• Title/Summary/Keyword: Experimental

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A Study on the Vibrational Characteristics of the Continuous Circular Cylindrical Shell with the Multiple Supports Using the Experimental Modal Analysis (실험모드해석에 의한 다점지지된 연속원통셸의 진동특성에 관한 연구)

  • 한창환;이영신
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.4
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    • pp.43-51
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    • 2001
  • An experimental modal analysis is the process to identify structure's dynamic characteristics such as resonant frequencies, damping values and mode shapes. An experimental model was made of stainless steel in the shape of a circular cylindrical shell and installed on the test bed with jigs. For investigating vibrational characteristics of the continuous circular cylindrical shell with intermediate supports, modal testing is performed by using impact hammer, accelerometer and 8-channel FFT analyzer. The frequency response function(FRF) measurements are also made on the experimental model within the frequency range from 0 to 4kHz. Modal parameters are identified from resonant peaks in the FRF's and animated deformation patterns associated with each of the resonances are shown on a computer screen. The experimental results are compared with analytical and FEA results.

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Histological and Immunohistological Studies of the Thyroid Glands of the Osteoporotic Rats Induced by Ovariectomy (난소절제로 유발된 골다공증 시 흰쥐 갑상샘에 대한 조직학적 및 면역조직화학적 연구)

  • 김대영;구세광;이재현;장인호;이형식
    • Journal of Veterinary Clinics
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    • v.15 no.2
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    • pp.235-241
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    • 1998
  • In order to investigate the histological and immunohistochemical changes of thyroid glands, and serum osteocalcini estradiol, pmgesterone, follicular-stimulating hormone (FSH), and calcium levels in the osteoporotic rats induced by ovariectomy, normal(sham-operated group) and experimental groups(ovariectomized group) were divided. The experimental groups were subdivide6 to 5, 10, 15, and 20 weeks after ovariectomized groups. The histological structure of the thyroid gland were observed in normal structure throughout all experimental periods but the calcitonin-immunoreartive cells in the experimental groups were significantly decreased compared with normal groups and degranulations of calcitonin-immunoreactive cells were observed. Theses numbers were decreased with time after ovariectomy. However, the serum osteocalcin and FSH levels of experimental groups were significantly increased compared with normal groups and these levels were increased along with time after ovariectomy, but serum estradiol, progestemn and calcium levels of experimental group were significantly decreased compared with normal groups and these levels were decreased with time after ovariectomy.

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Experimental Method in Library and Information Science Research (문헌정보학에 있어서의 실험적 연구 방법)

  • Chang Hye-Rhan
    • Journal of the Korean Society for Library and Information Science
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    • v.25
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    • pp.325-341
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    • 1993
  • The experimental method, when carried out properly, is the most powerful way of seeking answers to research questions. The purpose of this study is to provide practical and theoretical insights as well as to discuss technical skills needed to design and implement the experimental research in library and information science. The levels of empirical research methods, the logic and types of the experimental designs, the application status of the experimental methods through content analysis of the published papers, and strategies to plan the research and to collect and analyze data are examined. This study also brings suggestions how experimental research can be made more meaningful and puts emphasis on the need of the research method education in library and information science field.

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Experimental Design for Port Investment Analysis : A Case Study in a Bulk Terminal (항만투자분석을 위한 실험계획법 : 산물터미널에서의 사례연구)

  • Chang, Young-Tae
    • Journal of the Korea Society for Simulation
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    • v.11 no.3
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    • pp.1-12
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    • 2002
  • Experimental design in simulation provides an efficient way of economizing simulation runs since a considerable number of simulation runs that originally were planned can be reduced by this approach. This experimental design method is an active area of research together with the output analysis and so no single panacea seems to exist so far. Thus, selection of techniques of experimental design and output analysis more likely depends upon the objective of simulation analysis, budget constraint and sometimes the analyst's subjective judgment. This paper attempts to describe an experimental design methodology for port investment analysis using a case study in a bulk terminal in Korea. Detailed display will be focused on simulation period, warm-up period, the number of replications needed in production runs after brief explanation on the system configuration.

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A study on simplified Textile testing apparatus for teaching high school students (중고등학교 피복재료 학습효과를 높이기 위한 시험장치 개발에 관한 연구)

  • 장경연
    • Journal of the Korean Home Economics Association
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    • v.26 no.2
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    • pp.69-79
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    • 1988
  • This study was to increase the experimental learning effect of textile materials in middle and high school. To this study, three kinds of simply devised apparatus were used for warmth retaining test, air permeability test and static electricity test. Two classes were chosen in a girls' high school comparing learning effect and classified the theoretical learning group and the experimental learning group. In the experimental group, a teaching plan to teach the properties of textile materials was made to use these apparatuses. The results were. 1. In the interest on the unit either the theoretical learning group or the experimental learning group were not different significantly. 2. In the items facilitation of motivation, unsatisfied desires and prevention of failure, effect of transfer and development of inquiry power, both groups were significant. 3. For the purpose of comparing the learning effect, two groups were examined for determining the level of understanding after teaching properties of textile materials. The mean value of the experimental learning group was higher than that of the theoretical learning group. The experimental learning group had more higher markers(over the point of 90) than the theoretical learning group.

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Experimental Study on the Evaluation of Heat Transfer Characteristics of Buildings' External Walls -Focusing on the winter heat transfer characteristics of four experimental model buildings in accordance with the location of insulation- (건물(建物) 외벽(外壁)의 전열특성(傳熱特性) 평가(評價)에 관한 실측(實測) 연구(硏究) - 단열재 위치에 따른 실험용 건물의 겨울철 열특성 평가를 중심으로 -)

  • Sohn, J.Y.;Yoon, D.W.;Park, J.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.3
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    • pp.228-234
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    • 1989
  • This paper describes the experimental thermal performance results of four experimental model buildings insulated differently. For the purpose of examining the thermal characteristics of external walls and indoor thermal conditions, four experimental model buildings are constructed as externally insulated, internally insulated, non-insulated &light-weight curtain wall types with different K-values and heat capacities, respectively.
    Through the measurements of temperatures at various points and solar insolation, the effects of insulation and heat capacities are evaluated, and the evaluated effects of each experimental model buildings are compared. Hence, the characteristics of temperature profiles, time-lag effects and decrement factors are discovered.

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Object Recognition Algorithm with Partial Information

  • Yoo, Suk Won
    • International Journal of Advanced Culture Technology
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    • v.7 no.4
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    • pp.229-235
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    • 2019
  • Due to the development of video and optical technology today, video equipments are being used in a variety of fields such as identification, security maintenance, and factory automation systems that generate products. In this paper, we investigate an algorithm that effectively recognizes an experimental object in an input image with a partial problem due to the mechanical problem of the input imaging device. The object recognition algorithm proposed in this paper moves and rotates the vertices constituting the outline of the experimental object to the positions of the respective vertices constituting the outline of the DB model. Then, the discordance values between the moved and rotated experimental object and the corresponding DB model are calculated, and the minimum discordance value is selected. This minimum value is the final discordance value between the experimental object and the corresponding DB model, and the DB model with the minimum discordance value is selected as the recognition result for the experimental object. The proposed object recognition method obtains satisfactory recognition results using only partial information of the experimental object.

Identification of the strain-dependent coefficient of permeability by combining the results of experimental and numerical oedometer tests with free lateral movement

  • Balic, Anis;Hadzalic, Emina;Dolarevic, Samir
    • Coupled systems mechanics
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    • v.11 no.1
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    • pp.1-14
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    • 2022
  • The key parameter that affects the consolidation process of soil is the coefficient of permeability. The common assumption in the consolidation analysis is that the coefficient of permeability is porosity-dependent. However, various authors suggest that the strain-dependency of the coefficient of permeability should also be taken into account. In this paper, we present results of experimental and numerical analyses, with an aim to determine the strain-dependency of the coefficient of permeability. We present in detail both the experimental procedure and the finite element formulation of the two-dimensional axisymmetric numerical model of the oedometer test (standard and modified). We perform a set of experimental standard and modified oedometer tests. We use these experimental results to validate our numerical model and to define the model input parameter. Finally, by combining the experimental and numerical results, we propose the expression for the strain-dependent coefficient of permeability.

Development and evaluation of a pediatric nursing competency-building program for nursing students in South Korea: a quasi-experimental study

  • Koo, Hyun Young;Lee, Bo Ryeong
    • Child Health Nursing Research
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    • v.28 no.3
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    • pp.167-175
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    • 2022
  • Purpose: The present study aimed to develop and examine the effectiveness of a pediatric nursing competency-building program for nursing students. Methods: This was a quasi-experimental study with a nonequivalent control group pretest-posttest design conducted between October and December 2021. The participants included 40 nursing students (20 each in the experimental and control groups) at a university in a South Korean city. The pediatric nursing competency-building program integrated problem-based learning and simulation into clinical field practice. The experimental group participated in the program, while the control group did not. Data were analyzed using the 𝑥2 test, the independent t-test, and repeated-measures analysis of variance. Results: Pediatric nursing competency and clinical performance showed a greater increase in the experimental group than in the control group. However, the change in problem-solving ability in the experimental group was not significantly different from that in the control group. Conclusion: The pediatric nursing competency-building program effectively improved students' pediatric nursing competency and clinical performance.