1,586 research outputs found
Efficient multi-standard cognitive radios on FPGAs
Cognitive radios that support multiple standards and modify operation depending on environmental conditions are becoming more important as the demand for higher bandwidth and efficient spectrum use increases. Traditional implementations in custom ASICs cannot support such flexibility, with standards changing at a faster pace, while software baseband implementations fail to achieve the performance required. Hence, FPGAs offer an ideal platform bringing together flexibility, performance, and efficiency. This work explores the possible techniques for designing multi-standard radios on FPGAs, and explores how partial reconfiguration can be leveraged in a way that is amenable for domain experts with minimal FPGA knowledge
Shaping spectral leakage for IEEE 802.11 p vehicular communications
IEEE 802.11p is a recently defined standard for the physical (PHY) and medium access control (MAC) layers for Dedicated Short-Range Communications. Four Spectrum Emission Masks (SEMs) are specified in 802.11p that are much more stringent than those for current 802.11 systems. In addition, the guard interval in 802.11p has been lengthened by reducing the bandwidth to support vehicular communication (VC) channels, and this results in a narrowing of the frequency guard. This raises a significant challenge for filtering the spectrum of 802.11p signals to meet the specifications of the SEMs. We investigate state of the art pulse shaping and filtering techniques for 802.11p, before proposing a new method of shaping the 802.11p spectral leakage to meet the most stringent, class D, SEM specification. The proposed method, performed at baseband to relax the strict constraints of the radio frequency (RF) front-end, allows 802.11p systems to be implemented using commercial off-the- shelf (COTS) 802.11a RF hardware, resulting in reduced total system cost
The accumulative effect of Finnsheep breeding in crossbreeding schemes
Finnsheep (F) was used in a crossbreeding project to improve overall productivity of the DLS breed. Productive and reproductive traits of seven crossbred combinations ranging from 1/8F to 7/8F breeding were compared to those of the two parental breeds. Suffolk rams were used to mate all ewes (361) for five parturitions (1312 records). Ovulation rate (OR) and litter size (LS) at birth for all the groups increased progressively as F breeding increased. The 4/8F ewes weaned the heaviest litters. Percentage of ova lost per ewe mated ranged from 18 % to 29 %. Preweaning mortality rate was highest in F ewes. Total kg of lambs weaned per ewe exposed was highest in 4/8F followed by F whereas that of DLS was lowest. The 4/8F exhibited 25 % heterosis (H) in kg of lambs weaned per ewe exposed. The linear regressions of OR (b = .24), of LS at birth (b = .14) and at weaning (b = .08) on proportion of F breeding in crosses were significant. The regressions were quadratic for percent ova lost and lamb mortality at weaning. The crosses showed positive H in grease fleece weight (GFW), the highest being expressed by the 4/8F and 5/8F crosses. Significant linear relationships were observed between F breeding and GFW (2nd shearing), fiber thickness and variability in both fiber length and fiber thickness, whereas the relationships of F breeding with GFW (3rd and later shearings), clean wool percentage and fiber length were quadratic. Most of the crosses exhibited positive H particularly in clean wool percentage and in staple and fiber length. H was often highest in the 4/8F cross. Genetic group of dam had a significant effect on age at slaughter, leg, loin and kidney fat as a percent of the carcass, lean, fat and bone percent of the 12th rib and fat thickness over loin-eye muscle. A significant linear relationship existed between most of these carcass measurements and the proportion of F breeding in the lambsâ dam
Will cool roofs improve the thermal performance of our built environment? A study assessing roof systems in Bahrain
A number of international campaigns have recently proposed the use of cool roofs worldwide in order to cope with the summer urban heat island (UHI) effect. This work investigates cool roof strategy and examines the potential of such a strategy for Bahrain. Full-scale measurement, meteorological modelling and thermal simulation of five standard roofs were performed during particular summer days due to the high intensity levels of solar irradiation. This work shows that the light tile roof and metal decking are relatively cooler and more comfortable than others and that the maximum reduction in heat gain occurs for a light tile roof with thermal insulation materials. Nevertheless, without insulation the cooling load is increased by only 1.3%. This percentage seems not to be cost-effective where economics and building construction are concerned. In contrast, the reduction percentage due to the use of thermal insulation in the case of dark tile roof, felt bitumen roof and screed roof increases to 5â7%, which is more cost effective. This work concludes that the cool roof strategy is the most cost-effective for the hot climate of Bahrain, which has a long cooling season. With the current levels of urban development in Bahrain, cool roofs can reduce UHI intensity and building cooling loads, lowering demand for electricity and greenhouse gas emissions from power plants. To avoid any negative consequences from using this strategy, however, trade-offs between urban mitigation and adoptation strategies and complementary technologies should be accounted for in future urban development plans
Acceleration of Amphibian Forelimb Regeneration By Polypeptide Growth Factors
Growth factors are potentially important modulators of epimorphic regeneration. This study examined effects of intraperitoneal administration of selected growth factors on limb regeneration of adult newts, Notophthalmus viridescens. These agents stimulated regeneration, producing overlapping but nonidentical effects. Fibroblast growth factor-2 (FGF-2) and insulin-like growth factor I (IGF-I) stimulated bud emergence (8.3 ± 0.6 and 8.3 ± 0.7 days, respectively, vs 11.4 ± 1.1 days for controls). Progression to the cone stage was enhanced by both FGF-2 and transforming growth factor beta 5 ( TGF-~ 5) ; 14.6 ± 0.5 and 15.4 ± 0.4 days with FGF-2 and TGF-~5 , respectively, vs 16.5 ± 0.5 days in controls. Insulin accelerated attainment of the palette stage, 17.0 ± 0.7 days vs 19.0 ± 0.4 days for controls. No treatments affected attaining the digital stage; means between 22.4 and 23.4 days. Histological analysis revealed changes consistent with gross observations. In addition, regenerates from newts treated with FGF-2, TGF-~5. and insulin displayed signs of greater (or earlier) histogenesis than did control animals. These results are consistent with the notion that FGF-2, TGF-~5. and possibly lGF-I stimulate proliferation of blastema cells and that insulin, FGF-2, and TGF-~5 promote differentiation and histogenesis during forelimb regeneration. In conclusion, these results demonstrate that several polypeptide growth factors positively affect the progress of forelimb regeneration, that different growth factors influence the same or similar events of epimorphic regeneration, and that diverse growth factors have nonidentical effects on regeneration
ES2008-54362 A HIGH STANDARD ISOLATED INSOLATED PHOTOVOLTAIC EGYPTIAN SAFARI REST RED SEA AREA
ABSTRACT: Where renewable energy sources, solar, hydro, wind are available the remote communities and businesses can be provided with the most reliable and affordable source of electrical energy. This paper presents a model of safari rest contains all the necessary services for the interested tourists who visit the safari Sinai desert. The PV energy system provides the rural energy needs of remote communities. A photovoltaic renewable energy system is designed to feed the global Ac and Dc electrical required load of this safari rest. The benefits of photovoltaic renewable energy at rural applications are its versatility and convenience. This model of safari rest must be taken in consideration by Egyptian Government as it will provide the tourism plane by new interested tourism field which put a big spot on Red sea area: El Ghordaka
Impact of Designed Teaching Program for Pregnant Women with Gestational Diabetes on Maternal outcomes
Background: Gestational diabetes mellitus (GDM) was deïŹned as any degree of glucose intolerance with an onset or ïŹrst recognition during pregnancy. Aim of this research: was to examine the impact of designed teaching program for pregnant women with gestational diabetes on maternal outcomes. Subjects & Methods:- Design: quasi experimental pre-post one group design was utilized for the current study. Setting: The study was carried out at Antenatal outpatient clinic at El-Manial Obstetrics and Gynecology Hospital. Sample: A convenient sample of 100 gestational diabetic women was recruited for the study. Data collection: different tools were used to collect the data; (1) Structured Interviewing Schedule; (2) Physical assessment sheet; (3) Pretest for assessing knowledge; (4) Follow up tool to asses women's compliance to the given instructions; (5) Post test for assessing knowledge, and Post partum questionnaire. Results: revealed that, the mean post-test knowledge score (18.45) was significantly higher than the mean pre-test knowledge score, there was weak positive relationship between the mean post-test knowledge score and maternal compliance to the given instructions (r = 0.304), no statistically significant relationship were found in relation to post test knowledge score and blood glucose level in the current pregnancy (P=0.37), Moreover, there was high statistically significant relationship between the mean posttest knowledge score and mode of the current delivery (P =0.016). All over there was high statistically significant relationship between post-test knowledge score and maternal outcomes (P < 0.001). In conclusion: participating of designed teaching program for gestational diabetic women lead to increase knowledge score about the disease and increase women's awareness of how to decrease its complications. This research recommended that: Raise pregnant mother's awareness regarding Gestational Diabetes Mellitus, definition, diagnosis, symptoms and signs , frequency of antenatal visits, and ways to adopting healthy life style as follow dietary program and practice exercises. Keywords: Gestational Diabetes Mellitus, Women compliance, , Postpartum questionnair
Stock Pricing Analysis of PT. LEN as Alternative Sources of Fund Through the Initial Public Offering (IPO)
PT. LEN is one of state owned companies (BUMN) in Indonesia which is engaged in technology industries. As one of state owned companies (BUMN) which enroll in strategic industries, PT. LEN has a very important role in supporting the growth of Indonesia\u27s development, PT. LEN\u27s business performance has successfully led PT. LEN as a trillion company. In 2011, the life cycle of this company has been projected from phase stability to phase growth. Nevertheless, one issue has arisen when the growth of the company is hampered by funding issue, especially the lack of capital to run the projects. The growth of revenues become unbalanced with working capital, especially liquid working capital (cash). The objective of the company is to Go Public with huge amount of capital which can support the business activities and also to strengthen the capital structure and the liquidity of assets. The sales revenue from some of its stocks is used as an alternative source of fund apart from bank loans. The fund is used to expand the company\u27s activities, to build the facility of developing system, and also to build fabrication workshop. The total amount of fund needed is 590 billion. During the IPO process, there are several things to be concerned, internally and externally. From the company\u27s internal perspective, several things to be be concerned are company\u27s feasibility studies in doing IPO. From the external perspective will affect investors\u27 interest to the company. This thesis uses discounted cash flow as a method to calculate the valuation of the company. This method is used to value stock\u27s price and the amount of stocks issued by PT. LEN for IP process so the price will be interesting to the investors. Other than to fulfill the needs of source funding, IPO process is also one of the program to privatize the state owned companies in Indonesia which is included in BUMN\u27s Masterplan 2010-2014
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