• Journal of Multimedia Information System
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• 제7권4호
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• pp.269-276
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• 2020

The small craft including jet-board for leisure are commonly smaller than the general commercial vessels. For the floating vessel, the motion analysis is significantly important component to design the shape. It is, however, hardly predicting its behavior by using conventional boundary element method due to violating small amplitude assumption for potential theory. The computational fluid dynamics method can afford to simulate such small craft, but its grid system was not able to calculate motion, because movable body disturbs the grid system by confliction. The dynamics fluid body interaction model with over-set mesh system can be dealt with movable floating body under irregular ocean wave. In this study, several cases were considered to reveal that DFBI is essential method to predict floating body motion. The single phase simulate was conducted to establish the shape perfection, and then the validated vessel was simulated with ocean waves weather DFBI option on or off. Through the comparison, the results between the cases of DFBI on and off shows significantly difference. It was claimed that the DFBI was necessary not only to calculation body motion, but also to predict accurate drag and lift force on the floating body for small size craft.

• 대한안전경영과학회지
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• 제12권3호
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• pp.189-195
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• 2010

ERP system has been spreaded from large companies to many small and medium sized companies, and it is recognized as a basic system for optimum and efficient work process. The focus is moving from manufacturing companies to various specialized companies. Once ERP system was introduced to those specialized companies, there was attempt to customize an ordinary system which used in manufacturing companies, but it was hard to take effect due to the lack of experience and an inadequate analysis of work process. Some of foreign ERP packages are possible to be constructed for some companies. However, they are originally aim at a large enterprise and it is also very difficult to construct and maintain. For this reason, small and midium sized companies are having a difficulty to construct ERP system. This study deals with the construction of ERP system for small and medium sized design engineering company and introduction of the crucial points throughout the construction and requirements for composition module and customization of each main module. Based on the findings of this study, the specialized non-manufacturing companies are expected to have efficient and practical application of ERP system when they select and customize the ERP package of manufacturing companies.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.41-45
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• 1997

To design a control system, it is a elementary point that the stability of the system should be guaranteed. Also, the phase of the system plays an important role for its frequence performance. In this paper, we present two stability criterion of repetitive control system with phase-lead and lag compensator. First, the stability criterion for the servo control system with phase-lead and lag compensator is shown by using small-gain theorem. Second, for the repetitive control system with the compensator, the stability criterion, also, is determined by using small-gain theorem. Two stability criterions show the same results that the stability depends on a coefficient of the phase-lead and lag compensator under some condition in servo control system and repetitive control system.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.9-15
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• 1999

A digital CDI(Capacitive Discharge Ignition) system on small two stroke motorcycle engine was developed in this paper, This CDI system with microprocessor as its main part has more flexible spark timing than the conventional CDI system because of its programmable characteristics. The principle of this digital CDI system and the design methods of hardware and software were presented in this paper, Two stroke small engine was tested to investigate the performance of digital CDI system And also this system was investigated to optimize the engine performance. Also comparison between conventional CDI can provide better spark timing variation than the conventional system. The part and full load test results show that the engine power was increased about 10-20% and fuel consumption was decreased about 10-20% simultaneously. Furthermore, this digital CDI system has simple structure, low cost and very little modification are required. It is a promising technology to substitute for the widely used conventional CDI system.

• 경영과학
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• 제10권2호
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• pp.43-59
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• 1993

A production control information system developed for multi-product, small-lot-sized production is presented. The system is composed of interrelated modules for production planning, shop floor control, and inventory/material management. The architecture of the system, functions of each module, and information processing procedures of each function are discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.267-270
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• 2000

The feasibility of small linear antenna for near range wireless communications was studied. The requirement of the system are frequency range 9∼12 MHz and antenna size 15 cm. The communication range is about 15 m. The antenna input impedance is very small radiation resistance and very large capacitive reactance. The lossless impedance matching is nearly impossible, therefore lossy matching is considered. The antenna has very low radiation efficiency. The near field calculation has a large uncertainty, but the results can be used as the guideline of a small linear antenna system for a near range wireless communication.

• 항공우주시스템공학회지
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• 제6권2호
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• pp.1-6
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• 2012

On this study, as a Human Factor(HF)'s point of view, typical PVI(Pilot Vehicle Interface) evaluation for small airplane cockpit design, PVI evaluation items and procedures to show compliance to KAS Part 23 "Airworthiness Standards : Normal, Utility, Acrobatic, And Commuter Category Airplanes" are introduced and reviewed. This study is based on the experience of Korean small civil airplane development and certification program.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.301-309
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• 2009

This study focuses on event-driven social media (EDSM), which supports the production of unique cultural items of small groups by satisfying the conflicting desires of distinctiveness and assimilation that small groups possess. EDSM is a system which promotes the production of idioculture through small group interaction by using an actual event in which people participate in small groups. By setting up an EDSM system in a university festival in which 10,000 to 15,000 people gather in small groups, idioculture production was tested for approximately eight hours and a half. Interaction records gathered from the test, as well as focus group interview data garnered soon after were used to analyze usage patterns of EDSM, types of idiocultures produced, and resulting factors of user experience. Through this, considerations upon designing future EDSM were proposed.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1997년도 추계학술대회발표논문집; 홍익대학교, 서울; 1 Nov. 1997
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• pp.117-120
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• 1997

In this paper, we analyze Inventory Strategy of our country middle-small Company which are ordered form large Company which product using JIT(just in time) System. Until now, we have not found a good inventory strategy for middle small Company which such like above. In this paper, we first simply survey product lead time, lot size and safety inventory in continuous product system which idea can be adapted our object. We try to mathematical modelling of product lead time, total inventory cost of bur country middle-small Company. We suggest inventory strategy for middle-small Company.

• 한국유체기계학회 논문집
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• 제14권6호
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• pp.5-10
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• 2011

Recently, small hydropower attracts attention because of its renewable, clean and abundant energy resources to develop. Therefore, a tubular type hydro turbine is proposed for small hydropower in this study because the turbine has relatively simple structure and high possibility of applying to small hydropower. The purpose of this study is to investigate the performance characteristics of the turbine by field test. Field test iss conducted using one tubular turbine system as well as serial arrangement system by two tubular turbines taking into consideration of actual operation conditions. The results show that efficiency of test turbine changes considerably by the runner vane angle. Best efficiency of one turbine arrangement is higher than that of two turbine serial arrangement.