• The Korean Journal of Applied Statistics
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• v.31 no.3
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• pp.315-328
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• 2018

In this paper, we examine the methodology to predict consumer preferences using several groups of attributes of products and application to real data. In the food industry, studies are in progress to investigate the relationship between product attributes and consumer preferences; consequently, various methodologies are proposed. Among these methodologies, we consider multiple factor analysis (MFA). The result of the MFA enable the division of consumers into four clusters with similar liking and the defining of preference characteristics for each cluster. Also, using the results of multiple factor analysis, we find the partial least squares path model to predict consumer preferences through the characteristics of the product and the characteristics evaluated by consumers. We can understand the relationship between the cluster of consumers and the preferred/undesirable characteristics of products through the partial least squares path model applied to two clusters with different liking. When multiple factor analysis is used in the partial least squares path model, it is possible to investigate relationships between products and consumers by analyzing product characteristics and consumer preferences simultaneously. The results can be applied to product developments and sales which makes this methodology important and useful.

• Food Science and Preservation
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• v.23 no.3
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• pp.347-354
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• 2016

To investigate the effect of different acetic acid bacteria on qualities of detoxified Rhus verniciflua vinegar (DRV), different DRVs were produced by using three acetic acid bacterial strains including Acetobacter pasteurianus KACC16934 (AP), Acetobacter malorum V5-7 (AM), and Gluconoacetobacter entanii RDAF-S (GE). Little difference in pH (2.87~2.90) or titratable acidity (5.33~5.68%) was observed among different DRVs. Acetic acid yields of the AP, AM, and GE strains were 78.6%, 85.3%, and 85.9%, respectively. Organic acid content in different DRVs was in the range of 69.84~73.83 mg/mL. Oxalic acid, malic acid, succinic acid, acetic acid, and fumaric acid were detected in all DRVs. And glutamic acid, alanine, valine, leucine, tyrosine, lysine, anserine, and arginine were detected in all DRVs. Arginine and alanine were the predominant amino acids in all DRVs. PCA plots of electronic nose analysis data showed a significant differentiation of DRVs from different acetic acid bacterial strains. A sensory evaluation of all DRVs indicated that DRV fermented using AM was superior in the aspect of flavor, tasted and overall preference.

• Food Science and Preservation
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• v.22 no.4
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• pp.528-534
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• 2015

This study was performed to analyze the processing and quality characteristics of whey Makgeolli prepared with different types of yeast and ratio of the whey content. Lactose content of yeast culture medium containing S. cerevisiae. was 1.36% whereas lactose content of yeast culture containing K. marxianus KCCM 12015 was very little. Yeast culture of both K. marxianus KCCM 35455 and K. marxianus KCCM 50700 did not produce lactose. Until the 10th day, ethanol production ability of S. cerevisiae, K. marxianus KCCM 12015, K. marxianus KCCM 35455, and K. marxianus KCCM were 0.31%, 2.51%, 2.53%, and 2.59%, respectively. Total acids content increased rapidly with the increase in the addition of whey content in the initial 2 days and then decreased during 4~10 days of fermentation. In the aspect of pH, the pH was rapidly decreased in the initial 2 days and then increased until 10th day of fermentation with the increase in whey content. Ethanol content of whey Makgeollis at 10th day of fermentation was the highest in yeast culture containing K. marxianus. From the sensory evaluation, the flavor score of whey Makgeollisin was higher than that of control. The color and taste scores were increased as the increase in the addition of whey. The comprehensive preference indicated that Makgeolli prepared with 100% whey was the best among other samples.

• Food Science and Preservation
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• v.23 no.4
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• pp.530-537
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• 2016

The purpose of this study was to evaluate the effects of barley cultivars (Saessalbori, Saechalssalbori and Huinchalssalbori) and different milling recovery (95%, 85% and 75%) on quality characteristics of barley Makgeolli. The content of moisture, ash, crude protein, and crude fat in barley seeds were reduced with decreasing milling recovery. The qualities of barley Makgeolli were also significantly affected by the milling recovery. Decreasing milling recovery of all cultivars resulted to increase in total sugar content and reducing sugar content but decrease in pH while alcohol content and total acidity were not significantly affected. Moreover, the lightness and yellowness of barley Makgeolli increased by milling while its redness decreased. The sensory evaluation showed that the consumer preference for barley Makgeolli increased at the lowest milling recovery (75%). The results of this study suggest that the milling recovery and cultivar of barley were important factors to improve the taste and color of barley Makgeolli.

• Food Science and Preservation
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• v.18 no.1
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• pp.33-38
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• 2011

We investigated the quality characteristics of cookies prepared after addition of various concentrations of used coffee grounds (0%, 1%, 3%, and 5%, all w/w) as a substitute for flour. As coffee grounds concentration rose, decrease in the pH of cookie dough was evident. In terms the water-holding capacity of dough, cookies prepared 3% (w/w) coffee grounds yielded the highest value. With an increase in coffee grounds concentration, the color a value rose, but the L and b values fell. The gelatinization temperature became higher, but both peak viscosity and 15 min-height values declined. The spread and loss ratios decreased but the leavening rate rose significantly with elevation of coffee grounds concentration. The hardness of cookies rose but slightly, as coffee grounds concentration rose. Upon sensory evaluation of all of appearance, flavor, and overall preference, cookies prepared with addition of used coffee grounds were superior to those without grounds, whereas those prepared using 1%-3%(w/w) coffee grounds showed the highest overall acceptability. Thus cookies made using coffee grounds can be economically competitive. In addition, the ingredients of coffee powder and used coffee grounds were shown to be very similar, except that coffee grounds contain 15-fold less caffeine than dose coffee powder. As health concerns are popular today, the use of coffee grounds to manufacture processed food may be acceptable.

• Food Science and Preservation
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• v.17 no.2
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• pp.230-235
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• 2010

We investigated the physicochemical quality characteristics of apple juice upon sterilization using hot water, and under various storage conditions. None of sugar content, acidity, or pH differed significantly among various sterilization conditions but chromaticity was considerably reduced in sterilized juice compared with control material. The chromaticity of non-sterilized juice decreased significantly after sterilization compared with material supplemented with vitamin C (0.1%, w/v). Fungi, yeast, and aerobic bacteria were detected in juice sterilized at $65^{\circ}C$ for 10 or 20 min, but no microorganisms were observed in juice sterilized by other procedures. Vitamin C content affected sterilization temperature to a greater extent than sterilization time. When juice was stored at $4^{\circ}C$ or $37^{\circ}C$ for 3 weeks after application of different sterilization conditions, almost no change in acidity, sugar content, or pH was observed, regardless of sterilization mode or storage period. However, chromaticity decreased with longer storage. Vitamin C levels were reduced by higher sterilization temperatures. However, longer storage periods had the greatest effect on reduction of vitamin C levels, which tended toward lower values regardless of differences in sterilization and storage conditions. In sensory evaluation tests, all of taste, color, and overall preference were highest for juice sterilized at $75^{\circ}C$ for 20 min. The ASC value was low at a storage temperature of $4^{\circ}C$ and at high sterilization temperatures, and a long storage period was associated with a greater ASC value. Thus, the quality of apple juice was excellent when juice was hot water-sterilized, with additional vitamin C, at $75^{\circ}C$ for 20 min, followed by storage at $4^{\circ}C$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.743-748
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• 2019

This study suggested a process of redesigning and implementing problem based learning to enhance students' active and collaborative learning activities and learning outcomes. The results of this study are as follows. First, the ef ect of class participation, academic self-regulated learning, and academic self-efficacy were examined. As a result, first, the average of learning activity, class extension, and participation in class was high in the difference between before and after class. Second, the post average scores of all the factors except the 'evaluation' were higher than before. Third, academic self-efficacy showed a significant difference only in 'task preference'. Finally, students' satisfaction with the class was also high. The professor was also able to grasp the characteristics of individual students by designing and operating the classes using PBL, and it was confirmed that the interaction with students increased. Based on the results of this study, we discussed the limitations and educational implications of the problem based learning class and propose successful problem based learning design and operation of the classroom.

• Journal of the Ergonomics Society of Korea
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• v.34 no.3
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• pp.247-264
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• 2015

Objective: The purpose of this study is to determine the priority of information presentation and the effective menu type to be placed in the center of a gauge cluster display for commercial trucks and to present a set of ergonomic designs for the gauge cluster display. Background: An effective ergonomic design is specifically needed for the development of the gauge cluster display for the commercial trucks, because more diverse and heavier information is delivered to truck drivers, compared to the information to passenger car drivers. Method: First, all the information that must be shown on the commercial truck display was collected. Then, the severity, frequency of use, and display design parameters were evaluated for those information by commercial truck drivers. Next, an analysis on the information attributes and the heuristic evaluation utilizing the display design principles were carried out. According to the results, a design alternative of the main screen to be displayed was constructed by priority. A comparative analysis between the alternative and existing main screens was also conducted to see the efficacy of the designs. Lastly, we conducted an experiment for the selection of menu type. The experiment was conducted using the driving simulator with an eye-tracking device. The independent variables were four types of the menu reflecting the commercial truck characteristics such as grid type, icon type, list type, and flow type. We measured preference, total execution time, the total duration of fixation on the gauge cluster area, and the total number of fixation on the gauge cluster area as dependent variables. Results: Four types of driver convenience information and six types of driver assistance information were selected as the information to be placed primarily on the main screen of the gauge cluster. The Grid type was the most effective among the menu types. Conclusion: In this study, the information that appears on the main screen of the display, the division of the display and the design of the menu type for commercial truck drivers were suggested. Application: This study is expected to be utilized as guidelines on the ergonomic design of a gauge cluster display for commercial trucks.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.141-147
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• 2015

The contrast of a display is generally evaluated by using the ratio of the minimum luminance to the maximum luminance of the display. However, this contrast ratio is not matched with perceived contrast because it uses only physical characteristic of display without considering human perceptual characteristics. In this paper, the proposed contrast measure that considers perceptually discriminable brightness within the range of display brightness is suggested. First, the range between the minimum and maximum brightness of display in CIECAM02 color space is calculated to measure the length of perceived brightness for the display. Next, brightness ranges which are perceptually same at each brightness level are determined by applying Weber-Fechner ratio and then, the number of brightness values within each brightness range is counted. Finally, perceptually discriminable brightness is defined as the sum of ratio between the number of brightness values in each brightness range and the perceptual contrast length of the display. In the experiments, preference test using various displays with random brightness patches is performed to evaluate perceived contrast. As a result, the proposed measure is more consistent with human perception than the previous contrast measures.

• Culinary science and hospitality research
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• v.22 no.7
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• pp.36-46
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• 2016

The study examined the kinds of sweeteners(xylitol, sorbitol, acesulfame K, aspartame, stevioside) instead of sugar for vanilla sauce to satisfy customers' health needs. According to the results, the sauce with sugar had lowest salinity, highest sugar content, and sauce with aspartame had lowest sugar content. pH were highest in sauce with sorbitol, with aspartame were lowest. L-value, a-value was the highest in sauce with aspartame, while b-value was the lowest. The moisture content was the lowest, while viscosity was the highest in the sauce with xylitol. In a sensory evaluation, texture and overall preference was the highest in vanilla sauces with aspartame which have proper color intensity and strong flavor in mouth feel. The result indicated that health-oriented consumers and satisfy the health of modern people's needs when using the vanilla sauce with aspartame instead of sugar. It is also advised to vanilla sauce with aspartame for preventing adult disease and using the diets for patient.