• 제목/요약/키워드: Cognitive complexity

검색결과 193건 처리시간 0.02초

디자인 예술과 인지과학을 활용한 건축 디자인언어의 분석 (A Study on the Architectural Design Language by Design art and Cognitive science)

  • 송석현
    • 한국실내디자인학회논문집
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    • 제24권3호
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    • pp.30-37
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    • 2015
  • The target of design is a harmony between Beauty and Usefulness. Design is a result from representation of visual language by designer's creative thinking system. also, As an ill-defined problem cannot be described completely. and subjectively interpret depend on the situation, it is very difficult to present a theoretical standard. There have been many Design Sciences researches in recent years. such as Rule Based Design, Parametric Design, Replacement Design, Analogy Design, Metaphor Design, Genetic Algorithm. but Objective research is still unsatisfactory condition to investigate true nature about Design. At this point, It is very important to formulating about meaning of Design Language and Thinking. This study will define about that, and based on this definition, Lay out a logical basis for Treatment design variable and materialization of process by "Elements", "Relationship", "Schema". ultimately it look forward to provide a framework and minimize the complexity about Design Thinking.

Adaptive Adjustment of Compressed Measurements for Wideband Spectrum Sensing

  • Gao, Yulong;Zhang, Wei;Ma, Yongkui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권1호
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    • pp.58-78
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    • 2016
  • Compressed sensing (CS) possesses the potential benefits for spectrum sensing of wideband signal in cognitive radio. The sparsity of signal in frequency domain denotes the number of occupied channels for spectrum sensing. This paper presents a scheme of adaptively adjusting the number of compressed measurements to reduce the unnecessary computational complexity when priori information about the sparsity of signal cannot be acquired. Firstly, a method of sparsity estimation is introduced because the sparsity of signal is not available in some cognitive radio environments, and the relationship between the amount of used data and estimation accuracy is discussed. Then the SNR of the compressed signal is derived in the closed form. Based on the SNR of the compressed signal and estimated sparsity, an adaptive algorithm of adjusting the number of compressed measurements is proposed. Finally, some simulations are performed, and the results illustrate that the simulations agree with theoretical analysis, which prove the effectiveness of the proposed adaptive adjusting of compressed measurements.

An Interference Avoidance Method Using Two Dimensional Genetic Algorithm for Multicarrier Communication Systems

  • Huynh, Chuyen Khoa;Lee, Won Cheol
    • Journal of Communications and Networks
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    • 제15권5호
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    • pp.486-495
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    • 2013
  • In this article, we suggest a two-dimensional genetic algorithm (GA) method that applies a cognitive radio (CR) decision engine which determines the optimal transmission parameters for multicarrier communication systems. Because a CR is capable of sensing the previous environmental communication information, CR decision engine plays the role of optimizing the individual transmission parameters. In order to obtain the allowable transmission power of multicarrier based CR system demands interference analysis a priori, for the sake of efficient optimization, a two-dimensionalGA structure is proposed in this paper which enhances the computational complexity. Combined with the fitness objective evaluation standard, we focus on two multi-objective optimization methods: The conventional GA applied with the multi-objective fitness approach and the non-dominated sorting GA with Pareto-optimal sorting fronts. After comparing the convergence performance of these algorithms, the transmission power of each subcarrier is proposed as non-interference emission with its optimal values in multicarrier based CR system.

다중 안테나를 사용하는 무선 인지 네트워크를 위한 전력 조절 및 스케줄링 알고리즘 (Joint Power Control and Scheduling Algorithm for Cognitive Radio Network Exploiting Multi-Antennas)

  • 유승진;왕한호;이제민;안성우;홍대식
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.237-238
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    • 2008
  • This paper presents a cognitive radio network where a base station exploits multi-antennas. For the system, a joint power control and user selection greedy algorithm which achieve a significant fraction of sum-capacity at lower complexity cost is proposed.

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Efficient Resource Allocation with Multiple Practical Constraints in OFDM-based Cooperative Cognitive Radio Networks

  • Yang, Xuezhou;Tang, Wei;Guo, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권7호
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    • pp.2350-2364
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    • 2014
  • This paper addresses the problem of resource allocation in amplify-and-forward (AF) relayed OFDM based cognitive radio networks (CRNs). The purpose of resource allocation is to maximize the overall throughput, while satisfying the constraints on the individual power and the interference induced to the primary users (PUs). Additionally, different from the conventional resource allocation problem, the rate-guarantee constraints of the subcarriers are considered. We formulate the problem as a mixed integer programming task and adopt the dual decomposition technique to obtain an asymptotically optimal power allocation, subcarrier pairing and relay selection. Moreover, we further design a suboptimal algorithm that sacrifices little on performance but could significantly reduce computational complexity. Numerical simulation results confirm the optimality of the proposed algorithms and demonstrate the impact of the different constraints.

The cellular basis of dendrite pathology in neurodegenerative diseases

  • Kweon, Jung Hyun;Kim, Sunhong;Lee, Sung Bae
    • BMB Reports
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    • 제50권1호
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    • pp.5-11
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    • 2017
  • One of the characteristics of the neurons that distinguishes them from other cells is their complex and polarized structure consisting of dendrites, cell body, and axon. The complexity and diversity of dendrites are particularly well recognized, and accumulating evidences suggest that the alterations in the dendrite structure are associated with many neurodegenerative diseases. Given the importance of the proper dendritic structures for neuronal functions, the dendrite pathology appears to have crucial contribution to the pathogenesis of neurodegenerative diseases. Nonetheless, the cellular and molecular basis of dendritic changes in the neurodegenerative diseases remains largely elusive. Previous studies in normal condition have revealed that several cellular components, such as local cytoskeletal structures and organelles located locally in dendrites, play crucial roles in dendrite growth. By reviewing what has been unveiled to date regarding dendrite growth in terms of these local cellular components, we aim to provide an insight to categorize the potential cellular basis that can be applied to the dendrite pathology manifested in many neurodegenerative diseases.

Energy Efficiency Resource Allocation for MIMO Cognitive Radio with Multiple Antenna Spectrum Sensing

  • Ning, Bing;Yang, Shouyi;Mu, Xiaomin;Lu, Yanhui;Hao, Wanming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권11호
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    • pp.4387-4404
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    • 2015
  • The energy-efficient design of sensing-based spectrum sharing of a multi-input and multi-output (MIMO) cognitive radio (CR) system with imperfect multiple antenna spectrum sensing is investigated in this study. Optimal resource allocation strategies, including sensing time and power allocation schemes, are studied to maximize the energy efficiency (EE) of the secondary base station under the transmit power and interference power constraints. EE problem is formulated as a nonlinear stochastic fractional programming of a nonconvex optimal problem. The EE problem is transformed into its equivalent nonlinear parametric programming and solved by one-dimension search algorithm. To reduce searching complexity, the search range was founded by demonstration. Furthermore, simulation results confirms that an optimal sensing time exists to maximize EE, and shows that EE is affected by the spectrum detection factors and corresponding constraints.

스마트 가공 시스템 (A Smart Machining System)

  • 박홍석
    • 한국정밀공학회지
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    • 제32권1호
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    • pp.39-47
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    • 2015
  • Globalization, unpredictable markets, increased products customization and frequent changes in products, production technologies and machining systems have become a complexity in today's manufacturing environment. One key strategy for coping with the evolution of this situation is to develop or apply an enable technology such as intelligent manufacturing. Intelligent manufacturing system (IMS) is characterized by decentralized, distributed, networked compositions of heterogeneous and autonomous systems. The model of IMS is inherited from the organization of the living systems in biology and nature so that the manufacturing system has the advanced characteristics inspired from biology such as self-adaptation, self-diagnosis, and selfhealing. To prove this concept, an innovative system with applying the advanced information and communication technology such as internet of things, cognitive agent are proposed to integrate, organize and allocate the machining resources. Innovative system is essential for modern machining system to flexibly and quickly adapt to new challenges of manufacturing environment.

Sensing Performance of Efficient Cyclostationary Detector with Multiple Antennas in Multipath Fading and Lognormal Shadowing Environments

  • Zhu, Ying;Liu, Jia;Feng, Zhiyong;Zhang, Ping
    • Journal of Communications and Networks
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    • 제16권2호
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    • pp.162-171
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    • 2014
  • Spectrum sensing is a key technical challenge for cognitive radio (CR). It is well known that multicycle cyclostationarity (MC) detection is a powerful method for spectrum sensing. However, a conventional MC detector is difficult to implement because of its high computational complexity. This paper considers reducing computational complexity by simplifying the test statistic of a conventional MC detector. On the basis of this simplification process, an improved MC detector is proposed. Compared with the conventional detector, the proposed detector has low-computational complexity and high-accuracy sensing performance. Subsequently, the sensing performance is further investigated for the cases of Rayleigh, Nakagami-m, Rician, and Rayleigh fading and lognormal shadowing channels. Furthermore, square-law combining (SLC) is introduced to improve the detection capability in fading and shadowing environments. The corresponding closed-form expressions of average detection probability are derived for each case by the moment generation function (MGF) and contour integral approaches. Finally, illustrative and analytical results show the efficiency and reliability of the proposed detector and the improvement in sensing performance by SLC in multipath fading and lognormal shadowing environments.

형태에 있어서 미학 특성의 평가를 위한 스키마 표현과 방법론의 이론적 고찰 (Shape Schema representation for Evaluation of Aesthetic value on Shape)

  • 차명열
    • 디자인학연구
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    • 제16권2호
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    • pp.141-150
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    • 2003
  • 건축디자인을 평가하는 방법에는 상당히 맡은 요소를 고려 할 수 있다. 기능성, 구조성, 형태, 환경 등 다양한 요소를 고려하여 최종의 디자인을 생산해 낸다. 여기서 computer와 같은 자동화된 기계에 의해서 디자인이 생성된다면, 그 결과는 경우에 따라서 무수히 맡아 우리 인간의 평가 능력 범위를 넘는 수 가 있다. 따라서 디자인을 자동으로 생산할 뿐 만 아니라 자동으로 최선의 결과물을 자동적으로 평가하여 선택하는 것도 상당히 중요하다. 본 논문에서는 상기에서 언급한 요소 중 미학적 특성을 기계가 자동으로 평가하여 최적의 결과물을 선택할 수 있도록 평가 방법을 제시하였다. 평가 방법은 고전적으로 내려오는 미적 평가방법의 하나인 질서와 무질서의 상관 관계를 측정하는 것으로 이는 형태요소와 공간관계를 나타내는 형태 디자인 지식의 스키마적 표현을 적용한다.

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