494 research outputs found
Criterion for polynomial solutions to a class of linear differential equations of second order
No full textPT: JSource type: Electronic(1
Solutions for certain classes of the Riccati differential equation
No full textWe derive some analytic closed-form solutions for a class of Riccati equations y'(x) - lambda(0)(x) y(x) +/- y(2)(x) = +/- s(0)(x) where lambda(0)( x), s(0)( x) are C-infinity- functions. We show that if delta(n) = lambda(n)s(n-1) - lambda(n-1)s(n) = 0, where lambda(n) = lambda(')(n-1) + s(n-1) + lambda(0)lambda(n-1) and s(n) = s(n-1)(')+ s(0)lambda(k-1) , n = 1, 2, ... , then the Riccati equation has a solution given by y( x) = -/+ s(n-1)(x)/ lambda(n-1)(x). Extension to the generalized Riccati equation y'(x) + P(x) y(x) + Q(x) y(2)(x) = R(x) is also investigated
Inquiry and Reply in the Works of Nasser Khosrow
No full textNasser Khosrow (394-481 AH), the authoritative poet-author, is one of the outstanding figures of the 5th century AH. He considered science and knowledge as the highest levels, and valued them greatly. His scientific approach accompanied by his pragmatism can be a perfect model for any human being. One of the instructional methods used by Nasser Khosrow is inquiring or asking questions through different methods. He had the knowledge of various sciences of his age such as philosophy, religion, etc. and he used each of these sciences for expressing his ideas. His questions are posed among his odes, but the answers to these questions are presented through different methods. Sometimes, one should look for the answers to these questions in his prose works. At times, he uses rhetorical questions as an alert for the audience, at other times he may ask a question in his ode and provide the answer somewhere in the same ode. On the whole, Nasser Khosrow uses all rhetorical methods in his works to impress his audience. This study classifies these questions based on their content, investigates his purposes, and determines the methods of answering the questions in order to illustrate his way of thinking. Examples have been extracted from some of his works including his Divan, Zaad-ol-Mosaferin, Safarnameh (Travelog), Goshyesh va Rahayesh, Jaame-ol-Hekmatein, Vajh-e Din, and Khan-ol-Ekhva
Corresponding Author: Nasser Najibi, Shanghai Astronomical Observatory
No full textAbstract: The establishment and maintenance of marine structures and near-shore constructions together require having sufficient and accurate information about sea level variations not only in the present time but also in the near future as a reliable prediction
Screening for abnormal eating attitudes in a population of Egyptian secondary school girls
No full textThe author screened a population of secondary school girls in Cairo, Egypt (n= 351), for abnormal eating attitudes, using a translated version of the Eating Attitude Test questionnaire (EAT-40). 11.4% scored positively on the questionnaire, a higher percentage than those reported by Mann et al (1983), Szmukler (1983) and Sabine et al (1988) of 6.9%, 6.2% and 8.2% respectively. This variance could be interpreted as a measure of genuine concern over weight or a reflection of a difference in the performance of the questionnaire in this population. In an attempt to determine the latter a confirmatory factor analysis was carried out modelled on Garner et al (1982) and Eisler & Szmukler (1985). The results of the analyses pointed to the coherence of the instrument which showed reasonable psychometric standards in this population. Three cases clearly fulfilled Russell's criteria for a diagnosis of a full syndrome of bulimia nervosa (1.2%), this is broadly in keeping with the rates of the UK studies of 1.9% and 1.1% in Cooper & Fairburn (1983) and King (1989) respectively. Twelve pupils (3.35) showed sufficient concern over their weight to qualify for partial syndrome of bulimia nervosa. The results of this study confirm the initial impression that disorders of eating are emerging in cultures that did not produce such morbidity before with more or less the same prevalence as in the UK. The author discussed the findings in relation to issues of cultural immunity and vulnerability in this respect, and concluded that no society is truly protected against the development of such disorders due to the globalisation of culture by virtue of the media.</p
Adapting authoritarianism: institutions and co-optation in Egypt and Syria
No full textThis PhD thesis compares Egypt and Syria’s authoritarian political systems. While the tendency in social science political research treats Egypt and Syria as similarly authoritarian, this research emphasizes differences between the two systems with special reference to institutions and co-optation. Rather than reducibly understanding Egypt and Syria as sharing similar histories, institutional arrangements, or ascribing to the oft-repeated convention that “Syria is Egypt but 10 years behind,” this thesis focuses on how events and individual histories shaped each states current institutional strengthens and weaknesses. Specifically, it explains the how varying institutional politicization or de-politicization affects each state’s capabilities for co-opting elite and non-elite individuals.
Beginning with a theoretical framework that considers the limited utility of democratization and transition theoretical approaches, the work underscores the persistence and durability of authoritarianism. Chapter two details the politicized institutional divergence between Egypt and Syria that began in the 1970s. Chapter three and four examines how institutional politicization or de-politicization affects elite and non-elite individual co-optation in Egypt and Syria. Chapter five discusses the study’s general conclusions and theoretical implications.
This thesis’s argument is that Egypt and Syria co-opt elites and non-elites differently because of the varying degrees of institutional politicization in each governance system. Rather than view one country as more politically developed than the other, this work argues that Syria’s political institutions are more politicized than their Egyptian counterparts. Syria’s political arena is, thus, described as politicized-patrimonialism. Syria’s politicized-patrimonial arena produces uneven co-optation of elites and non-elites as they are diffused through competing institutions. Conversely, the Egyptian political arena remains highly personalized as weak institutions and individuals are manipulated and molded according to the president’s ruling clique. This is referred to as personalized-patrimonialism. As a consequence, Egypt’s political establishment demonstrates more flexibility in ad hoc altering and adapting its arena depending on the emergence of crises.
This study’s theoretical implications suggest that, contrary to modernization and democratization theory’s adage that institutions lead to a political development, politicized institutions within a patrimonial order actually hinder regime adaptation because consensus is harder to achieve and maintain. It is within this context that Egypt’s de-politicized institutional framework advantages its top political elite. In this reading of Egyptian and Syrian politics, Egypt’s personalized political arena is more adaptable than Syria’s. These conclusions do not indicate that political reform is a process underway in either state
Estimation of Reservoir Discharges from Lake Nasser and Roseires Reservoir in the Nile Basin Using Satellite Altimetry and Imagery Data
No full textThis paper presents the feasibility of estimating discharges from Roseires Reservoir (Sudan) for the period from 2002 to 2010 and Aswan High Dam/Lake Nasser (Egypt) for the periods 1999–2002 and 2005–2009 using satellite altimetry and imagery with limited in situ data. Discharges were computed using the water balance of the reservoirs. Rainfall and evaporation data were obtained from public domain data sources. In situ measurements of inflow and outflow (for validation) were obtained, as well. The other water balance components, such as the water level and surface area, for derivation of the change of storage volume were derived from satellite measurements. Water levels were obtained from Hydroweb for Roseires Reservoir and Hydroweb and Global Reservoir and Lake Monitor (GRLM) for Lake Nasser. Water surface areas were derived from Landsat TM/ETM+ images using the Normalized Difference Water Index (NDWI). The water volume variations were estimated by integrating the area-level relationship of each reservoir. For Roseires Reservoir, the water levels from Hydroweb agreed well with in situ water levels (RMSE = 0.92 m; R2 = 0.96). Good agreement with in situ measurements were also obtained for estimated water volume (RMSE = 23%; R2 = 0.94) and computed discharge (RMSE = 18%; R2 = 0.98). The accuracy of the computed discharge was considered acceptable for typical reservoir operation applications. For Lake Nasser, the altimetry water levels also agreed well with in situ levels, both for Hydroweb (RMSE = 0.72 m; R2 = 0.81) and GRLM (RMSE = 0.62 m; R2 = 0.96) data. Similar agreements were also observed for the estimated water volumes (RMSE = 10%–15%). However, the estimated discharge from satellite data agreed poorly with observed discharge, Hydroweb (RMSE = 70%; R2 = 0.09) and GRLM (RMSE = 139%; R2 = 0.36). The error could be attributed to the high sensitivity of discharge to errors in storage volume because of the immense reservoir compared to inflow/outflow series. It may also be related to unaccounted spills into the Toshka Depression, overestimation of water inflow and errors in open water evaporation. Therefore, altimetry water levels and satellite imagery data can be used as a source of information for monitoring the operation of Roseires Reservoir with a fairly low uncertainty, while the errors of Lake Nasser are too large to allow for the monitoring of its operation
Intensity extraction and normalization algorithm development for DNA microarray image processing
No full textMaster of Science in Electronic EngineeringMicroarray has several thousands of spots that represent various parts of human genes
on a slide. Each of the spot consists of two samples (normal as a reference and cancer as
a target). The samples are labeled into green (reference) and red (target) dyes. If the spot
is indicating green dye, it shows a high expression of the normal sample whereas red
dye shows a high expression of the target spotted on that gene. In order to indicate the
percentage of red and green intensity for every spot, microarray undergoes image
processing where there are huge amount of data that increase the probability of error
and consume much time. Applying the image processing clears unwanted residues on
the microarray image and solves the spot finding problem with high accuracy and short
time consumption. The image processing involves gridding, segmentation, intensity
extraction and normalization. Gridding addresses the spots on the microarray image.
Then segmentation can perform separation between the foreground and background
pixels. Thirdly, the averages of the foreground and background intensity for each spot
are computed. Fourthly, unwanted balance of the colors is balanced to cut back the
noises. The aim of this work is to improve the intensity extraction and normalization
step for DNA microarray image processing algorithm using MATLAB. Three methods
for allocating and calculating the background intensity values were discussed and
compared. These methods were GenePix, ScanAlyze, and QuantArry. Besides that, five
alternatives for intensity extraction were applied to a microarray slide image in order to
find the most accurate intensity value for each spot in the two-color microarray. These
alternatives were Standard, Kooperberg, Edward, Morph and No-background. Based on
the results, Edward method shows the most accurate results to extract foreground and
background intensity and to calculate the ultimate intensity for each spot by 39.7 dB in
term of PSNR. An improved method was proposed for intensity extraction by increasing
background locations, where this method showed very accurate results by 41.36 dB in
term of PSNR and 2.2 in term of RMSE. Besides that, using the proposed method the
MAE is around 9 while it is very high for the other intensity extraction existing
algorithms. On the other hand, five normalization algorithms, Global, Lowess, Housekeeping,
Quantile, and Print-tip, have been tested and compared to find the most
suitable approach for normalization process. Print Tip normalization was chosen for
normalization because of its high accuracy which was around 32.89 dB in term of
PSNR and its final MA graph shape was well normalized. In relation to this matter, a
proposed method for normalization was applied. It increases the accuracy by 33.15 dB
in term of PSNR, 32.63 in term of MSE and the occurrence of errors become very small
by around 12 in term of MAE. Finally, algorithm profiling has been done, it proved that
the proposed algorithm consumes less time than the Bemis project by around 347.7
milliseconds
- …
