A Blockchain Based Certificate Revocation Scheme For Vehicular Communication Systems

Both the academy and industry believe that Intelligent Transportation System (ITS) would be achievable in one decade since modern vehicle and communication technologies advanced apace. Vehicular Communication System (VCS) introduces information technology to the ITS and aims to improve road safety and traffic efficiency. In recent year, security and privacy schemes in VCS are becoming important. However, recovery mechanisms to eliminate the negative effect of security and privacy attacks are still an important topic for research. Therefore, the certificate revocation scheme is considered as a feasible technique to prevent the system from potential attacks. The major challenge of the certificate revocation scheme is to achieve low-cost operation since the communication resources must be capable of carrying various applications apart from the security and privacy purposes. In this paper, we propose an efficient certificate revocation scheme in VCS. The Blockchain concept is introduced to simplify the network structure and distributed maintenance of the Certificate Revocation List (CRL). The proposed scheme embeds part of the certificate revocation functions within the security and privacy applications, aiming to reduce the communication overhead and shorten the processing time cost. Extensive simulations and analysis show the effectiveness and efficiency of the proposed scheme, in which the Blockchain structure costs fewer network resources and gives a more economic solution to against further cybercrime attacks

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions

Dynamic pseudonym management for privacy preservation in vehicular communication systems.

Research into the established area of Intelligent Transportation System (ITS) is still evolving and fast-moving fuelled in part by rapid changes in vehicular technologies and mobile communication network. A practical challenge is that many vehicular communication applications and services make use of the Basic Safety Messages that contain the vehicle location and other personal data. A popular way of dealing with this privacy issue is to utilise a pseudonym change scheme to protect the vehicle’s identity and location. However, many such schemes suffer from poor scalability and the certificate management difficulty raises with the number of pseudonyms generated and stored in the ITS system, casting doubt of the economic feasibility of such approaches. In this thesis, firstly, Cooperative Pseudonym Change Scheme (CPCS) for VCS is proposed for providing high level of anonymity. In this model, the Road Side Units (RSUs) is the key factor by storing generated pseudonym sets from the Trusted Authority (TA), then delivering sets of pseudonyms to vehicles which has similar context. Secondly a Decentralised Pseudonym Management System (DPMS) Using Distributed Ledger Technology is proposed to overcome limits that CPCS and most other pseudonym change schemes of low scalability and high cost of managing large numbers of pseudonym certificates in ITS. This scheme consists of pseudonym distribution and a shuffle operation, allowing the re-distribution and re-usage of existing pseudonyms by different vehicles. The results demonstrate that the proposed scheme achieves a better degree of anonymity and low request delay at a lower cost than existing schemes. Thirdly a Distributed Pseudonym Certificate Revocation Scheme (DPCRS) for VCS is proposed based on the framework that DPMS introduced. The proposed scheme embeds part of the certificate revocation functions within the security and privacy applications, aiming to reduce the communication overhead and shorten the processing time cost. Extensive simulations and analysis show the effectiveness and efficiency of the three proposed schemes

Skuldra-nacke exponering i monteringsarbete samt betydelsen av rationalisering

The main purpose of this thesis was to investigate the implications of different rationalization levels of assembly work on shoulder-neck exposure. Three levels were studied: (1) a Chinese Tayloristic system, (2) a Swedish Tayloristic system, and (3) an assembly workplace rationalization in Sweden according to 'modern' rationalization principles including ergonomic purposes. A laboratory study was carried out to compare different electromyography (EMG) normalization procedures. It was found that different upper trapezius EMG normalization procedures may give widely differing load estimations. Translations between occupational EMG results normalized by different procedures may only be made at a very approximate level. A cross-sectional epidemiological study was carried out among 1603 workers among ten different Chinese occupational groups with an aim of providing prevalence data of musculoskeletal disorders. The results showed that the 12-month prevalence of musculoskeletal disorders, particularly in the low back and shoulder-neck regions, was high at many Chinese workplaces. Large differences of the prevalence rates occurred between different occupations. A more detailed follow-up study on one Chinese assembly line showed that, in general, the ergonomic working condition was not satisfactory according to general ergonomic principles. This appeared to cause poor working postures (upper arm flexion and abduction larger than 30° during a large proportion of the assembly cycle) and high 'static' upper trapezius load (= 5% Maximal Voluntary Electrical activation -- MVE). Further examination revealed that the Chinese assembly line was not well balanced and the assembly line organization was sensitive to production irregularities. This caused frequent breaks (idle time) between assembly operations and reduced total exposure time to the assembly operations. Compared with the Chinese line, the Swedish Tayloristic line had better ergonomically designed work stations which implied improved working postures on the assemblers. However, EMG amplitudes of the right upper trapezius and infraspinatus muscles did not decrease. This may be explained by a reduced idle time on the Swedish line due to an improved industrial engineering (better line balancing and less sensitivity to production irregularities). This hypothesis was supported by a further analysis of the EMG data, which showed that the Swedish subjects had less muscle activity of low amplitudes (< 2% Maximal Voluntary Electrical activation -- MVE), which may correspond to the idle periods, compared with the Chinese subjects. In the 'modern' Swedish assembly workplace, the realized rationalization led to only minor changes in most exposure parameters. Several expected exposure improvements were not observed possibly because a number of planned initiatives were never implemented after a policy shift of the company's management. For example, multi-skills were not provided to all assembly operators so that no actual job rotations were possible between different assembly stations. Only a few non-assembly tasks were introduced into the new assembly system and the operators still spent the majority of their time on assembly tasks, with the result that an expected varied exposure pattern was not seen. Based on these findings, it is concluded that ergonomic measures on work station design improvements may play an important role in improving mechanical exposure of assembly work. However, industrial engineering measures may also influence the mechanical exposure. Therefore, ergonomic implications of rationalization as well as the ergonomic potential of 'modern' rationalization should be considered in future studies of rationalization

A lightweight authentication and privacy-preserving scheme for VANETs using TESLA and Bloom Filters

In Vehicular Ad hoc Networks (VANETs), broadcasted beacon messages are critical as most safety applications rely on them. However, the design of a secure broadcast authentication faces many security and privacy challenges as vehicles are vulnerable to active attacks and the revealing of location. In this paper, we propose a lightweight authentication scheme using Timed Efficient Stream Loss-Tolerant Authentication (TESLA) scheme and Bloom Filters that not only prevents active attacks but also adds a privacy-preserving feature to make the scheme have better performance. Simulation results indicate the scheme outperforms the existing schemes in terms of verification time and the level of anonymity. Keywords: Bloom Filters, Authentication, Privacy, VANETs, TESL

Comprehensive evaluation of the effect of five sterilization methods on the quality of black carrot juice based on PCA, TOPSIS and GRA models

The effect of thermal pasteurization (TP), high temperature long time (HTLT), ultra-high temperature instantaneous (UHT), high hydrostatic pressure (HHP) and thermosonication (TS) sterilization on the physicochemical, sensory and functional properties of black carrot juice (BCJ) were studied. And for the first time, the comprehensive quality of sterilized BCJ was quantified by mathematical modeling. UHT was the least suitable sterilization method for BCJ resulting from the most severe deterioration in functional properties. TS had adverse effects on sensory and physicochemical properties, but significantly increased the total flavonoids and anthocyanins contents (p < 0.05) and showed the strongest antioxidant activity, making it a nutritional high-value processing method. TP and HHP balanced the improvement of sensory properties and the retention of functional properties, which were the most suitable sterilization methods for BCJ. This study determined the optimal sterilization methods of BCJ, and provided a scientific solution for the screening of high quality processing methods

Genetic polymorphism and forensic application of 23 autosomal STR loci in the Han population of Panjin City, Liaoning Province, Northeastern China

Background Short tandem repeats (STRs) are consecutive repetition of a repeat motif and widely used in forensic medicine and human genetics because of their high polymorphism. Subjects and methods In the current study, 23 autosomal STR loci were genotyped from 1263 unrelated healthy individuals living in Panjin City, Liaoning Province, Northeastern China using the VeriFilerTM Express PCR Amplification Kit. The population comparison was performed between the Panjin Han population and the other relevant groups to further explore the structure of Panjin Han and its relationship with the other groups. Results The results found 316 alleles across the 23 STRs and the corresponding allelic frequencies ranged from 0.5198 to 0.0004. Except for D3S1358, TPOX, TH01, and D3S1358, all STR loci were highly polymorphic (PIC > 0.7), with the Penta E locus having the highest degree of polymorphism (0.9147). For population comparison, the exact test of population differentiation found that no significant difference was observed between the Panjin Han and the other Han populations, except for Guangdong Han and Jiangxi Han. Conclusion The Panjin Han population showed significant differences with the other ethnic groups in China (Bouyei, Dong, Hui, Miao, Tibetan, and Uygur) and the foreign ethnic groups

Security and Privacy in Location-Based Services for Vehicular and Mobile Communications: An Overview, Challenges and Countermeasures

Location-based Services (LBS) have gained popularity as a result of the advances in mobile and communication technologies. LBS provide users with relevant information based on their location. In spite of the desirable features provided by LBS, the geographic location of users are not adequately protected. Location privacy is one of the major challenges in vehicular and mobile networks. In this article, we analyse the security and privacy requirements for LBS in vehicular and mobile networks. Specifically, this paper covers privacy enhancing technologies and cryptographic approaches that provide location privacy in vehicular and mobile networks. The different approaches proposed in literature are compared and open research areas are identified

Antitussive and Anti-inflammatory Dual-active Agents Developed from Natural Product Lead Compound 1-Methylhydantoin

Natural products play an important role in drug discovery. This work employed a natural product 1-methylhydantoin as the lead compound to develop novel dual-active drugs. 1-Methylhydantoin was isolated from Oviductus Ranae, which is a traditional Chinese medicine that has been used for tussive and inflammation treatment for a long time. An in silico study screened the more active 1-methylhydantoin derivatives. Antitussive assessment indicated that the newly synthesized agent had similar bioactivity with the natural product. An anti-inflammatory model used xylene induced ear edema model. At the same dosage (100 mg/Kg), the newly prepared agent had an inhibition rate 53.18% which was much higher than that of the lead compound (22.69%). The results might be ascribed to the cyclooxygenases-1 (COX-1) and cyclooxygenases-2 (COX-2) selectivity, and the fitness of the compound, and the binding pocket. The anti-particulate matter (PM 2.5) acute pneumonia was evaluated through an in vivo model constructed by nasal instillation with PM 2.5 suspension. The results of the above models suggested that this novel agent had remarkable antitussive, anti-inflammatory, and anti-PM 2.5 acute pneumonia activities