• Title/Summary/Keyword: degree distribution

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Numerical Study on Wafer Temperature Considering Gap between Wafer and Substrate in a Planetary Reactor (Planetary 형 반응기에서 웨이퍼와 기판 사이의 틈새가 웨이퍼 온도에 미치는 영향에 대한 연구)

  • Ramadan, Zaher;Jung, Jongwan;Im, Ik-Tae
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.3
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    • pp.1-7
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    • 2017
  • Multi-wafer planetary type chemical vapor deposition reactors are widely used in thin film growth and suitable for large scale production because of the high degree of growth rate uniformity and process reproducibility. In this study, a two-dimensional model for estimating the effect of the gap between satellite and wafer on the wafer surface temperature distribution is developed and analyzed using computational fluid dynamics technique. The simulation results are compared with the results obtained from an analytical method. The simulation results show that a drop in the temperature is noticed in the center of the wafer, the temperature difference between the center and wafer edges is about $5{\sim}7^{\circ}C$ for all different ranges of the gap, and the temperature of the wafer surface decreases when the size of the gap increases. The simulation results show a good agreement with the analytical ones which is based on one-dimensional heat conduction model.

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Thermal Flux Analysis for the Wearable NOx Gas Sensors (웨어러블 NOx 가스센서의 열유동 해석)

  • Jang, Kyung-uk
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.793-799
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    • 2019
  • In this study, the diffusion process and the thermal energy distribution gradient of the sensor were confirmed by using the finite element analysis program (COMSOL) of the mesh method to analyze the thermal diffusion in the wearable fabric (Nylon) + MWCNT gas sensor. To analyze the diffusion process of thermal energy, the structure of the gas sensor was modeled in a two dimension plane. The proposed modeling was presented with the characteristic value for the component of the sensor, and the gas sensor designed using the mesh finite element method (FEM) was proposed and analyzed by suggesting the one-way partial differential equation in the governing equation to know the degree of thermal energy diffusion and the thermal energy gradient. In addition, the temperature gradient 10[K/mm] of the anode-cathode electrode layer and the gas detection unit was investigated by suggesting the heat velocity transfer equation.

Genetic Diversity of the Pear Scab Fungus Venturia nashicola in Korea

  • Choi, Eu Ddeum;Kim, Gyoung Hee;Park, Sook-Young;Song, Jang Hoon;Lee, Young Sun;Jung, Jae Sung;Koh, Young Jin
    • Mycobiology
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    • v.47 no.1
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    • pp.76-86
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    • 2019
  • Scab disease caused by Venturia nashicola is of agroeconomic importance in cultivation of Asian pear. However, little is known about the degree of genetic diversity in the populations of this pathogen. In this study, we collected 55 isolates from pear scab lesions in 13 major cultivation areas in Korea and examined the diversity using sequences of internal transcribed spacer (ITS) region, ${\beta}$-tubulin (TUB2), and translation elongation factor-$1{\alpha}$ ($TEF-1{\alpha}$) genes as molecular markers. Despite a low level of overall sequence variation, we found three distinctive subgroups from phylogenetic analysis of combined ITS, TUB2, and $TEF-1{\alpha}$ sequences. Among the three subgroups, subgroup 1 (60% of isolates collected) was predominant compared to subgroup 2 (23.6%) or subgroup 3 (16.4%) and was distributed throughout Korea. To understand the genetic diversity among the subgroups, RAPD analysis was performed. The isolates yielded highly diverse amplicon patterns and none of the defined subgroups within the dendrogram were supported by bootstrap values greater than 30%. Moreover, there is no significant correlation between the geographical distribution and the subgroups defined by molecular phylogeny. Our data suggest a low level of genetic diversification among the populations of V. nashicola in Korea.

A stress model reflecting the effect of the friction angle on rockbursts in coal mines

  • Fan, Jinyang;Chen, Jie;Jiang, Deyi;Wu, Jianxun;Shu, Cai;Liu, Wei
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.21-27
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    • 2019
  • Rockburst disasters pose serious threat to mining safety and underground excavation, especially in China, resulting in massive life-wealth loss and even compulsive closed-down of some coal mines. To investigate the mechanism of rockbursts that occur under a state of static forces, a stress model with sidewall as prototype was developed and verified by a group of laboratory experiments and numerical simulations. In this model, roadway sidewall was simplified as a square plate with axial compression and end (horizontal) restraints. The stress field was solved via the Airy stress function. To track the "closeness degree" of the stress state approaching the yield limit, an unbalanced force F was defined based on the Mohr-Coulomb yield criterion. The distribution of the unbalanced force in the plane model indicated that only the friction angle above a critical value could cause the first failure on the coal in the deeper of the sidewall, inducing the occurrence of rockbursts. The laboratory tests reproduced the rockburst process, which was similar to the prediction from the theoretical model, numerical simulation and some disaster scenes.

Scientometric Analysis through Centrality Analysis of Graph for Linkage Relation of Keyword for Elder's Rehabilitation and Healthcare (노인 재활 헬스케어에 대한 키워드 연결 관계의 그래프 중심성 분석을 통한 계량 정보 분석)

  • Kim, Myung-Mi
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.2
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    • pp.447-452
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    • 2019
  • The elder problem is very serious stage in the age of present. This paper carries out scientometric analysis based on keyword that effort of global researcher for this research field as viewpoint of ICT and healthcare in order to settle physical exercise and rehabilitation of elder. First, this paper performs analysis of linkage relation of keyword. Second this paper carries out the analysis of degree distribution and centrality analysis of network based on betweenness centrality, closeness centrality and harmony centrality. Through this process, this paper reviews research trend of present and future through core keyword in the field of ICT and healthcare.

Factors Influencing on Consumer's Decision on Vegetarian Diets in Vietnam

  • NGO, Vu Quynh Thi;VO, Thi Anh Dao;NGO, Anh Phung;NGUYEN, Do Mai Anh;LE, Minh Thu;TO, Thi Phuong Loan;NGUYEN, Thi Thuy Phi
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.485-495
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    • 2021
  • Recently, vegetarian diets have experienced a dramatic increase in popularity. The aim of the study is to explore and test the relationship between the factors influencing consumers' dietary decisions in Ho Chi Minh City, Vietnam. The questionnaire applied a five-point Likert scale to investigate factors that affect Ho Chi Minh City's citizens when they have a vegetarian diet. 497 respondents (68% female; 61.2% aged 18-22; 82.7% had regular vegetarian diets) living in Ho Chi Minh City took part in both online and offline surveys. The results were processed by SPSS 22.0 software. The reliability was checked by Cronbach Alpha and Exploratory factor analysis (EFA) to identify the underlying relationships between measured variables. The Correlation analysis was implemented to show how strong and degree of two variables are related to each other before the multivariate regression equation was analyzed. The result showed the Five factors that were motivating people in Ho Chi Minh City to decide on plant-based diets, such as Animal Welfare, Health, Religion, Mood, and Reference groups. The mood is the most influential variable that significantly influences people's food choices. Attitudes toward vegetarian diets are changing. Therefore, recognizing the trends in food consumption might help companies take advantage of investment opportunities and build their marketing strategies.

Evaluation Factors Influencing Construction Price Index in Fuzzy Uncertainty Environment

  • NGUYEN, Phong Thanh;HUYNH, Vy Dang Bich;NGUYEN, Quyen Le Hoang Thuy To
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.195-200
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    • 2021
  • In recent years, Vietnam's economic growth rate has been attributed to the growth of many well-managed industries within Southeast Asia. Among them is the civil construction industry. Construction projects typically take a long time to complete and require a huge budget. Many socio-economic variables and factors affect total construction project costs due to market fluctuations. In recent years, crucial socioeconomic development indicators of construction reached a fairly high growth rate. Also, most infrastructure and construction projects have a high degree of complexity and uncertainty. This makes it challenging to predict the accurate project price. These challenges raise the need to recognize significant factors that influence the construction price index of civil buildings in Vietnam, both micro and macro. Therefore, this paper presents critical factors that affect the construction price index using the fuzzy extent analysis process in an uncertain environment. This proposed quantitative model is expected to reflect the uncertainty in the process of evaluating and ranking the influencing factors of the construction price index in Vietnam. The research results would also allow project stakeholders to be more informed of the factors affecting the construction price index in the context of Vietnam's civil construction industry. They also enable construction contractors to estimate project costs and bid rates better, enhancing their project and risk management performance.

The Effects of Socially Responsible Activities on Management Performance of Internationally Diversified Firms: Evidence from the KOSPI Market

  • AN, Sang Bong;YOON, Ki Chang
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.251-265
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    • 2021
  • It seems a common sense that corporate social responsibility (CSR) is a key driver to attain business sustainability. Nevertheless, there has been little research on the performance of socially responsible activities, including economic and environmental responsibility activities in internationally diversified firms. The purpose of this study was to evaluate the effects of CSR activities on management performance. For this evaluation, an empirical analysis was conducted with a total of 2,520 cases, selected from companies listed on the Korea Composite Stock Price Index market for six years from 2013 to 2018. As proxies for management performance, financial date such as a total asset net profit ratio and a total asset-operating ratio were used. A multivariate regression analysis was conducted to test hypotheses. The results of this analysis indicated that firms in the CSR outstanding group are significantly higher than other groups in management performances. In addition, CSR activities of internationally diversified firms positively influence their total asset net profit ratio and total asset-operating ratio. The results suggested that CSR activities of these firms can play a significant role in enhancing management performances amid the economic status of Korea, where a degree of export dependency is high.

Topic Modeling Analysis of Beauty Industry using BERTopic and LDA

  • YANG, Hoe-Chang;LEE, Won-Dong
    • The Journal of Economics, Marketing and Management
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    • v.10 no.6
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    • pp.1-7
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    • 2022
  • Purpose: The purpose of this study is identifying the research trends of degree papers related to the beauty industry and providing information which can contribute to the development of the domestic beauty industry and the direction of various research about beauty industry. Research design, data and methodology: This study used 154 academic papers and 189 academic papers with English abstracts out of 299 academic papers. All of these papers were found by searching for the keyword "beauty industry" in ScienceON on August 15, 2022. For the analysis, BERTopic and LDA (Latent Dirichlet Allocation) analysis were conducted using Python 3.7. Also, OLS regression analysis was conducted to understand the annual increase and decrease trend of each topic derived with trend analysis. Results: As a result of word frequency analysis, the frequency of satisfaction, management, behavior, and service was found to be high. In addition, it was found that 'service', 'satisfaction' and 'customer' were frequently associated with program and relationship in the word co-occurrence frequency analysis. As a result of topic modeling, six topics were derived: 'Beauty shop', 'Health education', 'Cosmetics', 'Customer satisfaction', 'Beauty education', and 'Beauty business'. The trend analysis result of each topic confirmed that 'Beauty education' and 'Health education' are getting more attention as time goes by. Conclusions: The future studies must resolve the extreme polarization between the structure of the small beauty industry and beauty stores. Furthermore, the researches have to direct various ways to create the performance of internal personnel. The ways to maximize product capabilities such as competitive cosmetics and brands are also needed attentions.

A Study on Unfolding Asymmetric Volatility: A Case Study of National Stock Exchange in India

  • SAMINENI, Ravi Kumar;PUPPALA, Raja Babu;KULAPATHI, Syamsundar;MADAPATHI, Shiva Kumar
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.4
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    • pp.857-861
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    • 2021
  • The study aims to find the asymmetric effect in National Stock Exchange in which the Nifty50 is considered as proxy for NSE. A return can be stated as the change in value of a security over a certain time period. Volatility is the rate of change in security value. It is an arithmetical assessment of the dispersion of yields of security prices. Stock prices are extremely unpredictable and make the investment in equities risky. Predicting volatility and modeling are the most profuse areas to explore. The current study describes the association between two variables, namely, stock yields and volatility in equity market in India. The volatility is measured by employing asymmetric GARCH technique, i.e., the EGARCH (1,1) tool, which was used in building the study. The closing prices of Nifty on day-to-day basis were used for analysis from the period 2011 to 2020 with 2,478 observations in the study. The model arrests the lopsided volatility during the mentioned period. The outcome of asymmetric GARCH model revealed the subsistence of leverage effect in the index and confirms the impact of conditional variance as well. Furthermore, the EGARCH technique was evidenced to be apt in seizure of unsymmetrical volatility.