• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.103-124
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• 2006

This paper is concerned with a comparative study on the economic effects upon the Korean economy by transport mode, ie road, rail, air, and coastal and inland water transportation between 1990 and 2000, using input-output analysis. The economic effects consist of backward and forward linkage effects, production inducing and import-inducing effects. The data employed for this study come from the Bank of Korea database for Input-Output structure of the Korean economy. The major findings in this study are, among others:(1) the power of dispersion(=backward linkage effect) of coastal and inland water transportation sector is the highest among the four transport sectors, while road cargo transport mode showed the highest the degree of sensitivity (=forward linkage effect); (2) rail cargo transport recorded the highest production inducing effects; and (3) air transport mode achieved the highest ranking in the import-inducing effects.

• Advances in Energy Research
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• v.4 no.3
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• pp.223-237
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• 2016

The excess use of conventional sources of energy by the industries and power sector result in acute shortage of energy produced by fossil fuel. To overcome this energy crisis, biomass feedstock is used to produce syngas or producer gas. For cleaning the dust particle present in the producer gas cyclone separators are largely used. In this paper we investigate the performance parameters of cyclone separator mainly efficiency and pressure drop for different feedstock. Cyclone performance has been evaluated based on experimentation and empirical approach using Leith and Licht model. The same has also been calculated by using turbulent RSM in Ansys Fluent for Wood and Coconut shell feedstock. Experimental results show that using feed stock with 10 % Calcium oxide (CaO) by weight, the efficiency of cyclone got reduced from 71.87% to 70.75% for wood feed stock, whereas in case of coconut shell, the cyclone efficiency got reduced from 78% to 73.44%. It is also seen that Leith and Licht model and Reynolds stress model (RMS) predicts very close to the particle collection efficiency evaluated by using experimental data.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.7
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• pp.409-416
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• 2009

On 21st century, global warming is the most serious environmental problem threatening the existence of lives on the earth. One of the serious reasons of this nature phenomena was due to the greenhouse effect by carbon dioxide mainly produced with the combustion process of hydro-carbon fuel. and it is mostly produced. In the high oil prices age, intensification of energy efficiency promotion in the building sector is required. Windows are dominating large percentage whole building loads, and are regarding as the primary target of energy efficiency. The purpose of this research is on the obtaining of the renewable energy source in the skyscrape buildings in the metropolitan area. The air movement is happens due to the atmospheric pressure differences in the air. Due to this simple physical theory, it is easily expected to obtain the useful renewable nature energy through the high -raised vertical air stack installed in a tall building. However, there is one problem that should be resolved which is called air-hole effect in the sky -scrape buildings.

• Convergence Security Journal
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• v.21 no.3
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• pp.39-47
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• 2021

Standardization of the security operation dashboard is essential for efficient operation of security operation center. The security operation dashboard should be configured so that it is widely used by security operation workers who have to live together 24 hours a day, 365 days a year. In addition, it must be able to comprehensively express the business activities of the security operation center. In addition, it should be possible to easily explain the business activities of the security operation center. Therefore, in this paper, we would like to explain the design of a security control dashboard based on blockade, detection, and response that is actually applied to case organizations in the power sector. Through this, it is intended to reduce the effort and time required for configuring a custom dashboard for VIPs, and contribute to the efficient operation of the security operation center.

• Acta Via Serica
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• v.6 no.1
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• pp.55-90
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• 2021

In the last several decades, and especially since the Chinese launching of the Belt and Road (BRI) initiative in 2013, the Chinese presence in Central Asia has intensified. Russia and Chinese leaders deny that there is any conflict of interests between them, while the standard narrative has been that the two states adhere to a functional division of tasks in which China concentrates on economic activity while Russia acts as the security guarantor for the region. This article argues that the professed equanimity between the Russian and Chinese leaderships masks the emergence of widening cracks in their relationship with regard to Central Asia. The convenient narrative of a functional division of tasks between the two states is called into question by China's increasingly active presence in the military and security sector in the region, but China's influence is growing throughout the Central Asian economic, political, and social order. China's movement into Central Asia challenges Russia's claim to act as an equal partner of China, as well as its pretensions to regional hegemony. This development reflects the widening disparity between the two states with respect to their power capabilities but it also exposes the interactions between Russia and China in Central Asia as the most vulnerable aspect of their relationship. In Central Asia, a defensive Russia encounters an ascendant China.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1249-1256
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• 2021

This study investigates the company value determinant by observing the effect of financial performance and Corporate Social Responsibility (CSR) and its role in moderating performance achievement. The macro-economy variables such as inflation and interest rate are also used as the controlling variable. This research employs the sample of manufacturing companies of the food and beverage sub-sector listed on the Indonesia Stock Exchange. This study used panel data from 2013 to 2017, with the moderating regression analysis. The result shows that the profitability of the current or previous period affects the company's value. CSR and company size affect the company value at the next period shows that stock price, which reflects the investor's perception today, will be affected by the CSR, Size, and Return On Asset of the previous year. CSR also shows that it can be the substitute for profitability since a company that performs CSR is the one that has a good performance. The regression moderating model and the profitability of the previous period have a higher explanatory power than the higher R square value in explaining company value.

• Convergence Security Journal
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• v.20 no.4
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• pp.125-134
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• 2020

The potential security threat is increasing as the supply of ICT products to the defense sector increases with the development of information and communication technology. Attempts to neutralize, such as intelligence gathering and destruction, through attacks on the defense power support system and the intelligence system of the weapons system could pose a fatal threat.Therefore, security measures of supply chain shear system that take into account ICT product production and operation stage to maintenance stage are needed in defense field. In the paper, technical and administrative measures for responding to 12 ICT supply chain security threats at each stage of the defense ICT supply chain life cycle were presented.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.459-471
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• 2022

Purpose: The purpose of this study was to increase prediction accuracy for an anomaly interval identified using an artificial intelligence-based time series anomaly detection technique by establishing a pre-processing process. Methods: Significant variables were extracted by applying feature selection techniques, and anomalies were derived using the TadGAN time series anomaly detection algorithm. After applying machine learning and deep learning methodologies using normal section data (excluding anomaly sections), the explanatory power of the anomaly sections was demonstrated through performance comparison. Results: The results of the machine learning methodology, the performance was the best when SHAP and TadGAN were applied, and the results in the deep learning, the performance was excellent when Chi-square Test and TadGAN were applied. Comparing each performance with the papers applied with a Conventional methodology using the same data, it can be seen that the performance of the MLR was significantly improved to 15%, Random Forest to 24%, XGBoost to 30%, Lasso Regression to 73%, LSTM to 17% and GRU to 19%. Conclusion: Based on the proposed process, when detecting unsupervised learning anomalies of data that are not actually labeled in various fields such as cyber security, financial sector, behavior pattern field, SNS. It is expected to prove the accuracy and explanation of the anomaly detection section and improve the performance of the model.

• New & Renewable Energy
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• v.19 no.1
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• pp.12-21
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• 2023

Governments and global companies are working towards using renewable sources of energy, such as solar, wind, and biomass, to reduce dependency on fossil fuels. In the defense sector, the new strategy seeks to increase the sustainable use of renewable energy sources to improve energy security and reduce military transportation. Renewable energy technologies are affected by factors such as climate, resources, and policy environments. Therefore, governments and global companies need to carefully select the optimal renewable energy sources and deployment strategies. Biomass is a promising energy source owing to its high energy density and ease of collection and harvesting. Many techniques have been developed to convert the biomass into electrical energy. Recently, diverse types of fuel cells have been suggested that can directly convert the chemical energy of biomass into electrical energy. The recently developed biomass flow fuel cell has significantly enhanced the power density several hundred times, reaching to ~100 mW/cm². In this review, we explore various strategies for producing electrical energy from biomass using modern methods, and discuss the challenges and potential prospects of this method.

• Restorative Dentistry and Endodontics
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• v.49 no.1
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• pp.3.1-3.8
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• 2024

This article is a narrative review that discusses the recommended sample size requirements to design a pilot study to assess the reliability of a questionnaire. A list of various sample size tables that are based on the kappa agreement test, intra-class correlation test and Cronbach's alpha test has been compiled together. For all calculations, type I error (alpha) was set at a maximum value of 0.05, and power was set at a minimum value of 80.0%. For the kappa agreement test, intra-class correlation test, and Cronbach's alpha test, the recommended minimum sample size requirement based on the ideal effect sizes shall be at least 15, 22, and 24 subjects respectively. By making allowances for a non-response rate of 20.0%, a minimum sample size of 30 respondents will be sufficient to assess the reliability of the questionnaire. The clear guideline of minimum sample size requirement for the pilot study to assess the reliability of a questionnaire is discussed and this will ease researchers in preparation for the pilot study. This study provides justification for a minimum requirement of a sample size of 30 respondents specifically to test the reliability of a questionnaire.