• Korean Chemical Engineering Research
• /
• v.48 no.1
• /
• pp.110-115
• /
• 2010

The experiment was designed to compare pyrolysis kinetics of two different classes of imported coal. The pyrolysis behaviors of the coals were first observed with thermogravimetric analyzer(TGA). The kinetic analysis was further done based on a new distributed activation energy model(New DAEM). During the analysis, weight loss curves measured at three different heating rates were used to obtain the activation energy distribution function curve f(E) of a given coal sample where a mean activation energy is determined by its peak. The results show a significant difference in the mean activation energy between two coals for the pyrolytic reaction. The prediction of a chemical percolation devolatilization(CPD) model where the kinetics obtained from the New DAEM method were incorporated is in much closer agreement with an experimental data of TGA particularly for the bituminous coal.

• Journal of Ecology and Environment
• /
• v.38 no.3
• /
• pp.327-334
• /
• 2015

We investigated the current and potential spatial distributions and habitable areas of Biston robustum and Camellia japonica in South Korea in order to provide useful data for the conservation of C. japonica and minimize the damage caused by B. robustum. It was predicted that, by 2070, although B. robustum would be widely distributed throughout the Korean Peninsula, except for the western and eastern coastal areas, it would be narrowly distributed along the Sokcho-si and Goseong-gun coastlines in Gangwon Province. C. japonica is currently located along the southern coastline but its critical habitable area is predicted to gradually disappear by 2070. Assessment of the potential distribution probabilities of B. robustum and C. japonica revealed that the area under the curve (AUC) values were 0.995 and 0.991, respectively, which indicate high precision and applicability of the model. Major factors influencing the potential distribution of B. robustum included precipitation of wettest quarter and annual precipitation (BIO16 and BIO12), whereas annual mean temperature and mean temperature of wettest quarter (BIO1 and BIO8) were important variables for explaining C. japonica distribution. Overlapping areas of B. robustum and C. japonica were $11,782km^2$, $5447km^2$, and $870km^2$ for the current, 2050-predicted, and 2070-predicted conditions, respectively, clearly showing a dramatic decrease in area. Although it is predicted that B. robustum would cause continuous damage to C. japonica in the southern part of the Korean Peninsula, such impacts might diminish over time and become negligible in the future.

• The Journal of Pediatrics of Korean Medicine
• /
• v.30 no.4
• /
• pp.87-98
• /
• 2016

Objectives The purpose of this study is to evaluate the effect of herbal medicine in children's growth. Methods 51 children from the age of 5 to 16 were participated in this study (27 of boys and 24 of girls). The participants were from the department of the pediatrics in Daegu hanny university oriental medical hospital. They were measured their body composition and their bone age, the height percentile of their first and the last visit. Then, those were compared by the Korean Association of Pediatrics' Growth Statistics Curve. Results 1. Generally, total children's average height and weight were significantly increased after the herbal medical treatment. The differences between their height and the general populations' average height, their weight and general populations' average weight were significantly decreased after the treatment. 2. Total children's average soft lean mass, body fat mass, BMI were also significantly increased after the herbal medical treatment. 3. The mean height percentiles of the children has increased by 1.47 percentile. The mean weight percentiles of the children decreased 1.08 percentile. 4. The height percentiles were increased in every group except the group of boys younger than 9 and older than 12 year old. Other than the group of boys younger than 9-year-old and the group of 10-11-year-old boys, every group showed decreasing weight percentile. Conclusions The herbal medical treatment helped children with growth retardation.

• Clinical and Experimental Pediatrics
• /
• v.61 no.3
• /
• pp.84-89
• /
• 2018

Purpose: Timely antibiotic therapy in selected cases of diarrhea associated with bacterial infections can reduce the duration and severity of illness and prevent complications. The availability of a predictive index before identification of causative bacteria would aid in the choice of a therapeutic agent. Methods: The study included patients admitted to the pediatrics unit at Konyang University Hospital for acute inflammatory diarrhea from August 1, 2015 to July 31, 2016 who underwent multiplex polymerase chain reaction testing. Of 248 patients, 83 had positive results. The clinical symptoms and blood test results were examined in 61 patients with Campylobacter spp. (25 patients), Salmonella spp. (18 patients), and Clostridium perfringens (18 patients) infections. The mean age of the 61 patients (male:femal=31:30) was $84.0{\pm}54.8months$, and the mean hospital stay was $4.6{\pm}1.7days$. Results: There were no statistical differences in sex, age, clinical symptoms, or signs. Patients with Campylobacter infection were significantly older (P=0.00). C-reactive protein (CRP) levels in patients with Campylobacter infection were higher than those in the other 2 groups, at $9.6{\pm}6.1mg/dL$. The results of receiver-operating characteristic curve analysis showed that the cutoff age was ${\geq}103.5months$ (sensitivity, 72%; specificity, 86%) and the CRP cutoff level was ${\geq}4.55mg/dL$ (sensitivity, 80%; specificity, 69%). Conclusion: Age (${\geq}103.5months$) and higher CRP level (${\geq}4.55mg/dL$) were good predictors of Campylobacter enterocolitis. If neither criterion was met, Campylobacter enterocolitis was unlikely (negative predictive value 97.2%). When both criteria were met, Campylobacter enterocolitis was highly likely.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.5
• /
• pp.722-730
• /
• 2001

The local heat transfer of an axisymmetric submerged air jet impinging on a heated flat plate is investigated experimentally with the variation of mesh-screen solidity. The screen installed in front of the nozzle exit modifies the flow structure and local heat transfer characteristics. The mean velocity and turbulence intensity profiles of streamwise velocity component are measured using a hot-wire anemometry. The temperature distribution on the heated flat surface is measured with thermocouples. The smoke-wire flow visualization technique was employed to understand the near-field flow structure qualitatively for different mesh screens. Large-scale toroidal vortices and high turbulence intensity enhance the heat transfer rate in the stagnation region. For a higher solidity, turbulence intensity become higher which increases the local heat transfer at small nozzle-to-plate spacings such as L/D<6. The local and average Nusselt numbers of impinging jet from the $\sigma$(sub)s=0.83 screen at L/D=2 are about 5.6∼7.5% and 7.1% larger than those for the case of no screen, respectively. For the nozzle-to-plate spacings larger than 6, however, the turbulence intensities for all tested screens approach to an asymptotic curve and the mean velocity along the jet centerline decreases monotonically. As the nozzle-to-plat spacing increases for high solidity screens, the heat transfer rate decreases due to the reduction in turbulence intensity and jet momentum.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.12
• /
• pp.1391-1400
• /
• 1992

In this paper, we suggested a method for evaluating the type-I/II error which is proposed by the CCITT as a criterion for the accuracy of policing algorithms in ATM networks, By the analysis of the type-I/II error of the Leaky Bucket(LB) algorithm, we investigated the relationships between the traffic parameters and the LB parameters to police the mean and peak cell rate effectively in the ON/OFF traffic. We showed that the LB parameters, the leaky rate a and the threshold M of the LB counter, could be determined as a pair of (a, M) satisfying the type-I/II error and minimizing the response time. In the ON/OFF traffic, it has been observed that the a-M characteristic curve of the LB policing algorithm only depends on the burstiness. As the results of the performance analysis, we found that the LB algorithm exhibits a good performance in the peak rate policing, but has some problems in the mean rate policing due to the trade-off between the accuracy and the response time.

• The Journal of Pediatrics of Korean Medicine
• /
• v.25 no.1
• /
• pp.49-62
• /
• 2011

Objectives: The purpose of this study is to evaluate the effect of the herbal medicine in children's growth. Methods: 67 of the children in the age from 3 to 16 were participated in this study(31 of boys and 36 of girls). Department of the pediatrics, $\bigcirc\bigcirc$ university oriental medical hospital, and the participants were measured their body composition and their bone age, the height percentile of the first and the last visit were measured, and those were compared by the Korean Association of Pediatrics' Growth Statistics Curve. Results: 1. Generally, total children's average height and weight were significantly increased after the herbal medical treatment. The comparison between the height and the average height, the weight and the average weight were significantly decreased after the herbal medical treatment. 2. Total children's average soft lean mass, body fat mass, BMI, basal metabolic rate, abdominal circumference and hip circumference were also significantly increased after the herbal medical treatment. 3. The mean height percentile of the children showed 0.88 percentile upwardly. The mean weight percentile of children showed 1.84 percentile upwardly. 4. The height percentile was increased in the group of boys younger than 13, and a group of girls older than 12 year old. Other than a group of boys older than 14, every group showed increasing weight percentile. Conclusions: The herbal medical treatment helped children with growth retardation.

• Biomolecules & Therapeutics
• /
• v.6 no.3
• /
• pp.296-302
• /
• 1998

The bioequivalence of two cyclosporin A products was evaluated in 26 normal male volunteers (age 25 ~33 yr, body weight 56~84 kg) following single oral administration. Test product was a hard capsule containing the granule of cyclosporin A (Chong Kun Dang Corp., Korea) and reference product, Sandimmun", was a soft capsule containing surfactant, oil, alcohol and cyclosporin A (Sandoz, Swiss). Both products contain 100 mg of cyclosporin A. Four capsules of the test and the reference product were administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). Average drug concentrations at each sampling time and pharmacokinetic parameters were not significantly different between two products (p>0.05); the area under the concentration-time curve to last sampling time (24 hr) (AU $Co_{24}$) (5034.8$\pm$ 1760.6 vs 4635.4$\pm$ 1158.9 ng . h/ml), maximum plasma concentration ( $C_{max}$) (1002.7$\pm$353.1 vs 980. 4$\pm$ 171.7 ng/71), and mean residence time (MRT) (6.16$\pm$0.81 vs 5.64$\pm$0.50 h). The differences of mean AUC 7-,4,7~, T_ and MRT between the two products (7.93,2.22,16 and 8.39%, respectively) were less than 20% given as a guideline. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24}$, $C_{max}$ and MRT were more than 0.8 and less than 0.2, respectively. Although $T_{max}$ of the two products was significantly different each other (p<0.05), $T_{max}$ might be an insignificant parameter because cyclosporin A generally requires long-term administration. From these results, the two products are bioequivalent.alent.t.

• Biomolecules & Therapeutics
• /
• v.15 no.3
• /
• pp.187-191
• /
• 2007

This study was conducted to compare the bioavailability of two brands of atenolol (50 mg) tablets, which are a generic product of $Ditent^{\circledR}$ (Daewon Pharmaceutical Co., Ltd., Korea) and an innovator product $Tenormin^{\circledR}$ (Hyundai Pharm. Ind. Co., Ltd., Korea), in 20 healthy Korean male volunteers. The volunteers received a single 50 mg dose of each atenolol formulation according to a randomized, two-way cross-over design. The washout period between treatments was 1 week. Plasma samples were obtained over a 24-hour interval, and atenolol concentrations were determined by HPLC with a fluorescence detector. From the plasma atenolol concentration vs. time curves, the following parameters were compared: area under the plasma concentration-time curve ($AUC_{0-24}$), peak plasma concentration ($C_{max}$), time to reach peak plasma concentration ($T_{max}$), and terminal first order elimination half-life ($t_{1/2}$). No statistically significant difference was obtained between the $T_{max}$ values, and the logarithmic transformed $AUC_{0-24}$ and $C_{max}$ values of the two products. The 90% confidence interval for the ratio of the logarithmically transformed AUC and $C_{max}$ values of $Ditent^{\circledR}$ over those of $Tenormin^{\circledR}$ were calculated to be between 0.85 and 1.04, and 0.89 and 1.07, respectively; both were within the bioequivalence limit of 0.80-1.25. The mean of $T_{max}$ in $Tenormin^{\circledR}$ group was 3.1 hour, and that in Ditent$^{\circledR}$ group was 3.2 hour. The values of $t_{1/2}$ between the two products were found comparable, and the mean values were 5.2 hour in the both products. Based on these results, it was concluded that $Ditent^{\circledR}$ was comparable to $Tenormin^{\circledR}$ in both the rate and extent of absorption, indicating that $Ditent^{\circledR}$ was bioequivalent to the reference product, $Tenormin^{\circledR}$.

• The Korean Journal of Nuclear Medicine
• /
• v.29 no.1
• /
• pp.61-72
• /
• 1995

The author performed radionuclide esophageal transit studies(RETS) with liquid and solid boluses using the same day protocol in 90 normal controls and 164 patients with various primary esophageal motility disorders who were diagnosed by manometric criteria and clinical courses. The authors calculated mean esophageal transit time(MTT) and mean residual retention(MRR) in each of the liquid and solid studies, and classified time-activity curve(TAC) patterns. The normal criteria of RETS with liquid bolus were MTT<24 sec, MRR<9%, and the TAC pattern that showed rapid declining slope and flat low residual(Type 1). The normal criteria of RETS with solid bolus were MTT<35 sec, MRR<9% and TAC of type 1. With these normal criteria, the sensitivity and the specificity of the liquid study were 62.2 % and 97.8%, respectively. The sensitivity increased to 75.4% with the solid study. The author also found that the RETS was highly reproducible. The achalasia typically showed no effective emptying of both liquid and solid boluses during the whole study period, and was well differentiated by its extremely long transit time and high retention from the other motility disorders. The diffuse esophageal spasm (DES) and nonspecific esophageal motility disorder(NEMD) showed intermediate delay in transit time and increased retention. In the groups of hypertensive lower esophageal sphincter(LES), hypotensive LES and nutcracker, there noted no significant difference with the normal control group in terms of MTT and MRR. The DES and NEMD could be more easily identified by solid studies that showed more marked delay in MTT and increased MRR as compared with the liquid study. In conclusion, esophageal scintigraphy is a safe, noninvasive and physiologic method for the evaluation of esophageal emptying.