirical data, such as gravitational and gyroscopic nonlinearities; the comparison of simulation results to empirical data validates the dynamic model. [ABSTRACT FROM AUTHOR]

The time‐dependent operation of methanol, ammonia, and urea production units embedded in a steel mill environment is analyzed with dynamic simulation models. From different process concepts and gas availability scenarios, a set of simulation cases is defined with blast furnace gas as carbon and coke oven gas as hydrogen source. Dynamic simulations indicate that significant CO2 reductions require large amounts of additional H2 from sustainable sources. From the results, global data such as carbon footprint or energy demands and details about process unit operation are obtained and processed. [ABSTRACT FROM AUTHOR]

An outstanding question for induced seismicity is whether the volume of injected fluid and/or the spatial extent of the resulting pore pressure and stress perturbations limit rupture size. We simulate ruptures with and without injection‐induced pore pressure perturbations, using 2‐D dynamic rupture simulations on rough faults. Ruptures are not necessarily limited by pressure perturbations when (1) background shear stress is above a critical value, or (2) pore pressure is high. Both conditions depend on fault roughness. Stress heterogeneity from fault roughness primarily determines where ruptures stop; pore pressure has a secondary effect. Ruptures may be limited by fluid volume or pressure perturbation extent when background stress and fault roughness are low, and the maximum pore pressure perturbation is less than 10% of the background effective normal stress. Future work should combine our methodology with simulation of the loading, injection, and nucleation phases to improve understanding of injection‐induced ruptures. Plain Language Summary: Earthquakes can be induced or triggered by fluid injected deep underground, if the fluid encounters faults. Previous studies of induced seismicity at different injection sites around the world have empirically found that in many cases the maximum magnitude earthquake is found to scale with total volume of injected fluid. However, this is not always the case, and the level and heterogeneity of preexisting stress on faults likely plays an important role in determining the final earthquake size. In this paper, we use numerical simulations of earthquakes to quantify one source of stress heterogeneity—that arising from geometric roughness—and study how changes in pore pressure and stress from fluid injection interact with preexisting stress to influence earthquake size. We find that earthquakes are not limited by the injected volume, except under specific conditions. Instead, earthquakes stop where preexisting conditions are unfavorable for continued rupture; in our case because of bends in the fault geometry. Earthquakes can well exceed the predicted maximum magnitude, depending on the preexisting stress on the fault, how rough it is, and the magnitude and extent of the perturbation from injection. Key Points: Rupture size is not necessarily limited by the volume of injected fluid in earthquake simulations with imposed pore pressure perturbationsStress heterogeneity arising from geometric roughness may be the primary cause for rupture termination on rough faultsHigh initial shear stress or pore pressure can trigger a rupture larger than the volume‐based magnitude limit on faults with low roughness [ABSTRACT FROM AUTHOR]

The research about finding the effective membrane material is in progress; however, there are pros and cons for each material. Graphene membrane is a single layer of atoms in a two-dimensional hexagonal lattice which achieved high performance in water purification field. Addition of TiO2 to the graphene membrane has been studied for the membrane modifications due to its high stability and photocatalytic performance. In this study, graphene/TiO2 bilayer nanocomposite membrane has been simulated to enhance the mechanical and electronic properties of graphene membrane. Anatase TiO2 (A-TiO2), rutile TiO2 (R-TiO2), and their composite with graphene (G) have been simulated to evaluate the stability of the nanocomposite bilayers in water desalination for higher salt rejection percentage and water permeation. The membrane structure has been created and optimized using the geometry optimization task. The simulation of electronic and mechanical properties has been done by using Material Studio 2019. TiO2 consisting rutile and anatase phases showed a band gap of 2.248 eV, which was reduced to 1.175 eV in combination with graphene. The bilayer composite of TiO2 and graphene achieved higher membrane stability, and the salt rejection was 98% under applied pressure of 100 MPa. The graphene/TiO2 bilayer nanocomposite membranes have been evaluated by simulation for water desalination process using molecular dynamics by ReaxFF software. In comparison with a graphene membrane, the results showed an increment in salt rejection and water permeability under different applied pressure. [ABSTRACT FROM AUTHOR]

Many researchers rely on simulations to analyze and validate their researched methods on Cloud infrastructures. However, determining relevant simulation parameters and correctly instantiating them to match the real Cloud performance is a difficult and costly operation, as minor configuration changes can easily generate an unreliable inaccurate simulation result. Using legacy values experimentally determined by other researchers can reduce the configuration costs, but is still inaccurate as the underlying public Clouds and the number of active tenants are highly different and dynamic in time. To overcome these deficiencies, we propose a novel model that simulates the dynamic Cloud performance by introducing noise in the computation and communication tasks, determined by a small set of runtime execution data. Although the estimating method is apparently costly, a comprehensive sensitivity analysis shows that the configuration parameters determined for a certain simulation setup can be used for other simulations too, thereby reducing the tuning cost by up to 82.46 percent, while declining the simulation accuracy by only 1.98 percent on average. Extensive evaluation also shows that our novel model outperforms other state-of-the-art dynamic Cloud simulation models, leading up to 22 percent lower makespan inaccuracy. [ABSTRACT FROM AUTHOR]

A model simulating an autonomous battery electric vehicle system for agricultural field use was created, assuming a 200-ha conventional cereal farm in Swedish conditions. The different subsystems were verified against sources in the literature, field experiments and general common practice. The model was used to compare two different charging systems (conductive charging and battery exchange) for battery electric tractors to each other. A comparative simulation was made with conventional diesel systems (fully autonomous or manned for 10 h d−1). The simulation results indicated that battery exchange was generally a faster system than conductive charging. The results also showed that both electric systems were able to achieve similar active time during spring field operations as a corresponding system of a simulated manned diesel tractor for battery sizes from 50 kWh and charge powers from 50 kW. • A dynamic discrete-event model of a 200-ha Swedish grain farm was constructed. • Autonomous electric tractors and diesel counterparts were simulated and compared. • Weather and charging queues had high impacts on time requirements. • Electric tractors compared well with manned diesel systems in spring operations. • Battery exchange systems outperformed conductive charging in most cases studied. [ABSTRACT FROM AUTHOR]

In this study, a solar-powered absorption cooling system was modelled using the TRNSYS software. The performance of the system was investigated using dynamic modelling under the weather conditions of Mugla, Trabzon, Izmir, Konya, Canakkale and Istanbul. The external catalog data file of the absorption chiller model was created to get more realistic results. A parametric study was carried out to evaluate the selected parameters' influence on system efficiency. Various parameters such as solar collector type, area, storage tank volume, collector slope, boiler setpoint temperature, room thermostat set point temperature were investigated to see their impact on the performance of the solar-absorption system, in every city. Instead of using a constant boiler setpoint temperature, a novel control strategy is proposed. Besides, the payback period and the levelized cost of cooling of the optimized systems were studied. Results showed that, in terms of financial analysis, Izmir is the most suitable city for solar-based absorption cooling system applications with a payback period of 10.7 years. Trabzon is found to be the least suitable city due to the longest payback period, and the highest levelized cost of cooling among all locations. • A model of a solar-driven, absorption cooling is developed using TRNSYS software. • The external catalog data of the ACS for TRNSYS is created using the EES software. • Six cities with different climate characteristics are considered in the analysis. • Evacuated tube solar collectors show better performance than flat plate collectors. • The minimum payback period and levelized cost are 10.7 years and 0.128 €/kWh. [ABSTRACT FROM AUTHOR]

This paper takes the Type JJ-I waterjet cutting machine (WCM) as the research object, and establishes a mathematical model for its waterjet pressurization system, then it applies SIMULINK, the dynamic simulation tool package in MATLAB, to simulate the pressure fluctuations of the ultra-high pressure pressurization system and the outlet velocity of the high-speed waterjet. The simulation research showed that, the greater the working pressure, the greater the pressure fluctuations, and the pressure fluctuation rate was decreased. By adjusting the reversing time, the pressure fluctuations increased from 16.01Mpa to 25.31Mpa. It can be seen that the reversing time had a great impact on pressure fluctuations. Under the same working pressure, the size and the frequency of pressure fluctuations remained unchanged. As the volume of the energy accumulator decreased, the increment in pressure fluctuations increased accordingly. As the volume of the energy accumulator decreased from 0.7L to 0.3L, the pressure fluctuations increased by 13.38Mpa. The simulation research in this paper pointed out a direction for improving the dynamic performance of the waterjet system. [ABSTRACT FROM AUTHOR]

Production systems present a different complex consisting of interconnected sub-units. For their proper functioning, it is necessary to use approaches in the design process that will fully accept the interaction of individual units. A dynamic simulation is now a powerful tool for the need of designing production systems. However, in its application in practice, we often encounter various. This paper presents a framework for using dynamic simulation in production systems design. It describes suggested steps to take when we start the process of production systems design, mainly the process of data collection and simulation model building (current and future virtual systems). The article details framework usage and describes the most important challenges of each step. The proposed framework is then successfully applied to a real-life project of innovation of a production system in a pressing shop, where every step of the framework is documented with a working example and with described difficulties or outcomes that each step gave to the team. The result of the dynamic simulation application at the presented real example by the software Witness, the saving was 40.000 EUR. [ABSTRACT FROM AUTHOR]

The boundary integral equation method (BIEM) is one of the important numerical techniques used to simulate geophysical phenomena including dynamic propagation, nucleation, and sequence of earthquake ruptures. We studied the stability and convergence of two time-marching schemes numerically for 2-D problems in Mode I, II, and III conditions. One was a conventional method based on piecewise-constant spatiotemporal distribution of the rate of displacement gap V (CM), and the other was a slightly modified scheme from a predictor–corrector method previously applied to a spectral BIEM (NL). In the stability analysis, we simulated behavior of a traction-free fault under uncorrelated random distributions of initial traction. The growth rate of the perturbation is negative in a parameter regime of complex shape with CM, which has two numerical parameters, and the intersection for all the modes is very restricted as reported previously. In contrast, NL has only one parameter and yields simpler and a wide parameter regime of stability, conceivably allowing more flexible meshing on the fault. In the convergence analysis in which a smooth problem was solved, CM resulted in a numerical error scaled as Δ x 1 while NL led to the scaling of Δ x 2 typically or of Δ x 1.5 under certain conditions in Mode II problems. NL requires negligible additional computational costs and modification of the code is quite straightforward relative to CM. Therefore, we conclude that NL is a useful time-marching scheme that has wide applicability in simulations of earthquake ruptures although the reason for the rather complicated convergence behavior and verification of the findings here to more general conditions deserve further study. [ABSTRACT FROM AUTHOR]

Systems-of-Systems (SoS) combine heterogeneous, independent systems to offer complex functionalities for highly dynamic smart applications. Besides their dynamic architecture with continuous changes at runtime, SoS should be reliable and work without interrupting their operation and with no failures that could cause accidents or losses. SoS architectural design should facilitate the prediction of the impact of architectural changes and potential failures due to SoS behavior. However, existing approaches do not support such evaluation. Hence, these systems have been usually built without a proper evaluation of their architecture. This article presents Dynamic-SoS, an approach to predict/anticipate at design time the SoS architectural behavior at runtime to evaluate whether the SoS can sustain their operation. The main contributions of this approach comprise: (i) characterization of the dynamic architecture changes via a set of well-defined operators; (ii) a strategy to automatically include a reconfiguration controller for SoS simulation; and (iii) a means to evaluate architectural configurations that an SoS could assume at runtime, assessing their impact on the viability of the SoS operation. Results of our case study reveal Dynamic-SoS is a promising approach that could contribute to the quality of SoS by enabling prior assessment of its dynamic architecture. [ABSTRACT FROM AUTHOR]

• Shared ride services with autonomous vehicles result in lower user waiting times. • Sharing also results in lower operational costs for operators than no sharing. • Trade-offs examined from perspective of operators, users and policymakers. • Benefits accrue only when demand pool is sufficiently large. • Role for public sector to incentivize shared ride offering and use. This paper presents a quantitative analysis of the operations of shared-ride automated mobility-on-demand services (SRAMODS). The study identifies (i) operational benefits of SRAMODS including improved service quality and/or lower operational costs relative to automated mobility-on-demand services (AMODS) without shared rides; and (ii) challenges associated with operating SRAMODS. The study employs an agent-based stochastic dynamic simulation framework to model the operational problems of AMODS. The agents include automated vehicles (AVs), on-demand user requests, and a central AV fleet controller that can dynamically change the plans (i.e. routes and AV-user assignments) of AVs in real-time using optimization-based control policies. The agent-based simulation tool and AV fleet control policies are used to test the operational performance of AMODS under a variety of scenarios. The first set of scenarios vary user demand and a parameter constraining the maximum user detour distance. Results indicate that even with a small maximum user detour distance parameter value, allowing shared rides significantly improves the operational efficiency of the AV fleet, where the efficiency gains stem from economies of demand density and network effects. The second set of scenarios vary the mean and coefficient of variation of the curbside pickup time parameter; i.e. how long an AV must wait curbside at a user's pickup location before the user gets inside the AV. Results indicate that increases in mean curbside pickup time significantly degrade operational performance in terms of user in-vehicle travel time and user wait time. The study quantifies the total system (user plus fleet controller) cost as a function of mean curbside pickup time. Finally, the paper provides an extensive discussion of the implications of the quantitative analysis for public-sector transportation planners and policy-makers as well as for mobility service providers. [ABSTRACT FROM AUTHOR]