• Title/Summary/Keyword: DC/DC

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Low-Power Operation Method of Thermal-Energy Harvesting Sensor Circuit (Thermal Energy Harvesting용 센서회로의 저전력 구동 방법)

  • Nam, Hyun Kyung;Pham, Van Khoa;Tran, Bao Son;Nguyen, Van Tien;Min, Kyeong-Sik
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.842-845
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    • 2018
  • In this paper, we propose low-power operational methods for thermal-energy-harvesting sensor circuits. Here, the amount of harvested current has been measured as low as 8uA. However the DC power consumption of the sensor circuit is known to consume much larger than 8uA. Thus, We propose the hardware-based power gating and software-based active/sleep timing control schemes, respectively, for controlling the power consumption of sensor circuit. In the hardware-based power gating scheme, if the ratio of Toff/Ton is larger than 22, the sensor can consume less than 8uA. For the software-based active/sleep control scheme, if the ratio of Tslp/Tact is larger than 3, we can suppress the current consumption below 8uA. The hardware-based and software-based schemes proposed in this paper would be helpful in various applications of energy-harvesting sensor circuits, where the power consumption is limited by an amount of harvested energy.

A Study on the Fabrication of the Sensor Module for the Detection of Resistive Leakage Current (Igr) in Real Time and Its Reliability Evaluation (실시간 Igr 검출을 위한 센서 모듈의 제작 및 신뢰성 평가에 관한 연구)

  • Lee, Byung-Seol;Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.33 no.1
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    • pp.28-34
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    • 2018
  • The purpose of this study is to fabricate a sensor module to detect the resistive leakage current (Igr) in real time that occurs to low voltage electric lines and to verify its reliability. In the case of the developed sensor module, wires are inserted into the zero current transformer (ZCT) and current transformer (CT) in advance and then the branch line is connected to the circuit breaker. The measurement result of the resistance of the distribution panel equipped with the developed sensor module shows that the resistance is $0.151m{\Omega}$ between the R and R phases, $0.169m{\Omega}$ between the S and S phases, and $0.178m{\Omega}$ between the T and T phases, respectively. The insulation resistance measured at AC 500 V and 1,000 V is $0.08m{\Omega}$ between the R, S, T and N phases, respectively. Then, the insulation resistance measured at DC 500 V is $83.3G{\Omega}$ between the R, S, T and G terminal, respectively. In addition, the applied withstanding voltage is AC 220 V/380 V/440 V and it was found that characteristics between all phases are good. This study measured the standby power by installing the developed sensor module at the rear of the MCCB and switching the circuit breaker on sequentially. The standby power is 1.350 W when one circuit breaker is turned on, 1.690 W when 2 circuit breakers are turned on, and 4.371 W when 10 circuit breakers are turned on. This study also verified the reliability of the standby power of the distribution panel equipped with the developed sensor module using the Minitab Program (Minitab PGM). Since the analysis shows the statistical average of 1.34627 in the reliable range of normal distribution, standard deviation of 0.001874, AD of 0.554, and P value of 0.140, it is found that the distribution panel equipped with the developed sensor module has high reliability.

Income Analysis on the Cultivation of Major Medicinal Herbs (주요 약초류 재배에 대한 소득분석)

  • Kang, Hag Mo;Chang, Cheol Su;Kim, Hyun;Choi, Soo Im
    • Journal of Korean Society of Forest Science
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    • v.104 no.3
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    • pp.495-502
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    • 2015
  • This study intended to provide basic data required in establishing policies for improving the forestry management and the compensation standard for the loss from non-timber forest products by examining the cost of cultivating key medicinal herbs and the earnings from them to analyze the income. According to the income analysis on the cultivation of medicinal herbs, the average annual income per unit area of Adenophora triphylla var. japonica Hara was the highest as it recorded 14,233,000 won/10a and was followed by Pleuropterus multiflorus TURCZ. which recorded 4,121,000 won/10a, Gastrodia elata Blume 3,766,000 won/10a, Epimedium koreanum Nakai 3,537,000 won/10a, Atractylodes ovata (Thunb.) DC. 2,655,000 won/10a, Aralia continentalis Kitagawat 1,048,000 won/10a, Paeonia lactiflora Pallas 1,025,000 won/10a, and Bupleurum falcatum L. 919,000 won/10a. Compared with the income from major nuts and fruits analyzed in 2014, the average annual income per unit area for medicinal herbs was relatively higher. For Adenophora triphylla var. japonica Hara and Aralia continentalis Kitagawat, soots are used for food and the roots for medicine, it appears that it can become a new income source for the farming and mountain villages. Meanwhile, the price for Paeonia lactiflora Pallas is dropping due to Chinese imports, and also damage to the income from other medicinal herbs due to Chinese imports is expected with the implementation of Korea-China FTA in the future.

Identification of Single Nucleotide Polymorphism of H-FABP Gene and Its Association with Fatness Traits in Chickens

  • Wang, Yan;Shu, Dingming;Li, Liang;Qu, Hao;Yang, Chunfen;Zhu, Qing
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.12
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    • pp.1812-1819
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    • 2007
  • Heart fatty acid-binding protein gene (H-FABP) is an important candidate gene for meat quality. One of the objectives of this study was to screen single nucleotide polymorphisms (SNP) of chicken H-FABP gene among 252 individuals that included 4 Chinese domestic chicken breeds (Fengkai Xinghua (T04), Huiyang Huxu (H), Qingyuan Ma (Q), Guangxi Xiayan (S1)), 2 breeds developed by the Institute of Animal Science, Guangdong Academy of Agricultural Sciences (Lingnan Huang (DC), dwarf chicken (E4)) and one introduced broiler (Abor Acre (AA)). Another objective of this study was to analyze the associations between polymorphisms of the H-FABP gene and fat deposition traits in chickens. PCR-SSCP was used to analyze SNPs in H-FABP and 4 SNPs (T260C, G675A, C783T and G2778A) were detected. Associations between polymorphic loci and intramuscular fat (IMF), abdominal fat weight (AFW) and abdominal fat percentage (AFP) were analyzed by ANCOVA method. The results showed that the T260C genotypes were significantly associated with IMF (p = 0.0233) and AFP (p = 0.0001); the G675A genotypes were significantly associated with AFW, AFP (p<0.01) and IMF (p<0.05); at the C783T locus, AFW and AFP differed highly between genotypes. However, the G2778A loci did not show any significant effect on fat deposition traits in this study. In addition, we found that there were some differences between AFP and definite haplotypes through a nonparametric statistical method, so the haplotypes based on the SNPs except G2778A loci were also significantly associated with IMF, AFW (g) (p<0.05) and AFP (%) (p<0.001). Significantly and suggestively dominant effects of H4H4 haplotype were observed for IMF and the H2H3 was dominant for AFW (g) and AFP (%). The results also revealed that H5H7 haplotype had a negative effect on IMF, while the H5H6 had a positive effect on AFW (g) and AFP (%).

Mycobacterium abscessus ᴅ-alanyl-ᴅ-alanine dipeptidase induces the maturation of dendritic cells and promotes Th1-biased immunity

  • Lee, Seung Jun;Jang, Jong-Hwa;Yoon, Gun Young;Kang, Da Rae;Park, Hee Jo;Shin, Sung Jae;Han, Hee Dong;Kang, Tae Heung;Park, Won Sun;Yoon, Young Kyung;Soh, Byoung Yul;Jung, In Duk;Park, Yeong-Min
    • BMB Reports
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    • v.49 no.10
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    • pp.554-559
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    • 2016
  • Mycobacterium abscessus, a member of the group of non-tuberculous mycobacteria, has been identified as an emerging pulmonary pathogen in humans. However, little is known about the protective immune response of antigen-presenting cells, such as dendritic cells (DCs), which guard against M. abscessus infection. The M. abscessus gene MAB1843 encodes ᴅ-alanyl-ᴅ-alanine dipeptidase, which catalyzes the hydrolysis of ᴅ-alanyl-ᴅ-alanine dipeptide. We investigated whether MAB1843 is able to interact with DCs to enhance the effectiveness of the host's immune response. MAB1843 was found to induce DC maturation via toll-like receptor 4 and its downstream signaling pathways, such as the mitogen-activated protein kinase and nuclear factor kappa B pathways. In addition, MAB1843-treated DCs stimulated the proliferation of T cells and promoted Th1 polarization. Our results indicate that MAB1843 could potentially regulate the immune response to M. abscessus, making it important in the development of an effective vaccine against this mycobacterium.

Antioxidant Favors the Developmental Competence of Porcine Parthenogenotes by Reducing Reactive Oxygen Species

  • Hossein, Mohammad Shamim;Kim, Yeun Wook;Park, Seon Mi;Koo, Ok Jae;Hashem, Md Abul;Bhandari, Dilip P;Jeong, Yeon Woo;Kim, Sue;Kim, Ji Hye;Lee, Eu Gine;Park, Sun Woo;Kang, Sung Keun;Lee, Byeong Chun;Hwang, Woo Suk
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.3
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    • pp.334-339
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    • 2007
  • Reactive oxygen species (ROS) generate during electrical activation of oocytes which has detrimental effects on embryo survival when overwhelmed. The present study was designed to investigate the ability of L-ascorbic acid, a novel water soluble antioxidant, to reduce the ROS level in developing embryos and their subsequent effects on embryo development in vitro. The compact cumulus oocyte complexes (COCs) were cultured in tissue culture medium (TCM)-199 supplemented with 10 ng/ml epidermal growth factor, 4 IU/ml pregnant mare serum gonadotropin (PMSG), and human chorionic gonadotropin (hCG) and 10% (v/v) porcine follicular fluid (pFF) for 44 h. After maturation culture, the denuded oocytes were activated with a single DC pulse of 2.0 kV/cm in 0.3 M mannitol solution containing 0.5 mM of HEPES, 0.1 mM of $CaCl_2$ and 0.1 mM of $MgCl_2$ for $30{\mu}s$ using a BTX Electro-cell Manipulator. The activated oocytes were cultured in modified North Carolina State University-23 (mNSCU-23) medium for 168 h. The level of $H_2O_2$ in each embryo was measured by the dichlorohydrofluorescein diacetate (DCHFDA) method at 48 h after activation. The blastocyst formation rate was significantly higher when culture medium was supplemented with 50 and $100{\mu}M$ L-ascorbic acid (31.2 and 38.7%, respectively) compared to non-supplemented (16.1%) group. Accordingly, significantly more cells in blastocyst were found for 50 and $100{\mu}M$ L-ascorbic acid (50.0 and 56.4, respectively) compared to 0 and $200{\mu}M$ L-ascorbic acid (36.5 and 39.8, respectively). L-ascorbic acid reduces the $H_2O_2$ level in developing embryos in a dose-dependant manner. The $H_2O_2$ level (pixels/ embryos) was 191.5, 141.0, 124.0 and 163.3 for 0, 50, 100 and $200{\mu}M$ L-ascorbic acid, respectively. So, we recommend to supplement 50 or $100{\mu}M$ L-ascorbic acid in porcine in vitro culture medium.

The Design of an Auto Tuning PI Controller using a Parameter Estimation Method for the Linear BLDC Motor (선형 추진 BLDC 모터에 대한 파라미터 추정 기법을 이용하는 오토 튜닝(Auto Tuning) PI 제어기 설계)

  • Cha Young-Bum;Song Do-Ho;Koo Bon-Min;Park Moo-Yurl;Kim Jin-Ae;Choi Jung-Keyng
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.4
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    • pp.659-666
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    • 2006
  • Servo-motors are used as key components of automated system by performing precise motion control as accurate positioning and accurate speed regulation in response to the commands from computers and sensors. Especially, the linear brushless servo-motors have numerous advantages over the rotary servo motors which have connection with the friction induced transfer mechanism such as ball screws, timing belts, rack/pinion. This paper proposes an estimation method of unknown motor system parameters using the informations from the sinusoidal driving type linear brushless DC motor dynamics and outputs. The estimated parameters can be used to tune the controller gain and a disturbance observer. In order to meet this purpose high performance Digital Signal Processor, TMS320F240, designed originally for implementation of a Field Oriented Control(FOC) technology is adopted as a controller of the liner BLDC servo motor. Having A/D converters, PWM generators, rich I/O port internally, this servo motor application specific DSP play an important role in servo motor controller. This linear BLDC servo motor system also contains IPM(Intelligent Power Module) driver and hail sensor type current sensor module, photocoupler module for isolation of gate signals and fault signals.

Effects of Photo/dark period and Relative Humidity during Dark Period on Growth and Tipburn Occurrence of Water Dropwort (Oenanthe stolonifera DC.) in a Closed-type Plant Factory (밀폐형 식물공장에서 명/암주기와 암기동안의 상대습도가 미나리 생육과 팁번 발생에 미치는 영향)

  • An, Jae Uk;Joung, Kyoung Hee;Yoon, Hae Suk;Hwang, Yeon Hyeon;Hong, Gwang Pyo
    • Journal of Bio-Environment Control
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    • v.26 no.2
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    • pp.146-150
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    • 2017
  • This research investigated the effect of photo/dark period and relative humidity during dark period on the growth and quality of water dropwort in a closed-type plant factory system. At 30 days after planting, the shoot fresh weight of water dropwort under relative humidity of 60/90%(light/dark) treatment significantly higher than that under relative humidity of 60/60% treatment. The shoot fresh weight of water dropwort increased by extending light period under relative humidity of 60/60% treatment, but 16/8h photo/dark period showed the best shoot fresh weight, followed by 20/4h and 22/2h under relative humidity of 60/90% treatment. In the relative humidity of 60/90% treatment, the tipburn occurrence was reduced under 16/8h photo/dark period condition as 1.4%, whereas it was significantly increased under 20/4h and 22/2h of relatively long light time duration as 15.5% and 30.3%, respectively. In the relative humidity of 60/60% treatment, the tipburn occurrence was 15.5% under 16/8h photo/dark period condition and those under 20/4h and 22/2h photo/dark period condition were higher than 25%. The stem hardness of water dropwort was lowest in relative humidity of 60/90% and 16/8h photo/dark period treatment. The mineral contents of leaves were decreased by extending light period, but the contents of Ca were not different significantly among the treatments except the 60/60% and 22/2h treatment.

Development of PC Based Signal Postprocessing System in MR Spectroscopy: Normal Brain Spectrum in 1.5T MR Spectroscopy (PC를 이용한 자기공명분광 신호처리분석 시스템 개발: 1.5T MR Spectroscopy에서의 정상인 뇌 분광 신호)

  • 백문영;강원석;이현용;신운재;은충기
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.2
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    • pp.128-135
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    • 2000
  • Purpose : The aim of this study is to develope the Magnetic Resonance Spectroscopy(MRS) data processing S/W which plays an important role as a diagnostic tool in clinical field. Materials and methods : Post-processing software of MRS based on graphical user interface(GUI) under windows operating system of personal computer(PC) was developed using MATLAB(Mathwork, U.S.A.). This tool contains many functions to increase the quality of spectrum data such as DC correction, zero filling, line broadening, Gauss-Lorentzian filtering, phase correction, etc. And we obtained the normal human brain $^1H$ MRS data from parietal white matter, basal ganglia and occipital grey matter region using 1.5T Gyroscan ACS-NT R6 (philips, Amsterdam, Netherland) MRS package. The analysis of the MRS peaks were performed by obtaining the ratio of peak area. Results : The peak ratios of NAA/Cr, Cho/Cr, MI/Cr for the different MRS machines have a little different values. But these peak ratios were not significantly different between different echo time MRS peak ratios in the same machine (p<0.05). Conclusion : MRS post-processing S/W based on GUI using PC was developed and applied to the analysis of normal human brain $^1H$ MRS. This independent MRS processing job increases the performance and throughput of patient scan of main console. Finally, we suggest that the database for normal in-yivo human MRS data should be obtained before clinical applications.

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TiO2 Nanotubular Formation on Grade II Pure Titanium by Short Anodization Processing (Grade II 순수 타이타늄의 단시간 양극산화에 의한 TiO2 나노튜브 형성)

  • Lee, Kwangmin;Kim, Yongjae;Kang, Kyungho;Yoon, Duhyeon;Rho, Sanghyun;Kang, Seokil;Yoo, Daeheung;Lim, Hyunpil;Yun, Kwiduk;Park, Sangwon;Kim, Hyun Seung
    • Korean Journal of Materials Research
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    • v.23 no.4
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    • pp.240-245
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    • 2013
  • Electrochemical surface treatment is commonly used to form a thin, rough, and porous oxidation layer on the surface of titanium. The purpose of this study was to investigate the formation of nanotubular titanium oxide arrays during short anodization processing. The specimen used in this study was 99.9% pure cp-Ti (ASTM Grade II) in the form of a disc with diameter of 15 mm and a thickness of 1 mm. A DC power supplier was used with the anodizing apparatus, and the titanium specimen and the platinum plate ($3mm{\times}4mm{\times}0.1mm$) were connected to an anode and cathode, respectively. The progressive formation of $TiO_2$ nanotubes was observed with FE-SEM (Field Emission Scanning Electron Microscopy). Highly ordered $TiO_2$ nanotubes were formed at a potential of 20 V in a solution of 1M $H_3PO_4$ + 1.5 wt.% HF for 10 minutes, corresponding with steady state processing. The diameters and the closed ends of $TiO_2$ nanotubes measured at a value of 50 cumulative percent were 100 nm and 120 nm, respectively. The $TiO_2$ nanotubes had lengths of 500 nm. As the anodization processing reached 10 minutes, the frequency distribution for the diameters and the closed ends of the $TiO_2$ nanotubes was gradually reduced. Short anodization processing for $TiO_2$ nanotubes of within 10 minutes was established.