• Title/Summary/Keyword: frequency-response

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A study on elementary school students' and middle school students' attitudes toward environmental problems (환경 문제에 대한 평가 도구 개발 및 국민학생과 중학생의 태도 조사 연구)

  • Woo, Hyun-Kyung;Chung, Young-Lan
    • Journal of The Korean Association For Science Education
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    • v.14 no.2
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    • pp.225-235
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    • 1994
  • Concidering environmental education as an ultimate resolution for environmental problems, we conducted a study focusing on affective matters. An instrument was developed to evaluate attitudes of elementary and middle school students toward environmental problems. To develop a reliable Likert-type evaluation instrument scale with which emotional intensity could be judged, mean, standard deviation, response frequency distribution, discrimination index, reliability were calculated. As a result, 21 statements for recognition level and 14 statements for behavioral level were made(The Cronbach alpha coefficient of the instrument was .786). This instrument was used to evaluate 5th and 6th grade elementary school students and 1st and 2nd grade middle school students(total number of subjects was 980). The result of this survey can be summarized as follows. 1. Students recognized the seriousness of environmental problems but they did not behave in such a manner as to prevent it. 2. As a result of t-test, behavioral level score of elemenatary school students was significantly higher than that of middle school students(p<.001). 3. This study showed that there was a significant correlation between the recognition level score and the behavioral level score(r=.386, p<.001). 4. Two-Way ANOVA was used to analyze that there was any significant difference according to grade and sex. The results were as follows. (1) No significant difference was found in total score. (2) On recognition level, female students' score was signigicantly higher than that of male students(p<.01). (3) On behavioral level, higher-grade students' score was lower than that of lower-grade-students (p<.001).

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Assessment of Lifeline Construction Technology for Buried Alive in Building Collapse (도심지 붕괴사고에 따른 매몰지역 생명선 시공기술 평가)

  • Ryu, Byung-Hyun;Kang, Jae-Mo;Lee, Jangguen;Kim, Young-Sam;Joo, Rak-Bong
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.9
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    • pp.47-52
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    • 2016
  • Unusual extreme weather events, which exceed a safe design capacity of the infrastructure, increase the frequency of natural disasters and has also been enlarged damage scale. Aging buildings and rapid urban progress act as weighting factors for the new composite disasters. Technological advances support detecting pre-disaster risk, real-time data analysis, and rapid response to the disaster site, but it is insufficient that emergency relief for buried alive must take advantage of the proven technologies through field tests. This study aims to evaluate directional drilling performance through underground soils and the reinforced concrete structure for primary lifeline installation in order to quickly provide relief supplies for buried alive when urban structures collapse.

Optimum design and vibration control of a space structure with the hybrid semi-active control devices

  • Zhan, Meng;Wang, Sheliang;Yang, Tao;Liu, Yang;Yu, Binshan
    • Smart Structures and Systems
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    • v.19 no.4
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    • pp.341-350
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    • 2017
  • Based on the super elastic properties of the shape memory alloy (SMA) and the inverse piezoelectric effect of piezoelectric (PZT) ceramics, a kind of hybrid semi-active control device was designed and made, its mechanical properties test was done under different frequency and different voltage. The local search ability of genetic algorithm is poor, which would fall into the defect of prematurity easily. A kind of adaptive immune memory cloning algorithm(AIMCA) was proposed based on the simulation of clone selection and immune memory process. It can adjust the mutation probability and clone scale adaptively through the way of introducing memory cell and antibody incentive degrees. And performance indicator based on the modal controllable degree was taken as antigen-antibody affinity function, the optimization analysis of damper layout in a space truss structure was done. The structural seismic response was analyzed by applying the neural network prediction model and T-S fuzzy logic. Results show that SMA and PZT friction composite damper has a good energy dissipation capacity and stable performance, the bigger voltage, the better energy dissipation ability. Compared with genetic algorithm, the adaptive immune memory clone algorithm overcomes the problem of prematurity effectively. Besides, it has stronger global searching ability, better population diversity and faster convergence speed, makes the damper has a better arrangement position in structural dampers optimization leading to the better damping effect.

Burnout among Medical Education Specialists in Korean Medical Colleges (의학교육 전문부서 교원의 탈진현상)

  • Park, Kwihwa;Lee, Young-Mee
    • Korean Medical Education Review
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    • v.16 no.2
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    • pp.92-98
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    • 2014
  • Medical education departments or offices are established in response to public expectations relating to health care, societal trends towards increased accountability, educational developments, increased interest in what to teach and how to educate doctors. However, heavy workloads and mixed feelings towards medical education departments or offices by the other members of a medical school can threaten job satisfaction and increase burnout. The authors investigated the prevalence of burnout among medical education specialists and related issues. Individual in-depth interviews with four medical education specialists were conducted to develop a questionnaire. After content analysis of the interview, the authors generated a survey form with 28 items including 6 categories: motivation to choose medical education as a career, job satisfaction, intention to leave their current position in medical education, the frequency and causes of burnout, and demographics. In September 2013, an email survey was administered to 43 faculty including non-tenure staff who were working in the department/office of medical education in 41 medical colleges in Korea. Of 43 medical education specialists, 25 (60%) returned surveys. Forty three-point-three percent of them felt encouraged when their endeavors generated a visible educational improvement in the medical school. A majority (87%) reported feeling burned out. Fifty percent of them experienced the feeling once or twice a year. The extent of burnout tended to be greater in women, those in their forties, those with non-medical doctor degrees, and in non-tenured staff. To reduce and prevent burnout among medical education specialists, the participants suggested that leadership of medical schools and a systematic approach to medical education should be established. A majority of the medical education specialists reported experiencing burnout, although they were satisfied with their jobs. To reduce their burnout and allow them to focus on their own work in medical education, the following factors are needed: perceptual changes of other members of the college about medical education; more systematic institutional strategies; networking among medical education specialists; and personal efforts for professional development.

p.R72P, PIN3 Ins16bp Polymorphisms of TP53 and CCR5Δ32 in North Indian Breast Cancer Patients

  • Guleria, Kamlesh;Sharma, Sarika;Manjari, Mridu;Uppal, Manjit Singh;Singh, Neeti Rajan;Sambyal, Vasudha
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3305-3311
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    • 2012
  • Background: The present study aimed to find the prognostic implications of two polymorphisms in TP53 (p.R72P, PIN3 Ins16bp) and one in CCR5 ($CCR5{\Delta}32$) in sporadic breast cancer patients. Methods: DNA samples of 80 breast cancer patients and 80 age and gender matched unrelated healthy control individuals from Punjab, North West India were analyzed. Results: For p.R72P, the genotype frequency was 13.8% (RR), 58.8% (RP), 27.5% (PP) in patients and 33.9% (RR), 40.0% (RP), 26.5% (PP) in controls. For PIN3 Ins16bp, the genotype frequencies were 53.75% (A1A1), 37.5% (A1A2), 8.75% (A2A2) in patients and 66.3% (A1A1), 31.3% (A1A2), 2.5% (A2A2) in controls. Only 4 (5%) breast cancer patients were heterozygous for $CCR5{\Delta}32$ deletion. Common RR-A1A1-WT/WT genotype was lower while RP-A1A2-WT/WT genotype was higher in patients as compared to controls. RP-A1A1-WT/WT genotype was significantly higher in patients as compared to control individuals (p = 0.008). Conclusion: Though a clear association of any particular genotype with sporadic breast cancer or stage was not apparent, the results of present study were suggestive that sporadic breast cancer patients with RR-A1A1-WT/WT genotype might have a better response to chemotherapy, thus improving their chances of survival.

Pathophysiology of orthostatic tremor: a multiple case study (길입성 진전의 병태생리: 다증 증례 연구)

  • Seo, Man-Wook;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
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    • v.4 no.1
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    • pp.44-50
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    • 2002
  • Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

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The Experiment of Flow Induced Vibration in PWR RCCAs

  • Kim, Sang-Nyung;Cheol Shin
    • Journal of Mechanical Science and Technology
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    • v.15 no.3
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    • pp.291-299
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    • 2001
  • Recently, severe wear on the shutdown rod cladding of Ulchin Nuclear Power Plant #1, #2 were observed by the Eddy Current Test(E.C.T.). In particular, the wear at the sixth card location was up to 75%. The test results indicated that the Flow Induced Vibration(F.I.V.) might be the cause of the fretting wear resulting from the contact between Rod Cluster Control Assemblies(RCCAs) and their spacing cards(guide plates) arranged in the guide tube. From reviewing RCCAs fretting wear repots and analyzing the general characteristics of F.I.V. mechanism in the reactor, geometric layout and flow conditions around the control rod, it is concluded that the turbulence excitation is the most probable vibration mechanism of RCCA. To identify the governing mechanism of RCCA vibration, an experiment was performed for a representative rod position in which the most serious fretting wear experienced among the six rod positions. The experimental rig was designed and set up to satisfy the governing nondimensional numbers which are Reynolds number and mass damping parameter. The vibration amplitude measurement by the non-contact laser displacement sensor showed good agreements in the frequency and the maximum wearing(vibration) location with Ulchin E.C.T. results and Framatome report, respectively. The sudden increase in the vibration amplitude was sensed around the 6th guide plate with mass flow rate variation. Comparing the similitude rod behaviour with the idealized response of a cylinder in flow induced vibration, it was found that he dominant mechanism of vibration was transferred from turbulence excitation to periodic shedding at the mass flow ate 90ι/min. Also the critical velocity of the vibration in RCCAs was determined and the vibration can be prevented by reducing the bypass flow rate below the critical velocity.

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Vibration Characteristic Analysis of Gimbal Structure System with Observation Reconnaissance Camera Module (감시 정찰 카메라부를 포함한 짐발 구조 시스템의 진동 특성 해석)

  • Lee, Sang-Eun;Lee, Tae-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.4
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    • pp.409-415
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    • 2011
  • A gimbal system in observation reconnaissance aircraft was fabricated by assembling many parts and bearings. This system consists of a camera module and a stabilization gimbal that supports the camera module. During the flight for recording images, the gimbal system experiences various accelerations with wide frequencies. Although base excitation of stabilization gimbal results in vibration of the camera module, the camera module must be able to capture the correct and clear image even while vibrating. Hence, it is important to know the natural frequencies and vibration modes of the gimbal system with the camera module. Considering bearings as spring elements, the vibration characteristic of the gimbal system was analyzed by finite element method. In addition, harmonic response analysis was performed to determine the correct transmissibility of acceleration for the camera module in the frequency range of 0-500 Hz.

Numerical and Experimental Analysis for Disc Brake Squeal Induced by Caliper Mode (캘리퍼 모드에 의한 디스크 브레이크 스퀼 시험 및 해석)

  • Choi, Hoil;Kang, Jaeyoung;Gil, Hojong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.12
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    • pp.1351-1358
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    • 2014
  • This study numerically simulates brake squeal and validates it experimentally by using a lab-scaled brake dynamometer. The system frequencies of the disc brake are traced with respect to the brake pressure by using a modal test and FEM. Then, the squeal frequencies measured from the brake dynamometer are found to correspond to the brake system mode with the dominant displacement of the caliper and pad. Furthermore, a complex eigenvalue analysis conducted using the finite element model confirms that the caliper mode generating the rotational displacement of the pad becomes unstable owing to the negative friction-velocity slope.

Combined Treatment of Oriental Herbal Medicine and Prescribed Drugs among Cancer Patients (암 환자의 한약${\cdot}$양약 병용투여)

  • Kim, Chun-Bae;Park, Jong-Ku;Koh, Kwang-Wook;Choi, Seo-Young;Yoo, Jun-Sang
    • The Journal of Korean Medicine
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    • v.28 no.2 s.70
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    • pp.205-212
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    • 2007
  • Objectives : Combined treatment (CT) of oriental herbal medicine and prescribed drugs is now being increasingly used among cancer patients around the world. However, in Korea, clinical information on the frequency, efficacy and safety of CT among cancer patients has not yet been thoroughly reported. This study aimed to identify the status and adverse effects of CT for the management of cancer patients. Methods : A questionnaire and medical record survey by oriental medical doctors or physicians were performed at two oriental medical hospitals and one general hospital. Of the initial 400 in-patients, 368 participated in this survey, representing a response rate of 92.0%. Results : Among cancer patients in oriental medical hospitals, the proportion of CT was 45.9%. In contrast, the proportion of CT in the general hospital was only 0.6%. The proportion of CT among breast cancer patients (20) and gastric cancer patients (35) were 85.0% and 51.4%, respectively. The proportion of CT among cancer patients was high in younger, female or married patients groups. 10 respondents (11.1%) among 90 cancer patients experienced several adverse effects including nausea, fatigue, etc. Conclusions : This study suggests that many more patients in oriental medical hospitals than general hospitals use combined treatment of oriental herbal medicine and prescribed drugs for management of cancer. Therefore, medical professionals should provide comprehensive and up-to-date clinical information about potential benefits and risks of CT to cancer patients in Korea.

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