• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.514-519
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• 2011

Recently, the interest in technologies for a highly efficient powertrain, i.e. a variable displacement engine or a light weight car body, to improve the fuel efficiency of automobile saving the environment has been increased. However this trend deteriorates NVH performance of a vehicle and the use of a conventional engine mounting system becomes unsatisfactory. In order to solve this dilemma, an active engine mounting system that could isolate or cancel out vibrations occurred at the powertrain was suggested. In this paper, In order to optimize the electromagnetic active engine mount performance, the actuator of the engine mount through FEM analysis and optimal design, noise and elastomer testing of the prototype through the optimal design of actuators for the electromagnetic active engine mount on the impact of the performance improvement is verified.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.10
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• pp.1380-1391
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• 1997

A 150 m$^{3}$/hr, 30 kg/cm$^{2}$, air-cooled 3-stage reciprocating air compressor is designed to be used in starting large diesel engines. A basic design procedure is presented to meet the targeted pressure and flow rate, and especially the volumetric efficiency. Temperature and stress analyses of the cylinder are performed using FEM modelings. The dynamics of valve system is analyzed and stress at the valve seat due to valve impact is evaluated. To reduce friction loss and wear at the compressor engine system, tribological design practices are suggested. Fin-type coolers are designed to dissipate generated compression heat at each stage. Finally, a prototype is manufactured and performance test is carried out utilizing an air tank. Performance results are compared to the design targets, other foreign specifications, and some quality standards.

• Journal of the Korea Society of Computer and Information
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• v.20 no.9
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• pp.97-104
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• 2015

Recently, the need for real-time systems which are providing various types of information that occur in large quantities in IoT environment is increasing. In this paper, we propose a middleware system which can monitor in real time on a web environment. The proposed system is designed to be integrated by using communication functions provided by a network operating system and external sensors. The proposed system is compared with an existing system and analysed by the server performance testing tool.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.70-77
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• 2017

Dynamic visual acuity is used as an important factor to measure athletic performance in sports field. A study on visual acuity testing system using non-see head mounted display (NST-HMD) was conducted recently. However, the NST-HMD has a problem that the sense of space felt by the subject differs from the actual environment. This is because the view is blocked so that it is only implemented in a virtual space. This paper proposes a dynamic visual acuity testing system using optical see through head mounted display (OST-HMD). To do this, OST-HMD and NST-HMD comparative tests were conducted using existing K-D (King-Devick) charts. Experiments were performed on 30 subjects and their visual acuity was measured and analyzed by parametric statistics and one-sample T-test. The results of the study demonstrate the effectiveness of the proposed OST-HMD. This study is expected to use the visual inspection and training equipment of OST-HMD.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.146-151
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• 1993

A new hydrodynamic mock circulation system was developed, which can test prosthetic heart valves of various sizes in order to obtain valve parameters, such as pressure drop, regurgitation and valve performance index with a high reproducibility. High reproducibility can be obtained only under equal testing conditions, i.e., the compliance, resistance and inertance of the mock circulation system must be constant parameter estimation using actual pressure and flow data was applied to calculate these systemic variables in order to adjust them to create the necessary equal testing conditions.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.397-398
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• 2016

This paper analyzes switching losses, efficiency and temperature depending on Si and SiC devices applied in two stage AC-DC converter. To evaluate the charge and discharge performance and stability of the battery pack, there is a need for a battery pack testing system. To do battery charge and discharge experiment used in battery pack test, A topology, two stage AC-DC converter, has been built. SiC devices more decrease switching losses than that of Si. Also, cooling system was applied in Si and SiC devices. When using SiC devices, it can be confirmed that the size of heat sink is reduced for small loss.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.296-303
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• 2007

This paper proposes a new width control system composed of an ANWC(Automatic Neural network based Width Control) and a fuzzy-PID controller in hot strip finishing mills which aims at obtaining the desirable width. The ANWC is designed using a neural network based width prediction model to minimize a width variation between the measured width and its target value. Input variables for the neural network model are chosen by using the hypothesis testing. The fuzzy-PlD control system is also designed to obtain the fast looper response and the high width control precision in the finishing mill. It is shown through the field test of the Pohang no. 1 hot strip mill of POSCO that the performance of the width margin is considerably improved by the proposed control schemes.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.182-183
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• 2006

It has been studied about the important consideration in designing and construction of the reliability assessment facilities including the combined testing system for simulating condition of acceleratedly deteriorated environment, which enable to test and evaluate the large-sized HV power apparatus without any disassembly up to transmission class in this paper. Also it is described simply about its ratings and main technical specifications and trial running of the system. To evaluate the performance characteristics against combined test condition for various power installation, especially for the polymer type insulators and kinds of bushings, brief investigation and an analysis of test objects and related international codes and standards have been conducted.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.296-299
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• 2013

A low density lipoprotein (LDL) cholesterol testing device, structured with serial reflected face-to-face mirror (SRM) allowing spectrophotometry measurements, is presented. The spectrophotometry has been employed to measure the amount of light that a sample absorbs, but it generally should have had path length longer than 10 mm to secure enough sensitivity. Such requirement of path length has often been problematic in implementing a thin type of lab on a disc (LOD). We developed the SRM system which was implemented in a detection chamber with 1.4mm thickness, providing path length longer than 10mm, and thus straightforwardly being applicable to LOD as thin as a compact disc. The experimental results show that the SRM system gives not only a much thinner design compared to the conventional spectrophotometry-based LOD but also a comparable performance to already commercialized spectrometers.

• The Journal of Korea Robotics Society
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• v.19 no.1
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• pp.71-78
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• 2024

The paper presents a hardware-in-the-loop (HIL) system designed for satellite movement testing in the microgravity environment on the ground with two industrial robots. Especially, the paper deals with the contact between satellites during rendezvous and docking simulations of satellites using a robotic HILS system. For this purpose, the admittance control method plays a core role in preventing damage to the satellite or robot from contact force between satellites. The coordinate frames are transformed into the mass center of the satellite and the admittance control at the level of exponential coordinates is adopted to actively use the properties of Lie groups related to tracking errors. These methods effectively mitigate the risk of robot damage during inter-satellite contact and ensure efficient tracking performance of satellite movements.