• Title/Summary/Keyword: T-test analysis

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Analysis of Vehicle Noise Effect by Microphone Position and Road Geometry (도로 기하구조에 따른 차량 Microphone 위치별 소음 영향 분석)

  • Moon, Hak Ryong;Han, Dae Cheol;Kang, Won Pyoung
    • International Journal of Highway Engineering
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    • v.15 no.4
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    • pp.75-83
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    • 2013
  • PURPOSES: The purpose of study is to understand the characteristic of driving noise from the front and rear tire for effective active noise cancellation application. METHODS : As literature review, noise measurement methods were reviewed. Noise measurement conducted at three kind of section by road slope using CPX(Close Proximity Method). Noise data was compared by total sound pressure level and 1/3 octave band frequency sound pressure level. Also, each section was compared by T-test using SPSS. RESULTS : In the case of the uphill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low and high frequency band. In the case of high slope section of Sangsaek-Ri, the sound pressure level of the front tire was higher than that of the rear tire in high frequency. Also, in the case of the downhill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low frequency band. However, the sound pressure levels of both the front and rear tires were approximately the same in the high slope section of Sangsaek-Ri. The result of T-test showed that total sound pressures of the front and rear tires were not different from each other in the case of high slope and high speed. CONCLUSIONS: Road slope was not an important variable for effective active noise cancellation.

Factor Analysis of Type I Osteoporosis and Evaluation on Tuna Bone Powder Compounds through Small Scale Pilot Study (I형 골다공증의 요인분석과 다랑어골분 복합제제의 pilot study를 통한 평가)

  • Chi Gyoo Yang;Kim Young Man
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.1
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    • pp.93-100
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    • 2004
  • This study was carried out for analyzing pathological and epidemiological factors of osteoporosis and doing pilot test using trial compounds of tuna bone and oriental herbs based on the factors. Osteoporosis is originated from osteoblast, osteoclast, organic and inorganic factors etc. Therefore the pathology of osteoporosis is not simple because the cytokine, growth factors and hormones of the components are various a lot. Taking a view of epidemiological factors of type I osteoporosis, ageㆍmenarcheㆍcholesterolㆍBMI etc. have definite relation to them. So we can approach to aging or consumptive disease in oriental medicine, specifically differential diagnosis of blood depletion with deficiency of qi, deficiency of kidney, deficiency of yin, bony weakness etc. And it should be considered together with rules for maintaining good health or habit concomitantly. Therefore IL1ㆍ6 or TNF αㆍβ are generally used as molecular biological index for osteoblast and osteoclast because the most important index is bone mineral density and strength, but the factors like collagen and noncollagen protein must be accounted as biomarkers. Trial compounds generally showed favorable effects on accompanying subjective symptoms of osteoporosis in the pilot test for menopausal woman. But if she didn't have specific symptoms of osteoporosis there wasn't any specific change. And osteocalcin was increased in case of being under standard level, but wasn't changed in case of normal level. Therefore these trial compounds can be used as a funcdonal diet for type I osteoporotic patients or preventive measures.

Comparison of Mitochondria-related Conserved Genes in Eukaryotes and Prokaryotes (진핵생물과 원핵생물의 미토콘드리아 관련 보존적 유전자 비교)

  • Lee, Dong-Geun
    • Journal of Life Science
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    • v.24 no.7
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    • pp.791-797
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    • 2014
  • Sixty-two conserved orthologous groups (OGs) of proteins, in 63 prokaryotes and seven eukaryotes were analyzed to identify essential proteins in the mitochondria of eukaryotes, and their counterparts in prokaryotes. Twenty OGs were common in eukaryotic mitochondria, and all were translation related. Encephalitozoon cuniculi, an obligate parasitic eukaryote, shares no common mitochondrial OGs with the other 69 organisms. Seventeen conserved OGs were mitochondria related in the 69 organisms. Mitochondria related- and nonrelated-OGs were divided into prokaryotic genomes (p<0.001, paired t-test) unlike eukaryotic genomes in the distance value analysis. The most commonly conserved mitochondria-related OG was COG0048-KOG1750 (ribosomal small subunit S12), whereas it was COG0100-KOG0407 (ribosomal small subunit S11) in nonrelated OGs. These results could be applied in scientific research to determine phylogenetic relationships and in areas such as drug development.

The Effect of 12Weeks Sling Exercise on the Change of Muscular Body Type in Patients with Work-related Musculoskeletal Disorders (12주간의 슬링운동이 작업관련성 근골격계 질환자의 근체형 변화에 미치는 영향)

  • Baek, Soon-Gi;Lee, Jong-Bok;Jeong, Hae-Cheon
    • Journal of Digital Convergence
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    • v.12 no.3
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    • pp.317-323
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    • 2014
  • This research has a purpose of providing base data to prevent musculoskeletal disorders, by analyzing the changes in muscle body due to sling exercises, of the industrial laborers with work-related musculoskeletal disorders. The subjects of this research are 20 volunteers who applied for musculoskeletal treatment exercises in hospitals, from region D industry H. 10 of the 20 subjects were involved in sling exercise program for 12 weeks, and the other 10 subjects were ordered to retain their common practices. We have used the statistics software SPSS ver.18.0 to analyze the data, and have offered a descriptive analysis of the measured variables. To discover the sling exercise effects, we have executed a t-test (paired sample t-test) comparing the before-after relationship of 12-week sling exercise program, and the level of significance were set to a=.05. With these set of research methods and procedures, we have concluded the following. As a result, we have concluded that 12-week sling exercise program does exert influence in changing muscle body of work-related musculoskeletal patients.

Manufacturing and Characteristics Analysis of a Testing Device for the Evaluation of a Distribution Board Management System (분전반 관리시스템 평가를 위한 시험 장치의 제작 및 특성 분석)

  • Ko, Wan Su;Lee, Byung Seol;Choi, Chung Seog
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.31-36
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    • 2019
  • This study made a testing device to evaluate the distribution board management system. Power was supplied to the testing device using a loading-back method and the voltage applied to it was 440 V at the same turn ratio. When the human body electric shock current is 30 mA, the breaking time is set to be less than 240 ms while 30~45 mA current is flowing. The test result shows that in the case of the R-phase it was measured to be 5.19 Hz (193 ms). And the S-phase and T-phase were perfectly cut off at 5.39 Hz (186 ms) and 5.71 Hz (175 ms), respectively. When the human body electric shock current is 60mA, the breaking time is set to be less than 120 ms while 45~75 mA current is flowing. The test result shows that the R-phase, S-phase, and T-phase were accurately cut off at 8.39 Hz (11 ms), 8.87Hz (113 ms) and 9.69 Hz (103 ms), respectively. When the human body electric shock current is 90 mA, the breaking time is set to be less than 48 ms while 75 mA current is flowing. The test result shows that the R-phase, S-phase, and T-phase were accurately cut off at 19.8 Hz (50.4 ms), 16.9 Hz (59.2 ms), and 17.9 Hz (56.0 ms), respectively. That is, the developed testing device satisfied all the requirements of the distribution board evaluation criteria, and it becomes available for the performance evaluation of the distribution board management system.

A Study on Asymmetry Effect and Price Volatility Spillover between Wholesale and Retail Markets of Fresh squid (신선 물오징어의 도·소매시장 간 가격 변동성의 전이 및 비대칭성 분석에 관한 연구)

  • Kim, Cheolhyun;Nam, Jongoh
    • The Journal of Fisheries Business Administration
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    • v.49 no.2
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    • pp.21-35
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    • 2018
  • Squid is a popular seafood in Korea. However, since the 2000s, the squid production has been declining. The unstable supply of the squid products may cause price fluctuations of fresh and chilled squid. These price fluctuations may be relatively more severe than them of other commodities, because the fresh and chilled squid can not be stored for a long period of time. Thus, this study analyzes the structural characteristics of price volatility and price asymmetry of fresh squid based on off-diagonal GARCH model. Data used to analysis of this study are daily wholesale and retail prices of fresh squid from January 1, 2006 to December 31, 2016 provided in the KAMIS. As theoretical approaches of this study, first of all, the stability of the time series is confirmed by the unit root test. Secondly, the causality between distribution channels is checked by the Granger causality test. Thirdly, the VAR model and the off-diagonal GARCH model are adopted to estimate asymmetry effect and price volatility spillover between distribution channels. Finally, the stability of the model is confirmed by multivariate Q-statistic and ARCH-LM test. In conclusion, fresh squid is found to have shock and volatility spillover between wholesale and retail prices as well as its own price. Also, volatility asymmetry effect is shown in own wholesale or retail price of fresh squid. Finally, this study shows that the decrease in the fresh squid retail price of t-1 period than the increase in the t-1 period has a greater impact on the volatility of the fresh squid wholesale price in t period.

Effects of a virtual reality simulation integrated with problem-based learning on nursing students' critical thinking ability, problem solving ability, and self-efficacy: a non-randomized trial (문제중심학습 기반 가상현실 시뮬레이션 교육이 간호대학생의 비판적 사고능력, 문제해결능력 및 자기효능감에 미치는 효과: 유사실험 연구)

  • Young A Song;Minkyeong Kim
    • Women's Health Nursing
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    • v.29 no.3
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    • pp.229-238
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    • 2023
  • Purpose: This study analyzed the effects of virtual reality simulation-based problem-based learning on nursing students' critical thinking ability, problem-solving ability, and self-efficacy in the nursing care of women undergoing induction of labor. Methods: A nonequivalent control group pretest and posttest design was employed. The study participants included 52 nursing students (24 in the experimental group and 28 in the control group). The experimental group took a problem-based learning (PBL) class in the first week, and then engaged in self-directed learning using virtual reality simulation. In the second week, lectures about emergency nursing care for induction of labor and drug administration were given. The control group participated in PBL in the first week and lectures in the second week. The study was conducted from April 17 to May 19, 2023. Data were analyzed using the chi-square test, Fisher exact test, analysis of variance, and the independent t-test. Results: Before-and-after differences between the two groups were statistically significant in problem solving ability (t=-5.47, p<.001) and self-efficacy (t=-5.87, p<.001). Critical thinking ability did not show a statistically significant difference between the two groups. The score for satisfaction with the virtual reality simulation program was 3.64±5.88 out of 5 in the experimental group. Conclusion: PBL education using a virtual reality simulation was found to be an effective way of teaching. Although convenience sampling was used, PBL education using virtual reality can be used as an educational strategy to enhance nursing students' problem-solving ability and self-efficacy.

Analysis of the Customers' Expectation and Satisfaction for Service Quality in Restaurants (외식업체 고객의 서비스 품질에 대한 기대도/만족도 분석)

  • Yang, Il-Sun;Kim, Heh-Young;Shin, Seo-Young;Kim, Sung-Hye
    • Journal of the Korean Society of Food Culture
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    • v.15 no.1
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    • pp.41-49
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    • 2000
  • The effort to understand customer is essential and customer satisfaction measurement tool is needed in today's intensively competitive environment of restaurants. The objectives of this study were to measure customers' expectation and satisfaction of service quality attributes and to identify relatively important attributes for overall satisfaction in restaurants. The questionnaires were distributed to 232 customers at 78 family-style, pizza and fast food restaurants. Statistical data analysis was completed using SPSS for t-test, ANOVA, factor analysis, Pearson's correlation and regression analysis. The results of this study were as follows: 1) four and six- dimensional structures were established from 25 expectation and satisfaction attributes, respectively. 2) Demographic variables and usage characteristics didn't affect on service quality expectation, but expectations were significantly different according to the types of restaurant. 3) Expectation/satisfaction matrix showed different patterns in 3 types of restaurant. 4) 'Quality of food' and 'atmosphere' were the most relatively important attributes for overall satisfaction in restaurants.

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A CEPHALOMETRIC AND PANORAMIC ANALYSIS OF THE CHANGES OF THE CONDYLAR POSITION AFTER ORTHOGNATHIC SURGERY (하악전돌증 환자의 악교정 수술후 하악과두의 위치변화에 대한 연구)

  • Kang, Young-Ki;Kim, Jong-Ryoul;Yang, Dong-Kyu
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.22 no.4
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    • pp.411-419
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    • 2000
  • Purpose: This study was aimed at analysis of the changes in the condyle position in subjects with mandibular setback osteotomies Method: Twenty patients were evaluated retrospectively for their changes in the condyle position who underwent surgical mandibular setback using bilateral sagittal split osteotomies with a manual condyle repositioning technique and rigid fixation. The cephalometric and panoramic analysis was performed preoperatively, 1 week, 6 months, and 1 year postoperatively. And postoperative noise, temporomandibular joint pain, and mouth opening were clinically examined 2 months, 4 months, 6 months, 8 months, 10 months, and 12 months postoperatively. Result: The condyles rotated posteriorly and laterally immediately after surgery, and they returned to the preoperative position during follow-up period but it is not significant. The statistical analysis (Paired t-test) showed no significant effects in postsurgical stability. The changes in the condyle position didn't have a significant harmful influence on temporomandibular joint disorder. Conclusion: A careful surgical mandibular setback using manual condyle repositioning and fixation technique will move condyle minimally and that will decrease the relapse and temporomandibular joint disorder.

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Factors Affecting Food Carving among Hemodialysis Patients (혈액투석 환자의 음식갈망 영향요인)

  • Kim, Ju Yeun;Joo, Hyun Sil
    • Journal of Korean Clinical Nursing Research
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    • v.23 no.3
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    • pp.398-406
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    • 2017
  • Purpose: The purpose of this study was to evaluate food carving among hemodialysis patients and to identify factors affecting the food carving. Methods: A descriptive correlational study was conducted. Data were collected from 129 patients receiving hemodialysis between March 15 and April 15, 2017. Measurement instruments included the general food craving questionnaire trait, the center for epidemiological studies-depression scale, and stress response inventory-modified form. The statistical analysis included t-test, analysis of variance, pearson correlation analysis, and stepwise multiple regression analysis. Results: Mean food craving score was $53.00{\pm}12.36$. Food craving was higher in patients younger than 40 years (F=4.36 p=.006) and having occupation (t=2.18 p=.031). Patients receiving hemodialysis demonstrated higher levels of depression ($21.37{\pm}9.62$) and stress ($39.68{\pm}15.95$). Factors influencing food craving were depression (${\beta}=.52$, p<.001), stress (${\beta}=.65$, p<.001), and age 50~59 years old (${\beta}=-.28$, p=.001) and 60~69 years old (${\beta}=-.19$, p=.026), which accounted for 25.6% of total variance. Conclusion: Food craving among hemodialysis patients was influenced by patients' depression, stress and age. Assessment and management of depression and stress needs to be incorporated as a nursing strategy for dietary management for hemodialysis patients.