• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1735-1737
• /
• 2003

To find the best intagliated shape on edgelit signboard, it was prepared wilt variations of illumination by changing the depth and angle of an engraved letter, the thickness of acrylic panel and wavelength of light source in this paper. As the result of analyzing optical design program, shallower depth and larger than critical angle on a visible side of panel, a favorable illumination characteristics was found. Also considering those factors, it was able to select the model which showed effectively engraved letter.

• Proceedings of the KIEE Conference
• /
• 2004.11a
• /
• pp.261-263
• /
• 2004

This paper studies the lighting pattern control of a high-brightness LED warning light. The driving circuit for the warning light is composed of a full-wave rectified circuit and of a control circuit using a micro-controller (AT89c2051). The micro-controller is programmed in a suitable manner to accomodate a number of variable lighting patterns and to adjust the blinking speed. To reduce the total number of LEDs installed a special consideration is made to the bundled pattern in a lamp module which is lit simultaneously. The resultant LED warning light has merits not only over the conventional incandescent warning light on the energy saving aspect but also over some other LED-type ones in the market.

• Proceedings of the KIPE Conference
• /
• 2002.11a
• /
• pp.147-151
• /
• 2002

액정표시장치(LCD; Liquid Crystal Display)는 표현된 정보를 가시화하기 위해 램프의 백라이트가 필수적인데 대부분 부피가 작고 효율과 휘도특성이 좋은 냉음극 방전램프가 사용된다. 램프는 고압으로 구동되며 높은 전압을 얻기 위해 일반적으로 권선 변압기를 사용한다 그러나 권선 변압기의 경우 자체의 철심이나 권선의 손실로 인하여 출력 효율의 한계가 있으며, 고압을 위해 감긴 코일은 부피를 크게 하며 무겁게 만든다. 이를 해결하기 위해 본 논문에서는 변압기 자체 손실을 줄이고 소형화가 가능하며 높은 승압비을 가진 PAN-PZT계의 적층형 압전 변압기를 제작하였으며, 회로의 손실을 줄이기 위한 영전압 스위칭(ZVS; Zero Voltage Switching)과 그리고 LCD패널과 인버터의 불필요한 간섭현상(EMI; Electro-Magnetic Interference)을 줄일 수 있으며 소형화가 가능한 풀 브리지형 압전 인버터를 설계하였다.

• Food Science and Preservation
• /
• v.12 no.6
• /
• pp.546-551
• /
• 2005

The new developed production process and the coating equipment were used to prepare the alginate coated rice having functional property. Then, the quality characteristics such as proximate analysis, moisture sorption properties, influence on the retrogradation, sensory evaluation were investigated. The moisture content of the alginate coated rice was $16.5-18\%$ which is $1.5\%$ higher than the normal rice. About $0.3\%$ alginate was coated on the rice by the measurement of carbohydrate content after coating with $2\%$ alginate. The rice coated with higher alginate concentration showed the higher moisture absorption. The rice coated with $2\%$ alginate solution stored $30^{\circ}C$ and $85\%$ RH conditions for 6 weeks and it increased $1.8\%$ of the moisture content The alginate coated rice has delayed the retrogradation more than 6 hrs as well as got the higher scores for the appearance, stickiness, and taste. The alginate coated rice is a good source of the fiber in the nutritional aspect and it improves the quality and functionality of the rice.

• Proceedings of the Zoological Society Korea Conference
• /
• 2000.10a
• /
• pp.256.3-257
• /
• 2000

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 1999.10b
• /
• pp.263.2-263
• /
• 1999

No Abstract, See Full Text

• Journal of Korea Foundry Society
• /
• v.24 no.4
• /
• pp.231-237
• /
• 2004

Bake hardenable steel utilizes the phenomenon of strain aging to provide an increase in the yield strength of formed components. An increase of the carbon content will improve the bake hardening response: more solutes are available to pin mobile dislocations and to form the clusters more rapidly. But aging resistance decrease as increasing solute carbon. In order to under-stand the compatibility between bake hardenability and aging resistance. The optimum solute carbon control methods during manufacture should be determined. In this paper, the effect of continuous heat cycle conditions such as soaking temperature, rapid cooling start temperature, cooling rate on BH(Bake Hardenability), AI(Aging Index), YP-El(Yield Point Elongation) and other mechanical properties have been investigated. and following results were obtained. In the case of soaking temperature, BH increases with higher soaking temperature because of NbC $dissolution(830^{\circ}C)$, Therefore the solute carbon and BH at $850^{\circ}C$ and $870^{\circ}C$ are higher than these at $810^{\circ}C$. But BH at $870^{\circ}C$ is a little lower than that at $850^{\circ}C$ owing to the ferrite grain size. The measurement of amount of dissolution C using IFT(Internal Friction Test) can explain the relation of solute carbon and BH.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.7B
• /
• pp.481-488
• /
• 2005

As the demand on the multimedia application increases, the congestion control algorithm for the multimedia applications becomes an important research issue. The ultimate goal of congestion control is to adapt the trans-mission rate at the sender to the mont of network resource available on the forward path. In general, the congestion control algorithms use the round trip time(RTT) to estimate the network congestion on the forward path. however, since the RTT includes the delay on both forward and backward paths, it is possible for the algorithms using the RTT to make a wrong decision such as deciding the congestion on the forward path due to the congestion built on the backward path. In this paper, we enhance the performance of RRC-OTT(Receiver-based rate control with one-way Trip Time) algorithm, which uses the one-way trip time(OTT) to estimate the network congestion. By separating the estimation mechanism on the forward path from the backward path, the performance of RRC-OTT algorithm is hardly affected by the congestion built on the backward path.

• Journal of Sensor Science and Technology
• /
• v.10 no.5
• /
• pp.329-336
• /
• 2001

This paper describes the steering control and geomagnetism cancellation for an autonomous vehicle using an MR sensor. The magneto-resistive (MR) sensor obtains the vector summation of the magnetic fields from embedded magnets and the Earth. The vehicle is controlled by the magnetic fields from embedded magnets. So, geomagnetism is the disturbance in the steering control system. In this paper, we propose a new method of the sensor arrangement in order to remove the geomagnetism and vehicle body interference. The proposed method uses two MR sensors located in a level plane and the steering controller has been developed. The controller has three input variables ($dB_x$, $dB_y$, $dB_z$) using the measured magnetic field difference, and an output variable (the steering angle). A simulation program was developed to acquire the data to teach the neural network, in order to test the ability of a neural network to learn the steering control process. Also, the computer simulation of the vehicle (including vehicle dynamics and steering) was used to verify the steering performance of the vehicle controller using the neural network. From the simulation and field test, good result was obtained and we confirmed the robustness of the neural network controller in a real autonomous vehicle.

• Food Science and Preservation
• /
• v.12 no.3
• /
• pp.282-286
• /
• 2005

This study was to investigate the content of total phenolic compounds, electron donating ability, nitrate-scavenging effect, and angiotensin converting enzyme(ACE) inhibition effect of medicinal plant liquors prepared from Cnidium officinale, Angelica gigas, Pueraria thunbergiana(root), Pueraria thunbergiana (flower), and Glycyrrhiza uralensis. Physicochemical characteristics of the medicinal plant liquors are as follows: pH $5.65{\sim}6.36$; reducing sugar, $0.13{\sim}0.45\%$. The highest value of total phenolic compounds was found in liquor prepared with Pueraria thunbergiana(root) as $23.9{\sim}54.3\;mg\%$. The electron donating ability of liquor prepared with Pueraria thunbergiana showed the highest value($67.4{\sim}85.3\%$) among the liquors, and its nitrite scavenging ability($24.56{\sim}78.3\%$) showed the highest value than those of other medicianal plant liquors. ACE inhibitory activity showed the highest value in liquor prepared with Cnidium officinale.