934 research outputs found
X-ray photoemission study of NiS_{2-x}Se_x (x = 0.0 - 1.2)
Electronic structure of NiS_{2-x}Se_x system has been investigated for
various compositions (x) using x-ray photoemission spectroscopy. An analysis of
the core level as well as the valence band spectra of NiS_2 in conjunction with
many-body cluster calculations provides a quantitative description of the
electronic structure of this compound. With increasing Se content, the on-site
Coulomb correlation strength (U) does not change, while the band width W of the
system increases, driving the system from a covalent insulating state to a
pd-metallic state.Comment: 19 pages, 6 figures, To appear in Phys. Rev. B, 200
To what extent does disability discourage from work? An empirical analysis of labour force participation of disabled people in Italy
This paper is an empirical study on the work opportunities of people with disability
using Italian data collected through a survey carried out by ISTAT in 2004. Our analysis
is guided by the conceptual framework of the capability approach and investigates the
role of conversion factors in the ability to be employed and the type of employment.
We rst use a simple probit for labour force participation and then a sequential logit
for the outcomes of participation as well as employment status. In all variants we nd
that chronic illness is a stronger deterrent for labour force participation than disability.
Women are more discouraged by disability compared to men. Among the various types of
disabilities, `intellectual' disability is the strongest barrier as can be expected and hearing
the least in
uential. In a sequential decision-making process, we nd that disability
a ects both labour force participation decision and the ability to be employed but not so
much the choice between part-time and full-time
An Optimal Control Modification to Model-Reference Adaptive Control for Fast Adaptation
This paper presents a method that can achieve fast adaptation for a class of model-reference adaptive control. It is well-known that standard model-reference adaptive control exhibits high-gain control behaviors when a large adaptive gain is used to achieve fast adaptation in order to reduce tracking error rapidly. High gain control creates high-frequency oscillations that can excite unmodeled dynamics and can lead to instability. The fast adaptation approach is based on the minimization of the squares of the tracking error, which is formulated as an optimal control problem. The necessary condition of optimality is used to derive an adaptive law using the gradient method. This adaptive law is shown to result in uniform boundedness of the tracking error by means of the Lyapunov s direct method. Furthermore, this adaptive law allows a large adaptive gain to be used without causing undesired high-gain control effects. The method is shown to be more robust than standard model-reference adaptive control. Simulations demonstrate the effectiveness of the proposed method
A clinical study of carcinoma stomach in patients presenting in Government Mohan Kumaramangalam Medical College Hospital, Salem.
BACKGROUND:
Second most common cancer related death worldwide. There is change in the site of occurance of gastric cancer, there is increase in occurance of proximal tumours than the distal tumours.
OBJECTIVES:
Study was undertaken in Government Mohan Kumaramangalam Medical College Hospital, Salem, to study the prevalence, clinical features, association of risk factors, site of occurance and histopathology.
METHODS:
All patients with histopathology confirmed as stomach carcinoma was studied and details regarding clinical feautures, subsites, pathology, investigations and treatment modalities was collected.
RESULTS:
36 Patients with histology confirmation of stomach carcinoma was studied. There is a increase in male preponderance and old age. Association of risk factors was studied. Majority are present with distal tumours and in advanced stage.
INTERPRETATION AND CONCLUSION:
Stomach carcinoma is commonly seen in old age with male
preponderance. Patients are mostly present in advanced stage. But the use of endoscopy early gastric cancers can be identified. Association of risk factors is well known and can be used in promodial prevention of disease. Despite of
increase in proximal tumours in west, Distal tumours predominate in our study
Artificial Immune System Approach for Airborne Vehicle Maneuvering
A method and system for control of a first aircraft relative to a second aircraft. A desired location and desired orientation are estimated for the first aircraft, relative to the second aircraft, at a subsequent time, t=t2, subsequent to the present time, t=t1, where the second aircraft continues its present velocity during a subsequent time interval, t1.ltoreq.t.ltoreq.t2, or takes evasive action. Action command sequences are examined, and an optimal sequence is chosen to bring the first aircraft to the desired location and desired orientation relative to the second aircraft at time t=t2. The method applies to control of combat aircraft and/or of aircraft in a congested airspace
Assessing the impacts of climate change on marine fisheries of Karnataka and identifying regime shifts
Climate related regime shifts, namely the rapid reorganization of marine ecosystems from one relatively stable state to another, have been reported from several parts of the world, and found responsible for the fluctuations of major fisheries. Time series on ocean-atmosphere parameters together with time series on plankton and/or fish abundance has been extensively used for identifying regime shifts in the oceans from several parts of the globe
Bounded Linear Stability Analysis - A Time Delay Margin Estimation Approach for Adaptive Control
This paper presents a method for estimating time delay margin for model-reference adaptive control of systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent the conventional model-reference adaptive law by a locally bounded linear approximation within a small time window using the comparison lemma. The locally bounded linear approximation of the combined adaptive system is cast in a form of an input-time-delay differential equation over a small time window. The time delay margin of this system represents a local stability measure and is computed analytically by a matrix measure method, which provides a simple analytical technique for estimating an upper bound of time delay margin. Based on simulation results for a scalar model-reference adaptive control system, both the bounded linear stability method and the matrix measure method are seen to provide a reasonably accurate and yet not too conservative time delay margin estimation
Aircraft system modeling error and control error
A method for modeling error-driven adaptive control of an aircraft. Normal aircraft plant dynamics is modeled, using an original plant description in which a controller responds to a tracking error e(k) to drive the component to a normal reference value according to an asymptote curve. Where the system senses that (1) at least one aircraft plant component is experiencing an excursion and (2) the return of this component value toward its reference value is not proceeding according to the expected controller characteristics, neural network (NN) modeling of aircraft plant operation may be changed. However, if (1) is satisfied but the error component is returning toward its reference value according to expected controller characteristics, the NN will continue to model operation of the aircraft plant according to an original description
MarkerMiner 1.0: a new application for phylogenetic marker development using angiosperm transcriptomes
Premise of the study: Targeted sequencing using next-generation sequencing (NGS) platforms offers enormous potential for plant systematics by enabling economical acquisition of multilocus data sets that can resolve difficult phylogenetic problems. However, because discovery of single-copy nuclear (SCN) loci from NGS data requires both bioinformatics skills and access to high-performance computing resources, the application of NGS data has been limited.
Methods and Results: We developed MarkerMiner 1.0, a fully automated, open-access bioinformatic workflow and application for discovery of SCN loci in angiosperms. Our new tool identified as many as 1993 SCN loci from transcriptomic data sampled as part of four independent test cases representing marker development projects at different phylogenetic scales.
Conclusions: MarkerMiner is an easy-to-use and effective tool for discovery of putative SCN loci. It can be run locally or via the Web, and its tabular and alignment outputs facilitate efficient downstream assessments of phylogenetic utility, locus selection, intron-exon boundary prediction, and primer or probe development
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