• 한국전자파학회논문지
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• 제23권6호
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• pp.756-759
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• 2012

본 논문은 한반도 지역에 보편적 위성 통신 서비스를 제공하기 위한 정지궤도 위성의 다중 빔 서비스 커버리지 요구에 따라, 서비스 영역 내의 이득을 높일 수 있는 구현 가능한 안테나 구성 시나리오를 제안하였다. 제안된 시나리오는 위성 탑재가 가능하도록 안테나 및 급전 네트워크 구성을 간소화하고, 제한된 주파수 및 편파자원을 효율적으로 사용하기 위한 급전 네트워크 설계를 포함하고 있다. 또한, 전기적 성능 만족을 위하여 배열소자의 배치 및 여기 계수 최적화가 수행되었다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2017년도 추계학술대회
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• pp.189-192
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• 2017

본 논문에서는 하이브리드라디오 서비스를 성공적으로 도입하기 위해 필요한 정책적 조건들을 제안한다. 하이브리드라디오는 그 UI(User Interface) 특성과 오디오 방송 콘텐츠 외 서비스 구현으로 인해 기존 지상파플랫폼 외 추가적인 플랫폼이 필요하며, 이들 플랫폼을 구축하고 운영하는 새로운 플랫폼사업자의 등장을 수반하게 된다. 콘텐츠공급자와 플랫폼사업자가 일치하던 지상파 방송 산업과 달리 콘텐츠사업자와 플랫폼사업자가 분리되는 산업에서는 소수 플랫폼사업자가 다수 콘텐츠사업자에 비해 협상력 우위에 서는 역학관계가 생기게 되고, 이런 게임의 룰에 익숙하지 않고 사업적 규모도 영세한 지상파라디오 사업자들은 힘겹고 불공정한 사업 환경 속에 던져지는 상황을 맞게 될 수도 있다. 따라서 플랫폼사업자와 콘텐츠사업자가 상생하면서도 경쟁의 효율을 높이기 위해선 정교한 정책적, 제도적 장치가 필요하다. 또 하이브리드라디오가 기존 라디오 산업 내 제로섬 경쟁을 넘어 전체 이용자 규모를 확대하고 이를 효과적으로 수익과 연결하기 위해서는, 하이브리드라디오의 기술적 특성이 수용자에게 의미 있는 편익이 될 수 있도록 하이브리드라디오의 사업적 가능성을 충분히 활성화할 수 있는 제도 개선이 필요하다. 마지막으로 급변하는 미디어 빅뱅 상황에서 유의미한 유효 기간 내에 하이브리드라디오라는 신규 콘텐츠 유통 플랫폼을 성공적으로 도입하기 위해서는 산업 플레이어 간 불필요한 오해를 줄여 무의미한 논란을 최소화해야 한다.

• 전기전자학회논문지
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• 제19권3호
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• pp.327-334
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• 2015

다양한 형태의 미들웨어가 레거시 시스템과 신규 시스템의 통합을 위해 고안되었다. 미들웨어의 대표적인 형태로는 RPC(Remote Procedure Call), MOM(Message Oriented Middleware), TM(Transaction processing Monitor) 등이 있다. MOM 방식의 대표적인 모델인 PS(Publish/Subscribe)는 시스템의 결합도(coupling)가 낮고 낮은 결합도로 인해 높은 확장성(Scalability)를 얻을 수 있다는 장점이 있으나 한편으로는 응집도(cohesiveness) 또한 낮아진다는 단점이 있다. 이에 비해 RPC 방식은 응집도가 높으나 결합도 역시 높다는 단점이 있다. 본 논문에서는 RPC와 PS의 단점을 서로 상쇄시킬 수 있는 하이브리드 모델의 설계와 구현 방안을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1249-1272
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• 2016

In this paper, we propose a symmetric key establishment scheme for wireless sensor networks which tries to minimize the resource usage while satisfying the security requirements. This is accomplished by taking advantage of the communication pattern of wireless sensor networks and adopting heterogeneous wireless sensor networks. By considering the unique communication pattern of wireless sensor networks due to the nature of information gathering from the physical world, the number of keys to be established is minimized and, consequently, the overhead spent for establishing keys decreases. With heterogeneous wireless sensor networks, we can build a hybrid scheme where a small number of powerful nodes do more works than a large number of resource-constrained nodes to provide enhanced security service such as broadcast authentication and reduce the burden of resource-limited nodes. In addition, an on-demand key establishment scheme is introduced to support extra communications and optimize the resource usage. Our performance analysis shows that the proposed scheme is very efficient and highly scalable in terms of storage, communication and computation overhead. Furthermore, our proposed scheme not only satisfies the security requirements but also provides resilience to several attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권3호
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• pp.1363-1376
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• 2020

An improved clustering scheme based on user group is proposed. Every two users are grouped among N-users in the allowed system according to their link gain from large to small. Each user group is numbered sequentially. Two user clusters are obtained according to the principle of maximizing link gain difference for the users in the first and last user groups. The remaining user groups are added to the two existing user clusters according to the parity of the group number. The clustering should be clustered again among the users in either user cluster if the throughput summation of a user cluster in NOMA is less than that of these users in orthogonal multiple access. The simulation results show that the proposed clustering scheme can increase the system throughput by about 8% compared with the hybrid clustering scheme when the number of users requiring service is 12.

• 전기학회논문지
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• 제65권6호
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• pp.1032-1037
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• 2016

In this paper, the method of isolation enhancement for the mobile phone MIMO antenna of LTE class 40(2300~2400MHz) was studied. Design of MIMO antenna was based on the hybrid antenna that operates both a monopole and an IFA(Inverted F Antenna). A structure for the isolation enhancement which controls induced electric field on the ground plane is located between MIMO antenna, and was not connected with the ground but apart 0.3mm. A MIMO antenna that operates on class 3~40(1710~2400MHz) of LTE service bands and a structure for the isolation enhancement at the class 10 band were designed. VSWR measurement of implemented antenna on the FR4 board showed within 3:1 at entire design bands, and isolation between antennas at the class 40 band was less than -30dB. Isolation was enhanced more than 20dB by the studied structure. ECC(Envelope Correlation Coefficient) for MIMO performance was under 0.1, and antenna average gain and efficiency measured in the anechoic chamber were -4.28~-1.40dBi and 37.32~72.36% respectively.

• 성인간호학회지
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• 제20권5호
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• pp.707-718
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• 2008

Purpose: The present study was designed to understand the conceptual definition and attributes of the clinical critical thinking ability(CCTA) in nursing and to grasp the characteristics of clinical critical thinking abilities. Methods: The data were analyzed using the Hybrid model of Schwartz-Barcott and Kim(2000). Results: Having the skills and dispositions to think critically, CCTA refers to something that implies the cognizant ability to interpret contextual meanings, analyze the relationships between materials or circumstances, draw out the best conclusions, predict things using relevant information and evaluate the reliability of information and the strength of inference on the one hand and the emphatic disposition to be curious, open-minded, intellectually integral, systematic and creative and to reflect on things in contextual terms on the other. Conclusion: CCTA is characterized by clinical circumstances, such as guessing the reasons for facts, predicting things, connecting theory to practice and approaching individual situation in total terms as well as by the Korean circumstances, such as taking another person's perspective. Hence, this study proposes developing the tools to measure the clinical critical thinking ability and the strategies to improve the clinical critical thinking ability and seeking to verify their validity, on the basis of the findings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권2호
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• pp.723-743
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• 2016

Indoor positioning is considered an enabler for a variety of applications, the demand for an indoor positioning service has also been accelerated. That is because that people spend most of their time indoor environment. Meanwhile, the smartphone integrated powerful camera is an efficient platform for navigation and positioning. However, for high accuracy indoor positioning by using a smartphone, there are two constraints that includes: (1) limited computational and memory resources of smartphone; (2) users' moving in large buildings. To address those issues, this paper uses the TC-OFDM for calculating the coarse positioning information includes horizontal and altitude information for assisting smartphone camera-based positioning. Moreover, a unified representation model of image features under variety of scenarios whose name is FAST-SURF is established for computing the fine location. Finally, an optimization marginalized particle filter is proposed for fusing the positioning information from TC-OFDM and images. The experimental result shows that the wide location detection accuracy is 0.823 m (1σ) at horizontal and 0.5 m at vertical. Comparing to the WiFi-based and ibeacon-based positioning methods, our method is powerful while being easy to be deployed and optimized.

• 한국비블리아학회지
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• 제25권4호
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• pp.109-128
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• 2014

디지털도서관을 단순한 정보유통 구조의 한 부분으로 정의하지 않고 디지털도서관 그 자체를 자원의 생산, 유통 그리고 재생산을 위한 무형의 가치창출 행위로 인식하였으며 디지털자원의 속성을 해석함으로써 디지털도서관을 설계하였다. 즉, DRM(Digital Resources Management)의 가치를 디지털도서관으로 보았으며 그것을 전통적 도서관의 진화로 인식하였다. 이미 대학도서관들의 오픈액세스 자원생산이 이루어지고 있으며 클라우드 컴퓨팅 환경에서의 도서관 디지털장서 관리와 공유가 가능함을 보여줌으로써 출판이 가미된 디지털도서관의 가능성을 보여주었다.

• 대한간호학회지
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• 제50권1호
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• pp.81-100
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• 2020

Purpose: The purpose of this study was to define and clarify the concept of political competence for nurses. Methods: A hybrid model method was used to investigate the dimensions, attributes, and definitions of the concept. In the theoretical stage of the study, literature on nursing, politics, and other discipline were reviewed. In the fieldwork stage, individual in-depth interviews and focus groups interviews were conducted with politically seasoned experts or activists who had an understanding of the concept of political competence for extensive descriptions in nursing and field of health care. Results: The concept of political competence was represented in four dimensions as political knowledge, political efficacy, political interaction, and political activity. In the political knowledge dimension, there were three attributes, namely, political knowledge, political information and systematic analysis ability. The political efficacy dimension had three attributes of internal political efficacy, external political efficacy, and self-pride of nursing profession. The political interaction dimension had three attributes of organizations and community service, networking, and persuasive power. The political activity dimension had six attributes of political leadership, political expression, assertive behavior, political advocacy, political participation, and policy intervention. Conclusion: This concept development might provide a basic understanding of developing a measurement tool and for constructing a theory promoting nurses' political competence.