• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.3133-3141
• /
• 2011

The next generation domestic high speed railway system is a power distributed type and uses vector control method for motor speed control. Nowadays, inverter driven induction motor system is widely used. However, recently PMSM drives are deeply considered as a alternative candidate instead of an induction motor drive system due to their advantages in efficiency, noise reduction and maintenance. The next-generation high speed train is composed of 2 converter units, 4 inverter units, and 4 Traction Motor units. Each motor is connected to the inverter directly. In this paper, the effect of IPMSM parameter variations to the system operation characteristics of the multi inverter drive high speed train system are investigated. The parallel connected inverter input-output characteristics are analyzed to the parameter mismatches of IPMSM using the 1C1M control simulator based on Matlab/Simulink.

• 대한임베디드공학회논문지
• /
• 제12권2호
• /
• pp.97-103
• /
• 2017

Thermal imaging is mainly used in military equipment required for night observation. In particular, technologies of uncooled thermal imaging detectors are being developed as applied to low-cost night observation system. Many system integrators require different specifications of the uncooled thermal imaging camera but their development time is short. In this approach, EOSYSTEM has developed a small size, TEC-less uncooled thermal imaging camera module with $32{\times}32mm$ size and low power consumption. Both domestic detector and import detector are applied to the EOSYSTEM's thermal imaging camera module. The camera module contains efficient infrared image processing algorithms including : Temperature compensation non-uniformity correction, Bad/Dead pixel replacement, Column noise removal, Contrast/Edge enhancement algorithms providing stable and low residual non-uniformity infrared image.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.406-408
• /
• 1996

This paper describes the BLDC motor which is applicated for a top front loading domestic washing machine. This motor is adopted direct drive washing machine without gear-belt-pulley system. Because gear box is removed, machine volume and noise are reduced. Moreover mechanical troubles in gear box are removed. Realization of variable speed region through of PWM control and high speed is able to efficient washing and spinning.

• 한국항공운항학회지
• /
• 제18권2호
• /
• pp.1-8
• /
• 2010

In order to determine the possibility of using NDGPS signals for flight operations, in-flight measurements of signals transmitted from various ground reference stations(RS) were conducted along the air routes of South Korea. Signal strength and signal to noise ratio(SNR) data were collected along domestic flight routes and recorded with time. By using three-dimensional geographical position data of the aircraft, signal strength data of en-route position were calculated and used to obtain scatter-plot of signal strength. These results were used to outline the effective coverage and field strength hemispheres of the selected DGPS signals.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.40-43
• /
• 2003

An electric propulsion system integrated with the ship service distribution system offers the naval architect considerable flexibility, and often the choice of a more affordable ship to acquire and operate as compared to a segregated mechanical drive option. United States of America navy announced in 2000 that they selected the electric propulsion system on next generation warship. Specially there is excellent advantages in superconductivity motors which can have higher efficiency, less vibration and noise, smaller dimensions compared with the conventional motors. The 5 MW HTS motor for warship test of electric propulsion was developed and tested. Also it was contracted between AMSC and United States of America navy to develop a 36.5 MW HTS motor in 3 years since March 3, 2003. This paper deals with the technical development tendency of HTS motors in foreign countries as well as in domestic, and it is focused on the application of HIS motors to the electrical propulsion system.

• 한국철도학회논문집
• /
• 제2권3호
• /
• pp.54-60
• /
• 1999

In this paper, design and construction process for the standardized electric motor car according to standard specification is described. Aluminum extrusion profiles and power and control system made domestically are used in the electric motor car. Also, plug-sliding door system for noise reduction and automatic train control system are developed and applied. Through the development of the electric motor car, most electric and control systems can be substituted by domestic standard systems, and safety and reliability of electric motor cars can be secured.

• 전자공학회논문지A
• /
• 제31A권10호
• /
• pp.10-20
• /
• 1994

This paper presents a CATV SMS (Status Monitoring System) using HDLC (High Level Data Link Contorl) protocol and the system implementation.The system specifications were derived from the analysis of technical status and requirement of the domestic CATV industry. For the interoperability with a global network management system in the future, HDLC protocol was adopted in the system. The system performance was improved by using the communication controller chip and the large data buffer. For reducting the communication problems induced by accumulated noise in up-stream data channels, the system was designed that the different communication channel can be assigned to each proper mass of terminal. The operating software was designed with menu driven user interface and have various functions for the convenience of users. The test result of the implemented system at the experimental network showed good performance and suitability for a coaxial CATV Status Monitoring System.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
• /
• pp.699-702
• /
• 2005

This study evaluates the properties of porous concrete for pavement according to content of silica fume and steel fiber. The results of the test indicate that in every condition, the void ratio and the coefficient of water permeability of porous concrete for pavement satisfy both the domestic standards and proposition values. Among the properties of strength, the compressive strength satisfies the standards in the specification of KNHC as for every factor of mixture but in the case of the flexural strength, more than $0.6vol.\%$ of steel fiber satisfied the JCI proposition values. The case when silica fume and steel fiber are used simultaneously presents the strongest durability and Noise Reduction Coefficient is 0.48 to prove that it possesses almost $50\%$ sound absorption.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
• /
• pp.144-149
• /
• 2000

Porous cement concrete was developed to prevent hydroplaning of airway pavement or to reduce noise emission in highway. In has been introduced in domestic since early 1980' and applied to a pedestrian road or bike way. The concrete, however, has problems such as lack of optimized mix design, low strength and deterioration, etc. The purpose of this study is to manufacture porous cement concrete using blast-furnace slag to enhance mechanical properties. The results of this study are as follows; the compressive strength range is 102∼247kgf/㎠, the tensile strength range is 16∼70kgf/㎠, the bending strength range is 43∼70kgf/㎠, and the coefficient permeability range is 6.79 ×10-2∼1.17∼10-1cm/sec. To develope high-performance porous concrete, further studies are needed on optimum mixture of fineness modulus and admixture.

• 전자공학회논문지A
• /
• 제31A권5호
• /
• pp.58-67
• /
• 1994

In this paper, It was designed the 2.8GHz local oscillator which convert 14.5 14.8GHz uplink frequency to 11.7 12.0GHz downlink frequency by the receiving mixer on the communication satellite transponder according to the rating of domestic satellite. Mukunghwa 1. To prevent the variation of the communication channel bandwidth, it needs a high stability and low phase noise characteristics. So we designed to get the target frequencey by multipling the output signal from the crystal oscillator. We got the simplicity of the circuit by manufacturing the X4 multiplier with transistor which is ordinarily used as a device of a below X3 multiplier for the efficiency.