• Title/Summary/Keyword: Ventilation Noise

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Recent Progress in Air Conditioning and Refrigeration Research - A Review of papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 1998 and 1999 - (공기조화, 냉동 분야의 최근 연구 동향 - 1998년 1999년 학회지 논문에 대한 종합적 고찰 -)

  • 이재헌;김광우;김병주;이재효;김우승;조형희;김민수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.12
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    • pp.1098-1125
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    • 2000
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

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A Study on the Environmental Performance Level Measurement in the Lecture Room during Winter Time (동계 대학강의실 환경성능수준 측정에 관한 연구)

  • Ahn, Tae-Kyung
    • Journal of the Korean Institute of Educational Facilities
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    • v.25 no.2
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    • pp.3-9
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    • 2018
  • This study is designed to measure the indoor environment and research on the environmental situation in the lecture room where the lecture is conducted during the winter time in order to understand the level of environment in the lecture room and then suggest the method of improving the environment in the lecture room in the future. The findings are as follows. First, the number of ventilation measured at Lecture Room 1 was 1.2 times/hour while that at Lecture Room 2 was 2.2 times/hour. Second, the lighting at Lecture Room 1 and 2 was 650~700 lux while the noise at Lecture Room 1 and 2 was not more than 60dB. Third, Group 1 and Group 2 felt in the same way that the air quality in the lecture room was not good when the air quality was measured in 30 minutes after the start of lecture. Fourth, both Group 1 and Group 2 showed the lowered concentration on the class in 30 minutes after the start of the class when the room was heated. But Group 1 got less drop in the concentration when they was put in the non-heated room. Fifth, As for the change in the carbon dioxide volume during lecture, the carbon dioxide volume in the room where the windows was closed rose 1,000~1,400ppm from that at the time of start, thus showing that the indoor air quality got worsened. In addition, it is hard to control the indoor temperature due to the heating and non-heating. Accordingly, it is necessary to get the heating system which can make the ventilation in order to keep the environmental level in the lecture room to a certain level and keep the proper indoor temperature.

A Study on The Performance of Ventilation and Maintaining Thermal Environment for a Combined Type Diffuser (급·배기 일체형 디퓨저의 환기 및 온열환경 유지성능에 대한 연구)

  • Lim, Seok-Young;Chang, Hyun-Jae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.232-241
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    • 2016
  • Installing a ventilator for an apartment house composed of over 100 dwelling units was mandated in 2006 to improve indoor air quality. In the case of mechanical ventilators, the air change rate is kept stable, however 68% of dwellers do not operate their ventilator because of an increased electrical bill and noise. In the case of natural ventilators, the former problems are settled, but there are concerns about cold draught and an increase of heating/cooling cost. Authors are developing a heat recovery type natural ventilator which is a natural ventilator equipped with total heat recovery element, and it is expected that those problems of mechanical ventilator and natural ventilator are resolved by this. The combined type diffuser of this study is an under developed fit to the heat recovery type natural ventilator above. There are no standards to evaluate the performance for this type of diffuser. Due to this issue this study investigated the performance of the ventilation and maintained a thermal environment for the combined type diffuser by comparing it with existing diffusers. The results revealed that the performances of the combined type of diffusers showed different features from the existing ones, and was estimated to be high enough in the performances above.

Study on Hospital Environmental Causes Affected the Mother′s Comfort After Her Child Birth (산욕부 안위에 영향을 미치는 병원환경 요인에 관한 연구)

  • 변수자
    • Journal of Korean Academy of Nursing
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    • v.8 no.1
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    • pp.1-15
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    • 1978
  • The Purpose of this study is to examine closely the causes influenced upon the comfort and recovery of the woman delivered of a child in the hospital at the same time to understand environmental status of hospitals in order to promote mother's health recovery, and to improve hospital environment by emphasizing the meaning of environment and health before the medical staff and hospital administrative authority. In the method of servery of the research, 165 post paestum patients have been randomly selected who were accommodated and delivered their babies at OB(obstetric ) & GY (Gynecologic) unit the 7 general hospitals for the period of 6 December 1976 through 17 December 1976. As for the survey, it has been used of Questionnaire where we have 65 items in the respect of personal environment in the hospital such as trusting nurse, ability, reliability, kindness and etiquette of nurse and tile character of nurse the relationship with patients the other respect of physical environment included 9f temperature, moisture. air-ventilation lightening noise, cleanness. facilities, and the third realm being of mother's hearth ground to have the following conclusion 1. The feature of the collected personnel they are from OB or GY sects of from OB unit of the other 5 hospitals except the two general hospitals of the college or school Otherwise the rate of the patients to nurses would be 9 : 1. As for the nurses'ground it would be appeared of 20-25 years of age as the 76%. either 3 year course or 4 year course in the education would be each 50% and less than 2 year experience case would record as of 60 %. In the respect of hospital physical environmental status, there we have two hospitals without any thermometers, on the other han4 nowhere there's hygrometer, otherwise, the lightening is normal or over than normal As for the structure of noise protection the corridors're, generally speaking worse than rooms, nerver hueless, there's no ventilating system in the hospitals. The rooms'repainted in white and yellow, light green white, or green color. The patient's clothing were in green pink blue, light green or in white co for. There're not anything special in both decoration and equipments. Most of them used tall beds except in one hospital 2. To the extent of perception of patient's hatch 9round and hospital environment it is presented that they perceived nurse's ability in highest in total human variable, though perceived kindness or etiquette in the lowest otherwise, comparatively high in total average. 3. In the respect of physical environment it is highest perceived of lightening terms, otherwise, lowest perceived of air ventilation and total average became lowest than the one of the original record 4. To ages, in the respect of hatch ground rather old aged mother than the younger one has perceived that nurse would be trusting, in good service character, able, at the same time, liable, Otherwise, in physical environment regardless of age, they perceived lightening in high and remarkably lower in ventilation As a result of the examination of the difference in hospital environment to each age it is appeared of statistical difference at 5% level of ability in the personal environment otherwise little difference as for physical environment 5. In the respect of perceiving level to educational standard it is highly perceived of personal environment for higher ranking group rather than lower group in the educational standard. In case of physical environment it is highly perceived for lower level group rather than higher level group in educational background. The variables which have statistical significance at 5% level are from trusting kindness, etiquette and total kindness, etiquette and total all significance at 5% level are from trusting, kindness, etiquette and total human environment variable in personal environment, otherwise, there's little difference in the physical environment. 6. The perceiving level due to times of admission and accommodation at the hospital would be cleared out as gradual higher perception both physical and personal environment in the hospital. At 5% significant level of the ventilation condition in physical environmental variable it is presented of meaningful difference otherwise, there we have little difference both in Personal variable and other one. 7. In accordance with living standard, the perception degree of personal environment in tee hospital would be inclined to increase to higher living standard on the other hand, in case of the physical environment, the perception level world increase to lower living standard At 5 % level, the trustuariable and total scores in the personal eicuironmectal variable there appeared a meaningful/ significant difference otherwise, there presented little difference both in physical environmental and other variable to the living standard 8. Pertaining to family unit, the mother of an independent family unit perceived highly in all respect of the personal and the physical environment in the hospital rather than the woman of succeeding family unit. At 5 % level there appeared a difference in the respect of kindness and etiquette both in personal environment variable, on the other hand, there hardly marked a difference between other variable and physical environmental one. 9. The degree of perception to comforting level has little connection with a statistical difference the age, educational level hospital admitting times, living standard or family unit. 10. The most effective variable to mother's comforting level will be nurse's ability, reliability, trusting manner, and total physical environment variable in order.

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Working Environments and Working Conditions Affecting Workers' Stress Symptoms (작업환경과 조건이 근로자의 스트레스에 미치는 영향)

  • 이명선
    • Korean Journal of Health Education and Promotion
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    • v.19 no.3
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    • pp.107-120
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    • 2002
  • There has been a rapid industrial progress in Korea since 1962 by the success of 5-year economic development plan, and the number of industrial work has also made a rapid increase. Consequently, the management of the occupational health for the purpose of promoting the health of industrial workers and improving the working environment is badly needed in these days. Health services on industrial noisy environment have been provided only for noise-induced hearing loss management until now. But gradually, modem diseases and death have come to be related to the stress and mental health, therefore noise-induced mental disorder, like a stress became very important. Thus, this study has been carried out to analyze the relationship between workers' stress symptoms and the perceived working environment and the perceived working conditions. This study included 786 industrial workers selected from II factories in Buchun. The results were as follows: 1. For demographic characteristics, most of the workers were males(75.7%), the 20~29 years old were 33.8% and those who graduated from high school were 56.1%. The workers whose monthly income ranged from 700,000 to 1,500,000 won were 37.9% and who has a religion were 49.0%. 2. For occupational characteristics, workers who had worked 5~10 years in the factories were 35.8%. Those who felt much for them workload were 42.7% and who worked more than 8 hours a day were 73.7%. Those who were dissatisfied with their pay and job were 51.1 % and 31.2%. The workers who responded ventilation condition of their worksites were bad were 50.4% and the dissatisfied with working environment of their worksites were 43.8%. 3. For the noise exposure level in worksite, workers who were exposed to 70∼90㏈ were 37.4%, 90∼100㏈ were 25.2% and 50∼70㏈ were 18.8%. 4. Workers∼ stress symptoms were significantly related to marital status and their monthly income(P〈0.05). Workers who were single and had lower monthly income showed higher PSI(Psychiatric Symptom Index) scores than those who were married and had higher monthly income. Higher PSI scores were also significantly related to the night-work, workload, dissatisfaction with their job, and bad relationship with their bosses or co-workers. 5. The higher noise exposure level in worksite from 80㏈ was, the more severe stress symptoms including PSI subparts were reported; Anxiety, Anger, Depression, and Cognitive disorder symptom(P〈0.001). 6. According to the results of stepwise multiple regression analysis, factors affecting workers' PSI scores were noise exposure level in worksite(R2=0.150), relationship with coworkers, amount of workload, monthly income and relationship with bosses orderly and the total R2 of this 6 factors was 29.7%.

A Study on the Working Clothes in the Changwon National Industrial Complex -Considering Clothing Performance and Motion Factors in Work Places- (창원국가산업공단 근로자들 작업복 착용실태에 관한 연구 -작업분야별 작업복 기능성 및 동작요인 중심으로-)

  • Park, Gin-Ah;Bae, Hyun-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.10
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    • pp.1571-1583
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    • 2008
  • The study aimed to investigate the actual condition of working clothes in the Changwon National Industrial Complex and to analyze the industrial workers' satisfaction with and preference to the working clothes in terms of the clothing performance and work motion factors. 1 major companies in machinery, automotive, industrial engineering, shipbuilding and rolling stock industries located in the industrial complex were selected as the subject firms. Approximately 900 workers responded to the questionnaire designed for the research and the results derived from the research were as follows. (1) The subject employees were divided into 4 work groups, i.e. the $1^{st}$ work group: managerial, general affairs, sales, production planning; the $2^{nd}$ group: quality assurance, material planning and distribution, product inspection; the $3^{rd}$ group: electric, facilities, machinery, vehicles; and the $4^{th}$ group: cutting, pressing, rolling, welding and coating. (2) The significant work environmental factors considered by all work groups were air ventilation, noise and dust factors and in particular, the most dissatisfied factors evaluated by manufacture workers were insulation, noise, dust and vibration. (3) According to the employees' work motion evaluation, the work motion diversity and frequency increased in proportion to the degree of work intensity. Besides, manufacture workers more frequently wore the working clothes even during the off-duty hours comparing to the evaluation of the other work groups. (4) The most important clothing performance factors considered by manufacture work groups were perspiration absorption, stretch, air permeability, tactile sense softness, soil proof in order.

A Study on the Effect of School Construction Work on the Learning Environment (교내 건설공사로 인한 학습환경 영향요인에 관한 연구)

  • Park, Sung Choon;Lee, Young Dae;Go, Seong Seok
    • Journal of the Korean Society of Safety
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    • v.30 no.4
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    • pp.128-134
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    • 2015
  • The number of schools which have passed 30 years after the construction takes up 30% (5% falling to class D and E) in Korea. So, the offices of education across the nation conduct large works for the expansion, improvement and renovation of the school. But as the work takes a lot of time, the work is also conducted while the students are studying at the schools. The work at the school causes the noise, dust, vibration as the school often has the reinforced concrete structure. So, as the windows are closed to prevent the nuisance from hampering the education, the problems related to the illumination, ventilation, and control of humidity and temperature are give damages to students studying the school buildings. Actually, as the current renovation or expansion is conducted across the nation due to the implementation of the new education system and the resulting integration and construction of hub school, specialized school, meister school and it causes a lot of nuisance to the learning students and others, there are a lot of complaints from concerned people. Accordingly this study suggests the method of evaluating the factors which affect the learning environment such as the noise, dust or fine dust and reducing the nuisances to the level proper for the learning environment when the existing school is expanded, improved or renovated.

Development of the Sentiment Indicators of Housing Welfare (주거복지지표 개발에 관한 연구 II - 수요자 측면의 주거복지체감지표와 지수를 중심으로 -)

  • Jee, Eun-Young;Eun, Nan-Soon;Hong, Hyung-Ock
    • Journal of the Korean housing association
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    • v.19 no.5
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    • pp.85-92
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    • 2008
  • The aim of this research is to develop the sentiment indicators of housing welfare for evaluating housing welfare policies conducted by the Korean government. The methods of this research are used by analysis of related documents, FGI (Focus Group Interview), and survey. The survey was made by experts and consumers. To analyze the survey, this research also uses confirmatory factor analysis by SPSS (Statistical Package for the Social Science) program, AHP (Analytical Hierarchy Process) by Expert Choice program, frequency, average, percentages, Factor analysis etc. As a result of this research, selected housing welfare indicators are settled as follows: In the housing welfare aspect, 11 indicators in the department of 'Housing Satisfaction' and 11 indicators in the department of 'Community Satisfaction' (22 in total) are suggested. The indicators are 1) Water Supply and Distribution Equipment 2) Heating equipment 3) the size of the exclusive residential area 4) the number of rooms 5) Ventilation and Lighting 6) Sound Insulation (Indoor Noise) 7) Air Pollution/Odor 8) House Deposit 9) Rent Paid 10) Maintenance (Dwelling) Cost 11) The length of Occupation 12) Proximity to Welfare Facilities 13) Educational Environment 14) Convenience of Facilities (shops, hospitals etc.) 15) Convenience of Transportation and Commuting 16) Distance from Workplace 17) Landscape and Green Space (Tree, Flowers, Grass etc.) 18) Vandalism (Destruction Behavior, graffiti etc.) 19) Privacy 20) Noise in Public Places (Drinking, Loudly Talking etc.) 21) Safety from Crime 22) Safety from a Disaster. As of 2007, the housing welfare sentiment index is measured by the survey of 1,000 inhabitants in the public housing, which shows 3.51.

Assessment of Conscious Coginition Degree and Survey on the Indoor Air Quality at a public School in Seoul (서울시 일부 학교의 실내 공기질 조사 및 인식도 평가)

  • Sohn, Jong-Ryeul;Byeon, Sang-Hoon;Kim, Young-Whan;Kim, Jong-Hyeok;Cho, Yun-Su;Lee, Jae-Young;Park, Youn-Ju
    • Journal of environmental and Sanitary engineering
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    • v.18 no.3 s.49
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    • pp.100-109
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    • 2003
  • Recently, Indoor air quality(IAQ) in workplace, residential environments and schools has been concern of people, scientists and related the public. And so in Seoul has recognized the healthy effect related to IAQ in schools. Therefore, the objective of this study reported in this article were to measure and compare the perception of IAQ of selected air pollutants at three different schools in Seoul. We performed a questionnaire survey of 400 students about their awareness for the importance of IAQ in our school. And we measured the IAQ of 3 schools considering as site region, construction year and studying level. The indoor air pollutants and parameters such as temperature, relative humidity, respirable particulate matter(PM10), formaldehyde(HCHO), total bacteria counts(TBC), carbon dioxide(CO$_2$), and noise were monitored in indoors. In results, all most response of occupant has recognized the awareness of IAQ at schools. The PMIO, TBC and Noise level of all schools were higher than the standard of the public 150 ${mu}$g/m$^3$ and 500CFU/m$^3$, the level formaldehyde(HCHO) was below 0.1 ppm of the healthy guideline of Korea And the concentration of CO$_2$ were investigated below 1,000 ppm of the standard implying ventilation in 2 schools except for 1 school(c school). Finally, the control of most important pollutants of IAQ in school were PM10, TBC and Noise. Therefore, it can be concluded that the indoor air quality of selected 3 schools studied was perceived as acceptable, it is recommended that the government related IAQ was suggested the guideline and control of IAQ problems in schools, and all member relating school need to be effort to reduce the exposure of sources to undesirable indoor pollutants such as Particlate and Noise.

A Study on the Time-Sectional Analysis of Apartment Housing related research in Korea (국내 아파트 관련 연구의 연구주제 시계열 분석)

  • Kim, Tae-Sok;Park, Jong-Mo;Park, Eu-Gene;Han, Dong-Suk
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.3
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    • pp.45-52
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    • 2018
  • Currently, apartments have become an important research subject for the overall area of politics, economics, and culture as well as urban architectural study. However, there are few analyses of the research trends related to the current interest in the apartment research and prediction of the future changes of an apartment in politics and industry. In this study, the research information related to the apartment has classified, and the changes in the research trends have analyzed. Based on the classified data, the first thesis and dissertation related to the apartment and changes of academic notation have discovered. In addition, future interests and future research directions through Frequency of Appearance, Degree Centrality Analysis, and Betweenness Centrality Analysis of author keywords were predicted. As a result of the analysis, 'Space,' 'Residential Mobility' and 'Apartment Complex' studies were found to be important research topics throughout the entire period. 'Han Gang Apartment,' 'Small Size Apartment,' 'Civic Apartments,' 'Jamsil,' and 'Child' were newly interested topics until 70's era. '(Super) High-rise Apartment,' 'Perception,' 'Jugong Apartment,' 'Housing Environment,' 'Housewife,' 'Apartment Layout,' and 'Busan' were newly interested topics during the 80's and 90's era. 'Apartment Price,' 'Energy,' 'Remodeling,' 'Noise,' 'Resident Satisfaction,' 'Community,' and 'Apartment Lotting-out' were newly interested topics after the year 2000. New concerns for last decade are found to be 'Super High-rise Apartment', 'Remodeling', 'Indoor'(2007), 'Apartment Reconstruction Project', 'Brand', 'AHP', 'Housing Environment'(2008), 'Ventilation'(2009), 'Apartment Lotting-out'(2010), 'Economic Assessment'(2011), 'Cost'(2012), 'Green Building', 'Apartment Sales', 'Law', 'Society'(2013), 'Floor Impact Noise', 'Seoul'(2014), 'Noise'(2015), 'Hedonic Model'(2016). In addition, following research topics are expected to be active in the future: In maturity stage of the research development is going to be 'Apartment Price', 'Space', 'Management of Apartment Housing'; the hedonic model, which is research growth and development stage, is going to be '(Floor Impact) Noise', 'Community', 'Energy.