• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.252.2-252.2
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• 2013

ZnO nanostructures have a lot of interest for decades due to its varied applications such as light-emitting devices, power generators, solar cells, and sensing devices etc. To get the high performance of these devices, the factors of nanostructure geometry, spacing, and alignment are important. So, Patterning of vertically- aligned ZnO nanowires are currently attractive. However, many of ZnO nanowire or nanorod fabrication methods are needs high temperature, such vapor phase transport process, metal-organic chemical vapor deposition (MOCVD), metal-organic vapor phase epitaxy, thermal evaporation, pulse laser deposition and thermal chemical vapor deposition. While hydrothermal process has great advantages-low temperature (less than $100^{\circ}C$), simple steps, short time consuming, without catalyst, and relatively ease to control than as mentioned various methods. In this work, we investigate the dependence of ZnO nanowire alignment and morphology on si substrate using of nanosphere template with various precursor concentration and components via hydrothermal process. The brief experimental scheme is as follow. First synthesized ZnO seed solution was spun coated on to cleaned Si substrate, and then annealed $350^{\circ}C$ for 1h in the furnace. Second, 200nm sized close-packed nanospheres were formed on the seed layer-coated substrate by using of gas-liquid-solid interfacial self-assembly method and drying in vaccum desicator for about a day to enhance the adhesion between seed layer and nanospheres. After that, zinc oxide nanowires were synthesized using a low temperature hydrothermal method based on alkali solution. The specimens were immersed upside down in the autoclave bath to prevent some precipitates which formed and covered on the surface. The hydrothermal conditions such as growth temperature, growth time, solution concentration, and additives are variously performed to optimize the morphologies of nanowire. To characterize the crystal structure of seed layer and nanowires, morphology, and optical properties, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and photoluminescence (PL) studies were investigated.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.1
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• pp.25-34
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• 2008

Objectives The purpose of this study is to investigate whether Korean oriental pediatrics hospitals are using their feedback surveys to improve their medical conditions. Methods We selected 24 oriental medicine university hospitals and sent surveys to investigate. 15 of those surveys were analyzed. Results The results were classified as follows; Only 9 of university hospital said that they are currently using their feedback surveys to improve their services. Question for asking the purpose of doing their feedback surveys, 58.3% of hospital responded to get some information for diagnosis, 25% of them said to see the progress of treatment of specific disease, and 16.7% answered for using their data to the further studies. The question about the reason why hospital were need to make these feedback surveys, 46.2% of them answered to apply better service, 38.4% of them said to post medical journal. The question for asking what do oriental medical hospitals check from feedback surveys, 40% of them said they check Ryodoraku, 33.3% was pulse diagnostic apparatus, EAV(Electro-puncture According to Voll) was 26.7%. The classification according to purpose of test resulted as follows; information for diagnosis was 48.1%, the progress of a disease was 37.3%. In addition oriental medical test there were blood test, radiological test, brain waves test, Hair Tissue Mineral Analysis(HTMA), ultrasonic test, body composition analysis. Conclusions Further clinical research is necessary for improvement of using the feedback survey effectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.224-228
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• 2006

The pattern identification of exterior-interior syndrome and cold-heat syndrome is one of the diagnostic methods using most frequently in Oriental medicine. There was no systematic studies analyzing the characteristics of the 'exterior-interior and cold-heat' between healthy and disease group. In this study, cold-heat pattern, blood pressure, pulse rate, height and weight are recorded from 100 healthy subjects and 196 disease subjects with age ranging from 30 to 59 years. To analyze the differences between healthy and disease group, we used the descriptive statistics. And linear regression function, linear support vector machine and bayesian classifier were used for distinguishing healthy group from disease group. The score of both exterior-heat and interior-cold in healthy group is higher than the score in disease group. This means that if one belongs to the disease group, his(or her) exterior gets cold and his interior gets hot. And also, these result have no relevance to age. But, the attempt to classify healthy group from disease group with a exterior-interior and cold-heat and other vital signs did not have good performance. It mean that even though they have a different trend each other, only these kinds of information couldn't classify healthy group and disease group.

• The Korean Nurse
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• v.33 no.1
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• pp.37-51
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• 1994

The cutaneous stimulation is an independent nursing intervention used in various painful conditions, and is explained by gate control theory. This study was aimed at identifying the effect of cutaneous stimulation on reduction of arteriovenous fistula puncture pain of hemodialysis patients. One group repeated measurement post test research was designed. Forty-five hemodialysis patients who received arteriovenous fistula puncture regulary in hemodialysis units of an attacted D hospital to K university have been studied from August 16 to 21, 1993. First the arteriovenous fistula puncture pain of control period was measured, and then the arteriovenous fistula puncture pain of experimental period(with cutaneous stimulation) was measured. The instrument used for this study were visual analogue pain scale as subjective pain measurement, objective pain behavior checklist and Spielberger's Trait Anxiety Inventory as intervening variables. Analysis of data was done by use of paired t-test, t-test, ANOVA and Perarson correlation coefficient. The results of this study were summarized as follows; 1) The first hypothesis that the subjective pain score of arteriovenous fistula puncture pain in experimental period(with cutaneous stimulation) will be lower than in control period was partly supported. The subjective pain score of arterial line was rejected(paired t=-0.28, p=0.77) and the subjective pain score of venous line was supported(paired t=2.61, p=0.01). 2) The second hypothesis that the objective pain behavior score of arteriovenous fistula pain in experimental period(with cutaneous stimulation) will be lower than in control period was rejected(arterial line paired t=-0.45, p=0.65; venous line paired t=-0.36, p=0.72). 3) The third hypothesis that the cardiopulmonary signs of arteriovenous fistula puncture pain in experimental period(with cutaneous stimulation) will be lower than in control period was rejected(pulse paired t=-0.8, p=0.42; systolic BP paired t=0.98, p=0.33; diastolic BP paired t=0.43, p=0.66). Further experimental studies with simple intravenous injection patients will be recommended in order to identify the effect of cutaneous stimulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.278-281
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• 2012

Numerical studies were performed to investigate the three-dimensional front structure and dynamics features of detonation wave propagating in a circular tube such as Pulse Detonation Engine (PDE). By carrying out a series of parametric study using one step irreversible Arrhenius kinetics model, mechanisms of the three-dimensional front structure were investigated for two-, three-, four and six-cell mode detonations. A comparison with two-dimensional results, the effects of slapping transverse waves in radial direction were confirmed. In the all muti-cell modes, the detonation front structures and smoked-records on the wall are formed by the propagation of transverse waves along the wall in clockwise and counter-clockwise while the slapping move in radial direction. And the strength of reflected waves on the curved wall is changed by the multi-dimensional confinement effect.

• Journal of Korean Medicine for Obesity Research
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• v.12 no.2
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• pp.28-43
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• 2012

Objectives: The aim of the study was to investigate the efficacy of Boiogito for obesity. We examined the efficacy of Boiogito for obese patients and we expected the reaction of Boiogito would vary according to the single nucleotide polymorphism(SNPs). Methods: 111 subjects(body mass index${\geq}25m/kg^2$) were recruited and randomized to receive Boiogito(n=55) or Placebo(n=56) for 8weeks. Anthropometric factors, serum lipid profile, glucose, blood pressure(BP), pulse rate, resting metabolic rate and Korean version of obesity-related quality of life(KOQOL) scale measured at baseline and 8weeks. SNPs(${\beta}3$-adrenergic receptor(ADRB3), G protein ${\beta}3$(GNB3), peroxisome proliferator activated receptor gamma 2 gene(PPAR-${\gamma}2$), uncoupling protein(UCP2)) were conducted at baseline. Adverse reactions and safety outcome variables were also checked during trials. Results: Both groups showed significant improvement on obesity after treatment. Boiogito group decreased triglyceride than did control group and improved KOQOL. Boiogito showed a significant higher efficacy in C/T and T/T genotype of GNB3 gene / in Trp64 and Arg64 genotype of ADRB3 gene / in D/D genotype of UCP2 gene / in Pro/Pro genotype of PPAR-${\gamma}$ gene. Conclusions: Boiogito promoted obesity indexes without severe adverse reactions and proved its safety. Pharmacogenetical studies of Boiogito on obesity could be a effective method for the individualized treatment and prevention of obesity.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.322-329
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• 2021

Nano-cementitious composites may have defects due to poor dispersion of nanomaterials and fabrication process. These defects can cause critical problems for nano-cementitious composites, but studies related to non-destructive analysis of defects sizes inside nano-cementitious composites are insufficient. This study aims to perform non-destructive analysis of nano-cementitious composites by utilizing ultrasonic and electrical resistance. Various sizes of defects were implemented inside the specimens and the specimens were subjected to ultrasonic non-destructive analysis and electrical resistance non-destructive analysis depending on the size of defects and curing days. As a result of the experiment, ultrasonic pulse velocity decreased by up to 11% as the defects size increased, and the electrical resistance increased by up to 14% depending on the defects size. For this reason, this study concluded that non-destructive analysis using ultrasonic and electrical resistance can predict defects inside nano-cementitious composites.

• Geomechanics and Engineering
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• v.25 no.1
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• pp.41-48
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• 2021

In cold regions, the integrity of the infrastructures built on weak soils can be extensively damaged by weathering actions due to the cyclic freezing and thawing. This damage can be mitigated by exploiting soil stabilization techniques. Generally, ordinary Portland cement (OPC) is the most commonly used binding material for investigating the chemo-hydromechanical behavior. However, due to the environmental issue of OPC producing a significant amount of carbon dioxide emission, calcium sulfoaluminate (CSA) cement can be used as one of the eco-sustainable alternatives. Although recently several studies have examined the strength development of CSA treated sand, no research has been concerned about CSA cement-stabilized sand affected by cyclic freeze and thaw. This study aims to conduct a comprehensive laboratory work to assess the effect of the cyclic freeze-thaw action on strength and durability of CSA cement-treated sand. For this purpose, unconfined compressive strength (UCS) and ultrasonic pulse velocity (UPV) tests were performed on the stabilized soil specimens cured for 7 and 14 days which are subjected to 0, 1, 3, 5, and 7 freeze-thaw cycles. The test results show that the strength and durability index of the samples decrease with the increase of the freeze-thaw cycles. The loss of the strength and durability considerably decreases for all soil samples subjected to the freeze-thaw cycles. Overall, the use of CSA as a stabilizer for sandy soils would be an eco-friendly option to achieve sufficient strength and durability against the freeze-thaw action in cold regions.

• Korean Journal of Optics and Photonics
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• v.32 no.2
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• pp.62-67
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• 2021

We have experimentally demonstrated sum-frequency generation (SFG) in a periodically poled lithium niobate (PPLN) crystal, using a mode-locked picosecond-pulsed fiber laser and a continuous-wave (CW) diode laser with a narrow linewidth. The mode-locked fiber laser had a center wavelength of 1560.7 nm and a spectral width of 1.1 nm, and the CW diode laser had a center wavelength of 1551.0 nm and a spectral width of 6 MHz. To effectively realize SFG, both of the spatial modes of the two lasers were made to overlap in the PPLN crystal by using a single-mode optical fiber. The pulse-mode SFG with pulsed- and CW-mode lasers was successfully observed in the spectral and time domains. These results are expected to be applicable in various ways, such as optical frequency measurement and high-resolution laser spectroscopy studies using optical frequency combs.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.412-417
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• 2019

This study was proposed to investigate vital signs in subjects undergoing high magnetic field (3T) MR imaging for provide basic data on causes of claustrophobia as few previous studies were conducted on this special issue. Vital signs of 104 patients were monitored before and during the clinically indicated MR examinations to identify any relationship between MR scanning and the vital signs. An increase of systolic, diastolic blood pressure and pulse pressure were observed. However, they were not statistically significant(p>0.05), which meant the vital signs measured before and during the MRI scanning showed no significant change. This study is considered to be meaningful basic data for analyzing the links between vital sign fluctuations on claustrophobia during routine clinical MR examinations.