• Title/Summary/Keyword: control period

Search Result 9,308, Processing Time 0.04 seconds

Application of the Robust Control Theory to the Dynamic Voltage Restorer

  • Y. Chun;Kim, J.;J. Jeon
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.38.2-38
    • /
    • 2001
  • Recent trend of increasing automated factories needs supply of high quality power from the utilities. Among the items of the power quality, voltage sag can be compensated by Dynamic Voltage Restorer(DVR). The key feature of the DVR is high response with less transient period to recover from the voltage sag due to the lightning or line-to-ground faults. In this paper we report that H controller is very premising for the practical application to the controller of DVR. Experiment al results shown in this paper was obtained by applying the control algorithm to 20 kVA DVR system. The experimental set consist s of IGBT - based three phase inverter and the TMS320C32- 60 DSP used for main processor of the control board. T$\infty$ simulate the 50% voltage ...

  • PDF

The Effects of the Fun Factor and Immersion of marine Sports on Leisure Satisfaction (해양스포츠 참가자의 재미요인과 몰입이 여가만족에 미치는 영향)

  • Jang, Jae-Yong;Kwon, Oh-Ryun;Kang, Shin-Beum
    • Journal of Navigation and Port Research
    • /
    • v.37 no.1
    • /
    • pp.101-111
    • /
    • 2013
  • The following study holds its purpose on verifying primary fun factors of participation and satisfaction on marine sports. The results are: 1)The efficiency, effectiveness of exercise, self-satisfaction, and family support turned out to be higher in the group with longer and higher period, time, and frequency of participation than those of the control group. 2) The period of participation, speculation on engagement according to the frequency, and behavioral factors were shown to be higher in the group with longer and higher period, time, and frequency of participation than those of the control group. 3) Satisfaction on leisure on social, physical, emotional, and educational means were higher in the group with longer and higher period, time, and frequency of participation than those of the control group. 4) The fun factors of marine sports- self-satisfaction, effectiveness of excercise, efficiency, and family support- had a positive effect on increasing satisfaction in leisure. 5) The fun factors of marine sports- effectiveness of excercise, self-satisfaction, and family support- had a positive effect on increasing satisfaction in leisure. 6) The speculation of engagement in sports and the reinforcement of engagement had a positive effect on increasing satisfaction of leisure.

The Effects of Auricular Acupressure on Sleep Disorder in The Elderly: A Systematic Review and Meta-analysis (이압요법이 노인의 수면 장애 개선에 미치는 효과에 대한 체계적 문헌고찰 및 메타분석)

  • Jang, Minjin;Park, Hyojung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.6
    • /
    • pp.116-126
    • /
    • 2020
  • This study analyzed the effects of auricular acupressure on improving sleep disorders of the elderly. The data was collected from domestic and foreign databases. The keywords were 'auricular,' 'sleep,' 'insomnia, and so on. RoB and RoBANS were used to evaluate the risk of bias in the selected literature. Meta-analysis was performed using RevMan 5.3. Seven of 386 studies were selected. Regarding the sleep score, those studies with an intervention period of less than four weeks showed WMD of 25.66 (95% CI; 20.18 to 31.14), which was significantly higher than that of the control group. Similarly, the studies with an intervention period longer than four weeks had significantly higher WMD than that of the control group, and the former exhibited WMD of 8.59 (95% CI: 6.26 to 10.92). In contrast, sleep satisfaction was significantly higher in the studies with a maintenance period of three days or less, which resulted in SMD of 13.37 (95% CI: 5.29 to 21.45). The score in the studies with a maintenance period longer than four days was significantly higher than that of the control group with SMD of 2.27 (95% CI: 1.82 to 2.72). Auricular acupressure was effective in alleviating sleep disorders among the elderly in terms of both sleep quality and sleep satisfaction.

Quality Changes of Cherry Tomato by Aqueous Chlorine Dioxide Treatment during Storage (이산화염소수 처리에 의한 방울토마토의 저장 중 품질 변화)

  • Lee, Kyung-Haeng;Yoon, Young-Tae;Ra, So-Jung
    • The Korean Journal of Food And Nutrition
    • /
    • v.28 no.3
    • /
    • pp.396-403
    • /
    • 2015
  • To improve the shelf-life of cherry tomato, samples were treated with aqueous chlorine dioxide ($ClO_2$) at 30 ppm for 0~30 minutes and the weight loss rate as well as the changes in physico-chemical and sensory properties of treated samples were investigated. Weight change in the control and in the samples with aqueous $ClO_2$ treatment were decreased slightly, and there were no difference during the storage period. There were no differences in soluble solid content among the treatments and during the storage period. There were no differences in the firmness of samples among the treatments but the firmness of the aqueous $ClO_2$ treated samples were decreased slower than that of the control samples. No significant changes in lightness, redness and yellowness of the controls and the samples by aqueous $ClO_2$ treatment were observed during 4 weeks storage period. The sensory parameters including taste, flavor, color, texture and overall acceptance at the initial period did not differ among the treatments. The scores for taste, texture and overall acceptance of the control were decreased faster than those of the aqueous $ClO_2$ treated samples when 3 weeks reached.

Effect of inoculation of Lactobacillus plantarum isolated from swine feces on fermentation characteristics of hulless barley

  • Jeong, Yong Dae;Lee, Jung Jae;Seol, Kuk-Hwan;Kim, Doo Wan;Min, Ye Jin;Yu, Dong Jo;Cho, Kyu Ho;Kim, Young Hwa
    • Korean Journal of Agricultural Science
    • /
    • v.44 no.4
    • /
    • pp.558-565
    • /
    • 2017
  • This study was conducted to determine the effect of inoculation of microorganism isolated from pig feces on nutrient contents of fermented hulless barley. The microbial flora in feces of a total of four crossbred piglets ($Landrace{\times}Yorkshire{\times}Duroc$) was analyzed by 16s rRNA sequencing. The most abundant strain was then selected for fermentation of hulless barley. Lactobacillus plantarum (L. plantarum) was dominant (64.56%) in intestinal microbial flora in the pig feces. The selected candidate strain showed significantly higher survival rate at pH 7 than at pH 2.5 and 3.0 (p < 0.05). Incubated culture containing the candidate strain showed an increased growth rate with lower pH levels after 7.5 h incubation compared to initial incubation period (p < 0.05). When compared with commercial multiple probiotics which were used as control, the selected strain showed faster growth rate at 5 h post-incubation (p < 0.05). During the fermentation period, neither inoculated nor non-inoculated control hulless barley showed any change in pH value. Crude fat, fiber and ash contents were lower (p < 0.05) in hulless barley inoculated by the selected strain compared to control. However, moisture, energy, NDF and ADF were not affected by the inoculation of strain or fermentation period. Lactic acid was increased and acetic acid was decreased in the hulless barley inoculated with the selected strain during the fermentation period (p < 0.05). Taken together, our results suggest that L. plantarum derived from the pigs could be utilized as a new microorganism for manufacturing fermented feed stuffs.

Effects of Lonicera japonica extract on performance, blood biomarkers of inflammation and oxidative stress during perinatal period in dairy cows

  • Zhao, Yiguang;Tang, Zhiwen;Nan, Xuemei;Sun, Fuyu;Jiang, Linshu;Xiong, Benhai
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.33 no.7
    • /
    • pp.1096-1102
    • /
    • 2020
  • Objective: An experiment was conducted to evaluate the effects of Lonicera japonica extract (LJE) on milk production, rumen fermentation and blood biomarkers of energy metabolism, inflammation and oxidative stress during the perinatal period of Holstein dairy cows. Methods: Eighteen Holstein dairy cows were used in a complete randomized design experiment with 3 dietary treatments and 6 cows per treatment. All cows received the same basal total mixed ration (TMR) including a prepartal diet (1.35 Mcal of net energy for lactation [NEL]/kg of dry matter [DM], 13.23% crude protein [CP]) from -60 d to calving and a postpartal diet (1.61 Mcal of NEL/kg of DM, 17.39% CP) from calving to 30 days in milk (DIM). The 3 dietary treatments were TMR supplemented with LJE at 0 (control), 1 and 2 g/kg DM, respectively. LJE was offered from 21 d before calving to 30 DIM. Dry matter intake (DMI) and milk production were measured daily after calving. Milk and rumen fluid samples were collected on 29 and 30 d after calving. On -10, 4, 14, and 30 d relative to calving, blood samples were collected to analyze the biomarkers of energy metabolism, inflammation and oxidative stress. Results: Compared with control diet, LJE supplementation at 1 and 2 g/kg DM increased DMI, milk yield and reduced milk somatic cell count. LJE supplementation also decreased the concentrations of blood biomarkers of pro-inflammation (interleukin-1β [IL-1β], IL-6, and haptoglobin), energy metabolism (nonesterified fatty acid and β-hydroxybutyric acid) and oxidative stress (reactive oxygen metabolites), meanwhile increased the total antioxidant capacity and superoxide dismutase concentrations in blood. No differences were observed in rumen pH, volatile fatty acid, and ammonia-N (NH3-N) concentrations between LJE supplemented diets and the control diet. Conclusion: Supplementation with 1 and 2 g LJE/kg DM could increase DMI, improve lactation performance, and enhance anti-inflammatory and antioxidant capacities of dairy cows during perinatal period.

Growth performance, nutrients digestibility, and blood metabolites of lambs fed diets supplemented with probiotics during pre- and post-weaning period

  • Saleem, A.M.;Zanouny, A.I.;Singer, A.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.4
    • /
    • pp.523-530
    • /
    • 2017
  • Objective: Two experiments were conducted to evaluate the effects on growth performance, digestibility, and blood metabolites of lambs during pre- and post-weaning period of inclusion of a commercial probiotic (PRO) containing a mixture of two strains of Pediococcus, Pediococcus acidilactici ($1{\times}10^6$ colony-forming unit [cfu]/g) and Pediococcus pentosaceus ($1.3{\times}10^6cfu/g$), with dextrose as the carrier compound compared to a diet based on concentrate mixture and wheat straw. Methods: In exp. 1, 24 male lambs of about $15{\pm}2.6$ d age and initial body weight (BW) of $5.52{\pm}0.6kg$ were randomly allocated into three groups. One group received control diet without additives, and remainders received control diet supplemented with 0.5 or 1 g PRO/lamb/d. Daily feed intake and biweekly BW were recorded. In exp. 2, five lambs, (initial $BW=29.72{\pm}1.15kg$, $age=6.54{\pm}0.32mo$) were used as experimental animals in a digestion trial. They were fed the same diets as in Exp. 1. Results: The supplementation of PRO did not result in any significant differences in milk intake, average daily gain (ADG), or total gain between treatments during the pre-weaning period. Total dry matter intake tended to be greater (p = 0.07) with addition of PRO in the post-weaning diets. During post-weaning phase, the final BW, ADG, total gain, and feed conversion ratio of the lambs receiving PRO treatments tended to be greater ($p{\leq}0.10$) than the control group. Addition of PRO in post-weaning diet decreased ($p{\leq}0.01$) blood urea and cholesterol concentrations. With the exception of ether extract digestibility, all nutrients digestibility were improved with inclusion PRO in the post-weaning diets. Conclusion: Lambs that received PRO in post-weaning diet appeared to show a better performance than lambs in pre-weaning period. Addition of the probiotic in the post-weaning diet trended towards improved dry matter intake, growth performance, feed conversion ratio, and nutrients digestibility.

The Changes of Electrolytes Composition in Skeletal Muscles by Food Restriction and Rehabilitation (식이 섭취량의 제한과 회복으로 인한 골격근육내 성분변화)

  • Lee, Jae-Hoon;Kim, Sook-He
    • Journal of Nutrition and Health
    • /
    • v.14 no.4
    • /
    • pp.162-174
    • /
    • 1981
  • Fiftysix male weanling rats of the Sprague-Dawley strain weighing $52.6{\pm} 0.9g$ were fed with 77% starch-15% casein diet by ad libitum for four days to get them adapted and divided into eight groups. For three weeks, the body weight gain of rats was controlled in three different ranges. After the period of food restriction, the rats were recovered by being fed by ad libitum for seventeen days. During the experimental period, the amount of food intake and body weight were measured. And the experimental groups were compared when they reached at the same age and at the same body weight. Anterior Tibialis, Extensor Digitorum Longus, Soleus, Plantaris, Gastrocnemius were used as analytic items of skeletal muscle. Wet weight of muscle, muscle protein, water content were measured from each of five skeletal muscles. Sodium, potassium, magnesium content were measured from Anterior Tibialis, Extensor Digitorum Longus, Soleus ana Plantaris. Phosphorus was measured only from Gastrocnemius. The whole carcass protein except the skeletal muscles was also measured. During the period of food restriction, food intake was $311.7{\pm}19.5g$ for the control group. $130.2{\pm}1.5g$ for the second group and $161.7{\pm}2.1g$ for the third group. During the period of food restriction, body weight gain was $106.8{\pm}12.7g$ for the control group, $3.6{\pm}2.1g$ for the second group and $18.9{\pm}3.3g$ for the third group. Comparing the body weight when they reached at the age 66 days, the control group showed higher value than the other groups. In the concentration of electrolytes of skeletal muscles sodium and magnesium tend to increase and potassium and phosphorus tend to decrease by food restriction. But after their recovery, there was no significant difference between the groups. By the degree of food restriction, there was time difference in reaching at the same body weight. But when they reached at the same body weight, there was no significant difference in the value of electrolytes concentration. Regarding all the results of this study, the ages of rats which reached the same body weight were different by food restriction level during weanling. Once food·restricted rats reached the same body weight by recovery, the concentration of electrolytes and protein tend to become almost the same.

  • PDF

A Study on the adaptive Connection Admission Control Method in ATM Networks (ATM망에서 적응적 연결수락제어 방법에 관한 연구)

  • 한운영;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.19 no.9
    • /
    • pp.1719-1729
    • /
    • 1994
  • In this paper, an adaptive CAC(Connection Admission Control) method is proposed. The adaptive CAC uses traffic estimates derived from both traffic parameter specified by user and cell flow measurements. Traffic estimation using user-specified parameters is performed at every moment of connection request or connection release by recursive formula which makes real-time calculation possible. Traffic estimation using cell flow measurement is carried out when the number of connected calls does not change during a measurement reflection period-renewal period. The most import ant thing for the traffic estimation using cell flow measurement is the determination of the length of a renewal period to trace a real traffic flow with an allowable time lag and the measurement reflection ratio(MRR) both to reduce the portion of overestimation and to avoid underestimation of real traffic flow. To solve these problems, the adaptive CAC updates renewal period and MRR adaptively according to the number of connections and the elapsed time after last connection or release respectively. Performance analysis for the proposed method is evaluated in several aspects for the cases of both homogeneous and heterogeneous bursty traffic. Numerical examples show the adaptive CAC method has the better performance compared with conventional CAC method based on burst model from the both utilization and QOS point of view.

  • PDF

Physicochemical properties of chitosans produced from shrimp shell under the different conditions and their influences on the properties of Kakdugi during storage (제조조건이 다른 새우껍질 chitosan의 물리.화학적 성질 및 깍두기의 보존성에 미치는 영향)

  • Kim, Kwang-Ok;Kang, Hyen-Jun
    • Journal of the Korean Society of Food Culture
    • /
    • v.9 no.1
    • /
    • pp.71-77
    • /
    • 1994
  • This study was undertaken to investigate the physicochemical properties of chitosans produced from chitins which were prepared from shrimp shell under the 4 different conditions(HCl concentration : 1 N, 4 N and reaction temperature $0^{\circ}C,\;20^{\circ}C$). The effects of chitosan on the properties of Kakdugi during storage also were examined. Viscosity of chitosan was markedly different$(313.1{\sim}98.8\;cps)$ depending on the production conditon. Chitosan solution showed pseudoplastic property. The infrared(IR) spectrums of chitosans prepared under the conditions of this study were very simillar, and the degree of deacetylation of chitosan was relatively high$(92{\sim}96%)$ independent of the extraction conditions of chitin. As the storage period was extended, markedly lower pH and higher titratable acidity were resulted in all the groups. Throughout the storage period, pH and titratable acidity of kakdugies with chitosan were higher and lower, respectively than those of control. Viscosity of kakdugi juice was significantly different among the groups and as the storage period increased, the juice viscosity decreased. At the eighth day of storage, the juice of control group was more viscous than those of kakdugies containing chitosan. Throughout the storage period the numbers of total microorganisms and of microorgarnisms of Leuconostoc genus in control kakdugi tended to be higher and lower, respectively than those in kakdugies containing chitosan. The growth of Lac. plantarum was slightly lower in kakdugi containing chitosan C produced at low HCl concentration and high temperature compared to the others.

  • PDF