• Journal of IKEEE
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• v.23 no.2
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• pp.380-387
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• 2019

In recent years, solar energy PV/T research has been actively pursued by complementing solar heat acquisition and solar energy acquisition, and PV/T energy efficiency is generally excellent. In this study, the annual energy demand is calculated based on one building, and the energy production when PV / T installed on the roof and the energy production when PV are installed are compared and analyzed by simulation case. In conclusion, Busan which is the southern province in Korea, has the largest amount of energy generation, and introducing the concept of sharing surplus energy, excluding energy demand from generation. As a result, it can be supplied up to 3.3 households.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1354-1362
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• 2015

Heterogeneous network technology is expected to be a core technology for 5G mobile communications. 5G mobile network would be composed of many base stations even have mobility, then the operator should connect base stations through the wireless backhaul technology. This paper presents Ultra Wide Area Wireless Backhaul Network System with massive array antenna. We conducted link budget analysis for Ultra Wide Area Wireless Backhaul Network and performance analysis of massive array antenna system through the transmission simulator based on beamforming technology. In wide area ($10km^2$) wireless backhaul system composed of massive antenna, we achieved 5 bps/Hz average spectral efficiency with 1 W transmission power per beam.

• Journal of the Korean Solar Energy Society
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• v.24 no.3
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• pp.65-71
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• 2004

This study analysed data on the weather of Seoul, Gwangju and Mokpo to examine the degree of temperature increase in those Korean cities. 1) When the results of the analysis were compared with those of previously analysed temperature increase in 1990s and 1940s, there was an increase in temperature of $1.7^{\circ}C$ in Seoul, $1.5^{\circ}C$ in Gwangju and $0.7^{\circ}C$ in Mokpo. 2) According to the seasonal analysis, $1.7^{\circ}C$ in Seoul, $1.5^{\circ}C$ in Gwangju and $0.7^{\circ}C$ in Mokpo increased in Spring. On a monthly basis in Spring increase in April was highest($2.3^{\circ}C$ and $1.0^{\circ}C$ in Gwangju and Mokpo, respectively). As for Seoul, $2.4^{\circ}C$ increased in March, highest. In July and August of Summer, no significant change occurred in the three cities, but in Autumn, $1.0^{\circ}C,\;1.5^{\circ}C$, and $0.3^{\circ}C$ in Seoul, Gwangju and Mokpo increased, respectively. In Winter, $2.9^{\circ}C$ in Seoul, $1.9^{\circ}C$ in Gwangju, and $2.3^{\circ}C$ in Mokpo increased, respectively.

• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.13-26
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• 2014

Depending most of its energy sources on foreign countries, Korea efforts to reduce energy consumption in transportation. While studies on the relationship between gas price and transportation demand are many in number, most previous studies have focused on automobile and Seoul. This study analyzes the impact of gas price on transit (bus and subway) demand using monthly data and for various metropolitan areas (Seoul, Busan, Daejeon, Daegu and Gwangju). The research utilizes a time-series model and a multiple regression model, and calculates modal demand elasticities of gas price. The result shows that elasticities of subway demand with respect to gas price is higher than those of bus demand. In addition, elasticities of predominantly automobile cities are more likely to be more sensitive to gas price than those of cities with well-structured transit system.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.138-146
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• 2018

Photodynamic therapy (PDT) is a great potential approach for the localized tumor removal with fewer metastatic potentials and side effects in treating the disease. In the treatment process, a photosensitizer (PS) that absorbs a light energy to generate reactive oxygen is essential. In general, a visible light is used as a light source of PDT, so that side effects from the light source are inevitable. For this reason, upconversion nanoparticles (UCNPs) using near-infrared (NIR) as an excitation source are attracting attention in the field of disease diagnosis and treatment. UCNPs have the low cytotoxicity and phototoxicity, and also advantages such as deep tissue penetration and low background autofluorescence. For PDT, UCNPs should be combined with a PS which absorbs the light energy from UCNPs and transfers it to the surrounding oxygen to produce reactive oxygen. In addition, the therapeutic efficacy can be improved by modifying nanoparticle surfaces, adding anti-cancer drugs, or combining with photothermal therapy (PTT). In this review, we summarize the recent research to improve the efficiency of PDT using UCNPs.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.2
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• pp.1-7
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• 2018

The purpose of this study was to analyze the energy consumption of Elementary, Middle and High Schools in Daejeon Metropolitan City. The main results are as follow: 1) Annual energy consumption per class was 12,825 (kWh/class) at elementary schools, 15,780 (kWh/class) at middle schools, and 29,447 (kWh/class) at high schools, 2) Generally the smaller the size of the school, the higher the energy consumption per class. However according to the HVAC system there was no consistent pattern of energy consumption per class. 3) According to Box and Whisker's Chart, distribution of energy consumption of elementary and middle schools' had small range. However, the range of high schools increased. 4) Energy consumption in winter season was larger than that of summer season in schools.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.105-107
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• 2019

최근 몇 년간 소량의 데이터를 송수신하는 Massive IoT 네트워크에 많은 관심을 가지고 있다. 이러한 환경을 구축하기 위해서 저전력 광역 네트워크(LPWAN) 기술 중 LoRa(Long Range) 네트워크를 사용하고 있다. 대부분의 IoT 응용 서비스는 디바이스가 장시간 안정적으로 작동해야 하므로 에너지 효율성을 중점으로 두고 LoRa 디바이스의 수명을 최대화하기 위한 디바이스의 여러 동작들을 설계하는 에너지 소비 모델링이 중요하다. 따라서 본 논문에서는 LoRa Class B 통신 방식의 에너지 소비 모델을 정의하고 성능을 평가한다.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.865-885
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• 2022

Korean government updated her Nationally Determined Contribution (NDC) in 2021 and announced the target and various measures for reductions. Among the many issues, final energy demand and renewable energy power mix for 17 provinces to achieve the target are being analyzed using GCAM-Korea. Simulation results show that final energy demand of 2030 is approximated at the similar level to that of 2018. This is being enabled by the conservation of coal with higher electrification especially in industry sector. Higher power demand with lower coal consumption in final energy consumption is shown to be provided by 33.1% of renewable, 24.6% of gas, and 18.0% of nuclear power generation in 2030. Meanwhile, the share of coal-fired power generation is expected to be reduced to 12.8%. Major future power provider becomes Gyeongbuk (Nuclear), Gyeonggi (Gas), Jeonnam (Nuclear, Gas) and Gangwon (PV, Wind), compared to one of current major power provider Chungnam (Coal). This analysis is expected to provide a useful insight toward the national and provincial energy and climate change policy.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.74-79
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• 2008

영상 융합은 센서의 자료 저장 능력과 센서에 들어오는 방사에너지 감지의 한계를 해결하고 고해상도의 멀티스펙트럴 영상을 생성할 수 있다는 측면에서 중요한 의의를 지닌다. 특히, 성분대입(component-substitution) 기반의 영상융합 기법은 대용량의 자료를 빠르게 처리할 수 있고, 융합된 영상의 분광왜곡이 적다는 장점을 지니고 있다. 본 연구에서는 최적화기법 중의 하나인 담금질 모사기법(Simulated Annealing, SA)을 이용하여 다양한 성분대입 기반 영상융합 알고리즘들을 분석 및 평가하였다. 담금질 모사기법은 원하는 목적함수가 지역적 최소값이 아닌 광역적 최소값에 수렴이 가능하도록 하는 기법으로 다양한 분야에서의 광역 최적화 기법에 사용된다. 융합 기법의 최적화된 변수를 추출하기 위하여 인위적으로 공간해상도를 낮춘 위성영상을 입력자료로, 원 멀티스펙트럴영상을 참조자료로 사용하였으며, 두 영상간의 분광유사 척도를 담금질 모사 기법의 목적 함수로 구성하였다. 이를 통해 해당 목적함수의 광역적 최소값을 추출하고, 최종적으로 해당 영상에 융합 기법 별 최적화된 변수를 결정하였다. 제안된 최적화 변수의 평가를 위하여 IKONOS 위성영상에 융합을 적용하고, 알고리즘별 분광왜곡량을 비교하였으며 이를 통하여 고해상도 위성영상에 가장 적합한 성분대입 기반 영상융합 기법 및 그에 따른 최적화 변수를 도출할 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.410-410
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• 2022

기후변화에 관한 정부간 협의체(Intergovernmental Panel on Climate Change, IPCC)에서는 지난해부터 제6차 평가보고서(Sixth Assessment Report, AR6)를 준비하고 있으며, 최근 Working Group II에서 수행한 기후변화 영향, 적응 및 취약성(Impacts, Adaptation and Vulnerability) 보고서를 공개하였다. 보고서는 기존의 Representative Concentration Pathway (RCP) 시나리오에 사회경제적 조건을 추가로 고려한 Shared Socioeconomic Pathway (SSP) 시나리오를 제시하였고, 세계기후연구프로그램(World Climate Research Programme, WCRP)의 Coupled Model Intercomparison Project (CMIP)에서 제공하는 6단계(Phase 6) 미래 전망 자료를 적용하였다. 본 연구에서는 기후변화로 인한 미래 극한 강우량의 통계적 특성을 파악하기 위하여 CMIP6에서 제공하는 General Circulation Models (GCMs) 기반 미래 강우자료를 수집하여 부산광역시를 중심으로 분석하였다. 4개의 SSP (SSP126, SSP245, SSP370, SSP585) 시나리오별로 10개 GCMs의 모의 결과를 사용하였다. Gumbel 분포형과 확률가중모멘트법을 이용하여 미래 극한 강우량을 산정하였고, 현재 모의기간(S0, 1983-2014) 대비 미래 전망기간(S1, 2015-2044; S2, 2041-2070; S3, 2071-2100)의 변화를 재현기간(return period, T)별로 분석하여 제시하였다.