• Ocean Systems Engineering
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• v.9 no.4
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• pp.391-407
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• 2019

Tracking the location (position) of a surface or underwater marine vehicle is important as part of guidance and navigation. While the Global Positioning System (GPS) works well in an open sea environment but its use is limited whenever testing scaled-down models of such vehicles in the laboratory environment. This paper presents the design, development and implementation of a low energy ultrasonic augmented single beacon-based localization technique suitable for such requirements. The strategy consists of applying Extended Kalman Filter (EKF) to achieve location tracking from basic dynamic distance measurements of the moving model from a fixed beacon, while on-board motion sensor measures heading angle and velocity. Iterative application of the Extended Kalman Filter yields x and y co-ordinate positions of the moving model. Tests performed on a free-running ship model in a wave basin facility of dimension 30 m by 30 m by 3 m water depth validate the proposed model. The test results show quick convergence with an error of few centimeters in the estimated position of the ship model. The proposed technique has application in the real field scenario by replacing the ultrasonic sensor with industrial grade long range acoustic modem. As compared with the existing systems such as LBL, SBL, USBL and others localization techniques, the proposed technique can save deployment cost and also cut the cost on number of acoustic modems involved.

• Journal of Powder Materials
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• v.22 no.1
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• pp.10-14
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• 2015

In recent years, industrial demands for superior mechanical properties of powder metallurgy steel components with low cost are rapidly growing. Sinter hardening that combines sintering and heat treatment in continuous one step is cost-effective. The cooling rate during the sinter hardening process dominates material microstructures, which finally determine the mechanical properties of the parts. This research establishes a numerical model of the relation between various cooling rates and microstructures in a sinter hardenable material. The evolution of a martensitic phase in the treated microstructure during end quench tests using various cooling media of water, oil, and air is predicted from the cooling rate, which is influenced by cooling conditions, using the finite element method simulations. The effects of the cooling condition on the microstructure of the sinter hardening material are found. The obtained limiting size of the sinter hardening part is helpful to design complicate shaped components.

• Journal of Korean Library and Information Science Society
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• v.47 no.2
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• pp.175-200
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• 2016

As a part of the feasibility study of constructing the Maritime and Ocean Digital Library, we focused to examine the basic economic feasibility of the library in this study. In order to achieve the purpose, we analyzed related governmental policies, investigated the demand of the digital library, and tested the economic feasibility. As the tools of economic test, we calculated the size of benefit by Contingent Valuation Method, and estimated the Benefit/Cost Ratio, Net Present Value and Internal Rate of Return. As the result, we could get an assessment of positive economic feasibility mainly from the quite high level of WTP for the Maritime and Ocean Digital Library.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.665-674
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• 2018

In this paper, we propose a development results of a D-type non-rechargeable lithium battery($Li/SOCl_2$) on improvement in a low cost protection circuit of discharge for domestic military power source. According to this study, we describe a new design and product with 8-bit microcontroller in the protection circuit which can estimate state of health of the battery regardless of occurring an initial voltage delay. Also this paper discuss and facilitate development as solution to a safety about the non-rechargeable lithium batteries. As a result, we verified a quality of the protection circuit by a development test and evaluation(DT&E) process.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.2 s.344
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• pp.96-104
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• 2006

This paper presents design methodology, encient verification and implementation of a CAN protocol controller. The design methodology uses a heuristic technique to make the design flexible and cost effective. Using the design methodology, we created architecture for a CAN controller which has flexible and low cost features. For faster time-to-market and reliable operation of the designed CAN protocol controller, we p개posed a three-step verification process which uses three different kinds of verification techniques. The goal of this three-step verification is to reduce the number of test sequences in order to rapidly implement the design without loss of reliability for faster time-to-market. The designed CAN protocol controller was fabricated using a 0.35 micrometer CMOS technology.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.37-44
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• 1978

The purpose of this study is to search for an efficient application method in solving delay-phenomenon problems which influence upon total production cost through case study. The method of this study is an experimental study based on cutting time data in lead cutting operations from "Lead Cutting Machine (Stripper)" and its service rate data from a large electronic products company which utilizes conveyor line system for the products "Car Stereo" The procedure of this experimental study is as follows; 1) Using loading(Man-Hour) analysis technique j,1 order to analyse and evaluate Production capacity, efficiency, operation and idle rate assembly charge, waiting and service cost -when its are controlled by stripper operator(server) 2) Establishing adequate waiting time model of finite population caused by the interference of 4 stripper machine which is drawn from mathematical statistics testing, that is, goodness of fit test in the waiting and service rate and to search for optimal solution by utilizing the above mentioned model The experimental result was that amount to 8,546,618won Per year was brought down, that is, by optimum point, it shows a decrease as compared with Present point. The major limitation of this experimental study is that the Queue in the Finite Population, so to speak. it comes from the interference of 4 stripper machine dealt with this case were limited only on the Car Stereo conveyor line. Further study of application of this application method to the areas such as material handling, personnel management marketing and transportation management is strong1y recommended.trong1y recommended.

• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.373-381
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• 2004

Using standard components of a press die is recognized as a way for a cost reduction and a short lead time. It also provides a way for a quick maintenance of a die under repair. It is expected to contribute to integration of CAD/CAM system for manufacturing dies in the future. This paper presents a 3D CAD library which is constructed using the standard components and is used for designing a press die. This 3D CAD library is generated by a database system made of Microsoft Access for standard components and by CATIA V5 R10 API for geometric features. The library is implemented using Visual Basic 6.0 utility of CATIA API function in the Windows NT environment. It creates a 3D model of the standard components of press die easily when a die designer inputs numerical values of geometric features and the BOM of the completely assembled parts. It also generates automatically the assembly drawing of die set by using variables for standard values of die parts. Therefore users can save the cost of time to design the press die components, and even a beginner can use this program with ease. The test results of the 3D CAD library for designing shearing and bending dies verify its usefulness and feasibility.

• Journal of Families and Better Life
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• v.23 no.5 s.77
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• pp.181-190
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• 2005

The purpose of this study was to investigate the characteristics of leisure behavior of the five-day workweek company employees for developing leisure facilities in residential environment. The questionnaire survey was used. The subjects of questionnaire survey were 247 staffs of 4 banks. The questionnaire consisted of leisure time, the cost of leisure, consciousness of leisure, actual condition and need of leisure activities and spaces, leisure satisfaction and limitation on leisure. Frequency, percentage, and mean, correlation, $x^2-test$, and factor analysis were used for data analysis. The major results were as follows. 1) Leisure is necessary to strengthen the unity of family and cultivate the sentiment. 2) The degree of satisfaction of leisure facilities was lower than neutral. The satisfaction of leisure facilities related with cost, time of leisure, information of leisure facilities and program, and leisure environment. 3) Present leisure behavioral characteristics were restrictive and passive. However, the subjects showed hopes to increase their leisure activities and to engage in diverse forms of leisure in the future. Also, they showed an increased desired ratios in participating in each leisure activities. 4) In terms of location, they needed leisure facilities which was closer to their house.

• Asia pacific journal of information systems
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• v.11 no.1
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• pp.91-115
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• 2001

Faced with tougher competition in global, organizations are pressured to improve organizational productivity, including information systems(IS) departments. Especially related to IS, trying to remain competitive and up-to-date in rapidly changing world is becoming a financial burden to many organizations. Through outsourcing, organizations can provide better services and acquire and maintain a competitive advantage. In recent years IS outsourcing related researches have appeared in trade and academic literature. However the research on accounting information systems(AIS) outsourcing is very little or limited. This study attempts to empirically test the relationship between determinant factors and the degree of accounting information systems outsourcing as well as the relationship between success factors and the interactions between the degree of accounting information systems outsourcing and outsourcing success. Based on the previous studies on IS outsourcing and its related theories, determinant factors(transaction characteristic, resource performance, and risk dependence) and success factors(monitor, participation, and vendor capability) were identified and their measures were developed. Empirical results demonstrate that the change in the degree of AIS outsourcing is determined by the specificity of accounting information asset, uncertainty, the effect of internal AIS, AIS cost-effectiveness, and cost increase risks, and that monitor and vendor capability are implementation factors determining the degree of outsourcing success.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.557-563
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• 2010

This paper addresses the issue of adaptive global optimization using Kriging metamodel known as EGO(Efficient Global Optimization). The algorithm adaptively chooses where to generate subsequent samples based on an explicit trade-off between reduction of global uncertainty and exploration of the region of the interest. A strategy that saves the computational cost by using expectations derived from probabilistic nature of approximate model is proposed. At every iteration, a candidate test point that seems to be feasible/inactive or has little possibility to improve for minimum is identified and excluded from updating approximate models. By doing that the computational cost is saved without loss of accuracy.