• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.121-127
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• 2011

Many peer-to-peer (p2p) systems have been studied in distributed, ubiquitous computing environments. Distributed hash table (DHT)-based p2p systems can improve load-balancing even though locality utilization and user mobility are not guaranteed. We propose a mobile locality-based hierarchical p2p overlay network (MLH-Net) to address locality problems without any other services. MLH-Net utilizes mobility features in a mobile environment. MLH-Net is constructed as two layers, an upper layer formed with super-nodes and a lower layer formed with normal-nodes. Because super-nodes can share advertisements, we can guarantee physical locality utilization between a requestor and a target during any discovery process. To overcome a node failure, we propose a simple recovery mechanism. The simulation results demonstrate that MLH-Net can decrease discovery routing hops by 15% compared with JXTA and 66% compared with Chord.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.666-675
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• 2008

The IEEE 802.22 standard is being developed with the target of improving the efficiency of spectrum utilization and importing the new wireless communication service. The WRAN standard based on Cognitive Radio is being processed for sharing TV bands. In this paper, the efficient spectrum allocation scheme and the optimal power allocation scheme, Partial Constant Power Water Filling (PCPWF), are proposed to maximize the channel capacity and spectrum efficiency and minimize the interference between adjacent cells. And we maximize the system throughput and fairness by using proposed dynamic cell plan that efficiently allocates channel. The results of the simulations are presented to verify the utilization of our proposed scheme.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.171-176
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• 2000

Bioremediation of hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), is a major environmental concern due to their toxic and carcinogenic properties. Due to their hydrophobicity, the hydrophobic organic compounds are mainly associated with the soil organic matter or nonaqueous-phase liquids. A major question concerns the relationships between biodegradation and sorption. This work develops and utilizes a non- steady state model for evaluating the interactions between sorption and biodegradation of phenanthrene, a 3-ring PAH compound, in soil-slurry systems. The model includes sorption/desorption of a target compound, its utilization by microorganisms as a primary substrate existing in the dissolved phase and/or the sorbed phase in biomass and soil, oxygen transfer, and oxygen utilization as an electron acceptor. Biodegradation tests with phenanthrene were conducted in liquid and soil-slurry systems. The soil-slurry tests were performed with very different mass transfer rate: fast mass transfer in a flask test at 150 rpm, and slow mass transfer in a roller-bottle test at 2 rpm. In the slurry tests, phenanthrene was degraded more rapidly than in liquid tests, but with a similar rate in both slurry systems. Modeling analyses with several hypotheses indicate that a model without biodegradation of compound sorbed to the soil was not able to account for the rapid degradation of phenanthrene, particularly in the roller bottle slurry test. Reduced mass-transfer resistance to bacteria attached to the soil is the most likely phenomenon accounting for rapid sorbed-phase biodegradation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.2815-2839
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• 2020

In a cloud computing paradigm, allocation of various virtualized ICT resources is a complex problem due to the presence of heterogeneous application (MapReduce, content delivery and networks web applications) workloads having contentious allocation requirements in terms of ICT resource capacities (resource utilization, execution time, response time, etc.). This task of resource allocation becomes more challenging due to finite available resources and increasing consumer demands. Therefore, many unique models and techniques have been proposed to allocate resources efficiently. However, there is no published research available in this domain that clearly address this research problem and provides research taxonomy for classification of resource allocation techniques including strategic, target resources, optimization, scheduling and power. Hence, the main aim of this paper is to identify open challenges faced by the cloud service provider related to allocation of resource such as servers, storage and networks in cloud computing. More than 70 articles, between year 2007 and 2020, related to resource allocation in cloud computing have been shortlisted through a structured mechanism and are reviewed under clearly defined objectives. Lastly, the evolution of research in resource allocation techniques has also been discussed along with salient future directions in this area.

• Korean Journal of Community Nutrition
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• v.4 no.4
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• pp.587-593
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• 1999

The purpose of this study were to : (a) analyzed price elasticity of university students in foodservice operations and (b)provide insight for price decision-making. Questionnaires were composed of price elasticity, the utilization and opinions of students on university foodservice operations, and demographic information regarding respondents. The questionnaires were distributed to 600 university students of 6 universities located in Seoul. Statistical data analysis was completed using the SAS package for descriptive analysis, t-test, ANOVA, and Pearson’s correlation. The results of this study can be summarized as follows: The average price for lunch was ￦1,663 for campus food, and ￦2,965 for off-campus restaurants. The frequency of utilizing the university cafeteria was fairly high. Students felt that the proper price for lunch was ￦1,446, presenting a lower price than the actual average price for lunch. The price elasticity was investigated in relation to the change in utilization rate when these was a price increase. The price elasticity was 2.03, with significant differences between sex, age, and major. The groups utilizing the university cafeteria frequently, taking longer time to go to off-campus or that were satisfied with the university cafeteria, had a lower price elasticity than those that did not. The results of this study suggest that predicting the price elasticity of the target market would assist the pricing policy, and the fact that the same students have different price elasticity by place and atmosphere can be used in marketing strategies.

• Journal of the Semiconductor & Display Technology
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• v.7 no.1
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• pp.29-34
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• 2008

In this paper, the DE(double erosion) cathode for the reactive magnetron sputtering system is developed for high deposition rate and high target utilization efficiency. The utilization efficiency of the developed DE cathode is 22% higher than that of normal SE(single erosion) cathode. Sputtering process for the nickel oxide thin films with the DE cathode is performed under the following conditions; power with $1kW{\sim}3kW$, pressure with 4mtorr and 8mtorr, oxygen flow ratio with $0%{\sim}80%$. As a result, the hysteresis phenomenon of discharge voltage in 4mtorr is lower than that in 8mtorr and the hysteresis phenomenon of discharge voltage is getting lower as the applied power is getting higher. The structure of cross section and surface roughness of the thin films are observed by FE-SEM and AFM. The structure of cross section of the thin films is columnar and the average surface roughness under oxygen flow ratio of 0%, 52.5% and 65.0% are $2.08{\AA}$, $2.20{\AA}$ and $0.854{\AA}$, respectively.

• New & Renewable Energy
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• v.19 no.1
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• pp.41-52
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• 2023

Various carbon upcycling technologies have been proposed and are under development to achieve Korea's carbon neutrality target. Many chemical reactions are under development through various chemical reaction pathways, and different technological maturity levels are shown for each country and company. In this situation, it is essential to establish investment decisions such as research funds and human resources allocation through technological and economic analysis for close commercialization technologies and basic technologies with low technology readiness levels (TRL). Therefore, in this study, the technology development priority for developing carbon upcycling items was selected according to the domestic Carbon Capture & Utilization (CCU) technology roadmap using the stakeholder selection tool released by EU CarbonNext. As a result of the analysis, the TRL level of Korea's major carbon upcycling technologies was analyzed to be lower than that of other carbon resource technologies, and it was considered desirable to invest in mineral carbonization technologies among various candidate technologies.

• Journal of Information Management
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• v.39 no.1
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• pp.83-108
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• 2008

This thesis investigated disabled students' actual status of applying for university libraries. This thesis investigated how many times the university disabled students utilized the libraries, if facilities, apparatuses, materials, and regular employees were operated properly, and if they were established actually on the target at thirty private university libraries located at Seoul and Gyeonggi regions in operation of specially screening the objective students for special education in 2008. The investigation found that the general operation level of university libraries for disabled students were less than "medium"(average 2.38). As for utilization ratio, the most university students responded that "they didn't utilize libraries so many times(60%)". As for the response ratio of university library facilities and services, the most university students responded, "very insufficient", 99 items(32.27%), and the least university students responded, "very excellent", 28 items(7.0%). On the other hand, as for the analysis of each field, building facilities, in all of the items, were established more than "medium"(average 3.26), but material preparation level(average 1.8 point), employee education for softly supporting disabled students, and library utilization education on the target at disabled students(average 1.87) were less than "insufficient". Especially, the field of service was "insufficient level"(average 2.48), and standard deviation was more than 1.4. Manpower stationing and material delivery services have the biggest standard deviation between universities. So, this investigation found that university libraries reformed access to facilities a lot, but that its level of fundamental policy for library, such as materials, manpower, and the education on utilization, were in insufficient level.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.245-251
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• 2013

In this paper, the expert system to reduce the amount of food waste is proposed. The method of material flow analysis (MFA) is applied. Proper handling of waste beyond the terms of the need for proactive research been mentioned before, but actually cause the waste generator research focuses on consumer behavior and the business community to analyze the flow of materials within the study are insufficient. In this paper, the type of food consumption and food waste, look at the relationship between the occurrence of secondary schools in the diet is provided for students to examine the preferences of the target model diet expert system was reconfigured. Preference for leaving the food in the diet leads to the important information that is Each diet recipes that make up the target material flow analysis (MFA) was constructed to perform all the database. This database is currently being generated from the rain while cooking diet edible plants and materials to reflect the self-esteem following the recommended diet is used to create. Reducing food waste is actually being used currently in research knowledge to the knowledge base was constructed. Future Home Smart System was developed in conjunction with the system to the user, by providing guidelines for the utilization can be expected.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.932-947
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• 2000

The purpose of this study was to suggest directions for developing a Health Promotion Program for the elderly in Korea for the future. For this, twenty previously developed & implemented health promotion programs were reviewed and analyzed in terms of target population of the program, components of the program, measurement variables for effects of program, the effects of the program. The results were as follows. 1. Most of the target populations were older adults living independently in the community. 2. Components of the program were health education, health assessment and counseling and exercise program. - Health education was done in most of programs. The topics of health education that were often included in the programs were life style changes, medical knowledge, independent living, the concept of health promotion and changes related to aging. - In health assessment and counseling, health professionals discovered their health problems through health assessment or health risk appraisal. Then they developed health recommendations on each health problem and encouraged the elderly to implement the recommendations. 3. Variables measuring the direct effects of the program were health behavior, knowledge, attitude, skill, use of medical/health reference book. Variables measuring the indirect effects, biometric outcome, health status, functional status, medical service utilization, medical cost and wellbeing. 4. The analysis showed that health education was effective for changing health behaviors, improving knowledge, skill and attitude in the elderly. Those results were suggested to be used as guidelines for developing a health promotion program for the elderly in Korea for the future.