• Title/Summary/Keyword: Expanding rate

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A Study on Forecasting the Rural Rental Housing Demand (농촌 임대주택 수요분석 연구)

  • Lee, Chang-Woo;Yun, Kap-Sik
    • Journal of the Korean Institute of Rural Architecture
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    • v.19 no.3
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    • pp.33-41
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    • 2017
  • Recently, it is recognized that the increase of return farmers is an important task to revitalize rural areas. There is a growing need to improve the housing environment in rural areas by expanding rental housing supply in order to increase return farmers. The purpose of the study is to forecast the rural rental housing demand based on the questionnaire survey and to suggest the rural rental housing supply in the public sector. The rural rental housing demand consists of demand for rural residents and demand for return farmers. The survey was conducted for rural residents and potential return farmers. The rural rental housing demand was analyzed by using prospect of rural residents and return farmers in the future and the rate of intention to move into rural rental house derived from the survey. In this study, rural rental housing demand which does not take into consideration the rent level and rural rental house demand considering it are presented respectively.

Normal Mode Approach to the Stability Analysis of Rossby-Haurwitz Wave

  • Jeong, Hanbyeol;Cheong, Hyeong Bin
    • Journal of the Korean earth science society
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    • v.38 no.3
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    • pp.173-181
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    • 2017
  • The stability of the steady Rossby-Haurwitz wave (R-H wave) in the nondivergent barotropic model (NBM) on the sphere was investigated with the normal mode method. The linearized NBM equation with respect to the R-H wave was formulated into the eigenvalue-eigenvector problem consisting of the huge sparse matrix by expanding the variables with the spherical harmonic functions. It was shown that the definite threshold R-H wave amplitude for instability could be obtained by the normal mode method. It was revealed that some unstable modes were stationary, which tend to amplify without the time change of the spatial structure. The maximum growth rate of the most unstable mode turned out to be in almost linear proportion to the R-H wave amplitude. As a whole, the growth rate of the unstable mode was found to increase with the zonal- and total-wavenumber. The most unstable mode turned out to consist of more-than-one zonal wavenumber, and in some cases, the mode exhibited a discontinuity over the local domain of weak or vanishing flow. The normal mode method developed here could be readily extended to the basic state comprised of multiple zonalwavenumber components as far as the same total wavenumber is given.

FORMATION OF LINE PROFILES BY THE WINDS OF EARLY TYPE STARS

  • KANG IVIIN-YOUNG;KIM KYUNG-MEE;CHOE SEUNG-URN
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.263-264
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    • 1996
  • We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V{\infty},\;V_{sto},\;{\beta}$ (parameter for the velocity field), M and $\epsilon$ (parameter for collisional effect) as model parametrs. We have found that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V{\infty},\;V_{sto}$. The collisional effect tends to make the total flux increase but not so .much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as V$\infty$, M from the model calculation, which shows a good agreement with the observational results.

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Total Pressure Loss in a Supersonic Nozzle Flow with Condensation (凝縮을 隨伴하는 超音速 노즐흐름의 全壓損失)

  • 강창수;권순범
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.3
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    • pp.582-589
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    • 1988
  • A rapid expansion of moist air or steam in a supersonic nozzle gives rise to condensation, and the total pressure of the flow is decreased due to this irreversibility of condensation phenomenon. In the present paper, the loss in total pressure during the condensation process has been studied, by numerical analysis and pressure measurement, in the case of moist air expanding in a supersonic nozzle. The effects of the degree of supersaturation at the stagnation condition and expansion rate of the nozzle on the total pressure loss have been studied. The length of the region where the total pressure decreases during the condensation process is longer than that of the nonequilibrium condensation region, and of difference between the length of these two increases with the increase of the degree of supersaturation at the stagnation condition. Furthermore, the larger the expansion rate of the nozzle and the higher the temperature and the degree of supersaturation at the reservoir are, the larger the total pressure loss of the flow becomes. And, it is turned out that the total pressure loss be about 2 to 8 percent in the present study.

Bacterial Effects on Geochemical Behavior of Elements : An Overview on Recent Geomicrobiological Issues (원소의 지구화학적 거동에 미치는 박테리아의 영향 : 지구미생물학의 최근 연구 동향)

  • 이종운;전효택
    • Economic and Environmental Geology
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    • v.33 no.5
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    • pp.353-365
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    • 2000
  • After their first appearance on Earth, bacteria have exerted significant influence on geochemical behavior of elements. Numerous evidence of their control on geochemistry through geologic history has been observed in a variety of natural environments. They have mediated weathering rate, formation of secondary minerals, redox transformation of metals and metalloids, and thus global cycling of elements. Such ability of bacteria receives so considerable attention from microbiologists, mineralogists, geologists, soil scientists, limnologists, oceanographers, and atmospheric scientists as well as geochemists that a new and interdisciplinary field of research called 'geomicrobiology' is currently expanding. Some recent subjects of geomicrobiology which are studied extensively are as follows: 1) Functional groups distributed on bacterial cell walls adsorb dissolved cations onto cell surfaces by electrostatic surface complexation, which is followed by hydrous mineral formation. 2) Dissimilatory metal reducing bacteria conserve energy to support growth by oxidation of organic matter coupled to reduction of some oxidized metals and/or metalloids. They can be effectively used in remediating environments contaminated with U, As, Se, and Cr. 3) Bacteria increase the rate of mineral dissolution by excreting proton and ligands such as organic acids into aqueous system. 4) Thorough investigation on the effects of biofilm on geochemical processes is needed, because most bacteria are adsorbed on solid substrates and form biofilms in natural settings.

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Study of Regional Differences Between Attitudes Toward Service and Behavior of Chinese Passengers Using Incheon International Airport (인천국제공항 이용 중국여객의 권역별 서비스 인식 및 행동특성에 관한 연구)

  • Lee, Myeong-U;Choe, Yeon-Cheol;Lee, Su-Mi
    • 한국항공운항학회:학술대회논문집
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    • 2015.11a
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    • pp.231-236
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    • 2015
  • Ever since the permission of overseas travel by the Chinese government in 1983, the Chinese outbound travel market has been growing at an expanding rate. The Republic of Korea has been able to reap great benefits from this growth, and this has been noticeable especially in the aviation market. Chinese passengers count for 23.9% of the total passengers at Incheon International Airport (IIA), and it is no doubt Chinese passengers will remain important customers for IIA. Given the fact that China has such a huge territory and possesses a population of more than 1.3 billion, there rises the need to divide China into smaller regions. By doing so, the different thoughts Chinese passengers have, and the actions they show in terms of travel and airport service consumption according to differing regions can be figured out. With knowledge of the differences, IIA can provide different services to fit Chinese passengers from differing regions, hence increasing the total consumer value and satisfaction rate of IIA. This study has divided China into 5 different regions according to official regional recognition of China, and difference of economical, social factors, etc... With the results obtained from this study, different strategies can be implemented for the 5 regions.

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A study on Management Strategy and Cases of Failure of Low Cost Carriers (저원가 항공사의 경영전략과 실패사례에 관한 연구)

  • Ha, Su-Dong;Lee, Yun-Cheol
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.14 no.2
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    • pp.45-55
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    • 2006
  • Air transportation industry becomes more competitive because that the restrictions on new access to market were eased and related enough for each airline to choose the freight rate and the route without rein. New competitors are pursuing convergence strategy which focuses on low freight rate as a niche strategy for increasing market share by stimulating low cost demand. This strategy is now spreading all over the world such places as Europe, Asia, Oceania and etc. As of December 1, 2004, hundreds of low cost carriers are participating actively in the market and finding their level as a new strategic group in the air transportation industry with expanding their market. In case of USA, however, many airlines, which had newly entered to the market, went into bankruptcy in the mid-1980s. People Express in USA established in 1980 is one of the examples of failure. In case of Japan, Hokkaido International Airline, a typical low cost carrier which established in 1997, filed for bankruptcy. This study is for examining the strategic implication closely through the study on management strategy and cases of failure of low cost carriers.

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The Characteristics of Plate Type Ozonizer with Variation of Electrode Form (전극 형태에 따른 평판형 오존발생기의 특성)

  • Yoon, Byung-Han;Lee, Chang-Ho;Woo, Sung-Hun;Lee, Kwang-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.1
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    • pp.149-156
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    • 2008
  • Recently, ozone is utilized in various fields and its needs are expanding. In this paper, plate type ozonizer have been fabricated to investigate discharge parameter(input power, flow rate of supplied gas, electrode form, etc.) effect to discharge. And the conditions of discharge parameter have been investigated for optimum ozone generation. Ozone concentration is continuously increased with increasing input power for same discharge space, and ozone yield is also increased until maximum point after that it is saturated. Ozone concentration is inversely proportional to flow rate of supplied gas but ozone generation and ozone yield characteristics are improved.

A Study on the Inducement of Private Investment to the Rural Village Improvement (민간자본에 의한 농어촌 마을정비 방안 모색)

  • 박시현
    • Journal of Korean Society of Rural Planning
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    • v.4 no.1
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    • pp.32-39
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    • 1998
  • In Korea, rural village improvement has mainly been led by goverment investment. This approach, however, has its own limit since there are so many village to be improved while the budgetary sources are restricted, As an alternative, inducement of private investments to these area is considered in order to promote rural village improvement. The possibility of inducing private investments to the rural village improvement depends on the location of the village. The possibility may be highest in the sub-urban area since expected benefits from land development is usually high. One desirable approach to induce private investment to these area is the cooperative development system. Residents, private investors and governments plays its own role, independently and cooperatively, But benifits from the investment to improve rural village in general plain area are so low that it is difficult to induce the private investments to these area. In that case, indirect development system will be a proper strategy which maintaining government-led development method as usual, expanding the participation of private developers such as the construction companies. In general, rate of returns from investment to the rural sectors is lower than that to the other sectors, therefore financial support such as the long- term, low loan rate and a partial value-added tax exemption should be given to the investors to the rural village improvement projects.

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Prescription Characteristics of Antibiotics for Clinical Subjects of Acute Respiratory Infection Outpatients -Using National Health Insurance Big Data- (급성호흡기감염 환자의 표시과목별 항생제 처방특성 -국민건강보험 빅데이터를 활용하여-)

  • Gong, Mi-Jin;Hwang, Byung-Deog
    • The Korean Journal of Health Service Management
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    • v.13 no.4
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    • pp.121-132
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    • 2019
  • Objectives: This study analyzed the prescription antibiotics characteristics of Acute respiratory infection outpatients. It provides a basis for establishing the correct evaluation project on appropriate prescribing indicators. Methods: The research data were collected from the National Health Insurance Corporation's 2014 sample cohort for Internal Medicine, Pediatrics, Otorhinolaryngology, Family Medicine and General practitioner clinics classification of diseases codes J00-J06, J20-J22, J40 outpatients. Results: The antibiotic prescription rate on the evaluation project for appropriate prescribing indicators of Health Insurance Review & Assessment Service was 43.54%, whereas in this study it was about 10% higher because the analysis targeted the entire acute respiratory infection diagnosis. Conclusions: There is a need to identify the correct antibiotic prescription by expanding the current assessment standard. Such standard must include acute lower respiratory infections and minor diagnosis because current evaluation projects on appropriate prescribing indicators targets only the major diagnosis of acute upper respiratory infection.