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Mobile Station Movement Direction Prediction (MMDP) Based Handover Scanning for Mobile WiMAX System
No full textMobile WiMAX is a broadband technology that is capable of delivering triple play services (voice, data, and video). However, mobility in mobile WiMAX system is still an issue when the mobile station (MS) moves and its connection is handed over between base stations (BSs). In the handover process, scanning is one of the required phases to find the target BS. During the handover scanning process, the MS must synchronize with all the advertised neighbour BSs (nBSs) to select the best BS candidate for the incoming handover action. Without terminating the connection between the SBS and MS, the SBS will schedule the scanning intervals and sleep-intervals (also called interleaving interval) to MS for the handover scanning. However, during the scanning interval period, all the coming transmissions will be paused. Therefore, the redundant or unnecessary scanning of neighbouring BS cause delay and MAC overhead which may affect real-time applications. In this paper, the MS movement direction prediction (MMDP) based handover scanning scheme is introduced to overcome the mobile WiMAX handover scanning issue. It based on dividing the BS coverage area is into zones and sectors. According to the signal quality; there are three zones, no handover (No-HO), low handover (Low-HO) and high handover (High-HO) zones respectively and six sectors. In this scheme, only two BSs can become candidates; the two that the MS moves toward them will be chosen as the candidate for the handover scanning purpose. Hence, the handover scanning process repetition will be reduced with these two shortlisted BS candidates instead of scanning all nBSs. Thus, MMDP will reduce scanning delay and the number of exchange messages during the handover scanning comparing to the conventional scanning scheme. Although, the MMDP may need an extra computational time, the prediction and scanning process will be finished before the MS reach the High-HO zone, which mean the end-user's running application will be affected. Simulation results show that the proposed MMDP scheme reduces the total handover scanning delay and scanning interval duration by 25 and 50 % respectively. Also, the size of scanning message is reduced, which leads to reduced signalling overhead
Does Lowering Evening Rectal Temperature to Morning Levels Offset the Diurnal Variation in Muscle Force Production?
No full textMuscle force production and power output in active males, regardless of the site of measurement (hand, leg, or back), are higher in the evening than the morning. This diurnal variation is attributed to motivational, peripheral, and central factors and higher core and, possibly, muscle temperatures in the evening. This study investigated whether decreasing evening resting rectal temperatures to morning values, by immersion in a water tank, leads to muscle force production and power output becoming equal to morning values in motivated subjects. Ten healthy active males (mean +/- SD: age, 22.5 +/- 1.3 yrs; body mass, 80.1 +/- 7.8 kg; height, 1.72 +/- 0.05 m) completed the study, which was approved by the local ethics committee of the university. The subjects were familiarized with the techniques and protocol and then completed three sessions (separated by at least 48 h): control morning (07: 30 h) and evening (17: 30 h) sessions (with an active 5-min warm-up on a cycle ergometer at 150 W) and then a further session at 17: 30 h but preceded by an immersion in cold water (similar to 16.5 degrees C) to lower rectal temperature (T-rec) to morning values. During each trial, three measures of grip strength, isokinetic leg strength measurements (of knee flexion and extension at 1.05 and 4.19 rad s(-1) through a 90 degrees range of motion), and three measures of maximal voluntary contraction (MVC) on an isometric dynamometer (utilizing the twitch-interpolation technique) were performed. T-rec, rating of perceived exertion (RPE), and thermal comfort (TC) were also measured after the subjects had reclined for 30 min at the start of the protocol and prior to the measures for grip, isokinetic, and isometric dynamometry. Muscle temperature was taken after the warm-up or water immersion and immediately before the isokinetic and MVC measurements. Data were analyzed using general linear models with repeated measures. T-rec values were higher at rest in the evening (by 0.37 degrees C; p p > 0.05). Pre-cooling in the evening significantly reduced force or power variables towards morning values. In summary, effects of time of day were seen in some measures of muscle performance, in agreement with past research. However, in this population of motivated subjects, there was evidence that decreasing evening T-rec to morning values by coldwater immersion decreased muscle strength to values similar to those found in the morning. It is concluded that diurnal changes in muscle performance are linked to diurnal changes in T-rec. (Author correspondence: [email protected]
Extensive in-silico analysis of cis-acting DNA sequences in 5’ regulatory regions of sucrose synthase, cell wall invertase and sucrose transporter gene families
No full textCis-acting regulatory elements are important molecular switches involved in the temporal and spatial expression of a dynamic network of gene activities. This network control hormone responses, abiotic stress responses and developmental events such as juvenility, floral signal transduction and senescence. In this analysis, a particular emphasis was placed on cis-acting regulatory elements present within the 5’ regulatory region of sucrose synthase (SuSy), cell wall invertase (CWI) and sucrose transporter (SUT) gene families in Arabidopsis thaliana and Oryza sativa. The potential cis-acting regulatory elements were predicted by scanning 1.5 kbp of 5’ regulatory regions of the SUT, CWI and SuSy genes translational start sites, using various resources for cis-element bioinformatics. Cis-elements associated with hormone responsiveness, light responsiveness, elicitor responsiveness and abiotic stress were predicted in varying frequencies within the 1.5 kbp of 5’ regulatory sequences. In addition, cis-elements involved in sugar repression, mineral responses, and cold- and light-inducible gene expression were also identified. Some of the predicted cis-elements have experimental precedent, but many are novel and encourage further exploration. This analysis provides a basis for elucidating transcription regulatory interactions of SUT, CWI and SUSY gene families during development or under abiotic stress conditions
What price free schools?: the continued insidious privatisation of UK state education
No full textA review of American charter schools and Swedish free school research is outlined providing strong evidence that both free market models are flawed in their claims of enhancing young peoples' educational experience. A substantial body of work is included strongly indicating charter and free schools increase social segregation and lower educational attainment. It is also agued that the rationale and commitment to competition undermines cooperation between schools and reinforces class differentiation suggesting the argument that the model facilitates choice is a misnomer. It is also argued their inception in the UK are, like the academies model, driven by a narrow ideological stance and should be replaced by a non-selective, state funded, comprehensive school model accessible to all
Fiction denial and the liberation of games
No full textSince its inception, the field of game studies has pursued an attitude of exceptionalism that treats the videogame as a unique form that must be approached differently from the ways other media are studied. This stance is parallel to the exceptionalism towards humanity that continued to treat animals and humans as radically distinct concepts until the late twentieth century. By examining different aspects of videogame exceptionalism, particularly the fiction denial that considers the rules of games to be radically more important than their representational elements, an argument is advanced that videogame exceptionalism is distorting our understanding of both videogames and other forms of play and narrative. It is further argued that it is misleading to talk of the difference between videogames and other creative media without saying which genres are being compared within each medium. There is therefore a need for a 'game liberation' that will cease to treat the history and genealogy of videogames as constrained solely to digital artefacts – rather, a complete understanding of videogames requires an appreciation for their connectivity with the other forms of play and fiction that both predate it, and that continue to exchange conventions with it. Short Description: Fiction denial claims that rules are more important than representation in videogames, and is an archetypal form of exceptionalism that treats videogames as radically distinct from other media. However, it is misleading to talk of the difference between videogames and other media without saying which genres are being compared within each medium
Characterization of the surface acoustic wave devices based on ZnO/nanocrystalline diamond structures
No full textNanocrystalline ZnO films with strong (0002) texture and fine grains were deposited onto ultra-nanocrystalline diamond (UNCD) layers on silicon using high target utilization sputtering technology. The unique characteristic of this sputtering technique allows room temperature growth of smooth ZnO films with a low roughness and low stress at high growth rates. Surface acoustic wave (SAW) devices were fabricated on ZnO/UNCD structure and exhibited good transmission signals with a low insertion loss and a strong side-lobe suppression for the Rayleigh mode SAW. Based on the optimization of the layered structure of the SAW device, a good performance with a coupling coefficient of 5.2% has been realized, promising for improving the microfluidic efficiency in droplet transportation comparing with that of the ZnO/Si SAW device. An optimized temperature coefficient of frequency of -23.4ppm degrees C-1 was obtained for the SAW devices with the 2.72 mu m-thick ZnO and 1.1 mu m-thick UNCD film. Significant thermal effect due to the acoustic heating has been redcued which is related to the temperature stability of the ZnO/UNCD SAW device
Efficient computational modelling of carbon fibre reinforced laminated composite panels subjected to low velocity drop-weight impact
No full textThis paper reports on the actual and virtual low velocity impact response of carbon fibre composite laminates. It utilises the contribution of through-thickness stresses, in the prediction of the onset of internal damage created by this type impact scenario.The paper focuses on the damage imparted by the flat nose impactor since this induces a different type of damage and structural response compared to that of the standard test method of using a round nose impactor.Vulnerability of the fibrous composites to vertical drop-weight impact can result in premature failure which is a major concern in their widespread usage. The topic has been of intense research to design more damage tolerant and resistant materials. However, due to materials' anisotropic and three-dimensional nature and complicated damage mechanisms no standard model could have been achieved. Designers predict consequences of a local impact within the global structural context without full-scale testing.Majority of the existing simulation models neglect through-thickness stresses that are regarded as the major cause of catastrophic failures. Efficient and reliable investigations are required to reduce testing and include through-thickness stresses. Drop-weight impact simulation models were developed herein using ABAQUS (TM) software. Simulations were carried out to compute in-plane stresses subjected to flat and round nose impacts on laminates of differing thicknesses. These stresses once computed were numerically integrated employing the equilibrium equations to efficiently predict through-thickness stresses. The predicted stresses were then utilised in failure criteria to quantify the coupled and embedded damage. This provides a quick insight into the status and contribution of through-thickness stresses in failure predictions. The computed values were compared to the experimental results and found to be in good agreement. (C) 2013 Elsevier Ltd. All rights reserved
Vertically aligned graphene based non-cryogenic bolometer
No full textWe report the photoresponse of vertically aligned graphene upon IR irradiation at room temperature. Four probe measurements have shown electrical switching in I-V characteristics during pulsed IR irradiation. The photoresponse reported here for vertically aligned graphene (VAG) is much higher than carbon nanotube (CNT) samples. Our investigation has shown that such photoresponse arise solely due to bolometric effect, where the conductivity changes with temperature. The magnitude of the resistance of VAGs increases by ~ 2 fold for 6 0C increase in temperature. Also the Thermal Coefficient of Resistance (TCR) in this region is ~11%/K, which is the highest TCR value reported so far for any carbon nanomaterials
Continuous production of piezoelectric PVDF fibre for e-textile applications
No full textPolymers have been widely used as piezoelectric materials in the form of films and bulk materials but there are limited publications on piezoelectric fibre structures. In this paper the process of preparing piezoelectric polyvinylidene fluoride (PVDF) fibres from granules by continuous melt extrusion and in-line poling is reported for the first time. The poling of PVDF fibres was carried out at an extension ratio of 4:1, a temperature of 80 ° C and a high voltage of the order of 13 000 V on a 0.5 mm diameter fibre in a melt extruder. The entire process of making PVDF fibres from granules and poling them to make piezoelectric fibres was carried out in a continuous process using a customized melt extruder. The prepared piezoelectric fibres were then tested using an impact test rig to show the generation of voltage upon application of an impact load. PVDF granules, unpoled fibres and poled fibres were examined by Fourier transform infrared spectroscopy (FTIR) which showed the presence of β phase in the poled fibres. The ultimate tensile stress and strain, Young's modulus and microstructures of poled and unpoled fibres were investigated using a scanning electron microscope (SEM)