• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.475-479
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• 2012

We present a novel polymer fabrication process involving direct UV patterning of a hyperbranched polymer, AEO3000. Compared to PDMS, which is the most widely used polymer in bioMEMS devices, the present polymer has advantages with regard to electrode integration and fast fabrication. We designed a four-chip microelectrofluidic bench having three electrical pads and two fluidic I/O ports. We integrated a microfluidic mixer and a cell separator on the bench to characterize the interconnection performance and sample manipulation. Electrical and fluidic characterization of the microfluidic bench was performed. The measured electrical contact resistance was $0.75{\pm}0.44{\Omega}$, which is small enough for electrical applications, and the pressure drop was 8.3 kPa, which was 39.3% of the value in the tubing method. By performing yeast mixing and a separation test in the integrated module on the bench, we successfully showed that the interconnected chips could be used for bio-sample manipulation.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.59-64
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• 1993

To evaluate the usefulness and differences in diagnosing coronary artery disease (CAD) between men and women of intravenous dipyridamole $^{99m}Tc$-MIBI myocardial SPECT, we obtained $^{99m}Tc$-MIBI myocardial SPECT and compared with the findings of coronary angiographies. Ninety eight male and 37 female patients who underwent dipyridamole $^{99m}Tc$-MIBI myocardial imaging within one month of cardiac catheterization were studied. Scans were considered abnormal if perfusion defect was detected and the defect size was more than 12% for left anterior descending artery (LAD) and circumflex (LCX) and 8% for right coronary artery (RCA) territories. Lesions${\geqq}$50% luminal diameter narrowing were considered significant CAD. Overall sensitivity for detection of CAD was 94.3% in men and 96.4% in women; specificity was 70% in men and 52.6% in women (P=not significant, ns). Vessel-matched sensitivity was 75.3% in men and 72.7% in women (P=ns): specificity was 84.6% in men and 67.9% in women (P < 0.025). For individual coronary artery, the sensitivity in men and women was 87.7%, 81.8% for LAD; 78%, 83.3% for RCA and 52.2%, 46.7% for LCX (P=ns): the specificity was 80%, 40% for LAD (P<0.01), 82.5%, 68.4% for RCA, 88.9%, 86.4% for LCX (P=ns). The hemodynamic parameter after intravenous dipyridamole in men and women were significantly changed; the heart rate was increased and systolic, diastolic blood pressure was decreased. Adverse effects were reported in 58.8% of men and 72.7% in women (P=ns). The incidence of chest pain and headache were higher in women. There was no significant difference in the incidences of nausea, abdominal pain, dizziness, facial flushing, dyspnea. In conclusion, dipyridamole $^{99m}Tc$-MIBI myocardial SPECT is a safe, noninvasive test for evaluation of CAD. There was no gender difference to detect CAD, but more false-positive rate in women especially in the territory of LAD.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.204-205
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• 2011

In thin film silicon solar cells, p-i-n structure is adopted instead of p/n junction structure as in wafer-based Si solar cells. PECVD is a most widely used thin film deposition process for a-Si:H or ${\mu}c$-Si:H solar cells. For best performance of thin film silicon solar cell, the dopant profiles at p/i and i/n interfaces need to be as sharp as possible. The sharpness of dopant profiles can easily achieved when using multi-chamber PECVD equipment, in which each layer is deposited in separate chamber. However, in a single-chamber PECVD system, doped and intrinsic layers are deposited in one plasma chamber, which inevitably impedes sharp dopant profiles at the interfaces due to the contamination from previous deposition process. The cross-contamination between layers is a serious drawback of a single-chamber PECVD system in spite of the advantage of lower initial investment cost for the equipment. In order to resolve the cross-contamination problem in single-chamber PECVD systems, flushing method of the chamber with NH3 gas or water vapor after doped layer deposition process has been used. In this study, a new plasma process to solve the cross-contamination problem in a single-chamber PECVD system was suggested. A single-chamber VHF-PECVD system was used for superstrate type p-i-n a-Si:H solar cell manufacturing on Asahi-type U FTO glass. A 80 MHz and 20 watts of pulsed RF power was applied to the parallel plate RF cathode at the frequency of 10 kHz and 80% duty ratio. A mixture gas of Ar, H2 and SiH4 was used for i-layer deposition and the deposition pressure was 0.4 Torr. For p and n layer deposition, B2H6 and PH3 was used as doping gas, respectively. The deposition temperature was $250^{\circ}C$ and the total p-i-n layer thickness was about $3500{\AA}$. In order to remove the deposited B inside of the vacuum chamber during p-layer deposition, a high pulsed RF power of about 80 W was applied right after p-layer deposition without SiH4 gas, which is followed by i-layer and n-layer deposition. Finally, Ag was deposited as top electrode. The best initial solar cell efficiency of 9.5 % for test cell area of 0.2 $cm^2$ could be achieved by applying the in-situ plasma cleaning method. The dependence on RF power and treatment time was investigated along with the SIMS analysis of the p-i interface for boron profiles.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.239-240
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• 2012

With advancements in semiconductor device technologies, manufacturing processes are getting more complex and it became more difficult to maintain tighter process control. As the number of processing step increased for fabricating complex chip structure, potential fault inducing factors are prevail and their allowable margins are continuously reduced. Therefore, one of the key to success in semiconductor manufacturing is highly accurate and fast fault detection and classification at each stage to reduce any undesired variation and identify the cause of the fault. Sensors in the equipment are used to monitor the state of the process. The idea is that whenever there is a fault in the process, it appears as some variation in the output from any of the sensors monitoring the process. These sensors may refer to information about pressure, RF power or gas flow and etc. in the equipment. By relating the data from these sensors to the process condition, any abnormality in the process can be identified, but it still holds some degree of certainty. Our hypothesis in this research is to capture the features of equipment condition data from healthy process library. We can use the health data as a reference for upcoming processes and this is made possible by mathematically modeling of the acquired data. In this work we demonstrate the use of recurrent neural network (RNN) has been used. RNN is a dynamic neural network that makes the output as a function of previous inputs. In our case we have etch equipment tool set data, consisting of 22 parameters and 9 runs. This data was first synchronized using the Dynamic Time Warping (DTW) algorithm. The synchronized data from the sensors in the form of time series is then provided to RNN which trains and restructures itself according to the input and then predicts a value, one step ahead in time, which depends on the past values of data. Eight runs of process data were used to train the network, while in order to check the performance of the network, one run was used as a test input. Next, a mean squared error based probability generating function was used to assign probability of fault in each parameter by comparing the predicted and actual values of the data. In the future we will make use of the Bayesian Networks to classify the detected faults. Bayesian Networks use directed acyclic graphs that relate different parameters through their conditional dependencies in order to find inference among them. The relationships between parameters from the data will be used to generate the structure of Bayesian Network and then posterior probability of different faults will be calculated using inference algorithms.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.20-27
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• 1988

Continuous cervical epidural anesthesia with two different concentrations of bupivacaine had been performed in 43 cases for surgery of upper extremity and cervical spine. After the initial dose of 0.33% bupivacaine 15ml to Group I(n=22) and 0.5% bupivacaine 15ml to Group II(n=21) was injected respectively, we observed the circulatory and pulmonary functions to be changed, and evaluated the duration of those analgesic action. The number of spinal segment to be affected and the complications were checked. Statistical significance of changes after the initial dose in both groups was determined by student's t-test. All values are impresed as mean$\pm$1S.D.. The results were as follows: 1) Circulatory functions; Systolic B.P. and Pulse rate were decreased by 10~15torr and 5~6 beats per minute respectively between 10~30 minutes following the initial dose, which were statistically significant in both groups. 2) Pulmonary functions; The diminution of minute volume showed to 20% and a rise of $PaCO_2$ level to 5~6 torr respectively between 30~60 minutes following the initial dose, which were statistically significant in both groups. There were no significant changes in self respiration and respiratory rate in both groups. 3) The duration of analgesic action was $72.3{\pm}25.7$(min) in Group I and $83.5{\pm}28.5$(min) in Group II which was not statistically significant between two groups, and the number of affected spinal segment at ore hour following the Anesthusia was $8.7{\pm}2.0$ in Group I and $10.5{\pm}2.4$ in Group II which was statistically significant between two groups. 4) Complications; a. Hypotension(below 80torr in systolic pressure) was appeared in 5% of all patients. b. Bradycardia(below 60 beats per minutes) was appeared in 25% of all patients. c. Inadvertent dural puncture was developed in only one patient, In conclusion, the 0.33% bupivacaine as well as 0.5% bupivacaine were enough for those analgesic effect in the above mentioned surgery even though the duration of analgesic action was about 10 minutes shorter in Group I than that of Group II. The cardiopulmonary function was clinically rather stable in Group I than that of Group II. Therefore we thought 0.33% bupivacaine was satisfactory for the clinical practicality in the cervical epidural anesthesia.

• Journal of Pharmaceutical Investigation
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• v.30 no.1
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• pp.61-65
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• 2000

Doxazosin, a postsynaptic selective ${\alpha}1-adrenoceptor$ antagonist, is a potent antihypertensive agent which reduces peripheral resistance and blood pressure by vasodilatation of peripheral vessels. It is also used in the treatment of urinary obstruction by benign prostatic hypertrophy. The purpose of the present study was to evaluate the bioequivalence of two doxazosin tablets, $Cardura^{TM}$ (Pfizer Korea Ltd.) and $Cardil^{TM};$ (Kyungdong Pharmaceutical Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Sixteen normal male volunteers, $24.19{\pm}2.48$ years in age and $62.41{\pm}6.66$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 2 mg of doxazosin was orally administered, blood was taken at predetermined time intervals and the concentrations of doxazosin in serum were determined with an HPLC method using spectrofluorometric detector. Pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets were -1.54%, -1.51 % and 3.42%, respectively, when calculated against the $Cardura^{TM}$ tablet. The powers $(1-{\beta})$ for $AUC_t,\;C_{max}\;and\;T_{max}$ were all more than 99.00%. Minimum detectable differences $(\Delta)$ at ${\alpha}=0.05\;and\;1-{\beta}=0.8$ were all less than 20% (e.g., 12.73%, 12.84% and 13.01% for $AUC_t,\;C_{max}\;and\;T_{max}$, respectively). The 90% confidence intervals were all within :${\pm}20%$ (e.g., $-8.97{\sim}5.90,\;-9.01{\sim}6.00\;and\;-4.16{\sim}11.05\;for\;AUC_t,\;C_{max}\;and\;T_{max},\;respectively)$. All of the above para- meters met the criteria of KFDA for bioequivalence, indicating that $Cardil^{TM}$ tablet is bioequivalent to $Cardura^{TM}$ tablet.

• Korean Journal of Community Nutrition
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• v.21 no.4
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• pp.366-377
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• 2016

Objectives: The purpose of the study was to compare intake of energy nutrients, physical characteristics, and the prevalence of metabolic syndrome according to protein intake group. Methods: Subjects were 827 men aged 40-65 years. The results presented were based on data from the 2012-2013 National Health and Nutrition Examination Survey and analyzed using SPSS. The odds ratio (OR) of metabolic syndrome was assessed according to the protein intake group and intake pattern of protein-rich foods. Results: The mean of protein intake was $73.96{\pm}0.71g$. According to level of protein intake, four groups (deficient, normal, excess 1, excess 2) were created and their percentages were 8.3%, 39.6%, 37.1%, and 15.0% respectively. The mean of daily energy intake was $2,312.33{\pm}24.08kcal$. It was higher in excess group 2 than in the deficiency group (p < 0.001). Moreover, the intake of all energy nutrients increased significantly with protein intake group (p < 0.001). The main contribution to daily protein included mixed grains ($10.96{\pm}0.32g$), milled rice ($7.14{\pm}0.30g$), chicken ($3.50{\pm}0.21g$), and grilled pork belly ($3.04{\pm}0.16g$). With regard to physical characteristics, and blood pressure and blood test results, only body mass index increased significantly according to protein intake groups (p < 0.05). The prevalence of metabolic syndrome in subjects was 38.5%, and there was no significant correlation with protein intake group. The OR of metabolic syndrome increased with protein intake, and was higher 4.452 times in excess group 2 than in the normal group (p < 0.05). Conversely, the OR of metabolic syndrome according to the frequency of protein-rich food intake did not show a significant correlation. Conclusions: The results of this study can be used as significant supporting data to establish guidelines for protein intake in middle-aged men.

• Korean Journal of Community Nutrition
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• v.21 no.4
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• pp.378-385
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• 2016

Objectives: This study was conducted to investigate the association between sarcopenia and sarcopenic obesity and cardiovascular disease risk in Korean postmenopausal women. Methods: We analyzed data of 2,019 postmenopausal women aged 50-64 years who participated in the Korea National Health and Nutrition Examination Survey in 2008-2011 and were free of cardiovascular disease history. Blood pressure, height, and weight were measured. We analyzed the serum concentrations of glucose, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglyceride levels. Waist circumference was used to measure obesity. Appendicular skeletal muscle mass was measured by dual-energy X-ray absorptiometry. Sarcopenia was defined as the appendicular skeletal muscle mass/body weight<1 standard deviation below the gender-specific means for healthy young adults. The estimated 10-year risk of cardiovascular disease risk was calculated by Pooled Cohort Equation. Subjects were classified as non-sarcopenia, sarcopenia, or sarcopenic obesity based on status of waist circumference and appendicular skeletal muscle mass. Results: The prevalence of sarcopenia and sarcopenic obesity was 16.3% (n=317) and 18.3% (n=369), respectively. The 10-year risk of cardiovascular disease risk in the sarcopenic obesity group was higher ($3.82{\pm}0.22%$) than the normal group ($2.73{\pm}0.09%$) and sarcopenia group ($3.17{\pm}0.22%$) (p < 0.000). The odd ratios (ORs) for the ${\geq}7.5%$ 10-year risk of cardiovascular disease risk were significantly higher in the sarcopenic obesity group (OR 3.609, 95% CI: 2.030-6.417) compared to the sarcopenia group (OR 2.799, 95% CI: 1.463-5.352) (p for trend < 0.000) after adjusting for independent variables (i.e., exercise, period of menopausal, alcohol use disorders identification test (AUDIT) score, income, education level, calorie intake, %fat intake and hormonal replacement therapy). Conclusions: Sarcopenia and sarcopenic obesity appear to be associated with higher risk factors predicting the 10-year risks of cardiovascular disease risk in postmenopausal women. These findings imply that maintaining normal weight and muscle mass may be important for cardiovascular disease risk prevention in postmenopausal women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5169-5175
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• 2014

The aim of this study was to find the factors related to smoking-cessation among citizens receiving smoking-cessation clinics' services in a public health center in Daejeon metropolitan city. The study subjects were 2,125 participants registered in "smoking-cessation clinic", public health centers in 2007. Frequency analysis, chi-squared test and multiple logistic regression analysis were used to determine the relationships between the success rate of smoking-cessation and the characteristics. The success rate of smoking-cessation during 6 months was 39.8%. Males had a higher rate than females, and people over 65 years of age had a higher rate than those less than 40 years of age. High blood pressure, drinking of more 2 times per week, regular exercise, CO under 10ppm had significantly relationships with the smoking-cessation rate. The other independent variables had no statistically significance with the smoking-cessation success rate. Logistic regression analysis showed that age, number of nicotine patches used and total consultation times had significantly relationships with the smoking-cessation success rate. The total consultation times showed the highest odds ratio than the other significant factors. This study suggests that regular consultations will be the most effective intervention towards maintaining smoking cessation programs of smoking-cessation clinics in public health centers.

• Journal of the Korean Geotechnical Society
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• v.32 no.6
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• pp.49-59
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• 2016

We develop liquefaction resistance curves, which represent the correlation between cyclic resistance ratio (CRR) and number of cycles (N) to estimate the build-up of residual excess pore pressure from simple shear tests performed for this study and also from published literature. The liquefaction curve is calculated from two models. The comparisons show that one of the models is not reliable because it underestimates CRR. The scatter of the data is shown to be significantly reduced when CRR is normalized to the resistance ratio at N = 15 ($CRR_{N=15}$). Use of the normalization is particularly useful because CRR can be easily estimated from field tests. From normalization, we propose mean, upper, and lower curves. The corresponding design equation and its parameters are also proposed. We believe that the proposed curves can be used for effective stress site response analyses and evaluation of the seismic performance of port structures.