• Title/Summary/Keyword: 열분석적 특성

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A Study on Korean FDI in China by Industries and Intra Industry Trade between Two Countries (한국의 대 중국 업종별 FDI와 산업내무역에 관한 연구)

  • Kim, Seong Ki;Kang, Han Gyoun
    • International Area Studies Review
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    • v.13 no.3
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    • pp.759-780
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    • 2009
  • The purpose of this paper is to analyse the effect of Korean FDI(1990-2008) in China by industries on exports and imports between two countries. We use time series regression, Vector Error Correction Model and Impulse Response Function as methodologies. Our findings through empirical tests are as follows. First Korean FDI in China increases Korean exports with China but shows a tendency to decrease due to the local content of China. Second Korean FDI in China increases Korean imports in SITC 8 with China. Finally Korean trade surplus caused by Korean FDI in China shrinks due to the decreasing of exports and increasing of imports in Korea. Korean FDI in China should be oriented host country's market oriented rather than production efficiency oriented because of unfriendly foreign investment environments in China.

A Decision Tree Analysis-based Exploratory Study on the Effects of Using Smart Devices on the Expansion of Social Relationship (의사결정나무 분석을 활용한 스마트 기기의 사용이 사회관계 확대에 미치는 영향에 관한 탐색적 연구)

  • Son, Woong-Bee;Jang, Jae-Min
    • Informatization Policy
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    • v.26 no.1
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    • pp.62-82
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    • 2019
  • This study attempts to make an empirical analysis on how mobile devices affect users in building their social relationship and if their influences are negative or positive. The purpose of this research is to explain the results by considering all the possibilities and exploring everyday lives of using mobile devices. We used the survey data from the "Research on Mobile Environment Awareness" conducted by Gyeonggi Research Institute(GRI). The main question was about the use of mobile devices and social network services (SNS) and users' opinions on using the devices. All of the 31 municipalities in Gyeonggi Province were included as a spatial range, and the final validity sample was 1,004 residents. The extent of the relationship with people is selected as a dependent variable through the multinomial logistic model and the decision tree model. As a result of the multinomial logistic analysis on the questionnaire, the characteristics of the respondents with some changes in the scope of the human relationship were found to have a significant (+) effect on conversation with family, SNS usage, residence in the rural area but not urban area, and device usage for obtaining news. The largest variable affecting the extent of relationship was the SNS usage. As the amount of SNS usage increases, the extent of the relationship also changes a lot.

Analysis of Physicochemical Properties and Firing Temperature for the Clay Bricks Excavated from the Maritime Province of Severia (연해주 콕샤로프카-1 평지성 출토 토벽의 물리화학적 특성 및 소성온도 분석)

  • Kim, So-jin;Heo, Jun-su;Kim, Jin-hyoung;Kim, Dong-hun;Han, Min-su
    • Korean Journal of Heritage: History & Science
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    • v.46 no.2
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    • pp.206-219
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    • 2013
  • This study aims to estimate firing temperature and physicochemical properties of the four clay bricks excavated from the Maritime Province of Siberia. Analysis result shows that the specimens are composed of clay, quartz and feldspar, and some specimens include carbonized organic materials which were probably added in order to enhance its physical strength in bricks. Major mineral components of the bricks are quartz, illite and clay minerals. The result identifying the existence of silimanite by XRD suggests that white material of the Koc 1 was painted for a certain purpose. Unlike most specimens which contained hematite, several samples contain Mullite. Such result suggests that some bricks were fired at high temperature. Furthermore, the results from TG analysis which does not display exothermic peak which appears at between $800^{\circ}C$ to $1,000^{\circ}C$ but display endothermic peak at $900^{\circ}C$ and it also confirms that they were exposed at $900^{\circ}C$ or higher.

Photoelectric Properties of PbTe/CuPc Bilayer Thin Films (PbTe/CuPc 이층박막의 광전 특성)

  • Lee, Hea-Yeon;Kang, Young-Soo;Park, Jong-Man;Lee, Jong-Kyu;Jeong, Jung-Hyun
    • Journal of Sensor Science and Technology
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    • v.7 no.1
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    • pp.67-72
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    • 1998
  • The crystallized CuPc and PbTe films are formed by thermal evaporation and pulsed ArF excimer laser ablation. Structural and electrical properties of thin film is observed by XRD and current-voltage(I-V) curves. From XRD analysis, both PbTe and CuPc thin films show a-axis oriented structure. For the measurement of photovoltaic effect, the transverse current-voltage curve of CuPc/Si, PbTe/Si and PbTe/CuPc/Si junctions have been analyzed in the dark and under illumination. The PbTe/CuPc/Si junction exthibits a strong photovoltaic characteristics with short circuit current($J_{sc}$) of $25.46\;mA/cm^{2}$ and open-circuit voltage($V_{oc}$) of 170 mV. Quantum efficiency and power conversion efficiency are calculated to be 15.4% and $3.46{\times}10^{-2}$, respectively. Based on the results of QE and ${\eta}$, the photocurrent process of PbTe/CuPc/Si junction can be explained as following three effective steps; photocarrier generation in the CuPc layer, carrier separation at PbTe/CuPc interface, and finally a transportation of electrons through the PbTe layer.

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Online Signature Verification by Visualization of Dynamic Characteristics using New Pattern Transform Technique (동적 특성의 시각화를 수행하는 새로운 패턴변환 기법에 의한 온라인 서명인식 기술)

  • Chi Suyoung;Lee Jaeyeon;Oh Weongeun;Kim Changhun
    • Journal of KIISE:Software and Applications
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    • v.32 no.7
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    • pp.663-673
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    • 2005
  • An analysis model for the dynamics information of two-dimensional time-series patterns is described. In the proposed model, two novel transforms that visualize the dynamic characteristics are proposed. The first transform, referred to as speed equalization, reproduces a time-series pattern assuming a constant linear velocity to effectively model the temporal characteristics of the signing process. The second transform, referred to as velocity transform, maps the signal onto a horizontal vs. vertical velocity plane where the variation oi the velocities over time is represented as a visible shape. With the transforms, the dynamic characteristics in the original signing process are reflected in the shape of the transformed patterns. An analysis in the context of these shapes then naturally results in an effective analysis of the dynamic characteristics. The proposed transform technique is applied to an online signature verification problem for evaluation. Experimenting on a large signature database, the performance evaluated in EER(Equal Error Rate) was improved to 1.17$\%$ compared to 1.93$\%$ of the traditional signature verification algorithm in which no transformed patterns are utilized. In the case of skilled forgery experiments, the improvement was more outstanding; it was demonstrated that the parameter set extracted from the transformed patterns was more discriminative in rejecting forgeries

Preparation of Al/RDX/AP Energetic Composites by Drowning-out/Agglomeration and Their Thermal Decomposition Characteristics (결정화/응집에 의한 구형 Al/RDX/AP 에너지 복합체 제조 및 그 열분해 특성)

  • Lee, Jeong-Hwan;Shim, Hong-Min;Kim, Jae-Kyeong;Kim, Hyoun-Soo;Koo, Kee-Kahb
    • Applied Chemistry for Engineering
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    • v.28 no.2
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    • pp.214-220
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    • 2017
  • The spherical Al/RDX/AP composites with an average size of $550{\mu}m$ were successfully prepared by drowning-out/agglomeration (D/A) process. The surface morphology and dispersion of Al particles of those composites were investigated using SEM and EDS (energy dispersive spectrometry). As a result of thermal analysis, the onset temperature of thermal decomposition of the Al/RDX/AP composites by the D/A process was found to decrease about $50^{\circ}C$ and their thermal stability was shown to be relatively enhanced due to the increase of activation energy compared to those of using the physical mixing method. In the first decomposition region of AP, Prout-Tompkins model was shown to describe well the thermal decomposition of both composites by the physical mixing and D/A process. On the other hand, in the second decomposition region of AP, the decomposition mechanisms of composites by the physical mixing and D/A process were explained by the zero-order and contracting volume model, respectively.

Preparation and Characterization of Poly(ethylene glycol) Based Pranlukast Solid Dispersion (친수성 Poly(ethylene glycol)을 이용한 프란루카스트 고체분산체의 제조 및 특성 분석)

  • Kim, Hyeong-Eun;Hwang, Jun-Seok;Cho, Sun-Hang;Kim, Young-Jin;Huh, Kang-Moo
    • Polymer(Korea)
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    • v.36 no.1
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    • pp.41-46
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    • 2012
  • In this study, poly(ethylene glycol) (PEG) was used as a hydrophilic polymer carrier to develop solid dispersion formulations for enhancing solubility and dissolution rate of pranlukast, one of poorly soluble drugs that has been broadly used for the treatment of asthma. PEG based solid dispersions with or without poloxamer were prepared by hot melting and solvent evaporation methods. The resultant solid dispersions were characterized by DSC and powder X-ray measurements, and their morphological properties were observed to be partially changed to amorphous state with reduced crystallinity. Dissolution and solubility tests showed that the solubility and dissolution rate of the solid dispersions were significantly enhanced. The solid dispersion formulation prepared by the hot melting method with a chemical composition of pranlukast:PEG:poloxamer = 1:5:1 demonstrated the most enhanced solubility and dissolution rate. The results suggest that the solid dispersions based on PEG and poloxamer are promising systems for the enhancement of solubility and bioavailability of pranlukast.

Trend Analysis of Vegetation Changes of Korean Fir (Abies koreana Wilson) in Hallasan and Jirisan Using MODIS Imagery (MODIS 시계열 위성영상을 이용한 한라산과 지리산 구상나무 식생 변동 추세 분석)

  • Minki Choo;Cheolhee Yoo;Jungho Im;Dongjin Cho;Yoojin Kang;Hyunkyung Oh;Jongsung Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.3
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    • pp.325-338
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    • 2023
  • Korean fir (Abies koreana Wilson) is one of the most important environmental indicator tree species for assessing climate change impacts on coniferous forests in the Korean Peninsula. However, due to the nature of alpine and subalpine regions, it is difficult to conduct regular field surveys of Korean fir, which is mainly distributed in regions with altitudes greater than 1,000 m. Therefore, this study analyzed the vegetation change trend of Korean fir using regularly observed remote sensing data. Specifically, normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST), and precipitation data from Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievalsfor GPM from September 2003 to 2020 for Hallasan and Jirisan were used to analyze vegetation changes and their association with environmental variables. We identified a decrease in NDVI in 2020 compared to 2003 for both sites. Based on the NDVI difference maps, areas for healthy vegetation and high mortality of Korean fir were selected. Long-term NDVI time-series analysis demonstrated that both Hallasan and Jirisan had a decrease in NDVI at the high mortality areas (Hallasan: -0.46, Jirisan: -0.43). Furthermore, when analyzing the long-term fluctuations of Korean fir vegetation through the Hodrick-Prescott filter-applied NDVI, LST, and precipitation, the NDVI difference between the Korean fir healthy vegetation and high mortality sitesincreased with the increasing LST and decreasing precipitation in Hallasan. Thissuggests that the increase in LST and the decrease in precipitation contribute to the decline of Korean fir in Hallasan. In contrast, Jirisan confirmed a long-term trend of declining NDVI in the areas of Korean fir mortality but did not find a significant correlation between the changes in NDVI and environmental variables (LST and precipitation). Further analyses of environmental factors, such as soil moisture, insolation, and wind that have been identified to be related to Korean fir habitats in previous studies should be conducted. This study demonstrated the feasibility of using satellite data for long-term monitoring of Korean fir ecosystems and investigating their changes in conjunction with environmental conditions. Thisstudy provided the potential forsatellite-based monitoring to improve our understanding of the ecology of Korean fir.

Can Index Decomposition Analysis Give a Clue in Understanding Industry's Greenhouse Gas Footprint? (산업의 온실가스 배출 행태 이해를 위한 지수분해분석 적합성 실증 연구)

  • Chung, Whan-Sam;Tohno, Susumu
    • Environmental and Resource Economics Review
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    • v.24 no.1
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    • pp.55-84
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    • 2015
  • Korea is one of the few OECD countries having no binding Greenhouse gas (GHG) emissions reduction obligations under the Kyoto Protocol. Korea is going to enforce a powerful greenhouse gas emissions control to the industry from 2015. Current GHG reduction policies do not take into account the trade-off between economic growth and GHG mitigation, this approach will not be sustainable. Sectoral approach, considering industry by industry may be more eco-friend approach. This study verified the validity of the analysis results counted from whole procedure of energy input-output analysis and decomposition analysis to sector 'Organic basic chemical products' and 'Cement and concrete products'. Empirical test was performed using changes in energy consumption, production, process improvements and new facilities. Although the results showed unstable fluctuations from Divisia index decomposition analysis, it was verified that the entire procedure can provide a clue in understanding of the industry's energy and GHG footprint.

Effects of Physical Characteristics Factors on Ankle Joint Injury during One Leg Drop Landing (외발 착지 시 신체적 특성 요인들이 발목 관절 상해에 미치는 영향)

  • Lee, Seong-Yeol;Lee, Hyo-Keun;Kwon, Moon-Seok
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.4
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    • pp.839-847
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    • 2020
  • The purpose of this study was to analyze the effects of ankle flexibility, gender, and Q-angle on the ankle joint injury factors during one leg drop landing. For this study, 16 males(age: 20.19±1.78 years, mass: 69.54±10.12 kg, height: 173.22±4.43 cm) and 16 females(age: 21.05±1.53 years, mass: 61.75±6.97 kg, height: 159.34±4.56 cm) in their 20's majoring in physical education using the right foot as their dominant feet were selected as subjects. First, an independent t-test of joint motion and joint moment according to the experience of ankle injury was conducted to determine the effect of physical characteristics on ankle joint injury during one leg drop landing(α = .05). Second, the variable that showed a significant difference through t-test was set as the dependent variable, and the ankle flexibility, gender difference, and Q-angle were designated as independent variables to use Multiple Linear Regression(α =. 05). As a result of this study, it was found that the group that experienced an ankle joint injury was found to use a landing strategy and technique through adduction of the ankle joint and internal rotation of the knee joint, unlike the group without an injury. It was also confirmed that this movement increases the extension moment of the ankle joint and decreases the extension moment of the hip joint. In particular, it was found that the dorsi flexion flexibility of the ankle affects the ankle and knee landing strategy, and the gender difference affects the ankle extension moment. Therefore, it was confirmed that physical characteristics factors affecting ankle joint injuries during one leg drop landing.