Representation and Reasoning with Multi-Point Events

Allen's Interval Algebra (IA) and Vilain & Kautz's Point Algebra (PA) consider an interval and a point as basic temporal entities (i.e., events) respectively. However, in many situations we need to deal with recurring events that include multiple points, multiple intervals or combinations of points and intervals. In this paper, we present a framework to model recurring events as multi-point events (MPEs) by extending point algebra. The reasoning tasks are formulated as binary constraint satisfaction problems. We propose a polynomial time algorithm (based on van Beek's algorithm) for finding all feasible relations. For the problem of finding a consistent scenario, we propose a backtracking method with a local search heuristic. We also describe an implementation and a detail empirical evaluation of the proposed algorithms. Our empirical results indicate that the MPE-based approach performs better than the existing approaches.     

Improved phenol adsorption from aqueous solution using electrically conducting adsorbents

The electrically conducting and partially porous graphite based adsorbent (called NyexTM 2000) was tested for its adsorption capacity and electrochemical regeneration ability for the removal of phenol from aqueous solution. Nyex? 2000 was tested in comparison with Nyex? 1000, which is currently being used for a number of industrial waste water treatment applications. Nyex? 1000 exhibited small adsorption capacity of 0.1 mg g^?1 for phenol because of having small specific surface area of 1 m² g^?1. In contrast, Nyex? 2000 with specific surface area of 17 m² g^?1 delivered an adsorption capacity of 0.8 mg g^?1, which was eight-fold higher than that of Nyex? 1000. Nyex? 2000 was successfully electrochemically regenerated by passing a current of 0.5 A, charge passed of 31 C g^?1 for a treatment time of 45 minutes. These electrochemical parameters were comparable to Nyex? 1000 for which a current of 0.5 A, charge passed of 5 C g^?1 for a treatment time of 20 minutes were applied for complete oxidation of adsorbed phenol. The comparatively high charge density was found to be required for Nyex? 2000, which is justified with its higher adsorption capacity. The FTIR results validated the mineralization of adsorbed phenol into CO₂ and H₂O except the formation of few by-products, which were in traces when compared with the concentration of phenol removed from aqueous solution. The electrical energy as required for electrochemical oxidation of phenol adsorbed onto Nyex? 1000 & 2000 was found to be 214 and 196 J mg^?1, respectively. The comparatively low energy requirement for electrochemical oxidation using Nyex? 2000 is consistent with its higher bed electrical conductivity, which is twice that of Nyex? 1000.     

Adventitious sounds identification and extraction using temporal-spectral dominance-based features

Respiratory sound (RS) signals carry significant information about the underlying functioning of the pulmonary system by the presence of adventitious sounds (ASs). Although many studies have addressed the problem of pathological RS classification, only a limited number of scientific works have focused on the analysis of the evolution of symptom-related signal components in joint time-frequency (TF) plane. This paper proposes a new signal identification and extraction method for various ASs based on instantaneous frequency (IF) analysis. The presented TF decomposition method produces a noise-resistant high definition TF representation of RS signals as compared to the conventional linear TF analysis methods, yet preserving the low computational complexity as compared to those quadratic TF analysis methods. The discarded phase information in conventional spectrogram has been adopted for the estimation of IF and group delay, and a temporal-spectral dominance spectrogram has subsequently been constructed by investigating the TF spreads of the computed time-corrected IF components. The proposed dominance measure enables the extraction of signal components correspond to ASs from noisy RS signal at high noise level. A new set of TF features has also been proposed to quantify the shapes of the obtained TF contours, and therefore strongly, enhances the identification of multicomponents signals such as polyphonic wheezes. An overall accuracy of 92.4±2.9% for the classification of real RS recordings shows the promising performance of the presented method.     

Iterated Belief Change

Most existing formalizations treat belief change as a single-step process, and ignore several problems that become important when a theory, or belief state, is revised over several steps. This paper identifies these problems, and argues for the need to retain all of the multiple possible outcomes of a belief change step, and for a framework in which the effects of a belief change step persist as long as is consistently possible. To demonstrate that such a formalization is indeed possible, we develop a framework, which uses the language of PJ-default logic (Delgrande and Jackson 1991) to represent a belief state, and which enables the effects of a belief change step to persist by propagating belief constraints . Belief change in this framework maps one belief state to another, where each belief state is a collection of theories given by the set of extensions of the PJ-default theory representing that belief state. Belief constraints do not need to be separately recorded; they are encoded as clearly identifiable components of a PJ-default theory. The framework meets the requirements for iterated belief change that we identify and satisfies most of the AGM postulates (Alchourrón, Gärdenfors, and Makinson 1985) as well.     

Economics of drying timber in a greenhouse type solar kiln

The economics of drying timber was assessed for a green-house type solar kiln along with the conventional drying techniques. Both the operating and capital costs of the solar kiln were much lower than those of the steam kiln. Compared to air drying the solar drying was cheaper and cost less than one-half of the steam kilning. The pay back period was about one year for the solar kiln against 31–45 years for the steam kiln. Solar drying was thus found economically attractive and viable technology in Bangladesh.     

EFFECT OF COMBINATION METHODS ON INSECT DISINFESTATION AND QUALITY OF PLANT NUTS

Almond, groundnut, pinenut and walnut, were radiated (0.25 kGy) after packing in coloured and clear polyethylene bags (0.04mm) and subsequently stored for 24 weeks at room (16-36℃) and low temperatures (10-20℃). The effect of these treatments on insect infestation and quality was studied. It was observed that radiation (0.25 kGy) treatment in combination with low temperature (10-20℃) completely checked the insect infestation of nuts during 24 weeks of storage. Peroxidation was higher in samples stored at room than at low temperature. Storage period had a marked adverse influence on sensory quality of nuts, however, samples kept at low temperature were comparatively rated higher.     

Simplified method of determining fetal brain weight in utero

Analysis of autopsy data shows that, from the 26th through the 38th gestational weeks, fetal brain weight (BrW) is a function of the 3.124 power of the largest head circumference (HC). Because there is excellent correlation between prenatal ultrasound measurement and postnatal tape measurement of the HC, it is possible to determine fetal BrW in utero. An alteration of the BrW:somatic weight (SW) relationship is an important physical stigma of asymmetric intrauterine growth retardation (IUGR). The value of longitudinal studies of fetal BrW and SW as a means of discriminating between normal and asymmetric growth is tested in a population at risk for IUGR.     

Magnetic and dielectric properties of polycrystalline La doped barium Z-type hexaferrite for hyper-frequency applications

La³⁺ ion substituted barium Z-type hexaferrite, Ba_3?XLa_XCo₂Fe₂₄O₄₁ powders (X = 0.0, 0.05, 0.10 and 0.15), have been synthesized using sol gel auto-combustion method. The phase identification, microstructure, complex permittivity, complex permeability and static magnetic properties of the samples were studied using X-ray diffraction, scanning electron microscopy, vector network analyzer and vibrating sample magnetometer. The results revealed that introducing La³⁺ ion instead of Ba²⁺ ion led to an obvious enhancement of the electromagnetic properties. The crystallite size of the produced powders was slightly increased with increasing La³⁺ content. The microstructure of the produced powders appeared as hexagonal-platelet like structure. As the La content increase, the static magnetic properties were increased, the real part of complex permittivity was increased while the imaginary part was decreased. Moreover, the real part of complex magnetic permeability was decreased and the imaginary part was increased. The reasons of the obtained results were discussed on basis of electromagnetic theory.     

A first-order coalition logic for BDI-agents

Coalition logic (CL) enables us to model the strategic abilities and specify what a group of agents can achieve whatever the other agents do. However, some rational mental attitudes of the agents are beyond the scope of CL such as the prestigious beliefs, desires and intentions (BDI) which is an interesting and useful epistemic notion and has spawned substantial amount of studies in multi-agent systems. In this paper, we introduce a first-order coalition BDI (FCBDI) logic for multi-agent systems, which provides a semantic glue that allows the formal embedding and interaction of BDI, coalition and temporal operators in a first-order language. We further introduce a semantic model based on the interpreted system model and present an axiomatic system that is proved sound and complete with respect to the semantics. Finally, it is shown that the computational complexity of its model checking in finite structures is PSPACE-complete.