• Journal of Astronomy and Space Sciences
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• 제34권2호
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• pp.127-138
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• 2017

The current study designs the mission orbit of the lunar CubeSat spacecraft to measure the lunar local magnetic anomaly. To perform this mission, the CubeSat will impact the lunar surface over the Reiner Gamma swirl on the Moon. Orbit analyses are conducted comprising ${\Delta}V$ and error propagation analysis for the CubeSat mission orbit. First, three possible orbit scenarios are presented in terms of the CubeSat's impacting trajectories. For each scenario, it is important to achieve mission objectives with a minimum ${\Delta}V$ since the CubeSat is limited in size and cost. Therefore, the ${\Delta}V$ needed for the CubeSat to maneuver from the initial orbit toward the impacting trajectory is analyzed for each orbit scenario. In addition, error propagation analysis is performed for each scenario to evaluate how initial errors, such as position error, velocity error, and maneuver error, that occur when the CubeSat is separated from the lunar orbiter, eventually affect the final impact position. As a result, the current study adopts a CubeSat release from the circular orbit at 100 km altitude and an impact slope of $15^{\circ}$, among the possible impacting scenarios. For this scenario, the required ${\Delta}V$ is calculated as the result of the ${\Delta}V$ analysis. It can be used to practically make an estimate of this specific mission's fuel budget. In addition, the current study suggests error constraints for ${\Delta}V$ for the mission.

• 원예과학기술지
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• 제31권4호
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• pp.503-511
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• 2013

본 연구는 돌나물과 한국잔디를 식재한 경량 모듈형 옥상녹화시스템의 온도저감과 열수지를 평가하였다. 식물생육은 초고와 피복율을 측정하였으며, 2012년 8월 2일부터 3일까지 48시간 동안 콘크리트와 옥상녹화 표면, 토양 속, 모듈 하부의 온도와 순복사, 증발산량을 측정하였다. 기온이 $34.6^{\circ}C$로 가장 높았던 8월 3일 15:00시의 표면온도는 콘크리트가 $57.5^{\circ}C$로 가장 높았으며, 그 다음으로 돌나물 $40.1^{\circ}C$, 한국잔디 $38.3^{\circ}C$의 순으로 옥상녹화 조성 시 큰 폭으로 온도가 저감되는 것으로 나타났다. 토양 속과 모듈 하부도 옥상녹화에 의한 온도저감 효과가 나타났으며, 한국잔디가 돌나물보다 온도저감 효과가 큰 것으로 나타났다. 콘크리트 표면과 비교하여 옥상녹화 최고 온도는 약 2시간 정도 지연되는 것으로 나타났다. 표면의 온도저감에는 식물종, 기온, 토양수분이 영향을 미치고, 모듈 하부의 온도저감에는 식물종, 기온, 토양수분, 표면온도가 유의하게 영향을 미친 것으로 나타났다. 열수지 분석결과, 현열은 콘크리트 표면이 가장 높았으며, 옥상녹화 시 감소하는 경향을 보였으며 잠열은 한국잔디가 돌나물보다 높았다. 따라서 온열환경 개선을 위해서는 한국잔디가 돌나물보다 옥상녹화 적용에 더 효과적임을 알 수 있었다.

• 한국대기환경학회지
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• 제32권6호
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• pp.583-592
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• 2016

In this study, we attempt to provide empirical evidence for the effect of the expenditure of the local governments on the air quality management. Based on the statistical data, the concentrations of air pollutants including $PM_{10}$, $O_3$, and $NO_2$ were analyzed in accordance with local characteristics of the local governments' environmental expenditure, demographic characteristics, and economic and human resources between 2008 and 2014. The results showed that government spending is estimated to have insignificant impact on air pollutants concentration. All these results are consistently corroborated from the analysis based on different alternative measure of local governments' expenditure (budget composition and measure of expenditure residuals). Subsequently, this study implies that environmental expenditures of local governments have not been effectively enforced to enhance the air quality of the region in Korea.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.405-413
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• 2013

During the land operations, the enemy's gunnery is the primary threat. For the military vehicle, the bulletproof effect is the one of the important issues regarding the safety of soldiers on duty. Recently, the advanced military vehicles have planned to install armor plates. However, due to the budget problem, it is difficult to equip the protection systems. Hence, the optimum approach to increase bulletproof capability is essential. In this paper, the optimum thickness and component of the armor of military vehicles were evaluated by using finite element analysis for bullet impact effects. To achieve this aim, 7.62mm NATO bullet, 1.6mm steel and Kevlar-29 composite have been modeled and the simulations were conducted with various thickness cases by using MSC Nastran sol 700. Consequently, it was revealed that Kevlar-29 45 Layer is appropriate thickness for 7.62 bulletproof. Furthermore, Kevlar-29 in front of steel was effective by comparison with the back of steel for bulletproof.

• 방송공학회논문지
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• 제26권5호
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• pp.575-582
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• 2021

본 논문에서는 국회 FM라디오의 신규 재정 투입에 따른 경제적 효과 분석을 하고자 한다. 최근 4차 산업혁명과 뉴미디어 패러다임 변화로 모바일, 인터넷, OTT 등 다매체 다채널로 변화하고 있다. 이러한 변화하는 대내외적 여건을 반영하여 국회방송에서도 시청자가 공간과 시간적 제약 없이 공공서비스를 이용할 수 있도록 FM라디오 방송의 도입이 요구된다. 따라서 본 연구는 국회 FM 라디오의 신규 정부 재정 투입 소요 예산을 추계하여 분석을 수행하고자 한다. 주요 분석결과는 생산유발계수는 1.661이며, 부가가치 계수는 1.141, 고용유발계수는 7.1로 도출되었다. 수도권권역기준으로 생산유발효과 69.28억원, 부가가치유발효과 47.58억원, 고용유발효과 28.4명으로 분석되었다. 또한, 전국권역기준으로 생산유발효과는 132.57억원, 부가가치유발효과는 91.06억원 고용유발효과는 49.7명으로 추정되었다.

• Journal of Contemporary Eastern Asia
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• 제16권1호
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• pp.82-92
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• 2017

The objective of this study is to analyze the relationship between organizational capacity and the use of firefighter volunteers by volunteer fire departments within local/county governments. The study is based on a nonrandom sample of 213 U.S. volunteer fire departments within local governments. The fire chief of these fire departments responded to an annual survey conducted by Firehouse Magazine in 2010 and 2011. This study uses OLS regression analysis to assess the impact of organizational capacity (measured as annual budget) on the number of firefighter volunteers used by the volunteer fire department. There is evidence to suggest that organizational capacity has a positive and statistically significant effect on the number of volunteers used among U.S. volunteer fire departments. This study extends current literature on public volunteerism by analyzing factors that explain variation in the use of volunteers by local governments, specifically fire departments. Findings suggest that fire departments with greater resources in terms of revenue are more likely to use volunteers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.44-45
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• 2019

Tower cranes are essential equipments that play a key role in the overall process of large-scale construction projects, as well as high-rise apartments construction projects. Tower cranes hoist various loads near and over people, working in crowded environments, sometimes in overlapping work areas, and often under the constraints of time, budget, and labor. This work system further increases the safety risks of sites with inherently hazardous workplaces. The methodology of this research was based on a comprehensive inquiry of a team of experts, including safety managers and equipment managers of major construction companies and previous literature search. Due to the limited resources available to improve safety and prevent accidents, more attention should be paid to all parties involved in factors that have been evaluated to have a significant impact on site safety due to tower crane operations.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.413-413
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• 2023

Wetlands are a critical component of the global carbon cycle and are essential in mitigating climate change. Accurately quantifying wetland carbon emissions is crucial for understanding and predicting the impact of wetlands on the global carbon budget. The uncertainty quantifying carbon in wetlands may comes from the ecosystem's hydrological, biochemical, and microbiological variability. The Community Land Model is a sophisticated and flexible land surface model that offers several configuration options such as energy and water fluxes, vegetation dynamics, and biogeochemical cycling, necessitating careful consideration for the alternative configurations before model implementation to develop a practical model framework. We conducted a systematic literature review, analyzing the alternatives, focusing on the carbon stock pools configurations and the parameters with significant sensitivity for carbon quantification in wetlands. In addition, we evaluated the feasibility and availability of in situ observation data necessary for validating the different alternatives. This analysis identified the most suitable option for our study site, the Binbong Wetland, in Korea.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.658-668
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• 2009

Earth-moving operation has a great impact on the overall budget and schedule of any heavy civil projects. More often than not, the operational decisions are made largely based on field personnel's experience and judgment. In particular, decisions on earth moving operations by scraper-dozer fleets have been heavily influenced by the following belief: "The longer a dozer pushes a scraper for loading, the better earth-moving productivity is gained by the fleet." Even though there is some truth to this notion, scraper-dozer earth moving operations involve a much complex process that requires a systematic analysis for predicting the maximum production. To this end, this paper presents a spreadsheet-based scraper-dozer fleet operation model for its production optimization. Various optimization techniques, including a genetic-algorithm method, are presented for comparison and each technique's pros and cons are discussed.

• 정보화정책
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• 제22권1호
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• pp.47-72
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• 2015

전세계적으로 국가정보화가 진전됨에 따라 다양한 분야에서 개인정보의 침해위협이 급증하고 있어, 이에 대응하기 위한 정부차원에서의 정보보호대책이 마련되어지고 있다. 특히, 우리나라에서는 개인정보처리시스템의 안전성을 높이기 위한 방안으로, 2011년 개인정보 보호법에 근거한 개인정보 영향평가제도가 도입되었다. 그러나 개인정보 영향평가를 위한 대가기준의 변동요소들이 반영되지 못하고, 안전행정부(2011)에서 제시한 기본 예산보다 낮게 책정되면서 영향평가과정의 품질관리 및 영향평가서의 질적 수준도 저하되었다. 따라서 본 연구에서는 개인정보 영향평가가 개인정보보호를 위한 사전예방적 제도로 정착될 수 있게 필요한 예산 산정과 적용이 이루어지는 기준을 제시해보고자 한다. 이를 위해 기존 문헌, 유사제도의 대가기준, 개인정보 영향평가서 등을 검토하였으며, 전문가대상의 델파이분석을 통한 개선된 기준을 도출하였다. 이에 따라 개인정보 영향평가의 대가 산정 모델은 개인정보 영향평가고시에 따른 인력구성에 따라 기본인건비로 삼고, 대상시스템의 구분, 대상시스템의 구축 운용비, 대상시스템의 유형 등에 따라 가중치하는 방식을 채택하였다. 이처럼 개인정보 영향평가를 위한 대가 산정의 모델은 공공기관에서 개인정보보호를 위한 예산집행의 투명성과 영향평가사업의 신뢰성을 확보하는데 기여하리라 본다.