• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2005년도 추계학술대회
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• pp.61-66
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• 2005

Spatiotemporal data mining represents the confluence of several fields including spatiotemporal databases, machine loaming, statistics, geographic visualization, and information theory. Exploration of spatial data mining and temporal data mining has received much attention independently in knowledge discovery in databases and data mining research community. In this paper, we introduce an algorithm Max_MOP for discovering moving sequences in mobile environment. Max_MOP mines only maximal frequent moving patterns. We exploit the characteristic of the problem domain, which is the spatiotemporal proximity between activities, to partition the spatiotemporal space. The task of finding moving sequences is to consider all temporally ordered combination of associations, which requires an intensive computation. However, exploiting the spatiotemporal proximity characteristic makes this task more cornputationally feasible. Our proposed technique is applicable to location-based services such as traffic service, tourist service, and location-aware advertising service.

• Journal of the Korean Data and Information Science Society
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• 제17권4호
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• pp.1261-1270
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• 2006

This paper proposes a mobile computing prefetching method providing the effective information about location change of mobile user or mobile computing in mobile information services. For mobile computing environments, there exist restrictions as like low bandwidth, latency and traffic. To solve those problems, a variety of techniques have been developed including caching and prefetching. In this paper we present a Statistical Poisson Prefetching Scheme using the reference count to provide a mobile user information that will be likely referenced in the near future. Comparing to existing methods in numerical results, the proposed method improves the prefetching performance to give the maximum effectiveness and reduces the failure rate of information searching.

• 대한임베디드공학회논문지
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• 제5권4호
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• pp.195-205
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• 2010

The popularity of Smartphones makes new fields of applications based on location based service easily feasible with a new user interface called augmented reality (AR). It presents a particularly powerful user interface to context-aware computing environments. AR on Smartphones integrates virtual information into a person's physical environment by overlaying information on an image taken through Smartphone's camera and motion sensors. Mobile augmented reality systems provide this service without constraining the individual's whereabouts to a specially equipped area. This work presents an overview of handheld augmented reality focusing on applications with introducing the basic issues of them. For this purpose, an example system, Studierstube ES (embedded system), is cited, which introduces the most significant problems and various methods of solving them through the experience of converting existing PC-based AR system into handheld AR.

• Journal of information and communication convergence engineering
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• 제6권1호
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• pp.6-9
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• 2008

In future domestic context aware applications the location of mobile devices is often required. Ultrasonic technology enables high resolution indoor position measurements. A disadvantage of state-of-art ultrasonic systems is that several base stations are required to estimate 3D position. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The processes include the design and testing of UPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.289-295
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• 2011

본 연구는 안전체험관 특히 재난 재해 체험시설에 방문한 관람객들의 흥미유발과 적극적인 참여를 유도하기 위하여 도입되는 상호작용 체험 시스템의 설계에 대한 것이다. 설계된 안전 체험 시스템은 첫째, 관람객들에게 개별적으로 제공된 단말기의 체험관 내 위치정보와 체험 기기들의 동작감지센서정보를 기반으로 체험 여부 판단 및 체험 점수를 자동으로 산출하는 증강현실 서비스와 둘째, 체험관 내 긴급 호출 등의 안심 서비스를 제공한다. 설계된 시스템의 구현을 통하여 향후 안전테마파크 외에도 체험시설이 구비된 교통 및 과학 전시관, 체감형 게임센터 등에도 충분히 적용가능하다고 사료된다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.700-702
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• 2004

최근 유비쿼터스 네트워크 환경을 통해 새롭고 다양한 서비스가 개발되고 있다. 그 중, 위치기반 서비스(Location Based Services: LBS)는 GPS나 이동 통신망을 사용해 사용자나 사물의 위치를 파악하고 이를 기반으로 유용한 서비스를 제공하는 기술이다. 이 기술은 공공 안전 서비스나 위치 추적, 항법 서비스, 정보제공 서비스 등에 적용되어 사용될 수 있다. 하지만 기존의 위치 기반 시스템은 실내 및 건물 밀집지역에서 위치 인식이 쉽지 않고 사용자의 위치 정보가 누출될 위험성이 있다는 문제점을 가진다. 본 논문에서는 이동 통신망과 무선 근거리 통신망에서 동작하는 이동 에이전트를 이용하여 위치기반 서비스를 구성하였다. 본 기법은 Hybrid Peer to Peer 방식을 이용하여 건물 밀집 지역이나 지하, 실내에서도 정확한 위치측정이 가능하고 개인의 위치 정보도 노출되지 않으며, 나아가 개인 이동 단말기의 상황 인식 컴퓨팅(Context-Aware Computing) 환경 구축에도 도움을 줄 수 있을 것으로 기대 된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.177-178
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• 2006

The real-time tracking system is an essential factor for the development of low cost sensor networks for use in pervasive computing and ubiquitous networking. In this paper, we address the interference problems of the sensor network platform with ultrasonic for location tracking system. Ubiquitous indoor environments often contain substantial amounts of metal and other such reflective materials that affect the propagation of radio frequency signals in non-trivial ways, causing severe multi-path effects, dead-spots, noise, and interference. Especially we present a novel reducing interference location system that is particularly well suited to support context-aware computing. The system called Pharos, aims to combine the advantages of real-time tracking systems that implement distributed environment with regardless of infrastructure or infrastructure-less wireless sensor networks.

• 정보학연구
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• 제10권4호
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• pp.11-26
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• 2007

EDS is a typical convergence service performing convergence between functions owned by multiple SPs. EDS provides users with the relevant information and the communication by the various personal conditional environment. An alternative terminology for events for net- work related applications is 'triggers'-these are assumed to be included in the present description. Events could be defined as any activities which occur within a service avail ability, signals. Events can be managed, for example, as part of a context-aware application. EDS carry out a procedure for processing user's requested information about mobil network-based entities, such as the combination with various applications, such as a LBS (Location Based Service) and area information. In AS (Application Service) network environments, the user has his customized EDS in the network, the EDS automatically connects the appropriate Terminals consistent with a user profile. EDS can also send the collected information to other requesting users by way of event information and using the procedures of combination with other services. The user can record/retrieve the user-related information to from the information base through EDS.

• 한국정보통신학회논문지
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• 제10권11호
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• pp.2083-2090
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• 2006

제안된 OSGi 플렛폼(Platform) 기반의 상황인식 서비스지향 아키텍쳐에서 서비스공급자는 다양한 센서들로부터 상대적인 서비스들을 통합하여 각각 서비스를 SOAP 메시지로 묶어서 웹서비스를 서비스중재자의 UDDI서버에 등록하면, 서비스요청자는 UDDI서버에서 특정한 서비스를 검색하고, 서비스공급자에게 해당 SOAP메시지를 호출한다. 최근 유비쿼터스 홈네트워크 상황인식기술은 RFID/USN. 위치기반 기술을 중심으로 연구가 진행되고 있으나 이를 위한 서비스 지향 아키텍쳐에 대한 연구는 원만하게 진행되지 않고 있다. 따라서, 본 논문에서는 OSGi Platform 기반에서 다양한 센서 들로부터 수많은 상황인식 서비스가 동적 으로 움직이게 되고 사용자 요구 및 필요성에 따라 신규서비스의 제공 및 기존 서비스의 변경과 제공된 서비스간에 데이터 공유, 서비스 라이프사이클, 서비스분배의 효과적인 관리를 위하여 ATAM으로부터 추출된 성능 유티리티 트리에서 이산 Little's Law를 적용함에 따라 546 TPS 에서 초당 상황인식트랜잭션 처리횟수를 향상시키는 OSGi Platform을 이용한 eclipse STP 기반의 상황인식 SOA를 제안하고자 한다.

• Journal of Korean Neurosurgical Society
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• 제47권3호
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• pp.169-173
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• 2010

Objective : The normal anatomic relationships characteristic of the pituitary stalk area were previously thought to involve only one location. The purpose of this study was to re-evaluate the anatomic location of the pituitary stalk and possible varying locations in relation to the tuberculum sellae and dorsum sellae using morphometric evaluation and anatomic dissection of human cadaveric specimens. The surgical implications of the variations are discussed. Methods : The calvaria were removed via routine autopsy dissections, and the brains were removed from the skull while preserving the pituitary stalk. The diaphragma sellae, tuberculum sellae, and the location of the pituitary stalk were examined in 60 human cadaveric heads obtained from fresh adult cadavers. Empty sellae were excluded. Results : The openings of the diaphragma sellae averaged $6.62{\pm}1.606mm$ (range, 3-9 mm). The distance between the tuberculum sellae and the posterior part of the pituitary stalk was 1 to 8 mm. The upper face of the diaphragma sellae appeared flat in 26 (43%), concave in 24 (40%), and convex in 6 cases (10%), with a prominent tuberculum sellae in 4 cases (7%). The location of the chiasm was normal in 47 cases (78%), with a prefixed chiasm in 3 cases (5%) and a postfixed chiasm (17%) in the 10 cases. Four cadaver specimens had prominent tuberculum sellae and other parameters were not evaluated. Conclusion : When opening the chiasmatic cistern, neurosurgeons should be aware about the relationship between the pituitary stalk and the surrounding structures to prevent inadvertent injury to the pituitary stalk.