Blazars exhibit the most extreme variability of the class of objects known asactive galactic nuclei (AGN). They are characterized by a featureless continuum, high polarization, and variability at all wavelengths and timescales. The amplitude of optical variations can range from less than 0.1 magnitude on the timescale of minutes to hours, to greater than 5.0 magnitudes on timescales of months to years, and gamma-ray variability amplitudes can span a range of as much as three orders of magnitude in a time-scale as short as a few days. These characteristics are consistent with a supermassive black hole accreting matter at the heart of the host galaxy. However, the observed properties of these objects don't necessarily reflect the intrinsic properties because the emissions have been modified by cosmological distances. The variability of these blazars, which have very different redshifts, have been investigated using several different analytical approaches; i.e. structure function analysis, variability index analysis, and light curve analysis. By transforming observed measurements into the rest frame of the source, the intrinsic properties of the variability can be compared. These variability characteristics of blazars, as seen in their rest frame, and as a function of state, will be discussed in reference to their general characteristics and classification schemes.

To promote people's contact with nature is both an environmental and a health issue. Previous studies show that being in natural environments provides mental, physical and emotional health benefits and is significant in the formation of environmental attitudes, which is also known to be important during child development. This study is about the opportunities that children have to experience natural environments within pre-schools in Sao Paulo Municipality (Brazil) considering their pre-school leaders and teachers' perspectives. Through qualitative interviews and text analysis, five kindergartens were studied. One aim has been to get a better understanding of the preschool's official policy on environmental education and a picture of pre-school leaders and preschool teachers' attitudes regarding children's access to nature. The other goal was to investigate the concrete pre-school activities in which children participate, as reported by their pre-school leaders and preschool teachers. The results show that the municipal curriculum recommends interaction with nature through goal-oriented activities, but does not specifically emphasise free play in nature. It has also been shown that pre-school principals and teachers have a positive attitude towards including nature in unstructured as well as structured pre-school activities. However, the degree to which this is reflected in the current activities is strongly dependent on other factors, such as physical,administrative or organizational conditions that exist in each pre-school. These so-called frame factors need to be known and taken into consideration, whether it is the education planners, pre-school leaders or preschool teachers that are trying to implement change. The study also highlights the importance of a work environment that encourages preschool teachers to seek self-development in their professional capacity, which in turn affects the quality of environmental education that is taught.

Thanks to development of power semiconductor devices and integrated circuits, active front-end converters with controllability of bidirectional power flow have become popular and viable in industrial applications. This thesis proposes an improved resonant current control for the active front-end converter with LCL filter. The proposed control consists of a band-pass filter tuned at fundamental frequency and various band-rejected filters resonant at harmonic frequencies to provide fundamental current tracking capability as well as enhance harmonic current rejection. Based on this algorithm, the active front-end converter can control dc voltage with unity power factor by sensing converter output current, LCL filter voltage and dc voltage. This approach also conducts harmonic current rejection under distorted line voltage with no phase-locked-loop used, which is the significant advantage in terms of phase lag of frame transformation and computing effort of digital signal processing. Current tracking performance and harmonic rejection capability of the proposed method are verified based on frequency-domain analysis. Computer simulations and experimental results are also implemented to validate effectiveness.

The expressed sequence tags, derived from the developing tilapia brain, were established in our laboratory. An unique gene, high mobility group proteins 2 (HMG2), were investigated. HMG2 is a non-histone chromatin protein. HMG2 cloned from tilapia, Oreochromis mossambicus, is a gene with open reading frame 642bps, and deduced as 213 amino acid protein sequence. NCBI Conserved Domain search, the Gene Ontology, NEBcutter restrict enzyme analysis, NCBI blastx, and neighbor phylogenetic tree were used for the bioinformatic analysis. In the present study, the protein expression of HMG2 in the BL21 E.coli system, a prokaryotic system, and purified with 6X His Tag NI-NTA affinity chromatography.

In real-time, two way video communications, how to minimize the end-to-end delay for transmitting video data is very important. Since the delay produced by bits accumulated in the encoder buffer must be very small, we need an improved rate control to encode the video with high quality and maintain low buffer fullness. One approach to reduce the buffer fullness is to skip the encoding frames, but the frame-skipping will produce undesirable motion discontinuity in the encoded video sequence. In this thesis, we study the impact of low delay constraint in H.264 rate control and its improvements. The drawback of the H.264 rate control is it cannot handle the frame-skipping mechanism well. To modify this, we control the quantization parameter of each I-frame to avoid the buffer overflow and frame-skipping. Since encoding the I-frame by different quantization parameter will generate different rate and distortion for a group of pictures (GOP), we use Lagrangian optimization to find the tradeoff between rate and distortion for a GOP. By the estimation models of rate and distortion for a GOP, calculate the Lagrangian cost for each possible quantization parameter of I-frame, the quantization parameter with minimum Lagrangian cost will be our choice for I-frame. Simulation results show that our proposed rate control encode the video sequence with less skipped frames and with higher PSNR compared to H.264 rate control under low delay constraint.

There are many Operation Systems provide the interface likes the frame buffer in Linux. It let Application Programs can read and write the memory block tightly connecting the operating registers of display card directly to get the goal of directly modifying the monitor display. However, although we have the frame buffer, this kind of graphic processing method is not enough to provide a real-time graphic performance under the needed of huge block drawing and moving. In order to eliminate the drawback of the low graphic performance of using pure software, there are many cards with 3D graphic engine produced for speeding up the performance of 3D games, like ATI Radeon X850[1] , NVIDIA GeForce 6800[2] and so on. Although the embedded products like digital TV or mobile phone are not needed to have a complex and powerful 3D graphic engine, the idea of speeding up drafting can be provided for the embedded system as a reference. The graphic engine can not only provide a real-time performance of drafting, but also share the work of CPU in embedded system, to achieve the goal of improving graphic performance and cost down. In the paper, we will implement a 2D graphic engine dynamic shared library for combining the 2D graphic engine and frame buffer on the V/PB926EJ-S target board. To achieve the goal of improving graphic performance, come true the real-time graphic processing ability of Embedded LINUX. And providing a convenient, quickly and reliable software technique of combining hardware resource and operation system together based on the experiment.

In recent years, with the prevailing of outdoor activity, the bicycle has already become one of the most attractive products on equipment market of the outdoor activity, the bicycle styles on the market are numerous at present, but after most products still introduce the new car fund with the leading brand industry person, other same trades and then imitate with its products. Thesis this purpose lie in use concept , project of design method, put forward one systematized two design theory , bicycle of system. Investigate the basic demand for the business bicycle at first, carry on the performance specification of setting up two bicycles system of the decision¡FSecondly the structure of the frame selected separately, ago it suspend organization in midair, after suspend by organization, handlebar in midair it adjust there aren't device ; Use morphology matrix to solve systematically finally, set up the procedure of formating at the same time , solve the system formated and specify to design.

This thesis presents a systematic scheme to design the optimal efficiency operations and axial force control of a single-sided permanent-magnet axial-flux motor with center pole (SPAMC) through the detailed mathematical model and operational analysis. According to the rotating magnetic field theory combining with the recoil line characteristics of permanent magnet and the magnetic equivalent circuit, appropriate projection of the stator currents to achieve the optimal efficiency operations and axial force control can be realized. From these evaluations, a feasible operational guidance for SPAMC field oriented control (FOC) framework can be successfully developed. Finally, based on the proposed operational scheme, a DSP-based drive system has been successfully implemented, and the optimal efficiency operations and axial force control objectives can be achieved.

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The trend towards Information Systems (IS) Outsourcing has become an important trend in recent years. With the prevalence of the Internet, international-based, as well as integration of, up-downstream outsourced IS is no longer independently contracted by single contractor units. This has seen relationships between contractor and customer - and between large contractors and small contractors - become increasingly complicated. This is further complicated by the dual pressures on the contractor of offering both a better customer service and controlling cost and quality issues while re-outsourcing to other end contractors. Conflicts can often occur between the members of any outsourcing project because acknowledgement diversities will result in different points of view. The purpose of this research is to identify the possible acknowledgement diversities that may occur between the three types of outsource (Customer, Contractor, End Contractor) during the four key stages of outsourcing (public bidding, contract signing, project development, checking before acceptance). The research basic of the dissertation will be structured by technology frame theories and interviewing will occur in several cases in order to obtain pointed theoretical and practical values for other researchers' reference.