• Smart Structures and Systems
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• 제25권5호
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• pp.631-641
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• 2020

To meet the urgent requirements of safety surveillance from civil engineering management authorities, this study proposes a refined and efficient approach to generate full-field high-resolution panorama of construction sites using camera-amounted UAV (Unmanned Aerial Vehicle). GPS (Global Position System) information extraction for pre-registration, feature points filtering for efficient registration and optimal seaming line seeking for fusion are performed in sequence to form the full-field panorama generation framework. Advantages of the proposed method are as follows. First, GPS information can sort images for pre-registration, avoiding inefficient repeated pairwise calculations and matching. Second, the feature points are filtered according to the characteristics of the construction site images to reduce the amount of calculation. The proposed framework is validated on a road construction site and results demonstrate that it can generate an accurate and high-quality full-site panorama for the safety supervision in a much efficient manner.

• Geomechanics and Engineering
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• 제10권4호
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• pp.527-546
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• 2016

This paper discusses improvements of compressibility, permeability, static and liquefaction strengths of in-situ soils by grouting. Both field testing and laboratory evaluation of the on-site samples were conducted. The improvement of soils was influenced by two main factors, i.e., the grout materials and the injection mechanisms introduced by the field grouting. On-site grout mapping revealed the major mechanism was fracturing accompanied with some permeation at deeper zones of sandy soils, where long-gel time suspension grout and solution grout were applied. The study found the compressibility and swelling potential of CL soils at a 0.5 m distance to grout hole could be reduced by 25% and 50%, respectively, due to the grouting. The effect on hydraulic conductivity of the CL soils appeared insignificant. The grouting slightly improved the cohesion of the CL soils by 10~15 kPa, and the friction angle appeared unaffected. The grouting had also improved the cohesion of the on-site SM soils by 10~90 kPa, while influences on the friction angle of soils were uncertain. Liquefaction resistances could be enhanced for the sandy soils within a 2~3 m extent to the grout hole. Average improvements of 40% and 20% on the liquefaction resistance were achievable for the sandy soils for earthquake magnitudes of 6 and ${\geq}7.5$, respectively, by the grouting.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1002-1006
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• 2000

It is diffuse sound field that measuring condition of absorption ratio and sound transmission loss for material consist of building are measured in reverberartion room and on-site. In this study, for upkeeping diffuse sound field in reverberation room, it is measured and etimated that sound field is effected according to sound source lacation and characteristics of emission directivity for sound source.

• 한국건설관리학회논문집
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• 제25권4호
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• pp.15-23
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• 2024

최근에 건설 중인 공동주택 구조물이 분괴하는 등 부실시공이 사회적 이유로 대두되고 있는 실정이다. 부실시공에 대한 원인은 다양하게 있고 요인별 미치는 영향도 다르겠지만 건설회사 시공관리자 측면에서 문제점을 알아보고자 하였다. 따라서 본 연구는 품질·안전문제 해결을 위해 건설현장의 건설회사 시공관리자의 배치에 있어 기술자 경력, 기술자 인원수, 기술자 투입시기 등의 적정성에 대해 알아보고자 한다. 본 연구 수행을 위해 객관적인 의견 조사를 위해 건설사업관리자를 대상으로 설문조사를 실시하였고, 그 결과 건설회사 시공관리자 수를 늘려야 하며, 또한 중간 경력의 시공관리자를 투입하여 실질적 관리가 가능하도록 하여야 하는 것으로 나타났다. 그리고 건설회사의 시공관리자의 계약직을 대폭 축소하는 동시에 안전관리자나 품질관리자와 유사하게 현장 시공관리자 투입인원을 제도적으로 규정할 필요가 있는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1110-1116
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• 2010

Void ratios are one of the key parameters for exact calculation of settlement of soft groundse. In the study, shear wave velocities of a soft ground were used to measure the field void ratio using bender elements sensors. The bender-element probes were installed in situ at the depths of 3, 5 and 8m on a pre-loading site near Incheon, Korea. During 90 days after installation, the changes of shear wave velocity and ground surface settlement were measured. The field void ratio was estimated from measured shear wave velocities. The void ratio estimated by the shear wave velocity measured by bender elements agrees well with the measured values in the field.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.604-609
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• 2005

Runoff characteristics of organic matters and nutrients from greenhouse site in paddy field area were investigated during the irrigation period in 2004. The greenhouse selected which situated near the Nam river, Jinju, Korea used the ground water as the irrigation purpose. And, the rotating system of paddy field to upland was adapted as a cropping system which is a typical practice in this area. Various items such as total phosphorus(T-P), total nitrogen(T-N), dissolved oxygen(DO), BOD, etc. were observed to figure out the seasonal and spatial variation in the study sites. it was found that the risk of water pollution due to the contamination of nutrients in canals in green house sites, and their neighbouring small sized streams are much higher than those in ordinary paddy field areas. Further surveys and investigations are required to find out the counter measures to reduce water pollution occurred in greenhouse sites.

• 한국농공학회논문집
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• 제51권5호
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• pp.101-106
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• 2009

The previous study developed the Filter-Disinfection-Adsorption (FDA) system to provide clean irrigation water for greenhouse cultivation as well as convenience water to farmers. In this study, the field examination was undertaken to assess performance of the FDA system. The field application was made in the suburb of Daegu, one of the large city in Korea. The study area located near by down-stream of Gum-Ho river is suffering low irrigation water quality problems with no water supply service facilities. Four water quality parameters including Suspended Solid (SS), Biological Oxygen Demand (BOD), coliform, and turbidity were selected to test the purification performance of FDA system. Also in order to improve the system, this study investigated the defects of using the FDA system through field monitoring. As results, it was found that this system can be used to supply good quality of irrigation water for greenhouse cultivation and also provide convenience water to farmers in the field areas of no water supply services.

• 한국안전학회지
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• 제27권5호
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• pp.95-98
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• 2012

There are many high-rise apartment building construction in Korea. There was an accident to pass through worker head by rebar dropped from height place. Therefore, low cost-high effectiveness method to prevent this type of accident should be revised and applied into the construction site. This study is to find out which method could be effectively applied to a site with low cost. Practical field test at 4th floor, 10th floor of apartment building site using re-bar diameter D10, D13, D16, D19, D22 with a length of 1 m, 1.5 m, 2 m, 2.5 m, 3 m which are common by used in a site. The test has also been done with a cover of styrofoam thickness 4.5 cm and thickness 9cm on field drop preventing net. One sheet of styrofoam thickness 45 mm has approximately two times stronger than only prevention net, It is found. Also, Two sheets have approximately two times stronger than one sheet of it.

• 한국농공학회논문집
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• 제60권5호
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• pp.95-104
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• 2018

The purpose of this study was to explore the extent of difficulties experienced by facilitators in the rural field forum and to derive a theoretical model for improving the satisfaction of facilitators in the rural field forum. Based on grounded theory, qualitative analysis used data collected through individual in-depth interviews with 10 facilitators who are working at the rural field forum. This collected data was analyzed using the Nvivo 11 program. Using a derived theoretical model, the result of analyzing the difficulties experienced by facilitators in the rural field forum showed the core phenomenon identified as difficulties on-site the forum. There was a clarification of the issues regarding improvement of their labour conditions in order to solve the difficulties on-site the forum. The issues towards improving labour conditions were low allowance, equal assignment, guaranteed four major insurances and so on. The facilitators have been trying to activate the rural field forum by promoting their own capacity through the cooperation between colleagues, post training, seminars, and conferences.

• 융합정보논문지
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• 제10권8호
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• pp.239-249
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• 2020

본 연구는 미용전공 졸업생 205명을 대상으로 미용교육과정 인식이 현장활용성, 직무활용도, 직무만족도에 미치는 영향을 알아보고 전공별 각 요인들의 차이를 분석하는 것을 연구목적으로 설문을 진행하였다. 연구결과 피부는 실습, 기타 전공은 기술적인 면, 실기 테크닉 및 현장감 있는 교육에 대한 요구가 가장 많았고, 모든 전공이 이론<실습 형태의 교육과정, 실습 위주 수업을 요구하였다. 미용교육과정 인식 및 현장활용성이 낮게 나타났고 자격증 교육과정, 직무활용도 및 직무만족도 인식이 낮게 나타났다. 미용교육과정 인식이 현장활용성에 유의한 정(+)의 영향을 나타냈고(p<0.001), 교육내용은 직무활용도 하위요인과 직무만족도에 유의한 정(+)의 영향을 나타냈다(p<0.001). 결론적으로 모든 전공에서 현장활용성, 직무활용도 및 만족도를 높이기 위해 실기교육 보완, 실습 비율 증가 등 교육과정 내용을 개선할 필요성이 있는 것을 알 수 있었다.