Human sound localisation cues and their relation to morphology

Binaural soundfield reproduction has the potential to create realistic threedimensional sound scenes using only a pair of normal headphones. Possible applications for binaural audio abound in, for example, the music, mobile communications and games industries. A problem exists, however, in that the head-related transfer functions (HRTFs) which inform our spatial perception of sound are affected by variations in human morphology, particularly in the shape of the external ear. It has been observed that HRTFs simply based on some kind of average head shape generally result in poor elevation perception, weak externalisation and spectrally distorted sound images. Hence, HRTFs are needed which accommodate these individual differences. Direct acoustic measurement and acoustic simulations based on morphological measurements are obvious means of obtaining individualised HRTFs, but both methods suffer from high cost and practical difficulties. The lack of a viable measurement method is currently hindering the widespread adoption of binaural technologies. There have been many attempts to estimate individualised HTRFs effectively and cheaply using easily obtainable morphological descriptors, but due to an inadequate understanding of the complex acoustic effects created in particular by the external ear, success has been limited. The work presented in this thesis strengthens current understanding in several ways and provides a promising route towards improved HRTF estimation. The way HRTFs vary as a function of direction is compared with localisation acuity to help pinpoint spectral features which contribute to spatial perception. 50 subjects have been scanned using magnetic resonance imaging to capture their head and pinna morphologies, and HRTFs for the same group have been measured acoustically. To make analysis of this extensive data tractable, and so reveal the mapping between the morphological and acoustic domains, a parametric method for efficiently describing head morphology has been developed. Finally, a novel technique, referred to as morphoacoustic perturbation analysis (MPA), is described. We demonstrate how MPA allows the morphological origin of a variety of HRTF spectral features to be identified

Security and Privacy for Modern Wireless Communication Systems

The aim of this reprint focuses on the latest protocol research, software/hardware development and implementation, and system architecture design in addressing emerging security and privacy issues for modern wireless communication networks. Relevant topics include, but are not limited to, the following: deep-learning-based security and privacy design; covert communications; information-theoretical foundations for advanced security and privacy techniques; lightweight cryptography for power constrained networks; physical layer key generation; prototypes and testbeds for security and privacy solutions; encryption and decryption algorithm for low-latency constrained networks; security protocols for modern wireless communication networks; network intrusion detection; physical layer design with security consideration; anonymity in data transmission; vulnerabilities in security and privacy in modern wireless communication networks; challenges of security and privacy in node–edge–cloud computation; security and privacy design for low-power wide-area IoT networks; security and privacy design for vehicle networks; security and privacy design for underwater communications networks

Internet of Underwater Things and Big Marine Data Analytics -- A Comprehensive Survey

The Internet of Underwater Things (IoUT) is an emerging communication ecosystem developed for connecting underwater objects in maritime and underwater environments. The IoUT technology is intricately linked with intelligent boats and ships, smart shores and oceans, automatic marine transportations, positioning and navigation, underwater exploration, disaster prediction and prevention, as well as with intelligent monitoring and security. The IoUT has an influence at various scales ranging from a small scientific observatory, to a midsized harbor, and to covering global oceanic trade. The network architecture of IoUT is intrinsically heterogeneous and should be sufficiently resilient to operate in harsh environments. This creates major challenges in terms of underwater communications, whilst relying on limited energy resources. Additionally, the volume, velocity, and variety of data produced by sensors, hydrophones, and cameras in IoUT is enormous, giving rise to the concept of Big Marine Data (BMD), which has its own processing challenges. Hence, conventional data processing techniques will falter, and bespoke Machine Learning (ML) solutions have to be employed for automatically learning the specific BMD behavior and features facilitating knowledge extraction and decision support. The motivation of this paper is to comprehensively survey the IoUT, BMD, and their synthesis. It also aims for exploring the nexus of BMD with ML. We set out from underwater data collection and then discuss the family of IoUT data communication techniques with an emphasis on the state-of-the-art research challenges. We then review the suite of ML solutions suitable for BMD handling and analytics. We treat the subject deductively from an educational perspective, critically appraising the material surveyed.Comment: 54 pages, 11 figures, 19 tables, IEEE Communications Surveys & Tutorials, peer-reviewed academic journa

NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

Large-scale Wireless Local-area Network Measurement and Privacy Analysis

The edge of the Internet is increasingly becoming wireless. Understanding the wireless edge is therefore important for understanding the performance and security aspects of the Internet experience. This need is especially necessary for enterprise-wide wireless local-area networks (WLANs) as organizations increasingly depend on WLANs for mission- critical tasks. To study a live production WLAN, especially a large-scale network, is a difficult undertaking. Two fundamental difficulties involved are (1) building a scalable network measurement infrastructure to collect traces from a large-scale production WLAN, and (2) preserving user privacy while sharing these collected traces to the network research community. In this dissertation, we present our experience in designing and implementing one of the largest distributed WLAN measurement systems in the United States, the Dartmouth Internet Security Testbed (DIST), with a particular focus on our solutions to the challenges of efficiency, scalability, and security. We also present an extensive evaluation of the DIST system. To understand the severity of some potential trace-sharing risks for an enterprise-wide large-scale wireless network, we conduct privacy analysis on one kind of wireless network traces, a user-association log, collected from a large-scale WLAN. We introduce a machine-learning based approach that can extract and quantify sensitive information from a user-association log, even though it is sanitized. Finally, we present a case study that evaluates the tradeoff between utility and privacy on WLAN trace sanitization

Advanced Network Inference Techniques Based on Network Protocol Stack Information Leaks

Side channels are channels of implicit information flow that can be used to find out information that is not allowed to flow through explicit channels. This thesis focuses on network side channels, where information flow occurs in the TCP/IP network stack implementations of operating systems. I will describe three new types of idle scans: a SYN backlog idle scan, a RST rate-limit idle scan, and a hybrid idle scan. Idle scans are special types of side channels that are designed to help someone performing a network measurement (typically an attacker or a researcher) to infer something about the network that they are not otherwise able to see from their vantage point. The thesis that this dissertation tests is this: because modern network stacks have shared resources, there is a wealth of information that can be inferred off-path by both attackers and Internet measurement researchers. With respect to attackers, no matter how carefully the security model is designed, the non-interference property is unlikely to hold, i.e., an attacker can easily find side channels of information flow to learn about the network from the perspective of the system remotely. One suggestion is that trust relationships for using resources be made explicit all the way down to IP layer with the goal of dividing resources and removing sharendess to prevent advanced network reconnaissance. With respect to Internet measurement researchers, in this dissertation I show that the information flow is rich enough to test connectivity between two arbitrary hosts on the Internet and even infer in which direction any blocking is occurring. To explore this thesis, I present three research efforts: --- First, I modeled a typical TCP/IP network stack. The building process for this modeling effort led to the discovery of two new idles scans: a SYN backlog idle scan and a RST rate-limited idle scan. The SYN backlog scan is particularly interesting because it does not require whoever is performing the measurements (i.e., the attacker or researcher) to send any packets to the victim (or target) at all. --- Second, I developed a hybrid idle scan that combines elements of the SYN backlog idle scan with Antirez\u27s original IPID-based idle scan. This scan enables researchers to test whether two arbitrary machines in the world are able to communicate via TCP/IP, and, if not, in which direction the communication is being prevented. To test the efficacy of the hybrid idle scan, I tested three different kinds of servers (Tor bridges, Tor directory servers, and normal web servers) both inside and outside China. The results were congruent with published understandings of global Internet censorship, demonstrating that the hybrid idle scan is effective. --- Third, I applied the hybrid idle scan to the difficult problem of characterizing inconsistencies in the Great Firewall of China (GFW), which is the largest firewall in the world. This effort resolved many open questions about the GFW. The result of my dissertation work is an effective method for measuring Internet censorship around the world, without requiring any kind of distributed measurement platform or access to any of the machines that connectivity is tested to or from

Modeling Deception for Cyber Security

In the era of software-intensive, smart and connected systems, the growing power and so- phistication of cyber attacks poses increasing challenges to software security. The reactive posture of traditional security mechanisms, such as anti-virus and intrusion detection systems, has not been sufficient to combat a wide range of advanced persistent threats that currently jeopardize systems operation. To mitigate these extant threats, more ac- tive defensive approaches are necessary. Such approaches rely on the concept of actively hindering and deceiving attackers. Deceptive techniques allow for additional defense by thwarting attackers’ advances through the manipulation of their perceptions. Manipu- lation is achieved through the use of deceitful responses, feints, misdirection, and other falsehoods in a system. Of course, such deception mechanisms may result in side-effects that must be handled. Current methods for planning deception chiefly portray attempts to bridge military deception to cyber deception, providing only high-level instructions that largely ignore deception as part of the software security development life cycle. Con- sequently, little practical guidance is provided on how to engineering deception-based techniques for defense. This PhD thesis contributes with a systematic approach to specify and design cyber deception requirements, tactics, and strategies. This deception approach consists of (i) a multi-paradigm modeling for representing deception requirements, tac- tics, and strategies, (ii) a reference architecture to support the integration of deception strategies into system operation, and (iii) a method to guide engineers in deception mod- eling. A tool prototype, a case study, and an experimental evaluation show encouraging results for the application of the approach in practice. Finally, a conceptual coverage map- ping was developed to assess the expressivity of the deception modeling language created.Na era digital o crescente poder e sofisticação dos ataques cibernéticos apresenta constan- tes desafios para a segurança do software. A postura reativa dos mecanismos tradicionais de segurança, como os sistemas antivírus e de detecção de intrusão, não têm sido suficien- tes para combater a ampla gama de ameaças que comprometem a operação dos sistemas de software actuais. Para mitigar estas ameaças são necessárias abordagens ativas de defesa. Tais abordagens baseiam-se na ideia de adicionar mecanismos para enganar os adversários (do inglês deception). As técnicas de enganação (em português, "ato ou efeito de enganar, de induzir em erro; artimanha usada para iludir") contribuem para a defesa frustrando o avanço dos atacantes por manipulação das suas perceções. A manipula- ção é conseguida através de respostas enganadoras, de "fintas", ou indicações erróneas e outras falsidades adicionadas intencionalmente num sistema. É claro que esses meca- nismos de enganação podem resultar em efeitos colaterais que devem ser tratados. Os métodos atuais usados para enganar um atacante inspiram-se fundamentalmente nas técnicas da área militar, fornecendo apenas instruções de alto nível que ignoram, em grande parte, a enganação como parte do ciclo de vida do desenvolvimento de software seguro. Consequentemente, há poucas referências práticas em como gerar técnicas de defesa baseadas em enganação. Esta tese de doutoramento contribui com uma aborda- gem sistemática para especificar e desenhar requisitos, táticas e estratégias de enganação cibernéticas. Esta abordagem é composta por (i) uma modelação multi-paradigma para re- presentar requisitos, táticas e estratégias de enganação, (ii) uma arquitetura de referência para apoiar a integração de estratégias de enganação na operação dum sistema, e (iii) um método para orientar os engenheiros na modelação de enganação. Uma ferramenta protó- tipo, um estudo de caso e uma avaliação experimental mostram resultados encorajadores para a aplicação da abordagem na prática. Finalmente, a expressividade da linguagem de modelação de enganação é avaliada por um mapeamento de cobertura de conceitos

Sandpile-simulation-based graph data model for MVD generative design of shield tunnel lining using information entropy

BIM standard development is central to the performance and behavior of BIM model application across transmission, visualization, and information management perspectives. Tremendous effort has been made to ease the implementation of IFC data model in practice. Yet, the complexity of IFC data model hurdles the implementation of the import and export functionality by software vendors. To overcome this, buildingSMART introduced the concept of Model View Definitions to define which parts of an IFC data model need to be implemented for a specific data exchange scenario. With such, the certification of compatibility for software products with the IFC standard is formed. The Model View Definition is use case orientated to determine whether the specific information should be included in an IFC partial model. With the creation of ad-hoc, project-specific Exchange Requirements increasing, associated MVD development requires much more work to incorporate standard development. To resolve this issue, this paper attempts to exploit the potential of information entropy which has proven itself extremely crucial in many other industries in terms of information management, and then integrates it with sandpile simulation to propose a Top-down hierarchy to structure as well as interpret IFC partial model via Model View Definition. The proposed information entropy shifted MVD development approach would manage to unify the MVD development process that enables the reduction on confusion for various end users, specific organization, or project needs. Moreover, to better translate the BIM standard topology into sandpile simulations, a new notion system is proposed. Sandpile simulations are further implemented to prove their applicability, during the simulation, self-organized criticality is identified, and the existence of chaos is observed