• Title/Summary/Keyword: systems tract

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A Novel Discrete-Time Predictive Current Control for PMSM

  • Sun, Jung-Won;Suh, Jin-Ho;Lee, Young-Jin;Lee, Kwon-Soon
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1915-1919
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    • 2004
  • In this paper, we propose a new discrete-time predictive current controller for a PMSM(Permanent Magnet Synchronous Motor). The main objectives of the current controllers are to ensure that the measured stator currents tract the command values accurately and to shorten the transient interval as much as possible, in order to obtain high-performance of ac drive system. The conventional predictive current controller is hard to implement in full digital current controller since a finite calculation time causes a delay between the current sensing time and the time that it takes to apply the voltage to motor. A new control strategy in this paper is seen the scheme that gets the fast adaptation of transient current change, the fast transient response tracking and is proposed simplified calculation. Moreover, the validity of the proposed method is demonstrated by numerical simulations and the simulation results will be verified the improvements of predictive controller and accuracy of the current controller.

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Ontogenetic Development of the Digestive System in Chub Mackerel Scomber japonicus Larvae and Juveniles

  • Park, Su-Jin;Lee, So-Gwang;Gwak, Woo-Seok
    • Fisheries and Aquatic Sciences
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    • v.18 no.3
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    • pp.301-309
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    • 2015
  • Chub mackerel, Scomber japonicus, larvae and juveniles were reared from hatching to 35 days after hatching (DAH), and the development of their digestive systems was histologically investigated. The larvae were initially fed on rotifers and Artemia nauplii starting around 19 DAH, and thereafter on Artemia nauplii, fish eggs, and a formulated feed mixture. The primitive digestive system differentiated at 3 DAH; the digestive tract was distinctively divided into the buccopharyngeal cavity, esophagus, stomach, air bladder, intestines, and rectum. The gastric gland and pyloric caeca first appeared at 5 and 7 DAH, respectively. The stomach was divided into cardiac, fundic, and pyloric regions in the preflexion phase. The number of gastric glands and pyloric caeca, as well as the volume of the gastric blind sac increased markedly, with development continuing into the juvenile stage. The precocious development of the digestive system during the larval period might be related to the early appearance of piscivory, which is able to support high growth potential. The organogenesis results obtained for this precocial species represent a useful tool to aid our understanding of the physiological requirements of larvae and juveniles to ensure optimal welfare and growth under aquaculture conditions, which will improve current rearing practices of this scombrid species.

Clinical Applications of Bioactive Milk Components: A Review (우유 생리활성 물질의 임상적 적용)

  • Han, Rae Hee;Yoon, Sung Hee;Kim, Geun-Bae
    • Journal of Dairy Science and Biotechnology
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    • v.37 no.3
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    • pp.167-176
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    • 2019
  • Milk contains essential nutrients and functional compounds, such as calcium, fat-soluble vitamins A, D, E, and K, carotenoids, bioactive peptides, and sphingolipids. The bioactive molecules from milk are not expensive and have an added advantage of being derived from food. Therefore, they are more stable and have a broader spectrum than that of other chemicals. Bioactive milk components are useful for treating non-digestive tract disorders, such as cancer, cognitive decline, and hypertension. However, the clinical application of certain breast milk ingredients is limited due to the lack of a large-scale production technology. Once the scaled-up production of lactoferrin became possible, clinical applications were devised and evaluated. Similarly, human alpha-lactalbumin made lethal to tumor cells (HAMLET) can be produced on a large scale as a recombinant protein in microorganisms or in transgenic cattle using suitable separation systems. HAMLET can be used to treat human skin papilloma and cancer. Studies on breast milk that explored the clinical applications of the bioactive components of breast milk have spurred the development of translational medicine and breast milk-derived therapeutics. Some breast-milk derived therapeutic agents are already available to clinicians. Many components of breast milk have shown efficacy in pre-clinical studies and have valid clinical evaluations.

A Novel Discrete-Time Predictive Current Control for PMSM

  • Sun, Jung-Won;Lee, Jin-Woo;Suh, Jin-Ho;Lee, Young-Jin;Lee, Kwon-Soon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2503-2508
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    • 2005
  • In this paper, we propose a new discrete-time predictive current controller for a PMSM(Permanent Magnet Synchronous Motor). The main objectives of the current controllers are to ensure that the measured stator currents tract the command values accurately and to shorten the transient interval as much as possible, in order to obtain high-performance of ac drive system. The conventional predictive current controller is hard to implement in full digital current controller since a finite calculation time causes a delay between the current sensing time and the time that it takes to apply the voltage to motor. A new control strategy in this paper is seen the scheme that gets the fast adaptation of transient current change, the fast transient response tracking. Moreover, the validity of the proposed method is demonstrated by numerical simulations and the simulation results will present the improvements of predictive controller and accuracy of the current controller.

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Canada's Regional Innovation Support System and Cluster Policy (캐나다의 지역혁신지원체제와 클러스터정책)

  • Nahm, Kee-Bom
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.4
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    • pp.647-660
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    • 2008
  • The main thrusts of Canadian regional innovation policy lies in the two tract system. Federal government decides only the strategic research and development sectors and priorities, and then researchers and stockholders in the regions decide and implement the specific networking relationships and appropriate governance system. This paper reviewed the decentralized and market-friendly Canadian regional innovation support system and the characteristics of Canadian innovation clusters: Learning, Labour, Location, Leadership, Legislation/ Labs. finally, policy implications for Korean regional innovation system such as networking, formation of social capital, and business support systems are offered.

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Morphological Study of the Digestive Tract of the Mud Crab (Hemigrapsus Penicillatus De Haan) and the Symbiotic Crab (Pinnotheres cyclinus Shen)

  • Moon, Young-Wha;Kim, Han-Hwa
    • Animal cells and systems
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    • v.3 no.4
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    • pp.407-412
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    • 1999
  • The influence of eating habits and food type on the ultrastructural characteristics of the digestive tracts was studied under the scanning and transmission electron microscopes in two crustacean decapods (Hemigrapsus penicillatus De Haan; mud crab, Pinnotheres cyclinus Shen; symbiotic crab). The relative ratio of the length of midgut versus hindgut was 1:1 in the mud crab, but 4:1 in the symbiotic crab. Observation through the scanning electron microscope revealed that the midguts of both species have densely-arranged longitudinal mucosal folds with a smooth surface. In the hindgut of the mud crab, mucosal folds were longitudinally oriented, clusters of two to five spines were observed on the cuticular surface, and the length of the spine in the distal hindgut was longer than that in the proximal portion. In the symbiotic crab, the mucosal folds were irregulary arranged, and numerous rudimentary spinal structures were noted on the cuticular surface. Through observation of a transmission electron microscope, the epithelial cells of the midgut in both species had numerous microvilli, but the length of the microvilli was slightly longer in the mud crab than in the symbiotic crab. The central layer of the basement membrane and the muscular layer of the midgut were more developed in the mud crab than in the symbiotic crab. The thickness of the cuticular layer over the hindgut surface in the mud crab was about 4 times than that of the symbiotic crab.

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The role of ginseng total saponin in transient receptor potential melastatin type 7 channels

  • Kim, Byung Joo
    • Animal cells and systems
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    • v.16 no.5
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    • pp.376-384
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    • 2012
  • Although ginsenosides have a variety of physiologic or pharmacologic functions in various regions, there are only a few reports on the effects of transient receptor potential melastatin 7 (TRPM7) channels. Here, we showed evidence suggesting that TRPM7 channels play an important role in ginseng total saponin (GTS)-mediated cellular injury. The combination techniques of electrophysiology, pharmacological analysis, small interfering RNA (siRNA) method and cell death assays were used. GTS depolarized the resting membrane potentials and decreased the amplitude of pacemaker potentials in cultured interstitial cells of Cajal (ICCs) in gastrointestinal (GI) tract. The TRPM7-like currents in single ICCs and the overexpressing TRPM7 in HEK293 cells were inhibited by GTS. However, GTS had no effect on $Ca^{2+}$-activated $Cl^-$ conductance. GTS inhibited the survival of human gastric (AGS) and brea (MCF-7) adenocarcinoma cells. Also, GTS inhibited the TRPM7-like currents in AGS and MCF-7 cells. The GTS-mediated cytotoxicity was inhibited by TRPM7-specific siRNA. In addition, we showed that overexpression of TRPM7 channels in HEK293 cells was inhibited by GTS. Thus, TRPM7 channels are involved in GTS-mediated cell death in AGS and MCF-7 cells, and these channels may represent a novel target for physiological disorders where GTS plays an important role.

The Sensory-Motor Fusion System for Object Tracking (이동 물체를 추적하기 위한 감각 운동 융합 시스템 설계)

  • Lee, Sang-Hee;Wee, Jae-Woo;Lee, Chong-Ho
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.3
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    • pp.181-187
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    • 2003
  • For the moving objects with environmental sensors such as object tracking moving robot with audio and video sensors, environmental information acquired from sensors keep changing according to movements of objects. In such case, due to lack of adaptability and system complexity, conventional control schemes show limitations on control performance, and therefore, sensory-motor systems, which can intuitively respond to various types of environmental information, are desirable. And also, to improve the system robustness, it is desirable to fuse more than two types of sensory information simultaneously. In this paper, based on Braitenberg's model, we propose a sensory-motor based fusion system, which can trace the moving objects adaptively to environmental changes. With the nature of direct connecting structure, sensory-motor based fusion system can control each motor simultaneously, and the neural networks are used to fuse information from various types of sensors. And also, even if the system receives noisy information from one sensor, the system still robustly works with information from other sensors which compensates the noisy information through sensor fusion. In order to examine the performance, sensory-motor based fusion model is applied to object-tracking four-foot robot equipped with audio and video sensors. The experimental results show that the sensory-motor based fusion system can tract moving objects robustly with simpler control mechanism than model-based control approaches.

Yew Poisoning in 17 Dairy Cattle (젖소 17두의 주목나무 독성 중독)

  • 이수한;배춘식;정병현
    • Journal of Veterinary Clinics
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    • v.20 no.3
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    • pp.406-409
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    • 2003
  • We found seventeen dairy cattle with the abnormal signs in cardiovascular and gastrointestinal systems after feeding of the yew foilage. Among them three cattle were dead due to yew poisoning. Among the remaining fourteen dairy cattle, four cattle showed similar symptoms as did dead cattle. Although the remaining ten dairy cattle did not show any abnormal signs, we conducted a therapy of forced magnesium sulfate infusion because the yew consumption might have been occurred in all cattle. As a result of the therapy, we could not found further signs of yew poisoning. The performance of the therapy and the treatment procedures adapted by the therapy could be concluded as follows: The cardioselective toxicity and inhibition of peristaltic activity by the taxine in yew foilage might be involved in the symptoms of acute poisoning as anorexia, dullness, muscle tremor, dyspnea, and sudden death. We also performed the dose response relationship of taxine to the range of clinical symptoms and examined recovery performances. Through the autopsy of the cattle, we could confirm the presence of yew foilages that might have caused the poisoning in the gastrointestinal tract. However, we could not identify further abnormalities in other organs. In this case report, we demonstrated that practice of the forced magnesium sulfate infusion in yew poisoning was helpful for the attenuating the taxine poisoning by blocking the further proceeding of the toxic effect.

A Case of Intoxication of Ingested Formalin (포르말린에 의한 급성 중독 1례)

  • Baek, Seon-Hee;Kim, Kyung-Hwan;Park, Jun-Seok;Shin, Dong-Wun;Roh, Jun-Young;Lee, Kyoung-Mi;Kim, Ah-Jin
    • Journal of The Korean Society of Clinical Toxicology
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    • v.7 no.1
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    • pp.38-40
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    • 2009
  • Formalin is a water-soluble, colorless, pungent, irritating and highly reactive gas. A 40% solution of formaldehyde in water, also known as formalin, is used as a disinfectant, antiseptic, deodorant, tissue fixative and embalming fluid. Ingestion can lead to immediate deleterious effects on almost all systems of the body including gastrointestinal tract, central nervous system, cardiovsacular system and hepato-renal system, causing gastrointestinal hemorrhage, cardiovsacular collapse, unconsciousness or convulsions, severe metabolic acidosis and acute respiratory distress syndrome. We treated a 39-year-old woman who ingested 300 ml formalin in a suicidal attempt. Despite hemodialysis, death occurred after 23 h.

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