• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.197-201
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• 2008

Conceptual cost estimates for domestic highway projects have generally been conducted using governmental unit-price references. Inaccuracies in governmental unit-price data has repeatedly addressed in the Korean construction industry which often lead to poor decision making and cost management practices. Thus, needs for developing a better way of conceptual cost estimating has been widely recognized. This research is considered as the first step in developing such model using real-world cost data based on actual construction activities. The data analyzed in this paper includes 41 P.S.C (Prestressed Concrete) Box bridges which broke into 4 categories based on construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). Actual design documents; including actual cost estimating documents, drawings and specifications were carefully reviewed to effectively break down cost structures for PSC girder bridges. Among more than 40 cost categories for each P.S.C girder bridge type, 7 of them were identified which accounted for more than 95% of total construction cost (ILM: 99.47%, MSS: 99.22%, FSM: 98.18%, and FCM: 98.12%). In order to validate the clustering of cost categories, the variation of each cost category has been investigated which resulted in between -1.16 % and 0.59%.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.28-55
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• 2010

Currently, the natural monument system of Korea for naming and designation of natural monuments is based on "Chosun Natural Monument Conservation Acts for Treasure, Ancient Landmark, and Natural Beauty" enacted in 1934 during Japanese colonization period. The framework of natural monument system is still in effect, which is pointed out as a problem. The Dangsan forests and Bibo forests are Korean traditional cultural resources representing countryside of Korea. Cultural Heritage Administration follows and relies on the 'Limsu of Chosun' (1938), a report written by a Japanese, for naming and classification of natural monuments. A Dangsan forest at Yesong-ri was named "Yesong-ri evergreen forest" in 1938. They followed the naming system of "evergeen forest" until today. The objective of this study is to review the issues and problems of 'Limsu of Chosun' and natural monument naming system begun during Japanese occupation period, and suggest an alternative to the current situation where naming natural monument accordingly without discretion. Eighteen dangsan forests bibo forests were selected for examination and analysis. The names of the dangsan forests bibo forests were evaluated to find out whether various aspects of the forests are reflected in the name. The study suggests that many forests and old trees designated as natural monument should be named as "~Dangsan forest", "~Dangsan forest Bibo forest", or "~Dangsan tree" with consistency accordingly. The new names will bring a momentum to overcome the limitation of natural monument naming system continued since Japanese occupation period, and also enhance the value of Dangsan forests and Bibo forests as Korean traditional and cultural landscapes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.781-790
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• 2013

This research focuses on development of the conceptual cost estimation models for I.L.M box girder bridge. The current conceptual cost estimation for public construction projects is dependent on governmental average unit price references which has been regarded as inaccurate and unreliable by many experts. Therefore, there have been strong demands for developing a better way of conceptual cost estimating methods. This research has proposed three different conceptual cost estimating method for a P.S.C. girder bridge built with the I.L.M method. Model (I) attempts to seek the proper breakdown of standard works that are accountable for more than 95 percentage in total cost and calculates the amount of standard work's materials from the standard section and volume of I.L.M box girder bridge. Model (II) utilizes a correlation analysis (coefficient over 0.6 or more) between breakdown of standard works and input data that would be considered available information in preliminary design phase. Model(III) obtains conceptual estimating through multiple-regression analysis between the breakdown of standard works and all of input data related to them. In order to validate the clustering of coverage in the preliminary design phase, the variation of I.L.M cost coverage from multiple-regression analysis[model(III)] has been investigated which result in between -3.76% and 11.79%, comparing with AACE(Association for the Advancement of Cost Engineering) which informs its variation between -5% and +15% in the design phase. The model proposed from this research are envisioned to be improved to a great distinct if reliable cost date for P.S.C. girder bridges can be continually collected with reasonable accuracies.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.135-142
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• 2020

In the recent farming industry, there is a growing diffusion of drones, which are recognized as a crucial technology of the 4 th industrial revolution to cope with aging. Especially, filming and pest control using drones are representative fields that have different age groups for obtaining a national license of multicopter that is a ultra-light flying device, and can create profits after getting a license. However, pest control technology using drones has different spray effects depending on levels of operational proficiency, since this highly relies on an operator's operating skills. It is anticipated that if this issue is supplemented, the use of drones for pest control in the farming industry will diversify. For analysis of spraying characteristics of agricultural pest control drones, this study aims to formulate effective spraying hours and effective spraying intervals and suggest an algorithm, which facilitates an accurate calculation of pest control area depending on the kinds of pest control drones. This algorithm can be used in the field of pest control by improving scatterling issues caused by drone flight methods of drone pest controllers and building an optimum pest control manual in future.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.969-974
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• 2008

This study was carried out to investigate the service life of reinforced concrete structures for durability design. The service life has three aspects physical service life, functional service life, and social service life, and that a structures are normally demolished to end its service life when either the functional or social service life is over before the physical service life comes to end an end. In the future, it is very important that durability design shall be performed establishing design service life and the unallowable state of deterioration in the course of design service life.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.95-103
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• 2009

The case of rivers facilities works, expense the standard unit cost for the quality and a rough public corporation expense estimating of the rivers public corporation which is fixed form with the information available which it follows basic design phase absently and possibility of fluctuation. It exists many difficulties in rough public corporation expense estimating. The rivers public corporation expense rough estimating method of existing produces does not exist the amount of material of representative section of the rivers dike and the rough public corporation expense estimating method which is systematic with the method which multiples the seniority (M). The research sees the rough public corporation expense predictive model from the planning stage which is not basic design to consider the quality of the rivers facility public corporation. From this study, it can prevent the waste of national budget from the general public corporation and is more accurate and public corporation expense production possibly.

• 월간 기계설비
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• s.292
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• pp.70-78
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• 2014

가락동 농수산물도매시장은 지난 1985년 개설된 국내 최초 공영도매시장이자 연간 230만톤 거래 규모의 세계 최대 도매시장으로 서울시민 농수산 먹거리의 약 50%를 담당하고 있으며 전국 공영도매시장 물량의 약 33%를 처리하는 등 전국 농수산물 유통의 중추 기능을 담당하고 있다. 가락시장은 5,000여개 유통업체가 영업 중이며 하루 이용객은 13만명, 출입차량은 6만7,000대에 달할 정도로 과부하를 겪고 있다. 또한 도시 주거환경을 저해하는 혐오시설로 치부돼 이전 압박을 받아왔으며 전반적인 시설 노후화와 유통 수요에 부적합한 물류구조, 주변 교통정체 야기 등의 문제로 시설현대화 필요성도 제기되어 왔다. 이에 따라 서울시농수산식품공사가 지난 2009년 재건축을 통한 시설현대화 사업을 발표하고 기존의 시장 기능을 유지하면서 재건축을 하는 순환식 시설현대화 사업을 3단계(당초 계획은 2009년~2018년까지 10년 예상했으나 가락시장 계획변경 타당성 검토용역 결과에 따라 2025년까지 지연될 것으로 예상됨)에 걸쳐 추진키로 했다. 이에 따라 1단계 사업은 지난 2011년 6월부터 진행되어 2015년 2월 준공 예정이다. 본지는 가락시장 시설현대화 1단계 공사에서 기계설비 및 소방공사를 담당한 (주)성아테크(대표 정해돈) 이완식 현장소장과 시공사인 대림산업(주) 박승재 현장소장을 만나 현장 이야기를 들어 보았다.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.1-7
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• 2010

Rural facilities need to be changed to be industrialized and long span structures due to accelerating aging of the rural population. In this study, the optimized structure was developed by applying Pre-Engineered Building System using the tapered member to make that the Korea standard green house has a long span. When considering design load, reasonable values were adapted by reviewing existing design codes. As a result, applying pre-engineered building system was efficient in structural system that has span longer than 16 m. And it was concluded that the increase with the longitudinal span from 4 m to 12 m was more efficient in aspect of steel amount.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.190-191
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• 2016

국제 핵융합실험로인 ITER 장치의 초전도자석 전원장치용 CCU/L(Correction Coil Upper/Lower), CCS(Correction Coil Side) 그리고 VS1($1^{st}$ Vertical Stabilization) 형식 등 각 변압기 초도품의 제작을 완료하고 공장시험(FAT, Factory Acceptance Test)을 실시하였다. 이 변압기들은 각 형식별로 2대에서 6대를 제작하지만 각 형식별 초도품 1대에 대해서는 Type Test를 실시하고 나머지 후속물량에 대해서는 Routine Test로 공장시험을 실시하도록 계획되어 있다. 따라서 이 초도품 변압기들에 대해서는 Type Test로 공장시험으로 실시하였고, 그 대표적인 시험항목으로는 단락시험, %임피던스 시험, 뇌임펄스 시험, 정격전류 온도상승시험, 상용주파수 내전압시험 등이 있다. 이들 중 CCU/L, CCS 각 형식의 초도품에 대해서는 2015년도 공장시험을 실시하여 요건에 부합됨을 확인하였고, 본 논문에서는 VS1 컨버터 변압기 초도품에 대하여 Type Test로 실시한 공장시험 내용과 그 결과를 보여준다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.705-716
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• 2017

As many environmental pollution problems have arisen, various studies related to the environmental evaluation have been carried out in the construction industry. However, there is no methodology for estimating the environmental load quickly for design alternatives of civil facilities in the design phase. This study aim to establish criteria of works information and designed parts which can efficiently estimate environmental loads of PSC beam bridge based on standard quantity at the early design phase. For this purpose, a detailed environmental loads database was constructed by performing Life Cycle Assessment (LCA) based on detailed design data of 25 bridges. In addition, major work with high impact on environmental load were selected, and the analysis of characteristics of environmental load according to the required materials and 8 impact categories were conducted. As a result, the superstructure accounted for 42.91%. In the superstructure, remicon of the material base and PSC beam work occupied 53.13% and 31.25%. In the substructure, remicon, rebar, and cement, which are material base, accounted for more than 93%. It is expected that this major work and material information for each part of bridge can be utilized in the construction of the model, which can estimate the approximate environmental load, reflecting the characteristics of the structure in the design phase.