• Title/Summary/Keyword: Strength Case Management

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Optimum Mix Proportion of the High Strength and Self Compacting Concrete Used Above-Ground LNG Storage Tank (지상식 LNG 저장탱크용 고강도 자기충전 콘크리트의 최적배합에 관한 연구)

  • Kwon, Yeong-Ho
    • Journal of the Korea Concrete Institute
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    • v.23 no.1
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    • pp.99-107
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    • 2011
  • This study is to performed to find the optimum mix proportion of the high strength and self compacting concrete for the above-ground LNG storage tank construction and field application. If LNG storage tank wall thicknesscan be reduced, the construction cost and quality can be improved by using self-compacting high strength concrete with compressive strength 60~80 MPa. For this purpose, low heat cement (Type IV) and class F fly ash are used in concrete mix to control hydration heat, flowability, and viscosity. Mix design variables of unit water, fly ash replacement ratio, water-binder ratio, and fine aggregate ratio are selected and tested for material properties and manufacturing cost of the concrete. Also, fly ash replacement ratio is considered using confined water ratio test. The test results showed that the optimum mix proportion of the self-compacting high strength concrete characteristics are as follows. 1) In case of the concrete with specified compressive strength of 60 MPa, the optimum mix proportion is fly ash replacement ratio of 20% and water- binder ratio of 27~30%. 2) In case of the concrete with the strength of 80 MPa, the optimum mix proportion is fly ash replacement ratio of 10% and water-binder ratio 25%. But unit water and fine aggregate ratio are 165 $kg/m^3$ and $51{\pm}2%$, respectively, regardless of the traget concrete compressive strength range. Also, test results showed that concrete manufacturing cost of 60 MPa and 80 MPa concrete require additional costs of 14~22% and 33%, respectively, compared to the manufacturing cost of 40 MPa concrete. Therefore, application of the self-compacting high strength concrete has proven to be economical in the perspective of the material cost, quality control, and site management.

A Case Study on RFID-PPS(Radio Frequency IDentification-Pallet Pool System) (RFID-PPS (Radio Frequency IDentification-Pallet Pool System) 사례연구)

  • 안종윤;양광모;진향찬;강경식
    • Proceedings of the Safety Management and Science Conference
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    • 2004.05a
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    • pp.303-307
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    • 2004
  • Is not used by consistency transport at transport of freight nothing but is using Pallet only by pedestal when work palletized unit load or materials handling when keep simplicity receptacle which fill raw material or product in factory in our country. Therefore, pallet that is most important function of Pallet is not empled circulation to end consumer from manufacturing plant which is circulation process whole path being done and factory. It is real condition stopping only in extremely determinate part process use of warehouse back. Additionally, it is possible to figure out the flow of all the materials loaded on the RFID pallet; product, material, raw material immediately, so that epoch-making management is possible and it contributes to the reduction of logistics cost because there are little loss or outflow of pallet. The materials flow is getting speedy and inventory is decreasing in the logistics process, and also bad inventory and loss problems are prevented. As a result, not only logistics cost of company but also national logistics cost is decreased. Thus it contributes to the strength of national competitiveness.

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Field Application of Insulation Curing Method with Double Bubble Sheets Subject to Cold Weather (이중버블시트를 이용한 단열양생공법의 한중콘크리트 현장적용)

  • Hong, Seak-Min;Baek, Dae-Hyun;Kim, Jong;Jeon, Chung-Kun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.57-60
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    • 2008
  • This study investigated the results of insulation heat curing method using double layer bubble sheet in slab concrete and mass concrete in cold weather environment. First of all, when double bubble sheets are applied, it was shown that slab concrete was protected from early freezing by remaining between 6 and 15℃ even in case outside temperature drops -9℃ below zero until the 2nd day from piling, and in the case of mass concrete, with the maximum temperature difference between the center and surface less than 4℃, crack occurrence index was close to 2 and no hydration heat crack occurred by internal constraint. The insulation heat preservation curing method using the double bubble sheet applied in this field prevented early freezing owing to stable curing temperature management, deterring concrete strength development delay at low temperature, and obtained the needed strength. Also, it was proven that the method is highly effective and economic for cold weather concrete quality maintenance through curing cost reduction like construction period shortening and labor cost reduction, etc by reducing the process of temporary equipment installation and disassembling.

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A Study on Improvement of Safety & Quality Management Standard Based on Compression Tests of Steel Pipe Supports (강재 파이프서포트의 압축하중 시험에 따른 안전 및 품질관리 기준 개선에 관한 연구)

  • Oh, Byoung-Han;Choi, Byong J.
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.94-103
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    • 2018
  • As of July 1, 2017, the method of quality management of construction equipment had been changed completely. In case of manufacturing and distributing pipe supports, the support length according to the safety certification standard shall be not more than 6 m and the compressive strength shall be not less than 40,000 N at the maximum height. However, the field tests for the quality control standard were usually performed at 3.5 m when the length of the pipe supports is 3.5 m to 4.0 m, and the compression strength was specified to be more than 35,300 N. This difference in the two standards can cause confusion in practice. In this study, the compression load of the pipe supports was tested and found to be more than 30% defective. Therefore, it is necessary to review the modification of the safety certification and quality standards to improve the standard requirements.

An Exploratory Study of the Effect of Buyer-supplier Relationship on Supplier's Innovation : Cases from Semiconductor Equipment Industry (구매자-공급자 관계가 공급자 혁신에 미치는 영향에 대한 탐색적 연구 : 반도체 장비 산업 사례를 중심으로)

  • Lee, Kangmun;Cho, Dong-sung;Lee, Yun-cheol
    • Knowledge Management Research
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    • v.10 no.4
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    • pp.163-183
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    • 2009
  • Numerous studies in the field of buyer-supplier relationship research have focused on the buyer's performance. In contrast, supplier's performance has been paid relatively little attention by researchers, especially the research about the supplier's innovation in the relationship is still in its early stage. In this paper, we examine the relation between the attribute of buyer-supplier relationship and the attribute of supplier's innovation through case research. We define the attribute of buyer-supplier relationship as 'tie strength' (Granovetter, 1973), and the attribute of supplier's innovation as 'exploitation or exploration' (March, 1991). We selected the semiconductor equipment industry of U.S.A, Japan and Korea and firm (JUSUNG Engineering) as cases that examine the relation. We found that a strong tie relationship is positively associated with supplier's exploitation based innovation, and a weak tie relationship is positively related to it's exploration based innovation in this research also. In addition, we could verify reduction of strong tie relationship cause supplier's organizational change.

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A Case Study on the Marketing Strategy for a Take-Out Specialty Store through Analysis of Customer Informations (소비자 정보 분석을 통한 Take-out 전문점의 마케팅 전략 사례연구)

  • Lee, So-Jung;Shin, Seo-Young;Yang, Il-Sun;Lee, Myung-Kang
    • Journal of the Korean Society of Food Culture
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    • v.21 no.2
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    • pp.131-141
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    • 2006
  • The purpose of this research is to develop the management strategy for a take-out specialty sore on the basis of SWOT analysis which requires analysis of internal and external environmental informations. The survey was performed in order to gather the internal and external customer informations for a take-out specialty store. The questionnaires developed were distributed to customers (N=188) and employees (N=23) at 5 take-out specialty store branches from April 25, 2002 to April 29, 2002. The statistical data analysis was completed by SPSS WIN 10.0 for descriptive analysis, factor nalaysis, and Pearson's correlation. IPA(Importance-Performance Analysis) was applied in order to identify the critical management issues which would be explained with the organization's weakness or strength. SWOT analysis was performed through identifying the organizational strength and weakness as internal environment factors and external environmental opportunity and threat as uncontrollable external factors.

competition strategies for traditional market -focus on strength strategies of inner core competency- (재래시장 경쟁력 방안 -내부 핵심능력 강화방안을 중심으로-)

  • Lee, Jang-Whan
    • Journal of Global Scholars of Marketing Science
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    • v.7
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    • pp.55-69
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    • 2001
  • This article focuses on subject of the present question to traditional market. These days traditional markets have systemic problems due to deterioration of the outer market circumstance and the inner defect and the inner frailty. In this situation, from the SangNam market case analysis, was traced the alternative activation strategies. Issued the 6 inner competency competition strategies for traditional market and issued 7 functional frame for organization system construction. Struggle strategies is built up of the inner organization solidarity and effective management system. So as to build struggle strategies, suggested and issued the 4 phase organization frame to strength stage of traditional market organization operating.

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Integrated Flood Risk Management through Modelling of Nature Based Solutions

  • Bastola, Shiksha;Kareem, Kola Yusuff;Park, Kiddo;Jung, Younghun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.160-160
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    • 2022
  • Floods are the most common natural disasters and are annually causing severe destructions worldwide. Human activities, along with expected increased extreme precipitation patterns as a result of climate change enhance the future potential of floods. There are proven evidence that infrastructure based responses to flood disaster is no longer achieving optimum mitigation and have created a false sense of security. Nature-based solutions(NBS) is a widely accepted sustainable and efficient approach for disaster risk reduction and involves the protection, restoration, or management of natural and semi-natural ecosystems to tackle the climate and natural crisis. Adoption of NBS in decision-making, especially in developing nations is limited due to a lack of sufficient scenario-based studies, research, and technical knowledge. This study explores the knowledge gap and challenges on NBS adoption with case study of developing nation, specially for flood management, by the study of multiple scenario analysis in the context of climate, land-use change, and policies. Identification and quantification of the strength of natural ecosystems for flood resilience and water management can help to prioritize NBS in policymaking leading to sustainable measures for integrated flood management.

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Morphological Changes of Pre-Astronaut's Hair During Spaceflight Training - A Case Report - (우주비행 훈련 기간에 채취한 예비우주인 모발의 형태적인 변화 - 증례 보고 -)

  • Lee, Weon-Kun;Chang, Byung-Soo
    • Applied Microscopy
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    • v.39 no.4
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    • pp.365-371
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    • 2009
  • This study was investigated to observe morphological changes of two pre-astronauts' hair, male and female by electron microscopy and to analyze its tensile strength by using rheometer. The surface of those two pre-astronauts' hair, which were very rough and irregular, contained separated scales and destroyed remnants of cuticular cells. Also, there were many holes on the cytoplasm of the cuticular cells which forms the cuticle layer. The destruction begins when the endocuticle where the holes form gets destroyed. And then, The tensile strength of female pre-astronaut's hair was 14.60 mm which is 10% reduced, compared to that of the normal healthy hair. Thus, this result thought to be due to the prolonged change of the biorhythm and psychological instability of the pre-astronauts.