• Journal of Gifted/Talented Education
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• v.5 no.2
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• pp.139-156
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• 1995

The purpose of the study is to examine the effects of Gifted Education Isnstitute of Korea (GEIK) programs for gifted children especially in the areas of reasoning skills and creativity, thereby proving the effectiveness of the program. The subjects are 136 (103 boys and 33 girls) fourth, fifth, and sixth grade gifted children, who have participated in GEIK programs for more than six moths. They were stratified by the length of participation in GEIK programs. Ninety four children have participated for more than one year. Forty-two children have participated for less than one year. Both groups are rather homogeneous in IQ scores and school achievement levels at the time of enterance into GEIK programs. Both a Group Assessment of Logical Thinking (GAIT) and a Creativity test were used for the study on reasoning skills and creativity. GALT, developed by V. Roadranka, R. H. Yeany and M. J. Padilla in 1983, consists of 12 questions. It is classified into six subscales: conservation, proportional reasoning, controlling variables, provability reasoning, correlational reasoning, and combinatorial reasoning. The reliability of this test is .85. This test recommends to classify the stages of child development as follows according to the total test score. 0-4 point: Concrete Stage, 5-7 points: Transitional Stage, and 8 and above points: Formal stage. The Creativity Test was developed by Y. Lee and W. Chung (1971). It consists of four components: fluency, flexibility, originality, and openness. Only both fluency and openness were used in this study. In order to analyze data, T-Test, Intercorrelational Analyses, ANOVA, and Nultiple Regression were used. Followings are the results deduced from the above analoyses of the data. First, 43.48% of the subjects were on Concrete Stage, 36.78% were on the Transitional Stage, and 19.86% were on the Formal Stage in the developmental level classified by Piaget. Second, the students who have participated in GEIK programs more than one year acquired significantly higher score in GALT than the students who have participated in GEIK programs less than one year. Third, boys showed higher score in GALT than girls did. Fourth, there were statistically significant intercorrelations between six subscales of GALT. Fifth, the students who have participated in GEIK programs more than one year acquired significantly higher score in openness of creativity test than the students who have participated in GEIK programs less than one year. There were no significant differences in openness of creativity test between boys and girls. Sixth, the students who have participated in GEIK programs more than one year acquired significantly higher score in fluency of creativity test than the students who have participated in GEIK programs less than one year. Girls showed higher score in fluency of creativity test than boys did. Seventh, the students who acquired higher score in GALT showed higher score in both openness and fluency of creativity test. Followings are the conclusions deduced form the above results. First, the developmental level of reasoning skills of the fourth grade students participationg in GEIK programs is the same as that of 7th grade of normal Korean students and the same as those of 10th grade of U.S.A. and Philipoine students. Second, the GEIK programs are effective in improving reasoning skills. Third, the GEIK programs are effective in improving creativity. Fouth, reasoning skills and creativity can be improved by well planned programs. In conclusion, this study suggests that beyond reasoning skills and creativity, other areas such as areas in science skills, mathmatical skills, or verbal skills, etc., should be studied in the future.

• Membrane Journal
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• v.24 no.6
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• pp.463-471
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• 2014

While poly(styrene)-based anion exchange membranes have the advantage like easy and simple manufacturing process, they also possess the disadvantage of poor durability due to their brittleness. Acrylonitrile-butadiene rubber was used here as an additive to make the membranes have improved flexibility and durability. For the preparation of the anion exchange membranes, a PP mesh substrate was immersed into monomer solutions with vinylbenzyl chloride, styrene, divinylbenzene and benzoyl peroxide, then thermally polymerized & crosslinked. The prepared membranes were subsequently post-aminated using trimethylamine to result in $-N+(CH_3)_3$ group-containing composite membranes. Various contents of vinylbenzyl chloride and acrylonitrile-butadiene rubber were investigated to optimize the membrane properties and the prepared membranes were evaluated in terms of water content, ion exchange capacity and electric resistance. It was found that the optimized composite membranes showed higher IEC and lower electric resistance than a commercial anion exchange membrane(AMX) and have excellent flexibility and durability.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.241-249
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• 2006

Due to the long tectonic history and the very complex geologic formations in Korea, the anisotropic characteristics of subsurface material may often change very greatly and locally. The algorithms commonly used, however, may not give sufficiently precise computational results of traveltime data particularly for the complex and strong anisotropic model, since they are based on the two-dimensional (2D) earth and/or weak anisotropy assumptions. This study is intended to develope a three-dimensional (3D) modeling algorithm to precisely calculate the first arrival time in the complex anisotropic media. Considering the complex geology of Korea, we assume 3D TTI (tilted transversely isotropy) medium having the arbitrary symmetry axis. The algorithm includes the 2D non-linear interpolation scheme to calculate the traveltimes inside the grid and the 3D traveltime mapping to fill the 3D model with first arrival times. The weak anisotropy assumption, moreover, can be overcome through devising a numerical approach of the steepest descent method in the calculation of minimum traveltime, instead of using approximate solution. The performance of the algorithm developed in this study is demonstrated by the comparison of the analytic and numerical solutions for the homogeneous anisotropic earth as well as through the numerical experiment for the two layer model whose anisotropic properties are greatly different each other. We expect that the developed modeling algorithm can be used in the development of processing and inversion schemes of seismic data acquired in strongly anisotropic environment, such as migration, velocity analysis, cross-well tomography and so on.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.53-64
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• 2003

Many transmission towers, high-rise buildings and bridges are constructed near steep slopes and are supported by large-diameter piles. These structures may be subjected to large lateral loads, such as violent winds and earthquakes. Widely used types of foundations for these structures are pier foundations, which have large-diameters with high stiffness. The behavior of a pier foundation subjected to lateral loads is similar to that of a short rigid pile because both elements seem to fail by rotation developing passive resistance on opposite faces above and below the rotation point, unlike the behavior of a long flexible pile. This paper describes the results of several numerical studies performed with a three-dimensional finite element method (FEM) of model tests of a laterally loaded short pile located near slopes, respectively. In this paper, the results of model tests of single piles and pile groups subjected to lateral loading, in homogeneous sand with 30$^{\circ}$ slopes and horizontal ground were analyzed by the 3-D FE analyses. The pile was assumed to be linearly elastic. The sand was assumed to have non-associative characteristics, following the MC-DP model. The failure criterion is governed by the Mohr-Coulomb equation and the plastic potential is given by the Drucker-Prager equation. The main purpose of this paper is the validation of the 3-D elasto-plastic FEM by comparisons with the experimental data.

• Korean Journal of Radiology
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• v.21 no.7
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• pp.812-828
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• 2020

Objective: To provide an evidence-based guide for the MRI interpretation of complete tumor response after neoadjuvant chemoradiation therapy (CRT) for rectal cancer using visual assessment on T2-weighted imaging (T2) and diffusion-weighted imaging (DWI). Materials and Methods: PubMed MEDLINE, EMBASE, and Cochrane Library were searched on November 28, 2019 to identify articles on the following issues: 1) sensitivity and specificity of T2 or DWI for diagnosing pathologic complete response (pCR) and the criteria for MRI diagnosis; 2) MRI alone vs. MRI combined with other test(s) in sensitivity and specificity for pCR; and 3) tests to select patients for the watch-and-wait management. Eligible articles were selected according to meticulous criteria and were synthesized. Results: Of 1615 article candidates, 55 eligible articles (for all three issues combined) were identified. Combined T2 and DWI performed better than T2 alone, with a meta-analytic summary sensitivity of 0.62 (95% confidence interval [CI], 0.43-0.77; I² = 80.60) and summary specificity of 0.89 (95% CI, 0.80-0.94; I² = 92.61) for diagnosing pCR. The criteria for the complete response on T2 in most studies had the commonality of remarkable tumor decrease to the absence of mass-like or nodular intermediate signal, although somewhat varied, as follows: (near) normalization of the wall; regular, thin, hypointense scar in the luminal side with (near) normal-appearance or homogeneous intermediate signal in the underlying wall; and hypointense thickening of the wall. The criteria on DWI were the absence of a hyperintense signal at high b-value (≥ 800 sec/mm²) in most studies. The specific algorithm to combine T2 and DWI was obscure in half of the studies. MRI combined with endoscopy was the most utilized means to select patients for the watch-and-wait management despite a lack of strong evidence to guide and support a multi-test approach. Conclusion: This systematic review and meta-analysis provide an evidence-based practical guide for MRI assessment of complete tumor response after CRT for rectal cancer.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.157-168
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• 2008

Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1217-1221
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• 2008

Purpose : An association between idiopathic thrombocytopenic purpura (ITP) and systemic lupus erythematosus (SLE) has been recognized for decades because thrombocytopenia is the first manifestation in some patients with SLE. However, the risk of later development of SLE in childhood ITP is currently unknown. We retrospectively evaluated the incidence and clinical significance of the positive antinuclear antibody (ANA) in children with acute ITP. Methods : This study was retrospectively performed to review the clinical and laboratory characteristics in 77 children diagnosed to have acute ITP and admitted to the Pusan National University Hospital between January 2003 and December 2006. Patients tested positive for ANA were regularly followed-up for at least 12 months for symptoms indicative of SLE. Results : Seventy-seven children were included in the study; 38 males (49.4%) and 39 females (50.5%), the mean age was 4.5 years. Sixteen (20.8%) ITP patients had a positive ANA, with a median titer of 1:320. The mean age of the patients with positive ANA was 9.3 years, which is much older than 3.3 years for patients with negative ANA (P<0.05). The positive ANA group was predominantly female (81.3%) compared to the negative ANA group (P<0.05). There was no statistically significant difference in mean platelet counts between both groups. No statistically significant difference was found in ANA positivity and progression to chronic ITP or SLE. After the median follow-up of 32 months, SLE was diagnosed only in one ITP patient with positive ANA. Conclusion : Our data demonstrated that ANA positivity is often found in children with acute ITP. Large-scale studies should be considered to determine the significance of ANA positivity in childhood ITP for the later development of SLE.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.376-379
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• 2005

Purpose : Mycoplasama pneumoniae is a leading cause of pneumonia and exacerbates other respiratory conditions such as asthma. Surfactant protein A(SP-A) is involved in surfactant physiology and surfactant structure, and plays a major role in innate host defense and inflammatory processes in the lung. In this study, SP-A mediated mycoplasma cidal activity. The candidate-gene approach was used to study the association between the SP-A gene locus and Mycoplasama pneumoniae pneumonia in the genetically homogeneous Korean population. Methods : PCR-cRFLP-based methodology was used to detect SP-A genotype. The forty nine children with Mycoplasama pneumoniae pneumonia were matched to 50 nomal neonates. Results : The specific frequencies for the alleles of the SP-A1 and SP-A2 gene in the study population were : $6A^2=21$ percent, $6A^3=45$ percent, $6A^4=11$ percent, $6A^8=9$ percent, $6A^{14}=8$ percent, 1A=11.3 percent, $1A^0=38$ percent, $1A^1=12.7$ percent, $1A^2=9.2$ percent, $1A^5=15.5$ percent, $1A^7=2.9$ percent, $1A^8=4.9$ percent, $1A^9=2.2$ percent, others=3.3 percent. The frequencies of specific genotypes such as $1A^2$ was higher than control group, significantly. Conclusion : $1A^2$ are susceptible factors for Mycoplasama pneumoniae pneumonia. We conclude that the SP-A gene locus($1A^2$) is an important determinant for predisposition to Mycoplasama pneumoniae pneumonia in children.

• Journal of the Korean Geographical Society
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• v.30 no.3
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• pp.296-310
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• 1995

Classification of spatial units into meaningful sets is an important procedure in spatial analysis. It is crucial in characterizing and identifying spatial structures. But traditional classification methods such as cluster analysis require an exact database and impose a clear-cut boundary between classes. Scrutiny of realistic classification problems, however, reveals that available infermation may be vague and that the boundary may be ambiguous. The weakness of conventional methods is that they fail to capture the fuzzy data and the transition between classes. Fuzzy subsets theory is useful for solving these problems. This paper aims to come to the understanding of theoretical foundations of fuzzy spatial analysis, and to find the characteristics of fuzzy classification methods. It attempts to do so through the literature review and the case study of urban classification of the Cities and Eups of Kyung-Nam Province. The main findings are summarized as follows: 1. Following Dubois and Prade, fuzzy information has an imprecise and/or uncertain evaluation. In geography, fuzzy informations about spatial organization, geographical space perception and human behavior are frequent. But the researcher limits his work to numerical data processing and he does not consider spatial fringe. Fuzzy spatial analysis makes it possible to include the interface of groups in classification. 2. Fuzzy numerical taxonomic method is settled by Deloche, Tranquis, Ponsard and Leung. Depending on the data and the method employed, groups derived may be mutually exclusive or they may overlap to a certain degree. Classification pattern can be derived for each degree of similarity/distance $\alpha$. By takina the values of $\alpha$ in ascending or descending order, the hierarchical classification is obtained. 3. Kyung-Nam Cities and Eups were classified by fuzzy discrete classification, fuzzy conjoint classification and cluster analysis according to the ratio of number of persons employed in industries. As a result, they were divided into several groups which had homogeneous characteristies. Fuzzy discrete classification and cluste-analysis give clear-cut boundary, but fuzzy conjoint classification delimit the edges and cores of urban classification. 4. The results of different methods are varied. But each method contributes to the revealing the transparence of spatial structure. Through the result of three kinds of classification, Chung-mu city which has special characteristics and the group of Industrial cities composed by Changwon, Ulsan, Masan, Chinhai, Kimhai, Yangsan, Ungsang, Changsungpo and Shinhyun are evident in common. Even though the appraisal of the fuzzy classification methods, this framework appears to be more realistic and flexible in preserving information pertinent to urban classification.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.167-174
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• 2012

Purpose: The purpose of this study is investigation of clinical and functional outcomes in homogeneous group with positive culture after arthroscopic management for pyogenic knee arthritis and analysis of factors affecting those outcomes. Materials and Methods: Thirty-two patients with positive culture after arthroscopic management were included. Mean follow-up period was 41.6 months. Clinical evaluation included death related to infection, recurrence, time to normalize erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), duration of administration of intravenous antibiotics and readmission. Radiographic evaluation was performed according to Kellgren and Lawrence. The prevalence of total knee arthroplasty was investigated and functional evaluation included modified Lysholm, Tegner activity and Korean version of the Western Ontario and McMaster Universities (K-WOMAC) score. Results: Staphylococcus aureus was identified in 21 patients. Time to normalize ESR and CRP was 78.0 and 67.6 days, respectively. Two patients died while there were six recurrences and five readmissions. Rate of recurrence was significantly high in patients with chronic renal failure (P=0.034) and incidence of readmission was associated with higher radiographic grade of osteoarthritis and rate of reoperation (P=0.032 and P=0.006, respectively). At the final follow-up, radiographic grade worsened in 21 patients and was associated with those at first visit. Five arthroplasties were performed. Average modified Lysholm score, Tegner activity score and K-WOMAC score were 53.5, 2.7, 44.2 points, respectively. Conclusion: The severity of osteoarthritis on final radiographs was associated with those at first visit. Patients with higher grade of osteoarthritis at first visit showed higher incidence of readmission and those with chronic renal failure demonstrated higher chances of recurrence.