Archive for July 15th, 2012

A limited view of realism






In the paper we argue that no neat border line between ontology and epistemology can be drawn. This is due to the fact that the separation between factual and conceptual is rather fuzzy, and the world is characterized by a sort of ontological opacity which makes the construction of any absolute ontology difficult. Our ontology is characterized by the fact that the things of nature are seen by us in terms of a conceptual apparatus that is inevitably influenced by mind-involving elements, and all this has important consequences on both the question of scientific realism and the realism/anti-realism debate. Conceptualization gives us access to the world, while, on the other, it is the most important feature of our cultural evolution. While the idealistic thesis according to which the mind produces natural reality looks hardly tenable, it is reasonable to claim instead that we perceive this same reality by having recourse to the filter of a conceptual apparatus whose presence is, in turn, connected to the development of language and social organization. Our science is essentially relational, and not absolute. The information with which it provides us is appropriate, but from our point of view. Science provides reliable information on the world, but this information is always relative to a particular framework, and it is a mistake to think that the limits of our cognitive capacities only have an aprioristic character. Science constantly attempts at providing answers to our questions about how things stand in the world, and thus purports to offer reliable information about it. But it should also be recognized that the extent to which science succeeds in accomplishing this task is disputable. What kind of realism, thus, can we actually endorse? Despite what many relativists claim, realism still is an arguable and defendable position. If one asks what difference is made to our knowledge claims if we accept the existence of an extra-conceptual world, the answer is the following: such recognition undermines the diffused anthropocentric stance which identifies reality with our limited knowledge of it. [ABSTRACT FROM AUTHOR]


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A common fixed point theorem in fuzzy metric space using e. a. property and implicit function

In this paper, we prove common fixed point theorems in fuzzy metric spaces for weakly compatible mappings along with property (E. A.) satisfying implicit relation. Property (E. A.) buys containment of ranges without any continuity requirement besides minimizing the commutativity conditions of the maps to commutativity at their point of coincidence. Moreover, property (E. A.) allows replacing the completeness requirement of the space with a more natural condition of closeness of the range. [ABSTRACT FROM AUTHOR]

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10 undersea tales

CAPE GELIDONYA, TURKEYArchaeologists long assumed the Greeks ran the economic show in the Mediterranean during the Late Bronze Age. Then, in the summer of 1960, George Bass excavated a ship dating to 1200 B.C. off the southern coast of Turkey. The vessel-the first completely excavated underwater-was carrying Near Eastern plaques (below), copper ingots, and other ... Read More

 

Viscosity approximations with weak contraction for finding a common solution of fixed points and a general system of variational inequalities for two accretive operators

In this paper, we prove a strong convergence theorem for finding a common solutions of a general system of variational inequalities involving two different inverse-strongly accretive operators and solutions of fixed point problems involving the nonexpansive mapping in a Banach space by using a modified viscosity extragradient method with weak contraction. Moreover, using the above results, we can apply to finding solutions of zeros of accretive operators and the class of k-strictly pseudocontractive mappings. The results presented in this paper extend and improve the corresponding results of Qin et al. [Convergence of an iterative algorithm for systems of variational inequalities and nonexpansive mappings with applications, J. Comput. Appl. Math., 233 (2009), 231-240.], Aoyama et al. [Weak convergence of an iterative sequence for accretive operators in Banach spaces, Fixed Point Theory and Applications, vol. 2006, Article ID 35390, 1-13.], Yao et al. [Modified extragradient methods for a system of variational inequalities in Banach spaces, Acta. Appl. Math., 110(3) (2010), 1211-1224.], Katchang et al. [A viscosity iterative scheme for inverse-strongly accretive operators in Banach spaces, Journal of Computational Analysis and Applications, 12(3) (2010), 678 686.] and many others. [ABSTRACT FROM AUTHOR]

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Viability of bradyrhizobium japanicum on soybean seeds enhanced by magnetite nanoparticles during desiccation

The aim of this study was to investigate whether magnetite nanoparticles affect the viability of Bradyrhizobium japanicum cells residing on the surface of soybean seeds during desiccation. Different concentrations of nanoparticles suspended in liquid medium, mixed with and adhering to Bradyrhizobium japanicum, were investigated at two temperatures, using both soybean seeds and glass beads as surrogates. Statistical design was a complete randomized block (CRB) in a factorial 6×2×2×6 experimental arrangement with four replications. The most important variable was the viability of Bradyrhizobium on the surface of the seeds. The nanoparticles increased Bradyrhizobium viability and inoculated seeds stored at low temperature had greater viability when nanoparticles had been added. At the optimum nanoparticle concentration, 50% bacterium viability on the seeds was retained after 5 days at 4°C. Possible explanations for the observed effects are proposed. [ABSTRACT FROM AUTHOR]

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Validation on 3d surface roughness algorithm for measuring roughness of psoriasis lesion

Psoriasis is a widespread skin disease affecting up to 2% population with plaque psoriasis accounting to about 80%. It can be identified as a red lesion and for the higher severity the lesion is usually covered with rough scale. Psoriasis Area Severity Index (PASI) scoring is the gold standard method for measuring psoriasis severity. Scaliness is one of PASI parameter that needs to be quantified in PASI scoring. Surface roughness of lesion can be used as a scaliness feature, since existing scale on lesion surface makes the lesion rougher. The dermatologist usually assesses the severity through their tactile sense, therefore direct contact between doctor and patient is required. The problem is the doctor may not assess the lesion objectively. In this paper, a digital image analysis technique is developed to objectively determine the scaliness of the psoriasis lesion and provide the PASI scaliness score. Psoriasis lesion is modelled by a rough surface. The rough surface is created by superimposing a smooth average (curve) surface with a triangular waveform. For roughness determination, a polynomial surface fitting is used to estimate average surface followed by a subtraction between rough and average surface to give elevation surface (surface deviations). Roughness index is calculated by using average roughness equation to the height map matrix. The roughness algorithm has been tested to 444 lesion models. From roughness validation result, only 6 models can not be accepted (percentage error is greater than 10%). These errors occur due the scanned image quality. Roughness algorithm is validated for roughness measurement on abrasive papers at flat surface. The Pearson’s correlation coefficient of grade value (G) of abrasive paper and Ra is -0.9488, its shows there is a strong relation between G and Ra. The algorithm needs to be improved by surface filtering, especially to overcome a problem with noisy data. [ABSTRACT FROM AUTHOR]

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Typical joint defects in laser welded aluminium-lithium alloy

Welding trials of autogenous laser welding, laser welding with filling wire and laser-MIG arc hybrid welding were carried out. The characteristics, causes and controlling methods of joint defects were analysed by optic microscope, X-ray detection and numerical simulation. The results indicated that the common defects were imperfect shape and porosity inside the weld. The characters of weld surface defects varied during different welding processes, porosity were also different in shape and formation during full penetration welding and incomplete penetration welding. All most defects mentioned above could be controlled and avoided by optimizing the welding process procedures. [ABSTRACT FROM AUTHOR]

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Towards controlled three-dimensional laser forming

Two-dimensional (2-D) laser forming (LF) can currently control bend angle, with reasonably accurate results, in various materials including aerospace alloys. However, this is a different situation for three-dimensional (3-D) LF. To advance this process further for realistic forming applications and for straightening and aligning operations in a manufacturing industry it is necessary to consider larger scale controlled 3-D LF. The work presented in this paper uses a predictive and adaptive approach to control the LF of mild steel and aluminium sheet into a desired surface. Key to the control of the process was the development of a predictive model to give scan strategies based on a required geometry and the surface error. The forming rate and distribution of the magnitude of forming across the surface were controlled in the closed loop by the process speed. When the geometry is not formed within one pass, an incremental adaptive approach is used for subsequent passes, utilising the error between the current and desired geometry to give a new scan strategy, thus any unwanted distortion due to material variability can be accounted for and distortion control and removal is possible. [ABSTRACT FROM AUTHOR]

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The finite difference methods and their extrapolation for solving biharmonic equations

In this paper, we research the standard 13-point difference scheme for solving the biharmonic equation. Existence and convergence of finite difference methods(FDM) solutions are obtained by estimating the lower bounds of the minimum eigenvalues of the discrete matrix and making use of the Taylor series expansions, respectively. The accuracy are proved to be O(h²). Moreover, the extrapolation techniques are used to improve the high accuracy of the solutions. For the given examples, numerical results show that the errors O(h4) is obtained from the first level extrapolation. The very accurate solutions with the errors O(10-8) are obtained by the third level extrapolation techniques under the homogeneous essential boundary conditions. [ABSTRACT FROM AUTHOR]

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