• Title/Summary/Keyword: Statistical Testing

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The Immediately Effect of Narrow Squats on the Knee Joint Biomechanics During a Gait and Distance Between the Knees of Person With Genu-varum (내로우 스쿼트 운동이 내반슬 성인의 무릎 사이 거리와 보행 시 무릎 관절의 생체역학에 미치는 즉각적인 영향)

  • Han, Seok-kyu;Kim, Tack-hoon;Rho, Jung-suk;Choi, Houng-sik;Lee, Jun-young
    • Physical Therapy Korea
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    • v.25 no.3
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    • pp.19-26
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    • 2018
  • Background: Genu varum is also known as bow leg. It is a deformity wherein there is lateral bowing of the legs at the knee. it does give rise to pain, and persistent bowing can often give rise to discomfort in knees, hips and ankles. Objects: This study investigated the effect of narrow squats on the knee joint during a gait and distance between the knees of person with genu varum. Methods: This study analyzed 23 patient with genu varum that grade III, 12 narrow squat group and 11 genenal squat group in motion analysis laboratory. The subjects of experiment took gait before and after intervention, the range of joint motion, moment of knee joint adduction, power, distance of the knees were measured. And in order to make an analysis between groups, an paiered t-test and independent t-test was carried out. For statistical significance testing, it was decided that significance level ${\alpha}$ be .05. Results: It was shown that the group of narrow squat exercise significantly decreased in distance of knees (p<.05),In moment of adduction of knee joint, it was shown to significantly decrease in two groups (p<.05), was significantly decreased in adduction, abduction, and rotation (p<.05). In relation of peak-knee adduction moment and valgus angle, there was significant decrease in narrow squat group (p<.05). Conclusion: When the above result of study were examined, a narrow squat exercise given to the genu varum patients significantly decreased the distance between the knees, range of knee adduction and abduction, knee adduction moment, knee power. And stability gains through the decrease of excursion of knee medial part be effective for the correction of genu varum deformation.

INFLUENCE OF THICKNESS OF EMPRESS 2 CERAMIC ON FRACTURE STRENGTH (Empress 2 도재의 두께에 따른 파절강도에 관한 연구)

  • Koh, Jung-Woo;Yang, Jae-Ho;Lee, Sun-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.4
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    • pp.446-460
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    • 2000
  • All-ceramic restorations have had a more limited life expectancy than metal ceramic crowns be-cause of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300 MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thick-ness (a total of 75 specimens) were prepared. Control group : Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I : IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I (Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.4mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm. 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).

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EFFECT OF SURFACE TREATMENT METHODS ON THE SHEAR BOND STRENGTH OF RESIN CEMENT TO ZIRCONIA CERAMIC

  • Lee, Ho-Jeong;Ryu, Jae-Jun;Shin, Sang-Wan;Sub, Kyu-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.6
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    • pp.743-752
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    • 2007
  • Statement of problem. The aims of the study were to evaluate the effect of current surface conditioning methods on the bond strength of a resin composite luting cement bonded to ceramic surfaces and to identify the optimum cement type. Material and methods. The sixty zirconia ceramic specimens(10 per group) with EVEREST milling machine and 60 tooth block were made. The zirconia ceramic surface was divided into two groups according to surface treatment: (1) airborne abrasion with $110{\mu}m$ aluminum oxide particles; (2) Rocatec system, tribochemical silica coating. The zirconia ceramic specimens were cemented to tooth block using resin cements. The tested resin cements were Rely X ARC, Panavia F and Superbond C&B. Each specimen was mount in a jig of the universal testing machine for shear strength. The results were subjected to 2-way ANOVA and Post hoc tests was performed using Tukey, Scheffe, and Bonferroni test. Results. The mean value of shear bond strength(MPa) were as follows: $$RelyXARC(+Al_2O_3),5.35{\pm}1.69$$; $$RelyXARC(+Rocatec),8.50{\pm}2.13$$; $$PanaviaF(+Al_2O_3),9.58{\pm}1.13$$; $$PanaviaF(+Rocatec),12.98{\pm}1.71$$; $$SuperbondC&B(+Al_2O_3)8.27{\pm}2.04$$; $$SuperbondC&B(+Rocatec),14.46{\pm}2.39$$. There was a significant increase in the shear bond strength when the ceramic surface was subjected to the tribochemical treatment(Rocatec 3M) in all cement groups(P<0.05). Bonding strengths of cements applied to samples treated with $Al_2O_3$ were compared; Rely X ARC showed the lowest values, whereas Panavia F cement showed higher value than that of Superbond C&B group with no statistical significance. When the bond strength of cements with of Rocatec treatment was compared, Rely X ARC showed lowest values. Overall, it was apparent that tribochemical treated Super-Bond possessed higher mean bond strength (14.46MPa; P<0.05) than that of Panavia F cement group with no significance. Conclusions. Silica coating followed silanization(Rocatec treatment) increase the bond strength between resin cement and zirconia ceramic. Panavia F containing phosphate monomer and Superbond C&B comprised of 4-META tend to bond chemically with zirconia ceramic, thus demonstrating higher bond strength compared to BisGMA resin cement. Superbond C&B has shown to have highest value of bonding strength to zirconia ceramic after Rocatec treatment compared to other cement.

A COMPARATIVE STUDY OF THE 1-PIECE AND 2-PIECE CONICAL ABUTMENT JOINT: THE STRENGTH AND THE FATIGUE RESISTANCE

  • Kwon, Taek-Ka;Yang, Jae-Ho;Kim, Sung-Hun;Han, Jung-Suk;Lee, Jai-Bong
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.6
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    • pp.780-786
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    • 2007
  • Statement of problem. The performance and maintenance of implant-supported prostheses are primarily dependent upon load transmission both at the bone-to-implant interface and within the implant-abutment-prosthesis complex. The design of the interface between components has been shown to have a profound influence on the stability of screw joints. Purpose. The Purpose of this study was to compare the strength and the fatigue resistance of 1-piece and 2-piece abutment connected to oral implant, utilizing an internal conical interface. Material and methods. Twenty $Implatium^{(R)}$ tapered implants were embedded to the top of the fixture in acrylic resin blocks. Ten $Combi^{(R)}$(1-piece) and $Dual^{(R)}$(2-piece) abutments of the same dimension were assembled to the implant, respectively. The assembled units were mounted in a testing machine. A load was applied perpendicular to the long axis of the assemblies and the loading points was at the distance of 7mm from the block surface. Half of 1-piece and 2-piece abutment-implant units were tested for the evaluation of the bending strength, and the others were cyclically loaded for the evaluation of the fatigue resistance until plastic deformation occurred. Nonparametric statistical analysis was performed for the results. Results. Mean plastic and maximum bending moment were $1,900{\pm}18Nmm,\;3,609{\pm}106Nmm$ for the 1-piece abutment, and $1,250{\pm}31Nmm,\;2,688{\pm}166Nmm$ for the 2-piece abutment, respectively. Mean cycles and standard deviation when implant-abutment joint showed a first plastic deformation were $238,610{\pm}44,891$. cycles for the 1-piece abutment and $9,476{\pm}3,541$ cycles for the 2-piece abutment. A 1-piece abutment showed significantly higher value than a 2-piece abutment in the first plastic bending moment (p<.05), maximum bending moment (p<.05) and fatigue strength (p<.05). Conclusion. Both 1-piece and 2-piece conical abutment had high strength and fatigue resistance and this suggests long-term durability without mechanical complication. However, the 1-piece conical abutment was more stable than the 2-piece conical abutment in the strength and the fatigue resistance.

An Exploratory Study on the Moderated Role of Cognitive Style in Entrepreneurial Process (기업가적 과정에서 인지양식의 조절적 역할에 대한 탐색적 연구)

  • Kim, Dae Eop;Sun, Chang Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.4
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    • pp.121-131
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    • 2017
  • The most important points in the field of entrepreneurship research are new venture creation and behaviors for start-up venture. Most of past researches are limited to the formation of entrepreneurial intention, and researches on entrepreneurial activities, specifically nascent entrepreneurial behavior, have not been studied well. In this study, we view entrepreneurial process as gestation process from entrepreneurial intention to nascent entrepreneurial activities, and identify the moderating effects of cognitive style, which is the way of thinking about the information in entrepreneurial process. In addition, we find the moderating effects of cognitive style on the relationships between perceived barriers and support in environmental factors and nascent entrepreneurial activities. Subjects of this study are potential entrepreneurs. So we selected university students who are taking venture start-up course, conducted a survey, collected 367 questionnaires. In statistical test, we applied PLS-SEM for testing hypotheses because CB-SEM is too sensitive to test more than two moderating effects in th research model. As a result of the analysis, it was found that entrepreneurial intention, cognitive planning style, cognitive creative style, perceived support had a significant effect on nascent entrepreneurial behavior. The results of the analysis of the moderating effects of cognitive style which are the hypotheses in the research are as follows. First, the cognitive planning style did not have a significant moderating effect on the relationship between entrepreneurial intention and nascent entrepreneurial activities. Second, in the relationship between perceived barriers and nascent entrepreneurial activity, cognitive planning style did not have significant moderating effect, and cognitive creating style had significant negative moderating effect. Third, in the relationship between perceive support and nascent entrepreneurial activity, cognitive planning style had significant positive moderating effect, and cognitive creating style did not have significant moderating effect.

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A study of the measurement systems implementation for the interior impulse noise (실내 충격소음 측정시스템 구현에 관한 연구)

  • Song, Kee-Hyeok;Chung, Sung-Hak
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.6
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    • pp.93-100
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    • 2014
  • The objective of this study is to propose the measurement system implementation method for the evaluation and measurement of the indoor-impulsive over 170 dB noise source. For the purpose of measuring impulse noise, design and implementation constructed followed subsystems of the testing center, microphone, ear simulator, head and torso simulator and so on. Measurement systems for the accuracy and reliability of impulse noise are implemented when measuring 3 ways of measurements method by the simultaneous measurement system design. For the accuracy and reliability of three mutually indoor-impulse noise measurements were compared, three kinds of measuring methods in accordance with the peak sound pressure level and octave band. Comparing the results of data, the indoor-impulse noise by analyzing a frequency characteristic was validated in difference for the statistical significance. Result are determined by the influence of the reflected wave. Therefore, the flexible size of the interior test site while interior impulse noise measurement system was constructed. Throughout this system can be affected by parameters that are the impulse noise source and the corresponding frequency-characteristic analysis to determine the spectrum of the reflected wave. And, in the near future, indoor impulse noise measurement systems for acquisition and analysis are utilized in useful data.

기도와 찬송이 통증과 불안, 외로움, 안녕감에 미치는 영향

  • Kim Su-Ho;Kim Sin-Su;Kim Jae-Song;Park Hui-Myeong;O Seung-Hun;Won Ju-Hui;Lee Seong-Ok;Lee Chae-Yeong
    • Korean Journal of Hospice Care
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    • v.5 no.1
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    • pp.74-81
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    • 2005
  • Purpose: The purpose of this study is to help apply spiritual care in clinics by testing whether spiritual support like prayer and praise, which is appled on a patient who has been cared for by Facility Hospice can have an effect on their physical pain, emotional anxietv, loneliness and well being. Method: This research was done on a subject patient who had been hospitalized in Saemmul from Jan, 2002 to June, 2003, and who could easily communicate. Questionnaire of quality of life, they had this test from the date of admission into the hospital 1week, 3week, 5week later. The Target was 182 people for the hospital data, 124 people after one week, 84 people after 3 weeks and 54 people after for 5 weeks later. For statistics, SPSS for Window(SPSS inc. ver.10), student T-test and one way ANOVA were used. The interrelation between pray and pain was analyzed by the "Pearson correlation". In case where the P-value was below 0.05, we concluded it had statistical-value. Results: When we compared both the party which had a low degree of peace by prayer and praise and the B party which had the highest degree, B party had an increasing tendency for less anxiety and loneliness and more well-being. Each of the data 0, 1, 3 and 5 week showed visible difference between both parties. Conclusion: First, in case that a late cancer patient is hospitalized, the difference for tranquility and pain control by prayer and praise is not noticeable. While, 1 and 3 weeks later, the difference is visible, so we concluded the relationship between the cancer patient's spiritual tranquility and physical pain are closely related with each other. Also the patients who are in spiritual peace by prayer and praise can control the pain better than the other patients. Second, because the patient who can feel calm from the data of being admitted into the hospital is mentally calm, both party's difference is noticeable in each period of the 1, 3 and 5th week. Compared with other patients, the object patients who have spiritual tranquility will have less anxiety and loneliness and more tranquility.

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A Study on the Analysis of Cause and Effect Relationship between Korea Image Attributes and Korea Image Making in Uzbekistan (우즈베키스탄에서의 한국 이미지 속성과 한국 이미지 메이킹의 인과관계 분석)

  • Ryu, Ki-Hwan;Park, Myung-Chan
    • International Commerce and Information Review
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    • v.15 no.1
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    • pp.161-183
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    • 2013
  • The essential purpose of this study is to exemplify empirically some relations of between Korea image attributes and Korea image making in Uzbekistan. This study is for providing basically empirical analysis for intensifying Korea's economic capacity based on Korean image in Uzbekistan and for offering any kinds of implications for the entry and management activities of Korean enterprises in world-wide business. This study is organized in two stages. First, the study model is designed by reappraising relevant theories, previous studies and the current investment qualifications concerning the country image attributes and image making. Second, the survey of Uzbekistan people who are living in South Korea is accomplished by collecting questionnaires. SPSS 15.0 for windows is being activated for correlation, reliability, validity and finally the statistical method of structural equation modeling is utilized to testing the hypothesis by AMOS 7.0 for windows. In conclusion partially, Korea image attributes: economic capability, popular culture, national traits and enterprise competence are proved to influence positively to Korea image making: recognition, attractiveness and confidence which is considered generally by Uzbekistan people.

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Change of fracture mode of orthodontic resin bracket wings under water immersion and thermocycling (침수 및 열순환에 따른 레진브라켓 wing의 파절강도 변화)

  • Son, Ji-Hyeong;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.30 no.4 s.81
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    • pp.475-481
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    • 2000
  • The purpose of this study was to evaluate the effect of oral environment on the strength of resin bracket wings by comparing fracture mode according to water immersion and thermocycling. Seventy-five resin brackets(Spirit MB, Ormco, California) were divided into three groups and treated for six months as follows; (1) untreated, (2) water immersion in distilled water at $37^{\circ}C$, (3) water immersion in distilled water at $37^{\circ}C$ with total 2,100 times of thermocycling taken 350 times each month. Fracture mode of the wing was tested on universal testing machine. In addition to resin brackets, 25 metal brackets were used as controls. Through the statistical analyses, following results were obtained. 1. Resin bracket wings showed significantly lower fracture strength than metal brackets(p<0.001). 2. Water immersion and water immersion with thermocycling groups showed significantly lower fracture strength than open air condition group(p<0.001). 3. Water immersion with thermocycling group showed significantly lower fracture strength than water immersion group(p<0.001). The above results suggest that the mechanical property of resin bracket wing nay be influenced by oral environment and further research is needed to improve the strength of the wing in the resin bracket.

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A SHEAR BOND STRENGTH OF RESIN CEMENT BONDED TO HUMAN UNCUT ENAMEL, CUT ENAMEL, AND DENTIN IN VITRO

  • Lee Jong-Yeop
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.319-324
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    • 2003
  • Statement of problem. Adhesives in dentistry playa major role in the success of restorative treatments. In the treatment of all ceramic restoration it is needed to find the adequate bond strength between enamel and dentin. Purpose. The purpose of this study was to evaluate shear bond strength of resin cement bonded to extracted human uncut enamel, cut enamel, and dentin in vitro. Material and methods. Ten freshly extracted anterior teeth without any previous restorative treatments were chosen. The extracted teeth were embedded in PMMA cold acrylic in the shape of a cylinder, 25 mm in diameter by 25 mm in height. The bonding system used was as follow: Uni-Etch (32% phosphoric acid), One-Step adhesive, Duolink resin cement. The specimens were acid etched and rinsed with water. Two layers of One-Step adhesive were coated with a disposable brush on the uncut enamel. VIP curing light at $500mV/cm^2$ was used to cure the adhesive. For cut enamel shear bond test, the specimen used for uncut enamel was further reduced approximately $0.3{\sim}0.5mm$ using a laminate preparation diamond bur (0.3 mm in depth). The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit SiC paper and cleaned with distilled water. The bonding procedure on the cut enamel was same as uncut enamel bonding procedure. For dentin bonding test, the specimen used for cut enamel was further reduced approximately $0.5mm{\sim}1.0mm$ using a laminate preparation diamond bur (0.5 mm in depth of diamond cutting). The amount of reduction was evaluated with the silicone mold. The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit silicon carbon paper and cleaned in distilled water. The bonding procedure on the dentin was same as uncut enamel bonding procedure. All samples were mounted and secured on the Ultradent shear bond test sample holder, and Ultradent restricted shear bond testing device was used with Universal Instron machine until fracture. Analysis of variance (ANOVA) test was performed comparing the result at P<0.05. Multiple comparison (Tukey) was used to compare each groups. Result. The result showed that the mean value in shear bond strength of resin cement bonded to uncut enamel, cut enamel and dentin were 27.04 Mpa, 30.25 Mpa and 26.39 Mpa with respect. Conclusion. Within the limitation of this study, the mean value of the shear bond strength of cut enamel was higher than those of uncut enamel or dentin. However there existed no statistical differences between three different human dentition substrates due to increased adhesive characteristics.