• Title/Summary/Keyword: local extinction

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A Study on the Measurement of Burnet Gas Temperature in Premized Combustion by Modified Two-Color Method (변형 2색법에 의한 예혼합기 연소의 연소가스온도 측정에 관한 연구)

  • 배명환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.43-54
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    • 1999
  • The effects of equivalence ratio and pressure on burnt gas temperature in premixed fuel rich propane-oxygen-inert gas combustion are investigated over the wide ranges of equivalence ration from 1.5 to 2.7 and pressure from 0.1 to 7 MPa by using a specially designed disk -type constant-voume combustion chamber, The premixtures are simultaneously ignited by eight spark plugs located on the circumference of combustion chamber with 45 degree interals. The eight converging flames compress the end gases to high pressures. The burnt gas temperature is meausured by the nmodifie dtow-colr pyrometry method. The transmissivity in the chamber center during the final stage of combustion at the hightest pressure is meausred by in situ laser extinction method. It is found that a temperature difference between the burnt gas temperature measured by mofidied and conventrational two-color method is 10 to 20 K, but the accuracy of the modified two-color methdo is higher if the local transmissivity in observed region is uniform , and the combustion at higher pressures results gas density conditions and the burnt gas temperature increases as the volume fraction of argon is increased because the specific heat of argon is lower compared to that of nitrogen with a constant equivalence ratio.

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FUV Observations of The Taurus-Auriga-Perseus complex

  • Lim, Tae-Ho;Min, Kyung-Wook;Park, Jae-Woo;Kim, Il-Joong;Park, Sung-Joon;Lim, Yeo-Myung;Lee, Dae-Hee;Seon, Kwang-Il
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.32.5-32.5
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    • 2010
  • We present the FUV continuum map of The Taurus-Auriga-Perseus complex, which is one of the largest local association of dark clouds. The map is well consistent with the dust extinction and the CO emission map of the T-P-A region. The region is divided into 3 sub-regions by diffuse FUV intensities and the spectra of each region imply that the radiation field due to the Per OB2-association can be a main source of the H2 fluorescent emission of the nearby cloud region. We used the PDR H2 model, named CLOUD, developed by van Dishoeck &Black for the sake of comparing our results to the H2 model.

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An Exploratory Study on the Introduction of Basic Income Guarantee for Rural Residents (농촌기본소득제 도입에 관한 탐색적 연구)

  • Park, Kyong-Cheol;Han, Seung-Seok
    • Journal of Agricultural Extension & Community Development
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    • v.28 no.2
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    • pp.69-83
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    • 2021
  • Under the premise of unbalanced development between urban and rural areas, this study raised criticism that the balanced national development policies in South Korea, which had been promoted in earnest after 'the Participatory Government' has adversely deepened the development gap between urban and rural areas by promoting the development of urban. In the meantime, the agricultural economy that supported the rural economy has gradually collapsed after reckless market opening, and due to the balanced national development policy focusing on urban infrastructure construction, rural areas are facing a crisis of 'depopulation' and 'regional extinction.' For this reason, many local governments have recently recognized the public values of agriculture and have introduced 'agrarian basic income' for the sustainability of agriculture. However, there is a limit to overcoming the crisis in rural areas because the population of farmers among rural residents is only 25%. Therefore, this study proposes the necessity of introducing the basic income for rural residents as a new paradigm for balanced development between urban and rural areas beyond the existing policy limits, based on surveys of opinions of residents living in Chungchengnam-do, South Korea and experts on the introduction of 'basic income for rural residents' in the future.

2 - 4 ㎛ Spectroscopy of Red Point Sources in the Galactic Center

  • Jang, DaJeong;An, Deokkeun;Sellgren, Kris;Ramirez, Solange V.;Boogert, Adwin;Geballe, Tom
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.49.2-49.2
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    • 2019
  • We present results from our long-term observing campaign, using the NASA IRTF at Maunakea, to obtain 2 - 4 ㎛ spectra of 118 red point sources in the line of sight to the Galactic Center (GC). Our sample is largely composed of point sources selected from near- and mid-infrared photometry, but also includes a number of massive young stellar objects. Many of these sources show high foreground extinction as shown by deep 3.4 ㎛ aliphatic hydrocarbon absorption feature, which is a characteristic of the diffuse ISM and comes from the long line of sight through the diffuse medium toward the Central Molecular Zone (CMZ), the central 300 pc region of the GC. The deep 3.1 ㎛ H2O ice absorption band coming from the local, dense material in the GC CMZ suggests that most sources are likely located in the GC CMZ. A few of these sources show weak CCH3OH ice absorption at 3.535 ㎛, which can provide a strong constraint on the CCH3OH ice formation in the unique environment of the CMZ. From the best-fitting models, the optical depths of these features are determined and used to generate a well-rounded view of the ice composition across the GC CMZ and the spectral characteristics of massive YSOs in the GC.

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A Plan to Create New Job Positions for the Elderly in the Era of the 4th Industrial Revolution : Focused on Cheonan-Si (4차 산업혁명 시대 노인 일자리 창출 방안: 천안시를 중심으로)

  • Kim, Chilhyeon;Kim, Taehong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.159-160
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    • 2021
  • We are facing major changes such as an aging population along with the 4th industrial revolution based on ICT technologies such as artificial intelligence, the Internet of Things, autonomous driving, and factory automation. For the local governments that are indexed in high population extinction risk, it is essential to consider market expansion and re-education policies suitable for regional characteristics in order to respond to changes such as advanced industrial automation and population aging. For the reemployment of the elderly, we will analyze previous public strategies for elderly-friendly jobs, expand investment in age-friendly industries. In this study, we suggest to improvement direction of the elderly labor market in Cheonan-Si.

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Regional Inequalities in Healthcare Indices in Korea: Geo-economic Review and Action Plan (우리나라 보건지표의 지역 격차: 지경학적 고찰과 대응방안)

  • Kim, Chun-Bae;Chung, Moo-Kwon;Kong, In Deok
    • Health Policy and Management
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    • v.28 no.3
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    • pp.240-250
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    • 2018
  • By the end of 2017, in a world of 7.6 billion people, there were inequalities in healthcare indices both within and between nations, and this gap continues to increase. Therefore, this study aims to understand the current status of regional inequalities in healthcare indices and to find an action plan to tackle regional health inequality through a geo-economic review in Korea. Since 2008, there was great inequality in life expectancy and healthy life expectancy by region in not only metropolitan cities but also districts in Korea. While the community health statistics from 2008-2017 show a continuous increase of inequality during the last 10 years in most healthcare indices related to noncommunicable diseases (except for some, like smoking), the inequality has doubled in 254 districts. Furthermore, health inequality intensified as the gap between urban (metropolitan cities) and rural regions (counties) for rates of obesity (self-reported), sufficient walking practices, and healthy lifestyle practices increased from twofold to fivefold. However, regionalism and uneven development are natural consequences of the spatial perspective caused by state-lead developmentalism as Korea has fixed the accumulation strategy as its model for growth with the background of export-led industrialization in the 1960s and heavy and chemical industrialization in the 1970s, although the Constitution of the Republic of Korea recognizes the legal value of balanced development within the regions by specifying "the balanced development of the state" or "ensuring the balanced development of all regions." In addition, the danger of a 30% decline or extinction of local government nationwide is expected by 2040 as we face not only a decline in general and ageing populations but also the era of the demographic cliff. Thus, the government should continuously operate the "Special Committee on Regional Balanced Development" with a government-wide effort until 2030 to prevent disparities in the health conditions of local residents, which is the responsibility of the nation in terms of strengthening governance. To address the regional inequalities of rural and urban regions, it is necessary to re-adjust the basic subsidy and cost-sharing rates with local governments of current national subsidies based mainly on population scale, financial independence of local government, or distribution of healthcare resources and healthcare indices (showing high inequalities) overall.

Regional Development and the Improvement of Water Quality using Bivalves in Lake Suwa (Japan) (조개를 이용한 일본 수와호의 수질개선과 지역발전의 역사)

  • Okino, Tokio
    • Korean Journal of Ecology and Environment
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    • v.47 no.spc
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    • pp.1-9
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    • 2014
  • Lake Suwa is a natural lake which is well-known for sightseeing and fisheries. It had suffered severe eutrophication during 1960s and 1970s with the occurrence of cyanobacterial blooms and the extinction of some benthic animals. Since 1980 water quality has been improved due to efforts of local government, scientists, and citizens. Of various methods that were attempted to improve the water quality of Lake Suwa biological methods received much attention, because it can improve the lake ecosystem integrity and fisheries in addition to the water quality. The aim of this paper is to introduce the biological methods for water quality improvement that had been employed in Lake Suwa, Japan, and their contribution to the economic benefit of local residents. Until now a significant restoration of water quality has been achieved, but there are insufficient recovery of the sediment and biota due to anoxic hypolimnion of the lake. This study proposed suspended cage culture of bivalves as a feasible method of water quality improvement. Increased grazing by bivalves will contribute to the improvement of water quality and fisheries production, which will contribute both to the ecological restoration and economy of local residents.

MONTE-CARLO RADIATIVE TRANSFER MODEL OF THE DIFFUSE GALACTIC LIGHT

  • Seon, Kwang-Il
    • Journal of The Korean Astronomical Society
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    • v.48 no.1
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    • pp.57-66
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    • 2015
  • Monte-Carlo radiative models of the diffuse Galactic light (DGL) in our Galaxy are calculated using the dust radiative transfer code MoCafe, which is three-dimensional and takes full account of multiple scattering. The code is recently updated to use a fast voxel traversal algorithm, which has dramatically increased the computing speed. The radiative transfer models are calculated with the generally accepted dust scale-height of 0.1 kpc. The stellar scale-heights are assumed to be 0.1 or 0.35 kpc, appropriate for far-ultraviolet (FUV) and optical wavelengths, respectively. The face-on optical depth, measured perpendicular to the Galactic plane, is also varied from 0.2 to 0.6, suitable to the optical to FUV wavelengths, respectively. We find that the DGL at high Galactic latitudes is mostly due to backward or large-angle scattering of starlight originating from the local stars within a radial distance of r < 0.5 kpc from the Earth. On the other hand, the DGL measured in the Galactic plane is mostly due to stars at a distance range that corresponds to an optical depth of $${\sim_\sim}$$ 1 measured from the Earth. Therefore, the low-latitude DGL at the FUV wavelength band would be mostly caused by the stars located at a distance of $r{\leq}0.5$ kpc and the optical DGL near the Galactic plane mainly originates from stars within a distance range of $1{\leq}r{\leq}2kpc$. We also calculate the radiative transfer models in a clumpy two-phase medium. The clumpy two-phase models provide lower intensities at high Galactic latitudes compared to the uniform density models, because of the lower effective optical depth in clumpy media. However, no significant difference in the intensity at the Galactic plane is found.

A Study on the Heat Transfer Characteristics of Liquid Droplet Radiator for Air Conditioning (공기조화용 액적방열기의 열전달특성에 관한 연구)

  • 김금무;김춘식;김용모;김종헌
    • Journal of Advanced Marine Engineering and Technology
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    • v.19 no.4
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    • pp.17-26
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    • 1995
  • In general existing air conditioning devices, which are carried out by convection heat transfer, are very popular compared with the radiation type air conditioning devices. But perconal convection tpe air conditioning units are unuseful air conditioning type because it handles amount of surrounded air to meet the temperature and humidity. In this view, this study is intended to develope personal dir conditioning units using a radiation type radiator. Liquid Droplet Radiator(L.P.R.) radiates the energy by means of thermal radiation. Radiative energy from L.P.R. is the infrared rays which heat the objects without lose of energy. It is a desirable heating method for the local area within the large room. In this study, the analysis uses the Monte Carlo methd to predict the temperature distribution in the droplet sheet and the net heat flux from the L.D.R.. And for this study and experiment was carried out to analyse the radiative and convective heat transfer characteristics in the L.D.R.. And the experiment was investigated the effects of inlet temperature, feed rate, optical thickness and droplet diameter on heat transfer characteristics of L.D.R.. The obtained results from the numerical and experimental studies of L.D.R. were as follows ; (1) The heat flux of L.D.R. was effected by extinction coefficient of droplet sheet, optical thickness and droplet temperature, surface area and emissivity of the droplet. And it was increased with the temperature, feed rate and optical thickness, on the other hand decreased with increasing of droplet diameter. (2) The experimental results for heat flux was ecalucted below 20% than that of the numerical solution by Monte Carlo method, but the tendency of the variation shows relatively good agreement.

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First record of Sparganium subglobosum Morong (Typhaceae) from Korea (한반도 미기록식물 가는흑삼릉)

  • Lim, Chang-Kun;Kim, Juhyeon;Kim, Young Chul;Lim, Chae Eun;Won, Hyosig
    • Korean Journal of Plant Taxonomy
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    • v.47 no.4
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    • pp.322-327
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    • 2017
  • We report the distribution of Sparganium subglobosum Morong (Typhaceae) for the first time in Korea. Sparganium subglobosum is readily distinguishable from other Korea Sparganium species by having a short plant height, narrow leaves (${\leq}4mm$), thin inflorescence branches, and a ripe fruiting head globose and ca. 1 cm in diam. The species is under great threat of local extinction due to a recent disturbance of one of only two known distribution sites. Further conservation plans for S. subglobosum and surveys are needed. We provide a revised key to five Sparganium species of Korea, with descriptions, pictures, and figures of S. subglobosum.