• Journal of Digital Contents Society
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• v.19 no.4
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• pp.639-647
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• 2018

A common core network is the one of main architectural principles in 3GPP 5G System which has common interfaces with different multiple accesses. 3GPP 5G System Phase 1 (Release 15) supports Untrusted Non-3GPP access as well as 3GPP access with common interfaces. Non-3GPP Interworking Function (N3IWF) has been defined to interface with a UE and a core network for supporting Untrusted Non-3GPP access in 3GPP Release 15. However, interworking with Trusted Non-3GPP access is under study to be completed in 3GPP 5G System Phase 2 (Release 16). Therefore, this paper proposes a Trusted Non-3GPP access network architecture and related signaling procedures, and then the implementation based on the proposal shows how to interwork between Trusted Non-3GPP access and the 5G core network. In our proposal, N3IWF can interwork with either Untrusted or Trusted Non-3GPP access without any architectural modification or addition of 3GPP 5G system Phase 1.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.75-83
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• 2008

We propose a welfare interface using multiple fecial features tracking, which can efficiently implement various mouse operations. The proposed system consist of five modules: face detection, eye detection, mouth detection, facial feature tracking, and mouse control. The facial region is first obtained using skin-color model and connected-component analysis(CCs). Thereafter the eye regions are localized using neutral network(NN)-based texture classifier that discriminates the facial region into eye class and non-eye class, and then mouth region is localized using edge detector. Once eye and mouth regions are localized they are continuously and correctly tracking by mean-shift algorithm and template matching, respectively. Based on the tracking results, mouse operations such as movement or click are implemented. To assess the validity of the proposed system, it was applied to the interface system for web browser and was tested on a group of 25 users. The results show that our system have the accuracy of 99% and process more than 21 frame/sec on PC for the $320{\times}240$ size input image, as such it can supply a user-friendly and convenient access to a computer in real-time operation.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.707-710
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• 2005

In this paper, we propose a new communication network for on-chip communication. The network is based on a direct sequence code division multiple access (DS-CDMA) technique. The new communication network is suitable for a parallel processing system and also drastically reduces the I/O pin count. Our network architecture is mainly divided into a CDMA-based network interface (CNI), a communication channel, a synchronizer. The network includes a reverse communication channel for reducing latency. The network decouples computation task from communication task by the CNI. An extreme truncation is considered to simplify the communication link. For the scalability of the network, we use a PN-code reuse method and a hierarchical structure. The network elements have a modular architecture. The communication network is done using fully synthesizable Verilog HDL to enhance the portability between process technologies.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.4
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• pp.277-284
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• 2004

CDMA (Code Division Multiple Access) is a promising air interface technique for digital cellular systems. The soft handoff between base stations is one of many important features of CDMA for the mobile stations crossing the cell boundaries. The service areas of MSC's (Mobile Switching Centers) are defined as the unions of the service areas of the base stations connected to MSC's and are assumed to have hexagonal shapes. An analytical approach to the performance analysis of the link between MSC's for supporting the inter-MSC soft handoff scheme will be developed to obtain the probability that a soft handoff to an adjacent MSC will be blocked due to the shortage of the link capacity. Also, the rate of new connection establishments that are requested by the mobile stations moving to the service area of an MSC according to the inter-MSC soft handoff scheme will be obtained.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.50-58
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• 2007

We design a filtering management scheme with synchronization function under a realtime RFID middleware system for larger-scale data processing. The application interface(AI) is to support a various access protocol, HTTP, XML, JMS, and SOAP for the RFID applications. Generally, the synchronization problem is occurred in multiple accessing of clients for single filtering file. In this paper, we implement a filtering management scheme supporting the synchronization using the filter management process, and then demonstrate the RFID middleware filtering scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.2033-2042
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• 1996

In this papre, we describe a recently implemented echo canceller for digital cellular communication of Code Division Multiple Access(CDMA) that features time sharing of digital signal processor(DSP) over four channels in one DSP to reduce per channel costs. In the Public Land Mobile Network(PLMN), it is important to cancel the echo reflected from the Public Switched Telephone Network(PSTN) side. In case of digital mobile system, the round-trip delay of the echo is in excess of about 180 milliseconds due to frame-by-frame voice coding. It is necessary to cancel the echo in PLMN. We have developed a multi-channel echo canceller tht operates with Time Switch Module in a Mobile Switching Center(MSC). The general echo canceller needs PCM trunk interface circuits and the tone detection and disabling circuits, but the multi-channel echo canceller linked with Time Switch Module does not need them. Therefore we could develop the effective and economical echo canceller.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.152-156
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• 2006

기존의 가정용 건강측정기는 기기만이 독립적으로 사용되거나 기기로부터 생체정보를 전송 받아 로컬 컴퓨터에서만 처리하는 시스템이 주를 이루었다. 본 논문에서는 가정용 건강측정기 중 혈당측정기를 적외선 통신(Infrared Communication, IrDA)으로 PocketPC에 연결하여 혈당정보를 전송받는다. 이러한 정보를 PocketPC용 CDMA(Code Multiple Access) 확장 팩을 이용하여 문자메시지(Short Message Service, SMS)로 다른 휴대폰에 전송하고, 무선 랜(WLAN, IEEE 802.11)을 이용하여 웹서버에 있는 게시판에 건강측정정보를 자동 등록 하여 정보를 공유할 수 있는 시스템을 구축하였다. 특히 비공개된 혈당측정기의 프로토콜을 분석하여 통신에 사용하였으며, API(Application Programming Interface)를 제공하지 않는 CDMA 확장팩 시스템의 사용자용 프로그램을 IPC(Inter Process Communication)를 이용한 제어를 통해 필요한 태스크를 수행하는 기법을 사용하였다.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.47-53
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• 2017

Recently, huge datasets have been generating rapidly in a variety of fields. Then, there is an urgent need for technologies that will allow efficient and effective processing of huge datasets. Therefore the problems of partitioning a huge dataset effectively and alleviating the processing overhead of the partitioned data efficiently have been a critical factor for scalability and performance in distributed database system. In our work we utilized multicore servers to provide scalable service to our distributed system. The partitioning of database over multicore servers have emerged from a need for new architectural design of distributed database system from scalability and performance concerns in today's data deluge. The system allows uniform access through a web service interface to concurrently distributed databases over multicore servers, using SQMD (Single Query Multiple Database) mechanism based on publish/subscribe paradigm. We will present performance results with the distributed database system built on multicore server, which is time intensive with traditional architectures. We will also discuss future works.

• ETRI Journal
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• v.38 no.5
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• pp.988-995
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• 2016

In this paper, we present a new specific and customized interface tool with parameter identification of Modified Butterworth-Van Dyke models for ladder bulk acoustic wave filters. The aforementioned tool is easy to use and flexible because it allows simulations and reengineering to be conducted in an application. A modular design approach is applied to simplify the extension of the proposed tool for different topologies. The proposed tool was validated using measurements from an aluminum-nitride based ladder BAW filter dedicated to the frequency ranges of the Universal Mobile Telecommunications Service and standards and Wideband Code Division Multiple Access.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.8
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• pp.492-499
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• 2003

This paper presents the analysis and the implementation of the asynchronous communication portion of the IEEE 802.11 MAC protocol. We have used PRISM2 chipsets from INTERSIL to build baseband, IF, and RF parts and PCI controller from PLX to interface LLC Layer. We have implemented DCF(Distributed Coordination Function) service using CSMA/CA(Carrier Sense Multiple Access with Collision Acoidance) with backoff algorithm and RTS/CTS protocol. Also, we have implemented TSF(Timing Synchronization Function) which can be used for power management frequency hop synchronization, and other management function. This study can be used as a reference for the MAC protocol implementation and MAC controller design in very high speed wireless LAN which complies with the IEEE 802.11 standard.