• Journal of the Korean Magnetics Society
• /
• v.20 no.2
• /
• pp.35-40
• /
• 2010

The GMR-SV (giant magnetoresistance-spin valve) device depending on the micro patterned features according to two easy directions of longitudinal and transversal axes has been studied. The GMR-SV multilayer structure was Ta(5 nm)/NiFe(8 nm)/Cu(2.3 nm)/NiFe(4 nm)/IrMn(8 nm)/Ta(2.5 nm). The applied anisotropy direction of the GMR-SV thin film was performed under the magnitude of 300 Oe using by permanent magnet during the deposition. The size of micro patterned device was a $1\;{\times}\;18\;{\mu}m^2$ after the photo lithography process. In the aspects of the shape magnetic anisotropy effect, there are two conditions of fabrication for GMR-SV device. Firstly, the direction of sensing current was perpendicular to the magnetic easy axis of the pinned NiFe/IrMn bilayer with the transversal direction of device. Secondly, the direction of shape magnetic anisotropy was same to the magnetic easy axis of the free NiFe layer with the longitudinal direction of device.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.1
• /
• pp.1-4
• /
• 2002

To obtain the blue emission of powder electroluminescent device, the emission properties of ZnS:Cu were estimated by the variation of applied frequency and the addition of dye to ZnS:Cu phosphor. The variation of applied frequency was from 400 to 4kHz and the addition ratio of dye was from 0 to 5 weight percent respectively. The increment of applied frequency made that emission peaks were shifted from 500.5nm and 460nm at 400Hz to 490nm and 450nm at 4kHz. CIE coordinate system was shifted from x=0.1647, y=0.3711 at 400Hz to x=0.1543, y=0.1856 at 4kHz. On the basis of applied voltage 100V, 400Hz, the increment of addition ratio of dye also made that emission peak was shifted from 505nm(0wt%) to 490nm(5wt%) and the CIE coordinate system was shifted from x=0.1647, y=0.3711(0wt%) to x=0.1334, y=0.2363 (5wt%). The brightness was increased from 60 cd/$m^2$(400Hz) to 174 cd/$m^2$(4kHz) with increment of frequency. When the addition ratio of dye was above 1wt%, the brightness was decreased below 42% of initial brightness and changed from 60 cd/$m^2$(0wt%) to 20.84 cd/$m^2$(5wt%).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.3
• /
• pp.1299-1304
• /
• 2014

This paper is a study for developing an agriculture automatic hose reel of mobile robot. One of the important works in farming is pesticide spraying because it is related to the growth of crops. Therefore, we develop an automatic reel hose and mobile robot. Conducting kinematic analysis of steering performance, the mobile robot is designed to move smoothly even in a small space, and that is verified by simulation. To increase supplying accuracy of the automatic hose reel, the mobile robot use detecting tension mechanism on a hose and a device for the hose deployment. We conduct performance and on-farm evaluation. This system has been maximum speed of 2.5m/s, driving accuracy of ${\pm}0.18^{\circ}$ and driving safety speed of 2m/s. The system would solve an aging population and shortage of workforce in agriculture.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.285-292
• /
• 2007

This study was developed the metallic plate for fixation in the femur fracture for the orthopedic region and rigid fixation with plates has a firm place in fracture treatment. Most plates can be used for rigid as well as biological and dynamical fracture fixation. The device's designation and sizing has a specific with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. Short plate have a wrapping of femur and long plate have to preserve a pole of femur. The bending strength of the curved metallic long plate has to evaluate a 11,000N and The bending strength of the curved metallic short plate has to evaluate a 6,525N. The tensile stress through to press a plate is $1573N/m^2\;and\;1539N/m^2$. The device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture.

• Journal of Biosystems Engineering
• /
• v.26 no.2
• /
• pp.115-122
• /
• 2001

An impact-type seed-metering device was developed for the planting of rice-pellets. In this study, new design of pellet-metering device focused on simplicity and precision seeding for the planting of rice-seed pellets. In addition of seed-metering device, several devices were also developed such as seed-guiding device, seed-supplying tube and furrow opener for precision pellet planting. Field test was conducted to estimate the planting performance of the developed metering device. As a cam rotates, the impact bar of the metering device pushes a rice-seed pellet so that the seed can be discharged from the seed-supplying tube in the impact-type seed-metering device. Results of the tests showed that mean seeding spacing was 12cm at the traveling speed of 1.0m/s, corresponding to a target spacing for planting of rice-seed pellets. Also, both miss-seeded rate and damaged-seed rate were less than 2.0%, indicating acceptable levels for the precision planting. The developed mechanism of the impact-type metering device can be directly applied to the design of metering devices for the precision pellet planting of other crops.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.4
• /
• pp.270-274
• /
• 2009

In this paper, we propose an efficient computation method over GF($2^m$) for memory-constrained devices. While previous methods concentrated only on fast multiplication, we propose to reduce the amount of required memory by cleverly changing the order of suboperations. According to our experiments, the new method reduces the memory consumption by about 20% compared to the previous methods, and it achieves a comparable speed with them.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.1
• /
• pp.11-18
• /
• 2017

Finite field arithmetic has been extensively used in error correcting codes and cryptography. Low-complexity and high-speed designs for finite field arithmetic are needed to meet the demands of wider bandwidth, better security and higher portability for personal communication device. In particular, cryptosystems in GF($2^m$) usually require computing exponentiation, division, and multiplicative inverse, which are very costly operations. These operations can be performed by computing modular AB multiplications or modular $AB^2$ multiplications. To compute these time-consuming operations, using $AB^2$ multiplications is more efficient than AB multiplications. Thus, there are needs for an efficient $AB^2$ multiplier architecture. In this paper, we propose a low latency Montgomery $AB^2$ multiplier using redundant representation over GF($2^m$). The proposed $AB^2$ multiplier has less space and time complexities compared to related multipliers. As compared to the corresponding existing structures, the proposed $AB^2$ multiplier saves at least 18% area, 50% time, and 59% area-time (AT) complexity. Accordingly, it is well suited for VLSI implementation and can be easily applied as a basic component for computing complex operations over finite field, such as exponentiation, division, and multiplicative inverse.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.05a
• /
• pp.79-80
• /
• 2023

CPU 와 GPU 의 성능이 지속적으로 발전함에 따라 객체 인식 인공지능의 정확도와 추론 속도는 점차 향상되고 있으나 이러한 성능을 Edge Device 와 같은 제한된 환경에서 구현하기에 아직 여러 한계점이 존재한다. 본 논문에서는 여러가지 Edge Device 에서 객체 인식을 위한 경량화 된 모델 중 하나인 SSD-Mobilenet-V2 를 활용하여 결과값을 통해 각 Device 간 경향성을 분석하였다. 본 결과를 바탕으로 다양한 환경에서의 객체인식 인공지능 모델의 성능 개선을 위한 연구에 활용할 수 있다.

• Applied Chemistry for Engineering
• /
• v.21 no.2
• /
• pp.137-141
• /
• 2010

Poly [4,7-Di-thiophen-2-yl-benzo(1,2,5)thiadiazole]-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene (PPVTBT) was synthesized by the Heck coupling reaction between 4,7-Di-thiophen-2-yl-benzo(1,2,5)thiadiazole and 1,4-bis(dodecyloxy)-2,5-divinylbenzene. The maximum absorption and band gap of PPVTBT were 550 nm and 1.74 eV, respectively. The HOMO and LUMO energy level of PPVTBT were -5.24 eV and -3.50 eV, respectively. The photovoltaic device based on the blend of PPVTBT and (6)-1-(3-(methoxycarbonyl)propyl)-{5}-1-phenyl[5,6]-$C_{61}$ (PCBM) (1 : 6 by weight ratio) was fabricated. The efficiency of device was 0.16%. The short circuit current density (Jsc), fill factor (FF) and open-circuit voltage (Voc) of the device was $0.74mA/cm^{2}$, 31% and 0.71 V, respectively, under AM 1.5 G and 1 sun condition ($100mA/cm^{2}$).

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.23 no.1
• /
• pp.11-17
• /
• 1987

This paper describes an availability of the teltmeter device made as a trial to measure the under-water noise, and the results of the test. This telemeter device adopts FM-FM system, and its main carrier wave is 146.2MHz. The trans-mission power is about 1w, and the available distance of transmission is 2.5KM. The timer built in the telemeter device controls transmission time and pause time automatically by the R-C time-constant. The former is 30-32 seconds and the latter is 10-12 seconds. The underwater noise in the set net fishing ground and at the breeding tank was measured, and recorded simultaneously on land and at sea with the telemeter device. When the input voltages of the transmitter is 100-300mV, the value of telemetering ambient noise and bio-acoustic underwater noise well agreed with that of the direct measurement. And the teleme-tered underwater noise decreases in proportion the distance between the transmitter and receiver.