• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.183-190
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• 1995

The use of ultrasound pulsed Doppler systems has become increasingly popular due to the advantages of easy measurements of blood velocity, volume blood blow, and irregularities of the circulatory system. However, the 2-D Doppler systems have several problems, such as range ambiguity, low signal to noise ratio, and slow frame rate. The mean frequency aliasing problem originating from the pulse repetition frequency is one of major limitations in pulsed Doppler systems. A conventional approach to resolve this problem is tracking the mean frequency close to and beyond the Nyquist frequency along the temporal axis. In this paper, a new concept of tracking the mean frequency along the spatial axis is proposed. The proposed technique is fault tolerant by nature and more suitable for multi gate and 2-D Doppler system than conventional methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.119-127
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• 1998

Assuming that the static loaded square tube and the dynamic loaded one have no difference in their characteristics of the crush distance, the theoretical mean dynamic crush load was calculated with respect to the impact speed considering the strain rate sensitivity of the material. The ratio of dynamic to static mean crush load was predicted with previous results. The theoretical analysis was compared with the experimental results of aluminum square tubes axially loaded dynamically.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.1169-1183
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• 2008

In this paper, a method to find the weighted possibilistic variance and moments about the mean value of fuzzy numbers via applying a difuzzification using minimizer of the weighted distance between two fuzzy numbers is introduced. In this way, we obtain the nearest weighted point with respect to a fuzzy number, this main result is a new and interesting alternative justification to define of weighted mean of a fuzzy number. Considering this point and the weighted distance quantity, we introduce the weighted possibilistic mean (WPM) value and the weighted possibilistic variance(WPV) of fuzzy numbers. This paper shows that WPM is the nearest weighted point to fuzzy number and the WPV of fuzzy number is preserved more properties of variance in probability theory so that it can simply introduce the possibilistic moments about the mean of fuzzy numbers without problem. The moments of fuzzy numbers play an important role to estimate of parameters, skewness, kurtosis in many of fuzzy times series models.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.28-33
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• 1992

The paper describes a new mean specific cutting pressure model in order to improve the accuracy of prediction of cutting force for face milling. The new mean specific cutting pressure model produces a mean specific cutting pressure and coefficients applied to existing cutting model not by traditional method but by considering intermittence and variation of chip width according to insert cutting position to take into cutter geometry machining condition and width of workpiece, and considering a mean measure force according to spindle eccentricity and mean measure force according to spindle eccentricity and insert initial position errors.. The simulated forces in X, Y, Z directions resulted from the simulated cutting model and the new cutting model are compared with measured forces in the time end frequency domains. The simulated forces in the time and frequency domains. The simulated forces resulted from the new cutting model have a good degreement with measured forces in comparison with these resulted from the existing cutting model

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.3
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• pp.220-228
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• 1996

This paper presents a extended stochastic Petri net (ESPN) model for CTN(Circulated Token with No duration) service in the data link layer of IEC/ISA fieldbus. It is assumed that a station on the fieldbus has a specified minimum token holding time, a finite capacity buffer, and one transmitter queue with the highest priority. The mean transmission (or service) time at a station and the mean token rotation time for the symmetric fieldbus system atr derived using the presented SPN model and the moment generating function. These performance measures are represented in terms of the minimum token holding time, the number of stations, the arrival rate of messages, and the mean length of messages. The presented performance measure are validated by computer simulations.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.159-162
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• 2008

This paper presents a modified mean curvature diffusion filter to smooth speckle noise in images. Mean curvature diffusion filter has already shown good results in reducing noise in images while preserving fine details. In the mean curvature diffusion, the rate of smoothing is controlled by the local value of the diffusion coefficient chosen to be a function of the local image gradient magnitude. In this paper, the diffusion coefficient is modified to be controlled adaptively by local image surface slope and heterogeneity. The local surface slope contributes to preserving details (e.g.edges) in image and the local surface heterogeneity helps the smoothing filter consider the amount of noise in both edge and non-edge area. The proposed filter's performance is demonstrated by quantitative experiments using speckle noised aerial image and TerraSAR-X satellite image.

• Journal of the Korean Society of Food Culture
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• v.24 no.6
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• pp.588-596
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• 2009

To determine the relationships between soybean food intake, dietary isoflavone intake, and osteoporosis incidence, questionnaire surveys, bone mineral density measurements, and dietary surveys by food record were performed with 19 postmenopausal women ($57.6{\pm}7.3$ yrs of age) in Daejeon city. The subjects were divided into two groups: an 'osteoporosis group' (OG, n=10) and a 'normal group' (NG, n=9). Mean age, height, and body weight were similar between the two groups but BMI was higher in OG than in NG. Mean age at menarche was not different between the two groups. However, mean number of childbirths was greater in OG than in NG and mean total period of lactation was shorter in OG. Mean exercise time per week was similar between the two groups, and mean time of sunlight exposure tended to be shorter in OG. Mean daily intake of calcium was lower in OG whereas sodium intake was higher in OG. Mean daily intakes of total soybean food (OG: $203.8{\pm}84.6\;g/d$, NG: $285.0{\pm}146.3\;g/d$) and total dietary isoflavone (OG: $29.1{\pm}14.3\;mg/d$, NG: $38.3{\pm}23.1\;mg/d$) were not different between the two groups. However, greater intakes of soybean food and dietary isoflavone were associated with higher bone mineral density, respectively. The above results indicate that osteoporosis incidence tends to be influenced by BMI, maternal factors, dietary nutrient intakes, soybean food intakes, and dietary isoflavone intakes in postmenopausal women; although no significant differences in soybean food and dietary isoflavone intake were found between the two groups. This tendency implies that greater intakes of soybean food and dietary isoflavone lead to lower incidence of osteoporosis in postmenopausal women.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.347-356
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• 1993

Plasma concentrations of zinc and copper were measured in 59 non-pregnant women and 105 pregnant women(12 ; early pregant, 93 ; late pregnant) to estimate and compare both groups and to detect the effects of iron supplementation on the plasma zinc and copper concentrations in the pregant women. The mean plasma zinc concentration of the early pregnant group was not significantly different with those of the non-pregnant group. But in contrast, the mean plasma zinc concentration of the late pregnant group was significantly lower than those of the non-pregnant and early pregnant group. Mean plasma copper concentration were significantly elevated in ealry pregnant group and doubled in late pregnant compared to non-pregnant. In Fe supplemented group, mean plasma zinc concentrations were lower and mean plasma copper higher than those of Fe non-supplemented group. It appeared that Fe supplementation had effects on the decrease of plasma zinc concentrations in pregnancy.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.32-39
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• 2010

In this study, we consider Taylor-Couette flow with the outer cylinder at rest and the inner one oscillating with a mean angular velocity. Varying the mean angular velocity, amplitude and frequency of the oscillation, we investigate the characteristics of modulated Taylor vortices. At a constant mean angular velocity, Taylor vortices intensify as the amplitude increases and frequency decreases. The axial wavenumber is calculated by spectral analysis. When the frequency varies, the axial wavenumber does not change at a constant mean angular velocity and amplitude. But, the axial wavenumber increases, as the mean angular velocity increases.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.1
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• pp.35-42
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• 2009

In Taguchi's quadratic expected loss function used as robustness metric of performance characteristics, the mean and variance contributions are confounded. The consolidation of the mean and variance in the expected loss function may not always be the ideal approach. This paper presents a procedure for multi-attributes design optimization, where the mean and variance of performance characteristics are considered as separate attributes having designer's relative preferences for them and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS) is introduced to attain robust optimal design. The effectiveness of proposed approach is shown with an example of a weld line minimization problem in the injection molding process.