• Analytical Science and Technology
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• v.8 no.4
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• pp.603-610
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• 1995

The charge transfer rate in polypyrrole(PPy) electropolymerized within poly(acrylonitrile-co-butadiene)(PAB) was compared with that in PPy deposited Pt electrodes by using cyclic voltammetry, chronoamperometry, and chronopotentiometry in acetonitrile. For both electrodes anodic and cathodic peak currents were proportional to scan rates below 100 mV/sec, but to square root of scan rates beyond 200 mV/sec. The apparent diffusion coefficient of $ClO{_4}^-$ in the PPy/PAB composite is estimated to be 1.6 times larger than that in PPy. The PPy films composited within PAB layer showed higher anodic and cathodic currents and possessed faster charging-discharging process and larger capacity.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.4
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• pp.161-164
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• 2005

Viologen has been extensively investigated in the paper because their well-behaved electrochemistry has led to their use in a variety of theses, including the electron acceptor for the electric charge delivery mediation of the devices. It was formed monolayer in QCM by self-assembly method. We could know the adsorbed mass of viologen molecules from the frequency shift. We calculated that the adsorbed mass was about 196 [$ng/cm^2$]. We studied the electron transfer property of viologen by the cyclic voltammetry among the electrochemical process so we changed an anion like 0.1 M $NaClO_4$ and $Na_3PO_4$ electrolyte solution and investigated the interrelationship between scan rate and peak current when scan rates were increased twice.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.225-232
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• 1998

Todays, the efficient management of container has not been realized in container terminal, because of the excessive quantity of container transported and manual system. For the efficient and automated management of container in terminal, the automated container identifier recognition system in terminal is a significant problem. However, the identifier recognition rate is decreased owing to the difficulty of image preprocessing caused the refraction of container surface, the change of weather and the damaged identifier characters. Therefore, this paper proposes more accurate system for container identifier recognition as suggestion of LSPRD(Line-Scan Proper Region Detection) for stronger preprocessing against external noisy element and MBP(Momentum Back-Propagation) neural network to recognize the identifier.

• Analytical Science and Technology
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• v.14 no.6
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• pp.540-544
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• 2001

Determination of cyanide ion has been studied by adsorptive stripping voltammetry using hanging mercury electrode. Cyanide ion complexed with copper ion is adsorpbed on the electrode and oxidised at the positive potential scan. Optimal conditions of CN determination were found to be ; supporting electrolyte solution ; 0.1 M NaCl of ammonium buffer at pH 10, accumulation potential; -800 mV vs Ag/AgCl, accumulation time ; 300 s, scan rate ; 50mV/s. The linear concentration of cyanide ion was observed in the range $1{\times}10^{-8}$, $1{\times}10^{-7}M$. The detection limit(n/s=3) was $0.13{\mu}g/L$($5{\times}10^{-9}M$) with 3.5% RSD.

• Analytical Science and Technology
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• v.17 no.6
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• pp.464-469
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• 2004

Cyclic voltammetry was used for elucidating the electrochemical behavior of Ru-cupferron complex in 1 mM phosphate buffer. The optimal conditions of ruthenium were found to be 1 mM phosphate buffer solution (pH 6.0) containing 0.1 mM cupferron, scan rate of 100 mV/s. By using the plot on the reduction peak currents of linear scan voltammograms vs. ruthenium concentration, the detection limit ($3{\sigma}$) was $1.2{\times}10^{-7}M$.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.277-285
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• 2012

This research studied how to develop tight upper sportswear from 3D scan data considering fabric stretch property. Subjects were five Korean men of average figure in their 20's. Scanning was done for ten postures via vitus smart/pro(Techmath LTD). Analyzing from 3D scan data, more than 70% of the upper body surface showed surface change rate under 20%. It was shoulder and under arm side part that showed most noticeable body surface change when moving. A parametric model with convex surface was generated and flattened onto the plane, resulting 2D pattern. The error rate occurring in the process of 3D to 2D conversion was 0.2% for outline and 0.13% for area, respectively. Thirteen kinds of stretchable fabrics in the market were collected for this study. Stretch property was in the range of 16.0~58.2% for wale direction; 23.1~78.4% for course. Based on wear trial test, four fabrics were chosen for making the 1st experimental garment and finally one fabric was chosen for the 2nd one, which was developed applying 4 kinds of crosswise reduction rate on 2D pattern: 0, 5, 10, and 15%. Through wear trial test and garment pressure measurement, experimental garment applied with 10% pattern reduction rate was evaluated as most comfortable and considerable.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.10a
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• pp.181-188
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• 2000

The electrocatalytic reduction of NAD$^{＋}$ using diaphorase was studied. methyl viologen (MV$^{2＋}$) mediator between an electrode and the enzyme. Steady-state currents could be obtained under the conditions of slow scan rate, low MV$^{2＋}$concentration, and high NAD$^{＋}$ concentration as the electrode reaction was converted to an electrochemical-catalytic (EC') reaction. The biomecular rate constant for the reaction of the reduced methyl viologen with the oxidized diaphorase was estimated as 7.5$\times$10$^3$M$^{-1}$ s$^{-1}$ from the slope of the current versus [MV$^{2＋}$] plot. And the optimal concentrations of diaphorase, MV$^{2＋}$ and NAD$^{＋}$ in the mediated electrocatalytic reduction of NAD$^{＋}$ were decided by applying the cyclic voltammetry. The optimal concentrations of the species were obtained by finding the conditions which gave the highest and steady-state current at a gold-amalgam electrode. The highest and steady-state catalytic current was achieved under the conditions of 1.5 U/ml diaphorase, 0.2 mM MV$^{2＋}$, and 4.8 mM NAD$^{＋}$ at the scan rate of 2 mV s$^{-1}$ , suggesting that the rate of the electrocatalytic reation is the higest under the former conditions. The electrochemical procedure under the conditions of 1.5 U/ml diaphorase,0.2 mM MV$^{2＋}$, and 4.8 mM NAD$^{＋}$ was used favorably to drive an enzymatic reduction of pyruvate to D-lactate.

• Childhood Kidney Diseases
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• v.10 no.2
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• pp.201-212
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• 2006

Purpose : Vesicoureteral reflux(VUR) is the major risk factor of urinary tract infection(UTI) in children and may result in serious complications such as renal scarring and chronic renal failure. The purpose of this study was to evaluate the relationship between VUR and renal scar formation, the usefulness and correlation of various imaging studies in reflux nephropathy, and the spontaneous resolution of VUR. Methods : We retrospectively reviewed 106 patients with VUR with no accompanying urogenital anomalies in the Department of Pediatrics, Bundang CHA Hospital during the period from Jan. 1996 to Mar. 2005. Ultrasonography and $^{99m}Tc$-dimercaptosuccinic acid(DMSA) scan were performed in the acute period of UTI. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. Follow-up DMSA scan was performed 4 to 6 months after treatment and a follow-up VCUG was performed every 12 months. Results : The mean age at detection of VUR was $13.8{\pm}22.2$ months and the male to female ratio was 2:1. The incidence of renal scarring showed a tendency of direct correlation between severity of VUR(P<0.001) and abnormal findings of renal ultrasonography(P<0.01). 63.2%(24 of 38 renal units) of renal parenchymal defects present in the first DMSA scan disappeared on follow-up DMSA scans. Follow-up DMSA scans detected renal scars in 7(14%) of 50 renal units with ultrasonographically normal kidneys. Meanwhile, ultrasonography did not show parenchymal defects in 7(36.8%) of 19 renal units where renal scarring was demonstrated on a follow-up DMSA scan. The spontaneous resolution rate of VUR was higher(75%) in cases with low grade(I to III) VUR(P<0.01). Conclusions : The presence and severity of VUR and abnormal findings of renal ultrasonography significantly correlated with renal scar formation. DMSA scan was useful in the diagnosis of renal defects. Meanwhile renal ultrasonography was an inadequate method for evaluating renal parenchymal damage. Therefore, follow-up DMSA scans should be performed to detect renal scars even in children with low-grade VUR and normal renal ultrasonography.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.212-219
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• 2007

Purpose : It is difficult to diagnose acute pyelonephritis(APN) in young children, because of their nonspecific symptoms. The younger the age, the higher the risk of renal scars after APN, which can be prevented by early diagnosis and treatment. We compare the significance of renal imaging studies by age for diagnosis of APN in febrile urinary tract infection(UTI) in children. Methods : Fifty-three hospitalized children(34 patients under age 2 and 19 patients over age 2) with febrile UTI and who had undergone dimercaptosuccinic acid(DMSA) scan, renal ultra sonography(RUS) and voiding cystourethrography(VCUG) during the acute stage were re-viewed. We compared the renal imaging studies between the different age groups. Results : The DMSA scan showed cortical defects in 23.5% of patients under age 2, which was significantly lower than 63.2% of patents over age 2(P<0.05). The renal cortical defects on DMSA scan were associated only with a high peripheral leukocyte count, but not with fever duration, erythrocyte sedimentation rate(ESR), and C-reactive protein(CRP). And there was no correlation between the DMSA scan, VCUG or RUS findings. Conclusions : The DMSA scan is not sensitive for diagnosis of APN in children less than 2 years of age and the findings cannot predict the presence of vesicoureteral reflux(VUR). VCUG may be necessary for proper management in this age group.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.285-290
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• 2016

The purpose of our study was to retrospectively evaluate the cause of a decreased calcium score of follow-up studies on coronary artery calcium scores (CACs) computed tomography (CT). The subjects were healthy 100 people(85 males $60.6{\pm}6.9$ years, 15 females $67.2{\pm}7.3$ years). The subjects decreased CACs were divided into 4 subgroups depending on Agatston classification, minimal (1-10), mild (11-100), moderate (101-400), severe (400<). As a result of decreased CACs were scan location disagreement 51%, motion artifact 26%, equipment changes 14%, operator mistakes 5%, input miss 2%, image loss 1%, arrhythmia 1%. In the mild group, the most common decreased CACs were 49 people. In the minimal group, the most significant variation reduction has occurred to 6 people. Scan location disagreement was considered a partial volume effects due to the scan starting position. It showed less than 100 CACs a high variation (19.7%) in more than 100 CACs, a lower variation (2.2%), these could be seen that the variation range is different that can be tolerated according to the calcification score. Motion artifact factor was found in 26%, which is so closely related to the preceding tests that affect the higher heart rate like this pulmonary function test, exercise stress test.