Automatic Generation of High-Coverage Tests for RTL Designs using Software Techniques and Tools

Register Transfer Level (RTL) design validation is a crucial stage in the hardware design process. We present a new approach to enhancing RTL design validation using available software techniques and tools. Our approach converts the source code of a RTL design into a C++ software program. Then a powerful symbolic execution engine is employed to execute the converted C++ program symbolically to generate test cases. To better generate efficient test cases, we limit the number of cycles to guide symbolic execution. Moreover, we add bit-level symbolic variable support into the symbolic execution engine. Generated test cases are further evaluated by simulating the RTL design to get accurate coverage. We have evaluated the approach on a floating point unit (FPU) design. The preliminary results show that our approach can deliver high-quality tests to achieve high coverage

Towards Open Scan for the Open-source Hardware

The open-source hardware IP model has recently started gaining popularity in the developer community. This model offers the integrated circuit (IC) developers wider standardization, faster time-to-market and richer platform for research. In addition, open-source hardware conforms to the Kerckhoff’s principle of a publicly-known algorithm and thus helps to enhance security. However, when security comes into consideration, source transparency is only one part of the solution. A complex global IC supply chain stands between the source and the final product. Hence, even if the source is known, the finished product is not guaranteed to match it. In this article, we propose the Open Scan model, in which, in addition to the source code, the IC vendor contributes a library-independent information on scan insertion. With scan information available, the user or a certification lab can perform partial reverse engineering of the IC to verify conformance to the advertised source. Compliance lists of open-source programs, such as of the OpenTitan cryptographic IC, can be amended to include this requirement. The Open Scan model addresses accidental and dishonest deviations from the golden model and partially addresses malicious modifications, known as hardware Trojans. We verify the efficiency of the proposed method in simulation with the Trust-Hub Trojan benchmarks and with several open-source benchmarks, in which we randomly insert modifications

Machinability assessment and tool selection for milling.

SIGLEAvailable from British Library Document Supply Centre-DSC:DX204223 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The Application of Zeeko Polishing Technology to Freeform Femoral Knee Replacement Component Manufacture

The purpose of this study was to develop an advanced 7-axis Computer Numerical Controlled (CNC) Polishing Machine from its successful original application of industrial optics manufacture into a process for the manufacture of femoral knee components to improve wear characteristics and prolong component lifetimes. It was indentified that the successful manufacture of optical components using a corrective polishing procedure to enhance their performance could be applied to femoral knee implant components. Current femoral knee implants mimic the natural shape of the joint and are freeform (no axis of symmetry) in nature hence an advanced CNC polishing machine that can follow the contours associated with such shapes could improve surface finish and conformity of replacement femoral knee bearing surfaces, leading to improved performance. The process involved generating machine parameters that would optimize the polishing procedure to minimize wear of materials used in femoral knee implant manufacture. Secondly a design of a Non-Uniform Refind B-Spline (NURBS) model for control of the Polishing Machine over the freeform contours of the femoral component. Completing the process involved development of a corrective polishing process that would improve form control of the components. Such developments would improve surface finish and conformity which are well documented contributors to wear and hence the lifeline of orthopaedic implants. By the means of comparison of this technique to that of a conventional finishing technique using pin-on-plate disc testing it was concluded that performance of the CNC polished components was an improvement on that of the conventional technique. In the case of form control their were slight indications through small decreases in peak to valley (PV) error that the process helped reduce form error and could increase the lifetime of femoral knee replacement components. The overall study provided results that indicate the the Zeeko process could be used in the application of polishing of hard-on-hard material combinations to improve form control without compromising surface finish hence improving lifetimes of the implant. The results have their limitations in the fact that the wear test performance was only carried out on orthopaedic implant materials using a pin-on-plate wear test rig. Due to the time limitations on the thesis it can be said that further analysis of correcting form without compromising surface finish on entire implant systems under full joint simulator testing which would provide mre realistic contitions would a more definitive answer be achieved

Improvement of volumetric sweep efficiency during oil production using ECO-clay

Excess water production during oil production is a big challenge that may affect the economics and environmental concerns. Different methods have been developed to reduce water production and improve the efficiency of oil recovery. One promising approach is using a nanocomposite that creates a gel for plugging fractures in the reservoir. This system can potentially improve volumetric sweep efficiency during oil production by decreasing water permeability and creating a better path for the oil to flow to the well. This study investigates the potential of an ECO-clay system comprising Laponite and Hydrolyzed Polyacrylamide (HPAM) as a water conformance technique in fractured reservoirs. The investigation involves bulk experiments to screen different concentrations of clay and polymer, while also evaluating the effects of various ions and additives on gel performance. Promising systems are subsequently subjected to filtration tests to assess their suitability for gel placement into fractures. Ultimately, the goal was to identify the most effective gel system and conduct core flooding tests to evaluate its potential for plugging fractures and improving oil recovery. Among the systems tested, two were selected for dynamic experiments: A Laponite S482-CaCl2 system and a nanocomposite system with HPAM addition. Both showed good results in the filtrations and floods, achieving a water permeability reduction of 19.6 and 5.3 times lower than the pre-treatment permeability respectively. Finally, the Laponite S482-CaCl2 system represented the most promising gel system for fracture plugging in chalk, because its higher permeability reduction. These findings highlight the potential of the identified gel system for effectively addressing water production issues in fractured chalk reservoirs, thereby improving oil recovery efficiency, reducing water production and CO2 emission. To improve the understanding and implementation of these gel systems, further work is required in a more in-depth gel structure tests, long-term stability and performance evaluation, compatibility with other reservoir fluid study, and finally field-scale experiments and simulations. Addressing these issues will help create a reliable and cost-effective fractured reservoir water conformance technique

Overview of CO₂ leakage problems and sealants for CO₂ leakage remediation

Excessive Carbon Dioxide (CO₂) emission has become a serious issue and caused lots of environmental problems. Carbon Capture and Storage (CCS) program has been developed to reduce the CO₂ content in the atmosphere. CO₂ storage has been targeted mainly on depleted oil or gas reservoirs and deep saline aquifers. However, leakage could occur through wellbores, cap rocks, formation faults, and fractures during and after CO₂ injection. To minimize the risk, different types of sealants have been investigated to prevent CO₂ leaks. The aim of this thesis is to provide a comprehensive review of the materials which could be used as CO₂ sealants. Based on the difference of materials components, this research has classified the sealants into seven types, including cements, geopolymers, foams, gel systems, resin systems, biofilm barriers, and nanoparticles. For each type of sealants, its chemical components, physical properties, stabilities, impact factors, applied environments, advantages and limitations were summarized. The most commonly used sealant for CO₂ leakage control from wellbore is still cement, and the aluminate-calcium based cement has the best properties. It is very challenging to seal the fractures and faults, far from wellbore due to the difficulty to deliver plugging materials into the in-depth of a reservoir. The thermo-stability is also a great challenge for most materials and should be evaluated under supercritical CO₂ condition --Abstract, page iii

AMCIS 2007 Panel Summary: The Promise of RFID Technologies

Radio Frequency Identification (RFID) has started to revolutionize the way today\u27s organizations do business. Since its highly publicized adoption by Wal-Mart, several companies have started using RFID in their supply chains with varying results. On the academic level, many new research streams have been launched concerning the applications of RFID in business. However, whether or not the academic community is ready to adopt this technology itself remains a question. To consider the future of this technology in research and industry alike, the authors organized two panels on the topic of the promise of RFID technologies at the 2007 Americas Conference on Information Systems (AMCIS) held in Keystone, Colorado. They also demonstrated the capability of the technology using a proof-of-concept pilot system as a means for providing added services to conference attendees. This article reports on the two panels, as well as on the results from the pilot experiment