• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.344-347
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• 2011

In this paper, we propose the power control problem for cognitive radio networks (CRNs) that maximizes the total utility of the secondary users (SUs). We use the interference temperature constraints to protect the primary users (PUs). The utility functions of SUs can be any increasing functions. We formulate the power control problem as monotonic optimization that can be solved in centralization to achieve the global optimum.

• International Journal of Advanced Culture Technology
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• 제1권2호
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• pp.18-23
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• 2013

In this paper, we consider the problem of designing optimal sensing time and the minimization of energy consumption in the Cognitive radio Network. Trade-off between throughput and the sensing time are observed, and the equations are derived for the optimal choice of design variables. In this paper, we also look at the optimization problem involving all the design parameters together. The advantages of the proposed scheme for the spectrum sensing and access process are shown through simulation.

• Journal of Platform Technology
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• 제9권1호
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• pp.3-14
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• 2021

Cognitive Radio network (CR) is a promising paradigm that helps the unlicensed user (Secondary User) to analyse the spectrum and coordinate the spectrum access to support the creation of common control channel (CCC). The cooperation of secondary users and broadcasting between them is done through transmitting messages in CCC. In case, if the control channels may get jammed and it may directly degrade the network's performance and under such scenario jammers will devastate the control channels. Hopping sequences may be one of the predominant approaches and it may be used to fight against this problem to confront jammer. The jamming attack can be alleviated using one of the game modelling approach and in this proposed scheme stochastic games has been analysed with more single users to provide the flexible control channels against intrusive attacks by mentioning the states of each player, strategies ,actions and players reward. The proposed work uses a modern player action and better strategic view on game theoretic modelling is stochastic game theory has been taken in to consideration and applied to prevent the jamming attack in CR network. The selection of decision is based on Q learning approach to mitigate the jamming nodes using the optimal MDP decision process

• 무역학회지
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• 제44권4호
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• pp.189-203
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• 2019

In recent years, most companies are making strategic strides to respond to changes in the competitive landscape. This trend is proceeding independently from industry to industry, and the Chinese cosmetics industry, which is at its peak, is no exception. In the meantime, the question of whether the concept of strategy group and related theories are suitable for advanced markets and whether they are applicable to emerging markets such as China is an interesting subject of inquiry. The purpose of this study is to classify strategic groups based on the cognitive approach of CEO's in the Chinese cosmetics industry. Some of the existing studies on strategic groups have raised limitations on the theoretical validity of the classification and criteria of strategic groups. However, since the concept of the strategic group becomes a middle level analysis unit between the enterprise and the industry, applying this concept to the Chinese cosmetic industry will help identify the strategic group existing in the industry and grasp the composition of the entire industry.

• 한국실내디자인학회논문집
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• 제20권2호
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• pp.120-130
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• 2011

The purpose of this study is to propose cognitive ecological effects of fractal patterns in space design. This study investigated the perception and cognition problems regarding landscape patterns showing fractal properties from the cognitive perspective instead of the traditional speculative approach. In particular, the researcher has verified that fractal geometry theory and fractal pattern concept provide insight in space aesthetic values and cognitive effects. Research results are as follows. First, most environmentally-friendly fractal urban forms provide cognitive connectivity. In particular, this space provides a positive emotional response and preference to humans and displays self-organized complexity. This study found that such complexity of space form has characteristics corresponding to parallel cognitive structures of the human brain. Simultaneously, the researcher suggests that the fractal landscape pattern is an alternative for stiff and homogenized modern space. Second, fractal patterns provide hierarchical connectivity within the brain through continuous difference and repetition. In particular, self-similarities of fractal patterns administer significant visual grouping and coherence in human perception. It can be determined whether scaling coherence facilitates easier organization in cognitive organization. Third, fractal patterns in space design provide the basic method for achieving the connection between concept, construction, and urban factors. As a result, the researcher has suggested that scale distribution of geometrical factors, such as fractal patterns, an be a design method to connect various space typologies.

• 인지과학
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• 제1권2호
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• pp.193-220
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• 1989

인지과학의 지각심리학적 기초를 모색하기 위해 지각심리학 고유의 연구주제,주요개념 및 방법론 등을 개관하고, 지각심리학에서 인지과학적 물음이 어떻게 제기될 수 있는 지를 검토하였다.지각심리학이 인지과학의 다른 분야들에 제공할 수 있는 기본개념,방법론,현상 등을 정리하고,인지과학적 시각을 받아 들일때,지각심리학자들이 어떤 태도를 취해야 할 지를 논의 하였다.

• 시스템엔지니어링학술지
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• 제9권2호
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• pp.15-22
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• 2013

The aim of this study is to propose the design process suitable for developing the cognitive interface considering system engineering process (SEP) models. Due to the cognitive workload in an operation of HMS, some cognitive interfaces have been developed. It is somehow difficult to use the developed cognitive interface in real working environment since they often showed a conflict to stereotyped interface. So it is necessary to develop the design process suitable for the more operator-specific interface. Various SEP models were reviewed for selecting the suitable design process which might resolve the problem from design-specific interface. The suitable process for designing cognitive interface was proposed considering currently usable SEP models. The findings from the study may be helpful for systematic approach to designing cognitive interface in digitalized environment. The proposed design process would be applied for easily employing the cognitive interface in digitalized working environment such as main control room in nuclear power plant.

• 한국전문물리치료학회지
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• 제30권4호
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• pp.306-313
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• 2023

Background: As social problems due to the acceleration of the aging era and the increase in the elderly population are becoming serious, virtual reality (VR)-based healthcare is emerging as an approach for preventing and managing health issues. Objects: This study used validity and reliability analyses to examine the clinical efficacy that is, the clinical value and usability of a novel VR cognitive evaluation system index that we developed. Methods: We developed a VR cognitive evaluation system based on motion recognition analysis evaluation for individuals aged 65 to 85. After conducting the Korean version of the Mini-Mental State Exam (K-MMSE) cognitive evaluation, the evaluation score was verified through correlation analysis in the VR cognitive evaluation system. To verify the construct validity of the two groups, the Global Deterioration Scale (GDS) grades were categorized into a normal cognitive group (GDS grade 1) and a cognitive impairment group (GDS grades 2 and 3). The data were measured twice to determine the reliability between the two measurements and assess the stability and clinical value of the evaluation system. Results: Our evaluation system had a high correlation of 0.85 with the widely used K-MMSE cognitive evaluation. The system had strong criterion-related validity at the 95% confidence interval. Compared to the average score of GDS grade 1 in the VR cognitive evaluation system, the average score of GDS grades 2 and 3 in the VR cognitive evaluation system was statistically significantly lower while also having strong construct validity at the 95% confidence interval. To measure the reliability of the VR cognitive evaluation system, tests-retests were conducted using the intraclass correlation coefficient (3,1), which equaled 0.923 and was statistically significant. Conclusion: The VR cognitive evaluation system we developed is a valid and reliable clinical tool to distinguish between normal cognitive status and mild cognitive impairment.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제15권4호
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• pp.373-386
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• 2011

Students approach mathematical problem solving in fundamentally different ways, particularly problems requiring conceptual understanding and complicated strategies. The main objective of this study is to compare students' performance with different thinking styles (Field-dependent vs. Field independent) in mathematical problem solving. A sample of 242 high school males and females (17-18 years old) were tested based on the Witkin's cognitive style (Group Embedded Figure Test) and by a math exam designed in accordance with Bloom's Taxonomy of cognitive level. The results obtained indicated that the effect of field dependency on student's mathematical performance was significant. Moreover, field-independent (FI) students showed more effective performance than field-dependent (FD) ones in math tasks. Male students with FI styles achieved higher results compared to female students with FD cognitive style. Moreover, FI students experienced few difficulties than FD students in Bloom's Cognitive Levels. The implications of these results emphasize that cognitive predictor variables (FI vs. FD) could be challenging and rather distinctive factor for students' achievement.

• 한국정보시스템학회지:정보시스템연구
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• 제27권3호
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• pp.203-225
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• 2018

Purpose This study investigated the impact of review language style (affective vs. cognitive) on review helpfulness and the moderating effects of the types of attractions in the relationships between the review language and its helpfulness. Design/methodology/approach This study investigates the impact of review language style (affective vs. cognitive) on review helpfulness and the moderating effects of the types of attractions in the relationships between the review language and its helpfulness. This study selected two hedonic and utilitarian attractions (Hedonic: Brandenburg Gate, Utilitarian: Peragamon Museum) located in Berlin. A total of 3,320 reviews was collected from TripAdvisor. We divided online reviews posted for these places into reviews with more affective language and with more cognitive language by using the LIWC. Then, we investigated the impact of language effect on review helpfulness across the attraction type. Findings The findings suggest that peers tend to judge more helpful toward cognitive language in attraction reviews regardless of attraction type. This study found that peers tend to perceive more helpful toward cognitive review in utilitarian attractions. Even though there was an interaction effect between review language and attraction type, in hedonic attractions, the influence of cognitive language was reduced, but still cognitive reviews would get more helpful votes.