• Title/Summary/Keyword: Down-cutting

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A Study on Railway Electric Traction Protection System (전철용 보호계전기 시스템에 관한 연구)

  • Lee, Hee-Yong;Kim, Wang-Gon;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1390-1395
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    • 2004
  • Recently, the load increasement and new regenerative systems of electrified railway system make it a difficult to distinguish between the load current and fault current. The failure of traction system perhaps causes over-current to flow. The high current can collapse other railway systems. If failures of the traction system takes place, the failures are detected and protected lest it should provoke high current flow. The over current from such a traction system failure permit to charge high tension voltage and produces high temperature arc, voltage instability, current cutting, and break down railway systems. The traction system failures detect and the system has to immediately cut off from over-current flow. To isolate the failure, the system can distinguish failure current from current flows. It forces us to adapt such as a new intelligent protection system. The protective system in traction system play a role of detecting and isolating failure points. In this paper, we proposed intelligent algorithm for discriminating normal and abnormal situation instead of the system being operated abnormally.

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A Comparative Study of the Citrus Production Cost in the Three Countries : Korea, Taiwan, and Japan (한국, 대만, 일본의 감귤 생산비 비교분석)

  • Choi, Chan-Ho
    • Journal of Agricultural Extension & Community Development
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    • v.3 no.1
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    • pp.43-54
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    • 1996
  • Citrus farming become one of highly potent area for the farmer s income in the Asia region. Because of its favorable taste and distinctive aroma, attractive color, and nutritional values, market demand has increased steadily along with the income increases in the region. However, realization of the potent have been constrained due to poor orchard management, frequent occurrences of pest and diseases, and a high cost in production besides of the market failures. Cutting down of production cost should be an operational goal to obtain mope profit where marketing structure has yet been underdeveloped. The objective of this study was to provide a comparative information to those program efforts of searching comparative advantage in production. For the three countries, reduction of labor cost by reduction of chemical application frequency was recommended while pursuing further mechanization in those operation such as in pruning, harvesting and pest control. Adoption of the IPM (integrated pest management) will be useful to reduce the number of spraying chemicals with changed knowledge and attitude of the farmers.

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Algorithm for Improvement Alternatives of the Multi-stage Manufacturing Process - For the Application of Enterprise Environment Enhance (다단계 제조공정의 개선을 위한 알고리듬 - 기업환경개선을 위한 활용을 중심으로)

  • 조남호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.36
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    • pp.121-131
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    • 1995
  • The purpose of a business's existence is to make profit. The objective of business can be attained through the most profitable activities such as the improvement of productivity, quality and the reduction of the manufacturing cost. In order to produce the goods with above said goal, it can be achieved by inducing and improving the manufacturing process. In this viewpoint, We'd like to develope an algorithm for improving productivity, quality and cutting the manufacturing cost under the limitation of the resources. This paper showed a practical method which gradually improves three factors [productivity, quality and cost-down] by calculating the effective value of single and multi process mutually.

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Development of Cable Management System for Ship (선박 전선 관리 시스템 개발)

  • Lee, Jae-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.1987-1992
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    • 2008
  • In recent years, the shape of ship building have been advanced. Thus the system is complex and cable is much used in ship. In this paper, Dijkstra algorithm is used to solve the shortest path of cable laying. Cable laying is given much weight in fable management system of ship. The developed cable management system is cut down on expenses and is improve the operation efficiency for ship building. Therefore, the developed cable management system can be used a support system in order to achieve a management target of company.

Common Earth Network constitution for minimize surge damage (낙뢰 피해 최소화를 위한 공동 접지망 구성)

  • Kim, Yong-Kyu;Baek, Jong-Hyun;Choi, Kyoung-Il;Yoo, Keun-Su
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.190-195
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    • 2008
  • Surge proof equipment is an installation to make surge flow on the ground promptly so as to reduce surge-related damage on infrastructure, not to prevent surge from falling down on infrastructure directly. Compared with classical line individual earth, High speed line common earth has higher surge characteristic and plays a significant role to prevent infrastructure damage and injuries from surge, or short circuit accident between 25kV catenary and rail. In this paper, we analyzed the case of accident that caused communication/signaling system impaired while a tractor crossing level crossing at Honam line; in addition, we examined the accident reduction measures to minimize injury and property damage from cutting accidents with respect to common earth network.

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A Study on The Frost Penetration Depth of Pavement with Field Temperature Data (도로포장 현장계측 온도데이터를 이용한 도로포장체의 동결깊이 연구)

  • Shin, Eun-Chul;Lee, Jae-Sik;Cho, Gyu-Tae
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.21-32
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    • 2011
  • The frost penetration depth of pavement is usually estimated from the freezing index that made temperature data analysis of 30 years and decided the thickness of anti-frost layer. The field monitoring region in study was divided into five regions by freezing index 550~650$^{\circ}C{\cdot}$day, 450~550$^{\circ}C{\cdot}$day and 350~450$^{\circ}C{\cdot}$day. Each region has three-section of road pavement such as cutting area, boundary area of cutting and banking, and lower area of banking. The field monitoring system was established both in the section of anti-frost layer and in the section without anti-frost layer. The data analysis was conducted for determination of frost penetration depth within the paved road by the field monitoring system. The result showed that The temperature of subgrade without anti-frost layer shows below zero in centigrade for the region of freezing index 550~650$^{\circ}C{\cdot}$day, up and down around zero degree in subgrade for the region of freezing index 450~550$^{\circ}C{\cdot}$day, and there is no place existed below zero degree in subgrade for the region of freezing index below 450$^{\circ}C{\cdot}$day. With comparison of field frost penetration depth for the cross-sections of pavement, the cutting area shows the greatest frost penetration depth, and less influence of frost penetration depth for the boundary area of cutting and banking, and the least influenced for the lower area of banking.

Asexual Propagation of Kalopanax pictus by Root Cutting (근삽에 의한 음나무의 무성번식)

  • Kim, Chul-Woo;Song, Jae-Mo;Bae, Chan-Ho;Park, Bong-Jae;Moon, Heung-Kyu;Hwang, Suk-In;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.18 no.1
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    • pp.1-6
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    • 2001
  • This research was carried out to establish the large quantity propagation system for Kalopanax pictus using root cutting. The results are as follows. As there was no significant difference in the promotion of adventitious shoot development from the root cuttings of Kalopanax pictus among kinds (IBA, NAA and Kinetin) and concentrations (0 to 2000 mg/L) of growth regulators, no application is recommended, which showed more than 90% of shoot development. Horizontal and vertical placement of rooting showed more than 93% of shoot occurrence, but the latter showed more desirable growth traits in the number of shoot development, number of leaf, petiole length, and leaf length and leaf width Polarity was observed and thus normal vertical placement of root cutting is preferred. However, root cuttings placed upside down showed the shoot development at the distal end, which indicates further sophisticated test is necessary to investigate this phenomenon.

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The Study on the Selection of Revegetation Methods on Weathered Granite Cut-soil Slopes (화강풍화토 흙깎기 비탈면 녹화공법 선정 방안 연구)

  • Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.2
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    • pp.121-135
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    • 2016
  • The present study is an analysis of the monitoring results of the four areas that underwent the experimental construction of Straw-net+seedspray, Vegetation media spray method(t=2cm), and Vegetation media spray method(t=3cm), with the purpose of selecting the adequate revegetation of cutting slopes in weathered granite soil. Cutting slopes are mostly designed in the Straw-net+seedspray method, but since weathered granite soil slopes tend to have an infertile soil quality that runs down, it is difficult for seed germination and growth. It is difficult to apply Straw-net+seedspray to weathered granite soil slopes considering the germination rate and coverage rate of the Straw-net+seedspray method, which accompanies erosion and scouring. The final conclusions are summarized as follows. First, Straw-net+seedspray has difficulty recruiting plants to infertile weathered granite soil, which results in a lower coverage rate and fewer species, so it is not adequate construction method. Second, Vegetation spraying methods with wet media are more advantageous in early revegetation. The wet construction methods are faster than the dry construction methods in terms of early germination and its early growth are more excellent. Third, when constructing Vegetation spray methods with dry media, it were more advantageous if the thickness was thicker. When the soil-media is thicker, the soil is resilient to droughts, so the thickness must be flexibly applied according to the soil quality and slant of the weathered granite soil slope. The present study is a monitoring result for some areas of Gangwon-do, so its results may differ from other areas.

A Leverage Strategy of the Defense Export Based on System Thinking (시스템사고를 이용한 한국 방산수출 레버리지 전략)

  • Lee, Sang-Eun;Seo, Hyeok;Jung, Jong-Hee;Yang, Ho-Kyung;Kang, Seok-Joong
    • Journal of the military operations research society of Korea
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    • v.36 no.1
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    • pp.103-121
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    • 2010
  • As a cutting edge technology intensive value-added business, the defense industry is jumping into a new engine of a national growth. Also, the defense industry export is recognized not only as the field to activate the Korean economy but also as an important field to create the national brand value. However, though the consensus on the importance of defense industry export helps achieve the remarkable performance in reality, the rate of increase in the budget for national defence is slowing down gradually, and the investment in R&D is not so big, and there are a lot of drawbacks with the management of core technology and the development of cutting edge weapon system. Accordingly, this thesis tried to find the leverage to make the structure of defense industry export work normally after analyzing the systematical structure of defense industry export to understand its characteristics. Also, through the process to make the leverage a strategy, the thesis tried to present the optimal direction of policy to join the ranks of the advanced countries in defense industry export.

Effects of leaf-defoliation and different nitrogen, phosphorus and potassium application on maturity and yield of rice (질소 인산 가리의 시용량의 차이 및 전엽처리가 수도의 등숙 및 수량에 미치는 영향)

  • Dong-Sam Cho;Eun-Woong Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.15
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    • pp.61-67
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    • 1974
  • Field experiment was conducted to disclose some effects of leaf defoliation in heading time and the application of different combinations of nitrogen, phosphorus and potassium on the maturity and yield of paddy rice. The results obtained are as follows; 1.All were components considered were increased as the amounts of nitrogen, phospgorus and potassium applied were increased, except the maturity rate had the tendancy to be decreased with the increase of the above fertilizer applications. 2.As the rate of cutting leaves went higher, the weight of rough rice, the maturity rate and the weight of 1, 000 kernels of perferct brown rice were decreased, and there were significant differences among the treatments of leaf blade cutting. 3. The contribution of each leaf to yield through the maturity, number of spikelets per panicle and 1, 000 kernel weight were 61.87-66.18-65.61% respectively for the flag leaf, 17.50-20.65-23.41%for the 2nd leaf, 12-71-12.73-10.11%for the 3rd lead and 7.93-6.44-0.87%for the 4th leaf respectively. This simply indicared that the effects of the leaves to the yield were decreased as their position went down. This tendency was specially emphasized in the case of the weight of 1, 000 kernels of perfect brown rice.

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