• The Journal of the Acoustical Society of Korea
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• v.28 no.4
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• pp.356-362
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• 2009

In modern society, most people of the world are densely populated in cities so that the traffic sound has a very significant meaning. people tend to classify traffic sound as a noise pollution while they are likely to categorize most nature sound as positive. In this paper, we applied various forms of FFT filters into white noise belonged in nature sound to find frequency characteristics of white noise which preferred by people and confirm its correlation with nature sound. In addition, we conducted an analysis through the comparison of various traffic and nature sound waveforms and spectra. As a result of analysis, the traffic sound have characteristics which sound energy had concentrated on specific frequency bandwidth and point of time compared to nature sound. And we confirmed the fact that these characteristics had negative elements to which could affect to people. Lastly, by letting the subjects listen directly to both traffic and nature sound through brainwave experiment using electrode, the study measured the energy distribution of alpha waves and beta waves. As a result of experiments, it has been noted that urban sound created a noticeably larger amount of beta waves than nature sound; on the contrary, nature sound generated positive alpha waves. These results could directly confirm the negative effects of traffic sound and the positive effects of nature sound.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.2
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• pp.80-86
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• 2024

Large-scale earthquakes are occurring globally, especially in the South Asian crust, which is experiencing a state of tension in the aftermath of the 2011 East Japan Earthquake. Uncertainty and fear regarding the possibility of further seismic activity in the near future have been on the rise in the region. The National Disaster Management Research Institute has previously studied and analyzed the overflow characteristics of a tsunami and the rate of flood forecasting through tsunami numerical simulations of the East Sea of South Korea. However, there is currently a significant lack of research on the Southern Coast tsunamis compared to the East Coast. On the Southern Coast, the tidal difference is between 1~4 m, and the impact of the tides is hard to ignore. Therefore, it is necessary to analyze the impact of the tide propagation characteristics on the tsunami. Occurrence regions that may cradle tsunamis that affect the southern coast region are the Ryukyu Island and Nankai Trough, which are active seafloor fault zones. The Southern Coast has not experienced direct damage from tsunamis before, but since the possibility is always present, further research is required to prepare precautionary measures in the face of a potential event. Therefore, this study numerically simulated a hypothetical tsunami scenario that could impact the southern coast of South Korea. In addition, the tidal wave propagation characteristics that emerge at the shore due to tide and tsunami interactions will be analyzed. This study will be used to prepare for tsunamis that might occur on the southern coast through tsunami hazard and risk analysis.

• Journal of Intelligence and Information Systems
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• v.18 no.2
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• pp.143-156
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• 2012

People easily believe that news and stock index are closely related. They think that securing news before anyone else can help them forecast the stock prices and enjoy great profit, or perhaps capture the investment opportunity. However, it is no easy feat to determine to what extent the two are related, come up with the investment decision based on news, or find out such investment information is valid. If the significance of news and its impact on the stock market are analyzed, it will be possible to extract the information that can assist the investment decisions. The reality however is that the world is inundated with a massive wave of news in real time. And news is not patterned text. This study suggests the stock-index invest model based on "News Big Data" opinion mining that systematically collects, categorizes and analyzes the news and creates investment information. To verify the validity of the model, the relationship between the result of news opinion mining and stock-index was empirically analyzed by using statistics. Steps in the mining that converts news into information for investment decision making, are as follows. First, it is indexing information of news after getting a supply of news from news provider that collects news on real-time basis. Not only contents of news but also various information such as media, time, and news type and so on are collected and classified, and then are reworked as variable from which investment decision making can be inferred. Next step is to derive word that can judge polarity by separating text of news contents into morpheme, and to tag positive/negative polarity of each word by comparing this with sentimental dictionary. Third, positive/negative polarity of news is judged by using indexed classification information and scoring rule, and then final investment decision making information is derived according to daily scoring criteria. For this study, KOSPI index and its fluctuation range has been collected for 63 days that stock market was open during 3 months from July 2011 to September in Korea Exchange, and news data was collected by parsing 766 articles of economic news media M company on web page among article carried on stock information>news>main news of portal site Naver.com. In change of the price index of stocks during 3 months, it rose on 33 days and fell on 30 days, and news contents included 197 news articles before opening of stock market, 385 news articles during the session, 184 news articles after closing of market. Results of mining of collected news contents and of comparison with stock price showed that positive/negative opinion of news contents had significant relation with stock price, and change of the price index of stocks could be better explained in case of applying news opinion by deriving in positive/negative ratio instead of judging between simplified positive and negative opinion. And in order to check whether news had an effect on fluctuation of stock price, or at least went ahead of fluctuation of stock price, in the results that change of stock price was compared only with news happening before opening of stock market, it was verified to be statistically significant as well. In addition, because news contained various type and information such as social, economic, and overseas news, and corporate earnings, the present condition of type of industry, market outlook, the present condition of market and so on, it was expected that influence on stock market or significance of the relation would be different according to the type of news, and therefore each type of news was compared with fluctuation of stock price, and the results showed that market condition, outlook, and overseas news was the most useful to explain fluctuation of news. On the contrary, news about individual company was not statistically significant, but opinion mining value showed tendency opposite to stock price, and the reason can be thought to be the appearance of promotional and planned news for preventing stock price from falling. Finally, multiple regression analysis and logistic regression analysis was carried out in order to derive function of investment decision making on the basis of relation between positive/negative opinion of news and stock price, and the results showed that regression equation using variable of market conditions, outlook, and overseas news before opening of stock market was statistically significant, and classification accuracy of logistic regression accuracy results was shown to be 70.0% in rise of stock price, 78.8% in fall of stock price, and 74.6% on average. This study first analyzed relation between news and stock price through analyzing and quantifying sensitivity of atypical news contents by using opinion mining among big data analysis techniques, and furthermore, proposed and verified smart investment decision making model that could systematically carry out opinion mining and derive and support investment information. This shows that news can be used as variable to predict the price index of stocks for investment, and it is expected the model can be used as real investment support system if it is implemented as system and verified in the future.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.846-856
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• 2005

Purpose : To measure the peak myocardial tissue velocities and patterns of longitudinal motion of atrioventricular(AV) annuli and assess body weight and heart rates-related changes in normal children. Methods : Using pulsed wave Tissue Doppler Imaging(TDI), we measured peak systolic, early and late diastolic myocardial velocities in 72 normal children at six different sites in apical-4 chamber (A4C) view and at four different sites in apical-2 chamber(A2C) view and compared those values with each other, also observing effects with body weights and heart rates. Longitudinal motions of the AV annuli were measured at three different sites in A4C. Results : There were no significant differences of the TDI parameters between gender, ECHO-machines and among the three Doctors performing TDI. Peak myocardial velocities were significantly higher at the base of the heart than in the mid-ventricular region and in the right lateral ventricular wall than in the left lateral ventricular wall or IVS. The TDI parameters showed no significant correlation with fractional shortening(%). Peak systolic and early diastolic myocardial velocities had no correlation with heart rates, but peak late diastolic velocities and A/E ratio correlated positively with heart rates. Correlations between the TDI parameters and body weight were inconsistent. Absolute longitudinal displacement and % displacement were not differ between gender and not correlated with the TDI parameters. Conclusion : We measured the peak myocardial velocities with TDI and the longitudinal motion of the AV annuli using M-mode echocardiography in normal children. With more large scale evaluation, we may establish reference values in normal children and broaden clinical applicabilities in congenital and acquired heart diseases.

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.85-93
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• 1999

Some reports have shown a decreased effectiveness of extracorporeal shock wave lithotripsy(ESWL) with newer lithotriptors. We compared the treatment results of ESWL with a second generation Northgate SD-3 and a third generation Modulith SLX device. A total of 2,000 patients underwent ESWL treatments for single urinary calculus between September, 1988 and July, 1998. 1,241 patients were treated with Northgate SD-3 between September, 1988 and December, 1995. And 759 patients were treated with Modulith SLX between January, 1996 and July 1998. The treatment results were compared using chi-square test to determine statistical significance. The overall success rate, success rate according to the location and size, the mean number of sessions, complication rate and retreatment rate were calculated, according to lithotriptor. The overall success rate was 90.6% with Northgate SD-3 and 89.1% with Modulith SLX. With Northgate SD-3 and Modulith SLX, the success rate according to the location was 91.0%(579/636) and 88.1%(236/268) in kidney: 93.2%(517/555) and 89.9%(258/287) in upper ureter: 83.3%10/12) and 94.4%167/177) in middle and lower ureter: 47.4%(18/38) and 55. 6%(15/27) in staghorn stone, respectively. The success rate according to the size of stone with Northgate SD-3 and Modulith SLX for stones with the size under 10mm was 96.1%(612/637) and 93.1%(470/505); from 11mm to 20mm was 87.3%(421/482) and 86.4%(165/191); from 21mm to 30mm, 77.5%(62/80) and 67.5%(23/34): and for stones larger than 31mm was 69%(29/42) and 62.1%(18/29), respectively. Mean number of sessions for successful fragmentation was 1.21 and 1.69, respectively with Northgate SD-3 and Modulith SLX. Retreatment rate was 16.7% and 17.5%, respectively. The complications after treatment were severe pain(6.2% with Northgate SD-3 vs. 2.0% with Modulith SLX), steinstrasse(3.4% vs. 1.9%), fever(1.2% vs. 0.5%) and perirenal hematoma(0.2% vs. 0%) in order of frequency. There was no significant difference in the effectiveness of Northgate SD-3 and Modulith SLX. However, a statistically significant difference was observed between the two lithotriptors. We concluded that ESWL with Modulith SLX is more safe compared to Northgate SD-3.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.417-423
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• 2006

Purpose : The objectives of this study were to assess ventricular function by tissue Doppler imaging in children who were receiving chemotherapy or who had received chemotherapy, and to apply repeated tissue Doppler imaging to make an early assessment in cardiac toxicity studies. Methods : This study was conducted on 23 oncology patients on-treatment or off-treatment from April 2005 to July 2005 at Dongsan Medical Center, Keimyung University. All patients(group 1) were divided into two groups, fractional shortening(FS) over 29 percent(group 2) and FS under 28 percent (group 3) in the first category. These same patients were also divided into the following groups : group treated with anthracyclin(group 4) and group treated without anthracyclin(group 5). Deceleration time(DT), isovolumic relaxation time(IVRT), FS, peak early diastolic(E), and peak late diastolic (A) velocity of transmitral flow were measured by M-mode and pulsed wave Doppler. Systolic(Sm), peak early diastolic(Em), and peak late diastolic(Am) velocity in apical 4-chamber and 2-chamber views were measured by tissue Doppler imaging. The author calculated a modified Tei index, E/A, E/Em ratio by using measured values. Results : Twenty three patients were enrolled : 12 boys and 11 girls. The average age of patients was 8 years and 4 months. Thirteen out of 23 patients were in the group treated with anthracyclin (group 4) and 6 had FS under 28 percent(group 3). E/Em ratio showed a significant difference between group 1 and control group($6.46{\pm}1.85$ vs $7.06{\pm}1.64$, P<0.05). Other parameters had no difference statistically. Conclusion : This study showed that the change of cardiac function developed earlier in diastolic function than in systolic function, as E/Em ratio reflecting the mean LV diastolic pressure showed a significant difference between the control group and chemotherapy groups. Echocardiography using tissue Doppler imaging is a non-invasive, comfortable and reliable method for post-chemotherapy follow up.

• Radiation Oncology Journal
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• v.14 no.2
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• pp.115-122
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• 1996

Purpose : To improve the treatment results of locally advanced nonsmall cell lung cancer (NSCLC) patients we treated those patients with regional hyperthermia combined with radiotherapy. And we conducted a retrospective analysis of the results. Material and Methods Thirty two nonsmall cell lung cancer Patients treated at the Department of Radiation Oncology, St. Mary's hospital, Catholic University Medical College were the base of this analysis. Fourteen patients of above them were treated with hyperthermia and radiotherapy of more than 3000 cGy in radiation dose. Radiofrequency capacitive hyperthermia was administered twice weekly immediately after radiotherapy. Total sessions of hyperthermia ranged from 3 to 13 times (mean 7.8). Eighteen patient received an external radiation therapy alone Median radiation dose was 5580 cGy (range, 3000-7000 cGy) in fraction of 180-300 cGy, 5 fractions per week. Results: The results of themoradiotherapy group (HTRT group) were compared with radiation alone group (RT group). There were no complete response (CR) and 12 Partial responses (PR) (CR rate $0\%$, response rate $85.7\%$) in HTRT group, whereas there were 2 CRs, 8 PRs and 8 no responses (CR rate $11.1\%$, response rate $55.6\%$) in RT group. There was significant differece in local response rate of the tumors between RT group and HTRT group (p < 0.05). Overall 2 rear survival rate and mean survival were $7.1\%$ and 10.5 months for HTRT group, and $0\%$ and 8.1 months for RT group. However, by the number of hyperthermia. in cases with more than or equal to 10 sessions of hyperthermia, there were significant improvement in 2 year year survival rate and mean survival ($40.0\%$ and 18.2 months) compared with those in cases with less than 10 sessions of hyperhtemia ($7.4\%$ and 7.4 months) (p < 0.05). Conclusion : Thermoradiotherapy in locally advanced NSCLC patients increased their response rate but not 2 year survival and mean survival, therefore thermoradiotherpy with enough number of hyperthermia is suggested that may be one of the effective palliative treatments of those patients. And in cases with more than 10 sessions of hyperthermia, there showed improved 2 year survival rate and mean survival But the number of the cases was small further study in this aspect is required.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.476-483
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• 2007

Purpose : The objective of this study was to assess ventricular function by tissue Doppler imaging (TDI) in children with congenital heart disease (CHD) who have been undergoing open heart surgery (OHS) using cardiopulmonary bypass. We tried to compare the parameters of tissue Doppler imaging before and after OHS in patients with congenital heart disease. Methods : This study was conducted on 32 patients with CHD after OHS from January 2005 to December 2005 at Kyungpook National University hospital. Patients who underwent 2-D echocardiography before and after their OHS. All patients were divided into three groups, left ventricular volume overloading group (group 1), and right ventricular volume overloading group (group 2), and right ventricular pressure overloading group (group 3). The TDIs were examined before and 1 to 3 months after OHS. Peak early diastolic (E), and peak late diastolic (A) velocity of transmitral flow were measured by pulsed wave Doppler examination. Peak systolic (Sm), peak early diastolic (Em), and peak late diastolic (Am) velocity in apical 4-chamber and 2-chamber views were measured by TDI. The author calculated E/Em ratio. Results : The patients were 14 boys and 18 girls and the average age of patients was 2 years and 3 months. The congenital heart diseases which have to get OHS were ventricular septal defect (13 cases), atrial septal defect (7), atrioventricular septal defect (3), isolated pulmonary stenosis (2) and tetralogy of Fallot (7). There were significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view (P<0.05). Conclusion : This study showed significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view after OHS. These changes might be due to the effects of cardiopulmonary bypass in OHS and/or hemodynamic changes after correction of congenital heart disease. To clarify these changes, further study on more patients is needed.

• Sleep Medicine and Psychophysiology
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• v.12 no.2
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• pp.117-121
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• 2005

Objectives: The purpose of this study was to assess the difference of subjective daytime sleepiness level between primary insomnia patients and healthy control subjects. We also investigated the relationship between subjective daytime sleepiness level and variables of nocturnal polysomnograghic sleep architecture of insomnia patients. Method: Total subjects were 87 patients with primary insomnia diagnosed with polysomnography and 88 normal controls. The daytime sleepiness level in each group was measured by Korean version of Epworth Sleepiness Scale (ESS). The correlations of ESS score and nocturnal polysomnographic variables were calculated in the patient group. Results: Patients with insomnia had the lower ESS scores than the control group. In patients group, the ESS score showed significant negative correlations with total sleep time, sleep efficiency%, and stage 2 sleep time%. The ESS score also showed significant positive correlations with number of awakenings, number of awakenings more than 2 minutes, and wake after sleep onset time. Conclusions: Insomnia patients showed lower level of subjective daytime sleepiness that may indicate their higher alertness comparing to control subjects. Daytime sleepiness of patients with insomnia was associated with polysomnographic variables including total sleep time, sleep efficiency%, stage 2 sleep time% and disrupted continuity of nocturnal sleep.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1389-1396
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• 2002

Purpose : This study was done to analyze the changes in the clinical conditions and the diagnosis of hypertrophic pyloric stenosis. Methods : We report a retrospective clinical analysis of 39 patients with hypertrophic pyloric stenosis from Jan. 1992 to Aug. 2001. The age and sex distribution, family and birth history, clinical symptoms, the ultrasonographic and the operative sizes of pyloric canals were compared. Results : The body weight was below the 3 percentile at admission in eight cases(20.5%). "Olive like mass" in right upper quadrant was palpated during physical examination in 23 cases(59%) and gastric peristaltic wave observed in six cases(15%). The ultrasonographic measurements showed that the pyloric muscle thickness to be $4.95{\pm}0.99mm$($mean{\pm}SD$), pyloric diameter $14.42{\pm}2.64mm$, and pyloric length $20.17{\pm}3.92mm$. Fredet-Ramstedt pyloromyotomy was employed in all cases. The operative measurements of the pyloric muscle thickness was $5.11{\pm}1.01mm$, pyloric diameter $15.01{\pm}2.47mm$, and pyloric length $22.32{\pm}3.43mm$. Conclusion : There was no significant difference between the ultrasonographic and operative measurements. Currently, the hypertrophic pyloric stenosis patients showed lesser clinical hallmarks of the disease. The earlier diagnosis using imaging studies before development of significant metabolic abnormalities is becoming an important factor that change the future outcomes of hypertrophic pyloric stenosis.