• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.365-373
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• 2009

Since 1990, identifying the sex of fetus and illegal abortion has brought the sex ratio imbalance at birth in Korea due to a notion of preferring a son to a daughter, socio-economic development, population policy, and so forth. Although there have been many researches such as time series analysis and region difference analysis to monitor this sex ratio imbalance, they have a defect that time and space could not be included in the analysis simultaneously. This study analyzes the sex ratio imbalance at birth, taking into account time and region at the same time. The analysis considered the numbers of male and female babies, who were born as the third or latter in their families, in 2000 and 2001 at 234 Gu / Si / Goon administrative districts. Here, we suggest a mixture model of binomial distributions, assuming heterogeneous populations. The estimation of the location parameters, weights and correlation coefficient of the mixture model is conducted by the EM algorithm, and the heterogeneity of the regions is expressed as a picture using ArcView GIS.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.241-250
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• 2011

The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has clearly become a public health issue. To date many $in$ $vivo$ and $in$ $vitro$ studies revealed that EMF exposure can alter cellular metabolism, endocrine function, immune activity, reproductive function, and fetal development in animal system. The major parameters found to be altered in cells or individuals following EMF exposure include an increase of free radicals, DNA damage, cancer risk, developmental defect, and reproductive dysfunctions. Epidemiological studies reported EMF can increase life-threatening illnesses such as leukemia, brain cancer, amyotrophic lateral sclerosis, clinical depression, suicide, and Alzheimer's disease has been identified. These effects of EMF exposure differ according to duration of exposure, frequency of waves, and strength (energy) of EMF. In the present review, we briefly introduced the physical properties of EMF and summarized the effect of EMF on human and wildlife animals according to types of EMF, duration of exposure at cellular and organism levels.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.2
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• pp.169-176
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• 2001

In modern industry, the accuracy and the sulfate-finish requirements for machined parts have been becoming ever more stringent. In addition, the measurement and understanding of surface topography is rapidly attracting the attention of the physicist and chemist as well as the engineer. Optical measuring method is used in vibration measurement, crack and defect detection with the advent of opto-mechatronics, and it is expected to play an important role in surface topography. In this study, the principle of confocal microscope is described, and the advanced 3-D surface measuring system that has better performance than the traditional confocal microscope is developed. Suitable fixtures arc developed and integrated with the computer system for generating 3-D surface and form data. Software for data acquisition and analysis of various parameters in surface geometrical features has been developed.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.564-569
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• 2013

Background Scalp defects may be caused by various etiological factors, and they represent a significant surgical and aesthetic concern. Various surgical techniques can be applied for reconstructive work such as primary closure, skin grafting, pedicled or free flaps. In this article, the authors share their clinical experience with scalp operations using the technique of local flaps and discuss the application of this method from the perspective of not only the size of the defect, but also in relation to the anatomical area, quality of surrounding tissue, and patient's condition. Methods During the period from December 2007 to December 2012, 13 patients with various scalp defects, aged 11 to 86 years, underwent reconstruction with local pedicle flaps. The indications were based on the patients' condition (age, sex, quality of surrounding tissue, and comorbidities) and wound parameters. Depending on the size of the defects, they were classified into three groups as follows: large, 20 to 50 $cm^2$; very large, 50 to 100 $cm^2$; extremely large, 100 $cm^2$. The location was defined as peripheral (frontal, temporal, occipital), central, or combined (more than one area). We performed reconstruction with 11 single transposition flaps and 1 bipedicle with a skin graft on the donor area, and 2 advancement flaps in 1 patient. Results In all of the patients, complete tissue coverage was achieved. The recovery was relatively quick, without hematoma, seroma, or infections. The flaps survived entirely. Conclusions Local flaps are widely used in scalp reconstruction since they provide healthy, stable, hair-bearing tissue and require a short healing time for the patients.

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.129-138
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• 2009

Purpose: This study was designed to compare the bond regeneratiom effects of treatment using silk fibroin membrane ( Nanogide-S$^{(R)}$ ) resorbable barrier with control group treated by polyactic acid / polylacticglycolic acid membrane(Biomesh$^{(R)}$ ) Methods: 44 severe bone loss on extraction socket from 44 patients were used in this study. In experimental group 22 sites of them were treated by silk fibrin membrane as and the other 22 sites were treated by polyactic acid/ polylacticglycolic acid membrane as a control group. Clinical parameters including recovered bone width, length and radiographic parameter of vertical length were evlauated at base line and 3 months after surgery. Results: 1) Severe bone width, length was significantlly decreased in two group. 2) Bone width, length was significantlly decreased in two group. 3) Decreased bone width, length and radiographic examination differences between group. Conclusions: On the basis of these results, silk fibrin resorbable membrane has similar bone regeneration ability to polyactic acid / polylacticglycolic acid membrane in guided bone regeneration for severe bone loss defect on extraction socket.

• Archives of Reconstructive Microsurgery
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• v.14 no.2
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• pp.152-156
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• 2005

Purpose: We reconstructed the thumb with groin flap combined with secondary heterodigital neurovascular island flap and report our 6 cases. Materials and Methods: Between March 2003 and August 2004, 6 degloving thumbs or amputation of thumbs were reconstructed with groin flap combined with secondary heterodigital neurovascular island flap. There ware 4 men and 2 women, and mean age was 42.2 years. The following parameters were evaluated. Results: Recipient thumb was no limitation of apposition. but flexion contracture of interphalangeal joint was about 10 degree in two cases. Average grip power were 80% and average pinch power were 70% that of the normal thumb. The two point discrimination was average 10.5 mm and double sensibility in 2 cases. 2 patients have cold intolerance. Neuroma formation was not made. Cosmetic results as judged by patients were that 4 cases are good and 2 cases are fair. Conclusion: If massive skin defect after degloving thumb or amputation of thumb are present, we consider the numerous methods for reconstruction of thumb. This surgical procedure is good methods because of it's pliability, sensation, satisfactory functional results but major disadvantage are the staged operation and cosmetic effect of the absence of thumb nail.

• Journal of IKEEE
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• v.26 no.2
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• pp.306-312
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• 2022

We investigated electrical properties and deep level traps in 4H-SiC merged PiN Schottky (MPS) diodes with different barrier heights by different PN ratios and metallization annealing temperatures. The barrier heights of MPS diodes were obtained in IV and CV characteristics. The leakage current increased with the lowering barrier height, resulting in 10 times larger current. Additionally, the deep level traps (Z_1/2 and RD_1/2) were revealed by deep level transient spectroscopy (DLTS) measurement in four MPS diodes. Based on DLTS results, the trap energy levels were found to be shallow level by 22~28% with lower barrier height It could confirm the dependence of the defect level and concentration determined by DLTS on the Schottky barrier height and may lead to incorrect results regarding deep level trap parameters with small barrier heights.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.413-417
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• 2002

Gitelman's syndrome is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria that has recently been reported to be linked to thiazide- sensitive Na-Cl cotransporter gene mutation. In this study, we performed renal clearance studies to differentiate Gitelman's from Bartter's syndrome and to confirm the diagnosis in two patients clinically diagnosed with Gitelman's syndrome. Each patient was hydrated by 20 mL/kg body weight of oral water within 30 minutes, which was followed by intravenous half saline. When urinary flow reached 10 mL/min, samples of urine and serum were obtained to calculate the osmolar clearance, free water clearance, chloride clearance, and distal fractional chloride reabsorption. Subsequently, furosemide or hydrochlorothiazide was administered. Samples were collected and the same parameters were calculated. In our patients, chloride clearance was increased more than 10 times after furosemide administration(2.1 : 25.7 and 2.2 : 27.4 mL/min/100 mL GFR), but not increased after hydrochlorothiazide treatment(2.1 : 1.6 and 2.2 : 2.6 mL/min/100 mL GFR). And the distal fractional chloride reabsorption was significantly decreased by furosemide injection (73% : 15% and 75% : 4.6%), whereas hydrochlorothiazide had no effect on it(73% : 63% and 75% : 78%). These findings indicate that our patients have a defect in thiazide-sensitive Na-Cl cotransporter in the distal tubule, which is compatible with the pathophysiology of Gitelman's syndrome.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.423-435
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• 1998

In this paper fatigue strength reduction of butt weld with penetration defect, which can be seen frequently in the steel bridge, was assessed quantitatively. S-N curves were derived and investigated through the constant amplitude fatigue test of fully or partially penetrated welded specimen made of SWS490 steel. The fracture mechanical method was applied in order to calculate the remaining fatigue life of the partially penetrated butt welds. The fatigue limit of the fully penetrated butt welds was higher than that of category A in AASHTO's fatigue design curves, and the slope of S-N curves with 5.57 was stiffer than that of other result for welded part generally accepted as 3. The fatigue strength of the partially Penetrated butt weld was strongly influenced by the size of lack of penetration, D. It decreased drastically with increasing D from 3.9 to 14.7mm. Fracture behaviour of the partially penetrated butt weld is able to be explained obviously from the beach mark test that a semi-elliptical surface crack with small a/c ratio initiates at a internal weld root and propagates through the weld metal. To estimate the fatigue life of the partially penetrated butt weld with fracture mechanics, stress intensity factors K of 3-dimensional semi-elliptical crack were calculated by appling finite elements method and fracture mechanics parameters such as C and m were derived through the fatigue test of CT-specimen. As a result, the fatigue lives obtained by using the fracture mechanical method agreed well with the experimental results. The results were applied to Sung-Su bridge collapsed due to penetration defects in butt weld of vertical member.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.65-69
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• 1974

Noodles were made from composite flours based on barley or sweet potato/wheat flour and their quality was assessed to obtain the following results. 1) In noodle sheet and dried noodle formation, barley flour could substitute 100% and sweet potato flour, 70% of wheat flour and their textural characteristics were improved by addition of glyceryl monostearate and sodium polycrylate. 2) Textural parameters such as hardness, cohesiveness and gumminess of noodle sheet and dried noodle were decreased by admixture of barley of sweet potato flour whereas they were increased by use of the additives. Noodle sheet required hardness over 6.2 and gumminess over 430 while dried noodle needed hardness over 6.8. 3) In cooked noodle, replacement of wheat flour and use of additives tended to lower the textural parameters. With respect to the cooking quality, barley flour could substitute 60% and sweet potato flour, 40% of wheat flour. 4) In organoleptic evaluation of cooked noodle with respect to its color, taste and texture, 20% replaced composite flour was not different significantly at 5% level from wheat flour and the quality defect was mainly due to discoloration of the product.