1,225 research outputs found
Class Representation of Shapes Using Qualitative-codes
This paper introduces our qualitative shape representation formalism that is devised to overcome, as we have argued, the class abstraction problems created by numeric schemes. The numeric shape representation method used in conventional geometric modeling systems reveals difficulties in several aspects of architectural designing. Firstly, numeric schemes strongly require complete and detailed information for any simple task of object modeling. This requirement of information completeness makes it hard to apply numeric schemes to shapes in sketch level drawings that are characteristically ambiguous and have non-specific limitations on shape descriptions. Secondly, Cartesian coordinate-based quantitative shape representation schemes show restrictions in the task of shape comparison and classification that are inevitably involved in abstract concepts related to shape characteristics. One of the reasons why quantitative schemes are difficult to apply to the abstraction of individual shape information into its classes and categories is the uniqueness property, meaning that an individual description in a quantitative scheme should refer to only one object in the domain of representation. A class representation, however, should be able to indicate not only one but also a group of objects sharing common characteristics. Thirdly, it is difficult or inefficient to apply numeric shape representation schemes based on the Cartesian coordinate system to preliminary shape analysis and modeling tasks because of their emphasis on issues, such as detail, completeness, uniqueness and individuality, which can only be accessed in the final stages of designing. Therefore, we face the need for alternative shape representation schemes that can handle class representation of objects in order to manage the shapes in the early stages of designing. We consider shape as a boundary description consisting of a set of connected and closed lines. Moreover, we need to consider non-numeric approaches to overcome the problems caused by quantitative representation approaches.This paper introduces a qualitative approach to shape representation that is contrasted to conventional numeric techniques. This research is motivated by ideas and methodologies from related studies such as in qualitative formalism ([4], [6], [19], [13], [31]), qualitative abstraction [16], qualitative vector algebra ([7], [32]), qualitative shapes ([18], [23], [21]), and coding theory ([20], [25], [26], [1], [2], [3], [22]). We develop a qualitative shape representation scheme by adopting propitious aspects of the above techniques to suit the need for our shape comparison and analysis tasks. The qualitative shape-encoding scheme converts shapes into systematically constructed qualitative symbols called Q-codes. This paper explains how the Q-code scheme is developed and applied
The Use of Flow Cytometric DNA Ploidy Analysis of Liver Biopsies in Liver Cirrhosis and Hepatocellular Carcinoma
Evolved Representation and Computational Creativity
Advances in science and technology have influenced designing activity in architecture throughout its history. Observing the fundamental changes to architectural designing due to the substantial influences of the advent of the computing era, we now witness our design environment gradually changing from conventional pencil and paper to digital multi-media. Although designing is considered to be a unique human activity, there has always been a great dependency on design aid tools. One of the greatest aids to architectural design, amongst the many conventional and widely accepted computational tools, is the computer-aided object modeling and rendering tool, commonly known as a CAD package. But even though conventional modeling tools have provided designers with fast and precise object handling capabilities that were not available in the pencil-and-paper age, they normally show weaknesses and limitations in covering the whole design process.In any kind of design activity, the design worked on has to be represented in some way. For a human designer, designs are for example represented using models, drawings, or verbal descriptions. If a computer is used for design work, designs are usually represented by groups of pixels (paintbrush programs), lines and shapes (general-purpose CAD programs) or higher-level objects like ‘walls’ and ‘rooms’ (purpose-specific CAD programs).A human designer usually has a large number of representations available, and can use the representation most suitable for what he or she is working on. Humans can also introduce new representations and thereby represent objects that are not part of the world they experience with their sensory organs, for example vector representations of four and five dimensional objects. In design computing on the other hand, the representation or representations used have to be explicitly defined. Many different representations have been suggested, often optimized for specific design domains or design methods, but each individual computational design system has only one or very few different representations available.Whatever the choice of the representation, it is likely to influence the outcome of the design process. In any representation, some designs may be more difficult to represent than others, and some designs may not be representable at all.The same applies if the design process is implemented in a computer program. If a design cannot be represented with a given representation, it cannot be the outcome of a design process using this representation. As is the case for human designers, it is also possible that the representation influences a computational design process such that it is easier for the program to find some designs than others. Depending on the design process used, this might make those designs a more likely outcome of the design process. This is for example the case with stochastic optimization processes, like evolutionary systems and simulated annealing. In these cases, the representation is likely to introduce a bias into the design process.The selection of the representation is therefore of high importance in the development of a computational design system. Obviously, while choosing the representation the programmer has to ensure that all or as many as possible potentially ‘interesting’ designs can be represented. But it is also generally desirable to minimize the bias introduced by the representation. In contrast to the user-provided design criteria, the bias caused by the representation influences the outcome of the design process in an implicit way which is not obvious to the user, and is difficult to predict and control.The idea developed in this research is that it is possible to turn the bias caused by the representation into a virtue, by deliberately choosing or modifying the representation to influence the design process in a certain desired way. The resulting ‘focusing’ of the search process is connected to the idea of ‘expansion of search spaces’, a notion used in some definitions of computational creativity. Both ‘focusing’ and ‘expansion of search space’ will be explored in this research
PP-172 Detection of the relation between the presence of Chlamydial antigen in the cervix of infertile women and the condition of their tubes
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Sugar Alcohols Have a Key Role in Pathogenesis of Chronic Liver Disease and Hepatocellular Carcinoma in Whole Blood and Liver Tissues.
The major risk factors for hepatocellular carcinoma (HCC) are hepatitis C and B viral infections that proceed to Chronic Liver Disease (CLD). Yet, the early diagnosis and treatment of HCC are challenging because the pathogenesis of HCC is not fully defined. To better understand the onset and development of HCC, untargeted GC-TOF MS metabolomics data were acquired from resected human HCC tissues and their paired non-tumor hepatic tissues (n = 46). Blood samples of the same HCC subjects (n = 23) were compared to CLD (n = 15) and healthy control (n = 15) blood samples. The participants were recruited from the National Liver Institute in Egypt. The GC-TOF MS data yielded 194 structurally annotated compounds. The most strikingly significant alteration was found for the class of sugar alcohols that were up-regulated in blood of HCC patients compared to CLD subjects (p < 2.4 × 10-12) and CLD compared to healthy controls (p = 4.1 × 10-7). In HCC tissues, sugar alcohols were the most significant (p < 1 × 10-6) class differentiating resected HCC tissues from non-malignant hepatic tissues for all HCC patients. Alteration of sugar alcohol levels in liver tissues also defined early-stage HCC from their paired non-malignant hepatic tissues (p = 2.7 × 10-6). In blood, sugar alcohols differentiated HCC from CLD subjects with an ROC-curve of 0.875 compared to 0.685 for the classic HCC biomarker alpha-fetoprotein. Blood sugar alcohol levels steadily increased from healthy controls to CLD to early stages of HCC and finally, to late-stage HCC patients. The increase in sugar alcohol levels indicates a role of aldo-keto reductases in the pathogenesis of HCC, possibly opening novel diagnostic and therapeutic options after in-depth validation
Epidemiological survey on mange mite of rabbits in the Southern Region of Egypt
The aim of the present study was to estimate the epidemic situation of mites, in rabbit dermatologic disease in and around Qena province, in the southern region of Egypt. Two hundred cases of dermatologic disease from the formentioned province were investigated by conducting deep skin scraping between May 2011 and October 2012. The overall prevalence was 25%. Sarcoptic scabiei uniculi (22.5%) was the most frequent mite, followed by Notoedres cati cuniculi (2.5%). To the best of our knowledge this is the first report of Notoedres cati cuniculi among studied rabbits in the study region. Study on different breeds, English represents highest prevalence of mites 30%. Moreover, there was no significant difference in the prevalence of mange mite infection between male and female rabbits (p > 0.05). Similarly, the prevalence was not significant among the age groups and rabbit breeds (p > 0.05). In conclusion, the present prevalence of mange mites was still high enough to cause significant economic losses in the study area. Therefore, strengthening the control effort was suggested
Effect of Soil Types on the Development of Water Levels and Erosion Processes during Overtopping Test
The construction of dike materials is an essential parameters in controlling the safety of hydraulic engineering. The dike material is an earthfill material constructed from non-cohesive materials or mixed from cohesive and non-cohesive materials. Overtopping failure can affect the dike stability during water cross above dike crest and could threat people lives and property. It is reduced the matric suctions binds soil particles due to the increasing volumetric water content during the transition of water level from the upstream into downstream slopes. In this paper, two spatial overtopping tests are conducted in Hydraulic Geotechnical laboratories at the Universiti Sains of Malaysia to observe the evolution of horizontal and vertical water levels as well as the development of lateral and vertical erosion processes under constant inflow discharge of 30 L/min. The vertical and horizontal water levels as well as the vertical erosion process are measured using one digital camera installed in front of dike embankment, while the horizontal erosion process was measured using another digital camera installed in front of downstream slope. Two types of coarse sand and very silty sand soils are used to construct dike embankment in small flume channel. The small flume is constructed from transparent PVC material to observe the development of water distributions and erosion processes with sediment box to collect the eroded materials. A pilot channel is cut in dike crest along the side wall of small flume channel to initiate breach channel in the dike crest. The initiation of breach channel is crucial for the evolution breach channel failure in the downstream and upstream slopes. The results show that the vertical and horizontal water levels are distributed faster in coarse sand soil compared with those in the very silty sand soil while the horizontal water levels are distributed faster than vertical water levels for both soils. The permeability of coarse sand increases the velocity of water flow for occupation soil particles and beginning failure in dike crest faster. The presence of fine particles in the very silty sand has reduced the rate of erosion processes inside dike particles in horizontal and vertical directions. The fine particles absorb a large amount of water content and, thus reduce the easiest water infiltration into particles with higher matric suctions. The analyzing of the distributions of water levels and erosion process help to understand the behavior of dike embankment during overtopping failure and increase the maintenance for dikes parts to reduce the potential danger
Survey of Personalized Learning Software Systems: A Taxonomy of Environments, Learning Content, and User Models
This paper presents a comprehensive systematic review of personalized learning software systems. All the systems under review are designed to aid educational stakeholders by personalizing one or more facets of the learning process. This is achieved by exploring and analyzing the common architectural attributes among personalized learning software systems. A literature-driven taxonomy is recognized and built to categorize and analyze the reviewed literature. Relevant papers are filtered to produce a final set of full systems to be reviewed and analyzed. In this meta-review, a set of 72 selected personalized learning software systems have been reviewed and categorized based on the proposed personalized learning taxonomy. The proposed taxonomy outlines the three main architectural components of any personalized learning software system: learning environment, learner model, and content. It further defines the different realizations and attributions of each component. Surveyed systems have been analyzed under the proposed taxonomy according to their architectural components, usage, strengths, and weaknesses. Then, the role of these systems in the development of the field of personalized learning systems is discussed. This review sheds light on the field’s current challenges that need to be resolved in the upcoming years
Component-based mixed reality environment for the control and design of servo-pneumatic system
Synopsis
Considerable research efforts have been spent over the last two decades on improving the
design, control, and modelling of pneumatic servo drive systems including the
development of dedicated controllers and control valves. However, the commercial
updates in employing pneumatic servos are still largely limited to laboratory research
usage and the initiatives in developing seem to have lost their momentums. Although this
situation has some to do with the rapid development and availability of cost effective
electric servo technologies, one reason is considered to be a lack of design and simulation
tools for employing pneumatic servo drives. This research has therefore been conducted
to address these concerns, and to demonstrate how appropriate tools and environments
can be developed and used to aid in the design, control and commissioning of pneumatic
servo drives. Because of the inherent high nonlinearities associated with pneumatic
systems, it would be highly desirable if the simulation environment could be run in time
domain so that it can be mixed with the real system. This would make the simulation
more accurate and reliable especially when dealing with such nonlinear systems.
Unfortunately, the tools that are available in the market such as Propneu (Festo, 2005)
and Hypneu (Bardyne, 2006) are dedicated for pneumatic circuit design only.
This research is aimed at developing a mixed reality environment for the control and
design of servo-pneumatic systems. Working with a mixed reality environment would
include both the capability to model the system entirely as a simulation, the so-called
"off-line", as well as being able to use real components running against simulations of
others "on-line", or in a Mixed Reality (MR) manner. Component-based paradigm has
been adopted, and hence the entire pneumatic system is viewed as a series of component
modules with standardised linking variables. The mathematical model of each individual
component has been implemented in simulation software which produces time domain
responses in order to allow for mixing the simulation with the real system.
The main outcome of this research can be seen as a successful development and
demonstration of the Component-based Mixed Reality Environment (CMRE), which
would facilitate the control and design of servo-pneumatic systems. On the one hand, the
CMRE facilitates the identification of some nonlinear parameters such as frictional
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ynopsis
parameters. These parameters could cause great difficulties in servo-pneumatic modelling
and control. Accurate friction parameters would give the ability to attain an accurate
model, and therefore provide more flexibility in applying different control and tuning
strategies on the real system. On the other hand, the CMRE facilitates the design process
by enabling the designer to evaluate the servo-pneumatic system off-line prior to building
the system. This would reduce the design time, increase the reliability of the design, and
minimize the design cost.
The concept of the CMRE was validated by tests carried out on laboratory-based
prototype servo-drive. Close agreement between the experimental and simulated
responses was obtained showing that the models have represented the real system
adequately. Case studies were then conducted to demonstrate the validity of the proposed
methodology and environment. In these case studies, PIDVF controller and cascade
control structure were successfully implemented, synthesised, and tuned. The results
revealed that the CMRE is an easy, accurate and robust way of implementing different
control and tuning strategies on servo-pneumatic systems. Furthermore, the research has
shown how the CMRE can lead to significant improvements in certain life cycle phases
of the system, e.g. commissioning, maintenance, etc.
This research has contributed to knowledge in the following:
(1) Adopting the mixed reality concept and the component-based approach in order to
create a CMRE in facilitating the control and design of servo-pneumatic systems.
(2) A method to identify the friction parameters of a single-axis pneumatic machine,
(3) Encapsulate existing control methods within the CMRE to be applied on the real
system.
(4) A scheme for controller tuning, in which the controller is tuned off-line and then
applied on the real system, and hence avoided on-line tuning which can be
troublesome and time consuming.
It is anticipated that the concept of the CMRE can be extended to include multi-axes
servo-pneumatic system, servo-hydraulic, and servo-electric drives. Therefore,
conceptual model structures have been introduced in this research which can be
considered as the foundation for creating similar environments for those systems
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