Chen Kuilin, Feng Xi, Fu Yingchun, Liu Liang, Feng Wennan, Jiang Minggang, Hu Yi and Tang Xiaoke
The data protection is always a vital problem in the network era. High-speed cryptographic chip is an important part to ensure data security in information interaction. This paper…
Abstract
Purpose
The data protection is always a vital problem in the network era. High-speed cryptographic chip is an important part to ensure data security in information interaction. This paper aims to provide a new peripheral component interconnect express (PCIe) encryption card solution with high performance, high integration and low cost.
Design/methodology/approach
This work proposes a System on Chip architecture scheme of high-speed cryptographic chip for PCIe encryption card. It integrated CPU, direct memory access, the national and international cipher algorithm (data encryption standard/3 data encryption standard, Rivest–Shamir–Adleman, HASH, SM1, SM2, SM3, SM4, SM7), PCIe and other communication interfaces with advanced extensible interface-advanced high-performance bus three-level bus architecture.
Findings
This paper presents a high-speed cryptographic chip that integrates several high-speed parallel processing algorithm units. The test results of post-silicon sample shows that the high-speed cryptographic chip can achieve Gbps-level speed. That means only one single chip can fully meet the requirements of cryptographic operation performance for most cryptographic applications.
Practical implications
The typical application in this work is PCIe encryption card. Besides server’s applications, it can also be applied in terminal products such as high-definition video encryption, security gateway, secure routing, cloud terminal devices and industrial real-time monitoring system, which require high performance on data encryption.
Social implications
It can be well applied on many other fields such as power, banking, insurance, transportation and e-commerce.
Originality/value
Compared with the current strategy of high-speed encryption card, which mostly uses hardware field-programmable gate arrays or several low-speed algorithm chips through parallel processing in one printed circuit board, this work has provided a new PCIe encryption card solution with high performance, high integration and low cost only in one chip.
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Hongyan Shi, Xiaoke Lin and Yun Wang
The purposes of this paper are to study the characterization of drill bit breakage in printed circuit board (PCB) drilling process based on high-speed video analysis and to…
Abstract
Purpose
The purposes of this paper are to study the characterization of drill bit breakage in printed circuit board (PCB) drilling process based on high-speed video analysis and to provide an important reference for micro drill bit breakage prediction.
Design/methodology/approach
Based on PCB drilling experiment, the high-speed camera was used to observe the micro drill breakage process and the chip removal process. The variation of chip in the drilling process was studied and one of the key reasons for the drill bit breakage was analysed. Finally, the swing angles’ feature during the breakage process of the micro drill was analysed and researched with the image processing tools of MATLAB.
Findings
The micro drill was prone to breakage mainly because of the blocked chips. The breakage process of the micro drill can be divided into the stage of stable chips evacuation, the stage of blocked chips and the stage of drill bit breakage. The radians of swing angles were basically in the range of ±0.01 when the drilling possess is normal. But when the radians of swing angles considerably exceeded the range of ±0.01, the micro drill bit may be fractured.
Originality/value
This paper presented the method to study the characterization of drill bit breakage in the PCB drilling process by using high-speed video analysis technology. Meanwhile, an effective suggestion about monitoring the radians of swing angles to predict the breakage of micro drill bit was also provided.
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Nour el Imane Harrat, Sabrine Louala, Fatima Bensalah, Fouad Affane, Hadjera Chekkal and Myriem Lamri-Senhadji
The purpose of this study was to investigate the effects of prickly pear (Opuntia ficus indica (OFI)) nopalitos on body weight, food consumption, arterial blood pressure, glucidic…
Abstract
Purpose
The purpose of this study was to investigate the effects of prickly pear (Opuntia ficus indica (OFI)) nopalitos on body weight, food consumption, arterial blood pressure, glucidic homeostasis, cholesterol metabolic pathway and tissues redox status in type 2 diabetic (T2D) rats fed a high-fat diet (HFD).
Design/methodology/approach
Rats were fed by a HFD containing 30 per cent sheep fat for 10 weeks, after which they were rendered diabetic by an injection of a low dose of streptozotocin (STZ) (35 mg/kg). The diabetic rats were then divided into two groups. The first group consumed the HFD supplemented with 5 per cent (g/100 g diet) of freeze-dried OFI nopalitos (HFD-OFI), and the second group received the HFD without supplementation (HFD).
Findings
OFI nopalitos treatment decreased significantly arterial diastolic (−20%; p = 0.0001) and systolic (−16%; p = 0.0001) pressures, glycemia (−14%; p = 0.03), insulinemia (−50%; p = 0.04), glycated hemoglobin (−49%; p = 0.003), homeostasis model assessment insulin resistance (−67%; p = 0.03), cholesterolemia (−31%; p = 0.003), very-low and low-density lipoprotein cholesterol (−38%; p = 0.002 and −63% p = 0.0002, respectively); thiobarbituric acid reactive substances and lipid hydroperoxide contents, respectively, in liver (−26% p = 0.02, −20% p = 0.02), adipose tissue (−30% p = 0.002, −25% p = 0.001), muscle (−29% p = 0.003, −25% p = 0.008) and kidney (lipid hydroperoxides only (−28%; p = 0.001) but increased high-density lipoprotein (HDL2) cholesteryl esters (+61%; p = 0.0001), serum lecithin: cholesterol acyltransferase activity (+21%; p = 0.006) and antioxidant enzymes activities (superoxide dismutase, glutathione peroxidase and catalase) of some tissues (liver, adipose tissue, muscle and kidney).
Originality/value
Freeze-dried OFI nopalitos improves arterial blood pressure, glycemic control, metabolic pathway of cholesterol and redox status in T2D rats.
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Xiaoke Li, Haobo Qiu, Zhenzhong Chen, Liang Gao and Xinyu Shao
Kriging model has been widely adopted to reduce the high computational costs of simulations in Reliability-based design optimization (RBDO). To construct the Kriging model…
Abstract
Purpose
Kriging model has been widely adopted to reduce the high computational costs of simulations in Reliability-based design optimization (RBDO). To construct the Kriging model accurately and efficiently in the region of significance, a local sampling method with variable radius (LSVR) is proposed. The paper aims to discuss these issues.
Design/methodology/approach
In LSVR, the sequential sampling points are mainly selected within the local region around the current design point. The size of the local region is adaptively defined according to the target reliability and the nonlinearity of the probabilistic constraint. Every probabilistic constraint has its own local region instead of all constraints sharing one local region. In the local sampling region, the points located on the constraint boundary and the points with high uncertainty are considered simultaneously.
Findings
The computational capability of the proposed method is demonstrated using two mathematical problems, a reducer design and a box girder design of a super heavy machine tool. The comparison results show that the proposed method is very efficient and accurate.
Originality/value
The main contribution of this paper lies in: a new local sampling region computational criterion is proposed for Kriging. The originality of this paper is using expected feasible function (EFF) criterion and the shortest distance to the existing sample points instead of the other types of sequential sampling criterion to deal with the low efficiency problem.
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Abstract
Purpose
This study aims to improve the force sensing performance of the robot joint for the safety and flexibility of physical human–robot interaction.
Design/methodology/approach
A force sensing mechanism (FSM) for an S-shaped spring of a robot variable stiffness actuator (VSA) was designed. The yield strength of the spring material, geometric and assembly structure constraints of the VSA are all considered for the actuator deflection limit design. The elastic deformation model is solved in reverse to obtain the local deformation limit profile of the S-spring at different spring angles. The deformation limit mechanism is manufactured by three-dimensional printing and assembled with S-springs. The force sensing function for the VSA is achieved by the input and output shaft encoders and stiffness model. The FSM is verified by torque-deflection experiments with variable stiffness.
Findings
The yield strength of the S-spring material is the strictest constraint for elastic deformation. Experimental results show that the external force can be quickly and reliably perceived. As the spring angle increases (stiffness increases), the hysteresis and nonlinear error decrease. Under the constraint of the FSM, the maximum deflection also decreases rapidly.
Originality/value
The designed FSM based on the deformation and stiffness model provides a comprehensive design reference in a VSA with nonlinear elastic mechanisms, which is ignored but important for exploring the VSAs potential.