• Title/Summary/Keyword: Current Modulating

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Current Status and Future Promise of the Human Microbiome

  • Kim, Bong-Soo;Jeon, Yoon-Seong;Chun, Jongsik
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.16 no.2
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    • pp.71-79
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    • 2013
  • The human-associated microbiota is diverse, varies between individuals and body sites, and is important in human health. Microbes in human body play an essential role in immunity, health, and disease. The human microbiome has been studies using the advances of next-generation sequencing and its metagenomic applications. This has allowed investigation of the microbial composition in the human body, and identification of the functional genes expressed by this microbial community. The gut microbes have been found to be the most diverse and constitute the densest cell number in the human microbiota; thus, it has been studied more than other sites. Early results have indicated that the imbalances in gut microbiota are related to numerous disorders, such as inflammatory bowel disease, colorectal cancer, diabetes, and atopy. Clinical therapy involving modulating of the microbiota, such as fecal transplantation, has been applied, and its effects investigated in some diseases. Human microbiome studies form part of human genome projects, and understanding gleaned from studies increase the possibility of various applications including personalized medicine.

Start-up Strategy at Sensorless Control of BLDC for Vehicle Fuel Pump (자동차 연료펌프용 BLDC의 센서리스제어 기동기법)

  • Tran, Quang Vinh;Chun, T.W.;Lee, H.H.;Kim, H.G.;Loh, E.C.
    • Proceedings of the KIPE Conference
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    • 2009.11a
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    • pp.268-270
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    • 2009
  • This paper proposes a simple starting method to arrange the rotor position of the blushless DC motor (BLDC) without additional sensors and any information of motor parameters. Both the stator current and time period for arranging the rotor position can be easily adjusted by modulating a pulse width of switching devices. Using the proposed method, it is demonstrated experimentally that the BLDC starts up very smoothly.

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Control Techniques of Sensorless BLDC Motor Drive for a Vehicle Fuel Pump Application (자동차 연료펌프용 BLDC 전동기구동의 센서리스 제어기법)

  • Tran, Quang-Vinh;Chun, Tae-Won;Lee, Hong-Hee;Kim, Heung-Geun;Nho, Eui-Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.10
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    • pp.1858-1864
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    • 2011
  • This paper suggests a control technique of the sensorless brushless DC (BLDC) motor drive for a vehicle fuel pump application. The sensorless technique based on a comparator and a potential start-up method with high starting torque are proposed. The comparator is used to generate the commutation signals in phase with the three-phase back-EMFs. The rotor position is aligned at standstill for maximum starting torque without an additional sensor and any information of motor parameters. Also, the stator current can be easily adjusted by modulating the pulse width of the switching devices during alignment. Some experiments are implemented on a single chip 16-bit DSP controller to demonstrate the feasibility of the sensorless techniques.

Reduced Swing Polarity Inversion Driving Method for a-Si:H TFT Based AMOLED

  • Lee, Woo-Cheul;Park, Hyun-Sang;Kuk, Seung-Hee;Kang, Dong-Won;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1792-1795
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    • 2007
  • We have proposed a new driving method which improve the current stability of a-Si:H TFTs for AMOLED. It performs the negative bias annealing on driving TFTs during a certain period of a frame time. In the proposed method, the range of data signals is significantly reduced by modulating VSS.

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An overview of the endocrine functions of osteocalcin

  • Baek, Kyunghwa
    • International Journal of Oral Biology
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    • v.44 no.4
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    • pp.125-129
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    • 2019
  • Osteocalcin is the most abundant non-collagenous protein produced in bone. It has traditionally been regarded as a marker of bone turnover and is thought to act in the bone matrix to regulate mineralization. However, emerging knowledge regarding osteocalcin has expanded to include functions in energy metabolism, fertilization, and regulation of cognition. Fully carboxylated osteocalcin binds to hydroxyapatite, thereby modulating bone turnover, whereas undercarboxylated osteocalcin in the circulation binds to osteocalcin-sensing receptors and acts as a hormone that affects multiple physiological aspects. In this review, we summarize the current knowledge regarding the hormonal actions of osteocalcin in various organs and potential cellular downstream signaling pathway that may be involved.

Targeting the Gut Microbiome to Ameliorate Cardiovascular Diseases

  • Hwang, Soonjae;Park, Chan Oh;Rhee, Ki-Jong
    • Biomedical Science Letters
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    • v.23 no.3
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    • pp.166-174
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    • 2017
  • The bacterial cells located within the gastrointestinal tract (GIT) outnumber the host's cells by a factor of ten. These human digestive-tract microbes are referred to as the gut microbiota. During the last ten years, our understanding of gut microbiota composition and its relation with intra- and extra-intestinal diseases including risk factors of cardiovascular diseases (CVD) such as atherosclerosis and metabolic syndrome, have greatly increased. A question which frequently arises in the research community is whether one can modulate the gut microbial environment to 'control' risk factors in CVD. In this review, we summarized promising intervention methods, based on our current knowledge of intestinal microbiota in modulating CVD. Furthermore, we explore how gut microbiota can be therapeutically exploited by targeting their metabolic program to control pathologic factors of CVD.

Autophagy Dysregulation and Obesity-Associated Pathologies

  • Sim, Namkoong;Cho, Chun-Seok;Semple, Ian;Lee, Jun Hee
    • Molecules and Cells
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    • v.41 no.1
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    • pp.3-10
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    • 2018
  • Autophagy is one of the major degradative mechanisms that can eliminate excessive nutrients, toxic protein aggregates, damaged organelles and invading microorganisms. In response to obesity and obesity-associated lipotoxic, proteotoxic and oxidative stresses, autophagy plays an essential role in maintaining physiological homeostasis. However, obesity and its associated stress insults can often interfere with the autophagic process through various mechanisms, which result in further aggravation of obesity-related metabolic pathologies in multiple metabolic organs. Paradoxically, inhibition of autophagy, within specific contexts, indirectly produces beneficial effects that can alleviate several detrimental consequences of obesity. In this minireview, we will provide a brief discussion about our current understanding of the impact of obesity on autophagy and the role of autophagy dysregulation in modulating obesity-associated pathological outcomes.

Light Induced Structural Transition in $B_7$ phase of Bent-shaped Liquid Crystals containing Azo dye

  • Kim, Hee-Kyung;Shin, S.T.;Lee, C.K.;Jang, Chi-Woong;Lim, Tong-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.494-497
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    • 2002
  • The influence of isomeric state of doped azo dye on the $B_7$ phase of bent-shaped liquid crystal (LC) is studied. It was found that modulating the isomeric trans-cis state of azo dye can change the molecular arrangement of the bent-shaped LCs. To identify these phenomena the observations of microscopic texture, electro-optic response, second harmonic wave generation (SHG) and switching current were carried out..

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Autophagy in Neurodegenerative Diseases: From Mechanism to Therapeutic Approach

  • Nah, Jihoon;Yuan, Junying;Jung, Yong-Keun
    • Molecules and Cells
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    • v.38 no.5
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    • pp.381-389
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    • 2015
  • Autophagy is a lysosome-dependent intracellular degradation process that allows recycling of cytoplasmic constituents into bioenergetic and biosynthetic materials for maintenance of homeostasis. Since the function of autophagy is particularly important in various stress conditions, perturbation of autophagy can lead to cellular dysfunction and diseases. Accumulation of abnormal protein aggregates, a common cause of neurodegenerative diseases, can be reduced through autophagic degradation. Recent studies have revealed defects in autophagy in most cases of neurodegenerative disorders. Moreover, deregulated excessive autophagy can also cause neurodegeneration. Thus, healthy activation of autophagy is essential for therapeutic approaches in neurodegenerative diseases and many autophagy-regulating compounds are under development for therapeutic purposes. This review describes the overall role of autophagy in neurodegeneration, focusing on various therapeutic strategies for modulating specific stages of autophagy and on the current status of drug development.

Reduction of switching loss and low-order harmonics in three-phase PWM inverter using the selected harmonic elimination (특정고조파제거기법을 이용한 3상 PWM 인버터의 저차고조파제거 및 스위칭손실 저감에 관한 연구)

  • Jang, Chul;Lee, Byung-Jin;Yun, Jae-Sung;Suh, Yoon-Chul;Yu, Chul-Ro
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1960-1962
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    • 1998
  • Reference/modulating waveform continuity is not a necessary condition for the implementation of switching patterns for three-phase pulse-width modulated(PWM) converters. This is based on the fact that the converter phase-voltages do not need to be sinusoidal and switching pattern discontinuities do not degrade the quality of output/input voltage/current waveforms by introducing low-order harmonics if certain parameters are optimized. This paper introduces the selected harmonic elimination to reduce the switching frequency and low-order harmonics compared with continuous PWM techniques and some discontinues switching patterns for PWM converter.

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