• Title/Summary/Keyword: rain fall

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A research for improvement methods in the aspect of safety engineering through risk analysis of facilities for multiple use - Focused on escalator and passenger conveyors - (다중이용시설물 위험분석을 통한 안전공학적 개선 방안에 관한 연구 (에스컬레이터 및 수평보행기를 중심으로))

  • Kwon, Sun-Geol;Kim, Jin-Soo;Kim, Chang-Eun
    • Journal of the Korea Safety Management & Science
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    • v.15 no.1
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    • pp.31-40
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    • 2013
  • For the matter of elevator, one of the multi-use facilities for unspecified public, the JIS has re-established and reformed to apply to the environment in South Korea for the past 20 years. In the aspect of safety assurance, it was inevitable to suggest improved measures. The government, Ministry of Public Administration and Security has secured the safety by enhancing the safety management functions in the elevator inspection standards and expanding its safety device measures. Further, the international inspection standard has been introduced, which is about unifying inspection standard system into the international standard code. In March 14th 2012, the international standard (EN) has been amended and fully announced. Escalator and passenger conveyor among lift devices have several common danger factor that cause safety accident. First, the accident caused by decreased braking power of brake. Second, the accident caused by the rate difference between handrail and tread-board. Third, the accident caused by defects of contraflow preventing device or carelessness inspection. Fourth, the accident caused by wet tread-board or wet floor of platform which makes passenger slip and fall. As the improvements to prevent and reduce these negligent accidents, the inspection list to check and methods should be subdivided and applied for each accident likelihood cause for safety management enhancement and safety assurance of existing escalator and passenger conveyors. The escalators and passenger conveyors without safety devices in existence should be obliged to modify the part of the system or install additional safety device. With making these measures obligations, it requires to improve the system to be suitable for the international inspection standard and to have measures to prevent safety accidents. It also needs to arrange improvements for skid accident of tread-board by the external environment factors such as snow and rain.

Vegetation Influences on the Slope Stabilization (식생(植生)이 비탈면의 안정(安定)에 미치는 영향)

  • Woo, Bo Myeong
    • Journal of Korean Society of Forest Science
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    • v.35 no.1
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    • pp.47-55
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    • 1977
  • As the development of national lands increase, the necessity to develop less favorable terrain also increases. It also becomes more difficult and complicated to provide access that is both economical and safe from contributing to soil erosion on roadsides and to londscape damages. Because of the increased and justified emphasis upon environmental degradation, proper stabilization of the cut-and bank slopes of roadsides, plant sites and building sites in Korea requires careful planning as well as execution of the constructions. All fill slopes should be compacted to a degree consistent with design standards and material properties. Drainage facilities should be provided to prevent damaging concentrations of surface runoff and to avoid high pore pressures in cuts and fills. All surfaces of cut-fill slopes should be revegetated with suitable species as soon as possible after construction. To stabilize the cut-fill slopes of highway roadsides should be considerded the factor of stabilization as well as landscape conservation especially. Such basic influences as the effects of vegetations on water balance of rain fall, on the control of surface erosion and on the surface slope failures are briefly discussed in the report.

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Estimation of Erositivity Using an Impact Disdrometer in East of Alagoas (충격 입자 분포 탐지기를 이용한 침식도 추정)

  • Tenorio, R.S.;Kwon, Byung Hyuk;Moraes, M.C. da S.;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.2
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    • pp.371-378
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    • 2020
  • Rainfall is one of the most active forces that cause soil erosion. The action of rain on the soil exerts an erosive power caused by the impact of the drops, which fall with variable speed and kinetic energy, depending directly on the diameter of the drop. The objective of this study is to determine algorithms capable of estimating rainfall erosivity for the region of Maceió-AL. For this purpose, erosion rains were collected between 2003 and 2006 using a RD-69 disdrometer, which continuously and automatically measures rainfall distribution in a range of 1 min. The determination of algorithms in the form of power equation to estimate was adjusted with one and two independent variables (amount of rainfall, duration and maximum intensity).

A Study on the Change of Non-Working Days Based on the Rainfall in Incheon Area Using the Climate Change Scenarios (기후변화 시나리오를 활용한 인천지역 강우에 의한 작업불능일 변화 연구)

  • Jang, Junyoung;Lee, Chansik
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.1
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    • pp.103-113
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    • 2018
  • In this study, Construction work is mainly done outdoors, so earth works, reinforced concrete works, etc. are Non-Working Days to rainfall. In particular, changes in rainfall due to global warming have made air calculation more difficult. Therefore, when establishing the process plan, the change of the rainfall in the area should be identified and Non-Working Days should be calculated. In this study, the time of rainfall change point was identified using the meteorological 'observation' data from 1960 to 2016 in Incheon and RCP 4.5, 'weather forecast' data from 2018 to 2074, Year rainfall and seasonal rainfall. The results showed that rainfall changed point in 1972, 1988, 2013, 2038, 2050 and 2069. In particular, it has been found that non-working days due to rainfall has big changed point as of 2013, 2038 and 2069.

Development of a Prototype System for Slope Failure Monitoring Based on USN Technology (USN 기술을 이용한 사면붕괴모니터링 시범시스템 개발)

  • Han, Jae-Goo;Kim, Kyoon-Tai
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.316-321
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    • 2007
  • The casualties due to slope failures such as landslide, rock fall, debris flow etc. are about 24% in total casualties caused by natural disasters for the last 10 years. And these slope failures are focused in the season in which typhoon and torrential rain take place. Not much attention, however, have been put into landslide mitigation research. Meanwhile, USN(Ubiquitous Sensor Network) forms the self-organization network, and transfers the information among sensor nodes that have computing technology ability. Accordingly, USN is embossed a social point technology. The objective of this paper is to develop a prototype system for slope failure monitoring using USN technology. For this we develop module that collects and change slope movement data measured by two tiltermeter and a tension wire, store transferred data in database. Also we develop application program that can easily analyze the data. We apply the prototype system to a test site at KICT for testing and analyzing the system's performance.

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Reconstruction of May~June Precipitation (253 Years: A.D. 1746~1998) in East-Coastal Region (Yungdong) of Korea from Tree Rings of Pinus densiflora S. et Z. (소나무 연륜연대기를 이용한 영동지방의 5~6월 강수량 (253년간: A.D. 1746~1998) 복원)

  • 박원규;서정욱
    • The Korean Journal of Quaternary Research
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    • v.14 no.2
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    • pp.87-99
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    • 2000
  • May-June precipitation (253 years : A.D. 1746∼1998) of Yungdong region (coastal area of East-central Korea) was reconstructed using two tree-ring chronologies of Pinus densiflora sampled from Daeseung Fall area in Sorak Mountains. Dry periods were 1765∼1800 (longest dry period), 1835∼1845, 1890∼1910, 1920∼1940 and 1980∼1995, and wet ones 1810∼1830, 1850∼1890 and 1950∼1970. In long-term variation, late 18th century was dry. The 19th century May-June (250㎜) was wetter than the 20th century (231㎜) and the former indicated higher variability than the latter. Major wet/dry periodicities in May-June precipitation series reconstructed were 3 years in short term and 60∼80 years in long term. The present reconstructed data agreed to the ancient rain gauge 'Chukwooki' data (1777∼1907) of Seoul (central-west Korea) in low frequency variations except early 1800s.

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Validation of an Unsteady Two-dimensional Hydrodynamic and Transport Model with Experiments (비정상상태 하천흐름에서 오염물질 혼합 수치모형의 신뢰성 평가)

  • Moon, Hyoung-Bu
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.11
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    • pp.1168-1179
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    • 2006
  • The validity of an unsteady two-dimensional(2-D) numerical hydrodynamic and pollutant dispersion model(2DNHPDM) was evaluated using the data obtained from I-sa streams in Sooncheon, Chonnam, during rain-fall run-off. Field observations was conducted for 35 hours during the 10 hours rainfall event on 7th May 2005. The water level, 2-D velocity, flow field, and COD at seven points selected along the river were measured at intervals of one hour. The model was applied to describe two-dimensional movement of dissolved pollutants in meandering non-uniform river. Major physical processes affecting the lateral and horizontal mixing of the river flow were simulated. The model was proved effective in describing the hydrodynamics and dispersion of the river pollutants from its major tributaries as well as non-point sources.

Studies on the Consumptive Use of Irrigated Water in Paddy Rice (수도 품종간의 필요수량 차이에 관한 연구)

  • 김시원;오완석;김선주
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.23 no.2
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    • pp.35-44
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    • 1981
  • This experiment was conducted to find out the consumptive use of irrigated water for calculation of duty water in paddy rice. Tall statured Japonica rice varieties, Nongbaek (early), Jinheung (medium) and Akibare (late), and short statured Tongil typed varieties, Josaeng Tongil(early), Suweon 264 (medium) and Suweon 258(late) were planted on the experimental farm of Kon-Kuk University in 1979. The results obtained in this study were as follows: 1. During the experimental period, the daily mean temperature was almost similar, the relative humidity was higher as much as 2.8%, the amount of rain fall was 100mm less and the pan evaporation was 70mm less compared with those of 30 years average, respectively. 2. The paddy soil was silty loam, which was suitable for the rice cultivation. 3. Varietal differences were find out for plant height, culm length, number of tillers, number of panicles, heading date, matured grain ratio, 1000-grain weight and rough rice yield. This difference might he the cause of varietal difference of the consumptive use of irrigated water during the rice growing period. 4. The evapotranspiration was gradually increased after transplanting and showed the peak from booting to heading stage of rice varieties. The average evapotranspiration through the whole growing period was 5.67-5. 80mm/day for tall statured Japonica varieties, and 5.99-6. 39mm/day for short statured Tongil typed varieties. 5. The ratio of evapotranspiration to pan-evaporation through the whole growing period was 1.49-1.50 for Japonica varieties, and 1.60-1.66 for Tongil typed varies. 6. Average amount of percolation in paddy field was 3. 62mm/day through the whole growing period of rice plant. 7. K-value in Blaney & Criddle formula was 0.94-0.98 for Japonica varieties and 1.02-1.08 for Tongil typed varieties, and coefficient consumptive water use (Kc-value) was 0.95-1.02 for Japonica varieties and 1.04-1.12 for Tongil typed varieties in this study. The modified coefficient for consumptive water use, which was calculated from data collected through the country including this study, was as follows;

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The investigation of tracking resistant sheath material for ADSS Optic cable (ADSS 광 케이블 시스용 내 트래킹 재료의 특성에 관한 연구)

  • Lee, Jung-Hee;Seo, Il-Gun;Whang, Sun-Ho;Lee, Gun-Joo;Bak, Seung-Yup;Kim, Kyeung-Min;Lee, Seung-Chan
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.102-105
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    • 2002
  • ADSS(All Dielectirc Self-Supporting) cable installed under high voltage power cable line suffers a variety of environmental influence, rain, wind, snow fall, chemical pollution, salt fog and electrical stress. Its lifetime is required to be at least 20 years with this harsh weathering condition. The electrical stress under high voltage power line gives rise to dry band arcing and tracking, the severest damage, on the outer sheath of cable. Finally tracking might penetrate sheath and cause the break-down of ADSS cable. Tracking resistant sheath material, therefore, should be used to protect the core of ADSS from dry band arcing and to be sure long lifetime. In this work, we discuss various commercial tracking resistant material to investigate the way of track resistance and compare their mechanical, electrical, weathering and tracking properties through serial experiments. We found track resistant material is categorized into two main type : polyethylene with metal hydroxide and polyethylene with reduced carbon black. The Liquid contaminant, Inclined plane Tracking and Erosion test says the time to track of tracking resistant material with metal hydroxide has a little longer time to track in the high applied voltage than that with carbon black, but mechanical and weathering properties were inferior to.

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Seasonals Pollutant Outflow Analysis in the Watershed of Soyang Lake by using Multivariate Analysis (다변량 분석을 이용한 소양호 유역의 계절별 오염물질 유출 해석)

  • Park, Soo-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3726-3734
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    • 2012
  • This study evaluated the behavior of pollutants based on the seasonal change by selecting the branch river's factors that influence the outflow of pollutants in Soyang lake basin. The analysis method was the factor analysis that classified the factors of the drainage area influencing the outflow of pollutants, and evaluated selected representative factors. As a result of the study, SS and T-P factors should be classified as similar factors to the storm water runoff, and the improvement of water must be strived through managing source of pollution at the time of no rain. Second, as the result of the influence from the factors, spring and winter seasons usually exert 36% influence and summer and fall exert over 90% significant influence that the improvement of water through managing source of water seems possible. At last, the prediction about delivery pollution load considering the outflow characteristic of pollutants at the drainage area based on seasonal change by regarding selected factors as independent variables is possible.