• Title/Summary/Keyword: High-frequency floor

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Performance Analysis of GFSK Systems by Impulsive Electromagnetic Noise in Indoor Radio Fading Channel Environment (실내 무선 페이딩 채널 환경에서 임펄스성 전자간섭파에 의한 GFSK시스템의 성능 분석)

  • 이양선;김지웅;강희조
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.7
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    • pp.1115-1121
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    • 2001
  • In this paper, we analyzed the performance of GFSK system that presence fading effect in indoor radio communication environments and impulsive electromagnetic noise from electronic equipments then we applied the Truncated Type- II Hybrid ARQ scheme to make satisfied in data transmission service. As a result, the system was influenced by fading and impulsive electromagnetic noise. Especially, the system was much degraded by high occurrence frequency and amplitude of impulsive electromagnetic noise than fading which has direct frequency. By adopting the Truncated Type-II hybrid ARQ technique we can also obtained the performance improvement in the low signal power(20 dB) arid over 24 dB in strong impulsive electromagnetic noise environment which is occurred error floor and terribly influenced by the system.

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A Study on the Rent Characteristics of Small Shopping Malls

  • KIM, Sun-Ju
    • Journal of Distribution Science
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    • v.20 no.12
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    • pp.109-116
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    • 2022
  • Purpose: The purpose of this study is to analyze the rental determinants of a small shopping mall located in Seoul, Korea, and the characteristics of four commercial districts (CBD, GBD, YSD, etc.). Research design, data, and methodology: For the characteristics of the data, descriptive statistics and frequency analysis were used. Artificial Neural Networks (ANNs) have been used as rental determinants for small shopping malls. The characteristics of 4 commercial districts were analyzed using Analysis of variance (ANOVA) and post-hoc analysis. Results: 1) CBD 14.8%, GBD 16.7%, YSD 13.0%, others 55.6%. 2) The order of important variables affecting rent: CBD=1> GBD=1> vacancy rate> rental index> number of buildings> YBD=1> average gross floor area> conversion rate> average floor. 3) Characteristics of commercial district: Rents in CBD and GBD are high. The conversion rate is high in the GBD commercial area. The number of buildings is high in the CBD. The average area of GBD is larger than that of other commercial districts. Conclusions: 1) Several factors should be considered when investing in or renting a small shopping mall. 2) Depending on the investment and business purpose, factors such as rent, conversion rate, building, and area average should be considered.

A survey on the clothing consumption activity and the home background (피복의 소비행동과 가정 배경에 관한 실태조사)

  • 남이경
    • Journal of the Korean Home Economics Association
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    • v.25 no.2
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    • pp.1-11
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    • 1987
  • The purpose of the study is to researdch clothing consumer behavior of men and women over age of 20 years and to find out the reasonable maximum utility on clothing behavior. The factors are eight distinguished parts such as sex, age, monthly income, occupation, floor space, number of room, number of family and place of residence. A common questionaire is introduced to survey the clothing consumption activity and the home background. Sources to measure them are gathered in the whole country including major cities. The questionaire of 915 correspondents of 368 males and 547 females is investigated for this research. Some of the data are analyzed by correlation, frequency, percentage, mean, and S.D. Others are investigated by ANOVA Test, x2-Test, and Multiple Range Test. The results from the survey are as followings: 1. Only four factors such as sex, monthly income, occupation, and floor space have a significance in the clothing consumption activity. 2. This survey reveals that many cloths have been kept in dead storage and concerns of utility have risen high. 3. This survey has shown that the correspondents have deep concerns about using colthing exchange store, clothing lending store, and trunk room to utilize dead storage clothing efficiently.

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Sound Insulation Design of the Corrugated Steel Panel Considering Local Resonance (국부 공진을 고려한 주름강판의 차음 설계)

  • Kim, Seock-Hyun;Lee, Hyun-Woo;Kim, Jung-Tae;Kim, Jae-Cheol
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.7
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    • pp.672-676
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    • 2010
  • In a railway vehicle, corrugated steel panel is widely used for the floor structure because of its high bending stiffness and light weight. However, this panel shows lower sound insulation performance than that of the flat plate with the same weight. Especially, in a particular frequency region, transmission loss(TL) rapidly decreases and it results in the deterioration of sound insulation performance of the overall floor structure. This study identifies that the severe decrease in TL is caused from the local resonance of the periodic corrugated structure. TL decrease by local resonance is investigated by experiment and finite element analysis. Finally, design modification of the corrugation is proposed to improve TL and the effect is verified by experiment.

The Floor Structure of Korean High Speed Train : Equivalent Plate Model and Acoustic Power Radiation (한국형 고속전철 하니콤 바닥구조의 등가평판모델 및 방사소음평가)

  • 장준호;이상윤;홍성철;이우식;박철희
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.398-404
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    • 1998
  • The acoustic power reduction methods of the vibrating structures are valid to design the quite structure. To calculate the acoustic power, the dynamic responses have to be determined. It is not easy to analyse the structure composed of the corrugated panels. Because of the structural complexity and the many analysing times. To make up for these defects, the equivalent orthogonal panel is presented. Also the acoustic power prediction method of the vibrating structures is proposed. As examples, the equivalent material properties of the corrugated plates are obtained and the acoustic powers of the floor structure are calculated at several frequency regions for KHST.

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An Analysis of Human Reaction & IAQ Analysis by Changing the Floor Temperature & Ventilation (바닥온도와 실내 환기에 따른 인체반응 및 실내공기질 분석)

  • Lee, Ji-Weon;Chin, Kyung-Il;Kim, Se-Hwan
    • KIEAE Journal
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    • v.15 no.1
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    • pp.97-102
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    • 2015
  • Recently many buildings are airtight, deterioration takes the high stage. As this room ventilation is increasingly difficult, the importance of indoor air was emphasized. And Got a few provisions on the indoor ventilation, the building is used for other purposes also requires a lot of careful research. In this study, consisting of floor heating ventilation in the room and wants to know the impact on the human body react with the carbon dioxide concentration in the indoor air were investigated PMV. We have get the data through the experimental study like this. It can be inferred correlations of ventilation and temperature according to human comfort that you should consider when using the work of residential buildings in accordance with the changing social conditions and social. It is also determined that in the future through additional experiments related data can be established basic experimental data.

A Comparative Study on the Effects on Urinary Incontinence between Pelvic Floor Muscle Exercise and Magnetic Stimulation Therapy (지역사회 요실금 여성의 골반저근운동과 자기장자극 효과비교)

  • Cho, Myung-Sook;Kang, Hae-Young
    • Research in Community and Public Health Nursing
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    • v.19 no.4
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    • pp.696-703
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    • 2008
  • Purpose: To Perform a randomized comparative study investigating the effects of Pelvic Floor Muscle Exercise(PME) and Magnetic Stimulation Therapy(MST) and to identified the problems in each of PME & MST Method: Forty-nine patients with mild stress incontinence were randomly assigned to either of two treatment groups (24 patients in the PME group and 25 in the MST group). The PME group had a video exercising program for 40 times every day during 6 weeks. The MST group was treated with BioCon-2000TM, 2times/ week for six weeks. Pre-test and post-test were performed by Prineometer, 1-hour pad test. and Jackson's BFLUTS questionnaire of Jackson. Collected data were analysed using SAS 9.1 by frequency, Kolmogorov-Smirnov Z. Chi Square-test, t-test, Fisher Exact probability test, Paired t-test, and Wilcoxon's rank sum test. Results: In comparison between before and after PME and MST, statistically significant difference was observed in maximal vaginal pressure, duration of vaginal contraction, amount of urine, and symptom of urination. In the comparison of the effectiveness between PME & MST, only the maximal of vaginal pressure (Z=2.58, p= .010) was significantly different. Conclusion: The factor more effective in the MST group than in the PME group was high compliance.

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The Characteristics of Blasting Vibration in the Construction of Apartment and Buildings in Urban Area (도심지 발파공사장의 발파진동 특성)

  • 이연수;장서일
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.521-526
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    • 2004
  • In order to evaluate the effect of blasting vibration in buildings and it's resident located around blasting construction field in urban area, blasting vibration characteristics were measured the vibration level, vibration velocity. The 250g and 750g of charged powder were used at the apartment and at the ground, respectively. In the measurement of the ground, Z(perpendicularity) axis was the highest value in vibration level, but vertical axis was the highest value at 25m point and longitudinal axis was the highest value at 50m point in vibration velocity. The amount of measurement was high value when measuring point is higher than blasting source, while that of measurement was low value when measuring point is lower than blasting source. In the measurement of the apartment, 2 axis was the highest value in vibration level, but in vibration velocity transverse axis was the highest value at ground, was vertical axis at 1st floor, was longitudinal axis at 3rd floor and was vertical and longitudinal axis at 5th floor. The vibration level and the vibration velocity of 50m point showed higher correlation value than 25m point at the ground, but those of 25m point showed higher correlation value than 50m point at the apartment.

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Satisfaction with the Function of Interior Space of household -With a Focus on Apartments in Seoul- (주택 내부공간의 기능성에 대한 만족도 조사연구 -서울시 아파트를 중심으로-)

  • 윤복자;신화경
    • Journal of Families and Better Life
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    • v.2 no.1
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    • pp.165-177
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    • 1984
  • The purpose of this study was to investigate satisfaction with the function of interior space of apartment and factor which influence it, and then to provide housing practitioners with basic data for more desirable apartment interior environment. On the basis of the review of literature, questionnaire was developed. The sample was classified into type of unit floor plan and house size of 17 districts in Seoul. 139 households were selected in three districts which were the first three regions of high apartment density. Data were analyzed by computer using frequency, percentage, mean, standard deviation, F-test, Duncans multiple range test, η2 , person's product moment correlation coefficient. the results are as follows: Factors which influence satisfaction with the functionality of interior were household size and family life cycle as sociodemographic variable, and type of unit floor plan as physical variable. It was shown that the satisfaction with the functionality of interior was related to satisfaction with the external environment. More specifically, (1)the smaller a household size was the more the owner became satisfied. (2)households were in the stage of establishment in the family life cycle and households with C type of unit floor plan showed higher degree of satisfaction. (3) satisfaction with the functionality of interior had positibly related to satisfaction with the external environment.

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A Study on the Proper Quantity of Ventilation through Changing Floor Temperature in Sleeping (수면시 바닥표면온도에 따른 적정 환기량에 관한 연구)

  • Kim, Dong-Gyu;Lee, Sung;Kim, Se-Hwan
    • KIEAE Journal
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    • v.10 no.1
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    • pp.19-24
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    • 2010
  • Modern people are spending most of time in interior area. Indoor air environmental problem is one of the most effective factors influenceable to human health. Furthermore, saving energy and making ventilation system for pleasant indoor environment are necessary when it is faced shortage of energy over the world. In our country's case, it is already imposed that required quantity of air ventilation in buildings is 0.7 times per hour on "The regulation on building engineering system". As on the rise of the interests about Indoor air environment, Heat and Carbon dioxide emissions from User's metabolism, activity, furniture, and construction materials etc. could be the causes of Indoor air pollution. If these materials stays in Indoor air for so long, it could directly influence the user's health condition with a disease. As of building's sterilization improved that raised more mechanical ventilation. It also leads much energy waste in a period of high price of fossil fuel. Therefore, the way that saves energy and effective control of indoor ventilation is urgently needed. So, this study places the purpose on validating volume of indoor ventilation and user's comfortable degree by comparison CO2 emission rate through changing floor temperature.