• 한국대기환경학회지
• /
• 제6권1호
• /
• pp.51-56
• /
• 1990

This Study shows the effect of the district heating on the $SO_2$ concentration reduction. In order to analyze the effect of the district heating, three alternatives were set up as follows; Alternative I represented present central heating system, and Alternative II and Alternative III represented district heating system of which the scale were different from. The concludions of this study are as follows; In case of the Alternative II and III, annual average $SO_2$ concentration are reduced by 9.0% and 14.6% respectively, and winter season $SO_2$ concentrations are reduced by 12.2% and 15.8% respectively, at the highest points. The average reduction rates of $SO_2$ concentration in the district heating area are about the same as the reduction rates at the highest points. Also, it was found that using the district heating system, the ground level $SO_2$ concentrations could be reduced within the area of 5 to 10 km radius.

• 신재생에너지
• /
• 제19권3호
• /
• pp.1-12
• /
• 2023

This study aims to evaluate the optimal size of the hydrogen facility to be installed in a zero-energy district in terms of load matching and facility efficiency. A mismatch between energy generation and consumption is a common occurrence in zero-energy districts. This mismatch adversely effects the energy grid. However, using an energy carrier such as hydrogen can solve this problem. To determine the optimal size of hydrogen fuel cells to be used on-site, simulation of hydrogen installation is required at both district-and building- levels. Each case had four operating schedules. Therefore, we evaluated eight scenarios in terms of load matching, heat loss, and facility operational efficiency. The results indicate that district-level installation of hydrogen facilities enables more efficient energy use. Additionally, based on the proposed model, we can calculate the optimal size of the hydrogen facility.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.284.3-285
• /
• 2002

Paraquat(methyl viologen) is a bis-quaternary ammonium compound as a wide range herbicide. which was first introduced as an oxidation-reduction indicator dye. When paraquat(fatal dose. 1-2g) was administered to men, the oxido-reduction system of cell was repeatedly acted to perpetuate the cell membrane system, Many death cases had been occurred after ingestion of paraquat around Daejon area for the last six months. (omitted)

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.42.1-42
• /
• 2002

A model to predict population by sex, age and district over a long-range period is proposed based on fuzzy theories. First, a fuzzy model is described. Second, a method to estimate the social increase by sex and age in each district is proposed based on a fuzzy clustering method for dealing with long-range socioeconomic changes in population migration. By the proposed methods, it became possible to predict the population by sex, age and district over a long-range period. Third, the structure and characteristics of the three models of employment model, time distance model, and land use model constructed to predict various socioeconomic indicators, which are require...

• 한국농공학회지
• /
• 제25권4호
• /
• pp.50-60
• /
• 1983

305 samples of alluvial deposit in inland and harbour districts were selected and consolidation charateristics of the alluvium were put in order statiscally. The correlations between them were as follows. 1. The relationships between LL(liguid limit) and Cc (compression index) were explained as Cc=0. 03(LL-21. 7) in case of inland district soil and as Cc=0. 019(LL-19) in case of harbour district soil. As compared with formular proposed by Skernpton, the gradient of this linear line was slight steep. 2. The relationships between PI(plastic index) and Cc were explained as Cc=0. 063 PI-0. 52 in case of inland district soil and Cc=0. 043 PI-0. 31 in case of harbour district soil. 3. As void ratio and natural moisture content were increased, Cc was increased, and as wet density was increased, Cc was decreased with a gentle curve. 4. As LL and P1 increased, mv(coefficient of volume compressibility) was increased but if LL and P1 was increased beyond a certain extend, mv has a tendency of constant value, that is, mv show a tendency to take constant value in the very soft clay. and mv in P=2. 5kg/cm$^2$ was about l${\times}$ l0-$^1$cm$^2$/kg in case of land district soil and 6x 10-$^1$crn$^2$/kg in case of harbour district soil lower than that in P=0. 25kg/crn2. 5. Cv(coefficient of consolidation) was a tendency to decrease with a gentle curve as LL was increased, and Cv in P=0. 25kg/crn2 was about 3x l0-$^1$crn$^2$/min larger than that in P=2. 5kg/crn$^2$. 6. Relationships between Py(pre-consolidation pressure) which is included over consolidation soil and ∑r1h(effective over-burden pressure) were explained as Py=l. 12 ∑r'h in case of land district soil and as Py=l. l5∑r'h in case of harbour district soil. 7. Some of the properties show good correlations between them, practical and effective applications of these correlations are expected in the planning and excution of soil investigation and also in the evaluation of the results.

• 자원환경지질
• /
• 제9권1호
• /
• pp.27-43
• /
• 1976

The flourite in Hwacheon, Hwanggangri and Keumsan district are major fluorite producing areas in Korea. The fluorite deposits of Hwacheon district are wholly fissure filling hydrothermal veins embedded in Precambrian gneiss and schists and Jurassic granites. Also some fluorite deposits are emplaced in felsite whose age is unknown. Emplacement of most fluorite veins of the district are controlled by EW fracture system. Fluorites are generally accompanied to chalcedonic quartz and also kaolinite, montmorillonite, dickite and calcite in parts. Vertical and lateral mineral zonings are not distinct. The fluorite deposits in the Hwanggangri district are wholly embedded in limestone and other calcareous sediments of Paleozoic Yeongweol Group. Most of the fluorite deposits belong to one of two categories which are steeply. dipping veins and gently dipping replacement deposits adjacent to Late Cretaceous(83-90mys) granite bodies. The strikes of fluorite veins of Hwanggangri district mostly occupy the fractures of $N30^{\circ}-40^{\circ}E$ and $N30^{\circ}-40^{\circ}W$ system. Fluorites are accompanied to calcite, milky quartz, chalcedonic quartz, and also montmorillonite, kaolinite in parts. But in some deposits, scheelite, various sulfide minerals and barite are accompanied. Emplacement of fluorite deposits are largely controlled by lithology and structures of this district. In some deposits fluorite veins gradate to scheelite veins and also telescoping of the mineral zones are found in this district. In the Keumsan district, fissure-filled fluorite veins and replacement deposits are mostly emplaced in limestone of Paleozoic Yeongweol Group, late Cretaceous quartz-porphyry, granite and sandstone. Some deposits are emplaced in Precambrian metasediments. Mineralogy and other characteristics of the deposits in this district is similar to those of Hwanggangri district. Fluid inclusion studies reveal the difference of salinities, $CO_2$ contents of ore fluid and temperatures during fluorite mineral deposition in the these districts. In Hwacheon district, ore-fluids were comparatively dilute brine and low $CO_2$ content. Filling temperatures ranges $104^{\circ}C$ to $170^{\circ}C$. In the Chuncheonshinpo mine, most deeply exploited one in this district, salinitles range 0.5-2. 2wt. % NaCl and filling temperatures range from $116^{\circ}C$ to $143^{\circ}C$. In the Hwanggangri district, ore fluids were complex and filling temperature ranges very widly. In the contact metasomatic fluorite deposits, ore fluid were NaCl rich brines with moderate $CO_2$ content and filling temperatures range from $285^{\circ}C$ to above $360^{\circ}C$. Fluids inclusions in tungsten and sulfide minerals bearing fluorite veins show high $CO_2$ content up to 31wt. %. Filling temperature ranges from $101^{\circ}C$ to $310^{\circ}C$. Fluids inclusions In mainly fluorite bearing veins were more dilute brine and low $CO_2$ contents. Filling temperatures range from $95^{\circ}C$ to $312^{\circ}C$. Filling temperature of fluid inclusions of Keumsan district are between $95^{\circ}C$ and $237^{\circ}C$. Data gathered from geologic, mineralogic and fluid inclusion studies reveal that fluorite mineralization in H wacheon district proceeded at low temperature with dilute brine and low $CO_2$ content. In Hwangganri district, fluorite mineralization proceeded by several pulse of chemically distinct ore fluids and formed the mineralogically different type of deposits around cooling granite pluton which emplaced comparatively shallow depth.

• Mass Spectrometry Letters
• /
• 제3권1호
• /
• pp.15-17
• /
• 2012

Eighteen of the PDE-5 inhibitors and their analogues were analyzed using GC-EI-MS. Fourteen of them could be identified by simple GC-MS method without derivatization, but hydroxyhongdenafil, hydroxyvardenafil, xanthoanthrafil and mirodenafil could not be identified without derivatization for the high polarity due to the presence of hydroxyl groups. N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), widely used trimethylsilyl (TMS) derivatizing reagents, were used to improve the sensitivity of the hydroxylated analogues. And the analytes could be identified by GC-MS after the derivatization.

• 한국통신학회논문지
• /
• 제42권3호
• /
• pp.698-701
• /
• 2017

현재 우리나라의 130만여 가구는 지역난방 열에너지를 사용하고 있다. 이러한 지역난방 열에너지 시스템은 한국지역난방공사에서 공급하는 1차측과 이를 개별 가구에 공급하는 2차측으로 구분되어 있다. 본 논문에서는 체계적이지 않고, 전문인력에 대한 의존도가 높은 2차측의 관리 및 유지보수 시 문제점을 보완하기 위한 IoT 기반 열에너지 원격 관리시스템의 구축에 대하여 논의한다.

• 한국건설관리학회논문집
• /
• 제16권6호
• /
• pp.144-155
• /
• 2015

본 연구는 서울에 위치한 오피스 빌딩 및 소매용 부동산 자산 간 권역별 포트폴리오의 구성을 통해 서로 다른 용도의 상업용 부동산 간의 분산 투자 시, 포트폴리오의 위험-수익률 관계를 파악함으로써 투자의 효율성과 성과를 알아보는 것을 목적으로 한다. 이를 위해 Markowitz의 평균-분산모델을 토대로 서울지역의 오피스 빌딩 자산과 소매용 부동산 자산을 권역별로 분류하여 이들 간의 포트폴리오를 구성한 후, 포트폴리오의 투자성과, 효율성, 그리고 Sharpe 지수에 기반한 최적의 포트폴리오를 확인하였다. 구체적으로, 서울의 3대 오피스 빌딩 시장인 강남권, 여의도 마포권, 그리고 도심권과 소매용 부동산의 3대 시장인 강남권, 신촌 마포권, 그리고 도심권에 대하여, 부동산 자산의 용도와 권역에 따라 투자비율을 달리해가며 포트폴리오를 구성하였다. 분석결과, 도심권 오피스 권역의 자산비중 10~30%와 도심권 소매용 부동산 권역의 자산 비중 70~90%로 구성한 포트폴리오가 가장 높은 분기별 Sharpe 지수인 2.7118~2.7776을 제시해 최적의 자산구성임을 알 수 있었으며 이때의 분기별 수익률은 1.826%~1.838% 그리고 분기별 위험은 0.573~0.589였다. 또한 부동산 자산 간 권역별 포트폴리오의 구성 시, 서로 다른 용도를 지닌 자산간의 포트폴리오 구성에 의한 분산투자가 동일한 투자자산의 권역별 분산투자 보다 더 좋은 투자성과를 보여주는 것을 알 수 있었다. 마지막으로, 본 연구의 결과를 바탕으로 부동산간접투자시장에서도 지역 및 용도별 분산투자에 대한 이해의 폭을 넓혀 부동산 및 건설경기의 활성화에 도움이 되기를 기대한다.

• Journal of Korean Neurosurgical Society
• /
• 제42권4호
• /
• pp.258-264
• /
• 2007

Objective : The purpose of this study is to investigate the incidence of aneurysmal subarachnoid hemorrhage (SAH) in Youngdong district for 10 years. Methods : From Jan. 1997 to Dec. 2006, 732 patients (327 males, 405 females, mean age: $54.8{\pm}13.1$ years) with spontaneous SAH were admitted to our hospital. We reviewed the medical records and radiological findings regarding to the ictus of SAH, location and size of the ruptured aneurysms, Hunt-Hess grade and Fisher grade on admission, personal details such as address, age, and sex, and previous history of medical diseases. Results : In these 732 patients, 672 cases were confirmed as aneurysmal SAH. Among them, 611 patients (262 males, 349 females, mean age: $54.9{\pm}13.2$ years) came from Youngdong district. The average crude annual incidence of aneurysmal SAH for men, women, and both sexes combined in Youngdong district was $7.8{\pm}1.7$, $10.5{\pm}2.7$, and $9.1{\pm}2.1$ per 100,000 population, respectively. Because of the problems related to the observation period and geographical confinement, it was suspected that the representative incidence of aneurysmal SAH in Youngdong district should be made during the later eight years in six coastal regions. Therefore, the average age-adjusted annual incidence for men, women, and both sexes combined was $8.8{\pm}1.4$, $11.2{\pm}1.3$ and $10.0{\pm}1.0$, respectively in the coastal regions of Youngdong district from 1999 to 2006. Conclusion : In overall, our results on the incidence of aneurysmal SAH was not very different from previous observations from other studies.