Matter Inheritance Symmetries of Spherically Symmetric Static Spacetimes

In this paper we discuss matter inheritance collineations by giving a complete classification of spherically symmetric static spacetimes by their matter inheritance symmetries. It is shown that when the energy-momentum tensor is degenerate, most of the cases yield infinite dimensional matter inheriting symmetries. It is worth mentioning here that two cases provide finite dimensional matter inheriting vectors even for the degenerate case. The non-degenerate case provides finite dimensional matter inheriting symmetries. We obtain different constraints on the energy-momentum tensor in each case. It is interesting to note that if the inheriting factor vanishes, matter inheriting collineations reduce to be matter collineations already available in the literature. This idea of matter inheritance collineations turn out to be the same as homotheties and conformal Killing vectors are for the metric tensor.Comment: 15 pages, accepted for publication in Int. J. of Mod. Phys.

A partitioning strategy for nonuniform problems on multiprocessors

The partitioning of a problem on a domain with unequal work estimates in different subddomains is considered in a way that balances the work load across multiple processors. Such a problem arises for example in solving partial differential equations using an adaptive method that places extra grid points in certain subregions of the domain. A binary decomposition of the domain is used to partition it into rectangles requiring equal computational effort. The communication costs of mapping this partitioning onto different microprocessors: a mesh-connected array, a tree machine and a hypercube is then studied. The communication cost expressions can be used to determine the optimal depth of the above partitioning

Efficient algorithms for a class of partitioning problems

The problem of optimally partitioning the modules of chain- or tree-like tasks over chain-structured or host-satellite multiple computer systems is addressed. This important class of problems includes many signal processing and industrial control applications. Prior research has resulted in a succession of faster exact and approximate algorithms for these problems. Polynomial exact and approximate algorithms are described for this class that are better than any of the previously reported algorithms. The approach is based on a preprocessing step that condenses the given chain or tree structured task into a monotonic chain or tree. The partitioning of this monotonic take can then be carried out using fast search techniques

Loss aversion and anchoring in commercial real estate pricing: Empirical evidence and price index implications

Loss aversion behavior plays a major role in the pricing of commercial properties, and it varies both across the type of market participants and across the cycle. We find that sophisticated and more experienced investors are at least as loss averse as their counterparts and that loss aversion operated most strongly during the cycle peak in 2007. We also document a possible anchoring effect of the asking price in influencing buyer valuation and subsequent transaction price. We demonstrate the importance of behavioral phenomena in constructing hedonic price indices, and we find that the impact of loss aversion is attenuated at the aggregate market level. This suggests that the pricing and volume cycle during 2001–2009 was little affected by loss aversion.Real Capital Analytics (Firm)Real Estate Research Institut

Ricci Collineations for Non-Degenerate, Diagonal and Spherically Symmetric Ricci Tensors

The expression of the vector field generator of a Ricci Collineation for diagonal, spherically symmetric and non-degenerate Ricci tensors is obtained. The resulting expressions show that the time and radial first derivatives of the components of the Ricci tensor can be used to classify the collineation, leading to 64 families. Some examples illustrate how to obtain the collineation vector

Terminal ballistics of 7.62 mm armour piercing projectiles against spaced, oblique RHA plates

Spacing and obliquity, when used together, are known to provide one of the most weight efficient solutions for armor protection. Although this configuration has been widely used over almost 100 years there is little quantitative or design data for such systems. In the present study a series of tests were performed using a steel-cored 7.62mm bullet (DAG 7.62x51) against RHA plates of varying thicknesses, spacing and obliquity of the front plate. This work showed that front plate should be substantially thinner than the rear, a ratio of 0.48:1 gave the best results. The highest mass efficiency (2.00) was for a large spacing (400mm) but this could be reduced to 50mm with only a 17% reduction in ballistic efficiency if a slightly more oblique front plate was used

Forecasting Inflation Through Econometric Models : an Empirical Study on Pakistani Data

Bu makale Pakistan’daki enflasyonu modellemeyi ve tahmin etmeyi amaçlamaktadır. Bunun için bir takım ekonometrik yaklaşımlar uygulanmış ve sonuçları karşılaştırılmıştır. ARIMA modellerinde p ve/veya q için fazladan gecikme eklenmesi, hesaplanan hata terimlerinin karelerinin toplamını her zaman azaltmadığı görülmüştür. Gecikmeli değerlerle bir model oluşturulduğunda ise bazı gözlemlerin kaybedildiği ortaya çıkmıştır. Sonuçlar ayrıca şunu göstermiştir ki VAR modelleri ARIMA (2,1,2) modellerinden daha iyi performans sergilememekte ve iki faktörlü ARIMA (2,1,2) modeli ARIMA (2,1,2) modelinden az da olsa daha iyi sonuçlar ortaya koymaktadır. Bu çalışma makroekonomik tahmin sorunu üzerine odaklanmasına rağmen elde edilen ampirik sonuçlar küçük ölçekli makro-ekonometrik modeller için daha genel implikasyonlar taşımaktadır.This article aims at modeling and forecasting inflation in Pakistan. For this purpose a number of econometric approaches are implemented and their results are compared. In ARIMA models, adding additional lags for p and/or q necessarily reduced the sum of squares of the estimated residuals. When a model is estimated using lagged variables, some observations are lost. Results further indicate that the VAR models do not perform better than the ARIMA (2, 1, 2) models and, the two factor model with ARIMA (2, 1, 2) slightly performs better than the ARIMA (2, 1, 2). Although the study focuses on the problem of macroeconomic forecasting, the empirical results have more general implications for small scale macroeconometric models

Forecasting Inflation Through Econometric Models : an Empirical Study on Pakistani Data

Bu makale Pakistan’daki enflasyonu modellemeyi ve tahmin etmeyi amaçlamaktadır. Bunun için bir takım ekonometrik yaklaşımlar uygulanmış ve sonuçları karşılaştırılmıştır. ARIMA modellerinde p ve/veya q için fazladan gecikme eklenmesi, hesaplanan hata terimlerinin karelerinin toplamını her zaman azaltmadığı görülmüştür. Gecikmeli değerlerle bir model oluşturulduğunda ise bazı gözlemlerin kaybedildiği ortaya çıkmıştır. Sonuçlar ayrıca şunu göstermiştir ki VAR modelleri ARIMA (2,1,2) modellerinden daha iyi performans sergilememekte ve iki faktörlü ARIMA (2,1,2) modeli ARIMA (2,1,2) modelinden az da olsa daha iyi sonuçlar ortaya koymaktadır. Bu çalışma makroekonomik tahmin sorunu üzerine odaklanmasına rağmen elde edilen ampirik sonuçlar küçük ölçekli makro-ekonometrik modeller için daha genel implikasyonlar taşımaktadır.This article aims at modeling and forecasting inflation in Pakistan. For this purpose a number of econometric approaches are implemented and their results are compared. In ARIMA models, adding additional lags for p and/or q necessarily reduced the sum of squares of the estimated residuals. When a model is estimated using lagged variables, some observations are lost. Results further indicate that the VAR models do not perform better than the ARIMA (2, 1, 2) models and, the two factor model with ARIMA (2, 1, 2) slightly performs better than the ARIMA (2, 1, 2). Although the study focuses on the problem of macroeconomic forecasting, the empirical results have more general implications for small scale macroeconometric models

Open source tools: Empowered the e-learning pedagogy in distance education 1

E-learning is defined as pedagogy empowered by digital technology which involves learning done at a computer, usually connected to a network, giving us the opportunity to learn almost anytime, anywhere. Today, E-learning allows to share and manage knowledge and skills of the professionals and to get the right information to the right people whenever they need it.. There are many software systems available that provide distance learning environment. This software is in both forms, commercial and open source software (OSS). Moodle is one of the Open source tool that have been increasingly gaining worldwide popularity in e-learning system. This paper is highlights, how the open source tools empowered e-learning. In turn, the popularity of open source tools day by day increases. A huge number of Students are linked and gaining degree in feasible mode. 1