• 대한임베디드공학회논문지
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• 제3권3호
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• pp.136-142
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• 2008

Mobile robots can offer services like intelligent monitoring in an indoor environment using network connection with remote users. In this paper, we designed and developed a networked security robot system with various sensors, such as flame detector, gas detector, sound monitoring module, and temperature sensor, etc. The robot can be accessed through a web service and the user can check the status of the environment. Using ADAMS software, we defined the motor specification for a worst-case condition of climbing over a obstacle. We applied the robot system in monitoring office condition.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1188-1190
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• 2003

Taipei Watershed Management Bureau (WRATB) is a government agency entitled for water resources protection at two major watersheds in order to provide drinking water for about four millions population in Taipei on a sustainable basis. At WRATB, there are two major public sewage treatment facilities which can convert sewage in each watershed into an acceptable state before they were discharged into rivers. More than 82% of household wastewater have been collected and treated by the two public sewage systems. However, households at remote area still need more effective sewage management prescriptions. The objective of this paper is to implement geographic information systems in order to provide more effective approaches that sewage management can be easier and cost effective. ArcIMS was implemented for Internet browsing and map server of those sewage facilities on personal computers, laptop computers. In the open field, ArcPAD was implemented with personal digital assistant (PDA) such that compact flash type's global positioning systems (GPS) and digital camera can be utilized with PDA. All sewage facilities digital files were convert into ArcMap format files. MapObjects and visual BASIC were used to create sewage application modules to meet every single technician personal flavor. ASP.NET was implemented for Internet database manipulations of all sewage databases. Mobile GIS was the key component of GIS applications in the open field for sewage management on a basis of house by house. Houses at remote area, which can not cover by the two public sewage systems, were managed by PDA and laptop computers with GPS and digital camera. Sewage management at Taipei Watershed Management Bureau is easier both in the open field and in the office. Integration of GPS, GIS, and PDA makes sewage management in the open field much easier. ArcIMS, MapObjects, ASP.NET and visual BASIC make sewage management can be done in the office and over Internet.

• 제어로봇시스템학회논문지
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• 제14권2호
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• pp.141-147
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• 2008

In this paper, we present one approach to achieve safe navigation in indoor dynamic environment. So far, there have been various useful collision avoidance algorithms and path planning schemes. However, those algorithms have a fundamental limitation that the robot can avoid only "visible" obstacles. In real environment, it is not possible to detect all the dynamic obstacles around the robot. There exist a lot of "occluded" regions due to the limitation of field of view. In order to avoid possible collisions, it is desirable to consider visibility information. Then, a robot can reduce the speed or modify a path. This paper proposes a safe navigation scheme to reduce the risk of collision due to unexpected dynamic obstacles. The robot's motion is controlled according to a hybrid control scheme. The possibility of collision is dually reflected to a path planning and a speed control. The proposed scheme clearly indicates the structural procedure on how to model and to exploit the risk of navigation. The proposed scheme is experimentally tested in a real office building. The presented result shows that the robot moves along the safe path to obtain sufficient field of view, while appropriate speed control is carried out.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.135-139
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• 2012

LTE (long-term evolution) 를 비롯한 4G 이동통신 기지국 시스템에 있어서 최근에 DU(digital unit)와 RU(radio unit) 로 분리된 형상의 기지국들이 많이 등장하고 있다. 이러한 형태의 기지국에서 DU 는 전화국사에 설치하고 RU 는 옥외에 설치하는 형태로서, DU와 RU 간의 분리 가능한 거리는 이동통신 망 설계를 하는데 있어서 매우 중요한 요소가 된다. 하지만, DU와 RU 간 허용거리는 이동통신의 물리계층 기술에 의해 제약을 받을 수 있다. 본 논문에서는 FDD (frequency division duplexing) 기반의 4G 이동통신 시스템에서 Closed-Loop MIMO (multiple input multiple output) 기술에 의해 제한되는 DU와 RU 간 한계거리에 대해 분석하였다. DU와 RU 간 한계거리는 이동통신 시스템의 동작 주파수에 따라 다른 결과를 나타내며, 2 GHz의 동작주파수를 가정할 경우에는 약 11 km의 한계거리를 가지는 것으로 분석되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2033-2038
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• 2003

This paper describes an integrated navigation strategy for the autonomous service robot PSR. The PSR is under development at the KIST for service tasks in indoor public environments. The PSR is a multi-functional mobile-manipulator typed agent, which works in daily life. Major advantages of proposed navigation are as follows: 1) Structured control architecture for a systematic integration of various software modules. A Petri net based configuration design enables stable control flow of a robot. 2) A range sensor based generalized scheme of navigation. Any range sensor can be selectively applied using the proposed navigation scheme. 3) No need for modification of environments. (No use of artificial landmarks.) 4) Hybrid approaches combining reactive behavior as well as deliberative planner, and local grid maps as well as global topological maps. A presented experimental result shows that the proposed navigation scheme is useful for mobile service robot in practical applications.

• 한국전자통신학회논문지
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• 제10권12호
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• pp.1381-1388
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• 2015

스마트워크는 정보통신기술을 활용하여 다양한 장소와 이동환경에서도 언제 어디서나 편리하게, 효율적으로 업무에 종사할 수 있도록 하는 미래지향적인 업무 환경이다. 본 연구에서는 다가구주택을 관리하는 소규모의 영세 주택관리업체들이 세입자와 임대사업자에게 양질의 주택관리업무 제공할 수 있도록 스마트 모바일 기기와 SNS를 연동하여 실시간 업무 처리가 가능하도록 하여 효율적 주택관리를 지원하는 주택관리 업무지원 스마트워크 플랫폼을 제시하였다. 본 논문에서는 주택관리 업무지원 스마트워크 플랫폼의 한부분인 SNS 연동 실시간 민원 처리 서비스 부분을 기술한다.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2002년도 추계학술대회
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• pp.120-135
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• 2002

인터넷의 발달로 e-Commerce가 발달했듯이 무선 인터넷의 발달은 M-Commerce의 시대를 예견하고 있다. 현재의 M-Commerce는 간단한 정보 서비스에 머물고 있지만 머지않아 e-Commerce의 대표적인 거래형태가 무선 인터넷으로 확장될 것이다. 본 논문에서는 PDA 등을 비롯한 이동형 기기를 이용하여 기존의 오프라인 형태의 택배 시스템을 배달하는 시점에서 효과적인 배달 정보를 제공할 수 있는 모바일 오피스를 구현하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.305-311
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• 2014

In this paper, a new switching pattern is presented for multilevel inverters. With changing off-angel of each switch, the on time interval of all switches will approximately be equal and then the lifetime of inverter will increase, also using this method can reduce electrical stress on switches in higher levels of inverter. Switching angels as for desired modulation index are calculated using genetic algorithm whereas selective harmonics are controlled within the allowable range. The computed angels are simulated in Matlab/Simulink for respective circuits to validate the results.

• 경영과정보연구
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• 제15권
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• pp.187-222
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• 2004

The existing fixed telematics facilities for car were restricting of efficiency, utilization, communication, possibility, so it become disconnected with reality in the domestic and foreign market within thy near future, like as the case of 'car-phone'. It is too difficult to make a various business model on the restrict basis. To solve these problems, We suggested Tablet PC system as a new mobile telematics platform. The telematics platform based on the Tablet PC realize the perfect office, because it shows an excellent portability, high power and extension, various input equipment, and environment of communication in the car. To realize this concreteness, it needs a proper marketing strategy for a new business model. For this purpose, We analyzed the structure of industry, selected a proper target market, and established the strategy of marketing. Additionally, We proposed new business models ; particularly Portal site, Car-Home network, Car Software Tuning, and T-Vaccine(Intelligent Car Inspection System). These are made possible by the only Tablet PC platform.

• 한국문헌정보학회지
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• 제40권1호
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• pp.353-372
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• 2006

이 연구는 우리나라 공공도서관 분관 운영체제에 대한 설문조사와 주요지역 사례 조사를 통해 분관 체제의 실태와 문제점을 분석하고 효율성 증진 방안을 도출하였다. 분관의 담당 업무는 대체적으로 타당한 편이나. 분관의 유형에 대한 구분과 이에 대한 명확한 개념 정립이 시급하며, 그 유형에 따라 공립문고와 이동도서관도 개념에 포함시켜 공공도서관 시스템의 효율성을 극대화 할 필요성이 제기되었다. 공공도서관 분관은 기초자치단체 행정구역 단위로 운영하되 중앙관-분관-이동도서관-공립문고-순회문고로 시스템화하구 민간단체가 운영 주체인 새마을이동도서관이나 사립문고는 분관과 연계 운영하는 방안이 가장 바람직한 것으로 밝혀졌다. 또한 도교육청 소관의 분관은 기능 위주가 아니라 구조조정 목적으로 이루어져 왜곡 운영되고 있는 바, 시정이 필요하다.