• Title/Summary/Keyword: T-test analysis

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A study on seasonal characteristics through long-term water quality monitoring in the Nakdong River Watershed (낙동강유역 장기 수질모니터링을 통한 계절적 특성분석 연구)

  • Kal, Byungseok;Park, Jaebeom;Kim, Seongmin;Shin, Sangmin;Jang, Soonja;Jeon, Minjae
    • Journal of Wetlands Research
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    • v.24 no.4
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    • pp.301-311
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    • 2022
  • The purpose of this study is to analyze the seasonal characteristics of water quality using long-term water quality monitoring data. Seasonal characteristics of water quality were analyzed using monitoring data from 34 tributaries where long-term monitoring was performed in the Nakdong River system, and average data analysis of water quality, coefficient of variation analysis, and trend analysis were performed for seasonal analysis. For seasonal analysis, average data analysis of water quality, coefficient of variation analysis, and trend analysis were performed. As a result of the evaluation of the coefficient of variation, tributaries were larger than main streams, and BOD, T-P, and TOC were larger in autumn and T-N were larger in spring. Trend analysis was analyzed using Mann-Kendall and Sen's Slope. BOD, T-N, and T-P tended to decrease, but TOC had a lot to increase. Through this study, it was possible to evaluate the availability of long-term water quality monitoring data and analyze seasonal characteristics, and to analyze the stabilization period of water quality and changes in pollutant sources for watershed management.

The Effect of an Exercise Program with Patella Mobilization on Range of Motion, Muscle Strength and Gait in Patients with Total Knee Arthroplasty (무릎뼈 관절가동술을 동반한 운동프로그램이 무릎관절 전치환술 환자의 관절가동범위, 근력, 보행에 미치는 영향)

  • Lee, Jaehong;Min, Dongki;Lee, Sangjae
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.1
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    • pp.1-14
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    • 2020
  • Purpose : The purpose of this study was to investigate the effect of an exercise program with patella mobilization on range of motion, muscle strength, and gait in patients with total knee arthroplasty. Methods : Thirty patients under the age of 65 who visited the T hospital in Daegu Metropolitan City and underwent total knee arthroplasty surgery were selected for this study. Fifteen patients were randomly assigned to the experimental group and took part in an exercise program with patella mobilization, and fifteen patients were randomly assigned to the control group and took part in just the exercise program. Each group took part in their intervention three times a week for four weeks. The measurement tools used included a goniometer, handheld dynamometer, and 10-meter walking test. In the statistical analysis results, to compare the about pre and post test differences within each group, a paried t-test was used, and to compare the differences between each group, an independent t-test was used. Results : There was a significant difference (p<.05) in the range of motion, muscle strength of the quadriceps femoris and, hamstrings, and 10-meter walking test within each individual group and between the two groups before and after the intervention (p<.05). Conclusion : All the results for the experimental group were significant. Therefore, it is expected that an exercise program with patella mobilization will be helpful for the recovery of the knee joint in patients who have undergone total knee arthroplasty.

An Evaluation of the Statistical Techniques Used in Papers of the Journal of Sasang Constitutional Medicine (2000-2009) (최근 10년간(2000-2009) 사상체질의학회지 게재논문의 통계분석방법에 대한 연구)

  • Park, Ki-Hyun;Kim, Sang-Hyuk;Kim, Hong-Gie;Lee, Si-Woo
    • Journal of Sasang Constitutional Medicine
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    • v.22 no.4
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    • pp.49-55
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    • 2010
  • 1. Objectives The purpose of this study is to assess the statistical methods used in the Journal of Sasang Constitutional Medicine and to identify the types of errors in the statistical analysis. 2. Methods We have reviewed quantitative articles published in the Journal of Sasang Constitutional Medicine from 2000 to 2009. Except for the case report, a total of 505 articles was reviewed by year. We focused on the methods of statistics in these articles. We have analysed the number of thesis used the statistical methods, the number of the statistical methods, the types of the statistical methods, and the errors of the statistical methods with the object of 202 thesis used the statistical method. 3. Results 1. Of the 370 articles, 202 used inferential statistics. 2. The most dominant was the thesis with one type of the statistical method forming 61.9% (125 thesis) of the total. 3. The ANOVA was the statistic of choice overall (40.1%), followed by the t-test (35.6%). 4. By examining the errors of the statistical methods, there were 49 thesis with errors among 81 thesis using ANOVA, 25 thesis among 72 thesis using t-test, and 18 over 62 thesis using chi-squared test. 4. Conclusions We have found various mistakes or misuses in the applications of statistical methodologies in the articles published in the Journal of Sasang Constitutional Medicine. It is necessary to present the cases of inappropriate statistical methods in order to improve the quality of academic researches. So long as Sasang constitutional medicine uses the statistical methods, researchers should fully examine and be aware of the statistical methods which they wish to use through other research articles, and statistic publications.

A Study on the Expectation and Satisfaction of Parents on Cooking Activity Programs for Children (아동 요리활동 프로그램에 대한 학부모의 기대와 만족에 관한 연구)

  • Yang, Yeo-Jung;Yoon, Hye-Hyun
    • Culinary science and hospitality research
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    • v.20 no.2
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    • pp.152-164
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    • 2014
  • This research attempts to analyze the significant factors that affect the level of expectation and satisfaction of parents on cooking activities for their child(ren) by comparing the levels of their original expectation and satisfaction; based on the understanding of the educational values and effects of cooking activities for children. To conduct the empirical studies, 254 survey samples were collected from the parents who have had their child(ren) participate in cooking activities; in addition, the data was processed and analyzed by using various comparative statistical analysis; including t-test, IPA analysis, regression analysis, one-way ANOVA. And Duncan's multiple test was added to verify the outcome afterwards. As the result of the research, the expectation and satisfaction of parents who let their child(ren) participate in cooking activities were significantly different by such variables as 'improvement of linguistic expression,' 'development of understanding numbers and scientific concepts,' 'extension of capability to give his/her emotional expressions,' 'assistance in soothing his/her psychological stresses.' Besides, 'educational contents and methods' were revealed as another factor that influenced parents' satisfaction, and it is clarified that the level of satisfaction is significantly different according to the organizations offering activity programs.

Study on Analysis and Evaluation of Performance for Evacuated Tubular Solar Collector System (진공관형 태양열 집열장치의 성능평가 및 해석 연구)

  • Chun, Tae-Kyu;Ahn, Young-Chull
    • Journal of Energy Engineering
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    • v.22 no.2
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    • pp.112-119
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    • 2013
  • The thermal performance for test system with evacuated tubular solar collector is experimentally investigated to obtain the basis data for developing new type solar collector. For this purpose, the test system was designed using CATIA and then after being manufactured, the system was tested using evacuated tubular solar collector. Numerical analysis, furthermore, was performed using ANSYS Fluent V.13 for glass evacuated tubular solar collector. The results showed that as setting temperature difference(${\Delta}T$) of system was increased, total operating(working) time was almost same in all cases, even though operating count was decreased. The results of numerical analysis showed that as temperature of solar absorber in glass evacuated tubular solar collector was high, the drop-rate of temperature of center part was increased.

The Relationship Between Attitude Toward Pets and Elementary School Students' Empathy Ability (애완동물에 대한 태도와 초등학생의 공감능력과의 관계)

  • Han, A-Ram
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.570-578
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    • 2016
  • This study examined the relationship between the attitudes toward pets and elementary school students' empathy ability, and analysed the difference in the attitude toward pets and the level of elementary school students' empathy depending on gender, school year and rearing period. To carry out this study, data were collected by giving a test on the attitudes toward pets and a test in empathy ability to 220 elementary school students in Daejeon Metropolitan City, who had a pet rearing experience in the past. With regard to the data collected, correlation analysis, multiple regression analysis, t-test and analysis of variance were carried out using SPSS win23. As a result of the analysis, the following facts were revealed. First, the attitudes and the degree of empathy ability for pets showed relevance. Second, affection for pets, interaction, and the joy of having pets were closely related to the empathy ability. Third, there was a significant difference in the attitude toward pets depending on gender and rearing period. Finally, there was a significant difference in empathy ability depending on the gender and rearing period. However, there was no significant difference depending on the school year.

Mediation Effect of Cognitive Emotion-regulation Strategy in the Relationship between Family Stress and Marital Satisfaction -focused on the comparison of husbands and wives- (중년기 부부의 가족스트레스와 결혼만족도 관계에서 인지적 정서조절전략의 매개효과 -남편과 아내의 비교를 중심으로-)

  • Kim, Du-Gil;You, Young-Dal
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.177-191
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    • 2015
  • This study was designed to investigate the differences in the mediation effects of cognitive emotion-regulation in the relationships between family stress and marital satisfaction of middle-aged husbands and wives. The data were underwent through the SPSS 19. Win for frequency, paired-t-test, multiple regression analysis, and for the further analysis of hiearchical multiple regression and the analysis for the mediation effect proposed by Baron & Kenny(1996) and Sobel test(Sobel, 1982). The results were as follows. First, hiearchical multiple regression analysis showed that education level, couples' problems, replanning strategies were proved to be significant for the marital satisfaction of the husbands, while age, couples' problems, acceptance strategies were significant for the marital satisfaction of the wives. Second, cognitive emotion-regulation strategies were proved to partially mediate in the relationship between family stress and marital satisfaction. The limitations of the study and implications for the further research were discussed based on the results.

FATIGUE LIFE ESTIMATION OF IMPLANT USING A FINITE ELEMENT METHOD (유한요소법을 이용한 치아 임플랜트 피로수명 예측)

  • Han In-Sook;Son Jung-Hun;Yang Young-Soo;Lee Seung-Young
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.4
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    • pp.414-420
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    • 2006
  • Purpose : The purpose of this study is to use finite element analysis to predict the fatigue life of an implant system subjected to fatigue load by mastication (chewing force). The reliability and the stability of implant system can be defined in terms of the fatigue strength. Not only an implant is expensive but also it is almost impossible to correct after it is inserted. From a bio-engineering standpoint, the fatigue strength of the dental implant system must be evaluated by simulation (FEA). Material and Methods Finite element analysis and fatigue test are performed to estimate the fatigue strength of the implant system. Mesh of implant is generated with the actual shape and size. In this paper, the fatigue strength of implant system is estimated. U-fit (T. Strong, Korea, internal type). The stress field in implant is calculated by elastic-plastic finite element analysis. The equivalent fatigue stress, considering the contact and preload stretching of a screw by torque for tightening an abutment, is obtained by means of Sine's method. To evaluate the reliability of the calculated fatigue strength, fatigue test is performed. Results: A comparison of the calculated fatigue strength with experimental data showed the validity and accuracy of the proposed method. The initiation points of the fatigue failure in the implant system exist in the region of high equivalent fatigue stress values. Conclusion: The above proposed method for fatigue life estimation tan be applied to other configurations of the differently designed and improved implant. In order to prove reliability of prototype implant, fatigue test should be executed. The proposed method is economical for the prediction of fatigue life because fatigue testing, which is time consuming and precision-dependent, is not required.

A Study on Numerical Analysis of Flexible Pavements under Moving Vehicular Loads (차량의 이동하중을 고려한 연성포장의 수치해석 기법 연구)

  • Park, Seoksoon;Kim, Nakseok
    • Journal of the Society of Disaster Information
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    • v.7 no.3
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    • pp.206-219
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    • 2011
  • The important elements in pavement design criteria are the stress and strain distributions. To obtain reasonable stress and strain distribution, tire contact area and tire pressures are very important. This study presents a viscoelastic characterization of flexible pavement subjected to moving loads. During the test, both longitudinal and lateral strains were measured at the bottom of asphalt layers and in-situ measurements were compared with the results of numerical analysis. A 3-dimension finite element model was used to simulate each test section and a step loading approximation has been adopted to analyze the effect of a moving vehicle on pavement behaviors. For viscoelastic analysis, relaxation moduli, E(t), of asphalt mixtures were obtained from laboratory test. Field responses reveal the strain anisotropy (i.e., discrepancy between longitudinal and lateral strains), and the amplitude of strain normally decreases as the vehicle speed increases. In most cases, lateral strain was smaller than longitudinal strain, and strain reduction was more significant in lateral direction.

The Moderating Effect of Perceived Values on The Luxury Brand Preference Depending on Consumers' Regulatory Focus (소비자 조절초점이 명품브랜드의 가치와 브랜드태도의 관계에 미치는 조절효과)

  • Suh, Yong-Han
    • Management & Information Systems Review
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    • v.30 no.4
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    • pp.73-92
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    • 2011
  • The purpose of this study was to investigate the differences of influence between luxury brand value and preferences according to consumers' regulatory focus. For data collection, research questionnaires were responded by females consumers living in Pusan and Ulsan. The collected data were analyzed according to the frequency-factor analysis using SPSS 14.0 for windows Package, the factor analysis using Varimax, reliability analysis, T-test, multi-regression analysis, and chow-test. The results were as follows: First, Based on an independent samples t-test, It was found that prevention-oriented respondents were significantly more qualify value and economic value than promotion-oriented respondents, promotion-oriented respondents were significantly more aesthetic value than prevention-oriented respondents. Second, concerning the worth of luxury brands that aesthetic value, qualify value, economic value, conspicuous value, and emotional value significantly affected the consumers' preference about luxury brand. On the other hand, only social value of the luxury brand did not have a significant effect on the consumers' preference about luxury brand. Second, the study was to investigate whether the luxury brand value has an effect on the brand preference depending on the consumer's regulatory focus. The results showed that there were different perceived values of luxury brand preference between the promotion-focused and the prevention-focused consumers. The promotion focus group had the effect on conspicuous value and emotional value, while the prevention focus group had the effect on quality value and economic value for luxury brand preference.

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