• 제목/요약/키워드: Direct Construction System

검색결과 308건 처리시간 0.03초

유리섬유를 이용한 하수관의 고강도 현장경화 비굴착 보수 공법 재료의 개발 및 물성 특성 연구 (Study of structural properties and development of high strength Cured-In-Place Pipe (CIPP) liner for sewer pipes using glass fiber)

  • 지현욱;;유성수;강정희
    • 상하수도학회지
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    • 제34권2호
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    • pp.149-159
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    • 2020
  • Cured-in-place-pipe(CIPP) is the most adopted trenchless application for sewer rehabilitation to extend the life of the existing sewer without compromising both direct construction and indirect social costs especially applied in the congested urban area. This technology is globally and domestically known to be the most suitable for partial and full deteriorated pipe structure rehabilitation in a sewer system. The typical design of CIPP requires a significant thickness of lining to support loading causing sewage flow interruption and increasing material cost. This paper presents development of a high strength glass fiber composite lining material for the CIPP application and structural test results. The test results exhibit that the new glass fiber composite lining material has 12 times of flexural strength, 6.2 times of flexural modulus, and 0.5 Creep Retention Factor. These test results can reduce lining design thickness 35% at minimum. Even though taking into consideration extra materials such as outer and inner films for actual field applications, the structural capacity of the composite material significantly increases and it reduces 20 percent or more line thickness as compared to the conventional CIPP. We expect that the newly developed CIPP lining material lowers material costs and minimizes flow capacity reduction, and fully replaceable to the conventional CIPP lining materials.

마이다스아이티의 뇌과학 기반 인적자원 관리 사례 연구 (Neuroscience based human resource management at Midas IT Co._A case study)

  • 이지훈
    • 한국산학기술학회논문지
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    • 제21권5호
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    • pp.240-248
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    • 2020
  • 지난 20여 년 간 뇌 과학은 기능성 자기공명영상(fMRI) 등 새로운 기술에 힘입어 크게 발전했으며, 우리는 인간의 본성과 행동 변화에 대해 더욱 정확한 지식을 얻게 됐다. 이 같은 지식은 경영 분야에도 활발하게 응용되고 있다. 이 연구는 마이다스아이티의 사례를 통해 뇌과학을 경영에 어떻게 접목할 수 있는지 통찰을 얻는 것이 목적이다. 건설 소프트웨어 회사인 이 회사는 별도 조직을 두어 뇌 과학을 연구하고 있으며, 뇌 과학에 기반한 인사 정책을 만들어 시행하고 있다. 창업자 이형우 사장은 인본주의 경영 철학을 갖고 있으며, 뇌 과학 연구는 그 철학을 뒷받침한다. 연구 방법으로 사례연구 방법을 채택하였으며, 인터뷰와 직접 관찰, 참여 관찰, 문서 정보 등의 절차를 수행했다. 이 회사의 인적자원 관리 시스템은 뇌과학 연구가 응집된 'SCARF'라는 뇌과학 모델로 설명이 가능하다. 이 회사는 이 모델이 제시하는 것처럼 일터에서 지위감(Status), 확실성(Certainty), 자율감(Autonomy), 관계성(Relatedness), 공정성(Fariness) 위협을 줄임으로써 구성원의 신뢰와 만족도를 제고했고, 이는 창의적이고 고성과 조직이 되는 발판이 되었다.

전단파 속도를 이용한 지하 저류조 주변 지반특성 평가 (Evaluation of ground characteristics near underground rainfall storage facilities using shear wave velocity)

  • 조선아;오태민;조계춘
    • 한국터널지하공간학회 논문집
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    • 제16권2호
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    • pp.225-236
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    • 2014
  • 본 연구에서는 지하 저류조 설치에 따른 주변지반의 지반공학적인 특성(간극비, 전단강도)을 전단파 속도를 이용하여 예측하는 것을 목적으로 하였다. 이를 위해 응력 단계별로 전단파 속도와 밀도 상관관계를 실험을 통해 도출하고 밀도와 전단강도 상관관계를 직접전단실험을 통해 획득하였다. 도출된 응력 단계별 전단파 속도와 밀도 상관관계 및 밀도와 전단강도 상관관계를 바탕으로 현장 전단파 속도를 이용하여 대상 지반의 깊이별 전단 강도를 산정하는 방법을 제시하였으며 제시된 기법을 이용하여 지하 저류조 구조물 적용에 따른 시공후 지반거동을 평가하였다. 제시된 방법으로 도출된 전단강도는 현장실험 결과와 유사한 값을 보이며 지반특성 분석에 적용 가능성을 확인하였다.

초미세입자 제거를 위한 나노세라믹 필터의 성능 평가 (Performance of Nano Ceramic Filter for the Removal of Ultra Fine Particles)

  • 김종원;안영철;이병권;정현재
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.751-756
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    • 2009
  • In the perspective of saving energy in buildings, the high performance of insulation and air tightness for improving the heating and the cooling efficiency, has brought economically positive effects. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and is also very harmful to the residents, because they spend over 90% of their time indoors. Therefore, the ventilation is important to keep the indoor environment clean and it can also save the energy consumption. In this study, a HEPA type nano ceramic filter is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. The double layer filter, which has $30{\mu}m$ in diameter at the conditions of 10wt% of concentration and 3kV/cm of the electric intensity, is produced by electrospinning. The filtration coating technology is confirmed in the solution with $SiO_2$ nano particles using polymer nano fibers. Also double layer filters are coated with $SiO_2$ nano particles and finally the porous construction materials are made by sintering in the electric furnace at $200{\sim}1400^{\circ}C$. The efficiency is measured 96.67% at the particle size of $0.31{\mu}m$, which is slightly lower than HEPA filter. However the efficiency is turned out to be sufficient.

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현장 및 실내조사를 통한 일반국도교량의 화재위험요소 분석 (Investigation of Potential Fire Hazard Resources of Bridges on National Routes by Field and Web-based Satellite)

  • 김용재;김승원;안호준;공정식;박철우
    • 한국도로학회논문집
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    • 제19권6호
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    • pp.105-115
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    • 2017
  • PURPOSES : The occurrence of unexpected disasters, including fire events, increases as the road network becomes complicated and traffic volume increases. When a fire event occurs on and under bridges, the damage extensively influences direct damage to structures, vehicles, and human life and secondary socioeconomic issues owing to traffic blockage. This study investigated potential fire-hazard risks on bridges of the Korean national route road. METHODS : The investigation was conducted using field investigation and analysis with satellite pictures and road views from commercial websites and the Bridge Management System (BMS). From the filed investigation, various potential fire resources were identified. The satellite pictures and road views were helpful in measuring and recognizing conditions underneath bridges, stowage areas, etc. RESULTS : There are various potential fire resources underneath bridges such as piled agricultural products, parked petroleum tanks, construction equipment, and attached high-voltage cables. A total of 94.6% of bridges have underneath clearances of less than 15 m. A bridge underneath volume that can stow a potential fire hazard resource was $7,332m^3$ on average, and most bridges have about $4,000m^3$ of space. Based on the BMS data, the amounts of PSC and steel girders were 29% and 25%, respectively. CONCLUSIONS : It was found that the amount of stowed potential fire hazard resources was proportional to the underneath space of bridges. Most bridges have less than 15 m of vertical clearance that can be considered as a critical value for a bridge fire. The fire risk investigation results should be helpful for developing bridge fire-protection tools.

계측자료를 이용한 흙막이 구조물의 수정된 관리기준치 제안 (Proposal of the Modified Management Criteria Value in Earth Retaining Structure using Measured Data)

  • 김정규;박흥규;남진원
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권1호
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    • pp.95-103
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    • 2016
  • 대다수의 흙막이 공사 계측현장에서 적용하고 있는 절대치 관리방법은 관리기준치와 계측결과를 절대 비교함으로서 공사현장의 안전성을 평가하는 기법이다. 따라서, 안전성 평가의 판단기준이 되는 관리기준치는 평가결과에 직접적으로 영향을 미치게 된다. 즉 아무리 최적의 계측시스템이 적용된 현장이라고 하더라도 관리기준치가 타당하지 않으면, 공사현장의 안전성을 정확히 판단할 수 없으므로 관리기준치의 선정은 매우 중요하다. 그러나 실질적으로 현장 기술자 등은 기존 절대치관리기준치에 대한 신뢰성이 매우 낮으며 관리기준치의 수정보완의 필요성을 인식하고 있다. 이에 본 연구에서는 계측관리기준치의 수정보완 필요성에 대한 조사결과를 바탕으로 하여 흙막이 구조물의 거동 중 가장 기본이 되며 중요한 흙막이 벽체의 변위에 대한 계측결과를 토대로 확률론적 이론에 의해 관리기준치를 보다 적절하게 설정하여 적용하는 연구를 수행하였다. 본 연구에서는 계측관리기법 중 시공 전에 설정된 관리기준치와 시공 시 측정된 설측치를 비교 검토하여 그 시점에서 공사의 안전성을 확인하는 방법인 절대치관리방법을 적용하여 관리기준치를 수정하였다.

성인 여성의 발 형태 분석에 관한 연구 (A Study on Foot Shape of Women)

  • 서추연;석은영
    • 대한가정학회지
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    • 제41권6호
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    • pp.1-12
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    • 2003
  • The purpose of this study were to analyze the anthropometric data of feet of Korean women with aging, to categorize the women's foot shapes, and to compare the shoe size according to the foot shapes in order to provide the basic information for more comfortable shoes. Subjects of this study were 181 women over age 20. They were measured with the direct measurement method and the indirect measurement method. 26 items were measured from the right foot and 6 items were taken on foot outline. Factor analysis, cluster analysis, analysis of variance, post-hoc test, and cross tabs were peformed for statistical analysis of the data by SPSS program. There were significant differences in height items, breadth items, girth items, and angle items by subjects' age. The older subjects' feet were wide and thick with big deformity on toes. The arch height of the older ones was low. This implicates that the degree of deformity on toes, the foot ratio, the foot girth, the foot breath and the arch height as well as the foot length are needed to be considered in developing comfortable shoes. Nine foot construction factors were extracted by the factor analysis of anthropometric measurements; foot size factor, heel and instep factor, malleolus lateralis factor, malleolus medialis factor, foot shape factor, shape of toes factor, heel height factor, big toe height factor, and internal factor. On the basis of the cluster analysis, three different foot shapes were categorized. Type 1 was large and wide foot with little deformity on little toe. Type 2 was medium foot with deformation of big toe, and with the lowest arch height. Type 3 was small and narrow foot with the highest arch height. Distribution of shoe size according to the foot shape was analyzed. The ball of foot breath was of wide distribution than the ball of foot girth. This implicates that girth items and breath items of the foot should be enclosed for the same foot length in the shoe sizing system.

지역 정보 인프라와 기업 경쟁력 강화 방안 (Regional Information Infrastructure and Competitiveness)

  • 김유일;조영복;방호열;장활식;서문식;신종국
    • 한국정보시스템학회지:정보시스템연구
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    • 제8권1호
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    • pp.149-176
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    • 1999
  • Regional information infrastructure(RII) plays an increasingly important role in determining the competitiveness of companies operating within the region. The purposes of this research are (1) to identify the types of RII demanded by the companies operating within Pusan and KyungNam areas in Republic of Korea, (2) to explain the levels of RII demand using variables including organizational environment, organizational strategy, and the importance of information systems for the organization, and (3) to examine whether the types of RII demand are different depending on the competition strategies that companies are pursuing. The most important type of RII that region companies demand is information systems personnel having knowledge in systems control, systems planning, communication network, database administration, and system construction. In addition, demanded are TSDN, satellite communication network, and shareable software and hardware. The levels of RII demand are different depending on the importance of information systems(IS) roles for the businesses. The more important IS role is for a company, the more sharable computing equipments and facilities are demanded. The importance of IS role is affected by the organizational environment and organizational strategy. The levels of RII demand are different also depending on the competitive advantages that companies are pursuing. Companies focusing on achieving short-term and direct benefits using information technology tend to have higher demands on sharable computing equipments and facilities as well as on information communication services. This research is explorative in nature One major limitation of this research, therefore, is that the plausibility of the postulated hypotheses was not examined simultaneously. This research is meaningful in that it first attempted to measure the demands of regional companies for RII.

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Indirect Detection of Internal Defects in Wooden Rafter with Ultrasound

  • Lee, Sang-Joon;Lee, Sangdae;Pang, Sung-Jun;Kim, Chul-Ki;Kim, Kwang-Mo;Kim, Ki-Bok;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • 제41권2호
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    • pp.164-172
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    • 2013
  • The purpose of this research was development of quantitative ultrasonic test methodology for detecting internal defects in members of ancient wooden building. Connection part between wooden members and/or contacted or hidden part by wall of ceiling or other construction materials make it hard to apply direct way of ultrasonic test. So indirect way of ultrasonic test needed to be applied. Test methodology with newly developed prototype of ultrasonic system was proposed. Homogeneous material with polypropylene was also tested for establishing the criterion. Results showed that TOF(time of flight)-energy and pulse length were found out to be proper ultrasonic parameters for predicting depth of defect in wood different from polypropylene. It was not possible to directly apply prediction equation derived from polypropylene. Newly established prediction equation shows coefficient of determination of 0.73 for wood. Finally, defect of replaced rafter members was predicted with the coefficient of determination of 0.32. Various aspects of ultrasound propagation in wood including anisotropy need to be carefully considered to raise up the prediction accuracy.

일상적 창의성과 문제해결능력의 관계에서 공학계열 대학생의 팀워크역량과 자기주도학습력의 이중매개효과 분석 (Analysis of Dual Mediation Effect of Teamwork Competence and Self-Directed Learning Ability between Daily Creativity and Problem Solving Ability of Engineering Students)

  • 배성아;옥승용;노수림
    • 공학교육연구
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    • 제23권6호
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    • pp.17-26
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    • 2020
  • In this paper, the effect of daily creativity of engineering students on problem-solving ability is addressed through the dual mediating effect of teamwork competency and self-directed learning ability. To this end, a regression-based statistical mediation analysis has been performed on the dual mediation model in which daily creativity and problem solving ability were treated as independent and dependent variables respectively, and teamwork competence and self-directed learning ability were included as mediation variables. The analysis result confirmed that the daily creativity has direct effect on the problem-solving ability, as well as indirect effects through teamwork competence and self-directed learning ability. In particular, the serial mediating effect of teamwork competency and self-directed learning ability was also confirmed to be statistically significant in the relationship between daily creativity and problem-solving ability. This verifies that problem-solving ability can be improved not only directly by improving daily creativity but also indirectly by improving teamwork competence and self-directed learning ability. In addition, teamwork competency showed greater indirect effect on problem-solving ability than self-directed learning ability, so increasing teamwork competency has a more significant effect on improving problem-solving ability than increasing self-directed learning ability. Therefore, in order to develop better problem-solving ability, it is necessary to identify and improve the learners' teamwork competency first and to strive to create an environment where learners can solve problems based on mutual trust with their teammates.