• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제8권4호
• /
• pp.254-259
• /
• 2008

Uncertainty of result of context awareness always exists in any context-awareness computing. This falling-off in accuracy of context awareness result is mostly caused by the imperfectness and incompleteness of sensed data, because of this reasons, we must improve the accuracy of context awareness. In this article, we propose a novel approach to model the uncertain context by using ontology and context reasoning method based on Bayesian Network. Our context aware processing is divided into two parts; context modeling and context reasoning. The context modeling is based on ontology for facilitating knowledge reuse and sharing. The ontology facilitates the share and reuse of information over similar domains of not only the logical knowledge but also the uncertain knowledge. Also the ontology can be used to structure learning for Bayesian network. The context reasoning is based on Bayesian Networks for probabilistic inference to solve the uncertain reasoning in context-aware processing problem in a flexible and adaptive situation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권12호
• /
• pp.4819-4834
• /
• 2015

The spectral efficiency of cellular networks can be improved when proximate users engage in device-to-device (D2D) communications to communicate directly without going through a base station. However, D2D communications that are not properly designed may generate interference with existing cellular networks. In this paper, we study resource allocation and power control to minimize the probability of an outage and maximize the overall network throughput. We investigate three power control-based schemes: the Partial Co-channel based Overlap Resource Power Control (PC.OVER), Fractional Frequency Reuse based Overlap Resource Power Control (FFR.OVER) and Fractional Frequency Reuse based Adaptive Power Control (FFR.APC) and also compare their performance. In PC.OVER, a certain portion of the total bandwidth is dedicated to the D2D. The FFR.OVER and FFR.APC schemes combine the FFR techniques and the power control mechanism. In FFR, the entire frequency band is partitioned into two parts, including a central and edge sub-bands. Macrocell users (mUEs) transmit using uniform power in the inner and outer regions of the cell, and in all three schemes, the D2D receivers (D2DRs) transmit with low power when more than one D2DRs share a resource block (RB) with the macrocells. For PC.OVER and FFR.OVER, the power of the D2DRs is reduced to its minimum, and for the FFR.APC scheme, the transmission power of the D2DRs is iteratively adjusted to satisfy the signal to interference ratio (SIR) threshold. The three schemes exhibit a significant improvement in the overall system capacity as well as in the probability of a user outage when compared to a conventional scheme.

• 한국전기전자재료학회논문지
• /
• 제24권2호
• /
• pp.102-107
• /
• 2011

In multicell wireless systems with insufficient frequency reuse, user transmission will suffer other-cell interference (OCI). Cell cooperation is an effective way to mitigate OCI and increase the system sum rate. An adaptive scheme for serving one user in each cell was proposed in [1]. In this paper, we generalize that scheme by serving two users in each cell with adaptive zeroforcing beamforming (ZF) strategies. Based on our derived statistics of the signal-to-noise plus interference ratios, we choose the scheme to maximize the total ergodic sum-rate based on user locations. Through the numerical examples, we show that the total system sum rate can be improved by selecting appropriate transmitting strategy adaptively. As a result, our proposed system can explore spatial multiplexing gain without additional power and thus improves total system sum rate significantly.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권4호
• /
• pp.514-523
• /
• 2017

In this paper, we propose Adaptive Writeback-aware Cache management (AWC) to prolong the lifetime of non-volatile main memory systems by reducing the number of writebacks. The last-level cache in AWC is partitioned into Least Recently Used (LRU) segment and LRU using Dirty block Precedence (DP-LRU) segment. The DP-LRU segment evicts clean blocks first for giving reuse opportunity to dirty blocks. AWC can also determine the efficient size of DP-LRU segment for reducing the number of writebacks according to memory access patterns of programs. In the performance evaluation, we showed that AWC reduced the number of writebacks up to 29% and 46%, and saved the energy of a main memory system up to 23% and 49% in a single-core and multi-core, respectively. AWC also reduced the runtime by 1.5% and 3.2% on average compared to previous cache managements for non-volatile main memory systems, in a single-core and a multi-core, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권4호
• /
• pp.1424-1441
• /
• 2014

Two-tier femtocell networks, consisting of a conventional cellular network underlaid with femtocell hotspots, play an important role in the indoor coverage and capacity of cellular networks. However, the cross- and co-tier interference will cause an unacceptable quality of service (QoS) for users with universal frequency reuse. In this paper, we propose a novel downlink interference mitigation strategy for spectrum-shared two-tier femtocell networks. The proposed solution is composed of three parts. The first is femtocells clustering, which maximizes the distance between femtocells using the same slot resource to mitigate co-tier interference. The second is to assign macrocell users (MUEs) to clusters by max-min criterion, by which each MUE can avoid using the same resource as the nearest femtocell. The third is a novel adaptive power control scheme with femtocells downlink transmit power adjusted adaptively based on the signal to interference plus noise ratio (SINR) level of neighboring users. Simulation results show that the proposed scheme can effectively increase the successful transmission ratio and ergodic capacity of femtocells, while guaranteeing QoS of the macrocell.

• 농촌계획
• /
• 제17권3호
• /
• pp.81-90
• /
• 2011

The altitude criteria of 'Management of Mountains District Act' and 'National Land Planning and Utilization Act' are different because the adaptive reuse permissions on mountains district by two acts have been operated individually and each criteria has some problems for application. This study aims to suggest proposals for improvements of altitude criteria by two acts. The altitude criteria of the duel legal systems were researched by literature review and inherent issues were derived by interview with public officers and GIS tools applied to cases. The results are as follows : First, duel criteria systems need to be integrated based on the format by 'Management of Mountains District Act'. Second, the criteria index(50/100) by 'Management of Mountains District Act' need to be adjusted due to the preserved area ratio in mountains district and the each definition of 'the peak point of the mountain' and 'the tail of the mountain' can be changed as 'the highest point within the same slope(including ridge)' and as 'the average of the highest and the lowest point on boundary between the mountain district and the other land use district'. Third, the method of slope division may be determined by the conditions of local areas and the discrepancy between the two slopes in common boundaries must be adjusted. Finally, the maps containing preservation areas and development areas need to be notified.

• 농촌계획
• /
• 제20권1호
• /
• pp.161-173
• /
• 2014

This study aimed to adaptive reuse plan a take advantage of Suncheon Bay Garden Expo 2013. Detailed objectives included: to identify and foster cultural and ecological resources in Suncheon Bay and Garden Expo Site; and to search and propose characterized program in the site for efficient utilization; and to revitalize a site for the vitalizations of the region where garden culture and garden industries for strengthening local competitiveness. The study was multi-phased. The first stage included basic surveys such as site status and environmental context analysis, and questionnaires and similar case studies, and the second stage was to review the direction of preliminary planning, develop associated industries and strategies for regional revitalization and review and incorporate project details. And the third stage aimed to develop a comprehensive plan from spatial plans and program plans and suggest plans to vitalize the operation of the site. The results of the study are as follows: First, the characterization strategy is 'healing experience tourism', 'healing garden', 'healing herbal care' are suitable for the site and regional revitalization. Second, the dimension of 2013 Suncheon Bay Garden Expo which was distinguished into four areas, in consideration of the characteristics and contents of the garden expo site for efficient operation and maintenance. Four area are as follows: the park oriented area, the experiential tourism oriented area, the existing conservation oriented area, and the area for associated industries. Third, the practice of private and public partnerships is needed in order to efficiently manage and operations. The significance of this study is that it is seeking to take advantage of the Garden Expo site and set the plan by existing resources and in consideration of local characteristics, in conjunction with area to envision and proposed management plan. Some problems are remained which have not been able to deal with details program and organization and financial planning programs for the operation of the site. This is for further study.

• 산업융합연구
• /
• 제20권3호
• /
• pp.73-79
• /
• 2022

본 연구는 발달장애 아동의 심리운동센터 이용 부모의 선택 동기, 만족도, 재이용 의사의 관계를 검증하고자 하였다. 이를 위해 수도권 소재의 사설 심리운동센터에서 심리운동프로그램에 참여하고 있는 아동의 부모를 대상으로 설문조사를 실시하였다. 수집된 자료는 188부이며, 서술통계, 요인분석과 신뢰도분석 그리고 상관분석과 회귀분석을 통하여 인과관계를 검증하였다. 분석 결과 다음과 같은 결론을 얻었다. 첫째, 발달장애 아동의 심리운동 참여에 대한 부모님의 선택동기와 만족도 관계에서 하위요인인 이용만족은 즐거움과 사교요인, 성과만족에서는 사교, 건강과 체력요인에서 유의미한 영향력을 나타내었다. 둘째, 선택 동기와 재이용 의사의 관계에서 즐거움, 기술발달 및 성취감, 사교요인에서 유의미한 영향력을 나타내었다. 셋째, 만족도와 재이용 의사의 관계에서 이용만족과 성과만족 요인에서 재이용 의사를 유의미하게 설명하였다. 향후 심리운동센터 재이용률을 높이기 위해 본 연구의 측정변인 외에 추가적인 분석이 필요하다고 판단된다.

• 전자공학회논문지
• /
• 제50권11호
• /
• pp.90-98
• /
• 2013

지역적 정합방법을 이용한 스테레오 시스템은 알고리즘의 특성상 하드웨어 설계가 용이하여 많이 사용되나 낮은 정합률로 인해 정확한 깊이 영상을 얻기 힘들기 때문에 많은 응용 분야에 사용하기에 제한이 있다. 본 논문에서 제안한 스테레오 시스템은 픽셀의 변화도(gradient)를 기반으로 한 적응적인 가중치 알고리즘을 이용하여 높은 정합 성능을 보이며 하드웨어로 설계하였을 때 실시간처리가 가능하다. 일반적으로 적응적인 가중치 윈도우를 적용할 경우 중간 결과를 재사용하기 불가능하지만 행, 열을 분리하여 처리함으로써 데이터를 재사용할 수 있고 따라서 처리성능이 개선되었다. 알고리즘에 필요한 지수 및 아크탄젠트 함수를 구현하기 위해 선형(PWL, piecewise linear) 및 계단(step) 함수 등으로 근사화한 뒤 에러를 분석하여 최선의 파라미터를 선택하였다. 제안한 구조는 실시간처리를 위하여 9개의 프로세서를 사용하여 병렬처리를 하였으며, 동부하이텍 0.18um 라이브러리로 합성하였을 경우 최대 동작주파수 350MHz(33 fps)와 424K 게이트의 하드웨어 복잡도를 나타내었다.

• Asia pacific journal of information systems
• /
• 제16권4호
• /
• pp.103-119
• /
• 2006

One of the most important reasons for using online game is intrinsic motivation which relates the drive to perform a behavior for perceptions of pleasure and satisfaction from the behavior itself. Therefore, most studies for using online game have been based on theories for intrinsic motivation such as flow. However, such theories have some limitations for explaining social aspects of online games such as Massively Multiplayer Online Role Game (MMORPG), which provides a society for game players by using a virtual space for playing games so called 'persistent world'. Adaptive structuration theory (AST) is one of trying to capture the change of using IT due to social interactions between users and system. In order to explain online game players' behavior considering social interaction, we suggest a research model based on AST. Our model aims to investigate the relationship between appropriation which is determined by faithfulness of appropriation (FOA) and consensus on appropriation (COA) and performance which is represented by the relationship among perceived winning, flow, and intention of reuse. An empirical test of our model for 125 MMORPG users which is analyzed by Partial Least Square method shows very satisfactory and interesting results. While hypotheses suggested in our model are supported, the influence of COA on game performance is shown to be stronger than that of FOA.