• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.278-283
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• 2017

Purpose: The aim of this study was to evaluate the interdental distances of anterior, premolar, and molar teeth at the cementoenamel junction (CEJ) and 2 mm below the CEJ in healthy natural dentition with cone-beam computerized tomography (cone-beam CT) in order to provide valuable data for ideal implant positioning relative to mesiodistal bone dimensions. Materials and Methods: Two hundred patients who visited Dental Hospital, Wonkwang University, who had natural dentition with healthy interdental papillae, and who underwent cone-beam CT were selected. The cone-beam CT images were converted to digital imaging and communication in medicine (DICOM) files and reconstructed in three-dimensional images. To standardize the cone-beam CT images, head reorientation was performed. All of the measurements were determined on the reconstructed panoramic images by three professionally trained dentists. Results: At the CEJ, the mean maxillary interdental distances were 1.84 mm (anterior teeth), 2.07 mm (premolar), and 2.08 mm (molar), and the mean mandibular interproximal distances were 1.55 mm (anterior teeth), 2.20 mm (premolar), and 2.36 mm (molar). At 2mm below the CEJ, the mean maxillary interdental distances were 2.19 mm (anterior teeth), 2.51 mm (premolar), and 2.60 mm (molar), and the mean mandibular interproximal distances were 1.86 mm (anterior teeth), 2.53 mm (premolar), and 3.01 mm (molar). Conclusion: The interdental distances in the natural dentition were larger at the posterior teeth than at the anterior teeth and also at 2 mm below the CEJ level compared with at the CEJ level. The distances between mandibular incisors were the narrowest and the distances between mandibular molars were the widest in the entire dentition.

• Journal of Elementary Mathematics Education in Korea
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• v.3 no.1
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• pp.1-20
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• 1999

What do our mathematics teachers now do in the classroom？ What does it actually mean to teach mathematics？ Every preparatory mathematics teacher is confronted with these questions since they have studied to become a teacher. Almost all in-service teachers are faced by of questions, too, as they evaluate their teaching in the light of that of their colleagues. In this sense, Jon L. Higgins has proposed mathematics teaching patterns of five categories, i. e., exploring, modeling, underlining, challenging, and practicing, for the sake of our all teachers. Next, J. P. Guilford has suggested three faces of intellect presented by a single solid model, which we call the 'structure of intellect' Each dimension represents one of the modes of variation of the factors. It is found that the various kinds of operations are in one of the dimensions, the various kinds of products are in another, and the various kinds of contents are in the other one. In order to provide a better basis for understanding this model and regarding it as a picture of human intellect, I've explored it systematically and shown some concrete examples for its tests. Each cell in the model stands for a certain kind of ability that can be described in terms of operation, content, and product, for each cell is at the intersection uniquely combined with kinds of ope- ration, content, and product. In conclusion, how could we use the teaching patterns of five categories, that is, exploring, modeling, underlining, challenging, and practicing, according to the given mathematics learning substances？ And also, how could children constitute the learning sub- stances well in their mind with a viewpoint of constructivism if teachers would connect the mathematics teaching patterns of five categories with any factors among the three faces of intellect？ I've made progress this study focusing on such problems.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.67-73
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• 1997

The changes of electroencephalogram(EEG) in patients with dementia are most commonly studied by analyzing power or magnitude in certain traditionally defined frequency bands. However because of the absence of an identified metric which quantifies the complex amount of information, there are many limitations in using such a linear method. According to chaos theory, irregular signals of EEG can also result from low dimensional deterministic chaos. Chaotic nonlinear dynamics in the EEG can be studied by calculating the correlation dimension. The authors have analyzed EEG epochs from three patients with dementia of Alzheimer type and three matched control subjects. The multichannel correlation dimension is calculated from EEG epochs consisting of 15 channels with 16,384 data points per channel. The results showed that patients with dementia of Alzheimer type had significantly lower correlation dimension than non-demented controls on 12 channels. Topographic analysis showed that the correlation dimensions were significantly lower in patients with Alzheimer's disease on frontal, temporal, central, and occipital head regions. These results show that brains of patients with dementia of Alzheimer type have a decreased complexity of electrophysiological behavior. We conclude that the nonlinear analysis such as calculating correlation dimension can be a promising tool for detecting relative changes in the complexity of brain dynamics.

• Journal of Global Scholars of Marketing Science
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• v.8
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• pp.429-449
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• 2001

Objectives of this study were: First, The Purpose of this study is to develope the concept of Third-Party Logistics choice factors and to review effects of Third-Party Logistics choice Factors on the Logistics Performance. Second, to set up research model specifying relationships between Third-Party Logistics choice factors and the Logistics Performance of EC(Electronic Commerce) firms. Third, to test hypotheses derived from the research model of this study and to attempts to explain how to have the effect the Logistics Performance of EC firms. Marketing Implications of this study were: First, As a result factor analysis, Third-Party Logistics choice Factors was divided into three dimensions, credibility, the pursuit of relationship, and assets factors. Second, three factors which are credibility, the pursuit of relationship, and assets factors increase and enhance the Logistics Performance of EC firms. Limitations of this study were: First, validity and reliability of data collection methods used in this study were questionable for the lack of past researches in korea. Second, static research method was employed in this study. Generalization over different time interval was almost impossible from results of this study.

• 대한공업교육학회지
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• v.34 no.2
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• pp.331-345
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• 2009

In this research Sagnac interferometer three different types of mandrel are suggested and this fiber optic sensor is using in monitoring of electric transformer. Vibration characteristics of those mandrels were analyzed and finally more sensitivity mandrel are suggested. Three different mandrels using in fiber optic sensor are hollow cylinder with outer bump, pure hollow cylinder, hollow cylinder with inner bump. Natural frequencies and mode shapes are investigated using finite element method. Mode shape are considered at the frequency range from 2 kHz to 20 kHz. Fundamental dimensions of the hollow cylinder type's mandrel are 30 mm in outer diameter, 50 mm in length, 1 mm in cylinder thickness, $2mm{\times}2mm$ in bump size. Based on the finite element results, when the outer acoustic frequency is near 11 kHz outer bump type and hollow cylinder can get higher sensitivity. Near 17 kHz outer bump and inner bump mandrel can get higher sensitivity. Near 20 kHz hollow cylinder and inner bump mandrel is useful. This results can be applied to design of fiber optic sensor using in monitoring the electrical transformer. Several MHz of outer acoustic frequency can be easily detected using more sensitive mandrel in pursuing expand this technique.

• Journal of Nutrition and Health
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• v.53 no.2
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• pp.129-140
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• 2020

Purpose: Although the importance of life satisfaction in patients with chronic diseases has been emphasized, limited studies have been performed on the health-related quality of life (HRQoL) among elderly patients with chronic diseases. This study examined the HRQoL among Korean patients with diabetes aged 65 years or older. Methods: This study used data from the Korea National Health and Nutrition Examination Survey 2008-2016. The analysis included data of 2,353 elderly patients with diabetes aged 65 years or older who were aware that they had type 2 diabetes. Each participant was categorized into one of three age groups (65-69 years, 70-74 years, and ≥ 75 years). The EuroQol-5 Dimensions (EQ-5D) scale was computed to estimate the HRQoL. Multivariate linear regression analysis was used to compare the demographic characteristics, lifestyle characteristics, nutrient intake, and EQ-5D scores between the age groups. Results: The intake levels of most nutrients were similar in the three age groups, but the total energy intake levels were significantly lower, and the sodium intake levels were significantly higher in the older age groups (p < 0.001). In addition, all items of the EQ-5D index, except for anxiety/depression, tended to decrease with age. In particular, the oldest age group (≥ 75 years) showed significantly lower levels on most items and the EQ-5D index than those in the other age groups (p < 0.001). Conclusion: Elderly patients with type 2 diabetes may have low levels of life satisfaction, which worsens with increasing age. Therefore, it is important to develop and manage personalized guidelines and medical systems so that elderly patients have a higher quality of life for the remainder of their lives. The results of this study are expected to be used as basic data for the systematic management of diabetes in elderly Korean patients.

• Health Policy and Management
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• v.28 no.2
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• pp.151-161
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• 2018

Background: Family values of a married woman may be related to her own depressive mood. Since depressive mood of a married woman is likely to exert a negative influence, in terms of mental health, on her, her family members, and the whole society's, it may be very important to explore the relationship between family values in married women and their depressive mood. Methods: In this study, we analyzed nationally representative 5,818 married women aged 20 years or older from the 4th panel data of 2012 Korean Longitudinal Survey of Women and Families. As for variables of interest, we constructed three family values variables: family-oriented view of marriage, individualistic view of marriage, and traditional view of marital roles. Then we employed multivariate logistic regression analyses to explore the relationship between family values and depressive mood, adjusting for family and socio-demographic factors. Results: In total, 804 married women (18.4%) had experienced depressive mood. All of the three family values variables were significant in their relationships with depressive mood. The women categorized as 'very weak' in family-oriented view of marriage were more likely to experience depressive mood than the women categorized as 'very strong' (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.53-2.55). By contrast, the women categorized as 'very weak' in individualistic view of marriage (OR, 0.43; 95% CI, 0.33-0.55) and in traditional view of marital roles (OR, 0.68; 95% CI, 0.51-0.92) were less likely to experience depressive mood than their respective counterpart women categorized as 'very strong.' Conclusion: In Korea, married women's values towards marriage itself and roles between wives and husbands had significant associations with their depressive mood. This suggests that in order to improve mental health in married women, we need to take social and cultural dimensions into consideration along with public health interventions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.897-908
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• 2019

The objective of this study is to evaluate the field support performance of highperformance lattice girder (BK-Lattice Girder) by using numerical analysis. Three types (50, 70, 95-type) of existing and high performance lattice girders were applied to the cross section of highway 2, 3, and 4 lane tunnels to compare the supporting performance. The numerical analysis was the finite element method and the lattice girder was modeled in three dimensions with an elasto-plastic frame. The ground was modeled as a spring receiving only compression. The load was applied as a concentrated load on the central ceiling of the tunnel section. The yield strengths of the lattice girders were determined from the numerical results to compare the supporting performance of lattice girder. In case of 50-type, the yield strengths of high-performance lattice girders were increased by 6.7~10.0% compared with those of the existing lattice girders. In the case of 70-type, the high-performance lattice girders increased yield strengths by 12.1~14.9% than the existing lattice girder. In the case of 95-type, the high-performance lattice girders increased yield strengths by 13.3~20.0% than the existing lattice girder. As a result of numerical analysis, it was considered that the high-performance lattice girder supported better than the existing lattice girder when only the lattice girders were constructed.

• Korean Journal of Optics and Photonics
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• v.23 no.4
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• pp.167-171
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• 2012

This paper reports on the stray light analysis results of a compact imaging spectrometer (COMIS) for a microsatellite STSAT-3. COMIS images Earth's surface and atmosphere with ground sampling distances of 27 m at the 18~62 spectral bands (0.4 ~ 1.05 ${\mu}m$) for the nadir looking at an altitude of 700 km. COMIS has an imaging telescope and an imaging spectrometer box into which three electronics PCBs are embedded. The telescope images a $27m{\times}28km$ area of Earth surface onto a slit of dimensions $11.8{\mu}m{\times}12.1mm$. This corresponds to a ground sampling distance of 27 m and a swath width of 28 km for nadir looking posture at an altitude of 700 km. Then the optics relays and disperses the slit image onto the detector thereby producing a monochrome image of the entrance slit formed on each row of detector elements. The spectrum of each point in the row is imaged along a detector column. The optical mounts and housing structures are designed in order to prevent stray light from arriving onto the image and so deteriorating the signal to noise ratio (SNR). The stray light analysis, performed by a non-sequential ray tracing software (LightTools) with three dimensional housing and lens modeling, confirms that the ghost and stray light arriving at the detector plane has the relative intensity of ${\sim}10^{-5}$ and furthermore it locates outside the concerned image size i.e. the field of view of the optics.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.12.1-12.5
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• 2019

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.