• Title/Summary/Keyword: eigen-analysis

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Parametric resonance of a spinning graphene-based composite shaft considering the gyroscopic effect

  • Neda Asadi;Hadi Arvin;Yaghoub Tadi Beni;Krzysztof Kamil Zur
    • Steel and Composite Structures
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    • v.51 no.4
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    • pp.457-471
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    • 2024
  • In this research, for the first time the instability boundaries for a spinning shaft reinforced with graphene nanoplatelets undergone the principle parametric resonance are determined and examined taking into account the gyroscopic effect. In this respect, the extracted equations of motion in our previous research (Ref. Asadi et al. (2023)) are implemented and efficiently upgraded. In the upgraded discretized equations the effect of the Rayleigh's damping and the varying spinning speed is included that leads to a different dynamical discretized governing equations. The previous research was about the free vibration analysis of spinning graphene-based shafts examined by an eigen-value problem analysis; while, in the current research an advanced mechanical analysis is addressed in details for the first time that is the dynamics instability of the aforementioned shaft subjected to the principal parametric resonance. The spinning speed of the shaft is considered to be varied harmonically as a function of time. Rayleigh's damping effect is applied to the governing equations in order to regard the energy loss of the system. Resorting to Bolotin's route, Floquet theory and β-Newmark method, the instability region and its accompanied boundaries are defined. Accordingly, the effects of the graphene nanoplatelet on the instability region are elucidated.

Colon Cancer among Older Saudis: Awareness of Risk Factors and Early Signs, and Perceived Barriers to Screening

  • Galal, Yasmine Samir;Amin, Tarek Tawfik;Alarfaj, Abdulelah Khalid;Almulhim, Abdulaziz Abdullah;Aljughaiman, Abdullah Abdulmohsen;Almulla, Abdulrhaman Khaled;Abdelhai, Rehab Ahmed
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1837-1846
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    • 2016
  • Background: Colon cancer screening (CRCS) uptake is markedly affected by public awareness of the disease. This study was conducted to assess levels of knowledge of CRC, to explore the pattern of CRCS uptake and identify possible barriers to screening among Saudis older than 50 years of age and primary care providers (PCPs) in Al Hassa region, Saudi Arabia. Materials and Methods: This cross-sectional study was conducted in randomly selected primary health care (PHC) centers, 884 Saudis and 39 PCPs being enrolled for data collection. Structured interviews were conducted to obtain information regarding socio-demographic characteristics, personal information relevant to CRC, awareness about early signs/symptoms and risk factors, and barriers to CRCS. Also, a self- administered data collection form was used to assess barriers to CRCS from the physicians' perspectives. Results: More than 66% of participants were lacking knowledge about CRC. Participants with higher educational levels, having ever heard about CRC, and having relatives with CRC had a significantly higher awareness of the disease. The rate of reported CRCS was low (8.6%). After conducting a logistic regression analysis, it was observed that female gender (OR=0.28; 95% CI=0.14-0.57; P=0.001), being unmarried (OR=0.11; 95% CI=0.10-0.23; P=0.001), lower levels of education (OR=0.36; 95% CI=0.16-0.82; P=0.015), and having no relatives with CRC (OR=0.30; 95% CI=0.17-0.56; P=0.001) were significantly associated with a lower CRCS uptake. There was a significant difference between most of the perceived barriers to CRCS and gender. Exploratory factor analysis showed that personal fear (especially fear of the screening results and shyness) was the major factor that hindered CRCS with high loading Eigen value of 2.951, explaining 34.8% of the barriers of the included sample toward utilization of CRCS, followed by lack of awareness of both person and providers (high Eigen value of 2.132, and explaining 23.7% of the barriers). The most frequently cited barriers to CRCS from the physicians' perspectives were lack of public awareness, lack of symptoms and signs, and fear of painful procedures. Conclusions: Poor levels of knowledge about CRC were found among older Saudis attending PHC centers in Al Hassa, Saudi Arabia. It is crucial to implement an organized national screening program in Saudi Arabia to increase public awareness.

Development of A Nurse는s Suffering Experience Scale (말기 암 환자를 간호하는 간호사의 고통경험 척도개발)

  • 조계화
    • Journal of Korean Academy of Nursing
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    • v.32 no.2
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    • pp.243-253
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    • 2002
  • The purpose of this study was to develop Nurse's Suffering Experience Scale and to test the reliability and validity of the instrument. Method: The subjects used to verify the scale's reliability and validity were 220 nurses who were taking care of the end stage cancer patients, while working at university and general hospitals in Daegu and Kyungbuk province from April 20. to July 10, 2001. The data was analyzed by the SPSS/WIN 8.0 program. Results: A factor analysis was conducted, and items that had a factor loading more than .40, and an eigen value more than 1.0. were selected. The factor analysis classified a total of seven factors statistically, and it's communality was 44%. The explanation of factors based on the conceptual framework and item content are as follows: The first factor was expanding self consciousness, the second factor was forming empathy with family, the third factor was professional challenge, the fourth factor was change of values, the fifth factor was spiritual sublimation, the sixth factor was helplessness, and finally the seventh factor was rejection to death. Cronbach's coefficient to test reliability of the scale was .8665 for total of 44 items. The Scale for Nurse's Suffering Experience developed in the study was identified as a tool with a high degree of reliability and validity. Therefore this scale can be effectively utilized for the evaluation of the degree of nurse's suffering experience in clinical settings.

Development of Nurse Presence Scale (Nurse Presence 도구개발)

  • 조계화;조영숙
    • Journal of Korean Academy of Nursing
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    • v.31 no.3
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    • pp.369-379
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    • 2001
  • Purpose: The purpose of this study was to develop the Nurse Presence Scale and to test the reliability and validity of the instrument. Method: The subjects verifying the scale's reliability and validity were adult patients being treated in three artificial kidney unit in Pusan and Taegu from August 1 to October 15, 2000. The data was analyzed by the SPSS/WIN 8.0 program. Result: A factor analysis and was conducted items that had a factor loading more than .40, and an eigen value more than 1.0 were seleclted. The factor analysis classified a total of seven factors statistically, but the seventh factor was excluded because community was less than 4%. Therefore, there were six factors, and its communality was 62%. The explanation of domain and factors based on the conceptual framework and item content are as follows: The first factor was 'interaction' in emotional areas, the second domain was 'empathy' in cognitive areas, the third was 'attention' in emotional areas, the fourth was 'openness' in emotional areas, the fifth was 'sensitivity' in behavioral areas, and the sixth was 'physical assist' in behavioral areas. Cronbach's α coefficient to test reliability of the scale was .9766 for a total 49 items. Conclusion: The Scale for Nurse Presence developed in the study was identified as a tool with a high degree of reliability and validity. Therefore, this scale can be effectively utilized for the evaluation of nurse presence in clinical settings.

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Appearance-based Object Recognition Using Higher Order Local Auto Correlation Feature Information (고차 국소 자동 상관 특징 정보를 이용한 외관 기반 객체 인식)

  • Kang, Myung-A
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.7
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    • pp.1439-1446
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    • 2011
  • This paper describes the algorithm that lowers the dimension, maintains the object recognition and significantly reduces the eigenspace configuration time by combining the higher correlation feature information and Principle Component Analysis. Since the suggested method doesn't require a lot of computation than the method using existing geometric information or stereo image, the fact that it is very suitable for building the real-time system has been proved through the experiment. In addition, since the existing point to point method which is a simple distance calculation has many errors, in this paper to improve recognition rate the recognition error could be reduced by using several successive input images as a unit of recognition with K-Nearest Neighbor which is the improved Class to Class method.

Dynamic Instability of Rocket-Propelled Flying Bodies

  • Sugiyama, Yoshihiko
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.1-5
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    • 2003
  • This paper deals with dynamic instability of slender rocket-propelled flying bodies, such as launch vehicle and advances missiles subjected to aerodynamic loads and an end rocket thrust. A flying body is simplified into a uniform free-free beam subjected to an end follower thrust. Two types of aerodynamic loads are assumed in the stability analysis. Firstly, it is assumed that two concentrated aerodynamic loads act on the flying body at its nose and tail. Secondly, to take account of effect of unsteady flow due to motion of a flexible flying body, aerodynamic load is estimated by the slender body approximation. Extended Hamilton's principle is applied to the considered beam for deriving the equation of motion. Application of FEM yields standardeigen-value problem. Dynamic stability of the beam is determined by the sign of the real part of the complex eigen-values. If aerodynamic loads are concentrated loads that act on the flying body at its nose and tail, the flutter thrust decreases by about 10% in comparison with the flutter thrust of free-free beam subjected only to an end follower thrust. If aerodynamic loads are distributed along the longitudinal axis of the flying body, the flutter thrust decreases by about 70% in comparison with the flutter thrust of free-free beam under an end follower thrust. It is found that the flutter thrust is reduced considerably if the aerodynamic loads are taken into account in addition to an end rocket thrust in the stability analysis of slender rocket-propelled flying bodies.

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A Study on the Expectation Factor of Female Customers about the Role of a Food Coordinator (푸드 코디네이터 역할에 대한 여성 고객들의 기대 요인에 관한 연구)

  • Park, Ji-Soo;Choi, Soo-Keun
    • Culinary science and hospitality research
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    • v.14 no.4
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    • pp.244-256
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    • 2008
  • This study is intended to be used as basic data to understand the role of a food coordinator who creates an environment for eating and to develop menus by studying the expectations of female customers about the food coordinator's role. The reported concepts of the role of a food coordinator were divided into six factors-food(Eigen value 3,181), seat, cutlery, atmosphere, convenience, and sanitation. According to an analysis of the expected factors concerning the role of a food coordinator in terms of the amount paid, when women visited any restaurant once, the factors of "food" and "atmosphere" showed a significant difference(p<0.05) while the other factors did not. According to an analysis of the recognition of a food coordinator in terms of the number of visits, the questions concerning recognition of the job of "food coordination," the necessity of the role and the expectations of the role showed a significant difference (p<0.05). The question on willingness to pay, in relation to the role of a food coordinator, showed a negative response about the direct payment of guests regardless of the number of restaurant visits.

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A Study on the College Students' Behavior of Hyo(filial-piety) (대학생의 孝行에 관한 연구)

  • 고경미;서병숙
    • Journal of Families and Better Life
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    • v.6 no.1
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    • pp.205-221
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    • 1988
  • The purpose of this study is to classify several variable which were assumed to have relationship with the college students behavior of Hyo, to see their possible correlation with demographic characteristics, and to proved some useful data for their possible correlation with demographic characteristics. and to provide some useful data for their sound value system. The data for this study was obtained form the survey of the 477 students who reside in the city of Seoul by using questionnaire methods. The frequency of variables was statistically analyzed to see the general character of the samples and factor analysis was made for classification of the college student's behavior of Hyo. In order to study th characteristic of demographic variables, t-test and ANOVA were conducted The major findings of this study can be summarized as follows. 1) As the result of factor analysis about behavior of Hyo, six factors (Which Eigen value was above 1.0) out of 64 questions were extracted : 'respect' familiarity' 'family consciousness' 'serve' self-preservation, establishmence of them-selves in life' and 'self-reliance' were selected. 2)In general, it can be said that the college students' behavior of Hyo varies by demographic variables. 3) By surveying the level of actualizing Hyo of the college students' all of factors ranged from 'the middle' to 'the high level'. The result confirmed that students fulfilled the behavior of Hyo to their parents in all items.

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Development of an Osteoporosis Awareness Scale for Women (골다공증에 대한 인지측정도구 개발)

  • Choi, Euy-Soon;Kim, Ju-Hu;Chung, Mi-Young;Hwang, Kyung-Hye
    • Journal of Korean Academy of Nursing
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    • v.38 no.6
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    • pp.813-821
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    • 2008
  • Purpose: This study was conducted to develop an instrument measuring awareness of osteoporosis. Methods: The process included construction of a conceptual framework, generation of 86 preliminary items, verification of content validity, selection of secondary items, verification of construct validity and extraction of final items. The 86 items were reviewed for content validity by two groups of experts and were tested to evaluate inter item correlation coefficient by two groups of adult women. From June to August 2007, data were collected from 383 adult women who lived in Seoul and provinces in Korea. Data were analyzed by performing item analysis, Varimax factor analysis and Cronbach's alpha. Results: There were 31 items in the final instrument categorized into 5 factors. The factors were labeled as "preventive behaviors (10 items)", "risk factors (5 items)", "characteristics of osteoporosis (6 items)", "improving bone health (5 items)", and "bone physiology (5 items)". Cumulative percent of variance was 60.92% and eigen values ranged from 1.20 to 12.44. Cronbach's alpha was .948 and ranged from .804 to .917. Conclusion: Validity and reliability of the scale are confirmed in this study showing its utility for measuring awareness of osteoporosis for women. Utilization of the scale will also contribute to designing an appropriate prevention program for osteoporosis.

Gate Management System by Face Recognition using Smart Phone (스마트폰을 이용한 얼굴인식 출입관리 시스템)

  • Kwon, Ki-Hyeon;Lee, Hyung-Bong
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.9-15
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    • 2011
  • In this paper, we design and implement of gate management system by face recognition using smart phone. We investigate various algorithms for face recognition on smart phones. First step in any face recognition system is face detection. We investigated algorithms like color segmentation, template matching etc. for face detection, and Eigen & Fisher face for face recognition. The algorithms have been first profiled in MATLAB and then implemented on the Android phone. While implementing the algorithms, we made a tradeoff between accuracy and computational complexity of the algorithm mainly because we are implementing the face recognition system on a smart phone with limited hardware capabilities.