• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.56-67
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• 1999

This study was performed to suggest the basic data and plans for the establishment of safe water supply plans in simple water supply piped system in the rural areas. In 4 different places, 24 points of water sources 36 points of taps from water sources were sampled. Of the whole 60 points, 55 points were ground water and 5 points were surface water. 14 items were measured for the analysis of water quality on each samples. The measured items were analyzed again by statistical method ; cluster analysis and principle components analysis. The results of this study are as followed. 1) In water quality analysis on water sources, 4 items, bacteria, E.coli, NH3-N and Fe exceed the standard. Of 24 points, 20 points(83%) on bacteria, 1 point(4%) on NH3-N and Fe exceed the standard. 2) In water quality analysis on near and remote taps, 4 items, bacteria, E.coli, NH3-N and Fe , exceed the standard. Of 36 points, 20 points (81%) on bactria, 1 pint(3%) on NH3-N and Fe exceed the standard. 3)Cluster analysis on water quality shows the differences by the kinds of water sources, geographical characteristics and distance from water sources. 4) Principle components analysis on ground water shows that Factor 1 and Factor 3 are natural fluctuation by the content of soil. Also, Factor 2 and Factor 4 are penetration of pollutants to underground. Therefore, it is needed to take deeper ground water in order to prevent from pollution in the areas which have ground water as water source . 5) Principle components analysis on surface water shows that Factor 1 is penetration of vacteria from surface to water source when rainfalls. Also, Factor 2 is fluctuation of water quality by the geographical characteristics. Therefore, the counterplans against non-point pollution source must be taken. Filtration and disinfection facilities are needed in the areas which have surface water as water source.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.5
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• pp.1-16
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• 2018

The purpose of this study is to identify the fragmented points of mountain ranges in Daegu metropolitan city using New Sangyeongpyo (Chart of Mountain Ranges), road system map and GIS spatial analysis, and to prioritize the identified fragmented points for restoration based on quantitative assessment. Moreover, this study proposes restoration plans reflecting the assessment results and characteristics of each fragmented point. The results of this study are summarized as follows: First of all, analysis of the distribution of mountain ranges in Daegu metropolitan city showed that jimaek and semaek in Daegu account for 2% of all mountain ranges in the country, implying that the mountain ranges of Daegu do not hold significant ranking on a national level. However, it was found that numerous fragmented points are appearing due to roads. According to the analysis, 35 fragmented points were identified, of which 15 were found to be restorable. In terms of restoration potential and involved risks, assessment results of the 15 fragmented points indicated that 6 points are at Grade I, 3 points are at Grade II and 6 points are at Grade III. Therefore, a methodology of restoring fragmented mountain ranges was proposed through three suggestions of restoration plans that consider the characteristics of each fragmented points. The results of this study are expected to be highly useful as basic data for effective restoration of mountain ranges in connection with mountain range restorations and relevant projects implemented on a national level in the future.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.387-395
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• 2015

This study analyzed the Importance-Performance Analysis (IPA) of purchase behaviors and attributes for Hangwa. The data for this study were collected over 10 days from April 10 through April 19, 2013. For empirical research, married women over the age of 20 in Gwangju with buying experience of Hangwa were surveyed. A total of 172 questionnaires were completed and statistically analyzed by SPSS 18.0 package. Analysis rate was 96.6%. To review Hangwa purchase behaviors, most respondents bought Hangwa four or five times per year for memorial services or ancestral rites. Respondents bought Hangwa at big supermarkets and the types of Hangwa bought were Yukwa and Yakgwa. Their average expenses were 20,000 to 30,000 won per purchase. Among purchase attributes of Hangwa, respondents considered the importance of 'sanitation' (4.76 points) a top priority, followed by 'origin' (4.75 points), 'quality' (4.74 points), 'taste' (4.57 points) and 'appearance' (3.82 points). However in the case of satisfaction, 'sanitation' (3.85 points) was the most satisfying aspect, followed by 'package' (3.82 points), 'amount' (3.80 points), 'appearance' (3.51 points) and 'taste' (3.41 points). According to the IPA results, 'quality' and 'origin' purchase attributes, should be quickly improved. 'Sanitation' and 'taste' should be maintained. This survey found that satisfaction levels for Hangwa purchase attributes had a significant influence on overall satisfaction (F=29.11, p<.001), and especially 'taste' ($\beta$=.42, t=6.69, p<.001) had a meaningful effect on overall satisfaction. In addition, satisfaction levels for Hangwa purchase attributes affected repurchase intention (F=20.05, p<.001). From these results, Hangwa manufacturers should make efforts in product development to induce customers satisfaction and repurchase intention.

• The Mathematical Education
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• v.55 no.3
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• pp.335-355
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• 2016

The purpose of this study is to analyze tasks to find intersection points of a function and its inverse function. To do this, we produced a task and 64 people solved the task. As a result, most people had a cognitive conflict related to inverse function. Because of over-generalization, most people regarded intersection points of a function and y=x as intersection points of a function and its inverse. To find why they used the method to find intersection points, we investigated 10 mathematics textbooks. As a result, 23 tasks were related a linear function, quadratic function, or irrational function. 21 tasks were solved by using an equation f(x)=x. 3 textbooks presented that a set of intersection points of a function and its inverse was not equal to a set of intersection points of a function and y=x. And there was no textbook to present that a set of intersection points of a function and its inverse was equal to a set of intersection points of $y=(f{\circ}f)(x)$ and y=x.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1732-1738
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• 2003

The test specimen in environmental vibration test is connected to the fixture through several attachment points. The forces generated by the shaker must be transmitted equally to all attachment points. The forces transmitted to attachment points, however, are different because of the flexural vibration of the fixture. The variations of the transmitted force cause the under-test, especially at anti-resonance frequencies, in vibration test control. Anti-resonance frequencies at the attachment points of the fixture must be same in order to avoid the under-test in vibration test control. The structural modification of the fixture is needed so that anti-resonance frequencies at attachment points have the same value. In this paper, the method to calculate the anti-resonance frequencies and those sensitivities is presented. This sensitivity analysis is applied to the structural modification of the fixture excited at multi-points by the shaker. The antiresonance frequencies at the attachment points of the fixture can have the same value after structural modification, and the under-test in the vibration test control can be removed. Several computer simulations show that the proposed method can remove the under-tests, which are not removed in conventional vibration test control.

• Korean Management Science Review
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• v.27 no.3
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• pp.149-160
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• 2010

This paper focuses on frequent flyer programs (FFPs), which have long been used by most airlines as a powerful marketing tool. Since the preference for FFPs reward services and the customer perceived values of mileage points differ among FFPs members, airlines should design a customer-oriented reward service based on customer preference to motivate the use of mileage points. The intention for using mileage points is affected by various kinds of attributes such as reword items, consuming mileage points for rewards and time of usage. In this paper, we focus on evaluating customer perceived values of attributes of FFPs reward services. A conjoint analysis model is applied to get the preference value of each attribute. Some empirical experiments are conducted in relation to Korean customers. From the empirical survey, the preference values of attributes are evaluated for different scenarios with respect to the number of mileage points. With the preference values of attributes, we can find several implications for airlines regarding the development of various FFPs strategies.

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.100-109
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• 2003

Objectives : The purpose of this study is to 1. measure the skin resistance of jeong-acupuncture points using compound electrode, and 2. develop a database of skin resistance based on age and gender. Methods : The skin resistance of jeong-acupuncture points on the hands and feet of 191 healthy volunteers was measured using a specially designed compound electrode. A constant current of $5{\mu\textrm{A}}$ was applied to the measurement points and the skin resistance was obtained using amplifier, A/D converter and Acknowledge software program, Results : 1. ANOVA statistical analysis showed no significant differences between jeong-acupuncture points on hands and feet. 2. Paired samples t-test showed no significant differences between Yin-Yang meridian points, 3. When the data were sorted by gender, factor analysis showed statistically significant differences between male and female groups in all measured points except for left foot. 4. Based on the factor analysis, a significant relationship between the skin resistance and age was found in feet. However, no such relationship was found in hands. Conclusions : There are differences in skin resistance according to sex and age, Further clinical research is necessary using compound electrode method.

• Journal of Fisheries and Marine Sciences Education
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• v.19 no.1
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• pp.19-28
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• 2007

The aim of this study is to analyze the frequency of the mark points of all examination subjects, the correlation between all examination subjects and the factors to influence pass of the examination. The methodology of this study are as follows.1. The descriptive analysis mark points of the examination subjects. 2. The correlation analysis between the examination subjects. 3. The multiple regression analysis among the examination subjects. Every mark points tend to be changed in wide ranges according to the student's learning ability. On the certificates examination for marine officers, Students in deck part recorded higher in rate of successful applicants, but showed more subject failure than those in engine part. It is especially suggested for the students to improve the teaching and learning skills of the subject. The high correlation subject to total and average points were found in English subject. The high correlation subject was shown between English & Ship handling, Engineering 1&2 and English & Engineering 1,2,3. The most influential subjects to pass the examination were Navigation, English, Engineering 3.

• Advances in concrete construction
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• v.10 no.6
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• pp.527-536
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• 2020

In this study, a process is proposed to calculate analytical correction values for the vertical shortening of all columns on all floors in a high-rise building that minimizes the error between the structural analysis predictions and values measured during construction. The weight ratio and the most probable value were accordingly considered based on the properties of the shortening value analyzed at several points in each construction stage and the distance between these measured points and unmeasured points at which the shortening was predicted. The effective range and shortening value normalization were considered using the column grouping concept. These tools were applied to calculate the error ratio between the predicted and measured values on a floor where a measured point exists, and then determine the estimated error ratio and estimated error value for the unmeasured point using this error ratio. At points on a floor where no measured point exists, the estimated error ratio and the estimated error value were calculated by applying the most probable value considering the weight ratio for the nearest floor where measured points exist. In this manner, the error values and estimated error values can be determined at all points in a structure. Then, the analytical correction value, defined as this error or estimated error value, was applied by adding it to the predicted value. Finally, the adequacy of the proposed correction method was verified against measurements by applying the analytical corrections to all unmeasured points based on the points where the measurement exists.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.267-278
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• 2009

The purpose of this study was to examine parents' perceptions towards, and the importance and performance levels of, foodservices in child-care centers and to suggest ways to increase foodservice quality and promote efficient operations in the future. A questionnaire survey was provided to 540 parents and the return rates 82%. The survey period was from June 20 to July 27,2007. The collected data were statistically analyzed with the SAS package program using descriptive statistical analysis, t-tests, ANOVA, Duncan's multiple comparisons, factor analysis, and multiple regression analysis. The results were as follows: The parents perceived that foodservice operations promoted their children's health and helped them form desirable dietary habits. The parents also had a high level of perception toward the need for foodservice, earning greater than 4.5 points out of 5 points. Their perceptions of foodservice quality were examined by four dimensions of importance and performance levels. While the parents gave 4 points or greater of 5 points to most quality attributes of importance level, they gave 4 points of less out of 5 points to most quality attributes of performance level. As for the importance and performance levels of the quality dimensions of meal service, the parents regarded sanitation as the most important dimension. IPA showed that 'organic food materials' was included as a 'focus here' area. The overall satisfaction level for foodservice was 3.59 out of 5 points. A higher level of satisfaction was shown when a dietitian was present as well as in public childcare centers. According to multiple regression analysis, 53.51% of the variance in the respondents' overall satisfaction scores was explained by factors such as food, sanitation, environment, and foodservice effects.