Computer Science

A conceptual schema can be viewed as a language to describe the phenomena in a system to be modelled, i.e. a set of derivation rules and integrity constraints as well as a set of event-rules describing the behaviour of an object system. In this paper, we investigate the relationship between the Lyee software requirements concepts with various constructs in conceptual modelling. Within our work we choose the Unified Modelling Language (UML) as a modelling notation for explaining conceptual models. The result obtained models a fully expressive set of UML and First Order Logic constructs mapped into Lyee concepts. q 2003 Elsevier B.V. All rights reserved.

Eye-gaze tracking through camera is commonly used in a number of areas, such as computer user interface systems, sports science, psychology, and biometrics. The robustness of the head and camera rotation tracking algorithm has been a critical problem in recent years. In this paper, Haar-like features and a modified version of the group method of data handling, as well as segmented regression, are used together to find the base points of the eyes in a facial image. Then, a geometric transformation is applied to detect precise eye-gaze direction. The proposed algorithm is tested on GI4E and Columbia Gaze datasets and compared to other algorithms. The results show adequate accuracy, especially when the head/camera is rotated.

The purpose of this study is to provide an overview of primary modulation based scatter estimation techniques and evaluate their performance as well as to propose improvements. There have been published two distinct approaches to estimate scatter with primary modulators; however they have not been compared, so far. This work seeks to quantify their performance (focusing on how accurately they can estimate a smooth scatter from primary modulated images with real textures and signal to noise ratios) along with that of proposed improved variants. The influence of the parameters of the described algorithms on the estimation error is also investigated. Simulations were carried out using primary components derived from real chest DTS projections. After modulation, artificial scatter distributions were added to these projections, and the difference between the estimated and the artificial scatter distributions was quantified. Two existing and four proposed methods were assessed. The performance of the scatter estimators was examined under noisy and noiseless circumstances and with scatter distributions of different bandwidths. The proposed methods (SSE, SSENP, ADASE) solve the problem of varying effective transmission factors in the case of cell-image based methods, and they include an improved gradient based method (LSGSE) as well, which estimates scatter distribution more accurately. It was found that the gradient based algorithms outperformed the cell-image based algorithms under noiseless conditions, while the cell-image based solutions proved to be insensitive to noise. The proposed improved methods reached considerably lower scatter estimation errors than the existing ones. Modulator cell sampling windows of different sizes and shapes were examined. Although much lower effective transmission factors (higher contrast between the attenuated and unattenuated cells) can be achieved using narrow windows, in our case the best estimation results are provided by windows that cover about half of the pixels of a modulator cell. The effect of detector backscatter on scatter estimation was also studied, and a solution was proposed to incorporate this type of scatter into the primary modulation framework. Considering all the above results, the authors suggest the use of LSGE for scatter estimation with primary modulation.

This paper studies the problem of unsupervised domain adaption in the universal scenario, in which only some of the classes are shared between the source and target domains. We present a scoring scheme that is effective in identifying the samples of the shared classes. The score is used to select samples in the target domain for which to apply specific losses during training; pseudo-labels for high scoring samples and confidence regularization for low scoring samples. Taken together, our method is shown to outperform, by a sizeable margin, the current state of the art on the literature benchmarks.

The progress of computer technology has helped many people in various fields of life. Expert systems are computer programs with expert knowledge to solve certain problems such as imitating human thought. Air Conditioner (AC) is a machine made to stabilize the humidity of an area and the temperature of the air. The lack of knowledge of the owner of the AC equipment has resulted in the equipment being damaged and the technical maintenance of the AC, and the amount of costs incurred for maintenance services is one of the obstacles. Based on these problems, the author made an expert system application to detect damage to Android-based air conditioners. . This application is expected to help the community in detecting damage, causes and solutions in Air Conditioning (AC). Interview and literature studies are data collection techniques used by the authors. In making the program the author uses the Forward Forward Chaining method. In this application there are 4 main menus, namely diagnosi...

Lot-sizing and scheduling has become an important aspect of manufacturing businesses nowadays. The effective and efficient management of scheduling and planning has the potential of reducing production cost which leads to increase in quality of products, which brings about competitive advantage. Lot-sizing and scheduling is a critical success factor especially in developing countries that lack technological infrastructure and resources available in developed countries. Due to the peculiar nature of the issue in Nigeria, the unit commitment problem (UCP) has to added to production planning to include energy considerations. Inspired by the complexity and the challenges faced by the soft drink industry in Nigeria. The aim of this thesis is to develop mathematical models for production planning that minimises production and backorder cost, evaluate the models under various demand profiles and determine the power needs of the factory under various demand profiles. Secondly, the thesis examine...

Misfolded endoplasmic reticulum (ER) proteins are retro-translocated through the membrane into the cytosol, where they are poly-ubiquitinated, extracted from the ER membrane, and degraded by the proteasome(1-4), a pathway termed ER-associated protein degradation (ERAD). Proteins with misfolded domains in the ER lumen or membrane are discarded through the ERAD-L and -M pathways, respectively. In S. cerevisiae, both pathways require the ubiquitin ligase Hrd1, a multi-spanning membrane protein with a cytosolic RING finger domain(5,6). Hrd1 is the crucial membrane component for retro-translocation(7,8), but whether it forms a protein-conducting channel is unclear. Here, we report a cryo-electron microscopy (cryo-EM) structure of S. cerevisiae Hrd1 in complex with its ER luminal binding partner Hrd3. Hrd1 forms a dimer within the membrane with one or two Hrd3 molecules associated at its luminal side. Each Hrd1 molecule has eight trans-membrane segments, five of which form an aqueous cavi...

Radiographic inspection is the most appreciated technique among the other non-destructive testing methods due to producing unique finger print record as the film. Converting of radiographs to a digital format and further digital image processing is the best method of enhancing the image quality and assisting the interpreter on his evaluation. In this research, different algorithms were used for image

Se plantea el desarrollo de un framework orientado a objetos para Sistemas de Generacion de Lenguaje Natural (GLN). Se revisan las arquitecturas utilizadas hasta la fecha, se revisa una propuesta de arquitectura generica, y se describe el tipo de solucion que se aspira a conseguir. A partir de esa informacion se muestra como la utilizacion de metodologias tipicas de Ingenieria de Software, como la Orientacion a Objeto o los Patrones de Diseno, resuelve algunos de los problemas mas acuciantes de los desarrolladores de aplicaciones de GLN. Se presenta el framework implementado y se plantean las aplicaciones en desarrollo que se basan en el codigo presentado