• Imaging Science in Dentistry
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• v.42 no.1
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• pp.25-33
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• 2012

Purpose : This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). Materials and Methods : MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. Results : All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Conclusion : Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements.

• Imaging Science in Dentistry
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• v.47 no.4
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• pp.255-259
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• 2017

Purpose: Underlying bone sclerosis is frequently observed in clinical settings when oral squamous cell carcinoma (OSCC) invades the jaw bone. The aim of this study was to assess the prevalence and characteristics of underlying bone sclerosis in patients with OSCC. Materials and Methods: We retrospectively reviewed the computed tomographic (CT) images of 131 patients who underwent mandibulectomy between January 2012 and December 2015 to treat OSCC. The presence, degree, and extent of underlying bone sclerosis were assessed on CT images and correlated with the following imaging patterns of bone invasion: cortical invasion, medullary invasion with a smooth margin, and medullary invasion with an irregular margin. The chi-square test was used to determine the relationships between the variables. Results: The prevalence of underlying bone sclerosis on CT images was 70.1% (47 of 67). The prevalence was 85.7% (42 of 49) in patients with medullary invasion, but it was 27.8% (5 of 18) in patients with only cortical invasion, indicating a significant increase in the prevalence of underlying bone sclerosis in patients with medullary invasion (P<.05). Aggressive patterns of bone invasion were associated with increases in the degree and extent of the underlying bone sclerosis(P<.05). Conclusion: More than two-thirds of OSCC cases with bone invasion showed underlying bone sclerosis. On CT images, reactive sclerosis in the remaining margin of the alveolar bone should not be used as the primary means to differentiate periodontal inflammatory lesions from those resulting from OSCC.

• Bulletin of the Korean Chemical Society
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• v.26 no.9
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• pp.1390-1394
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• 2005

Dimeric metallamacrocycles of 2 : 2 (metal-to-ligand) stoichiometry, [Pd{${\alpha},{\omega}$-bis(diphenylphosphino)oligothienylene}$Cl_2]_2$ 1-3 were prepared from a self-assembly reaction of $[Pd(CH_3CN)_2Cl_2]$ and ${\alpha},{\omega}$-bis-(diphenylphosphino)oligothienylene in 90-94% yields. The structures of metallamacrocycles 1-3 were determined by X-ray diffraction. 1 crystallizes in the monoclinic space group $P2_1$/n with a/$\AA$ = 12.0737(13), b/$\AA$ = 17.1993(18), c/$\AA$ = 13.0951(14) and ${\beta}/^{\circ}$ = 101.505(2). 2 crystallizes in the triclinic space group P with a/$\AA$ = 10.2634(4), b/$\AA$ = 19.7855(9), c/$\AA$ = 21.0851(9), ${\alpha}/^{\circ}$ = 63.1010(10), ${\beta}/^{\circ}$ = 86.5880(10), ${\gamma}/^{\circ}$ = 81.2280(10). 3 crystallizes in the triclinic space group P with a/$\AA$ = 10.4353(19), b/$\AA$ = 13.482(3), c/$\AA$ = 13.816(3), ${\alpha}/^{\circ}$ = 108.027(4), ${\beta}/^{\circ}$ = 90.461(4), ${\gamma}/^{\circ}$ = 93.261(4). The UV spectra of 1-3 were characterized.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.25 no.3
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• pp.136-141
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• 2014

Objectives : The aim of this study was to examine the relationship between internet game addiction and psychiatric symptoms. Methods : A total of 447 adolescents who were recruited from a child and adolescent psychiatric clinic of university hospital completed a self-report questionnaire consisting of Korean Internet Addiction Self-scale (K-scale), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Korean-Attention-Deficit Hyperactivity Disorder Rating Scale (K-ARS), and Adolescent Happiness Index (AHI). They were classified into three internet user groups, non-addicted group (below or equal to 94), potential risk group (95 to 107) and high risk group (above or equal to 108) according to K-scale total score. Results : Significant mean differences in BDI, BAI, K-ARS, and AHI scores were observed among the three groups. The BDI, BAI and K-ARS scores showed positive correlation with K-score. The AHI score showed negative correlation with K-score. Conclusion : Findings of this study suggest that depression, anxiety, inattention, hyperactivity/impulsivity, and happiness are associated with internet game addiction.

• The Journal of Korean Association of Computer Education
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• v.6 no.2
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• pp.95-105
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• 2003

This purpose of this study was to investigate learning effects of Web-based 3-dimensional VR(Virtual Reality) program and a 2-dimensional HTML program, and to find out interaction effects between the types of web-based instruction program(3-dimensional VR program and 2-dimensional HTML program) and the levels of spatial perception of the learners on learning achievement and satisfaction in an educational aspect. In conclusion, there was a significant difference in learning achievement and general satisfaction of the learners between the group providing 3-dimensional VR program and the group 2-dimensional HTML program(F=4.85, p<.05). The 3-dimensional VR program was found to be more effective. And, there was a significant interaction effect in learning achievement effects between the types of web-based instruction program and the level of spatial perception of the learners(F=32.48, p<.05).

• IMMUNE NETWORK
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• v.5 no.4
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• pp.252-257
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• 2005

Background: This study was designed to investigate the effect of exercise training on defense mechanism of chronic degenerative disease, aging, and memory impairments of senescence-accelerated mouse (SAM)P8 under the hypothesis that "Senile dementia may be prevented by regular exercises". Methods: To evaluate the effects of exercise training on the defense mechanism of aging and memory impairment, SAMP8 were divided into two groups, the control group and exercise training groups. the exercise training group were performed with low $(\dot{V}O_2max\;25{\sim}33%)$, middle ($\dot{V}O_2max$ 50%) and high $(\dot{V}O_2max\;66{\sim}75%)$ intensity exercise. All SAMP8 mice were fed experimental diet ad libitum until 4, 8 months, and dead period. Results: Median lifespan in middle exercise group resulted in a significantly increased (23.5% and 18.7%, respectively), whereas these lifespan in high exercise group resulted in an unexpectedly decreased (13.5% and 12.1%, respectively) compared with control group. Body fat levels in 4 and 8 months of age were significantly decreased 43% to 51% in middle exercise group, whereas were remarkably deceased to 57% in high exercise group compared with control group. It is believed that extended median and maximum lifespan may be effected by calory restriction through the exercise training. Acetylcholine (ACh) levels were significantly increased 6.7% and 8.5% in middle and high exercise groups, and also choline acetyltransfease (ChAT) activities were significantly increased 10.3% and 11.9% in middle and high exercise groups. Conclusion: These results suggest that proper and regular exercises such as middle group ($\dot{V}O_2max$ 50%) may play an effective role in attenuating an oxygen radicals and may play an important role in improving a learning and memory impairments of senile dementia.

• Journal of the Korean Dietetic Association
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• v.13 no.2
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• pp.101-113
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• 2007

The purpose of this study was to measure hospitalized patients' satisfactions with hospital foodservices, and thereby identify areas for improvement and provide basic data for the introduction of total quality management with hospital foodservices. This survey was carried out questionnaires by 382 hospitalized patients into 7 hospitals in Deagu, Busan, Changwon. The subjects were 50.5% male and 49.5% female. Sixty-two percent of the subjects were over 40age, 31.4% were only educated to middle school or below, 28.3% were hospitalized for 7-14 days. The result of evaluation for hospital foodservice during the length of hospitalization are as follows : Taste, seasoning, temperature, apperance of foods were higher in the short hospitalized patients than in the long hospitalized patients, especially kind and combinazation of food were significantly higher(p<0.001). The result of the foodservice with appetite status was significantly higher score(3.33) in the good appetite patients than in the bad appetite patients score(2.00)(p<0.001). As the hospitalization rooms were the significantly difference in the taste(p<0.05), seasoning(p<0.001), apperance(p<0.01) of the foods, amount of service(p<0.01), variety of menu(p<0.05), combinazation of foods(p<0.01) and opinion of patients(p<0.05).

• Journal of Digital Convergence
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• v.12 no.12
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• pp.107-117
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• 2014

Organizational Service Orientation is an essential factor to survive competition. So, a number of studies have investigated the impact of service orientation on Job Performance, and many evidence testify with certainty variable. Accordingly, this study investigated the impacts of Service Orientation on Turnover Intention and Organizational Commitment. In addition, this study examined the mediating effects of Emotional Labor. The results of this study are as followings ; First, Service Orientation are negatively related to Turn over Intention. Second, Service Orientation are positively related to Organizational Commitment. Third, Emotional Labor have partially moderated effect on the relationship between Service Orientation and Turnover Intention, Organizational Commitment. These findings provide the theoretical and practical implications.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.124-129
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• 2006

The grades of burley tobacco stems and scraps were classified followed by the nicotine and nitrate contents by using the cluster analysis. The chemical components of the burley tobacco stems and scraps gathered from 2002 to 2005 were analyzed with auto analyzer. According to the nicotine contents and the nitrate contents, the burley stems and scraps could be classified three groups, respectively. In case of the burley scraps, the AB3T, AB4TR, B1T and B2T grades belonged to the $1^{st}$ a group. The C1W and C2W grades belonged to the $2^{nd}$ group and the CD3W and CD4TR belonged to the $3^{rd}$. In case of the burley stems, the AB3T and AB4TR grades belonged to the $1^{st}$ group. The B1T, B2T, C1W and C2W grades belonged to the $2^{nd}$ group and the CD3W and CD4TR belonged to the $3^{rd}$ group. This classification of raw materials depending on the similarity in the chemical components might be helpful to control the properties of the Reconstituted Tobacco sheet.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.623-634
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• 2007

The aim of this research is development and verification of resistivity seismic dilatometer (RSDMT) system. The resistivity module for obtaining resistivity-depth plot and seismic module for obtaining wave velocity-depth plot are attached to the conventional flat dilatometer testing equipment. To enhance reliability and repeatability of seismic part in RSDMT, automatic testing system including automatic surface source, PC based data acquisition system and operating program were developed. To obtain real resistivity value of soil, geometric factor for the array of electrodes in RSDMT was derived empirically. The verification studies for the developed RSDMT system were performed at the southeast side of Korea where soil improvement work is planned. SPT, CPT, geophysical subsurface imaging techniques and some laboratory tests were performed for the comparisons. As one penetration of RSDMT, various soil parameters could be obtained. The results of field test showed good repeatability and reliability in every part. From these studies, developed RSDMT system was checked and the effectiveness of this system was verified in light of proper evaluation of geotechnical characteristics of soft soil.