• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.151-158
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• 2010

In line with the requirement of appropriate protocol support for such mission-critical wireless sensor network (WSN) applications as patient monitoring, we investigate the framework for designing medium access control (MAC) schemes. The data traffic in medical systems comes with inherent traffic heterogeneity as well as strict requirement of reliability according to the varied extents of devise-wise criticality in separate cases. This implies that the quality-of-Service (QoS) issues are very distinctly delicate requiring specialized consideration. Besides, there are features in such systems that can be exploited during the design of a MAC scheme. In a monitoring or routine surveillance application, there are degrees of regularity or predictability in traffic as coordinated from a node of central control. The coordinator thus takes on the role of marshaling the resources in a neighborhood of nodes deployed mostly for upstream traffic; in a collision-free scheme, it schedules the time slots for each superframe based on the QoS specifications. In this preliminary study, we identify the key artifacts of such a MAC scheme. We also present basic performance issues like the impact of superframe length on delay incurred, energy efficiency achieved in the network operation as obtained in a typical simulation setup based on this framework.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.25 no.4
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• pp.187-195
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• 2014

Objectives : The objective of this study was to investigate the relationship between restricted, repetitive behaviors and interests (RRBI) and autistic symptoms in Korean high functioning autism spectrum disorder (ASD) children and to examine the structure of RRBI. Methods : Participants included 147 high functioning ASD subjects and 181 unaffected siblings. ASD subjects were divided into two groups based on the presence of RRBI. The domain scores of the Korean version of Autism Diagnostic Interview-Revised (K-ADI-R), Korean version of Asperger Syndrome Diagnostic Scale and total scores of Korean translated version of Social Responsiveness Scale, Korean version of Social Communication Scale were used for comparison of ASD symptoms between the groups. Eleven items from the RRBI domain of the K-ADI-R were used in principal axis factor analysis (PAF). Results : A statistically lower nonverbal IQ score was observed for ASD with RRBI than for ASD without RRBIs, and more social deficit, communication deficit, and behavioral and emotional problems were observed for ASD with RRBI compared to ASD without RRBI. Using PAF, two distinct factors were identified. 'Resistance to trivial changes in environment', 'Difficulty with minor changes in personal routine & environment', and 'Compulsion/ritual' were included as one factor. Conclusion : Analysis of the data suggests that the presence of RRBI in high functioning ASD is associated with a more severe presentation of autistic disorder. In addition, there appears to be heterogeneity within RRBI in autism except insistence on sameness.

• Journal of Environmental Science International
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• v.18 no.4
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• pp.423-434
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• 2009

In recent years, the urban thermal environment has become worse, such as days on which the temperature goes above $30^{\circ}C$, sultry nights and heat stroke increase, due to the changes in terrestrial cover such as concrete and asphalt and increased anthropogenic heat emission accompanied by artificial structure. The land use type is an important determinant to near-surface air temperature. Due to these reasons we need to understand and improve the urban thermal environment. In this study, the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model(MMS) was applied to the metropolitan of Daegu area in order to investigate the influence of land cover changes and urban modifications increase of Albedo to the surface energy budget on the simulated near-surface air temperature and wind speed. The single urban category in existing 24-category U.S. Geological survey land cover classification used in MM5 was divided into 6 classes to account for heterogeneity of urban land cover. As a result of the numerical simulation intended for the metropolitan of Daegu assumed the increase of Albedo of roofs, buildings, or roads, the increase of Albedo (Cool scenario)can make decrease radiation effect of surface, so that it caused drops in ambient air temperature from 0.2 to 0.3 on the average during the daylight hours and smaller (or near-zero) decrease during the night. The Sensible heat flux and Wind velocity is decreased. Modeling studies suggest that increased surface albedo in urban area can reduce surface and air temperatures near the ground and affect related meteorological parameters such as winds, surface air temperature and sensible heat flux.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4871-4875
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• 2013

This meta-analysis was performed to evaluate and compare the outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for treating gastric cancer. A systematic literature search was carried out using the PubMed database, Web of Knowledge, and the Cochrane Library database to obtain comparative studies assessing the safety and efficiency between RG and LG in May, 2013. Data of interest were analyzed by using of Review Manager version 5.2 software (Cochrane Collaboration). A fixed effects model or random effects model was applied according to heterogeneity. Seven papers reporting results that compared robotic gastrectomy with laparoscopic gastrectomy for gastric cancer were selected for this meta-analysis. Our metaanalysis included 2,235 patients with gastric cancer, of which 1,473 had undergone laparoscopic gastrectomy, and 762 had received robotic gastrectomy. Compared with laparoscopic gastrectomy, robotic gastrectomy was associated with longer operative time but less blood loss. There were no significant difference in terms of hospital stay, total postoperative complication rate, proximal margin, distal margin, numbers of harvested lymph nodes and mortality rate between robotic gastrectomy and laparoscopic gastrectomy. Our meta-analysis showed that robotic gastrectomy is a safe technique for treating gastric cancer that compares favorably with laparoscopic gastrectomy in short term outcomes. However, the long term outcomes between the two techniques need to be further examined.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2049-2053
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• 2016

Background: The LigaSure vessel sealing system has been proposed to save operation time and reduce intraoperative blood loss for various surgeries. However, its usage for gastric cancer is still controversial. The aim of the present meta-analysis was to compare the effectiveness of LigaSure with conventional surgery in gastrectomy. Materials and Methods: Sources were retrieved from the Cochrane Library, MEDLINE, EMBASE, SCOPUS and Google Scholar until February, 2015. All randomized controlled trials comparing LigaSure with conventional surgery in curative gastric cancer resection were selected. After data extraction, statistics were performed by Review Manager 5.1 software. Results: Three eligible randomized controlled trials were evaluated, with a total of 335 patients. The quality of the included trials was good, yet some methodological and clinical heterogeneity existed. There were no significant differences between the LigaSure and conventional groups in operative time (weighted mean difference [WMD], -22.95 minutes; 95% confidence interval [CI], [-59.75, 13.85]; P = 0.22), blood loss (WMD, -45.8 ml; 95% CI, [-134.5, 42.90]; P = 0.31), nor the incidence of surgical complications (odds ratio, 1.18; 95% CI, [0.68, 2.05]; P = 0.54). But there was a longer duration of hospital stay in LigaSure group (WMD, 1.41 days; 95% CI, [0.14, 2.68]; P = 0.03). Conclusions: All available randomized evidence has been summarized. LigaSure does not confer significant advantage over conventional surgery for curative gastric cancer resection. The usefulness of the device may be limited in gastrectomy. But, more trials are needed for further assessment of the LigaSure system for gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5673-5679
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• 2014

Background: Previous published data on the association between CYP1A2 rs762551, rs2069514, rs2069526, and rs2470890 polymorphisms and lung cancer risk have not allowed a definite conclusion. The present meta-analysis of the literature was performed to derive a more precise estimation of the relationship. Materials and Methods: 8 publications covering 23 studies were selected for this meta-analysis, including 1,665 cases and 2,383 controls for CYP1A2 rs762551 (from 8 studies), 1,456 cases and 1,792 controls for CYP1A2 rs2069514 (from 7 studies), 657 cases and 984 controls for CYP1A2 rs2069526 (from 5 studies) and 691 cases and 968 controls for CYP1A2 rs2470890 (from 3 studies). Results: When all the eligible studies were pooled into the meta-analysis for the CYP1A2 rs762551 polymorphism, significantly increased lung cancer risk was observed in the dominant model (OR=1.21, 95 % CI=1.00-1.46). In the subgroup analysis by ethnicity, significantly increased risk of lung cancer was observed in Caucasians (dominant model: OR=1.29, 95%CI=1.11-1.51; recessive model: OR=1.33, 95%CI=1.01-1.75; additive model: OR=1.49, 95%CI=1.12-1.98). There was no evidence of significant association between lung cancer risk and CYP1A2 rs2069514, s2470890, and rs2069526 polymorphisms. Conclusions: In summary, this meta-analysis indicates that the CYP1A2 rs762551 polymorphism is linked to an increased lung cancer risk in Caucasians. Moreover, our work also points out the importance of new studies for rs2069514 associations in lung cancer, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the rs2069514 polymorphism in lung cancer development.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5311-5316
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• 2013

A functional polymorphism in the NQO1 gene, featuring a 609C>T substitution,leading to proline to serine amino-acid and enzyme activity changes, has been implicated in cancer risk. However, individually published investigations showed inconclusive results, especially for leukemia. In this study, we therefore performed a meta-analysis of 21 publications with a total of 3,634 cases and 4,827controls, mainly for leukemia. We summarized the data on the association between the NQO1 609C>T polymorphism and risk of leukemia and performed subgroup analyses by ethnicity and leukemia type. We found that the variant TT homozygous genotype o was associated with a modestly increased risk of leukemia (TT versus CT/CC: OR=1.23, 95%CI=1.00-1.51, heterogeneity=0.76; $I^2$=0%). Following further stratified analyses, increased risk was only observed in subgroups of Caucasians. This meta-analysis suggests that the NQO1 609T allele is a high-penetrance risk factor for leukemia in Caucasians. The effect on leukemia may be modified by ethnicity and leukemia type, and the small sample sizes of the subgroup analyses suggest that further larger studies are needed.

• Investigative Magnetic Resonance Imaging
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• v.19 no.1
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• pp.37-46
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• 2015

Purpose: This report compared the diagnostic effectiveness between ultrasmall superparamagnetic iron oxide (USPIO) and gadolinium (Gd) based magnetic resonance imaging (MRI) for differentiation of axillary status in breast cancer patients. Materials and Methods: The present authors performed a meta-analysis of previous studies that compared USPIO or Gd based MRI with histological diagnosis after surgery or biopsy. We searched PubMed, EMBASE, Cochrane Library, ScienceDirect, SpringerLink, Ovid databases and references of articles to identify studies reporting data until December 2013. Pooled sensitivity and specificity were calculated for every study; summary receiver operating characteristic and subgroup analysis was done. Analyses of study quality and heterogeneity were also assessed. Results: There were 14 publications that met the criteria for inclusion in our meta-analysis. USPIO based MRI showed 0.83 (95% CI: 0.75-0.89) and 0.97 (95% CI: 0.94-0.98) for pooled sensitivity and specificity, respectively. Gd based MRI represented pooled sensitivity and specificity of 0.61 (95% CI: 0.55-0.67) and 0.90 (95% CI: 0.87-0.92) for each. Overall weighted area under the curve for USPIO and Gd based MRI were 0.9563 and 0.9051, respectively. Conclusion: USPIO based MRI had a tendency toward high pooled sensitivity and specificity in detection of axillary metastases for breast cancer. This result may mean that USPIO based MRI could be used as complementary modality to differentiate axillary status more precisely, and assist in the decision-making process regarding possible invasive procedures, such as sentinel node biopsy.

• The KIPS Transactions:PartD
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• v.12D no.4 s.100
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• pp.553-568
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• 2005

In order to integrate distributed biological information sources physically or virtually, it is necessary to overcome the heterogeneity of information sources and support a superior generality and adaptation in order to satisfy user's various demands. In this paper, we present a flexible and general XML query engine of a wrapper system in designing the middleware system to integrate data as well as application programs. Since this query engine applies user-defined XML view, it is possible to composite flexible integrated query. The query processing in a wrapper requires view composition, query translation into local sources, and generation of XML documents from local query results. We present a query processing model based on the view tree, where the n views and the XML queries are represented by the view tree. Moreover, to confirm the generality of our query processing model, we present a methodology of query processing for relational databases, web sources, and application programs whose return types of query results are relational tuples or XML documents.

• Survey Research
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• v.12 no.1
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• pp.65-88
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• 2011

This study analyzed the work and retirement behavior of middle- and old-aged Koreans using panel-data based multi-state life table models. Compared to previous studies that have mainly focused on gender differences in the work and retirement behavior, this study also analyzed educational differences in the retirement life course. With respect to the heterogeneity of work and retirement experiences, this study finds that the retirement life course of men and women differs substantially. Despite their longer life spans, women are expected to have shorter working life expectancies but live in a non-working state longer, resulting in a substantially higher proportion of non-working state in their lives. In terms of educational differences, this study finds that there is little difference in the expected length of stay in the labor force across educational levels but that poorly educated persons are more likely to spend a greater proportion of their lives in the labor force due to their shorter non-working life expectancies.