• 제목/요약/키워드: Boost ability

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듀얼 인버터 개방 권선형 영구자석 동기 전동기 제어를 위한 PWM 가변 캐리어 생성법 및 영벡터 위치에 따른 전류 리플 분석 (PWM Variable Carrier Generating Method for OEW PMSM with Dual Inverter and Current Ripple Analysis according to Zero Vector Position)

  • 심재훈;최현규;하정익
    • 전력전자학회논문지
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    • 제25권4호
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    • pp.279-285
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    • 2020
  • An open-end winding (OEW) permanent magnet synchronous motor with dual inverters can synthesize large voltages for a motor with the same DC link voltage. This ability has the advantage of reducing the use of DC/DC boost converters or high voltage batteries. However, zero-sequence voltage (ZSV), which is caused by the difference in the combined voltage between the primary and secondary inverters, can generate a zero-sequence current (ZSC) that increases system losses. Among the methods for eliminating this phenomenon, combining voltage vector eliminated ZSV cannot be accomplished by the conventional Pulse Width Modulation(PWM) method. In this study, a PWM carrier generation method using functionalization to generate a switching pattern to suppress ZSC is proposed and applied to analyze the control influence of the center-zero vector in the switching sequence about the current ripple.

초등학교 교과전담교사 배정 현상에 대한 경험 탐색 (The Experience Study on Patterns Phenomenology in the Allocation of Subject-specialized Teachers at Elementary Schools)

  • 추갑식
    • 수산해양교육연구
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    • 제26권4호
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    • pp.736-748
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    • 2014
  • The purpose of the study is to examine various conditions, which are recognized by teachers in the allocation of subject-specialized teachers at elementary schools, into five types of conflicts, in order to offer implications for the operation and allocation of the subject exclusive system henceforth. The study, therefore, categorized the actual allocation process experienced by subject-specialized teachers at elementary schools into five aspects the first is, understanding of students, the second, the ability to teach exclusive subjects, the third, a relationship with students, the fourth, workplace environment at schools, and the fifth, the continuity of subject specialist teachers. Conditions demonstrated in each category are classified into the types that occurred by individual and mutual roles demonstrated through in-depth, where keywords are selected by aspects to suggest conflict conditions. In order to operate the subject exclusive system more efficiently and to boost the effects of positive education, the workplace environment at schools need to be improved urgently, including a variety of training, program development, and financial support. The most vital requirement is to prepare groundwork through mutual understanding and collection of extensive opinions from field teachers based on a consensus that a school is an educational community. The study anticipates that the result could provide a foundation for the preparation of qualitative improvement and development measures for the subject exclusive system at elementary schools.

Determinants of E-invoice Adoption: Empirical Evidence from Vietnam

  • NGUYEN, Anh Huu;NGUYEN, Thao Phuong;DANG, Giang Tra Thi
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.311-321
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    • 2020
  • This paper aims to investigate the effect of the factors on the e-invoice at its infant stage of adoption in the context of Vietnam. Data were collected by using a questionnaire delivered to 318 participants who are managers and accountants of companies in Vietnam from June to September 2019. The statistical methods approaches are employed to address the research issues including Cronbach's Alpha testing, Explanatory Factor Analysis (EFA), and Confirmation Factor Analysis (CFA). Then, Structural Equation Modeling (SEM) is employed to assess the proposed hypotheses model of e-invoice adoption in Vietnam. The research findings showed that direct factors have a statistically significant impact on the e-invoice adoption towards behavior, and perceived behavioral control. Perceived usefulness and perceived ease-of-use positively affect attitude towards the behavior. These factors, in turn, are impacted by perceived compatibility. Based on the research results, some practicable suggestions are proposed in order to boost the number of Vietnamese enterprises voluntarily adopting e-invoice. This study indicates the important impacts of the user's attitude and perception about control ability on intention to use. In addition, some key intuitive recommendations were proposed aiming to improve the success of the e-invoice adoption of enterprises in the context of Vietnam.

건설업 중대재해 예방을 위한 PSM 제도 활용에 관한 연구 (A Study on Using PSM Policy for the Serious Accident Prevention of Construction)

  • 정범모;양광모;강경식
    • 대한안전경영과학회지
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    • 제4권4호
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    • pp.1-14
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    • 2002
  • As domestic buildings have been large-scaled, diversified and high-rise, there have been a consistent demand for design, development of construction technology and accident prevention activity as well as quality enhancement. In spite of governmental and related institutions' efforts for reducing national losses which come from numerous accidents, there have been endless small and large accidents on the construction site and thus, it is urgent to conduct empirical researches in this area. Currently safety supervision system in construction industry has enforced harm and danger prevention planning system, however it merely stick to other existing materials. In addition, it is difficult to put it into practice in that it requires bearing too much burden to draw out the planning itself in a case of large construction work. Consequently in this paper we select evaluation criteria by construction progress, classify into several categories, and regard potential danger which often occurs, as a evaluation criterion. Further step is to allow workers or collaborated companies to express their expert opinions or experiences and to encourage quality and process control and autonomous safety control by applying PSM method. The reason why PSM method should be quantitative and substantial progress is because it contributes Korean constructing companies to enhancing their safety control ability and to taking an equal stance just like developed countries,' thereby strengthening there competitive edges. Boost of safety control system by PSM method will make an enormous contribution to preventing construction accidents on the site by establishing and securing an autonomous safety control system.

Multi-dimensional Emotional Intelligence Effects on Intrinsic/Extrinsic Motivation and Job Satisfaction: Analysis Using Laborer Perceived Organizational Support

  • Yang, Hoe-Chang;Cho, Hee-Young;Lee, Won-Dong
    • Asian Journal of Business Environment
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    • 제5권4호
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    • pp.13-18
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    • 2015
  • Purpose - Based on previous studies, this study extends current research and investigates whether the sub-factors of emotional intelligence increase job satisfaction or employee intrinsic and extrinsic motivation and perceived organizational support. Research design, data, and methodology - This study categorizes service employees' (consultants) emotional intelligence into four sub-factors: regulation of emotion, appraisal of emotion, utilization of emotion, and expression of emotion. The study then investigates the sub-factor effects on job satisfaction. A total of 353 valid questionnaires were collected. Results - The results of the path analysis showed that appraisal, utilization, and expression of emotion had a positive effect on intrinsic motivation, and utilization of emotion had a positive effect on extrinsic motivation. Extrinsic motivation had a positive effect on perceived organizational support and job satisfaction, and perceived organizational support had a positive effect on job satisfaction. Conclusion - As consultants' utilization of emotion is rendered as the ability to use emotion to improve performance, the conclusion is that such factors as monetary performance incentives are important in order to boost job satisfaction of the consultants.

Optimal Capital Adequacy Ratios for Commercial Banks: Empirical Evidence from Vietnam

  • LUONG, Thi Minh Nhi;NGUYEN, Phuong Anh
    • The Journal of Asian Finance, Economics and Business
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    • 제8권10호
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    • pp.47-56
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    • 2021
  • It is unavoidable for businesses, especially commercial banks, to compete with other firms and financial institutions in a globalized and internationalized world. Basel I, II, and III were developed by the Basel Committee on Banking Supervision with the primary purpose of supporting banks in dealing with potential risks and enhancing their ability to absorb losses. Basel II and III require the minimum capital adequacy ratio (CAR) of 8% and 10.5%, respectively. This paper estimates the optimal CAR of 26 commercial banks in Vietnam from 2016 to 2020 using the two-stage DEA method. According to the empirical findings, banks with ideal CARs exceeding 8% (as defined by Basel II) and 10.5 percent (as defined by Basel III) account for approximately 98 percent and 88 percent of all banks, respectively. Furthermore, 75.83 percent of all banks need to boost their existing CAR to achieve the optimal level of CAR as well as obtain the best performance. On average, the optimal CAR of state-owned banks is higher than other joint-stock banks, respectively 26 percent and 19 percent. Consequently, it is recommended for Vietnam commercial banks to reach optimal CAR and comply with the new policy set by Basel III with the purpose of approaching the efficient frontier.

Comparative Study on Convective and Microwave-Assisted Heating of Zeolite-Monoethanolamine Adsorbent Impregnation Process for CO2 Adsorption

  • Oktavian, Rama;Poerwadi, Bambang;Pardede, Kristian;Aulia, Zuh Rotul
    • Korean Chemical Engineering Research
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    • 제59권2호
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    • pp.260-268
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    • 2021
  • Adsorption is the most promising technology used to adsorb CO2 to reduce its concentration in the atmosphere due to its functional effectiveness. Various porous materials have been extensively synthesized to boost CO2 adsorption efficiency, for example, zeolite. Here, we report the synthesis process of zeolite adsorbent impregnated with amine, combining the benefit of these two substances. We compared conventional heating with microwave-assisted heating by varying concentrations of monoethanolamine in methanol (10% v/v and 40% v/v) as a liquid solution. The results showed that monoethanolamine impregnation helps significantly increase adsorption capacity, where adsorption occurs as a physisorption and not as chemisorption due to the adsorbent's steric hindrance effect. The highest adsorption capacity of 0.3649 mmol CO2 / gram adsorbent was reached by microwave exposure for 10 minutes. This work also reveals that a decrease in CO2 adsorption capacity was observed at a longer exposure period, and it reached a constant 40-minute adsorption rate. Impregnating activated zeolite with 40% monoethanolamine for 10 minutes in addition to microwave exposure (0.8973 mmol CO2 / gram adsorbent) is the maximum adsorption ability achieved.

Capital Structure and Trade-Off Theory: Evidence from Vietnam

  • KHOA, Bui Thanh;THAI, Duy Tung
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.45-52
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    • 2021
  • The capital structure is one of the hot financial topics among researchers and scholars. Its importance comes from the fact that capital structure is closely related to companies' ability to meet different stakeholders' needs. A suitable capital structure will boost the business and create a competitive advantage in the context of fierce competition. Many companies choose an optimal debt level based on the trade-off between interest and debt costs. This study aimed to test the existence of trade-off theory in capital structure, the case of Vietnam's real estate companies, which are growing very fast recently. Instead of considering constant optimal leverage to test the trade-off model, we take advantage of the dynamic capital structure determined by growth opportunities, profitability, tax incentives, tangibility, liquidity, and firm size. The dynamic panel data regression was estimated by the system Generalized Method of Moment (Sys-GMM). The empirical evidence showed that real estate companies listed in the Vietnamese stock market might change their leverage toward a target capital structure determined by influential factors in a long-term perspective. In particular, the debt-to-asset ratio will change by approximately 14 percent, positively, in response to the difference between the current debt-to-asset ratio and the dynamic target debt-to-asset ratio.

Fast and Accurate Single Image Super-Resolution via Enhanced U-Net

  • Chang, Le;Zhang, Fan;Li, Biao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권4호
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    • pp.1246-1262
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    • 2021
  • Recent studies have demonstrated the strong ability of deep convolutional neural networks (CNNs) to significantly boost the performance in single image super-resolution (SISR). The key concern is how to efficiently recover and utilize diverse information frequencies across multiple network layers, which is crucial to satisfying super-resolution image reconstructions. Hence, previous work made great efforts to potently incorporate hierarchical frequencies through various sophisticated architectures. Nevertheless, economical SISR also requires a capable structure design to balance between restoration accuracy and computational complexity, which is still a challenge for existing techniques. In this paper, we tackle this problem by proposing a competent architecture called Enhanced U-Net Network (EUN), which can yield ready-to-use features in miscellaneous frequencies and combine them comprehensively. In particular, the proposed building block for EUN is enhanced from U-Net, which can extract abundant information via multiple skip concatenations. The network configuration allows the pipeline to propagate information from lower layers to higher ones. Meanwhile, the block itself is committed to growing quite deep in layers, which empowers different types of information to spring from a single block. Furthermore, due to its strong advantage in distilling effective information, promising results are guaranteed with comparatively fewer filters. Comprehensive experiments manifest our model can achieve favorable performance over that of state-of-the-art methods, especially in terms of computational efficiency.

Generate Optimal Number of Features in Mobile Malware Classification using Venn Diagram Intersection

  • Ismail, Najiahtul Syafiqah;Yusof, Robiah Binti;MA, Faiza
    • International Journal of Computer Science & Network Security
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    • 제22권7호
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    • pp.389-396
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    • 2022
  • Smartphones are growing more susceptible as technology develops because they contain sensitive data that offers a severe security risk if it falls into the wrong hands. The Android OS includes permissions as a crucial component for safeguarding user privacy and confidentiality. On the other hand, mobile malware continues to struggle with permission misuse. Although permission-based detection is frequently utilized, the significant false alarm rates brought on by the permission-based issue are thought to make it inadequate. The present detection method has a high incidence of false alarms, which reduces its ability to identify permission-based attacks. By using permission features with intent, this research attempted to improve permission-based detection. However, it creates an excessive number of features and increases the likelihood of false alarms. In order to generate the optimal number of features created and boost the quality of features chosen, this research developed an intersection feature approach. Performance was assessed using metrics including accuracy, TPR, TNR, and FPR. The most important characteristics were chosen using the Correlation Feature Selection, and the malicious program was categorized using SVM and naive Bayes. The Intersection Feature Technique, according to the findings, reduces characteristics from 486 to 17, has a 97 percent accuracy rate, and produces 0.1 percent false alarms.