• 대기
• /
• 제29권2호
• /
• pp.213-218
• /
• 2019

A valuation of air pollution is critical for relevant policy-making for the public and research direction. This study conducted a willingness-to-pay (WTP) survey using contingent valuation method (CVM) in Seoul Korea. In detail, this study puts an emphasis on its temporal changes referred on two surveys conducted in 2014 and 2019. In reference to the previous studies in 2002, our survey indicated that the public awareness of air pollution and interests on its sources and solutions increased noticeably. Our survey showed that WTP increased significantly from 2588 to 4827 and 8240 Korean Won $month^{-1}$ in 2002, 2014, and 2019, respectively. Moreover, the percentage of respondents to pay the WTP also increased from 48% to 68% and 79% in 2002, 2014, and 2019, respectively. Our analysis based on the number of Google search on particulate matters (PMs) strongly suggests that such the noticeable increases of the public attention to air pollution is well accorded with the moment of the announcement of a standard for ultra-fine particles and the start of PM prediction in late 2013. But the Google search rate grew about 16.7 times in 2009 compared to 2014, which is much larger than the growth rate of interest and WTP between 2014 and 2019. Our results shed light on policy decision for the right person in the right place on the right time in the era of air pollution.

• 대한건축학회논문집:구조계
• /
• 제36권4호
• /
• pp.153-161
• /
• 2020

This study investigates the recycling potential of demolition waste (DW) according to building structure, while considering economic aspects. For that, this study surveyed 1,034 residential buildings to collect reliable information on demolition waste generation rates (DWGRs). This study suggested a method for operational cost calculation for each stage and carried out an inventory analysis. The economic value of recycled DW materials was also calculated. And then, the recycling potential(RP) was calculated by building structures and waste types. RP by building structure was low (27-40%), and RP was found in the order of masonry-block, wooden, RC and concrete-brick. By type of DWs, the RP of aggregates was considerably lower than 7%, and DWs such as wood, plastics, and metals showed more than 100% RP. Considering the results of this study, In order to improve the RP of buildings and DWs, the diversification of products that recycled waste like aggregates (i.e., mortar, concrete, bricks, blocks, tiles) and the development of high value-added products are considered to be the most urgent problems. Based on the above RP results, this study proposed a more advanced method for life cycle assessment of buildings and demolition waste.

• 대한건축학회논문집:구조계
• /
• 제34권2호
• /
• pp.57-66
• /
• 2018

When developing projects to build facilities to be shared by both military bases and surrounding communities, strategies are needed to achieve two objectives: 1) minimize missteps and opposition from local communities in the process of developing and implementing such projects, and 2) promote cost-benefit optimization and user-satisfaction. With aim of promoting co-operation and co-existence between military bases and adjust communities, this research proposes esthetical factors to be considered in conceiving civil-military sharing facilities. It seeks experts' opinions on the development of civil-military sharing facilities, and examines critical factors (economic feasibility, security, and satisfaction, etc.) for project development as well as building types suitable for shared-use between military bases and local residents. It then establishes a method to prioritize facility-type and narrow down design factors (considerations and restrictions) in project development by applying quantitative analysis. The methodological approach of the research employs the Delphi survey method to quantitatively analyze qualitative information drawn from experts' opinions. At the first round of the survey, facility types, items for consideration and restrictions are drawn, and then at the second round of the survey, criticality of each item is analyzed. Finally, it reaches a conclusion on suitability of facility types for civil-military sharing facilities, and selects project considerations and restrictions when developing this kind of project.

• 한국산학기술학회논문지
• /
• 제14권4호
• /
• pp.1896-1902
• /
• 2013

무기체계에 상용부품을 적용하는 개념인 COTS (Commercial-Off-The-Shelf)는 국방기술이 민수기술을 선도하던 시기에 크게 호응을 얻지 못했다. 그러나 IT기술의 급속한 성장과 민수산업의 빠른 확장은 짧은 시간에 저가의 대량생산 체계를 갖추게 되었고, 비용과 일정의 장점이 부각되면서 민수분야에 생산되는 부품들이 무기체계에 적용되었다. 민수기술이 국방 무기체계에 사용되기 위해서는 전투 환경의 극한 제약사항에서 성능을 보장할 수 있어야 한다. 일반적으로 상용부품은 설계 및 생산에 대한 요구조건이 군용과 비교하여 다르기 때문에 근본적인 한계가 있다. 따라서, 상용부품이 무기체계에 사용되기 위해서는 시스템공학적 접근을 통한 확인이 요구된다. 본 연구에서는 무기체계에 COTS를 적용하기 위한 방안으로 해양 무기체계 특성에 적합한 프로세스와 제약사항 분석방안을 제시하였다. 해양 무기체계의 제약사항을 일반 환경 및 특수 환경 제약사항으로 구분하고 세부적인 프로세스를 제시하였으며, 시장에서 이러한 제약사항에 적합한 제품을 선택할 때 유용한 도구를 제시하였다. 마지막으로 COTS의 해양 무기체계 적용을 위한 사례연구로 전투함 전기시스템의 COTS 적용 및 제약사항 분석 결과를 확인하였다.

• 한국사회복지학
• /
• 제62권2호
• /
• pp.187-208
• /
• 2010

본 논문의 목적은 1980, 90년대 독일의 '경과적 일자리 중심 노동통합형 사회적기업'이 공공부문의 재정건실화라는 의도를 통해 확대되는 현상을 분석하는 데 있다. 이를 위해 우선 독일 2차 노동시장의 개념과 유형을 고찰하고 2차 노동시장이 80년대 이 후 공공부문의 일자리창출 인프라로 지역사회에 정착되게 되는 과정을 분석하였다. 다음으로 2차 노동시장의 사회적기업이 공공부문의 재정건실화에 기여하고 있는 바를 기이센의 사례를 통해 <비용-편익> 분석으로 시도하였다. 마지막으로 독일의 경과적 일자리 중심 노동통합형 사회적 기업이 실업자 사회안전망으로 갖는 한계와 잠재력을 '공공부문으로의 종속화'와 '과도(過渡)노동시장의 형성'이라는 측면에서 논의하였다.

• 품질경영학회지
• /
• 제43권4호
• /
• pp.589-606
• /
• 2015

Purpose: In developing new products, reducing performance variation is important for competitiveness factors such as quality, cost, and delivery. This paper aims at evaluating three performance variations; measurement, performance evaluation, and manufacturing variations, and then improving product and process design, focused on paper helicopter making case study. Methods: For measurement system analysis, gage R&R (repeatability and reproducibility), linearity, stability are evaluated. Since gage R&R are not satisfactory, the measurement system is improved by adopting voice memos application of iPhone and providing standard measurement procedure. To evaluate performance variation, product deterioration and environment factor (wind speed) is considered. Since the existing design is sensitive to these noise factors, a new product design is developed, which is proven to be robust to the noise factors. Finally, manufacturing variations are evaluated with five factors which can cause variation in flight time. To reduce the impact of three significant factors, three improvement methods are applied. Results: Three performance variations are evaluated and robust paper helicopter design is presented. Conclusion: To reduce measurement and process variations, improved measurement method and paper helicopter making procedure are proposed. A new product design is also presented which is robust to deterioration and environmental variation. This paper is expected to benefit students and practitioners who want to have hands-on knowledge on new product quality improvement.

• Structural Engineering and Mechanics
• /
• 제78권4호
• /
• pp.473-484
• /
• 2021

Similar to other structures, ultimate strength values showing the maximum load that the structure can resist without damaging has great importance on ships. Therefore, increasing the ultimate strength values will be an important benefit for the structure. Low carbon steels used in ships due to their low cost and good weldability. Improving the ultimate strength values without interfering with the chemical composition to prevent of the weldability properties of these steels would be very beneficial for ships. Grain refinement via severe plastic deformation (SPD) is an essential strengthening mechanism without changing the chemical composition of metallic materials. Among SPD methods, equal channel angular pressing (ECAP) is one of the most commonly used one due to its capacity for achieving bulk ultrafine-grained (UFG) materials. When the literature is examined, it is seen that there is no study about ultimate strength calculation in ships after ECAP. Therefore, the mean purpose of this study is to apply ECAP to a shipbuilding low carbon steel to be able to achieve mechanical properties and investigate the alteration of ship hull girder grillage system's ultimate strength via finite element analysis approach. A fine-grained (FG) microstructure with a mean grain size of 6 ㎛ (initial grain size was 25 ㎛) was after ECAP. This microstructural evolution brought about a considerable increase in strength values. Both yield and tensile strength values increased from 280 MPa and 425 MPa to about 420 MPa and 785 MPa, respectively. This improvement in the strength values reflected a finite element method to determine the ultimate strength of ship hull girder grillage system. As a result of calculations, it was reached significantly higher ultimate strength values (237,876 MPa) compared the non-processed situation (192,986 MPa) on ship hull girder grillage system.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2023년도 학술발표회
• /
• pp.446-446
• /
• 2023

우리나라는 물의 재이용 촉진 및 지원에 관한 법률에 따라 수자원의 지속 가능한 이용을 목적으로 빗물이용시설의 설치 및 운영을 법·제도적으로 의무화하고 있으며, 위 법에 근거하여 지방자치단체에서는 빗물이용시설의 설치를 장려하기 위한 재정 지원 정책을 시행하고 있다. 환경 투자사업의 일환인 빗물이용시설 설치 사업은 장기간에 대한 경제성 분석이 요구되며, 분석에 이용된 경제성 분석 방법 및 사회적 할인율에 따라 분석 결과가 상이할 수 있다. 이에 따라, 이 연구에서는 순현재가치와 편익-비용 비율을 비교·검토하여 빗물이용시설의 경제성 분석에 적합한 방법을 제시하였으며, 경제성 분석에서 불확실한 요소인 사회적 할인율과 물가상승률에 대한 민감도 분석을 통해 두 요소의 불확실성을 평가하였다. 분석 대상 시설은 인천 청라지구 1공구에 계획된 빗물이용시설이며, 경제성 분석 기간은 지방공기업법 시행규칙에 제시된 건축물의 내용 연수인 30년으로 하였다. 편익-비용 비율을 이용하여 빗물이용시설의 경제성을 분석한 결과, 저류용량이 285 m³에서 최대 수익률이 나타났으며, 순현재가치는 저류용량이 1105 m³일 때 최대 수익이 발생하는 것으로 분석되었다. 분석 대상 지역의 경우에 285 m³에 대한 양적 신뢰도는 7.3%로 빗물이용시설의 효과를 기대하기 어려운 결과이며, 이와 같은 결과는 편익-비용 비율이 사업의 경제성을 수익률로 평가함에 따라 투자 규모를 반영하지 않는 한계로 인한 것으로 판단된다. 사회적 할인율과물가상승률에 대한 민감도 분석 결과, 사회적 할인율이 낮아지고 물가상승률이 높아짐에 따라 빗물이용시설의 저류용량과 그에 상응하는 최대 순현재가치가 커지는 경향을 보였다. 이는 미래가치를 높게 평가할수록 빗물이용시설의 저류용량이 크게 설계될 수 있음을 의미한다.

• 한국환경복원기술학회지
• /
• 제26권6호
• /
• pp.33-50
• /
• 2023

This study is to propose the ecosystem service valuation method as a complementary or alternative tool to overcome the limitations of the contingent valuation method(CVM), typically used to assess social benefits in preliminary feasibility studies. With an increasing interest in natural and environmental restoration projects, we assessed social benefits with theses CVM and ecosystem service valuation method from a case of Janghang wetland restoration project and compared the extent of the two social benefits. For quantitative evaluation of ecosystem services, the biophysical quantity for each ecosystem service indicator was calculated and then converted into currency (KRW) units to estimate the economic value of ecosystem services. The four ecosystem regulating service indicators were selected including greenhouse gas capture/storage, air pollution, water quantity and quality regulation. The amounts of CO₂ sequestration and storage as a ecosystem's greenhouse gas regulating service in the study area were 73.04 tCO₂/yr and 5,867.53 tCO₂/yr respectively. The reduction of SO₂, one of air pollutant gases by ecosystems was calculated to be 180.27 kg/yr, the reduction of NO₂ to be 378.90 kg/yr, and the reduction of fine dust (PM10) to be 9,713.92 kg/yr. The amount of freshwater regulating service by the ecosystem was estimated to be 459,394,319ℓ/yr, and the amount of nitrogen in freshwater removed by the ecosystem was 78.00kg/yr. Study results show that the benefits derived from the CVM were KRW 227.8 billion over the 30-year analysis period and those from the ecosystem service valuation method were KRW 41.4 billion for regulatory services and KRW 148.8 billion for cultural services, totaling KRW 189.5 billion. With KRW 184.8 billion of the total costs, the benefit/cost ratio using the CVM was 1.23 and that with the ecosystem service valuation method was 1.03. This study implications include that the CVM and ecosystem service valuation method can be applied together to assess and compare social benefits for natural and environmental restoration projects.

• Journal of Preventive Medicine and Public Health
• /
• 제28권3호
• /
• pp.640-650
• /
• 1995

After the introduction of National Medical Insurance in 1989, the medical demand has rapidly increased. The impact of increased medical demand was followed by an increase in the number of claims in need of review. We studied a new, fair method for reducing the number of claims reviewed. We analysed 90,583 outpatient claims submitted between September and October; claims were made for services given August of 1994. We finally suggested a screening system for claims review using a statistical method of discriminant analysis of the medical costs. The results were as follows. 1. In the cut-off group, age, days of medication, number of hospital or clinic visits, and total charge were significantly high. The cut-off rates according to the hospital-type and existence of accompanied disease were significantly different 2. According to ICD, the cut-off rate was highest in peripheral enthesopathies and allied syndromes(20.76%), lowest in acute sinusitis(0.93%). The mean charges were significantly different according to ICD and existence of cut-off. 3. We build discriminant functions by ICD with such discriminant variables as patient age, sex, existence of accompanied disease, number of hospital or clinic visits, and 9 detailed hospital or clinic charges included in claim. 4. We applied the discriminant function for screening those claims that were expected to be cut-off. The sensitivities comprised from 40% to 70%, and specificities from 70% to 95% by ICD. Acute rhinitis had highest sensitivity(100.00%) and other local infections of skin and subcutaneous tissue had highest specificity(98.45%). The expected number of cut-off was 17,762(19.61%). The total sensitivity was 49.62%, the total specificity was 82.57% and the error rate was 19.66%. We lacked economic analysis such as cost-benefit analysis. But, if the new method of screening claims using discriminant analysis were applied, the number of claims in need of review will reduce considerably.