• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.147-154
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• 2020

In this study, we created a system that can determine the number of vehicles entering and departing a charging station in real time for solving waiting time problems during refueling. Accordingly, we use the You Only Look Once object detection algorithm to detect and count the number of vehicles in the charging station and send the data to the Firebase Realtime Database. The result is shown using an Android application that provides a map function with the Kakao Maps API at the user interface side. Our system has an accuracy of 91% and an average response time of 3.1 s. Therefore, this system can be used by drivers to determine the availability of a charging station and to identify the charging station with the least waiting time for charging their vehicle.

• 한국정보통신학회논문지
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• 제20권3호
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• pp.519-526
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• 2016

해양사고가 빈번히 발생함에 따라 해상교통관제를 통해 항해의 안전성과 효율성을 개선하기 위한 해상 트래픽 모니터링 시스템을 구축할 필요성이 대두되고 있다. 이와 같은 목적을 위해, 최근에 X-대역 해양 레이더는 해수면 정보를 수집하는데 사용하고 있는데, 파랑 정보를 정확하게 측정하여 해상교통관제 영역 내에서 선박의 안전하고 효율적인 움직임을 제공하는 것이 요구된다. 본 논문에서는 세 가지의 다른 해류 속도를 산출하는 방법 즉, 최소자승법을 이용한 방법, 해류 속도를 반복 최소자승 갱신 방법, 가변적인 해류 속도의 정규화된 스칼라 곱을 극대화하여 해류 속도 추정치를 제공하는 방법 등에 대해 부이 데이터와 비교하고, 그런 후에 반복 갱신 방법을 수정하여 초기의 해류 속도를 개선하여 효과적으로 파랑 정보를 예측하도록 설계된다. 다수의 실험을 통하여 제안한 방법은 기존 방식에 비해 파랑 정보를 효과적으로 추출할 수 있음을 보인다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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• pp.181-184
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• 2002

This paper describes remote control RS232 communication using internet service, safety of exchange data and internet traffic by Denial of Service Attacks. In case of Denial of service Attacks, it makes connection of internet service failed. So in this Paper, this solution was examined and implemented for receiving data in safety against Denial of Service Attacks by LabVIEW program of National Instruments.

• 한국통신학회논문지
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• 제34권3B호
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• pp.225-234
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• 2009

Recently IPTV service is penetrating to the ordinary home users very swiftly. One of the first phase of IPTV service is considered to be VoD, and a nationwide availability of the VoD service imposes tremendous pressure to the network resource due to its requirements for the broad bandwidth, the inherent nature of unicast technology, and the large scalability, etc. This work suggests a novel and practical method to the design of network resource for the VoD service. Especially, we explore the distributed content storage problem that takes into account the popularity of the video contents and its corresponding link dimensioning problem that takes into account the grade of service for the flow level quality of service about the VoD service. By assuming a realistic topology for the nationwide IP backbone network of Korea, which is a typical tree topology, we suggest an analytic method for the design of VoD service.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.57-60
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• 2011

도로 환경에서 이동하는 객체에 효율적인 위치기반 서비스를 제공하기 위해 다양한 브로드캐스트 기법들이 연구 되어 왔다. 하지만 실시간으로 변하는 도로 환경을 고려한 효율적인 브로드캐스트 기법이 요구되고 있다. 본 논문에서는 도로 특성을 고려한 양방향 선형 브로드캐스트 색인 구조를 제안하고, 빈번하게 변화하는 도로 환경을 고려하여 센서 네트워크를 통해 수집되는 도로 정보를 기반으로 최적의 QoS(Quality of Service)를 유지시키는 브로드캐스트 전략 갱신 기법을 제안한다. 또한 질의 처리 속도 향상을 위해 서비스 지역을 센서 클러스터 기반의 지역 세그먼트로 분할하여 불필요한 데이터의 브로드캐스트를 제거하는 분산 브로드캐스트 서비스 구조를 제안한다. 제안하는 기법의 우수성을 증명하기 위해 기존에 제안된 브로드캐스트 기법과 성능을 비교 평가한다.

• Asian Journal of Innovation and Policy
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• 제5권3호
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• pp.315-329
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• 2016

Public R&D investment information has diverse implications for researching R&D trends. Also, as it is important for the establishment of R&D policy to grasp the current situation and trends of R&D to improve science and technology level, science and technology information service system, such as NTIS (National Science & Technology Information Service), is operated at a national level in most countries. However, since the data forms provided by current NTIS are raw data, it is necessary to develop the R&D performance indicator or to use additional scientometric methods by analyzing scientific papers or scientific R&D project information for grasping R&D trends or analyzing R&D task results. Thus, this study applied public R&D investment information to investigate and monitor R&D trends in the field of information & communication technology (ICT) of meteorology and climatology by using NTIS data of Korea and NSF (National Science Foundation) data of USA.

• 대한산업공학회지
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• 제32권4호
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• pp.347-357
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• 2006

Six sigma activities in an information and communication technology company in Korea are introduced. Korea Telecom(KT) was a public company for a long time and became a private enterprise not long ago. Although this company adopted many innovation programs, they were not effective because of the company's characteristics : long-time government-owned and information service industry. This paper describes the reason why KT introduced six sigma, some implementation strategy, and key factors to successfully deploy it. This paper is expected to be helpful to public or service industry in which it is very difficult to implement innovation activities.

• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.97-102
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• 2012

The differential global positioning system (DGPS) transmits a GPS enhancement signal using a top-loaded monopole antenna in the medium frequency range. The top-loaded antenna in the medium frequency band can attain a radiation efficiency on the order of 10%. The antenna ground plane characteristics affect the antenna radiation efficiency. To improve the radiation efficiency, it is necessary to install the antenna on a ground plane with large enough physical dimensions and good conductivity. The antenna radiation efficiency is a primary factor in determining the DGPS service area. The service area of the DGPS using a medium frequency band is dominantly affected by the antenna radiation efficiency. To determine antenna radiation efficiencies accurately, the antenna radiation efficiencies of DGPS are deduced from the propagation power in this paper. Based on the deduced antenna radiation efficiencies, the service area for the Korean nationwide-DGPS is analyzed and evaluated.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2656-2664
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• 2015

IoT 단말을 관리하는 IoT 관리 허브가 수집한 센싱데이터를 원격의 서버로 저장하기 위해서 인터넷 네트워킹이 가능해야 한다. 네트워크에 접속하기 위한 방법은 유선연결 방법과 WLAN AP에 접속하는 방법이 있는데, WLAN AP에 접속하기 위해서는 접속 가능한 영역의 AP 목록을 조회하고 특정 AP를 선택해야 한다. AP에 보안키가 설정되어 있는 경우에는 해당 보안키를 입력 할 수 있는 방법 또한 필요하다. 기존 방식에서는 IoT 관리 허브가 AP의 목록조회를 위한 디스플레이 장치가 필요했고, 목록을 선택하고 보안키를 입력하기 위한 입력 장치가 필요했다. 이러한 방식은 IoT 관리 허브가 디스플레이 장치와 입력 장치를 포함한 형태로 구성되기 때문에 단말의 소형화와 저가격화를 방해하게 된다. 또한 IoT 서비스가 대중화 되었을 때 사용자들에게 불편한 서비스로 인식될 우려가 있다. 본 논문에서는 스마트폰의 Wifi, 디스플레이 장치, 입력 장치를 이용하여 사용자에게 친숙한 방법으로 IoT 관리 허브를 WLAN 네트워크에 연결하는 방법을 제안한다.

• 한국통신학회논문지
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• 제41권12호
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• pp.1721-1735
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• 2016

Power-efficient base station (BS) operation is one of the important issues in future green cellular networks. Previously well-known BS operation schemes, the cell zooming scheme and the cell wilting and blossoming scheme, require tight cooperation between cells in cellular networks. With the previous schemes, the non-cooperative BSs of a serving cell and neighboring cells could cause coverage holes between the cells, thereby seriously degrading the quality of service as well as the power saving efficiency of the cellular networks. In this paper, we propose a novel power-efficient BS operation scheme for green downlink heterogeneous cellular networks, in which the networks virtually adjust the coverage of a serving macrocell (SM) and neighboring macrocells (NMs) without adjusting the transmission power of the BSs when the SM is lightly loaded, and the networks turn off the BS of the SM when none of active users are associated with the SM. Simulation results show that our proposed scheme significantly improves the power saving efficiency without degrading the quality of service (e.g., system throughput) of a downlink heterogeneous LTE network and outperforms the previous schemes in terms of system throughput and power saving efficiency. In particular, with the proposed scheme, macrocells are able to operate independently without the cooperation of a SM and NMs for green heterogeneous cellular networks.