• Title/Summary/Keyword: Control experiment

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A Study on the Manufacture of Lower Control Arm by Casting/Forging Process (주조/단조 기술을 이용한 알루미늄 Lower Control Arm 제조에 관한 연구)

  • 유민수;권오혁;배원병
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.139-142
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    • 2003

  • In this study, casting/forging process was used to produce an aluminum lower control arm for automobiles. Firstly, casting experiments were carried out to get an enhanced preform for forging the lower control arm. In the casting experiment, the effect of an additive, Sr, on the mechanical properties such as tensile strength and elongation and the microstructure of a cast preform were investigated. And a finite element analysis was peformed to determine an optimal configuration of the cast preform. Lastly, a forging experiment was carried out to make the final product of aluminum lower control arm by using the above cast preform. In the casting experiments, when 0.025% Sr was added into molten A356, the maximum values of tensile strength and elongation of the cast preform were obtained. In the forging experiment, It was confirmed that the optimal configuration of a cast preform predicted by FE analysis was very useful. The cast/forged product using designed preform was made without any defects.

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Vibration control of the vibration isolation system using the electromagnetic actuator (전자석 액츄에이터에 의한 수동방진 테이블의 제어)

  • Choi, Hyun;Lee, Jung-Youn
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.227-232
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    • 2003

  • As the most precision equipment requiring very strict vibration environment are vulnerable to the surrounding vibration condition, they adapt the passive or active vibration isolation system. When it comes to the passive isolation system, the resonance of the isolation system causes excessive resonance response, and finally results in the degrade the equipment performance. This paper deals with the active control method to control this resonance induced response, and includes the experiment on the active control for controlling the resonance response on the table against the excitation of the same frequency with the natural frequency of the isolation system. The electromagnetic actuator was designed and the control effect was verified by the experiment. The experiment showed that the electromagnetic actuator is effective for controlling the low frequency isolation resonance response of the precision equipment.

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Effects of Feeding Single or Multiple Probiotics on Performance and Intestinal Microflora of Broiler Chicks (단일 및 혼합 생균제의 급여가 육계의 생산성 및 장내 미생물에 미치는 영향)

  • 류경선;여영수;류명선;박홍석;김상호
    • Korean Journal of Poultry Science
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    • v.28 no.1
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    • pp.41-47
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    • 2001

  • Two experiments were conducted to investigate the effents of feeding single or combined probiltics on performance and intestinal micreflora of broiler chicks for five weeks. Diets based on corn and soybean meal contained 21.50, 19% CP and 3,100, 3,150kcal/kg ME for starting and finishing period, respectively. Lactobacillus salvarius isolated from chicks intestine(LSC), Lactobacillus salvarius isolated from piglet(LSP), Bacillus polyfermenticus(BP) were fed with alone and mixed ones at the level of 0.21 and 0.1% in experiment 1 and 2, respectively. Three hundred eighty four chicks were randomly assigned to eight treatments with four replicates of 12 chicks each per treatment. Weight gain, feed consumption, feed conversion ratio(FCR) were weekly measured for 5 weeks. The number of intestinal micreflora was examined at the end of experiment. In both experiments, weight gain of chicks fed probiltics tended to be similar or higher than control, but was not in LSC+LSP treatment. Feed intake was not consistent among treatments. In experiment 1, FCR of chicks fed LSC alone was the lowest of all treatments, whereas it was significantly higher in LSC+LSP treatments than control(P〈0.05). In experiment 2, LSP supplemental groups tended to increase FCR compared to the control. The number of ileal E. coli was the lowest in LSP alone treatment of experiment 1, whereas cecal E. coli was higher concentration in probiotics supplemental groups than control. Total Lactobacillus of chicks fed probiotics was decreased in ileum, but was no consestency in cecum. In experiment 2, ileal total yeast tended to be higher in probiotics supplemental groups except LSP alone supplement than control. Total Lactobacillus of chicks fed LSC or LSP alone treatments was significantly higher than control(P〈0.05).

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Micro-current Treatment Effects on Pain, Balance of the Degenerative Knee Arthritis (미세전류치료가 퇴행성 무릎관절염 환자의 통증과 균형에 미치는 영향)

  • Chung, Joonsung;Cho, Namjeong
    • Journal of The Korean Society of Integrative Medicine
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    • v.3 no.2
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    • pp.9-16
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    • 2015

  • Purpose: The purpose of this research was to ascertain the effect of Micro-current on a pain, balance, of knee joint in the patients with degenerative arthritis. Method: The 30 subjects who had micro-current in this research and randomly assigned into two group, an experiment group and a control group. micro-current was applied to 15 subject in the experiment group after general physical therapy. experiment group was applies general therapies and micro-current stimulation. The measurement were analyzed by using SPSS(V.20). In order to compare the post to the amount of pre-changes and post-changes of each group, the paired t-test was used. The difference between the experiment group and the control group was analyzed by using the analysis of convariance. Results: The results of this study were as follows; 1) In VAS measures, the pain point was significantly decreased in both the experimental and the control group. 2) Mc Gill Pain Questionnaire(MPQ), the pain point was significantly decreased in both the experimental and the control group. 3) TUG measures, the second was significantly decreased in both the experimental and the control group. 4) Weight distribution measures, the authority was significantly decreased in both the experimental and the control group. Conclusion: The micro-current is considered a degenerative knee arthritis that can be presented as an effective physical therapy intervention.

  • https://doi.org/10.15268/ksim.2015.3.2.009 인용 PDF KSCI