• Journal of KIISE
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• v.42 no.9
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• pp.1162-1174
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• 2015

These days, the networks have exhibited HBDP (High Bandwidth Delay Product) characteristics. The legacy TCP slowly increases the size of the congestion window and drastically decreases the size of a congestion window. The legacy TCP has been found to be unsuitable for HBDP networks. TCP mechanisms for solving the problems of the legacy TCP can be categorized into the loss-based TCP and the delay-based TCP. Most of the TCP mechanisms use the standard slow start phase, which leads to a heavy packet loss event caused by the overshoot. Also, in the case of congestion avoidance, the loss-based TCP has shown problems of wastage in terms of the bandwidth and RTT (Round Trip Time) fairness. The delay-based TCP has shown a slow increase in speed and low occupancy of the bandwidth. In this paper, we propose a new scheme for improving the over shoot, increasing the speed of the bandwidth and overcoming the bandwidth occupancy and RTT fairness issues. By monitoring the buffer condition in the bottleneck link, the proposed scheme does congestion control and solves problems of slow start and congestion avoidance. By evaluating performance, we prove that our proposed scheme offers better performance in HBDP networks compared to the previous TCP mechanisms.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.666-673
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• 2023

The runway occupancy time of landing aircraft is an important factor in determining runway capacity. The purpose of this study is to suggest improvement measures for runway occupancy time to improve the operation of existing airports. In order to derive improvement measures, a comparative analysis was conducted on the effectiveness of improvement using aircraft operation status data for specific days at the case airport. The FAA REDIM model was used to analyze the improvement plan, and the improvement application function of the model was used to confirm the effect of improving runway capacity by adding a rapid escape taxiway to an airport without a rapid escape taxiway. This study's approach can be applied to the derivation of runway improvement measures and preliminary prediction of effectiveness, and it presents cases that can be applied to future airport construction projects or airport improvement projects.

• Journal of the Korean Institute of Educational Facilities
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• v.10 no.2
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• pp.15-22
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• 2003

The purpose of this study is to find problems and to provide architectural design standards of the Learning Space Unit(L.S.U.) in Elementary Schools through the Post-occupancy Evaluation(POE). In this study, we found six major problems of the type of the L.S.U. in elementary schools. More than 50% of users expressed dissatisfactions in these items : size, safety, cooling facility, noise, privacy and primary meaning for its original purpose. After the interrelation-analysis, we checked pros and cons about each forms of L.S.U. It is the result of analysis of the layout method in L.S.U. 1) "$8.4m{\times}8.4m$" classroom unit got the highest positive responses 2) "2-classroom type" and "4-classroom type" got higher score than "3-classroom type" 3) "Whole faced type" 1) made more active Multi-space than "Partial faced type" 4) prefered prepared "Open-classroom" to "Closed-classroom" 5) 'Zoning type between L.S.U.s' couldn't influence to user's responses. Designers can consult those informations when they plan a new, remodeling and additional elementary school.

• Journal of the Korean housing association
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• v.25 no.5
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• pp.63-71
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• 2014

Recently, many researches on the supply of public rental-housings that utilize modular houses have been conducted for the expanded supply of public rental house and consumer-customized supply. For this reason, a research on recognition and satisfaction of residents who live in modular houses was conducted based on their evaluations on public rental houses utilizing actual modular houses. Consequently planning guidelines that would increase residency satisfaction was drawn. Surveys and interviews of 'The Gongneung Hee-mang Housing' were conducted, and analyses of descriptive statistics, multiple regression analysis and importance-satisfaction analysis were conducted. The post occupancy evaluations inform that to gain extra recognition by promoting advantages of modular houses and engaging in educational activities are needed. Dealing with issues such as external noises and vibrations, proper common facility, interior space plan, taking account of facility plan is also needed. This study would contribute to establish modular house planning, reflecting the residents' practical demands.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.41-48
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• 2011

The purpose of this study was to analyze research trends in post-occupancy evaluation and to explore Improvement Directions. Also this study investigated historical development of domestic POE researches and current discussions to POE in architecture and interior design fields. The results were as follows. For the purpose of this study, 55 articles from 3 journals were selected and analyzed. 55 articles analyzing POE methodology and applying POE method were published from 1990 to 2010. In the 1990s, studies on introduction of POE method, potential and limitation were conducted. In the 2000s, the research theme showed the study for evaluation of apartment measuring the residents satisfaction. Gathering the opinions of designers and people in architecture field, they have recognized the need to perform POE, indeed it has been difficult to find POE researchers and utilized POE data. Nevertheless, some of them have performed POE of their building and got feedback from residents. In conclusion, to apply POE method and develop its potential, it is necessary to minimize the barriers. It should Therefore, be performed POE by stakeholders who are designers, builders and residents and POE data would be provided a variety of types. Furthermore, POE certification system should be designed at the government level and basically, POE courses must be included in the architectural curriculum.

• KIEAE Journal
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• v.14 no.6
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• pp.31-41
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• 2014

This study aims to POE(Post-Occupancy Evaluation) analyze the characteristics of residents and their demands on community facilities by types of supplying housing, which can be the basis for making the housing regulations. The following five types of housing are considered in this study ; 1) National Rental Housing(L), 2) Public Rental Housing(L), 3) Permanent Rental Housing(S), 4) Public Rental Housing(S), 5) Private Rental Housing. We surveyed 527 residents from 20 housing complexes in those four housing types. First, each housing type has different household characteristics. Second, the criteria for housing selection are different. Third, local community activities and satisfaction are different in each housing type. Lastly, residents are generally satisfied with service facilities, but their satisfaction level and the facilities they need are different depending on housing type, accordingly. The housing community space plan be should be improved to the amount of areas of community facilities.

• 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.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.4
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• pp.1-11
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• 1997

In this paper, modeling of the communication channel occupancy characteristics at the base station in the wide area radio trunking syste has been performed. Using the results, mathematical analysis for the switching capacity at the network switch has also been done. Specificatlly, we propose a G/M/m queueing model for the single service area modeling, and analyze changes in call blockingprobabilities accoridng to changes in the burstness characteristics of group paging calls. As a result, we have observe dthat the channel occupancy variations become larger as the burstness characteristics become more apparent, to make the call blocking probability higher. Next, based on the single service area analysis, we have anayzed mathematically the average switching capacity required to serve mobile subscribers for a wide area radio trunking sytem, where multiple switching port assignments are required when the people in the same group are distributed over several base stations. Accordingly, we have observed that the average and the variance of switching channel occupancy are closely related to the mobility characteristics of subscribers, and that we need a netowrk switch having bigger capacity as subscribers show wider distribution. Especially, with the call dropping probability within 0.2%, a switch having about 5 to 6 times bigger can be required, compared with the one when the mobility of subscribers is mostly restricte dto a single service area.

• Korean Institute of Interior Design Journal
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• no.23
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• pp.116-123
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• 2000

The importance of evaluation in design activity has been increased. Specially, it is necessary to take into consideration of user's needs as design criteria nowadays. Through these evaluations, the comprehensive quality of architectural design could be substantially improved and play the part of recycling at least in cases of theme similar structures. By a viewpoint of library patrons, there have increased many problems In library environment because more library patrons use the reference room for their study since reform of university education was carried out In 1981. Therefore, after post occupancy evaluation and spatial-planning matters of architecture are taken into consideration in this study, the problems of the plan-composition on the existing structure is pointed out and introduced the concept of post occupancy evaluation to grope the solution. With the question about users's needs and the state of use in the K-University Library, this study aims to investigate the actual use circumstance of space and maintenance of facilities as well as giving the most relevant alternatives instead of already existing one. This also intends to propose the essential date to meet the users' sociopsychological needs and environment innovation when planning the university library.

• 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.