• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.1
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• pp.17-23
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• 2007

The home network has been revitalized due to the emergence of the high-speed broadband network and explosive increases of the home network services. Especially multicast based high-definition (HD) IPTV service is on high demand from both Internet service provider (ISP) and users. In order to provide high quality HD IPTV service without packet loss and delay, the ISP utilizes various network QoS mechanisms. Due to the misleading fact, that the home gateway is considered as an end terminal in terms of the ISP's viewpoint, the ISPs can not guarantee the end-to-end QoS within the scope of the current home network architecture. Therefore, an independent QoS guaranteed mechanism should be considered within the home network domain. As the home gateway manages both private home and public access network within the home network, we propose and implement a novel QoS mechanism for the multicast based HD IPTV service over the home gateway. In order to provide QoS guaranteed HD IPTV service, the proposed mechanism classifies the packets, manages home network bandwidth resources, and executes call admission control using the channel join message. Also, we utilize layer 2 multicast packet forwarding scheme to improve the overall performance of the home network services. Through the experiments of implementing the multicast based HD IPTV services, we will verify the efficiency of the proposed mechanism.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2430-2441
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• 2000

A visual concurrent programming environment, called ESTGVP is designed and implemented, which is easy to understand, highly portable, and can represent parallel behaviors. For our purpose, a conventional state transition graph is extended so as to enable both of synchronous and asynchronous parallel operations. We call it extended state transition graph (ESTG). ESTGVP uses the ESTG and texts for programming, and makes it easy programming sequential and parallel behaviors. Also, it is easy to understand the control structure of a program because ESTGVP is a visual programming environment based on the graph. ESTGVP is written in Tel language and thus it is highly portable on various operating systems. It consists of three major components; edition, transformation and execution. If necessary, ESTG can be transformed into C or Tel language, and its execution is based on Tel.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.21-31
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• 1994

This paper describes the multichannel combined R2MFC/DTMF/CCT reciver which provides a signaling service functions for call processing control in digital switching system. Using the TMS320C25 DSP chip, we have implemented multi-function receriver shich processes 8 channels of R2MFC, DTMF, and CCT signals simultaneously. In order to increase the channel multiplicity of the combined receiver. R2MFC and CCT receiver were employed by discrete Fourier transform(DFT) method using Goertzel algorithm, and DTMFreceiver was employ by infinite impulse reponse(IIR) filtering method using 4KHz subsampling technique. The combined receiver has 4 function modes for each channel such as R2MFC, DTMF, CCT, and Idle modes. The function mode of each channel may be selected at any time by single-chip micro-controller(.mu.C). Hence, the number of channels assigned for each function mode can be adjusted dynamically according to the signaling traffic variations. From the experimental test results using the test-bed, it has been proved that the combined receiver statisfies all receiver satisfies all receiver specifications, and provides good channel multiplicity and performance, Therefore, it may give a great improvement than existing receiver in cost, reliability, availability, and serviceability.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup2
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• pp.1-5
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• 2016

To reduce tobacco use and related harm in Korea, telephone based cessation services (Quitlines) began full operation to provide regular behavioral counseling for smoking cessation in 2006. After registration in the cessation program, at least 21 calls per year are given to each client to help quit and encourage maintenance. Tailored programs for males, females, and adolescent smokers have been offered taking into account smokers' characteristics and smoking behavior. Mailing self-help quit packs and e-mail and SMS services are allowable as additional services.A total of 23,201 smokers were registered on the Quitline program from 2006 to 2014. In 2014, an average of 13,343 calls per month have been received by 28 coaches, the 1 year abstinence rate of clients is 26%, and clients' satisfaction rate is 81.6%. After introduction of the call system in 2007, client convenience and effective operations have been achieved with high technology support of a computer-based telephone system. Systematic education and evaluation programs for quit coaches have contributed to quality assurance of the services. Currently, research into development of new programs and evaluation of Quitline performance is being undertaken. A Comprehensive Multi-channel Cessation Center (CMCC) has been suggested and is now planned as a next step in the national program for smoking cessation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.439-440
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• 2006

This research proposes a novel method of shape display to present 3-dimensional objects. Shape displays allow us to feel the actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wire frame structure to present 3D objects. The wire frame is composed of small units driven by shape memory alloy(SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wire frame structure. By controlling the current into the SMA actuator and locking mechanism, we call control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

• Journal of Internet Computing and Services
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• v.3 no.3
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• pp.95-104
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• 2002

The interworking for voice service between next generation mobile network and traditional network can be deployed better flexible and expansible network conditions with providing efficiency and economy of network at the same time. So it is essential to develop the interworking strategies together with a evolved network and traditional network. This paper describes a design and verification of internetworking protocol for CC of next generation mobile network and SIP of IP network for applying interworking technology to next generation mobile network, which can harmoniously expropraise voice service from traditional network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1801-1816
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• 2014

Because HTTP-related ports are allowed through firewalls, they are an obvious point for launching cyber attacks. In particular, malware uses HTTP protocols to communicate with their master servers. We call this an HTTP-based command and control (C&C) server. Most previous studies concentrated on the behavioral pattern of C&Cs. However, these approaches need a well-defined white list to reduce the false positive rate because there are many benign applications, such as automatic update checks and web refreshes, that have a periodic access pattern. In this paper, we focus on finding new discriminative features of HTTP-based C&Cs by analyzing HTTP activity sets. First, a C&C shows a few connections at a time (low density). Second, the content of a request or a response is changed frequently among consecutive C&Cs (high content variability). Based on these two features, we propose a novel C&C analysis mechanism that detects the HTTP-based C&C. The HAS-Analyzer can classify the HTTP-based C&C with an accuracy of more than 96% and a false positive rate of 1.3% without using any white list.

• Journal of Electrical Engineering and information Science
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• v.2 no.3
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• pp.29-40
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• 1997

Two asymptotic analyses of the queue length distribution at a statistical multiplexor supporting heterogeneous exponential on-off sources are considered. The first analysis is performed by approximating the cell generation rates as a multi-dimensional Ornstein-Uhlenbeck process and then applying the Benes queueing formula. In the second analysis, w state with a system of linear equations derived from the exact expressions of the dominant eigenvalue of the matrix governing the queue length distribution. Assuming that there are a large number of sources, we obtain asymptotic approximations to the dominant eigenvalue. Based on the analyses, we define a traffic descriptor to include the mean and the variance of the cell generation rate and a burstiness measure. A simple expression for the quality of service (QoS) in cell loss rate is derived in terms of the traffic descriptor parameters and the multiplexor parameters (output link capacity and buffer size). The result is then used to quantify the factors determining the required capacity of a call taking the statistical multiplexing gain into consideration. As an application of the analyses, we can use the required capacity calculation for simple yet effective connection admission control(CAC) algorithms.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.35-39
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• 2010

UCC is a key characteristic of so-called Web 2.0 which encourage the publishing of one's own content and commenting on other people's. Nowadays, UCC has become a widely used. Accordingly, problem of copyright become a issue. In this paper, we propose the DRM system for UCC rights protection. The system solve the copyright problem in UCC. Therefore, UCC creator can exert the right of UCC. In addition, if the problem of copyright occur, we can find the illegal user and call a him to account by CE information which is stored in UCC server and have a property that a manufacture of original contents can control the copyright.

• The KIPS Transactions:PartA
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• v.13A no.7 s.104
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• pp.599-606
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• 2006

As the P2P service does not have any administration authorities that are able to manage the behavior of participants and control the malicious users, malicious user can give harm to legitimate users for the benefit of themselves. To perform the secure transaction with new members who did not have past experiences on transaction, service users can differentiate malicious users and legitimate users by referring to the reputation information that provided by users having past experience. However, users can intentionally give false evaluation to other users on Performed transaction. We call these users as 'liar'. In this Paper, we propose a new reputation system for liar reduction to guarantee an accuracy on reputation information.