• Neonatal Medicine
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• v.18 no.2
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• pp.310-319
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• 2011

Purpose: The aim of this study was to investigate the effect of perinatal risk factors on brain maturation and the relationship of brain maturation and neurodevelopmental outcomes with brain maturation scoring system in brain MRI. Methods: ELBWI infants born at the Seoul National University Children's Hospital from January 2006 to December 2010 were included. A retrospective analysis was performed with their medical record and brain MR images acquired at near full term. We read brain MRI and measured maturity with total maturation score (TMS). TMS is a previously developed anatomic scoring system to assess brain maturity. The total maturation score was used to evaluate the four parameters of maturity: (1) myelination, (2) cortical infolding, (3) involution of glial cell migration bands, and (4) presence of germinal matrix tissue. Results: Images from 124 infants were evaluated. Their mean gestational age at birth was 27.1${\pm}$2.1 weeks, and mean birth weight was 781.5${\pm}$143.9 g. The mean TMS was 10.8${\pm}$2.0. TMS was significantly related to the postmenstrual age (PMA) of the infant, increasing with advancing postmenstrual age (P<0.001). TMS showed no significance with neurodevelopmental delay, and with brain injury, respectively. Conclusion: TMS was developed for evaluating brain maturation in conventional brain MRI. The results of this study suggest that TMS was not useful for predicting neurodevelopmental delay, but further studies are needed to make standard score for each PMA and to re-evaluate the relationship between brain maturation and neurodevelopmental delay.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.181-193
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• 2018

The present study was conducted to analyze the quality of the habitats of Abies koreana WILS. by using the InVEST model based on the analytic hierarchy process (AHP) technique and to evaluate the economic value by estimating the carbon fixation. Abies koreana WILS., an original biological species of South Korea, may be an essential element in establishing the national biological sovereignty in the future. The subjects of the present study were the national parks in Mt. Halla, Mt. Jiri, and Mt. Sobaek, which are the habitats of Abies koreana WILS. As suggested by previous studies as a limitation of the InVEST model, the utilization of the data from relevant international publications as the input data, due to the lack of the domestic input data, may decrease the accuracy of the modeling. Therefore, the AHP technique was applied for the input data. The modeling was performed with reference to the years of 1980, 1990, and 2000 for the scenario analysis. The result of the modeling showed that the habitat quality was changed most in the national park in Mt. Halla, as the habitat quality score was decreased from 0.96 in 1980 to 0.97 in 1990 and 0.94 in 2000. In the national part of Mt. Sobeak, the habitat quality was changed most in the sub-alpine zone, as the habitat quality score was decreased from 0.98 in 1980 and 0.98 in 1990 to 0.97 in 2000. The habitat quality was best conserved in the national part in Mt. Jiri, as the habitat quality score was 0.98 in 1980, 0.99 in 1990, and 0.99 in 2000. The estimated economic loss by the change of the habitat quality was 19,280,000 USD for Mt. Halla and 8,030,000 USD for Mt. Sobeak. In the present study, the habitat quality of the Abies koreana WILS, the original species of South Korea, was evaluated and the economic value of the ecological services provided by the habitats was estimated quantitatively. The result showed that the ecosystem service model may be used to qualitatively analyze the quality of a habitat located in a specific region and to estimate the economic value quantitatively. The objective evaluation of ecosystem services demonstrated in the present study may be applied to promote sustainable utilization of natural resources and conservation of the ecosystem by predicting the changes that may be caused by external factors including the development of preservation areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.2
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• pp.70-80
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• 2011

Estuarine ecosystem responds sensitively to natural and anthropogenic perturbations. lt is necessary to identify the direction of the change when the perturbation occurs as well as to understand the structure and functioning of estuarine ecosystem for a proper management of the area. In this study, the estuarine habitats were classified into different ecological districts so as to the switch from one district to another district could be related to the environmental change due to the perturbations. Total 16 ecological districts was defined according to the presence of barrage, salinity and vegetation characteristics. The defined ecological districts were applied to small estuaries in Goseong bay, south sea of Korea (Baedun, Guman, Maam, Goseong) to distinguish different regions which might have characteristic bottom topography, inclinations of river bottom, sediment characteristics, salinity structure and area of vegetation. Total 7 out of 16 ecological district was identified in this region; NFB (natural, fresh, bare), NHB (natural, high salinity, bare), NLV (natural, low salinity, vegetated) in natural (without barrage) estuaries and CFB (closed, fresh, bare), CFV( closed, fresh vegetated), CLV (closed, low salinity, vegetated), CHB (closed, high salinity, bare) in closed (with barrage) estuary. A comparison of environmental factors and biota between CHB and CLV demonstrated the effect of barrage on estuarine ecosystem. The height and sediment characteristics of CHB and CLV were similar but the average salinity was lower in CLV than in CHB due to the barrage, which produced favorable condition for the Phragmites australis in CLV. Information regarding the ecological districts in various sizes and location could be useful for predicting the ecosystem change due to natural and anthropogenic perturbations and for preparing management actions.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.1
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• pp.25-35
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• 2003

Objectives: The aim of this study was to investigate 1) the prevalence of depressive symptoms, 2) the severity of depressive symptoms, 3) the correlation of depressive symptoms with clinical variables, and 4) factors that contribute to depressive symptoms in patients with Parkinson's disease. Methods: One hundred eighteen patients with Parkinson's disease referred from the Parkinson's Disease Clinic of Dong-A University Hospital, Busan, Korea, completed a self-administered questionnaire package, which included basic demographic data, the Beck Depression Inventory, the Parkinson's disease quality of life questionnaire, the Symptom Checklist-90-Revision(SCL-90-R), and the Spielberger's State-Trait Anxiety Inventory. In addition, a structured interview and a complete neurological examination, including the Hoehn and Yahr stage, the motor part of the Unified Parkinson's Disease Rating Scale(some selected scales of UPDRS part III), the Schwab and England Activities of Daily Living scale(ADL), and the Korean version of Mini-Mental State Examination were performed. Results: 1) Based on BDI score, subjects were divided into four groups:severely(40.7%), moderately(13.6%) and mildly(12.7%) depressive and non-depressive(33.1%). 2) The severity of depressive symptom in Parkinson's disease was positively correlated with Hoehn and Yahr(H & Y) stage(r=0.34, p<0.0001), the severity of motor symptom(r=0.35, p<0.0001), and trait anxiety inventory(r=0.33, p<0.001). On the other hand, the severity of depressive symptom was negatively correlated with educational level(r=-0.34, p<0.001), ADL(r=-0.37, p<0.0001) and Parkinson's disease quality of life (PDQL)(r=-0.69, p<0.0001). Among several clinical variables, the PDQL was the most influential factor predicting whether the depressive symptom was present or not. Conclusion: This study suggests that depressive symptom is very prevalent among patients with Parkinson's disease. Data from this study indicate that medical staffs who take care of patients with Parkinson's disease should pay attention to finding and treating depressive symptom among their patients. With appropriate psychiatric intervention, patient's depressive symptom can be minimized or alleviated and thus, the quality of life in these patients is likely enhanced.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.63-70
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• 2011

Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.66-76
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• 1999

Background : To assess the utility of HRCT in the evaluation of visceral pleural invasion and to determine whether visceral pleural invasion and bronchovascular bundle thickening on the same lobe could be related to the recurrence and survival in non-small cell lung cancer (NSCLC) Method: Eighty one patients, which were fulfilled long-term follow-up at least 18 months (maximum 103 months) among which 434 patients had underwent curative surgical resection for NSCLC from 1986 to 1995, were studied. They were analyzed to evaluate whether the prognostic factors such as the recurrence and survival depend on visceral pleural invasion and bronchovascular bundle thickening to the same lobe. Thirty two patients adjacent to a chest wall or a fissure were evaluated for visceral pleural invasion by HRCT. CT criteria included abutting pleura along the chest wall, abutting and/or compressing fissure, croosing fissure, and pleural tail. Results: The positive predictive value and the negative predictive value of crossing fissure were 100% and 100%, respectively. Two patients showing spiculated interface between a mass and abutting fissure were confirmed to have visceral pleural invasion at surgery. Visceral pleural invasion confirmed at surgery was significant to local recurrence and survival (p<.05. p<.05, respectively). Brochovascular bundle thickening to the same lobe on CT scan was significant to survival (p<.05) but was not significant to local and distant recurrence (p>.05). Conclusion : Visceral pleural invasion and bronchovascular bundle thickening to the same lobe have a role in predicting prognosis such as recurrence and survival in NSCLC. Therefore, the analysis of visceral pleural invasion on CT scan and the pathological analysis of bronchovascular bundle thickening to the same lobe may be necessary to predict the prognosis in NSCLC.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1172-1178
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• 2005

Purpose : Childhood Obesity is increasing throughout the world, and it is known to incur many diseases especially in later life such as diabetes and cardiovascular disorders. The purpose of this study was to investigate the association between obesity and insulin, insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-3(IGFBP-3) and know if these factors are useful in predicting cardiovascular diseases. Methods : The study group consisted of 64 moderate and severe obese adolescents and the controls were normal adolescents of the same age. body mass index(BMI) was calculated by height and weight; systolic and diastolic blood pressure was measured at resting state. After 10-hour fasting period, blood cholesterol, triglyceride, high density lipoprotein(HDL) cholesterol, low density lipoprotein(LDL) cholesterol, glucose, insulin, free fatty acid, IGF-I and IGFBP-3 were measured. Results : Insulin was significantly higher in the obese adolescent group than the control group(obese group $15.6{\pm}7.0{\mu}IU/mL$, P<0.01). IGF-I was also significantly higher in the obese adolescent group than the control group(obese group $498.1{\pm}122.2ng/mL$, P<0.05). In addition, IGFBP-3 was significantly higher in the obese adolescent group than the control group(obese group $3,777{\pm}4,721ng/mL$, P<0.05). Insulin showed significantly positive correlation with BMI(r=0.3944) and obesity index(r=0.34). IGFBP-3 were significantly correlated with obesity index(r=0.419), diastolic blood pressure (r=0.264) and BMI(r=0.247). Insulin resistance index significantly positive correlation with BMI(r=0.595), blood triglycerid level(r=0.515) and obesity index(r=0.469). Conclusion : Serum insulin, insulin resistance index, IGF-I and IGFBP-3 levels may be useful to predict cardiovascular diseases in adolescent obesity.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.305-316
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• 2011

Recommender system is the system which, by using automated information filtering technology, recommends products or services to the customers who are likely to be interested in. Those systems are widely used in many different Web retailers such as Amazon.com, Netfix.com, and CDNow.com. Various recommender systems have been developed. Among them, Collaborative Filtering (CF) has been known as the most successful and commonly used approach. CF identifies customers whose tastes are similar to those of a given customer, and recommends items those customers have liked in the past. Numerous CF algorithms have been developed to increase the performance of recommender systems. However, the relative performances of CF algorithms are known to be domain and data dependent. It is very time-consuming and expensive to implement and launce a CF recommender system, and also the system unsuited for the given domain provides customers with poor quality recommendations that make them easily annoyed. Therefore, predicting in advance whether the performance of CF recommender system is acceptable or not is practically important and needed. In this study, we propose a decision making guideline which helps decide whether CF is adoptable for a given application with certain transaction data characteristics. Several previous studies reported that sparsity, gray sheep, cold-start, coverage, and serendipity could affect the performance of CF, but the theoretical and empirical justification of such factors is lacking. Recently there are many studies paying attention to Social Network Analysis (SNA) as a method to analyze social relationships among people. SNA is a method to measure and visualize the linkage structure and status focusing on interaction among objects within communication group. CF analyzes the similarity among previous ratings or purchases of each customer, finds the relationships among the customers who have similarities, and then uses the relationships for recommendations. Thus CF can be modeled as a social network in which customers are nodes and purchase relationships between customers are links. Under the assumption that SNA could facilitate an exploration of the topological properties of the network structure that are implicit in transaction data for CF recommendations, we focus on density, clustering coefficient, and centralization which are ones of the most commonly used measures to capture topological properties of the social network structure. While network density, expressed as a proportion of the maximum possible number of links, captures the density of the whole network, the clustering coefficient captures the degree to which the overall network contains localized pockets of dense connectivity. Centralization reflects the extent to which connections are concentrated in a small number of nodes rather than distributed equally among all nodes. We explore how these SNA measures affect the performance of CF performance and how they interact to each other. Our experiments used sales transaction data from H department store, one of the well?known department stores in Korea. Total 396 data set were sampled to construct various types of social networks. The dependant variable measuring process consists of three steps; analysis of customer similarities, construction of a social network, and analysis of social network patterns. We used UCINET 6.0 for SNA. The experiments conducted the 3-way ANOVA which employs three SNA measures as dependant variables, and the recommendation accuracy measured by F1-measure as an independent variable. The experiments report that 1) each of three SNA measures affects the recommendation accuracy, 2) the density's effect to the performance overrides those of clustering coefficient and centralization (i.e., CF adoption is not a good decision if the density is low), and 3) however though the density is low, the performance of CF is comparatively good when the clustering coefficient is low. We expect that these experiment results help firms decide whether CF recommender system is adoptable for their business domain with certain transaction data characteristics.

• Radiation Oncology Journal
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• v.26 no.3
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• pp.142-148
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• 2008

Purpose: We analyzed the treatment outcomes and prognostic factors of breast conserving surgery, followed by postoperative radiotherapy.Materials and Methods: A total of 424 breast cancer patients treated with breast conserving surgery and postoperative radiotherapy between February 1992 and January 2001 were retrospectively analyzed. A quadrantectomy and axillary lymph node dissection was performed in 396 patients. A total of 302 patients had T1 disease, and 122 patients had T2 disease. Lymph node involvement was confirmed in 107 patients. Whole breast irradiation was administered at up to 50.4 Gy in 28 fractions, followed by a 10 Gy boost in 5 fractions to the tumor bed. In addition, 57 patients underwent regional lymph node irradiation. Moreover, chemotherapy was administered in 231 patients. A regimen consisting of cyclophosphamide, methotrexate, and 5-fluorouracil was most frequently used with 170 patients. The median follow-up time was 64 months. Results: The 5-year local control rate was 95.6%. During the follow-up period, local tumor recurrence was observed in 15 patients. The 5-year overall and disease-free survival rates were 93.1% and 88.7%, respectively. The 5-year overall survival rates, by stage, were 94.8% for stage I, 95.0% for stage IIA, 91.1% for stage IIB, 75.9% for stage IIIA, and 57.1% for stage IIIC. As for disease-free survival, the corresponding figures, by stage (in the same order), were 93.1%, 89.4%, 82.8%, 62.0%, and 28.6%, respectively. The advanced N stage (p=0.0483) was found to be a significant prognostic factor in predicting poor overall survival, while the N stage (p=0.0284) and age at diagnosis (p=0.0001) were associated with disease-free survival. Conclusion: This study has shown that breast conserving surgery and postoperative radiotherapy for early breast cancer results was excellent for local control and survival.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.231-238
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• 1999

Background: Nocturnal hypoxemia occurs in patients with chronic obstructive pulmonary disease(COPD) and the detection and treatment of nocturnal hypoxemia should be part of the management of COPD patients. We performed this study to evaluate the factors influencing to sleep related arterial oxygen desaturation($SaO_2$) in patients with COPD. Methods: Resting and exercise cardiopulmonary function test, polysomnography, and $SaO_2$ during resting, exercise and sleep were measured in 12 patients with COPD. Results: The $SaO_2$ fell twice as much during sleep as during maximal exercise($13.1{\pm}9.3%$ fall in nocturnal $SaO_2$ vs. $6.4{\pm}3.3%$, p<0.05). Fall in nocturnal $SaO_2$ was well correlated with mean exercise $SaO_2$(r=-0.78, p<0.05), minimum exercise $SaO_2$(r=-0.90, p<0.01), and resting $SaO_2$(Cr=-0.82, p<0.05). Lowest sleep $SaO_2$ was well correlated with mean exercise $SaO_2$(r=0.80, p<0.05), lowest exercise $SaO_2$(r=0.90, p<0.01), and resting $SaO_2$(r=0.84, p<0.05). Conclusion: Resting and exercise $SaO_2$ was well correlated with nocturnal $SaO_2$, but exercise study add no additional information to predicting the nocturnal oxygen desaturation in patients with COPD.