• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.287-293
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• 2008

As the instability of international societies on the energy resources has increasingly been deepened due to excessive use of fossil fuels, the importance of energy saving and global environment protection has highlighted, So the interests in environment-friendly and stable new & renewable energy have been dramatically increased. The studies on reconstructing the old-fashioned towns economically, socially and physically have been also significantly increased. In this urban regeneration, renewable-energy using systems were aggressively applied to overcome the energy and environmental problems of the existing towns. There have been many of studies on the compound applications of the renewable-energy using systems in the advanced countries while they are insufficient in Korea. As a preliminary study of urban renewable-energy using system development, this paper surveyed the foreign cases applied to key technologies such as geothermal energy, hydrogen fuel cell and bioenergy among the renewable-energies in urban built environment.

• 무역상무연구
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• 제20권
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• pp.495-522
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• 2003

As a rapid development of electronic commerce transactions in these days, the security and private protection problems became more important matters under the electronic transaction base. Because electronic transaction using electronic documents be carried without direct person to person meeting, there can be the possibility to use other's identity illegally without notice, and very hard to verify authenticity of transaction as well. In addition, it is very hard to find out that the electronic documents on the process of submitting is forged documents or not, and also have much difficulty in maintaining transmitting secret. Therefore, to solve such problems on electronic commerce transactions and electronic documents, the digital signature and certification system with cryptography skill is inevitably necessary. As the wide use of digital signature together with beginning of digital government and financial transaction, not only the issuance of electronic certification, but certification market came to gradually expand. In Korea, after enacting digital signature act in 1999, the act contents were expanded to the wide range of contents complying with global standards from the end of 2001 to April, 2002, including the new clause of certification problems. And the act was put into operation now. Therefore, in this paper, we'd like to suggest development scheme through the investigation on electronic certification related problems, such as, concepts, procedures, service conditions here and abroad.

• International Journal of Aeronautical and Space Sciences
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• 제16권1호
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• pp.89-101
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• 2015

To satisfy civil aviation requirements using the Global Navigation Satellite System (GNSS), it is important to guarantee system integrity. In this work, we propose a fault detection algorithm for GNSS ephemeris anomalies. The basic principle concerns baseline length estimation with GNSS measurements (pseudorange, broadcasted ephemerides). The estimated baseline length is subtracted from the true baseline length, computed using the exact surveyed ground antenna positions. If this subtracted value differs by more than a given threshold, this indicates that an ephemeris anomaly has been detected. This algorithm is suitable for detecting Type A ephemeris failure, and more advantageous for use with multiple stations with various long baseline vectors. The principles of the algorithm, sensitivity analysis, minimum detectable error (MDE), and protection level derivation are described and we verify the sensitivity analysis and algorithm availability based on real GPS data in Korea. Consequently, this algorithm is appropriate for GNSS regional implementation.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.187-195
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• 2021

The intensification of the processes of the digital economy development is leading to the transformation of the higher education system. Universities are forced to digitalize their own educational, research, international, marketing, financial and economic activities in order to maintain a competitive position in the global market of educational services. The purpose of the article is to study the role of information and communication technologies in the development of the higher education system and to ensure its adaptability to modern challenges of digital economy. To achieve this goal, methods of content analysis, logical generalization, systematization and a structural-functional method are used. In the article, the authors substantiate the urgency of forming a holistic strategy to ensure the adaptability of higher education to the challenges of digital economy. In the structure of this strategy, the information-technological block is singled out and described. The authors specified a set of positive synergetic effects from the introduction of modern information and communication technologies in the activities of universities. The main information threats to the digitalization of higher education related to the protection of personal data and university systems from cyberattacks and fraudulent schemes are identified. In conclusion, the authors detail the measures for the strategy implementation to ensure the adaptability of higher education to digital economy.

• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.279-286
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• 2022

In this paper, we designed a software library that produces integrated Global Navigation Satellite System (GNSS) / Inertial Navigation System (INS) navigation information using the raw measurements provided by the GNSS chipset, gyroscope, accelerometer and magnetometer embedded in android smartphone. Loosely coupled integration method was used to derive information of GNSS /INS integrated navigation. An application built in the designed library was developed and installed on the android smartphone. And we conducted field experiments. GNSS navigation messages were collected in the Radio Technical Commission for Maritime Service (RTCM 3.0) format by the Network Transport of RTCM via Internet Protocol (NTRIP). As a result of experiments, it was confirmed that design requirements were satisfied by deriving navigation such as three-dimensional position and speed, course over ground (COG), speed over ground (SOG), heading and protection level (PL) using the designed library. In addition, the results of this experiment are expected to be applicable to maritime navigation applications using smart device.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4884-4890
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• 2015

전 세계의 인구가 1인 평균 2대의 모바일 디바이스를 소지하는 시대가 다가오고 있으며 무선 네트워크 시장이 점차 확장되고 있다. 모바일 기기의 활용도가 높아짐에 따라서 와이파이(Wi-fi, Wireless Fidelity=Wireless LAN)가 선호하는 네트워크로 떠오르고 있다. 와이파이를 기반으로 공공기관, 의료, 교육러닝 및 콘텐츠, 제조, 리테일 등 다양한 영역에서 새로운 가치를 창출해가고 있으며, 글로벌 네트워크가 구축되어 복합적인 서비스를 제공하고 있다. 하지만 차세대 무선 네트워크 환경에서 무선 디바이스 식별자 취약, MAC 위조를 통한 네트워크 자원의 불법 이용, 무선 인증키 크래킹, 미허가 AP/디바이스에 대한 공격과 같은 취약점이 존재하고 있다. 또한 인증 고도화 및 안전한 고속 보안 접속과 같은 보안기술연구가 거의 진행되고 있지 않다. 그러므로 본 논문에서는 차세대 무선 네트워크 환경의 메시지 보호를 위한 디바이스 식별과 콘텐츠 분류 및 저장 프로토콜을 설계하여 안전한 통신 시스템을 설계한다. 제안한 프로토콜은 기존의 무선 네트워크 환경에서 발생하는 보안취약점에 관하여 안전성을 분석하였고 기존의 무선 네트워크 환경의 암호기법을 비교분석하여 보안성을 분석하였다. 기존의 암호시스템 WPA2-PSK보다는 대략 0.72배 느리지만, 보안성에서는 안전성을 강화되었다.

• 한국태양에너지학회 논문집
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• 제31권2호
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• pp.89-98
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• 2011

This study examined the energy performance according to the main design parameters of a solar water heating system for an office building using the life cycle cost (LCC) optimization simulations. The LCC optimization simulations of the system were conducted with TRNSYS and GenOpt employing the Hooke-Jeeves algorithm for cases where water temperature was $60^{\circ}C$ and $50^{\circ}C$. The results showed that for water temperature at $60^{\circ}C$ and $50^{\circ}C$ the global radiation incident on the collector could be decreased by 16.98% and 28.52%, collector useful energy gain could be decreased by 15.04% and 22.59%, energy to load from storage tank could be decreased by 10.86% and 18.06% and AH energy to load could be increased by 16.86% and 38.50% respectively compared to a non-optimized system. The annual average collection efficiency of the collector was increased by 0.88% for $60^{\circ}C$ and 2.78% for $50^{\circ}C$ because of increase of collector slope and decrease of the mass flow rate per collector area. The annual average efficiency of the system was increased by 1.74% and 3.47% compared to the basis system. However, the annual solar fraction of the system was decreased by 6.68% for $60^{\circ}C$ and 11.26% for $50^{\circ}C$ due to decrease of collector area and storage tank volume.

• 한국항공우주학회지
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• 제43권1호
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• pp.49-61
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• 2015

GBAS는 Differential GPS(DGPS) 개념을 활용하여 공항근처 23NM 반경 이내에 위치한 항공기에 정밀위치서비스와 정밀접근서비스를 제공하는 시스템으로, GBAS 지상장비는 공항에 설치된 이후에 지상 및 비행시험평가를 통해 그 기능 및 성능을 검증하도록 되어있다. 본 논문에서는 김포국제공항에 설치된 GBAS 지상장비에 대해 비행검사용 항공기를 이용한 비행시험 방법 및 결과를 분석하여 기술하였다. 시험 결과 김포공항의 GBAS 신호통달범위 내에서 VDB 데이터가 오류 없이 정상적으로 수신되었으며, VDB 전계강도, 보호수준, 코스정렬 정확도 등도 평가 요구조건을 충분히 만족시키는 것을 확인하였다.

• 디지털융복합연구
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• 제18권6호
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• pp.17-32
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• 2020

본 연구는 주인-대리인 모델을 적용하여 데이터 산업의 이해관계자인 정부, 개인, 기업의 규제 이슈를 분석해내는 데 목적이 있다. 데이터 산업은 거대한 딜레마적 상황에 직면해 있다. 데이터 경제의 중요성이 빠르게 부상하고 있으나, 데이터 사용에 대한 국가의 규제로 인해 산업 발전이 저해되는 한편, 데이터의 무분별한 활용으로 인한 개인의 프라이버시 역시 침해받고 있다. 본 연구에서는 기술적 사례연구의 방식을 이용하여 딜레마적 상황에서 각각의 행위자들의 이해관계에 기반한 규제 이슈를 분석하고, 그에 대응할 수 있는 전략을 제시하였다. 사례분석 결과 첫째, 국내 데이터 산업의 주요 정책행위자는 데이터 회사와 정부이다. 둘째, 데이터 기반 사회에서 가장 우려스러운 두 가지 문제점은 기업이 빈번하게 개인정보를 침해한다는 것과 국제적 기업의 데이터 독과점 현상이 나타난다는 점이다. 이러한 규제 이슈를 해결하기 위해 본 논문에서는 이에 대한 전략을 다음과 같이 제시하고 있다. 정부는 글로벌 기업의 감독을 위한 국내 대리인제도를 활성화하고 데이터 보호를 증대해야 한다. 기업은 차별적인 규제환경을 해결하고 합법적인 데이터 활용기준을 확장해야 한다. 마지막으로 개인은 능동적인 동의 행태를 구현해야 한다.

• 전자통신동향분석
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• 제36권1호
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• pp.54-63
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• 2021

Since the recent COVID-19 pandemic, countries have been strengthening trade protection for their security, and the importance of securing strategic materials, such as food, is drawing attention. In addition to the cultural aspects, the global preference for food produced in Korea is increasing because of the Korean Wave. Thus, the Korean food industry can be developed into a high-value-added export food industry. Currently, Korea has a low self-sufficiency rate for foodstuffs apart from rice. Korea also suffers from problems arising from population decline, aging, rapid climate change, and various animal and plant diseases. It is necessary to develop technologies that can overcome the production structures highly dependent on the outside world of food and foster them into export-type system industries. The global agricultural industry-related technologies are actively being modified via data accumulation, e.g., environmental data, production information, and distribution and consumption information in climate and production facilities, and by actively expanding the introduction of the latest information and communication technologies such as big data and artificial intelligence. However, long-term research and investment should precede the field of living organisms. Compared to other industries, it is necessary to overcome poor production and labor environment investment efficiency in the food industry with respect to the production cost, equipment postmanagement, development tailored to the eye level of field workers, and service models suitable for production facilities of various sizes. This paper discusses the flow of domestic and international technologies that form the core issues of the site centered on the 4th Industrial Revolution in the field of agriculture, livestock, and fisheries. It also explains the environmental awareness production technologies centered on sustainable intelligence platforms that link climate change responses, optimization of energy costs, and mass production for unmanned production, distribution, and consumption using the unstructured data obtained based on detection and growth measurement data.