• Journal of KIISE:Software and Applications
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• v.37 no.5
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• pp.341-353
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• 2010

Mobile Internet Device (MID) allows users to flexibly use various forms of wireless internet such as Wi-Fi, GSM, CDMA, and 3G. Using such Internet, MID users can utilize application services. MID usage is expected to grow due to the benefits of portability, Internet accessibility, and other convenience. However, it has resource constraints such as limited CPU power, small memory size, limited battery life, and small screen size. Consequently, MIDs are not capable to hold large-sized complex applications and to process a large amount of data in memory. An effective solution to remedy these limitations is to develop cloud services for the required application functionality, to deploy them on the server side, and to let MID users access the services through internet. A major concern on running cloud services for MIDs is the potential problems with low Quality of Service (QoS) due to the characteristics of MIDs. Even measuring the QoS of such services is more technically challenging than conventional quality measurements. In this paper, we first identify the characteristics of MIDs and cloud services for MIDs. Based on these observations, we derive a number of quality attributes and their metrics for measuring QoS of mobile services. A case study of applying the proposed quality model is presented to show its effectiveness and applicability.

• Journal of Distribution Research
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• v.16 no.3
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• pp.33-75
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• 2011

The ownership structure of a franchise system is determined by the franchisor's strategic choice. A close look at the extant theories and perspectives in economics and management such as resource scarcity theory, agency theory, transaction cost analysis, and mixed ownership theory reveals that firms choose their ownership structure for the sake of economic efficiency, profit potentials, the chance of survival, and other strategic concerns. The present study, on the basis of strategic choice perspective, reviews the divergent theories of a franchise system's ownership structure and its determinants, thus providing a theoretical framework for comparing the contradictory arguments along the several critical dimensions. We also developed and tested the conflicting hypotheses regarding key determinants of ownership structure including firm's age, size, transaction-specific investments, uncertainty, and risk-sharing propensity. Using a FDD (Franchise Disclosure Document) data set of 543 Korean franchisors, we found that the years in business, the total number of employees, days of training, the inverse of the years of franchising, and the requirement of royalty payment have positive relationships with the proportion of company-owned outlets to total number of outlets. On the other hand, the proportion of company-owned outlets was found to have negative relationships with the total number of outlets and the extent of geographic dispersion of outlets, but to have no significant relationships with the initial investment required and the inverse of contract length. Based on the findings, we provide several theoretical and managerial implications for studying ownership structure of franchise systems.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.149-155
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• 2003

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP. According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• Journal of KIISE:Information Networking
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• v.35 no.1
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• pp.21-33
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• 2008

The wireless sensor nodes near to the fixed sink node suffer from the quickly exhausted battery energy. To address this problem, the mobile sink node has been applied to distribute the energy consumption into all wireless sensor nodes. However, since the mobile sink node moves, the data collection scheduling scheme is necessary for the sink node to receive the data from all sensor nodes as fair as possible. The application fields of wireless sensor network need the real-time processing. If the uneven data collection occurs in the wireless sensor network, the real-time processing for the urgent events can not be satisfied. In this paper, a new method is proposed to support the lair data collection between all sensor nodes. The proposed method performs the scheduling algorithm based on the resident time of the sink node staying in a radius of communication range and the amount of data transferred already. In this paper, the proposed method and existing data collection scheduling schemes are evaluated in wireless sensor network with the mobile sink node. The result shows that the proposed method provides the best fairness among all data collection schemes.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.234-244
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• 2007

Both competent authorities and private entrepreneurs face plenty of risks when negotiating BTO(Build Transfer Operation) methods of PPI(Private Participations in Infrastructures) projects. Also, success and failure of projects largely depend on the concession agreement contract. In this study, for more efficient negotiation, major issues are examined, and quantitatively analyzed to find out not only the relationship but also the characteristics of which these issues share. Questionnaire research was conducted through both research and by experts who were divided into an ordering agency, design company and constructor. Characteristics of major issues were quantitatively analyzed using the Likert index method, ANOVA(ANalysis of VAriance) and AHP(Analytic Hierarchy Process) analysis. Case studies were examined in order to estimate construction cost, rates of return, government finance support, level of operation-revenues guarantees, estimating operational costs and usage fees. With these 6 items, relative priority, relative impression which is sensible to risk and extent of difficulty in presenting data which is objective were quantitatively analyzed by the ordering agency, design company and constructor groups. From the analysis, there were some similarities between the design company and constructor groups while there was less of similarities between the ordering agency and design company or constructor. The government is diversifying the methods of project promotion, and PPI project from infrastructure-centered to public culture facilities are being expand. The current study will provide not only supporting efficient negotiation but also revitalizing PPI projects.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.3
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• pp.189-199
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• 2009

The amount of information on the Web is explosively growing as the Internet gains in popularity. However, only a small portion of the information on the Web is truly relevant or useful to the user. Thus, offering suitable information according to user demand is an important subject in information retrieval. In e-commerce, the recommender system is essential to revitalize commercial transactions, raise user satisfaction and loyalty towards the information provider. The existing recommender systems are mostly based on user data collected at servers, so user data are dispersed over several servers. Therefore, web servers that lack sufficient user behavior data cannot easily infer user preferences. Also, if the user visits the server infrequently, it may be hard to reflect the dynamically changing user's interest. This paper proposes a novel personalization system analyzing the user preference based on web documents that are accessed by the user on a user device. The system also identifies non-content blocks appearing repeatedly in the dynamically generated web documents, and adds weight to the keywords extracted from the hyperlink sentence selected by the user. Therefore, the system establishes at an early stage recommendation strategies for the web server that has little user data. Also, user profiles are generated rapidly and more accurately by identifying the information blocks. In order to evaluate the proposed system, this study collected web data and purchase history from users who have current purchase activity. Then, we computed the similarity between purchase data and the user profile. We confirm the accuracy of the generated user profile since the web page containing the purchased item has higher correlation than other item pages.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.3
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• pp.159-168
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• 2012

Relation in the new IT environment, such as the SNS, Cloud, Web3.0, has become an important factor. And these relations generate a transaction. However, existing relational database and graph database does not processe graph structure representing the relationships and transactions. This paper, we propose the technique that can be processed concurrently graph structures and transactions in a scalable complex network system. The proposed technique simultaneously save and navigate graph structures and transactions using the Topic Maps data model. Topic Maps is one of ontology language to implement the semantic web(Web 3.0). It has been used as the navigator of the information through the association of the information resources. In this paper, the architecture of the proposed technique was implemented and design using Cassandra - one of column type NoSQL. It is to ensure that can handle up to Big Data-level data using distributed processing. Finally, the experiments showed about the process of storage and query about typical RDBMS Oracle and the proposed technique to the same data source and the same questions. It can show that is expressed by the relationship without the 'join' enough alternative to the role of the RDBMS.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.121-131
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• 2014

Due to the high UV light scattering effect of Zinc oxide (ZnO), it is frequently used in sunscreen skincare products. Recently ZnO coated with silica has been used in cosmetics to improve UV protection, texture, decreased photocatalytic activity, dispersibility and stability of the skin care product. In this study, we developed a ZnO composite powder coated with silica for the future application to skincare products to block UV rays that could cause photoaging. To improve consumer's satisfaction rating, we used ZnO microparticles which are widely used in the cosmetics industry. The silica was coated using hydrothermal method with sodium silicate and acid hydrolysis. UV protection of the composite powder was analyzed by UV-Vis and in-vitro test and the advantages for practical use of this powder as a skincare product were determined.

• Korean Security Journal
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• no.59
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• pp.91-108
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• 2019

The purpose of this study is to investigate the relationship between the number of first aid training and safety performance. The researcher's questionnaire consisted of three variables: necessity of first aid education, application to security practice, and improvement of job satisfaction. In this study, Chronbach's Alpha coefficients were calculated to measure the internal validity for the reliability of the questionnaire. In order to verify the validity of the measured variables, exploratory factor analysis was carried out using the Berimax rotation method. The mean variance extracted AVE and the conceptual reliability CR value of the measurement result variables were both above the allowable reference value of 0.5 and it was judged to be a good test in terms of intensive validity. As a result of the hypothesis test, the standardization coefficient was 1.106 for 'necessity of first aid education ⇒ applied to security practice work', and 'applied to security work practice ⇒ improvement of job satisfaction' was 1.063 and the relationship of hypothesis 1 hypothesis 2 was significant (+), Respectively. Therefore, in order to increase the job satisfaction of security related workers, it is necessary to support first aid education and to receive first aid education.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.46-48
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• 2002

본 연구는 신문지 고지의 점착성 이물질 중 Primary Stickies의 정 량에 관한 것으로 서, 실제 신문지료를 화상분석하여 실시간으로 매크로크기의 점착성 이물질올 측정할 때 효율적인 측정조건을 탐색하여 제지공정의 l 현장에서 일차 점착성 이물질을 정량 하는 새로운 측정기의 측정 기준을 제시하고자 하였다. 이물질이란 제지공정에 의도적으로 첨가되지 않은 불질의 총칭으로 dirt 및 각종 점착 성 이물질 즉, stickies를 들 수 있다. 이 가운데 스틱키{stickies}란 부드럽고, 점착성을 나타내는 이물질의 총청으로 주로 점착제와 확스에 의해 형성된다. 스틱키는 고지 재활 용의 효율성을 가장 크게 저해하는 이물질로 와이어, 펠트 및 기타 공정요소에 부착되 어 초지 시 지절을 발생시킴으로써 생산성을 저하시킬 뿐 아니라, 외관상 상품가치와 인쇄적성올 저하시키며, 최종 제품의 강도적 물성 및 가공적성에도 영향을 미친다. 특 히 국내에서는 원가절감을 위해 고지의 재활용율올 증대시키고자 전력을 다하고 있으 며 환경보호 및 용수 절감올 위해 공정수를 절감하고 궁극적으로는 무방류화를 목표로 하고 있어 토지 계 내의 점착성 이물질의 투입과 농축 현상이 심각하게 진행되고 있는 실정이다. 초지공정에서 발생하는 스틱키 즉 점착성 이물질은 미세한 스크린의 슬롯 폭인 0.15 - -0.3mm 이상의 크기를 가져 스크린에 의해 분리될 수 있는 매크로 스틱키{macro s stickies}와 이보다 작은 마이크로 스틱키(micro stickies)로 크게 분류된다. 즉 매크로 스틱키는 스크린에 의해 분리될 수 있으나 마이크로 스틱키는 스크린을 통하여 기계적 으로 분리할 수 없다는 문제점을 지니고 있다. 스틱키는 또 거동 특성에 따라 primary s stickies와 secondary stickies로 구분할 수 있다. primary stickies는 펄핑과정에서 점착 성 이물질이 파괴됨에 따라 나타나지만, secondary stickies는 지류 제지공정의 백수에 용해 되거나 분산된 상태인 1때1 이하의 콜로이 드로 폰재 한다. 이 러 한 secondary stickies 는 pH, 온도의 변화나 각종의 첨가제에 의해 웅집이나 홉착 등을 발생할 수 있는 잠재 적 문제점 등을 가지고 있다. 예를 들어 양성 고분자의 첨가는 펄프 섬유를 웅집시킬 뿐 아니라 지료에 함유된 secondary dtickies의 안정성을 저하시켜 응집, 침적시키는 작용을 한다. 따라서 분리가 어렵고, 제지공정에서 문제를 일으키기 쉬운 2차 스퇴키를 적절히 제어하기 위한 기술 개발은 용수절감 뿐 아니라, 초지공정의 침적물 절감을 통 한 공정개선에도 매우 중요한 요소기술이라 할 수 있다.