• 한국기계가공학회지
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• 제10권5호
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• pp.1-6
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• 2011

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. Therefore, it is very important to assess errors in machine tools. Volumetric error analysis has been developed by many researchers. This paper presents a useful technique for analyzing the volumetric errors in machine tools using the ball bar. The volumetric error model is proposed in specific vertical machining center and the program is developed for generating NC code, acquiring the ball bar data, and analyzing the volumetric errors. The developed system assesses the volumetric errors such as positional, straightness, squareness, and back lash. Also this system analyzes the dynamic performance such as servo gain mismatch. The radial data acquired by ball bar on 3D space is used for analyzing these errors. It is convenient to test the volumetric errors on 3D space because all errors are calculated at once. The developed system has been tested using an actual vertical machining center.

• 대기
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• 제25권3호
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• pp.407-433
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• 2015

First half of my article focused on analyzing the current state of historical materials regarding weather and climate, and established a list of weather-related historical literature collection of Korea with which to make a lexical approach to the situations of all kinds of weather literature. It also put emphasis on gathering information and data of weather logs from journal-type historical records which were contained in 48 weather-related journals of Choseon period. The results of this research are expected to be useful for the activation of study in historical meteorology. The latter half of my research focused on analyzing various meteorological states of sunny, cloudy, rainy, snowy and frosty weather which were recorded in the official Annals of King Kojong (1864~1907). And it re-verified historical rainfall data of preceding researches of Wada Yuji (1917), Jung-Lim (1994), Jhun-Moon (1997). In result, different records were found between data of theirs and mine. It means that we have to analyze and reconstruct newly the meteorological data of the Annals of King Gojong and the Daily Records of Royal Sungjungwon (1623~1910) during the late Choseon period.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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• pp.53-62
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• 2004

A single layer latticed dome is one of the most efficient structures because of its low specivic gravity. For easily analyzing of a single layer latticed dome, joint system is assumed to be pin or rigid joint. However, its joint uses ball whose system has intermediate properties of pin and rigid joint. Therefore this study has a grasp of bending rigidity, stress and mechanical properties through experimental and analyzing method of the bolt inserted ball joint. To analyze the stress of bolt and sleeve, this study uses through 3D elastic contact and cubic element, and then the ball and the bolt are perfectly connected for easily analyzing Compared experimental results to F.E.M, each specimen has an error of less than 12 percent. In the results of stress distribution through F.E.M, stress occurs from bottom of bolt to top of sleeve, and most of tension appears on the bolt, also compression occurs from upper parts of the bolt to the sleeve. The assumption of bending stiffness in ball joint is well known that bolt resists only tension and upper sleeve resiss compression. The results of experiment and analysis have $7{\sim}56%$ error, assuring that upper part of bolt occurs of partial compression. In the result of modified assumption have $4{\sim}20%$ error.

• 복식문화연구
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• 제9권5호
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• pp.770-782
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• 2001

The definite objects of this study are as follows; 1. The study presents the methods of the designing collar pattern and bodice pattern by each concrete object after comparing and analyzing the factors among the features which are in need of clothes designing. 2. The object of this study is to make body-suitable ready-made clothes by comparing and analyzing the methods of designing collar pattern and bodices pattern presented by each concrete objects and Bunka Pattern. The results of this study are as follows; 1 . The results of this study developed the body-suitable bodice pattern of bend-forward type, straight type and lean-back type Compared with the Bunka pattern by physical function test, this study was rated high in the aspects of the shape of neck and shoulder. 2. The collar pattern was designed according to each type. The front center rising point of straight type is 2.5cm, lean-back type is 3.0cm and bend-forward type is 1.5cm. Compared with the Bunka pattern by physical function test, this study is rated high in the aspects of the shape. To confirm the increase and change of the measure definitely, the complete examination of each subject is necessary. This developed and investigated pattern must be supplemented more by comparing and analyzing with other pattern and body types.

• 농업과학연구
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• 제31권1호
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• pp.26-34
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• 2004

In this study, motion characteristics and power requirement of rotary tilling according to shape of conventional rotary blade were measured. This study was performed to establish factors which needed to develop energy saving rotary blade. Starting point of edged curve of imported rotary blade was faster than that of domestic rotary blade after measuring and analyzing edged curve of rotary blade. So domestic rotary blade tills much soil than imported rotary blade. In analyzing motion of rotary blade, Rotary blade of A, D type was begun to contact at part 3. Analyzing back surface of rotary blade which contact to soil at critical $\lambda$ results in contacting at e-f part. In measuring power requirement of rotary blade, specific torque and specific work of rotary blade are $160{\sim}170kgf{\cdot}m/m^2$, $3,700kgf{\cdot}m/m^3$. It shows power requirement of rotary blade according to shape of rotary blade are very different.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.479-483
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• 1997

In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• 한국멀티미디어학회논문지
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• 제18권12호
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• pp.1501-1508
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• 2015

In this paper, we describe a case study to improve performance through the load testing of multi-tired system for financial accounts before the system opening. The load test was conducted after the data collection tools(Performance Monitor, DB PSSDiag) were installed. By analyzing the collected log, we were able to identify the main sector requiring performance improvements among the presentation tier, web tier, business logic tier and data tier. The ASP.NET server-down on the web tier could be improved by modifying the parameter values in the configuration file. Some server downs occurred on the business logic tier when a large number of users access at the same time, were more difficult to be solved. By analyzing the hang-dump at the server-down time, we were able to find a process that caused the problem. and we had to modify the relevant codes. For major performance improvements of the data-tier, indices of some queries was optimized by using the built-in DBMS query analyzer, after analyzing the log of long-response-time queries. The problems and solutions considered in this case study will be a reference for the performance improvement of a multi-layer system with the similar structure.

• 한국멀티미디어학회논문지
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• 제21권3호
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• pp.400-414
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• 2018

It is required for today's video contents to interact with a viewer in order to provide more personalized experience to viewer(s) than before. In order to do so by providing friendly experience to a viewer from video contents' systemic perspective, understanding and analyzing the situation of the viewer have to be preferentially considered. For this purpose, it is effective to analyze the situation of a viewer by understanding the state of the viewer based on the viewer' s behavior(s) in the process of watching the video contents, and classifying the behavior(s) into the viewer's emotion and state during the flow. The term 'Flow-emotion-state' presented in this study is the state of the viewer to be assumed based on the emotions that occur subsequently in relation to the target video content in a situation which the viewer of the video content is already engaged in the viewing behavior. This Flow-emotion-state of a viewer can be expected to be utilized to identify characteristics of the viewer's Flow-situation by observing and analyzing the gesture and the facial expression that serve as the input modality of the viewer to the video content.

• 한국정밀공학회지
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• 제20권4호
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• pp.128-135
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• 2003

To decrease environmental damage, the development of environmental friendly fluids provides attractive alternative to the conventional fluids. In this study, the effects of harmful ingredients (Cl, S) contained in the fluids that used in grinding and cutting processes to influence on the nasal cavities of the white rats were measured indirectly. Also, the level of the environmental influence in workshops was graded through analyzing the concentration and chemical ingredients of flying-dust, which generated from the friction and combustion in the cutting process, that for analyzing how harmful the influence of particles to workers then it could be used as the basic data for improving the environment. To improve the conventional machining fluid, which can be harmful on worker's bodies and the environment, the environmental friendly machining method was suggested through analyzing each lubrication properties of vegetable fluid and used-edible oil as alternative fluid. As a result, it was known that an emulsion type fluid might be the main cause leading to some respiratory ailments. Also this paper presents the possibility to use vegetable fluid and used-edible oil as the alternative of cutting fluids.

• 한국컴퓨터정보학회논문지
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• 제12권2호
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• pp.333-339
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• 2007

대부분의 조직에서 정보시스템의 의존도가 높아짐에 따라 정보시스템 보안 사고에 대한 위험이 증가하고 있다. 본 논문에서는 정보보호관리체계와 위험분석방법을 적용하여 보안 위험분석을 위한 안정성 평가시스템을 설계 및 구현하였다. 또한, 위험평가 시 동일한 가중치를 적용한 평가와 조직의 특성에 따라 보안요소의 가중치를 가변적으로 적용한 평가를 할 수 있도록 하였으며 각 조직이 자체적으로 보안 점검을 할 수 있도록 설계함으로서 관리 측면에서 취약점을 쉽게 찾을 수 있도록 지원하며. 안정성 확보를 위하여 수행해야 할 권고를 제시한다.