• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.251-256
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• 2003

This study focuses on the development of the conceptual criteria which could be applied to the speed-up strategy of urban rail operation. Down town segment or not, and peak hour or not are the criteria. The author suggests that in the case of down town segment and peak hour urban rail should take the all-stop pattern, if down town segment and off peak hour, then skip-stop pattern, if not-down town segment and peak hour, the A, B skip-stop, and if not-down town segment and off peak hour, the A, B, C skip-stop. If side lines, three rail, or 2 double lines, then express train operation is recommended in the peak hour. Then this study recommends speed-up strategies of each 8 urban lines.

• Journal of Astronomy and Space Sciences
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• 제32권4호
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• pp.395-401
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• 2015

We investigated the six remaining Yang-cheon-cheoks (量天尺), which were first described in the Veritable Record of King Sukjong (肅宗實錄). These woodblock sundials from Korea are structurally very similar to a Gyupyo (圭表, gnomon) or an altitude sundial and are light, compact, and portable. The front side of a Yang-cheon-cheok has two holes for styluses and several hour-lines. We compared the intervals of the hour-lines from the originating point of the stylus placement on all Yang-cheon-cheoks and found that two of the relics had the same hour-lines using the standard of the unit of 1 chon (寸). These two were actually the same sundial although the physical size was different. In spite of the lack of time accuracy, we hypothesize that various-sized Yang-cheon-cheoks were made and widely distributed throughout the public in the late Joseon Dynasty.

• Journal of Astronomy and Space Sciences
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• 제34권1호
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• pp.55-65
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• 2017

We studied the hour-lines of six extant Yangcheon-cheoks in Korea. To find whether Yangcheon-cheok was used in the whole area of Korea, we calculated the length of shadows of Yangcheon-cheok on the Korean Peninsula, Nanjing and Beijing as well as Hanyang (Seoul), according to 24 solar terms. Comparing the length of shadows with hour-lines of those relics, we could find that Yangcheon-cheok was suitable for use at limited times (from 9:00 to 15:00) during the year. Also, this sundial is more appropriate for use at low latitudes than high ones. Among existing relics, that of Seoul Museum of History made with porcelain was much more suitable to use at Hanyang and its higher latitude. Lee's collection was also suitable to use at Nanjing. It is certain that Yangcheon-cheok was a portable sundial which could be used from nine to fifteen of clock all the year around except for the winter season.

• Journal of Astronomy and Space Sciences
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• 제34권2호
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• pp.161-170
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• 2017

In this study, the characteristics of a horizontal sundial from the Joseon Dynasty were investigated. Korea's Treasure No. 840 (T840) is a Western-style horizontal sundial where hour-lines and solar-term-lines are engraved. The inscription of this sundial indicates that the latitude (altitude of the north celestial pole) is $37^{\circ}$ 39', but the gnomon is lost. In the present study, the latitude of the sundial and the length of the gnomon were estimated based only on the hour-lines and solar-term-lines of the horizontal sundial. When statistically calculated from the convergent point obtained by extending the hour-lines, the latitude of this sundial was $37^{\circ}$ $15^{\prime}{\pm}26^{\prime}$, which showed a 24' difference from the record of the inscription. When it was also assumed that a convergent point is changeable, the estimation of the sundial's latitude was found to be sensitive to the variation of this point. This study found that T840 used a vertical gnomon, that is, perpendicular to the horizontal plane, rather than an inclined triangular gnomon, and a horn-shaped mark like a vertical gnomon is cut on its surface. The length of the gnomon engraved on the artifact was 43.1 mm, and in the present study was statistically calculated as $43.7{\pm}0.7mm$. In addition, the position of the gnomon according to the original inscription and our calculation showed an error of 0.3 mm.

• Journal of Astronomy and Space Sciences
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• 제27권2호
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• pp.161-172
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• 2010

In this paper, we investigate the sundials made by the Kang Family of Jinju in the later period of the Joseon dynasty in terms of their characteristics, functions and the manufacturing technique. One of the characteristics of these sundials is that the value of polar height (i.e., the latitude of Seoul), the name of manufacturer, 24 seasonal subdivisions and so forth are written on the surface. In particular, polar height is expressed as '$37^{\circ}$ 39' 15"' in all 12 sundials examined in this study. To investigate the manufacturing technology in terms of astronomy, we analyze the positions of gnomon and of the lines corresponding to 24 seasonal subdivisions (season lines) and to each hour (hour lines). To verify the accuracy of the positions, we use a planar projection method. That is, we obtain 2D images of the sundials using a camera or scanner, and compare these with astronomical calculations for the positions of gnomon and season/hour lines. We believe that this method will be very useful for the study of sundials preserved elsewhere.

• 전자공학회논문지T
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• 제35T권1호
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• pp.105-110
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• 1998

통신망을 설계할 때 최번시 사용자를 기준으로 사용자당 예상되는 사용 용량을 계산하여 이를 근거로 회선 규모를 결정한다. 그러나 이와 같은 설계방식은 최번시의 용랑으로 회선 규모를 결정하기 때문에 대부분이 낭비된다. 본 논문에서는 유선에 CDMA를 적용하여 이를 개선할 수 있는 해결방법으로 제시하였으며 비트 오류율을 얼마로 할 것인가에 따라 회선의 규모가 달라짐을 보였다. 예를 들어 El에 13kbps의 음성을 전송할 때 2%의 비트 오류율을 적용하였을 때 채널수가 120채널을 얻을 수 있는 결과를 보였으며 비트오류율을 높게 함에 따라 채널수가 큰 폭으로 증가하게된다. 따라서 최번시 대신 비트오류율에 의해 통신망의 설계를 할 수 있음을 보였다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.415-422
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• 2014

This paper presents a new approach to solve the multi area unit commitment problem (MAUCP) using an evolutionary programming based particle swarm optimization (EPPSO) method. The objective of this paper is to determine the optimal or near optimal commitment schedule for generating units located in multiple areas that are interconnected via tie lines. The evolutionary programming based particle swarm optimization method is used to solve multi area unit commitment problem, allocated generation for each area and find the operating cost of generation for each hour. Joint operation of generation resources can result in significant operational cost savings. Power transfer between the areas through the tie lines depends upon the operating cost of generation at each hour and tie line transfer limits. Case study of four areas with different load pattern each containing 7 units (NTPS) and 26 units connected via tie lines have been taken for analysis. Numerical results showed comparing the operating cost using evolutionary programming-based particle swarm optimization method with conventional dynamic programming (DP), evolutionary programming (EP), and particle swarm optimization (PSO) method. Experimental results show that the application of this evolutionary programming based particle swarm optimization method has the potential to solve multi area unit commitment problem with lesser computation time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.1047-1053
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• 2005

This study explored pattern of train operation between Seoul Cheonan after the introduction of KTX in 2004. Both number of trains and seat capacity per day have increased but maximum number of trains per specific hour hasn't changed much. Demand for train shows that it concentrated in a specific time, so number of trains during the peak hour should be increased. But, it is difficult due to line capacity, so increasing seat capacity per train might be an option. An increase in seat capacity should be considered the characteristics of each train lines.

• Journal of Acupuncture Research
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• 제19권5호
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• pp.57-72
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• 2002

Objectives : This study was undertaken to determine the cytotoxic effects of crude bee venom which is widely used for aqua-acupuncture in oriental medical clinic. Methods : We compared the effects of crude bee venom, apamin, melittin and MCD peptide on cellviability by MTT asssay. Results : The obtained results are summarized as follows: 1. Bee venom, apamin, melittin and MCD peptide showed concentration--dependent cytotoxic effect in some human cell lines(human glioma cell line과 neuroblastorna, human mast cell line) for 24 and 48 Hour treatment. 2. Bee venom, apamin, melittin and MCD peptide showed dose-dependent cytotoxic effect in some human cell lines for 24 and 48 Hour treatment. 3. Bee venom treatment for 24 and 48 hour showed higher cytotoxic effects than apamin, melittin and MCD peptide. Conclusions : These results suggest that bee venom, apamin, melittin and MCD peptide have concentration- and dose- dependent cytotoxic effect in some human cell lines. But further study is needed for optimal concentration and dose.

• 대한전기학회논문지:전력기술부문A
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• 제53권6호
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• pp.316-323
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• 2004

This paper develops an ADWHM(Advanced Digital Watt-Hour Meter) which integrates and implements the voltage management data record function and the load management data record function in the electronic watt-hour meter. ADWHM is developed based on PIC16F874 which is 8bit micro-controller of RISK type for the easy of programing and maintenance, and electronic power signal processing module is located at front of it to reduce the computing load of processor. Also, a 16kbyte EEPROM is used to record the voltage management data and load management data for a week as well as watt-hour data and USART communication mode is used to transfer data from ADWHM to PC. The accuracy of the voltage and unt measuring for ADWHM is verified by identifying the LCD display values of the ADWHM after the voltage signals of id levels from digital function generator is applied to PT(Potential Transformer) and CT(Current Transformer) output under state which it is separated from real power line. On the its basic functions such as watt-hour data recording function, voltage management data recording function and load management data recording function was verified by showing data for three days among the collected data to PC by RS232C communication from ADWHM which was connected to real power lines for a week.