• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3856-3872
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• 2018

HTTP-based adaptive streaming (HAS) has recently been widely deployed on the Internet. In the HAS system, a video content is encoded at multiple bitrates and the encoded video content is segmented into small parts of fixed durations. The HAS client requests a video segment and stores it in the playout buffer. The rate adaptation algorithm employed in HAS clients dynamically determines the video bitrate depending on the time-varying bandwidth. Many studies have shown that an efficient rate adaptation algorithm is critical to ensuring quality-of-experience in HAS systems. However, existing algorithms have problems estimating the network bandwidth because bandwidth estimation is performed on the client-side application stack. Without the help of transport layer protocols, it is difficult to achieve accurate bandwidth estimation due to the inherent segment-based transmission of the HAS. In this paper, we propose an alternative approach that utilizes the playout buffer occupancy rather than using bandwidth estimates obtained from the application layer. We start with a queueing analysis of the playout buffer. Then, we present a buffer-aware rate adaptation algorithm that is solely based on the mean buffer occupancy. Our simulation results show that compared to conventional algorithms, the proposed algorithm achieves very smooth video quality while delivering a similar average video bitrate.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.227-232
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• 2008

Since 2000, there have been many changes in the residential types, such as an intelligent apartment which integrates both resting space and production space with comfort able, pleasant and safe environments based on internet systems. As the result of the rapid decrease in the birth rate and the prolonged lifespan around the world, it is expected that we will enter into an aging society by 2026. With such the expected change in the living patterns, many issues concerning the increased number of the elderly people have emerged as major social problems such as changes of family formation, its function and values, responsibility of caring for the aged, health and medical care, habitation policies and so on, and it is required to reconsider the social awareness on the living qualities of each old person. However, we have not yet satisfied such requirements with appropriate policies for the improvement of the living environment for them. It is considered, therefore, that we need to develop a new tool that, according to our goals, can give us a broad understanding on several considerations in designing the future homes for the elder people, making it possible to check the process changed by residents' needs in real time and apply it immediately to the space. As we have seen, it is required that spatial design process and design methodology should be considered in designing the homes for the aged for the pre-occupancy design evaluation.

• Korean Journal of Human Ecology
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• v.24 no.6
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• pp.887-901
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• 2015

This study aims to identify limitations and pending problems after reviewing the overall policies and status of rural Newtown projects, and to seek solutions to its problems. This study targeted the villages of 5 districts, which were developed as rural new-towns after 2009 and included the basic status and progress of the pilot districts. This study conducted a literature review to examine the basic status and progress of the pilot districts, and based on this, analyzed the demand prediction, site selection, project implementation, and housing and amenity facilities of the pilot districts. The study methods included literature reviews, on-site surveys, interviews with village representatives, and consultations with experts. According to the analysis results, a low occupancy rate of the Newtown project districts is because the prediction of occupancy demand was incorrectly completed before implementing the projects. Also, the eligibility for occupancy, such as age restriction and mandatory farming was too strict. Other problems included an absence of income generation support policies for rural returnees, a housing supply policy in disregard of agricultural characteristics, and a lack of understanding of maintenance of communal space, etc.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.214-220
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• 2015

This study examines whether the two variables that encompass the number of rooms sold and occupancy, as independent variables, positively affect a total of revenue generated from the hotel industry. Using a simple regression analysis and a standard multiple regression analysis, the study evaluates if the two independent variables play an important role in influencing a total of revenue in the hotel industry. A finding tells that researchers need consider a removal of the occupancy rate for a better and accurate prediction. It is expected that this study will contribute to a theoretical development of a study group that focuses on what determinants enable to improve a financial performance in the hotel sector.

• Journal of Korea Port Economic Association
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• v.32 no.2
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• pp.137-156
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• 2016

This study analyzes the optimal service levels of exclusive container terminals in terms of the optimal berth occupancy rate and the ships' waiting ratios, based on the number of berths. We develop a simulation model using berth throughput data from pier P, Busan New Port, a representative port in Korea, and apply the simulation results to different numbers of berths. In addition to the above results, we analyze the financial data and costs of delayed ships and delayed cargoes for the past three years from the viewpoints of the terminal operation company (TOC), shipping companies, and shippers to identify the optimal service level for berth occupancy rates that generate the highest net profit. The results show that the optimal levels in the container terminal are a 63.4% berth occupancy rate and 10.6% ship waiting ratio in berth 4,66.0% and 9.6% in berth 5, and 69.0% and 8.5% in berth 6. However, the results of the 2013 study by the Ministry of Maritime Affairs and Fisheries showed significantly different optimal service levels: a 57.1% berth occupancy rate and 7.4% ship waiting ratio in berth 4; 63.4% and 6.6% in berth 5; and 66.6% and 5.6% in berth 6. This suggests that optimal service level could change depending on when the analysis is performed. In other words, factors affecting the optimal service levels include exchange rates, revenue, cost per TEU, inventory cost per TEU, and the oil price. Thus, optimal service levels can never be fixed. Therefore, the optimal service levels for container terminals need to be able to change relatively quickly, depending on factors such as fluctuations in the economy, the oil price, and exchange rates.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.331-335
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• 2006

We investigated the distribution of three anuran species, Three-striped pond frogs (Rana nigromaculata), Bullfrogs (Rana catesbeiana), and Narrow-mouthed toads (Kaloula borealis), in an administrative district, Haenam Gun, Junnam Province, Korea using volunteer call surveys. Twenty-eight volunteer call surveyors were assigned to each $2{\times}2km^2$ survey plot. Call surveys on whether the species are present or not were conducted for 5 minutes between 30 minutes after sunset and the midnight on rice fields and ponds from 10 April to 28 August in 2005. Depending on species, call surveys were carried out at seven to 28 plots with average 8.4 to 10.7 visits per the plot. We calculated the detection probabilities and occupancy rates of the three species using four models with three covariates: temperature, humidity, and the amount of water at the habitat. The model average detection probabilities of three anuran species of R. nigromaculata, R. catesbeiana, and K. borealis were 0.53, 0.74, and 0.41 respectively, and the site occupancy rates of them were 0.93, 0.94, and 0.86 respectively. Our results indicate that R. nigromaculata, R. catesbeiana, and K. borealis are common in Haenam Gun.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.313-320
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• 2018

The purpose of the study is to suggest ways to reduce the difference in occupancy rate and cost of incubation centers and surveyed 262 business disclosures of KBIA. the region, the subject of management, and the technology field are set as independent variables among the management disclosure items, and the occupancy rate, cost, and assigned grade are defined as dependent variables. As a result of the correlation analysis, it was found that about 19.4%($R^2=0.194$) and about 7.0%($R^2=0.059$) explain the cost of the operation, Respectively. finally Costs are high in metropolitan areas, public organizations and technology-intensive centers are inexpensive, occupancy rates are high in government and universities, and low in large cities. In order to resolve the gap, $5,720won/m^2$ is appropriate, and the center operates as a technology-intensive specialization center.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3D
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• pp.335-345
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• 2009

Generally, density is used as a measure of effectiveness (MOE) of the level of service (LOS) for the basic segment of the roadway facility, but can not express the operational condition of the roadway facility properly because there can be an error in the computed density compared with the density measured in the field. Thus, the purpose of this study is to investigate the real-time traffic characteristic data (traffic flow, speed, occupancy, headway, spacing, etc.) from the detectors installed on the mainline section of urban freeway under the study, analyze the maximum flow rate from the relationship between the real-time traffic characteristics collected, and evaluate the LOS criteria within the basic segment of the urban freeway based on the relationship between the occupancy and the v/c ratio depending on the level of service.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.146-147
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• 2010

• International Journal of Human Ecology
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• v.7 no.1
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• pp.13-23
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• 2006

The purpose of this study was to provide basic information regarding the planning of lounge and hallway areas for skilled nursing facilities for the elderly, given that residents spend much of their time in these areas. This study examined Korean elderly residents' occupancy and behavior in lounges and hallways in order to analyze how plan type, spatial composition, and equipment affect residents. To do this, observations were conducted in five facilities that were provided to the elderly at no charge. Results indicate that a central garden offers a wide hallway area that can be used not only for strolling but also for list of activities; at the same time, it can reduce the overall rate of inactivity. A shorter distance between the lounge and hallway on the opposite side is likely to help better disperse residents' throughout the facility. Hallway corners have potential for activities that may require sofas, tables, or equipment for individual activities; they could also be used for planned interaction programs or unplanned collaboration on the part of small groups of residents.