• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.219-233
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• 1999

Purpose : Respiratory syncytial virus(RSV) is the major cause of lower respiratory tract infection in infants and young children. This study was performed to analyze antigenic and genetic variation of G protein of subgroup A RSV. Methods : One hundred seventy-nine strains isolated at the Seoul National University Children's Hospital over 8 years-period from 1990 through 1998 were analysed for antigenic and genetic variability. Analysis was made by reactivity with monoclonal antibodies raised against RSV, and by restriction mapping and, for selected strains, nucleotide sequencing following amplification of full sequence of G gene by reverse transcription-polymerase chain reaction. Results : Restriction fragment analysis of the amplified G protein gene revealed 23 restriction patterns, 12 of which included more than 2 isolate, and the most frequent genetic type comprised 30% of the strains. Indirect immunofluorescent staining with monoclonal antibodies revealed 6 antigenic types with one predominant pattern accounting for 91% of the total strains. The most frequent antigenic type had 21 restriction patterns, and some viruses with same restiction pattern had different monoclonal antibody reaction pattern. Nucleotide sequence homology of subgroup A was 91~93% between reference(A2, Long) and Korean isolates, 93~99% among Korean isolates. Maximum-parsimony analysis demonstrated that Korean isolates were distinct from reference strains and subgroup A strains were clustered in 4 groups. Conclusion : The restriction analysis pattern of G protein gene identified greater diversity within subgroup A than was seen with the monoclonal analysis and a variety of antigenic and genetic types of RSV are circulating in Korea which are different from reference strains or strains isolated from other countries.

• Korean Business Review
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• v.17
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• pp.153-183
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• 2004

The Gaisong Merchants can be regarded to playa pioneering role to activate the Korea's trade with foreign countries. In the early period of Yi-Dynasty, the Gaisong Merchants focused on personal trade, but in the middle period of Yi-Dynasty, they entered to the realm of governmental trade. Furthermore, their business activities widened to various forms of trades, for example, smuggling. Utilizing accumulated capital, Gaisong merchants expanded their trading activities to their neighboring countries such as Japan and China. In recent times, it is necessary for modem Korean companies to diversify risks through the establishment of corporations for production, marketing and R&D abroad or through joint venture, M&A and strategic alliance with foreign companies in order to reduce the risks originated from volatile economic and political situations. In this study, we utilize tools of comparative study to compare Gaisong Merchants' foreign trade strategies with those of modem companies such as AMOREPACIFIC, HANILCEMENT and SHINDORICO. The purpose of the paper is to test the hypothesis that modem Korean companies grew up by following the cases of Gaisong Merchants' business activities. We summarize our main findings as follows. First, both Gaisong Merchants and modem Korean companies have common functional core capability in the field of marketing, manufacturing technology, R&D, and human resources development. Second, both Gaisong Merchants and modem Korean companies have common organizational core capability. Third, both Gaisong Merchants and modem Korean companies have common infrastructures such as planning, finance, accounting and MIS. It constitutes the infrastructure of Korea's foreign trade sector. Fourth, both Gaisong Merchants and modem companies have common organizational culture in the field of management policy and philosophy. Actually, those factors are evaluated to be driving forces of Koera's success in foreign trade. In conclusion, the business activities of Gaisong Merchants who represented the peculiarity of Korean business spirit are partially inherited to current Korean business management. The value system and behavior pattern of modern Korean companies is succeeded from the spirit of Gaisong Merchants and it playa major role to specify the identity of Korean business administration.

• Progress in Medical Physics
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• v.21 no.3
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• pp.253-260
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• 2010

Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

• Neonatal Medicine
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• v.16 no.1
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• pp.55-63
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• 2009

Purpose: This study was conducted to investigate the incidence and clinical manifestations of rotaviral infections in the neonatal intensive care unit (NICU). We also investigated whether neonates referred from other hospitals cause outbreaks of rotaviral infections in the NICU. Methods: Neonates diagnosed wit rotaviral infections in the NICU at Korea University Ansan Hospital between January 2002 and December 2006 were evaluated retrospectively. Results: Of 1,501 neonates admitted to the NICU, the number of rotaviral infections was 94 (6.3%) and the prevalence was 4.9 cases per 1,000-hospital days. Of 223 neonates referred from other hospitals to our NICU, 24 (10.8%) were confirmed to have rotaviral infections at the time of referral. Common symptoms of rotaviral infections were jaundice diarrhea or loose stools, vomiting, fever, apnea, irritability, seizures, and moaning sounds. Necrotizing enterocolitis of stage II or more was diagnosed in 3 premature neonates, accounting for 3.2% of total infected neonates and 6.8% of premature infected patients. There were no statistically significant differences in the prevalence of symptoms between term and preterm neonates, except for jaundice that is more frequent in premature infants. In time series analysis, the admission of neonates who were born at other hospitals and diagnosed with rotaviral infections were associated 1 month later by increased cases of neonates with rotaviral infections who were born at our hospital, whereas new cases of rotaviral infections among inborn neonates were decreased 2 and 4 months later (P<0.05). Conclusion: Rotaviral infections in NICU were not rare and showed vague symptoms. Three cases (3.2%) were diagnosed with stage II or more necrotizing enterocolitis. The referred neonates with rotaviral infections may induce outbreaks in the NICU, therefore awareness and strict surveillance for rotaviral infections should be performed at the time of referral.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.31-39
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• 2011

Purpose : This study was performed for the purpose of finding causative organisms and clinical features of septic arthritis or acute osteomyelitis in children. Methods : The study involved a retrospective review of the medical records of 63 microbiologically confirmed cases of acute pyogenic arthritis and osteomyelitis. All of the cases were brought about by community-associated infections and managed at the Seoul National University Children's Hospital or Seoul National University Bundang Hospital from June 2003 to July 2009. Results : The median age of all cases was 60 months and there were 35 males and 28 females. Major involved joints included the hip joint (15 cases), knee joint (7 cases), shoulder joint (4 cases), and elbow joint (4 cases). Also, major involved bones included the femur (20 cases), tibia (13 cases), humerus (7 cases), and radius (7 cases). Staphylococcus aureus was the most commonly identified causative organism, accounting for 49 cases (77.8%). Of the 49 isolates of S. aureus, methicillin-resistant S. aureus (MRSA) accounted for 8 cases (16.3%). Group B streptococcus spp. (GBS) and Salmonella spp. accounted for 3 cases, respectively. Nafcillin or cefazolin was often prescribed as an initial empirical antibiotic. There were 9 cases that were managed by a regimen that included vancomycin as the first choice. Fifty four cases (85.7%) recovered without any complications. Methicillin-sensitive S. aureus (MSSA), responsible for 41 cases, caused chronic complications in 3 cases. Of 8 cases caused by MRSA, 1 case showed chronic complication. There were no fatal cases. Conclusion : S. aureus remains the most common organism causing acute pyogenic arthritis and osteomyelitis of childhood acquired in the community. The high prevalence of methicillin resistance among S. aureus should be considered carefully in the selection of initial empirical antibiotics.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.523-530
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• 2011

This study was carried out to understand the characteristic relations fruit changes caused by adjusting the amount of the fruit load in 'Niitaka' and 'Whangkeumbae'. The average fruit weight of 'Niitaka' was 672.0 g and the amount of fruit in the range of 601-750 g was the highest, accounting for 33.8% of the production and as for 'Whangkeumbae', the average fruit weight was 477.5 g and fruit in the range of 401-600 g accounted for 72.5% of total production. The weight of the 'Niitaka' was evenly distributed in each range from below 300 g to over 1 kg and the percent of the regular shaped fruit in 'Whangkeumbae' was high as the distribution range of the fruit weight was narrow. The brix degree and the soluble solid content (SSC)/acidity ratio of 'Niitaka' had a significantly positive correlation with the fruit weight, the length, and the diameter of the fruit. The brix degree also had a positive correlation with weight and diameter of the fruit for 'Whangkeumbae'. As for the difference in fruit quality according to fruit weight for each variety, the brix degree was low in 'Niitaka' that were below 451 g and the fruit firmness was low in fruits weighing under 400 g. There was no difference according to fruit weight in 'Whangkeumbae'. The fruit size was impacted by the fleshy part and the ratio of fleshy part was higher as the fruit size became larger. The weight of the fruit, brix degree, and the SSC/acidity ratio were low while the firmness was high in light thinning treatment for 'Niitaka' and in the case of 'Whangkeumbae', the fruit weight and brix degree were both low in light thinning treatment. The brix degree was higher in bigger sized fruit in all thinning intensity for 'Niitaka', the case in light thinning treatment especially where the quality was poor due to low brix degree in fruits that weighed less than 450 g, on the other hand, there was no difference in the quality due to the fruit weight among the thinning intensity for 'Whangkeumbae'. Therefore, it is possible to produce smaller sized fruits in 'Niitaka' by controlling the thinning intensity, as it is inevitable to result in lower quality fruits, however, it is projected that we can produce small to mid-sized fruits in 'Whangkeumbae' by controlling the thinning intensity without causing the decline in fruit quality.

• Management & Information Systems Review
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• v.28 no.2
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• pp.41-67
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• 2009

Organizational interpersonal supervisory trust, organizational justice(distributive and procedural justice) and job satisfaction have been lately more spotlighted as generally concluded by many previous studies. The purpose of this study is to find out possible effects of these three factors upon organizational commitment. The results of this study can be outlined as follows: First, it was found that organizational trust, a preceding variable, had significant positive effects on distributive and procedural justice, as well as on organizational commitment as a dependent variable. Second, it was found that two independent variables, i.e. distributive and procedural justice had significant positive effects upon job satisfaction, and procedural justice had significant positive effects on organizational commitment as a dependent variable, but distributive fairness had no significant effects on organizational commitment. Third, it was found that job satisfaction, an independent variable, had significant positive effects on organizational commitment. Fourth, it was found that organizational trust had significant positive secondhand associations with organizational commitment by way of distributive and procedural justice and job satisfaction, and also had overall significant positive effects on organizational commitment. Thus, it is concluded that the higher organizational trust is an index of higher organizational commitment. Fifth, it was found that distributive justice had just significant secondhand effects on organizational commitment by way of job satisfaction, but it had no significant effects overall upon organizational commitment, since such secondhand effects were considerably set off due to negative firsthand effects of distributive justice upon organizational commitment. But procedural justice and job satisfaction had significant firsthand and overall effects on organizational commitment, so it is concluded that the higher procedural justice and the higher job satisfaction are good indices of the higher organizational commitment. Hence, it is concluded that organizational supervisory trust has positive effects on distributive and procedural justice and organizational commitment; distributive justice has positive effects on job satisfaction; procedural justice has positive effects on job satisfaction and organizational commitment; and job satisfaction has positive effects on organizational commitment, so these empirical findings hereof are consistent with general results of previous studies.

• Management & Information Systems Review
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• v.35 no.3
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• pp.1-22
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• 2016

We analyzed the international comovements and structural changes in the quarterly real GDP by the Markov-switching vector autoregressive model (MS-VAR) from 1971(1) to 2016(1). The main results of this study were as follows. First, the business cycle phenomenon that occurs in the models or individual time series in real GDP has been grasped through the MS-VAR models. Unlike previous studies, this study showed the significant comovements, asymmetry and structural changes in the MS-VAR model using a real GDP across countries. Second, even if there was a partial difference, there were remarkable structural changes in the economy contraction regime(recession), such as 1988(2) ending the global oil shock crisis and 2007(3) starting the global financial crisis by the MS-VAR model. Third, large-scale structural changes were generated in the economic expansion and/or contraction regime simultaneously among countries. We found that the second world oil shocks that occurred after the first global oil shocks of 1973 and 1974 were the main reasons that caused the large-scale comovements of the international real GDP among countries. In addition, the spillover between Korea and 5 countries has been weak during the Asian currency crisis from 1997 to 1999, but there was strong transmission between Korea and 5 countries at the end of 2007 including the period of the global financial crisis. Fourth, it showed characteristics that simultaneous correlation appeared to be high due to the country-specific shocks generated for each country with the regime switching using real GDP since 1973. Thus, we confirmed that conclusions were consistent with a number of theoretical and empirical evidence available, and the macro-economic changes were mainly caused by the global shocks for the past 30 years. This study found that the global business cycles were due to large-scale asymmetric shocks in addition to the general changes, and then showed the main international comovements and/or structural changes through country-specific shocks.

• Management & Information Systems Review
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• v.36 no.4
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• pp.21-32
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• 2017

Motivated by the recent cases of negligent social responsibility as manifested by foreign luxury fashion brands in Korea, this study investigates whether agency costs depend on the sustainability of different types of corporate governance. Agency costs refer either to vertical costs arising from the relationship between stockholders and managers, or to horizontal costs associated with the potential conflicts between majority and minority stockholders. The firms with luxury fashion brand could spend large sums of money on maintenance of magnificent brand image, thereby increasing the agency cost. On the contrary, the firms may hold down wasteful spending to report a gaudily financial achievement. This results in mitigation of the agency cost. Agency costs are measured by the value of the principal component. First, three ratios are constructed: asset turnover, operating expense to sales, and earnings before interest, tax, and depreciation. Then, the scores of each of these ratios for individual firms in the sample are differenced from the ratios for the benchmark firm of S-OIL. S-OIL was designated as the best superior governance model firm for 2013 by CGS. We perform regression analysis of each agency cost index, luxury fashion brand dummy and a set of control variables. The regression results indicate that the agency costs of the firms with luxury fashion brand exceed those of control group in the fashion industry in the part of operating expenses, but the agency cost falls short of those of control group in the part of EBITD, thus the aggregate agency costs are not differential of those of the control group. In sensitivity test, the results are same that the agency cost of the firms are higher than those of the matching control group with PSM(propensity matching method). These results are corroborated by an additional analysis comparing the group of the companies with the best brands with the control group. The results raise doubts about the effectiveness of management of the firms with luxury fashion brand. This study has a limitation that the research has performed only for 2013 and this paper suggests that there is room for improvement in the current research methodology.

• Progress in Medical Physics
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• v.19 no.1
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• pp.14-20
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• 2008

Accounting for tumor motion in treatment planning and delivery is one of the most recent and significant challenges facing radiotherapy. The purpose of this study was to investigate the correlation and clarified the relationship between the motion of an external marker using the Real-Time Position Management (RPM) System and an internal organ motion signal obtained fluoroscope. We enrolled 10 patients with locally advanced lung cancer and liver cancer, retrospectively. The external marker was a plastic box, which is part of the RPM used to track the patient's respiration. We investigated the quantitatively correlation between the motions of an external marker with RPM and internal motion with fluoroscope. The internal fiducial motion is predominant in the caraniocaudal direction, with a range of $1.3{\sim}3.5cm$ with fluoroscopic unit. The external fiducial motion is predominant in the caraniocaudal direction, with a range of $0.43{\sim}2.19cm$ with RPM gating. The two measurements ratio is from 1.31 to 5.56. When the regularization guided standard deviation is from 0.08 to 0.87, mean 0.204 cm, except only for patients #3 separated by a mean 0.13 cm, maximum of 0.23 cm. This result is a good correlation between internal tumor motion imaged by fluoroscopic unit and external marker motion with RPM during expiration within 0.23 cm. We have demonstrated that gating may be best performed but special attention should be paid to gating for patients whose fiducials do not move in synchrony, because targeting on the correct phase difference alone would not guarantee that the entire tumor volume is within the treatment field.