• Journal of Communications and Networks
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• v.8 no.3
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• pp.290-296
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• 2006

In this paper, a generalized blind adaptive algorithm is introduced for multi-user detection of direct sequence code division multiple access (OS-COMA) wireless communication systems. The main property of the proposed algorithm is its ability to resolve the multipath fading channel resulting in inter symbol interference (ISI) as well as multiple access interference (MAI). Other remarkable properties are its low complexity and mitigation to the near-far problem as well as its insensitivity to asynchronous transmission. The proposed system is based on the minimization of the output energy and convergence to the minimum mean square error (MMSE) detector. It is blind in the sense that it needs no knowledge of the other users' signatures, only the intended user signature and timing are required. Furthermore, the convergence of the minimum output energy (MOE) detector to the MMSE detector is analytically proven in case of M-ary PSK. Depicted results show that the performance of the generalized system dominates those previously considered. Further improvements are obtained when multiple input multiple output (MIMO) technique is employed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.264-270
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• 2006

In this paper we verified that the window based TCP performance of throughput can be improved by the traffic connection efficiency. and have studied the performance of traffic congestion control that is controlling transmission rate. In wireless network, the bidirectional node is run by estimating the usage rate of link of error control idle and the throughput is shown by transmitting segments. The throughput rate shows almost no delay due to the bidirectional traffic connection efficiency up to the allowable point as increasing the transport rate by the critical value, depending on the size of end-to-end node queue of the increase of transport rate. This paper reports the performance improvement as the number of feedback connection traffic congestion control increases because of the increase of the number of asynchronous transport TCP connections.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1266-1268
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• 1996

In this study an automatic roiling-coli labeling system using robot vision system and peripheral mechanism is proposed and implemented, which instead of the manual labor to attach labels Rolling-coils in a steel miil. The binary image process for the image processing is performed with the threshold, and the contour line is converted to the binary gradient which detects the discontinuous variation of brightness of rolling-coils. The moment invariants algorithm proposed by Hu is used to make it easy to recognize even when the position of the center are different from the trained data. The position error compensation algorithm of six degrees of freedom industrial robot manipulator is also developed and the data of the position of the center rolling-coils, which is obtained by floor mount camera, are transfered by asynchronous communication method. Therefore even if the position of center is changed, robot moves to the position of center and performs the labeling work successfully. Therefore, this system can be improved the safety and efficiency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.828-836
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• 2008

This paper suggests a method for verification of temporal relations on SMIL 2.0 document using an extended temporal interval model. The SMIL 2.0 document has more asynchronous temporal relations and supports more interactive relations between objects than traditional SMIL document. But it is higher to produce temporal inconsistency by various interactive relations between objects. So the suggested verification method expresses SMIL 2.0 document as functional relations based on an extended temporal interval model and verifies SMIL 2.0 document using interactive relations and temporal intervals between objects. Applications to the verification method are as follows; multiuser interactive contents, online-learning, etc.

• Journal of information and communication convergence engineering
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• v.20 no.3
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• pp.181-188
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• 2022

An intelligent distributed multi-agent system (IDMS) using reinforcement learning (RL) is a challenging and intricate problem in which single or multiple agent(s) aim to achieve their specific goals (sub-goal and final goal), where they move their states in a complex and cluttered environment. The environment provided by the IDMS provides a cumulative optimal reward for each action based on the policy of the learning process. Most actions involve interacting with a given IDMS environment; therefore, it can provide the following elements: a starting agent state, multiple obstacles, agent goals, and a cluttered index. The reward in the environment is also reflected by RL-based agents, in which agents can move randomly or intelligently to reach their respective goals, to improve the agent learning performance. We extend different cases of intelligent multi-agent systems from our previous works: (a) a proposed environment-clutter-based-index for agent sub-goal selection and analysis of its effect, and (b) a newly proposed RL reward scheme based on the environmental clutter-index to identify and analyze the prerequisites and conditions for improving the overall system.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.219-227
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• 2014

Ethernet, ATM, and CAN are wide-utilized communication protocols for information transfer by internet. Many researches about Network Time-delay have been based on network modeling. But almost of them have not shown an optimal solution in various communication environments. So, asynchronous sample system modeling based internet is needed to be robust in various network environments. Also as closed loop system in internet has a different operational characteristics and noise characteristics comparing with conventional control system, new robust control method is needed in instruments which demand to be safe and precise for internet environments. In order to achieve the safe and precise real-time control in remote plant, this paper is aimed to analysis the transfer characteristics and time-delay of control system in cluster web server.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.609-616
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• 2018

The purpose of this study is to describe the technologies necessary to design responsive web with the use of the responsive website based on implementation structure as a prototype. Responsive design means the process of analyzing prototype requirements on the basis of implementation and applying the analysis results to development. The design method based on the principle of priority in development was established, and then flexibility and variability through design formula were set up. After that, the user-oriented primary principle and secondary principle were drawn to establish implementation structure. In the way of discussing compression technologies, a method of combination was searched for, and then a method of asynchronous script scalability in line with a web prototype was found. Today, a website or a web application needs to be adopted and accessed regardless of device types. As a solution, a responsive website design method was found. Important technologies for the implementation structure for the responsive website design method and its relevant prototype website were came up with.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2479-2484
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• 2018

The filter bank multicarrier modulation (FBMC) technique is one of multicarrier modulation technique (MCM), which is mainly used to improve channel capacity of cognitive radio (CR) network and frequency spectrum access technique. The existing FBMC System contains serial to parallel converter, normal QAM modulation, Radix2 inverse FFT, parallel to serial converter and poly phase filter. It needs high area, delay and power consumption. To further reduce the area, delay and power of FBMC structure, a new clock gating technique is applied in the QAM modulation, radix2 multipath delay commutator (R2MDC) based inverse FFT and unified addition and subtraction (UAS) based FIR filter with parallel asynchronous self time adder (PASTA). The clock gating technique is mainly used to reduce the unwanted clock switching activity. The clock gating is nothing but clock signal of flip-flops is controlled by gate (i.e.) AND gate. Hence speed is high and power consumption is low. The comparison between existing QAM and proposed QAM with clock gating technique is carried out to analyze the results. Conversely, the proposed inverse R2MDC FFT with clock gating technique is compared with the existing radix2 inverse FFT. Also the comparison between existing poly phase filter and proposed UAS based FIR filter with PASTA adder is carried out to analyze the performance, area and power consumption individually. The proposed FBMC with clock gating technique offers low power and high speed than the existing FBMC structures.

• Journal of Digital Contents Society
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• v.3 no.1
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• pp.47-57
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• 2002

Recently, wireless networks have been pursuing multimedia data service as voice, data, image, video and various form of data according to development of information communication technology. It guarantees cell delivery delay of real time data in efficient real time multimedia data transfer. Also, it minimizes cell loss rate of non-real time multimedia data. In the wireless ATM, there are based on Asynchronous Transfer Mode(ATM). It implies that there are various service with difficult transmission rates and qualities in the wireless communication network. As a result, it is important to find out the ways to guarantee the Quality of Service(QoS) for each kind of traffic in wireless network. In this thesis, we propose an improved TCRM scheduling algorithms for transmission real-time multimedia data service in wireless ATM Networks. We appear real time multimedia scheduling policy that apply each different method to uplink and downlik to wireless ATM network. It can guarantee QoS requirements for each real time data and non-real time data. It also deals the fairness problem for sharing the scarce wireless resources. We solve fault of TCRM as inefficient problem of non-real data by using arbitrary transmission speed and RB(Reservation Buffer) through VC(Virtual Control) and BS(Base Station).

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.651-656
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• 2010

In the homepage of 16 municipal provincial office of education, school information service displays text-based results through search step or presents the simple information of the selected area when an area is clicked on the static image map. And it has several problems such as server load and slow transfer speed by the search of the synchronous transfer. Thus, in this study, we used the open API of Google map to provide location-based school information and implemented the mash up service for school information with the Ajax program of asynchronous transfer to reduce server load and to increase transmission speed. This service gives the efficiency and convenience to students, teachers, parents and education family members of various levels because it includes the location with school information on a dynamic map.