• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.425-430
• /
• 2005

This Study presents to be Agitator maintenance for Water and Wastewater treatment Plant. This procedures offers methods of Design Creteria and performance tests on mixing equipment. These tests may be conducted to determine process performance, mechanical reliability. or suitability of equipment for the intended use. The reasons for conducting performance tests can be varied, but the methods presented should be generally applicable to most situations.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.6
• /
• pp.98-111
• /
• 2009

The objective of this study is to revise the related regulations and laws of intelligent transport systems performance tests and methods. This study improves the reliability of present traffic information, reduce public discontent by systematic reforms and reduce national and social costs through the analysis of intelligent transport system performance tests'current status and problems. This study will maximize the investment profits and efficiency of ITS system as the reliability of transportation information which is created through the maintenance of ITS equipment and center, systemization of work responsibility through close analysis of ITS performance test and overall evaluation of role of ITS performance assessment organization will improve and new level of service will be born.

• Transactions of Materials Processing
• /
• v.32 no.3
• /
• pp.114-121
• /
• 2023

During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

• Journal of Power Electronics
• /
• v.14 no.5
• /
• pp.989-999
• /
• 2014

High-performance Current Source Inverter (CSI)-fed, variable speed alternating current drives are prepared for various industrial applications. CSI-fed Induction Motor (IM) drives are managed by using different control methods. Noteworthy methods include scalar Control (V/f), Input-Output Linearization (IOL) control, Field-Oriented Control (FOC), and Direct Torque Control (DTC). The objective of this work is to compare the dynamic performance of the aforementioned drive control methods for CSI-fed IM drives. The dynamic performance results of the proposed drives are individually analyzed through sensitivity tests. The tests selected for the comparison are step changes in the reference speed and torque of the motor drive. The operation and performance of different vector control methods are verified through simulations with MATLAB/Simulink and experimental results.

• Transactions of the Korean hydrogen and new energy society
• /
• v.23 no.6
• /
• pp.612-618
• /
• 2012

In this paper, in order to prevent electric shock of high voltage system of HFCV after crash test, insulation performance measurement methods were studied. Under conditions of in-use, insulation performance tests can be divided into measurement method using the vehicle's own RESS as DC voltage source and measurement method using DC voltage from off-vehicle sources. However, these tests can not be applied after a post-crash because parts of high voltage system cover should be removed, and insulation performance can be influenced during these tests. Therefore, we proposed post-crash insulation performance test methods for preventing electric shock through problem analysis of previous post-crash insulation performance tests. Also, test equipment which can measure voltage absence and total energy was developed. We verified performance of the equipment through experiments with vehicle test.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.9
• /
• pp.842-850
• /
• 2003

The suspension insulators are subjected to harsh environments in service for a long time. The long-term reliability of tile insulators is required for both mechanical and electrical performances. This study describes some basic performance tests and accelerated aging test by cool-heat cycling methods and thermal mechanical performance test methods on alumina porcelain insulators (new and aged) used for transmission line in KOREA. There was no fail in electrical and mechanical performance tests such as a high voltage strength, a flashover voltage, and an impact strength in all samples. But in the case of accelerating aging tests which have above 9$0^{\circ}C$ temperature gradient, fracture phenomena was happened by a thermal shock in tile aged sample(sample A) with low alumina porcelain body. It was indicated that sample A was more severely aged than other samples. According to results of HRB test and microstructural analysis, it was reasoned that insulator bodies with the matrix reinforced with alumina crystalline phase have advantages over the suppression of crack advance. And cool-heat aging and mechanical thermal ageing tests shows that a temperature gradient is more effective to accelerating than a cycling number.

• Journal of Applied Reliability
• /
• v.17 no.2
• /
• pp.103-111
• /
• 2017

Purpose: Accelerated degradation tests can speed time to market and reduce the test time and costs associated with long term reliability tests to verify the required service life of a product or material. This paper proposes a service life prediction method for components or materials using an accelerated degradation tests based on the relationships between temperature and the rate of failure-causing chemical reaction. Methods: The relationship between performance degradation and the rate of a failure-causing chemical reaction is assumed and least square estimation is used to estimate model parameters from the degradation model. Results: Methods of obtaining acceleration factors and predicting service life using the degradation model are presented and a numerical example is provided. Conclusion: Service life prediction of a component or material is possible at an early stage of the degradation test by using the proposed method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.387-391
• /
• 2001

In evaluating sound performance of building, it is important to carry on tests and evaluations based upon residential sound performances. Korean Standards include test methods on sound performance, but don't include any code on evaluation methods. Therefore, evaluation methods from Japan or ISO have been used for evaluating sound performance in domestic so far. In this study, a draft of Korean Standards on a sound performance evaluation method in buildings is proposed.

• Asia pacific journal of information systems
• /
• v.11 no.1
• /
• pp.139-154
• /
• 2001

Recently, more firms have shown an interest in implementing knowledge management methods. However, few companies are capable of adopting knowledge management methods effectively to improve organizational performance because it is still unclear how these methods improve corporate performance. To find this relationship between knowledge management methods and organizational performance, this paper analyses effects of knowledge management methods on corporate performance empirically. 51 Korean firms are selected as a sample base for empirical tests. Knowledge management methods can be categorized into four styles; harmony, codification, personalization, and ignorance. For example, the emphasis of harmony style is on both knowledge reusability using information technologies and knowledge sharing through informal intimacy among employees. Corporate performance varies depending on styles. Harmony style is founded to be most effective for corporate performance. Personalization and codification styles don't show any difference. This outcome is in line with the general observation that both tacit knowledge and explicit knowledge are important for effective knowledge management.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.416-419
• /
• 2008

In order to ensure the safety, the performance evaluation of the safety-related components in a nuclear power plant such as air-operated valves. In this paper, the diagnostic system(MOVIDS $A^+$) for the performance of air-operated valves was developed. For this purpose, the characteristics of their operation and the methods of the diagnostic tests were reviewed. The setup and diagnostic functions of the system were mentioned. Its applicability was validated through the diagnostic tests of air-operated valves in nuclear power plants. This diagnostic system is now applied in nuclear power plants for performance tests.