• 대한수학회보
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• 제47권5호
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• pp.889-905
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• 2010

In this paper, a distribution free approach to the parameter estimation of a simple bilinear model with periodic coefficients is presented. The proposed method relies on minimum distance estimator based on the autocovariances of the squared process. Consistency and asymptotic normality of the estimator, as well as hypotheses testing, are derived. Numerical experiments on simulated data sets are presented to highlight the theoretical results.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2003년도 international symposium on advanced powder metallurgy
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• pp.62-63
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• 2003

The inter-particle distance between diamonds on the segment surface of sawing blade predicted theoretically and measured experimentally followed a Gamma or Weibull function, rather than a normal distribution function. These results suggest that random dispersion of diamond particles in the segment may not be an efficient way of improving cutting efficiency of the blade.

• 천문학회지
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• 제29권spc1호
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• pp.179-180
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• 1996

The aim of the paper is to analyse the extinction law in the giant H II region NGC 3603. The ratio R is found to be greater than 5.0. In front of the cluster the reddening law is found to be normal. We have obtained a distance of $\~$5.3 Kpc which is significantly smaller than those adopted so far.

• Current Optics and Photonics
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• 제6권3호
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• pp.337-343
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• 2022

Microfluidic chips are new devices that can manipulate liquids at the micrometer level, and terahertz (THz) time-domain spectroscopy has good applicability in biochemical detection. The combination of these two technologies can shorten the distance between sample and THz wave, reduce THz wave absorption by water, and more effectively analyze the kinetics of biochemical reactions in aqueous solutions. This study investigates the effects of different external magnetic field intensities on the THz transmission characteristics of deionized water, CuSO₄, CuCl₂, (CH₃COO)₂Cu, Na₂SO₄, NaCl, and CH₃COONa; the THz spectral intensity of the sample solutions decrease with increasing intensity of the applied magnetic field. Analysis shows that the magnetic field leads to a change in the dipole moment of water molecules in water and electrolyte solutions, which enhances not only the hydrogen-bond networking ability of water but also the hydration around ions in electrolyte solutions, increasing the number of hydrogen bonds. Increasing the intensity of this magnetic field further promotes the hydrogen-bond association between water molecules, weakening the THz transmission intensity of the solution.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.510-518
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• 2009

Purpose: In this study, we analyzed and compared the anatomical position of the mandibular canal in normal occlusion and mandibular prognathism patients. Patients and Methods: Computed tomography image from 58 patients were divided into normal occlusion group and mandibular prognathism group, and each measurement were taken in the each measuring points(2nd premolar, 1st molar, 2nd molar, 3rd molar, ramus). Measurements were statistically analyzed by student's t-test. Results: BC (Thickness of the buccal cortex) value was 2.3~2.7 mm, CB (Distance from the canal to the lingual aspect of the buccal cortex) value was 1.3~4.3 mm, MC (Diameter of the canal) value was 3.2~3.8 mm, LI (Distance from the canal to the lingual aspect of the lingual cortex) value was 2.0~3.7 mm, TM (Thickness of the total mandible) value was 9.5~12.9 mm and CM (Distance from the canal to the inferior border of the mandible) value was 6.9~17.5 mm. Conclusion: In the comparison between two groups, there was statistically significant difference in CB value of 2nd, 3rd molar between normal occlusion and mandibular prognathism, and other value in the rest of the measuring points didn't show statistically significant difference.

• 한국임상수의학회지
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• 제28권5호
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• pp.506-509
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• 2011

본 실험은 임상적으로 건강한 시츄 견 36 두, 비글 견 16 두에서 컴퓨터단층촬영을 이용하여 비중격의 해부학적 차이와 편위 정도를 평가하고자 실시되었다. 비중격의 편위 정도는 비중격 편위의 각도 및 거리 측정에 의해 평가되었다. 비중격 편위의 각도 및 거리는 비글 견보다 시쮸 견에서 유의적으로 높은 수치를 나타냈다. 시츄, 비글견 두 품종에서 체중 및 나이는 비중격 편위의 각도 및 거리와 모두 유의적인 관계는 관찰되지 않았다. 이 결과에 기초하여 비중격의 편위는 임상적으로 건강한 개에서도 관찰 가능하며, 특히 시츄 견에서 쉽게 관찰되는 것으로 생각된다.

• Journal of Korea Trade
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• 제23권5호
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• pp.27-44
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• 2019

Purpose - The purpose of this paper is to analyze the net effect of the green total factor productivity (GTFP) of China's manufacturing industry from the China-Korea Free Trade Area (China-Korea FTA) quantitatively. Design/methodology - Firstly, the Global Malmquist-Luenberger (GML) index based on the SBM directional distance function is used to measure the GTFP of China's manufacturing and analyze the driving force for its growth. Secondly, the regression discontinuity quantitative analysis is used to determine the impact of the China-Korea FTA on China's manufacturing GTFP. Findings - Our main findings can be summarized as follows: the China-Korea FTA has promoted the GTFP of China's manufacturing with an effect evaluation mainly resulting from green technology progress. And there is industry heterogeneity in the policy effect on the manufacturing GTFP due to the China-Korea FTA. Namely, policy promotion from the China-Korea FTA is more effective on the GTFP of equipment manufacturing than it is on those of other industries. Originality/value - First, an evaluation and analysis of the GTFP development of China's manufacturing that employs GML index based on SBM directional distance function. Second, a quantitative estimate of China-Korea FTA's net effect on China's manufacturing industrial GTFP that uses regression discontinuity analysis, which is considered to be the closest method to natural experiments and superior to other causal inference methods. Third, an in-depth discussion of the practical steps that China's manufacturing can take to improve GTFP development and integrate China-Korea FTA construction into economic development.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.99-108
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• 2000

This study was performed to investigate the effect of suboccipital stretch on the head and neck posture and the electromyographic(EMG) activity of some cervical muscles. For this study, 39 patients with temporomandibular disorders(TMD) and 34 dental students without any signs and symptoms in the masticatory system were selected as the patients group and as the normal group, respectively. Head position by goniometer CROM$^{(R)}$(Performance attainment, St. Paul, USA), EMG activity by BioEMG$^{(R)}$(Bioresearch Inc., Milwaukee, USA), and craniocervical posture by cephaloradiography were observed in both natural head posture(NHP) and head posture with suboccipital stretch(tuck posture) abtained from slight posteroinferior finger pressure on the chin. Variables measured on the cephaloradiograph were SN angle, atlas angle, CVT angle, occiput-atlas and atlas-axis distance, and pharyngeal width. The data obtained were analysed by SPSS windows program and the results of this study were as follows : 1. In the sagittal plane, degree of anterior rotation of the head by suboccipital stretch was 6.3 in the patients group, and 6.2 in the normal group, respectively. So there was no significant difference between the two groups for degree of anterior rotation, but the position of the head in the patients group were more posteriorly extended than in the normal group in both NHP and tuck posture. 2. EMG activity of the stemocleidomastoideus in the patients group, and that of the upper trapezius and the sternocleidomastoideus in the normal group were increased by suboccipital stretch. The range of EMG activity, however, in these cervical muscles were 1.6 -2.3)u.V. 3. Cephalometric variables such as SN angle, atlas angle, CVT angle, occiput-atlas and atlas-axis distance except pharyngeal width were generally increased by suboccipital stretch. There was some difference, however, in results between the two groups. Atlas angle was not changed in the patients group whereas CVT angle was not changed in the normal group. 4. The distance from subocciput to spinous process of axis was significantly increased as much as 3.0mm in the patients group, and 3.7mm in the normal group by suboccipital stretch.

• 한국전산유체공학회지
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• 제6권3호
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• pp.32-40
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• 2001

Viscous solutions of supersonic jet impinging on a flat plate normal to the flow are simulated using three-dimensional Navier-Stokes solver. The jet impinging flow structure exhibits such complex nature as shock shell, plate shock and Mach disk depending on the flow parameters. Among others, the dominant parameters are the ratio of the nozzle exit pressure to the ambient pressure and the distance between the nozzle exit plane and the impinging plane. In the present study, the nozzle contour and the pressure ratio are held fixed, while the jet impinging distance is varied to illuminate the characteristics of the jet plume with the distance. As the plate is placed close to the nozzle at 3D high, the computed wall pressure at or near the jet center oscillates with large amplitude with respect to the mean value. Here D is the nozzle exit diameter. The amplitude of wall pressure fluctuations subsides as the distance increases, but the maximum mean pressure level at the plate is achieved when the distance is about 4D high. The frequency of the wall pressure is estimated at 6.0 kHz, 9.3 kHz, and 10.0 kHz as the impinging distance varies from 3D, 4D, to 6D, respectively.

• 대한심미치과학회지
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• 제4권1호
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• pp.23-36
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• 1995

The purpose of this artic1e is to compare soft tissue profiles between Korean adults with normal occ1usion and malocclusin and to identify the differences between them. The subjects of this cephalometric study were 40 males with normal occlusion(Group 1), 27 females with normal occlusion(Group 2), 28 adults with Angle's Class II malocclusion(Group 3) and 41 adults with Angle's Class III malocclusion(Group 4). The results of this study were as follows ; 1) People with Angle's Class II malocclusion had tendency to have more labial tipping of lower teeth than people with normal occ1usion. Through NOA angle measurement, it was determined that people with Angle's Class II malocclusion had more protruding midface than people with normal occlusion and people with Angle's Class III malocclusion had retruding midface. 2) Through Powell's esthetic triangle analysis, it was determined that people with Angle's Class II malocclusion had retruding chin and protruding nose. 3) No significant differences between people with normal occlusion and maloclusion could be identified by measuring soft tissue profile angle basis of S-NS plane. 4) There were significant differences between groups with normal occlusion and malocclusion by measuring Facial convexity angle(Significance level 99%). 5) By measuring the distance between each landmark basis of N-Pog plane, People with Angle's Class II malocclusion were identified as having more protruding midface, but there were no significant differences between people with normal occlusion and Angle's Class III malocclusion. 6) By measuring the vertical dimension of the face, it was determined that the lower facial height was higher than the upper facial height in all groups, particularly in group with Angle's Class III malocclusion. 7) By measuring the lips basis of E-line and S-line, it was determined that people with Angle's Class III malocclusion had more, protruding lower lips than people with normal occlusion, while people with normal occlusion, while people with Angle's Class II malocclusion had more protruding upper lips. By measuring the distance between the superior sulcus and inferior sulcus basis of H-line, people with Angle's Class II malocclusion had thicker upper lips than the other's.