• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.521-524
• /
• 2003

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250kHz and some specific conditions.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.32 no.5
• /
• pp.430-436
• /
• 2008

This paper proposes a way to predict electrical lifetime of a relay using Accelerated Life Testings (ALTs). The relay of interest mounting on printed circuit boards is usually under an inrush current stress. The inrush current is generated and accelerated through controlling a lamp switching device in the ALT. We find that the dominant failure mechanism under high levels of inrush current would be contact welding in the contact surface of the relay and the contact welding process is accelerated according to increase in inrush current. The electrical lifetime model based on Inverse Power Law in term of inrush current is proposed, and parameters characterizing relay's lifetime distribution are statistically estimated using ALTA 6 PRO software.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2031-2034
• /
• 1999

현재 우리나라에서는 도로망의 급속한 확충에 따라 터널의 수가 급속히 증가하고 있다. 터널은 운전자들이 주야간으로 안전하고 쾌적하게 주행할 수 있도록 설계되어야 한다. 이런 관점에서 터널의 조명설계는 매우 중요하다고 할 수 있으며, 터널의 안전성, 쾌적성, 경제성을 확보하기 위한 여러 가지 복합적인 요소들을 고려한 분석이 필요하다. 이 논문에서는 터널조명에 일반적으로 사용되고 있는 저압나트륨등에 대하여 대안으로 대두되고 있는 형광등에 대한 경제성 측면에서의 비교 방법론 연구를 수행한다. 각각의 등에 대하여 동일 한 터널 노면기준조도를 구현하기 위한 필요 등의 수를 시뮬레이션을 통하여 결정하고, 이를 기반으로 각 터널 조명에 소요되는 Life Cycle Cost를 기본 Model을 통하여 산정하고 비교하는 방법을 제시한다. 이러한 분석은 터널개발 사업의 정책적 결정에 있어 기초 방법과 자료로서 활용될 수 있을 것이다.

• Journal of Applied Reliability
• /
• v.11 no.3
• /
• pp.267-279
• /
• 2011

LEDs have been used extensively in the mobile device, automobile, and general lighting because they are semi-permanent, long life, less power consumption, reliable and environmentally friendly. In this paper, the accelerated degradation test(ADT) for a general lighting 4W LED Lamp using external converter is considered. The conditions of ADT are high temperature and high humidity. We show that its life time is log-normally distributed with same parameters under both a normal condition and an accelerated condition, and also derive an accelerated factor.

• IE interfaces
• /
• v.14 no.2
• /
• pp.205-209
• /
• 2001

The number of tunnel has fast increased with the rapid expansion of highway network. Tunnel should be designed to provide for drivers both safety and pleasant driving conditions. In this perspective, the design for tunnel lightning is very important in order to provide its safety, pleasantness, and cost-efficienty of maintenance, all of which should be considered and analyzed for a better tunnel lighting. This paper attempts to compare the low-pressure sodium lamp, which has usually been used for tunnel lighting, with the fluorescent lamp, which we consider as an alternative for the former. In an effort to determine the number of lamps to meet the required illuminance in the tunnel, this research employs a simulation technique which would allow us to conjecture, with the aid of basic model, the life cycle cost for illumination per each tunnel. This analysis is expected to provide a basic method and related information for tunnel development and design.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.10
• /
• pp.1543-1552
• /
• 2019

Salmonella is a common zoonotic and foodborne pathogen that causes high morbidity and mortality in developing countries. In this study, we established and validated a polymerase spiral reaction (PSR) assay which targeted the conserved invasion gene (invA) of Salmonella by SYBR Green I indicator methods. Subsequently, assays for determination of the optimal conditions for optimal specificity and sensitivity of PSR were performed. We performed comprehensive evaluations using loop-mediated isothermal amplification (LAMP) and real-time PCR. A total number of 532 samples of daily food were analyzed by PSR. Twenty-seven bacterial strains were tested in the specificity assay, from which positive results were obtained only for 14-Salmonella strains. However, none of the 13 non-Salmonella strains was amplified. Similarly with LAMP and real-time PCR, the detection limit of the PSR assay was 50 CFU/ml. The PSR method was also successfully applied to evaluate the contamination with Salmonella in 532 samples of daily food, corroborating traditional culture method data. The novel PSR method is simple, sensitive, and rapid and provides new insights into the prevention and detection of foodborne diseases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.5
• /
• pp.552-559
• /
• 2004

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficiency replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program(Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 KHz and some specific conditions. The optical characteristics were measured luminance and a temperature and an optical spectrum distribution for 10 min in a one minute interval at the same time. With a goal of finding alternative materials, we show measurement results of electrical characteristics of a ring-shaped electrodeless fluorescent lamp as a function of frequency and the number of coil turns using a highly permeable($\mu$$_{r}$(equation omitted) 2,000) Mn-Zn ferrite. These results are compared with those of conventional ring-shaped electrodeless fluorescent lamp. It is found that the resistance, inductance and impedance are increased while the quality factor decreases as frequency increases.s.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.33 no.12
• /
• pp.947-951
• /
• 2009

LED has the merits of high reliability, semi-permanent life, rapid-response and its small size for use as light source of head lamp. But the dependence of its performance and life on temperature affect on its practical use. Which dependence makes problem when the LED is heated up to a higher temperature level by self-generation of heat, due to "highly integration" to get enough quantity of light. To solve this problem, effective cooling system is needed that consider conduction, convection and radiation. This study points out the limits of natural convection cooling system and propose of forced convection with heat sink. Also, it describes a correlation between heat sink area and fluid velocity using numerical analysis to optimize the cooling system.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1673-1674
• /
• 2006

The most ideal light source known to the mankind is sunlight. Therefore, whenever an artificial light source is needed in a dark place such as in a shadowed houses, the utmost goal is to find an artificial light characteristics of which approaches that of sunlight. On this ground, we have investigated a Neodymium lamp as a possible substitute for sunlight. Especially, the local and the color rendering, a life expectancy, and the overall efficiency are carefully studied.

• Journal of the Optical Society of Korea
• /
• v.19 no.4
• /
• pp.409-414
• /
• 2015

Light-emitting diodes (LED) have many advantages for dental astral lighting because of their high color rendering index (CRI), low power consumption, light weight and longer life. A dental astral lamp is specially designed and simulated for securing the extra space for installing a multimedia display that will be helpful for treating young patients. The optical system using the reverse dual reflection method consisted of four illumination modules disposed at the four corners of the dental astral lamp, and each module comprises a high power LED, an elliptical mirror, and a multifacet reflector assembly using eight cylindrical mirrors. It is shown that the required illuminance, illumination pattern, and the illumination uniformity are well satisfied.