• Title/Summary/Keyword: T-test analysis

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Motion Analysis of Head and Neck of Human Volunteers in Low-Speed Rear Impact (저속 후방 추돌 자원자 실험을 통한 두부와 경부의 동작분석)

  • Hong, Seong Woo;Park, Won-Pil;Park, Sung-Ji;You, Jae-Ho;Kong, Sejin;Kim, Hansung
    • Journal of Auto-vehicle Safety Association
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    • v.4 no.2
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    • pp.37-43
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    • 2012
  • The purpose of this research is to obtain and analyze dynamic responses from human volunteers for the development of the human-like mechanical or mathematical model for Korean males in automotive rear collisions. This paper focused on the introduction to a low-speed rear impact sled test involving Korean male subjects, and the accumulation of the motion of head and neck. A total of 50 dynamic rear impact sled tests were performed with 50 human volunteers, who are 30-50 year-old males. Each subject can be involved in only one case to prevent any injury in which he was exposed to the impulse that was equivalent to a low-speed rear-end collision of cars at 5-8 km/h for change of velocity, so called, ${\Delta}V$. All subjects were examined by an orthopedist to qualify for the test through the medical check-up of their necks and low backs prior to the test. The impact device is the pendulum type, tuned to simulate the crash pulse of a real vehicle. All motions and impulses were captured and measured by motion capture systems and pressure sensors on the seat. Dynamic responses of head and T1 were analyzed in two cases(5 km/h, 8 km/h) to compare with the results in the previous studies. After the experiments, human subjects were examined to check up any change in the post medical analysis. As a result, there was no change in MRI and no injury reported. Six subjects experienced a minor stiffness on their back for no more than 2 days and got back to normal without any medical treatment.

Effect of tack of Fusion Defects on Short-Term Performance of Polyethylene Electrofusion Joints (폴리에틸렌 배관 전기융착부 단기성능 평가를 위한 융합물량 영향 평가)

  • Kil, Seong-Hee;Kwon, Jeong-Rock;Jo, Ji-Hwan
    • Journal of Energy Engineering
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    • v.14 no.2 s.42
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    • pp.153-158
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    • 2005
  • In order to investigate the short-term performance of polyethylene electrofusion joints, the mechanical tests and stress analysis have been conducted to the artificially defected weld joints. The defects of lack of fusion with a square-type were fabricated with 10, 20, 30, 40, 50, 60$\%$ size of the width of heat-ing wire zone, respectively. In this defect sires range, both tensile and bending test results showed the dependence of defect size to the electrofusion joints performance, but both sustained pressure and crush test results didn't. The numerical stress analysis results including the soil and internal pressures, tensile and bend-ing stresses clearly showed the dependence of fusion defect size. Based on both mechanical test and stress analysis results, the maximum acceptable defect size in polyethylene electrofusion joints is discussed.

The Effects of Well-being Consciousness and Appearance Management of Korean and Japanese Consumers on Attitudes toward Korean Herbal Cosmetics (한국과 일본 소비자의 웰빙의식과 외모관리에 따른 한방화장품 태도 연구)

  • Lee, Yu-Ri;Jung, Hye-Jung
    • Journal of the Korean Society of Costume
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    • v.62 no.2
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    • pp.87-102
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    • 2012
  • The purpose of this study is to identify conceptual constructs of well-being consciousness and appearance management behaviors, and to examine the effects of these two variables on attitudes toward Korean herbal cosmetics for Korean and Japanese consumers. A survey was carried out among female consumers between the ages of 20 and 50, and a total of 500 responses were analyzed by descriptive analysis, reliability test, t-test, and confirmatory factor analysis, structural equation modeling and multi group analysis. The results of this study were as follows: 1) The result of CFA and the reliability test on well-being consciousness and appearance management of Korean and Japanese respondents clearly showed factorial structures on each of the variant assessments. 2) In regards to the well-being consciousness, Korean and Japanese respondents highly tended to perceive well-being as a benefit to the physical health and an eco-friendly lifestyle respectively. In the area of appearance management, Korean and Japanese respondents had similar patterns that showed high scores of skin care and weight control. Both Korean and Japanese consumers showed favorable attitudes toward Korean herbal cosmetic products. 3) The consumers' well-being consciousness revealed to have positive influences on appearance management behavior. Both well-being consciousness and appearance management positively influenced attitudes toward Korean herbal cosmetics. 4) As a result of MGA, the well-being consciousness had more positive impacts on Korean respondents' attitudes toward Korean herbal cosmetics than the appearance management variable when compared to the Japanese respondents. On the other hand, appearance management had more positive impacts on Japanese respondents' attitudes to-ward Korean herbal cosmetics than well-being consciousness when compared to the Korean respondents. These results suggest that differentiated marketing strategies for Korean herbal cosmetics are crucial when targeting Korean and Japanese consumers.

Study on Risk Reduction Behavior According to Participation Motivation of Mountain Climbing Activity and Level of Risk Perception (등산 활동 참여동기와 위험지각 수준에 따른 위험감소행동 연구)

  • Bang, Gi Seong;Yoo, Shin Jung
    • Fashion & Textile Research Journal
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    • v.15 no.4
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    • pp.523-532
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    • 2013
  • This study investigates risk reduction behavior with risk perception in outdoor wear purchase situations. Data were collected via a questionnaire from 400 consumers between the ages of 20 to 50 residing in Seoul and Kyonggi-do. Data analysis were conducted with SPSS 20 program on the reliability test, factor analysis, cluster analysis, t-test, ANOVA, and Duncan's multiple range test. Factor analyses were employed for the participation motivation of mountain climbing activities, risk reduction behavior and risk perception. Five factors were for the participation motivation of mountain climbing activities (health and fitness, external ostentation, achievement and excitement, improvement of climbing skills, and society). Five factors were for risk perception (fashionability loss and social risk, time and convenience loss, economic risk, performance risk, and psychological risk). Five factors were for the risk reduction behavior (interpersonal information sources use, marketer-dominated information sources use, professional information sources use, pre-purchase deliberation/observation/experience, and brand dependence). Three clusters were identified based on the motivation of outdoor activities (the affiliation/display, the health/internal informativeness and low motivation). The participation motivation for mountain climbing activities were varied. Manufacturers should increase efforts to develop products with good qualities at a reasonable cost as well as establish new marketing strategies since the risk of product performance and economic efficiency in the purchase of outdoor wear was a significant consumer perception.

Experimental studies of validation and stability of Sweet Bee Venom using HPLC (Sweet BV의 조제물 농도분석 및 안정성 확인을 위한 시험적 연구)

  • Kang, Kye-Sung;Kwon, Ki-Rok
    • Journal of Pharmacopuncture
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    • v.12 no.4
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    • pp.33-50
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    • 2009
  • Objectives : This study was conducted to confirm validation and stability of concentration analysis method of pure melittin (Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods : All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Standard solutions of melittin (SIGMA, USA) and test substances were dispensed and were analyzed with HPLC for Sweet BV to secure the validation of analysis. Results : 1. Measurement of system suitability of Sweet BV satisfied criterion of below 3%. 2. Confirming Linearity of Sweet BV in 10-200${\mu}g/m\ell$ solution yielded correlation coefficient (r) of 0.995 and accuracy of 85-115% which satisfy criterion. 3. Measurement of Specificity of Sweet BV didn't yield any substance affecting the peak of test substances, but detected at 21.22min verified as the test substance. 4. Confirming Intra-day of Sweet BV, accuracy and precision of 0.1, 100${\mu}g/m\ell$ were 105.70, 95.81 and 0.66, 0.73, respectively, satisfying both criteria of accuracy (85-115%) and precision (within 10%). 5. To measure Stability in autosampler, all samples used in Intra-day reproducibility sat in the autosampler for five hours and were re-analyzed. Both variability and precision satisfied the criteria. 6. Homogeneity of Sweet BV (0.1, 100${\mu}g/m\ell$) at upper, middle, and lower layers all satisfied the accuracy and precision criteria. 7. Stability of Sweet BV (0.1, 100${\mu}g/m\ell$) at room temperature for four hours and refrigerated for 7 days all satisfied the criterion. 8. For the measurement of Quality control, QC samples measured on the first and eighth day all satisfied accuracy and precision criteria. Conclusion : Above experiment data satisfies validation and stability of concentration analysis method of Sweet BV.

Shear bond strength in bilayer metal-heat pressed glass ceramic structure (열가압 방식의 금속-유리도재 이중 구조물의 전단결합강도에 대한 연구)

  • Lee, Kyungeun;Park, Jin-Young;Kim, Ji-Hwan;Kim, Woong-Chul
    • Journal of Technologic Dentistry
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    • v.39 no.2
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    • pp.101-107
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    • 2017
  • Purpose: The purpose of this study was to compare the shear bond strength of the metal-heat pressed glass ceramic bilayer structure. Methods: Metal framework specimens were prepared and surface is spreaded opaque(IPS InLine system opaque, IvoclarVivadent, Liechtenstein). There were 10 specimens for each bilayer dental ceramic group. The first group was porcelain fused metal, Press on metal IPS Inline press group, and press on metal HASS prototype group. Specimens measured for the shear bond strength on Schwickerath test by Instron universal testing machine(Instron3345, Instron Corp., USA). Mean average bond strength values of each specimen group were analyzed using a one-way ANOVA analysis of variance Saphiro-wilk's test. Statistical analysis were performed using IBM SPSS 23.0(IBM Co., Armonk, USA) Results: $RMS{\pm}SD$ The highest mean average HASS POM showed a bond strength value ($47.55{\pm}12.80Mpa$). The lowest mean average values Porcelain fused metal ($33.30{\pm}2.00Mpa$). Independent t-test was conduct to analysis the significant difference (p<0.05) (Table 3). Conclusion: Three kinds of Metal/ glass bilayer dental ceramics bond strength were clinical acceptability. Especially, as lithium disilicate containing represents higher bond strength.

Accuracy of provisional crowns made using stereolithography apparatus and subtractive technique

  • Kang, Seen-Young;Park, Jung-Hyun;Kim, Ji-Hwan;Kim, Woong-Chul
    • The Journal of Advanced Prosthodontics
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    • v.10 no.5
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    • pp.354-360
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    • 2018
  • PURPOSE. To compare and analyze trueness and precision of provisional crowns made using stereolithography apparatus and subtractive technology. MATERIALS AND METHODS. Digital impressions were made using a master model and an intraoral scanner and the crowns were designed with CAD software; in total, 22 crowns were produced. After superimposing CAD design data and scan data using a 3D program, quantitative and qualitative data were obtained for analysis of trueness and precision. Statistical analysis was performed using normality test combined with Levene test for equal variance analysis and independent sample t-test. Type 1 error was set at 0.05. RESULTS. Trueness for the outer and inner surfaces of the SLA crown (SLAC) were $49.6{\pm}9.3{\mu}m$ and $22.5{\pm}5.1{\mu}m$, respectively, and those of the subtractive crown (SUBC) were $31.8{\pm}7.5{\mu}m$ and $14.6{\pm}1.2{\mu}m$, respectively. Precision values for the outer and inner surfaces of the SLAC were $18.7{\pm}6.2{\mu}m$ and $26.9{\pm}8.5{\mu}m$, and those of the SUBC were $25.4{\pm}3.1{\mu}m$ and $13.8{\pm}0.6{\mu}m$, respectively. Trueness values for the outer and inner surfaces of the SLAC and SUBC showed statistically significant differences (P<.001). Precision for the inner surface showed significance (P<.03), whereas that for the outer surface showed no significance (P<.58). CONCLUSION. The study demonstrates that provisional crowns produced by subtractive technology are superior to crowns fabricated by stereolithography in terms of accuracy.

A Reserch on the Effect Neurofeedback Traing before & After About Emotional and Attention Deficit Characteristics by Timeseries Linear Analysis : for Primary Student (시계열 선형 분석을 통한 뉴로피드백 훈련 전, 후의 주의력 결핍 성향과 정서적 성향에 미치는 영향에 관한 연구)

  • Bak, Ki-Ja;Park, Pyung-Woon;Yi, Seon-Gyu
    • Journal of Information Technology Applications and Management
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    • v.14 no.4
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    • pp.43-59
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    • 2007
  • The purpose of the study was to examine the effectiveness of Neuro Feedback training by observing the pre and post brainwave measurement results of about 50 (experimental group 25. comparative group 25) subjects who have shown psychological difficulties in studying. attention deficit, and personalities. The study took place at Neuro Feedback training Center B. in between the months of July 2006 and May 2007. The methodology involved in the study included the Coloring Analysis Program of the Brain Quotient Test. As the brain waves are adjusted by timeseries linear analysis. the brain function quotients can reflect the functional states of the brain. Through the test, three parameters relaxation, attention and concentration-were initially measured for one minute each and the lowest parameter out of the three was selected as the training mode or improvement target. The training took place two or three times a week. for about 40 to 60 minutes per session. Because the clients have come to the training center at different times. the researcher sampled the results of only those who had attended more than 30 training sessions. The tool used to measure the psychological reaction was POMS (Profile of Mood State). while the tool used to measure the emotional and attention-deficit characteristics was the Amen Clinic ADD Type questionnaire. Hypothesis testing included t-test. The result of the study showed the Theta: SMR ratio of (left)p = .013. (right) p = .019. The result also confirmed the differences of both ATQ(left) p = .011. (right)p = .030 and SQ(left) p = .017. (right) p = .022. The result confirmed of emotional p = .000. attention-deficit characteristics p = .000. The result of the study suggest Neuro Feedback technique's possibility in positively affecting the subjects' mental state and attention-deficit characteristics.

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Comprehensive Analysis for Risk Factors of Lower Extremity Amputation as a Treatment of Complicated Diabetic Foot (당뇨 합병증으로 인한 하지 절단술의 위험 인자의 포괄적 분석)

  • Chung, Hyung-Jin;Bae, Su-Young;Min, Byoung-Kwon;Park, Jae-Gu;Kam, Min-Cheol;Choi, Ji-Won
    • Journal of Korean Foot and Ankle Society
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    • v.16 no.4
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    • pp.257-264
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    • 2012
  • Purpose: The diabetic foot lesions are intractable, and aggravation often leads to amputation. None or minor amputation group was treated debridement or toe amputation and major amputation group was treated Ray, Lisfranc, Chopart, Below Knee and Above Knee amputation. We investigate the risk factors for major limb amputations among patients with diabetic foot lesion. Materials and Methods: The subjects were 73 diabetic foot lesion patients (83 diabetic foot lesions) treated at our department from January 2006 to December 2010. Non or Minor amputation group of 44 cases were treated with debridement or toe amputation. Major amputation group of 39 cases were treated with Ray, Lisfranc, Chopart, below or above Knee amputation. We investigated socioeconomic factors, diabetes mellitus related factors and wound related factors and laboratory factors. Statistical analysis was done by Students t-test, Chi-square test, Mann-Whitney's U test. Results: In our analysis, wound size, wound classification (Wagner classification, Brodsky classification), white blood cell counts, polymorphoneuclear neutrophil percentage, hemoglobin, C-reactive protein and albumin were risk factors for major amputation (p<0.05). Conclusion: Low education level, nutritional condition, premorbid activity level and progressed wound condition were observed in major amputation group compared with non or minor amputation group. In the major amputation group, higher white blood cell count, C-reactive protein level and lower albumin level were observed. Together with maintenance of adequate nutritional condition, early detection of lesions and foot care for early treatment is important. Therefore, active investigation with full risk evaluation of vascular complication is also important.

A Study on $360^{\circ}$ Feedback of Nursing Unit Manager in a Hospital (병원 간호단위관리자의 다면평가($360^{\circ}$ feedback)에 관한 연구)

  • Lee, Jung-Hee;Kwon, Sung-Bok;Chi, Sung-Ai
    • Journal of Korean Academy of Nursing Administration
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    • v.9 no.3
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    • pp.495-505
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    • 2003
  • Purpose: The purpose of this study was to develop 360 feedback for nursing unit manager based on the current personnel evaluation system and to evaluate the new tool according to evaluation subjects. Total of 277 subjects of nurse unit managers and staff nurses were participated in this study. Method: The study was conducted in three phases each for development, application, and analysis of 360 feedback. SAS program was utilized for data analysis with descriptive statistics, t-test, and analysis of variance. Result: The evaluation criteria of the developed 360 feedback tool consisted of 13 subscales such as professional knowledge, apprehension & judgement, job performance, applicability, creativity, leadership, responsibility, promptness & accuracy, administrative ability & sense of mission, activeness, cooperation, communicability, and general attitude. The internal consistency of the tool was Cronbach's alpha .939. The evaluation score by! peers(M=4.30) was the highest one, followed by self-evaluation(M=4.23), evaluation by supervisor(M=4.17), and evaluation by subordinate(M=4.10). The differences in the total evaluation scores among the subjects supervisor, self, peer, and subordinate were not statistically significant, but significant differences were found in some subscales scores. Conclusion: Further research is required to test the reliability and validity of the $360^{\circ}$ feedback tool, and to test the outcome and the process of $360^{\circ}$ feedback system.

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