• Title/Summary/Keyword: combined systems

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Nonlinear instability problems including localized plastic failure and large deformations for extreme thermo-mechanical loads

  • Ngo, Van Minh;Ibrahimbegovic, Adnan;Hajdo, Emina
    • Coupled systems mechanics
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    • v.3 no.1
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    • pp.89-110
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    • 2014
  • In this work we provide the theoretical formulation, discrete approximation and solution algorithm for instability problems combing geometric instability at large displacements and material instability due to softening under combined thermo-mechanical extreme loads. While the proposed approach and its implementation are sufficiently general to apply to vast majority of structural mechanics models, more detailed developments are provided for truss-bar model. Several numerical simulations are presented in order to illustrate a very satisfying performance of the proposed methodology.

A Flexibility Analysis of Depots Location Considering Physical Distribution Design (판매물류시스템 설계상 Depots 입지선정의 유연성 분석)

  • 강인선
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.65
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    • pp.81-88
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    • 2001
  • In logistics decision making, Key elements in the design of any physical distribution are the location of depots and the distribution of goods from the depots to the customers. Considering open and close the depots, This paper presents a flexible analysis on the combined location-routing problem(LRP) the case for variation capacity of vehicle and customers demands each. The scenario examples are given the use of heuristic(Saving-Drop) in LRP types. The results is useful in apply to the logistics environment changes.

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A Convergent and Combined Activation Plan for Exercise Rehabilitation in the Era of the Fourth Industrial Revolution (4차 산업혁명시대에 운동재활분야의 융·복합적 활성화 방안)

  • Cho, Kyoung-Hwan
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.8
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    • pp.407-426
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    • 2020
  • The purpose of this study was to make convergent and combined analysis of the sport industry and exercise rehabilitation in the era of New Normal based on the Fourth Industrial Revolution and devise a comprehensive plan for future activation. For this purpose, literature review was performed mainly by analyzing the environment of the sport industry in the New Normal era based on the Fourth Industrial Revolution and by carrying out convergent and combined analysis of the sport industry to present a convergent and combined activation plan for exercise rehabilitation comprehensively as follows: First, it is necessary to make a strategy of promoting exercise rehabilitation in convergent and combined ways at the sport industry level. This means development of a convergent and combined exercise rehabilitation-tourism-ICT model as well as a convergent and combined exercise rehabilitation-ICT model through collaboration among ministries, including those of health and sports. Second, it is necessary to convert into a convergent and combined way of thinking and extend and reinforce educational competitiveness in the area of exercise rehabilitation. That is, it is necessary to refine the education and training systems for reinforcing personal ICT competence of exercise rehabilitation majors and relevant ones and provide convergent and combined business commencement education. Third, it is necessary to make different types of research and development by applying practical, convergent and combined skills based on the industrial field to exercise rehabilitation and relevant areas. Efforts should be made to overcome any risk in the era of New Normal and support business commencement with convergent and combined skills for exercise rehabilitation. Fourth, it is necessary to make mid- and long-term clusters where exercise rehabilitation and relevant businesses can be accumulated. This means building an industrial hub and complex for exercise rehabilitation and requires making an R&D-based cluster with industrial-academic-governmental collaboration, maximizing the synergy effects with local infrastructures, and fulfilling the function of realizing a spontaneous profit-generating structure.

In situ analysis of capturing dynamics of magnetic nanoparticles in a microfluidic system

  • Munir, Ahsan;Zhu, Zanzan;Wang, Jianlong;Zhou, H. Susan
    • Smart Structures and Systems
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    • v.12 no.1
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    • pp.1-22
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    • 2013
  • Magnetic nanoparticle based bioseparation in microfluidics is a multiphysics phenomenon that involves interplay of various parameters. The ability to understand the dynamics of these parameters is a prerequisite for designing and developing more efficient magnetic cell/bio-particle separation systems. Therefore, in this work proof-of-concept experiments are combined with advanced numerical simulation to design and optimize the capturing process of magnetic nanoparticles responsible for efficient microfluidic bioseparation. A low cost generic microfluidic platform was developed using a novel micromolding method that can be done without a clean room techniques and at much lower cost and time. Parametric analysis using both experiments and theoretical predictions were performed. It was found that flow rate and magnetic field strength greatly influence the transport of magnetic nanoparticles in the microchannel and control the capturing efficiency. The results from mathematical model agree very well with experiments. The model further demonstrated that a 12% increase in capturing efficiency can be achieved by introducing of iron-grooved bar in the microfluidic setup that resulted in increase in magnetic field gradient. The numerical simulations were helpful in testing and optimizing key design parameters. Overall, this work demonstrated that a simple low cost experimental proof-of-concept setup can be synchronized with advanced numerical simulation not only to enhance the functional performance of magneto-fluidic capturing systems but also to efficiently design and develop microfluidic bioseparation systems for biomedical applications.

Performance Comparison of Molten Carbonate Fuel Cell Hybrid Systems Minimizing Carbon Dioxide Emissions (이산화탄소 배출을 최소화하는 용융탄산염 연료전지 하이브리드 시스템들의 성능 비교)

  • AHN, JI HO;YOON, SUK YOUNG;KIM, TONG SEOP
    • Journal of Hydrogen and New Energy
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    • v.28 no.1
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    • pp.30-39
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    • 2017
  • Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.

A Study on the Development of Internet Purchase Support Systems Based on Data Mining and Case-Based Reasoning (데이터마이닝과 사례기반추론 기법에 기반한 인터넷 구매지원 시스템 구축에 관한 연구)

  • 김진성
    • Journal of the Korean Operations Research and Management Science Society
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    • v.28 no.3
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    • pp.135-148
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    • 2003
  • In this paper we introduce the Internet-based purchase support systems using data mining and case-based reasoning (CBR). Internet Business activity that involves the end user is undergoing a significant revolution. The ability to track users browsing behavior has brought the vendor and end customer's closer than ever before. It is now possible for a vendor to personalize his product message for individual customers at massive scale. Most of former researchers, in this research arena, used data mining techniques to pursue the customer's future behavior and to improve the frequency of repurchase. The area of data mining can be defined as efficiently discovering association rules from large collections of data. However, the basic association rule-based data mining technique was not flexible. If there were no inference rules to track the customer's future behavior, association rule-based data mining systems may not present more information. To resolve this problem, we combined association rule-based data mining with CBR mechanism. CBR is used in reasoning for customer's preference searching and training through the cases. Data mining and CBR-based hybrid purchase support mechanism can reflect both association rule-based logical inference and case-based information reuse. A Web-log data gathered in the real-world Internet shopping mall is given to illustrate the quality of the proposed systems.

A Knowledge-Based Machine Vision System for Automated Industrial Web Inspection

  • Cho, Tai-Hoon;Jung, Young-Kee;Cho, Hyun-Chan
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.13-23
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    • 2001
  • Most current machine vision systems for industrial inspection were developed with one specific task in mind. Hence, these systems are inflexible in the sense that they cannot easily be adapted to other applications. In this paper, a general vision system framework has been developed that can be easily adapted to a variety of industrial web inspection problems. The objective of this system is to automatically locate and identify \\\"defects\\\" on the surface of the material being inspected. This framework is designed to be robust, to be flexible, and to be as computationally simple as possible. To assure robustness this framework employs a combined strategy of top-down and bottom-up control, hierarchical defect models, and uncertain reasoning methods. To make this framework flexible, a modular Blackboard framework is employed. To minimize computational complexity the system incorporates a simple multi-thresholding segmentation scheme, a fuzzy logic focus of attention mechanism for scene analysis operations, and a partitioning if knowledge that allows concurrent parallel processing during recognition.cognition.

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Problems and improvement methods of passive treatment systems for acid mine drainage in Korea

  • Ji, Sang-Woo;Ko, Ju-In;Kim, Sun-Joon
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.504-510
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    • 2003
  • This study has been carried out to evaluate the passive treatment systems for acid mine drainage in Korea and to suggest, if possible, the method for the improvement. 35 passive treatment systems in 27 mines have been constructed since 1996. SAPS, being the main process, was combined with more than one of processes such as anaerobic wetland, aerobic wetland, and oxidation pond for the construction of passive treatment system. Problems observed during the operation include the poor sulfate removal ratio, overflow, leakage, unusabless of the whole system, and inefficiency. The reasons of the poor sulfate removal ratio are believed that the low temperature during the winter prohibits the SRB activity and HRT for bacterial sulfate reduction is insufficient. An alternative method In Adit Sulfate Reducing System which enables to keep the temperature constant at about $15^{\circ}C$ was suggested. IASRS is the methods of placing the SAPS inside the adit, which enables the temperature around the system constant can be maintained. The experiments using the laboratory scaled model systems made up of four sections showed high efficiencies in pH control and metal removal ratios, but showed still low sulfate removal ratio of about $23\%$ also with high COD at the beginning of the operation.

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Task Rescheduling Using a Coordinator in a Structural Decentralized Control of Supervisory Control Systems

  • Lee, Sang-Heon;Kim, Ill-Soo;Kai C. Wong
    • International Journal of Precision Engineering and Manufacturing
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    • v.5 no.2
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    • pp.22-31
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    • 2004
  • A problem of task rescheduling using a coordinator in a structural decentralized control of supervisory control theory is formulated. we consider that the overall system is divided into a number of local systems. Using an example of a chemical batch reaction process, it has shown that after local supervisors have been established for a given task, a coordinator can be used to solve some rescheduling problems among local plants for new or modified tasks. The coordination system models the interactions of local plants, and is consisting of only the shared events of local plants, so simpler to synthesize. A coordinator is designed based on the specifications given for the coordination system. Under the 'structural' conditions developed in this paper, the combined concurrent actions of the coordinator with the existing local supervisors will achieve the rescheduling requirements. Again since the conditions are structural (not specification-dependent), once the coordination architecture has been established, it can be used for a number of different tasks without further verifications.