317 research outputs found
Human text processing and models of knowledge representation
Two experimental studies on human text processing and knowledge representation are reported. They are designed to explore the nature of cognitive processes in working
memory and long term representations associated with the resolution of reference in texts.
Resolution of references occurs when properties of distinct individuals are bound together
in memory. Stenning Shepherd and Levy (1988) propose that binding is achieved by
recruiting existing general knowledge associations based on the semantic structure of texts.
They present models of representation structures employed in a novel Memory for Individual
Task (MIT), and show that these models can explain certain patterns of retrieval error
frequencies. A statistical model of construction of representation processes which account
for a particular pattern of reading times in terms of key aspects of the structure of MIT
texts is also presented.The reading times results of the first MIT experiment, in which the order of switches
in reference between individuals is unpredictable, is presented together with as extended
construction processing model which capture phenomena of reference changes. The new
models show that unpredictable reference changes cost time as a function of the complexity
of the individual to which reference is switched, without disrupting the modular
account of processing centred on referenced individual reported by Stenning, Shepherd and
Levy (1988). Analysis of recall errors reveal an effect of presentation order, which results
in confusion over identity of individuals' properties, providing a basis for a distinction
between `primary' and `secondary' individual, each requiring different syllabic rehearsal
processing. These working memory processes are incorporated in a model, which reveals
interaction between rehearsal and semantic processes.The error data is further analysed with respect to logically constraining solutions to
representations of bindings with `direct' and `indirect' structures. Direct systems represent
binding by structural devices referring to individual identities in their representation;
indirect systems represent binding only through quantificational facts. Both direct and
indirect models are developed and the latter one shown to be at least as good a fit to the
data as the former, which suggests that solution to the binding problem is represented in a distributed manner closer to PDP systems.Much of the theoretical underpinning of the findings of the first study, is dependent
on aspects of the semantic structures which reflect regularities in the temporal order of
descriptions of individuals in MIT texts. The second study investigates the extent to which
such regularities facilitated the sorts of structures constructed in representations of solutions
to the binding problem, and interaction between temporal order of presentation and
working memory processes. Analyses of reading times show that, while order of presentation
of properties has no significant effect on working memory processes, differences in
availability of information about higher level semantic structure does require extra processing.
A statistical model which factors out some of this processing load as due to specific
changes in the semantic structure of MIT texts is presented.Detailed analyses of recall error data further reveals differences in indirect representational
features which reflect changes in temporal order of individuals' descriptions.
These models show how texts with the same literal meaning obtain significantly different
representations in memory, not because of different contexts which would be expected, but
due to differences in temporal order of the same sorts of descriptions. This suggests that
the theoretical distinction between working memory processes and long term representations
is not as simple as it might appear. These findings also serve to support our methodological
approach to the study of human text processing
A Revised Textual Tree Trace Notation for Prolog
This paper describes a ''textual tree trace'' (TTT) notation for representing the execution of Prolog programs. Compact, textual and non-linear, it provides detailed information about variable binding and execution history, and distinguishes several modes of goal failure. The revised form given here, yet to be empirically tested, is partly informed by Paul Mulholland's empirical comparisons of Prolog trace notations, in which an earlier version of the TTT notation was amongst those studied and criticised. The work presented here is an updated version of a previous workshop paper (Taylor, du Boulay, & Patel, 1994)
Prediction of Subgrade Strength Parameters from Dynamic Cone Penetrometer Index, Modified Liquid Limit and Moisture Content
AbstractSubgrade soil is an essential component for design of both flexible and rigid pavement structures. Laboratory investigation of subgrade strength parameter as California Bearing Ratio beneficial for design of flexible pavement, Coefficient of subgrade reaction K-Value required for design of rigid pavement, raft footing and unconfined compressive strength (UCS) is useful for determination of shear strength parameter of subgrade. These tests are time consuming and demand significant effort but mandatory. This study considers the use of multiple variable regression analysis (MLR) to predict the California Bearing Ratio (CBR), Coefficient of subgrade reaction K-Value, unconfined compressive strength (UCS), Field dry density from Dynamic Cone Penetrometer (DCP), modified liquid limit and moisture content of subgrade. This paper presents the empirical correlations developed from multiple variable regression analysis from test results obtained from experimental investigation of soil sample taken from different locations of Gujarat region in India. The formulations are validated using other sets of tests data. The developed empirical correlations may be useful in quick determination of strength parameters of subgrade from physical properties of subgrade and Dynamic Cone penetrometer. Results obtained from validation of these developed empirical correlation proves their reliably and accuracy to perform subgrade strength evaluation for both rigid and flexible pavement
Knowledge of IPM Practices among Cotton Growers of Sabarkantha District; Gujarat, India
India is the pioneer country for the commercial cultivation of hybrid cotton. Cotton is one of the principal commercial crops and has been one of the main sources of Indias economic growth and foreign exchange earner. Gujarat is the second largest cotton producing state of India. In Gujarat state Sabarkantha is also has major area under cotton crop. The study was conducted in Sabarkantha District of Gujarat State. Sabarkantha district was selected purposively on the basis of leading hybrid cotton growing area. Total sample size 240 respondents of cotton growers were selected from twelve villages of the district. The cotton crop is attacked by a number of insect, pests, diseases, nematodes and weeds. So, the aims of the study were to study the knowledge of cotton growers about IPM technology and find correlation between selected personal, socio-economic and psychological characteristics of cotton growers and their knowledge of IPM technology. A perusal of the data indicated that cotton growers had medium level of knowledge regarding IPM technology in cotton, In case of independent variable like age and land holding was found no-significant relationship with their knowledge level while selected remaining independent variables were found significant relationship with their knowledge level of farmer regarding IPM technology.
DOI: 10.17762/ijritcc2321-8169.15020
Development and Validation of a Stability Indicating RP-UPLC Method for Determination of Quetiapine in Pharmaceutical Dosage Form
The present work reports a stability indicating reversed phase ultra performance liquid chromatography (RP-UPLC) method for the quantitative determination of quetiapine in pharmaceutical dosage form. The chromatographic separation is performed on an Agilent Eclipse Plus C18, RRHD 1.8 μm (50 mm x 2.1 mm) column using gradient elution. The optimized mobile phase consists of 0.1 % aqueous triethylamine (pH 7.2) as a solvent-A and 80:20 v/v mixture of acetonitrile and methanol as solvent-B. The eluted compounds are monitored at 252 nm wavelength using a UV detector. The developed method separates quetiapine from its five impurities/degradation products within a run time of 5 min. Stability indicating capability of the developed method is established by analyzing forced degradation samples in which the spectral purity of quetiapine is ascertained along with the separation of degradation products from analyte peak. The developed RP-UPLC method is validated as per International Conference on Harmonization (ICH) guidelines with respect to system suitability, specificity, precision, accuracy, linearity, robustness and filter compatibility
Contrast Enhancement and Brightness Preservation of Radiography Images using Gamma Correction
In this Research paper, the purpose of Image enhancement is to process an image so that result is more suitable than original image for particular application. Digital image enhancement techniques provide a multitude of choices for improving the visual quality of images. Appropriate variety of such techniques is greatly influenced by the imaging modality, undertaking at hand and viewing situation. This paper will provide an overview of underlying concepts, along with algorithms normally used for image enhancement. An image can have low contrast or undesirable quality due to a number of reasons like reduced quality of imaging device, unfavorable external conditions at the time of image preprocessing and many more. Image enhancement is used to improve the usual effects and clarity of image or to make the original image more favorable for computer to process. In proposed method, full image has been divided into two parts in low contrast and high contrast on the basis of their threshold value. We have applied large gamma values only on low contrast image using gamma correction which will be more informative. With the help of merging we get the resultant radiography image. The results will be compared on the basis of histograms, mean, standard deviation, variance and average gradient values and compared with existed gamma correction techniques using matlab
A Stability Indicating Method for the Determination of the Antioxidant Sodium Bisulfite in Pharmaceutical Formulation by RP-HPLC Technique
A stability-indicating reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed for the determination of sodium bisulfate (SB), an antioxidant, in injectable dosage form. The chromatographic separation was achieved on a Zorbax CN (250 mm × 4.6 mm, 5 μm) column, with a mobile phase consisting of a buffer mixture of 0.03 M tetrabutylammonium hydrogen sulfate, 0.01 M potassium dihydrogen orthophosphate, and acetonitrile at a ratio of 70:30 (v/v) and a flow rate of 0.7 mL/min. The eluted compound was monitored at a wavelength of 215 nm using a UV detector. The method described herein separated sodium bisulfite from all other formulation components within a run time of 10 min. The method also generated linear results over an SB concentration range of 10 to 990 μg/mL, and the limit of quantification was found to be 10 μg/mL. The stability indicating capability of the method was established by performing forced degradation experiments. The RP-HPLC method that was developed was validated according to the International Conference on Harmonization (ICH) guidelines. This method was successfully applied in the quantitative determination of SB in a stability study of Amikacin sulfate injection. The procedure described herein is simple, selective, and reliable for routine quality control analysis as well as stability testing
Serrated Sickle for Reducing the Drudgery of Farm Women in Mehsana District, North Gujarat
Most of the works performed by farm women are tedious as well as time consuming. Also many of these operations are traditionally done in varying body, which if done for long duration cause inconvenience and body pain. Hence, a study was conducted on testing and evaluation of serrated sickle made by CIAE, Bhopal. Farm woman is participatory mode of reduce their drudgery. It was observed during the course of investigation that farm women were using desi sickle while harvesting their crops. The labour requirment by using serrated sickle was 16 labour/ha as against the harvesting by lockle sickle 18 labour/ha
- …