• Journal of Chest Surgery
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• v.29 no.7
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• pp.769-776
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• 1996

The application of video-assisted thoracic surgery (VATS) in the examination of the thoracic cavity can be a new option in patients with mediastinal tumor because it provides outstanding visibility of the structures of the mediastinum. By clear viewing through the thoracoscope, a mediastinal tumor can be biopsied or resected, depending on the findings during an operation. We reviewed all patients who underwent curative or diagnostic operations from March 1990 to August 1995 under the impression of a mediastinal mass. The total number of patients were 113 with 59 males and 54 females. Group A underwent resection of tu or by thoracotomy(38 patients: 18 males, 20 females), and group B underwent resection of tumor by VATS (36 patients : 20 males and 16 females). Seven patients in group B were excluded because they underwent thoracotomy due to pleural adhesion or intra-operative bleeding ; therefore, the true VATS group numbered 29 cases. Group C underwent Iymph node biopsy by VATS(33 patients'16 males, 17 females), and group D(6 patients: 5 males, 1 female) underwent Iymph node biopsy through anterior mediastinotomy. The mean age in group A was 36.2 years compared to 41.3 years In group B. We compared operation time, frequency of injection for pain control, duration of chest tube insertion, postoperative hospital stay, and diagnostic yield. In group A, they were 164 minutes, 3.4 times, 5.2 days, and 11.3 days, respectively, in comparison to 152 minutes, 2 times, 4.7 days, and 8.3 days, respectively, in group B. These data revealed that the day of discharge was significantly shorter in group B (p valu : 0.03). In group C, the mean age was 45.8 years (range 1 ∼70). The operation time was from 30 to 335 minutes (mean 105), pain control was required from 0 to 15 times(mean 3.2), and a chest tube was needed for 1 to 36 days (mean 6.1). In group D, mean age was 53.3 years, operation time 121 minutes, pall control injec- tion frequency 2.6 times, and mean chest tube duration 10.5 days. The diagnostic yield in group C was 8 oyo compared to 100 oyo in group D although the number of patients in group D is small.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.405-416
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• 2017

This study evaluated a model unconfined aquifer comprising a sand or gravel layer, a filter layer, a pumping well, and an observation well. The model was employed in step drawdown tests and then used to assess the permeability of each test tank. The optimal yield and well efficiency were then calculated. Evaluation of yield by step in sand layer filters of equal thickness gave optimized watering rates of 22.03 L/min in the double filter and 19.71 L/min in the single filter. The double filter's yield was 115.0% that of the single filter. A comparison of double and single filters, each 10 cm thick, showed the double filter to have a maximum yield of 182.7%. Yields for the gravel layer were 73.56 L/min for a double filter and 65.47 L/min for a single filter of the same thickness; the former value is 112.3% of that of the latter. Comparison of double and single filters with 10-cm-thick gravel layers revealed that the double filter had a maximum yield of 160.9%. Results for sand wells showed the double filter to have a maximum efficiency of 70.4% and the single filter to have a minimum efficiency of 37.1%. Gravel-layer well efficiencies were >66.5% for both double and single filters (each 30 cm thick), but only 22.5% for a 10-cm-thick single filter. This study confirms that permeability improved as the filter material became thicker; it also shows that a double filter has a higher yield and well efficiency than a single filter. These results can be applied to the practical design of wells.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.211-224
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• 1996

The patients of developmental dislocation of the hip(DDH) are almost found after walking age because of early diagnosis of DDH in younger children is not easy. A controversy still exists as to the relative value of closed and operative management in the treatment of a child who has reached walking age. This study is a report of the results of 16 patients(17 cases) in developmental dislocation of the hip who have visited our hospital at the age of 9 months to 3 years old, and have been followed more than 12 months (12-112 months) on review of plain radiographs and arthrograms. The results were as follows : 1. The age at diagnosis was 16.4 months(9-31 months) in average. The methods of treatment were conservative for 8 cases, and operation for 4 cases and secondary operation for 5 cases who were failed with conservative therapy. 2. By Severin's radiologic grade, the result was good in 4 cases, fair in 3 cases and poor in 1 case in conservative treatment. In operative treatment, fair was in 2 cases and poor in 2 cases. In secondary operative patients who were failed with conservative therapy, good was in 2 cases, fair in 2 cases and poor in 1 case. 3. Avascular necrosis of femoral head was developed in 3 cases. 4. In the good reduction as determined by arthrogram according to Race and Herring, we can get a favorable result in conservative treatment, and in the poor reduction as determined by arthrogram, the better result in operative treatment can be expected.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.117-131
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• 2006

A coupled T-H-M(Thermo-Hydro-Mechanical) analysis was carried out for KENTEX (KAERI Engineering-scale T-H-M Experiment for Engineered Barrier System), which is a facility for validating the coupled T-H-M behavior in the engineered barrier system of the Korean reference HLW(high-level waste) disposal system. The changes of temperature, water saturation, and stress were estimated based on the coupled T-H-M analysis, and the influence of the types of mechanical constitutive material laws was investigated by using elastic model, poroelastic model, and poroelastic-plastic model. The analysis was done using ABAQUS, which is a commercial finite element code for general purposes. From the analysis, it was observed that the temperature in the bentonite increased sharply for a couple of days after heating the heater and then slowly increased to a constant value. The temperatures at all locations were nearly at a steady state after about 37.5 days. In the steady state, the temperature was maintained at $90^{\circ}C$ at the interface between the heater and the bentonite and at about $70^{\circ}C$ at the interface between the bentonite and the confining cylinder. The variation of the water saturation with time in bentonite was almost same independent of the material laws used in the coupled T-H-M processes. By comparing the saturation change of T-H-M and that of H-M(Hydro-Mechanical) processes using elastic and poroelastic material mod31 respectively, it was found that the degree of saturation near the heater from T-H-M calculation was higher than that from the coupled H-M calculation mainly because of the thermal flux, which seemed to speed up the saturation. The stresses in three cases with different material laws were increased with time. By comparing the stress change in H-M calculation using poroelasetic and poroelasetic-plastic model, it was possible to conclude that the influence of saturation on the stress change is higher than the influence of temperature. It is, therefore, recommended to use a material law, which can model the elastic-plastic behavior of buffer, since the coupled T-H-M processes in buffer is affected by the variation of void ratio, thermal expansion, as well as swelling pressure.

• Clinical and Experimental Pediatrics
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• v.45 no.4
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• pp.505-511
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• 2002

Purpose : Mean platelet volume(MPV) and platelet distribution width(PDW) are useful parameters in evaluating disorders of platelets. In cases with idiopathic thrombocytopenic purpura(ITP), they change as platelet count increases. In this study, we compared the values of MPV and PDW in ITP patients at diagnosis with those of normal children. We also studied whether the early changes in MPV may predict the clinical course. Methods : From December 1995 to May 2001, 71 patients with ITP were admitted to Ajou University Hospital. They were treated with IVIg 400 mg/kg for five days and MPV, PDW, platelet count were analysed. Normal control group(n=38) was compared. The study group was divided into acute and chronic forms, and also divided into group A, good early responders whose platelets increased more than $100,000/{\mu}L$ within 5 days and group B who did not. Results : Mean value of MPV at diagnosis in ITP patients was lower than the normal control group(P<0.05). In group A, MPV was abruptly increased on the first day after IVIg and then started to decrease. But in group B, MPV was steadily increased until the fourth day after IVIg. In the normal control group, there were inverse correlations between platelet count and MPV(r=-0.415, P<0.05), but in ITP patients, there were positive relationships between platelet count and MPV(r=0.646, P<0.05) at diagnosis. Conclusions : MPV at diagnosis of ITP was lower than the normal control. MPV and PDW could not predict the course of ITP patients, but MPV could distinguish good early responders. More research is needed to find out the reasons of decreased MPV at diagnosis of ITP.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.371-384
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• 2014

This study developed a new algorithm of extreme rainfall extraction based on the Communication, Ocean and Meteorological Satellite (COMS) and the Tropical Rainfall Measurement Mission (TRMM) Satellite image data and evaluated its applicability for the heavy rainfall event in July-2011 in Seoul, South Korea. The power-series-regression-based Z-R relationship was employed for taking into account for empirical relationships between TRMM/PR, TRMM/VIRS, COMS, and Automatic Weather System(AWS) at each elevation. The estimated Z-R relationship ($Z=303R^{0.72}$) agreed well with observation from AWS (correlation coefficient=0.57). The estimated 10-minute rainfall intensities from the COMS satellite using the Z-R relationship generated underestimated rainfall intensities. For a small rainfall event the Z-R relationship tended to overestimated rainfall intensities. However, the overall patterns of estimated rainfall were very comparable with the observed data. The correlation coefficients and the Root Mean Square Error (RMSE) of 10-minute rainfall series from COMS and AWS gave 0.517, and 3.146, respectively. In addition, the averaged error value of the spatial correlation matrix ranged from -0.530 to -0.228, indicating negative correlation. To reduce the error by extreme rainfall estimation using satellite datasets it is required to take into more extreme factors and improve the algorithm through further study. This study showed the potential utility of multi-geostationary satellite data for building up sub-daily rainfall and establishing the real-time flood alert system in ungauged watersheds.

• Journal of Soil and Groundwater Environment
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• v.13 no.4
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• pp.22-29
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• 2008

To understand environmental characteristics and contamination assessment of the Namsan Park soil in Seoul, we divided the Namsan map into 33 sectors and sampled mixed soil in depth 0${\sim}$15 cm, in 5${\sim}$10 points at the sites. We analyzed soil samples collected at 21 sectors twice on May and September. The results were as follows. The hue color ranges of the Namsan soil were 2.5YR${\sim}$10YR, the value ranges were 1${\sim}$4, the water rates were 3.1${\sim}$22.3 and the Ignition losses were 3.4${\sim}$10.4%. The average concentration of Cu and Pb were determined 3.374 and 15.000 mg/kg, Cd and As showed very low level. The mean concentrations of Zn and Ni were showed 103.290 and 11.649 mg/kg and this amount is not different from the nationalwide mean in 2005. The mean pH showed 5.41. The Zn, Ni and Cd in the soil of the circular road of Namsan showed 1.33, 1.48, 1.46 times higher than the other sector of the Namsan soil. The corelation coefficient between water rate and ignition loss were 0.720 and the correlation coefficient between Cu and Pb, Cu and Zn showed 0.827, 0.694 respectively. There was weak corelationship between pH and Zn. The Uniformity coefficient (Uc) of all the survey sites was determined below 5 in the range of 1.5${\sim}$4.4.

• Journal of Global Scholars of Marketing Science
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• v.19 no.2
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• pp.17-26
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• 2009

As the lifestyle of consumers changes and the need for various products increases, new products are being developed in the market. Each household owns various home appliances which are purchased through the choice of a decision maker. These appliances include not only large-sized products such as TV, refrigerator, and washing machine, but also small-sized products such as microwave oven and air cleaner. There exists latent correlation among possession of home appliances, even though they are purchased independently. The purpose of this research is to analyze the effect of demographic factors on the purchase and possession of each home appliances, and to derive some relationships among various appliances. To achieve this purpose, the present status on the possession of each home appliances are investigated through consumer survey data on the electric and energy product. And a multivariate probit(MVP) model is applied for the empirical analysis. From the estimation results, some appliances show a substitutive or complementary pattern as expected, while others which look apparently unrelated have correlation by co-incidence. This research has several advantages compared to previous literatures on home appliances. First, this research focuses on the various products which are purchased by each household, while previous researches such as Matsukawa and Ito(1998) and Yoon(2007) focus just on a particular product. Second, the methodology of this research can consider a choice process of each product and correlation among products simultaneously. Lastly, this research can analyze not only a substitutive or complementary relationship in the same category, but also the correlation among products in the different categories. As the data on the possession of home appliances in each household has a characteristic of multiple choice, not a single choice, a MVP model are used for the empirical analysis. A MVP model is derived from a random utility model, and has an advantage compared to a multinomial logit model in that correlation among error terms can be derive(Manchanda et al., 1999; Edwards and Allenby, 2003). It is assumed that the error term has a normal distribution with zero mean and variance-covariance matrix ${\Omega}$. Hence, the sign and value of correlation coefficients means the relationship between two alternatives(Manchanda et al., 1999). This research uses the data of 'TEMEP Household ICT/Energy Survey (THIES) 2008' which is conducted by Technology Management, Economics and Policy Program in Seoul National University. The empirical analysis of this research is accomplished in two steps. First, a MVP model with demographic variables is estimated to analyze the effect of the characteristics of household on the purchase of each home appliances. In this research, some variables such as education level, region, size of family, average income, type of house are considered. Second, a MVP model excluding demographic variables is estimated to analyze the correlation among each home appliances. According to the estimation results of variance-covariance matrix, each households tend to own some appliances such as washing machine-refrigerator-cleaner-microwave oven, and air conditioner-dish washer-washing machine and so on. On the other hand, several products such as analog braun tube TV-digital braun tube TV and desktop PC-portable PC show a substitutive pattern. Lastly, the correlation map of home appliances are derived using multi-dimensional scaling(MDS) method based on the result of variance-covariance matrix. This research can provide significant implications for the firm's marketing strategies such as bundling, pricing, display and so on. In addition, this research can provide significant information for the development of convergence products and related technologies. A convergence product can decrease its market uncertainty, if two products which consumers tend to purchase together are integrated into it. The results of this research are more meaningful because it is based on the possession status of each household through the survey data.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.2
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• pp.113-127
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• 2012

From the end of 1st quarter of 2012, Korean mandatory firms had started releasing financial reports conforming to the K-IFRS(Korean adopted International Financial Reporting Standards). Major characteristics of IFRS, such as 'principles based' features, consolidated reporting, 'fair value' measurement, increased pressure for non-financial disclosures have resulted in brief and various disclosure practices regarding the main body of each statements and vast amount of note description requirements. Meanwhile, a host of previous studies on IFRS disclosures have incorporated regulatory and/or 'compete information' perspectives, mainly focusing on suggesting further enforcement of strengthened requirements and providing guidelines for specific treatments. Thus, as an extension of prior findings and suggestions this study had explored to conduct an integrative approach embracing views of the reporting entities and the users of financial information. In spite of all the state-driven efforts for faithful representation and comparability of corporate financial reports, an overhaul of disclosure practices of fiscal year 2010 and 2011 had revealed numerous cases of insufficiency and discordance in terms of mandatory norms and market expectations. As to the causes of such shortcomings, this study identified several factors from the corporate side and the users of the information; some inherent aspects of IFRS, industry/corporate-specific context, expenditures related to internalizing IFRS system, reduced time frame for presentation. lack of clarity and details to meet the quality of information - understandability, comparability etc. - commonly requested by the user group. In order to improve current disclosure practices, dual approach had been suggested; Firstly, to encourage and facilitate implementation, (1) further segmentation and differentiation of mandates among companies, (2) redefining the scope and depth of note descriptions, (3) diversification and coordination of reporting periods, (4) providing support for equipping disclosure systems and granting incentives for best practices had been discussed. Secondly, as for the hard measures, (5) regularizing active involvement of corporate and user group delegations in the establishment and amendment process of K-IFRS (6) enforcing detailed and standardized disclosure on reporting entities had been recommended.

• Journal of the Korean Society of Food Culture
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• v.13 no.1
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• pp.19-26
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• 1998

This study was carreid out to investigate present comsuming behavior and consumer preference of SEAFOODS as a stuff in KIMCHI making, adopting a questionaire survey for 500 housewives living in Korea except Chejudo Province. Frequency distribution and percentage of preferences were measured. Out of total housewives responded, 65.5% consider, THEY SHOULD EAT KIMCHI DAILY. Which conforms, kimchi is still an important side dish at most of the households On the other hand, some others consider EATING KIMCHI EVERY DAY is not neccesary(6.0%) or dislike it(0.5%). This result might suggest that kimchi may or may not be an essential sidedish for every households in the future. 96.3% of Housewives used fermented salited fish and 45% used seafoods as a staffing in making kimchi. Major reasons for adding seafoods in kimchi were: it improves teste and flavor(79.5%) and nutritional value(54.2%). Reasons for rejecting seafoods as a stuffing in making kimchi were: it worsens taste and flavor(13.5%), hygenic treatments of seafoods are below the necessary level(13.5%) and shelf life become shorter(12.8%), respectively. Among the fermented salted sauces, 84.9% and 69.1% of house wives responded as anchovy and shrimp sause were most favorite(base) material in Kimchi making, respectively. Out of total seafoods utilized in making kimchi,76.4%, 54.7% and 31.4% of housewives responded as oyster, small shrimp and sea-staghorn as the favorite seafoods in Kimchi making(raw material). Majority of housewives responded to develop it's taste and flavor to meet that of international one(86.5%) and that hygienic level(treatments) should be upgraded(50.9%).