• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.865-878
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• 1996

We consider numerical methods for finding a solution to a nonlinear system of algebraic equations $$ (1) f(x) = 0, $$ where the function $f : R^n \to R^n$ is ain $x \in R^n$. In [10], a quasi-Gauss-Newton method is proposed and shown the computational efficiency over SQRT algorithm by numerical experiments. The convergence rate of the method has not been proved theoretically. In this paper, we show theoretically that the iterate $x_k$ obtained from the quasi-Gauss-Newton method for the problem (1) actually converges to a root by Kantorovich-type convergence analysis. We also show the rate of convergence of the method is superlinear.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.5-17
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• 1970

The effects of Physical exercise, gymnastics and sports on the cardiopulmonary function were studied in the middle and high school toys. The subjects were divided into 4 groups; non-training group and training group in both middle school and high school boys. In the above groups, pulmonary function studies were performed, and blood pressure and the heart rate were also checked to evaluate physical fitness during and immediately after running exercise on the tread-mill, with the speed of 5 MPH and elevation of 9% and 11.25%. The types of sports in the training group were base ball, body building, Taekwondo (Korean style boxing) and hand ball. The results obtained were as followings: 1) In the training group, cardiopulmonary function showed some tendency of the increase comparing to the non-training group. 2) The increase in cardiopulmonary function was observed according to the age became older, but the clear changes on cardiopulmonary function was not observed as the difference of the group between the training and the non-training. 3) The expiratory volume was decreased as the increase of age except 17 years of age for the value of the per kg body weight. 4) In the non-training group, the mean value of oxygen consumption under maximum work load was increased, while those in the training group was decreased. But it may be noted that oxygen consumption for the expiratory volume was increased in the training group, and that the oxygen cost in the training group was .higher than that of the non-training group. 5) The pulse pressure of the high school group during and immediately after running exercise was observed in the higher value comparing with that of the middle school group It was suggested that the changes of the pulse pressure was owing to the method of determination and that to the decrease of diastolic pressure caused by the decrease of peripheral vascular resistance up to critical closing pressure. 6) Any differences of the changes in the heart rate between the training group and non-training group was not observed during and immediately after running exercise. 7) The relative value of the expiratory volume to the heart rate was decreased in the elder age group.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.132-139
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• 2009

The objective of this study was to investigate the most effective analysis methods for palatability grading of Hanwoo beef by comparing the results of discriminant analysis with sensory data. The sensory data were obtained from sensory testing by 1,300 consumers evaluated tenderness, juiciness, flavor-likeness and overall acceptability of Hanwoo beef samples prepared by boiling, roasting and grilling cooking methods. For the discriminant analysis with one factor, overall acceptability, the linear discriminant functions and the non-parametric discriminant function with the Gaussian kernel were estimated. The linear discriminant functions were simple and easy to understand while the non-parametric discriminant functions were not explicit and had the problem of selection of kernel function and bandwidth. With the three palatability factors such as tenderness, juiciness and flavor-likeness, the canonical discriminant analysis was used and the ability of classification was calculated with the accurate classification rate and the error rate. The canonical discriminant analysis did not need the specific distributional assumptions and only used the principal component and canonical correlation. Also, it contained the function of 3 factors (tenderness, juiciness and flavor-likeness) and accurate classification rate was similar with the other discriminant methods. Therefore, the canonical discriminant analysis was the most proper method to analyze the palatability grading of Hanwoo beef.

• Korean Journal of Pharmacognosy
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• v.50 no.1
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• pp.37-45
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• 2019

Portulaca oleracea L. (PL) has been used in traditional medicine herb for treatment of various diseases, such as diarrhea, dysentery, and skin inflammation. Previous studies have shown that the PL regulates the inflammation by inhibition of pro-inflammatory cytokines. Although PL might have improvement effects of intestinal function and bioactive effects, there are not enough studies to demonstrate. This study investigated the effects of KDC16-2 on the improvement of intestinal function and anti-inflammatory effects in vivo and in vitro. The improvement effect of intestinal function was measured fecal amount, water content and intestinal transit rate in KDC16-2 treated ICR mice. As results, compared with the control group, the KDC16-2 group showed a significant increase in wet fecal weight, dry fecal weight and fecal water content. The intestinal transit rate of KDC16-2 group was significantly increased. Based on the results, KDC16-2 is considered to have effects on improving intestinal function. The effect of anti-inflammatory demonstrated by using dextran sulfate sodium (DSS)-induced colitis mice. The mice were administered 3% DSS along with KDC16-2 (100, 300 mg/kg) for 14 days. DSS-induced colitis mice were significantly ameliorated in KDC16-2 treated group, including body weight loss, colon length shortening, tight junction protein of colon and histological colon injury. The levels of inflammatory mediators (IgG2a, IgA, C-reactive protein and Myeloperoxidase) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-${\alpha}$, Interleukin (IL)-6) which are involved in inflammatory responses were increased in the DSS-treated group as compared to those in the control group, and the levels were significantly decreased in the KDC16-2 groups. In addition, we investigated the impact of KDC16-2 on lipopolysaccharide (LPS)-induced inflammatory responses in J774A.1 cells. KDC16-2 inhibited production of prostaglandin E2 (PGE2) and reactive oxygen species (ROS). These results suggested that the KDC16-2 could effectively alleviate the dysfunction of intestinal and inflammatory mediators. Thus, these KDC16-2 can be potentially used as health functional food of intestinal.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.123-128
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• 2003

This paper has addressed the implementation of the single rate Rate Adaptive Shaper(srRAS) described in RFC2963. This shaper has been proposed to use at the ingress of differentiated services networks providing Assured Forwarding Per Hop Behavior (AFPHB). srRAS is typically used in conjunction with single rate Three Color Marker(srTCM) described in RFC2697. srRAS itself is the tail-drop FIFO that is drained at a variable rate, and srTCM is the marker with metering function. G-srRAS is the same as srRAS except that RAS receives the green token state information from the downstream srTCM to avoid delaying a packet in RAS although there are sufficient tokens available to color the packet green. In this paper, we have addressed the algorithm and the architecture of srRAS, and the scheme to implement srRAS using VHDL(Very high-speed integrated circuit Hardware Description Language) and its related tools.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.48-53
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• 2006

A methodology is described for predicting the fatigue life of the resistance spot weldment including strain rate effect. Because it is difficult to perform a physical failure test with high strain rate, an analytical method is necessary to get the mechanical properties of various strain rate, To this end, quasi-static tensile-shear tests at several strain rate were performed on spot weldments of SPC. These test provided the empirical data with the strain rate. With these results, we formulated the function of fatigue life prediction using the lethargy coefficient which is the global material property from tensile test. And, we predicted the fatigue life of spot weldment at dynamic strain rate. To confirm this method for fatigue life prediction, analytical results were compared with the experimental fatigue data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.305-310
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• 2008

Deep trench etching of silicon was investigated as a function of RF source power, DC bias voltage, $C_4F_8$ gas flow rate, and $O_2$ gas addition. On increasing the RF source power from 300 W to 700 W, the etch rate was increased from $3.52{\mu}m/min$ to $7.07{\mu}m/min$. The addition of $O_2$ gas improved the etch rate and the selectivity. The highest etch rate is achieved at the $O_2$ gas addition of 12 %, The selectivity to PR was 65.75 with $O_2$ gas addition of 24 %. At DC bias voltage of -40 V and $C_4F_8$ gas flow rate of 30 seem, We were able to achieve etch rate as high as $5.25{\mu}m/min$ with good etch profile.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.500-506
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• 2017

In 2014, ISO 55000s has been enacted and the power plant asset management is becoming a hot issue for all over the world. The asset management system is being developed as a combination of CBM(Condition Based Maintenance) and RCM(Reliability Centered Maintenance). Therefore, the research on the calculation of the failure rate which is the most basic index of RCM is actively carried out. The failure rate calculation has been going on for a long time, and the most widely used probability distribution is the Weibull distribution. In the Weibull distribution, the failure rate function is determined in three types according to the value of the shape parameter. However, the Weibull distribution has a limitation that it is difficult to apply it when the trend of failure rate changes-such as bathtub curves. In this paper, the failure rate is calculated using the mixture Weibull distribution which can appropriately express the change of the shape of the failure rate. Based on these results, we propose the necessity and validity of applying mixture Weibull distribution.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1060-1068
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• 2019

This work aims to establish a model of a primary water stress corrosion crack growth rate of Alloy 690 material for the head penetration nozzles of Korean pressurized water reactors. The test material had an inhomogeneous microstructure with bands of fine-grains and intragranular carbides in the matrix of coarse-grains, which was similar to the archive materials of the head penetration nozzles. The crack growth rate was measured from the strain-hardened materials as a function of the stress intensity factor in simulated primary water at various temperatures and dissolved hydrogen contents. The effects of strain-hardening, temperature, and dissolved hydrogen on the crack growth rate were analyzed independently, and were then introduced as normalizing factors in the crack growth rate model. The crack growth rate model proposed in this work provides a key element of the tools needed to assess the progress of a stress corrosion crack when detected in thick-wall Alloy 690 components in Korean reactors.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.588-593
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• 2005

Purpose : Obesity is associated with disturbances of ventilatory functions in adults. But few studies have evaluated the pulmonary complications of obesity in the pediatric population. The purpose of this study is to clarify the effects of obesity on pulmonary function and body composition in obese children. Methods : Forty seven obese children whose ages ranged from nine to twelve years were evaluated for their body composition(intracellular fluid, extracellular fluid, protein mass, mineral mass, soft lean mass, fat mass, percent body fat, fat distribution) by bioelectrical impedance analysis. Hemoglobin, serum glucose, aspartate aminotransferase(AST), alanine aminotransferase(ALT), total cholesterol and triglycerides were measured. Pulmonary function test was performed by spirometer. Results : Intracellular fluid, protein mass, fat mass, percent body fat and fat distribution were significantly higher in severely obese children with an obesity index of more than 150 percent compared with those with an index of less than 150 percent. Peak expiratory flow rate(PEFR) was significantly lower in severely obese children with obesity index of more than 150 percent compared with those with less than 150 percent($241.7{\pm}14.6L/sec$ vs $276.8{\pm}64.3L/sec$). PEFR, forced expiratory flow 25 percent($FEF_{25}$), mid expiratory flow rate(MEFR), forced expiratory flow 50 percent($FEF_{50}$), forced expiratory volume in 1st second($FEV_1$) and forced vital capacity(FVC) were decreased in 37.0 percent, 14.8 percent, 14.8 percent, 11.1 percent, 3.7 percent and 3.7 percent of obese children, respectively. Conclusion : PEFR was significantly decreased in obese children. Pulmonary function test must be performed in severely obese children and more extended study is needed in other age groups.