• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.88-95
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• 2001

To convert the construction industry from 'the high cost, the low efficiency' to 'the low cost, the high efficiency and value-added industry' and to enhance the performance and quality of products while reducing the cost, the related law and guideline were established and promulgated, which regulate that value engineering workshop during the preliminary design and the detail design stage should be a mandatory process. But VE practitioners are still confusing in choosing the proper value engineering process, because processes those are described in the various references use the different terms, steps and activities, even though they have their own specific characteristics. To resolve these confusions, the existing steps and activities of three kinds of the literature, four kinds of the organization's policy and other four kinds of study examples relating to the design VE were examined. And then, the differences and expecting problems were extracted through the comparison and analysis of those materials. After that, VE specialists' opinion through the questionnaire survey were grasped. Based on those studies the improved design VE Job Plan and activity statements were suggested.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.222-227
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• 2001

Full scale construction tests of CFT(concrete filled steel tube) column to solve construction problem and to confirm quality were performed in apartment site. To improve construction efficiency, the tests has been accomplished two stages after the tests for material mixing design had been completed. In the first stage, the experimental variables were the placing methods, existence of guiding pipe, placing velocity and drop height and the height of specimen were $3.6{\cal}m$. In the second stage, Filling steel tube of 9.6m height with concrete was performed by two ways, that is, the pump-up method and the dropping method. The filled condition of the concrete and concrete strength distribution according to the column height were checked and the quality of the CFT column was confirmed.

• Korean Journal of Construction Engineering and Management
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• v.8 no.2
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• pp.68-74
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• 2007

It has been recognized that safety management is activated during the construction phase to prevent accidents and fatalities of workers. However, It is revealed that about 15% of fatal death accidents is caused by the lack of management of planning and design phases. There is a crucial need of assessing safety risk during building design phase. This paper is aimed to develop a safety risk assessment checklist that can be used during building design phase, utilizing the concept of Design for Safety. In doing so, a broad literature survey on safety management of building Process, various safety risk assessment toolboxes being utilized in the HSE and the BAA of UK. The proposed checklist contains the followings: 1) classification structure for safety design on space, element, and trade work 2) hazard risk factor, probability and degree of intensity of accident occurrence, and 3) safety assessment criteria. It is expected that the checklist would be an effective tool of preventing and minimizing fatal accidents of building construction projects.

• Journal of the Korean Geotechnical Society
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• v.20 no.3
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• pp.97-106
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• 2004

In case of tunnel construction with a shallow soil cover in cohesionless soils or highly weathered rocks, reinforcement measures are required for a tunnel stability during the tunnel construction. Recent developments show that the use of Umbrella Arch Method(UAM) as tunnel reinforcement and water cut-off in domestic projects has increased. Unfortunately, guidelines for the design and construction of UAM have not been established, only empirical designs and applications in tunnel construction have been performed so far. In this study, behaviour of the steel pipes installed on the tunnel roof was analyzed through the monitoring of bending and axial stresses of the pipes with the advance of the tunnel face. The monitoring results were used in the establishment of the loading mechanism around the pipe. This paper suggests, the guidelines used in the determination of the total length, overlapping length and lateral spacing of the reinforcing pipes obtained from the established loading mechanism.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.231-235
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• 2015

The characteristics of binderless briquettes for dried low-rank coal was studied in this work. Two kinds of Indonesian coals were used to briquette after drying them in electric oven. The characteristics of briquettes have been examined by moisture contents, particle size, hydraulic force, and storing period. The optimum moisture contents of briquettes were observed at between 10 wt% and 15 wt%. The strength of coal briquette was stronger as particle size became smaller. The strength of coal briquette was proportional to the hydraulic force under 300 kN, whereas there was little difference among the briquettes made at more than 300 kN of hydraulic force. The strength of briquettes sharply decreased for a week after produced, and then showed the tendency of converging. The results from this work can be a useful guideline of manufacturing and managing upgraded coal briquettes.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.69-83
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• 2020

Light olefins are important petrochemicals as well as primary building blocks for various chemical intermediates. As the number of ethane cracking center (ECC) process, in which ethylene accounts for most of the production, has increased in recent years, propylene supply is not catching up with steadily increasing propylene demand. This trend makes the conversion of methanol to olefins to get more industrial importance. The methanol to olefins (MTO) process produces methanol through syngas and obtain olefins such as propylene through methanol. Since the reaction from methanol to olefins provides different product compositions depending on the catalyst used for the reaction, it is important to choose an appropriate separation process for the reaction product with different composition. Four different separation processes are considered for four representative cases of product compositions. The separation processes for the reaction products are evaluated by techno-economic analysis based on the simulation results using Aspen plus. Guidelines are provided for selecting a suitable separation process for each of representative case of product compositions in the MTO process.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.604-610
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• 2018

Recently, due to the rapid growth of the leisure industry, demand for small-scale flotation and mooring pontoon platforms has been increasing rapidly. Standard rules for the design and structural safety of such structures have become necessary. This paper provides criteria that can be referenced when designing pontoon platforms, and also introduces structural safety evaluation procedures. In this study, the structural safety and stability of a 15-meter pontoon platform were investigated through structural design and finite element analysis. For platforms of less than 10 meters in length, a simple structural calculation can be used, but for platforms over 10 meters, a detailed structural strength review must be considered to meet safety guidelines defined in existing regulations. The structural strength of the initial design was examined and its structural safety was verified. For future research, it is an evaluative system was developed that can be used to examine the various loading conditions during design.

• Proceedings of the KOR-BRONCHOESO Conference
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• 2003.09a
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• pp.108-108
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• 2003

식도 천공의 치료는 최근 치료법의 발전에도 불구하고 여전히 난해한 문제이다. 이 환자들은 천공의 원인이나 위치, 심한 정도가 다양한 이질적인 군이며, 반수 이상이 이미 식도에 기존의 질환을 가지고 있어 문제를 더욱 복잡하게 한다. 따라서 절대적이고 획일적인 치료방법은 아직 확립되어 있지 않으며 많은 다양한 방법들이 제시되고 있다. 2002년 11월부터 2003년 7월까지 총 8명의 환자가 식도 천공으로 동아대학교병원 흥부외과에서 치료를 받았으며, 원인별로는 의인성(iatrogenic) 손상이 6례, 자발성(spontaneous) 손상이 2례였고 부위별로는 경부가 3례, 흥부가 5례였다. 의인성 손상에는 내시경 검사중 정상 경부 식도에 발생한 1례, 부식성 식도협착 환자의 풍선 확장술과 스텐트 삽입시 흉부 식도에 발생한 경우가 각각 1례씩, 외상성 경추손상의 수술시 정상 경부 식도에 발생한 경우가 2례, 선천성 식도폐쇄증(esophageal atresia)의 술후 문합부 누출이 생긴 경우가 1례 있었으며, 자발성 손상에는 하부식도에 발생한 기압성(barogenic) 손상 1례와 상흉부 식도암 천공 1례가 있었다. 경부 식도 천공 3례는 모두 경부 배액(drainage)과 식이용 장루술(feeding jejunostomy)을 시행하였고, 부식성 식도협착이 있던 환자 2례는 식도절제술과 흉부내 식도-위 문합을 시행하였으며, Boerhaave씨 증후군 환자는 1차 봉합술, 술후 문합부 유출이 있었던 환자와 식도암 천공이 있었던 환자는 식도절제 및 경부 식도루(esophagostomy), 배액용 위루(gastrostomy), 식이용 장루술을 시행하였다. 모든 환자는 패혈증 등의 심각한 합병증으로의 진행 없이 회복되었다. 현재 위장관의 연속성이 유지 혹은 복원된 환자는 경구식이 중이며 그 외의 환자들은 장루를 통해 영양을 공급하며 식도재건술을 기다리고 있다. 식도 천공은 최근 항생제의 사용, 과영양요법(hyperalimentation), 술후 환자관리의 개선 등으로 치료에 많은 발전이 있었으나, 치료 방침에 있어서는 여전히 논란이 있으며 높은 사망률을 보이는 난제로 남아있다. 비록 일반적인 지침이 도움이 되겠지만, 치료 방침은 환자 개개인의 상황에 따라 적절하게 선택해야 하며, 임상경과에 따라 언제라도 방침을 변경할 수 있는 유연함이 필요하리라 생각한다.

• Geophysics and Geophysical Exploration
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• v.9 no.2
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• pp.148-154
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• 2006

The effect of small-scale near surface inhomogeneity on Rayleigh wave propagation and dispersion has been investigated in this study using two-dimensional FEM elastic modeling. Various inhomogeneity models with a variety of geometrical shape and embedment depth which exist in homogeneous half-space and two-layered media are considered. Results show that any near surface inhomogeneity greater than one wavelength in terms of minimum wavelength of Rayleigh wave shows dispersion characteristics. Such dispersion effect become stronger as the dimensions of the inhomogeneity increase. The effect of horizontal dimension is more dominant factor governing the dispersion characteristics than vertical dimension. However, the dispersion effect can not be identifiable in seismogram if the horizontal dimension is not wide enough. Nonetheless, even in this case, the existence of inhomogeneity can be inferred by the reflection or transmission event of Rayleigh wave. The results can be expected to provide insights on the behavior of Rayleigh wave which may be helpful for designating field work or new processing scheme to detect near surface inhomogeneity by surface wave method.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.339-351
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• 2016

Comprehensive Understanding of the Double-sidedness of Sexual Fantasy: focused on disability, crime and treatment. This study was to understand the double-sidedness of sexual fantasy. First, definition of normal sexual fantasy and abnormal sexual fantasy in former researches is discussed. Secondly, sexual fantasy's role as a risk factor in the context of obsessional discomfort or sexual crime. Thirdly, guideline and principle when using sexual fantasy as a tool of treatment. Fourthly, measuring and evaluating tools of sexual fantasy were reviewed and necessity of developing new scale was proposed. In addition, summary and ideas for further research were suggested.