• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.114-122
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• 2011

In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a method to efficiently scan a restricted search area within the limited transmitter power and time in a bistatic radar and to track a series of transmitted pulses using the receiver beam which has ideally matched to the pulse propagation rate. In this paper, we have discussed the interrelationship between the pulse chasing and time and frequency/phase synchronization and described the effects of the identified system instability factors on two kinds of MTI filter configuration, single delay-line and double delay-line, in the bistatic radar. And also, we have confirmed that the overall system improvement is restricted by a lower improvement factor among identified them, and discussed the allowable tolerance of the time and frequency/phase synchronization in the bistatic system.

• Ocean Systems Engineering
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• v.9 no.3
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• pp.329-347
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• 2019

The shipbuilding industry is characterized by order production, and various processes are performed simultaneously in the construction of ships. Therefore, effective management of the production process and productivity improvement form important key factors in the industry. For decades, researchers and process managers have attempted to improve processes by using business process analysis (BPA). However, conventional BPA is time-consuming, expensive, and mainly based on subjective results generated by employees, which may not always correspond to the actual conditions. This paper proposes a method to improve the production process of offshore plant modules by analysing the process mining data obtained from the shipbuilding industry. Process mining uses information accumulated from the system-provided event logs to generate a process model and determine the values hidden within the process. The discovered process is visualized as a process model. Subsequently, alternatives are proposed by brainstorming problems (such as bottlenecks or idle time) in the process. The results of this study can aid in productivity improvement (idle time or bottleneck reduction in the production process) in conjunction with a six-sigma technique or ERP system. In future, it is necessary to study the standardization of the module production processes and development of the process monitoring system.

• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.255-264
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• 2013

This paper diagnosed the assessment problems and development types of the simple statement of the Sea Area Utilization Consultation System. and suggested the key assessment items for system improvement. The major types of Public Water occupation and use, and distribution characteristic of regional and coastal were analyzed by evaluate 529 review items during 2010-2012. The artificial structure installation including harbor and fishing port facilities in the South and West coast, and seawater supply and drainage for land-based aquaculture and power plant were dominated. The checklists considering each types of occupation and use in Public Water were suggested. In addition, policy proposals for system improvement were suggested.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.192-201
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• 1997

The feedback control scheme of the pressure control system of the rear wheel steering gear which has relatively large volume and sprung load was built up in order to improve th response characteristic of the system. The control algorithm chosen was a feedback compensator joined by a feedfoward compensator and the model matching method was used in the process of control system design. The structures and properties of the reference models were inspected and the parameters of the controller were decided. The improvement of the response characteristic of the pressure control valve by means of the feedback control is affirmed. Particularly, when the order of the system model is higher than the 2nd order, the effectiveness of the feedback control on the improvement of the response characteristic of the valve is distinct. And the convenience of the model matching method is the process of control system design is confirmed as well.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.229-234
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• 2005

This study aims to build basic data for a optimization of a ventilation system for indoor environment improvement in school building. To this end, we conducted field tests and computation fluid dynamics simulations about a indoor environment in dependence on operation of a ceiling type inverter air conditioner and ventilation system. The results could be summarized as follows. (1) For the ventilation system of 350CMH, 500CMH and 850CMH, reduction of each $CO_2$ concentration was measured 662ppm, 748ppm and 526ppm. (2) A optimal discharge angle of the ceiling type inverter air conditioner system was evaluated 45 degree in heating and cooling.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.189-203
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• 2000

This paper deals with the improvement of defense codification system for the items of defense supplies. We review other country's codification systems, their concept and trend of the systems for development, and then apply the ideas to our defense codification system. The proposal for improvement of defense codification system consists of three parts. The first one is the aspect of policy, the second one is the aspect of organization, and the last one is the aspect of operation. This paper will be contributed to the development of national codification system, and defense logistics management.

• Journal of the Korean housing association
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• v.14 no.3
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• pp.77-84
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• 2003

This study analyzes the necessity and situation of the improvement of housing quality control system for the consumer. we find several defeats of the Housing Quality Control System in Korea. Especially there is no any organization that manange the total housing quality control. So this study suggest the home warranty system should be established as soon as possible for protectings home-buyers and improving housing quality.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.584-587
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• 2003

Iterative learning control is an approach to improve the transient response of systems that operate repetitively over a fixed time interval. It is useful for the system where the system output follows the different type input, in case of design or modeling uncertainty In this paper, we introduce the concept of iterative learning control and then apply the learning control algorithm for multi-motor system for performance Improvement.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.140-152
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• 2021

During the shift from gasoline vehicles to electric ones, auto parts manufacturing companies have realized the importance of improvement in the manufacturing process that does not require any layout changes nor extra investments, while maintaining their current production rate. Due to these reasons, for the auto part manufacturing company, I-company, this study has developed the simulation model of the PUSH system to conduct a process analysis in terms of production rate, WIP level, and logistics work's utilization rate. In addition, this study compares the PUSH system with other three manufacturing systems -KANBAN, DBR, and CONWIP- to compare the performance of these production systems, while satisfying the company's target production rate. With respect to lead-time, the simulation results show that the improvement of 77.90% for the KANBAN system, 40.39% for the CONWIP system, and 69.81% for the DBR system compared to the PUSH system. In addition, with respect to WIP level, the experimental results demonstrate that the improvement of 77.91% for the KANBAN system, 40.41% for the CONWIP system, and 69.82% for the DBR system compared to the PUSH system. Since the KANBAN system has the largest impacts on the reduction of the lead-time and WIP level compared to other production systems, this study recommends the KANBAN system as the proper manufacturing system of the target company. This study also shows that the proper size of moving units is four and the priority allocation of bottleneck process methods improves the target company's WIP and lead-time. Based on the results of this study, the adoption of the KANBAN system will significantly improve the production process of the target company in terms of lead-time and WIP level.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.117-123
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• 1998

The present study was performed to improve the Environmental Impact Assessment system by comparing and analysing EIA systems for Residential Developments in the light of the business practice. For the improvement of EIA system, future strategies from each of three part ; the organ of approval(Construction&Transportation Dept.) for residential developments, the organ of consultation(Environment Dept.) for EIA and a developer(Korea Nation Housing Corp.), were analysed, and EIA systems and the processes of Residential developments were analysed. Results from the analysis of problems have provided a proposal for improvement of the Environmental Impact Assessment.