• Journal of Korean Academy of Nursing
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• v.41 no.2
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• pp.256-268
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• 2011

Purpose: The purpose of this study was to use meta-analysis to examine recent domestic articles related to attention deficit hyperactivity disorder (ADHD) in school-age children. Methods: After reviewing 213 articles published between 1990 and 2009 from and cited in RISS, KISS, and DBpia, the researchers identified 24 studies with 440 research variables that had appropriate data for methodological study. SPSS 17.0 program was used. The outcome variables were divided into five types: Inattention, hyperactive impulsive, intrinsic, extrinsic, and academic ability variables. Results: Effects size of overall core symptoms was 0.47 which is moderate level in terms of Cohen criteria and effects size of overall negative variables related ADHD was 0.27 which is small level. The most dominant variable related to ADHD was obtained from hyperactive-impulsive (0.70). Also academic ability (0.45), inattention (0.37), and intrinsic variables (0.29) had a small effect whereas extrinsic variables (0.13) had little effect on descriptive ADHD study. Conclusion: The results reveal that ADHD core symptoms have moderate effect size and peripheral negative variables related ADHD have small effect size. To improve the reliability of the meta-analysis results by minimizing publication bias, more intervention studies using appropriate study designs should be done.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.167-172
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• 2000

This paper is aimed at developing an location tracking for mobile station employing currently available mobile communication network of cellular phone and PCS(Personal Communication System). When the location tracking of mobile stations is in services, the services such as Emergency-119, crime investigation, effective urban traffic management or the safety protection of Alzheimer's patients, ran be available. This paper is to track the mobile station in communication network in NLOS environment. To achieve reduction of the standard noise, Kalman filter is used. In terms of the distance, positions are located by using TOA and TDOA methods in the environment that removes NLOS bias in the measured data. And then smoothing method is used. to achieve reduction of the position error values

• Journal of the Korean Geographical Society
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• v.47 no.2
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• pp.245-267
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• 2012

This paper analyzes the discrimination of private property right protection in urban regeneration projects that is implemented by eminent domain based on public use in the United States. In spite of urban regeneration projects which depends on property condemnation for public use as a coercive power, it is executed on the discrimination of property right and sacrifice of the social disadvantages that transfer property from these private party to another big capitals and private developers. At first this paper investigates research trends in urban regeneration within the framework of multidisciplinary approach and suggests legal geographical perspective as a new research field. Next I figure out current state, types and numbers of brownfields site with the EPA and GAO data, and define these sites as results of deindustrialization and suburbanization process. Finally this paper uncover that the discrimination process of private property right is due to complex actions of expansion of public use concept in the U.S. Supreme Court from public ownership to economic public use, privatization of eminent domain, growth coalition regime and business friendly policy focused on economic development, class and racial bias, neoliberal movements of property right reform.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.347-355
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• 2018

A convergence study was conducted to identify effect size, intervention characteristics, and tendency of laughter therapies on depression for Korean older adults. Of the 486 studies searched in 10 databases, 20 studies in the inclusion criteria were selected. The risk of bias was assessed by SIGN's tool, and the data were analyzed using CMA 3.0 software. Overall effect size of laughter therapy on depression of older adults was medium (standardized mean difference [SMD]=-0.57, 95% CI: -0.70~-0.44, p<.001), and heterogeneity was small ($I^2=18%$). Subgroup analysis showed that the effect sizes of institutionalized group, mixed group, 4-6 weeks of duration, and group intervention were higher than the compared groups. Findings of this convergent meta-analysis would be helpful for health professionals to provide more effective laugher therapy sessions. Further replicative studies in long-term care facilities and more randomized controlled trials of laughter therapy are needed.

• Journal of the Ergonomics Society of Korea
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• v.34 no.5
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• pp.377-399
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• 2015

Objective: The aim of this study is to understand and identify the critical issues in vision research area using content analysis and network analysis. Background: Vision, the most influential factor in information processing, has been studied in a wide range of area. As studies on vision are dispersed across a broad area of research and the number of published researches is ever increasing, a bibliometric analysis towards literature would assist researchers in understanding and identifying critical issues in their research. Method: In this study, content and network analysis were applied on the meta-data of literatures collected using three search keywords: 'visual search', 'eye movement', and 'eye tracking'. Results: Content analysis focuses on extracting meaningful information from the text, deducting seven categories of research area; 'stimuli and task', 'condition', 'measures', 'participants', 'eye movement behavior', 'biological system', and 'cognitive process'. Network analysis extracts relational aspect of research areas, presenting characteristics of sub-groups identified by community detection algorithm. Conclusion: Using these methods, studies on vision were quantitatively analyzed and the results helped understand the overall relation between concepts and keywords. Application: The results of this study suggests that the use of content and network analysis helps identifying not only trends of specific research areas but also the relational aspects of each research issue while minimizing researchers' bias. Moreover, the investigated structural relationship would help identify the interrelated subjects from a macroscopic view.

• The Journal of Fisheries Business Administration
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• v.43 no.2
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• pp.79-94
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• 2012

The purpose of this study is to investigate the production efficiencies of the Korean aquaculture fishery with respect to species and methods using a Data Envelopment Analysis. The study extracted the 8 fishes in each of the sea cage culture, aquarium basin, and enclosed aquaculture for the analytical purposes. First, the study estimated the technical, pure technical, and scale efficiencies of the total of 24 aquaculture fishes based on the traditional DEA under the assumptions of both CRS and VRS. 2 fishes were identified as the efficient DMUs under the CCR-model, and 6 fishes under the BCC-model. Second, we tested to see if there was any difference in production efficiencies regarding those three different methods of aquaculture. we could not find any evidence of the differences in efficiency using a rank sum test based on the traditional DEA. However, we could do find that the pure technical efficiency in the sea cage culture was lower than others at 1% level of significance and the pure technical efficiency in enclosed aquaculture was also lower than others at 5% level of significance using Bilateral-DEA, which could explicitly consider the heterogeneity in the 3 production methods of aquaculture. Finally, the study obtained the 95% confidence intervals of the efficiency scores for the 24 fishes under our study using the smoothed bootstraping method in the process of the re-sampling in cooperation with both a kernel density estimation and a reflection method. At the same time, we could estimate the bias-corrected efficiency scores while the traditionally estimated efficiency scores suffered from the biases in the process of solving a linear programming with the deterministic nature of a production frontier. And hence, we could distinguish the differences in production efficiencies of the 8 fishes with respect to those 3 methods of aquaculture.

• Publications of The Korean Astronomical Society
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• v.23 no.1
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• pp.1-12
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• 2008

Understanding of the basic characteristics of an astronomical instrument is a prerequisite to obtaining reliable data from the instrument. We have analyzed more than 1,000 calibration images from the Fairchild 486 CCD (hereafter the Maidanak 4k CCD system) attached to the AZT-22 1.5m telescope at Maidanak Astronomical Observatory in Uzbekistan. The Maidanak 4k CCD system supports three readout modes through 1, 2, or 4 amplifiers. In most cases observers use 4-amplifier readout mode to save time. We have tested the stability and seasonal variation of zero levels and confirm that two quadrants of the images (Amp 1 & 2) show no appreciable seasonal variation. but the other two quadrants (Amp 3 & Amp 4) show an evident seasonal variation in the bias level. The Cryo Tiger, the cooling system used at the Maidanak 4k CCD system, maintains the CCD temperature at -108'E, and effectively suppresses the dark electrons. The mean value versus the variance plot of the flat images does not show the expected relation for an ideal Poisson noise distribution and this is attributed to the large variation in quantum efficiency between different pixels. In addition, we confirm that there is no appreciable difference in gain between readout amplifiers, but there is a large variation in quantum efficiency across CCD chip especially in U. Due to the finite length of shutter opening and closing time, the effective exposure time varies across the science images. We introduce two parameters to quantify the effect of this uneven illumination and present a method to remove these effects. We also present a method to remove the interference patterns appearing in the images obtained with longer wavelength filters and investigate the spatial variation of the point spread function.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.385-394
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• 2012

This study investigates whether earnings management behavior of chaebol firms differ from that of non-chaebol firms. The ownership structure of chaebol firms is characterized by the dominance of one largest shareholder and his family members who typically participate in the management of the firm directly or indirectly and influence most of the important management decision. This study adopts the random effect model and the hausman and talyor model, using a panel of 5092 firm-year over a period from 1991 to 2010 to control for potential heterogeneity and endogeneity that may cause sever bias. This study finds that there is no difference in accrual based earnings management level between chaebol firms and non-chaebol firms. However, chaebol firms appeared to engage less real earnings management that is known to negatively affect future earnings and share prices. The results are consistent when controlling for potential heterogeneity and endogeneity in the hausman and taylor model. The results may be of interest to various stakeholders, policy makers, standard setters and academic researchers.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3937-3942
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• 2012

Background: Many studies have investigated possible association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and ovarian cancer risk, but the impact is still unclear owing to the obvious inconsistencies. This study was performed to quantify the strength of the association with a metaanalysis. Methods: We searched the PubMed, Embase, and CNKI databases for studies relating the association between MTHFR C677T polymorphism and ovarian cancer risk and estimated summary odds ratios (ORs) with confidence intervals (CIs) for assessment. Results: Finally, eight studies with a total of 3,379 ovarian cancer cases and 4,078 controls were included into this meta-analysis. Overall the showed that MTHFR C677T polymorphism was not associated with ovarian cancer risk under all genetic models ($OR_{T\;versus\;C}$ = 1.03, 95%CI 0.90-1.18; $OR_{TT\;versus\;CC}$ = 1.08, 95%CI 0.79-1.47; $OR_{TT\;versus\;TC+CC}$ = 1.05, 95%CI 0.80-1.37; $OR_{TT+TC\;versus\;CC}$ = 1.05, 95%CI 0.86-1.21). Meta-analyses of studies with confirmation of HWE also showed no significant association. Subgroup analyses by ethnicity showed there was no significant association in the Caucasians but MTHFR C677T polymorphic variant T contributed to increased risk of ovarian cancer in East Asians. No evidence of publication bias was observed. Conclusion: Meta-analyses of available data show that MTHFR C677T polymorphism is not associated with ovarian cancer risk in Caucasians, but the MTHFR polymorphic variant T may contribute to increased risk in East Asians.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.12
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• pp.89-100
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• 1997

This paper investigated a new type of low voltage threshold switch (LVTS). As distinguished from the many other types of electronic threshold switches, the LvTS is ; voltage controlled, occurs at low voltages ($V_{2}$ $O_{5}$lV devices. The average low threshold voltage < $V_{LVT}$>=218 mV (standard deviation =24mV~kT/q, where T=300K), and was independent of the device area (x100) and amorphous oxide occurred in an ~22.angs. thick interphase of the V/amorphous- $V_{2}$ $O_{5}$ contacts. At $V_{LVT}$ there was a transition from an initially low conductance (OFF) state into a succession of quantized states of higher conductance (ON). The OFF state was spatically homogeneous and dominated by tunneling into the interphase. The ON state conductances were consistent with the quantized conductances of ballistic transport through a one dimensional, quantum point contact. The temeprature dependence of $V_{LVT}$, and fit of the material parameters (dielectric function, barrier energy, conductivity) to the data, showed that transport in the OFF and ON states occurred in an interphase with the characteristics of, respectively, semiconducting and metallic V $O_{2}$. The experimental results suggest that the LVTS is likely to be observed in interphases produced by a critical event associated with an inelastic transfer of energy.rgy.y.rgy.