Towards secure message systems

Message systems, which transfer information from sender to recipient via communication networks, are indispensable to our modern society. The enormous user base of message systems and their critical role in information delivery make it the top priority to secure message systems. This dissertation focuses on securing the two most representative and dominant messages systems---e-mail and instant messaging (IM)---from two complementary aspects: defending against unwanted messages and ensuring reliable delivery of wanted messages.;To curtail unwanted messages and protect e-mail and instant messaging users, this dissertation proposes two mechanisms DBSpam and HoneyIM, which can effectively thwart e-mail spam laundering and foil malicious instant message spreading, respectively. DBSpam exploits the distinct characteristics of connection correlation and packet symmetry embedded in the behavior of spam laundering and utilizes a simple statistical method, Sequential Probability Ratio Test, to detect and break spam laundering activities inside a customer network in a timely manner. The experimental results demonstrate that DBSpam is effective in quickly and accurately capturing and suppressing e-mail spam laundering activities and is capable of coping with high speed network traffic. HoneyIM leverages the inherent characteristic of spreading of IM malware and applies the honey-pot technology to the detection of malicious instant messages. More specifically, HoneyIM uses decoy accounts in normal users\u27 contact lists as honey-pots to capture malicious messages sent by IM malware and suppresses the spread of malicious instant messages by performing network-wide blocking. The efficacy of HoneyIM has been validated through both simulations and real experiments.;To improve e-mail reliability, that is, prevent losses of wanted e-mail, this dissertation proposes a collaboration-based autonomous e-mail reputation system called CARE. CARE introduces inter-domain collaboration without central authority or third party and enables each e-mail service provider to independently build its reputation database, including frequently contacted and unacquainted sending domains, based on the local e-mail history and the information exchanged with other collaborating domains. The effectiveness of CARE on improving e-mail reliability has been validated through a number of experiments, including a comparison of two large e-mail log traces from two universities, a real experiment of DNS snooping on more than 36,000 domains, and extensive simulation experiments in a large-scale environment

Can Culture Lead to Export?Empirical Data on the Belt and Road Initiative

The B&R Initiative is a modernized and specific manifestation of China’s“going global”development strategy. It undertakes the historic mission of promoting communication and exchange between cultures and nations, but also has a positive role in the development of international economy and trade relations. As a messenger of the essence of Chinese culture, Confucius Institutes have a positive impact on the development of Asian and world civilizations. Using Difference-in-Difference estimation methods to study the statistical data from the countries along the B&R routes, this paper examines the relationship between cultural and commodity outputs and comes to the following conclusions: Cultural output is an important factor in increasing commodity exports; Confucius Institutes help increase China’s exports to the countries along the B&R routes; and the growth in cultural exports shows regional differences, hysteresis, and fluctuations. As China’s cultural outputs are still at an immature stage, their promotional effects on exports are unstable. In the future, China should further standardize its management and operational systems and accelerate the Confucius Institutes’content-based development to enhance the effects of cultural outputs in increasing exports, boosting China’s soft powerThe B&R Initiative is a modernized and specific manifestation of China’s“going global”development strategy. It undertakes the historic mission of promoting communication and exchange between cultures and nations, but also has a positive role in the development of international economy and trade relations. As a messenger of the essence of Chinese culture, Confucius Institutes have a positive impact on the development of Asian and world civilizations. Using Difference-in-Difference estimation methods to study the statistical data from the countries along the B&R routes, this paper examines the relationship between cultural and commodity outputs and comes to the following conclusions: Cultural output is an important factor in increasing commodity exports; Confucius Institutes help increase China’s exports to the countries along the B&R routes; and the growth in cultural exports shows regional differences, hysteresis, and fluctuations. As China’s cultural outputs are still at an immature stage, their promotional effects on exports are unstable. In the future, China should further standardize its management and operational systems and accelerate the Confucius Institutes’content-based development to enhance the effects of cultural outputs in increasing exports, boosting China’s soft powe

Secure Decentralized IoT Service Platform using Consortium Blockchain

Blockchain technology has gained increasing popularity in the research of Internet of Things (IoT) systems in the past decade. As a distributed and immutable ledger secured by strong cryptography algorithms, the blockchain brings a new perspective to secure IoT systems. Many studies have been devoted to integrating blockchain into IoT device management, access control, data integrity, security, and privacy. In comparison, the blockchain-facilitated IoT communication is much less studied. Nonetheless, we see the potential of blockchain in decentralizing and securing IoT communications. This paper proposes an innovative IoT service platform powered by consortium blockchain technology. The presented solution abstracts machine-to-machine (M2M) and human-to-machine (H2M) communications into services provided by IoT devices. Then, it materializes data exchange of the IoT network through smart contracts and blockchain transactions. Additionally, we introduce the auxiliary storage layer to the proposed platform to address various data storage requirements. Our proof-of-concept implementation is tested against various workloads and connection sizes under different block configurations to evaluate the platform's transaction throughput, latency, and hardware utilization. The experiment results demonstrate that our solution can maintain high performance under most testing scenarios and provide valuable insights on optimizing the blockchain configuration to achieve the best performance

Evaluation and Analysis of Distributed Graph-Parallel Processing Frameworks

A number of graph-parallel processing frameworks have been proposed to address the needs of processing complex and large-scale graph structured datasets in recent years. Although significant performance improvement made by those frameworks were reported, comparative advantages of each of these frameworks over the others have not been fully studied, which impedes the best utilization of those frameworks for a specific graph computing task and setting. In this work, we conducted a comparison study on parallel processing systems for large-scale graph computations in a systematic manner, aiming to reveal the characteristics of those systems in performing common graph algorithms with real-world datasets on the same ground. We selected three popular graph-parallel processing frameworks (Giraph, GPS and GraphLab) for the study and also include a representative general data-parallel computing system— Spark—in the comparison in order to understand how well a general data-parallel system can run graph problems. We applied basic performance metrics measuring speed, resource utilization, and scalability to answer a basic question of which graph-parallel processing platform is better suited for what applications and datasets. Three widely-used graph algorithms— clustering coefficient, shortest path length, and PageRank score—were used for benchmarking on the targeted computing systems.We ran those algorithms against three real world network datasets with diverse characteristics and scales on a research cluster and have obtained a number of interesting observations. For instance, all evaluated systems showed poor scalability (i.e., the runtime increases with more computing nodes) with small datasets likely due to communication overhead. Further, out of the evaluated graphparallel computing platforms, PowerGraph consistently exhibits better performance than others

Activity-Based Household Travel Survey Through Smartphone Apps in Tennessee

RES 2020-19Activity-based household travel surveys (HTS) are one of primary data sources for many research fields at Tennessee Department of Transportation (TDOT). Traditional HTS methods are often costly, time-consuming, less scalable, and difficult to achieve high quality and accuracy. Recent years have witnessed a fast-growing interest in conducting HTS through smartphone apps to address survey issues and improve quality of collected survey data. A research project on activity based HTS through smartphone apps for both Android and iOS has been performed. The overarching goal of this research project is to develop an effective, economical, scalable HTS solution for TDOT. To achieve this goal, with the guidance and support from TDOT, the research team has 1) developed a smartphone-based effective, scalable, and secure application for household travel surveys that can span from days to months, 2) integrated fine-grained location information in submitted travel data by leveraging smartphone built-in sensor technologies, and 3) validated the developed HTS application by running a pilot HTS with the application. The pilot survey lasted three months. During the survey study, over 800 people downloaded the mobile apps and registered an account. Over 200 participants have been given a reward for completing the survey. Over 1,800 trips were submitted by those rewarded participants. This research project brings the following benefits to TDOT: 1) A tested, comprehensive smartphone app based HTS solution, 2) Important findings about smartphone app based HTS gained from running the pilot survey study, and 3) An anonymized survey dataset for research exploration obtained from the pilot survey study. A number of key findings as well as recommendations are also generated from this research project and they will help TDOT conduct HTS more effectively and generate more research results in the future

There is a Will, There is a Way: A New Mechanism for Traffic Control Based on

Abstract-Traffic light is regarded as one of the most effective ways to alleviate traffic congestion and carbon emission problems. However, traditional traffic light cannot meet the challenges in traffic regulation posed by the fast growing number of vehicles and increasing complexity of road conditions. In this paper, we propose a dynamic traffic regulation method based on virtual traffic light (VTL) for Vehicle Ad Hoc Network (VANET). In our framework, each vehicle can express its "will"-the desire of moving forwardand share among one another its "will"-value and related traffic information at a traffic light controlled intersection. Based on the traffic information collected in real time, the virtual traffic light in our scheme can be adaptive to the changing environment. We conducted a number of simulation experiments with different scenarios using network simulator NS3 combined with traffic simulator SUMO. The results demonstrate the viability of our solution in reducing waiting time and improving the traffic efficiency

Controllable ingestion and release of guest components driven by interfacial molecular orientation of host liquid crystal droplets

Controllable construction and manipulation of artificial multi-compartmental structures are crucial in understanding and imitating smart molecular elements such as biological cells and on-demand delivery systems. Here, we report a liquid crystal droplet (LCD) based three-dimensional system for controllable and reversible ingestion and release of guest aqueous droplets (GADs). Induced by interfacial thermodynamic fluctuation and internal topological defect, microscale LCDs with perpendicular anchoring condition at the interface would spontaneously ingest external components from the surroundings and transform them as radially assembled tiny GADs inside LCDs. Landau–de Gennes free-energy model is applied to describe and explain the assembly dynamics and morphologies of these tiny GADs, which presents a good agreement with experimental observations. Furthermore, the release of these ingested GADs can be actively triggered by changing the anchoring conditions at the interface of LCDs. Since those ingestion and release processes are controllable and happen very gently at room temperature and neutral pH environment without extra energy input, these microscale LCDs are very prospective to provide a unique and viable route for constructing hierarchical 3D structures with tunable components and compartments

Effects of BIS-MEP on Reversing Amyloid Plaque Deposition and Spatial Learning and Memory Impairments in a Mouse Model of β-Amyloid Peptide- and Ibotenic Acid-Induced Alzheimer’s Disease

Alzheimer’s disease (AD) is the main type of dementia and is characterized by progressive memory loss and a notable decrease in cholinergic neuron activity. As classic drugs currently used in the clinic, acetylcholinesterase inhibitors (AChEIs) restore acetylcholine levels and relieve the symptoms of AD, but are insufficient at delaying the onset of AD. Based on the multi-target-directed ligand (MTDL) strategy, bis-(-)-nor-meptazinol (BIS-MEP) was developed as a multi-target AChEI that mainly targets AChE catalysis and the β-amyloid (Aβ) aggregation process. In this study, we bilaterally injected Aβ oligomers and ibotenic acid (IBO) into the hippocampus of ICR mice and then subcutaneously injected mice with BIS-MEP to investigate its therapeutic effects and underlying mechanisms. According to the results from the Morris water maze test, BIS-MEP significantly improved the spatial learning and memory impairments in AD model mice. Compared with the vehicle control, the BIS-MEP treatment obviously inhibited the AChE activity in the mouse brain, consistent with the findings from the behavioral tests. The BIS-MEP treatment also significantly reduced the Aβ plaque area in both the hippocampus and cortex, suggesting that BIS-MEP represents a direct intervention for AD pathology. Additionally, the immunohistochemistry and ELISA results revealed that microglia (ionized calcium-binding adapter molecule 1, IBA1) and astrocyte (Glial fibrillary acidic protein, GFAP) activation and the secretion of relevant inflammatory factors (TNFα and IL-6) induced by Aβ were decreased by the BIS-MEP treatment. Furthermore, BIS-MEP showed more advantages than donepezil (an approved AChEI) as an Aβ intervention. Based on our findings, BIS-MEP improved spatial learning and memory deficits in AD mice by regulating acetylcholinesterase activity, Aβ deposition and the inflammatory response in the brain

The impact of “The Belt and Road Initiative” on the Competitiveness of the Construction industry of China

Improving the competitiveness of the construction industry is an important measure for developing countries. Xi Jinping put forward the “Belt and Road” initiative (BRI) in 2013, which is a comprehensive opening strategy. Not only has it strengthened trade development and opened up new markets for China, but it has also promoted the development of China’s construction industry(CCI). In addition to this, it is conducive to cultural exchanges, market investment, and even infrastructure construction between China and the world. The target of this study is to understand the impact of the “BRI” and to explore the impact of the “BRI” on the competitiveness of “CCI”. Porter's diamond model is used as a theoretical framework to analyze the market environment in China. Through reading relevant excellent literature, consulting professors and researchers to collect powerful data, qualitative method is used to explore the data. The results show that after the implementation of the “BRI”, China's market is more open and the construction industry has been developed. China's gdp, ppp, economic and trade development ; the improvement of Infrastructure technologies; the improvement of living standards. It is also important to note that strong government support for the “BRI” plays a key role. At the same time, further research on the “BRI” will help to explore how it enhances the competitiveness of “CCI”