• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.268-274
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• 2016

To find the location of a random noise source present in the three-dimensional space is required at least four microphones. Using four microphones distributed in a three-dimensional space, noise source imaging technique was applied and evaluated on their performance. To compensate resolution problem which comes from both the position of the sensor array is fixed and the sampling frequency is low, up-sampling technique and interpolation function were applied. Five different interpolation methods were applied such as zero-padding, zero-order hold, first-order hold, spline function, and random signal padding. The up-sampling rate were chosen by two, four, eight times, and counting up 16 times. As a result, it was possible to more accurately estimate the position of the noise source according to the higher of the up-sampling rate. It also found that the first-order hold and the spline function's performance were slightly falling relative to other methods.

• Journal of Korean Medical Science
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• v.33 no.43
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• pp.277.1-277.10
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• 2018

Background: To examine survival rates and renal function after partial nephrectomy (PN) and radical nephrectomy (RN) in patients with chronic kidney disease (CKD). Methods: We studied 4,332 patients who underwent PN or RN for pathological T1a-T2N0M0 renal cell carcinoma from 1988 to 2014. Patients were divided into two subgroups of CKD stage I-II and stage III. Kidney function, and survival outcomes were compared between groups. Results: We included 1,756 patients with CKD I-II and 276 patients with CKD III in the final pair-matched analysis. Kidney function was significantly better preserved in the PN than in the RN group among all patients. However, the beneficial effect of PN on kidney function gradually disappeared over time in CKD III patients. The 5-year overall survival (OS) rates after PN and RN differed in patients with CKD I-II disease (99.4% vs. 96.5%, respectively, P = 0.015). The 5-year OS rates after surgery were not affected by mode of nephrectomy in CKD III patients (97.8% vs. 93.5%, P = 0.103). The 5-year cancer-specific survival rates did not differ between treatment groups in all CKD stage. Cox hazard analysis showed that the operative method was a significant factor for OS in CKD I-II patients (hazard ratio [HR], 0.320; confidence interval [CI], 0.122-0.840; P = 0.021). However, PN was not beneficial in terms of OS in CKD III patients (HR, 0.395; CI, 0.086-1.172; P = 0.117). Conclusion: PN is associated with a higher OS rate and better kidney function in patients with preoperative CKD stage I and II, but not in those with CKD stage III.

• Reproductive and Developmental Biology
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• v.34 no.3
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• pp.143-151
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• 2010

Pluripotency of human embryonic stem cell (hESC) is one of the most valuable ability of hESCs for applying cell therapy field, but also showing side effect, for example teratoma formation. When transplant multipotent stem cell, such as mesnchymal stem cell (MSC) which retains similar differentiation ability, they do not form teratoma in vivo, but there exist limitation of cellular source supply. Accordingly, differentiation of hESC into MSC will be promising cellular source with strong points of both hESC and MSC line. In this study, we described the derivation of MSC like cell population from feeder free cultured hESC (hESC-MSC) using direct differentiation system. Cells population, hESC-MSC and bone marrow derived MSC (BM-MSC) retained similar characteristics in vitro, such as morphology, MSC specific marker expression and differentiation capacity. At the point of differentiation of both cell populations, differentiation rate was slower in hESC-MSC than BM-MSC. As these reason, to verify differentially expressed molecular condition of both cell population which bring out different differentiation rate, we compare the molecular condition of hESC-MSC and BM-MSC using 2-D proteomic analysis tool. In the proteomic analysis, we identified 49 differentially expressed proteins in hESC-MSC and BM-MSC, and they involved in different biological process such as positive regulation of molecular function, biological process, cellular metabolic process, nitrogen compound metabolic process, macromolecule metabolic process, metabolic process, molecular function, and positive regulation of molecular function and regulation of ubiquitin protein ligase activity during mitotic cell cycle, cellular response to stress, and RNA localization. As the related function of differentially expressed proteins, we sought to these proteins were key regulators which contribute to their differentiation rate, developmental process and cell proliferation. Our results suggest that the expressions of these proteins between the hESC-MSC and BM-MSC, could give to us further evidence for hESC differentiation into the mesenchymal stem cell is associated with a differentiation factor. As the initial step to understand fundamental difference of hESC-MSC and BM-MSC, we sought to investigate different protein expression profile. And the grafting of hESC differentiation into MSC and their comparative proteomic analysis will be positively contribute to cell therapy without cellular source limitation, also with exact background of their molecular condition.

• Journal of Nutrition and Health
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• v.20 no.6
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• pp.432-441
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• 1987

This study was undertaken to investigate effects of alcohol and fat content in a balanced diet on growth, hepatic function and some biochemical indices of blood in growing rats. Fourty eight male rats of Sprague-Dawley strain weighing about 160g were divided into 4 groups ; high fat diet group, alcohol-adminstered high fat diet group, low fat diet group and alcohol-administered low fat diet group. High and low fat diet supplied 30% and 12%, respectively, of total calorie intake from fat and alcohol-treated groups received water containing 10% ethanol. Diets contained adequate amounts of all nutrients required for rats, including lipotropic agents(choline and methionine) to minimize effects of factors other than alcohol on liver function. Growth rate was lowest in alcohol-administered low-fat diet group, despite that their energy intake was equivalent to the others. For a 3-week study period, 21.86% and 23.61% of total calorie intake were derived from alcohol in alcohol-adminitered high fat diet group and low fat diet group, respectively. There was no influenced on vitamin B$_1$ status by alcohol consumption. Concentration of triglyceride in plasma increased with alcohol comsumption, and the effect was greater after 6 weeks than after 3 weeks of alcohol consumption . Difference of dietary fat content did not affect the level of triglyceride . The levels of total cholesterol and HDL-cholesterol in plasma were not influenced by alcohol consumption. Serum glutamate pyruvate transaminase activity and hepatic mitochondrial respiration rate did not differ between groups. The results indicate that neither moderate alcohol drinking for 6 weeks nor fat content with a balanced diet caused any dramatic change of metabolism and liver function in rats. However they suggest that even moderate alcohol consumption can affect growth of animals dramatically and the effect may be lessened with relatively high fat content in diet.

• Journal of Digital Contents Society
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• v.17 no.2
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• pp.71-79
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• 2016

This study is intended to compare the performances of sound source localization methods used for stable automobile control by improving voice recognition rate in automobile environment and suggest how to improve their performances. Generally, sound source location estimation methods employ the TDOA algorithm, and there are two ways for it; one is to use a cross correlation function in the time domain, and the other is GCC-PHAT calculated in the frequency domain. Among these ways, GCC-PHAT is known to have stronger characteristics against echo and noise than the cross correlation function. This study compared the performances of the two methods above in automobile environment full of echo and vibration noise and suggested the use of a median filter additionally. We found that median filter helps both estimation methods have good performances and variance values to be decreased. According to the experimental results, there is almost no difference in the two methods' performances in the experiment using voice; however, using the signal of a song, GCC-PHAT is 10% more excellent than the cross correlation function in terms of the recognition rate. Also, when the median filter was added, the cross correlation function's recognition rate could be improved up to 11%. And in regarding to variance values, both methods showed stable performances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.303-309
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• 2021

This study examined the changes in the cardiopulmonary functions of stroke patients by adjusting the s heart rate during walking training. This study was conducted on 20 chronic stroke patients. The experimental group conducted walking training by varying the walking speed according to the change in heart rate on the treadmill. In contrast, the control group conducted walking training by the subjective speed of the subject. The walking training was conducted for 32 minutes, three times a week, for a total of six weeks. The changes after the intervention of the subjects were determined by measuring the VC, ERV, IRV, FVC, FEV1, and PEF. The study revealed interactions between the groups and timing in the VC, ERV, and IRV(p<.05). There were no interactions between the groups and timing in FEV1, FVC, and PEF. The main effects showed no significant differences between the groups (p>.05) but showed significant differences between periods (p<.05). These results suggest that the cardiopulmonary function was improved significantly when the training was conducted by changing the pace of the heart rate in the walking process, leading to significant changes in the cardiopulmonary function.

• KIEE International Transactions on Power Engineering
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• v.11A no.4
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• pp.45-50
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• 2001

The impact evaluation of a DSM program is a very important issue since the results are used to determine the sustainability of a program. In general. to estimate the impacts of a DSM program it is required to measure the electricity usage changes before and after a program. Since the measurement-based approaches cost highly, most of the conventional evaluations are based on the average figures. However estimation of the average-based impacts can lead to both distorted results of over/under estimation of kW and kWh savings and non-optimal DSM planning. In this paper, we have developed a new multi-point measurement approach which can evaluate kW and kWh savings of a DSM program more exactly. To do this, the saving rate and operating rate are defined and set as the function of load factor of a customer, and these rates are incorporated with the conventional diffusion function of Bass to project the future impacts of a DSM program. The case study is performed on the inverter program of Korea by using the suggested approach.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.3-46
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• 1999

A new method called SRICOS is proposed to predict the scour depth z versus time t around a cylindrical bridge pier of diameter D founded in clay. The steps involved are ; 1. taking samples at the bridge pier site, 2. testing them in an Erosion Function Apparatus called the EFA to obtain the scour rate z versus the hydraulic shear stress applied $\tau$, 3. predicting the maximum shear stress r max which will be induced around the pier by the water flowing at ν Ο before the scour hole starts to develop, 4. using the measured z versus r curve to obtain the initial scour rate zi corresponding to r max , 5. predicting the maximum depth of scour zmax for the pier, 6. using zi and zmarx to develop the hyperbolic function describing the scour depth z versus time t curve, and 7. reading the z vs. t curve at a time corresponding to the duration of the flood to find the scour depth which will develop around the pier. A new apparatus is developed to measure the z vs t curve of step 2, a series of advanced numerical simulations are performed to develop an equation for the $\tau$ max value of step 3, and a series of flume tests are performed to develop an equation for the zmax value of step 5. The method is evaluated by comparing predictions and measurements in 42 flume experiments.

• Journal of Sensor Science and Technology
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• v.15 no.2
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• pp.139-147
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• 2006

Lower urinary tract symptoms (LUTS) affect self-assessed quality of life. The prevalence of LUTS is commonly high in the elderly. The purpose of urodynamic investigation is to obtain information on the function of the urinary system. One of the most frequently used measurement procedures in urodynamics is filling and voiding cystometry. But in this system transurethral catheter is used and it makes patients uncomfortable. The aim of this study is to implement the system that could evaluate noninvasively the function of urinary tract. A new system has been developed to analyze urine flow rate and vesical pressure during voiding. These signals were recorded simultaneously and transmitted to a PC. For system evaluation, a model for the lower urinary system of men was constructed. From the evaluation of the model, vesical pressure was correlated with the occlusion degree. In a pilot study with five male subjects, maximum of standard deviation was 1.26, error rate was 3.49 and coefficient of variation was 3.48.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.6
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• pp.1113-1118
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• 2011

In this paper, when a physician make a diagnosis of the pattern identification (PI) in Korean stroke patients, the development methods of the PI classification function is considered by diagnostic questionnaire of the PI for stroke patients. Clinical data collected from 1,502 stroke patients who was identically diagnosed for the PI subtypes diagnosed by two physicians with more than 3 years experiences in 13 oriental medical hospitals. In order to develop the classification function into PI using Korean Stroke Syndrome Differentiation Standard was consist of the 44 items (Fire heat(19), Qi deficiency(11), Yin deficiency(7), Dampness-phlegm(7)). Using the 44 items, we took diagnostic and prediction accuracy rate through of discriminant model. The overall diagnostic and prediction accuracy rate of the PI subtypes for discriminant model was 74.37%, 70.88% respectively.