• Title/Summary/Keyword: in-water work

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An Analysis of Influences on Partial Work Rates under the Whole Work Rates on the Landscape Constructions in the Ulsan Grand Park (울산대공원 조경공사의 각 세부공정이 전체공정율에 미치는 영향분석)

  • 성백진;이재근;최종희
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.6
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    • pp.64-72
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    • 2004
  • This study analyses influences on partial work rates under whole work rates on landscape constructions in Ulsan Grand Park. The schedule management is one of the factors that are very important to the process management of landscape construction. The time process of the whole construction is supposed to be affected by several kinds of work that organize the whole construction. First, this study divides the construction of Ulsan Grand Park into 10 kinds of works: earth work, rain and sanitary sewage water work, water-supplying work, planting work, paving work, water proofing work, fountain work, instituting work and temporary work. Then the time-process curves of all kinds of work are statistically compared to that of the whole construction. The trial methods of statistics are lineal regression, non-lineal regression, and principal analysis. In the result of the non-lineal regression, the rain and sanitary sewage water work, the water-supplying work and the earth work strongly affected the whole construction. The principal analysis results show that the whole construction is affected strongly by the water-supplying work, the rain and sanitary sewage water work and the earth work. However the lineal regression is shown to be senseless because of its high collinearity.

A Cooling Method which Reduces the Tangential Tensile Stresses on a Work Roll Surface during Hot Slab Rolling (열연 슬라브 압연에서 워크롤 표면 원주방향 인장응력 감소를 위한 냉각 방법)

  • Na, D.H.;Lee, Y.
    • Transactions of Materials Processing
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    • v.21 no.1
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    • pp.58-66
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    • 2012
  • The work roll surface temperature rises and falls repetitively during hot slab rolling because the work roll surface is cooled continuously by water. This study focused on Std. No. 7 to determine a cooling method which significantly reduces the tangential tensile stresses on the work roll surface of the hot slab mill at Hyundai Steel Co. in Korea. A series of finite element analyses were performed to compute the temperature distribution and the tensile stresses in the circumferential direction of the work roll. The virtual slab model was used to reduce the run time considerably by assigning a high temperature to the virtual slab. Except for the heat generated by plastic deformation, this is equivalent to the hot rolling condition that a high temperature slab (material) would experience when in contact with the work rolls. Results showed that when the virtual slab model was coupled with FE analysis, the run time was found to be reduced from 2000 hours to 70 hours. When the work roll surface cooled with a certain on-off patter of water spray, the magnitude of the tangential stresses on the work rolls were decreased by 54.1%, in comparison with those cooled by continuous water spraying. Savings of up to 83.3% in water usage are possible if the proposed water cooling method is adopted.

Classification of Radiation Work in Korean Nuclear Power Plants

  • Changju Song;Tae Young Kong;Seongjun Kim;Jinho Son;Hwapyoung Kim;Jiung Kim;Hee Geun Kim
    • Journal of Radiation Industry
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    • v.17 no.3
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    • pp.239-256
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    • 2023
  • The classification of the radiation work performed in Korean nuclear power plants (NPPs) must be understood to provide workers with more comprehensive radiation protection. This study used annual reports on occupational exposure to investigate and analyze the similarities and differences in the radiation work performed in Korean NPPs with pressurized water reactors (PWRs) and pressurized heavy water reactors (PHWRs). The results showed that the radiation work performed in Korean NPPs could be classified into three categories. Category 1 contains work at the highest level. This work can be divided into individual tasks belonging to Category 2, which enables the evaluation of the radiation dose during the work. The work in Category 2 consists of tasks from Category 3, which contains basic detailed tasks that are not further subdivided. This study emphasized the need for the systematic management of the radiation work performed in both Korean PWRs and PHWRs, such as the tasks in Category 3, which are similar, with similar working conditions, for PWRs and PHWRs. It also suggested the need to establish a list of radiation work for decommissioning because Kori Unit 1 and Wolsong Unit 1 are currently in permanent shutdown and preparations are being made for their decommissioning.

Workability Characteristics of Cement-Mixed Soil for Architecture (건축용 시멘트 혼합토의 워커빌리티 특성)

  • Lee Sang-Ho;Kim Sang-Chul;Kim Jin-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.4
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    • pp.15-22
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    • 2006
  • This study was conducted by the slump test and the consistency test of the cement mixed soil which is soil mixed with cement to investigate and estimate the difficulty degree of work and the proper water content. So I would like to present the fundamental data that establish the work standard of the cement mixed soil. In conclusion, in this study the slump value of the cement mixed soil increases over-all according to the increase of the water content although it has a little difference of the increase range and it is smaller than one of the soil. It is estimated that the aggregating and throwing work of the cement mixed soil which is mixed with 6% and 9% cement would be fine when it has the $25%{\sim}27%$ water content and the wall plastering work is the $30%{\sim}32%$ and the floor plastering work is the $30%{\sim}35%$ and the flowing and pouring work is the $40%{\sim}42%$ water content as well as the mold compacting work is the 20%.

Development of On -Line Work Roll Surface Monitoring System At Hot Strip Mill

  • Moon, Bae-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.53.4-53
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    • 2001
  • This paper described about the system which can be inspect work roll surface for deciding a milling schedule and roll changing at hot strip mill in POSCO. Developed system consists of CCD camera, Xenon lamp with fiber bundle and mechanical control part. The water probe build up water pole between head of probe and roll surface to acquisite a good image from a work roll surface under the bad environment with steam, cooling water and high temperature. This system is possible to monitor a work roll surface of about 12${\times}$9mm. We have shown the validation of the developed system which can monitor the evolution of degradation on work roll surface.

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An evaluation of local waters productivity by operating types (운영형태별 수도사업 생산성 평가)

  • Kim, Shang-Moon;Lee, Ik-Gyu
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.3
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    • pp.325-334
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    • 2011
  • Market Environment around water work industry is rapidly changing. ISO, International Organization for Standardization, announced the international water work service standard for comparison and evaluation between nations and businesses. And developed countries in water work are introducing market principle for growth of nation's water industry and reinforcement of its competitiveness. Also, some local governments entrusted their water utilities for improvement of competitiveness of water work. However, as some failure cases from overseas came out with emphasis, there are many refuting perspective about entrusted operation achievements of domestic water market. Hence, this paper evaluated competitiveness of domestic local water utilities from the perspective of productivity. After evaluating productivity using Malmquist productivity index, the authors compared and analyzed whether there is a difference of productivity between two different operating types by using Mann-Whitney test. As a result of analysis, it has shown that local water utilities achieved higher productivity at entrusted operation type rather than direct operation type. The local water utilities which chose entrusted operation had increased the productivity 13.9% on total factor productivity(TFP) during experimenting period, while the local water utilities which chose direct operation had increased 0.2%. The background of achieving this high productivity in entrusted operation was analyzed as a result of the higher technological effectiveness of a special water company. The result of this study can be referred when local government needs to decide on what operating types they will use.

A study on EDP of water Rate Billing procedures (상수도 요금 과징업무 기계화 처리에 대하여)

  • 정규영
    • Water for future
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    • v.7 no.2
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    • pp.11-22
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    • 1974
  • Comparing with Seoul city's other administrative works, the work to arrange and collect monthly water rates with 470,000 faucets is tremendous in volume and simple repetition in quality. In order to cover the shortage of handling, it is urgent for us to replace the present manual system with EDP(Electronic Data Processing) system to mechanize a series of handling works of simple repeated calculation such as water consumption, rate calculation, statistics arrangement, bills and specification of water rate by computer. When this work is completely mechanized, inspectors of water meter just turn over their checking results to the Data Center and all data are processed through Input Media(OMR Card, Punched Card) and computer for programming final bills. Then, the delivery of the bills to citizens will be the only work to be carried out. such mechanization will bring about the following benefits: 1. Improvement of administrative work by efficiency and rationalization. 2. Improvement of administrative service with people. 3. Possibility of scientific with trustworthy multi-purpose policy-making data. 4. An effect to cover the personnel shortage of 252 persons (at all the water works offices) and save manpower of 166 persons (47,619 man-days). The application of the above mentioned mechanization will be started to only Chongro and Chung-ku water works offices as model cases out of all water works offices in Seoul. As the electronic calculating machines are inducted, this system will be gradually applied to other water works offices. The billing and collection works of water rates which are connected directly to the daily life of the citizenes, should be handled by the scientific EDP system as soon as possible in order to promote the convenience of consumers and effective operation. This study is to promote the sound and rational operation of this work.

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An overview and update on Rainfall Intensity Duration Frequency (IDF) and Flood Estimation work in the Asia Pacific Region

  • Jamieson, Dennis
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.2210-2214
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    • 2009
  • This paper summarizes progress on work under the Asian Pacific FRIEND(Flow Regimes from International Experimental and Network Data - APFRIEND) initiative of the International Hydrological Programme (IHP) of the United Nations Educational, Scientific and Cultural Organisation (UNESCO) from 2005 to 2009. The results of initial work on Rainfall Intensity Duration Frequency (IFD) have just been published as a volume by UNESCO. The results of work to date is concisely presented and observations made about lessons learnt on how to successfully integrate work from nine diverse countries with differing approaches to both hydrology and water resource management structures and on some possible directions for future work.

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Workability Characteristics of Fiber Mixed Soil (섬유 보강 혼합토의 워커빌리티 특성)

  • Song, Gyoo Bog;Lee, Sang Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.1
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    • pp.53-59
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    • 2016
  • This study was conducted by the slump test and the consistency test of the fiber mixed soil which is soil reinforced with fiber as a reinforced material to investigate and estimate the difficulty degree of work and the proper water content. So I would like to present the fundamental data that establishes the work standard of the fiber mixed soil. In conclusion, in this study the slump value of the fiber mixed soil increases over-all according to the increase of the water content although it has a little difference of the increase range and it is smaller than one of the soil. It is estimated that the aggregating and throwing work of the fiber mixed soil would be fine when it has the about 25 % water content and the wall and floor plastering work is the about 30 % ~ 35 % and the flowing and pouring work is the about 40 % water content as well as the mold compacting work is the about 20 %. There is no decreasing of the workability when the soil is reinforced by the fiber because the workability characteristics of the fiber mixed soil is similar to the one of the soil. Therefore, It is estimated that using the fiber as a reinforced material of soil would be appropriate for the construction.

A Calculation of Agricultural Water Demand According to the Farmland Developing Plan on the Saemangeum Tidal Land Reclamation Project (새만금 간척지구의 농업용지 토지이용계획을 고려한 농업용수 수요량 산정)

  • Jang, JeongRyeol;Lee, SungHack;Cho, Youngkweon;Choi, JinYong
    • KCID journal
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    • v.21 no.1
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    • pp.1-16
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    • 2014
  • The purpose of this study is to calculate agricultural water demand as considering landuse plan of the farm land on the Saemangeum tidal land reclamation project. This study based on the farm landuse plan(2012) and considered some items which did not included previous work like prevention water for resalinization for paddy and upland and muli-purpose water for upland. This study showed that the agricultural water demand estimated $145.123Mm^3/yr$, which is needed as much $14.792Mm^3/yr$ as more water than previous work. The difference comes from the change of unit water demand. Water demand is possible to be changed if guidelines are improved and detailed design work is completed through further study. Especially, the more studies for prevention water for resalinization in a tidal reclaimed farmland and water demand for a horticulture are needed.

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