• Title/Summary/Keyword: 열분석적 특성

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Chaotic Analysis of Water Balance Equation (물수지 방정식의 카오스적 분석)

  • 이재수
    • Water for future
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    • v.27 no.3
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    • pp.45-54
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    • 1994
  • Basic theory of fractal dimension is introduced and performed for the generated time series using the water balance model. The water balance equation over a large area is analyzed at seasonal time scales. In the generation and modification of mesoscale circulation local recycling of precipitation and dynamic effects of soil moisture are explicitly included. Time delay is incorporated in the analysis. Depending on the parameter values, the system showed different senarios in the evolution such as fixed point, limit cycle, and chaotic types of behavior. The stochastic behavior of the generated time series is due to deterministic chaos which arises from a nonlinear dynamic system with a limited number of equations whose trajectories are highly sensitive to initial conditions. The presence of noise arose from the characterization of the incoming precipitation, destroys the organized structure of the attractor. The existence of the attractor although noise is present is very important to the short-term prediction of the evolution. The implications of this nonlinear dynamics are important for the interpretation and modeling of hydrologic records and phenomena.

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Properties of Intumescence Alkali Silicates for Building Fire-Resistant (건축용 내화 재료로서의 포비성 알칼리 규산염의 특성에 관한 연구)

  • Kang, Hyun Ju;Kang, Seung Min;Song, Myong Shin;Kim, Young Sik;Park, Jong Hun
    • Applied Chemistry for Engineering
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    • v.20 no.4
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    • pp.416-422
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    • 2009
  • The buildings constructed with steel structure are coated with certified fire resistive material to resist from fire. All the building materials lose their initial performances as time passes by, so they need some maintenance. The Sprayed Fire Resistive Material (SFRM) also loses its performance and this performance loss of the SFRM is very important because fire resistance of buildings depends on SFRM. So this study was aimed to synthesis of alkali-silicates for SFRM and to evaluate the effect of alkali-silicates, K-silicates, Na-silicates and Li-silicates, by exchange of mole ratios as basic factors, tested solubility, intumescence ratios, thermal analysis, powder X-ray diffraction, fire-resistant and heat-resistant.

Estiamtion of Time Series Model on Forest Fire Occurrences and Burned Area from 1970 to 2005 (1970-2005년 동안의 산불 발생건수 및 연소면적에 대한 시계열모형 추정)

  • Lee, Byungdoo;Chung, Joosang
    • Journal of Korean Society of Forest Science
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    • v.95 no.6
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    • pp.643-648
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    • 2006
  • It is important to understand the patterns of forest fire in terms of effective prevention and suppression activities. In this study, the monthly forest fire occurrences and their burned areas were investigated to enhance the understanding of the patterns of forest fire in Korea. The statistics of forest fires in Korea, 1970 through 2005, built by Korea Forest Service was analyzed by using time series analysis technique to fit ARIMA models proposed by Box-Jenkins. The monthly differences in forest fire characteristics were clearly distinguished, with 59% of total forest fire occurrences and 72% of total burned area being in March and April. ARIMA(1, 0, 1) was the best fitted model to both the fire accurrences and the burned area time series. The fire time series have a strong relation to the fire occurrences and the burned area of 1 month and 12 months before.

Thermal Decomposition and Stabilization of the Lagoon Sludge Solid Waste after Dissolution with Water (라군 슬러지 물 용해 후 고체 패기물의 열분해 및 안정화)

  • Oh Jong-Hyeok;Hwang Doo-Seong;Lee Kue-Il;Choi Yun-Dong;Hwang Sung-Tae;Park Jin-Ho;Park So-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.3
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    • pp.249-256
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    • 2005
  • Thermal decomposition and stabilization characteristics of the solid cake after the dissolution of nitrate of the lagoon sludge was investigated. Most of the nitrates were dissolved in the water and removed to the filtrate, but small amount of nitrates, calcium carbonate and uranium were remained in the solid cake. The solid cake was thermally decomposed in the muffle furnace at $900^{\circ}C$ for 5 hours. Uranium, which is in the lagoon 1, was stabilized with $NaNO_3$ decomposition to $Na_{2}O{\cdot}2UO_3$ form. For the lagoon 2, it is confirmed that CaO, which was created by thermal decomposition of the $Ca(NO_3)_2$ and $CaCO_3$, was transferred to $Ca(OH)_2$ in the air with water. Because it is known that $Ca(OH)_2$ is stable material, further additives did not need to the stabilization of the thermal decomposition of the lagoons.

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Library and Information Science versus Commmication studies: A Comparison of Theoretical and Research Perspectives (문헌 정보학과 커뮤니케이션 연구의 학문적 연관성 고찰)

  • 정동열;권수영
    • Journal of the Korean Society for information Management
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    • v.8 no.2
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    • pp.125-138
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    • 1991
  • This paper focuses on issues in the relat~onshlp of library and information science with a closely allied chsciphne, communication studies. It is obvious that researchers in both fields study topics similar in focus, such as information theory, information-seeking behavior includ~ng user studies, systems theory, invisible colleges, the diffusion of knowledge, human interaction with information /communication technologies and the information society. In order to discuss the comparison of theoretical

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Evaluation of thermal environment in large scale indoor space of the nation museum of korea (국립중앙박물관의 대공간 열환경 분석)

  • 황원택;조춘식
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.28 no.1
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    • pp.16-24
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    • 1999
  • 박물관은 인류가 이룩한 물질문명과 정신문화의 집적을 특정한 주제를 중심으로 표현하는 문화공간으로서 한 나라의 문화수준을 측정할 수 있는 장소이며, 역사적으로 가치 있는 조형예술을 보존하고 계승할 수 있다는 점에서 중요한 의미를 지닌다. 현대사회에 들어오면서 박물관은 사회적 변화에 따른 가치관의 변화와 함께 관람자의 시각적 및 행태적 기능과 사회 문화적이고 사회 교육적인 기능을 통합하는 방향으로 나아가고 있다. 이에 대하여 자료를 가장 최적의 상태로 보관, 전시하여 보존에 가장 유리한 환경을 조성함과 동시에 이를 관람하는 사람들이 유물의 특성을 쾌적한 상태에서 쉽게 파악할 수 있는 환경을 조성해야 한다.

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Development of Heat Demand Forecasting Model using Deep Learning (딥러닝을 이용한 열 수요예측 모델 개발)

  • Seo, Han-Seok;Shin, KwangSup
    • The Journal of Bigdata
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    • v.3 no.2
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    • pp.59-70
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    • 2018
  • In order to provide stable district heat supplying service to the certain limited residential area, it is the most important to forecast the short-term future demand more accurately and produce and supply heat in efficient way. However, it is very difficult to develop a universal heat demand forecasting model that can be applied to general situations because the factors affecting the heat consumption are very diverse and the consumption patterns are changed according to individual consumers and regional characteristics. In particular, considering all of the various variables that can affect heat demand does not help improve performance in terms of accuracy and versatility. Therefore, this study aims to develop a demand forecasting model using deep learning based on only limited information that can be acquired in real time. A demand forecasting model was developed by learning the artificial neural network of the Tensorflow using past data consisting only of the outdoor temperature of the area and date as input variables. The performance of the proposed model was evaluated by comparing the accuracy of demand predicted with the previous regression model. The proposed heat demand forecasting model in this research showed that it is possible to enhance the accuracy using only limited variables which can be secured in real time. For the demand forecasting in a certain region, the proposed model can be customized by adding some features which can reflect the regional characteristics.

Subjective Wear Comfort and Related Fabric Surface Parameters Including Fractal Dimension of Contact Points (Fractal 차원과 면 혼방직물 셔츠의 착용 쾌적감)

  • 김정화;이현영;홍경희
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.11a
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    • pp.157-161
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    • 1999
  • 본 연구에서 직물의 열, 수분 전달특성과 KES-FB의 역학적 특성치, 직물표면의 fractal dimension을 측정하여 주관적 의복 착용 쾌적감을 예측하고자 하였다. 실험의복에 사용된 직물은 면 100% 평직물, 면/PET 혼방직물, 피치가공된 면/PET 혼방직물, PET 100% 평직물, 알칼리 감량가공된 PET 100% 크레이프 직물이었으며, 실험의복의 형태는 긴 소매 셔츠로 하였다. 착용실험은 온도 29$\pm$0.5$^{\circ}C$, 상대습도 75$\pm$2%RH, 기류 0.15m/s를 유지하는 항온항습실에서 실시하였고 36명의 여성 피험자(20-23세)들이 참여하였다. 의복 착용감의 하위 구성차원을 파악하기 위해 실험결과를 요인분석한 결과 5 개의 요인으로 추출되었다. 제 1 요인은 체온상승, 수분특성과 관련이 있는 온열.발한감이었으며, 제 2 요인은 무게ㆍ두께감, 제 3 요인은 회복특성감, 제 4 요인은 표면접촉감, 제 5 요인은 온냉감으로 구성되었다. 직물의 표면특성을 정량화하는 방법으로 도입한 fractal dimension 의 분석값들과 종래의 가장 보편적으로 이용되어 온 KES_FB 의 표면 특성치들이 주관적 착용쾌적감 예측에 얼마나 기여하는지 비교해 본 결과, 표면접촉감은 fractal dimension, 접촉점들의 총면적, 접촉점들의 평균 axis ratio, MMD, SMD와 높은 상관을 나타내었다. 또한 종합적 착용쾌적감에 대해서는 SMD 를 제외한 척도들이 유의한 상관을 보였으며, 그 중에서도 fractal dimension 과 접촉점들의 총면적은 0.8 이상의 높은 상관을 나타내었다. 착용쾌적감을 예측하기 위한 회귀분석결과에서는 fractal dimension 만으로 쾌적감의 74%가 설명되었으며 공기 투과도를 첨가하면 두 변수로 $R^2$=.792가 되었다. 설명되는 누적분산값은 67.18%였다.주관적 평가의 결과와 객관적 평가 결과를 이용해 마직물의 태를 평가하는 산출식을 제시하였다. 태 평가치의 경우 16가지 특성치를 모두 넣는 방법과 stepwise 방법, 또 Kawabatark 사용한 순차적 군 회귀법의 세가지 방법의 회귀식 중 16가지 특성치를 모두 넣는 방법의 결정계수가 가장 높았다.tosterone농도는 107.7$\pm$12.0 pmol/l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol/l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso." Therefore, the purpose of this study is to look into the origin of the letter designs in t

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Study on Spatial Characteristics of Physicochemical Components of Spring Water in Mts. Geumjeong and Baekyang Area Using Kriging (크리깅 기법을 이용한 금정산-백양산 일대 용천수의 물리화학적 성분의 공간적 분포 특성 연구)

  • 함세영;정재열;류상민;강래수
    • The Journal of Engineering Geology
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    • v.12 no.4
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    • pp.439-457
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    • 2002
  • Sping waters at 60 sites and groundwaters at 6 wells in Mts. Geumjeong and Baekyang area were investigated for measuring nine physicochemical components (temperature, pH, Eh, EC, TDS, DO, salinity, alkalinity and discharge rate). The pH of spring waters ranges from 5.06 to 8.38, alkalinity from 7.93 to 102.21 mg/ㅣ, electrical conductance from 9.5 to $270{\;}\mu\textrm{s}/cm$, Eh from 64.2 to 685.9 mV, DO from 4.57 to 12.13 mg/l, and the discharge rate from 4.26 to 182.2 ml/s. General statistics was carried out to analyze statistical characteristics of those components. To compare the components with one another, regression analyses were carried out. And the components of spring waters were compared to those of groundwaters. Kriging was used to estimate the spatial variation of DO, pH, Eh, EC, alkalinity and discharge rate in the study area. The kriged isopleth maps were made using normalized kriged values to find anomalies of the physicochemical components and to compare anomalies of different components.

The Characteristics Analysis of Novel Moat Structures in Shallow Trench Isolation for VLSI (초고집적용 새로운 회자 구조의 얕은 트랜치 격리의 특성 분석)

  • Lee, Yong-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.10
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    • pp.2509-2515
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    • 2014
  • In this paper, the conventional vertical structure for VLSI circuits CMOS intend to improve the stress effects of active region and built-in threshold voltage. For these improvement, the proposed structure is shallow trench isolation of moat shape. We want to analysis the electron concentration distribution, gate bias vs energy band, thermal stress and dielectric enhanced field of thermal damage between vertical structure and proposed moat shape. Physically based models are the ambient and stress bias conditions of TCAD tool. As an analysis results, shallow trench structure were intended to be electric functions of passive as device dimensions shrink, the electrical characteristics influence of proposed STI structures on the transistor applications become stronger the potential difference electric field and saturation threshold voltage, are decreased the stress effects of active region. The fabricated device of based on analysis results data were the almost same characteristics of simulation results data.