• Culinary science and hospitality research
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• v.24 no.2
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• pp.1-7
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• 2018

This study aims to find what attributes of consumer satisfaction are more important when consumers choose coffee shops. Factors when customers choose coffee shops that are considered to be more crucial, such as taste, price, brand, and atmosphere, were tested and also relations between satisfaction and revisit were studied. As a result, factors as 'taste', 'price', 'brand', and 'atmosphere' were found to significantly affect satisfaction; in addition, the path that satisfaction leads to revisit was found to be significant. However, consumers' coffee shop selection attributes differed depending on their psychological consumption value. The path-coefficients from taste and price to satisfaction were more significant in the function-oriented group, meanwhile the path-coefficient from brand to satisfaction was significant in the emotion-oriented group (+) and the function-oriented group (-). The results of this study suggest attributes of selecting coffee shops and provide meaningful implications of consumer value when they choose the attributes.

• International Journal of Reliability and Applications
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• v.3 no.1
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• pp.1-16
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• 2002

In reliability engineering, the bathtub-shaped hazard rates play an important role in survival analysis and many other applications as well. For the bathtub-shaped, initially the hazard rate decreases from a relatively high value due to manufacturing defects or infant mortality to a relatively stable middle useful life value and then slowly increases with the onset of old age or wear out. In this paper, we present a new two-parameter lifetime distribution function, called the Loglog distribution, with Vtub-shaped hazard rate function. We illustrate the usefulness of the new Vtub-shaped hazard rate function by evaluating the reliability of several helicopter parts based on the data obtained in the maintenance malfunction information reporting system database collected from October 1995 to September 1999. We develop the S-Plus add-in software tool, called Reliability and Safety Assessment (RSA), to calculate reliability measures include mean time to failure, mean residual function, and confidence Intervals of the two helicopter critical parts. We use the mean squared error to compare relative goodness of fit test of the distribution models include normal, lognormal, and Weibull within the two data sets. This research indicates that the result of the new Vtub-shaped hazard rate function is worth the extra function-complexity for a better relative fit. More application in broader validation of this conclusion is needed using other data sets for reliability modeling in a general industrial setting.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1291-1296
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• 2005

In this paper, we prevent a display quality drop for image of characteristics brightness ununiformity depend on LED use to LED vision. It is about that method also a control system development equipped with brightness compensation function of LED vision which is done easily for LED set up of LED vision. Generally, It is calculate driving current value is attended by each brightness to brightness characteristics mathematical function establish by "Y=aX+b", When is doing brightness value for "Y", driving current value for "X", brightness compensation value by using time for "b", characteristics value for "a" ground with characteristics curve of LED. So much, First It is create brightness data of each pixel take a photograph red, green and blue of LED vision. Second It is get average error about each pixel which get average brightness value of entire. Last, It is handle a complicated for about gradationally regulation to color and brightness of image send to LED vision. Also It raise the whole average brightness value of vision adjust for "b" value to solve brightness drop problem of LED using the long time.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.1-11
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• 2010

The provision of warning information on upcoming hazards leading to potential crash occurrence is a significant countermeasure to prevent crashes on the highway. This study presents a methodology for selecting more effective warning messages using a multi-criteria value function. The understandability, preference level, and message reading time were used as measures of effectiveness (MOE) for messages. Expert judgements were incorporated into the value function by analytical hierarchical process (AHP) technique. Field experiments to evaluate the warning messages were conducted in a testbed section on the Jungboo-Naeryuk freeway. The proposed methodology would be a useful tool to support the design of various traffic information messages.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.7
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• pp.1034-1045
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• 2008

The objectives of this study were to group female consumer types according to cosmetics benefits sought at online and off-line cosmetic shopping malls, and to investigate the differences in consumer values, cosmetic purchase behaviors, and demographic variables according to the consumer types. Subjects were 451 females residing in Seoul, of whom 212 were online shoppers and 239 were off-line shoppers. Five dimensions of cosmetics benefits sought were derived by factor analysis. These were functionality, economy, brand, fashion, and practicality. The female consumers were classified into four benefits sought types by cluster analysis of the five dimensions: T.1 'practicality sought type', T.2 'economy sought type', T.3 'brand function sought type', and T.4 'economic function sought type'. Economy sought consumers purchased cosmetics much more from online shopping malls than from off-line. The cosmetics expenses of practicality sought online consumers were low and many of them were in their 20's and middle-class. Economy sought online consumers preferred domestic brand, their cosmetics expenses were low, and many of them were career women. Practicality sought off-line consumers were high in independent value. Economy sought off-line consumers were low in independent value and social approval value, preferred domestic brand, and distributed more in college students than in career women. Brand function sought off-line consumers purchased cosmetics at department store and regarded social approval value as important. Economic function sought off-line consumers were distributed in middle-class and in diverse age range.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.145-151
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• 2000

The present study was performed to investigate the relationship between the salivary flow rate and the interpretation results of salivary scan in the patients with dry mouth. Twenty-five patients with dry mouth who visited the Dept. of Oral Medicine & Oral Diagnosis, Seoul National University Dental Hospital, were included. The unstimulated whole salivary flow rate was determined by the spitting method and the stimulated whole salivary flow rate was measured with gum-base chewing. Salivary scan was performed after the infusion of $^{99m}technetium$ pertechnetate(Tc) and interpreted. The obtained results were as follows: 1. The unstimulated and stimulated whole salivary flow rate were significantly decreased compared to normal value, which reflected the extensive destruction of salivary gland function in the patients with dry mouth. 2. The unstimulated and stimulated whole salivary flow rate were decreased in the group with decreased function in salivary scan compared with the group with normal function in salivary scan. However, there was no statistical significance between groups. 3. The difference between the stimulated and unstimulated whole salivary flow rates was greater in the group with normal function in salivary scan compared with the group with decreased function in salivary scan. 4. There was significant positive correlation between the stimulated and unstimulated whole salivary flow rates. The level of correlation was higher in the group with decreased function in salivary scan than the group with normal function in salivary scan. Collectively, these data suggested that salivary scan had the limited value. The comprehensive evaluation including history taking, clinical examination, clinical laboratory as well as the measurement of salivary flow rate are need for patients with dry mouth.

• Communications for Statistical Applications and Methods
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• v.24 no.5
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• pp.493-505
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• 2017

Maximum likelihood estimation (MLE) of the generalized extreme value distribution (GEVD) is known to sometimes over-estimate the positive value of the shape parameter for the small sample size. The maximum penalized likelihood estimation (MPLE) with Beta penalty function was proposed by some researchers to overcome this problem. But the determination of the hyperparameters (HP) in Beta penalty function is still an issue. This paper presents some data adaptive methods to select the HP of Beta penalty function in the MPLE framework. The idea is to let the data tell us what HP to use. For given data, the optimal HP is obtained from the minimum distance between the MLE and MPLE. A bootstrap-based method is also proposed. These methods are compared with existing approaches. The performance evaluation experiments for GEVD by Monte Carlo simulation show that the proposed methods work well for bias and mean squared error. The methods are applied to Blackstone river data and Korean heavy rainfall data to show better performance over MLE, the method of L-moments estimator, and existing MPLEs.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.2
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• pp.109-114
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• 2009

Carried out an experiment for quantitative evaluation about intraoral sensor among oral dental imaging equipments in PACS environment. For evaluation, testing environment & evaluation criteria are established that refer to the 'IEC 62220-1-2' and experimented with set up the standard radiation penetration that correspond with RQA-3(IEC 61267). Results of experiments using the image J, derived the ESF(edge spread function), LSF (line spread function) and calculated the MTF(modulation transfer function) finally. As a result, the MTF that 0.1, 0.2sec are 10% about 10 lp/mm and 0.32 sec is the 10% about 9 lp/mm in level represents the value of the MTF. Change of scan condition in dental environmental, according to the MTF value taken note that no changes can be seen enough. However, the dimensions of each other size $1(1200{\times}1600)$, size $2(1440{\times}1920)$ intraoral sensors for 3 lp/mm, respectively 40%, 90% of the note might have been the difference between the value of MTF, in accordance with standard sensors might note differences could be observed.

• Structural Engineering and Mechanics
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• v.22 no.4
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• pp.401-418
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• 2006

Solutions to the problems of structural parameter estimation from modal response using leastsquares minimization of force or displacement residuals are generally sensitive to noise in the response measurements. The sensitivity of the parameter estimates is governed by the physical characteristics of the structure and certain features of the noisy measurements. It has been shown that the regularization method can be used to reduce effects of the measurement noise on the estimation error through adding a regularization function to the parameter estimation objective function. In this paper, we adopt the regularization function as the Euclidean norm of the difference between the values of the currently estimated parameters and the a priori parameter estimates. The effect of the regularization function on the outcome of parameter estimation is determined by a regularization factor. Based on a singular value decomposition of the sensitivity matrix of the structural response, it is shown that the optimal regularization factor is obtained by using the maximum singular value of the sensitivity matrix. This selection exhibits the condition where the effect of the a priori estimates on the solutions to the parameter estimation problem is minimal. The performance of the proposed algorithm is investigated in comparison with certain algorithms selected from the literature by using a numerical example.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.638-645
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• 1993

Objectives: The functional effects of pulmonary resection are dependent on the preexisting function of resected and remaining tissue as well as on the compensatory potential of the remaining tissue. Nowadays, large pulmonary resections are usually applied to lung cancer patients often already compromised by chronic lung disease. It is important to evaluate the pulmonary reserve after lung resection preoperatively in the decision of operability and extent of resection. The aim of this study was to evaluate the changes of pulmonary function after pulmonary resection. Methods: 8 lobectomized and 8 pneumonectomized patients were evaluated. The pulmonary function test was performed preoperatively and in immediate postoperative period and thereafter to 5 years at 3 months interval. Results: 1) The pulmonary function 1 week after operation was significantly low compared with predicted values in, lobectomy and pneumonectomy groups(p<0.05), and improved closely to their predicted values 3 months after operation. 2) The FVC was maintained above predicted value at 6-24 months and similar to predicted value thereafter in lobectomy group. In pneumonectomy group, the FVC maintained similar to predicted value at 6-36 months and improved above its predicted value thereafter. 3) The FEV1 was maintained similar to their predicted values from 6 months to 5 years after operation in both groups. 4) The FEV1/FVC did not change in the course of time in both groups. 5) The FEF25-75% was maintained similar to predicted value at 6-60 months after operation in lobectomy group, but it decreased under predicted value after 1 year in pneumonectomy group. 6) The MVV was maintained similar to predicted value at 6-24 months and decrease thereafter in lobectomy group. In pneumonectomy group, the MVV was maintained at 6-60 months after operation. 7) The differeces in the pulmonary function(FVC, FEV1, FEF25-75%, MVV) between two groups were seen only at 6 months after operation(p<0.05). Conclusion: The pulmonary function was markedly decreased immediately after operation, improved similar to predicted value at 1-3 months, highest at 6 months, and maintained similar to the predicted value to 5 years after pulmonary resection. The difference in the pulmonary function between two groups was the most at 6 months after operation.