• 전기학회논문지
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• 제65권5호
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• pp.718-723
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• 2016

The temperature changes are very important in improving the accuracy of the load forecasting during the summer. It is because the cooling load in summer contribute to the increasing of the load. This paper proposes a weekend load forecasting algorithm using the temperature change characteristic in a summer of Jeju. The days before and after weekends in Jeju, when the load curves are quite different from those of normal weekdays. The temperature change characteristic are obtained by using weekends peak load and high temperature data. And load forecasted based on the sensitivity between unit temperature changes and load variations. Load forecast data with better accuracy are obtained by using the proposed temperature changes than by using the ordinary daily peak load forecasting. The method can be used to reduce the error rate of load forecast.

• 복식
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• 제51권1호
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• pp.129-143
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• 2001

Particular historic events such as revolution and wars have given rise to fashion. Luxurious costume representative of the aristocratic culture since the French Revolution was changed into popular look with the collapse of the royal regime. With the restoration of the royal regime by Napoleon, rapid changes associated with the reemergence of the costume of aristocratic brought an opportunity for the revolutionary fashion of bringing about new fashion in the fashion field. Especially, the New Look Presented by Christian Dior in 1947 shortly after the Second World War would be the typical style of revolutionary fashion. Accordingly, this study attempted to analyse the characteristics of new fashion regarding how new fashion occurred and developed in changes in revolutionary fashion after the Revolution and the War, in conjunction with the zeitgeist(time split) of rapid social changes. The ultimate purpose of this study was find out the significance of fashion as to how and why fashion changed in relation to the factors of changes in fashion in the history and create new future fashion by reinterpreting new aesthetic consciousness about the characteristic of new fashion found in changes in revolutionary fashion.

• 제어로봇시스템학회논문지
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• 제10권3호
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• pp.205-215
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• 2004

The characteristic ratio assignment (CRA) method〔1〕 is new polynomial approach which allows to directly address the transient responses such as overshoot and speed of response time in time domain specifications. The method is based on the relationships between time response and characteristic ratios($\alpha_i$ ) and generalized time constant (T), which are defined in terms of coefficients of characteristic polynomial. However, even though the CRA can apply to developing a linear controller that meets good transient responses, there are still some fundamental questions to be explored. For the purpose of this, we have analyzed several sensitivities of a linear system with respect to the changes of coefficients itself and $\alpha_i$ of denominator polynomial. They are (i) the unnormalized root sensitivity : to determine how the poles change as $\alpha_i$ changes, and (ii) the function sensitivity to determine the sensitivity of step response to the change of o, and to analyze the sensitivity of frequency response as o, changes. As an other important result, it is shown that, under any fixed T and coefficient of the lowest order of s in denominator, the step response is dominantly affected merely by $\alpha_1, alpha_2 and alpha_3$ regardless of the order of denominator higher than 4. This means that the rest of the$\alpha_i$ s have little effect on the step response. These results provide some useful insight and background theory when we select $\alpha_i$ and T to compose a reference model, and in particular when we design a low order controllers such as PID controller.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.157-162
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• 2003

Nakdong estuary is located at south-eastern coast of the Korea. A lot of sediment from upper river were deposited at this area. It has cause many problem such as changes in topography and tidal current. Changes of characteristic of deposition were cause by topographic change of nakdong estuary. Analyzing and evaluating data, we could predict the direction of movement of the sand bar and the growth toward south-eastern of Nakdong estuary. It was caused by decreasing river discharge after construction of Nakdong-kang barrage.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.743-750
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• 2002

Unsaturated soil has a possibility to induce a negative pore water pressure. Until now, saturated soil is mainly focused on the research of soil mechanics. Recently, soil mechanics is researched on two major parts such as saturated and unsaturated soil mechanics. Negative pore water pressure has a non-linear relationship with the water content changes. Soil-water characteristic curves of soil in Korea are not determined. There is no proper characteristic value such as air-entry value and residual water content. In this study, the characteristic curves of reclaimed soil, sand, and weathered granite soil were determined by laboratory tests. Air-entry value and residual water content were determined by fitting methods. Soil-water characteristic curves were estimated based on the particle-size distribution and compared with the laboratory test results. The results of soil-water characteristic curves estimation indicated that Fredlund and Wilson's model is excellent for sand and weathered granite soil. Arya and Paris's model is excellent for reclaimed soil.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1533-1538
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• 2011

The dynamic characteristics such as resonant frequencies and dampings have been utilized as important parameters in dynamic behavior and inverse analyses. In general, the dynamic parameters have been determined based on design and experimental data, but experimental studies on the time-dependent changes of the dynamic parameters during service have rarely been conducted. Especially, unlike highway bridges, it is much easier for railroad bridges to estimate accumulated amount of fatigue because of the controlled train operation, and the study of dynamic characteristic change due to fatigue is useful, since it can enhance the accuracy of dynamic analysis. In this paper, the dynamic characteristic change due to fatigue is measured via the modal test on the PSC girder during a fatigue test. The test specimen utilized in the test is the IT girder which enhances the sectional capacity of the conventional PSC girders. The test specimen is designed 10m long and the modal tests are conducted during the application of fatigue load two million times. The test result shows that considerable changes in the measured dynamic parameters are observed as the fatigue accumulates, and these changes during the service life should be considered in designing railroad bridges.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1108-1110
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• 1999

This paper describes the comparison results on electrical characteristic changes of ZnO blocks by lightning impulse current. The five types of ZnO blocks used in lightning arrester for distribution lines have been estimated repeatedly till about 400 times by a standard lightning impulse current of 3kA, $8/20{\mu}s$, and changes of the performance characteristics of them to operation times were examined and compared quantitatively every fifty times discharge. It is expected that the result will be useful to diagnose the soundness of ZnO blocks or lightning arresters, and to develope deterioration diagnosis device for them.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.699-705
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• 2013

This paper presents vibration testing, control, and finite element analysis of a piping system, which is subjected to the changes in fluid levels. Nuclear power plants typically employ a cooling system that uses sea water. These systems are subjected to dynamic characteristic changes caused by sea-level variations, which introduces failures of cooling system components. Therefore in this study, analytical and experimental studies were performed to understand the effect of sea-level changes on the dynamic characteristics of piping systems. It was shown that, as the sea-level increases, pipe's natural frequencies decreases in relation to its mode shape. A 1/14 scale model was also built to compare the results obtained by the analytical study. A good agreement between experiment and analytical studies were observed. Finally, an on-line resonant frequency identification system was proposed and developed, which utilizes piezoelectric transducers as sensors and actuators, in order to avoid catastrophic failure of piping systems.

• 한국의상디자인학회지
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• 제13권3호
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• pp.15-29
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• 2011

Fashion industry is high value added indust교, whose price is decided by design value so it requires creativity and uniqueness for competition. The purpose of this study is to grasp how the design characteristic of LED that can express new creativity and uniqueness is applied to fashion design and find out the expression characteristic of LED used in fashion design. The study subjects, the design to which LED is applied, were extracted from fashion show and internet search. As a study result, the expression characteristics of LED used for fashion design are as follows. First, for function, tool function that can provide convenience for life and expression function that can provide user with emotional and psychological satisfaction and communication were allowed. Second, for aesthetic changes, many-sided, multiple colors and pattern displays of LED changed design meaning visually and caused aesthetic emotion for observer. Third, for interaction, physical factor of LED, user, dress and environmental factor interacted each other, enabling both-sided communication. Fourth, for amusement, multiple lights of LED activated visual and tactile sense, expressing usefulness and joyfulness on the basis of various display possibilities and changes. The study result will be helpful for developing more unique, creative design according to the change of age and development of science.

• 한국실내디자인학회논문집
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• 제17권3호
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• pp.131-138
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• 2008

This research is on a seating posture happening at a chair in a cinema and looked into various changes in a posture through the analysis of bodily movement in a established space like a cinema. Through the behavioral analysis of a seating posture in a limited space, each behavioral characteristic shown by a male and female and interdependent relations with a limited space were grasped. The conclusion through the above research work was as follows: 1) This research suggested a frame of analysis by dividing a seating posture into the side and upper part and was able to analyze its subsequent change characteristic of a seating posture by a male and female. 2) As for the side posture, a male was found to change fewer postures than a female, but as for the upper posture, there appeared a high frequency in posture change in case of a female. 3) As for time of staying in the side posture, a female was found to keep up a specific posture, and relatively a male changes his postures frequently while appreciating a movie; likely, as for the upper posture, it was found out that there existed a difference between the preference for the upper posture and time to keep it up. 4) A male and female were establishing a comfortable environment through their change in a posture, and there appeared changes in a posture the most within every 10 minutes in both the side and upper part postures. 5) As for the correlation between a initial posture and keep-up posture, it was found that a male tend to pursue a comfortable posture as time goes by, while a female kept up a comfortable one from her initial seating posture.