Engineering Commons^™

3d Printing Technology On Spare Parts Business Supply Chain Management: A Case Study In Appliance Industry, Salih Boysan

Dissertations and Theses @ UNI

This study investigates the effects of using Additive Manufacturing (AM), also known as 3D printing, to produce spare parts within the supply chain of an appliance manufacturing company.

This research is based on an analysis of the operation of a spare parts business of an appliance manufacturing company. This research study used real data to investigate the feasibility of using 3D printing to reduce complexity in the spare parts division in terms of supplier rationalization, inventory reduction, and total cost of ownership. The research method used two scenarios: one where manufacturing spare parts traditionally was the baseline model and the …

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …

Reviewing The Potential And Constraints Of Modified Technology Options For Faecal Sludge Management In Dar Es Salaam, Tanzania, Amour Seleman

Tanzania Journal of Engineering and Technology (TJET)

Cities in the developing world face the challenge of safe management of faecal sludge because of rapid population growth that overwhelms the sanitation infrastructure and services. In developing countries, only 50% of faecal sludge (FS) generated is safely managed the remaining portion is haphazardly disposed of in the environment risking public health and environment. In response to the urgent need for safely managed sanitation services, technological options for containment, desludging and transportation of FS are being modified. This paper reviewed current desludging practices and the potential of modified technological options for addressing FSM at containment, desludging, and transportation in Dar …

Design And Development Of A Perfusion Bioreactor With Internal Volume Expansion And Cell Retention For Cell And Gene Therapy Manufacturing, Corinna Doris

KGI Theses and Dissertations

Economically producing patient-specific cell therapies at commercial levels remains a challenge as it requires manufacturing separate batches per patient where the production system must be scaled-out rather than scaled-up to supply more patient doses. The resulting high production cost and consequent price-point can limit patient access. Specifically, the current cell expansion processes are highly manual and laborious, with the number and complexity of operations and components increasing the opportunities for failure and contamination. This work therefore aims to design a mechanically simple bioreactor that is better suited for scale-out by consolidating the cell expansion process to fewer components, vessels, and …

Tracked Vehicle Physics-Based Energy Modelling And Series Hybrid System Optimisation For The Bradley Fighting Vehicle, Travis E. Mcwhirter, Torrey J. Wagner, John E. Stubbs, Denise M. Rizzo, Jada B. Williams

Faculty Publications

A hybrid electric tracked ground vehicle (HETGV) can reduce military fuel usage, however a review of current tools determined they are not suitable to estimate HEGTV performance. Based on topographic data and vehicle attributes, this research developed an estimation tool by creating a model to determine tracked vehicle energy and fuel requirements, and using these requirements, created a HEGTV cost and performance optimisation for the Bradley fighting vehicle energy system. The optimised design reduced fuel consumption by 15%, and met the vehicle's peak power requirement of 365 kW, with a recommended configuration of a 135 kW generator and 100 kWh …

Meal Duration: Implications For Restaurant Revenue Management, Dale F. Billings

UNLV Theses, Dissertations, Professional Papers, and Capstones

A comprehensive revenue management strategy addressing space, product, price and time, has been shown to increase profits within the hospitality sector. While the literature shows that the restaurant industry has frequently addressed space, product, and price when looking at financial strategy, the effect of the variable of time on revenue generation has not been adequately studied. Restaurants shy away from the practice of using time as a commodity, particularly regarding meal duration, due to fears of reducing customer satisfaction.

This project explores the use of time as a commodity in restaurant revenue management. In particular, it examines consumers’ feelings about …

Design Of A Flexible System Simulation Evaluation Framework, Rusheng Ju, Zimin Cai, Wang Song, Wang Peng

Journal of System Simulation

Abstract: To meet variable evaluation requirement of complex system simulation, this paper puts forward a design strategy of flexible effectiveness evaluation framework. The composition structure of system simulation evaluation framework is analyzed. To help users design reference dynamically, the method of evaluation reference edit and display is introduced based on Web. To enhance the extensibility of evaluation model, the method of interface design and code generation is investigated. To ensure the flexibility and extensibility of evaluation framework, the relation and mapping mechanism of evaluation references, evaluation model and evaluation result is studied. The framework is realized and verified in …

Research On Simulation Platform For Equipment System Analysis, Yuping Li, Shaojie Mao, Zhenqi Ju, Zhou Fang, Guoqiang Yan

Journal of System Simulation

Abstract: With the development of equipment construction from platform-centric to network-centric, simulation analysis of equipment system is an important means and tool to support the transformation and development of equipment construction under the condition of multi-task joint operation. Starting from the requirement of system simulation analysis, a cloud-based equipment system simulation architecture is proposed to realize flexible and configurable simulation environment according to task requirements; and a high-performance simulation framework is conducted, which provides strong support for different application modes, such as parallel hyper-real-time and distributed simulation deduction. The unified description, organization and management method of model and data resources …

Research On Corridor Setting Based On Pedestrian Simulation Of Social Groups, Yiting Xu, Zhang Rui

Journal of System Simulation

Abstract: As the connector of each space in the hub, the rail transit hub corridor plays the role of transition and buffer. The existence of social groups makes an important impact on pedestrian traffic and its simulation. The paper supplements the consideration of pedestrian traffic related studies on social groups travel, analyses the characteristics of social groups in rail transit hub corridor, improves Moussaïd social group force model, and redevelops AnyLogic micro-simulation platform based on Python language. Taking a subway station in Beijing as an example, fully considering the influence of social groups, it is obtained that the optimal channel …

Parallel Tasks Optimization Scheduling In Cloud Manufacturing System, Chenwei Feng, Wang Yan

Journal of System Simulation

Abstract: To solve the problem of unbalanced resource requirements and low resource utilization when the same type of tasks are executed in parallel in the cloud manufacturing system, a task resource scheduling model with the goal of minimizing cost, minimizing time, maximizing reliability and optimizing quality is established. A non-dominated sorting genetic algorithm based on reference points (NSGA-III) is adopted to solve the model by combining real number matrix coding and crossover and mutation based on real number coding instead of common evolutionary strategy. And an optimal decision strategy based on combination of analytic hierarchy process and entropy value method …

Research On The Value Accessing Method For Calibrating Micro Traffic Simulation Model Parameters, Chenjing Zhou, Rong Jian, Kwok Lam

Journal of System Simulation

Abstract: Parameter calibration is the precondition of the application of micro traffic simulation technology. This study focuses on the value accessing method for parameter calibration in order to further improve the parameter calibration process. The analysis of the distribution characteristics of each parameter calibration results shows that the parameters have different trends in the process of gradual iteration, and there are multiple optimal solutions for the model parameter calibration results. In this paper, the dispersion is used as the quantitative analysis index of the concentration degree of each parameter calibration result, and the parameter value of the model is determined …

Research On Source Seeking Methods Of Harmful Gas Leakage In Chemical Industry Parks, Zhao Yong, Bin Chen, Xiaodong Wang, Zhengqiu Zhu, Rongxiao Wang, Xiaogang Qiu

Journal of System Simulation

Abstract: Chemical production safety accidents often lead to harmful gas leakage, causing serious environmental damage and casualties. Mastering the information of leaking source quickly can assist in emergency disposal decisions and reduce the harm of accidents. In this paper, Entrotaxis algorithm is used to guide the ground source seeking equipment to move to the vicinity of the leaking source quickly and autonomously in a chemical park scene, and to master the source information. According to the characteristics of the chemical industry park scene, this paper applies intermittent search module into Entrotaxis algorithm and proposes a robust and suitable algorithm (Entrotaxis-Jump …

Numerical Simulation Analysis Of Anti-Blast Impact Of Underground Rescue Capsule Based On Ls-Dyna, Zhang Fan, Yuanhua Yang, Xiaoxu He, Deng Yu

Journal of System Simulation

Abstract: Aiming at the strength problem of the underground rescue cabin under explosion impact load, a finite element model of overall explosion impact load and fluid-solid coupling structure response is established in transient dynamic soft LS-DYNA. The flow field impact load is generated by explosion algorithm, and the propagation of the impact load in the air is calculated. The dynamic response of the rescue cabin structure under the impact load is calculated by the fluid-solid coupling method. The results show that the maximum load occurs on the end surface closest to the explosion source, and the structural deformation is small …

The Scheduling Algorithm Of Cloud Job Based On Hopfield Neural Network, Yudong Guo, Jinping Zuo

Journal of System Simulation

Abstract: Focusing on the low efficiency of cloud job scheduling and the insufficient utility of resource, a job scheduling algorithm based on Hopfield Neural Network is proposed. In order to improve the resource scheduling ability of the system, The resource characteristics which influence the cloud job scheduling are shown. The mathematical model of resource constraints is established, and the Hopfield energy function is designed and optimized. The average utilization rate of 9 nodes is analyzed by using the standard test cases, and the performance and resource utilization of the proposed strategy are compared with three typical algorithms. …

Simulation Research On Attitude Solution Method Of Micro-Mini Missile, Chunbo Zhao, Junfang Fan, Liu Ning

Journal of System Simulation

Abstract: Aiming at the problem of attitude measurement error in the inertial navigation system of micro and small guided ammunition under eccentric structure, the attitude solution and error compensation optimization are studied by using rotation vector optimization of multiple sub-samples, such as monotone sample, two sub-samples, three sub-samples and four sub-samples, and the fourth-order runge kutta algorithm. Through error compensation and optimization of measured data, the results show that the monomorphic modified algorithm has the worst optimization effect, the fourth-order runge kutta optimization algorithm has the best effect, and the maximum drift error of attitude Angle is better than 10 …

Multi-Objective Optimization Design Of Aerodynamic Layout For Twin Swept-Wing Aircraft, Yuchang Lei, Dengcheng Zhang, Yanhua Zhang, Guangxu Su, Luo Hao, Zhan Ren

Journal of System Simulation

Abstract: Multi-objective optimization of aerodynamic layout is a key technology in the design of vehicles. The overall configuration of the shape parameters is optimized with a double swept-shaped wave shape as the basic configuration. We use NSGA-Ⅱ multi-objective genetic algorithm, take the aircraft double sweep angle as the design variable, consider the maximum takeoff weight, range, volume ratio and other performance indicators, use Elman neural network to establish the relationship between shape parameters and performance parameters, and establish constraints based on mission planning requirements. The Pareto optimal solution set is obtained by using optimized design and the individuals with …

Fast Simulation Of Yacht In Calm Water Based On Improved Savitsky Method, Xiaochen Li, Yin Yong

Journal of System Simulation

Abstract: An improved Savitsky method is proposed to increase the accuracy of mathematical model of yacht in fast simulation. Three degrees of freedom mathematical model is established to simulate the motion in displacement regime. warped hull forms of yachts are simplified into prismatic hull and improved Savitsky method is used to calculate resistance. The simulation is carried out in pre-planing regime and planing regime. The validity of the proposed method has been assessed by comparing results with previous experimental data, which shows good agreements. The improved method runs well and the result is accurate when it is added to the …

Knowledge Representation Method Of Joint Operation Situation Based On Knowledge Graph, Baokui Wang, Wu Lin, Xiaofeng Hu, Xiaoyuan He

Journal of System Simulation

Abstract: Lacking of common knowledge for understanding and judging complex situation of operation by machines is one of the difficulties in intelligent situation cognition. The knowledge representation methods based on knowledge graph are reviewed. The characteristics and difficulties of joint operation situation knowledge representation are analyzed. Moreover, the concept of scenario knowledge graph is presented, as well as the knowledge sources and basic content of scenario knowledge graph are described. This paper also points out that the joint knowledge representation method based on discrete symbols and continuous vectors in specific scenario is an effective way to express joint operation situation …

Dynamic Collision Optimization Algorithm Based On Ray Detection, Li Xing, Yanfang Fu, Wang Liang, Chengtao Lu

Journal of System Simulation

Abstract: Aiming at the inaccurate collision detection problem in Unity 3D-based visual simulation systems, a dynamic collision optimization algorithm based on ray detection is designed and implemented. The 3D virtual scene is segmented by octree, which simplifies the detection range of obstacles during the operation of simulation systems. At the same time, based on ray detection, according to the quantization coefficient and distance of the threat degree of obstacles, an appropriate collision collider is dynamically added to the obstacles to complete collision detection. The results show that the algorithm not only improves the fluency of visual simulation systems but also …

Study On Optimization Of Shore Bridge Operator Scheduling Considering The Influence Of Ambient Temperature, Yibin Wang, Haihong Yu, Danlan Xie

Journal of System Simulation

Abstract: The refinement of port management puts forward new requirements for its service capacity, and human factors are the key factors affecting the port service capacity. It is a new and feasible research direction to improve port operation efficiency by adjusting human factors. Based on the theoretical model of temperature affecting efficiency, this paper uses FlexSim system simulation software to analyze the change of employee's working efficiency with time, and studies the optimal scheduling strategy of shore bridge operators under different temperatures. Finally, it is concluded that when the ambient temperature is suitable for human body, the eight-hour scheduling …

A Method Of Manifold Learning For Locality Preserving Projections Based On Geodesic, Lijun Xu, Jinghan Fang, Yiping Wang

Journal of System Simulation

Abstract: In order to solve the problem of under-fitting state of LPP algorithm in practical application,in this paper, the mapping principle of Locality Preserving Projections (LPP) is discussed in detail. The relationship of LPP method between the under-fitting state on certain dataset and adjacency graph is analyzed. The LPP manifold learning method (ISOLPP) is proposed on the basis of geodesic. The experiment results show that the good embedded effect is achieved by implenmenting ISOLPP method on multiple test data sets. It significantly improves the adaptability of the algorithm by not only inheriting the advantages of LPP algorithm with explicit projection …

Synergic Production Scheduling Method For Distributed Multi-Plants Based On Fusion Decision Tree, Wang Yan, Tianlun Jiang

Journal of System Simulation

Abstract: In the synergic production scheduling optimization problem of distributed multi-plants, it is necessary to consider the two stages of job allocation between factories and job scheduling in factories at the same time. This paper first establishes a distributed multi-plant scheduling model with total cost and advance/delay as the optimization objectives, and then proposes a nested optimization algorithm framework integrating ID3 decision tree with Gauss particle swarm optimization. In this framework, independent scheduling optimization within the factory is nested in the process of inter factory allocation optimization, and elite retention strategy is introduced to improve the algorithm optimization. In …

Overview Of Cooperative Target Assignment, Ou Qiao, Xiaoyuan He, Jiuyang Tao

Journal of System Simulation

Abstract: The concept and connotation of combat coordination are briefly analyzed. The historical origin of cooperative target allocation and its orientation in command and control process are expounded. The research status of collaborative target allocation in model building and algorithm solving is analyzed comprehensively, the shortcomings of current research is pointed out. It is proposed that for the next step we should pay more attention to large-scale collaborative target allocation under dynamic and confrontational conditions, and focus on the real-time, adaptability and iterative evolution mechanism of the algorithm.

A Mesh Model Simplification Method Based On Visual Feature Preservation, Che Li, Dejun Tang, Shimin Li, Fengju Kang

Journal of System Simulation

Abstract: Aiming at the problems of mesh visual feature loss and oversimplification in mesh simplification algorithm, a visual feature preservation based triangle mesh model simplification algorithm is proposed. The multi-viewpoint perception method is used to measure the visual perception error caused by the difference between the original and the simplified model in the two-dimensional view under the optimal viewpoint set. Based on QEM algorithm, a novel geometric error metric is built by introducing the triangle shape factor. The triangle collapse error function is defined by combining visual perception and geometric error to control the simplified depth of the model. Through …

Research On Clock Synchronization Of Simulation System Based On Ethernet And Optical Fiber Network, Yulin Meng, Shen Tao, Shuaihao Wang, Lüyi Zhao, Chengshi Tang

Journal of System Simulation

Abstract: With the development of simulation communication and Ethernet clock synchronization technology, the traditional timing simulation method based on real-time operating system can not meet the accuracy requirements of clock synchronization between multi-simulation systems. A time synchronization method between simulation systems based on IEEE1588 clock synchronization protocol and optical fiber reflection memory network is proposed, in which the Beidou/GPS timing device periodically calibrates the real-time operating system, and the real-time operating system divides the frequency of the calibrated clock information and synchronizes the clock of each simulation system through the high-speed optical fiber reflection memory network. The clock synchronization …

Research On Control Technology Of Aeroengine Heat Exchanger, Qingyang Jiang, Song Hua

Journal of System Simulation

Abstract: In order to solve the high temperature problem caused by the high speed of the synergistic aspirating engine, this paper designs a control algorithm for the heat exchanger. In the process of designing the control algorithm, considering the strong nonlinearity, uncertainty and strong coupling of the engine, The decoupling study of the multi-input and multi-output linear model of the heat exchanger is carried out. The decoupling effect of two different decoupling methods on the strongly coupled heat exchanger is obtained. The fuzzy decoupling PID controller has short adjustment time and overshoot. Small, conclusions with better decoupling effects.

Downhole Drilling Processing Data Acquisition And Stick Slip Characteristic Analysis, Huang Sheng, Zhang Tao, Chongjun Huang, Yumei Li, Deng Hu, Zhang Xia

Journal of System Simulation

Abstract: During oil drilling process, drill string vibrations are detrimental to the bit and drill string, which even causes failure of equipment. Researches show that, studying the law of near bit vibration data can reduce non-production time (NPT) and improve drilling efficiency. This paper uses power spectral density and wavelet transform to analyze vibration signals, then compares with normal drilling situation to find out stick slip characteristics. The results show that, when stick slip occurs, the mean value of lateral vibration fluctuates greatly, which indicates stick slip is mainly based on torsional vibration. From the perspective of power spectral density …

Research On Mechanical Configuration Of Automatic Container Terminals Based On Simulation Optimization Method, Shaozheng Yu, Dongshi Sun, Chen Jing, Yongchao Li

Journal of System Simulation

Abstract: In the study of mechanical configuration problem of automated container terminal, a system simulation model based on discrete event simulation is constructed. The key parameters and interference factors that affect the performance of the system are fully considered in the model and a mechanical scheduling algorithm interface to ensure the effectiveness of the simulation model is designed. On the premise of ensuring the reliability of the container terminal system, a cycle optimization method of mechanical configuration scheme is proposed to minimize the cost. An example is given to solve the mechanical configuration scheme of an automatic container terminal. …

Research On The Simulation Technology For Multi-Aerocraft Cooperative Guidance, Li Jing, Han Jian, Zhang Qing

Journal of System Simulation

Abstract: The formal system of multi- aerocraft cooperative simulation system is identified as the discrete event system & different equation system specifications (DEV&DESS) through the analysis of the composition and running mechanism. The running control problem of cooperative simulation system is transformed into simulation control problem of a specific DEV&DESS system. A dynamic operation control method for cooperative guidance simulation system based on coordinator is proposed, and this method is validated by real-time mathematical simulation experiments.

An Lstm-Based Motion Recognition Method For Power Operation And Maintenance, Peizhen Liu, Yuxiang Jia, Shihong Xia

Journal of System Simulation

Abstract: The security of power operation and maintenance has always been a subject of great social concern. In order to avoid serious consequences caused by the fault of staffs, a motion recognition method for power operation and maintenance jobs based on LSTM (Long Short-Term Memory) is proposed, which covers the whole process from data collection, data processing to motion classification and recognition, then it can recognise and supervise the behavior of staffs who are at work. In addition, a simulation experiment is conducted between the deep learning algorithm LSTM and the traditional machine learning algorithm KNN based on the newly …