• International Journal of Highway Engineering
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• v.11 no.2
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• pp.121-132
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• 2009

Thin bonded continuously reinforced concrete overlay(CRCO) was constructed on He existing jointed plain concrete pavement(HCP) surface at Seo-Hae-Ahn express highway in South Korea in order to evaluate its applicability and performance. Two sections of road were considered for this evaluation. In the first section, the concrete overlayer was placed and cut down to the existing layer to form transverse joints while CRCO was constructed on top of the existing layer in the second section. Early strength concrete(Type III) was utilized for both overlay sections. The depth of milling and the thickness of overlaid layer were 5 cm and 10 cm, respectively. Several vibrating wire gauges(VWG) were installed to evaluate the performance of CRCO with respect to curling, delamination, and crack propagation. As a result of the strength test, it was found that strength of the material reaches the design criteria within 1-3 days. Analysis with vibrating wire gauge(VWG) showed CRCO effectively restricts joint movement. High adhesive strength also was observed from the material regardless of length of aging. Meanwhile, transverse cracks were observed on the middle of the section where JPCP overlay was applied whereas arbitrarily cracks in transverse direction were observed on the section where CRCP was applied.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.519-527
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• 2011

The e-Learning program is a multimedia data program consisting of texts, images, animation, audio and video. The development of an e-Learning program requires time and is a complex process, requiring cooperation and open-communication between all parties involved, particularly in the event of a problem. This study will analyze the e-Learning contents development process from the Social Negotiation Perspective. An appropriate process for the development of the program and effective decision-making guidelines for those parties involved will be recommended. Participants' viewpoints regarding program development and guidelines were studied qualitatively, while the evaluation of developed content employed both qualitative and quantitative research. The study found the following results. First, the development of an e-Learning program requires a clear goal and purpose. Second, the target group must be clearly identified. Third, all parties involved must share in the development process and its outcomes. Fourth, the party requesting the program must allocate the appropriate time and budget for the development group. Finally, the project requires a strong, capable leadership for effective decision-making.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.311-318
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• 2016

IoT(Internet of Things areas) rich information based on the user easy access to service creation must be one of the power system of specificity due following: The IoT spread obstacle to the act be, and 'Smart Grid information of this is not easy under power plants approach the Directive on the protection measures, particularly when stringent security policies IoT technologies applied to Advanced Metering Infrastructure sector has been desired. This is a situation that occurs is limited to the application and use of IoT technologies in the power system. Power Information Network is whilst closed network operating is has a smart grid infrastructure, smart grid in an open two-way communication for review and although information security vulnerabilities increased risk of accidents increases as according to comprehensive security policies and technologies are required and can. In this paper, the IoT platform architecture design of information systems as part of the power of research and development IoT-based energy information platform aims. And to establish a standard framework for a connection to one 'Sensor-Gateway-Network-platform sensors Service' to provide power based on the IoT services and solutions. Framework is divided into "sensor-gateway" platform to link information modeling and gateways that can accommodate the interlocking standards and handling protocols variety of sensors Based on this real-time data collection, analysis and delivery platform that performs the role of the relevant and to secure technology.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.73-79
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• 2020

The objective of this study is to analyze the heat transfer loss of covering materials in a single-span plastic greenhouse under the steady-state wind environment. To achieve this objective, the following were conducted: (1) design of a small-scaled wind tunnel (SCWT) to analyze heat losses of the greenhouse and its performance; (2) determination of the overall heat transfer coefficient (OHTC) for the covering materials using a small-scaled greenhouse model. The SCWT consists of the blowing, dispersion, steady flow, reduction and testing areas. Each part of the SCWT was customized and designed to maintain air flow at steady state and to minimize the variances in the SCWT test. In this study, the OHTCs of the covering materials were calculated by separating each with the roof, side wall, front and back of the small-scaled greenhouse model. The results of this study show that the OHTC of the roof increases as wind speed increases but the zones in which the increase rate of the OHTC decreased, were distinguished by wind tunnel wing speed of 2 ms^-1. For the side wall, the increase rate of the OHTC was particularly higher in the 0-1 ms^-1 zone.

• Journal of Korea Technology Innovation Society
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• v.20 no.1
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• pp.175-204
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• 2017

The existing innovation policies and strategies mainly focused on the influencing factors for improvement of innovation outcome. However, these strategies were not always successful in driving innovative activities that make technology innovation disseminated. In this regard, innovation ecosystems approach has recently been coming to the force to establish a successful innovation strategy. The innovation ecosystems concept describes that innovation processes are evolved through collaborative networks of economic actors. In an innovation ecosystem, different organizations collaborate for technology development and its use. They interact for value co-creation by sharing mutual resources. The organizational networks are re-organized by dynamic changes of actors' interactions, which drive innovation mechanism of the networks. Recent studies on innovation ecosystems mostly have paid attention on developing theoretical frameworks to describe dynamics of an innovation ecosystem. There have hardly been empirical tests on the theoretical ecosystem models. In this vein, we investigated dynamics of an innovation ecosystem by analyzing structural characteristics of a collaborative network among organizations which are involved in the use of innovative technologies. Particularly, we examined the longitudinal changes of the interaction patterns among the organizations. This test was performed by an analysis of structural equivalence on the network dataset transformed from the organizational interactions. This result provides a guideline for an organization in developing an innovation strategy under a systemic perspective.

• Journal of Convergence Society for SMB
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• v.2 no.1
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• pp.51-58
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• 2012

Android platform is a powerful operating system developed on Linux 2.6 Kernel, and provides many features such as comprehensive libraries, a multimedia environment, and powerful interface for phone applications. Since Android is an open operating system, which can be installed in any vendors's equipments. Current smartphones as well as netbooks, navigations, car PCs, tablet PCs, Industrial PCs are used in various fields. It is difficult a lot that to mount to other devices on the Android platform or new devices. In this Paper, The process that data that occurred from a hardware was passed to the highest application and Android platform system for managing hardware devices were analyzed. Building Android & driver compilation environment, How to support the protocol for the use of WiFi in the kernel, How to Mount a WiFi device in the kernel, Device driver registration for the Android platform, WiFi Management Service Daemon (wpa_supplicant) and IP allocation services daemon (dhcpcd) registration, How to create a socket for communication between the daemon (wpa_supplicant) and HAL have been presented. In the experiment using the proposed method, WiFi devices were mounted on the Android platform in the X-86 & ARM family. Understanding the whole process of control flow in Android hierarchy is very important to porting a new device on it. The process included in this paper can help technicians who might encounter the obstacles in their porting works.

• International Commerce and Information Review
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• v.15 no.2
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• pp.387-410
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• 2013

The competition aspect of business has been transformed from competition among companies to competition among ecosystem, and has been grown to platform based business, which is defined as ecosystem among business. Coming to the spotlight with the advantages of platform business combined software and hardware like Apple, platform business have been emerging in many fields. In this research, we define platform and platform based business, and then review related researches. After this, we review four representative research methodologies which are Yin(2011)' s case analysis research, Eisenhardt(2007)' s case analysis research, Romano etc' s web based qualitative data analysis method(2003), and Creswll(2010)' s open coding technique. And then, we suggest this research' s natural methodology combined with the advantages of four research methodologies. Based on our research methodology, we choose three high commercialized categories, which are smartphone platform business, social platform business, and search engine platform business. And then, we choose seven companies in three categories with success cases & failure cases, and analysis each case in perspective of our research methodology. And then, we suggest critical success & failure elements. Based on our findings, we suggest three strategic elements for the longevity of platform based business. Finally, we suggest the limitations of our research and further research issues.

• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.27-35
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• 2007

When sensor networks are deployed in open environments, all the sensor nodes are vulnerable to physical threat. An attacker can physically capture a sensor node and obtain the security information including the keys used for data authentication. An attacker can easily inject false reports into the sensor network through the compromised node. False report can lead to not only false alarms but also the depletion of limited energy resource in battery powered sensor networks. To overcome this threat, Fan Ye et al. proposed that statistical on-route filtering scheme(SEF) can do verify the false report during the forwarding process. In this scheme, the choice of a security threshold value is important since it trades off detection power and energy, where security threshold value is the number of message authentication code for verification of false report. In this paper, we propose a fuzzy rule-based system for security threshold determination that can conserve energy, while it provides sufficient detection power in the SEF based sensor networks. The fuzzy logic determines a security threshold by considering the probability of a node having non-compromised keys, the number of compromised partitions, and the remaining energy of nodes. The fuzzy based threshold value can conserve energy, while it provides sufficient detection power.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.512-520
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• 2020

Recently, the applications of the standing column well (SCW) ground heat exchanger (GHX) have increased significantly in Korea as a heat transfer mechanism of ground source heat pump systems (GSHP) because of its high heat capacity and efficiency. Among the various design and operating parameters, bleeding was found to be the most important parameter for improving the thermal performance, such as ground thermal conductivity and borehole thermal resistance. In this study, a bleeding analysis model was developed using the thermal response test data, and the effects of bleeding rates and bleeding locations on the thermal performance of anSCW were investigated. The results show that, when the ground water flows into the top of anSCW, the time variation of circulating water temperature decreased with increasing bleeding rate, and the ground thermal conductivity increases by as much as 179% with a 30% bleeding rate. When the ground water flows into the bottom of the SCW, the circulating water temperatures become almost constant after the increase in the beginning time because the circulating water exchanges heat with the ground structure before mixing with the ground water at the bottom.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.2
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• pp.47-58
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• 2013

The purpose of this study is to categorize the types of sidewalk cafes, and to evaluate design factors with types of sidewalk cafes for street revitalization. Consequently, it may suggest efficient and systemic policies for the guidelines of sidewalk cafes. To ensure this end, the types of sidewalk cafes were categorized from the street relationship perspective by site investigation. A literature review and importance analysis were used to select the evaluation criteria, and the data were analyzed by statistic methods such as descriptive analysis and factor analysis. As a result, five main factors of the evaluation criteria were contracted: accessibility, aesthetics, identity, environmental, culturedness. Cumulative factor loading of these five factors was 68.731%, which was quite high. And the evaluation using the Likert scale was performed by 4 experts. Types of sidewalk cafes were categorized into 5 types: protruding, gating, blending stereoscopic, elevation angle, and sign provision from the street relationship perspective. On the evaluation by type, aesthetics and culturedness were the worst evaluated in the protruding type and the gating type, culturedness was the worst in the blending stereoscopic type, accessibility, aesthetics, culturedness were the worst in the elevation angle type, and accessibility, identity, culturedness were the worst in the sign provision type. On the evaluation by the indicators, culturedness was the worst evaluated, and on the evaluation by criteria, 'safety for impaired persons', 'interest of programs', 'openness of entrance' were the worst. It is recommended that a survey of importance-performance analysis focused on users be conducted.