Top PDF A Method To ModifyCorrect The Performance Of Amplifiers

A Method To ModifyCorrect The Performance Of Amplifiers

A Method To ModifyCorrect The Performance Of Amplifiers

component that makes the performance deviations and re- biasing it without changing other parts of the circuit. This is done by using the tool op-amp fixator. Hashemian [4] proposed a method to modify/tune amplifiers for a desirable performance and in that method, he uses partial local biasing (PLB). PLB allows us to locally modifying the Q-points of nonlinear components without affecting other parts of the circuit. It results in larger number of scattered DC sources. Voltage dividing, current mirroring and other source transformation techniques are used to reduce their number to one or two sources, but it is a time consuming and tedious task. Later, Hashemian [5] introduced a new technique to cut down the number of steps for a targeted biasing and it uses Fixator-Norator pairs. Fixators and norators are theoretical two terminal devices and are used in pairs. Circuit simulators like SPICE cannot directly model the pairs; therefore, ideal controlled sources with very high gain are used to model the pairs. The proposed method uses op-amp fixators. It doesnot ______________________________
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J. Braz. Chem. Soc.  vol.22 número6

J. Braz. Chem. Soc. vol.22 número6

The method proposed in this work for the determination of the acid number of several different biodiesels presents similar performance to the method of regulation ABNT NBR 14448. The experimental comparison between the two methods clearly shows that both procedures provide statistically equivalent results. However, the proposed method presents a signiicant advantage over the ABNT NBR 14448 method as it uses only ethanol and water as solvents, while the other needs the organic solvent toluene. As a consequence of the solvent mixture used in the ABNT NBR 14448 15 method (toluene:isopropanol:water;
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Analysis of the performance of different implementations of a heuristic method to optimize forest harvest scheduling

Analysis of the performance of different implementations of a heuristic method to optimize forest harvest scheduling

Finding an optimal solution of forest management scheduling problems with even flow constraints while addressing spatial concerns is not an easy task. Solving these combinatorial problems exactly with mixed-integer programming (MIP) methods may be infeasible or else involve exces- sive computational costs. This has prompted the use of heuristics. In this paper we analyze the performance of different implementations of the Simulated Annealing (SA) heuristic algorithm for solving three typical harvest scheduling problems. Typically SA consists of searching a better solution by changing one decision choice in each iteration. In forest planning this means that one treatment schedule in a single stand is changed in each iteration (i.e. one-opt move). We present a comparison of the performance of the typical implementation of SA with the implementation where up to three decision choices are changed simultaneously in each iteration (i.e. treatment schedules are changed in more than one stand). This may allow avoiding local optimal. In addi- tion, the impact of SA – parameters (i.e. cooling schedule and initial temperature) are tested. We compare our heuristic results with a MIP formulation. The study case is tested in a real forest with 1000 stands and a total of 213116 decision choices. The study shows that when the combinatorial problem is very large, changing simultaneously the treatment schedule in more than one stand does not improve the performance of SA. Contrarily, if we reduce the size of the problem (i.e. reduce considerably the number of alternatives per stand) the two-opt moves approach performs better.
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High Performance Carbon Nanotube based Cascode Operational Transconductance Amplifiers

High Performance Carbon Nanotube based Cascode Operational Transconductance Amplifiers

In the proposed CNT based COTAs, the effect of variation of the number of CNTs (N) on various performance measuring parameters have been studied. It has been seen that N changes performance significantly and its optimum value will result in an optimum performance. The effect of N on the DC gain of both PMOS-NCNT-COTA and NMOS-PCNT-COTA circuits is shown in Figure 6. It is clear from Figure 6 that with the increase in N, DC gain remains more or less constant (just around 2% variation in gain with 600% variation in N in NMOS-PCNT-COTA and less than 1% variation PMOS-NCNT-COTA). Though DC gain must increase with the increase in N due to increase in drive current/transconductance, however, reduction in output resistance and increase in screening effect with increase in N appears dominating always, and prevents the increase in gain. Further, the DC gain in PMOS-NCNT- COTA is more in comparison to NMOS-PCNT-COTA. This can be attributed to more number of N CNTFETS (ten) in PMOS-NCNT-COTA in comparison to just eight P CNTFETs in NMOS-PCNT-COTA. More CNTFETs will
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Outage performance of cooperative amplifyandforward OFDM systems with nonlinear power amplifiers

Outage performance of cooperative amplifyandforward OFDM systems with nonlinear power amplifiers

In the last years, cooperative diversity has emerged as a promising technology for wireless communication systems due to its ability to exploit spatial diversity without the need of multiple antennas. Co- operative diversity systems emulate an antenna array in a distributed manner, allowing one or more mobile units to relay the information data from a source node to the destination node [1]. The main ob- jective is to extend coverage, spectral efficiency and capacity while keeping the advantages of multiple-input multiple-output (MIMO) systems. Several cooperative relaying protocols have been proposed in the literature such as the amplify-and-forward (AF), fixed decode- and-forward and selective decode-and-forward [2]. In the present paper, we are interested in the AF protocol due to the fact that it avoids decoding at the relays and, therefore, it is often preferable when complexity or latency issues are of importance.
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J. Microw. Optoelectron. Electromagn. Appl.  vol.9 número2

J. Microw. Optoelectron. Electromagn. Appl. vol.9 número2

Lee et al. [12]–[14] have experimentally compared the performance of hybrid Raman+EDFA amplifiers, in which the Raman gain is provided in a dispersion compensating fiber (DCF) section of fiber. In their works the residual Raman pump power is recycled to pump the EDFA stage. Several different configurations based on a single pump laser over DCFs were studied. They found that by recycling the residual Raman pump in a cascaded erbium-doped fiber (EDF) section, as a secondary signal amplification stage, pump conversion efficiency can be increased. The amplifier characterization has been calculated in terms of global gain, and noise figure (NF). However, it has been restricted to the single channel characterization only, disregarding the ripple parameter within the amplifier effective gain bandwidth, which is a very important issue in WDM optical communication systems.
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Financial Performance Analysis Of Financial Service Cooperative

Financial Performance Analysis Of Financial Service Cooperative

Abstract: This research is aimed to test and identify empirical evidence regarding the effect of capital structure and loan to financial performance of cooperative, where the relationship between loan and financial performance is moderated by non-performing loan. The population of this research is 257 Financial Service Cooperative (hereinafter referred to as “KJK”, as the abbreviation for Koperasi Jasa Keuangan) of Urban Village Community Economic Empowerment (hereinafter referred to as “PEMK”, as the abbreviation for Pemberdayaan Ekonomi Masyarakat Kelurahan) in Jakarta, 2011 to 2013. Sample is determined by using purposive sampling method. The data is secondary data which is obtained from the Revolving Fund Management Unit (hereinafter referred to as “UPDB”, as the abbreviation for Unit Pengelola Dana Bergulir) Jakarta. Hypothesis is tested by using multiple linear regression analysis with SPSS 20.00. The number of sample used in this research is 120. Research findings explain that (1) Capital Structure (hereinafter referred to as “SM”, as the abbreviation for Struktur Modal) has positive and significant impact on financial performance (hereinafter referred to as “KIN” as the abbreviation for Kinerja Keuangan), because the probability value of 0,000 is smaller than α 0.05. Calculation shows that if the capital structure rises 1%, assuming that the loan and non-performing loan variables remain the same, then the financial performance will increase 0.017%. (2) Loans (hereinafter referred to as "PIN", as the abbreviation for Pinjaman) given has positive and significant impact on KIN, because the probability value of 0,001 is smaller than α 0.05. If the loan rises 1%, assuming that the capital structure and non-performing loan variables remain the same, then the KIN will increase 0.013%. (3) Non-performing loan has negative and significant effect on KIN, because the probability value of 0,000 is smaller than α 0.05. PBR varible increase 1%, assuming that the loan and capital structure variables remain the same, KIN would fall 0.001%. It can be concluded that the level of KIN in KJK PEMK Jakarta is determined by the relationship or interaction between the capital structure, loan, and non-performing loans.
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Method for measuring factors that affect the performance of pilots

Method for measuring factors that affect the performance of pilots

Such studies have emphasized a probabilistic approach analyzing human factors, organizational fac- tors and other factors associated with the environment and/or local infrastructure. Greenberg (2007) developed a general model of quantitative analysis related to aviation accidents using Bayesian net- works, but only factors that increase the threats of an accident. Roelen et al. (2011) developed a hybrid model for risk analysis jointly by Eurocontrol and the Federal Aviation Administration (FAA). In sum- mary the model shows the conjunction of the technical fault tree and event tree to the method of Bayes- ian networks. Martins and Maturana (2013) analyzed the human error contribution for ship collision taking into consideration the activities performed by the crew and is focused on the operation of an oil tanker in the Brazilian coast. The authors searched evidence related to the occurrences of the possible human errors (not found in literature) according to the routine of the ship thus obtaining the necessary data to build the network.
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Rapid method for determination of glyphosate in groundwater using high performance liquid chromatography and solid-phase extraction after derivatization

Rapid method for determination of glyphosate in groundwater using high performance liquid chromatography and solid-phase extraction after derivatization

There are various techniques for determination of glyphosate in environmental samples; however, its high solubility in water, insolubility in organic solvents and low volatility present analytical challenges (Hsu and Whang, 2009). Glyphosate also has high polarity and lacks a chromophore. Detection methods thus require adaptations utilizing derivatization reactions or alteration of some physical property that can be correlated to the amount of glyphosate in the sample (See et al., 2010).

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A Novel Method for Measuring the Performance of Software Project Managers

A Novel Method for Measuring the Performance of Software Project Managers

The actual number of respondents who completed the questionnaire was 48. The respondents were required to select the effective metrics from the available list in the questionnaire. In addition, they were required to determine the weight of each metric. After collecting the responses, the researcher filtered the questions and metrics to reach an enhanced list of metrics. The definition of each metric should include the mathematical or statistical techniques for calculating this metric. The enhanced list will include the most effective questions and metrics that may make it more practical and efficient. Table IV presents the enhanced list of questions and performance metrics for schedule/time project management as an example of SPM knowledge areas. The majority of metrics in table IV have the importance degree 3; that is because the researcher attempts to extract the most effective metrics. In addition, the metric ―M5‖ in question ―Q1‖ is same as the metric ―M4‖ in question ―Q7‖. Similarly, the metric ―M3‖ in question ―Q2‖ and the metric ―M3‖ in question ―Q7‖. The complete definition of the performance metrics should also include:
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APPLICATION OF SIMPLIFIED METHOD FOR DETERMINING THE WI TO PREDICT THE PERFORMANCE OF BALLS MILLS IN SOSSEGO PLANT

APPLICATION OF SIMPLIFIED METHOD FOR DETERMINING THE WI TO PREDICT THE PERFORMANCE OF BALLS MILLS IN SOSSEGO PLANT

Over the years Vale S.A. has developed a methodology for scaling industrial comminution circuit that is being constantly improved and implemented in developing new routes and process optimization of circuits in operation. This work will be given a focus on the methodology of simplified balls mill Work Index (WI Anaconda) in performance prediction of Sossego Plant ball mill. The great advantage of this methodology is to reduce the time and weight to determine the energy consumption in ball mills, whose values can be used in studies of variability, geometallurgy and design and control of industrial grinding circuits.
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J. Braz. Soc. Mech. Sci. & Eng.  vol.32 número2

J. Braz. Soc. Mech. Sci. & Eng. vol.32 número2

In this paper, we implemented the adjoint equations method for the inverse pressure design and the constrained drag minimization problems. In the inverse design problem, surface points, parameters of the NACA 4-digit airfoil series (Airfoil camber (m) and its thickness (t)) and the Hicks-Henne bump functions are used as the design variables. In this problem, values of design variables were obtained successfully. The results of the test case show that we can use the adjoint approach as an efficient tool in airfoil inverse design problem. To evaluate the performance of the adjoint method in design problems with numerous design variables and also to evaluate the effects of the adoption of the design vector on the optimization results in the drag minimization problem, the minimization was performed using two different design vectors. It was shown that the mechanism and the trend of drag reduction during the optimization process were strongly affected by the type of design vector. By using the adjoint equations method, we can design high lift or low drag airfoils according to the desired surface pressure.
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J. Microw. Optoelectron. Electromagn. Appl.  vol.15 número3

J. Microw. Optoelectron. Electromagn. Appl. vol.15 número3

Abstract — This paper presents a modification for the already consolidated analytical model that calculates the gain and ripple in multi-pump Raman amplifiers by considering energy conservation. The original analytical model precisely computes the pump-pump interaction to the C- and L-band for a WDM input signal. However, when this method is used to amplify a large bandwidth, as the entire C and a part of the L band, the increase in the number of pump lasers impacts the obtained results. The error, if compared with results obtained by a numerical method, becomes significant. An analysis in terms of energy is proposed to minimize the discrepancy between analytical and numerical results. An improvement is observed to the gain results.
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The Impact of the Expansion of the Bolsa Familia Program on the Time Allocation of Youths And Their Parents Lia Chitolina Miguel Nathan Foguel Naercio Menezes-Filho

The Impact of the Expansion of the Bolsa Familia Program on the Time Allocation of Youths And Their Parents Lia Chitolina Miguel Nathan Foguel Naercio Menezes-Filho

Table 6 shows the results of estimating equation (3) to obtain the effect of the introduction of BVJ on school enrollment. It shows that the estimated effect of the interaction between treatment and time is positive and significant at the 5 per cent level, regardless of whether the control variables are included (column 1) or not (column 2). The estimated effects evinces that the expansion of the PBF for young people of 16 years of age increased the probability attending school by approximately 4 percentage points with respect to 15-year-olds. This result is noteworthy because, in addition to the immediate relief of poverty, one of the main purposes of the PBF is to reduce the transmission of poverty in the medium and long terms by increasing school enrollment among the poorest households. The results suggest that the expansion of the PBF to 16-year-olds has contributed to that goal.
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Evaluation of susceptibility of the ZRE1 alloy to hot cracking in conditions of forced strain

Evaluation of susceptibility of the ZRE1 alloy to hot cracking in conditions of forced strain

The nil strength temperature (NST) for the alloy was determined by testing cylindrical Ø 6 x 90 mm specimens on the Gleeble 3800 simulator. S-type thermocouples were pressure welded to the specimens, and then the specimens were fixed in the chamber by means of copper holders. Constant distance of 52.4 mm was kept between the holders. After evacuation of air, the chamber was filled with argon (to 0.14 hPa). Then, the 0.6 – 0.7 kN minimum pre-load was applied and was maintained until the end of experiment. The specimens were heated at the 20 o C/s rate to 400 o C, and then at the 1 o C/s rate. The NST was determined as the temperature at which the specimen lost its cohesion. The NST for the ZRE1 alloy in as-delivered state is 535 o C.
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Analytic-numerical method of determining the freezing front location

Analytic-numerical method of determining the freezing front location

This approach indicates that regardless of the considered boundary condition, at the end we always receive the approximate solution. The same effect will be achieved if we assume that the function  (t ) , describing position of the freezing front, will be approximated with the aid of the broken line (see Figure 2), it means

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Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

Investigating The Use Of Mobile Computing In Zimbabwe Polytechnics Case Of A Polytechnic In Zimbabwe

outside staff and lecture rooms, send and receive emails and communicate on social networks. This Polytechnic in particular, was one of the first institutions to install the wireless access points that accessed internet through the main fibre backbone. In 2009 it went on to procure laptops for staff members, starting with senior management, the Heads of departments and finally lectures. Students were then allowed to bring their own devices which could be configured to be able to access institutional WIFI (The Polytechnic ICT policy document, 2010). This was the beginning of mobile computing at the Polytechnic. Since then further strides were made in such areas as installation of applications that run on mobile devices through wireless connections, increasing internet bandwidth to improve speed as demand for internet went up, upgrading wireless access points to improve strength of connectivity, upgrading of servers to handle the demand and volumes and expansion of campus area network to cover the whole Polytechnic, procurement of more mobile devices. And the institution now boasts of such things as e-learning, m- learning, m-education, among other technologies that are giving it a competitive advantage over sister Polytechnics.
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Synthesis Of Arts In Architecture Of Uzbekistan Of The Ancient Period

Synthesis Of Arts In Architecture Of Uzbekistan Of The Ancient Period

decoration in Airtam "the sculpture with the busts of musicians, gift-bearers was subjected to the unified principle of division of the entire space into rhythmic segments" [47, 86].As an example, one may consider the case when the sculpture had a religious or symbolic significance, and was a crucial element in resolving the entire interior ("Hall of Warriors" in Toprak-kale). But on the whole, in contrast to a more constrained medieval sculpture, antique one differed in realistic nature (right arrangement of the figures), expressiveness (the types of faces and their emotions), naturalness (in different curves of the body), through which the aesthetic sides of the structures were emphasized. Monumental characters of the structures, their ideological concepts (for example, the idea of greatness) were emphasized by means of sculpture. And, the most important aspect, the sculpture differed in architectonic manner (Buddhas - under the arches, gandharvas– between the acanthuses), as the determinant factor was still the scale of the monument, the height of the walls, the conditions of observation, the very architectonics of the interior. A high quality performance, especially in the Greco-Bactrian period, testified to the high skills of the artists, in the best traditions of Hellenic arts. "The artist could be acourt master from Seleucid accompanying the king to a distant Bactria" [30, 190]. It is assumed that in Bactria existed at least three sculptural schools; their students were familiar with Asia Minor sculpture schools [48, 125p]. Smooth walls of buildings were divided not only horizontally –by friezes, zofors, but also vertically - through door and window openings, columns and pilasters. The synthesis of architecture and decorative plastic forms, generally typical for later Hellenistic states, could be seen in the ancient Bactrian capitals - Corinthian and composite ones, representing a complete architectural form. Professional masters "were widely using the approach of architectonic
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Contribution To The Study Of Reproduction Parameters Of The European Conger Eel Conger Conger Linnaeus 1758 From The Western Algerian Coasts Oran Bay Algeria

Contribution To The Study Of Reproduction Parameters Of The European Conger Eel Conger Conger Linnaeus 1758 From The Western Algerian Coasts Oran Bay Algeria

The females G.S.I. presents two peak, the first in early winter, in January 2012, (1.15 % ± 0.66 %) and the second in the late winter, in March 2011, (1.45 % ± 0.83 %), and reached the lowest value in autumn. However, the higher values of males G.S.I. were observed in winter, in February 2012 (1.77 % ± 0.52 %), and in spring in March 2011( 1.72 % ± 1.4 %) and April 2011 ( 1.86 % ± 0.88 %) and reached the lowest value in autumn and summer. Similar findings have been reported by Hood and al., (1988) and Sullivan et al., (2003) on Conger. oceanicus and C.conger, respectively. Nevertheless, Correia et al., (2009), showed that the G. S. I. was lowest in autumn and high during winter and spring seasons. This was probably due to mobilization of somatic energy for the development of ovaries. The decline of G.S.I. from April to December 2011in female and from May 2011 to January 2012 in male may be due to the migration of the broodstock. Indeed, the reproduction is carried out in deep water, south-east of Sardinia in the Mediterranean Sea. A spawning ground exists in the Sardinia channel at depths between 600 and, at least, 800 m in the Mediterranean Sea (Cau and Manconi, 1983). The females H.S.I. showed two pairs of peak, first in winter, in January 2012 (1.89 % ± 0.36 %) and March 2011 (1.80 % ± 0.51 %), and the second in summer, in July 2011 (1.75 % ± 0.78 %) and September 2011 (1.84 % ± 0.66 %). The summer peaks coincided with hepatic fats deposits due to intense feeding activity, probably because of the abundant food, useful for fish gonad maturation (Abi-Ayad et al., 2011). The peaks measured in January and March was correlated with the dynamic of G. S. I. these can be explained either by the action of liver (precursor synthesis products involved in
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Performance of HIV Prevention of Mother-To-Child Transmission Programs in Sub-Saharan Africa: Longitudinal Assessment of 64 Nevirapine-Based Programs Implemented in 25 Countries, 2000-2011.

Performance of HIV Prevention of Mother-To-Child Transmission Programs in Sub-Saharan Africa: Longitudinal Assessment of 64 Nevirapine-Based Programs Implemented in 25 Countries, 2000-2011.

Routine collection, analysis, and strategic use of data gathered throughout the delivery of PMTCT services is essential for reducing the incidence of HIV infections in children and improving the health of HIV-positive mothers [8]. Despite this need, recent reports demon- strate that there are limited data on which to base decisions related to improving access and adherence to PMTCT regimens or defining or evaluating contextual factors that affecting the program’s efficacy [22, 23]. In particular, longitudinal data with long follow-up are lacking to investigate the sustainability of programs and their potential ability to improve over time. While current strategies for PMTCT have evolved to include more complex ARV regimens, longitudinal analysis of the performance of PTMCT programs that used sd-NVP may be useful in identifying programmatic approaches and innovations that correlate with improved pro- gram performance [24]. Lessons learned from the experiences of large programs that include long-term follow-up may be useful for defining the parameters of future efforts to expand and improve PMTCT services in low- and middle-income countries.
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