• Title/Summary/Keyword: variable-gain

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Analog Front-End Circuit Design for Bio-Potential Measurement (생체신호 측정을 위한 아날로그 전단 부 회로 설계)

  • Lim, Shin-Il
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.11
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    • pp.130-137
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    • 2013
  • This paper presents analog front-end(AFE) circuits for bio-potential measurement. The proposed AFE is composed of IA(instrument amplifier), BPF(band-pass filter), VGA(variable gain amplifier) and SAR(successive approximation register) type ADC. The low gm(LGM) circuits with current division technique and Miller capacitance with high gain amplifier enable IA to implement on-chip AC-coupling without external passive components. Spilt capacitor array with capacitor division technique and asynchronous control make the 12-b ADC with low power consumption and small die area. The total current consumption of proposed AFE is 6.3uA at 1.8V.

Lipid metabolic effects of caffeine using meta-analysis (메타분석을 이용한 카페인의 지질대사효과)

  • Kim, Na-Jung;Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.4
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    • pp.649-656
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    • 2012
  • The present study was carried out to summarize the effect of caffeine in the lipid metabolic by meta-analysis. The association measure to test effect of caffeine was the Hedges's standardized mean difference (HG). In this particular fixed-effect model of Hedges's standardized mean difference, weight gain, heart weight, serum total lipid, serum triglycerides and liver triglycerides were significantly decreased (p < 0.05). Also, serum HDL cholesterol and serum LDL cholesterol were significantly increased. In this case of heterogeneous variable, random effect model was applied. In this model, weight gain, heart weight, serum total lipid, serum triglycerides, serum LDL cholesterol and liver triglycerides were significantly decreased in caffeine treated group. Also HDL-cholesterol was significantly increased in caffeine treated group.

Analysis of the Influence Factors on Satisfaction of Returning to Farming in Farm-returning and Rural-returning : With Moderating Effect of Family Factor (귀농 귀촌에서 귀농만족에 미치는 영향요인 분석: 가족 지지도를 조절효과 중심으로)

  • Lee, Ji Heum;Ha, Kyu Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.5
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    • pp.39-53
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    • 2017
  • The purpose of this study was to investigate the effects of the rural migration factors, degree of preparation for migration, lifestyle conditions and support policies reflected against the family satisfaction of the migration. In this study family factors were used as control variables. Independent variables for this study will consist of the factors of rural migration, the degree of preparation for migration, living conditions of the farmers and the support policies, where as the dependent variable is the satisfaction of migration with an adjusting factor of the family satisfaction which will be further analysed to identify its effects on the dependent variable. For this study, a questionnaire survey was conducted for the residents and 237 valid questionnaires were collected. Multiple regression analysis was performed based on the collected data where demographic attributes being the controlling variable, and regression analysis was performed for the adjusting variable of the family. As the economic factor increases, the level of satisfaction generated to be higher in rural migration. As for the degree of preparation, living condition and support policies resulted, great quantity of green nature, safety and agriculture startup support, respectively, indicated a positive effect to the satisfaction level of migration. From the results, adjustment effect of the family factors on the economic, nature, convenience and satisfaction of the migration have appeared. The conclusion of this study is that policy support, regional stability, and economic gain are the most important factors to increase satisfaction and to reduce re-migration rate to city.

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Fast Motion Estimation for Variable Motion Block Size in H.264 Standard (H.264 표준의 가변 움직임 블록을 위한 고속 움직임 탐색 기법)

  • 최웅일;전병우
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.209-220
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    • 2004
  • The main feature of H.264 standard against conventional video standards is the high coding efficiency and the network friendliness. In spite of these outstanding features, it is not easy to implement H.264 codec as a real-time system due to its high requirement of memory bandwidth and intensive computation. Although the variable block size motion compensation using multiple reference frames is one of the key coding tools to bring about its main performance gain, it demands substantial computational complexity due to SAD (Sum of Absolute Difference) calculation among all possible combinations of coding modes to find the best motion vector. For speedup of motion estimation process, therefore, this paper proposes fast algorithms for both integer-pel and fractional-pel motion search. Since many conventional fast integer-pel motion estimation algorithms are not suitable for H.264 having variable motion block sizes, we propose the motion field adaptive search using the hierarchical block structure based on the diamond search applicable to variable motion block sizes. Besides, we also propose fast fractional-pel motion search using small diamond search centered by predictive motion vector based on statistical characteristic of motion vector.

The Study of the Changeable Table Design with Units that made of Wasted Wood (소경단목재(小輕短木材) 접목을 활용한 유니트 가변형 테이블디자인 연구개발)

  • Kim, Myeong-Tae;Seo, Seok-Min
    • Journal of the Korea Furniture Society
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    • v.23 no.1
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    • pp.26-37
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    • 2012
  • This is the study about the New Formation Developement, the Changeable Table Design with Units that made of Wasted Wood to use restricted material rationally and to improve the space efficiency in the Table Design. We made some changeable table design with units that made of laminated wood wasted. And we found out the following formative characteristic and physical merits through this study. First, the space efficiency can be improve technically through the unit combination and organic transfomation of the specific form and a new method by laminated wood make the personal originality and the structral stability be built up. Second, there are some merits, moveable convenience and variable layout by the combination or transformation or personal fondness so that economical efficiency and variable of design can be improved. Third, we can remove original faults inside wood like a knot or not-uniform of wood organ when we laminate wood so that we use proper units that have original beauty of wood and can represent mild mood of furniture wholly. Fourth, much more strengthen tensile strength by the reciprocal action among the units that be made of laminated wood reduces wood's metamorphosis like bending or twisting so that the uniformity of wood can be gain and furniture's metamorphosis can be reduced. According to changes of nature environment, the difficulty of supply and demand for wood may be happen. According to changes of life style these days, supply and demand for environment friendly material, processing technique and developement of design to improve the efficiency of using space must be very important factor in morden furniture design. So we propose changeable furniture design by using new environment friendly meterial and processing method from this study.

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Members of Ectocarpus siliculosus F-box Family Are Subjected to Differential Selective Forces

  • Mahmood, Niaz;Moosa, Mahdi Muhammad;Matin, S. Abdul;Khan, Haseena
    • Interdisciplinary Bio Central
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    • v.4 no.1
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    • pp.1.1-1.7
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    • 2012
  • Background: The F-box proteins represent one of the largest families of proteins in eukaryotes. Apart from being a component of the ubiquitin (Ub)/26 S proteasome pathways, their regulatory roles in other cellular and developmental pathways have also been reported. One interesting feature of the genes encoding the proteins of this particular family is their variable selection patterns across different lineages. This resulted in the presence of lineage specific F-box proteins across different species. Findings: In this study, 48 non-redundant F-box proteins in E. siliculosus have been identified by a homology based approach and classified into three classes based on their variable C-terminal domains. A greater number of the F-box proteins have domains similar to the ones identified in other species. On the other hand, when the proteins having unknown or no C-terminal domain (as predicted by InterProScan) were analyzed, it was found that some of them have the polyglutamine repeats. To gain evolutionary insights on the genes encoding the F-box proteins, their selection patterns were analyzed and a strong positive selection was observed which indicated the adaptation potential of the members of this family. Moreover, four lineage specific F-box genes were found in E. siliculosus with no identified homolog in any other species. Conclusions: This study describes a genome wide in silico analysis of the F-box proteins in E. siliculosus which sheds light on their evolutionary patterns. The results presented in this study provide a strong foundation to select candidate sequences for future functional analysis.

A Single-Fed Microstrip Parasitic Array Antenna for Low-Cost Three-Dimensional Beam Steering (저가 3차원 빔 조향을 위한 단일급전 마이크로스트립 기생배열 안테나)

  • Kim, Young-Goo;Kim, Tae-Hong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.5
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    • pp.223-230
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    • 2014
  • In this paper, the single-fed microstrip parasitic array antenna for low-cost three-dimensional beam steering in 5.8GHz ISM(5.725GHz~5.825GHz) band is designed and implemented. The antenna is comprised of one feed active element and four passive elements with variable reactance loads. The beam steering range of implemented antenna is achieved three-dimensional beam steering of ${\pm}28^{\circ}$ at azimuth angle ${\Phi}=0^{\circ}$, ${\Phi}=45^{\circ}$, ${\Phi}=90^{\circ}$, and ${\Phi}=135^{\circ}$ by adjusting variable reactance loads. The maximum gain of the antenna in the beam steering range have within 7.23dBi~9.36dBi and the bandwidth of return loss lower than -10dB covers 5.8GHz ISM band regardless of the beam steering angles.

A Variable Step-Size Adaptive Feedback Cancellation Algorithm based on GSAP in Digital Hearing Aids (가변 스텝 크기 적응 필터와 음성 검출기를 이용한 보청기용 피드백 제거 알고리즘)

  • An, Hongsub;Park, Gyuseok;Song, Jihyun;Lee, Sangmin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.12
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    • pp.1744-1749
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    • 2013
  • Acoustic feedback is perceived as whistling or howling, which is a major complaint of hearing-aids users. Acoustic feedback cancellation is important in hearing-aids because acoustic feedback degrades performance of the hearing aid device by reducing maximum insertion gain. Adaptive systems for estimate acoustic feedback path and feedback suppression algorithms have been proposed in order to solve this problem. A typical feedback cancellation algorithm is LMS(least mean squares) because of its computational efficiency. However it has problem of convergence performance in high correlated input signal. In this paper, we propose a new variable step-size normalized LMS(least mean squares) algorithm using VAD(voice activity detection) to overcome the limitation of the LMS algorithm. The VAD algorithm is GSAP(global speech absence probability) and the feedback cancellation algorithm is normalized LMS. The proposed algorithm applies different step-size between voice and non-voice using VAD, for high stability, fast convergence speed and low misalignment when correlated inputs, such as speech. The result of simulation with white noise mixed speech signal, the proposed algorithm shows high performance then traditional algorithm in terms of stability, convergence speed and misalignment.

A study on perceived value of work having effect on organizational attitude of dental hygienists (치과위생사들의 직업가치인식이 조직태도에 미치는 영향)

  • Yoon, Hee-Suk;Kim, Young-Sun
    • Journal of Korean society of Dental Hygiene
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    • v.8 no.3
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    • pp.65-72
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    • 2008
  • This study has collected 322 clinical dental hygienists working in Daegu and around Daegu, in order to investigate perceived value of work among dental hygienists and extent of organizational attitude and find relationship between these, and we can finds these conclusions as follows; 1. The total average point of perceived value of work is 3.36(5 is a full mark), and we could gain each points as follows; vision realizability 3.53, process efficiency 3.42, product usefulness 3.32, job significance 3.31, social recognition 3.23. 2. The total average point of organizational attitude is 3.13, and job satisfaction, organizational commitment are 3.14, 3.12 respectively. 3. Variables of perceived value of work related job satisfaction are social recognition, vision realizability, process efficiency,(Social recognition is the most effective variable, and next vision realizability, process efficiency are effective in the order named.)($R^2$=.24) and we could find that job satisfaction is proportion to perceived value of work, according to relationship of these variables. Variables of perceived value of work related to organizational commitment are also vision realizability, social recognition, process efficiency,(Vision realizability is the most effective variable, and next social recognition, process efficiency are effective in the order named.)($R^2$=.32) and we could find that organizational commitment is proportion to perceived value of work, according to relationship of these variables. According to these result, perceived value of work and organization attitude(job satisfaction, organizational commitment) of dental hygienists are affirmative. but to make their attitudes be more affirmative, the research about improving perceived value of work is needed. Especially, vision realizability and social satisfaction are very important variables at perceived value of work of dental hygienists.

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Comparing the Effect of Three Processing Methods for Modification of Filament Yarns with Inorganic Nanocomposite Filler and their Bioactivity against Staphylococcus aureus

  • Dastjerdi, Roya;Mojtahedi, M.R.M.;Shoshtari, A.M.
    • Macromolecular Research
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    • v.17 no.6
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    • pp.378-387
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    • 2009
  • This research compared three methods for producing and processing nanocomposite polypropylene filament yarns with permanent antimicrobial efficiency. The three methods used to mix antimicrobial agents based on silver nano particles with PP were as follows: 1) mixing of PP powder and inorganic nanocomposite filler with the appropriate concentration using a twin-screw extruder and preparing granules, 2) method 1 with a singlerather than twin-screw extruder, and 3) producing the masterbatch by a twin-screw extruder and blending it with PP in the melt spinning process. All pure polypropylene samples and other combined samples had an acceptable spinnability at the spinning temperature of $240^{\circ}C$ and take-up speed of 2,000 m/min. After producing as-spun filament yarns by a pilot plant, melt spinning machine, the samples were drawn, textured and finally weft knitted. The physical and structural properties (e.g., linear density, tenacity, breaking elongation, initial modulus, rupture work, shrinkage and crystallinity) of the as-spun and drawn yarns with constant and variable draw ratios (the variable draw ratio was used to gain a constant breaking elongation of 50%) were investigated and compared, while DSC, SEM and FTIR techniques were used to characterize the samples. Finally, the antibacterial efficiency of the knitted samples was evaluated. The experimental results revealed that the crystallinity reduction of the as-spun yarn obtained from method 1 (5%) was more than that of method 2 (3%), while the crystallinity of the modified as-spun yarns obtained with method 3 remained unchanged compared to pure yarn. However, the drawing procedure compensated for this difference. By applying methods 2 and 3, the drawing generally improved the tenacity and modulus of the modified fibers, whereas method 1 degraded the constant draw ratio. Although the biostatic efficiency of the nanocomposite yarns was excellent with all three methods, the modified fabrics obtained from methods 1 and 2 showed a higher bioactivity.