• 제목/요약/키워드: cognitive simulation

검색결과 462건 처리시간 0.024초

Fault Diagnostic System Based on Fuzzy Time Cognitive Map

  • Lee, Kee-Sang;Kim, Sung-Ho
    • Transactions on Control, Automation and Systems Engineering
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    • 제1권1호
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    • pp.62-68
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    • 1999
  • FCM(Fuzzy Cognitive Map) is proposed for representing causal reasoning. Its structure allows systematic causal reasoning through a forward inference. Authors have already proposed a diagnostic system based on FCM to utilized to identify the true origin of fault by on-line pattern diagnosis. In FCM based fault diagnosis, Temporal Associative Memories (TAM) recall of FCM is utilized to identify the true origin of fault by on-line pattern match where predicted pattern sequences obtained from TAM recall of fault FCM models are compared with actually observed ones. In engineering processes, the propagation delays are induced by the dynamics of processes and may vary with variables involved. However, disregarding such propagation delays in FCM-based fault diagnosis may lead to erroneous diagnostic results. To solve the problem, a concept of FTCM(Fuzzy Time Cognitive Map) is introduced into FCM-based fault diagnosis in this work. Expecially, translation method of FTCM makes it possible to diagnose the fault for some discrete time. Simulation studies through two-tank system is carried out to verify the effectiveness of the proposed diagnostic scheme.

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Optimal Sensing Time for Maximizing the Throughput of Cognitive Radio Using Superposition Cooperative Spectrum Sensing

  • Vu-Van, Hiep;Koo, Insoo
    • Journal of information and communication convergence engineering
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    • 제13권4호
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    • pp.221-227
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    • 2015
  • Spectrum sensing plays an essential role in a cognitive radio network, which enables opportunistic access to an underutilized licensed spectrum. In conventional cooperative spectrum sensing (CSS), all cognitive users (CUs) in the network spend the same amount of time on spectrum sensing and waste time in remaining silent when other CUs report their sensing results to the fusion center. This problem is solved by the superposition cooperative spectrum sensing (SPCSS) scheme, where the sensing time of a CU is extended to the reporting time of the other CUs. Subsequently, SPCSS assigns the CUs different sensing times and thus affects both the sensing performance and the throughput of the system. In this paper, we propose an algorithm to determine the optimal sensing time of each CU for SPCSS that maximizes the achieved system throughput. The simulation results prove that the proposed scheme can significantly improve the throughput of the cognitive radio network compared with the conventional CSS.

Development of Fruit and Vegetable Peels Extracts for Memory Improvement of Prevention and Treatment of Cognitive Impairment

  • Kim, Hyun-Kyoung
    • International journal of advanced smart convergence
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    • 제7권3호
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    • pp.1-7
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    • 2018
  • This study relates to a composition for improvement of memory or prevention and treatment of cognitive impairment using waste resources rich in beneficial substances. This study makes good effects to inhibit the activity of acetylcholinesterase in brain tissue and to improve the cognitive functions in a simulation model of cognitive impairment induced by scopolamine, so it can be available in the promotion of memory and the prevention and treatment of cognitive impairment. The composition uses the extract of fruit peels, which have long been used without causing toxicity in a wide range of food applications; therefore, it can be used safely without a risk of side effects, even in the case of a long-term administration for the preventive purpose. Furthermore, this research is a very beneficial invention in the environment-friendly aspect in association with the recycling of resources, as it is based on the novel efficacies of fruit peels, which have been conventionally disposed as a refuse of fruits due to their poor sensory qualities despite the content of beneficial substances.

Enhanced Adaptive Beamforming and Null Steering Algorithms in Cognitive Radio System

  • 장치리;손성환;김재명
    • 한국통신학회논문지
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    • 제34권11A호
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    • pp.822-830
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    • 2009
  • The spectrum efficiency of mobile communication networks can be improved dramatically adopting multiple antennas technologies. In order to guarantee the licensed rights of primary user (PU), the cognitive radio system should perform in a relatively low interference manner when it gets access to the spectrum of licensed networks. In this paper, we explore a uniformly distributed circular antenna array to implement beamforming algorithm that is accomplished by optimization method at the base station of cognitive radio networks, and therefore we can suppress the interference to PU by steering quite low transmission power toward PU and constructing a narrow beam toward cognitive user (CU). By reducing the constraint number of the optimization problem, we also propose a null steering algorithm that steers rather low radiation power toward PU, while the other areas in the same cell are covered by radiation power except the local area around PU. It is pursued to reduce the computation load and enlarge the capacity of cognitive radio networks extremely. The simulation results demonstrate that the proposed algorithms process superior performance.

A study on the perception of occupational therapy majors on Cognitive Impairment Screening Test (CIST)

  • Lee, Sun-myung;Chae, Joo-hyun;Sung, I-sul;Lee, Soo-jin;Moon, Soo-bin;Park, Da-hee;Park, So-hyun
    • 한국임상보건과학회지
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    • 제9권2호
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    • pp.1493-1501
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    • 2021
  • Purpose: The purpose of this study is to classify the characteristics of each item of CIST evaluation and to find out the degree of recognition of the characteristics of the cognitive tool. Methods: This study was conducted for occupational therapy majors at M University located in Gyeongsangnam-do. The data collection from May to June 2021. Total of 25 copies of the data were finally analyzed, SPSS Statistics 26 was used for data analysis. Results: As a result of the study, the significance level was visual reasoning 1 test strip and the visual reasoning 1 tool. In the relationship between the correspondence 1 figure simulation sheet and the figure simulation tool for each item and statistically significant, and the correspondence 2 visual reasoning 2 sheet. Visual reasoning 2 sheet and visual reasoning tool also showed that was found to be statistically significant. The correlation for visual reasoning 1 sheet and the visual reasoning 1 tool, reasoning 2 tool and visual reasoning 1 sheet, and the visual reasoning 2 tool and the verbal reasoning sheet. Conclusion: In this study, in the CIST items that may be difficult, it is better to attach the actual tool rather than the verbal explanation of the test paper to increase the efficiency of the test and the understanding of subjects with mild cognitive impairment. It was implemented by applying the tool, and it was found that the use of the tool in the visual reasoning item showed a high correlation by item. Furthermore, based on this study, it will be possible to suggest a method to control the difficulty of each subject of the cognitive evaluation tool, and to prepare a standard for future research.

인지 라디오 시스템에서 주파수 상황인지 능력 향상을 위한 감지 채널 스케줄링 기법 (A Sensing Channel Scheduling Scheme for Improving the Cognition Ability in Cognitive Radio Systems)

  • 한정애;전화숙
    • 한국정보과학회논문지:정보통신
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    • 제35권2호
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    • pp.130-138
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    • 2008
  • 주파수 상황에 대해 정확히 인지하는 기법은 사용되고 있지 않은 주파수를 활용하는 인지 라디오 시스템에서 중요한 연구 과제 중 하나이다. 본 논문에서는 인지 라디오 ad hoc 네트워크에서 주파수 상황인지 능력을 향상시키기 위한 감지(sensing) 채널 선택 기법을 제안한다. 제안하는 기법은 각 인지 라디오 사용자가 감지한 정보를 활용함으로써 협동 감지를 실현할 수 있도록, 마스터(master)를 가지는 일종의 클러스터(Cluster)를 이루어 채널 상황 정보를 수집/분석한다. 특히, 라이센스를 가진 사용자의 전송 반경이 한정되어 있다는 점을 활용하여 인지 라디오 사용자들이 각기 다른 주파수 대역을 감지하게 함으로써 좀 더 빠르고 정확하게 주파수 대역의 상황을 인지한다. 제안하는 기법의 성능을 시뮬레이션을 통해 평가하고 마스터 없이 개별적으로 주파수 상황을 인지하는 기법과 클러스터를 이루되 공간적으로 채널이 비어있을 수 있다는 점을 활용하지 않는 기법과 성능을 비교하였다. 시뮬레이션 결과 제안하는 기법이 많은 빈 채널을 확보하면서도 빠른 시간 내에 라이센스 사용자를 발견함으로써 라이센스 사용자와 인지 라디오 사용자의 요구를 동시에 만족시킬 수 있음을 보였다.

인지과학의 관점에서 본 서사극 이론 (Epic Theatre Reexamined from the Viewpoint of Cognitive Science)

  • 김용수
    • 한국연극학
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    • 제49호
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    • pp.133-169
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    • 2013
  • Reexamining Brecht's theoretical hypotheses in terms of cognitive science, this essay arrived at several temporary interpretations. Cognitive science implies that empathy can precede the rational understanding in Verfremdungseffekt. The spectator tends to simulate the unfamiliar incident and character and feels the consequential embodied emotion that leads to the cognitive understanding. The similar situation can be found in social gestus. According to cognitive science, gesture(social gestus) is simulated in the mirror-neuron of spectator, arousing consequently the embodied emotion that triggers the succeeding understanding. The spectator apts to experience and feel physically the moving gesture before decoding it as a social signification. Brecht's intention that attempts to reveal the duality of actor and character by eliminating the fourth wall is negated by cognitive science. According to the theory of conceptual blending, the spectator under the eliminated fourth wall mixes actor and character, and simulates this blending image so that he experiences it imaginatively. As such, another kind of illusion can be formed when a fourth wall is collapsed. Meanwhile, the critical thinking of spectator Brecht wanted can be hard to occur during the performance. It is necessary for the spectator to recollect the bygone dialogue and action in terms of social context as if he presses the pause, stopping the playback while watching a play in video. In this respect the social meaning Brecht intended can be achieved more effectively by the stop motion like tableau. It would not only give the time for the spectator to consider the implied social signification, but also make him possible to decode a semiotic meaning as if interpreting a still picture. Or it can be delivered by the dialogue that expresses the playwright's critical judgement. In this case, the subject of critical thinking is not the spectator but the author. The alternative explanation that the cognitive science suggests illuminates theoretically the reasons why Brecht's theory fails to be realized in practice. In a sense, Brecht's theory is nothing but a theoretical hypothesis. It takes the premise that the emotion hinders the rational thinking, understanding emotion and reason oppositively like Plato. This assumption is negated easily by the recent cognitive science that sees the reason as a by-product of physical experience including emotion. The rational understanding, in this sense, begins from the embodied emotion. As such the cognitive science denies the dichotomy of emotion and reason that Brecht adopted. The theoretical hypothesis of cognitive science makes us recognize again the importance of bodily experience in theatre. In theatre the spectator tends to experience physically before decoding the intellectual meaning. The spectator Brecht wanted, therefore, is far from the reality. The spectator usually experiences and reacts physically before decoding the meaning critically. Thus Brecht's intention can be realized by the embodied emotion resulted from simulation. This tentative interpretation suggests that we need to pay more attention to the empirical study of spectatorship, not remaining in a speculative study.

퍼지인식도와 미분게임에 기초한 전략계획 시뮬레이션에 관한 연구 (A Study on the Strategic Planning Simulation Based on Fuzzy Cognitive Map and Differential Game)

  • 이건창
    • 한국시뮬레이션학회논문지
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    • 제4권1호
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    • pp.45-57
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    • 1995
  • 본 연구는 불확실한 경영환경하에서 전략목표에 영향을 미치는 환경요인을 확인하고, 이를 다시 전략계획 시뮬레이션 모형에 체계적으로 반영하기 위한 새로운 전략계획 시뮬레이션 모형을 제안한다. 본 연구에서 제안하는 전략계획 시뮬레이션 모형은 (1) 환경요인 분석을 위하여 퍼지인식도(Fuzzy Cognitive Map)를 적용하고, (2) 경쟁관계를 체계적으로 반영하기 위하여 미분게임(Differential Game) 모형을 이용한다. 퍼지인식도는 특정 의사결정 문제에 있어서 관련된 여러 개념간의 인과관계를 해석하고 그를 통하여 해당 문제전체에 관한 효과적인 의사결정을 지원하는 소위 구조적 모형화(Structural Modeling)도구의 한 방법이다. 한편, 본 연구에서는 미분게임을 이용하여, 퍼지인식도에 의하여 확인된 환경요인을 변수로 감안하고, 아울러 경쟁관계를 수식화 하므로써 보다 체계적인 시뮬레이션이 가능하다. 제안된 전략계획 수립 시뮬레이션 모형을 동태적 광고모형(dynamic advertising model)에 적용하므로써 보다 효과적인 경영전략계획 수립이 가능함을 보였다.

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From Thinking to Action: The Moderating Effect of Perspective Taking on Embodied Cognition

  • Min, Dongwon;Kang, Hyunmo
    • Asia Marketing Journal
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    • 제15권2호
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    • pp.117-132
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    • 2013
  • Recent developments in embodied cognition suggest that people process environmental information by using their bodily state and mental simulation. The focus of embodiment theory is that cognitive processing is based on the interaction among the body, the mind, and the world. Based on embodied theories of cognition, the authors predict that when the representation of marathon running is activated, bodily feedback such as tiredness and thirst will occur because mental simulation of marathon running contains sensorimotor representation of marathon running. As a result, it is predicted that participants primed with marathon runner will have more desire to have products that enable thirsty-quenching. Specifically, this research proposes that consumers' tendency to adopt the perspective of others influences embodied cognition, since perspective taking leads people to assimilate their own self-judgments and behaviors toward the cognitive representations of others. An experiment reveals that both perceptual and cognitive perspective taking tendencies moderate how participants respond to the contextual cues. The effect of perspective taking is moderated by whether participants are prompted to adopt a first-person view or a third-person view. In detail, among the high perspective takers, those in the marathon-first-person condition drink more the mineral water than those in the marathon-third-person condition, who in turn drink more the mineral water than those in the control condition. Among the low perceptual perspective takers, however, there are no significant differences in the amount of mineral water intake. This research delivers important insights for advertising messages. When being exposed to an advertisement, high perspective taking consumers may be more engaged in the advertised message than low perspective taking consumers, which in turn high (vs. low) perspective taking consumers' tendency to respond behaviorally consistent with the message may be higher. Based on the findings of this research, if the message induces the high perspective taking consumers to have a first- (vs. third-) person view, this effect may be stronger. Moreover, if the advertising message contains behaviors, such as using the target product, inducing consumers to mimic the behaviors seems to bring more behavioral responses which marketers intend.

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무선 인지 네트워크에서 위성을 이용한 적응적인 자원 할당 기법 (An Adaptive Resource Allocation Scheme in Cognitive Radio Network Assisted Satellite)

  • 이선영;손성환;장성진;김재명
    • 한국위성정보통신학회논문지
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    • 제4권2호
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    • pp.5-11
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    • 2009
  • 본 논문에서는 무선 인지 시스템 사용자의 전송 품질을 향상시킬 수 있는 위성을 이용한 무선 인지 시스템의 무선 자원 할당 방법을 제안한다. 무선 인지 시스템은 주파수 사용의 효율성을 높이기 위해 제안된 시스템이다. 무선 인지 시스템은 주사용자의 성능에 영향을 미치지 않도록 동작하여야 하기 때문에 무선 인지 시스템 사용자의 상황에 따라서 전송 품질을 보장할 수 없는 경우가 생긴다. 특히, 무선 인지 시스템의 사용자가 늘어날수록 주사용자에게 미치는 간섭 외에도 무선 인지 사용자간의 간섭 또한 증가하기 때문에 시스템 성능이 저하 될 수 있다. 이런 문제를 해결하기 위해 무선 인지 시스템과 위성을 이용한 적응적인 자원 할당 기법을 제안한다. 이 방법을 통해 무선 인지 시스템의 성능을 향상 시킬 수 있다.

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