• Title/Summary/Keyword: Noise Floor

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A Qualitative Study on the Housework Space Viewed from Housewives and Husbands in Dual-Earner Families (맞벌이 가정의 부부와 남편을 통해 본 가사공간 연구)

  • Jang Sang-Ock
    • Journal of Families and Better Life
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    • 제23권6호
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    • pp.1-13
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    • 2005
  • The aim of this study is to investigate the housework space viewed from housewives and husband in dual-earner families. For this study, depth-interview method were used to collects the data. The depth-interview were conducted on the eight heusewives and two husbands in dual-earner families in Jinju and Gwangju in April 2005. The narratives were then analyzed to discover the demands of the kitchen and laundry room. The major results were as follows: 1) Dual-earner families want the kitchen design is they can share housework with their spouses, such as kitchen facing the front side of the floor plan and island counter. In addition, they want spacious, adjustable(flexible), visible storage to enable the housewives to work with their spouse efficiently. Space for Kimchi refrigerator should be considered in the kitchen. 2) They want the noise-free laundry because the interviewers did their laundry work in the night time. Also, they want a multi-purpose laundry mm where machine washing, hand washing, drying and ironing can be done. In addition, for hand-washing wives and husbands, specific space and facilities where they can hand washing on stand posture were needed.

Analysis on the Power Spectral Density of Ultra Wideband(UWB) Communication System (초광대역 통신 시스템의 전력 스펙트럼 밀도 분석)

  • Lee, Jung-Suk;Kim, Jong-Han;Kim, Yoo-Chang;Kim, Jung-Sun;Kim, Won-Hoo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • 제38권10호
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    • pp.34-40
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    • 2001
  • Ultra Wide Band (UWB) system uses wide band signal, which power spectral density is over all band, It likes as a noise floor, so UWB system can be used without interfering with other communication system. For the first time, we adopted Rayleigh mono pulse antipodal signal which had symmetric characteristic and zero mean. With the power spectral density using stochastic process, we knew that the antipodal signaling scheme removed discrete spectrum and concluded that this had much better spectral suppression, probability of error and data rate than PPM (Pulse Positioning Modulation).

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Survey on the Uses of Heating-Cooling Facilitis.Accessory Devices and Residents' Evaluation in Cheju Province (제주도 지역 냉난방 설비.보조기구 사용실태와 거주자의 평가)

  • 김봉애
    • Journal of the Korean Home Economics Association
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    • 제35권5호
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    • pp.239-248
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    • 1997
  • to design nature-affinitive, reasonable and effcient thermal environment plannings and facilities, the holding patterns of heating-cooling facilities·accessory devices and residents' evaluation in Cheju Province were surveyed as well as residents' understanding for them. Major findings of this study are summarized as follows: 1) In the cooling system, the percentage of air-conditioner possessor was 19.4%, which was lower possessive rate than mainland's. The location of air-conditioner was mainly public area. That is, 55.3% of the location is livingroom, and the rest was Anbang. the general cooling accessory device was a fan. It was frequently used at the children's room and the dining room. The possessive patterns of air-conditioner depend on the characteristics of residents, such as the academic carrier and the average monthly income. Characteristics of house for air-conditioner possess depend on the location, house type, the size of floor space. 2) In the heating system, individual heating system reached to 57.3%. Heating accessory devices were oil stove and electric heating blanket. Only 32.2% of survey population were holders. 3) Residents preferred better ventilated room arrangement, which was characteristic of subtropical areas. 4) The preferred condition for heating-cooling facilities and accessory devices were strong solidity, less air pollution, and less noise.

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A Study on the POE(Post Occupancy Evaluation) of Rural Han-ok (전라남도 농촌한옥의 거주성 평가에 관한 연구)

  • Lee, Chang-Jae;Choi, Il;Park, Sung-Jin
    • Journal of the Korean Institute of Rural Architecture
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    • 제16권1호
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    • pp.17-26
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    • 2014
  • This study examined the trend of floor space characteristics, size characteristics and modeling characteristics so as to evaluate the satisfactory level of subjects living in Hanok. By doing so, the type of Hanok was classified into 5 groups. The satisfactory level was evaluated after the subjects resided in Hanok based on each type of housing. In the satisfactory level investigation, which was conducted after the residence, the overall satisfactory level on Hanok showed to be high. In the evaluation on the residence scale, positive results were generally achieved regarding 'full size of residence', 'number of rooms compared to residence size', 'size of living room', etc. The indoor environment of residence evaluation mainly showed positive results regarding 'ventilation', but most subjects were unsatisfied in regard to 'heating', 'noise', 'lighting', etc. In the behavioral factor evaluation of residents, positive results were gained regarding 'health', but comparatively negative results showed based on items of 'construction expense', 'burden of maintenance expense', 'investment value', etc. After analyzing the influential factors on the overall satisfactory level, results showed that 'dust inflow' of the physical site environment evaluation, 'size of living room' of the residence size evaluation, 'heating' of the residence indoor environment evaluation, and 'burden of maintenance expense' in the behavioral factor evaluation significantly influences the overall satisfactory level.

A HYDROGEN FUELLED V-8 ENGINE FOR CITY-BUS APPLICATION

  • Sierens, R.;Verhelst, S.
    • International Journal of Automotive Technology
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    • 제2권2호
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    • pp.39-45
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    • 2001
  • Hydrogen is seen as one of the important energy vectors of the next century. Hydrogen as a renewable energy source, provides the potential for a sustainable development particularly in the transportation sector. Hydrogen driven vehicles reduce both local as well as global emissions. The laboratory of transporttechnology (University of Gent) converted a GM/Crusader V-8 engine for hydrogen use. Once the engine is optimised, it will be built in a low-floor midsize hydrogen city bus for public demonstration. For a complete control of the combustion process and to increase the resistance to backfire (explosion of the air-fuel mixture in the inlet manifold), a sequential timed multipoint injection of hydrogen and an electronic management system is chosen. The results as a function of the engine parameters (ignition timing. injection timing and duration, injection pressure) we given. Special focus is given to topics related to the use of hydrogen as a fuel: ignition characteristics (importance of electrode distance), quality of the lubricating oil (crankcase gases with high contents of hydrogen), oxygen sensors (very lean operating conditions), noise reduction (configuration and length of inlet pipes). The advantages and disadvantages of a power regulation only by the air to fuel ratio (as for diesel engines) against a throttle regulation (normal gasoline or gas regulation) are examined. Finally the goals of the development of the engine are reached: power output of 90 kW, torque of 300 Nm, extremely low emission levels and backfire-safe operation.

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Analysis on Results evaluated by "Housing Performance Grading System" in Korea (주택성능등급 인정 사례의 부문별 평가 결과 분석)

  • Lee, Sung Ok
    • KIEAE Journal
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    • 제10권6호
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    • pp.55-66
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    • 2010
  • The government is enacted "Housing Performance Grading Indication System" from qualitative housing supply policy and performance of housing under the background of looking for new plan to secure good housing stock and housing performance. This system consists of 5 main performance section, 14 performance categories and 20 detailed performance items. 5 main performance parts are sound insulation related grading(Light-weight impact sound insulation, heavy-weight floor impact sound insulation, noise emission in bathroom, airborne sound insulation for wall between units), Long-life housing related grading(flexibility, remodeling & maintenance, durability), environment related grading(landscape, indoor air quality and ventilation, energy performance), Living environment related grading(common resident facilities such as playground and consideration for the socially underprivileged such as the aged), Fire fire prevention grading(fire fire prevention). The purpose of this research is to analyze characteristics and assessment results of 20 detailed performance items on "Housing Performance Grading Indication System" which was enforced 240 cases from Jan 9th, 2006 to Sep 30th, 2010. The analysis of approval condition of detailed performance items will be important comments for understanding the current domestic level and development of technology.

Identification of Stiffness and Damping Matrix of Building Structures using Modal Characteristics (모드 특성을 이용한 건축 구조물의 강성 및 감쇠 행렬식별)

  • 강경수
    • Journal of the Earthquake Engineering Society of Korea
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    • 제8권2호
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    • pp.45-53
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    • 2004
  • In this paper, the stiffness and damping matrix are experimentally constructed using the structural modal information on frequencies, damping ratio and modal vectors, which are obtained by shaking table tests. Free vibration, harmonic and white noise vibration tests are performed. The acceleration of the shaking table was used as the input signal, and the corresponding accelerations of each floor were measured as output signals. The characteristics and limitations of modal information from each test are compared. The results of this study would be a basic resource of the analytical and experimental studies on the system identification of structures.

Damage detection using both energy and displacement damage index on the ASCE benchmark problem

  • Khosraviani, Mohammad Javad;Bahar, Omid;Ghasemi, Seyed Hooman
    • Structural Engineering and Mechanics
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    • 제77권2호
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    • pp.151-165
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    • 2021
  • This paper aims to present a novelty damage detection method to identify damage locations by the simultaneous use of both the energy and displacement damage indices. Using this novelty method, the damaged location and even the damaged floor are accurately detected. As a first method, a combination of the instantaneous frequency energy index (EDI) and the structural acceleration responses are used. To evaluate the first method and also present a rapid assessment method, the Displacement Damage Index (DDI), which consists of the error reliability (β) and Normal Probability Density Function (NPDF) indices, are introduced. The innovation of this method is the simultaneous use of displacement-acceleration responses during one process, which is more effective in the rapid evaluation of damage patterns with velocity vectors. In order to evaluate the effectiveness of the proposed method, various damage scenarios of the ASCE benchmark problem, and the effects of measurement noise were studied numerically. Extensive analyses show that the rapid proposed method is capable of accurately detecting the location of sparse damages through the building. Finally, the proposed method was validated by experimental studies of a six-story steel building structure with single and multiple damage cases.

Analysis of finishing details to Prevent leakage of PC Apartment Joints in Korea (국내 PC 아파트 접합부 누수 방지를 위한 마감상세 분석)

  • Kim, Tae-Ho;Ko, Hyo-Jin
    • Journal of Korean Association for Spatial Structures
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    • 제21권4호
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    • pp.81-89
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    • 2021
  • Recently, interest in OSC(Off Site Construction) is increasing due to the trend of a decrease in skilled workers and an increase in labor costs. In this regard, PC(Precast Concrete) is being reviewed for apartments, the most common type of housing in Korea. As the biggest concern for PC apartment houses, civil complaints such as inter-floor noise and leakage were presented. In this study, the details of the joints were reviewed based on the past cases of PC apartments, and the details of the recently constructed or planned PC apartments were investigated. Through this, the leakage path in the past was analyzed through the existing research literature and data. And wall type RC and PC apartment joint leakage test was performed and we found the needs for a detail of waterproof steps, sealant. Also, joint details were investigated for a rahmen type apartment housing under construction. At last, A discussion was conducted on the direction for a detailed proposal of an improved joint in the future.

Comparison of Characteristics for Establishing Quality Standards of Modular Buildings for Temporary Classrooms (임시교실용 모듈러 건축물의 품질기준 마련을 위한 특성비교)

  • Lee, Jong Sung;Park, Jae-Woong;Lim, Gun-Su;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.83-84
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    • 2023
  • Wall structure smart modular is a building construction method where modules are manufactured in a factory and assembled on-site. This method is gaining popularity in the construction industry as it reduces construction time and mitigates risks such as material supply and labor costs. Wall structure smart modular is necessary as it provides comfortable temporary classroom space during renovation and remodeling of aging school buildings. The structure and characteristics of each type of temporary classroom modular were compared, and wall structure modular showed superior performance in terms of height and weight competitiveness compared to mixed structures. With these advantages, wall structure modular can ensure economic efficiency and recyclability as a temporary classroom. In the future, we aim to compare and analyze the standards such as inter-floor noise and heat transfer coefficient for wall structure and mixed structures.

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