High-level synthesis (HLS) is becoming an increasingly important part of the computing landscape, even in safety-critical domains where correctness is key. As such, HLS tools are increasingly relied upon. But are they...
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ISBN:
(纸本)9781450382182
High-level synthesis (HLS) is becoming an increasingly important part of the computing landscape, even in safety-critical domains where correctness is key. As such, HLS tools are increasingly relied upon. But are they trustworthy?We have subjected three widely used HLS tools - LegUp, Xilinx Vivado HLS, and the Intel HLS compiler - to a rigorous fuzzing campaign using thousands of random, valid c programs that we generated using a modified version of the csmith tool. For each c program, we compiled it to a hardware design using the HLS tool under test and checked whether that hardware design generates the same output as an executable generated by the Gcccompiler. When discrepancies arose between Gcc and the HLS tool under test, we reduced the c program to a minimal example in order to zero in on the potential bug. Our testing campaign has revealed that all three HLS tools can be made either to crash or to generate wrong code when given valid c programs, and thereby underlines the need for these increasingly trusted tools to be more rigorously engineered. Out of 6700 test cases, we found 272 programs that failed in at least one tool, out of which we were able to discern at least 6 unique bugs.
The security of powerful systems and large networks is often addressed through complex defenses. While these types of defenses offer increased security, they are resource intensive and therefore impractical to impleme...
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The security of powerful systems and large networks is often addressed through complex defenses. While these types of defenses offer increased security, they are resource intensive and therefore impractical to implement on many new classes of networked systems, such as mobile phones and small, embedded network infrastructure devices. To provide security for these systems, new defenses must be created that provide highly efficient security. The Moving Target IPv6 Defense (MT6D) is a network layer moving target defense that dynamically changes Internet Protocol version 6 (IPv6) addresses mid-session while still maintaining continuous communication. MT6D was originally written in Python language, but this implementation suffers from severe performance limitations. By translating MT6D from Python to c and taking advantage of operating system specific application programming interfaces (APIs) and optimizations, MT6D can become a viable defense for resource constrained systems.
The Python version of MT6D is analyzed initially to determine what functions might be performance bottlenecks that could be performed more efficiently using c. Based on this analysis, specific parts of the Python version are identified for improvement in the c version by either using functionality of the Linux kernel and network stack or by reworking the code in a more efficient way. After this analysis, the information gathered about the Python version is used to write the c version, using methods specific to a moving target defense to capture, analyze, modify, and tunnel packets. Finally, tests are designed and run to compare the performance of the Python and c versions.
This paper aims at the development of an approach integrating the fuzzy logic strategy for a therapeutic hepatitis c virus dynamics optimal control problem. To test the efficiency of this strategy, the authors propose...
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This paper aims at the development of an approach integrating the fuzzy logic strategy for a therapeutic hepatitis c virus dynamics optimal control problem. To test the efficiency of this strategy, the authors propose a numerical comparison with the direct method by taking the values of determinant parameters of this disease for people administrating the drugs. The results are in good agreement with experimental data.
Seven new c 14 -polyacetylene glucosides codonopilodiynosides A–G ( 1 – 7 ) were isolated from an aqueous extract of the codonopsis pilosula roots. Their structures were determined by spectroscopic and chemical meth...
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Seven new c 14 -polyacetylene glucosides codonopilodiynosides A–G ( 1 – 7 ) were isolated from an aqueous extract of the codonopsis pilosula roots. Their structures were determined by spectroscopic and chemical methods as (–)-(5 S ,6 E ,12 E )-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5- O -β- d -glucopyranoside ( 1 ), (–)-(5 S ,6 E ,12 E )-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5- O -β- d -glucopyranosyl-(1″ → 2′)-β- d -glucopyranoside ( 2 ), (–)-(5 S ,6 E ,12 E )-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5,14-di- O -β- d -glucopyranoside ( 3 ), (–)-(5 S ,6 E )-tetradeca-6-en-8,10-diyn-1,5,14-triol 5- O -β- d -glucopyranoside ( 4 ), (–)-(5 S ,6 E ,12 E )-tetradeca-6,12-dien-8,10-diyn-1,5-diol 5- O -β- d -glucopyranosyl-(1″ → 2′)-β- d -glucopyranoside ( 5 ), (–)-(6 S ,4 E ,12 E )-tetradeca-4,12-dien-8,10-diyn-1,6-diol 6- O -β- d -glucopyranosyl-(1″ → 2′)-β- d -glucopyranoside ( 6 ), and (–)-(5 S ,6 E )-tetradeca-6-en-1,5-epoxy-8,10-diyn-14-ol 14- O -β- d -glucopyranosyl-(1″ → 2′)-β- d -glucopyranoside ( 7 ), respectively. The absolute configurations of 1 – 7 were assigned by enzymatic hydrolysis followed by isolation of glucose and aglycones ( 1a and 4a – 7a ), and subsequent comparison of specific rotation, TLc, and 1 H NMR data of the glucose with an authentic sugar sample and application of modified Mosher's method based on the MPA determination rule of Δδ RS values for 1a and 4a, and Δδ S values for 6a . The configuration of 7 was assigned by electroniccircular dichroism calculations based on the quantum-mechanical time-dependent density functional theory.
Study for influence of chronic Hepatitis c (HcV) on endogenous erythropoietin production and on anemia in dialysis patients remains inconclusive. We hypothesize that chronic hemodialysis patients with co-existing Hepa...
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Study for influence of chronic Hepatitis c (HcV) on endogenous erythropoietin production and on anemia in dialysis patients remains inconclusive. We hypothesize that chronic hemodialysis patients with co-existing Hepatitis c infection will have higher hemoglobin levels than chronic hemodialysis patients without hepatitis c infection. Secondly, we hypothesize that the higher hemoglobin levels will be associated with higher erythropoietin levels. Therefore we conducted a cross-sectional study of chronic hemodialysis patients with and without hepatitis c infection and evaluated associations with hemoglobin and erythropoietin levels. Our primary outcome was level of hemoglobin. Secondary outcome included association of hemoglobin and erythropoietin levels. 57 chronic hemodialysis patients (33 male, 24 female, mean age 46.05 ± 12.7 years) were included. The mean time spent on hemodialysis was 7.16 ± 6.2 years. None of the patients received any recombinant EPO therapy. Biochemical analyses include ALT, AST, Albumin, c-Reactive Protein, cholesterol levels and complete blood counts. Iron status of patients (transferrin saturation and serum ferritin levels) and parathyroid hormone were measured. Endogenous EPO serum levels were measured by a standardized enzyme-linked immunoassay. 23 of the hemodialysed patients (38.5%) were HcV (+). There was no difference in age, sex, distribution of primary renal diseases, iron status, albumin, c-Reactive-Protein and parathyroid hormone levels between HcV (+) and (-) patients. Mean duration time on dialysis was higher in HcV (+) than HcV (-) patients. Hemoglobin levels were similar between study groups. However serum endogenous erythropoietin levels were significantly higher in HcV (+) patients than HcV (-) patients (19.6 ± 10 mUI/ml vs 7.8 ± 7.7 mUI/ml, p = 0.03). No correlation has been found between the severity of anemia and HcV infection. However, HcV (+) hemodialysed patients had higher serum endogenous erythropoietin levels as comp
Parametric ordinary differential equations (ODE) arise in many engineering applications. We consider ODE solutions to be embedded in an overall objective function which is to be minimized, e.g. for parameter estimatio...
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Parametric ordinary differential equations (ODE) arise in many engineering applications. We consider ODE solutions to be embedded in an overall objective function which is to be minimized, e.g. for parameter estimation. For derivative-based optimization algorithms adjoint methods should be used. In this article, we present a discrete adjoint ODE integration framework written in c + + (NIXE 2.0) combined with Algorithmic Differentiation by overloading (dco/c + +). All required derivatives, i.e. Jacobians for the integration as well as gradients and Hessians for the optimization, are generated automatically. With this framework, derivatives of arbitrary order can be implemented with minimal programming effort. The practicability of this approach is demonstrated in a dynamic parameter estimation case study for a batch fermentation process using sequential method of dynamic optimization. Ipopt is used as the optimizer which requires second derivatives.
Patients who are infected with hepatitis c virus(HcV) and also have advanced fibrosis or cirrhosis have beenrecognized as "difficult-to-treat" patients during an era when peginterferon and ribavirin combinat...
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Patients who are infected with hepatitis c virus(HcV) and also have advanced fibrosis or cirrhosis have beenrecognized as "difficult-to-treat" patients during an era when peginterferon and ribavirin combination therapy is the standard of care. Recent guidelines have clearly stated that treatment should be prioritized in this population to prevent complications such as decompensation and hepatocellular carcinoma. Recent advances in the treatment of chronic hepatitis c have been achieved through the development of direct-acting antiviral agents(DAAs). Boceprevir and telaprevir are first-generation DAAs that inhibit the HcV NS3/4A protease. Boceprevir or telaprevir, in combination with peginterferon and ribavirin, improved the sustained virological response rates compared with peginterferon and ribavirin alone and were tolerated in patients with HcV genotype 1 infection without cirrhosis or compensated cirrhosis. However, the efficacy is lower especially in prior non-responders with or without cirrhosis. Furthermore, a high incidence of adverse events was observed in patients with advanced liver disease, including cirrhosis, in real-life settings. current guidelines in the United States and in some European countries no longer recommend these regimens for the treatment of HcV. Next-generation DAAs include second-generation HcV NS3/4A protease inhibitors, HcV NS5 A inhibitors and HcV NS5 B inhibitors, which have a high efficacy and a lower toxicity. These drugs are used in interferon-free or in interferon-based regimens with or without ribavirin in combination with different classes of DAAs. Interferon-based regimens, such as simeprevir in combination with peginterferon and ribavirin, are well tolerated and are highly effective especially in treatmentnave patients and in patients who received treatment but who relapsed. The efficacy is less pronounced in nullresponders and in patients with cirrhosis. Interferonfree regimens in combination with ribavirin and/or two or mo
Background: continuous exposure to millimolar (mM) Vitamin c (AA) in vitro kills cancer cells. For superficial bladder carcinoma (SBc), standard chemotherapy is instillation of Bacillus calmette-Guerin. The recurrence...
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Background: continuous exposure to millimolar (mM) Vitamin c (AA) in vitro kills cancer cells. For superficial bladder carcinoma (SBc), standard chemotherapy is instillation of Bacillus calmette-Guerin. The recurrence rate with this therapy is 91%. But high dosage vitamins including AA reduced the recurrence to 41%. Aim: To determine the oral dosage of AA that causes the highest concentration of AA [AA] in the bladder. Method: We conducted a clinical trial of 14 people who took various dosages of AA, and analyzed the [AA] in their urine. Results: AA above 2 g twice a day was not absorbed. But that intake produced a bladder [AA] above 1 mM in all participants. conclusion: Taking 2 g of AA BID will increase [AA] in the bladder to a level likely to kill cancer cells that cause SBc. Taking that dosage 2 consecutive days a week is likely to reduce the recurrence rate of SBc substantially.
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