• Journal of Welding and Joining
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• v.29 no.1
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• pp.90-98
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• 2011

Al-Si coated Boron steel and Zn coated DP steel were welded using DISK laser and the microstructure and hardness of the weld were investigated. Full penetration was obtained, when the welding speed was lower than 4m/min. In the specimen welded with laser power of 3 kW and welding speed of 2 m/min, the hardness was the highest in the heat affect zone in the boron steel (HAZ-B) and that of the heat affect zone in the DP steel (HAZ-D) was lower than HAZ-B. The hardness of fusion zone was in between those of HAZ-B and HAZ-D. The decreased hardness from each HAZ to base metal(BM) could be explained that ferrite contents increases when access to the BM. The variation of hardness in the welds could be explained by the difference of microstructure, that is, full martensite in HAZ-B, mixture of martensite and bainite in the fusion zone, and the mixture of martensite, ferrite and bainite in HAZ-D.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.687-698
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• 2001

This paper presents a three dimensional stacked pad area away (PAA) package configuration as an implementation method of radio frequency (RF) circuits. 224MHz RF circuits of intelligence traffic system(ITS) were constructed with the stacked PAA RF pakage configuration. In the process of manufacturing the stacked PAA RF pakage, RF circuits were partitioned to subareas following their function and operating frequency. Each area of circuits separated to each subunits. The operating characteristics of RF PAA package module and the electrical properties of each subunits were examined. The measurement of electrical parameters for solder balls which were interconnects for stacked PAA RF packages showed that the parasitic capacitance and inductance were 30fF and 120pH, respectively, which might be negligible in PAA RF packaging system. HP 4396B network/spectrum analyzer revealed that the amplification gain of a receiver and transmitter at 224 MHz was 22dB and 27dB, respectively. The gain was 3dB lower than designed values. The difference was probably generated from fabrication process of the circuits by employing commercial standard

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.247-256
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• 2004

In this paper, we propose the prediction search algorithm for block matching using the temporal/spatial correlation of the video sequence and the renter-biased property of motion vectors The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(Sum of Absolute Difference) value by the predicted motion vector from the same block of the previous frame and the predictor candidate pint in each search region and the predicted motion vector from the neighbour blocks of the current frame. And the searching process after moving the starting point is processed a adaptive search pattern according to the magnitude of motion vector Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improved up to the 0.75dB as depend on the video sequences and improved about 0.05∼0.34dB on an average except the FS (Full Search) algorithm.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.83-92
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• 2012

Multimedia contents can be copied and manipulated without quality degradation. Therefore, they are vulnerable to digital forgery and illegal distribution. In these days, with increasing the importance of multimedia security, various multimedia security techniques are studied. In this paper, we propose a content authentication algorithm based on reversible watermarking which supports JPEG compression commonly used for multimedia contents. After splitting image blocks, a specific authentication code for each block is extracted and embedded into the quantized coefficients on JPEG compression which are preserved against lossy processing. At a decoding process, the watermarked JPEG image is authenticated by extracting the embedded code and restored to have the original image quality. To evaluate the performance of the proposed algorithm, we analyzed image quality and compression ratio on various test images. The average PSNR value and compression ratio of the watermarked JPEG image were 33.13dB and 90.65%, respectively, whose difference with the standard JPEG compression were 2.44dB and 1.63%.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.17 no.1
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• pp.27-31
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• 2006

Objectives : We examined whether D8/17 expression in Tourette syndrome children who suggested PANDAS were higher than comparison group, and there was my clinical difference by D8/l7 expression. Methods : Nine Tourette's syndrome children suggested PANDAS and two ADHD children without tic disorder were evaluated far percentage of D8/17 expression-positive B cells by immunofluorescence flow cytometric assay and anti-streptolysin O titer. Results : The frequency of D8/17 positive B lymphocyte rate was significantly higher in Tourette's syndrome than ADHD, whose average rate were 77.9 and 24.8, respectively. Among 9 TD patients,4 patients showed above 90% D8/l7 expression. There was high concordance expression rate between mother (98.4%) and daughter (99.0%) The significant relation between percentage of D8/17 expression and tic severity were not detected. The significant relation between percentage of D8/17 expression and anti-streptolysin O titer were not detected, however in 66.7% TD patients showed above 100IU/ml. Conclusion : We concluded that subgroup of TD children are streptococcal infected tic disorder, so called PANDAS.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.1-6
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• 2003

In this paper, we extend the derivation of the iterative soft-output Viterbi algorithm (SOVA) for partial response (PR) channels, and modify its decoding process such that it works consistently for arbitrary high code rates, e.g., rate 64/65. We show that the modified SOVA always outperforms the conventional SOVA that appears in the literature with a significant difference for high code rates. It also offers a significant cut down in the trace-back computations. We further examine its performance for parallel and serial concatenated codes on a precoded Class IC partial response (PR4) channel. Code rates of the form $\frac{k_0}{k_0+1}$($k_0$ = 4, 8, and 64) are considered. Our simulations indicate that the loss suffered by the modified SOVA, relative to the APP algorithm, is consistent for all code rates and is at most 1.2 dB for parallel concatenations and at most 1.6 dB for serial concatenations at $P_b$ = $10^{-5}$.

• Journal of Acupuncture Research
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• v.29 no.5
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• pp.97-108
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• 2012

Objectives : To demonstrate the importance of syndrome differentiation in clinical research of herb medication, through the comparative study on efficacy and safety of herb medication according to cold-heat tendency of OA knee patients. Methods : During December 2010 to July 2011, 138 knee OA patients were randomly assigned to WIN-34B 600mg(300mg, b.i.d.), 1,200mg(600mg, b.i.d.) and placebo b.i.d. for 8 weeks. Patient were re-classified into cold-heat tendency group according to cold-heat questionnaires. To investigate efficacy and safety, we assessed the 100mm pain VAS at baseline and 8 weeks later, and we monitored adverse event of patients during treatment period. Results : 1. Efficacy study : In WIN-34B 1,200mg group, VAS mean changes of heat tendency group showed slightly increase than those of cold tendency, but no significant difference within two groups. In heat tendency group, WIN-34B 1,200mg group showed a significant decrease of VAS compared to placebo group. but there were no significant difference in cold tendency group. 2. Safety study; In WIN-34B 600mg group, incidence of adverse events of cold tendency group was higher than those of heat tendency, but not in WIN-34B 1,200mg group. Conclusions : This study suggests that WIN-34B tend to have more efficacy in heat tendency-knee OA patients and WIN-34B is safe drug relatively, regardless of cold-heat tendency. In further clinical research on efficacy and safety of WIN-34B, stratification using syndrome differentiation is required.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.2004-2010
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• 2018

We propose a small active antenna to receive Global Navigation Satellite System (GNSS) signals, i.e., Global Positioning System (GPS) L1 (1,575MHz) and Russian Global Navigation Satellite System (GLONASS) L1 (1,600 MHz) signals. A two-stage low-noise amplifier (LNA) with more than 27 dB gain is implemented in the bottom layer of a three-layer antenna package. In addition, a hybrid coupler is used to combine signals from pair of proximately coupled orthogonal feeds with $90^{\circ}$ phase difference to achieve the circular polarization (CP) characteristic. Three layers of high permittivity (${\varepsilon}_r=10$) substrates are stacked and effectively integrated to have a small dimension of $64mm{\times}64mm{\times}7.42mm$ (including both circuit and antenna). The reflection coefficient of the fabricated antenna at the target frequency is below -10 dB, the measured antenna gain is above 26 dBic and the measured noise figure is less than 1.4 dB.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.248-262
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• 1991

Simulation model was developed to analyze drying process for tray type red pepper dryer and validated by experiments. This model could predict satisfactorily temperatures and moisture contents of red pepper and temperatures of drying air during drying. Optimize algorithm was developed to search control valiables (drying air temperature, air recycle ratio and air flow rate) of red pepper dryer based on a criterion of minimizing energy consumption under the constraint conditions that statisfied carotenoid retension of at least 210mg per 100g dry matter, the moisture content of bottom layer of 15% (d.b) and drying time of less than 35 hours. Step changes in drying air temperature and air recycle ratio were considered in the optimization. In single step in control variables, the difference of the moisture content between top layer and bottom layer was great and more fan power was required. As the drying trays were exchanged when the moisture content of bottom layer reached to 100% (d.b), fifty percent of energy was saved and the difference of moisture content was little. In double step changes in control variables, optimal conditions were found by changing the step when the moisture content of bottom layer reached to 100% (d.b) (about 19.8 hours from starting drying). Optimum air flow rate was $18.1cmm/m^2$. Optimum drying air temperature and air recycle ratio in the first step was $55.8^{\circ}C$ and 0.80, and in the second step $65.6^{\circ}C$ and 0.88, respectively. In triple step changes in control variables, the optimal conditions were found by changing the steps when the moisture content of bottom layer reached to 250% (d.b) and 150% (d.b). Optimal air temperatures were $66.2^{\circ}C$, $58.4^{\circ}C$ and $66.9^{\circ}C$, and optimal air recycle ratios were 0.778, 0.785, 0.862 at each step, respectively. Optimal air flow rate was $18.9cmm/m^2$. The best operating mode was triple step mode considering energy consumption, drying time, fan power, and quality of dried red pepper. When the triple step mode was used to dry the red pepper, the energy consumption was about 16.5%~57.2% less than that of the single step mode and the drying time was 6.6 hours shorter than that of the double step mode.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.229-234
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• 2011

This study investigated quality characteristics of 4 year-old ginseng by enzymatic hydrolysis conditions to increase utilization. Ginseng was ground after steaming and was each treated with hydrolase A, B, C and D. When quality characteristics by the enzymes were examined, no significant difference was observed with pH of 5.5~5.6 and the sugar content of 4.0~4.33. The crude saponin content was the highest in ginseng treated with D, followed by B, C and A. The crude saponin, the reducing sugar and the total sugar contents increased until 0.3% (w/w) concentration in enzyme D with no significant difference by its concentration. Although active ingredients increased with time passage of hydrolysis, no significant change was found after three hours and the crude saponin content was the highest when ginseng was treated at $60^{\circ}C$. From these results, optimum conditions for 4 year-old ginseng were $60^{\circ}C$ for 3 hours with 0.3% (w/w) enzyme D, and under these conditions the reducing sugar, the total sugar and the crude saponin contents recorded 18.11, 36.21 and 4.23 mg/g, respectively. Therefore, enzymatic hydrolysis was found to be effective in increasing active ingredients of 4 year-old ginseng with various usages expected.