• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1288-1292
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• 2007

Because the indoor spaces of the passenger cabin is generally airtight to secure the safety of passengers and enhance the efficiency of the cabin air conditioning performances, the contamination pattern of them are largely similar to that of general indoor spaces. Therefore, continuous supply of outdoor air is required to keep the amenity of indoor space. Heating, ventilation, and air-conditioning (HVAC) system is composed of air cleaning filter, heater and air conditioned, blower and ducts. To achieve the clean indoor environment, an integrated control of each HVAC equipment are required. In this study, we developed the air cleaning system to enhance the amenity of the railroad passenger cabin.

• 공업화학
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• 제30권6호
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• pp.643-651
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• 2019

Polybenzimidazole (PBI), an engineering polymer with well-known excellent thermal, chemical and mechanical stabilities has been recognized as an alternative to high temperature polymer electrolyte membranes (HT-PEMs). This review focuses on recent advances made on the development of PBI-based HT-PEMs for fuel cell applications. PBI-based membranes discussed were prepared by various strategies such as structural modification, cross-linking, blending and organic-inorganic composites. In addition, intriguing properties of the PBI-based membranes as well as their fuel cell performances were highligted.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.900-905
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• 2004

Development of color printer, postal classification machine, ATM and so on requires higher moving performance of the flat belt. Skew of the flat belt running over misaligned roller has a bad effect on performances of media transport. The vibration of loose side of belt causes the escape of the belt from roller and the drop of velocity of driven roller after the start of driving roller revolution. The skew of flat belt is investigated by FEM and dynamic simulation. FEM results show parameters which affect the skew of belt and match with dynamic results qualitatively. The shape of loose side of belt can be found by dynamic simulation. Increase of the acceleration time and initial tension have diminished the unstable movement of the loose side of belt.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.151-156
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• 2000

The sound insulation performance of walls and floors for air-borne and structure-borne sounds in an apartment building is an important environmental factor which should be contemplated at the intial design stage for their thorough control. Recent increasing residents' demands for quality living spaces strongly urge the development of more accurate and efficient measurement and evaluation methods for the control of air-borne and structure-borne sound insulation. However, steel-structured apartment buildings, recently emerged as new building structures in the market, have not been thoroughly examined. The present work carried out an extensive survey for steel-structured apartment buildings, in an attempt to provide useful design data, and their sound insulation performances were compared with those of R.C. apartment buildings.

• Tribology and Lubricants
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• 제20권1호
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• pp.33-40
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• 2004

This study represents the newly advanced formulation of hydraulic fluids for extended drain interval and introduces the performance results of used oil samples from various excavators. The used oil samples, in this paper, show that there is a sharp change in viscosity drop and moderate additive depletion when viscosity index of hydraulic oil is very high. For the extension of hydraulic fluid life, it is necessary to improve the stability of viscosity and oxidation. New target properties from the used oil analysis were proposed for extended life. Performance of newly developed hydraulic oil based on used oil analysis is compared with previously used one. The properties of new formulation are the viscosity index of 140 and improved thermal stability consists of VHVI base oil. Field test results showed the possibility of extension of fluid life. Additionally, for development of high performance product, new required propertied and performances were discussed.

• 제어로봇시스템학회논문지
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• 제3권4호
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• pp.415-421
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• 1997

A car driving trainer for beginners developed under PC-based environment is described in this paper. For this trainer, a hardware is implemented as a practice car, and a trainer program is designed by computer image generation method to display 3-dimensional images on a CRT monitor. The trainer program consists of 3 main parts, that is, a speed estimate part, a wheel trace calculation part and a driving image generation part. Furthermore, a map editor is also installed for taking any test drive. After comparing this driving trainer to specify it was verified that the developed car driving trainer showed has good performances, such as lower cost, higher resolution and better image display speed.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.453-461
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• 2008

In this paper, new inspection method is proposed for the surfaces of lead frame and IC's. Optimal optical system and the accurate algorithm for the surface inspection are needed in machine vision area. The proposed optical system is composed of rectangular oblique light illumination and coaxial light illumination for the higher contrast and the results shows the better performances through experiments. The markings of IC surface are inspected using the accurate proposed method using the partitioned correlation coefficient, and the result shows reduction of under kill ratio compared to the previous method.

• 전자공학회논문지C
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• 제35C권8호
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• pp.68-74
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• 1998

The neural network predictiv econtroller (NNPC) is proposed for the attempt to mimic the function of brain that forecasts the future. It consists of two loops, one is for the prediction of output (NNP:neural network predictor) and the other one is for control the plant(NNC: neural network controller). The output of NNC makes the control input of plant, which is followed by the variation of both plant error and predictin error. The NNP forecasts the future output based upon the current control input and the estimated control output. The input and the output data of a system and a new method using evolution strategy are used to train the NNP. A two-step NNPC is applied to control the temeprature in boiler systems. It was compared with PI controller and auto-tuning PID controller. The computer simulaton and experimental results show that the proposed method has better performances than the other method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.214-216
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• 2005

The PAL (Pohang Accelerator Laboratory) is persuading to construct a SASE-XFEL facility (PAL XFEL) that supplies coherent X-rays. The bright and stable electron beam is essential for the PAL XEL. The electron beams has to have an emittance of 1.0 mm-mrad, a peak current of 3 kA, and a low energy spread of 1.0 MeV. In order to provide reasonably stable SASE output, the RF stability of 0.02% rms is required for both RF phase and amplitude. This is a technologically challenging issue for PAL XFEL. An inverter technology is to be applied to charge the PFN of a new modulator. Therefore, a new inverter system should provide very stable charging performances. This paper presents the development of an ultra stable klystron-modulator with an inverter power supply.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1935-1937
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• 1996

This paper deals with ACSR(Aluminum Conductor Steel Reinforced) inner corrosion detection using a detector which automatically runs on an ACSR transmission line and inspects the inner corrosion of the conductor by utilization of the nondestructive eddy current test. And the relationship between the corrosion grades and the tensile strength can be estimated by means of this test. According to corrosion appearance and development of ACSR, the impedance change of the eddy current coils is theoretically verified. And then specifications And performances of the detector are described. Experimental procedures and desirable test results are reported. In conclusion, this detector can realize the nondestructive detecting of an ACSR inner corrosion. Upgrading the maintenance effciency and improving the reliability of transmission line would be expected by this nondestructive test method.