• The Journal of Advanced Prosthodontics
• /
• v.6 no.1
• /
• pp.22-29
• /
• 2014

PURPOSE. This study aimed to investigate the potential clinical application of digitized silicone rubber impressions by comparing the accuracy of zirconia 3-unit fixed partial dentures (FPDs) fabricated from 2 types of data (working model and impression) obtained from a laser scanner. MATERIALS AND METHODS. Ten working models and impressions were prepared with epoxy resin and vinyl polysiloxane, respectively. Based on the data obtained from the laser scanner (D-700; 3Shape A/S, Copenhagen, Denmark), a total of 20 zirconia frameworks were prepared using a dental CAD/CAM system (DentalDesigner; 3shape A/S, Copenhagen, Denmark / Ener-mill, Dentaim, Seoul, Korea). The silicone replicas were sectioned into four pieces to evaluate the framework fit. The replicas were imaged using a digital microscope, and the fit of the reference points (P1, P2, P3, P4, P5, P6, and P7) were measured using the program in the device. Measured discrepancies were divided into 5 categories of gaps (MG, CG, AWG, AOTG, OG). Data were analyzed with Student's t-test ($\alpha$=0.05), repeated measures ANOVA and two-way ANOVA (${\alpha}=0.05$). RESULTS. The mean gap of the zirconia framework prepared from the working models presented a narrower discrepancy than the frameworks fabricated from the impression bodies. The mean of the total gap in premolars (P=.003) and molars (P=.002) exhibited a statistical difference between two groups. CONCLUSION. The mean gap dimensions of each category showed statistically significant difference. Nonetheless, the digitized impression bodies obtained with a laser scanner were applicable to clinical settings, considering the clinically acceptable marginal fit ($120{\mu}m$).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.8B
• /
• pp.1424-1435
• /
• 2000

A bit-rate controller that can achieve a constant bit rate when coding object-based video sequences is an important part to achieve an adaptation to bit-rate constraints, desired video quality, distribution of bits among objects, relationship between texture and shape coding, and determination of frame skip or not. Therefore we design content-based bit rate controller which will be used for relevant bit-rate control. The implementation is an extension of MPEG-4 rate control algorithm which employs a quadratic rate-quantizer model. The importance of different objects in a video is analyzed and segmented into a number of VOPs which are adaptively bit-allocated using the object-based modelling. Some test sequences are observed by a number of non-experts and interests in each object are analysed. The initial total target bit-rate for all objects is obtained by using the proposed technique. Then the total target bits are jointly analyzed for preventing from overflow or underflow of the buffer fullness. The target bits are distributed to each object in view of its importance, not only of statistical analysis such as motion vector magnitude, size of object shape, and coding distortion of previous frame. The scheme is compared with the rate controller adopted by the MPEG-4 VM8 video coder by representing their statistics and performance.

• Journal of Biosystems Engineering
• /
• v.20 no.4
• /
• pp.333-342
• /
• 1995

The resistance to air flow through fruits and vegetables in bulk was an important consideration in the design of the pressure cooling system. The amount of resistance to air flow through produce in bulk normally depended upon air flow rate, stacking depth, porosity, stacking patterns and shape and site of product. But, there was not enough information relating the effects of those factors on air flow resistance. The objectives of this study were to investigate the effect of stacking depth, stacking patterns, porosity and airflow rate on airflow resistance and to develop a statistical model to predict static pressure drop across the produce bed as a function of air flow rate, stacking depth, bed porosity, and product size. Mandarins and tomatoes were used in the experiment. The airflow rate were in the range of 0.1~1.0 ㎥/s.$m^2$, the porosity were in the range of 0.25~0.45, the depth were in the range of 0.3~0.9m and the equivalent diameters were 5.3cm and 6.3cm for mandarins, and 6.5cm and 8.5cm for tomatoes. Three methods of stacking arrangement were used i.e. cubic, square staggered, and staggered stacking arrangement. The results were summarized as follows. 1. The pressure drops across produce bed increased in proportion to stacking depth and superficial air velocity and decreased in proportion to porosity. 2. The increasing rates of pressure drop according to stacking patterns with the increase of superficial air velocity were different one another. The staggered stacking arrangement produced the highest increasing rate and the cubic stacking arrangement produced the lowest increasing rate. But it could be assumed that the stacking patterns had not influenced greatly on pressure drops if it was of equal porosity. 3. The statistical models to predict the pressure drop across produce bed as a function of superficial air velocity, stacking depth, porosity, and product diameter were developed from these experiments.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.6
• /
• pp.1263-1274
• /
• 2013

VaR (value at risk), which represents the expectation of the worst loss that may occur over a period of time within a given level of confidence, is currently used by various financial institutions for the purpose of risk management. In the majority of previous studies, the probability of return has been modeled with normal distribution. Recently Chen et al. (2010) measured VaR with asymmetric Laplacian distribution. However, it is difficult to estimate the mode, the skewness, and the degree of variance that determine the shape of an asymmetric Laplacian distribution with limited data in the real-world market. In this paper, we show that the VaR estimated with (symmetric) Laplacian distribution model provides more accuracy than those with normal distribution model or asymmetric Laplacian distribution model with real world stock market data and with various statistical measures.

• Journal of Environmental Science International
• /
• v.31 no.11
• /
• pp.941-950
• /
• 2022

This study was conducted to provide data and stem information to establish a local volume table of Cryptomeria japonica in Jeju Island. Stem analysis was performed on 26 trees by selecting two average trees from each site of the 13 plots of C. japonica stands in 2021 and 2022. During the analysis stage, one outlier tree was rejected, and a total of 260 observations of the specific stem height of 25 trees were used. Of the seven major taper equation models applied for parameter estimation and statistical verification, the Muhairwe 1999 model was found to be the best fit and selected as the optimal model. Stem shape-related estimates were acquired through the selected model, and sectional measurements according to the Smalian formula applied at an interval of 10 cm from the height of the stem were used to develop a volume table. A paired t-test comparison between the C. japonica volume obtained from the present study and those selected from the current yield table by NIFoS(2020), revealed significant differences (p<0.05), highlighting the necessity of a local volume table for C. japonica in Jeju Island.

• The Research Journal of the Costume Culture
• /
• v.5 no.4
• /
• pp.130-158
• /
• 1997

This study outputs calculation of regression of each items for production of torso basic pattern according to 6 body types as the result of another study and intends to present drawing method of torso model by short measure method modified and supplied and supplied by experiments of wearing clothing. SAS(Statistical Analysis System) is used for figures management and methods for analysis used are Frequency Analysis, Means Analysis, Regression Analysis, Correlation Analysis, etc. Results are as follows. 1. Correlation analysis is used to output the size necessary for torso prototype drawing by sort measure method and waist front length, back length, crotch length, shoulder point-cerricale-shoulder point, bust circumference, waist circumference, weight, etc, are set up as representative items calculation of regression of each type is suggested. 2. In the result of experiment of the first wearing clothing intended for 5 in each type and the whole 30, to develop torso prototype drawing method by short measure method, as we find some problems of the shape and propriety of neck root circumference line, the position of shoulder point, pulling or hold armpit parts, waist circumference line, the degree of dissatisfaction is high, so the second experiment of wearing clothing is propriety of each part is improved, all items except the length and quantity of shoulder dart, waist in back bodice, clearance quantity of hip circumference, and the place of shoulder line in side bodice. So, it was modifed and supplied and then the third torso prototyped drawing method by shout measure method was suggested. The third prototype drawing method was suggested, by modifying and supplying.

• Journal of Korean Biological Nursing Science
• /
• v.11 no.1
• /
• pp.51-58
• /
• 2009

Purpose: It is to verify learning effect of the instructional media on anatomy classes at a nursing college and to develop an alternative instructional media instead of cadaver. Method: Four groups pretest-posttest experimental design were used. One hundred twenty students who attended an Anatomy lecture in September, 2009 were selected After attending the anatomy lecture, the subjects were divided into four group (30 for each group) conveniently. The heart anatomy knowledge level were measured by a self evaluation questionnaire and quiz before and after a different instructional media being applied for each group including making heart shape using colored clay, taking picture of a real heart, sketching the heart model with color pencil and drawing heart presented in the anatomy textbook. Data was analyzed by t-test, ANNOVA test using the SPSS/PC WIN 12 version. Result: A statistically significant differences in the level of heart anatomy knowledge acquirement was noted after four different instructional media being applied, and four different instructional media was effective to the anatomy practice education. However, no difference in statistical post test results was noted among the four groups. Conclusion: It is recommended that further comparative studies on the learning effect between human cadaver practice and different instructional media is necessary.

• Journal of computational fluids engineering
• /
• v.20 no.3
• /
• pp.54-61
• /
• 2015

In the present study, a flow solver using a kinetic BGK scheme was developed for the compressible Navier-Stokes equation. The kinetic BGK scheme was used to simulate flow field from the continuum up to the transitional regime, because the kinetic BGK scheme can take into account the statistical properties of the gas particles in a non-equilibrium state. Various numerical simulations were conducted by the present flow solver. The laminar flow around flat plate and the hypersonic flow around hollow cylinder of flare shape in the continuum regime were numerically simulated. The numerical results showed that the flow solver using the kinetic BGK scheme can obtain accurate and robust numerical solutions. Also, the present flow solver was applied to the hypersonic flow problems around circular cylinder in the transitional regime and the results were validated against available numerical results of other researchers. It was found that the kinetic BGK scheme can similarly predict a tendency of the flow variables in the transitional regime.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.4
• /
• pp.347-355
• /
• 2013

A damage estimation method for monopile support structure of offshore wind turbine using modal properties and committee of neural networks is presented for effective structural health monitoring. An analytical model for a monopile support structure is established, and the natural frequencies, mode shapes, and mode shape slopes for the support structure are calculated considering soil condition and added mass. The input to the neural networks consists of the modal properties and the output is composed of the stiffness indices of the support structure. Multiple neural networks are constructed and each individual network is trained independently with different initial synaptic weights. Then, the estimated stiffness indices from different neural networks are averaged. Ten damage cases are estimated using the proposed method, and the identified damage locations and severities agree reasonably well with the exact values. The accuracy of the estimation can be improved by applying the committee of neural networks which is a statistical approach averaging the damage indices in the functional space.

• Journal of ILASS-Korea
• /
• v.20 no.4
• /
• pp.247-253
• /
• 2015

Recently, the engine calibration technique has been much more complicated than that of the past engine case in order to satisfy the strict emission regulations. The current calibration method for the diesel engine which has an increasing market is both costly and time-consuming. New engine calibration method is required to develop for high-quality diesel engines with low cost and release it at the appropriate time. This study provides the optimal calibrating technique for complex engine systems using statistical modeling and numerical optimization. Firstly, it design a test plan based on Design of Experiments, a V-optimality methodology which is suitable looking for set-points, and determine the shape of test engine response. Secondly, it uses functions to make linear regression model for data analysis and optimization to fit the models of engines behavior. Finally, it generates the optimal calibrations obtained directly from empirical engine models using Grey Relational Analysis and compares the calibrations with data. This method can develop a process for systematically identifying the optimal balance of engine emissions.