Light Scalar Decay in Diquark Chiral Effective Theory

We calculate the decay rate of light scalar mesons, using a diquark chiral effective theory, recently proposed to describe exotic hadrons. In the effective theory the light scalar mesons are postulated to be bound states of diquark and anti-diquark. We find our results are in good agreement with experimental data. The axial couplings of diquarks with pions and kaons are found to be quite small and the perturbation is reliable. It shows that the diquark picture captures the correct physics of light scalar mesons.Comment: 9pages, 4figures, RevTeX

La Sémiotique de l'espace dans l'oeuvre de Le Clézio. Le cas de La Quarantaine

[Résumé] Le langage des relations spatiales peut etre un moyen pour rendre compte du reel, meme au niveau de la modelisation ideologique. Les concepts haut/bas, droit/gauche, ouvert/ferme, delimite/non delimite prennent le sens de valable/non valable, bon/mauvais, accessible/inaccessible, mortel/immortel etc. Pour demontrer cette etude, nous avons choisi La Quarantaine de Le Clezio dans lequel l’espace n’est pas un simple decor, mais une langue. La forme de l’opposition de deux valeurs spatiales comme le haut/le bas et la gauche/la droite est tres marque dans le texte.Et cela fonctionne en tant que mode d’expression de concepts non spatiaux comme les idees politiques, sociales, morales et religieuses. Or la valeur semantique acquise par la structure de l’espace n’est pas definitive la valeur positive peut changer en valeur negative d’apres les espaces ou les personnages se trouvent, et vice versa. De plus, la forme de l’opposition ne reste pas toujours opposee : la reunion des opposes se realice par la structure circulaire ou par le retour a l’origine et c’est le message de l’ecrivain

Neural units with higher-order synaptic operations with applications to edge detection and control systems

The biological sense organ contains infinite potential. The artificial neural structures have emulated the potential of the central nervous system; however, most of the researchers have been using the linear combination of synaptic operation. In this thesis, this neural structure is referred to as the neural unit with linear synaptic operation (LSO). The objective of the research reported in this thesis is to develop novel neural units with higher-order synaptic operations (HOSO), and to explore their potential applications. The neural units with quadratic synaptic operation (QSO) and cubic synaptic operation (CSO) are developed and reported in this thesis. A comparative analysis is done on the neural units with LSO, QSO, and CSO. It is to be noted that the neural units with lower order synaptic operations are the subsets of the neural units with higher-order synaptic operations. It is found that for much more complex problems the neural units with higher-order synaptic operations are much more efficient than the neural units with lower order synaptic operations. Motivated by the intensity of the biological neural systems, the dynamic nature of the neural structure is proposed and implemented using the neural unit with CSO. The dynamic structure makes the system response relatively insensitive to external disturbances and internal variations in system parameters. With the success of these dynamic structures researchers are inclined to replace the recurrent (feedback) neural networks (NNs) in their present systems with the neural units with CSO. Applications of these novel dynamic neural structures are gaining potential in the areas of image processing for the machine vision and motion controls. One of the machine vision emulations from the biological attribution is edge detection. Edge detection of images is a significant component in the field of computer vision, remote sensing and image analysis. The neural units with HOSO do replicate some of the biological attributes for edge detection. Further more, the developments in robotics are gaining momentum in neural control applications with the introduction of mobile robots, which in turn use the neural units with HOSO; a CCD camera for the vision is implemented, and several photo-sensors are attached on the machine. In summary, it was demonstrated that the neural units with HOSO present the advanced control capability for the mobile robot with neuro-vision and neuro-control systems

Design and fabrication of novel microfluidic systems for microsphere generation

In this thesis, a study of the rational design and fabrication of microfluidic systems for microsphere generation is presented. The required function of microfluidic systems is to produce microspheres with the following attributes: (i) the microsphere size being around one micron or less, (ii) the size uniformity (in particular coefficient of variation (CV)) being less than 5%, and (iii) the size range being adjustable as widely as possible. Micro-electro-mechanical system (MEMS) technology, largely referring to various micro-fabrication techniques in the context of this thesis, has been applied for decades to develop microfluidic systems that can fulfill the foregoing required function of microsphere generation; however, this goal has yet to be achieved. To change this situation was a motivation of the study presented in this thesis. The philosophy behind this study stands on combining an effective design theory and methodology called Axiomatic Design Theory (ADT) with advanced micro-fabrication techniques for the microfluidic systems development. Both theoretical developments and experimental validations were carried out in this study. Consequently, the study has led to the following conclusions: (i) Existing micro-fluidic systems are coupled designs according to ADT, which is responsible for a limited achievement of the required function; (ii) Existing micro-fabrication techniques, especially for pattern transfer, have difficulty in producing a typical feature of micro-fluidic systems - that is, a large overall size (~ mm) of the device but a small channel size (~nm); and (iii) Contemporary micro-fabrication techniques to the silicon-based microfluidic system may have reached a size limit for microspheres, i.e., ~1 micron. Through this study, the following contributions to the field of the microfluidic system technology have been made: (i) Producing three rational designs of microfluidic systems, device 1 (perforated silicon membrane), device 2 (integration of hydrodynamic flow focusing and crossflow principles), and device 3 (liquid chopper using a piezoelectric actuator), with each having a distinct advantage over the others and together having achieved the requirements, size uniformity (CV ≤ 5%) and size controllability (1-186 µm); (ii) Proposing a new pattern transfer technique which combines a photolithography process with a direct writing lithography process (e.g., focused ion beam process); (iii) Proposing a decoupled design principle for micro-fluidic systems, which is effective in improving microfluidic systems for microsphere generation and is likely applicable to microfluidic systems for other applications; and (iv) Developing the mathematical models for the foregoing three devices, which can be used to further optimize the design and the microsphere generation process

Synthesis of bimodally porous titania powders by hydrolysis of titanium tetraisopropoxide

Bimodally porous titania powders with controlled phase composition and porosity were made by hydrolysis of titanium tetraisopropoxide (TTIP) and calcination. The extent of calcination was followed by thermogravimetric differential thermal analysis and Fourier transform infrared spectroscopy. The specific surface area (SSA) of the powders ranged from 10 to 500 m2/g as determined by nitrogen adsorption. The SSA increased by decreasing either the water concentration during hydrolysis or the calcination temperature. The pore size distribution was bimodal with fine intraparticle pore diameters at 1-6 nm and larger interparticle pore diameters at 30-120 nm as determined by nitrogen adsorption isotherms. The particle phase composition as determined by x-ray diffraction ranged from amorphous to crystalline anatase and rutile largely proportional to the calcination temperature and to a lesser extent on the initial H2O/TTIP molar rati

Investigating Information Structure of Phishing Emails Based on Persuasive Communication Perspective

Current approaches of phishing filters depend on classifying messages based on textually discernable features such as IP-based URLs or domain names as those features that can be easily extracted from a given phishing message. However, in the same sense, those easily perceptible features can be easily manipulated by sophisticated phishers. Therefore, it is important that universal patterns of phishing messages should be identified for feature extraction to serve as a basis for text classification. In this paper, we demonstrate that user perception regarding phishing message can be identified in central and peripheral routes of information processing. We also present a method of formulating quantitative model that can represent persuasive information structure in phishing messages. This paper makes contribution to phishing classification research by presenting the idea of universal information structure in terms of persuasive communication theories

Investigating Information Structure of Phishing Emails Based on Persuasive Communication Perspective

Current approaches of phishing filters depend on classifying messages based on textually discernable features such as IP-based URLs or domain names as those features that can be easily extracted from a given phishing message. However, in the same sense, those easily perceptible features can be easily manipulated by sophisticated phishers. Therefore, it is important that universal patterns of phishing messages should be identified for feature extraction to serve as a basis for text classification. In this paper, we demonstrate that user perception regarding phishing message can be identified in central and peripheral routes of information processing. We also present a method of formulating quantitative model that can represent persuasive information structure in phishing messages. This paper makes contribution to phishing classification research by presenting the idea of universal information structure in terms of persuasive communication theories