• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.984-998
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• 1999

최근 개인 휴대 통신에 대한 관심도가 증가하면서 B-ISDN (Broadband Integrated Services Digital Network)과 같은 기존의 유선 망에서 제공하던 다양한 멀티미디어 응용 지원을 무선 망으로 확장시키기 위한 연구가 활발히 진행되고 있다. 그러나 기존의 유선 망에서는 멀티미디어 응용 지원을 위해 QoS (Quality of Service) Provisioning에 관한 많은 연구가 되어 있으나 무선 망에서는 이동성과 무선 전파의 열악한 전송으로 인해 새로운 QoS Provisioning 방법에 관한 연구가 필수적이다. 본 논문에서는 이러한 무선 망의 특수성으로 인해 발생할 수 있는 서비스의 질 저하와 강제 종료를 줄임으로써 지속적인 QoS를 보장해 주고 한정된 무선 자원을 효율적으로 사용하며 처리에 의한 오버헤드를 줄이기 위하여 다음과 같은 세 가지 방법을 제안하였다. 첫째, 핸드오프 강제 종료율을 줄이기 위하여 대역폭 예약 방법을 사용하되 특정 셀의 트래픽 특성에 맞게 또한 시간대에 따른 트래픽 특성에 따라 예약 대역폭의 양을 조절하는 적응적 대역폭 예약 방법이다. 둘째, 많은 경우 각 셀의 트랙픽 변화는 일정한 주기로 변화한다는 특성에 따라 과거의 트래픽 정보를 이용하는 예측 기반의 대역폭 예약 방법이다. 마지막으로 호의 종류, 트래픽 특성, 단말기의 이동 속도에 따라 다른 우선 순위에 의해 호 수락 제어를 수행하는 우선 순위 기반의 호 수락 제어를 제안하였다. 시뮬레이션을 통하여 기존에 제안된 방법과 성능 비교하여, 요구되는 수준의 QoS 보장과 효율적인 자원의 사용, 요구되는 처리비용의 최소화를 통해 전체 시스템의 성능 향상을 입증하였다.Abstract As interest in wireless hand-held terminals and in personal communications services increases recently, there have been broad studies on the ways to support multimedia applications provided in wired networks such as B-ISDN (Broadband Integrated Services Digital Network) in wireless networks. However, since many studies have focused on Quality of Service (QoS) Provisioning in wired networks to provide multimedia applications, new methods of QoS Provisioning are needed in wireless networks to resolve the problem of wireless channel fading and the difficulty of mobility occurred in wireless networks. This paper proposes three schemes of QoS Provisioning in wireless networks which will make continuous QoS guarantee and efficient use of limited wireless resources possible. The first scheme reserves bandwidth in proportion to the amount of real-time traffic in the neighbor cells to decrease the handoff dropping rate of delay sensitive real-time connections, adapting reserved bandwidth for efficient resource utilization. The second scheme is predictive bandwidth reservation scheme that utilizes the past handoff information. It can decrease overheads required to adapt bandwidth reservation. The last scheme is priority-based call admission control prioritizing traffic type (real-time traffic/ non-real-time traffic), connection type (new connection /handoff connection), and mobile terminal speed (fast mobile/slow mobile). Simulation results show that the proposed QoS Provisioning schemes improve the total system performance by achieving three goals - required QoS guarantee, higher bandwidth utilization and less overhead.

• The Journal of the Korea Contents Association
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• v.16 no.9
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• pp.443-450
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• 2016

Korean biopharmaceutical industry is a high value-added industries of the country as a key business strategy of the country. The overseas market is accelerating rapidly due to drug demand according to population aging, new drug R&D investment performance visualization, changes in biopharmaceutical R&D center, strategic foreign technology exports, and the active support of government. Therefore, the domestic pharmaceutical companies also should enhance the competitiveness as global pharmaceutical companies and need to build the image of their own company that can be trusted by consumers. This study compared and analyzed visual characteristics shown in the CI symbol mark and age-specific preferences of domestic pharmaceutical companies recognizing the importance of CI as a marketing tool. As a result, preference for the symbol mark had been shown to be significantly higher preference of the old logotype as the age group is higher being proportional to awareness. In addition, the picture-type symbol mark was totally preferred rather than the word mark. Among the picture-type symbol mark, the form of the nature was strongly preferred rather than abstract form. The company also requires a sense of responsibility for recognizing changes in the mass to the globalization. It is hoped that this study will help to develop symbol mark direction as the basis for the identity strategies to improve the image of domestic pharmaceutical companies with global competitiveness.

• Journal of Korea Multimedia Society
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• v.3 no.5
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• pp.526-534
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• 2000

There have been many researches on the 3D graphic accelerator for high speed by needs of CAD/CAM,3D modeling, virtual reality or medical image. In this paper, an SIMD processor architecture for 3D graphic accelerator is proposed in order to improve the processing time of the 3D graphics, and a parallel Phong shading algorithm is presented to estimate performance of the proposed architecture. The proposed SIMD processor architecture for 3D graphic accelerator consists of PCI local bus interface, 16 Processing Elements (PE's), and Park's multi-access memory system (NAMS) that has 17 memory modules. A serial algorithm for Phong shading is modified for the architecture and the main key is to divide a polygon into $4\times{4}$ squares. And, for processing a square, 4 PE's are regarded as a PE Grou logically. Since MAMS can support block access type with interval 1, it is possible that 4 PE Groups process a square at a time. In consequence, 16 pixels are processed simultaneously. The proposed SIMD processor architecture is simulated by CADENCE Verilog-XL that is a package for the hardware simulation. With the same simulated results as that of the serial algorithm, the speed enhancement by the parallel algorithm to the serial one is 5.68.

• Korean Journal of Construction Engineering and Management
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• v.18 no.6
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• pp.3-12
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• 2017

In recent years, Project Management Consultant(PMC) project has been emerging as a high-value-added engineering project. However, domestic engineering firms have difficulties in entering the overseas PMC market because of poor project performance and lack of PMC capabilities. To overcome these limitations, this study analyzes the key competitiveness factors for successfully performing the global PMC projects. PMC competency factors based on Porter's double diamond theory were extracted, and a questionnaire survey was conducted on domestic and overseas engineering firms. In addition, the important PMC competency factors were derived through paired t-test and IPA matrix analysis. As a result, the PMC competitiveness of domestic engineering firms was analyzed as around 60% compared to that of global engineering firms. Furthermore, 'PMC track records' and 'project management/owner response skills' were identified as top priority competency factors which are the most necessary factors for present domestic engineering firms. This study is expected to support to establish the international PMC market entry strategies by providing priorities of key competitiveness factors.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.585-596
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• 2007

XML data generally consists of a hierarchical tree-structure which is reflected in mechanisms to store and retrieve XML data. Therefore, when storing XML data in the database, the hierarchical relationships among the XML elements are taken into consideration during the restructuring and storing of the XML data. Also, in order to support the search queries from the user, a mechanism is needed to compute the hierarchical relationship between the element structures specified by the query. The structural join operation is one solution to this problem, and is an efficient computation method for hierarchical relationships in an in database based on the node numbering scheme. However, in order to process a tree structured XML query which contains a complex nested hierarchical relationship it still needs to carry out multiple structural joins and results in another problem of having a high query execution cost. Therefore, in this paper we provide a preprocessing mechanism for effectively reducing the cost of multiple nested structural joins by applying the concept of equivalence classes and suggest a query path reduction algorithm to shorten the path query which consists of a regular expression. The mechanism is especially devised to reduce path queries containing branch nodes. The experimental results show that the proposed algorithm can reduce the time requited for processing the path queries to 1/3 of the original execution time.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.377-390
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• 2017

When conducting a survey, item nonresponse occurs if the respondent does not respond to some items. Since analysis based only on completely observed data may cause biased results, imputation is often conducted to analyze data in its complete form. The panel study is a survey method that examines changes of responses over time. In panel studies, there has been a preference for using information from response values of previous waves when the imputation of item nonresponses is performed; however, limited research has been conducted to support this preference. Therefore, this study compares the performance of imputation methods according to whether or not information from previous waves is utilized in the panel study. Among imputation methods that utilize information from previous responses, we consider ratio imputation, imputation based on the linear mixed model, and imputation based on the Bayesian linear mixed model approach. We compare the results from these methods against the results of methods that do not use information from previous responses, such as mean imputation and hot deck imputation. Simulation results show that imputation based on the Bayesian linear mixed model performs best and yields small biases and high coverage rates of the 95% confidence interval even at higher nonresponse rates.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.147-156
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• 2010

There are some of the studies on sensor middleware. However the standard middleware has not yet been defined. Especially, this paper focuses on the processing an intelligent service of the main functions of middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services based on sensors. However, the previous studies about USN middleware only mentioned the need for intelligent service and did not discuss the architecture and method for supporting the intelligent service in detail. Therefore this paper designs a USN middleware for providing intelligent services and proposes the method for processing the services. For this purpose, this paper proposes the Sensor-Service ontology to define the concept of services and sensors for USN applications and the relationship between them. The Sensor-Service ontology is used to infer high-level information from low-level information. To apply a variety of environmental context to intelligent services, the paper uses the rule-based reasoning. This paper implements the proposed intelligent service middleware as a prototype and then shows that the middleware can be used for a variety of USN applications through the performance evaluation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.35-46
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• 2011

Future Internet should support more efficient mobility management, flexible traffic engineering and various emerging new services. So, lots of traffic engineering techniques have been suggested and developed, but it's impossible to apply them on the current running commercial Internet. To overcome this problem, OpenFlow protocol was proposed as a technique to control network equipments using network controller with various networking applications. It is a software defined network, so researchers can verify their own traffic engineering techniques by applying them on the controller. In addition, for high-speed packet processing in the OpenFlow network, programmable NetFPGA card with four 1G-interfaces and commercial Procurve OpenFlow switches can be used. In this paper, we implement an OpenFlow test-bed using hardware-accelerated NetFPGA cards and Procurve switches on the KREONET, and implement CSPF (Constraint-based Shortest Path First) algorithm, which is one of popular QoS routing algorithms, and apply it on the large-scale testbed to verify performance and efficiency of multimedia traffic engineering scheme in Future Internet.

• Journal of Distribution Science
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• v.11 no.10
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• pp.5-15
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• 2013

Purpose - With the increase in fervor to purchase luxury brands, new social problems have arisen, such as excessive preoccupation with luxury brands and high preference for forged luxury goods. Therefore, the issues related to luxury brands, termed "Luxury Syndrome," have emerged as an area of great interest for researchers and practitioners. However, previous studies neglect to categorize this preference for luxury brands. Therefore, this study aims to identify the different purchasing behaviors of consumers using the types of luxury brands preferences as parameters. Research design, data, and methodology - This study arranges a causal relationship model assuming that purchase behaviors positively (+) affect typified preference for luxury brands and purchase intentions. We administered a questionnaire survey to the purchasers who bought luxury brands from department stores to secure additional data necessary to verify the hypotheses in this study. We then processed the data using SPSS 19.0. We further analyzed the basic data using frequency and descriptive statistical analysis, and verified the measurement tools through feasibility and reliability analyses. Moreover, this study uses multiple regression analysis to verify the hypotheses. Further, this study tests the path effect between luxury brand purchase attitude and purchase behavior, with non-intrinsic preference and intrinsic preference as the mediating variables. Results - Based on the results, the impact of tendencies of conspicuous consumption and self-monitoring on non-intrinsic preference was significantly positive (+), while the impact of tendencies of pursuit of a reference group, conspicuous consumption, and self-monitoring on intrinsic preference and purchase intentions was significantly positive (+). Further, non-intrinsic and intrinsic preferences positively (+) influence purchase intentions and the impact of non-intrinsic preference took an absolute portion. However, the tendency of dependence on brands negatively (-) impacts purchase intentions. The results showed that self-monitoring and conspicuous consumption tendencies have greater effect on purchase intention, which is mediated by non-intrinsic preference. In contrast, reference group following tendency has a greater effect on purchase intention, which is mediated by intrinsic preference. Conclusions - Based on the results, the study verifies that the consumption of luxury brands in Korea has not yet entered the settling period. The tendency for conspicuous consumption and the tendency for pursuit of the reference group were relatively important aspects for the consumers who prefer luxury brands non-intrinsically and intrinsically, respectively. Especially, it was found that the purchase intentions for forged brands originate from the tendency to depend on brands. Based on these findings, this study suggests the measures to develop and mature the luxury brands market, and reinforce marketing performance at the three levels, that is, government, distributors, and manufacturers. The luxury brands manufacturers should devote themselves to the production and design of products to catch the attention of mature consumers of luxury brands. The luxury brands distributors should then raise the level of Customer Relationship Management (CRM) for opinion leaders. Finally, the Government should prepare effective policies for the development of luxury brands and provide a variety of economic support.

• Journal of Information Management
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• v.42 no.3
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• pp.1-26
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• 2011

The domain of LED is analyzed for describing the current status of Korea's R&D in the domain comparing with those of others quantitatively. Fourteen sub-domains of LED manufacturing technology are selected and the time span for analysis is ten-year: 2001-2010. Bibiliometric analysis is performed by the unit of publication, core researcher, institution and country. Strategical diagram is also produced with devised two indicators: NGI and NPI. As a result, Korea is competitive in the area of Chip Scale Package, but R&D supports in another promising areas, such as large-caliber sapphire wafer, are necessary. It is also revealed that research activities are expanded dominantly in academia, but practical technologies are developed in industrial circle. It is suggested that to support core corporate and to encourage industrial-academic collaboration is essential for systematical technology development and high achievement in prominent areas.