• Title/Summary/Keyword: experimental work

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Rotation of Orthotropy Axes with Work Hardening of Anisotropic Sheet Metals (이방성 금속판재의 가공경화에 따른 직교대칭축의 회전)

  • 김권희;인정제
    • Transactions of Materials Processing
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    • v.5 no.4
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    • pp.320-326
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    • 1996
  • Based upon experimental observations the authors have shown in the previous studies that the orientations of orthotropy axes of anisotropic sheet metals are subjected to change during tensile loading at angles to the rolling direction. To predict the rotations of orthotropy axes under general plane stress conditions, a simple phenomenological model is proposed which accounts for the effect of work hardening. Predictions from the model are compared against the experiments for 0%, 3%, and 6% of 1st tensile prestrains in the rolling direction and 2nd tensile prestrains at 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$ to the 1st prestrains axis. The model showed good agreements with the experimental observations. A new interpretation of the experimental data is suggested regarding the rotations of orthotropy axes.

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Analysis on Effectiveness Research of Clinical Social Work Practice in Korea (한국 임상사회복지실천의 효과성 연구 경향에 관한 연구)

  • Yang, Ok-Kyung
    • Korean Journal of Social Welfare
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    • v.42
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    • pp.225-253
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    • 2000
  • The objective of this study is to analyze the research articles on clinical social work practice effectiveness to build a scientific and scholaristic image of clinical social work practice. The data for analysis were the articles published in 13 professional journals including Korean J. of Social Welfare in the period of 1979 to 1999. The appearance rate of effectiveness studies was 1.28% with only 18 articles. Experimental studies consisted only 4 out of 18, and there were only 10 Quasi-experimental studies. Statistical errors were observed in most studies, so it is too early to call that the clinical social work practice is either effective or not effective. In order to see the comprehensive trends of the clinical social work practice, other clinical papers were also examined. The appearance rate was also as low as 8.75% (effectiveness studies included). While 18 articles were about the therapy model, other clinical papers were about generic practice models. However, those newly developed generic practice models had not yet been widely used nor tested for effectiveness. Thus, the followings were suggested: active research activities with solid methodology, team work with the field, theory and method development, education and re-education, and collaborative team work with other related fields. It was also pointed that the cross analysis of research papers by the publishing period, authors major and other background variables would be useful.

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Effects of improvement of fishing operating system on a coastal improved stow net fishing vessel on the work safety and workload of seafarers (연안개량안강망어선의 조업 시스템 개선이 선원들의 작업 안전과 작업부하에 미치는 영향)

  • Min-Son KIM;Ho-Young CHANG;Bo-Kyu HWANG
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.1
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    • pp.74-84
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    • 2023
  • This paper is the result of a comparative analysis of crew members' workloads using the EMG and OWAS methods according to the fishing process before and after the improvement of the operating system of the experimental vessel, with the aim of improving operational efficiency and safety work of coastal improved stow net fishing vessels. The target crew members were three people with at least five years of experience on board the same fishing vessel as the experimental vessel. After improving the operating system, such as installing a power block crane and two capstans, change the location of the ball-roller, the time required for setting and hauling work decreased (p < .01), and the evaluation results by OWAS showed that the overall workload for setting and hauling net work decreased. The results of muscle activity analysis showed a decrease in lashing anchor work (p < .01) in the case of hauling net and in anchor dropping work in the case of setting net (p < .001). It is judged that the use of ball rollers in net handling has been reduced; consequently, work safety has been improved.

Influencing on the Increase of the Scientific Inquiry Abilities and Attitudes by Using the Work-Sheets for the Differentiated Learning (수준별 학습지 활용 수업이 과학적 탐구 능력과 태도에 미치는 영향)

  • 최윤미;남철우
    • Journal of Korean Elementary Science Education
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    • v.21 no.1
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    • pp.111-125
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    • 2002
  • The aim of this study is to make it sure how pupils' science inquiry skills and attitude are influenced when they are taught by using the work-sheets for the differentiated learning according to their ability. In order to accomplish this aim, two classes of the fourth grade in the elementary school were distinguished into two groups: one was the experimental class and the other, the comparative class. The experimental class was given 52 hours of science lessons using the above sheets, and the comparative class, the general method of teaching. In order to compare their scientific interest and learning ability of the two groups each other, pupils were tested the standardized achievement in advance. The two groups were also given "ex post facto test" to measure the variation of their inquiry skills and attitude after the lessons. In addition, the experimental class was tested to measure their learning attitude after they are teamed the science with the sheets. The results of this study are as follows: 1. According to the percentile statistics of the science inquiry skills test between the two groups, the work-sheets for the differentiated teaming helped pupils develope their inquiry skills remarkably. 2. The work-sheets did not lead to significant difference between the learning ability of boys and girls. 3. The science lesson using the work-sheets showed positive influences in increasing pupils' scientific attitude. 4. About 77.2 percent of pupils accepted the excellent records of the evaluation in the science lesson using the sheets. It can be, therefore, concluded that the science lesson using the work-sheets for differentiated teaming is one of effective science lessons to increasing pupils' science inquiry skills, compared with the general teaching method.

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Men's Work Clothes Jumper Pattern-making and Its Appearance Evaluation through 3-D Clothing Simulation (3차원 가상착의 시뮬레이션을 이용한 20~50대 연령별 남성 작업복 점퍼 패턴 설계 및 외관평가)

  • Park, Gin-Ah;Lee, Woo-Kyoung
    • Journal of Fashion Business
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    • v.16 no.1
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    • pp.103-120
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    • 2012
  • The study aimed to evaluate the appearance of the men's work clothes jumpers developed to suggest the prototype work clothes jumper patterns by using the 3-D clothing simulation technology. The 3-D simulated clothing images considered the upper body features of men in the age range between 20 and 59 in South Korea. A questionnaire survey conducted previously suggested a basic jumper style with shirt collar and snap opening cuffs for the heavy industry workers; and discomforting parts of the work clothes jumper of the subject workers have been referred to for the experimental jumper appearance test. Besides, defining the measurements of men's upper bodies enabled to generate the men's 3-D virtual models representing each age group's average body feature. The significant body measurement factors for men's 3-D body modeling and jumper pattern-making were stature for the height factor; chest, waist and hip circumferences for the circumference factor; waist back, hip and arm lengths and interscye front/back for the length factor; and back neck breadth for the breadth factor and armscye and scye depths for the depth factor. The men's body measurements of 30's were implemented to three experimental jumper pattern-making methods, i.e. the 1st method using the relations based on stature and chest circumference; the 2nd method using the direct body measurements; and the 3rd method adopting the maximum ease amount of given body measurements whether relations or direct measurements except the direct measurement of scye depth. A comparison among the three experimental jumpers' simulated images highlighted that the appropriate ease amount of the jumper gained higher scores in terms of the jumpers' front, side, back and sleeve parts and the total silhouettes. Therefore the 3rd experimental jumper was finally selected for the heavy industry workers.

Development and Evaluation of an Education Program Based on Whole Brain Model for Novice Nurses (신규간호사를 위한 홀 브레인 모델 기반 교육프로그램 개발 및 효과검증)

  • Cho, Moo Yong
    • The Journal of Korean Academic Society of Nursing Education
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    • v.26 no.1
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    • pp.36-46
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    • 2020
  • Purpose: This study was conducted to develop and implement an education program based on the Whole Brain Model for novice nurses, and to evaluate its effects on work performance, interpersonal skills and self-efficacy. Methods: A pretest-posttest quasi-experimental design was used with an experimental group (n=20) and a control group (n=21). The experimental group participated in an education program based on the Whole Brain Model for seven sessions over 4 weeks. An independent t-test, χ2-test, and Mann-Whitney U test were performed to analyze the data. Results: There were statistically significant differences in work performance (p=.015), interpersonal skills (p=.014) and self-efficacy (p=.021) between the experimental and the control group. Conclusion: This program was an effective learning strategy to enhance nursing competence for novice nurses. The novice nurses who participated this program were able to reflect deeply on themselves, improve interpersonal skills, and induce whole-brain integrated thinking in learning how to solve the problems caused by changes in patient conditions that can be experienced in clinical practice. Therefore, this program can be recommended for regular continuing education for novice nurses.

The Performance Analysis to Identify the Reuse and Assembly Impact of Temporary Equipment

  • Bae, Sung-Jae;Park, Jun-Beom;Kim, Jung-Yeol;Kim, Young-Suk;Kim, Jun-Sang;Jo, Jae-Hun
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1252-1252
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    • 2022
  • Temporary work that utilizes temporary equipment (e.g., system scaffold and system pipe support) in construction work is one of the most vulnerable work from a safety perspective in South Korea. Typically, temporary equipment is reused at construction sites. The Korea Occupational Safety and Health Agency announced guidelines regarding the performance standards for reusable temporary equipment to prevent the accidental collapse of temporary facilities. Nevertheless, temporary facilities' collapse still occurs, which could be attributed to a degradation in the performance due to the reuse of temporary equipment. Therefore, this study investigated the performance of simple temporary structures assembled with new and reused equipment. To this end, an experimental module was designed based on previous research cases, and two experimental models were constructed, in which one was assembled using new equipment (Model A), and the other was built using reused equipment (Model B). To determine the performance of each model, a load test was conducted to measure the maximum load that each model could withstand. The experimental results revealed that the maximum load of Model B was 15% lower than that of Model A. This indicates that there is a meaningful performance difference between those two models. Based on this result, the authors decided to perform additional tests with more realistic models than previous ones. The new experimental module was designed to ensure compliance with the Korean design guidelines. In this presentation, the authors show details of the first tests and their results and plan for the additional test.

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Stress jump: experimental work and theoretical modeling

  • Ning Sun;Kee, Daniel-De
    • Korea-Australia Rheology Journal
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    • v.13 no.3
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    • pp.109-123
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    • 2001
  • A stress jump, defined as the instantaneous gain or loss of stress on startup or cessation of a deformation, has been predicted by various models and has relatively recently been experimentally observed. In 1993, Liang and Mackay measured shear stress jump data of xanthan gum solutions, and in 1996, Orr and Sridhar reported extensional stress jump data of Boger fluids. Shear stress jumps of suspensions and liquid crystal polymers have also been observed. In this contribution, experimental work as well as a variety of theoretical models, which are able to predict a stress jump, are reviewed.

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Phase Separations in Random Copolymer Solutions by Continuous Thermodynamics (연속열역학을 이용한 랜덤공중합체 용액의 상분리)

  • Sheo, Shin-Ho;Kim, Ki-Chang;Lee, Kwang-Rae
    • Journal of Industrial Technology
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    • v.18
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    • pp.277-287
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    • 1998
  • In this work continuous thermodynamics was adopted for describing the influence of copolymer polydispersity on phase separations in random copolymer solutions. Continuous themodynamic frameworks were formulated using the Flory-Huggin's excess Gibbs free energy model in which the concentration- and temperature-depentent terms of interaction parameter x were modified. Cloud-point curves and coexistence curves of poly(ethylene-vinylactate)/methylacetate solutions and poly(ehtylene-vinylacetate)/ethylacetate solutions were measured, and experimental data were fitted with theoretical relations formulated in this work. Calculated could-point curves were more good ageeable with experimental data than the modified Flory-Huggins's relations. Coexistence curves which were evaluated by using parameters of x estimated from experimental cloud-point curves, were found to coincide with experimental data.

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Experimental and numerical analysis of mixed mode I/III fracture of sandstone using three-point bending specimens

  • Li, Yifan;Dong, Shiming;Pavier, Martyn J.
    • Structural Engineering and Mechanics
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    • v.76 no.6
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    • pp.725-736
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    • 2020
  • In this work the mixed mode I/III fracture of sandstone has been studied experimentally and numerically. The experimental work used three-point bending specimens containing pre-existing cracks, machined at various inclination angles so as to achieve varying proportions of mode I to mode III loading. Dimensionless stress intensity factors were calculated using the extended finite element method (XFEM) for and compared with existing results from literature calculated using conventional finite element method. A total of 28 samples were used to conduct the fracture test with 4 specimens for each of 7 different inclination angles. The fracture load and the geometry of the fracture surface were obtained for different mode mixities. Prediction of the fracture loads and the geometry of the fracture surface were made using XFEM coupled with a cohesive zone model (CZM) and showed a good comparison with the experimental results.