• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.283-293
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• 2016

Owing to an increase in the air tightness of recent buildings, the natural ventilation rate was significantly lowered and the removal of accumulated moisture became difficult in these buildings. The hygrothermal performance of these buildings should be carefully considered to provide comfortable indoor environment by removing the moisture condensation risk and the mold growth potential. In this study, hygrothermal performance of two selected wall structures was investigated based on WUFI simulation program. The results displayed that the indoor temperature had impact on the moisture accumulation in the insulation layer for both modeled walls, showing that lower indoor temperature resulted in higher moisture accumulation, especially in the wood frame structure. Also, the yearly moisture accumulation profile exhibited a downward shift throughout the year by adding a vapour retarder with a lower sd-value. In addition, both of the two walls have condensation risk in winter, due to low temperature level. The wood frame structure has a bigger fluctuation and higher condensation risk than the concrete structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.153-158
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• 2010

In this paper, we propose and analyze the positioning technique using TH-PPM ultra wideband for indoor environment. We employed AWGN and IEEE 802.15.3a channel as a simulation environment and used to TDOA algorithm. Positioning technique using ultra wideband has high accuracy in indoor environment. From the simulation results, it is analyzed the probability of error and positioning performance for channel effects and confirmed usefulness of the proposed scheme.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.579-588
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• 2010

According to the increasing concern about health and environment, students need to study in comfort and clean environment facilities. We did field survey on 40 primary schools to analyze the present condition of design and construction for the part of indoor environmental performance in the certificated green school building. We hope that this paper will offer the important data about the indoor environment standards and performances in primary school facilities.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.128-134
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• 2011

The objective of this study is to analyze the major factors of indoor environment that affect the satisfaction of the occupancy in multi-family residential buildings. The results of this study can contribute to improving the comfort of the residents effectively as they are applied preferentially at the design and construction stages. The indoor environment factors investigated for the analysis included thermal, light, air and the acoustic environment. The individual factors were derived from the 'indoor environment' assessment indices of the green building certificate systems of various countries. Based on these, a questionnaire was prepared to conduct the Post Occupancy Evaluation. The survey results were statistically analyzed.

• Journal of the Korean Solar Energy Society
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• v.38 no.3
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• pp.29-36
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• 2018

The goal of this study is to retrofit the windows of residential buildings and to activate the green remodeling by verifying energy saving and indoor thermal environment. As a result of analysis of the energy saving effect of 458 units window retrofits, it was possible to reduce the energy requirement by 48.20% ~ 54.97%. According to the improvement on indoor environment, it was possible to operate by reducing heating temperature and supply time. The actual gas consumption of the heating period was reduced by 25% compared with that of the window retarder to save 28,968 thousand won of heating energy cost. Resident's satisfaction surveys were conducted one year after window retrofit. More than 80% of the respondents answered that they satisfied the improvement on window performance, indoor thermal environment and indoor sound environment. As a result, we verified the energy saving effect and the improvement on the indoor environment through window retrofits.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.47-53
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• 2007

As more serious environmental problems of buildings, many researchers have recognized the importance of preserving the environment where we live as well as a necessity of developing architecture with eco-environmentally. As a result, our country and some advanced countries have tried to solve these problems in that developed green building assessment tools for estimating environmental performance of buildings. Among many kinds of buildings, hospital which have been relation with human beings has been laking in basic raw materials of researching hospital's environment. Especially, there are few materials about indoor environment of hospital. So, the facilities of patients not only have to depend on the quality of natural environment but be also taken into account of patients. The purpose of this study is to prepare the basic data to develop the items of indoor environmental assessment for hospital to improve the quality of hospital's indoor environment. To come to a conclusion, we used a method of comparing domestic green building certification criteria, LEED v.2.2 and GBTool 2005. Then, we analyzed them for the case studies. Consequently, we could grasp basic data to assist in effecting domestic green building certification criteria for hopital. Furthermore, we have made a progressive research about setting grades of it.

• KIEAE Journal
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• v.13 no.1
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• pp.75-81
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• 2013

The balcony of our apartment building consists of unique construction similar to double skin. It is announced broadly that double skin is very effective system in improvement of natural ventilation and indoor thermal environment, and outdoor sound protection. So, for the improvement of indoor climate and energy saving, many peoples studied about environmental performance of our balcony construction. This study focus on shaft box facade, special form of box window construction. It consists of a system of box window with continuous vertical shafts that extend over a number of stories to create a stack effect. Proto-type was decided by analyzing various types of exiting apartments. Shaft box type balcony was created by setting up shaft space at a part of balcony. Air flow and contribution of air temperature were simulated, performance of shaft box type balcony was compared with existing balcony. Finally, we confirmed that shaft box type balcony has many possibility for improvement of indoor environment.

• Journal of information and communication convergence engineering
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• v.4 no.3
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• pp.97-100
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• 2006

In this paper, the transmission service for medical image is proposed via IEEE 802.15.4a on WPAN environment. Also, transmission and receiving performance of medical image using TH UWB-IR system is evaluated on indoor multi-path fading environment. On the results, the proposed scheme can solve the problem of interference from the medical equipment in same frequency band, and minimize the loss due to the indoor multi-path fading environment. Therefore, the transmission with low power usage is possible.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.263-269
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• 2010

Multiple input multiple output (MIMO) has been considered one of the key enablers of broadband wireless communications. The indoor environment is known to be favorable to ensure both high rank property and high signal-to-interference/noise ratio (SINR) to fully exploit MIMO spatial multiplexing (SM) gain. In this paper, we describe several practical deployment cases where repeater links (or relay links), such as those present with an indoor distributed antenna system (DAS), can act as keyholes to degenerate the rank property of MIMO communications. In this case, we cannot exploit MIMO SM gain in indoor environment. We propose a novel MIMO communication scheme which uses simple converter in the devices in repeater links to resolve the rank degeneration issue and to ensure MIMO SM gain in highly MIMO-favorable indoor environment. MIMO SM is possible over the indoor DAS with single cable line through use of simple converters, which enables practical deployment in real fields.

• Journal of IKEEE
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• v.26 no.2
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• pp.186-195
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• 2022

In this paper, we propose a new algorithm to improve the accuracy of indoor positioning techniques using Wi-Fi access points as beacon nodes. The proposed algorithm is based on the Weighted Centroid algorithm, a popular method widely used for indoor positioning, however, it improves some disadvantages of the Weighted Centroid method and also for other kinds of indoor positioning methods, by using the received signal strength correction method and genetic algorithm to prevent the signal strength fluctuation phenomenon, which is caused by the complex propagation environment. To validate the performance of the proposed algorithm, we conducted experiments in a complex indoor environment, and collect a list of Wi-Fi signal strength data from several access points around the standing user location. By utilizing this kind of algorithm, we can obtain a high accuracy positioning system, which can be used in any building environment with an available Wi-Fi access point setup as a beacon node.