• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.263-270
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• 2016

This paper implemented an ultra-wideband(: UWB) antenna by using a modified barrel-shaped patch antenna. The designed UWB patch antenna was optimized to match UWB technical specifications by considering the sizes of barrel circle and oval(notch) which is distance between the patch and contact surface and designed antenna was implemented by $10mm(R1){\times}21.8mm$ size. Optimal values on the basis of simulated reflective loss results, the surface current distribution of designed patch antenna was analyzed in order to check operation mode of antenna and wideband mechanism. Experimental results of implemented UWB antenna, Return loss of UWB antenna the voltage standing wave ratio was 2 or less in the 1.775-13.075 GHz band, VSWR in 2 or less. And the maximum gain of approx. 1-3 dBi was found in 3.1-10.6 GHz. This result satisfied the characteristics of ultra-wideband and the proposed antenna will be applicable to an ultra-wideband system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.6
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• pp.785-791
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• 2000

GDI (Gasoline Direct Injection) engines are considered as one of the candidates for next generation engines of passenger cars, which reduce exhaust emissions and fuel consumption. In GOI engines, a high-pressure gasoline supply system is required to directly inject the fuel to combustion chambers. Because of low lubricity of gasoline fuel, the clearance between a plunger and a barrel in GDI fuel pumps is too wide to achieve smooth hydrodynamic lubrication. Thus, it is difficult to generate high-pressure condition in GDI fuel pump since large amount of leakage flow occurs between the plunger and the barrel In this study, an optimum plunger design is presented to minimize leakage in the aspect of flow control. This paper analyzes leakage flow characteristics in the clearance to improve pumping performance of GDI fuel pumps. Effects of groove in the plunger are studied according to variations of depth and width. Evaluations of pumping performance are determined by the amount of pressure drop in the leakage path assuming a constant leakage flows. Both of turbulence and incompressible models are introduced in CFD (Computational Fluid Dynamics) analysis. Design parameters have been introduced to minimize leakage in limited space, and a methodological study on geometrical optimization has been conducted. As results of CFD analysis in various geometrical cases, optimum groove depths have been found to generate maximum sealing effects on gasoline fuel between the plunger and the barrel. This procedure offers a methodological way of an enhancement of plunger design for high-pressure GDI fuel pumps.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1133-1138
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• 2018

Lightweight Encryption Algorithm (LEA) is one of the most promising lightweight block cipher algorithm due to its high efficiency and security level. There are many works on the efficient LEA implementation. However, many works missed the secure application services where the IoT platforms perform secure communications between heterogeneous IoT platforms. In order to establish the secure communication channel between them, the encryption should be performed in the on-the-fly method. In this paper, we present the LEA implementation performing the on-the-fly method over the ARM Cortex-M3 processors. The general purpose registers are fully utilized to retain the required variables for the key scheduling and encryption operations and the rotation operation is optimized away by using the barrel-shifter technique. Since the on-the-fly method does not store the round keys, the RAM requirements are minimized. The implementation is evaluated over the ARM Cortex-M3 processor and it only requires 34 cycles/byte.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.49-60
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• 2012

In this paper, we propose a hardware design for correction of barrel distortion using the nearest coordinates in the corrected image. Because it applies the nearest distance on corrected image rather than adjacent distance on distorted image, the picture quality is improved by the image whole area, solve the staircase phenomenon in the exterior area. But, because of additional arithmetic operation using design of bilinear interpolation, required arithmetic operation is increased. Look up table(LUT) structure is proposed in order to solve this, coordinate rotation digital computer(CORDIC) algorithm is applied. The results of the synthesis using Design compiler, the design of implementing all processes of the interpolation method with the hardware is higher than the previous design about the throughput, In case of the rear camera, the design of using LUT and hardware together can reduce the size than the design of implementing all processes with the hardware.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.149-157
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• 2015

The effects of feed moisture content (25, 35, and 45%), screw speed (230, 250, and 270 rpm), and barrel temperature (130, 140, and $150^{\circ}C$) on the product yield and soluble arabinoxylan (SAX) content from destarched corn fiber (DCF), and its optimization were investigated. The yield and SAX content of corn fiber gum (CFG) from the extruded destarched corn fiber (EDCF) were higher than those of DCF. Statistical analyses revealed that the feed moisture content and barrel temperature had a significant effect on the CFG yield and total SAX content. The optimum extrusion pretreatment conditions were as follows: feed moisture content, 30%; screw speed, 260 rpm; barrel temperature, $133^{\circ}C$. This study showed that the response surface methodology was suitable for the optimization of the extrusion conditions used to maximize the CFG yield and total SAX content from EDCF.

• Journal of IKEEE
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• v.26 no.2
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• pp.226-231
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• 2022

The concept of information entropy has been widely applied in various fields. Recently, in the field of image processing, many technologies applying the concept of information entropy have been developed. As the importance and demand of computer vision technologies increase in modern industry, real-time processing must be possible in order for image processing technologies to be efficiently applied to modern industries. Extracting the entropy value of an image is difficult to process in real-time due to the complexity of computation in software, and a hardware structure of an image entropy filter capable of real-time processing has never been proposed. In this paper, we propose for the first time a hardware structure of a histogram-based entropy filter that can be processed in real time using a barrel shifter. The proposed hardware was designed using Verilog HDL, and Xilinx's xczu7ev-2ffvc1156 was set as the target device and FPGA was implemented. As a result of logic synthesis using the Xilinx Vivado program, it has a maximum operating frequency of 750.751 MHz in a 4K UHD high-resolution environment, and it processes more than 30 images per second and satisfies the real-time processing standard.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.951-957
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• 2009

In this study, antibacterial activity of extruded ginseng extract by 60 and 80% Et-OH were investigated by agar diffusion assay against two bacteria causing dental caries (Streptococcus mutans and Lactobacillus casei). Extrusion conditions were 20% moisture content $100^{\circ}C$ and $140^{\circ}C$ barrel temperature. The inhibition effect of 60% Et-OH ginseng extract was higher than 80% Et-OH ginseng extract. The minimum inhibitory concentration (MIC) of 80% Et-OH extruded ginseng extract at 140 and $100^{\circ}C$ barrel temperature against L.casei were 100 and 150 mg/mL respectively using broth assay method. The amount of glucosyltransferase (GTase) inhibitory content was the highest in extruded ginseng at $140^{\circ}C$ barrel temperature with 60% Et-OH. Moreover, n-hexane and n-butanol fraction ginseng extract had potential against tested bacteria. Our results demonstrated that antibacterial activities of extruded ginseng extract at $140^{\circ}C$ barrel temperature were more effective than Ex-$100^{\circ}C$, RG and WG.

• Archives of Pharmacal Research
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• v.24 no.1
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• pp.64-68
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• 2001

Endothelin-1 (ET-1 ), a novel and potent vasoconstrictor in blood vessel, is known to have some functions in the rat central nervous system (CNS), In order to investigate the central functions of ET-1 , ET-1 was administered to the periaqueductal gray area (PAC) of anesthetized rats to induce barrel rolling and increase the arterial blood pressure (ABP). ET-1 had a modulatory effect on central cardiovascular and behavioral control. The selective N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (3${u}m/ol/kg$, i.p.) blocked the ET-1 induced responses, and both the nitric oxide synthase (NOS) inhibitor L-NAME (N-nitro-L-arginine mIThyl-ester 1 nmol/rat) and the nitric oxide (NO) scavenger hemoglobin (15 nmol/rat) had similar effects in redtAcing the IT-1 (10 pmol/rat)-induced behavioral changes and ABP elevation. However, NO donor sodium nitroprusside (SNP 10${u}g$, 1${u}g/rat$) decreased the ET-1 induced ABP elevation, and recovered the ET-1 -induced barrel rolling effect that was reduced by MK-801. These results suggest that ET-1 might have neuromodulatory functions such as ABP elevation and barrel rolling induction in the PAG of the rats via the NMDA receptor and NO.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.636-642
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• 2007

In order to develop a novel food utilization of germinated brown rice, physicochemical properties of germinated brown rice and its extrudates were investigated. The physical characteristics, the paste viscosity, and the anti-oxidation activity were analyzed. Brown rice was soaked for 10 hr and germinated for 24 and 48 hr at $30^{\circ}C$. Extrusion conditions of brown rice and germinated brown rice were barrel temperature at 100 and $120^{\circ}C$ and moisture content at 20%. The expansion ratio increased with the increase in germination time. It increased at barrel temperature of $100^{\circ}C$, and decreased at $120^{\circ}C$. The bulk density showed negative corporations with the expansion ratio. The paste viscosity of germinated brown rice was decreased with the increase in the germination time. However the paste viscosity of extrudates was lower as barrel temperature increased. Content of polyphenolic compound in extrudates was increased by increasing germination time and barrel temperature.

• Journal of Radiation Protection and Research
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• v.23 no.3
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• pp.175-184
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• 1998

In order to calculate dose rates from steam generators to be replaced from Kori unit 1 in 1998, radionuclide inventories inside steam generator were evaluated from smear test results and measured dose rates from S/G tubes withdrawn for the metallographical examination of damaged tubes. Based on the inventories, contact dose rates and dose rates at 1 m from the surface of a steam generator were calculated using the QAD-CG computer code. Contact dose rates ranged from 11.5 mR/hr at the bottom of channel head to 37.7 mR/hr at the middle of shell barrel, and showed no significant difference with dose rates at 1 m from the surface of steam generator. Shielding effects of lead and carbon steel were compared to provide basic shielding data. Lead shield showed excellent shielding effects. Dose rate at 1 m from the middle of S/G shell barrel decreased from 38.6 mR/hr to 15.5 mR/hr with the lead shield of 2 mm thickness. However, carbon steel showed a poor shielding effect even with the thickness of 2.0 cm. This can be explained with the great differences in the attenuation effect and buildup factor between lead and carbon steel for low energy photons.