• 정보처리학회 논문지
• /
• 제13권2호
• /
• pp.13-17
• /
• 2024

본 논문에서는 규칙의 수를 줄여 간결한 지식 기반을 보장할 수 있는 합 기반의 전건부를 가지는 뉴로-퍼지 제어기를 제안하였다. 제안된 뉴로-퍼지 제어기는 모든 입력 변수의 AND 조합을 전건부로 하는 구조의 퍼지 규칙보다 더 큰 입력 영역을 커버하기 위해 전건부에 입력 퍼지 집합의 합집합 연산을 허용하였다. 이러한 뉴로-퍼지 제어기를 구성하기 위해 본 논문에서는 OR 및 AND 퍼지 뉴런으로 구성된 multiple-term unified logic processor (MULP)를 고려하였다. 이러한 OR 및 AND 퍼지 뉴런은 조정 가능한 연결 강도 집합을 가지므로 학습을 통하여 최적의 연결 강도 집합을 찾을 수 있다. 초기 최적화 단계에서 유전 알고리즘은 제안된 뉴로 퍼지 제어기의 최적화된 이진 구조를 구성하고, 이후 확률에 기반한 강화 학습은 성능 지수를 더욱 향상시켜서 유전 알고리즘에 의해 최적화된 제어기의 이진 연결을 개선하였다. 역진자 시스템을 제어하기 위한 모의실험 및 실험을 통해 제안된 방법의 유효성을 검증하였다.

• 대한전자공학회논문지TC
• /
• 제42권8호
• /
• pp.33-40
• /
• 2005

본 논문은 DS/CDMA 신호 환경에서 동작하는 배열 안테나 시스템에서 다이버시티 이득을 이용하여 동기 성능을 향상시키는 탐색기를 제안한다. 제안한 PN 동기 검출 방법은, 대부분의 CDMA 기반 신호 환경에서 각 안테나 소자에 유기되는 간섭자의 실수-부 성분과 허수-부 성분이 서로 독립적인 가우시안 채널로 모델링할 수 있다는 사실에 근거를 둔다. 제안한 PN 동기 검출 방법은, 모든 PN 위상 오프셋에서 동기 에너지 값을 구하기 위해, 다수의 수신 신호를 안테나 별로 수신기의 PN과 독립적으로 코릴레이션하여 non-코히런트하게 선형 결합하는 단계인 검색 (searching) 단계와 구한 동기 에너지 값을 락-검출기에서 설정한 최적 기준값과 비교하여 동기 성공 여부를 판단하는 증명 (verification) 단계로 이루어진 single-dwell 방식이다. 본 논문에서는 평균 PN 동기 획득 시간 (Mean Acquisition Time)을 결정짓는 중요한 요소인 다이버시티 이득의 영향에 대해서 분석한다 일반적으로, 평균 PN 동기 획득 시간은 배열 안테나 소자의 수가 증가할수록 감소한다고 알려져 있다. 그러나, 다이버시티 차수 증가에 의한 PN 동기 획득 성능 개선은 포화된다. 따라서, 배열 안테나 수신기에서는 수신기의 동작 SNR 범위와 목표 검출 확률 $P_D$ 및 오-경보 확률 $P_{FA}$를 고려하여, 평균 PN 동기 획득 시간을 최소화하기 위한 최적의 배열 안테나 설계가 필요하다. 제안한 PN 동기 검출 방법의 성능은 주파수 선택적 레일레이 페이딩 채널에서 분석하였으며, 기존 단일 안테나에서의 PN 동기 획득 방법보다 우수함을 검출 확률 $P_D$ 및 오-경보 확률 $P_{FA}$항목에서 검증하였다.

• 대한간호학회지
• /
• 제36권4호
• /
• pp.612-620
• /
• 2006

Purpose. Smoking is the leading cause of death and smoking initiation rarely occurs after adolescence. Thus research on adolescent smoking is crucial. A consistent definition of smoking is important because inconsistent definitions make comparisons across studies an arduous task. Thus, the aim of the study was to suggest future research directions for smoking definitions after examining pitfalls in the literature. Methods. In this study the literature on adolescent smoking in the U.S. and South Korea was examined, and three types of smoking definitions were identified. Limitations in the studies are identified and future research directions are suggested. Results. In the U.S. literature, smoking definitions can be categorized into three groups: definitions based on stage models, smoking trajectories, and definitions derived from specific data. In the South Korean literature, various levels of smoking have not been differentiated. Conclusions. While the literature does not provide a definitive answer regarding the definition of smoking, it suggests three issues to consider for future research. First, multiple measures of smoking are more desirable than a one-time measure. Second, theory- or trajectory-based smoking definitions are more desirable than definitions derived from available data. Finally, regularity and amount of cigarette use should be incorporated in defining smoking behavior.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권1호
• /
• pp.1-19
• /
• 2020

In an underlay cognitive simultaneous wireless information and power transfer (SWIPT) network, communication from secondary user (SU) to secondary destination (SD) is accomplished with decode-and-forward (DF) relays. Multiple energy-constrained relays are assumed to harvest energy from SU via power splitting (PS) protocol and complete SU secure information transmission with beamforming. Hence, physical layer security (PLS) is investigated in cognitive SWIPT network. In order to interfere with eavesdropper and improve relay's energy efficiency, a destination-assisted jamming scheme is proposed. Namely, SD transmits artificial noise (AN) to interfere with eavesdropping, while jamming signal can also provide harvested energy to relays. Beamforming vector and power splitting ratio are jointly optimized with the objective of SU secrecy capacity maximization. We solve this non-convex optimization problem via a general two-stage procedure. Firstly, we obtain the optimal beamforming vector through semi-definite relaxation (SDR) method with a fixed power splitting ratio. Secondly, the best power splitting ratio can be obtained by one-dimensional search. We provide simulation results to verify the proposed solution. Simulation results show that the scheme achieves the maximum SD secrecy rate with appropriate selection of power splitting ratio, and the proposed scheme guarantees security in cognitive SWIPT networks.

• Journal of Information Technology Applications and Management
• /
• 제15권1호
• /
• pp.261-270
• /
• 2008

Wireless Mesh Networks (WMNs) have emerged as one of the new hot topics in wireless communications. WMNs have been suggested for use in situations in which some or all of the users are mobile or are located in inaccessible environments. Unconstrained transmission in a WMN may lead to the time overlap of two or more packet receptions, called collisions or interferences, resulting in damaged useless packets at the destination. There are two types of collisions; primary collision, due to the transmission of the stations which can hear each other, and hidden terminal collision, when stations outside the hearing range of each other transmit to the same receiving stations. For a WMN, direct collisions can be minimized by short propagation and carrier sense times. Thus, in this paper we only consider hidden terminal collision while neglecting direct collisions. To reduce or eliminate hidden terminal collision, code division multiple access (CDMA) protocols have been introduced. The collision-free property is guaranteed by the use of spread spectrum communication techniques and the proper assignment of orthogonal codes. Such codes share the fixed channel capacity allocated to the network in the design stage. Thus, it is very important to minimize the number of codes while achieving a proper transmission quality level in CDMA WMNs. In this paper, an efficient heuristic code assignment algorithm for eliminating hidden terminal collision in CDMA WMNs with general topology.

• 복식문화연구
• /
• 제22권4호
• /
• pp.565-578
• /
• 2014

This study is about the cases in fashion figure appearing the contemporary fashion and their characteristics. The work aims at providing a further active research opportunity for fashion figure in the modern fashion field and finding several possible utilizations to help the overall fashion industry through examination. Research methodology was followed up with the related literature review and empirical work through the case study of multiple fashion figures denoted in the contemporary fashion. The results showed in the following way for types of fashion figure in the modern fashion. The first type is that its figure was used for stage apparatus in fashion collection, various properties, or garment tool as doll shifted to a certain object. The second type is that art toy or fashion doll was used as specially added product via way of cooperation with fashion brand to be applied as fashion figure alone or other properties for T-shirt or something like that. The third type is the case that multifariously sized figures were applied to show window or shop display. This type of fashion figure is basically an imbedded fashionistic feature, reflecting the rarity, publicity, playfulness, and artistic value.

• 의학교육논단
• /
• 제17권3호
• /
• pp.97-104
• /
• 2015

This literature review explores relevant research and evaluation on pedagogy and physical learning spaces. This study also is intended to encourage discussion among stakeholders on the best medical school developments, in light of emerging learning trends relevant to their institutions. The study has revealed that new environments for learning are being designed or reshaped in response to changing pedagogical approaches, to incorporate new information technology, and to accommodate the changing abilities of new generations of learners. Formal teaching spaces for large groups with a 'sage on a stage' are becoming less common than smaller lecture rooms, although classrooms form a large component of universities and will continue to dominate in the future. However, the traditional layout of these spaces is being transformed to incorporate multiple learning modes. Classrooms should be profound places of revelation and discovery. A well-designed space has the ability to elevate discourse, encourage creativity, and promote collaboration. Within the classroom walls, a learning space should be as flexible as possible, not only because different teachers and classes require different configurations, but because in order to fully engage in learning, students need to transition between lectures, group study, presentations, discussions, and individual work time.

• 유통과학연구
• /
• 제12권3호
• /
• pp.85-98
• /
• 2014

Purpose - This study primarily aims to represent the current trend of research on CPFR as a promising supply chain collaboration program and proposes a new framework for analyzing any collaboration programs in terms of three key collaborative features. Research design, data, and methodology - This study employs a literature review of selected studies that conduct research on CPFR. CPFR is analyzed based on the proposed framework that characterizes collaboration programs in terms of three key collaborative features. Results - The analysis based on the proposed framework reveals that the current form of CPFR continues to have some collaborative features that are not fully utilized to create an advanced collaboration program. The literature review indicates that most past studies ignore critical issues including the dynamic nature of the multiple-stage supply chain system and negotiation process for collaborative agreement in CPFR implementation. Conclusions - Results indicate that CPFR can become a better supply chain collaboration program by incorporating coordinative cost payment and joint decision making processes. Based on observations on the existing literature of CPFR, this study indicates several important issues to be addressed by future studies.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권12호
• /
• pp.5212-5230
• /
• 2016

How to determine the right number of small base stations to activate in multi-cell uplinks to match traffic from a fixed quantity of K users is an open question. This paper analyses the uplink cooperative that jointly receives base stations activation to explore this question. This paper is different from existing works only consider transmitting power as optimization objective function. The global objective function is formulated as a summation of two terms: transmitting power for data and coordinated overhead for control. Then, the joint base stations activation and beamforming problem is formulated as a mixed integer second order cone optimization. To solve this problem, we develop two polynomial-time distributed methods. Method one is a two-stage solution which activates no more than K small base stations (SBSs). Method two is a heuristic algorithm by dual decomposition to MI-SOCP that activates more SBSs to obtain multiple-antennae diversity gains. Thanks to the parallel computation for each node, our methods are more computationally efficient. The strengths and weaknesses of these two proposed two algorithms are also compared using numerical results.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제10권2호
• /
• pp.141-152
• /
• 2018

The heating process such as line heating, triangular heating and so on is widely used in plate forming of shell plates found in bow and stern area of outer shell in a ship. Local shrinkage during heating process is main physical phenomenon used in plate forming process. As it is well appreciated, the heated plate undergoes the change in material and mechanical properties around heated area due to the harsh thermal process. It is, therefore, important to investigate the changes of physical and mechanical properties due to heating process in order to use them plate the design stage of shell plates. This study is concerned with the development of formula of plastic hardening constitutive equation for steel plate on which line heating is applied. In this study the stress correction formula for the heated plate has been developed based on the numerical simulation of tension test with varying plate thickness and heating speed through the regression analysis of multiple variable case. It has been seen the developed formula shows very good agreement with results of numerical simulation. This paper ends with usefulness of the present formula in examining the structural characteristic of ship's hull.