• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.375-382
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• 1999

Linear-by-linear association models are commonly used to analyze ordered categorical data. To fit these models appropriate scores need to be chosen. In this paper we perform sensitivity analyses in two-way contingency tables to investigate the effect of scores on goodness-of-fits and on tests of significance. In addition we show that the best score which yields the best fit of data can be selected based on the sensitivity analysis results.

• Korean Journal of Child Studies
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• v.12 no.2
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• pp.130-145
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• 1991

The purpose of this study was to investigate parental authority by sex and age of child. The subjects of this study were 546 elementary school and middle school children in Seoul. The instrument was the Parent Authority Scale (김경희, 1991). Statistical analysis of the data was by two-way multivaliate analysis of variance, simultaneous confidence interval and structure coefficients. There were sex and age differences in children's perception of parental authority. There was a significant interaction effect between children's sex and age on parental authority.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.653-664
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• 2007

Statement of problem: The screw detorque value is a measure of the preload remaining in the screw just before detorquing. Purpose: This study evaluated the effect of different screw tightening sequences and tightening methods on detorque values for a well-fitting implant superstructure. Material and method: An implant superstructure that connected directly to four implants (Astra Tech) was fabricated on a fully edentulous mandibular acrylic resin model. Six well-fitting dental stone casts were made with a pickup impression of the superstructure from the acrylic resin model. To evaluate the effect of three screw tightening sequences (1-2-3-4, 2-4-3-1, and 2-3-1-4) and two tightening methods (2-step and 1-step) on the stability of screw joint, the detorque values for a well-fitting implant superstructure were measured twice after screw tightening using 20 Ncm. Detorque values were analyzed using multi-way analysis of variance and two-way analysis of variance at a .05 level of significance. Results: 1. The mean detorque values for three screw tightening sequences were 12.3 Ncm, 12.6 Ncm, and 12.0 Ncm, respectively. 2. The mean detorque values for two screw tightening methods were 12.0 Ncm, and 12.2 Ncm, respectively. 3. The mean of mimimum detorque values for three screw tightening sequences and for two tightening methods were 10.6 Ncm, 11.1 Ncm, 10.5 Ncm, and 9.8 Ncm, respectively. 4. No statistically significant differences among the variables of screw tightening sequence and tightening method were found (p>.05) for detorque values and for mimimum detorque values. Conclusion: Within the limitations of this study, the screw tightening sequence and tightening method did not have a significant effect on the detorque values for a well-fitting implant superstructure.

• The KSFM Journal of Fluid Machinery
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• v.14 no.3
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• pp.33-38
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• 2011

Medicated water electrolysis apparatus, which electrolyzes water into acidic water and alkaline water, was in the spotlight as becoming known the effect of alkaline water. It is known as good for health as removing active oxygen in the human's body and promoting digestion. But, the customers could not get that desired water temperature because these apparatuses are directly connected with a water pipe. So, the cooling system was developed for controlling the temperature of the alkaline water. One of the typical way is to store water in water tank and control the temperature. But, in this way, storing water can be polluted impurities coming from outside. For protecting this pollution, the cooling system based on indirect heat exchange method through phase change between water and ice was developed. In this study, we have calculated efficiency of the cooling system with phase change by experiment and commercial CFD(Computational Fluid Dynamics) code, ANSYS CFX. To consider the effect of latent heat that is generated by melting ice, we have simulated two phase numerical analyses used enthalpy method and found the temperature, velocity, and ice mass distribution for calculating the efficiency of cooling. From the results of numerical analysis, we have obtained the relationship between the cooling efficiency and each design factor.

• Journal of Korean society of Dental Hygiene
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• v.18 no.6
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• pp.1037-1045
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• 2018

Objectives: The purpose of this study was to evaluation the effect of translucency on CAD/CAM ceramic according to different core/veneer thicknesses. Methods: A total of 42 samples from 2 groups of 7 ceramic cores, each with 3 thickness values (0.8, 1.0, 1.2 mm) were manufactured. The veneers were also manufactured in 3 thicknesses (0.3, 0.5, 0.7 mm). The group names were based on the name of the ceramic core (IPS e.Max CAD; LD, and IPS Empress CAD; LR). The associated number was determined by the combined thickness of the core and veneer: 1 = (0.8 + 0.7); 2 = (1.0 + 0.5); 3 = (1.2 + 0.3). The translucency was measured using a spectrophotometer and defined via the contrast ratio (CR) and translucency parameter (TP). Two-way ANOVA was performed to compare the 2 groups (material and thickness). Results: As the core thickness increased, the TP value also increased, and the CR value (for LR group) decreased. The results of 2-way ANOVA demonstrated that the thicknesses of different core/veneer combinations significantly affected the translucency (p<0.05). Conclusions: The different core and veneer thicknesses affected the translucency of CAD/CAM ceramic.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.238-243
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• 2020

Objective: The purpose of this study was to confirm the validity of a respiratory retraining exercise using pressure biofeedback units among individuals with stroke as an effective intervention for improving quality of life. Design: Randomized controlled trial. Methods: Thirty patients with stroke were recruited as subjects. Among them, 15 patients were randomly assigned to an experimental group performing lumbar stabilization exercise and respiratory retraining exercise, and the other 15 patients were randomly assigned to a control group conducting only lumbar stabilization exercises. Exercises were conducted 3 times a week for 6 weeks, and quality of life was evaluated in the pre-test, 3 weeks and 6 weeks periods. The respiratory retraining exercises were performed using a pressure biofeedback unit and the degree of the quality of life was measured using the Stroke- Specific Quality of Life. For data analysis on the study results, a two-way repeated ANOVA was used in order to observe for changes in the measured variables according to time for both groups. If there was a reciprocal action between the groups and the time in the effect test within the entities, a one-way repeated ANOVA was implemented and was statistically processed. Results: There was a significant difference in the main effect test between the 2 populations depending on the duration of the experiment (6 weeks) (p<0.05). Conclusions: The above results showed that respiratory retraining exercises may provide positive effects in the treatment of stroke as the quality of life showed significant differences according to the duration of treatment.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.7
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• pp.851-861
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• 1998

The present study examined the consumer's evaluations of apparel quality and price, and the brand recognition according to the consumer's decision making styles(quality-conscious, brand-conscious, and price-conscious consumers). The two hundred and three subjects were asked to evaluate the quality and price of the two almost identical experimental blouses except for brand labels. One was the national brand, Keith and the other was the private brand, Ivy house. Also, the subjects were asked to answer if they recognize these two brands. The data were collected by self-administered questionnaire and were analyzed by frequency, percentage, one-way ANOVA, two-way ANOVA, and factor analysis. The results of the study were as floows: (1) Examining the perceptions of product qualities, generally speaking, all three types of the consumers evaluated the national brand's qualities more highly than those of the private brand. However, in-part, the price-conscious consumers evaluated some product charac-teristics more highly than those of national brand: touch of fabric, sewing, and the hemline finishing. (2) Investigating the perceptions of product prices, All three types of the consumers evaluated the price of the national brand more highly than that of the private brand. Among those, the price-conscious consumers recognized the price of the national brands most expensively. (3) Identifying the brand recognition of the two brands, the brand-conscious consumers showed the highest brand recognition and the price-conscious consumers showed the lowest brand recognition in both national and private brands, 51.9% of the total respondents identified the private brand showing comparatively high brand recognition. (4) Examining the relationship between the demographic factors and the consumer decision making styles, the monthly household income was statistically significant. Namely, 71.4% of the brand-conscious consumers have the monthly household income of 3,000,000 Won or higher which means that the higher monthly household income, the higher tendency to be brand-conscious consumers.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.1
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• pp.15-24
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• 2009

The energy usage and the economical feasibility of the typical two story office building in the three urban locations of South Korea are evaluated as the eight orientations. The smallest energy consume is shown at the true south. The ranges of the low energy consume are $-3l5^{\circ}{\sim}0^{\circ}\;and\;-135^{\circ}{\sim}-180^{\circ}$. There are obvious advantages of passive solar designs such as using a fully glazed facade at the true south in the building. The General Low voltage plan is the effective way for the office building when does not required the high voltage electricity. The energy cost of KEPCO is compared to that of XCEL ENERGY. The portion of the customer charge of XCEL ENERGY is about 10% but it is about 50% of the total tariff of KEPCO. The effective way to save the energy cost is by reducing the operating energy of XCEL ENERGY plane but the most effective way is reduce the contracting energy of KEPCO plane.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.298-298
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• 1998

The delay on two-lane, Two-way roads is a very important factor which tends to cause relatively high driver loads and too much delay often leads to traffic accidents. In this study a generalized form of delay estimation model was developed based on constant slow moving vehicle speeds, 100% no-passing zone, and flat terrain highway sections. To validate the model, a comparison was made with John Morrall's SMV(Slow Moving Vehicle)model as well as with TWOPAS model. Also a sensitivity analysis was performed to check accuracy of the model. It was found that the model was easy to apply and yet provided reasonable results for experimental conditions specified in the study. It was recommended that speed calculation procedure of the model be improved by further studies, so that the effect of speed acceleration or deceleration according to highway geometries on delay could be analyzed more accurately.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.1
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• pp.67-71
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• 2010

Purpose: The effect of two different levels of illumination and the effect of three letter chart types on subjective refraction findings were investigated. Methods: This study involved thirty Malay university students aged between 19 to 23 years old (7 males, 23 females), with their spherical refractive error ranged between plano to -7.75D astigmatism ranged from plano to -1.75D, anisometropia less than 1D and with no history of ocular injury and pathology. Monocular subjective refraction was measured under two levels of illumination (with and without room light) and with three different letter charts (Snellen letter chart, wall mounted letter chart and projected letter chart). Subjective refraction finding was calculated in spherical equivalent in unit diopter (D). Results: There was no significant effect in the subjective refraction findings with Snellen letter chart (t-test=0.15, p-value=0.88), projected letter chart (t-test=-0.19, p-value=0.85) as well as wall mounted letter chart (t-test=0.12, p-value=0.94). One Way ANOVA also revealed when the subjective refractive measures were compared under two different level of room illumination (with and without room light), no significant effect of letter chart types on subjective refraction readings with room light ($F_{2.185}$=0.11, p-value=0.89) and without room light ($F_{2.185}$=0.02, p-value=0.98). Conclusions: Subjective refraction findings were not affected whether the room light was on or off. They were also not affected by the types of letter chart used.