• 정보처리학회논문지A
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• 제15A권2호
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• pp.101-110
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• 2008

유비쿼터스 컴퓨팅은 컴퓨터 시스템의 물리적인 공간을 확장시켰으며, 보다 동적인 분산 시스템으로 이끌었다. 이러한 환경에서는 다양한 디바이스와 자원 그리고 사용자 요구사항에 대한 새로운 QoS 파라미터가 요구되고 있다. 본 논문에서는 유비쿼터스 컴퓨팅 환경에 적합한 정적 QoS 파라미터와 동적 QoS 파라미터를 정의한 새로운 하이브리드 QoS 관리 모델을 제안하였다. 제안한 시스템 구성은 분산된 형태로 종단간 QoS 제어 및 관리할 수 있도록 클라이언트 측에는 QoS 제어 관리를 위한 모듈(QoS CMM), 서버 측에 QoS 관리 모듈(QoS MM), 그리고 중앙형 QoS 제어 및 관리를 위한 자원 QoS 관리 모듈(RQoS MM)을 구성하였다. 정적 QoS 파라미터는 자원 QoS 관리 모듈에서 처리하며, 동적 QoS 파라미터에 대한 전체적인 QoS 제어는 QoS CMM에 의해 다자간 통신의 경우에 서버 측의 부담을 최소화 시킬 수 있도록 하였다. 끝으로, 그래픽 사용자 인터페이스를 통해 위치 기반 애플리케이션으로 클라이언트 단말형태인 데스크탑 PC, 노트북, PDA에 따른 멀티미디어 서비스 수행 결과 화면을 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.822-825
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• 2002

Geographic Information System(GIS) has become an essential tool for making efficient interaction with both natural and artificial envirionment. Currently, it is being used on an inteligent tool in many device like the personal digital assistant(PDA) and the cellular phone and so on. However, these devices show very low performance comparing to a personal computer(PC). These devices(PDA, celluar phone) posses a less powered device profile. The less powerful hardware make these devices in capable to handle GIS based large spacial data. In this paper, we propose a new concept of multi-tier GIS oriented architecture to improve the data transfer performance providing only the necessary information required by the user using semantic filter.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (상)
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• pp.559-562
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• 2002

LBS (Location Based Services)란 휴대폰, PDA (Personal Digital Assistant), 노트북 PC 등 위치 추적이 가능한 단말기를 휴대한 사용자의 현재 및 과거 위치 정보를 활용한 유무선 인터넷 서비스를 말한다. 최근의 이동 통신 기술의 발달과 휴대폰, PDA 등과 같은 모바일 단말의 급속한 확산으로 인하여 LBS 는 유무선 인터넷의 응용 및 위치 정보를 사용한 부가 가치 창출에 있어 핵심적인 역할을 할 것으로 예상되고 있다. 이러한 LBS 를 위해서는 단말의 위치 정보들을 저장 및 관리하고 위치 정보를 이용하여 다양한 위치 기반 서비스를 지원하는 LBS 플랫폼의 역할이 매우 중요하다. 이를 위한 LBS 플랫폼은 위치 정보의 획득. 위치 정보의 저장 및 관리, 인증 및 정보 보호 등의 사용자 관리, 대용량 위치 정보 데이터베이스의 관리 등의 기능을 제공하여야 한다. 본 논문에서는 1) 위치 기반 서비스를 위한 LBS 플랫폼으로써 사용될 수 있는 참조 시스템을 설계한다. 이를 위하여 LBS 플랫폼으로써 참조 시스템이 제공하여야 하는 기능과 각 기능의 처리 흐름을 UML 의 유스케이스(Usecase)를 사용하여 분석 및 설명한다. 또한 2) 설계된 참조 시스템을 사용하여 제공될 수 있는 서비스 시나리오를 알아본다.

• Journal of information and communication convergence engineering
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• 제8권3호
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• pp.245-250
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• 2010

To support various bandwidth requirements for many kinds of devices such as PC, notebook, PDA, cellular phone, a transcoding proxy is usually necessary to provide not only adapting multimedia streams to the client by transcoding, but also caching them for later use. Due to huge size of streaming media, we proposed the 3 kinds of segmentation - PT-2, uniform, bitrate-based segmentation. And to reduce the CPU cost of transcoding video, we proposed the DQS service policy. In this paper, we simulate the combined our previous two researches that are bitrate-based segmentation and DQS(Degraded Quality Service) policy. Experimental results show that the combined policy outperforms companion schemes in terms of the byte-hit ratios and delay saving ratios.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.163-165
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• 2006

The subway passengers are usually alert to the current location of the train in order not to miss the destination or transfer stations. The Global Positioning System (GPS), although expensive, can give an alarm if properly programmed, but cannot receive the satellite signals, underground. Therefore, a novel approach to context-aware location-based subway information system is motivated. The passengers, who are equipped with mobile devices such as laptop, PDA, and mobile phone as clients of the Personal Area Network (PAN), request the Bluetooth connection to the server which is installed in each car of the train. While the sorrel broadcasts the location-based information including the previous station, the current velocity of the train, the distance and time to the next station, the clients provide additional services based on the recognized context of the information, and what the passengers individually want. The services are spontaneous and autonomous rather than passive. The services include not only the information on the nearby stations, exit numbers, connection buses but also the location-based alarms which can be set specific to various personal requests, and sounded by the location of the train rather than time. Whereas the arrival time may not be accurate due to the delays of the train, the location can be accurately traced and broadcast by the server. Also, the clients do not need any expensive systems like GFS. Towards validating the proposed approach, we implemented a Bluetooth PAN including a PC server, two PDA clients and a laptop client. We modeled a train on the Incheon Subway Line #1 and a train on the Seoul-to-Incheon Line on the server, simulated the virtual trains together with the real clients. and verified that all the services were successfully provided.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.114.4-114
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• 2001

Recently, variety services are more and more developed due to supply of PDA, cellular phone, and etc. Also, a services based on location information are very helpful in traffic, shopping, and emergency. Thus the user position is positively necessary for these services. One of the latest applications in GPS is the E911 call service for wireless phones. In this case, current GPS Navigation accuracy meets the FCC requirements but the hardware size and power consumption of GPS is issued for implementation. And, some case of applications need to snapshot location solution with fast TTFF(Time-To-Fist-Fix) than continuous location solution. The software GPS receiver could be the solution ...

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.211-216
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• 2001

Recently, the research for the mobile computing such as PDA, Palm PC and wearable computing related technologies is widely under development, specially for the input device. Among the mobile input methods are speech recognition, handwriting recognition and cording type. However these systems have the problems of the data input appraratus like input speed and recognition rate. This paper presents the Glove-based input device which could solve the system's data input problem. By the experimental results suggest the method of proposional input method that utilize the hand's movement is appropriate for the effective mobile input devices.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.821-822
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• 2006

Ubiquitous healthcare monitoring and measuring system based on wireless sensor network was implemented and tested. The system can measure the ECG and body temperature of patients or elderly persons and transfer the data wirelessly in ad-hoc network to remote base-station connected to doctor's PDA/PC or hospital server, using wireless sensor motes. The data obtained can be analyzed by doctors and care providers to monitor a health status of patient in real time environment. To prove the capabilities of the wireless sensor network platform for ubiquitous healthcare applications, the performance of our monitoring and measuring system was tested with positive results.

• 한국멀티미디어학회논문지
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• 제11권6호
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• pp.777-786
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• 2008

Human face avatar is important information in nowadays, such as describing real people in virtual world. In this paper, we have presented a face avatar creation and warping algorithm by using face feature analysis method, in order to detect face feature, we utilized local mean method based on facial feature appearance and face geometric information. Then detect facial candidates by using it's character in $YC_bC_r$ color space. Meanwhile, we also defined the rules which are based on face geometric information to limit searching range. For analyzing face feature, we used face feature points to describe their feature, and analyzed geometry relationship of these feature points to create the face avatar. Then we have carried out simulation on PC and embed mobile device such as PDA and mobile phone to evaluate efficiency of the proposed algorithm. From the simulation results, we can confirm that our proposed algorithm will have an outstanding performance and it's execution speed can also be acceptable.

• 한국멀티미디어학회논문지
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• 제21권2호
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• pp.261-270
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• 2018

Hearing-impaired people are increasing rapidly due to the global aging trend. Early detection of hearing loss requires an easy-to-use audiometry device for the public. Existing audiometry systems were developed as PC-based, PDA-based, or smartphone apps. These devices were often dependent on specific software platforms and hardware platforms. In this paper, we tried to improve software platform compatibility by using cross platform, and tried to implement IoT-based pure tone audiometry device which does not require sound pressure level correction due to hardware differences. Pure tone audiometry is available in a variety of ways depending on the type of hearing loss and age. Using the IoT-based audiometry device implemented in this paper, it will be possible for an app developer who lacks hardware knowledge to easily develop an app with various scenarios for hearing screening. The results of this study will contribute to overcoming the software and hardware dependency in the development of IoT-based healthcare device.