• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권7호
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• pp.320-326
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• 2003

Slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force, this paper applies the neural network to inserted core type of slotless PMLSM. The, Magnetic pole ratio, the width of the inserted core and the width of the coil are selected as a design parameter to minimize detent force. In comparison with inserted core type one, thrust ripple greatly decreases by minimizing detent force and also thrust increases in this optimal model.

• Journal of Ginseng Research
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• 제8권2호
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• pp.167-171
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• 1984

Soft X-ray is useful to identify the quality of fresh ginseng causing the inside cavity or white pan of red ginseng. The portion of low mass density identified by the difference in absorption of soft X-ray showed lower dry matter density and less or no response to iodine test indicating less accumulation or excess consumption of starch. The inside white part of red ginseng absorbed less X-ray than the normal part did. Probability for identification of the inside cavity or white at fresh ginseng was rather high (80-90%) in screen observation than f'3m reading and seemed to be increased further by using the developed screen and with training. The inside white of red ginseng appeared to be due to starch deficiency. Dry matter density appeared to be better than fresh weight density for the quality criterion.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1849-1854
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• 2018

The present study aims to investigate the feasibility of using a simple nonlinear acoustic method for the assessment of bone status and osteoporosis in trabecular bone. Correlations of linear and nonlinear ultrasound parameters with the apparent bone density were obtained in 32 bovine femoral trabecular bone samples. Highly significant positive correlations were observed between the apparent bone density and the two linear ultrasound parameters, the speed of sound (SOS) and the normalized broadband ultrasound attenuation (nBUA), with Spearman's correlation coefficients of r = 0.85 and 0.77. In contrast, the apparent bone density was found to be negatively correlated with the nonlinear ultrasound parameter introduced in the present study, the logarithmic difference between the power spectrum levels of the fundamental frequency and the second harmonic (PSL1-PSL2), with the highest correlation coefficient of r = -0.92. These results suggest that the PSL1-PSL2, in addition to the SOS and the nBUA, may be useful for the assessment of bone status and osteoporosis.

• Journal of Acupuncture Research
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• 제40권4호
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• pp.351-355
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• 2023

Background: Wet cupping (WC) is an efficient and cost-effective technique for removing metabolic waste from the bloodstream via the skin. The study aimed to examine the effect of WC on cholesterol levels including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in a Sudanese population. Methods: In this prospective cross-sectional study, 30 participants undergoing regular WC therapy were enrolled. Blood samples collected twice: pre-WC therapy (case group) and 10-14 days afterward (controls). Results: Of the participants, 56.67% were male and 43.33% were female, aged 24-69. Pre-WC TC and LDL-C levels were significantly higher than the post-WC control group (p = 0.001). Conversely, HDL-C levels decreased significantly in the pre-WC cases compared to controls (p = 0.001). No significant sex-based difference in mean cholesterol levels (p > 0.05). Conclusions: After WC, males and females experienced significant reductions in TC and LDL-C, and significant increase in HDL-C.

• 대한치과보철학회지
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• 제54권1호
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• pp.14-20
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• 2016

목적: 본 연구의 목적은 임플란트와 대합되는 부분의 상태에 따라서 임플란트 주위 골조직 변화에 차이가 있는지 알아보기 위함이다. 대상 및 방법: 원광대학교 대전치과병원에서 임플란트 식립을 받은 51명의 환자를 대상으로 하였고 총 51개의 임플란트가 분석에 사용되었다. 임플란트는 성별, 나이, 악골 위치, 환자의 대합되는 부위에 따라서 분류되었고 대합되는 부위는 자연치, 임플란트, 가공치, 무치악의 네 집단으로 나뉘었다. 프랙탈 분석을 위해 임플란트 식립 직후의 치근단 사진과 보철 수복 이후 10주 이상이 지난 치근단 사진이 사용되었다. 분석은 Image J를 이용하여 시행하였다. 통계학적 분석은 one-way ANOVA를 이용하여 시행하였고 Tukey multiple comparison test로 사후검정을 실시하였다. 결과: 임플란트의 보철수복 전후 프랙탈 값 차이의 평균은 자연치가 대합되는 경우 $0.009{\pm}0.048$이었으며 임플란트의 경우 $0.026{\pm}0.080$, 가공치의 경우에 $-0.025{\pm}0.068$이었으며 무치악은 $-0.093{\pm}0.171$으로 나타났다. 대합되는 부위가 무치악일 때와 임플란트일 때에 통계학적으로 유의한 차이가 나타났으며 나이와 성별, 악골 위치에 따른 프랙탈 수치 변화 차이는 통계적으로 유의하지 않았다. 결론: 임플란트 식립 후 대합되는 부위가 무치악일 때를 제외한 세 집단간 프랙탈 수치 변화 차이는 유의하게 나타나지 않았으며, 대합되는 부위가 무치악일 때와 임플란트일 때 유의한 차이가 나타났다. 그리고 환자의 나이와 성별, 악골의 위치에 따른 프랙탈 수치 변화 차이는 유의한 차이를 나타내지 않았다.

• 대기
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• 제26권3호
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• pp.483-492
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• 2016

We have examined the random error of eddy covariance (EC) measurements on the basis of two-tower approach during daytime. Two EC towers were placed on the grassland with different vegetation density near Gumi-weir. We calculated the random error using three different methods. The first method (M1) is two-tower method suggested by Hollinger and Richardson (2005) where random error is based on differences between simultaneous flux measurements from two towers in very similar environmental conditions. The second one (M2) is suggested by Kessomkiat et al. (2013), which is extended procedure to estimate random error of EC data for two towers in more heterogeneous environmental conditions. They removed systematic flux difference due to the energy balance deficit and evaporative fraction difference between two sites before determining the random error of fluxes using M1 method. Here, we introduce the third method (M3) where we additionally removed systematic flux difference due to available energy difference between two sites. Compared to M1 and M2 methods, application of M3 method results in more symmetric random error distribution. The magnitude of estimated random error is smallest when using M3 method because application of M3 method results in the least systematic flux difference between two sites among three methods. An empirical formula of random error is developed as a function of flux magnitude, wind speed and measurement height for use in single tower sites near Nakdong River. This study suggests that correcting available energy difference between two sites is also required for calculating the random error of EC data from two towers at heterogeneous site where vegetation density is low.

• 대한가정학회지
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• 제42권10호
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• pp.143-152
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• 2004

This study presents the effects of serum lipids and blood glucose on retort Samgyetang intake in rats. For this purpose, we measured the ingredients and contents of Samgyetang, and produced a diet for experimental rats. The animal experiment was done in three different diet groups: control, Samgyetang(I) and Samgyetang(II). The results were as follows; 1) There was no sign of difference between the three groups in the body weight gain and food intake due to the effect of dietary component. 2) The density of serum triglyceride in the Samgyetang(II) group was decreased, but there was no sign of difference between the control group and Samgyetang(II). 3) There were no statistically significant differences of serum cholesterol and phospholipid among my of the diet groups. 4) The free fatty acid density and blood glucose level in the Samgyetang(I) and (II) groups were higher than in the control group. In the author's opinion, it is necessary to reexamine them for a long period through the animal experiment.

• 한국해양공학회지
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• 제10권3호
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• pp.50-61
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• 1996

The breaking phenomenon of regular periodic waves generated by a numerical wave maker is simulated by finite-difference method which can cope with strong interface motions. The air and water flows are simultaneously solved in the time-marching solution procedure for the Navier-Stokes equation. A density-function technique is devised for the implemenation of the interface conditions. The accuracy is examined and applied to the simulation of two-dimensional breaking phenomena of periodic gravity waves.

• 한국해양공학회지
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• 제10권3호
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• pp.62-73
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• 1996

Numerical simulation is made of the three-dimensional wave breaking motion about a part of a floating offshore structure containing a circular cylinder mounted vertically onto a lower hull in regular periodic gravity wave generated by a numerical wave maker. TUMMAC-VIII finite-difference method is newly developed for such a problem. By use of density-function technique the three-dimensional wave breaking motion is approximately implenented in the framework of rectangular grid system. A porosity technique is devised for the implementation of the no-slip bydy boundary conditions. The generation of breaking waves by the interaction of incident waves with the structure is well simulated and interesting features of breaking waves are revealed with containing degree of quantitative and qualitative accuracy.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.169-177
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• 2005

A high resolution scheme for solving gas-liquid two-phase flows with cavitation is described. This scheme uses the curvilinear coordinate grid and solves the density based momentum equations for mixture of gas-liquid medium with a preconditioning method to treat both compressible and incompressible flow characteristics. The present preconditioned method is based on the Runge-Kutta explicit finite-difference scheme, and is improved by using the diagonalization, the flux difference splitting and the MUSCL-TVD schemes to save computational effort and to increase stability and resolvability, especially at gas-liquid contact surfaces. A homogeneous equilibrium cavitation model is used to treat the gas-liquid two-phase medium in cavitating flow as a locally homogeneous pseudo-single-phase medium. Therefore, it is easy to solve cavitating flow, including wave propagation, large density changes and incompressible flow characteristic at low Mach number. Some numerical results obtained by the present scheme are shown.