• ETRI Journal
• /
• 제10권3호
• /
• pp.157-164
• /
• 1988

In proportion to the increased density in electronic packaging from chip to system levels of telecommunication system, thermal management is becoming a vital subject to save the cost of the electronic product and to maintain high reliability. The key to the successful application of the thermal management technique is the capability to predict the equipment thermal behaviors in early stage of system development and product design. This paper describes the application of correlations of natural convection to TDX-10 digital switching system, which has been under the 5 year development project since 1987, in order to predict equipment temperature and thermal behaviors whihin a rack.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2013년도 추계학술대회 논문집
• /
• pp.227-228
• /
• 2013

The paper is related to smart maximum power system based on program logic. Especially, this system compares the total demand power with the target power by using the signal from the digital kilo watt meter. Based on the power information by the maximum power control equipment the consumed future power is anticipated. In addition, through consumed future power the controllable target power is set, and it applies on the maximum power control equipment. User or manager would control the load efficiently through the simple programming which could control load based on the control sequence and relay. So this system could control load more efficient and stable. Also the conventional load control circuit is not needed. Therefore, it is possible to improve the simple system configuration, which is resulted in cost effective and time saving. So this system is anticipated on time and coast.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1997년도 전력전자학술대회 논문집
• /
• pp.14-20
• /
• 1997

Due to several advantages of Pulse Width Modulated(PWM) Converter, such as unity power factor with low-harmonics and energy regeneration, PWM converter has been widely used in industrial application. In every application of energy conversion equipment, the design and implementation must be carried out considering performance and cost. High quality with low cost is the best choice for energy conversion equipment. High dc link voltage can reduce inverter and motor side losses and system dimension compare to low dc link voltage. Analog controller can make PWM converter cheaper without considerable degradation of the performance than digital controller. This paper shows the simplified analog controller-for 600V dc link voltage using stationary reference frame control and the simulation results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.173-175
• /
• 2003

To improve the power quality, various types of equipment are used. However, without determining the existing levels of power quality, electric utilities and customers cannot adopt suitable strategies and equipment to improve the power quality. Therefore, in this paper, power quality monitoring system is discussed.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2004년도 춘계학술대회 논문집
• /
• pp.1446-1448
• /
• 2004

Communication line used in the rail-road have different use from subscriber line in the public telecommunication. But, when an existing communication equipment is replaced, by applying new high-speed transfer technology, we can anticipate the increase of transmission rate and decrease of waiting time according to high-speed of communication line. cost reduction of infrastructure construction and maintenance/repair according to centralization of communication line and transmission equipment. In this study, the transmission scheme of several xDSL(Digital Subscriber Line) modems were compared and analyzed. The way of applying xDSL modem to the metal cable which is used in the JR(Japan Railroad) is analyzed. In addition, the result tested in railroad communication line was reviewed.

• 대한기계학회논문집
• /
• 제19권3호
• /
• pp.868-876
• /
• 1995

This study deals with a position control of an electro-hydraulic servo system which consist of cylinder and high speed on-off valves operated by microcomputer. The merits of PWM control of hydraulic equipment are the robustness of the high spee on-off valve, its low price and the direct control without D/A converter. In the PWM control of high speed on-off valve, the time lag and switching time existing between the input and output signals of valve are considered as demerit points. To get analytical results, the effects of these demerits have to be clarified in detail. The object of this study is to propose a mathematical model for the behavior of high speed on-off valve and to get analytical results of this system. The dynamic characteristics of this system is examined by digital computer simulation analytically and compared with experimental results to varify the proposed mathematical model.

• 한국응급구조학회지
• /
• 제8권1호
• /
• pp.189-197
• /
• 2004

The fate of a emergency patient is decided upon the extent of first aid in one hour after accident. Suitable diagnosis and treatment can raise the possibility of patient's life and reduce the recuperation time. We surveys papers which were The Korean Society Of Sports Medicine(1993-2004 yeas 405papers)and The Korean Society Of Emergency Medicine (1990-2004 yeas 797 papers). This paper got the following results through analyses of problems in emergency medical service system and of injures from sports. First, portable X-RAY equipment is needed to apply it to emergency. Second, it should have small and light structure compared with old equipments and have high voltage generator unit for X-RAY using inverter. Third, it should be able to send the shot data that is digital detector type without film to doctors in emergency center.

• 한국컴퓨터산업학회논문지
• /
• 제10권3호
• /
• pp.99-104
• /
• 2009

본 논문에서는 형광등 on/off 제어 및 조도를 전력선 통신을 이용하여 원격으로 제어할 수 있는 시스템을 설계하고자 하였다. 각각의 조명기기를 전력선으로 구성되는 네트워크를 구현하였으며 원격 제어 및 조명기기의 on/off 및 조도를 제어하기 위하여 서버를 구성하고 서버에서 각각의 크라이언트를 제어할 수 있도록 하였다. 또한 기존 on/off 시스템을 디지털화하여 에러율을 감소시켰으며 회로를 단순화하는데 주안점을 두었다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제16권1호
• /
• pp.21-26
• /
• 2016

Canine cataract is developed with aging and can cause the blindness or surgical treatment if not treated timely. The first observation must be made by pet owners but they do not have proper equipment and knowledge to see the abnormalities. In this paper, we propose an intelligent image processing method to extract canine cataract suspicious object from non-professional equipment such as ordinary digital camera and cellular phone photographs so that even casual owners of pet dog can make a pre-diagnosis of such a surgery-needed disease as soon as possible. The experiment shows that the proposed method is successful in most cases except the dog has similar colored hair to the color of cataract.

• 한국군사과학기술학회지
• /
• 제10권2호
• /
• pp.84-89
• /
• 2007

MIL-STD-461E, EMI military standard for the equipment and subsystems, requires reception characteristic tests to verify the susceptibility of a receiver against the jntermodulation and spurious signals. Because the CS103 and CS104 of MIL-STD-461E show the test configuration of the equipment unit like a traditional receiver, it is possible to verify the susceptibility only for the reception signal through analog filters. However, at present when software programming techniques make a progress, the CS103 and CS104 tests need to evaluate the reception signal of the subsystem which includes both the digital filtering effects and analog filter characteristics. These test and evaluation techniques applied to a surveillance radar subsystem. This paper researched the EMI test methods in order to confirm feasibility of these test and evaluation techniques. Also the test results are compared and analyzed.