• Journal of Digital Convergence
• /
• v.14 no.4
• /
• pp.419-424
• /
• 2016

In this paper, we studied a light distribution for the LED chips arrangement using an optical design software. The structures of the edge type LED luminaires are reflector plane, LGP(lighting guide plane) and diffuse plane. The reflector plane is on the middle of the overall structure. We had simulation that placing LED chips on the reflector center of the reflector edge by changing the position of LED chips above the reflector center at 1mm, 2mm, and 3mm respectively. In the case, when LED chips are on the center of the reflector, it shows the light distribution of the general diffuse illumination, the semi-direct distribution with 0.56 efficiency and the direct distribution with 0.31 efficiency. And the wedge type LGP shows more efficiency than the flat type. Gradually increasing shape of semi-spherical type by 0.015mm has power of 1.02W, efficiency of 0.25, and maximum luminous intensity of 0.104W/sr, it also and shows the better optical characteristics than the reflector plane that have no patterns. This semi-spherical type shows the better optical characteristics than the reflector plane that have no patterns.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.5
• /
• pp.213-217
• /
• 2015

Seoul has 25 areas of City Hall, the ward office has been operating theater at least 1 in maximum 4-5 locations to various sized places. The purpose of theater has been used for a variety of purposes to typical performances of Drama and Musicals, School play, Lecture. This points to a Variety of ideas for use, when replacing an exsting halogen luminaires, appropriate LED luminaires, Learn more if there is any advantage in terms of the energy saving part. it will be applied to the value for the energy saving to ward office hall of the actual targets. In case replacement in existing halogen luminaires to LED luminaires, to energy savings of about 80% appear around. Get the advantages of the various functional properties a device chip of the LED itself, Forward will be referred to as easy to replace the halogen luminaires and LED luminaires.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.6
• /
• pp.51-59
• /
• 2002

This paper deals with the measurement and analysis of the induced voltages and magnetic fields caused by the operation of home appliances. The induced voltage and magnetic field measurement circuit used in this work consists of the induction coil, the operational preamplifier and the active integrator. Television set and monitors for personal computer cause strong magnetic fields rich in harmonics and high induced voltages by using the switching power suppliers. The strong magnetic field intensity and high induced voltage were created by 14" television set, and their values are 2.1 ［$\mu$Tp-p］and 140 ［mVp-p］at the distance of 0.4 ［m］, respectively. However, the induced voltage per unit magnetic field intensity was created by 17" monitor for personal computer and the measured data was approximately 560［mV/$\mu$T］at the same distance. distance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.9
• /
• pp.47-54
• /
• 2008

Cost reduction requires lowering number of power devices used in the converter driving SRM. This is quite feasible in SRM drive systems than in other drive systems. This paper deals with analysis and simulation of a novel two phase SRM. A novel two phase SRM has high performance, self-starling capability, high efficiency, and low manufacturing cost. Additionally, the stator back iron does not experience any flux reversal as the flux is in the same direction whether phase A or B is excited leading to a greater reduction in core losses. The magnetic analysis and design considerations of the novel two phase SRM have been obtained by the finite element analysis (FEM).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.30 no.2
• /
• pp.78-84
• /
• 2016

This paper is focused on the measurement and analysis of an atmospheric electric field which is caused by thunderclouds. The electric field due to thunderclouds changes very slowly. For this reason, the extremely low frequency E-field sensor needs to be used for measuring the atmospheric electric field strength. The balloon-carried E-field sensor system with the time constant of 1sec was designed and fabricated. The electric field sensor consists of $100mm{\times}100mm$ copper plate, active integrator, high pass and low pass filters and batteries. The measurements of atmospheric electric fields were made by the balloon-carried E-field sensor and radiosonde, which sends the data back to ground in real time. From the calibration experiments, the response sensitivity of the E-field sensor was 0.154mV/kV/m in the frequency range of less than 1kHz. As a result from the actual experiment of the atmospheric electric field, the electric field signals were observed from the altitude of about 2.5km. Also, as the altitude was increased, the detected electric field wave oscillated with the fluctuation of sensing plate. The proposed method seems suitable for measurements of atmospheric electric fields, because it is inexpensive, simple to use and launch.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.145-148
• /
• 2009

It is sharply decreasing from several hundred[lx] to 1.0[lx] when it turn on the emergency lamps. The sharply decreasing illuminance makes peoples to have dark adaptation for long time. And they were with fear and confused. It also causes secondary accidents by people who take a mistake. This paper studied the combination style emergency lighting fixture to improve a problem of dark adaptations. But it was made an assumption that same conditions of battery capacity and a number of emergency lamps.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.5
• /
• pp.467-472
• /
• 2011

The heat transfer over a radial heat sink, adapted for LED (light emitting diode) downlights, was experimentally and analytically investigated. We added radiation heat transfer into a previous calculation that neglected this factor. The numerical results agreed well with experimental results. Parametric studies were performed to compare the effects of the geometric parameters (fin length, fin height, ideal number of fins) and the operating parameter (heat flux) on the average heat-sink temperature from the heat-sink array. We found the fin length that maximizes the heattransfer performance. As the emissivity increased, the effect of geometric parameters on the radiation heat transfer decreased.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.10
• /
• pp.151-157
• /
• 2006

As people's living standard is being improved, human works are being replaced by robots. However, because most robots are used in process industry, fixed on the ground, we need to develop human robots that have wide applications. Currently many researches are being conducted on human robots with the object of replacing human works, but because of lack of relevant hardware, such robots are being applied limitedly to very simple tasks. To overcome the limitation, the present study developed a kinematical mechanism and a controller. Based on human kinematics, the shoulders and the arms were composed of master arms with 3 degree of freedom, and we reproduced motions similar to human ones through the characteristics of joint variables and experiment on the trajectory of the end effector.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.8
• /
• pp.71-80
• /
• 2007

In this study, an inspection system for valve seal of automotive parts using standalone vision has been developed and presented. The system is comprised of eight CCD cameras, and mechanism that loads the automotive parts to the system for the inspection. An image processing algorithm for detecting two different types of defects of valve seals are developed and the effectiveness of the algorithm is experimentally verified. Inspection process is completed in 0.7 second with acceptable accuracy condition. It is envisaged that this inspection system will have a wide application in the automotive part manufacturing industry in the future.

• KIEAE Journal
• /
• v.13 no.4
• /
• pp.63-68
• /
• 2013

On the electricity consumption in Korea, the lighting sector takes about 17% of annual total electricity consumptions. In the midst of higher interests on energy conservation measures, design and choice of energy-saving lighting fixtures have been more important. With growth of technology-intensive industries like advanced material, semiconductor, and biotechnology from the 1980s, needs for clean room and thus illumination at clean rooms have been increased. In this paper, development, specification, and features of a Teardrop LED(hereinafter TD LED) lighting fixture as replacement of Teardrop florescent lighting one that has been popularly installed at clean rooms were presented. Also we performed the economic analysis of return on investment(ROI) about energy savings by the installation of the TD LED lighting fixture at a new-built clean room. The economic analysis showed that the new-developed TD LED lighting fixture would be able to withdraw the initial installation cost within 4 years. Lastly, improvement directions and development plans of the next TD LED lighting fixture for wider applications at clean rooms were described.