• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.253-257
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• 2000

A new improved variable structure controller is designed to drive uncertain linear systems to any given point by using a sliding surface with an integral of state error for removing any reaching phases. Predetermination or prediction of output response is feasible for all the persistent disturbances. The usefulness of the proposed algorithm is verified through an illustrative example.

• 기술사
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• 제41권3호
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• pp.45-49
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• 2008

Considering domestic situation such as economical crisis, $CO_2$ exhaust amount limit based on the Climatic Change Convention, sky-rocketed oil prices. 97% of energy import from abroad, and import sum reaching up to 20% of entire import, we need to invest new recycle energy and future energy development at a full blast.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.771-774
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• 1996

This paper presents a continuous time varying sliding surface that allows faster tracking and really guarantees robust contro land smooths control inputs. And this method is evaluated by applying to robot manipulator.

• 대한수학회논문집
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• 제9권4호
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• pp.803-808
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• 1994

Since L$\ddot{o}$b's announcement of his solution to Henkin's problem (L$\ddot{o}$b (1954, 1955)) there has been successful and fruitful research on provability logic tied up with modal logic. Specially, L$\ddot{o}$b's Theorem is of far-reaching significance in the following meta-mathematical and philosophical sense.

• 열처리공학회지
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• 제22권2호
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• pp.101-107
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• 2009

Effect of isochronic aging on transformation behavior of Ti-50.85at%Ni alloy were investigated by differential scanning calorimeter (DSC). The martensitic transformation temperature increases with increasing annealing temperature until reaching a maximum, and then decreases with further increasing annealing temperature. This can be rationalized by interaction between the distribution of $Ti_3Ni_4$ precipitates and Ni content in the matrix. The R-phase transformation temperature increases with increasing annealing temperature until reaching a maximum, and then decreases with a further increase of annealing temperature. This is attributed to the change of Ni content in the matrix caused by precipitation of $Ti_3Ni_4$. The occurrence of the multiple-stage martensitic and R-phase transformation is attributed to precipitation-induced inhomogeneity of the matrix, both in terms of composition and of internal stress fields.

• 한국어류학회지
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• 제22권2호
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• pp.129-131
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• 2010

우리나라 강원도 동해(주문진과 속초, 거진 연근해)에서 장갱이과에 속하는 어류 4개체(표준체장 218.3~234.5 mm)를 채집하였으며 한국미기록종인 Stichaeus nozawai Jordan and Snyder로 동정되었다. 본 종은 턱 뒤끝이 눈 뒤의 가장자리에 미치지 않고, 측선이 몸의 후반부인 등지느러미 극조 10~13개 부근까지 이어져 있으며, 등지느러미에는 사선의 검은 줄무늬가 있고, 뒷지느러미 기조수는 I, 36~37였다. 본 종의 국명은 '큰눈장갱이'로 명명하였다.

• Journal of Power Electronics
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• 제14권1호
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• pp.105-114
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• 2014

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.353-361
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• 2013

The objective of this study was to characterize the reproductive cycle of the chameleon goby, T. trigonocephalus. Gonadal development was investigated using a histological method. Specimens were collected monthly, from April 2009 to March 2010. The gonadosomatic index (GSI) of females began to increase in April, reaching the maximum in May, and declined sharply in August. In males, the GSI began to increase in April and reaching the maximum in July. The annual reproductive cycle of T. trigonocephalus can be divided into four successive stages in females: the growing (November-March), maturing (April-May), ripe and spawning (June-July), and recovery (August-October) stages. Males passed through growing (November-March), maturing (April-June), ripe and spermiation (July-August), and recovery (September-October) stages. These results indicate the spawning season is from June to July. The relationship between fecundity (Fc) and body length (BL) was $Fc=86.1511BL^{2.6506}$. Fecundity was ranged from 3,448-9,654 eggs in a BL of 4.8-7.2 cm and it was increased as BL increased.

• 한국지열·수열에너지학회논문집
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• 제11권3호
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• pp.13-19
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• 2015

This study was aimed at the heating tank with a screw-rotation device for improving the thermal efficiency of electric boiler. In the proposed system, analysis items were the heater rod surface temperature variation, reaching time for set temperature and thermal efficiency. The following conclusions are obtained from this experimental study. (1) When screw speed increases, the time reaching for set temperature tended to be shorter. (2) When the rotation speed becomes 300 rpm, the surface temperature difference between the right and left heater rod decreases by 49%, from $19.7^{\circ}C$ to $9.7^{\circ}C$ in average. (3) When the rotation speed is over 250 rpm, proposed heating tank structure appeared to be effective in terms of thermal efficiency. Thermal efficiency with the rotation speed 300 rpm is improved by 3.8% compared to the case of rotation speed 0 rpm.

• 복식문화연구
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• 제8권2호
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• pp.149-165
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• 2000

This study concerns the export-import demands for Korean textile, textile products and clothing products. The result from the practice of study is as follows ; it predicts the constant increase as a result of prediction in the nation's total amount of export-import including the export-import amount of textile, textile-product, and clothing product. It is estimated that nation's textile trade balance will be about U $ 13 billion of trade surplus in every year from 2000 to 2003. Other hand, the trade balance of textile product is predicted about U $ 1.39 billion surplus, so is clothing product about U $ 3.29 billion surplus. Textile ratio is presumed to gradually decrease in aspect of export. Also, the portion of textile export in our national total export is predicted to reduce to 11.61% in the 2003. On the other hand, Textile import ratio will be constantly increased and the portion of textile import in our national total import is predicted to reach to 3.92% in 2003. Textile-product ratio is also estimated to increase in the area of export & 33.12% in 2003. Clothing product ratio is also estimated to increase annually. What with increasing ratio of clothing-product export in textile-product export reaching to total 0.87% within for 4 years(62.96% in 2003, 63.83% in 2003) and what with increasing ratio of clothing-product import in textile-product import reaching to total 6.42%(83.89% in 2000, 90.31% in 2003), it can be said that increase of its import will be much higher than that of export.