• Title/Summary/Keyword: T-test analysis

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Effect of aerodynamic modifications on the surface pressure patterns of buildings using proper orthogonal decomposition

  • Tse, K.T.;Chen, Zeng-Shun;Lee, Dong-Eun;Kim, Bubryur
    • Wind and Structures
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    • v.32 no.3
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    • pp.227-238
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    • 2021
  • This study analyzed the pressure patterns and local pressure of tall buildings with corner modifications (recessed and chamfered corner) using wind tunnel tests and proper orthogonal decomposition (POD). POD can distinguish pressure patterns by POD mode and more dominant pressure patterns can be found according to the order of POD modes. Results show that both recessed and chamfered corners effectively reduced wind-induced responses. Additionally, unique effects were observed depending on the ratio of corner modification. Tall building models with recessed corners showed fluctuations in the approaching wind flow in the first POD mode and vortex shedding effects in the second POD mode. With large corner modification, energy distribution became small in the first POD mode, which shows that the effect of the first POD mode reduced. Among building models with chamfered corners, vortex shedding effects appeared in the first POD mode, except for the model with the highest ratio of corner modifications. The POD confirmed that both recessed and chamfered corners play a role in reducing vortex shedding effects, and the normalized power spectral density peak value of modes showing vortex shedding was smaller than that of the building model with a square section. Vortex shedding effects were observed on the front corner surfaces resulting from corner modification, as with the side surface. For buildings with recessed corners, the local pressure on corner surfaces was larger than that of side surfaces. Moreover, the average wind pressure was effectively reduced to 88.42% and 92.40% in RE1 on the windward surface and CH1 on the side surface, respectively.

Influence of marginal bone resorption on two mini implant-retained mandibular overdenture: An in vitro study

  • Guo, Ying;Kono, Kentaro;Suzuki, Yasunori;Ohkubo, Chikahiro;Zeng, Jian-Yu;Zhang, Jing
    • The Journal of Advanced Prosthodontics
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    • v.13 no.1
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    • pp.55-64
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    • 2021
  • PURPOSE. To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model. MATERIALS AND METHODS. The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05). RESULTS. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P<.05), while there was no statistical difference between the normal and resorption group (P>.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P<.05). CONCLUSION. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

The Effect of Depression on the Use of Medical Service: Focusing on Patients with Chronic Physical Illness among Middle-Aged and Elderly Women (우울 경험이 의료서비스 이용에 미치는 영향: 중·노년기 여성 만성신체질환자를 대상으로)

  • Cho, Hyo Eun;Jung, Hyun Woo;Lee, Jun Hyup
    • Health Policy and Management
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    • v.31 no.1
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    • pp.46-55
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    • 2021
  • Background: Patients with the chronic physical illness are more likely to experience depression, and the accompany of chronic physical illness and depression is particularly high in middle-aged and elderly women. Considering that depression is associated with somatization and the decline of therapeutic compliance when accompanied by chronic physical illness, middle-aged and elderly women who experience depression among chronic physical illness may increase their use of medical services. This study is to identify the effect of depression on the use of medical services, especially among middle-aged and elderly women with chronic physical illness. Methods: This study used the 2016 Korean Health Panel. For analysis, it used T-test, negative binomial regression, and multivariate regression combining propensity score matching. Results: First, depressive groups had a higher number of medical service utilization and total medical expenditure than the non-depressive group. Second, depression significantly increased medical service utilization (β=0.17, p=0.04) at the 5% significance level. Also, depression significantly increased total medical expenditure (β=0.37, p=0.08) at the 10% significance level. Conclusion: For those who have chronic physical illness among middle-aged and elderly women, the experience of depression was confirmed to be a factor affecting the use of medical services. In the end, it is important to come up with policy countermeasures for middle-aged and elderly women accompanied by depression and chronic physical illness.

The Effect of Cash Holdings on Firm Value in Export Companies Listed in the KOSDAQ (코스닥시장에서 수출기업의 현금보유수준이 기업가치에 미치는 영향)

  • Oh, Hee-Hwa;Han, Kil-Seok
    • Asia-Pacific Journal of Business
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    • v.10 no.4
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    • pp.205-221
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    • 2019
  • The purpose of this research is to investigate the effect of cash holdings on firm value in export companies. To investigate this effect, we analyzed 5,386 samples drawn from export companies listed in the KOSDAQ from 2011 to 2018. During this period, the International Financial reporting Standards have been employed. The research results are as follows. First, the results of a T-test showed that the level of the firm value of export companies with high levels of cash holdings is significantly higher than that of those with low levels of cash holdings. In addition, the level of the firm value of export companies with higher levels of cash holdings than in the previous year is higher than the level might otherwise be. Furthermore, the effects of cash holdings on firm value are similar to those on return on asset. These results suggested that export companies have little used a way of increasing their debt levels in order to increase cash holdings. Second, the results of a multivariate regression analysis presented that the cash holdings of export companies in listed the KOSDAQ significantly influence their firm value. Moreover, a higher level of cash holdings than in the previous year significantly affect firm value. These results proposed that making higher cash holdings than in the previous year might be useful in enhancing firm value. We found that export companies efforts to increase cash holdings positively influence changes in firm value. We also found that Korean export companies maintain their financial stability by obtaining sufficient liquidity specifically in a high uncertainty era like the recent time. We finally firmed an effort to maintain cash holdings as a reasonable choice for export companies.

A Study on the Oral Health Literacy and Related Factors of Mother's in Some Areas

  • Kim, Mi-Jeong;Lim, Cha-Young;Son, Ju-Lee
    • Journal of dental hygiene science
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    • v.21 no.1
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    • pp.52-62
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    • 2021
  • Background: This study aims to provide basic data for development of the level-based oral health care program depending on the mother's oral health literacy by finding out how mother's oral health literacy can effect on the preschool children's oral health and behavior. Methods: The survey was conducted on 192 mothers who have preschool children and the data were analyzed by t-test, ANOVA, multiple regression analysis to identify differences in verbal and functional oral health literacy. Results: The study showed statistical significance (p<0.05) in educational level depending on differences in verbal and functional oral health literacy by sociodemographic factor. In differences in verbal and functional literacy depending on experience of education for oral health behavior and oral health, statistical significance (p<0.05) was showed highly on verbal and functional literacy in the case that subjects have an experience of education for oral health and their children have not been experienced of oral illness. And when it comes to the case that subjects have experience of education for oral health within one to two years, statistical significance was showed highly on verbal literacy. It showed that verbal and functional oral health literacy effects to oral health care behavior of children judging from results that the higher level of mother's verbal oral health literacy, the higher score of children's oral health knowledge, attitude and behavior. Conclusion: It is necessary to develop the systematic program which is appropriate for characteristics of each oral period in childhood depending on level of primary caregiver's oral health literacy, and systematic education should be preceded to enhance the literacy of the caregiver. It is considered necessary to improve the oral health care of children by developing a manual for oral health care education to enhance primary caregiver's oral health literacy.

Assessment of the dimensions of the pterygoid hamulus for establishing age- and sex-specific reference standards using cone-beam computed tomography

  • Mehra, Archana;Karjodkar, Freny R.;Sansare, Kaustubh;Kapoor, Ruchika;Tambawala, Shahnaz;Saxena, Vasu Siddhartha
    • Imaging Science in Dentistry
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    • v.51 no.1
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    • pp.49-54
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    • 2021
  • Purpose: This study was conducted to establish age- and sex-specific reference standards for pterygoid hamulus(PH) dimensions using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 1,000 patients(493 males and 507 females) were retrospectively assessed in coronal sections for length and width measurements of the PH by 3 investigators. The study data were divided into 3 age groups(group 1: <20 years, group 2: 20-50 years, group 3: >50 years). Length and width were compared using one-way analysis of variance and the t-test for age and sex, respectively. Results: The length of the PH on the right side significantly increased from group 1 (6.11±1.47mm), through group 2 (6.65±1.67 mm) to group 3 (6.99±1.79 mm) and on the left side from group 2 (6.58±1.63) to group 3 (6.98±1.70). The width of the PH significantly decreased from group 1 (1.81±0.39 mm) to group 2 (1.61±0.39 mm) on the right side, and similarly from 1.87±0.36mm to 1.67±0.37mm on the left side. PH length (7.18±1.81mm on the right side and 7.10±1.72 mm on the left side) and width (1.68±0.38 mm on the right side and 1.74±0.36 mm on the left side) were significantly greater in males than in females. Conclusion: The length of the PH increased with age, whereas width first decreased and then increased. Length and width measurements were significantly higher in males than in females. These findings will aid in the diagnosis of untraceable pain in the oropharyngeal region related to altered PH morphology.

Factors Affecting Job Performance and Turnover Intention of Call Center Representatives : Focusing on Individual Characteristics and Organizational Characteristics (콜센터 상담사의 직무성과 및 이직의도에 영향을 미치는 요인 : 개인특성과 조직특성을 중심으로)

  • Jeong, Kyeongsook;QU, MIN
    • Journal of Information Technology Services
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    • v.19 no.6
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    • pp.55-82
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    • 2020
  • This study examined the factors that influence the turnover intention, job performance of call center representatives based on the adaptive structuration theory (AST). This study intended to empirically examine how individual characteristics of representative affect the technological and task adaptation, how they affect job performance and turnover intention. On the other hand, this study also explains how rational culture and organization a reputation which are considered as dimensions of organizational characteristics affects organizational commitment, and verifies the relationship between organizational commitment and job performance and turnover intention. Finally this paper aim to provide academic and practical implications. In order to solve the above research problems, this research proposed a model based on the adaptive structuration theory. In order to identify the relationship between the proposed variables and the AST for individual, we conducted an empirical test on the call center representatives. The structural equation model was used to verify the research model and hypotheses. The results of the empirical analysis show that the personal characteristics of counselors, such as communication skills, multitasking abilities, and innovativeness have a positive effect on skill adaptation, and skill adaptation has a positive effect on task adaptation, furthermore, it influences on job performance and turnover intention Respectively. In addition, among the factors of organizational environmental dimensions of the call center, it was found that organizational reputation not only increase continuance commitment but also increase normative commitment. Contrary to our expectations, perceived rational culture didn't have a positive effect on organizational commitment. Also, continuance commitment and normative commitment are valid predictors of job performance, but they have nothing to do with turnover intention. On the contrary, emotional commitment is the only one variable among three dimensions of organizational commitment have a positive effect on turnover intention, but is not a valid predictor of job performance.

Mediating Effects of Role Perception of Life-sustaining Treatment in the Relationship between Knowledge of Life-sustaining Treatment Plans and Attitudes toward Withdrawal of Life-sustaining Treatment among Nursing College Students

  • Park, Youngmi;Nam, Keumhee;Bae, Joohee
    • Journal of Hospice and Palliative Care
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    • v.24 no.1
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    • pp.36-45
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    • 2021
  • Purpose: This study examined the relationship between Knowledge of Life-sustaining Treatment Plans and Attitudes toward Withdrawal of Life-sustaining Treatment among nursing college students, and attempted to identify the mediating effect of Role Perception on Life-sustaining Treatment in that relationship. It is hoped that the findings will ultimately contribute to the development of active nursing strategies. Methods: The participants were 142 nursing college students in the third and fourth years of study who had experienced clinical practice at two universities in cities Y and C. Data were collected from November 1 to 30, 2019. For data analysis, SPSS for Windows version 22.0 was used to calculate descriptive statistics, the t-test, Pearson's correlation coefficients, and multiple regression. To analyze the mediating effect, the Baron and Kenny bootstrapping method was used. Results: Attitudes toward Withdrawal of Life-sustaining Treatment of nursing college students had a significant positive correlation with Knowledge of Life-sustaining Treatment Plans (r=0.34, P<0.001) and Role Perception on Life-sustaining Treatment (r=0.44, P<0.001). Role Perception on Life-sustaining Treatment partially mediated the relationship between Knowledge of Life-sustaining Treatment Plans and Attitudes toward Withdrawal of Life-sustaining Treatment (95% CI, 0.446~1.055). Conclusion: Based on the results of this study, improving nursing college students' Role Perception on Life-sustaining Treatment could be used as a coping strategy to establish positive Attitudes toward Withdrawal of Life-sustaining Treatment.

Analysis of Influencing Factors on the Outpatient Prescription of Antipsychotic Drugs in the Elderly Patients (노인환자의 항정신병 약물 원외처방 내역에 미친 영향 요인 분석)

  • Dong, Jae Yong;Lee, Hyun Ji;Lee, Tae Hoon;Kim, Yujeong
    • Korean Journal of Clinical Pharmacy
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    • v.31 no.4
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    • pp.268-277
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    • 2021
  • Background: Most antipsychotic drugs studies have been mainly conducted on side effects, randomized clinical trials, utilization rates, and trends. But there have been few studies on the influencing factors in elderly patients. The purpose of this study was to analyze the influencing factors on the outpatient prescription of antipsychotic drugs in the elderly patients. Methods: Active ingredients of antipsychotic drugs in Korea were selected according to the Korean Pharmaceutical Information Center (KPIC)'s classification. Data source was Korean Health Insurance Review and Assessment Service (HIRA) claims data in 2020 and target patient group was the elderly patient group. We extracted patients who have been prescribed one or more antipsychotic drugs and visited only one medical institution. Data were analyzed using descriptive statistics, chi-square, t-test, negative binomial regression. Results: A number of outpatients were 245,197 and prescriptions were 1,379,092. Most characteristics of patients were 75-85 year's old, female, health insurance type, no disease (dementia, schizophrenia), atypical drugs, cci score (>2) and characteristics of medical institution were neurology in specialty, rural region, general hospitals. Results of regression showed that patient's characteristics and medical center characteristics had significant effect on the outpatient prescription of antipsychotic drugs in the elderly patients. Conclusion: This study suggests that national policy of antipsychotic drugs in the elderly patients, with the consideration of the patients' and medical institutions' characteristics, is needed.

The relationship between empathic ability, communication competence, and attitudes toward the disabled among female dental hygiene students (일부 치위생과 여학생들의 공감능력 및 의사소통능력과 장애인에 대한 태도와의 연관성)

  • Park, Hye-Min;Kim, Jang-Rak;Kang, Yune-Sik;Jeong, Baek-Geun
    • Journal of Korean Dental Hygiene Science
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    • v.4 no.2
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    • pp.43-52
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    • 2021
  • Background: To explore the empathic abilities, communication competence, and attitudes toward the disabled, and to identify the relationship between these variables among female dental hygiene students. Methods: A self-administered questionnaire was used to collect data from 190 female students in their second and third year of study at the dental hygiene department of a university located in Gyeongsangnam-do province, South Korea, from September 2-11, 2020. Data were analyzed using descriptive analyses, t-test, analysis of variance, Pearson's correlation, and multiple regression using SPSS 20.0. Results: The participants' scores for empathic abilities, communication competence, and attitudes toward the disabled were 3.63, 3.69, and 3.54 points, respectively. A significant positive correlation was observed between empathic abilities and attitudes toward the disabled. Regarding the sub-elements of empathic abilities, the participants' attitudes toward the disabled had a significant positive correlation with the scales measuring their perspective-taking abilities and personal distress (p<.05). A positive correlation (p<.05) was observed between communication competence and attitudes toward the disabled. The students' attitudes toward the disabled were significantly influenced by the scale measuring their perspective-taking abilities (B=.210); those with a higher perspective-taking ability displayed more positive attitudes toward the disabled. Conclusion: Female dental hygiene students showed empathic abilities, which positively influenced their attitudes toward the disabled. Positive attitudes toward the disabled can contribute to improving the quality of medical services.