• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.1-7
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• 2016

When multiple applications are running concurrently on a multi-processor system, interferences between applications make it difficult to guarantee real-time constraints. We propose a novel interference analysis technique that allows sharing of share processors among dataflow applications, while satisfying real-time constraints. Based on the interference analysis, we develop a co-scheduling technique that aims to minimize the resource usage. Compared to an existent technique that involves converting application graphs to real-time tasks, the proposed technique shows better results in terms of resource usage, especially when it is applied to applications with tight time constraints.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.69-74
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• 2014

With the increasing interest of energy efficiency, several buildings and factories begin to monitor energy usages with a built-in energy management system. However, the built-in energy monitoring system does not reflect the dynamics of buildings and factories energy usage. To overcome the latter, we deploy several sensors to monitor the dynamics of buildings energy usage patterns. In this paper, we are proposing a framework of a sensor based energy monitoring system. Based on our limited experiments, we can monitor power usages by a person, device and time period. As a result, we can plan a better energy usage and improve energy efficiency by the monitored energy usage profile data.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.4
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• pp.189-211
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• 2011

With the changes in information production and transaction, the ratio of electronic resources in library collection is increasing. Statistical date on usage of electronic resources is an important indicator for library management and development of information service. This study analyzed current state of global standards of usage statistics, and definition and features on electronic resources. It also provides current states of usage statistics data on electronic resources applied by major vendors and publishers. Based on the results of the study, this study proposed the methods to apply statistical data on usage of electronic resources to library management and development of information service.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.515-524
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• 2015

The estimation of groundwater usage in Jeju island is important to understand hydrologic cycle system and to plan management of water resource because large amounts of groundwater have been used for agricultural and domestic purpose. The model has been developed to estimate agricultural groundwater usage for garlic at uplands and citrus at orchards raising outdoors using the soil water balance model from FAO 56, respectively. The total amount of water supplied for the crop evapotranspiration and the multipurpose function such as sprout promotion can be simulated by the model. However, due to the discrepancy of water use in initial stage between calculated and observed, the model was calibrated and verified using actual groundwater usage monitoring data for 3.5 years (2011.6 to 2014.12) at three uplands for garlic and three orchards for citrus. Consequently, it would be concluded that the model simulated efficiently actual water usage in that root mean square (RMS) and normalized RMS of the validation stage were less than 8.99 mm and 2.43%, respectively, in two different conditions.

• Journal of Information Management
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• v.38 no.4
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• pp.68-87
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• 2007

The purpose of the study is to understand the present state of practical use of electronic journal usage statistics at the academic libraries. For this purpose the study performed an online questionnaire survey to the 63 academic libraries located in Seoul and Gyeonggi Province. Based on the 48 responses, the study found out that the rate of satisfaction with the present usage data was low. Especially the rate of unsatisfaction with the absence of comparable data and the average usage rate of all the subscribing libraries appeared high. The study also examined 5 types of statistics for the evaluation of electronic journal.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.208-211
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• 2003

기존 IEEE 802.11 MAC (1)에서는 Fairness를 보장하며 Resource를 제공하는 것을 목표로 동일한 DIFS, Back-off 알고리즘, Source가 같은 경우 동일한 Frame size등을 사용하는 Specification을 작성하여 구현한다. 최근 Home Network과 같은 특수한 Ad-Hoc 환경에서의 이런 Fairness Resource Usage가 오히려 기대 성능을 떨어뜨리는 결과를 가져오고 있다. 이에 802.11 MAC에서 Backward Compatibility를 유지하면서 Prioritized DIFS/Backoff/Frame를 통해 차등화된 서비스를 제공하는 메커니즘을 제안하고자 하는 것이 본 논문의 목표이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.567-575
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• 2011

The two most popular virtual machine allocation schemes, both match making and round robin, do consider hardware specifications such as CPU, RAM, and HDD, but not CPU usage, which results in balanced resource distribution, but not in balanced resource usage. Thus, in this paper a new virtual machine allocation scheme considering current CPU usage rate is proposed while retaining even distribution of node resources. In order to evaluate the performance of the proposed scheme, a cloud computing platform composed of three cloud nodes and one front end is implemented. The proposed allocation scheme was compared with both match making and round robin schemes. Experimental results show that the proposed scheme performs better in even distribution of overall CPU usage, which results in efficient load balancing.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3350-3355
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• 1999

Modeling for the Internet resource is important to use of limited resource efficiently. Also, the modeling could guide how we can approach the Internet problems. The many studies of price mechanism to internalize the externality, to decrease the externality from congestion, and to use the Internet resource efficiently, are widely going on. The represent styles for Internet pricing are usage-based pricing(UBP) and flat-rat pricing(FRP) and the FRP could prefers for the beginning stage of Internet introduce. The purpose of this study is to examine the efficiency of Internet pricing mechanism based on flat-rate pricing, both consumer and producer side.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.27-42
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• 2009

In realizing ubiquitous computing, techniques of efficiently using the limited resource at client such as mobile devices are required. With a mobile device with limited amount of memory, the techniques of XML stream query processing should be employed to process queries over a large volume of XML data. Recently, several techniques were proposed which fragment XML documents into XML fragments and stream them for query processing at client. During query processing, there could be great difference in resource usage (query processing time and memory usage) depending on how the source XML documents are fragmented. As such, an efficient fragmentation technique is needed. In this paper, we propose an XML fragmentation technique whereby resource efficiency in query processing at client could be enhanced. For this, we first present a cost model of query processing over XML fragment stream. Then, we propose an algorithm for resource-efficient XML fragmentation. Through implementation and experiments, we showed that our fragmentation technique outperformed previous techniques both in processing time and memory usage. The contribution of this paper is to have made the techniques of query processing over XML fragment stream more feasible for practical use.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.119-120
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• 2022

As the seriousness of the climate crisis is emphasized, movements to solve it are becoming active. In Korea, efforts to reduce environmental impacts across all industries are being strengthened through the Framework Act on Low Carbon Green Growth. The construction industry predicts the environmental impact of buildings during the entire life cycle, but in the construction process, there is a difference in energy usage depending on the amount of input, and it is difficult to predict the environmental impact if data cannot be collected. Therefore, this study evaluated the environmental impact of energy usage in the apartment construction process as part of the study on predicting and reducing the environmental impact of the construction process of the construction site. To this end, the environmental effects of buildings were set as global warming, resource consumption, and ozone layer effects, and the environmental effects of the actual energy use in the case were evaluated. In addition, based on the evaluation results, the characteristics of the input energy usage were compared and analyzed.