• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2684-2686
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• 2003

공장, 상용 빌딩, 선박 등의 작업장 내에서 생산성, 품질, 에너지, 안전사고 등의 제반요소들을 종합 관리할 수 있는 개별 센서 및 종합시스템을 개발하였다. 개발된 시스템 사양은 다음과 같다. 입력전압:$12{\sim}24V$, 스캔 간격:100kHz, 펄스 채널: 8, 여기 채널: 8, 여기전압: ${\pm}5000mV$, 입력임피던스: $2.5G{\Omega}$, 사용온도: $-25{\sim}50^{\circ}C$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.621-629
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• 2007

In cognitive radio (CR) network, the channels are generally classified into either the unavailable channels that are occupied by incumbent users or the available channels that are not occupied. The conventional channel classification scheme may result in poor utilization of spectrum holes since it does not take the spatial relationship between CR node and incumbent users into consideration. In this paper, we propose an efficient channel management scheme for the centralized CR network to maximize the spectrum holes by overcoming the shortcomings of conventional scheme. In addition, we mathematically analyze the effectiveness of proposed scheme. Based on the proposed channel management scheme, we also propose the rendezvous algorithm, which can establish the control channels between base station and CR node under the dynamically changing spectrum environment.

• Journal of Internet Computing and Services
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• v.10 no.1
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• pp.123-134
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• 2009

The CRM(Customer Relationship Management) is a business strategy model which can reap higher profits and can provide a competitive edge to an enterprise in today's new business environments. Early next year (2009), the Capital Market Consolidation Act will be in effect in South Korea. This is required for a qualitative growth to provide QoS (Quality of Service) and ensure growth in finance, IT industry & service. Accordingly, the securities and insurance companies, banks and other financial institutions make efforts to improve their derivative financial product and also enhance their services. In this paper we design and implement a Channel Server model for a Scalable Service Channel Server to efficiently manage the high volumes of inbound customer interactions based on the requirements of a CRM center. The proposed Scalable Service Channel Server supports integration with other third party service and standardization of multiple inbound service channels. The proposed model can be efficiently used in an inbound CRM center of any banking, finance, securities and insurance establishments.

• Journal of Digital Contents Society
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• v.13 no.2
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• pp.197-203
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• 2012

Although the increase in number of the programs provides rich entertainment to viewers, it also has caused a negative of making it hard for viewers to find out their favorite programs. To address the problem, several researches have been performed mainly focusing on the technologies to analyze a viewer's TV watching-patterns and to recommend a program (or a channel) based on the analysis when a viewer changes channels. The researches, however, have the trouble of frequently failing to choose proper programs because, in the real-world broadcasting circumstance, the programs are re-broadcast over a number of the channels and a set of programs of a genre are usually playing in the overlapped times. To avoid the trouble, the data service, proposed in the paper, allows a viewer to book "explicitly" his/her favorite programs and provides a set of functions of listing up the booked program's broadcasting schedules and reserving viewing or recording the booked programs.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.9-16
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• 2003

In this paper, we propose a method for supporting VCR operations in a patching based multicast VOD system. Random access, pause and resume operations are supported in our system, and the channel and session scheduling algorithms for the VCR operations are proposed. When it is necessary to join a sharable multicast channel in the admission control for the VCR operations, the patching technique, which shares an on-going regular channel and allocates a new patching channel for the missing data, is used. Therefore, unlike the previous approach that allocates an excessive number of I-channels, service latency is minimized and channel usage is optimized in our system. Moreover buffered data. which is saved in disk during patching, is reused to prevent unnecessary patching channel allocation. For this. the patching management information is extended and a buffed data management scheme is proposed. In our system, the First-Come-First-Served scheduling is used to inform clients the service latency for the VCR operations immediately.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.305-313
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• 2020

Telemetry system is a system that transmits status information data acquired from the aircraft to the ground station. PCM encoder needs memory to store channel information in order to generate a frame format using the acquired data. Generally, telemetry systems in large aircraft require much larger memory for the increased acquisition channel information due to the increased sensors and subsystems. However, they have difficulty to store all channel information in limited memory. In this paper, we suggests and implements an advanced PCM encoder that can efficiently manage memory by minimizing duplicated channel information. This novel PCM encoder allocates duplicated channel information to memory only once. And, sub commutation channels having different information for each minor frame are allocated to the memory by multiples of sub commutation channels. Finally, the suggested PCM encoder was proved by simulation that composed channels of various measurement cycles.

• Optical Science and Technology
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• v.8 no.3
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• pp.30-39
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• 2004

파장분할다중화(WDM) 방식은 그 풍부한 수용능력 때문에 늘어나는 인터넷 망 또는 고품질 통신망의 대용량 정보수요를 충족할 수 있는 최상의 해법이다. WDM 방식을 이용한 광전송시스템은 관리가 용이하고 설치비가 저렴하여, 최근 십여년 간 집중적으로 연구 개발되어지고 있다. 수 년 전까지도 이 분야의 주된 연구목적은 WDM 채널간의 최소간격을 1000Hz로 고정하고 채널 수를 늘려서 전체 광전송 용량을 증가시키려는 것이었다. 그러나 점차 광섬유의 손실을 보상하기 위해 사용되는 광섬유 증폭기의 비용부담이 증가하면서 채널간격을 줄여 대역효율을 높이는 전송기술이 연구되고 있다.(중략)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.635-637
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• 2016

센서 네트워크에서 각 센서 노드의 에너지 소모를 최소화하여 에너지 소모를 줄임으로써 망의 지속시간을 늘이는 것이 중요하다. 기존의 MAC(Medium Access Control) 프로토콜은 채널 폴링 기법을 이용하여 효율적인 에너지 관리에 대한 해결책을 제시 하였으나, 그러한 방식에 따른 각 노드의 Duty Cycle이 길어짐으로써 발생하는 에너지 소모에 대한 해결책은 제시하지 못하였다. 본 논문에서는 기존의 채널 폴링과 함께 스케쥴링 알고리즘을 적용하여 Duty Cycle의 주기를 줄임으로써 에너지 소모를 줄인다. 특히 이 방식을 이용하여 멀티홉과 과다한 트래픽에 대한 성능의 평가를 위해 실험을 통해 제안하는 프로토콜의 우수한 성능을 보인다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.499-501
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• 2001

무선 채널 상태는 같은 셀 안의 사용자의 수 또는 사용자의 움직이는 속도 등과 같은 많은 변수들로 인해 급격히 변화한다. 따라서 무선 채널의 효율적 관리는 무선 통신에 있어서 가장 중요한 고려사항이다. 효율적인 무선 채널 관리를 위해서는 정량적인 근거를 제시해 주는 기준인 트래픽 양 측정방안이 요구된다. 현재 3GPP의 UMTS문서에서 제시하고 있는 정량적인 근거는 오직 RLC 대회에 있는 양만을 참조한다. 이 경우 일정한 레이트(rate)론 유지하는 음성형 서비스(conversational service)에는 적당할 수 있지만 멀티미디어와 같이 레이트가 일정하지 않은 서데스에 대해서는 이후에 전송될 데이터에 대한 정확한 트래픽 양 측정이 불가능하다. 따라서 본 논문에서는 토큰 버켓 모델을 이용하여 이후에 들어올 데이터 양에 대하여 보다 정확한 트래픽 양을 예측할 수 있는 메커니즘을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.3
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• pp.207-215
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• 2013

This paper is channel assignment and scheduling techniques for efficient wireless AMI network. In AMI system, the multi-channel cluster network to be proposed defines the communication channel between NC (Network Coordinator) and CDA (Clustered Data Aggregator) as the network channel. CDA and OMD(Out Meter display) and communication channel between SMD(Smart Meter Device) are defined as the group channel. AMI network of the multi-channel cluster based in which the network channel and group channel is mixed increases the administration efficiency through the physical/logical consumer channel clustering. The reliability of inspection data through the channel use distinguished between the adjacent cluster is enhanced. In addition, the fast aggregation of data is possible and the size of a metering network is increased through the channel allocation of the multichannel cluster based.