• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.644-655
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• 2015

This study was planned to examine the moderating effects of depression and anxiety and the relationship between online game addiction and adolescents' delinquency. Data were collected from children and youth's mental health advocacy research by National Youth Policy Institute. The subjects were 409 adolescents aged between 14 and 18. Correlational analysis and hierarchical regression analysis were conducted to test research hypotheses. Results of this study were as follows: first, online game addiction had a significant positive relations with adolescents' delinquency. Second, depression and anxiety were significant positive relations with each other. And depression and anxiety were significant positive relations with adolescents' delinquency. The result from hierarchical regression analysis showed that significant moderating effect of depression was found. But the result wasn't exhibited twithin hat the two-way interaction effects of depression. On the other hand, result from hierarchical regression analysis showed that significant moderating effect of anxiety wasn't found. In conclusion, this study proposed the need for counseling approach focused on 'depression' in order to reduce the adolescent's delinquency.

• Journal of KIISE:Databases
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• v.31 no.2
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• pp.132-139
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• 2004

A range $Top-\kappa$ query returns top k records in order of a measure attribute within a specified region on multi-dimensional data, and it is a powerful tool for analysis in spatial databases and data warehouse environments. In this paper, we propose an algorithm for answering the query via selective traverse of a Hierarchical Max R-Tree(HMR-tree). It is possible to execute the query by accessing only a small part of the leaf nodes in the query region, and the query performance is nearly constant regardless of the size of the query region. The algorithm manages the priority queue efficiently to reduce cost of handling the queue and the proposed HMR-tree can guarantee the same fan-out as the original R-tree.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1168-1179
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• 2007

The objective of this research is to validate the BRQ(Brand Relationship Quality) Construct perceived by fashion product consumers. In order to establish and verify the BRQ scale, qualitative survey and quantitative survey were conducted together. 1592 copies of questionnaire were distributed to women in their 20s to 40s living in Seoul and other metropolitan areas from Dec. 26, 2005 to Jan. 8, 2006, and 723 copies of them were used for statistical data. Samplel(n=482)was used for empirical analysis, and sample2(n=241) was used for cross validity test. The data was analyzed using Exploratory Factor Analysis, Confirmatory Factor Analysis, and Pearson's Correlation Analysis. BRQ emerged from exploratory factor analysis as the hierarchical construct composed of six facets including 'self-connective attachment', 'symbol/mystery', 'trust', 'nostalgia', 'intimacy', and 'knowledge'. As the fit of this structural model was not good as a result of Confirmatory Factor Analysis, it was revised to have better fitting. Finally, empirical survey results indicate the hierarchical construct consisting of eight distinct BRQ facets including 'love/commitment', 'self-connection', 'symbol', 'mystery', 'trust', 'nostalgia', 'intimacy', and 'knowledge' as best representing the final 39item BRQ Scale. Reliability, construct validity, and cross validity of the construct were verified.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.2042-2060
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• 2013

In wireless sensor networks (WSNs), energy efficiency is one of the most essential design considerations, since sensor nodes are resource constrained. Group communication can reduce WSNs communication overhead by sending a message to multiple nodes in one packet. In this paper, in order to simultaneously resolve the transmission security and scalability in WSNs group communications, we propose a hierarchical cluster-based secure and scalable group key management scheme, called HRKT, based on logic key tree and route key tree structure. The HRKT scheme divides the group key into cluster head key and cluster key. The cluster head generates a route key tree according to the route topology of the cluster. This hierarchical key structure facilitates local secure communications taking advantage of the fact that the nodes at a contiguous place usually communicate with each other more frequently. In HRKT scheme, the key updates are confined in a cluster, so the cost of the key updates is reduced efficiently, especially in the case of massive membership changes. The security analysis shows that the HRKT scheme meets the requirements of group communication. In addition, performance simulation results also demonstrate its efficiency in terms of low storage and flexibility when membership changes massively.

• Journal of Korea Game Society
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• v.8 no.1
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• pp.79-90
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• 2008

This paper describes a motivation-based hierarchical behavior planning framework to allow autonomous agents to select adaptive actions in simulation game environments. The combined behavior planning system is formed by four levels of specification, which are motivation extraction, goal list generation, action list determination and optimization. Our model increases the complexity of virtual human behavior planning by adding motivation with sudden and cumulative attributes. The motivation selection by probability distribution allows NPC to make multiple decisions in certain situations in order to embody realistic virtual humans. Hierarchical goal tree enhances the effective reactivity. Optimizing for potential actions provides NPC with safe and satisfying actions to adapt to the virtual environment. A restaurant simulation game was used to elucidate the mechanism of the framework.

• Journal of Communications and Networks
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• v.13 no.4
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• pp.319-326
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• 2011

Beamforming techniques have been successfully utilized for traffic channels in order to solve the interference problem. However, their use for control channels has not been sufficiently investigated. In this paper, a (semi-) centralized beamforming strategy that adaptively changes beam patterns and controls the total transmit power of cells is proposed for the performance enhancement of the common channel in hierarchical cell structure (HCS) networks. In addition, some examples of its practical implementation with low complexity are presented for two-tier HCS networks consisting of macro and pico cells. The performance of the proposed scheme has been evaluated through multi-cell system-level simulations under optimistic and pessimistic interference scenarios. The cumulative distribution function of user geometry or channel quality has been used as a performance metric since in the case of common control channel the number of outage users is more important than the sum rate. Simulation results confirm that the proposed scheme provides a significant gain compared to the random beamforming scheme as well as conventional systems that do not use the proposed algorithm. Finally, the proposed scheme can be applied simultaneously to several adjacent macro and pico cells even if it is designed primarily for the pico cell within macro cells.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.5
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• pp.261-271
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• 1988

This paper presents a hierarchical algorithm of the measurement system design by system partitioning. With the increase of system size, the conventional algorithms of the optimal measurement system design confront the problems of excessive memory requirements, long computation time and cumulative computation errors. In order to overcome these problems, a hierarchical approach by system partitioning is proposed with the introduction of equivalent measurements for all the extemal measurements. This approach has the advantage of remarkable reduction in computation time and memory requirements, and guarantees sufficient calculation accuracy in its application to large power systems. The proposed algorithm has been tested for various systems, which shows its applicability to practical power systems.

• Journal of Digital Contents Society
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• v.14 no.2
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• pp.143-149
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• 2013

Many researchers and developers take a greater interest on the LOD AI techniques as users demand more elaborate and sophisticated game AI in recent years. However, contrary to the traditional geometry LOD, existing LOD AI techniques can be used only to a limited extent. Therefore, in this paper, I propose an LOD AI technique, which uses HSM(Hierarchical State Machine) and the Lua script language as the method to control game objects. Using the proposed approach, we can easily produce multilevel AI models for LOD and design various objects without hard-coding state machines. Moreover, in order to show the effectiveness of the presented technique, this paper exemplifies the results of the efficiency test through the prototype engine.

• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.93-101
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• 2010

Although various network management architectures such as centralized, distributed, and hybrid have been presented, any one is not always efficient in all the environment. In this paper, we propose a hierarchical and split network management architecture based on MA+SNMP in order to manage a network of many small NEs distributed over the wide area. Our hierarchical architecture has MA-based proxy management nodes for the flexibility and overhead reduction in NMS as well as SNMP-based NEs considering NE's capacity. Through the analysis with real experiments, we show that our proposal improves some drawbacks and the processing delay of the existing architectures in the given environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8A
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• pp.779-785
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• 2002

This paper presents a phase-based stereo matching algorithm in order to efficiently extract 3-dimensional objects from two 2D images. Conventional phase-based methods, especially using windowed Fourier phases, inherit good properties in the case of hierarchical approaches, because they basically use a multi-resolution phase map. On the contrary, their computational costs are very heavy. Therefore, a fast hierarchical approach, using multi-resolution phase-based strategy and reducing the redundancy of phase calculations, is proposed in this pare. In addition, a structural matching algorithm on the phase domain is adopted to improve the matching quality. In experimental results, it is shown that the computation loads are considerably reduced about 8 times and stable outputs are obtained.