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Aiming at the problem of irregular waveform of nonrectangular wave voltage sags, the least square method is proposed to fit the nonrectangular wave voltage sags. Based on the fitting curve, the severity of nonrectangular wave voltage sag is assessed from load side and power grid side respectively. The proposed method improves the accuracy of nonrectangular voltage sag severity assessment. Firstly, the least square fitting method is used to fit the nonrectangular wave voltage sag. Secondly, the nonrectangular wave's amplitude and duration are used to generate a rectangular wave. The weight function method is used to assess the severity of the rectangular wave voltage sags. According to the area proportion of nonrectangular wave in rectangular wave, the severity of nonrectangular wave voltage sags from the equipment side is assessed. Concurrently, combined with the fitted nonrectangular wave mathematical model, the energy index function is used to assess the severity of nonrectangular wave voltage sag from the power side. A MATLAB model of the IEEE33 node system is built, and the severity of nonrectangular wave voltage sags obtained by simulation is assessed. The results indicate that the voltage sag severity assessment method is simple and efficient in calculation. And the assessment method is easy to operate and implement in engineering, and has high engineering application value. [ABSTRACT FROM AUTHOR]

When solving nonlinear algebraic equations that arise from discretization using the finite element method (FEM), it is often observed that the standard Newton-Raphson (N-R) iteration either fails to converge or necessitates a large number of iterations in the vicinity of critical points. This work proposes an additional numerical strategy, known as the Potra-Pták iterative cycle, to improve the efficiency of solving highly nonlinear structural problems. Therefore, the focus here is on making the nonlinear solver more robust and efficient, allowing the analysis of more complex nonlinear structures. In the Potra-Pták iterative cycle, two corrections of the objective function (energy function) are performed. The introduction of a second correction in the iterative cycle makes the Potra-Pták strategy more efficient than the standard or modified N-R iterations. This numerical strategy was implemented in the homemade Computational System for Advanced Structural Analysis (CS-ASA) program. The program is based on the FEM and is capable of performing static and dynamic nonlinear analysis of steel, concrete, and composite structures, and its efficiency is then verified through the analysis of slender frames and arches. The algorithm details for solving the nonlinear structural problem, characterized by the Potra-Pták scheme, are provided. [ABSTRACT FROM AUTHOR]

The equation of hyper-elastic Ricci flow amends classical Ricci flow by the addition of the Cauchy stress tensor which itself is derived from the a free energy. In this paper hyper-elastic Ricci flow is shown to possess three properties derived by G. Perelman for classical Ricci flow, specifically it is diffeomorphically equivalent to a gradient flow, unique smooth solutions exist locally in time, and the system possesses a non-decreasing energy function. [ABSTRACT FROM AUTHOR]

In multiagent systems, it can be hard to design individual models due to financial constraints and design challenges. Given this, most studies use the same models for each individual and fail to take into account intra-group differences. In this paper, the effects of differences within a group on flocking and obstacle avoidance movements are studied. Individual differences, group differences, and mutants are the most significant intra-group differences. The differences lie mostly in perceptual radius, inter-individual forces, and the ability to avoid obstacles and pursue goals. We designed a smooth and bounded hybrid potential function with indefinite parameters. This function satisfies the consistency control requirements of the three previously mentioned systems. It is also applicable to ordinary cluster systems without individual differences. As a result of the action of this function, the system has the advantages of rapid swarming and constant system connectivity during motion. Through theoretical analysis and computer simulation, we confirm the effectiveness of our theoretical class framework designed for a multi-agent system with internal differences. • The motion model and the force on the individual is studied. • We considered the differences that exist between individuals and between groups. • The influence of these differences on group consistency movement is analyzed. • The potential energy function allows the network topology to maintain connectivity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper suggests a nonlinear controller of a Static Synchronous Series Compensator (SSSC) and a doubly-fed induction generator (DFIG) for transient stability enhancement by transient energy function (TEF) technique and super-twisting differentiator in the multi-machine power system. Initially, the TEF approach is employed to damping control and stability enhancement in a multi-machine power system including an SSSC, DFIG, and synchronous generator (SG). Then, the signals of time-derivative in the controller with a super-twisting differentiator are estimated. The significance and novelty of this work are the employs of the TEF method obtained for the multi-machine power system containing DFIG and SG. Another novelty is the use of the DFIG and SSSC simultaneous control whose uncertain parameters are estimated with a super-twisting differentiator. The feature of the nonlinear control approach is robust versus modifications in the topology of the system. Simulation is performed on the IEEE 9-bus system to appraise the operation of the nonlinear controller approach compared to back-stepping and sliding mode control. The simulation results demonstrate that the nonlinear controller approach satisfactorily reduces the first swing of oscillations. • DFIG model is similar to a one-axis model of an SG. • The TEF is obtained in the power system with DFIG and SSSC. • Control laws are achieved with three control variables DFIG and SSSC. • The time-derivative signals of the DFIG and SSSC control are estimated based on a super twisting differentiator. [ABSTRACT FROM AUTHOR]

For the difficult problem that the shearer drum load is difficult to be detected and perceived directly, a shearer drum load indirect estimation measurement method and technique is proposed and invented. Based on the structural characteristics of the rocker arm, the basic rod system skeleton of the rocker arm is extracted. Based on the transfer route of the drum load on the rocker arm, the feasibility of using the rocker arm pin shaft load for drum load prediction is analyzed, and the correlation mechanics equation of load from the drum to the rocker arm pin shaft is constructed. To address the statically indeterminate problem in the equation, the Lagrange multiplier is introduced to construct the energy function of the rocker rod system skeleton. Based on the principle of minimum complementary energy and solving the extreme value of energy function, the statically indeterminate equation is transformed into the statically determinate equation, and a rough prediction model of drum load based on the force of the rocker arm hinged ear pin shaft is derived, and the maximum relative error of the model is 25.15 %. To address the low prediction accuracy of the model due to the dynamic characteristics of the drum rocker arm, the drum load is derived from the rocker arm hinged ear pin shaft load and the rough prediction model as input, and the experimentally measured drum load as output. The bp neural network error correction model is constructed, and the accurate estimation and perception of the drum load are realized by the prediction model and the bp neural network correction model. Finally, the accuracy of the prediction algorithm is verified by experiments. The results show that after correction by bp neural network, the average error of the drum three directional force is 0.14 × 104N ∼ 0.55 × 104N, the mean square error is 0.18 × 104N ∼ 0.65 × 104N, and the relative error is 3.99 %∼10.12 %. The average error of the drum three directional moment is 0.31 × 104N·m ∼ 0.40 × 104N·m, the mean square error is 0.16 × 104N·m ∼ 0.50 × 104N·m, and the relative error is 2.04 %∼11.44 %. The accuracy of drum load prediction is higher than 11.44 % in all cases. The research results can provide theoretical and technical support for intelligent shearer design, development, and healthy operation and maintenance. [ABSTRACT FROM AUTHOR]

This paper proposes a novel disturbance estimator-based nonsingular fast fuzzy terminal sliding-mode formation control method. The leader–follower formation control method is combined with the path planning strategy based on the artificial potential field to be collision-free and move in consensus for each AUV. An improved sliding-mode surface is incorporated into the controller, providing the system's state with a faster convergence rate away from the stable equilibrium. The chattering problem in the controller is eliminated by designing fuzzy control rules which are derived from the Lyapunov energy function. A disturbance estimator is proposed to compensate for unknown dynamic and disturbances, which enhances the robustness and stability of the system. Simulation and comparison results are provided to show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

• New segmentation deals with intensity inhomogeneity within biological images. • Use of continuous formulation of B-spline level set with RSF active contour model. • Use of Watershed algorithm with a relevant choice of object markers. • The efficiency is proved in terms of qualitative and quantitative evaluation. Image segmentation plays an important role in the analysis and understanding of the cellular process. However, this task becomes difficult when there is intensity inhomogeneity between regions, and it is more challenging in the presence of the noise and clustered cells. The goal of the paper is propose an image segmentation framework that tackles the above cited problems. A new method composed of two steps is proposed: First, segment the image using B-spline level set with Region-Scalable Fitting (RSF) active contour model, second apply the Watershed algorithm based on new object markers to refine the segmentation and separate clustered cells. The major contributions of the paper are: 1) Use of a continuous formulation of the level set in the B-spline basis, 2) Develop the energy function and its derivative by introducing the RSF model to deal with intensity inhomogeneity, 3) For the Watershed, propose a relevant choice of markers that considers the cell properties. Experimental results are performed on widely used synthetic images, in addition to simulated and real biological images, without and with additive noise. They attest the high quality of segmentation of the proposed method in terms of quantitative and qualitative evaluation. The proposed method is able to tackle many difficulties at the same time: overlapped intensities, noise, different cell sizes and clustered cells. It provides an efficient tool for image segmentation especially biological ones. [ABSTRACT FROM AUTHOR]

While there is a broad literature on ensuring access to affordable, reliable, sustainable and modern energy for all (SDG7), the positive impact of electrification on development and on electrification strategies, there is little literature on the topic of devolved electrification governance. The paper addresses this issue by analyzing opportunities and challenges of a devolved electrification governance with Kenya as a case study. Conceptually, we base our exploration on an analytical framework adapted from work on multi-level natural-resource governance, which not only includes actors and policies, but also their interactions and power relations, and the analysis of devolution outcomes in the light of (good) governance principles. Methodologically we rely on an extensive literature review and on 24 expert interviews in Kenya. Kenya is chosen as a case study because Kenya has, after its new Constitution came into force in 2010, implemented an ambitious devolution process and is one of the few countries in Sub-Saharan Africa that has devolved important energy functions. However, our results show that devolved electrification governance in Kenya is (still) fragmented and complex, partly due to the late enactment of the Energy Act (2019). Electrification is still mainly planned and implemented by actors on the national level, although decentralized structures and technologies have become more important in recent electrification policies. We found more challenges than opportunities in Kenya's devolved electrification governance. The biggest challenge is a lack of capability in the county governments; other challenges relate to legitimacy and overlapping responsibilities, transparency and information-sharing, accountability of national actors, as well as a lack of inclusiveness and participation of local communities. Despite existing challenges, our interviewees perceive devolution as dynamic and an opportunity for electrification and universal electricity access in the long run. Overall, the article shows that while devolution provides opportunities for electrification and associated development impacts, a devolved electrification governance is challenging and requires not only transparency and information-sharing, but also support for capacity building at decentralized levels. • Kenya has ambitious legislation regarding devolution in electrification governance. • However, the implementation is delayed or even impaired. • (Good) governance is a success factor for decentralized electrification governance. • Devolution-electrification interdependencies require more case studies and research. • Properly implemented, devolved electrification governance can help to reach universal access. [ABSTRACT FROM AUTHOR]

Sensor nodes in wireless sensor networks (WSN) are used for perceiving, monitoring, and controlling a wide range of applications. Owing to the small size of sensor nodes and limited power sources, energy-saving is critical for ensuring network longevity. Protocols in different layers consume energy for their function. It is possible to significantly reduce energy usage by implementing energy efficiency measures in the protocol design. Most protocols in the literature focus on the energy efficiency of individual layers. Recent studies have shown that cross-layer designs (CLD) are more energy-efficient than individual layer designs. Therefore, this article proposes a novel quality of service-based crosslayer (QSCL) protocol design by combining the IEEE 802.15.4-based MAC protocol in the data link layer and the LEACH-based routing protocol in the network layer to minimize energy consumption (EC). The dynamic duty cycle of the IEEE 802.15.4 protocol was modified based on the amount of data present in the node, which minimizes the EC of the data-transfer mechanism. The cluster head (CH) selection of the LEACH-based protocol was modified by considering the average residual energy (ARE) and distance of the nodes into account. This helps preserve the energy in the CH, thereby extending the lifespan of the network. Simulation results show that the proposed QSCL protocol outperformed existing protocols in terms of quality of service (QoS) parameters. [ABSTRACT FROM AUTHOR]

The increasing evidence of stress-strain hysteresis in large animal or human myocardium calls for extensive characterizations of the passive viscoelastic behavior of the myocardium. Several recent studies have investigated and modeled the viscoelasticity of the left ventricle while the right ventricle (RV) viscoelasticity remains poorly understood. Our goal was to characterize the biaxial viscoelastic behavior of RV free wall (RVFW) using two modeling approaches. We applied both quasi-linear viscoelastic (QLV) and nonlinear viscoelastic (NLV) theories to experimental stress relaxation data from healthy adult ovine. A three-term Prony series relaxation function combined with an Ogden strain energy density function was used in the QLV modeling, while a power-law formulation was adopted in the NLV approach. The ovine RVFW exhibited an anisotropic and strain-dependent viscoelastic behavior relative to anatomical coordinates, and the NLV model showed a higher capacity in predicting strain-dependent stress relaxation than the QLV model. From the QLV fitting, the relaxation term associated with the largest time constant played the dominant role in the overall relaxation behavior at most strains from early to late diastole, whereas the term associated with the smallest time constant was pronounced only at low strains at early diastole. From the NLV fitting, the parameters showed a nonlinear dependence on the strain. Overall, our study characterized the anisotropic, nonlinear viscoelasticity to capture the elastic and viscous resistances of the RVFW during diastole. These findings deepen our understanding of RV myocardium dynamic mechanical properties. Although significant progress has been made to understand the passive elastic behavior of the right ventricle free wall (RVFW), its viscoelastic behavior remains poorly understood. In this study, we originally applied both quasi-linear viscoelastic (QLV) and nonlinear viscoelastic (NLV) models to published experimental data from healthy ovine RVFW. Our results revealed an anisotropic and strain-dependent viscoelastic behavior of the RVFW. The parameters from the NLV fitting showed nonlinear relationships with the strain, and the NLV model showed a higher capacity in predicting strain-dependent stress relaxation than the QLV model. These findings characterize the anisotropic, nonlinear viscoelasticity of RVFW to fully capture the total (elastic and viscous) resistance that is critical to diastolic function. [Display omitted] [ABSTRACT FROM AUTHOR]

Generally, conventional image dehazing methods attempt to improve the initial transmission map by using guidance information from the input image as a structural prior. However, these methods do not consider the structural differences between the guidance and the initial transmission map. Furthermore, these methods provide limited robustness against outliers. This paper tackles these problems by optimizing a nonconvex energy function that jointly leverages structural information from the transmission map and guidance. Specifically, a nonconvex regularizer, and correspondingly, an efficient energy function are proposed. The energy function is solved using a majorize-minimize algorithm. Consequently, an improved transmission map is obtained in which the edges are well-preserved. Ultimately, this improved transmission map provides a high-quality haze-free image that has vivid colors and fine details. Experiments were performed on various synthetic and real hazy image datasets. The performance of the proposed method is compared with the state-of-the-art methods by using the root mean square error (RMSE), structural similarity index (SSIM), fog aware density evaluator (FADE), and visibility level descriptor (VLD). Both the qualitative and quantitative results demonstrate the effectiveness of the proposed robust regularization. [ABSTRACT FROM AUTHOR]

This study addresses three primary objectives related to lumbar intervertebral disc (IVD) biomechanics under ramping quasi-static loading conditions. First, we explore the conditions justifying the simplification of axisymmetric elastic fiber families into single fiber bundles through discretized strain energy functions. Simulations reveal that a concentration factor exceeding 10 allows for a consistent deviation below 10% between simplified and non-simplified responses. Second, we investigate the impact of elastic fibers on the physiological stiffness in IVDs, revealing minimal influence on biological motions but significant effects on degeneration. Lastly, we examine the initiation and progression of annulus fibrosus (AF) damage. Our findings confirm the validity of simplifying elastic fiber families and underscore the necessity of considering elastic fiber damage in biomechanical studies of AF tissues. Elastic fibers contribute to increased biaxial stretch stiffness, and their damage significantly affects the loading capacity of the inner AF. Additionally, degeneration significantly alters the susceptibility to damage in the AF, with specific regions exhibiting higher vulnerability. Damage tends to extend circumferentially and radially, emphasizing the regional variations in collagen and elastic fiber properties. This study offers useful insights for refining biomechanical models, paving the way for a more comprehensive understanding of IVD responses and potential clinical implications. [Display omitted] • Validated conditions for simplifying elastic fiber families for efficient modeling. • Revealed elastic fibers' significant role in enhancing biaxial stretch stiffness. • Unveiled both initiation and progression modes of AF damage under typical motions. • Disc degeneration greatly affects motions and initiates distinct damage patterns. • The posterior outer AF is more susceptible to damage than the anterior inner area. [ABSTRACT FROM AUTHOR]

Energy efficiency (EE) in large-scale high-density ad hoc networks is an NP-hard problem of fractional function optimization. Most traditional algorithms in the literature focus only on power control, mainly optimizing the solution of power control with the objective of sum-rate maximization or weighted sum-rate maximization, etc., and thus are unsuitable for solving fractional function EE optimization problems. In this paper, the architectural design of the neural network algorithm is directly guided with the objective of maximizing EE. Specifically, we first prove that the EE problem can be described as a graph optimization problem with permutation equivariance. Then, we propose an energy-efficient optimized graph convolutional neural network (EEOGCN) algorithm that satisfies permutation equivariance. Experiments show that the algorithm has better energy efficiency performance compared to other algorithms, can be directly applied to weighted energy efficiency optimization and beamforming energy efficiency optimization problems, and exhibits good generalization performance and scalability to large-scale high-density problems. In particular, the proposed method is computationally efficient and can solve the weighted energy efficiency optimization problem for 3000 transceiver pairs on a single GPU within 2 ms. [ABSTRACT FROM AUTHOR]

Carbon neutrality is the future development direction of China. Achieving the goal of carbon neutrality requires the combined efforts of all industries, especially heavy industries. As one of the heavy industries, the mining sector contributes significantly to China's national economic development. This paper calculates China's mining sector's rebound effect and explores the impact of market-oriented reform on its rebound effect. We use the Shephard energy distance function to measure energy efficiency and analyze the effect of marketization on the rebound effect with the threshold model. Based on our results, the mining sector's average rebound effect is 46.4%. Moreover, with the increase in the decision-making flexibility of mining enterprises, the rebound effect presents an upward trend. We conclude by urging policy-makers to implement energy price reforms and promote energy consumption permits [ABSTRACT FROM AUTHOR]

Copyright of Science of Sintering is the property of National Library of Serbia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] Understanding the response of skin to superphysiological temperatures is critical to the diagnosis and prognosis of thermal injuries, and to the development of temperature-based medical therapeutics. Unfortunately, this understanding has been hindered by our incomplete knowledge about the nonlinear coupling between skin temperature and its mechanics. In Part I of this study we experimentally demonstrated a complex interdependence of time, temperature, direction, and load in skin's response to superphysiological temperatures. In Part II of our study, we test two different models of skin's thermo-mechanics to explain our observations. In both models we assume that skin's response to superphysiological temperatures is governed by the denaturation of its highly collageneous microstructure. Thus, we capture skin's native mechanics via a microstructurally-motivated strain energy function which includes probability distributions for collagen fiber orientation and waviness. In the first model, we capture skin's response to superphysiological temperatures as a transition between two states that link the kinetics of collagen fiber denaturation to fiber coiling and to the transformation of each fiber's constitutive behavior from purely elastic to viscoelastic. In the second model, we capture skin's response to superphysiological temperatures instead via three states in which a sequence of two reactions link the kinetics of collagen fiber denaturation to fiber coiling, followed by a state of fiber damage. Given the success of both models in qualitatively and quantitatively capturing our observations, we expect that our work will provide guidance for future experiments that could probe each model's assumptions toward a better understanding of skin's coupled thermo-mechanics and that our work will be used to guide the engineering design of heat treatment therapies. Quantifying and modeling skin thermo-mechanics is critical to our understanding of skin physiology, pathophysiology, as well as heat-based treatments. This work addresses a lack of theoretical and computational models of the coupled thermo-mechanics of skin. Our model accounts for skin microstructure through modeling the probability of fiber orientation and fiber stress-free states. Denaturing induces changes in the stress-free configuration of collagen, as well as changes in fiber stiffness and viscoelastic properties. We propose two competing models that fit all of our experimental observations. These models will enable future developments of thermal-therapeutics, prevention and management of skin thermal injuries, and set a foundation for improved mechanistic models of skin thermo-mechanics. [ABSTRACT FROM AUTHOR]

Vitamin C, Ascorbic acid (AA) is an essential water-soluble nutrient involved in many physiologic functions such as energy metabolism, neurotransmitter synthesis, tissue repair, immune function, and the regeneration and the recycling of many molecules. The physiological need for this nutrient can vary widely and is increased in the presence of physiological stress such as trauma, infection, inflammation, increased toxin load, chemotherapy, radiotherapy, and diseases such as diabetes and cancer. It has been found that low plasma levels of ascorbate often correlate with increased severity of disease and symptoms. In addition, it has been reported that when ascorbic acid is given at supraphysiologic levels, a variety of pharmacologic effects can be observed. In-vitro and in-vivo clinical research has allowed us to understand some of the mechanisms involved and even correlate concentrations to effect. Recent reports suggest that, even in high-income coun‐ tries like the United States, a considerable proportion of the population have inadequate levels. Given the prevalence of ascorbate insufficiency and its role in maintaining homeosta‐ sis and tissue repair, it is important to evaluate plasma levels to properly assess the patient’s health. This assessment could be useful to optimize outcomes by providing the nutritional and pharmacologic benefits of AA as needed. We present a guide to the interpretation of plasma ascorbate. This guide includes seven levels with the corresponding descriptor, intake levels, and plasma concentrations to facilitate clinical decisions pertaining to intravenous Ascorbic Acid therapy. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Geografia: Revista Colombiana de Geografía is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] A constitutive model that explicitly considers the gradual recruitment of collagen fibers is applied to investigate the uniaxial properties of human ascending aortic aneurysms. The model uses an effective stretch, which is a continuum scale kinematic variable measuring the true stretch of the tissue, to formulate the fiber stress. The constitutive equation contains two shape parameters characterizing the stochastic distribution of fiber waviness, and two elastic parameters accounting for, respectively, the elastic properties of ground substance and the straightened collagen fibers. The model is applied to 156 sets of uniaxial stress-stretch data obtained from 52 aneurysm samples. Major findings include (1) the uniaxial response can be well described by a quadratic strain energy function of the effective strain; (2) the ultimate stretches, when measured in terms of the effective stretch, are closely clustered around 1.1, in contrast to a much wider range in the original stretch; and (3) the ultimate stress correlates positively with the fiber stiffness. The age dependence and directional differences of constitutive parameters are also investigated. Results indicate that only the waviness depends strongly on age; no clear alterations occur in elastic parameters. Further, the fibers are wavier and stiffer in the circumferential direction than in the longitudinal direction. No other parameters exhibit significant direction difference. We introduced a constitutive model which explicitly accounts for collagen fiber recruitment to investigate the uniaxial properties of human ascending aortic aneurysm tissues. Uniaxial response data from 156 specimens were considered in the study. It was found that the seemingly dissimilar response curves are, in fact, similar if we measure the deformation using an effective stretch which factors out the uncrimping deformation. The rupture stretches in terms of the effective stretch are closely packed around 1.1. And the stress-stretch curves collapse to a canonical curve after a transformation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Context-aware facial recognition regards the recognition of faces in association with their respective environments. This concept is useful for the domestic robot which interacts with humans when performing specific functions in indoor environments. Deep learning models have been relevant in solving facial and place recognition challenges; however, they require the procurement of training images for optimal performance. Pre-trained models have also been offered to reduce training time significantly. Regardless, for classification tasks, custom data must be acquired to ensure that learning models are developed from other pre-trained models. This paper proposes a place recognition model that is inspired by the graph cut energy function, which is specifically designed for image segmentation. Common objects in the considered environment are identified and thereafter they are passed over to a graph cut inspired model for indoor environment classification. Additionally, faces in the considered environment are extracted and recognised. Finally, the developed model can recognise a face together with its environment. The strength of the proposed model lies in its ability to classify indoor environments without the usual training process(es). This approach differs from what is obtained in traditional deep learning models. The classification capability of the developed model was compared to state-of-theart models and exhibited promising outcomes. [ABSTRACT FROM AUTHOR]

Bundle adjustment (BA) is a technique for refining sensor orientations of satellite images, while adjustment accuracy is correlated with feature matching results. Feature matching often contains high uncertainties in weak/repeat textures, while BA results are helpful in reducing these uncertainties. To compute more accurate orientations, this article incorporates BA and feature matching in a unified framework and formulates the union as the optimization of a global energy function so that the solutions of the BA and feature matching are constrained with each other. To avoid a degeneracy in the optimization, we propose a comprised solution by breaking the optimization of the global energy function into two-step suboptimizations and compute the local minimums of each suboptimization in an incremental manner. Experiments on multi-view high-resolution satellite images show that our proposed method outperforms state-of-the-art orientation techniques with or without accurate least-squares matching. [ABSTRACT FROM AUTHOR]

Wireless communication has become the promising technology in the recent times because of its applications in Internet of Things( IoT) devices. The IEEE 802.15.4e has become the key technology for IoT devices which utilizes the Time-Slotted Channel Hopping (TSCH) networks for the communication between the devices. In this paper, we develop a Two Level Scheduling Algorithm (TLSA) for scheduling multiple packets with different arrival rate at the source nodes in a TSCH networks based on the link activated by a centralized scheduler. TLSA is developed by considering three types of links in a network such as link i with packets arrival type 1, link j with packets arrival type 2, link k with packets arrival type 3. For the data packets arrival, two stages in a network is considered.At the first stage, the packets are considered to be of higher priority.At the second stage, the packets are considered to be of lower priority.We introduce level 1 schedule for the packets at stage 1 and level 2 schedule for the packets at stage 2 respectively. Finally, the TLSA is validated with the two different energy functions i.e., y =eax = 1 and y = 0.5x² using MATLAB 2017a software for the computation of average and worst ratios of the two levels. [ABSTRACT FROM AUTHOR]

• We argue that emotional geography adds a missing dimension to energy geography. • We use oral history to discuss how atmospheres arise in a mining energy system. • We show the affectual agency of the energy system in everyday production of space. • We argue that exploring emotion and affect is key for managing energy transitions. In this paper, we make a case for bringing energy geography into closer dialogue with emotional geography, and argue that doing so has the potential to greatly improve our understanding of energy systems and their intersection with everyday life, bringing essential but often overlooked aspects into view. We draw on research carried out as part of an arts and humanities-based project in South Wales (UK), a region once dominated by coal extraction. We present and discuss material from sixteen oral histories recorded with long-standing members of the village of Ynysybwl. Reading their accounts through the lens of emotional-affective constructs reveals not only participants' emotions about aspects of energy production and consumption, but also the atmospheres and affects arising within and out of the energy system. This brings to light the affectual agency of the energy system as an infrastructure assemblage and its role in everyday production of space. Related to this, it surfaces essential aspects of experiences of energy system change. We argue that recognising and exploring affect and emotion is crucial for energy geography as it continues to explore the functionings of energy systems, and energy transitions. [ABSTRACT FROM AUTHOR]

Significant progress was made in the 1980s and 1990s in the development and application of direct methods in power system transient stability analysis. However, there is still certain mistrust because most of them have been built on heuristics, simplifications and simulations. To build confidence in direct energy methods, a first version of a Hamiltonian energy balance method based on perturbation theory and wave energy function was recently proposed. In this method, the kinetic and potential Hamiltonian energies of the dynamical system are computed in the prefault, fault-on and postfault periods, using the time-independent Schrodinger equation, canonical transformation and calculus of variations. One major disadvantage of the method is that it still does not compute the critical clearing angle (CCA) and the critical clearing time (CCT). In the present paper, earlier and current theoretical concepts built on a preliminary topological characterization of the stable equilibrium energy boundary (also referred to as energy barrier) are used to address this deficiency, resulting in a new version of the Hamiltonian energy balance method that is tested for computing CCA and CCT, providing more accurate results than other methods available in the literature. [ABSTRACT FROM AUTHOR]

In this paper, the single leg of the jumpable bionic robot is designed, which is based on the analysis of the hind leg skeleton and muscle structure of the cheetah. The configuration of the single legs composed of a body module, a thigh module, a shank module, an ankle module and an energy storage unit. An energy storage unit is designed at each joint. The energy storage unit is driven by a servo motor, and servo motor drives a guide rod to compress a spring for energy storage, which can quickly release energy according to the action requirement to rapidly change motion state of the connected structure for realizing the jump of the single leg. In order to realize the simulation analysis of the robot motion, the single leg model was built using Solidworks software and the model was imported into ADAMS software for dynamic simulation. In the ADAMS software, the jumping ability of the robot is realized by motion planning, giving joint's driving functions and the foot trajectory function. The contact force curve and the corresponding motion parameters are obtained between the foot point and the ground at the moment of take-off and landing. The work provides a theoretical support for the optimal design and practical use of the robot's single leg. [ABSTRACT FROM AUTHOR]

Force-directed algorithms have been developed over the last 50 years and used in many application fields, including information visualisation, biological network visualisation, sensor networks, routing algorithms, scheduling, and graph drawing. Our survey provides a comprehensive summary of developments and a full roadmap for state-of-the-art force-directed algorithms in schematic drawings and placement. We classified the model of force-directed algorithms into classical and hybrid. The classical force-directed algorithms are further classified as follows: (a) accumulated force models, (b) energy function minimisation models and (c) combinatorial optimisation models. The hybrid force-directed algorithms are classified as follows: (a) parallel and hardware accelerated models, (b) multilevel force-directed models and (c) multidimensional scaling force-directed algorithms. Five categories of application domains in which force-directed algorithms have been adopted for schematic drawings and placement are also summarised: (a) aesthetic drawings for general networks, (b) component placement and scheduling in high-level synthesis of very-large-scale integration circuits design, (c) information visualisation, (d) biological network visualisation and (e) node placement and localisation for sensor networks. [ABSTRACT FROM AUTHOR]

Wet Lab methods used to resolve the native structure of a given protein such as X-ray Diffraction and NMR spectroscopy are time-consuming, expensive, and could be done multiple times due to failure. Those pitfalls led to the development of computationally automated prediction methods. Predicting the structure of a protein using its peptide sequence only — also known as ab initio Protein Structure Prediction "PSP"— is computationally challenging because of the large conformational space to be searched and the complexity of energy functions. Some successful predictive methods have been developed to solve PSP problem. In this paper, by using a set of peptide sequences, we compare a collection of PSP ab initio-based methods. Experiments show that using a metaheuristic-based search method that utilizes genetic algorithm can achieve same or better results than time consuming methods. [ABSTRACT FROM AUTHOR]

The annulus fibrosus of the intervertebral disc exhibits an unusual transversal behavior for which a constitutive representation that considers as well regional effect, chemical sensitivity and time-dependency has not yet been developed, and it is hence the aim of the present contribution. A physically-based model is proposed by introducing a free energy function that takes into account the actual disc annulus structure in relation with the surrounding biochemical environment. The response is assumed to be dominated by the viscoelastic contribution of the extracellular matrix, the elastic contribution of the oriented collagen fibers and the osmo-induced volumetric contribution of the internal fluid content variation. The regional dependence of the disc annulus response due to variation in fibers content/orientation allows a micromechanical treatment of the soft tissue. A finite element model of the annulus specimen is designed while taking into consideration the 'interlamellar' ground substance zone between lamellae of the layered soft tissue. The kinetics is designed using full-field strain measurements performed on specimens extracted from two disc annulus regions and tested under different osmotic conditions. The time-dependency of the tissue response is reported on stress-free volumetric changes, on hysteretic stress and transversal strains during quasi-static stretching at different strain-rates and on their temporal changes during an interrupted stretching. Considering the effective contributions of the internal fluid transfer and the extracellular matrix viscosity, the microstructure-based chemo-mechanical model is found able to successfully reproduce the significant features of the macro-response and the unusual transversal behavior including the strong regional dependency from inner to outer parts of the disc: Poisson's ratio lesser than 0 (auxetic) in lamellae plane, higher than 0.5 in fibers plane, and their temporal changes towards usual values (between 0 and 0.5) at chemo-mechanical equilibrium. The underlying time-dependent mechanisms occurring in the tissue are analyzed via the local numerical fields and important insights about the effective role of the interlamellar zone are revealed for the different disc localizations. The structural complexity of the annulus fibrosus has only been appreciated through recent experimental contributions and a constitutive representation that considers as well regional effect, chemical sensitivity and time-dependency of the unusual transversal behavior has not yet been developed. Here, a microstructure-based chemo-viscoelastic model is developed to highlight the interlamellar-induced time-dependent response by means of a two-scale strategy. The model provides important insights about the origin of the time-dependent phenomena in disc annulus along with regional dependency, essential for understanding disc functionality. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The generalized fractional Maxwell model, formulated for hyperelastic material within the framework of the nonlinear viscoelasticity with internal variables, is applied to identify viscoelastic constitutive equations from layer-specific experimental data obtained by uniaxial harmonic loading of ex-vivo human descending thoracic aortas. The constitutive parameters are identified by using a genetic algorithm for the optimal fitting of the experimental data. The accuracy of the fitted fractional model is compared to the fitted integer order model with the same number of Maxwell elements. The formulation of an original strain energy density function for anisotropic nonlinear viscoelasticity is introduced and constitutive parameters are obtained from the experiments. [ABSTRACT FROM AUTHOR]

The Black Oystercatcher Haematopus bachmani is a species of conservation concern that depends on marine intertidal prey resources. We examined diet, feeding rates, growth, and survival of Black Oystercatcher broods in southcentral Alaska, 2013-2014. To determine the importance of diet for brood survival, we modeled daily survival rates of broods as a function of energy intake rate and other ecological factors. We hypothesized that broods fed at higher energy intake rates would grow faster and fly earlier, and thus be less vulnerable to predators and have higher rates of survival. Consistent with our prediction, broods with higher energy intake rates had higher rates of growth and daily survival. Our best-supported model indicated that brood survival varied by energy intake rate and brood age. To understand how adults meet the increasing nutritional needs of developing chicks, we examined delivery rates, prey type, and prey size as a function of brood age. Delivery rates differed by age, but composition and size classes of prey items did not, indicating that adults respond to the rising energetic needs of broods by increasing parental effort rather than by switching prey. These findings demonstrate the importance of diet and provisioning to broods and, given the consequences of reduced energy intake on survival, indicate that climate change-related shifts in intertidal invertebrates could significantly impact Black Oystercatcher populations. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of Beijing Institute of Technology is the property of Beijing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of Beijing Institute of Technology is the property of Beijing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Characterizing material properties of lung parenchyma is essential in order to describe and predict the mechanical behavior of the lung in health and disease. Hence, we aim to identify the viscoelastic constitutive behavior of viable lung parenchyma with a particular focus on the nonlinear, compressible, and frequency-dependent material properties. To quantify the viscoelastic material behavior of rat lung parenchyma experimentally, we performed uniaxial tension tests with different frequencies, including the whole range of physiological frequencies, in combination with full-field displacement measurements (a total of 120 tests on 30 samples of 5 rats). By means of these experimental measurements, we identified the material parameters of two viscoelastic material models applicable to large three-dimensional deformations, i.e., the standard linear solid model and the model of fractional viscoelasticity. Our aim is to identify one set of material parameters that describes the whole range of physiological frequencies; therefore, we utilized a coupled inverse analysis, which equally incorporates all different tensile tests performed on one sample. The model most suitable for the description of the viscoelastic, nonlinear, and compressible material behavior of viable rat lung parenchyma is the strain energy function Ψ = 356.7 Pa ( I 1 − 3) + 331.7 Pa ( I 3 − 1.075 − 1) + 71.05 Pa ( J − 2 3 I 1 − 3) 3 + 5.766 Pa ( I 3 1 3 − 1) 6 in combination with the model of fractional viscoelasticity (τ = 0.06454 s , α = 0.5378 , and β = 1.856). This material model was validated to describe the complex nonlinear and compressible viscoelastic material behavior of lung parenchyma and can be utilized in finite element simulations of the whole range of physiological frequencies. Based on this model, it will be possible to quantify the stresses and strains of lung tissue during spontaneous and artificial breathing more reliable in the future. fx1 • Examined nonlinear, compressible, viscoelastic material behavior of lung parenchyma. • Viscoelasticity and frequency-dependence in uniaxial cyclic tension tests was measured. • The model of fractional viscoelasticity and standard linear solid model are compared. • Coupled inverse analysis equally incorporates all four frequency tests of each sample. • Identified one set of material parameters, which models physiological frequency-range. [ABSTRACT FROM AUTHOR]

In this paper, a coupled inverse analysis is proposed to identify nonlinear compressible hyperelastic material models described by two sets of experiments. While the overall approach is applicable for different materials, here it will be presented for viable lung parenchyma. Characterizing the material properties of lung parenchyma is essential to describe and predict the mechanical behavior of the respiratory system in health and disease. During breathing and mechanical ventilation, lung parenchyma is mainly subjected to volumetric deformations along with isochoric and asymmetric deformations that occur especially in diseased heterogeneous lungs. Notwithstanding, most studies examine lung tissue in predominantly isochoric tension tests. In this paper, we investigate the volumetric material behavior as well as the isochoric deformations in two sets of experiments: namely, volume–pressure-change experiments (performed with 287 samples of 26 rats) and uniaxial tension tests (performed with 30 samples of 5 rats). Based on these sets of experiments, we propose a coupled inverse analysis, which simultaneously incorporates both measurement sets to optimize the material parameters. Accordingly, we determine a suitable material model using the experimental results of both sets of experiments in one coupled identification process. The identified strain energy function with the corresponding material parameters Ψ = 356.7 Pa ( I 1 − 3) + 331.7 Pa ( I 3 − 1.075 − 1) + 278.2 Pa ( I 3 − 1 3 I 1 − 3) 3 + 5.766 Pa ( I 3 1 3 − 1) 6 is validated to model both sets of experiments precisely. Hence, this constitutive model describes the complex volumetric and isochoric nonlinear material behavior of lung parenchyma. This derived material model can be used for nonlinear finite element simulations of lung parenchyma and will help to quantify the stresses and strains of lung tissue during spontaneous and artificial breathing; thus, allowing new insights into lung function and biology. fx1 • The nonlinear elastic material behavior of lung parenchyma is investigated. • Uniaxial tension tests to measure the small volumetric and isochoric deformations. • Volume-pressure-change tests to quantify the physiological volumetric deformations. • A coupled inverse analysis is proposed, which incorporates both sets of experiments. • A suitable material model and the according material parameters are identified. [ABSTRACT FROM AUTHOR]

Molecular docking is a Bioinformatics method based on predicting the position and orientation of a small molecule or ligand when it is bound to a target macromolecule. This method can be modeled as an optimization problem where one or more objectives can be defined, typically around an energy scoring function. This paper reviews developments in the field of single- and multi-objective meta-heuristics for efficiently addressing molecular docking optimization problems. We comprehensively analyze both problem formulations and applied techniques from Evolutionary Computation and Swarm Intelligence, jointly referred to as Bio-inspired Optimization. Our prospective analysis is supported by an experimental study dealing with a molecular docking problem driven by three conflicting objectives, which is tackled by using different multi-objective heuristics. We conclude that genetic algorithms are the most widely used techniques by far, with a noted increasing prevalence of particle swarm optimization in the last years, being these last techniques particularly adequate when dealing with multi-objective formulations of molecular docking problems. We end this experimental survey by outlining future research paths that should be under target in this vibrant area. • We provide a thorough survey of molecular docking problems tackled with bio-inspired heuristics. • Algorithmic trends of single- and multi-objective formulations of this problem are identified. • We discuss results of a molecular docking problem comprising three conflicting objectives. • We conclude with a prospect of what paths should be explored in the future of this research area. [ABSTRACT FROM AUTHOR]

• New electrophilic reactivity index developed in the framework of the conceptual DFT. • The change in energy modeled by a cubic function of the number of transferred electrons. • Effectiveness of the developed electrophilic descriptor tested on electrophilic compounds. Through an alternative scheme of representation of energy as a function of the number of electrons, and using the canonical ensemble model, a new electrophilicity descriptor was developed. In our development, we accept the idea that when a system begins to accept electrons from the surroundings, its chemical potential increases, tending to zero when the system is saturated with the maximum amount of charge. In this way, the number of transferred electrons, and therefore the stabilization energy of the system, were modeled by means of a third order approximation which in the state of electronic saturation led to the definition of our electrophilic descriptor. This new reactivity parameter, was tested to reproduce relative electrophilicity tendencies of some chemical systems known for their electrophilic reactivity. Although the results reported here partially demonstrate the potentiality of our descriptor, more systems must be investigated to test the effectiveness of this new reactivity index. [ABSTRACT FROM AUTHOR]

The paper focuses on designing precoding matrices in multi-cell multiple-input multiple-output (MIMO) simultaneous wireless information and power transfer networks (SWIPT) where the sets of users are selected for data transmission in each time slot and the unselected users are dedicated to energy harvesting. The precoding design for the SWIPT problem is formulated as a general multi-objective maximization problem, in which the sum-rate (SR) and sum harvested energy (SHE) are maximized simultaneously under the transmit power constraints. Since the objective function of the maximization problem is not concave in the design matrix variables, it is difficult to directly obtain the optimal solutions. To tackle this challenge, we recast the SR function into one more amenable by applying the connection between the minimum mean square error and achievable data rate. In addition, to deal with the non-concavity of the harvested energy function, we derive its concave minorant. Then, we develop an efficient iterative algorithm based on alternating optimization (AO) to obtain the optimal precoders. We also analyze the convergence and computational complexity of the proposed algorithm. Finally, by numerical simulation results we investigate the trade-offs between the SR and SHE. [ABSTRACT FROM AUTHOR]

This paper presents developments in the area of brain-inspired wireless communications relied upon in dense wireless networks. Classic approaches to network design are complemented, firstly, by the neuroplasticity feature enabling to add the learning ability to the network. Secondly, the microglia ability enabling to repair a network with damaged neurons is considered. When combined, these two functionalities guarantee a certain level of fault-tolerance and self-repair of the network. This work is inspired primarily by observations of extremely energy efficient functions of the brain, and of the role that microglia cells play in the active immune defense system. The concept is verified by computer simulations, where messages are transferred through a dense wireless network based on the assumption of minimized energy consumption. Simulation encompasses three different network topologies which show the impact that the location of microglia nodes and their quantity exerts on network performance. Based on the results achieved, some algorithm improvements and potential future work directions have been identified. [ABSTRACT FROM AUTHOR]

Multi-objective evolutionary algorithms (MOEAs) have shown a good capability to approximate the Pareto front (PF) of complex multi-objective optimization problems (MOPs). Recently, several decomposition-based, indicator-based, and reference set-based MOEAs have been proposed to tackle MOPs with four or more objective functions, known as many-objective optimization problems (MaOPs). Some well-known MOEAs from these design strategies use a predefined reference set generated with uniformly distributed weight vectors on a unit simplex. These MOEAs have demonstrated good convergence, coverage, and uniformity of solutions on MOPs with regular PF shapes, i.e., simplex-like shapes. However, it has been shown that their performance degrades on MOPs with irregular PF shapes. In this paper, we proposed a pluggable reference set adaptation method based on niching and pair-potential energy functions (PPFs), called Ada K , to enhance the performance of these MOEAs on MOPs with irregular PF shapes while maintaining their good behavior on MOPs with regular PF shapes. Our adaptation method was validated by plugging it into three well-known MOEAs that use a predefined weight vector-based reference set. We perform an empirical study using different PPFs for our adaptation method on the DTLZ, WFG, Minus-DTLZ, Minus-WFG, IMOP, and VNT test suites. Our experimental results show the capability of our adaptation method to promote an invariant performance regardless of the PF shape. Additionally, we show that MOEAs with our adaptation method have a competitive performance against state-of-the-art MOEAs. • An adaptation method for weight vector-based reference sets is proposed. • The proposed adaptation method employs niching and pair-potential energy functions. • Our adaptation method is plugged into MOEAs with different algorithmic frameworks. • We validate our adaptation method on MOPs with regular and irregular PF shapes. • Our adaptation method promotes an invariant performance regardless of the PF shape. [ABSTRACT FROM AUTHOR]

[Display omitted] • We present quasi-classical trajectory calculations for the O + H(D) 2 + reaction. • Two reaction mechanisms are identified in the collision process. • The reagent vibrational excitation has different influence on dynamics of the two reactions. The reactions O + H(D) 2 + are studied based on the ground state potential energy surface (PES) 12A″ and the first excited PES 12A′. Both two potential energy surfaces comprise deep wells during the minimum energy reaction path. The average lifetimes of the complex-formation of the title reactions as a function of translational energy are calculated. The results indicated that the average lifetime of the complex-formation decreases with the increasing of collision energy for the two potential energy surfaces. There are two kinds of reaction mechanisms, one is direct reaction mechanism; another is indirect one. The indirect mechanism is dominated for all the collision energies studied. However, with the increasing of the collision energy, the direct reaction mechanism becomes more and more pronounced. Besides, the influences of reagent vibrational excitation and isotopic effect on the scalar properties and vector properties are studied in detail respectively in this work. The reagent vibrational excitation enhances the number of the direct reactive trajectories remarkably on 12A″, though it has nearly no influence on the average lifetime of the complex formation. In strong contrast, the reagent vibrational excitation suppresses the number of indirect reactive trajectories and reduces the average lifetime of the complex formation on the 12A′. The isotopic substitution has no influence on the scalar properties; however, it affects the vector properties strongly. [ABSTRACT FROM AUTHOR]

Abstract This paper presents a framework for segmenting flower images captured with a digital camera. Segmenting flowers from images is a complex problem attributed to translation, scaling, rotation with variable backgrounds in each captured image. We propose to solve this problem using principle component analysis based color texture fusion as a prior parameter for level set evolution (FCTAC). First, Color Gabor textures (CGT) and Color Level Covariance Matrix (CLCM) texture features are extracted. Principle component analysis based fusion constructs a color discriminative texture as a knowledge base with convex energy function for active contours without edges. The proposed global segmentation framework with fused textures will avoid the local minimums during curve evolution. We test the proposed segmentation model on the benchmark oxford flower image dataset and our own dataset. The results of FCTAC were tested against the state-of-the-art methods in accuracy and efficiency. [ABSTRACT FROM AUTHOR]

Highlights • Modeling protein structure prediction problem as a multi-objective optimization problem. • A physics-based energy function and a knowledge-based energy function are combined to construct a compound three-objective energy function to evaluate a predicted conformation of a protein. • An improved multi-objective particle swarm optimization coupled with two archives is employed to execute conformation space search. • A mechanism based on Pareto non-dominated sorting is designed to tackle the slightly worse solutions properly. It is analogous to other traditional methods based on single-objective optimization. Abstract The protein structure prediction (PSP) problem, i.e., predicting the three-dimensional structure of a protein from its sequence, remains challenging in computational biology. The inaccuracy of existing protein energy functions and the huge conformation search space make the problem difficult to solve. In this study, the PSP problem is modeled as a multi-objective optimization problem. A physics-based energy function and a knowledge-based energy function are combined to construct the three-objective energy function. An improved multi-objective particle swarm optimization coupled with two archives is employed to execute the conformation space search. In addition, a mechanism based on Pareto non-dominated sorting is designed to properly address the slightly worse solutions. Finally, the experimental results demonstrate the effectiveness of the proposed approach. A new perspective for solving the PSP problem by means of multi-objective optimization is given in this paper. [ABSTRACT FROM AUTHOR]

In this article, an engineering/physical dynamic system including losses is analyzed in relation to the stability from an engineer's/physicist's point of view. Firstly, conditions for a Hamiltonian to be an energy function, time independent or not, is explained herein. To analyze stability of engineering system, Lyapunov-like energy function, called residual energy function is used. The residual function may contain, apart from external energies, negative losses as well. This function includes the sum of potential and kinetic energies, which are special forms and ready-made (weak) Lyapunov functions, and loss of energies (positive and/or negative) of a system described in different forms using tensorial variables. As the Lypunov function, residual energy function is defined as Hamiltonian energy function plus loss of energies and then associated weak and strong stability are proved through the first time-derivative of residual energy function. It is demonstrated how the stability analysis can be performed using the residual energy functions in different formulations and in generalized motion space when available. This novel approach is applied to RLC circuit, AC equivalent circuit of Gunn diode oscillator for autonomous, and a coupled (electromechanical) example for nonautonomous case. In the nonautonomous case, the stability criteria can not be proven for one type of formulation, however, it can be proven in the other type formulation. [ABSTRACT FROM AUTHOR]