• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.218-219
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• 2011

This paper focuses on dispatching strategy for AGVs(Automated Guided Vehicle). The goal of AGV dispatching problem is allocating jobs to AGVs to minimizing QC delay and AGV total travel distance. Due to the highly dynamic nature of container terminal environment, the effect of dispatching is hard to predict thus it leads to frequent modification of dispatching results. Given this situation, single rule-based approach is widely used due to its simplicity and small computational cost. However, single rule-based approach has a limitation that cannot guarantee a satisfactory performance for the various performance measures. In this paper, dispatching strategy based on multicriteria heuristics is proposed. Proposed strategy consists of multiple decision criteria. A muti-objective evolutionary algorithm is applied to optimize weights of those criteria. The result of simulation experiment shows that the proposed approach outperforms single rule-based dispatching approaches.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.137-144
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• 2017

The business process of global third party logistics company is defined as a network of logistics activities which involves the products that are manufactured in the developing countries, such as Vietnam, China and so on, and delivered to North or South American countries via intermediate stopover sites. The third party logistics company usually uses proprietary logistics information system to support the related logistics activities. However, each consignor sometimes may require different business process based on the customer type or characteristics of their products. Therefore, the third party logistics company need to modify their business process to reflect customer's requirements, resulting in the modification of logistic information systems and additional costs. Therefore, a flexible mechanism is required to efficiently support the various types of requirements by the owners of the products. In this paper, first, we figured out various business rules related to third party global logistics activities. Second, we grouped the identified business rules into business processes, objects, relations, dependency, policy, representations, execution, and resources and further into precondition, postcondition, and invariant based on checking point in time. Furthermore, the categorized rules are classified into inter-activity and intra-activity rules based on the execution range. Third, we proposed a rule syntax to describe the defined rules into scripts which are understood by user and information system together. When each activity is executed, the rule manager checks whether there are rules related with the activity execution. Finally, we developed a prototype rule management system to show the feasibility of our proposed methodology and to validate it with an example.

• Journal of Engineering Education Research
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• v.16 no.4
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• pp.15-20
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• 2013

The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1205-1207
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researchs to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used a fuzzy system based on the rule bases. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In the simulations of several cases, our method showed better trajectory tracking performance compared with the CTM.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1253-1255
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• 1993

Double Injection(DI) switching devices consist of p+ and n+ contact separated by a nearly intrinsic semiconductor region containing deep trap. The FEM is chosen as a simulation method for DI switching device, because of the advantage in local mesh refinement and computer memory comparing with other methods. And Scharfetter-Gummel(S-G) scheme is applied, with which an accurate-seven point Gaussian Quadrature rule is combined. The existance of deed trap requires the modification of conventional equation set. So recombination rate equation is modified and a new equation is included in the equation set which conventionally consists of Poisson equation and current continuity equations.

• ETRI Journal
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• v.34 no.4
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• pp.629-632
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• 2012

This letter investigates the combination of the Chase-2 and sum-product (SP) algorithms for low-density parity-check (LDPC) codes. A simple modification of the tanh rule for check node update is given, which incorporates test error patterns (TEPs) used in the Chase algorithm into SP decoding of LDPC codes. Moreover, a simple yet effective approach is proposed to construct TEPs for dealing with decoding failures with low-weight syndromes. Simulation results show that the proposed algorithm is effective in improving both the waterfall and error floor performance of LDPC codes.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.271-287
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• 2019

The synchronization scheme based on moving average is robust and suitable for the same rule to be adopted in embedding watermark and synchronization code, but the imperceptibility and search efficiency is seldom reported. The study aims to improve the original scheme for robust audio watermarking. Firstly, the survival of the algorithm from desynchronization attacks is improved. Secondly, the scheme is improved in inaudibility. Objective difference grade (ODG) of the marked audio is significantly changed. Thirdly, the imperceptibility of the scheme is analyzed and the derived result is close to experimental result. Fourthly, the selection of parameters is optimized based on experimental data. Fifthly, the search efficiency of the scheme is compared with those of other synchronization code schemes. The experimental results show that the proposed watermarking scheme allows the high audio quality and is robust to common attacks such as additive white Gaussian noise, requantization, resampling, low-pass filtering, random cropping, MP3 compression, jitter attack, and time scale modification. Moreover, the algorithm has the high search efficiency and low false alarm rate.

• Journal of Korean Physical Therapy Science
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• v.5 no.3
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• pp.707-715
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• 1998

The technique of AKA were devised and modified several times after clinical trials to obtain better result and were though to be few years ago. The published literatures on joint mobilization were unsatisfactory to me since the subject of treatment was not confined to the synovial joint and techniques seemed too violent to treat diseased joints. Among the techniques distraction gliding and the use of convex-concave rule by F. M. Kaltenborn were acceptable theoretically but they required considerable technical modification. By that time it was evident that pain in numerous painful conditions including organic regions could be eliminated by AKA new disease entitles such as aseptic arthritis of the sacroiliac joint, hip joint, shoulder joint, 1st costovertebral joint etc and periradiculitis were elucidated.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.3
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• pp.11-17
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• 2001

The design and manufacture of injection molded polymeric parts with desired properties is a costly process dominated by empiricism, including the repeated modification of actual tooling. This paper presents an expert design evaluation system which can predict the mechanical performance of a molded product and diagnose the design before the actual mold is machined. The knowledge-based system synergistically combines a rule-based expert system with CAE programs. Heuristic knowledge of injection molding is formalized as rules of an expert consultation system. The expert system interprets the analytical results of the process simulation, predicts the performance, evaluates the design and generates recommendations for optimal design alternatives.

• Journal of Navigation and Port Research
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• v.35 no.6
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• pp.501-507
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• 2011

This paper focuses on dispatching strategy for AGVs(Automated Guided Vehicle). The goal of AGV dispatching is assigning AGVs to requested job to minimizing the delay of QCs and the travel distance of AGVs. Due to the high dynamic nature of container terminal environment, the effect of dispatching is hard to predict thus it leads to frequent modification of dispatching decisions. In this situation, approaches based on a single rule are widely used due to its simplicity and small computational cost. However, these approaches have a limitation that cannot guarantee a satisfactory performance for the various performance measures. In this paper, dispatching strategy based on multicriteria heuristics is proposed. The Proposed strategy consists of multiple decision criteria. A multi-objective evolutionary algorithm is applied to optimize weights of those criteria. The result of simulation experiment shows that the proposed approach outperforms single rule-based dispatching approaches.