• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.2972-2991
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• 2016

WLAN is the best choice in the place where complex network is hard to set up. Intelligent terminals are more and more assembled in some areas now. However, according to IEEE 802.11n/802.11ac, the access-point (AP) can only serve one user at a single frequency channel. The spectrum efficiency urgently needs to be improved. In theory, AP with multi-antenna can serve multiple users if these users do not interfere with each other. In this paper, we propose a user clustering scheme that could achieve multi-user selection through the mutual cooperation among users. We focus on two points, one is to achieve multi-user communication with multiple antennas technique at a single frequency channel, and the other one is to use a way of distributed users' collaboration to determine the multi-user selection for user clustering. Firstly, we use the CSMA/CA protocol to select the first user, and then we set this user as a source node using users' cooperation to search other proper users. With the help of the users' broadcast cooperation, we can search and select other appropriate user (while the number of access users is limited by the number of antennas in AP) to access AP with the first user simultaneously. In the network node searching, we propose a maximum degree energy routing searching algorithm, which uses the shortest time and traverses as many users as possible. We carried out the necessary analysis and simulation to prove the feasibility of the scheme. We hope this work may provide a new idea for the solution of the multiple access problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3455-3461
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• 2015

LTE and Wi-Fi networks provide wireless communication services to passengers in subway where the number of network access fluctuates according to passenger movement. While the number of network access increase, LTE can provide stable communication service but Wi-Fi suffers temporal access delay to network. This paper analyzes the increase in access delay of Wi-Fi network according to increasing user in subway section by making mathematical modeling of Wi-Fi network and simulation study. The access delay characteristics of Wi-Fi network is measured along an subway line and the results are compared to the theoretical study. These results can be applied to the connection method to build an efficient network structure between LTE and Wi-Fi interworking network and the future introduction of LTE-R.

• Management & Information Systems Review
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• v.37 no.4
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• pp.125-140
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• 2018

Technology cooperation is a necessary factor for small and medium sized firms to be survived and developed because small and medium sized firms can make economy scale and economy scope by new advanced technologies obtained from technology cooperation. Therefore, the technology cooperation of small and medium sized firms can be thought as their specific resource. Due to the importance of technology cooperation, many previous studies paid an attention on its positive effect. Unlike the related studies, this study examined the link among uncertainty of technology environment, relationship characteristics(such as degree of technology cooperation and influential strategy), and relationship tie. The empirical results are reported as follows: Firstly, uncertainty of technology environment positively affected on degree of technology cooperation. Secondly, degree of technology cooperation positively affected on uncoercive influential strategies of both own firm and partner firm. Thirdly, degree of technology cooperation and uncoercive influential strategy of own firm have positive effects on relationship tie while uncoercive influential strategy of partner firm does not. The positive effect of uncoercive influential strategy of own firm means the importance of strategic countermeasures to promote relationship tie in technology cooperation of both own firm and partner firm.

• Journal of the Korean Professional Engineers Association
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• v.33 no.4
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• pp.17-26
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• 2000

This study has been done to make a practical suggestion in figuring out required size of electricity power facility in preparation for reunion of Korean Peninsula, estimated based on capacity increase and demand changes in the past. In making the suggestion, balanced development of South and North Korea Economy, recovery of existing power facilities, and construction of new power facilities were taken into consideration. As an alternatives, study result of power system interconnections in Korean Peninsula and/or in North-East Asia Region, PEACE Network, is suggested with a cooperation scheme of information and communications technology as an extra advantage. Concluded a cooperation of electric power system and information & communications technology in the peninsula is expected to be a great opportunity in developing electric power economy, maintaining clear environment, improving security of power supply in the region, and in reunion of Korean Peninsula and peace in the world.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6196-6203
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• 2013

This study examined cadastral surveying technology regulated under the "Special Law for the cadastral surveying", and analyzed the related surveying methods currently used. Based on the analysis, this study suggested the efficient application plan future cadastral surveying projects. The new technologies analyzed were GNSS, GPS RTK, Network RTK, GPS Augmentation System, and the mobile and auto sighting TS. As a result of the analysis, this study suggests that if a receiving technology is possible for the integrated receiving of GPS/GLONASS/Galileo systems, both the accuracy of location determination could be enhanced and stable data could be obtained. The Network RTK technology may solve the constraint receiving factors of satellite information in the long term if a GPS Augmentation System is used. Finally, mobile and auto sighting TS technologies can reduce the personnel factors, but can be applied after the offset problem is overcome.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.668-670
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• 2011

본 논문에서는 고속 무선 데이터 전송을 위하여 멀티버스 구조 및 유연적인 데이터 버퍼시스템을 갖는 향상된 바이너리 CDMA에 시스템 설계에 관한 것이다. 개선된 바이너리 CDMA 시스템 구조는 제한된 리소스에서 시스템 버스의 Latency를 최대한 줄이고 고속 무선 데이터 전송을 위하여 버퍼접근구조를 변경하여 데이터 throughput을 향상하였다.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.1
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• pp.102-115
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• 2004

Recently, the cooperation among Korea, Japan, and China for the standardization of information technology is very well done due to the mutual countries' interests. Especially, in the field of digital home, that is consisted of next generation digital home technology and service based on the ubiquitous computing, the Korea and Japan have endeavored for several years, and now they are in good will competition in technology and the mutual cooperation for the standardization. In this article, the current trends of Japanese and Korean technology and service in ubiquitous home are discussed. From this discussion, the comparison between Japan and Korea will be used for the industrialization based on the best aspects from the view points of each other's technology and approach.

• Asia-Pacific Journal of Business
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• v.10 no.4
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• pp.49-63
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• 2019

The export regulation of semiconductor core materials, which began with the recent revision of the export management regulations of Japan, raises the need for a new cooperation network. A hierarchical management network that was effective in the fast-follower system requires organic cooperation between the public sector and industry through a multilateral network that emphasizes horizontal co-operation among innovation actors. This study focused on the relational capital that exists among members of a business association such as an association that has been relatively marginalized from previous studies. In addition, this study aimed to analyze the effect of network activity characteristics such as industry-university linkage and informal exchange on technological innovation. Through this, I would like to draw implications for enhancing the effectiveness of the government's R & D support and innovation performance of R & D companies. Based on the results of the SMEs R & D survey, this study found that relational capital, informal exchange had a positive effect on technological innovation performance. However, if the relational capital exceeds a certain level, it is analyzed that there is a negative effect due to group think and lock-in effect. This means that informal exchange channels should be expanded for innovation and enhancement, and relational capital should be managed in consideration of the negative effects that may occur when certain levels are exceeded.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2267-2285
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• 2016

Information Centric Networking that uses content name instead of IP address as routing identifier can handle challenges such as traffic explosion and user mobility, but it also suffers from scalability and incompatibility problems. In this paper by combining the concept of software defined networking and Internet end to end arguments, we propose a wide area deployable software defined information centric networking service model named SD-ICN. SD-ICN employs a dual space structure that separates edge service network and core transmission network. The enhanced SDN techniques are used in edge service network in order to implement intelligent data routing and caching, while traditional IP technique is reserved in core transmission network so as to provide wide area high speed data transmission. Besides, a distributed name resolution system based on the cooperation of different controllers is also presented. The prototype experiments in our campus network show that SD-ICN can be deployed in a scalable and incremental way with no modification of the core network, and can support typical communication modes such as multicast, mobility, multihoming, load balancing, and multipath data transmission effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.694-699
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• 2017

In accordance with the development of information and communications technology, a network user has to be able to use quality of service (QoS)-based multimedia services easily. Thus, information and communications operators began to focus on a technique for providing multimedia services. The IP Multimedia Subsystem (IMS) is a platform based on Internet Protocol (IP) as a technology for providing multimedia services and application services. The emerging 5G networks are described as having massive capacity and connectivity, adaptability, seamless heterogeneity, and great flexibility. The explosive growth in network services and devices for 5G will cause excessive traffic loads. In this paper, software-defined networking (SDN) is applied as a kind of virtualization technology for the network in order to minimize the traffic load, and Simple Network Management Protocol (SNMP) is used to provide more efficient network management. To accomplish these purposes, we suggest the design of a dynamic routing algorithm to be utilized in the IMS network using SDN and an SNMP private management information base (MIB). The proposal in this paper gives information and communications operators the ability to supply more efficient network resources.