• Title/Summary/Keyword: control period

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Precision Position Control of PMSM using Neural Observer and Parameter Compensator

  • Ko, Jong-Sun;Seo, Young-Ger;Kim, Hyun-Sik
    • Journal of Power Electronics
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    • v.8 no.4
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    • pp.354-362
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    • 2008
  • This paper presents neural load torque compensation method which is composed of a deadbeat load torque observer and gains compensation by a parameter estimator. As a result, the response of the PMSM (permanent magnet synchronous motor) obtains better precision position control. To reduce the noise effect, the post-filter is implemented by a MA (moving average) process. The parameter compensator with an RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller. The parameter estimator is combined with a high performance neural load torque observer to resolve problems. The neural network is trained in online phases and it is composed by a feed forward recall and error back-propagation training. During normal operation, the input-output response is sampled and the weighting value is trained multi-times by the error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. As a result, the proposed control system has a robust and precise system against load torque and parameter variation. Stability and usefulness are verified by computer simulation and experiment.

The Effect of Backward Walking Exercise using a Mirror on Balance and Gait in Patients with Stroke (거울을 이용한 뒤로 걷기 운동이 뇌졸중 환자의 균형과 보행능력에 미치는 영향)

  • Kang, Tae-Woo;Kim, Beom-Ryong
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.2
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    • pp.53-60
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    • 2018
  • PURPOSE: This study aimed to identify the effect of a backward walking exercise using a mirror on balance and gait in patients with stroke. METHODS: Twenty subjects with post-stroke hemiparesis volunteered to participate in this study. The experimental and control groups performed backward walking exercise plus conventional therapy or conventional physical therapy, respectively, for 6 weeks. Assessment instruments included the Berg Balance Scale (BBS), timed up and go test (TUG), and 10-m walking test (10MWT). Evaluation was performed before and after the 6-week training period. We conducted a paired t-test to compare the within-group changes before and after the intervention. An independent t-test was used to compare between-group differences. The statistical significance level was set at ${\alpha}=.05$ for all variables. RESULTS: The experimental group showed a significant within-group change in the BBS, TUG, and 10MWT (p<.05). The control group also showed a significant change (p<.05). A significant difference was observed between the experimental and control groups with regard to changes in the BBS, TUG, and 10MWT results after the interventions (p<.05). CONCLUSION: This study demonstrated that backward walking exercise using a mirror may be valuable for future research. Further studies with a wider range of pathology and longer experiment duration are required to validate the results of the present study.

Studies on the development of the tick (Haemaphysalis longicornis)-vaccine (I) - Immune responses on the crude soluble - (진드기 백신 개발을 위한 기초연구(I) - 수용성 항원에 대한 면역반응에 관하여 -)

  • Jeong, Woo-seog;Kang, Seung-won;Choi, Eun-jin;Yoon, Yong-dhuk
    • Korean Journal of Veterinary Research
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    • v.36 no.3
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    • pp.693-698
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    • 1996
  • Haemaphysalis longiscornis is the common cattle tick of great economic importance in Korea. Chemical control using dips or sprays has been the traditional method of attempting to kill these ticks during the infestation period. However, the presence of resistant forms to chemical, the rising costs of acaricides and environmental problems have made it almost impossible to use these chemicals on a regular basis according to the pest problem. For this reason, vaccination against ticks and breeding for host resistance against ticks are being studied. In order to determine the common proteins and antigens according to developmental stages, SDS-PAGE and western blotting were performed. In SDS-PAGE 103.3kD and 98.3kD proteins were observed as common proteins, and these proteins were observed as common antigens in western blotting. Unimmunized rabbits were infestated three times with H longicornis. The weight of the second and the third engorged ticks were 0.153g and 0.104g respectively. This weight is 69% and 47% of the first engorged ticks weight respectively. Immunized rabbits by adult ticks antigen and control were infested with H longicornis. The control taked 3-4 days to fully engorge, but the immunized rabbits taked about 7 days. So adult tick antigen may be effective to render the immunity to host.

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A Study on Peripheral T Cell Subsets in Patients with Thyroid Tumors (갑상선 종양에 있어서 말초혈의 T 세포 Subset에 관한 연구)

  • Kim, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.25 no.1
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    • pp.110-116
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    • 1991
  • To elucidate alteration of peripheral T cell subsets in thyroid tumors, the author enumerated T cell subsets in periphral blood by indirect immunofluorescent method, using monoclonal antibodies (CD3, CD4 and CD8) in 17 cases of thyroid cancer, 12 cases of thyroid adenoma, and 16 cases of adult healthy subjects as controls. Diagnoses were confirmed histopatologically in thyroid cancer and adenoma, and were established on the basis of commonly accepted clinical and biochemical criteria in Hashimoto's thyroiditis. The blood was drawn from veins of the patients and control subjects in Pusan National University Hospital during the period of January to October 1990. The results obtained were summarized as follow: 1) The percentage of CD3+ cells was significantly decreased in thyroid cancer as compared with healthy subjects. 2) The percentage of CD4+ cells was not different among thyroid cancer, thyroid adenoma, Hashimoto's thyroiditis and control subjects each other. 3) The percentage of CD8+ cells was significantly decreased in thyroid cancer as compared with adult healthy subjects, and tended to be decreased as compared with thyroid adenoma and Ha-shimoto's thyroiditis. 4) The CD/CD8 ratio was significantly increased in thyroid cancer as compared with control subjects, and tended to be increased as compared with thyroid adenoma and Hashimoto's thyroiditis. On the basis of the results, it can be suggested that the immunodysfunction may be due to decreased soppressor/cytotoxic T cells in thyroid cancer.

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Effects of Black Sugar® and Mineral® Supplementation on Growth performance and Meat Quality of Hamwoo Steers in Fattening Period

  • Kim, Kwan Sik;Lee, Sang Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.34 no.3
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    • pp.202-208
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    • 2014
  • This study was carried out investigate the effects of dietary addition of mineral and sugar on the dry matter intake, daily gain, yield grade and quality grade of Hanwoo (Bos taurus coreanae) steers. Three diets fed to steers included a control diet (concentrate mix and rice straw : C) and two treatments diet (control diet + black sugar 100 g + mineral 100 g : T1, and control diet + black sugar 150 g + mineral 50 g : T2). The results are summarized as follows; total feeding intake, body weight gain and daily gain did not show significant differences among the three treatments. Cold carcass weight was significantly (p<0.05) higher in T2 than in the other two treatments (C and T1). There was no significant difference in yield traits of back fat thickness, longissimus muscle area and yield grade among the three treatments (C, T1 and T2). Marbling score showed significantly (p<0.05) higher in order of T2 (5.67) > T1 (4.67) > C (3.67). Meat color, fat color, texture and maturity were no significant difference. Quality grade was higher in T2 than in the other two treatments (C and T1), but there was no significant difference. The results show that marbling score and quality grade of Hanwoo can be increased by high dry matter intake with feeding addition of mineral and sugar.

Properties and Quality Characteristics of the bread with added Moroheiya powder (모르헤이야 분말을 첨가한 식빵의 품질 특성)

  • Kim Hee-Joo;Chang Sang-Keun;Kim Hye-Jung
    • Korean journal of food and cookery science
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    • v.21 no.4 s.88
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    • pp.416-421
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    • 2005
  • This study was conducted to investigate the effect of the addition of moroheiya powder on the baking qualities of the bread. Three different powder concentration levels of $0.2\%,\;0.5\%\;and\;1.0\%$ were added to flour to make the bread. The volume of the bread dough containing moroheiya powder tended to be increased compared to that of control during the fermentation period. The percentage of baking loss of the bread containing moroheiya powder tended to be less than that of control. In the texture analyzer measurement, the hardness of the bread was significantly increased by adding the moroheiya powder Springiness, gumminess and brittleness of the bread tended to increase and were all higher in the bread containing $0.5\%$ moroheya powder than in the other breads. In sensory evaluation, the bread containing $0.2\%$ moroheiya powder showed a similar tendency with control and showed the best scores, especially in taste.

The Effect of Fresh Ginseng on the Quality Characteristics of Seukbakjee (수삼의 첨가가 섞박지의 품질특성에 미치는 영향)

  • Lim, Hee Jung
    • Korean journal of food and cookery science
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    • v.15 no.6
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    • pp.618-625
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    • 1999
  • This study was conducted to investigate the effect of fresh ginseng on the physicochemical, microbiological and sensory properties of Seukbakjee during 45 days of fermentation. Seukbakjee with various levels(0, 2, 4, 6%) of fresh ginseng were fermented at $4^{\circ}$. During fermentation, the pH values were lowered in all Seukbakjee samples, however, those with fresh ginseng were a little higher than control Seukbakjee. Acidity increased continuously during the entire fermentation, in which those of added fresh ginseng increased less than control. As the concentration of fresh ginseng increased, the pH of Seukbakjee were increased. Saltiness was maintained at 1.37~2.62% levels during the whole fermentation. The degree of degradation of reducing sugar and free sugar was much delayed in Seukbakjee added with fresh ginseng. Total vitamin C content of Seukbakjee with fresh ginseng was higher than that of Seukbakjee without fresh ginseng. The number of total bacteria and lactic acid bacteria in Seukbakjee with fresh ginseng was higher than control during the entire fermentation period. In sensory evalution, Seukbakjee with 4% fresh ginseng was the best for taste and flavor. Seukbakjee with 2% fresh ginseng was the best for texture and overall acceptability. Above results suggest that the addition of fresh ginseng improves the quality of Seukbakjee.

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Effect of Weight Shift Training with Electrical Sensory Stimulation Feedback on Standing Balance in Stroke patients

  • Kim, Da-young;Cha, Yong-jun
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.3
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    • pp.39-45
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    • 2015
  • PURPOSE: The purpose of this study was to investigate the effect of weight shift training with electrical sensory simulation feedback on quiet standing balance in hemiplegic stroke patients. METHODS: 30 stroke patients were equally allocated at random to an experimental group or a control group. Patients in both two groups underwent comprehensive rehabilitation physical therapy for 30 minutes per day for 5 days per week for 4 weeks. Members of the experimental group received additional weight shift training with electrical sensory simulation feedback was conducted for 15 minutes after 30 minute sessions, whereas members of the control group underwent additional leftward/rightward weight shift training by themselves after 30 minutes per day for four weeks. COP (center of pressure) path lengths, COP velocities, and foot forces were measured before and immediately after the 4-week training period in both groups and results were compared. RESULTS: COP path lengths significantly decreased by 3% after training in the experimental group and this was significantly greater than that observed in the control group (p<0.05). In both groups, foot forces of affected sides showed significant increases after intervention, whereas foot forces of unaffected sides showed significant decreases (p<0.05). No significant difference was observed between the two groups with respect to these changes. CONCLUSION: Weight shift training using electrical sensory simulation feedback has a positive effect on quiet standing balance in hemiplegic stroke.

Plant-derived Antibacterial Metabolites Suppressing Tomato Bacterial Wilt Caused by Ralstonia solanacearum

  • Vu, Thuy Thu;Choi, Gyung Ja;Kim, Jin-Cheol
    • Research in Plant Disease
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    • v.23 no.2
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    • pp.89-98
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    • 2017
  • Ralstonia solanacearum species complex (RSSC) causes bacterial wilt, and it is one of the most important soil-borne plant pathogenic bacteria. RSSC has a large host range of more than 50 botanical families, which represent more than 200 plant species, including tomato. It is difficult to control bacterial wilt due to following reasons: the bacterial wilt pathogen can grow inside the plant tissue, and it can also survive in soil for a long period; moreover, it has a wide host range and biological diversity. In most previous studies, scientists have focused on developing biological control agents, such as antagonistic microorganisms and botanical materials. However, biocontrol attempts are not successful. Plant-derived metabolites and extracts have been promising candidates to environmentally friendly control bacterial wilt diseases. Therefore, we review the plant extracts, essential oils, and secondary metabolites that show potent in vivo antibacterial activities (in potted plants or in field) against tomato bacterial wilt, which is caused by RSSC.

Experimental Study of the Effect on Cabin Thermal Comfort for Cold Storage Systems in Vehicles (축냉 시스템이 차 실내 열 쾌적성에 미치는 영향에 관한 실험적 연구)

  • Lee, Daewoong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.4
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    • pp.428-435
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    • 2015
  • This paper presents the experimental study of cabin thermal comfort using a cold storage heat exchanger in a vehicle air-conditioning system. Recent vehicle-applied ISG functions for fuel economy and emission, but when vehicles stop, compressors in the air-conditioning system stop, and the cabin temperature sharply increases, making passengers feel thermal discomfort. This study conducts thermal comfort evaluation in the vehicle, which is applied to a cold storage system for the climate control wind tunnel test and the vehicle fleet road test with various airflow volume rates and ambient temperatures blowing to the cold storage heat exchanger. The experimental results, in the cold storage system, air discharge temperature is $3.1-4.2^{\circ}C$ lower than current air-conditioning system when the compressor stops and provides cold air for at least 38 extra seconds. In addition, the blowing airflow volume to the cold storage heat exchanger with various ambient temperature was examined for the control logic of the cold storage system, and in the results, the airflow volume rate is dominant over the outside temperature. For this study, a cold storage system is economically useful to keep the cabin at a thermally comfortable level during the short period when the engine stops in ISG vehicles.