Nowadays the computer vision technique has widely found applicationsin industrial manufacturing process to improve their efficiency. However, it ishardly applied in the field of daily ceramic detection due to the foll...Nowadays the computer vision technique has widely found applicationsin industrial manufacturing process to improve their efficiency. However, it ishardly applied in the field of daily ceramic detection due to the following twokey reasons: (1) Low detection accuracy as a result of ceramic glare, and (2) Lackof efficient detection algorithms. To tackle these problems, a homomorphic filtering based anti-glare ceramic decals defect detection technique is proposed in thispaper. Considering that smooth ceramic surface usually causes glare effects andleads to low detection results, in our approach, the ceramic samples are takenin low light environment and their luminance and details restored by a homomorphic filtering based image enhancement technique. With relatively high quality preprocessed images, an effective ceramic decal defect detection algorithm isthen designed to rapidly locate those out-of-bounds defects and further estimatetheir size. The experimental results show that the proposed scheme could achieveits desired performance.展开更多
In recent years many security attacks occur when malicious codes abuse in-process memory resources.Due to the increasing complexity,an application program may call third-party code which cannot be controlled by progra...In recent years many security attacks occur when malicious codes abuse in-process memory resources.Due to the increasing complexity,an application program may call third-party code which cannot be controlled by programmers but may contain security vulnerabilities.As a result,the users have the risk of suffering information leakage and control flow hijacking.However,current solutions like Intel memory protection extensions(MPX)severely degrade performance,while other approaches like Intel memory protection keys(MPK)lack flexibility in dividing security domains.In this paper,we propose IMPULP,an effective and efficient hardware approach for in-process memory protection.The rationale of IMPULP is user-level partitioning that user code segments are divided into different security domains according to their instruction addresses,and accessible memory spaces are specified dynamically for each domain via a set of boundary registers.Each instruction related to memory access will be checked according to its security domain and the corresponding boundaries,and illegal in-process memory access of untrusted code segments will be prevented.IMPULP can be leveraged to prevent a wide range of in-process memory abuse attacks,such as buffer overflows and memory leakages.For verification,an FPGA prototype based on RISC-V instruction set architecture has been developed.We present eight tests to verify the effectiveness of IMPULP,including five memory protection function tests,a test to defense typical buffer overflow,a test to defense famous memory leakage attack named Heartbleed,and a test for security benchmark.We execute the SPEC CPU2006 benchmark programs to evaluate the efficiency of IMPULP.The performance overhead of IMPULP is less than 0.2%runtime on average,which is negligible.Moreover,the resource overhead is less than 5.5%for hardware modification of IMPULP.展开更多
基金supported by the Science and Technology Projects,Quzhou City,China(2019K12,X.Chen,www.qz.gov.cn)National Natural Science Foundation of China(61762054 and 62062044,X.Chen)。
文摘Nowadays the computer vision technique has widely found applicationsin industrial manufacturing process to improve their efficiency. However, it ishardly applied in the field of daily ceramic detection due to the following twokey reasons: (1) Low detection accuracy as a result of ceramic glare, and (2) Lackof efficient detection algorithms. To tackle these problems, a homomorphic filtering based anti-glare ceramic decals defect detection technique is proposed in thispaper. Considering that smooth ceramic surface usually causes glare effects andleads to low detection results, in our approach, the ceramic samples are takenin low light environment and their luminance and details restored by a homomorphic filtering based image enhancement technique. With relatively high quality preprocessed images, an effective ceramic decal defect detection algorithm isthen designed to rapidly locate those out-of-bounds defects and further estimatetheir size. The experimental results show that the proposed scheme could achieveits desired performance.
基金This work was supported by the National Key Research and Development Plan of China under Grant No.2016YFB1000200the National Natural Science Foundation of China under Grant No.61772497the State Key Laboratory of Computer Architecture Foundation under Grant Nos.CARCH4405 and CARCH2601.
文摘In recent years many security attacks occur when malicious codes abuse in-process memory resources.Due to the increasing complexity,an application program may call third-party code which cannot be controlled by programmers but may contain security vulnerabilities.As a result,the users have the risk of suffering information leakage and control flow hijacking.However,current solutions like Intel memory protection extensions(MPX)severely degrade performance,while other approaches like Intel memory protection keys(MPK)lack flexibility in dividing security domains.In this paper,we propose IMPULP,an effective and efficient hardware approach for in-process memory protection.The rationale of IMPULP is user-level partitioning that user code segments are divided into different security domains according to their instruction addresses,and accessible memory spaces are specified dynamically for each domain via a set of boundary registers.Each instruction related to memory access will be checked according to its security domain and the corresponding boundaries,and illegal in-process memory access of untrusted code segments will be prevented.IMPULP can be leveraged to prevent a wide range of in-process memory abuse attacks,such as buffer overflows and memory leakages.For verification,an FPGA prototype based on RISC-V instruction set architecture has been developed.We present eight tests to verify the effectiveness of IMPULP,including five memory protection function tests,a test to defense typical buffer overflow,a test to defense famous memory leakage attack named Heartbleed,and a test for security benchmark.We execute the SPEC CPU2006 benchmark programs to evaluate the efficiency of IMPULP.The performance overhead of IMPULP is less than 0.2%runtime on average,which is negligible.Moreover,the resource overhead is less than 5.5%for hardware modification of IMPULP.
