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With the frequent occurrence of automobile-related incidents, automobile forensics has gradually become a hot spot of concern. Due to the development of intelligent connected vehicles, drivers can drive the car directly through human manipulation or driver assistance systems. These factors have led to significant challenges in digital forensics and liability determination of automobile accidents. In addition, the terminal devices of intelligent connected vehicles have various memory chips, which record the vehicle's data during driving, making it possible to explore digital forensics and even realistically restore the truth of the accident in intelligent networked vehicles. In this work, we analyzed the working mechanism of intelligent connected vehicles and proposed a digital forensic model of automotive intelligent networked terminal devices. Based on this model, we give two sets of forensic cases applied to the T-Box and discuss the model's applicability and validity. We hope that our proposed forensic investigation model will be of some help for future automotive forensic investigations.

Mudstone and shale formations developed in the first sub-member of the third member of the Shahejie Formation (Es31Member) in the Qikou Sag, Bohai Bay Basin due to continuous lacustrine sedimentation. Atomic force microscopy, nitrogen adsorption, high-pressure mercury intrusion porosimetry, and field emission scanning electron microscopy were used to quantify the pore structure of the three main lithofacies in the study area. The results show that the average porosity and permeability of the mudstone are 3.54% and 0.00087 md, respectively. The pore structure is complex, and only the laminated shale has a high correlation between porosity and permeability. The laminated shale contains intergranular and intercrystalline pores, whereas the bedded shale primarily has intergranular dissolution pores and intergranular pores. The pore diameters of the two shales are predominantly at the submicron level. The pores of the laminated shale are located in and between the felsic laminae, and the pore connectivity is high. This lithofacies type is believed to be the most promising location for continental shale oil exploration in desert regions. The bedded shale is dominated by isolated pores with a large pore radius and large fluctuation. In contrast, to the laminated shale, the bedded shale has a high content of brittle minerals and low bedding density and is more likely to produce high-angle hydraulic fractures. The rock facies should be the focus of future shale oil evaluations in desert regions.

The presence of structural planes in rock masses reduces their mechanical properties and greatly affects their failure mode, resulting in physical and mechanical anisotropy. This study investigated the mechanical behaviors and damage characteristics of excavated jointed rocks in three-dimensional (3D) printed structures. A digital fracture network model based on the fractal principle was also developed to simulate a complex and rough network of fractures. Using 3D printing technology, rock specimens within a single rough structure surface, different dip angles, and rough fracture network models were established, considering different excavation sizes. Uniaxial compression was performed experimentally to investigate the mechanical response of rock masses. The failure processes of the jointed specimens were analyzed based on the digital image correlation (DIC) technique. The uniaxial compressive strength and elastic modulus were compared considering different excavation sizes. The results show that the geometric characteristics of the joints significantly influence the strength and failure mode of the rock mass. The strength of the layered rock mass shows a significant linear correlation with increasing excavation sizes. This research could provide a reference for studying the mechanical behavior of jointed rock masses using 3D printing technology.

In the current manufacturing environment, orders began to show trends in small batches and multiple varieties. Production workshops are expected to be more flexible and agile. This paper proposes a dynamic control system for the processing workshop based on the multi-agent architecture. The workshop layer is divided into multiple “processing cells” according to function. Machine agents and part agents are designed to achieve distributed control. In this paper, disturbances caused by random tasks to production are considered. A dynamic task dispatching mechanism based on the scrolling time window is investigated. When dispatching events occur, the machine agents and part agents determine the connection value between them through negotiation. An arbitration agent is designed to implement the dispatching through value matching. Finally, an actual experiment is carried out to verify the effectiveness of this dynamic control system.

ABSTRACTThe demand for customized products is increasing, which brings great challenges to the traditional manufacturing system. The traditional manufacturing system lacks the analysis and feedback of the data collected in manufacturing, which hinders the rational utilization of the resources. In order to reasonably allocate resources according to the production requirements and effectively avoid the influence of external interference on the manufacturing system, a framework for the intelligent digital twin shopfloor is proposed in this paper. The framework consists of three primary components, namely physical shopfloor, virtual shopfloor, and digital twin service system. A model of digital twin shopfloor, a self-organizing model which achieves automation function in physical shopfloor, and an adaptive model which provides additional external disturbance resistance in virtual shopfloor are developed to improve the above-mentioned components. The mechanism of a contract network protocol and some cooperation strategies used in multi-agents are applied to achieve the capabilities above, which improve the reconfiguration and response ability of the shopfloor. A design case is studied to illustrate that the intelligent digital twin shopfloor can configure resources and deal with disturbances effectively.

With the increasing requirement for personalized customization service, discrete manufacturing workshop, as the parts processing unit in manufacturing system, is expected for more agile and fast adaptation to environment changes, dynamically handling production tasks according to resource conditions. Simultaneously, distributed artificial intelligence system (e.g. multiagent manufacturing system and the holonic manufacturing system) has been considered as an important approach for developing industrial applications to solve the problems of complexity, uncertainty, and dynamic in the modern manufacturing environment. But the lack of universality and the difficulty in deployment have restricted the use of distributed artificial intelligence in actual industrial sites. For this issue, a new concept of agent computing node is proposed in this paper to enable the realization of multiagent manufacturing system. Adaptation layer, information development layer, and intelligent analysis layer are investigated for standardizing the configuration mode of agent computing node. Cooperating agent computing node with the radio frequency identification-based dynamic recognition technology for workpiece machining process is presented in this paper, and a practical approach for multiagent manufacturing system is considered, which can apply the functions regarding to deployment of dynamic scheduling and plug-and-play. A laboratory discrete manufacturing workshop system is used as a case study to prove the feasibility of this approach. In addition, a verification in industry is carried out, and the result proves the universality of this approach.

The Ma51-4submembers of Jingbian gas field in Ordos basin of China belongs to epeiric sea evaporative carbonate tidal flat facies. Supratidal zone of gypsum nodule dolostone and upper part of intertidal zone of gypsum crystal dolostone are most favorable reservoir. The carbonate rocks of Ma51-4had undergone complex diagenesis. Penecontem-poraneous dolomitization and gypsification provided the material foundation of the reservoir. Epidiagenesis selective dissolution of gypseous dolostone constructs the origin shape of pore structure. The dissolution and filling of various minerals in the burial period determine whether the early dissolution pores can be preserved, and the final state of the reservoir. Burial dissolution and filling of various minerals determined the preservation of early dissolved pores and the final condition of the reservoir. The concept of “minus cement porosity” directly reflects that sedimentary facies have great influence on the growth of reservoir in Ma51-4. Combined with sedimentary microfacies and diagenetic facies, a concise numerical symbol is used to express semiquantitatively sed-imentary microfacies and diagenesis facies. This descriptive method has great benefit in reservoir evaluation and prediction.

Anterior teeth with subgingival fractures require a multidisciplinary management approach with regards to biological, functional and aesthetic factors. This case report emphasises the use of a minimally invasive technique combined with a sequence of therapies to treat a complicated crown-root fracture and reviews the critical factors to ensure predictable outcomes. Endodontic treatment was undertaken due to exposure of the pulp in a complicated crown-root fracture of the maxillary right central incisor. Extrusion of the fractured fragment was performed to expose the fracture margin under the alveolar bone. Modified crown-lengthening surgery was used to reconstruct the biologic width. The traumatised tooth was restored with a glass fibre post and resin core, which fit the biological requirements. Finally, an all-ceramic crown fulfilled biomimetic aesthetics. This multidisciplinary approach achieved a good long-term prognosis with regards to periodontal and periapical healing.

Purpose: With the continuous upgrading of the production mode of the manufacturing system, the characteristics of multi-variety, small batch and mixed fluidization are presented, and the production environment becomes more and more complex. To improve the efficiency of solving multi-objective flexible job shop scheduling problem (FJSP), an improved hybrid particle swarm optimization algorithm (IH-PSO) is proposed. Design/methodology/approach: After reviewing literatures on FJSP, an IH-PSO algorithm for solving FJSP is developed. First, IH-PSO algorithm draws on the crossover and mutation operations of genetic algorithm (GA) algorithm and proposes a new method for updating particles, which makes the offspring particles inherit the superior characteristics of the parent particles. Second, based on the improved simulated annealing (SA) algorithm, the method of updating the individual best particles expands the search scope of the domain and solves the problem of being easily trapped in local optimum. Finally, analytic hierarchy process (AHP) is used in this paper to solve the optimal solution satisfying multi-objective optimization. Findings: Through the benchmark experiment and the production example experiment, it is verified that the proposed algorithm has the advantages of high quality of solution and fast speed of convergence. Research limitations/implications: This method does not consider the unforeseen events that occur during the process of scheduling and cause the disruption of normal production scheduling activities, such as machine breakdown. Practical implications: IH-PSO algorithm combines PSO algorithm with GA and SA algorithms. This algorithm retains the advantage of fast convergence speed of traditional PSO algorithm and has the characteristic of inheriting excellent genes. In addition, the improved SA algorithm is used to solve the problem of falling into local optimum. Social implications: This research provides an efficient scheduling method for solving the FJSP problem. Originality/value: This research proposes an IH-PSO algorithm to solve the FJSP more efficiently and meet the needs of multi-objective optimization. [ABSTRACT FROM AUTHOR]

Purpose Three-dimensional digital design and manufacturing technology are changing the current manufacturing pattern and have become the core of enterprise competition. However, the research and application of three-dimensional digital technology in the present phase have a strong bias toward the design of three-dimensional model and focus little on process planning. It restricts the development of manufacturing industry. Therefore, this paper aims to present a design scheme of three-dimensional digital process planning.Design/methodology/approach A three-dimensional digital process design method is developed by combining model-based definition technology and knowledge engineering technology. Model-based definition technology is used to display the process information. And knowledge engineering technology is used for process decision; meanwhile, ontology technology is introduced to describe process knowledge. And taking shaft part as an example, this paper establishes the general ontology of manufacturing process and the special ontology of shaft. This research provides an available method for the three-dimensional digital process planning.Findings Traditional process planning mainly is based on two-dimensional engineering drawing, which leads to the low efficiency and quality of process planning. Moreover, it cannot achieve effective mining and management of knowledge. Thus, applying an effective knowledge management technology into a three-dimensional process system is necessary.Research limitations/implications This paper contributes to an available method for three-dimensional digital process planning.Originality/value The introduction of model-based definition technology makes process information display in three-dimensional environment. And ontology technology achieves sematic reference and efficient management of process knowledge. [ABSTRACT FROM AUTHOR]

Accurate description of diagenetic controls on reservoir quality in “tight” sandstones can be difficult because of the inherent fine grain size and complex components of such oil reservoirs. In this study, petrological techniques and nuclear magnetic resonance (NMR) analysis were applied to fine-grained tight sandstones with varying grain sizes in order to reveal the diagenetic controls on reservoir quality. Results show that macropores in tight sandstones occur mainly as intergranular and dissolution pores, whereas micropores are distributed within ductile rock fragments, clay, and mica minerals, as well as occurring as dissolution micropores. Pore size distribution (PSD)/T2spectra display three distribution patterns: (i) a macropore-dominant bimodal distribution, (ii) a macropore–micropore bimodal distribution, and (iii) a micropore-dominant skewed distribution. A decrease in grain size correlates with weaker framework support of particles and thus more intensive mechanical compaction, resulting in the loss of both macroporosity and microporosity. Consequently, PSD change from macropore-dominant bimodal distributions to micropore-dominant skewed distributions as the pore type shifts from being dominated by macropores to intragranular micropores. In fine-grained sandstones, an increase in the abundance of ductile components corresponds to a loss of total porosity, related to the decrease in abundance of macropores, whereas the change in micropore abundance is negligible. This change is reflected in PSD by a shift from macropore-dominant bimodal distributions to macro–micropore bimodal distributions. The authigenic minerals in tight sandstone reservoirs occur mainly as late-stage carbonate minerals, and the precipitation of this carbonate cement preferentially occurs within macropores. When carbonate cement content is low, it has a limited influence on total porosity. However, it does significantly reduce the connectivity of the pore system, which is different from what might be expected in conventional sandstone reservoirs. Therefore, particle grain size, the abundance of ductile components, and late-stage cementation all contribute to the prediction of reservoir quality in oil-bearing tight sandstones.

Purpose With the customers’ increasing expectation on the product value, manufacturing enterprises around the world have made significant efforts to provide high value-added services in addition to their traditional product development and manufacturing business. For this reason, it is of great importance to research product service system. The purpose of this paper is to research on the key problem of integrated product service system (IPSS) design.Design/methodology/approach A value-oriented IPSS is developed, which is set up based on “requirements-functions-processes-structures” mapping model to give full consideration to customer value and service functions. An extended product-service blueprint, which stems from the service blueprint, is developed to describe product behaviors, service deliver processes, stakeholders’ activities and supporting activities. An ontology-based design support system is proposed to improve design efficiency and help designers making better-informed decisions. A computer-aided prototype system has been developed, and an initial attempt has been made to demonstrate the role of IPSS in the aerospace industry.Findings Many traditional design methods cannot effectively address the objects and processes integration problem of products and services. Moreover, both product and service should be considered in IPSS design, and both of them extremely depend on designers’ own experience and knowledge. Thus, a broader range of knowledge is required to understand product-service system (PSS) design.Research limitations/implications This research provides a solid foundation for PSS C and promotes an effective means for PSS design.Originality/value A customer value-oriented IPSS is presented. Customer requirements are considered during the design phase of PSS as well as both product and service knowledge. [ABSTRACT FROM AUTHOR]

Purpose – Product-service system (PSS) has been attracting attentions of global manufacturing to providing high-value added services in addition to their traditional product development and manufacturing business. For this reason, it is of great importance to research PSS. The purpose of this paper is to establish a systematic strategy and a system tool for PSS design. Design/methodology/approach – A requirement-driven product-service system (RdPPS) is developed using requirements analysis and knowledge management technologies. A framework is proposed to support RdPPS by providing tools and methods for requirement analysis and processing, formalization of PSS by ontology-based knowledge representation, reasoning method for PSS solution finding, and solution optimizing and assessing. Finally, the design support strategies for RdPPS are investigated to demonstrate the usability and functioning of the developed system. Findings – Many conventional design methods did not consider the influence of customer requirements (CRs) during the planning phase of PSS design. Moreover, a broader range of knowledge is required to PSS design, since both products and services are considered. Research limitations/implications – This research provides a solid foundation for PSS, and promotes an effective means for PSS design. Originality/value – A RdPSS is presented. CRs are considered during the design phase of PSS as well as both product and service knowledge. [ABSTRACT FROM AUTHOR]

Ag@AgCl-RGO composite photocatalyst with both graphene's special electronic state structure and Ag@AgCl's excellent visible light catalytic performance was fabricated. Phase composition of the photocatylst were characterized using X-ray diffraction. Scanning electron microscope and UV-vis absorption spectra characterize the surface morphology and spectroscopic properties. The RhB dye concentration was measured by UV-Vis spectra with the changes, the catalytic performance of different photocatalyst was tested, the mechanism of Ag@AgCl-RGO catalyzed degradation of RhB was explored in the presence of the catalyst. The research results show that the visible light absorption capacity and catalytic efficiency of Ag@AgCl-RGO was better than Ag@AgCl.