• 한국공간정보시스템학회 논문지
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• 제12권1호
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• pp.1-9
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• 2010

최근, 무선 센서 네트워크 기술은 유비쿼터스 컴퓨팅 시대의 핵심 기반 기술의 하나로 인식되고 있다. 센서 노드는 제한된 배터리 용량을 가지기 때문에, 장기간 생존하기 위해서 노드들의 동작에 적은 에너지를 소모해야한다. 따라서, 에너지를 효율적으로 사용하는 프로토콜이 필수적이다. 이를 위해 본 논문 에서는 에너지 사용량을 고려하여 에너지 소모가 적은 경로를 설정하는 위치 기반의 에너지 효율적인 라우팅 프로토콜을 제안한다. 아울러 메시지 전송이 원활하지 못한 경우를 처리하는 경로 재설정 알고리즘을 제안한다. 마지막으로 TOSSIM을 이용한 성능평가를 통해, 제안한 프로토콜이 에너지 효율성 측면에서 기존 위치기반 라우팅 프로토콜 보다 우수함을 보인다.

• 디지털산업정보학회논문지
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• 제10권1호
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• pp.139-146
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• 2014

Through numerous mobile device technology advances, various multimedia contents is moving towards mobile devices from existing personal computer (PC). These paradigm has emerged taking into account these idea, the so-called N-Screen, N-Screen is user-centric service to provide running and sharing on everywhere via advanced smart system in C-P-N-T (Content, Platform, Network, Terminal). Therefore we must provide securing of various contents, openended platform, and user-centric service for efficient N-Screen service. For These characteristic of N-Screen, this paper propose design and implementation of user location-based N-Screen service system. The proposed system realize user location through user's smart phone and offer automatic streaming service to user. And also, we provide web service-based extended N-Screen service. Thus, user can access various device, such as laptop, tablet, and mobile device.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권3호
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• pp.198-205
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• 2009

In this paper, design of framework architecture of pervasive computing system providing seamless inter space interactions between private and public smart spaces is presented. The seamless inter space interaction issues are related to establishing user's service environment by allocating relevant resources in a new location where there are no prior settings for the user or where there are current users already being served in the new location. In the realm of pervasive computing, we can have different types of smart spaces, offering proactive and intelligent services, which are islands of smart spaces independent from each other. As users move about, they will have to roam from private smart space to public smart space and vice versa. When they enter a new island of smart space, they will have to setup their devices and service manually to get the same or different services they had at the previous location. Users might be living in a non-pervasive computing environment because this manual operation is inappropriate to its generic features of proactive and intelligent services of pervasive computing. The framework architecture will provide seamless inter space interactions initiated by changes in users' location to acquire negotiations of resources for new and current residents regarding service provision with limited available networked devices.

• 산업공학
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• 제16권spc호
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• pp.21-27
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• 2003

Objective of this paper is to develop the user mobility model(UMM) which is used for the performance analysis of location update and paging algorithm and at the same time, consider the user mobility pattern(UMP) in zone-based cellular networks. User mobility pattern shows correlation in space and time. UMM should consider these correlations of UMP. K-dimensional Markov chain is presented as a UMM considering them where the states of Markov chain are defined as the current location area(LA) and the consecutive LAs visited in the path. Also, a new two dimensional Markov chain composed of current LA and time interval is presented. Simulation results show that the appropriate size of K in the former UMM is two and the latter UMM reflects the characteristic of UMP well and so is a good model for the analytic method to solve the performance of location update and paging algorithm.

• Spatial Information Research
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• 제19권2호
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• pp.57-64
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• 2011

이 논문은 PostgreSQL/PostGIS 기반의 궤적 정보 저장과 질의에 대하여 기술하고 있다. 최근 모바일 단말 기술의 발전과 함께 위치기반서비스와 이동 객체 궤적에 관련된 많은 연구들이 진행되고 있다. 궤적은 이동 객체가 시간에 따라 변하는 위치정보들의 모음이며, 위치기반서비스를 위한 가장 중요한 정보중 하나이다. 기존의 공간 데이터베이스 시스템은 이동 객체 데이터 타입을 지원하지 않는다. 이 논문에서는 공간 데이터베이스로 많이 활용되고 있는 PostgreSQL/PostGIS 상에서 궤적 데이터 타입을 구현하고, 궤적 연산을 위한 궤적 질의 함수들을 제안하고 있다.

• 제어로봇시스템학회논문지
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• 제12권9호
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• pp.876-882
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• 2006

This study presents an ultrasonic location awareness system for the ubiquitous computing with absolute position. The flight time of ultrasonic waves is determined by a period detecting technique which is able to extend the sensing range compared with traditional methods. For location awareness, ultrasonic waves are sent successively from each ultrasonic transmitter and synchronized by radio frequency (RF) signal, where the transmitting part is fixed and the receiving part is movable. To expand the recognizing range, cell matching technique and coded ultrasonic technique are introduced. The experimentation for various distances is accomplished to verify the used period detecting technique of U-SAT system. The positioning accuracy by using cell matching is also verified by finding the locations of settled points and the usability of coded ultrasonic technique is verified. As a result, the possibility of ultrasonic location awareness system for the ubiquitous computing can be discussed as a pseudo-satellite system with low cost, a high update rate, and relatively high precision, in the places where CPS is not available.

• 한국IT서비스학회지
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• 제15권4호
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• pp.125-151
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• 2016

In recent years, O2O (Online to Offline) services get a lot of attention to improve the trust in online shopping and minimize the inconvenience and the cost burden in offline shopping as the number of consumers, who do not show concern about the purchase platform like online or offline, increases. Even though the services have been getting the spotlight as a strong business platform for next generation commerce, there have been only a few studies on the O2O services. The purpose of this research is to investigate the factors which affect the consumer's intention to use location-based O2O services. The study is based on VAM (Value-based Adoption Model) which is able to analyze those factors from the aspects of benefit and sacrifice. We used the partial least squares (PLS) method for empirical analysis, and the result shows that contextual offers, instant connectivity, webrooming and economic efficiency, which fall under the benefit, affect perceived value positively while annoyance and face consciousness, which fall under the sacrifice, do not affect perceived value significantly. In addition, contextual offers and instant connectivity affect trust positively. Location accuracy, which falls under the benefit of location-based O2O service, do not significantly affect perceived value and trust while security risk affects trust and use intention negatively. It appears that trust affects perceived value and use intention positively.

• 방송공학회논문지
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• 제10권3호
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• pp.328-338
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• 2005

멀티채널 오디오 컨텐츠에 대한 사용자의 욕구가 증가하고 있는 가운데 서비스를 위한 저비트율 멀티채널 오디오 부호화 기술에 대한 표준화가 진행되고 있다. 본 논문에서는 협대역폭 채널환경에 적합한 고압축율의 멀티채널 오디오 부호화 기술인 음원위치단서 부호화 기술(Sound Source Location Cue Coding; SSLCC)을 제안하고, SSLCC가 기존 BCC (Binaural Cue Coding)의 압축 성능을 향상시키기 위하여 단서로 이용한 VSLI (Virtual Source Location Information)를 설명한다. 또한 객관적 평가로 기존의 BCC 시스템과의 평균 비트율을 비교하고, MUSHRA (Multi-Stimulus test with Hidden Reference and Anchor) 방법을 이용한 주관 청취 평가를 수행하여 제안된 SSLCC 부호화 기법의 우수성을 확인하였다.

• 한국해양공학회지
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• 제22권1호
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• pp.22-29
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• 2008

A numerical investigation is made on the effects of the location and shape of the front wall of an OWC(Oscillating Water Column) chamber on the hydroelastic response of a VLFS. Most of the studies on the effects of an OWC chamber on the response of a VLFS have assumed the location of the OWC chamber to be at the front of the VLFS. In the present study, an OWC-chamber is introduced at an arbitrary position in relation to a VLFS to determine the influence of the location and shape of the OWC chamber on the hydroelastic response of the VLFS. A finite element method is adopted as a numerical scheme for the fluid domain. or the finite element method, combined with a mode superposition method, is applied in order to consider the change of mass and stiffness The OWC chamber in a piecewise constant manner. or the facilitated anefficient analysis of The hydroelastic response of the VLFS, as well as the easy modeling of different shape and material properties for the structure. Reduction of hydroelastic response of the VLFS is investigated for various locations and front wall shapes of the owe chamber.

• 농업과학연구
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• 제45권4호
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• pp.871-878
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• 2018

The government of Gyeongbuk in Korea increased the financial input in the agricultural sector by 43% from 2008 through 2012. However, the productivity of the agricultural sector in Gyeongbuk rose only about 3.6% during the same period. This study evaluated the agricultural competitiveness of each city or county in Gyeongbuk using six evaluation indices (scale, productivity, finance input, location quotient, technical education, and total) and investigated the relationship between the indices and total values of agricultural productions. The results show that Sangju, Gyeongju, Andong, Uiseong, and Seongju have high competitiveness for the scale index. For the productivity index, Gimcheon, Mungyeong, Ulleung, Yeongju, and Seongju were highly evaluated. For the location quotient index, Yeongcheon, Uiseong, Cheongdo, Seongju, and Sangju have high competitiveness. Uiseong, Yeongdeok, Cheongsong, Gunwi, and Yeongyang were highly evaluated for the agricultural finance input index. For the agricultural technical education index, Chilgok, Sangju, Mungyeong, Uiseong, and Gyeongju have high competitiveness. Finally, Sangju, Euiseong, Yeongcheon, Gyeongju, and Andong were highly evaluated for the total competitive index, while Yeongdeok, Yeongyang, Goryeong, Uljin, and Cheongsong have a low competitiveness for the total competitive index. This study also found that out of five indices, scale, location quotient, and technical education indices have a positive and statistically significant effect on the total values of agricultural production. However, we did not find any statistically significant effect of the productivity and finance input indices on the total values of agricultural production. Hence, we can conclude that the government should focus their agricultural policy on scale, location quotient and education to improve total agricultural production.