• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.175-177
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• 2007

This paper is concerned with a performance analysis using a wired/wireless gateway based on DeviceNet. For the performance analysis, the data transmission time between DeviceNet and the wireless devices is investigated and analyzed. The experimental results show the perfom1ance in terms of the polling/COS service time and end-to-end delay.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.367-372
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• 2005

This study primarily is concerned with a new device which has been developed following the international standards to measure the ventilation performance at elevated temperature. This device can measure duration of ventilation, performance of electricity, static pressure at elevated temperature and also it is having provision to measure reversible performances during fire hazards. Invented device is closed circuit type system which is best suited for korean industrial environment with low cost and high efficiency. International standards has been compared and performance testing has been major using BS 7346 which is tested by Warrington Fire Research Centre.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.723-730
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• 2006

In the electrical railway, the tension ascension of contact wire is essential to speed up of train and current collection performance of catenary largely depends on the tension. The tension variation rate of the tensioning device used in existing line limits within 5%, and the tension variation rate of the spring-type tensioning device installed at the section where tensioning length is short bounds within 15%. So it is urgent for us to localize it for high speed line, which the tension variation rate is limited within 3%. Therefore in this study, a pulley-type tensioning device for high speed line is developed. To verify the performance of developed device, a performance test, overload test and failure test is carried out under the code of the Kyung-Bu High Speed line. And it is secured durability performance through a fatigue test.

• Journal of the Korean Society of Visualization
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• v.21 no.3
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• pp.23-32
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• 2023

This study aims to explore the heat transfer and flow phenomena inside an instant water heater and the influence of the design parameters of the water heater on the heating performance was investigated by 3-D numerical simulations considering heat convection. The design parameters are the heating ceramic dimension, the power of the heating device, and the water flow rate. The results show that a reasonable space for the heating device is required to optimize the heating performance. It is desirable to design higher heating device as possible for a given electric power. There exists a critical water flow rate that best meets the heating performance. The change in electric power has no impact on the flow phenomena and heating performance.

• The Journal of Information Systems
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• v.30 no.1
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• pp.85-104
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• 2021

Purpose This study aims to verify the mediating effect of the utilization performance of digital device on the relationship between user attitude and life satisfaction. Design/methodology/approach Using the data of 2018 Digital Divide Survey conducted by the National Information Society Agency(NIA), the mediating effect was verified by Baron & Kenny (1986)'s 3 step process, targeting 1,662 adults older than 55. Findings The result is as follows: first, the user attitude of middle and older aged people has a positive effect on their life satisfaction. Second, the effect of user Attitude towards Digital Device of middle and older citizens is partially mediated by the utilization performance of digital device. The results of this study indicate that when providing informatization education in the local community to promote the use of digital devices for the elderly, efforts should be made to grasp the level and inclination of informatization individually, and furthermore present improvements for wireless devices that the elderly can easily access in their daily lives. This study is expected to be a groundwork for a practical intervention to boost positive attitude towards using digital device to enhance the utilization performance of digital device and the life satisfaction of middle and older aged people.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.1
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• pp.99-111
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• 2010

Recently, a very large vessel's maneuvering performance, rudder performance and rudder design's importance is considered to be an important subject. There have been few studies on the design process of rudder device before. The aim of this paper is to investigate a design process of rudder device and to propose a generalized design process of rudder device. Firstly, we investigated the rudder device design process of Korean major shipyards. And the differences of a torque calculation method, rudder section design, maneuvering performance examination method, etc were analyzed theoretically. Secondly, the design process of rudder device was divided into concept design, initial design and detail design. In concept design, a rudder area was estimated and its validity was examined. In initial design, rudder profile and design method has been selected through rudder form determination process. And principal dimension and steering gear capacity were determined. Maneuvering performance was also examined by simulation tool. In detail design, design criteria considered in rudder initial design has been investigated thoroughly. Also a rudder torque, rudder cavitation performance and rudder structure analysis were estimated. And maneuvering performance was also examined by model test. Finally, based on the results of investigation, the design process of rudder device was generalized and proposed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2535-2539
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• 2003

The haptic system becomes an essential device in the area of tele-operation, video entertainment and medical operation. To control a haptic device, impedance control method is widely used, but force sensor costs so much that open-loop control method is usually preferred for commercial purpose. In this case, modeled/un-modeled dynamics affects the performance of device. In this paper, we present a new 3DOF five-link type haptic device that we can reduce the effect of device dynamics and compensate its dynamics. We also evaluate its performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.598-606
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• 2013

After the missile is launched, the umbilical connector should be separated from it without any physical interference. The umbilical separation device, for this purpose, was developed by means of new concept. Using the investigation of various methods to separate the umbilical connector, a suitable method was selected and a corresponding device was designed and manufactured. To ensure the performance of the developed device, numerical analysis and performance test were conducted and correction was followed. The umbilical separation device was applied to real system operation test and its operation performance was tested. In consequence, several problems were founded, however, good results were generally obtained.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1103-1107
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• 2016

The automatic tensioning device of the catenary system constantly maintains the tension of the trolley wire by absorbing the variations due to the elasticity of the line caused by temperature variation. The tension plays an important role in affecting the electric motorcar operation directly. This paper suggests the methodology of the life cycle extension and the maintenance of the automatic tensioning device by means of performance diagnosis of the pulley type automatic tensioning device which has been commonly used for the electric railway system. Through conducting performance diagnosis and comparative test for the wornout pulley type automatic tensioning device by replacing the components such as the bearing and the bearing shaft without replacing all the assembly, the tensioning device is analyzed whether it is properly functioned. Provided that the maintenance regulation is reinforced so as to implement the bearing replacement through periodical precise inspection along with random check-up inspection which is now carried out by the operating organizations, it is ensured that the life cycle extension and the reduction of maintenance cost of the tensioning device could be achieved.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.78-84
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• 2012

The purpose of this study is to investigate the performance characteristics of new exhaust heat recovery device for the engine's fast warm-up. In this study, two different interior area designed for prototyping and on the exhaust heat recovery device to evaluate the performance compare the performance characteristics were chosen a better product. A company's product and selected prototype-2 were evaluated and compared the performance. This experiment was conducted under the same conditions. The time from starting to warm-up of engine was measured. As a result, the performance characteristics of the prototype-2 was not higher than that of the A company's product. However, in comparison with base system, prototype-2 of the exhaust heat recovery device discover that the warm-up time was shortened.