• Title/Summary/Keyword: 열분석적 특성

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Exploring Spatio-Temporal Variations of Land Price in Daegu Metropolitan City (대구시 지가의 시공간적 변화 탐색)

  • Kim, Kamyoung
    • Journal of the Korean association of regional geographers
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    • v.18 no.4
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    • pp.414-432
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    • 2012
  • Land price is a kind of text to read urban spatial structure. The purpose of this paper is to inquire into the characteristics of Daegu's urban structure and its change in time through exploring spatio-temporal variations of land price with a detailed spatial and temporal resolution. To achieve this, land value surfaces were represented using the officially assessed land price every other year from 1995 to 2011. Through mapping and exploring spatio-temporal patterns and fluctuation rates of land price for this period, changes in urban structure, the effects of local decision makings such as Greenbelt adjustment, housing site development, and gentrification, and the effects of business fluctuations or policies at global or national scales could be caught. In addition, the trends for suburbanization and multi-centric urban form could be examined from the results of a negative exponential model explaining the effect of distance from an urban center on spatial variation of land price. These results demonstrate that urban analysis using land price mirroring spatial decision making at various scales could deepen understanding for internal structure and change of a city and provide useful information for establishing regional and urban development policies and evaluating their effects.

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Analysis of Material Characteristics for Blackwares at Excavated from the Bonggok Kiln Site of Jinan-gun (진안 봉곡도요지 출토 흑유자기의 재료학적 특성 분석)

  • Park, Minsoo;Chung, Kwang Yong
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.549-560
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    • 2016
  • The purpose of this study is to identify the material characteristics of blackwares excavated from the Bonggok kiln site in Jinan-gun, Jeollabuk-do Province, South Korea, by scientific analyses and a reproduction experiment. Scientific analyses were conducted to determine the physical properties, chemical composition and for microscopic observation of blackwares. A reproduction experiment was also conducted by producing ceramic samples with black glaze, red ocher and limestone, and then cross sections of the samples were observed. The analysis results showed that all the excavated blackwares have similar properties such as chromaticity, specific gravity, absorption factor and porosity, but there is a difference depending on the crystallization of the ceramics. Thermal analysis showed that the exothermic peak was observed at about $1200^{\circ}C$, and crystal structure analysis indicated the presence of mullite. Hence, it can be concluded that the firing temperature of the excavated blackwares was around $1100-1200^{\circ}C$. Moreover, the glaze present on these blackwares has about 22% higher $Fe_2O_3$ content than those excavated from other places; however, the former has lower CaO content. For the reproduction experiment, samples were made using limestone as a flux and red ocher as a glaze. The results show that the cross section of the glaze layer of the reproduced sample have iron crystals with dendritic structures, similar to those present in the excavated black-wares. It is assumed that such iron crystals were formed during the process of melting and solidification of the iron oxide present in the blackwares.

Intercomparison of the Global Ocean Reanalysis Data (전지구 해양 재분석 자료 비교 분석)

  • Chang, You-Soon
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.20 no.2
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    • pp.102-118
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    • 2015
  • This study summarized the results of the international ocean reanalysis intercomparison project. We introduced the characteristics of various ocean reanalysis systems and analyzed the assimilated performance on the typical eight oceanic variables (heat content, steric height, sea level, surface heat fluxes, mixed layer depth, subsurface salinity, depth of $20^{\circ}C$ isotherm, sea ice). In general, ensemble means show better estimations than those of any individual ocean reanalysis, but it depends on analyzed regions and variables. Among the eight oceanic variables, salinity and sea ice variabilities have large spreads among models. The deep sea, Southern Ocean, and coastal regions including western boundary current commonly appear as the areas with largest uncertainty between different objective analyses and assimilation models. We expect that intercomparison project for the ocean assimilation models independently operated in Korea should be processed, which allows us to join relevant international programs in the near future.

Turbidity Monitoring in Saemangum Area using Remote Sensing (RS를 이용한 새만금 지역의 탁수환경 모니터링)

  • Na, Sang-Il;Park, Jong-Hwa;Shin, Hyoung-Sub;Beak, Shin-Chul
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.472-472
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    • 2011
  • 탁도는 물의 상대적인 흐림 정도를 나타내는 척도로서 이는 빛이 물을 통과할 때 산란시키는 부유고형물질 때문에 발생한다. 토양침식에 의하여 지표수로 유입된 토사와 광물질은 하천의 수송 및 퇴적 과정을 거치며 이동한다. 이때 하상 퇴적물은 바닥으로부터 먹이를 찾는 유기체에 의해 뒤섞이며 입자들은 일정기간동안 물의 흐름에 의해 부유상태로 남아 있게 되고, 유입되는 영양소와 빛에 의하여 성장하는 조류 또한 탁도를 증가시키는 원인이 된다. 이러한 부유물질의 증가는 수중에 태양복사에너지 전달을 방해하여 수중생태계의 먹이사슬과 저서생물의 서식환경에 많은 영향을 미치고, 수표면 온도 또한 태양으로부터 열을 흡수하는 표면 근처의 부유물질에 의해 증가하여 용존산소의 양에도 영향을 미친다. 따라서 수체내 분포하고 있는 부유물질의 종류와 양 및 공간적 분포 파악은 수질문제와 재난 예방 및 생물의 서식환경 문제를 파악하고 해결하는 데 매우 중요하다. 그러나 부유물질에 부착되어 있는 영양소, 금속, 살충제 등은 물 순환 시스템을 통하여 끊임없이 운반되고 상류유역의 흐름 조건에 따라 시공간적으로 변화하기 때문에 이를 규명하는 것이 매우 어려운 실정이다. 이러한 문제를 해결하기 위하여 광역적인 탁수환경의 분석방법으로 원격탐사(Remote Sensing, 이후 RS) 기법을 이용한 방법이 제안되고 있다. 이미 선진국에서는 광역수계의 수질관리를 위해 RS 기법을 이용하여 신속하고 정확한 수질상태 파악을 시도하고 있으며, 우리나라에서도 KOMPSAT 발사를 계기로 RS 관련 기술이 비약적으로 진화하고 있다. 그러나 RS 데이터를 활용하는데 필수적인 분광학적 특성 규명에 대한 연구는 대부분 식생과 토양에 한정되어 있으며 수체에 대한 연구는 현장조사의 어려움으로 인하여 상당히 제한적인 수준이다. 따라서 본 연구에서는 탁도의 변화에 따른 분광반사 특성을 휴대용 분광복사계를 이용하여 규명하고, 이를 Landsat 위성영상에 적용하여 새만금 유역을 대상으로 완공 직후인 2006년부터 2010년까지의 탁수환경을 모니터링 하였다. 그 결과 새만금 유역 탁수환경을 정성적으로 확인할 수 있었으며, 이를 이용하여 탁수환경 연구에 RS 기법이 효과적임을 제시하고자 한다.

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A Study on the Effect of Metacognition to the Information-Seeking Behavior of Undergraduate Students (메타인지가 대학생의 정보탐색행위에 미치는 영향에 관한 연구)

  • Choi, Moon Jung;Jeong, Dong Youl
    • Journal of the Korean Society for Library and Information Science
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    • v.47 no.2
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    • pp.75-101
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    • 2013
  • This study analyzed the effect of metacognition to the information-seeking behaviors of 250 undergraduate students. For this, metacognition was examined by the inspection form that the Educational Psychology Programs of the Department of Education, at Seoul National University, developed in 2005. The information-seeking behaviors were examined by the observance of the established information-seeking performances and through a survey. As a result of the analysis, metacognition affected the items of the survey for the information-seeking behaviors, excluding one item. As metacognition is the cognitive characteristics acting after the cognitive process, it affected thinking activities that were conducted by the brain. In addition, metacognition affected the seeking process, the results of seeking, and the general information-seeking behaviors. Therefore, the study of metacognition is effective in the overall aspects of information-seeking behaviors including the seeking process, the results of seeking, and the general information-seeking behaviors.

Evaluation of Mesoporous Alumina Adsorbent for the Purification of Paclitaxel (Paclitaxel 정제를 위한 메조기공 알루미나 흡착제 평가)

  • Oh, Hyeon-Jeong;Jung, Kyeong Youl;Kim, Jin-Hyun
    • Microbiology and Biotechnology Letters
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    • v.41 no.2
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    • pp.176-182
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    • 2013
  • Several types of mesoporous alumina adsorbents with different physical properties were prepared by spray pyrolysis and were used for the separation/purification of the anticancer agent paclitaxel. The pore diameter of the adsorbents had a greater effect than did the surface area and the pore volume on the removal of plant-derived impurities. An appropriate pore diameter (~10.8 nm) was required for effective impurity removal. At a constant pore diameter, the surface area of the adsorbent affected not only the purity but also the yield of paclitaxel. Also, increasing the surface area of the adsorbent resulted in an increase in the adsorption of paclitaxel and impurities (biomass-derived tar and wax components). Removal of these impurities was confirmed by HPLC analysis of the absorbent after the treatment and TGA of the organic substances that were bound to the adsorbent.

Development of a Failure Probability Model based on Operation Data of Thermal Piping Network in District Heating System (지역난방 열배관망 운영데이터 기반의 파손확률 모델 개발)

  • Kim, Hyoung Seok;Kim, Gye Beom;Kim, Lae Hyun
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.322-331
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    • 2017
  • District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

A Study on the Characteristics of Time Dependent Temperature Change in a Automobile Washer Heater (자동차 워셔액 가열시스템의 온도 변화 특성에 관한 연구)

  • Ha, Ji-Soo;Lee, Seong-Bong;Lee, Dong-Kwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1040-1044
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    • 2013
  • The present paper has been accomplished to elucidate the characteristics of temperature change in a car washer heater system for removal of frost formed at the surface of a car. The previous studies had used a simplified mathematical modeling to analyse the temperature change characteristics for a car washer heater system. In the present study, an unsteady computational fluid flow and heat transfer analysis for a washer heater system has been done by using computational fluid dynamic analysis method. From the present CFD analysis, the time dependent temperature change in a car washer heater system has been analysed and derived the heating time and ejection temperature of the washer liquid to establish the optimal design basis for a washer heater system.

THE STUDY OF PHENOLOGICAL CHARATERISTICS IN GAEMA PLATEAU, NORTH KOREA USING TIME-SERIES MODIS NDVI DATA (시계열 MODIS 자료의 식생지수를 이용한 북한 개마고원 지역의 생물계절 특성 연구)

  • Cha, Su-young;Seo, Dong-jo;Park, Chong-hwa
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.477-480
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    • 2009
  • 최근 북한지역에 발생한 홍수와 가뭄 등 심각한 자연재해의 원인이 악화된 식량난으로 인한 과도한 산림의 훼손으로 추정되고 있어 북한 지역의 산림 생태계에 대한 연구의 필요성을 더욱 확인하는 계기가 되고 있다. 위성자료로부터 얻을 수 있는 식생지수(NDVI)는 농작물, 초목, 산림등과 같은 중요한 식생자원을 모니터링 하기 위해 설계된 도구로 식생의 활력도를 정량적으로 표현할 수 있다. 또한, 식생지수는 개략적인 식생을 파악하는데 주로 사용되기 때문에 초기조사에 많이 이용되고 있다. 따라서, 본 연구에서는 개마고원지대를 포함하는 표고 1000m 이상의 한대림지대의 산림식생에 대해 9년(2000~2008)간의 시계열 MODIS영상에서 나타나는 식생지수의 생물계절 특징을 분석하였다. 식생이 성장하기 시작하는 시기(the beginning of the growing season)는 5월 9일 이후부터 5월 25일 사이의 기간으로 나타났고, 식생의 휴면 시기(the end of growing season)는 9월 14일부터 9월 30일 사이 기간으로 관측되었다. 이는 4월 초에 시작하고 10월에 사라지는 한반도의 일반적이 식생패턴보다 성장은 한달 늦게, 휴면은 한달 이르게 한다는 것이 확인되었다. 또한, 8월 초순의 NDVI 값이 9년 동안 계속적으로 가장 높은 값을 보여주고 있다. 이것은 개마고원지역 및 주변 한대림 지대는 7월 말에서 8월 초순에 식생이 가장 활발한 것을 의미한다. 9년 동안 전반적인 식생지수는 0.2~0.9 값을 보였고, 특이할 점은 9년 동안의 평균적인 NDVI 값에 비해 2002년의 식생의 활동이 봄에 빨리 개화하고 가을에 일찍 지는 패턴을 보였다.

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An analysis of time series models for toilet and laundry water-uses (변기 및 세탁기 가정용수 사용량의 시계열모형 연구)

  • Myoung, Sungmin;Kim, Donggeon;Lee, Doo-Jin;Kim, Hwa Soo;Jo, Jinnam
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.6
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    • pp.1141-1148
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    • 2013
  • End-uses of household water have been influenced by a housing type, life style and housing area which are considered as internal factors. Also, there are external factors such as water rate, weather and water supply facilities. Analysis of influential factors on water consumption in households would give an explanation on the cause of changing trends and would help predicting the water demand of end-use in household. In this paper, we used real data to predict toilet and laundry water-uses and utilized the linear regression model with autoregressive errors. The results showed that the monthly autoregressive error models explained about 71% for describing the water demand of end-use in toilet and laundry water-uses.