Certificate-Based Parallel Key-Insulated Aggregate Signature Against Fully Chosen-Key Attacks for Industrial Internet of Things

With the emergence of the Industrial Internet of Things (IIoT), numerous operations based on smart devices contribute to producing convenience and comfortable applications for individuals and organizations. Considering the untrusted feature of the communication channels in IIoT, it is essential to ensure the authentication and incontestableness of the messages transmitted in the IIoT. In this paper, we firstly proposed a certificate-based parallel key-insulated aggregate signature (CB-PKIAS), which can resist the fully chosen-key attacks. Concretely, the adversary who can obtain the private keys of all signers in the system is able to forge a valid aggregate signature by using the invalid single signature. Furthermore, our scheme inherits the merits of certificate-based and key-insulated to avoid the certificate management problem, key escrow problems as well as the key exposures simultaneously. In addition, the rigorous analysis and the concrete simulation experiment demonstrated that our proposed scheme is secure under the random oracle and more suitable for the IIoT environment

Study on Temperature Distribution Characteristics of Condensate in Marine Condensator

According to the structure and working principles of marine condensator, utilizing FLUNET, a numerical model of the flow field related to the hot well is established and the results were analysed. The flow field and temperature distribution characteristics of hot well with metal mesh and different heat flow distribution schemes are compared and analysed to improve the operation economy and safety of steam turbine units

Design of Intelligent Customer Service Report System Based on Automatic Speech Recognition and Text Classification

In combination with features such as intensive labor and speech in the customer service report field, this paper discusses the design of a customer service report system based on artificial intelligence automatic speech recognition technology and big data text classification technology. The proposed system realizes functions like a flat IVR menu, quick transcription and input of work orders, dynamic tracking of failure hotspots, automatic classification and accumulation of the knowledge base, speech emotion detection and real-time supervision of service quality, and it can improve the user experience and reduce the labor strengths of customer service staff. The automatically accumulated knowledge base can further assist with feedback to resolve the difficult problem that the emerging intelligent network Q&A and intelligent robots rely on a manually summarized knowledge base

Development and Application of a Chemical Ionization Focusing Integrated Ionization Source TOFMS for Online Detection of OVOCs in the Atmosphere

Single photon ionization (SPI) based on vacuum ultraviolet (VUV) lamps has been extensively investigated and applied due to its clean mass spectra as a soft ionization method. However, the photon energy of 10.6 eV and photon flux of 1011 photons s−1 of a commercial VUV lamp limits its range of ionizable analytes as well as its sensitivity. This work designs a chemical ionization focusing integrated (CIFI) ionization source time-of-flight mass spectrometry (TOFMS) based on a VUV lamp for the detection of volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs). The photoelectrons obtained from the VUV lamp via the photoelectric effect ionized the oxygen and water in the air to obtain the reagent ions. The ion–molecule-reaction region (IMR) is constituted by a segmented quadrupole that radially focuses the ions using a radio-frequency electric field. This significantly enhances the yield and transport efficiency of the product ions leading to a great improvement in sensitivity. As a result, a 44-fold and 1154-fold increase in the signal response for benzene and pentanal were achieved, respectively. To verify the reliability of the ionization source, the linear correspondence and repeatability of benzene and pentanal were investigated. Satisfactory dynamic linearity was obtained in the mixing ratio range of 5–50 ppbv, and the relative standard deviation (RSD) of inter-day reached 3.91% and 6.26%, respectively. Finally, the CIFI−TOFMS was applied to the determination of OVOCs, and the LOD of 12 types of OVOCs reached the pptv level, indicating that the ionization source has the potential for accurate and sensitive online monitoring of atmospheric OVOCs

Analysis and Research on Flow Characteristics of Hot Water Pipeline System

Based on the CFD numerical simulation method, a pipe model was established to study the internal flow characteristics of two different specifications of hot water pipe system, and the related information of the flow field was obtained, such as the internal pressure, flow velocity and flow rate. The results showed that the smoother the pipeline transition was, the smaller the velocity uniformity coefficient would be, and the higher flow field uniformity means the smaller pressure and velocity fluctuations. Therefore, the pipeline vibration will be smaller, and the flow characteristics are greatly improved

Comparative Study on Flow Characteristics of Pipeline System Based on CFD

Based on the CFD numerical simulation method, this paper established a pipeline model to study the internal flow characteristics of three different combinations of hot water pipeline systems and thus obtained the flow field information such as pressure, flow rate, and flow rate inside the pipeline. The study results showed that the smoother the pipeline transition, the smaller the velocity uniformity coefficient; the higher the uniformity of the flow field, the smaller the pressure and velocity fluctuations, the smaller the resulting pipeline vibration. Besides, the flow characteristics have been greatly improved

An improved SDN-based fabric for flexible data center networks

Data centers play an important role with the fast growth of cloud computing used in our daily life. Traditional data center networks based on the fat-tree topology have their own drawbacks and limitations which prevent them from providing high performance to satisfy the increasing demand for cloud services. In this paper, we first design a new flexible network fabric for data center networks based on the concept of Software Defined Networks (SDN). Then, we also propose a simple yet efficient route calculation algorithm for this architecture. Simulation results show that the improved SDN-based switch fabric topology can support more hosts, provide more bandwidth and the shortest paths are found in a smaller amount of time