• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.799-818
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• 2014

Spectrum sensing is a key technical challenge for cognitive radio (CR). It is well known that multi-cycle cyclostationarity (MC) detector is a powerful method for spectrum sensing. However, conventional MC detector is difficult to implement due to its high computational complexity. This paper pays attention to the fact that the computation complexity can be reduced by simplifying the test statistic of conventional MC detector. Based on this simplification process, an improved MC detector is proposed. Compared with the conventional one, the proposed detector has the low-computational complexity and sufficient-accuracy on sensing performance. Subsequently, the sensing performances are further investigated for the cases of Rayleigh, Nakagami-m, Rician, composite Rayleigh fading-lognormal shadowing and composite Nakagami fading-lognormal shadowing channels, respectively. Furthermore, the square-law combining (SLC) is introduced to improve the detection capability over fading-shadowing channels. The corresponding closed-form expressions of average detection probability are derived for each case by the moment generation function (MGF) approach. Finally, illustrative and analytical results show that the efficiency and reliability of proposed detector and the improvement on sensing performance by SLC over composite fading-shadowing channels.

• 한국인터넷방송통신학회논문지
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• 제18권3호
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• pp.193-200
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• 2018

공식 연설에서 연설자의 목소리는 청취자에게 다양한 영향을 미칠 수 있다. 목소리 특징에 따라 연설의 효과성과 효율성도 변화하게 된다. 대통령 선거에서도 후보자의 목소리 특징은 유권자들의 인지에 영향을 미치게 될 것이다. 그래서 우리는 보다 효과적인 후보자의 목소리가 어떤 것인지를 파악할 필요가 있을 것이다. 이 연구는 후보자가 목소리를 변화시킨다면 이 목소리에 대한 유권자의 인지도 변화할 것인지를 입증한다. 한 후보자의 변화된 목소리 특징에 따라 유권자의 인지가 변화한다면, 우리는 후보자에게 필요한 목소리가 어떤 것인지를 설명할 수 있게 될 것이다. 또한 효과적인 연설을 위해 필요한 목소리 변화 전략에 대해서도 논의할 수 있을 것이다. 우리는 이 연구를 통해 대통령 후보자의 목소리 변화에 따른 유권자의 인지 변화를 소리공학의 차원과 인지 차원으로 설명하여, 효과적인 연설을 위해 후보자에게 필요한 목소리 특징과 변화 전략을 설명한다.

• 한국비블리아학회지
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• 제22권2호
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• pp.181-200
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• 2011

본 연구는 국립어린이청소년도서관이 청소년의 독서흥미를 고취하기 위하여 전국 학교도서관을 대상으로 수행하고 있는 청소년 독서진흥 프로그램의 운영을 심층적으로 평가하였다. 본 연구를 위하여 2007년부터 2010까지 이루어진 '1318 책벌레들의 도서관점령기' 프로그램에 참여한 학교도서관 사서들을 대상으로 그 운영전반에 대한 체계적인 설문조사를 실시하였고 또한 독서진흥 프로그램의 경험이 풍부한 학교도서관 사서들과의 표적집단 심층인터뷰를 실시하였다. 조사분석 결과 첫째, 사업성과에 대한 응답자의 만족도는 매우 높게 나타났으며 학생들의 인지, 정서, 사회성 발달에 효과성이 있는 것으로 평가하였다. 둘째, 기획과정, 계획과정, 운영과정의 만족도 중 계획과정, 운영과정의 만족도가 성과만족도를 예측하는 영역으로 확인되었다. 셋째, 서술형 문항에서 프로그램의 원활한 지원과 효율성을 위해 전문인력 충원 및 연구와 조직 확대의 필요성이 거론되었으며 다양한 콘텐츠 및 매뉴얼 개발과 보급 등이 제언되었다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제26권3호
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• pp.17-26
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• 2020

Purpose: This paper presents research evidence that the environmental design of the doffing area in a biocontainment unit (BCU) can have a measurable impact on increasing the safety of frontline healthcare workers (HCW) during doffing of high-level personal protective equipment (PPE), and proposes optimized biocontainment unit design. Methods: From 2016 to 2019, The SimTigrate Design Lab conducted 3 consecutive studies, focusing on ways in which the built environment may support or hinder safe doffing. In the first study, to identify the risky behaviors, we observed 56 simulation exercises with HCWs in 4 BCUs and 1 high-fidelity BCU mockup. In the second study, we tested the effectiveness of a redesigned doffing area on improving the HCWs performance and used simulation, observation, and rapid prototyping in 1 high-fidelity mockup of a doffing area. In a follow-up study, we used simulation and co-design with HCWs to optimize the design of a safer doffing area in a full-size pediatric BCU mock-up. Results: We identified 11 specific risky behaviors potentially leading to occupational injury, or contamination of the PPE, or of the environment. We developed design strategies to create a space for safer doffing. In the second study, in a redesigned doffing area, the overall performance of HCW improved, and we observed a significant decrease in the number of risky behaviors; some risky behaviors were eliminated. There was a significant decrease in physical and cognitive load for the HCWs. Finally, we propose an optimized layout of a BCU for a safer process of PPE doffing. Implications: The proposed BCU design supports better staff communication, efficiency, and automates safer behaviors. Our findings can be used to develop design guidelines for spaces where patients with other highly infectious diseases are treated when the safety of the patient-facing HCWs is of critical importance.

• 한국실내디자인학회논문집
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• 제23권5호
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• pp.165-173
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• 2014

Located in Dornach, Switcherland Eurythmeum Anbau zu Haus Brodbeck (Rudolf Steiner-Halde, Eurythmeum Anbau zu Haus Brodbeck, 1923-1935) is one of the architectural works created by Rudolf Steiner (1861-1925) who has studied and established the cognitive and spiritual aspects of a human being, and is often cited as being the founder of anthroposophy. In fact, Eurythmeum Anbau zu Haus Brodbeck is not as well known as Steiner's other works, and it is perceived as less important than his major works of architecture including "Goetheanum", "Modellbau zu Malsch", and "Rudolf Steiner Haus Stuttgart". Nonetheless, this study is meaningful in itself since it is an important piece of architecture to gain an understanding of the characteristics of Steiner's late works, and the architectural characteristics of the Waldorf School where various active educational activities are taking place around the world. Eurythmeum Anbau zu Haus Brodbeck clearly exhibits the characteristics of the architectural space based on Steiner's anthroposophy as well as provides a window into promoting space efficiency by extending an existing building. Moreover, it provides a good learning opportunity to find out about how Steiner's architectural disposition has changed and developed with the use of new materials. With these points as a backdrop, the study aims to develop an understanding of the architectural characteristics of Eurythmeum Anbau zu Haus Brodbeck. Another important objective of this paper is to gain insight into the architectural implications in connection with the influence Eurythmeum Anbau zu Haus Brodbeck has had on Steiner's later works, by comparing his early works of architecture with those of his late works.

• 한국인터넷방송통신학회논문지
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• 제13권6호
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• pp.101-108
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• 2013

본 논문에서는, NACK 메시지가 스펙트럼 공유와 협력을 위한 명령으로 사용되어지는 방법을 제안하였다. 1차 사용자의 직접 연결이 중단될 때, 협력과 공유의 자동 반복을 허가하고, 패러다임 기반의 협력 스펙트럼 공유의 조정 메시지의 수를 절약하기 위해 허가한다. 공유 시, ${\alpha}$의 남은 전력 부분이 1차 재전송 신호인 동안, 2차 전송된 신호를 위한 $1-{\alpha}$ 전력 부분은 중계기 공유로 선택된다. 중계기를 사용하지 않는 경우, 1차 송신단은 전체 전력($1-{\alpha}$)를 사용하여 신호를 재전송 하기 위해 NACK를 사용한다. 두 시스템은 BPSK 신호를 적용한 것으로 가정한다. 이 기법에서, 2차 사용자는 공동 최적화 복호를 하는 것으로 제안한다. 프레임 오류율(FER) 성능은 양 시스템에서 분석된다. 이론과 시뮬레이션 결과는 본 프로토콜의 유효성을 분석하고 효율적임을 확인하였다.

• 한국산림과학회지
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• 제99권6호
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• pp.891-899
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• 2010

이 연구의 목적은 선택실험기법을 활용한 조건부 로짓 모델을 이용하여 산림경관기능이 가지는 경제적 가치를 추정하는데 있다. 이를 위해 산림경관의 속성과 수준을 선정하였는데, 속성은 산림형태, 임상, 소밀도, 휴양적 요소, 지불의사금액 등이 그것이다. 이를 토대로 SAS 9.1을 이용하여 Orthogonal과 Balanced를 이루는 96개 선택 집합을 4개 타입으로 구성하였으며, 서울을 포함한 7개 광역시 시민을 모집단으로 설정하여 연간 가구당 지불할 의사를 면접조사방법으로 총 280부를 조사하였다. 그 결과, Non-ASC 모형에서 Mcfadden' ${\rho}$는 0.21, 우도통계량은 -2,631로 나타났다. 그리고 산림경관에 대한 가구당 평균 지불의사금액은 266,723원으로 나타났다.

• 대한인간공학회지
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• 제29권1호
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• pp.47-53
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• 2010

An analysis of biosignal and performance data collected during driving has increasingly employed in research to explore a human-vehicle interface design for better safety and comfort. The present study developed a protocol and a system to effectively analyze biosignal and driving performance measurements in various driving conditions. Electrocardiogram (ECG), respiration rate (RR), and skin conductance level (SCL) were selected for biosignal analysis in the study. A data processing and analysis protocol was established based on a comprehensive review of related literature. Then, the established analysis protocol was implemented to a computerized system so that immense data of biosignal and driving performance can be analyzed with ease, efficiency, and effectiveness for an individual and/or a group of individuals of interest. The developed analysis system would be of use to examine the effects of driving conditions to cognitive workload and driving performance.

• PNF and Movement
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• 제15권2호
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• pp.209-216
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• 2017

Purpose: The purpose of this study was to compare the status of the dementia prevention programs, dementia support centers, and elderly welfare centers in major metropolitan cities to acquire data for future program development and dissemination and the specialization of dementia prevention personnel. Methods: Data were gathered through internet surveys and telephone questionnaires from 15 special demented elderly care centers and elderly welfare centers registered in five metropolitan cities from June 27 to Oct 25, 2016. Results: Dementia care programs were available at 15 centers. Seoul City was running the most diverse dementia programs, and all five cities were spending a significant amount of time on the cognitive therapy program within several dementia programs. In addition, many social workers hosted the program and the frequency of social welfare work was three times a week. Conclusion: To increase the dementia prevention policies' efficiency, an understanding of dementia has already been established. Experts who can provide client-centered, problem-solving programs will play the role of physical therapists and occupational therapists. However, more research is needed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.4835-4855
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• 2015

TV white space (TVWS) is showing promise to become the first widespread practical application of cognitive technology. In fact, regulators worldwide are beginning to allow access to the TV band for secondary users, on the provision that they access the geolocation database. Device-to-device (D2D) can improve the spectrum efficiency, but large-scale D2D communications that underlie TVWS may generate undesirable interference to TV receivers and cause severe mutual interference. In this paper, we use an established geolocation database to investigate the power allocation problem, in order to maximize the total sum throughput of D2D links in TVWS while guaranteeing the quality-of-service (QoS) requirement for both D2D links and TV receivers. Firstly, we formulate an optimization problem based on the system model, which is nonconvex and intractable. Secondly, we use an effective approach to convert the original problem into a series of convex problems and we solve these problems using interior point methods that have polynomial computational complexity. Additionally, we propose an iterative algorithm based on the barrier method to locate the optimal solution. Simulation results show that the proposed algorithm has strong performance with high approximation accuracy for both small and large dimensional problems, and it is superior to both the active set algorithm and genetic algorithm.