• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.111-118
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• 2013

The connection based TCP protocol provides reliable packet delivery, but it takes certain overhead compare to the connection-less UDP protocol. Thus, 3GPP devise the upper-layer RLC protocol which provides reliability based upon the UDP protocol. Consequently, each implement of a base station and/or mobile terminal require the development of the RLC protocol, and it must qualify various interoperable tests. In this paper, we implement a testbed which verifies the RLC protocol under various packet losses/inversion circumstances of networks. Finally, we propose our testbed as the RLC protocol tester for the developments.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.4
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• pp.65-74
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• 2010

This study is for Hanbuk Mountain Range within Gyeonggi province which is to propose the conservation plan by each damage pattern through site survey of the mountain range. The damage patterns are classified by siding, pointing and lining. The total damaged area is 103 areas: The siding pattern is damaged by developing farmland, mineral and quarry mining, dam, large scale development complex and cemetery park; The pointing pattern is including the development of road, transmission tower and way and mountaineering trail; The construction of electricity and communication facility, military facility, mobile communication station, heliport and shelter. The damages by developing road and large scale development complex are the most cause, and military facility, dam and reservoir, and residential area are the main causes, respectively. One of the compromised situation Hanbuk-Mountain Range usage as per section 7 section (18.45%), 12 section (18.45%) is the largest number of compromised has been surveyed, undermine the situation if you look at the usage by the road 25 locations (24.22%), military facilities and dam and reservoir to undermine this 11 established respectively (10.68%) were the most undermine. Therefore, this research propose the conservation plan as follow: first, need to understand, educate and publicize on Hanbuk-Mounatin Range; second, manage through the regulations and ordinance of Gyeonggi province; third build and expand the law for protecting Baekdu-Great Mountain Range.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.1-7
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• 2011

Cell Capacity and cell layout are strongly dependent on the up-link interference caused by out-of-cell mobiles. Accurate prediction of the propagation path loss from out-of-cell mobiles is essential to achieve system designs that minimize the infrastructure required for a given quality of service (QOS). Less accurate predictions can be expected to yield designs requiring the use of a greater number of base stations. In order to quantify the dependence of infrastructure on prediction accuracy, this paper considers the cellular systems, LOS (line of sight) cells along a road or highway.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.260-263
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• 2003

This paper has developed the computer integration manufacturing system and Internet based tele-operations. The functions of CIMS include production planing, material requirement planning, work order generation, process control, quality control, shipping planning, warehouse and inventory management and material cost accounting.[1] In this paper focuses on the automatic warehouse control and inventory management by developing the information system as well as the Internet-based integration. The system overview is divided into three parts, the mechanical system, the computer and developed software to control and manage the information and the communication system. The mechanical system consists of the warehouse machine and forklift mobile robot controlled by programmable logic controller (PLC). The computer works on many functions such as control station interfaces with PLC, managing database and inventory, and Internet server to broadcast the inventory database to users via World Wide Web and monitoring the operation on web camera. Our scheme the inventory database can be checked easily anywhere and anytime when the users connect to the Internet. In this article, the lead-time and inventory level can be reduced therefore the holding cost and operating time is also decreased.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.9-17
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• 2004

In this paper, we examine the MIMO(Multiple Input Multiple Output) system in the point of mobile communication that is used for railway environment. First, under the radio environment, wireless channel characteristics are analyzed between moving train and base station, both assuming track side base stations and non-track side base stations. Next, the paper introduces the MIMO system which can be used to solve the problem of performance degradation in railway environment, and analyzes its performance in terms of channel capacity and diversity. We especially compares open-loop scheme with closed loop scheme at the diversity and analyses their performance according to antenna correlation. Finally, the we presents experimental result from the ESCORT project that was studied in railway environment with the MIMO system.

• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.28-35
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• 2018

The following research has focused and implemented on designing a system that classifies the severity of mass casualty situations across both normal and disaster levels. The system's algorithm has implemented requirements such as accuracy as well as user convenience. The developed e-Triage System has applied various severity classification algorithms implemented from IoT concepts. In order to overcome flaws of currently used severity classification systems, the e-Triage System used electronic elements including the NFC module. By using the mobile application's severity classification algorithm the system demonstrated quick and accurate assessment of patient. Four different LED lamps visualized the severity classification results and RTS scores were portrayed through FND(Flexible Numeric Display) after a two wave classification.

• ETRI Journal
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• v.40 no.3
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• pp.318-329
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• 2018

Femtocell (FC) technology envisaged as a cost-effective approach to attain better indoor coverage of mobile voice and data service. Deployment of FCs over macrocell forms a heterogeneous network. In urban areas, the key factor limits the successful deployment of FCs is inter-cell interference (ICI), which severely affects the performance of victim users. Autonomous FC transmission power setting is one straightforward way for coordinating ICI in the downlink. Application of intelligent control using soft computing techniques has not yet explored well for wireless networks. In this work, autonomous FC transmission power setting strategy using Adaptive Neuro Fuzzy Inference System is proposed. The main advantage of the proposed method is zero signaling overhead, reduced computational complexity and bare minimum delay in performing power setting of FC base station because only the periodic channel measurement reports fed back by the user equipment are needed. System level simulation results validate the effectiveness of the proposed method by providing much better throughput, even under high interference activation scenario and cell edge users can be prevented from going outage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.11
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• pp.771-778
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• 2014

We propose Femto-cell power control scheme in HeNet with Game Theory. The Femto-cell which provide high quality with low power is issued by many benefits, however there is a bunch of interferences when many Femto-cells use overlapped bandwidth with Macro-cell. We defined base station of cellular networks and mobile users as players of Game Theory, and configured interference effect among each other as power utility function. Futhermore, we showed enhanced overall system performance, lower power usage and interference decrease by using optimal power.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2697-2710
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• 2018

Owing to the development of Internet of Things (IoT), the fifth-generation (5G) wireless communication is going to foresee a substantial increase of mobile traffic demand. Energy efficiency and spectral efficiency are the challenges in a 5G network. Non-orthogonal multiple access (NOMA) is a promising technique to increase the system efficiency by adaptive power control (PC) in a 5G network. This paper proposes an efficient PC scheme based on evolutionary game theory (EGT) model for uplink power-domain NOMA system. The proposed PC scheme allows users to adaptively adjusts their transmit power level in order to improve their payoffs or throughput which results in an increase of the system efficiency. In order to separate the user signals, a successive interference cancellation (SIC) receiver installed at the base station (BS) site. The simulation results demonstrate that the proposed EGT-based PC scheme outperforms the traditional game theory-based PC schemes and orthogonal multiple access (OMA) in terms of energy efficiency and spectral efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.2
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• pp.187-194
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• 2014

In this paper, we analyze the outage probability of macro diversity combining in cellular networks in consideration of aggregate interference from other mobile stations (MSs). Different from existing works analyzing the outage probability of macro diversity combining, we focus on a diversity gain attained by selecting a base station (BS) subject to relatively low aggregate interference. In our model, MSs are randomly located according to a Poisson point process. The outage probability is analyzed by approximating the multivariate distribution of aggregate interferences on multiple BSs by a multivariate lognormal distribution.