• 한국건설관리학회논문집
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• 제8권4호
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• pp.155-166
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• 2007

본 연구는 건축공사 프로젝트의 기본 설계 단계에서의 개산견적 개념모델을 제안하고, 제안된 개산견적 개념을 적용하여 실제 주상복합 건물 프로젝트의 실적자료의 분석을 바탕으로 한 프로토타입 개발을 목적으로 한다. 국내의 건설산업은 급격한 시장 변화와 경쟁 심화의 과정을 겪고 있다. 특히 프로젝트의 조달 방식의 변화와 함께 입찰과 관련한 정보가 부족한 사업초기, 기본설계 단계에서 중요한 의사 결정이 이루어지며, 이러한 의사 결정의 기준이 되는 개산 견적의 중요성이 더욱 증가 되고 있다. 따라서 본 연구에서는 기존의 개산견적 방법을 분석하고 그것을 보완할 수 있는 공사 수량 변화 분석에 기반 한 개산견적 방법을 제안하고 프로토타입을 구축하였다. 또한, 이 연구에서는 기존의 공종별 공사비 분류체계에 빌딩구성요소(BE)별 및 층별 수량 분류를 추가하고 있다. 이러한 개념을 바탕으로 제안 모델을 Q-BASE (Quantity Based Active Schematic Estimating) 모델로 정의하였다.

• 한국산림과학회지
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• 제103권1호
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• pp.122-128
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• 2014

본 연구는 산마늘 노지재배와 임간재배의 수익성 차이를 비교 분석하고, 산마늘 임간재배가 앞으로 나가야할 방향을 제시하고자 수행되었다. 강원도, 충북, 전남, 경북지역에서 12명의 산마늘 재배자를 대상으로 작업공정별 투입인력 및 비용 등에 관해 심층면접설문조사를 실시하였다. 그 결과를 바탕으로 수익성 분석기법인 IRR, B/C ratio, NPV를 이용해 투자수익성을 분석하였다. 임간재배 산마늘의 판매가격 25,000원/kg과 노지재배 산마늘의 판매가격 15,000원/kg을 적용하여 분석한 결과 각각 IRR 36.2%과 54.2%로 나타나 산마늘 노지재배의 수익성이 더 큰 것으로 분석되었다. 산마늘 임간재배의 수익성이 다른 산림단기소득작물과 비교해도 결코 낮은 수준이 아니며, 집약재배를 위한 기술개발이 뒷받침된다면 노지재배 못지않게 높은 수익을 올릴 수 있을 것이다.

• 한국건축시공학회지
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• 제4권1호
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• pp.89-96
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• 2004

Porous concrete is used of various parts by advantage of porous. Example of growing of plant is possible, and dwelling of creature, and filter functions of various contaminant, and decrease of noise, and so on. This research is for porous concretes that were used by four aggregate rubble, refreshing aggregate, expanded clay, orchid stone. This research estimate that physical and mechanical characteristics of fresh concrete and hardened concrete. The purpose of this research is to make environment-friendly porous concrete. This research's conclusion is as following : 1. Porous Concrete's slump was measured 12~14cm with rubble, 12~16cm with refreshing aggregate, 11~13cm with expanded clay, 11~13cm with orchid stone. Weight of aggregate was bigger, slump price appeared by bigger thing. Because placed Porous Concrete is low viscosity and small resistance between aggregate, it estimated that have high workability. 2. Porous Concrete's unit weight was measured 1.71~1.75t/$\textrm{m}^3$ with rubble, 1.58~1.62t/$\textrm{m}^3$ with refreshing aggregate, 1.19~1.20t/$\textrm{m}^3$ with expanded clay, 0.98~1.06t/$\textrm{m}^3$ with orchid stone. Showed aspect such as weight of aggregate. 3. Porous Concrete's compressive strength was measured 76~102kgf/$\textrm{cm}^2$ with rubble, 51~60kgf/$\textrm{cm}^2$ with refreshing aggregate, 30~40kgf/$\textrm{cm}^2$ with expanded clay, 13~16kgf/$\textrm{cm}^2$ with orchid stone. 4. Tendency of tensile strength and bending strength showed generally similarly with compressive strength, but showed low value fewer than 15kgf/$\textrm{cm}^2$ Therefore, wire mesh, reinforcing rod, such as establishment of frame is considered to need in reinforcement about tensility or flexures in case receive tensility or produce product of thin absence form. It concludes by speculating on the consequences of extrapolating the results of study to remodelling the office building being already existence.

• 한국작물학회지
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• 제31권2호
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• pp.231-237
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• 1986

향미종 연초 재배에서 재식밀도 및 질소 시비량에 따른 생육특성 및 수량, kg당 가격과 향미종 연초의 특징인 휘발성 유기산 함량의 관계를 분석, 재배법에 활용코자 시험한 결과, 1. 10 a당 13,885주에서 24,997주로 밀식할수록, 주당 생장량은 감소하나 LAI는 증가하였으며 수량은 21.875주까지 유의성 없이 증가하였으나 그 이하에서는 증가를 보이지 않았다. 2. 10a 당 질소 시비량을 1.5, 3.0, 4.5kg 증비 할수록 주당 생장량, 잎의 크기 및 LAI가 증가하고 수량 및 kg당 가격이 유의하게 증가하는 경향이였다. 3. 발뢰 7 일 전 엽중 질소 함량은 처리간 차를 나타냈으나, 건조엽중의 질소, 환원당, 니코딘 함량에서는 재식밀도 및 질소수준간 일정한 경향을 보이지 않았다. 4. 초장 및 엽의 크기가 작을수록 건조엽중 2-methyl butanoic, 3- methyl butanoic 및 3- methyl pentanoic acid의 함량이 높은 경향이었으며, 5. 건조엽중 휘발성 유기산 함량과 개화기의 초장(r=-0.49), 최대엽장(r=-049), 일주당 엽면적(r=-0.47)은 유의한 부의 상관을 보였다. LAI 및 단위엽면적당과는 각각 유의한 상관을 보이지 않았다.

• 전기학회논문지
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• 제65권2호
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• pp.360-364
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• 2016

The rare earth output is concentrated in limited number of countries including China. Also the necessity for development of non-rare earth motor is getting signified due to the rapid increase of rare earth price and resource weaponizing policies. Non-rare earth motor is generally designed as spoke type PMSM (Permanent Magnet Synchronous Motor) in order to maximize the power density. Such spoke type PMSM has advantage in concentrating the flux but demonstrates lower efficiency compared to permanent magnet using Nd (Neodymium) permanent magnet. Therefore, applications with strong necessity for efficiency need rotor structure having improved efficiency compared to spoke type PMSM. Hence, this study suggested fan-shape type PMSM with somewhat lower power density but maximized efficiency. Fan-shape type PMSM is a rotor shape demonstrating outstanding reduction of iron loss compared to existing spoke type. Thus, this study analyzed the improvement of efficiency and reduction of loss arising from the suggested shape through parameter calculation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.414-415
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• 2005

A solar cell is an element to transform the solar light energy into the electric energy in a moment. The single crystal element of high quality on which many studies were conducted in the past has a high efficiency of energy transformation, but its price competitiveness is so poor that it has failed to be popularized However, recently, in terms of an environment-friendly alternative energy, studies on applicability of the polycrystal solar cell have been actively under way. Among subject substances for such solar cell, $CuInSe_2$ has several good physical properties so that the greatest attention is paid to it as an optical absorption layer material for a low-cost solar cell of high efficiency. In order to manufacture the $CuInSe_2$ compound thin film, the unit element was deposited by using the sputtering method and the evaporation method and the heat treatment process was used in an electric furnace. Thereby, we intended to get a single-phase $CuInSe_2$ compound thin film.

• 한국농공학회논문집
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• 제61권6호
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• pp.1-8
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• 2019

Carbon dioxide is one of the major driving forces causing climate changes, and many countries have been trying to reduce carbon dioxide emissions from various sources. Soil stores more carbon dioxide(two to three times) amounts than atmosphere indicating that soil organic carbon emission management are a pivotal issue. In this study, we developed a Soil Organic Carbon(SOC) storage estimation model to predict SOC storage amounts in soils. Also, SOC storage values were assessed based on the carbon emission price provided from Republic Of Korea(ROK). Here, the SOC model calculated the soil hydraulic properties based on the soil physical and chemical information. Base on the calculated the soil hydraulic properties and the soil physical chemical information, SOC storage amounts were estimated. In validation, the estimated SOC storage amounts were 486,696 tons($3.526kg/m^2$) in Jindo-gun and shown similarly compared to the previous literature review. These results supported the robustness of our SOC model in estimating SOC storage amounts. The total SOC storage amount in ROK was 305 Mt, and the SOC amount at Gyeongsangbuk-do were relatively higher than other regions. But the SOC storage amount(per unit) was highest in Jeju island indicating that volcanic ashes might influence on the relatively higher SOC amount. Based on these results, the SOC storage value was shown as 8.4 trillion won in ROK. Even though our SOC model was not fully validated due to lacks of measured SOC data, our approach can be useful for policy-makers in reducing soil organic carbon emission from soils against climate changes.

• 한국정보기술학회논문지
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• 제16권12호
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• pp.127-137
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• 2018

가축의 분만은 농가의 재산을 늘릴 수 있는 중요한 수단이므로 이를 관리하는 것은 농업 경영에 필수적인 항목이다. 특히 축우는 다른 가축에 비해 단가가 높고, 생산성 측면에서 농가의 소득과 밀접히 연관되어 있으며 축우의 42%는 밤에 분만이 이루어지고 있어 정확한 분만 예측은 더 중요하다고 할 수 있다. 그리하여 본 논문에서는 경구 투여용 센서를 통해 반추위 내의 심부 체온을 외부 환경의 간섭 없이 안정적으로 실시간 측정하고 이를 딥러닝에 적용함으로써 분만 시점을 예측하는 방법을 제안 하였고, 실제 축우를 대상으로 실험을 수행한 결과 실제 분만 시간 대비 평균 3시간 40분의 오차만 보여 기존 분만 예측 방법보다 정확하게 분만일을 예측하는 것을 확인하였다. 제안하는 방법을 통해 축우의 분만을 정확하게 예측하여 난산의 위험 없이 성공적으로 분만 하도록 도움을 줌으로써 농가의 경제적 피해를 절감할 수 있을 것으로 기대한다.

• 한국기계가공학회지
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• 제18권7호
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• pp.83-89
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• 2019

In the conventional casting and forging method, there is a disadvantage that a mold is an essential addition, and a production cost is increased when a small quantity is produced. In order to overcome this disadvantage, a metal 3D printing production method capable of directly forming a shape without a mold frame is mainly used. In particular, overseas research has been conducted on various materials, one of which is a metal printer. Similarly, domestic companies are also concentrating on the metal printer market. However, In this case of the conventional metal 3D printing method, it is difficult to meet the needs of the industry because of the high cost of materials, equipment and maintenance for product strength and production. To compensate for these weaknesses, printers have been developed that can be manufactured using sand mold, but they are not accessible to the printer company and are expensive to machine. Therefore, it is necessary to supply three-dimensional casting printers capable of metal molding by producing molds instead of conventional metal 3D printing methods. In this study, we intend to reduce the unit price by replacing the printing method used in the sand casting printer with the FDM method. In addition, Ag paste is used to design the output conditions and enable ceramic printing.

• 대한건축학회논문집:계획계
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• 제35권11호
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• pp.53-60
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• 2019

Multi-unit house, multi-household house, row house and apartments with less than 500 households were included in the list of anti-crime for buildings following the revision of the "notice of crime prevention building standards" on July 31, 2019. Strengthening the performance of crime prevention buildings is inevitable to increase the cost of building construction, including installation of preventive facilities and use of facilities that have secured performance. Thus an economic analysis on the costs and expected benefits of implementing the standards is required for social consensus. Economic analysis is divided into cost analysis and benefit analysis. This study aims to perform an economic analysis on the installation of crime prevention facilities in the buildings subject to expanded crime prevention obligations. Cost analysis is calculated as the sum of the cost of installation and the price of the crime prevention facilities installed for each target residential building. Benefit analysis is calculated as the social cost of targeted crimes that are expected to decrease due to the installation of crime prevention facilities. Economic analysis shows that the total cost of installing crime prevention facilities in residential buildings is estimated at 107.31 billion won per year, while the total benefit from enhanced crime prevention performance is estimated at 9.38 billion won per year. Considering inflation, benefits are expected to outpace costs in the 28th year since the system was implemented.