• 제목/요약/키워드: Higher-order

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Size-dependent thermal behaviors of axially traveling nanobeams based on a strain gradient theory

  • Li, Cheng
    • Structural Engineering and Mechanics
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    • 제48권3호
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    • pp.415-434
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    • 2013
  • This work is concerned with transverse vibrations of axially traveling nanobeams including strain gradient and thermal effects. The strain gradient elasticity theory and the temperature field are taken into consideration. A new higher-order differential equation of motion is derived from the variational principle and the corresponding higher-order non-classical boundary conditions including simple, clamped, cantilevered supports and their higher-order "offspring" are established. Effects of strain gradient nanoscale parameter, temperature change, shape parameter and axial traction on the natural frequencies are presented and discussed through some numerical examples. It is concluded that the factors mentioned above significantly influence the dynamic behaviors of an axially traveling nanobeam. In particular, the strain gradient effect tends to induce higher vibration frequencies as compared to an axially traveling macro beams based on the classical vibration theory without strain gradient effect.

A Higher-Order Theory for Laminated Composite Plates (적층복합평판을 위한 고차해석이론)

  • 신용석
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제18권1호
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    • pp.65-76
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    • 1994
  • A higher-oder laminated plate theory including the effect of transverse shear deformation is developed to calculate the gross response and the detailed stress distribution. The theory satisfies the continuity condition of transverse shear stress, and accounts for parabolic variation of the transverse shear stresses through the thickness of each layer. Exact closed-ply laminates are obtained and the results are compared with three-dimensional elasticity solutions and a simple higher-order theory solutions. The results of the present work exhibit acceptable accuracy when compared to the three-dimensional elasticity solutions.

Manifest Weeds and Self-Actualization of Patients with Essential Hypertension (본태성 고혈압 환자의 자기실현 및 욕구구조에 관한 연구)

  • 강익화
    • Journal of Korean Academy of Nursing
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    • 제8권1호
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    • pp.163-180
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    • 1978
  • Much of a person's energy is spent in the effort of becoming a productive member of to-day's complex society. This activity may cause tension, and chronic unrelieved tension is an influential factor in blood pressure elevation. The problem of this study was to identify manifest needs and self-actualization of patients with essential hypertension, and to analyse and compare their manifest needs and selt-actualization with the selected general characteristics of We, sex, religion, occupation and level of education with a control group of patients with normal blood pressure readings. The purpose was to contribute to the planning of nursing interventions toward reducing the impact of complex psycho-somatic factors on the anxiety of patients with essential hypertension. The instruments used included selected items from the Edwards (1959) Personal Preference Schedule (EPPS) as adapted by Hwang (1965) and from the Personal Orientation Inventory (POI) (Shostrom 1964, 1974) adapted by Kim and Lee (1977) to measure manifest needs and self-actualization. The convenience sample was chosen from 149 persons who presented themselves for general physical examinations at Ewha University Medical Centre and 41 patients diagnosed with essential hypertension at three general hospitals in Seoul during June 1 and August 31, 1977. Forty-nine persons from the Ewha group with blood-pressure readings exceeding 150/90 were added to the experimental group. Data were analysed by the S.P.S.S. computer programme using t-test and tests for statistical significance. Statistically significant findings were as follows: A. Blood Pressure and Manifest Needs. 1. with the exception of Autonomy, patients with hypertension had significantly high scores on all variables Abasement, Achievement, Affiliation, Aggression, Dominance, Emotionality, Exhibitionism and Sex. 2. When mean scores of normal persons were compared by age groups, normal persons had higher scores in the following order on Abasement (50's, 40's, 20's, 30's), Achievement (50's, 30's, 40's, 20's), Affiliation (50's, 40's, 30's, 20's), Dominance (50's, 40's, 40's, 20's) and Exhibitionism (30's, 50's, 40's, 20's). In each case, there was a significant difference between the first and last age group scores. 3. When the mean scores of normal persons were compared by sex, normal men had higher scores than women on Achievement, Affiliation, Aggression, Dominance, Exhibitionism and Sex. Male patients had higher scores than female patients on Achievement, Dominance, Exhibitionism and Sex, but female patients scored higher in Emotionality. 4. Normal persons had higher scores related to religion in the following order on Achievement (Buddhism, no religion, Christianity). Hyper tensive patients had higher scores on. Exhibitionism (no religion, Christianity, Buddhism). 5. Normal persons had higher scores related to occupation in the following order on Achievement and Exhibitionism (unemployed, office workers, teachless, businessmen), Emotionality (office workers, unemployed, businessmen, teacher) and Sex (office workers, unemployed, teachers, businessmen). Hypertensive patients had higher scores on Achievement and Aggression (teachers, businessmen, office worker, unemployed), Dominance and Exhibitionism (businessmen, teacher, of ace workers, unemployed) and Sex (teachers, office worker, businessmen, unemployed). 6. Normal persons had higher scores related to level of edification in the following order on Abasement, Emotionality and Autonomy (secondary school graduation, university). Hypertensive patients had higher scores on Abasement (no education, primary, university, secondary), Achievement (no education, secondary, university, primary) , Dominance (university, no education, secondary, primary), Exhibitionism (university, secondary, no education, primary), and Sex (university, secondary, primary, no education). B. Blood Pressure and Self_Actualization 1, Patients with hypertension had significantly lower scores on all variables. 2. Normal persons had higher scores related to age groups in the following order on Existentiality (20's, 30's, 40's, 50's). Hypertensive patients showed no significantly different scores. 3. Normal women had higher scores than men on Time Competence. Normal men had higher scores on Feeling Reactivity. Male patients had higher scores than women on Self-Actualizing Value and Self-Regard. 4. Normal persons ha 1 higher scores related to religion on spontaneity (Buddhism, no religion, Christianity). Hypertensive patients had higher scores on Time Competence and Nature of Man (Buddhism, Christianity, no religion). 5. Normal persons had higher scores related to occupation in the following order on Existentiality (teachers, office workers, businessmen, unemployed) and Self-Regard (unemployed, office workers, teachers, businessmen). Hypertensive patients showed no significantly different scores. 6. Normal persons had higher scores related to level of education in the following order on Existentiality and Self-Acceptance (university, secondary). Hypertensive patients had higher scores on inner-Director (university, secondary, no education, primary) and Existentiality (university, secondary, primary, no education). Recommendations for nursing interventions with hypertensive patients with emotional problems or low self-actualization were made. 1. The nurse should encourage the patient through her interactions with other members of the medical team to accept counselling and health education. 2. Through her therapeutic interpersonal relationships with the patient, the nurse should help him discover the causes of his emotional tension. 3. Through her health teaching with the family, the nurse should encourage them to participate with the medical team in the patient's therapeutic plan and in providing him with the minimum possible emotional support. 4. Through frequent counselling with the obsessive-thinking and inflexible patient, the nurse should reevaluate the patient's behaviour and her interventions. 5. Seriously ill patients should be given needed reeducation by members of the professional medical team.

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Dynamic Characteristics of Composite Plates Based On a Higher Order Theory Under Low-Velocity Impact (저속 충격시 고차이론을 이용한 복합 재료 판의 동적 특성)

  • 심동진;김지환
    • Journal of KSNVE
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    • 제8권1호
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    • pp.132-138
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    • 1998
  • The dynamic response of symmetric cross-ply and angle-ply composite laminated plates under impact loads is investigated using a higher order shear deformation theory. A modified Hertz law is used to predict the impact loads and a four node finite element is used to model the plate. By using a higer order shear deformation theory, the out-of-plane shear stresses, which can be a crucial factor in the failure of composite plates, are determined with significant accuracy. This is accomplished by using a stress recovery technique using the in-plane stresses. The results compared with previous investigations showed good agreement. It can be seen that this method of analyzing impact problems is more efficient than current three dimensional methods in terms of time and expense.

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An Analysis of the Wave Propagation of a Structure Based on STFT, Higher Order Time-frequency Analysis and Wavelet Transform (STFT, 고차위그너분포 및 웨이브렛 변환 기술을 이용한 탄성파 추적)

  • 이상권
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.827-832
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    • 2003
  • There has been a number methods for the presentation of time-frequency analysis of non-stationary signal. In this paper, STFT(short time Fourier transform), wavelet transform, Wigner distribution, and higher order Wigner distribution are discussed in details with simulation signals. They are also applied to the analysis of the wave propagation of a semi finite beam. Wigner distribution and higher order Wigner distribution have good time-frewuency resolutions. Wavelet transform is required for impact analysis but should be applied carefully. STFT suffers from time-frequency resolutions. Each method is has its advantage and disadvantage depending on each application signals.

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Unsteady Analysis of 3-Dimensional Hydrofoils Using a B-Spline Based High Order Panel Method

  • Jang, Hyun-Gil;Ahn, Byoung-Kwon;Lee, Chang-Sup
    • Journal of Ship and Ocean Technology
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    • 제12권2호
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    • pp.16-31
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    • 2008
  • The lifting-surface programs have been used successfully in practice for the design and global performance prediction of the marine propellers. To predict the pressures on the blade for the strength analysis, the constant panel method has been a good alternative. To meet the need for more accurate information on the pressure near the tip region and the trailing edge of the blade, the higher order panel method (HiPan, hereinafter) based on a B-spline is developed and now available. However, there is an increasing demand to get the highly reliable unsteady behavior of the pressure near the tip region by the HiPan. The ultimate goal of our efforts is to develop the fully unsteady higher order panel code for the propeller. In the present paper, we will show the numerical procedure applicable to unsteady problems of the three dimensional hydrofoil in a sinusoidal gust and heave motions.

Performance Analysis of M-ary APSK Modulation Signal due to Phase Noise (위상잡음에 의한 M-ary APSK 변조신호의 성능 분석)

  • Kim, Young-wan;Ji, Sek-geon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국정보통신학회 2014년도 춘계학술대회
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    • pp.679-681
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    • 2014
  • The performance of M-ary APSK modulation system due to phase noise are analyzed in this paper. The effects for phase noise in the higher order modulation are simulated by using constellation of the higher order modulation signals. the simulated results are verified by comparing with the analytic results for lower order PSK modulation signals. Based on the evaluation of simulation method, the phase noise effects for higher order APSK modulation signals are suggested in this paper.

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A Study on the Depression of Adolescence - A Comparative Study of Normal, Orphan, Physically Handicapped and Deaf - Mute Children - (사춘기 청소년의 우울병에 관한 연구 - 정상아.고아.지체부자유아 및 농아아의 비교연구-)

  • 오경옥
    • Journal of Korean Academy of Nursing
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    • 제7권2호
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    • pp.117-127
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    • 1977
  • Depressive status of the adolescence in 437 normal, 416 orphan, 133 physically handicapped and 109 deaf-mute children were compared with the Self- Rating Depression Scale developed by Zung, from April 26 to July 4, 1976. The subjects were divided into two groups, early adolescence for age of 10 to 14 and ate adolescence of age of 15 to 18. The results were as follows : 1. The depression score was higher in late adolesce co than in early adolescence except deaf - mutes, 2. The depression score was not different significantly between the sexes in all groups. 3. The depression score was significantly higher in the group of orphan, physically handicapped and deaf - mute children then in the normal. 4. The depression score was significantly higher in the orphans than in the physically handicapped children. It showed tendency to be higher in the deaf - mutes than in the physically handicapped children. 5. In comparison with the rank order of the Self - Rating Depression Scale items, normal group was inclined to have psychological symptoms in higher rank order, but orphan and deaf - mute group was inclined to have somatic symptoms in higher rank order.

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