• Journal of the Korean Institute of Landscape Architecture
• /
• v.24 no.3
• /
• pp.109-114
• /
• 1996

Generally, the size of our recreation sites is selected through use demand at the peak day. At same time, scale economic and diseconomic are applied to a recreation site. If you are a rational decision-maker, you would like to select the size of your park at profit-maximization point. This study is the first try for modelling a Gain-Loss by the size options of a theme park. For testing the validity of a financial model to select the size of theme parks. Ever-Land, Seoul-Land, Dream-Land's operating size was analyzed. By the size options, the revenue of each park was compared with cost. The profit-maximization point and break-even point of each park were found. Ever-Land and Dream-Land's size was selected between the profit-maximization point and the break-even point. In contrast with Ever-Land and Dream-Land's, Seoul-Land's was selected upper the break-even point. To increase the utility of this model in selecting the size of a theme park, a decision-maker must keep in mind a few limits of this study. That is, 1) this model can not be applied at public parks. 2) Sometimes the others can be more important than financial revenue and cost. Finally, there is the validity of Gain-Loss Model in estimating only the financial revenues and costs through the size options.

• Journal of International Academy of Physical Therapy Research
• /
• v.11 no.3
• /
• pp.2107-2112
• /
• 2020

Background: With the increasing elderly population, the need for gait analysis of these elderly individuals is also increasing. Most devices are costly and not portable; however, smartphones using built-in sensors capable of measuring motion and are easily available. Objectives: To examine the reliability and validity of knee joint angles of the elderly using smartphone measurements during walking. Design: Quasi-experimental research. Methods: Sixteen elderly people, aged 65+ and living in Daejeon and Chungbuk, South Korea, participated in the study. Electrogoniometers and smartphones were attached to the thigh and the side and front of the shank of each subject, respectively, using double-sided tape, an arm band, and an elastic band. Each subject completed two sets of at least seven gait cycles (14 steps). Results: Both the smartphones and electrogoniometers exhibited high agreement in terms of their primary and secondary measurements (ICC>.75). The agreement between the smartphones and electrogoniometers was also high in terms of both the primary and secondary measurements (ICC<.60). Conclusion: These results indicate that smartphones can be costly equipment cannot, even though they cannot completely replace existing clinical-grade devices. Their utility is emphasized herein for measuring knee joint angles of the elderly during walking.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.19 no.6
• /
• pp.361-367
• /
• 2019

Background: Although studies on dental fear in relation to sex and age have been conducted, there have been few nationwide studies particularly on the youth sector. In addition, no validity and reliability verifications have been implemented for new research groups on the Korean version of the Dental Fear Survey (K-DFS). Therefore, this study aimed to apply the K-DFS developed in a previous study on Korean youth to draw conclusions on dental fear among the youth. Methods: This study used the K-DFS, a Korean translation of Kleinknecht's Dental Fear Survey for elementary school, middle school, and high school students. This study selected 2,161 young people of various ages as participants and increased the validity of the research results by expanding nationwide the scope of the study area. Results: Differences in fear levels according to sex were higher in boys fear behavior scores than in girls' regarding dental treatment (P < 0.05). Students with dental fear had higher scores on items associated with dental treatment and fear of dental stimuli compared with students without dental fear (P < 0.05). Differences were observed among the three groups (P < 0.05). However, the results of logistic regression analysis showed no statistically significant differences for dental visits based on sex, grade, and other subcomponents (P > 0.05). Conclusion: By verifying the validity of the newly developed K-DFS, this research confirmed its utility as a dental fear questionnaire. Therefore, there can be no objection that the grounds for criticism have been established according to conventional wisdom. In the future, however, developing and studying the limits of K-DFS that overcome the factors of dental fear, especially pain, will help reduce dental fear in adolescents.

• Journal of The Korean Association For Science Education
• /
• v.15 no.1
• /
• pp.39-53
• /
• 1995

The purpose of this study was development of 'Environmental Science' of high school appropriate to Sixth Natinal Education Curriculum. In view that ultimate aim of environmental education is forming responsible environmental behaviors and the goals of values and behaviors are as important as knowledges and skills, A new environmental text of high school level was developed and it was based on analysis of seven texts and environmental education in Fifth Korean Curriculum. This text have seven units, 1.Habitates : What're the Meanings?, 2.Nuclear Energy: Can't be Avoid?, 3.Acid Rain : What're the Messages", 4.Ethanol : Is this Future Fuel?, 5.Wastes : A New War!, 6.What're the National and Global Environmental Issues? and 7.Our Water: Can Drink, Really? This text was stressed equally in goals of four environmental education and avoided from the array of knowledges. Therefore included various teaching strategies and independent actions of students. 'Open-ended value learning' and 'free behavior learning' in text were special learning parts for aquisition of values and formation of behaviors. To verify the effects of new developed environmental text, the direct learning was carried out by 286 students in total. Post test scores of experimental groups per each units were significantly higher than those of control groups about four goals, respectively. The Results of questionnaires by 50 teachers from five different schools were as follows. For validity of selecting contents for units, 74% of respondents replied positively. For classification and presentation of four goal-groups, 90% replied positively in validity and 82%, in utility. For validity of various teaching strategies, 88% and for the degree of including student-centered independent actions, 86% replied positively. For importances and expected effects of 'open-ended value learning' and 'free behavior learning', showed positive responses respectively, 88%, 92%. Therefore this text is effective to acheive four goals of environmental education equally.

• Physical Therapy Rehabilitation Science
• /
• v.5 no.3
• /
• pp.155-161
• /
• 2016

Objective: This study aimed to investigate the reliability and validity of a personal computer-based muscle viewer (PC-BMW) compared with that of a portable ultrasound (P-US) for measuring upper trapezius (UT) and transversus abdominis (TrA) muscle thickness at rest and during contraction. Design: Observational inter-rater reliability study. Methods: Fifty-five healthy participants (25 men, 30 women) participated in this study. PC-BMW and P-US were randomly measured at the UT and TrA muscles. Two examiners randomly obtained the images of all participants in 3 test sessions lasting 2 days. Intra-class correlation coefficients (ICCs), standard error of measurement, contraction ratio, and correlation were used to estimate reliability and validity. Pearson's correlation coefficients were used to analyze the relationship between muscle thickness measures taken from PC-BMW and P-US. Results: The intra-rater reliability ICCs of UT and TrA muscle thickness for the PC-BMW were >0.995, indicating excellent reliability. Inter-rater reliability ICCs for the PC-BMW ranged from 0.963 to 0.987. The P-US also exhibited high reliability. A high correlation was found between the measurements of the two muscles in PC-BMW and P-US (p<0.01). Conclusions: PC-BMW provides clear and excellent images, is pocket-sized and less expensive than a conventional ultrasound imaging system. PC-BMW can be utilized variously and has the advantage of rehabilitative ultrasound imaging. More research is needed to evaluate the utility of PC-BMW for rehabilitation.

• Journal of Korean Academy of Nursing
• /
• v.27 no.2
• /
• pp.377-388
• /
• 1997

This study was done to develop a eating behavior scale for high school girls using Stunkard and Messick(1985)'s three factors(dietary restraint disinhibition, hunger) as a conceptual framework and to test the validity and reliability of the scale. The subjects were 202 high school girls. The convenience sample is consist of 96 normal weight and 106 obese girls. Data were collected between October 28 and November 25 in 1996 and analyzed using the SPSS package. The new 32-item scale measuring these factors is presented 1. Three stable factors emerged and these contributed 45.7% of the variance in the total score. All 32 items loaded above .35 on each factor, 2. Factor 1 was named disinhibition(14 items), factor 2 was named cognitive restraint of eating(10 items), factor 3 was named hunger(8 items). Comparison of factor Ⅰ, factor Ⅱ, factor Ⅲ between normal subjects and obese subjects showed that there was a significant difference in factor Ⅱ & Ⅲ, not in factor Ⅰ. 3. Cronbach's alpha coefficient for internal consistancy was .9393 for total 32 items and .8820, .8652, .8490 for three dimensions of eating behavior in high school girls. Recommendations are suggested below : 1. Replication study with appropriate age groups be done to test validity and reliability, 2. The present developed scale must be a reliable measure of eating behavior and should have utility in further study on how effective nursing intervention related to different kind of groups such as disinhibition group and cognitive restraint of eating group. 3. To extend validity of the scale, further study is needs using more larger subjects which is consists of dieters and free eaters.

• Child Health Nursing Research
• /
• v.15 no.3
• /
• pp.271-281
• /
• 2009

Purpose: This study was conducted to develop an instrument to measure coping in emergency situations. Methods: The process included construction of a conceptual framework, generation 60 primary items, verification of construct validity and extraction of final items. The.60 preliminary items were reviewed for content validity by seven experts and were tested to evaluate inter-item correlation coefficient by three groups of elementary school students. From November 1 to December 10, 2008, data were collected from 920 elementary school students according to residential characters (major city, small town, rural area). Item analysis, factor analysis with rotation Varimax and Cronbach's alpha were used to analyze the data. Results: 1) There were 45 items in the final instrument categorized into 8 factors. 2) The factors were labeled as "Call for help and check" (8 items), "Care for common symptoms" (6 items), "Appropriate response for the situation" (5 items), "Evacuation" (6 items), "Care for tissue damage" (8 items), "Care for injury by heat, cold or foreign body" (6 items), "Offer help" (4 items) and "Rescue & escape" (2 items). 3) Cumulative percent of variance was 53.10% and eigen values ranged from 1.04 to 13.38. 4) Cronbach's alpha for the total was .943 and ranged from .527 to .869. Conclusion: Validity and reliability of the scale are confirmed in this study showing its utility for measuring coping in emergency situations with elementary school students. Utilization of the scale will also contribute to designing appropriate coping education programs for elementary school students.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.51-54
• /
• 2005

Generator efficiency optimization is important for economic saving and environmental pollution reduction. In general, the machine loss can be reduced by the decreasing the flux level, resulting in the significant reduction of the core loss. This paper proposesan model-based controller is used to decrement the excitation current component on the basis of measured stator current and machine parameters and the q-axis current component controls the generator torque, by which the speed of the induction generator iscontrolled according to the variation of the wind speed in order to produce the maximum output power. The generator reference speed is adjusted according to the optimum tip-speed ratio. The generated power flows into the utility grid through the back-to-back PWM converter. The grid-side converter controls the dc link voltage and the line-side power factor by the q-axis and the d-axis current control, respectively. Experimental results are shown to verify the validity of the proposed scheme.

• Journal of Power Electronics
• /
• v.14 no.2
• /
• pp.383-391
• /
• 2014

For the digital control of systems such as grid-connected inverters, measuring inverter output currents accurately is essential. However, current measurement offsets are inevitably generated by current measurement paths and cause DC current components in real inverter output currents. Real inverter output currents with DC components cause the DC-link capacitor voltage to oscillate at the frequency of a utility voltage. For these reasons, current measurement offsets deteriorate the overall system performance. A compensation strategy to eliminate the effect of current measurement offsets in grid-connected inverters is proposed in this study. The validity of the proposed compensation strategy is verified through simulations and experiments. Results show that the proposed compensation strategy improves the performance of grid-connected inverters.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.11
• /
• pp.1143-1153
• /
• 1991

In this paper, we proposed a new ATM switch structure which is based on the GAMMA network, proving multipath between an input and an output port. The size of the proposed new ATM switch will be smaller than the switches based on the BANYAN network, which includes the Sorting network to resolve the blocking in the switch fabric. Also, the validity and the utility of the proposed switch structure is verified through a simulation method.