A New Linear Group-Wise SIC Multiuser Detector

In this work, we introduce a new linear group-wise SIC multi-user detector that can converge to either the decorrelator or the least minimum mean-square error (LMMSE) detector. We study the convergence behavior of the proposed scheme and show that the latter is equivalent to the block Gauss-Seidel iterative method if the group-detection scheme used is the decorrelator detector. Moreover, we prove that the latter is convergent if the group-detection matrix is positive definite. Our simulation results are in excellent agreement with the proposed theory     

Application of genetic algorithm to color recipe formulation using reactive and direct dyestuffs mixtures

Color reproduction is a science in constant development. In this article, a new model to solve the color recipe prediction problem using a genetic algorithm is proposed. The objective is to optimize the color recipe prediction stage by determining the dyes to use in a mixture and their respective proportions to reproduce the target color. Two ranges of dyes were used for dyeing 100% cotton woven fabrics: three reactive dyes (CI Reactive Red 238, CI Reactive Yellow 145, and CI Reactive Blue 235) and four direct dyes (CI Direct Orange 34, CI Direct Red 227, CI Direct Blue 85, and CI Direct Black 22). The criterion of optimization, in reproducing the desired shades, is to minimize the CMC color difference between the desired reference color and the color resulting of the predicted recipe. The proposed algorithm revealed good results with small CMC color differences between target and reproduced colors. The effectiveness of the algorithm was also evaluated and proven by calculating errors between the predicted concentrations in the proposed recipes and the actual concentrations.     

Development of heat-resistant anticorrosion urethane siloxane paints

Three two-layer heat-resistant and anticorrosion paints have been formulated from urethane siloxane binder and traditional anticorrosion pigments such as micaceous iron oxide (MIO), zinc phosphate (ZP), and aluminum oxide. These pigments were used as the dominant components of different undercoats or topcoats. Heat-resistant pigments such as silicon nitride and glass-spheres were used in the composition of the topcoats. Thermogravimetric analysis of paints shows that the paint with ZP as dominant component of the undercoat have the highest heat-resistance and stability in inert gas and oxygen. The paint with a combination of MIO and ZP has the best hardness as well as the best protective and anticorrosion properties based on the electrochemical impedance spectroscopy. A maximum synergic effect of the properties of pigments seems to appear in this paint. Surface morphology of paints was studied by means of scanning electron microscopy. Heated at different temperatures and for several hours, paint containing MIO as the dominant component in the undercoat exhibits the best mechanical and adhesion properties.     

What is Initiative?

This paper presents some alternate theories for explaining the term 'initiative', as it is used in the design of mixed-initiative AI systems. Although there is now active research in the area of mixed initiative interactive systems, there appears to be no true consensus in the field as to what the term 'initiative' actually means. In describing different possible approaches to the modeling of initiative, we aim to show the potential importance of each particular theory for the design of mixed initiative systems. The paper concludes by summarizing some of the key points in common to the theories, and by commenting on the inherent difficulties of the exercise, thereby elucidating the limitations which are necessarily encountered in designing such theories as the basis for designing mixed-initiative systems.     

Requirements and design of a grasping system for personal robots

In this paper, we present a robotic grasping system for deployment in personal robots. The system learns how to grasp objects from experiments. This approach allows it to satisfy a number of requirements that we have identified as prerequisite for operation in personal robot environments. The system design consists of three control layers, each describing the control strategy of a predefined behavior. Learning of the behavior is performed using groups of neural networks. Testing of the system was performed in a simulated environment using a specially built grasping simulator and using a 15 objects database. Results show that, on average, each object needed 12 successful experiments before an accurate grasping model was achieved. Failed experiments averaged to 25% of the total experiments.     

Appraisal and reporting of security assurance at operational systems level

In this paper we discuss the issues relating the evaluation and reporting of security assurance of runtime systems. We first highlight the shortcomings of current initiatives in analyzing, evaluating and reporting security assurance information. Then, the paper proposes a set of metrics to help capture and foster a better understanding of the security posture of a system. Our security assurance metric and its reporting depend on whether or not the user of the system has a security background. The evaluation of such metrics is described through the use of theoretical criteria, a tool implementation and an application to a case study based on an insurance company network.     

Oxidation of iron (II) sulphate to iron (III) sulphate and use in water treatment

Iron (II) sulphate, a side product of the steel industry, can react with nitric acid in the presence or absence of sulphuric acid to give a solution of iron (III) sulphate and nitrate. This solution seems to be a good substitute for iron (III) chlorosulphate as a coagulant in water treatment processes. In the present work, a kinetic study of the different reactions taking place has been realised. Experimental measurements of the conversion of Fe(II) to Fe(III) have been carried out by means of a volumetric method. The influence of various operating parameters such as the reaction temperature and the concentration of reagents has been studied. Global kinetic data such as the reaction orders, the reaction rates and the activation energy have been determined. Measurements of the water turbidity and the concentrations of undesirable products such as nitrates, have been taken prior to and after the treatment process and are also reported.     

The economic impact of cowpea research in West and Central Africa: A regional impact assessment of improved cowpea storage technologies

Researchers from the Bean/Cowpea Collaborative Research Support Program (CRSP), a program supported by the USAID, developed several non-chemical cowpea grain storage technologies in the 1980s. These included hermetic storage in airtight containers, improved ash storage, and the solar heater. Impact studies conducted at the country level showed that the research program was economically a good investment. As the CRSP new storage technologies spread throughout West and Central Africa, a regional assessment including spillover effects became necessary to fully comprehend the impact and guide future research investments. Therefore, this study sought to measure the economic impact of the new CRSP cowpea storage technologies at a regional level. Surveys in seven countries were used to estimate storage technology adoption. Economic surplus was used to estimate annual benefits and internal rate of return (IRR), and net present value (NPV) were calculated to summarize the net benefits. From the perspective of recipients' countries the project was a good investment. The IRR, is found to be much greater than the cost of capital. The regional IRR was found to be about 29%, much higher than the real interest rate on government bonds in West Africa at the time. For example the real interest rate on bonds issued by the government of Ghana in 2004 and 2005 was 8.9% and 5.4% respectively. The IRR is also higher than the private bank real lending rates in West Africa. From the perspective of the principal donor, the US government, the project was a good investment given that the average real interest rate on US government’s bonds was 4.8% during the period. The net present value of the investment amounts to more than 295 million US dollars which yields an annualized value of about 17 million.