• 한국환경과학회지
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• 제29권6호
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• pp.623-631
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• 2020

This study analyzes the effect of negative air ions on the concentration of airborne particulate matter and evaluates the expected purification efficiency of open spaces for particulate matter by investigating the amount of negative air ions generated by plants. This study establishes a negative air ion generation treatment environment, plant environment, and control environment to measure the purification efficiency of particulate matter under the conditions of each, analyzing the expected purification efficiency by designing a particulate matter purification model. Results show that the amount of generated negative air ion according to environment was negative air ion generation treatment environment > plant environment > control environment; this order also applies to the particulate matter purification efficiency. Moreover, it took 65 min for the negative ion generation treatment environment, 90 min for the plant environment, and 240 min for the control environment to reach the standard expected purification efficiency of particulate matter concentration of 960 mg/㎥ for PM₁₀. For PM_2.5, with the designated maximum concentration of 700 mg/㎥, it took 60 min for the negative ion generation treatment environment, 80 min for the plant environment, and more than 240 min for the control environment. Based on these results, the expected purification efficiency compared to the control environment was quadrupled in the negative ion generation treatment environment and tripled in the plant environment on average.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.389-390
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• 2023

To improve the cost performance of construction sites, various systems and standards are constantly being developed and implemented. Although legal requirements for these system and standard improvements have been increasing, the cost efficiency performance of construction sites remains stagnant. We have digitized documents generated through construction supervision work at 39 building construction sites and proposed a model that can support decision-making in cost efficiency evaluation. This model selects key keywords that are considered to be highly related to cost efficiency by identifying the patterns and relationships of keywords through associated rule analysis and social network analysis using keywords derived from documents. In addition, it is expected to be used as a decision-making aid to determine the cost efficiency of a specific building construction site by establishing a logistic regression model using core keywords. As a systematic database of construction supervision documents and an integrated system of massive data generated by digital technology are established in the future, the accuracy and reliability of the cost efficiency evaluation model are expected to be reinforced.

• KDI Journal of Economic Policy
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• 제36권2호
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• pp.65-101
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• 2014

본 연구에서는 이자율 변수에 적절한 확률과정을 부여하고 이를 가격함수에 직접 대입한 뒤 최종적으로 자산가격 PDE를 도출하는 재무모형을 이용하여 우리나라 기대인플레이션을 추정하고 그 특성을 살펴보고자 한다. 우리나라의 기대인플레이션은 글로벌 금융위기 이전에는 4%를 상회하는 높은 수준을 보였으나 2008년 후반을 기점으로 하향 안정화되는 모습을 시현했다. 또한 수익률곡선에서 도출된 기대인플레이션과 서베이 등을 통해 실제로 자료의 입수가 가능한 기대인플레이션을 이용하여 경제주체의 기대인플레이션 형성에 체계적인 편의가 존재하지 않고(불편성), 기대형성에 활용 가능한 모든 정보가 반영되었는지(효율성)를 기준으로 합리성을 평가한 결과, 분석에 이용된 모든 기대인플레이션에서 효율성은 기각되나 기대편의는 발생하지 않는 것으로 나타났다. 한편, 실제인플레이션과 기대인플레이션 간의 Granger 인과관계 검정 결과, 대체로 컨센서스 및 BOK 전문가 기대인플레이션은 상대적으로 장기의 실제인플레이션과, 이자율모형에서 도출된 기대인플레이션은 단기의 실제인플레이션과 상호 인과관계가 발생하는 것으로 분석되었다. 이러한 결과는 각각의 인플레이션 지표들이 내포하는 인플레이션의 정보가 상이하다는 것을 방증하고 있다. 이는 중앙은행이 하나의 인플레이션 지표보다는 다양한 지표들을 균형 있는 시각으로 관찰하는 것이 필요함을 시사한다.

• 상하수도학회지
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• 제23권5호
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• pp.573-581
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• 2009

In the case that the average velocity within rectangular-shaped sedimentation basin is less than 1.5cm/sec, and Froude number less than $10^{-6}$, it can not be expected that the longitudinal baffle improves the sedimentation efficiency. Also, since relatively lower velocity increases the effect of geostrophic body force, asymmetric flow pattern on a plane occurs within the basin. From the results of CFD (Computational Fluid Dynamics) simulation, in the case that the highest velocity within rectangular-shaped sedimentation basin is over 1.5cm/sec, and Froude number over $10^{-6}$, it can be expected that the longitudinal baffle installed within rectangular-shaped sedimentation basin improves the sedimentation efficiency.

• Current Optics and Photonics
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• 제1권6호
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• pp.626-630
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• 2017

GaN-based green light-emitting diode (LED) structures suffer from low internal quantum efficiency (IQE), known as the "green gap" problem. The IQE of LED structures is expected to be improved to some extent by exploiting the Purcell effect. In this study, the Purcell effect on the IQE of green LED structures is investigated numerically using a finite-difference time-domain simulation. The Purcell factor of flip-chip LED structures is found to be more than three times as high as that of epi-up LED structures, which is attributed to the high-reflectance mirror near the active region in the flip-chip LED structures. When the unmodified IQE is 20%, the relative enhancement of IQE can be greater than 50%, without utilizing the surface-plasmon coupling effect. Based on the simulation results, the "green gap" problem of GaN-based green LEDs is expected to be mitigated significantly by optimizing flip-chip LED structures to maximize the Purcell effect.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.89-90
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• 2016

Despite the rise of importance of Facility Management(FM), relatively little attention was paid to evaluate FM efficiency and drive for greater FM efficiency. The purpose of the present paper is to offer a quantitative analysis of 14 Key Success Factors(KSF) and 22 detailed maintenance practices in order to develop FM evaluation system. In addition, from survey with Owner/Property Manager group and Facility Manager group, the present paper measures both importance of detailed maintenance practices and performance satisfaction. It is expected that by using the result of this survey, this paper helps increase efficiency in FM. Moreover, It is expected that this paper will be used as base line data in developing FM practice evaluation system.

• 한국수정란이식학회지
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• 제31권3호
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• pp.267-272
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• 2016

Wholesale beef price is the critical factor for determining Korean native cattle, Hanwoo, farm's income in short-term. Wholesale beef price has seasonality due to high demand in Korean traditional holidays such as Korean thanksgiving day and lunar new year's day. Therefore, it is important to make reproduction and marketing plans for Korean Hanwoo farmers, in order to increase their farm income. However, there is no study available on changes in the expected farm income depending on reproduction and marketing schedules. This study analyzed the expected farm income per head depending on the monthly-based marketing schedules. The analysis was conducted based on the seasonality of wholesale beef price, reproduction efficiency, operating costs, relationship between carcass grade and slaughter age. The result shows that slaughter Hanwoo at the age of 29 months-old in August and January generating the highest expected farm income per head.

• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.123-131
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• 2021

In this study, safety education contents for medical radiation workers were produced based on Mixed Reality(MR). Currently, safety training for radiation workers is based on theory. This is insufficient in terms of worker satisfaction and efficiency. To address this, we created ICT(Information and Communication Technologies)-based MR radiation worker safety education content. The expected effect of Mixed Reality worker safety education content is that education is possible without space and time constraints, realistic education is possible without on-site training, and interaction between images is possible through reality-based 3D images, enabling self-directed learning Is that. In addition, learning in a virtual space expressed through HMD(Head Mounted Display) is expected to make education more enjoyable and increase concentration, thereby increasing the efficiency of education. A quantitative evaluation was conducted by an accredited institution and a qualitative evaluation was performed on users, which received excellent evaluation. The MR safety education conducted in this study is expected to be of great help to the education of medical radiation workers, and is expected to develop into a new educational paradigm as online education in accordance with Corona 19 progresses.

• 한국항공운항학회지
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• 제29권3호
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• pp.44-51
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• 2021

PIP is an abbreviation of 'Performance Improvement Package', which is a package that can improve performance by applying some design changes to existing aircraft. Boeing provides PIP applicable to B777-200, and Airbus provides PIP applicable to A350-900 as standard. PIP provided by Boeing and Airbus is a separate task, but it is expected to reduce fuel consumption by reducing drag through aerodynamic improvements. The PIP applied to the A350-900 includes work such as increasing Winglet Height and re-twisting Outboard Wing. This study is to verify the effect of PIP application of the A350-900 aircraft and use it as basic data for economic analysis. The aerodynamic improvement studies and expected effects of the PIP application were examined, and the actual flight data of the PIP-applied and the non-applied aircraft were compared to confirm the PIP application effect. This paper provides empirical results for the aviation industry on the PIP application efficiency as a method of improving fuel efficiency and reducing carbon emission.

• 한국컴퓨터정보학회논문지
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• 제11권1호
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• pp.203-222
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• 2006

본 연구에서는 문화관광부의 소속기관 및 산하단체의 정보시스템 운영환경을 통합한 문화정보 통합센터의 구축 운영을 가정한 사례를 중심으로 기대성과를 분석하는 방법론을 제시하였다. 본 연구의 주요 목표로는 첫째, 문화정보 통합전산환경 구축 운영에 따른 성과를 사업적 기대가치와 전략적 기대가치로 구분하여 성과항목을 도출하도록 하였으며, 둘째, 사업적 기대가치의 경우에는 균형성과표(BSC) 관점에서 핵심성공요인(CSF) 기법을 이용하여 정보화업무 효율화성과, 조직혁신 및 발전성과, 대민서비스 향상성과, 문화적 가치제고 성과 등 4가지 관점으로 범주화하여 세부 성과항목을 도출하는 방법을 제시하였다. 셋째, 사업적 기대가치중 정보화업무 효율화 성과의 경우에는 TCO(Total Cost of Ownership) 관점에서 경제적 성과 측정을 위한 세부 평가항목 및 평가지표를 개발하고 문화정보화 부문의 사례를 중심으로 구체적인 측정방법을 제시하였다.