• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2353-2360
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• 2000

Statistical fatigue properties of metallic materials are increasingly required for reliability design purpose. In this study, static and fatigue tests were conducted and the normal, log-normal, two -parameter Weibull distributions at the 5% significance level are compared using the Kolmogorov-Smirnov goodness-of-fit test. Parameter estimation were compared with experimental results using the maximum likelihood method and least square method. It is found that two-parameter Weibull distribution and maximum likelihood method provide a good fit for static and fatigue life data. Therefore, it is applicable to the static and fatigue life analysis of the spheroidal graphite cast iron. The P-S-N curves were evaluated using log-normal distribution, which showed fatigue life behavior very well.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.81-86
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• 2010

In resistance spot welding, regardless of the optimal condition, bad weld quality was still produced due to complicated manufacturing processes such as electrode wear, misalignment between the electrode and workpiece, poor part fit-up, and etc.. Therefore, the goal of this study was to measure the process signal which contains weld quality information, and to develop the process fault monitoring system. Welding force signal obtained through variety experimental conditions was analyzed and divided into three categories: good, shunt, and poor fit-up group. And then a monitoring algorithm made up of an artificial neural network that could estimate the process fault of each different category based on pattern was developed.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.1
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• pp.94-109
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• 2004

Statement of problem : Several domestic dental implants have been developed since dental treatment being implants are increasing and popularized. However, they have not been used in domestic market like imported goods. Material and methods : This study was carried out to compare domestic and imported implants in aspect of fitness, dental implant fixture and abutment screw using scanning electron microscope. All experiments were performed under dry condition. Results : 1. Only in aspect of relation of dental implant fkxture and abutment screw, except only one group with point contact, good fitness was existed. 2. Home products must presevere in their efforts, so as excellent to fit.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.6
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• pp.354-359
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• 2000

A new method of measuring residual stress in micromachined film is proposed. An estimation of residual stress is performed by using least squares fit with an appropriate deflection modeling. an exact value of residual stress is obtained without any of the ambiguities that exist in conventional buckling method, and a good approximation is also obtained by using a few data points. Therefore, the test structures area could be greatly decreased by using this method. The measurement can be done more easily and simply without any actuation or any specific measuring equipment. The structure and fabrication processes described in this paper are simple and widely used in surface micromachining. In addition, in-situ measurement is available by using the proposed method when the test structure and the measurement structure are fabricated on a wafer simultaneously.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.4
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• pp.31-49
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• 1989

It is of the most urgent necessity to get hydrological time series of long duration for the establishment of rational design and operation criterion for the Agricultural hydraulic structures. This study was conducted to select best fitted frequency distribution for the monthly runoff and to simulate long series of generated flows by multi-season first order Markov model with comparison of statistical parameters which are derivated from observed and sy- nthetic flows in the five watersheds along Geum river basin. The results summarized through this study are as follows. 1. Both two parameter gamma and two parameter lognormal distribution were judged to be as good fitted distributions for monthly discharge by Kolmogorov-Smirnov method for goodness of fit test in all watersheds. 2. Statistical parameters were obtained from synthetic flows simulated by two parameter gamma distribution were closer to the results from observed flows than those of two para- meter lognormal distribution in all watersheds. 3. In general, fluctuation for the coefficient of variation based on two parameter gamma distribution was shown as more good agreement with the observed flow than that of two parameter lognormal distribution. Especially, coefficient of variation based on two parameter lognormal distribution was quite closer to that of observed flow during June and August in all years. 4. Monthly synthetic flows based on two parameter gamma distribution are considered to give more reasonably good results than those of two parameter lognormal distribution in the multi-season first order Markov model in all watersheds. 5. Synthetic monthly flows with 100 years for eack watershed were sjmulated by multi- season first order Markov model based on two parameter gamma distribution which is ack- nowledged to fit the actual distribution of monthly discharges of watersheds. Simulated sy- nthetic monthly flows may be considered to be contributed to the long series of discharges as an input data for the development of water resources. 6. It is to be desired that generation technique of synthetic flow in this study would be compared with other simulation techniques for the objective time series.

• Journal of Korean Critical Care Nursing
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• v.15 no.3
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• pp.37-50
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• 2022

Purpose : This study aimed to examine the item characteristics of the Korean version of the intensive care experience questionnaire (K-ICEQ) using the Rasch analysis model of the item response theory. Methods : In this methodological study, the validity of the scale was examined, and a secondary analysis was conducted using cohort data of patients who were discharged from the intensive care units (ICU). Data from 891 patients who responded to the K-ICEQ upon ICU discharge were analyzed. The WINSTEP program was used to analyze item characteristics, including item difficulty, fit indices, appropriateness scale, and separation reliability. Results : The difficulty level of all 26 items of the K-ICEQ was appropriate, and the fit indices of the 25 items, except for item 18, were good. The 5-point scale of the K-ICEQ was not appropriate in the three subscales. The item separation reliability was good in all subscales, but did not meet the criteria in terms of respondents. Conclusion : The results of examining the item characteristics of the K-ICEQ revealed a good degree of difficulty, fitness, and item separation reliability. To increase the validity of the K-ICEQ, we suggest the rearrangement of the overall item order, modification of the item description of the "recall of experience" subscale, and reduction of the scale response level.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.4
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• pp.443-455
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• 2012

In this research, a woman matched to the average Korean standard size specification of 21-24 years of age was scanned using Cyberware. Rapidform 2004 was used to separate the body zone into fit zone, action zone and design zone, depending on the function of the lower body. Each divided body zone expanded radially using 'offset' by 1.60mm at the cross section of the waist, and 6.36mm at the hip level. Resultant ease values were 1cm and 4cm along the waistline and hipline (respectively), as recommended in previous research. 2C-AN program and Yuka CAD was used to develop a pant pattern from the enlarged 3D body surface blocks. A total of five pants were constructed using conventional fabrics for light weight formal pants. The appearance of the experimental pants were evaluated by five clothing-major evaluators using a questionnaire that consisted of 21 questions. In addition, functional aspects of the experimental pants were also evaluated by wearer while performing five postures for the measurement of ease of movement. It was found that, the method of regional offset and suggested 3D to 2D pattern development generate reasonably good pant patterns. Among the pattern block arrangements, the method B was evaluated as the best way to generate formal pants from the tight-fit pattern, which fit smoothly over the lower body for maintaining ease of movement.

• The Journal of Advanced Prosthodontics
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• v.12 no.3
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• pp.173-180
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• 2020

PURPOSE. This study compared digital (reference point matching) and replica methods for measuring marginal and internal fit of full coverage restorations. MATERIALS AND METHODS. A maxillary left first molar typodent was fixed on to an aluminum base and prepared to receive all-ceramic full coverage restoration. The model was scanned with an intraoral scanner (CEREC Omnicam, Sirona, York, PA, USA). Twelve crowns were fabricated from lithium disilicate blocks (IPS emax CAD, Ivoclar Vivadent) and then crystalized. Marginal and internal fit of each restoration was measured by two examiners using replica and a new digital three-dimensional technique. Reliability between the two methods and two examiners was assessed by correlation and Cronbach's Alpha coefficient (P<.05). A Bland-Altman assessment for agreement was used to compare the two methods. RESULTS. Bland-Altman assessment showed that the mean of difference for marginal, absolute marginal, and axial gap was respectively -1.04 ㎛, -41.9 ㎛, and -29.53 ㎛ with limit of agreement (LOA) between -37.26 to 35.18 ㎛ for marginal, -105.85 to 22.05 ㎛ for absolute marginal and -80.52 to 22.02 ㎛ for axial gap. Positive correlation for repeatability (P<.05) in determining marginal and internal gaps by the two examiners in both techniques was revealed. Reliability of both techniques in all sites of measurements was at least good (0.8 ≤ α < 0.9). CONCLUSION. Both measuring techniques appeared highly reliable for evaluating fit of fixed dental restorations, while reference point matching provided higher values in axial and absolute marginal gap assessment.

• Journal of the Korean Home Economics Association
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• v.43 no.10 s.212
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• pp.179-190
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• 2005

The purpose of this study was to apply the three dimensional Replica method to the fabrication of dress forms of plus-sized women to attain proper ease through draping and based on the ease to develop good torso patterns with superior fit. The results were as follows. The physical characteristics of the dress forms of plus-sized women were divided into two: Types I and 11. The proper ease was calculated through draping using dummies of each somatotype and appropriate torso patterns were developed. The differences of the types for each pattern were as follows. The bust girth ease of Type II was 6cm as for Type I. As for the bust breadth 1.0cm was added to the anterior chest width, the armpit width was the actual measurement plus 0.5cm, and the back breadth was the posterior chest width plus 2.5cm. The bust breadth was smaller and the back breadth was bigger that those of Type I after improving the bust and back fit. The bust of Type I protrudes outwards relatively and so the shoulder dart of front-side of Type I was 1.2cm bigger than that of Type II which improved the bust region fit. Considering the characteristics of the protruding abdominal region the front- side waistline of type II was assigned W/4+3.5cm and the back-side waistline W/4cm, so that the sidelines divided the front and back properly. It was drafted so that the center-front became diagonal, thereby improving the middle-hip girth fit.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.555-561
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• 2008

Purpose: The goal of this study was to develop a technique for creating a computerized composite maxillofacial-dental model, based on point-based surface best fit algorithm and to test its accuracy. The computerized composite maxillofacial-dental model was made by the three dimensional combination of a 3-dimensional (3D) computed tomography (CT) bone model with digital dental model. Materials and Methods: This integration procedure mainly consists of following steps : 1) a reconstruction of a virtual skull and digital dental model from CT and laser scanned dental model ; 2) an incorporation of dental model into virtual maxillofacial-dental model by point-based surface best fit algorithm; 3) an assessment of the accuracy of incorporation. To test this system, CTs and dental models from 3 volunteers with cranio-maxillofacial deformities were obtained. And the registration accuracy was determined by the root mean squared distance between the corresponding reference points in a set of 2 images. Results and Conclusions: Fusion error for the maxillofacial 3D CT model with the digital dental model ranged between 0.1 and 0.3 mm with mean of 0.2 mm. The range of errors were similar to those reported elsewhere with the fiducial markers. So this study confirmed the feasibility and accuracy of combining digital dental model and 3D CT maxillofacial model. And this technique seemed to be easier for us that its clinical applicability can good in the field of digital cranio-maxillofacial surgery.