• The KIPS Transactions:PartC
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• v.8C no.4
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• pp.421-428
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• 2001

위성통신 시스템은 기존의 지상망이나 광 케이블 기술에 비해 통신 대역폭의 유연성과 다중 접속 능력, 이동 통신, 광역성, 멀티포인트 및 브로드캐스팅 등의 고유의 특징으로 인해 초 고속 정보 통신망 구축에 중요한 역할을 할 것이다. 또한 위성통신은 앞으로 도래할 브로드 캐스팅 및 멀티미디어 서비스 등의 통신환경을 지원하며, 지상중계망의 장애 및 트래픽 폭 주시에 대체경로를 제공함으로써 지상망 중심으로 진화·발전되어 온 B-ISDN망과 상호 보 완적인 보완망으로서의 역할을 수행할 것이다. 따라서 지상 B-ISDN과 위성망의 통합은 지 상망의 효율성고 안정성을 향상시킬 수 있을 뿐만 아니라 국가의 모든 통신망을 하나의 정 보 통신망으로 구성하여 국가의 정보를 효율적으로 이용, 관리 및 운용할 수 있기 때문에 위성망과 B-ISDN간의 연동에 대한 연구는 필수적이다. 본 논문에서는 OBP(On-Board Processing) 탑재 위성 B-ISDN 중계망의 호 처리 절차 연구를 수행하는 것으로서, 위성 B-ISDN 구조와 각 지구국별 신호 기능 및 B-ISDN 신호 시스템인 DSS2(Digital Subscriber Signalling No.2) 계층 3 신호 프로토콜, B-ISUP(B-ISDN User Part) 프로토콜, S-BISUP(Satellite BISUP) 프로토콜의 구조를 분석하였다. 또한 점-대-다지점 연결을 위한 B-ISDN의 연결과 소유권 및 각각의 프로토콜에 대한 메시지와 프리미티브를 정의하여, 이 를 토대로 OBP 탑재 위성 B-ISDN 중계망 연동을 위한 기본 호 처리 절차를 설계 및 검증 하고, 이를 구현하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.6
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• pp.361-361
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• 2000

In this paper, we propose a novel control signaling protocol that efficiently controls connection setup and increases the utilization of network resources. The proposed protocol, Separated Control Signaling Protocol(SCSP), separates bearer control from call control lot WDM optical networks. The main function of call control is to check the availability of network resources such as wavelengths and receivers at destination node. Bearer control is to reserve and assign wavelengths. The signaling architecture of this protocol consists of call controller and hearer controller The call controller handles call setup and release, activates the beater controller, and manages the status of call and bearer. The bearer controller reserves wavelengths, sets up bearer, tears down bearer. and notifies the status of beater to call controller. The state transition diagrams of each controller are designed. Using control messages and related primitives, the information flows for call setup and bearer setup, hearer teardown and call release, and reaction for setup failures are described to evaluate the performance. The simulation results show that the separated control signaling protocol is superior to conventional one in terms of call blocking probability and resource utilization.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.7
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• pp.63-70
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• 2004

This paper describes the link layer and physical layer of the Serial ATA which is the next generation for parallel ATA specification that defines data transfer between PC and peripheral storage devices. The link layer consists of CRC generation/error detection, 8b/10b decoding/encoding, primitive generation/detection block. For the physical layer, it includes CDR(Cock Data Recovery), transmission PLL, serializer/de-serializer. It also includes generation and receipt of OOB(Out-Of-Band) signal, impedance calibration, squelch circuit and comma detection/generation. Additionally, this chip includes TCB(Test Control Block) and BIST(Built-In Selt Test) block to ease debugging and verification. It is fabricated with 0.18${\mu}{\textrm}{m}$ standard CMOS cell library. All the function of the link layer operate properly. For the physical layer, all the blocks operate properly but the data transfer is limited to the 1.28Gbps. This is doe to the affection or parasitic elements and is verified with SPICE simulation.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.73-81
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• 2011

The WBAN(Wireless Body Area Network) technology is a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. The The WBAN servides consists of both medical and non-medical applications. The medical application service uses the sensor that transfer the periodic traffic and have different data rates. It uses GTS method to guarantee QoS. In this paper, a new method is proposed, which are suitable design for MAC Protocol. Firstly, MAC frame structure and a primitive based on the WBAN are proposed. Secondly, we proposed the GTS algorithm improved the channel utilization based on the WFQ(Weighted Fair Queuing). The proposed scheduling method is improved channel utilization compared with i-Game(Round Robin scheduling method).

• Journal of KIISE:Information Networking
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• v.32 no.2
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• pp.123-133
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• 2005

In recent years, service discovery is one of the major technologies of home networks which head for a pervasive computing environment. However, existing service discovery techniques are difficult to understand semantics, and they only provide syntactic level service matching. To solve these problems, we have designed and developed ontology for semantic service discovery. Our ontology could enrich the amount of devices and services representations with semantics, and the relation of devices and service could be efficiently described through primitive service. For representing context information of devices, we describe attributes of device including location information, device status and etc. To determine whether the developed ontology can be applied to service discovery systems, we have implemented a semantic service discovery system by extension of the existing Jini lookup service. Also, we have evaluated our ontology with associated software environment according to some experiment scenarios, and have proved the usefulness of our ontology-based semantic service discovery system.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.817-822
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• 2005

Recently tile study that exploits visual information for tile services of robot in indoor environments is active. Conventional image processing approaches are based on the pre-defined geometric models, so their performances are likely to decrease when they are applied to the uncertain and dynamic environments. For this, diverse researches to manage the uncertainty based on the knowledge for improving image recognition performance have been doing. In this paper we propose a Bayesian network modeling method for predicting the existence of target objects when they are occluded by other ones for improving the object detection performance of the service robots. The proposed method makes object relationship, so that it allows to predict the target object through observed ones. For this, we define the design method for small size Bayesian networks (primitive Bayesian netqork), and allow to integrate them following to the situations. The experiments are performed for verifying the performance of constructed model, and they shows $82.8\%$ of accuracy in 5 places.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.775-791
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• 1997

This paper describes Real-Time Trasport Protocol(RTTP) that procisdes for a ; user cmnnection-oriented sercices with performance fuarantee.Assuming that eral-time network services will be provided,RTTP solves provlems at end-hosts.RTTP has defined a new set of primitives for real-time communication servies based on the analysis of uwer requirements on various applications.Introducing the notion of Abstract Network Layer independent of real networks.RTTP's implementation scheme can be applied to various netwoeks.The study also intriduces an inplemenation strategy, provide prdeictability of protocol processing time,wich should be known a priori for performance guarantee.Intermally,RTTP has a set of QoS translation rules that change a user'w performance requirements to the equivalent network QoS paramenters.RTTP also introuduces a new apportunistic error control mehtod that can trade-off between overhead and error corredtion according to a uwer's requirement on reliability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.7B
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• pp.710-720
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• 2009

The Future Generation Networks(FGNs) are proposed to integrate various heterogeneous access technologies, and further expected to support both vertical and seamless handovers. In this motivation, the IEEE 802.21 specifies Media Independent Handover(Mlli) services to enhance the mobile user experience by optimizing handovers between heterogeneous access networks. Additionally, Fast handover for MIPv6(FM1Pv6) is introduced to provide transparent host mobility and to improve handover performance by reducing handover delay as well. This paper focuses on the coordination of FMIPv6 and MIH, and introduces an enhanced mobility management framework suited for FGN. This novel framework replaces handover signaling messages used in wireless networks with novel MIH messages and local primitives. Moreover, Serving Access Router(SAR) performs most of handover processes instead of Mobile Node(MN). Therefore, the proposed mobility management framework reduces handover latency, packet loss, and signaling overhead significantly. We further evaluate the performance of the proposed framework by using both numerical analysis and network simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.925-932
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• 2012

In this paper, we develop a pattern recognition algorithm applied to a humanoid robot which is exploited as a guide for visually handicapped persons to find a desired path to their destinations. Behavior primitives of a humanoid robot are defined, and Canny's edge detection algorithm is employed to extract the pattern and color of the paving blocks that especially devised for visually handicapped persons. Based on these, an efficient path finding algorithm is developed and implemented on a humanoid robot, running on an embedded linux operating system equipped with a video camera. The performance of our algorithm is experimentally examined in terms of the response time and the pattern recognition ratio. In order to validate our algorithm in various realistic environments, the experiments are repeatedly performed by changing the tilt of paving blocks and the brightness in surrounding area. The results show that our algorithm performs sufficiently well to be exploited as a path finding system for visually handicapped persons.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2473-2481
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• 2014

The majority of next generation information systems will be working on portable mobile devices such as smartphones. REST Open API web services have quickly become popular among mobile application development. The use of REST web services are not only growing in popularity but totally changing the way of mobile applications development. This is because REST web services could be used in application development as a form of building blocks, which is completely independent, compatible, to any platforms. With this strength, REST web services encourage third party application to build add-on functionality. This research proposes the use of REST web service to replace the use of socket APIs into major internet communication APIs. To this end, this paper also provide performance evaluation of the REST web services compared to the conventional socket APIs, focusing on scalability by analytical and experimental evaluations. Finally, we summarize the possibility whether REST Open API web services have enough performance as future major internet communication primitive APIs.