• Title/Summary/Keyword: z-test

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Effect of repeated use of an implant handpiece on an output torque: An in-vitro study

  • Son, KeunBaDa;Son, Young-Tak;Kim, Ji-Young;Lee, Jae-Mok;Yu, Won-Jae;Kim, Jin-Wook;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • v.13 no.3
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    • pp.136-143
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    • 2021
  • Purpose. This study aimed to evaluate the effect of repeated use of an implant handpiece under an implant placement torque (35 Ncm) and overloading torque condition (50 Ncm) on an output torque. Materials and Methods. Two types of implant handpiece systems (Surgicpro/X-DSG20L [NSK, Kanuma, Japan] and SIP20/CRB46LN [SAESHIN, Daegu, South Korea]) were used. The output torque was measured using a digital torque gauge. The height and angle (x, y, and z axes) of the digital torque gauge and implant handpiece were adjusted through a jig for passive connection. The experiment was conducted under the setting torque value of 35 Ncm (implant placement torque) and 50 Ncm (overloading torque condition) and 30 times per set; a total of 5 sets were performed (N = 150). For statistical analysis, the difference between the groups was analyzed using the Mann-Whitney U test and the Friedman test was used to confirm the change in output torque (α=.05). Results. NSK and SAESHIN implant handpieces showed significant differences in output torque results at the setting torques of 35 Ncm and 50 Ncm (P<.001). The type of implant handpiece and repeated use influenced the output torque (P<.001). Conclusion. There may be a difference between the setting torque and actual output torque due to repeated use, and the implant handpiece should be managed and repaired during long-term use. In addition, for successful implant results in dental clinics, the output torque of the implant handpiece system should be checked before implant placement.

Mediating Effect of Grit in the Relationship between Body Image and Health Promotion Lifestyle of Nursing Students (간호대학생의 신체이미지와 건강증진생활양식: 그릿의 매개효과)

  • Kim, Eun-A;Ha, Hey-Jin
    • The Journal of Korean Society for School & Community Health Education
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    • v.22 no.3
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    • pp.29-39
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    • 2021
  • Purpose: This study aims to investigate the mediating effect of grit in the relationship between body image and health promotion lifestyle for nursing students. It was implemented to present basic data for the development of educational programs to establish the health promotion lifestyle of nursing students. Methods: The participants of this study were 169 nursing students in three universities in G City, J Province. Data were descriptive statistics, t-test, ANOVA, Pearson correlation analysis. Also mediation analysis was performed according to the Baron and Kenny method and Sobel test. Results: Health promotion lifestyle is positively correlated with body image(r=.53, p<.001), grit (r=.37, p<.001), and body image is positively correlated with grit(r=.33, p<.001). The grit showed a partial mediating effect between the body image and the health promotion lifestyle(Z=3.21, p<.001), the positive the body image(β=.46, p<.001), the higher the grit(β=.22, p<.001), the healthier the health. The level of health promotion lifestyle increased, and the explanatory power to explain the health promotion lifestyle was 33%. Conclusion: Therefore, in order to improve the health promoting lifestyle level of nursing students, it is important to change their perception so that they can view their body image positively. In addition, it suggests that nursing students need to cultivate grit so that they can continuously pay attention to and strive for their health promotion lifestyle.

Investigation of the Influence of Induced Mood on Rehabilitation Engagement: a Study Focusing on Muscle Activity

  • Kim, Jung-Yeon;Jung, Bong-Keun
    • Journal of Biomedical Engineering Research
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    • v.43 no.3
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    • pp.161-169
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    • 2022
  • Engagement is an important factor in the field of rehabilitation as it is a known factor that have a positive influence on functional gaining in people who receive rehabilitation therapy. Although a number of measurements for engagement have been recently developed, investigation of possible factors that may have influence on engagement is not well established. Currently available evidence suggests that engagement is affected by mood and it is hypothesized that a personal factor may contribute to engagement. Therefore, this study aims to test the hypothetical relationship between mood and engagement while performing a manual dexterity task through an experiment in healthy participants prior to investigation on people with medical condition who requires rehabilitation therapy. After inducing target mood (positive or negative mood) for study participants by asking them to recall autobiographical memories, change in muscle activity, which was operationalized as an indicator of engagement, was investigated. Electromyogram (EMG) was recorded from four muscle areas in non-dominant hand side to quantify muscle activity. The results show that the target moods were appropriately induced with the method. Although there were subtle differences in the level of engagement between different moods, certain variables derived from muscle activity were significantly different; mean amplitude for wrist extensor EMG showed significant difference between different moods (Z = -2.023, p < .05) indicating that muscle activities in the wrist extensor are greater for positive mood than negative mood region during manual dexterity task. Meanwhile, performance outcomes of Minnesota Manual Dexterity Test (MMDT), such as mean completion time and number of errors, between moods showed no significant difference in two different moods, resulting in MMDT administration may not be useful task in distinguishing the level of rehabilitation engagement.

A novel radioactive particle tracking algorithm based on deep rectifier neural network

  • Dam, Roos Sophia de Freitas;dos Santos, Marcelo Carvalho;do Desterro, Filipe Santana Moreira;Salgado, William Luna;Schirru, Roberto;Salgado, Cesar Marques
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2334-2340
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    • 2021
  • Radioactive particle tracking (RPT) is a minimally invasive nuclear technique that tracks a radioactive particle inside a volume of interest by means of a mathematical location algorithm. During the past decades, many algorithms have been developed including ones based on artificial intelligence techniques. In this study, RPT technique is applied in a simulated test section that employs a simplified mixer filled with concrete, six scintillator detectors and a137Cs radioactive particle emitting gamma rays of 662 keV. The test section was developed using MCNPX code, which is a mathematical code based on Monte Carlo simulation, and 3516 different radioactive particle positions (x,y,z) were simulated. Novelty of this paper is the use of a location algorithm based on a deep learning model, more specifically a 6-layers deep rectifier neural network (DRNN), in which hyperparameters were defined using a Bayesian optimization method. DRNN is a type of deep feedforward neural network that substitutes the usual sigmoid based activation functions, traditionally used in vanilla Multilayer Perceptron Networks, for rectified activation functions. Results show the great accuracy of the DRNN in a RPT tracking system. Root mean squared error for x, y and coordinates of the radioactive particle is, respectively, 0.03064, 0.02523 and 0.07653.

Clinical Factors and Effects of Individual Art Therapy on Industrial Injured Workers (산재근로자에 대한 임상요인과 개인 미술치료의 효과)

  • Yang, Jung-Hye;An, Jung-Ah
    • Journal of the Korea Convergence Society
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    • v.12 no.4
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    • pp.293-302
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    • 2021
  • This study is designed to find out clinical factors and the effects of individual art therapy for workers involved in industrial accident. From January 2017 to July 2019, 10 industrially injured workers were individually subjected to 11 art therapy sessions, and a multidimensional psychological test S type was used to examine changes in clinical factors before and after individual art therapy. The results showed that the average of the five clinical factors ranges from 2.80 to 4.20, indicating that the psychological pain of workers injured was significant. As a result of bivariate correlation analysis, it was confirmed that meaningful correlation existed within the statistical scope of all factors. As for the difference in the results of multidimensional psychological tests before and after art therapy, out of the five clinical factors, the Z values of depressed, anger and anxiety were -2.405(p=.016), -2.148 (p=.032) and -2.102 (p=.036), to confirm that the depressed, anger and anxiety of the participants have eased somewhat after performing individual art therapy.

The mediating effect of task value between grit and academic stress on nursing students (간호대학생의 그릿과 학업스트레스와의 관계에서 과제가치의 매개효과)

  • Kang, Moon-Hee
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.471-479
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    • 2022
  • The purpose of this study is to investigate the mediating effect of task value on the relationship between grit and academic stress in nursing students. Data collection was conducted through a mobile Google questionnaire from August 31, to September 9, 2021, and the subjects were a total of 192 nursing students from three universities. The data were analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis with SPSS/WIN 20.0 program. The grit had statistically significant negative correlation with academic stress and positive correlation with task value, and task value and academic stress had positive correlation. Task value had a partial mediating effect on the between grit and academic stress. Thus intervention program that considers the task value along with the grit should be developed in order to alleviate the academic stress of nursing students.

Palatal vault configuration and its influence on intraoral scan time and accuracy in completely edentulous arches: a prospective clinical study

  • Dina Mohamed Ahmed Elawady;Wafaa Ibrahim Ibrahim;Radwa Gamal Ghanem;Reham Bassuni Osman
    • The Journal of Advanced Prosthodontics
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    • v.16 no.4
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    • pp.201-211
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    • 2024
  • PURPOSE. The aim of this prospective clinical study was to compare the influence of palatal vault forms on accuracy and speed of intraoral (IO) scans in completely edentulous cases. MATERIALS AND METHODS. Based on the palatal vault form, participants were divided into three equal groups (n = 10 each); Class I: moderate; Class II: deep; Class III: flat palatal vault. A reference model was created for each patient using polyvinylsiloxane impression material. The poured models were digitized using an extraoral scanner. The resultant data were imported as a solid CAD file into 3D analysis software (GOM Inspect 2018; Gom GmbH, Braunschweig, Germany) and aligned using the software's coordinate system to determine its X, Y, and Z axes. Five digital impressions (DIs) of maxilla were captured for each patient using an intraoral scanner (TRIOS; 3Shape A/S, Copenhagen, Denmark) and the resultant Standard Tessellation Language (STL) scan files served as test models. Trueness was evaluated by calculating arithmetic mean deviation (AMD) of the vault area between reference and test files while precision was evaluated by calculating AMD between captured scans to measure repeatability of scan acquisition. The scan time taken for each participant was also recorded. RESULTS. There was no significant difference in trueness and precision among the groups (P = .806 and .950, respectively). Average scan time for Class I and III palatal vaults was 1 min 13 seconds and 1 min 37 seconds, respectively, while class II deep palatal vaults showed the highest scan time of 5 mins. CONCLUSION. Palatal vault form in edentulous cases has an influence on scan time. However, it does not have a substantial impact on the accuracy of the acquired scans.

Structural and Resting-State Brain Alterations in Trauma-Exposed Firefighters: Preliminary Results (외상에 노출된 소방관들의 뇌 구조 및 휴식기 뇌기능 변화: 예비 결과)

  • Yae Won Park;Suhnyoung Jun;Juwhan Noh;Seok Jong Chung;Sanghoon Han;Phil Hyu Lee;Changsoo Kim;Seung-Koo Lee
    • Journal of the Korean Society of Radiology
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    • v.81 no.3
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    • pp.676-687
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    • 2020
  • Purpose To analyze the altered brain regions and intrinsic brain activity patterns in trauma-exposed firefighters without posttraumatic stress disorder (PTSD). Materials and Methods Resting-state functional MRI (rsfMRI) was performed for all subjects. Thirty-one firefighters over 40 years of age without PTSD (31 men; mean age, 49.8 ± 4.7 years) were included. Twenty-six non-traumatized healthy controls (HCs) (26 men; mean age, 65.3 ± 7.84 years) were also included. Voxel-based morphometry was performed to investigate focal differences in the brain anatomy. Seed-based functional connectivity analysis was performed to investigate differences in spontaneous brain characteristics. Results The mean z-scores of the Seoul Verbal Learning Test for immediate and delayed recall, Controlled Oral Word Association Test (COWAT) score for animals, and COWAT phonemic fluency were significantly lower in the firefighter group than in the HCs, indicating decreased neurocognitive function. Compared to HCs, firefighters showed reduced gray matter volume in the left superior parietal gyrus and left inferior temporal gyrus. Further, in contrast to HCs, firefighters showed alterations in rsfMRI values in multiple regions, including the fusiform gyrus and cerebellum. Conclusion Structural and resting-state functional abnormalities in the brain may be useful imaging biomarkers for identifying alterations in trauma-exposed firefighters without PTSD.

Variation in Growth Characteristics of Pinus densiflora S. et Z. at Eight Experimental Plantations of Korea (8개(個) 시험지(試驗紙)에서 소나무 산지별(山地別) 생장특성(生長特性) 변이(變異))

  • Kim, Kyu Sick;Han, Young Chang
    • Journal of Korean Society of Forest Science
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    • v.86 no.2
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    • pp.119-127
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    • 1997
  • Japanese red pines growing along the Taebaek mountains have been called "Kangsong" and considered to be superior in growth and wood quality. An attempt was made to determine whether their boundaries for planting may be expanded by testing their early growth at eight experimental plantations of the Republic of Korea. Seeds were collected from the six different natural populations including Uljin in Kyongbuk province. For the provenance test, they were planted in eight different regions including Taean in the spring of 1987. Experimental planting was a randomized complete block design with 3 replications. Height growth was measured at the ages of 2, 4, and 6 after planting, and the diameter at root collar at the age of 6 after planting. Significant variation in height growth was observed among the plantations. The height growth measured at the age of 6 after planting showed a positive correlation with the latitude of the test plantation, and the contents of phosphate, potassium and calcium in the soil. A negative correlation, however, was observed between the longitude of the test plantation and height growth. Ponghwa provenance appeared to be the best among the provenances in that the trees from the area grew 16% better in volume growth than the average of all the trees tested in the study, while the worst one was Kyongju from which trees grew 11% less than the average.

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Geographical Variation in Bud-burst Timing of Zelkova serrata Provenances (느티나무 산지별 개엽시기의 지리적 변이)

  • Kim, In Sik;Han, Sang Urk;Lee, Wi Young;Na, Sung Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.15 no.3
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    • pp.191-200
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    • 2013
  • This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.