• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1986-1995
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• 2018

In this paper, a novel neutral-point voltage balancing scheme for NPC three-level inverters using carrier-based sinusoidal pulse width modulation (SPWM) method is developed. The new modulation approach, based on the obtained expressions of zero sequence voltage in all six sectors, can significantly suppress the low-frequency voltage oscillation in the neutral point at high modulation index and achieve a fast voltage-balancing dynamic performance. The implementation of the proposed method is very simple. Another attractive feature is that the scheme can stably control any voltage difference between the two dc-link capacitors within a certain range without using any extra hardware. Furthermore, the presented scheme is also applicable to the single-phase NPC three-level inverter. It can maintain the neutral-point voltage balance at full modulation index and improve the voltage-balancing dynamic performance of the single-phase NPC three-level inverter. The performance of the proposed strategy and its benefits over other previous techniques are verified experimentally.

• Journal of East Asia Management
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• 제5권1호
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• pp.1-31
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• 2024

Based on the perspective of consumers and the method of value engineering, this paper uses "CSR expectation deviate level" to measure corporate social responsibility, and discusses the influence of corporate social responsibility on financial performance and its action path. This paper collected the questionnaire survey data of 878 consumers and the panel data of 98 listed companies from 2009 to 2012. The empirical results show that: (1) Consumers pay more attention to products and services, charity, environmental protection and their responsibilities to employees, and less attention to their responsibilities to shareholders or creditors and partners; (2) Corporate social responsibility is negatively correlated with financial performance, and corporate marketing ability plays a moderating role in it. That is, the smaller the gap between the level of corporate social responsibility fulfilled by enterprises and consumers' expectations, the better the financial performance of enterprises, which also reminds enterprises that they need to rationally allocate corporate social responsibility resources and constantly cultivate their own marketing capabilities, so as to better meet the level of corporate social responsibility expected by consumers. The value engineering method quantifies consumers' value perception of corporate social responsibility, which has a certain practical guiding role. Of course, there are some limitations in this paper, and future research can further explore the potential impact mechanism.

• Journal of the Korea Society for Simulation
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• 제1권1호
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• pp.87-102
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• 1992

This paper presents the development of event-driven system level simulation tool SMPLE(Smpl Extende, an extention fo smpl) and its application to the performance analysis of multiprocessor computer systems. Because of its data structure, it is very difficult to change, expand or add new functions to simulation language smpl implemented by MacDougall. In SMPLE, we change data structure with structure and pointer, add new functions, and enable dynamic memory management. Using new data structure, facilities, and functions added in SMPLE, we simulate job processing of a shared bus multiprocessor system with autonomous hierarchical I/O subsystem. We set system performance contribution of subsystems and units. The impact of disk I/O on system performance is evaluated under vairous conditions of number of processors, processing power, memory access time and disk seek time.

• Asian Journal of Business Environment
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• 제5권3호
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• pp.29-31
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• 2015

Purpose - The purpose of this country analysis is to examine its current state: economically, politically, legally, and ethically, and look at small and medium Algerian businesses to identify any issues that could hinder economic and business performance and growth. Research Design, and Methodology - This is a case study, an analytical approach, which focuses on exploring and analyzing different aspects of Algeria. Results - Since 2008, the Algerian economy has experienced a relative slowdown due to falling oil and gas prices and the economic recessions of its main trading partners, in particular, European countries. Algeria has still not managed to diversify its economy or establish competitive industrialization at the international level; it has had difficulty shifting from its economic dependence on hydrocarbons. Algerian businesses continue to face obstacles and constraints, penalized in their performance and prevented from success in a dense and competitive global marketplace. Conclusion - The Algerian economy and Algerian businesses have shown positive performance and growth over the last few decades. However, issues exist that may hinder both business and economic progress in the future.

• Structural Engineering and Mechanics
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• 제33권4호
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• pp.529-537
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• 2009

A key parameter in the design of a laterally loaded pile is the determination of its performance level. Performance level of a pile is usually expressed as the maximum head deflection and bending moment. In general, uncertainties in the performance of a pile originates from many factors such as inherent variability of soil properties, inadequate soil exploration programs, errors taking place in the determination of soil parameters, limited calculation models as well as uncertainties in loads. This makes it difficult for practicing engineers to decide for the reliability of laterally loaded piles both in cohesive and cohesionless soils. In this paper, limit state functions and consequent performance functions are obtained for single concrete piles to predict the maximum bending moment, a widely accepted design criterion along with the permissible pile head displacement. Analyses were made utilizing three dimensional finite element method and soil-structure-interaction (SSI) effects were accounted for.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제41권1호
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• pp.11-23
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• 2018

This paper investigated relationship among internal as well as external motive to receive the ISO 13485 certification, countermeasure to the certification examination, active reception/execution level of the certification, and operational as well as financial performance of the medical device related enterprises in South Korea which received and are maintaining the ISO 13485 certification. SEM (structural equation model) and related analyses using AMOS 21.0 and SPSS 21.0 have been applied to verify the hypotheses of the research. Result of the research showed that internal as well as external motive for certification positively(+) affects active reception/execution level of the certification as well as countermeasure to the certification examination. The reception/execution level of the certification also positively(+) affects on the operational as well as financial performance of the certified enterprises. However, countermeasure to the certification examination was found out to negatively(-) affects the active reception/execution level of the certification and we can interpret that relatively more countermeasure to the certification examination burdens the employees of the enterprise, causing them to be less active on the reception/execution level of the certification. This research found that an enterprise's operational/financial performance improves when an enterprise introduces the ISO 13485 certification standard spontaneously on the purpose of improving its system and the certification system is applied to the enterprise actively, not passively. This research emphasizes the need to recognize the difference of the level of active reception implication among members of an enterprise according to the motive of introduction of the certification system.

• The Journal of Korean Academic Society of Nursing Education
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• 제17권1호
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• pp.36-43
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• 2011

Purpose: The purpose of this study was to identify the level of role expectation and role performance in school health teachers recognized by nursing students experiencing health teacher practice and to compare role expectation and performance according to their characteristics. Method: The subjects in this study were 530 nursing students from 42 universities in Korea. The data was collected by a structured self-administered questionnaire and analyzed using descriptive statistics, t-test, and ANOVA by SPSS 17.0 program. Results: The student recognition in role expectation for school health teachers showed a high level and its level in the role performance was moderate. The students recognized the role expectation was greater than the role performance in school health teachers. The students' points of view for role expectation and performance were statistically different according to their practicing locations, practicing school sizes, and their expressions of health teacher's images. Conclusion: To improve health teacher training and to provide a high quality education, practice manuals, educational support, cooperation between the university and practice school, and support of human resources as school health teachers are necessary.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.17-20
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• 2008

An Electric motor is used for user-friendly equipment in vehicles. In this paper, an electric motor for windows is considered for the tunning of engineering inspection concerned with noise level from it. Noise from the electric window motor is a kind of structure-borne noise and becomes a reference parameter for its engineering performance. Estimation of noise from the motors shows the quantitative values such as overall noise. Noise level at each frequency and the qualitative figures for the transient characteristics of sound are also revealed. The loudness level, one of the qualitative parameters, distinguishes the performances of every components by the comparison of its magnitude. In summary, it is found that the qualitative comparisons become useful means for the inspection of electric motors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.6079-6097
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• 2018

Safety-related systems (SRSs) has widely used in shipbuilding and power generation to prevent fatal accidents and to protect life and property. Thus, SRS performance is a high priority. The safety integrity level (SIL) is the relative performance level of an SRS with regard to its ability to operate reliably in a safe manner. In this article, we proposed an optimal design procedure to achieve the targeted SIL of SRSs. In addition, a more efficient failure mode and effects diagnostic analysis (FMEDA) process and optimization model were developed to improve cost efficiency. Based on previous IEC 61508 diagnostic analyses that revealed unnecessary costs associated with excessive reliability, the new approach consists of two phases: (i) SIL evaluation by FMEDA, and (ii) solution optimization for achieving the target SIL with minimal cost using integer-programming models. The proposed procedure meets the required safety level and minimizes system costs. A case study involving a gas-detection SRS was conducted to demonstrate the effectiveness of the new procedure.

• Proceedings of the KSR Conference
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.584-589
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• 2002

Recently, in various industrial field standardization and performance improvement are actively on going. Noise barrier is generally used to reduce railway noise. But the effectiveness of its use is low because of low level of technology development. In this basic study, test item and its specification are suggested for standardization of railway noise barrier.