• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4878-4883
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• 2015

The IP Multimedia Subsystem(IMS) is a framework that provides access to the content of Internet and Telecom services anytime and anywhere with guaranteed Quality of Service(QoS) and manageability by separating control functions from bearer and services. The Service Delivery Platform(SDP) provides common interfaces and protocols to deploy existing or new services in an efficient way. Therefore SDP over IMS plays a role of bridge between established network and new IMS network by simplifying the interaction among application services. In order to enrich the multimedia network communication, we try to deploy the Push-to-talk over Cellular(PoC) service which is considered as the outstanding and distinguished half-duplex Voice over IP(VoIP) application service among deployable candidate services over mobile network. In this paper we investigate the advantages of PoC service and PoC architecture firstly, and then focus on the its practical implementation for the prototype to validate the feasibility of its deployment and realization.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.149-154
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• 2020

This paper presented a design and a implementation of prototype model which is the smart diffuser device controlled by using Bluetooth technology in the smart phone. We used the ultrasonic waves oscillator so that the smart diffuser was able to spray oil into a device. The device was developed to find out the high brightness led colors switched during spraying the oil. By using the Li-Po battery of 40mAh capacity, we were able to design this portable device was prolonged available time to use and to solve the charging time problem. We realized the availability of prototype model which is using the Bluetooth Low Energy for operating the low power driving.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.25-33
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• 2001

eProcurement System io for the improvement of costs and productivity, and consists of eCatalog, eSourcing supporting the supplier selection, and ePurchase system supporting purchase request, approval, and PO.(omitted)

• Journal of Environmental Policy
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• v.6 no.1
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• pp.1-40
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• 2007

The research in this paper, for the effective implementation of CBD PoW PA(Program of Work on Protected Areas of Convention on Biological Diversity) that was adopted by CBD COP7(Conference of the Parties) in 2004, shows the objectives and activities of 9 each subject in PoW PA regarding domestic status and cases of national park management. Before anything else, according to the result of the review on the status of protected areas in Korea, there are 1,119 protected areas which are classified into 14 types and the total area is about $15,621km^2$. After a thorough review on 9 each subject about the implementation of CBD PoW PA, we found out that some parts such as management planning, prevention and alleviation of threats, and establishment of PAs system, are improved while financial support, improved social benefit, and MEE(Management Effectiveness Evaluation} fields are need to be improved. Especially regarding time-bound, ecological gap analysis on national level and MEE are need to be improved immediately. This paper could help us to understand the current status of PAs management system in Korea and to prepare national reports of CBD and implementation report of PoW PA. Based on research and results of this paper, we need to find the fields that have gaps in order to meet the requirements of the CBD PoW PA and the implementation tools that are suitable for managing Korea's protected areas. To effectively implement the various activities which require a systematic approach on the national level, the establishment of the networks among relevant organizations for protected areas are vital. To effectively reach the ultimate goal of CBD PoW PA, reducing the rate of biodiversity loss, it is essential that lots of plans established by authorities must be carried out in a constant manner to achieve goals of CBD PoW PA.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.82-89
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• 2003

In this paper, an efficient threshold-based filtering (TF) buffer management scheme is proposed. The TF is capable of minimizing the overall loss performance and improving the fairness of buffer usage in a shared buffer packet switch. The TF consists of two mechanisms. One mechanism is to classify the output ports as sctive or inactive by comparing their queue lengths with a dedicated buffer allocation factor. The other mechanism is to filter the arrival packets of inactive output ports when the total queue length exceeds a threshold value. A theoretical queuing model of TF is formulated and resolved for the overall packet loss probability. Computer simulations are used to compare the overall loss performance of TF, dynamic threshold (DT), static threshold (ST) and pushout (PO). We find that TF scheme is more robust against dynamic traffic variations than DT and ST. Also, although the over-all loss performance between TF and PO are close to each other, the implementation of TF is much simpler than the PO.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.51-52
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• 2011

전류 적산법(Coulomb counting, Ampere counting)을 이용한 배터리 SOC(State of Charge) 추정 방식은 초기 SOC 값에 존재하는 오차와 SOC를 추정하는 시간동안 누적되는 전류값의 오차로 인해 추정이 실패할 수 있는 단점이 존재한다. 하지만 알고리즘이 직관적이며 단시간 내에서는 그 오차가 크지않고, 상용화된 배터리 SOC 추정 IC가 존재하여 구현이 간단하다는 장점 또한 있다. 본 논문에서는 전류 적산법 기반의 배터리 SOC 추정 IC를 사용하여 $LiFePO_4$ 리튬 폴리머 배터리의 SOC 추정 회로를 구현하는 과정을 제안한다. 또한 실험을 통해 제안된 배터리 SOC 추정 회로의 성능을 확인해본다.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.257-281
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• 2008

This study aims to draw meaningful points from the Chang Po Go period in which Chang Po Go, who established an integrated logistics system while operating on the seas of three nations including Japan, China, and Shilla by taking Chunghaejin, Shilla, as a base of operations in the 9th century, and to discover the need for the construction of the logistics system in northeast Asia. Also, the study intends to propose strategies for contemporary application of the logistics system used during the Chang Po Go period, based on the modern logistics concept. As a result of specifically reviewing the lesson from the Chang Po Go period, which created a paradigm for a new cooperation in logistics, the leadership of the CEO, who is prepared with the long-term vision of Chang Po Go, the implementation of an integrated system for logistics activity, and the political support of the government for private companies, will initiate a bright outlook for the construction of the logistics system in northeast Asia, amid the growing need for cooperation in logistics among the three northeast Asian countries. In this era in which northeast Asia is emerging as the center of the world economy, the cooperative model in the logistics field, which transcended the border of Chang Po Go, who built a maritime logistics network in the 9th century, will help implement a cooperative logistics system in the northeast Asian region.

• Journal of the Korean institute of surface engineering
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• v.28 no.1
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• pp.46-54
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• 1995

An electrochromic(EC) cell was constructed using $WO_3$ as a electrochromic material and NiO as a counter electrode, deposited onto ITO-coated glass by the implementation of electron beam evaporation. The electrolytic media were both lithium and proton conducting polymers such as poly-acrylonitrile(PAN)-$LiClO_4$, poly-ethylene oxide(PEO)-$LiClO_4$, poly-vinyl butyral(PVB)-LiCl and PVB-H$_3$$PO_4$. Potentiodynamic cycling of the cells using PAN-$LiClO_4$, or PVB-$H_3$$PO_4$ electrolyte yielded a transmission variation of more than 40% at the wavelength of 632.8 nm within less than 10 sec response time at room temperature. These results indicate that these electrolytes, transparent in gel type, are premising for the application in large area electrochromic windows.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1095-1099
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• 2000

최근 전자상거래의 상업성이 부각되면서 많은 기업들과 개인사업자들이 독자적인 웹서버를 구축하고 자사의 상품 또는 기업에 대한 광고 내용을 인터넷을 통해 서비스를 하고 있다. 그러나 소비자에게 홍보가 부족하고, 상품의 종류와 정보의 부족으로 외면을 당하고 있는 웹사이트들이 많이 있다. 본 논문에서는 이러한 기업들의 카탈로그를 수집하여 재구성한 후, 한 사이트에서 여러 기업의 상품을 검색할 수 있도록 하여 소비자의 접근과, 각 기업의 상거래 사이트를 활성화 할 수 있는 메타 전자 쇼핑몰 개발에 관해 기술한다. 본 시스템의 특징은 로봇이 자동으로 데이터 베이스를 구축하여 소비자가 쉽게 검색 할 수 있도록 주제어 검색과 디렉토리 검색 인터페이스를 구성을 가지고 있다는 점이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1537-1540
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• 2005

PTT 서비스란 무전기처럼 Half-duplex 통신에서 사용하는 방식으로 말하고자 하는 사람이 PTT 버튼을 눌러 그 권한을 얻은 후에야 말을 할 수 있는 일종의 그룹 통화 방식이다. 본 논문에서는 이동통신망에서 데이터 서비스의 하나로서 VoIP 에 기반한 PTT 서비스 및 부가 서비스를 구현하기 위한 구조를 제시할 뿐만 아니라, PTT 서비스를 위한 논리적 구성 요소인 서버 및 단말 등의 기능을 설계하고, 각 구성요소를 통한 각종 서비스 제어 알고리즘을 구현한다.