• Title/Summary/Keyword: Race Track

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Fabrication and Characteristics of HTS Field Winding of a 100 hp Synchronous Motor (100마력 동기전동기용 고온초전도 계자권선 제작과 특성)

  • Sohn Myung-Hwan;Baik Seung-Kyu;Lee Eon-Young;Kwon Young-Kil;Jo Young-Sik;Moon Tae-Sun;Kim Yeong-Chun;Kwon Woon-Sik
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.2
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    • pp.88-93
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    • 2005
  • To develop a 100 hp high temperature superconducting(HTS) motor with high efficiency first in Korea, we fabricated a HTS field winding and test. HTS field winding is composed of sixteen HTS race track shaped coils wound with stainless steel-reinforced Bi-2223 tape conductor by react and wind fabrication method. Nomex paper was used for electrical insulation. Each of four magnet pole assemblies was constructed with four double pancake sub-coils, mechanically stacked and electrically in series. Four magnet assemblies were fixed on an aluminum support structure to make effective heat transfer. The Critical current (Ic) was 41.5A at 77K and self field. However the lowest Ic value of sub-coils was 35A. Joule heat generated by each joints between sub-coils was lower than 1mW at 77K and 34A. And Joule heat generated by the joints between field coils was lower than 10mW at 77K and 34A. Joule heat of the whole field winding was 1W at 77K and 32A. And so, the lowest Ic value of sub-coils was more important than Joule heats generated by all joints. The operating current must be lower than the lowest Ic of all the sub-coils. In this paper, design, construction and testing of HTS field winding, Joule heat generated by the joints, and operating current were discussed.

Spray Pattern Analysis for a Centrifugal Fertilizer Distributor with Two Shutter Holes (두 개의 셔터 구멍이 적용된 원심식 비료 살포기의 살포패턴 분석)

  • Hwang, Seok-Joon;Park, Jeong-Hyeon;Lee, Ju-Yeon;Kim, Ki-Duck;Shin, Beom-Soo;Nam, Ju-Seok
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.10
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    • pp.8-19
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    • 2019
  • In this study, the spray pattern of a centrifugal fertilizer distributor with two shutter holes was analyzed and an effective driving width that satisfies proper spray uniformity was derived. The centrifugal fertilizer distributor was mounted on a tractor with a rated power of 23.7 kW and static and dynamic spray pattern tests were performed according to the standard procedure proposed by the American Society of Agricultural and Biological Engineers Standard ASAE S341.5. The height of the fertilizer distributor was 80 cm from the ground and the PTO (power take-off) shaft speed of the tractor was fixed at 540 rpm. The fertilizer scattered in space was collected using 275 evenly spaced collectors at shutter opening ratios of 25%, 50%, 75%, and 100%. The spray pattern was analyzed via the amount of sprayed fertilizer at each collector location and the coefficient of variation was used as an indicator of spray uniformity. Using the analyzed spray pattern, the effective driving width that satisfied less than 15% of the coefficient of variation was derived for different tractor driving patterns (race track mode, back and forth mode). From the results, spray uniformity increased as the shutter opening ratio decreased. The largest effective driving width was 8 m at a shutter opening ratio of 25% for both driving patterns.

Estimation of Annual Trends and Environmental Effects on the Racing Records of Jeju Horses (제주마 주파기록에 대한 연도별 추세 및 환경효과 분석)

  • Lee, Jongan;Lee, Soo Hyun;Lee, Jae-Gu;Kim, Nam-Young;Choi, Jae-Young;Shin, Sang-Min;Choi, Jung-Woo;Cho, In-Cheol;Yang, Byoung-Chul
    • Journal of Life Science
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    • v.31 no.9
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    • pp.840-848
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    • 2021
  • This study was conducted to estimate annual trends and the environmental effects in the racing records of Jeju horses. The Korean Racing Authority (KRA) collected 48,645 observations for 2,167 Jeju horses from 2002 to 2019. Racing records were preprocessed to eliminate errors that occur during the data collection. Racing times were adjusted for comparison between race distances. A stepwise Akaike information criterion (AIC) variable selection method was applied to select appropriate environment variables affecting racing records. The annual improvement of the race time was -0.242 seconds. The model with the lowest AIC value was established when variables were selected in the following order: year, budam classification, jockey ranking, trainer ranking, track condition, weather, age, and gender. The most suitable model was constructed when the jockey ranking and age variables were considered as random effects. Our findings have potential for application as basic data when building models for evaluating genetic abilities of Jeju horses.

Study on Perceptions through Big data Analysis on Gambling related News in Korea (한국 사행산업 관련 뉴스의 빅데이터 분석을 통한 인식 연구)

  • Moon, HyeJung;Kim, SungKyung
    • Journal of Broadcast Engineering
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    • v.22 no.4
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    • pp.438-447
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    • 2017
  • The purpose of this study is to understand the recognition of gambling industry through the semantic analysis of news data on lottery, sports betting, horse racing and casino that was reported between 1990 to 2015 in South Korea. This paper revealed the difference between journalists' intention and public's perception about news by analyzing the frequency and connectivity of news with framing and public's interest through semantic network analysis and explored the policy characteristics and innovation task. The result of analysis, news on lottery game mainly has been reported social issue related with win such as 'winning number', 'prize money', 'suspicion of manipulation' and etc. News on sports betting has been reported mandatory information related with business project and illegal site such as 'bidding', 'illegal site', 'sales target' and etc. News about horse racing has been reported the information about the business advertisement such as 'online race track' and 'promotion'. Lastly, casino related news has been reported 'major information' such as illegality', 'gambling place' and 'foreigner'. As a result of times series analysis, news about casino in the 1990s, news about lottery in the 2000s and news about horse racing in 2010s have been increased. Public's interest also has been moved to 'business scandal', 'winning game', 'citizens' campaign' and etc. Gambling related news has been classified by four types, 1. advertising publicity(horse racing), 2. mandatory information(sports betting), 3. social issue(public agenda, lottery), 4. major information(casino). We could get the insight that news can be formed a public agenda, when news is reported as a social issue with high frequency and public's interest like lottery related news.