• Journal of Sport and Applied Science
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• v.8 no.3
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• pp.1-6
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• 2024

Purpose: This study aims to verify the effectiveness of acute anodal transcranial direct current stimulation (A-tDCS) using Halo Sport headset device on golf performance in professional golfers. Research design, data, and methodology: Eight professional golfers who voluntary participated in high-level golf tournaments were recruited in this study. They attended one single-session intervention which was stimulated by Halo Sport headset device (n=8). The A-tDCS halo sport session lasted for 20 minutes and stimulated on the motor control area of the cortex (M1). Four golf swing performance tasks (driver, iron, 100-yard shot, 50-yard shot) were performed before and after halo intervention. Key indicators of golf swing performance (Club Speed, Face Angle, Ball Speed, Smash Factor, Spin Rate, Side, Carry, Total) were collected by Trackman launch monitor. Results: In Halo session, there were no found statistical significance in driver, iron and approach (100, 50 yards) after intervention (P<0.05). Even some of variables (face angle, smash factor, carry and total distance) in driver, distance accuracy of 100 yards and direction accuracy of 50 yards were slightly improved tendency, but it was not significant (P<0.05). Meanwhile, there was any enhance all of variables in iron. Conclusions: As a result, the current study concludes that the acute A-tDCS halo sport intervention has no effect on the positive golf performance improvement for professional players. Further implications were discussed.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.149-158
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• 2002

Recently, the minimum line width shows a tendency to decrease and the multi-level increases in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. However there are several defects in CMF, such as micro-scratches, abrasive contaminations and non-uniformity of polished wafer edges. Wet etching process including spin-etching can eliminate the defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(Interlayer-Dielectric) was removed by CMP and wet etching process using DHF(Diluted HF) in order to investigate the possibility of planrization by wet etching mechanism. In the thin film wafer, the results were evaluated from the viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And the pattern step heights were also compared for the purpose of planarity characterization of the patterned wafer. Moreover, Chemical polishing process which is the wet etching process with mechanical energy was introduced and evaluated for examining the characteristics of planarization.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.181-186
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• 2017

Single point incremental forming (SPIF) is a sheet-forming technique. It is a die-less sheet metal manufacturing process for rapid prototyping and small batch production. The Critical parameters in the forming process include tool diameter, step depth, feed rate, spindle speed, etc. In this study, these parameters and the die shape corresponding to the Varying Wall Angle Conical Frustum(VWACF) model were used for forming 0.8mm in thick Al5052-O sheets. The Taguchi method of Experiments of Design (DOE) and Grey relational optimization were used to determine the optimum parameters in SPIF. A response study was performed on formability, spring back, and thickness reduction. The research shows that the optimum combination of these parameters that yield best performance of SPIF is as follows: tool diameter, 6mm; spin speed, 60rpm; step depth, 0.3mm; and feed rate, 500mm/min.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.357-367
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• 2009

This study was carried out to investigate the current status of pesticide residues in 3,735 agricultural products in the northern area of Seoul from January to December in 2008. 3,735 samples, comprising 119 types of agricultrural products were assessed via a multiresidue method to detect 260 pesticides. Pesticide residues were detected in 19.7% (737 of 3,735 samples), and the rate at which the detected residues violated the maximum residue levels(MRLs) of the Korean Food Code was 3.2% (121 of 3,735 samples). Pesticide residues were detected in 72 spin-aches, 64 peppers, 45 sweet peppers, 40 perilla leaves, 38 korean cabbages and 37 dried agricultural products. The samples that violated the MRLs included 14 perilla leaves, 13 spinaches, 12 leek, 6 lettuces(leaf), 6 chards and 6 gyeojchaes. Procymidone, endosulfan, chlorfenapyr, cypermethrin, bifenthrin, tebuconazole and fenvalerate were all frequently observed. Procymidone, endosulfan, dimethomorph and diniconazole were the pesticides most frequently detected at levels that violated the Korean Food Code MRLs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.65-65
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• 2007

Microstructure and surface roughness of the sensing materials should be improved to use them in advanced sensor applications because the uneven surface roughness degrades the light reflection, pattern resolution, and devices performance. Chemical mechanical polishing (CMP) processing was selected for improving the surface roughness of $CeO_2$ which is one of the well known materials for the oxygen gas sensors. Surface roughness and removal rate of spin coated $CeO_2$ thin films were examined with a change of CMP process parameters such as down force and table speed. The optimized process condition, reflected by the surface roughness with the hillock-free surface as well as the excellent removal rate with the good uniformity, was obtained. The effects of the improved surface roughness on the sensing property of $CeO_2$ thin films were also confirmed. The improved sensitivity of $CeO_2$ thin films for oxygen sensors were obtained after CMP process by the improved surface characteristics. Therefore, we conclude that sensing property of $CeO_2$ thin film is strongly dependent on the surface roughness of $CeO_2$ thin films by using CMP process.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.151-159
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• 2016

In this research, we tried to suggest moderate FA(Flip Angle) for CE(Contrast Enhnaced)-Head&Neck MR Angiography with Gadoteridol. For this study, we did test MR phantom and clinical study according to FA change. After that, quantitative analysis was progressed. The results of MR phantom study were as follow: RSP(Reaction Starting Point)was recorded within 300~400 mmol. MPSI(Max Peak Signal Intensity) was 2,086, 3,705, 5,109, 6,194, 7.096, 7,192 [a.u]. MPP(Max Peak Point) was shown at 30, 50, 50, 40, 50, 40 mmol. IRMPSI(Increase Rate of MPSI) was 77.6%, 37.9%, 21.2%, 14.6%, 1.4% as increasing of FA. The results of clinical study were as follow SICB(Signal Intensity of Carotid artery Bifurcation) was recorded respectively 392.5, 4165.2, 4270, 3502.2, 3263.7, 3119.6 [a.u]. ORA(Occurence Rate of Artifact) was increased as 0, 0, 20, 40, 50, 70%. According to this research, we are not only able to assure that increase of FA can be effect on H1 spin's SI(Signal Intensity) which was combined with gadolinium agent, but also be effect on artifact rate in blood vessel. In clinical field, we expect that CE-Head&Neck MR Angiography can be performed in a practical way with this research.

• Investigative Magnetic Resonance Imaging
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• v.23 no.3
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• pp.251-258
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• 2019

Purpose: To assess the feasibility of the use of spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) in livers of children and young adults. Materials and Methods: Patients (${\leq}20$ years old) who underwent 3T SE-EPI MRE were included retrospectively. Subjects were divided into three groups according to the purpose of the liver MRI: suspicion of fatty liver or focal fat deposition in the liver (FAT group), liver fibrosis after receiving a Kasai operation from biliary atresia (BA group), and hepatic iron deposition after receiving chemotherapy or transfusions (IRON group). Technical failure of MRE was defined when a stiffness map showed no pixel value with a confidence index higher than 95%, and the patients were divided as success and failure groups accordingly. Clinical findings including age, gender, weight, height, and body mass index and magnetic resonance imaging results including proton density fat fraction (PDFF), $T2^*$, and MRE values were assessed. Factors affecting failure of MRE were evaluated and the image quality in wave propagation image and stiffness map was evaluated using the appropriate scores. Results: Among total 240 patients (median 15 years, 211 patients in the FAT, 21 patients in the BA, and 8 patients in the IRON groups), technical failure was noted in six patients in the IRON group (6/8 patients, 75%), while there were no failures noted in the FAT and BA groups. These six patients had $T2^*$ values ranging from 0.9 to 3.8 ms. The image quality scores were not significantly different between the FAT and BA groups (P > 0.999), while the scores were significantly lower in the IRON group (P < 0.001). Conclusion: The 3T SE-EPI MRE in children and young adults had a high technical success rate. The technical failure was occurred in children with decreased $T2^*$ value (${\leq}3.8ms$) from iron deposition.

• Clean Technology
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• v.28 no.4
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• pp.323-330
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• 2022

Microfluidic paper-based analytical devices (μPADs) have recently been in the spotlight for their applicability in point-of-care diagnostics and environmental material detection. This study presents a double-sided printing method for fabricating 3D-μPADs, providing simple and cost effective metal ion detection. The design of the 3D-μPAD was made into an acryl stamp by laser cutting and then coating it with a thin layer of PDMS using the spin-coating method. This fabricated stamp was used to form the 3D structure of the hydrophobic barrier through a double-sided contact printing method. The fabrication of the 3D hydrophobic barrier within a single sheet was optimized by controlling the spin-coating rate, reagent ratio and contacting time. The optimal conditions were found by analyzing the area change of the PDMS hydrophobic barrier and hydrophilic channel using ink with chromatography paper. Using the fabricated 3D-μPAD under optimized conditions, Ni²⁺, Cu²⁺, Hg²⁺, and pH were detected at different concentrations and displayed with color intensity in grayscale for quantitative analysis using ImageJ. This study demonstrated that a 3D-μPAD biosensor can be applied to detect metal ions without special analysis equipment. This 3D-μPAD provides a highly portable and rapid on-site monitoring platform for detecting multiple heavy metal ions with extremely high repeatability, which is useful for resource-limited areas and developing countries.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.182-192
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• 2015

In this paper, we introduce how to change the reaction rate as mol concentration when we scan enhanced MRI with GBCA(Gadolinium Based Contrast Agent), Also show the changing patterns depending on diverse MRI sequences which are made by different physical principle. For this study, we made MRI phantom ourselves. We mixed 500 mmol Gadoteridol with Saline in each 28 different containers from 500 to 0 mmol. After that, MR phantom was scanned by physically different MRI sequences which are T1 SE, T2 FLAIR, T1 FLAIR, 3D FLASH, T1 3D SPACE and 3D SPCIR in 1.5T bore. The results were as follows : *T1 Spin echo's Total SI(Signal Intensity) was 15608.7, Max peak was 1352.6 in 1 mmol. *T2 FLAIR's Total SI was 9106.4, Max peak was 0.4 1721.6 in 1 mmol. *T1 FLAIR's Total SI was 20972.5, Max peak was 1604.9 in 1 mmol. *3D FLASH's Total SI was 20924.0, Max peak was 1425.7 in 40 mmol. *3D SPACE 1mm's Total SI was 6399.0, Max peak was 528.3 in 3 mmol. *3D SPACE 5mm's Total SI was 6276.5, Max peak was 514.6 in 2 mmol. *3D SPCIR's Total SI was 1778.8, Max peak was 383.8 in 0.4 mmol. In most sequences, High signal intensity was shown in diluted lower concentration rather than high concentration, And also graph's max peak and pattern had difference value according to the each different sequence. Through this paper which have quantitative result of GBCA's reaction rate depending on sequence, We expect that practical enhanced MR protocol can be performed in clinical field.

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.88-93
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• 1979

The adsorption of propylene on copper(II)-exchanged zeolite Y was studied by temperature programmed desorption (TPD) technique and electron spin resonance. The amount of propylene adsorbed increased with increasing copper ion content. Four TPD peaks with desorption temperature maxima at $108^{\circ}C({\alpha})$, $243^{\circ}C({\beta})$, $284^{\circ}C({\gamma})$ and $420^{\circ}C({\delta})$ were observed (heating rate: $6.4^{\circ}C$/min). ${\alpha}$Peak which was also observed in the TPD of propylene from NaY may be assigned to propylene physically adsorbed on the zeolite surface, ${\beta}$ and ${\gamma}$ peaks to the chemisorbed propylene either on copper ion or Bronsted acid site produced by copper ion, and $\delta$ peak to cracking products from the polymeric material formed from propylene adsorbed.