Human activities and global warming: a cointegration analysis

Using econometric tools for selecting I(1) and I(2) trends, we found the existence of static long-run steady-state and dynamic long-run steady-state relations between temperature and radiative forcing of solar irradiance and a set of three greenhouse gases series. Estimates of the adjustment coefficients indicate that temperature series is error correcting around 5-65% of the disequilibria each year, depending on the type of long-run relation. The estimates of the I(1) and I(2) trends indicate that they are driven by linear combinations of the three greenhouse gases and their loadings indicate strong impact on the temperature series. The equilibrium temperature change for a doubling of carbon dioxide is between 2.15 and 3.4 C, which is in agreement with past literature and the report of the IPCC in 2001 using 15 different general circulation models.Global warming; Radiative forcing; Cointegration; I(1) process; I(2) process; Unit roots

An Overview of Cryptography (Updated Version, 3 March 2016)

There are many aspects to security and many applications, ranging from secure commerce and payments to private communications and protecting passwords. One essential aspect for secure communications is that of cryptography...While cryptography is necessary for secure communications, it is not by itself sufficient. This paper describes the first of many steps necessary for better security in any number of situations. A much shorter, edited version of this paper appears in the 1999 edition of Handbook on Local Area Networks published by Auerbach in September 1998

Logging and Analysis of Internet of Things (IoT) Device Network Traffic and Power Consumption

An increasing number of devices, from coffee makers to electric kettles, are becoming connected to the Internet. These are all a part of the Internet of Things, or IoT. Each device generates unique network traffic and power consumption patterns. Until now, there has not been a comprehensive set of data that captures these traffic and power patterns. This thesis documents how we collected 10 to 15 weeks of network traffic and power consumption data from 15 different IoT devices and provides an analysis of a subset of 6 devices. Devices including an Amazon Echo Dot, Google Home Mini, and Google Chromecast were used on a regular basis and all of their network traffic and power consumption was logged to a MySQL database. The database currently contains 64 million packets and 71 gigabytes of data and is still growing in size as more data is collected 24/7 from each device. We show that it is possible to see when users are asking their smart speaker a question or whether the lights in their home are on or off based on power consumption and network traffic from the devices. These trends can be seen even if the data being sent is encrypted

Quality aspects of Internet telephony

Internet telephony has had a tremendous impact on how people communicate. Many now maintain contact using some form of Internet telephony. Therefore the motivation for this work has been to address the quality aspects of real-world Internet telephony for both fixed and wireless telecommunication. The focus has been on the quality aspects of voice communication, since poor quality leads often to user dissatisfaction. The scope of the work has been broad in order to address the main factors within IP-based voice communication. The first four chapters of this dissertation constitute the background material. The first chapter outlines where Internet telephony is deployed today. It also motivates the topics and techniques used in this research. The second chapter provides the background on Internet telephony including signalling, speech coding and voice Internetworking. The third chapter focuses solely on quality measures for packetised voice systems and finally the fourth chapter is devoted to the history of voice research. The appendix of this dissertation constitutes the research contributions. It includes an examination of the access network, focusing on how calls are multiplexed in wired and wireless systems. Subsequently in the wireless case, we consider how to handover calls from 802.11 networks to the cellular infrastructure. We then consider the Internet backbone where most of our work is devoted to measurements specifically for Internet telephony. The applications of these measurements have been estimating telephony arrival processes, measuring call quality, and quantifying the trend in Internet telephony quality over several years. We also consider the end systems, since they are responsible for reconstructing a voice stream given loss and delay constraints. Finally we estimate voice quality using the ITU proposal PESQ and the packet loss process. The main contribution of this work is a systematic examination of Internet telephony. We describe several methods to enable adaptable solutions for maintaining consistent voice quality. We have also found that relatively small technical changes can lead to substantial user quality improvements. A second contribution of this work is a suite of software tools designed to ascertain voice quality in IP networks. Some of these tools are in use within commercial systems today

Digital Signal Processing Leveraged for Intrusion Detection

This thesis describes the development and evaluation of a novel system called the Network Attack Characterization Tool (NACT). The NACT employs digital signal processing to detect network intrusions, by exploiting the Lomb-Scargle periodogram method to obtain a spectrum for sampled network traffic. The Lomb-Scargle method for generating a periodogram allows for the processing of unevenly sampled network data. This method for determining a periodogram has not yet been used for intrusion detection. The spectrum is examined to determine if features exist above a significance level chosen by the user. These features are considered an attack, triggering an alarm. Two traffic statistics are used to construct the time series over which the periodogram analysis is accomplished. These two statistics are packet inter-arrival time and payload size. The traffic source for this research is the 1999 DARPA intrusion detection data set developed by MIT Lincoln Laboratories. Three specific attacks from this data set are examined; the Processtable attack, the Dictionary attack and the Teardrop attack. Of the three attacks the NACT was able to detect the Processtable attack with an accuracy of 100%. The Dictionary and Teardrop attacks were also detected with 100% and 85% accuracies respectively. This success in detecting these attacks establishes that digital signal processing methods can be a successful technique for network intrusion detection

Energy Efficient Security Framework for Wireless Local Area Networks

Wireless networks are susceptible to network attacks due to their inherentvulnerabilities. The radio signal used in wireless transmission canarbitrarily propagate through walls and windows; thus a wireless networkperimeter is not exactly known. This leads them to be more vulnerable toattacks such as eavesdropping, message interception and modifications comparedto wired-line networks. Security services have been used as countermeasures toprevent such attacks, but they are used at the expense of resources that arescarce especially, where wireless devices have a very limited power budget.Hence, there is a need to provide security services that are energy efficient.In this dissertation, we propose an energy efficient security framework. Theframework aims at providing security services that take into account energyconsumption. We suggest three approaches to reduce the energy consumption ofsecurity protocols: replacement of standard security protocol primitives thatconsume high energy while maintaining the same security level, modification ofstandard security protocols appropriately, and a totally new design ofsecurity protocol where energy efficiency is the main focus. From ourobservation and study, we hypothesize that a higher level of energy savings isachievable if security services are provided in an adjustable manner. Wepropose an example tunable security or TuneSec system, which allows areasonably fine-grained security tuning to provide security services at thewireless link level in an adjustable manner.We apply the framework to several standard security protocols in wirelesslocal area networks and also evaluate their energy consumption performance.The first and second methods show improvements of up to 70% and 57% inenergy consumption compared to plain standard security protocols,respectively. The standard protocols can only offer fixed-level securityservices, and the methods applied do not change the security level. The thirdmethod shows further improvement compared to fixed-level security by reducing(about 6% to 40%) the energy consumed. This amount of energy saving can bevaried depending on the configuration and security requirements

A Vulnerability Assessment of the East Tennessee State University Administrative Computer Network.

A three phase audit of East Tennessee State University\u27s administrative computer network was conducted during Fall 2001, Spring 2002, and January 2004. Nmap and Nessus were used to collect the vulnerability data. Analysis discovered an average of 3.065 critical vulnerabilities per host with a low of 2.377 in Spring 2001 to a high of 3.694 in Fall 2001. The number of unpatched Windows operating system vulnerabilities, which accounted for over 75% of these critical vulnerabilities, strongly argues for the need of an automated patch deployment system for the approximately 3,000 Windows-based systems at ETSU

The development of a discovery and control environment for networked audio devices based on a study of current audio control protocols

This dissertation develops a standard device model for networked audio devices and introduces a novel discovery and control environment that uses the developed device model. The proposed standard device model is derived from a study of current audio control protocols. Both the functional capabilities and design principles of audio control protocols are investigated with an emphasis on Open Sound Control, SNMP and IEC-62379, AES64, CopperLan and UPnP. An abstract model of networked audio devices is developed, and the model is implemented in each of the previously mentioned control protocols. This model is also used within a novel discovery and control environment designed around a distributed associative memory termed an object space. This environment challenges the accepted notions of the functionality provided by a control protocol. The study concludes by comparing the salient features of the different control protocols encountered in this study. Different approaches to control protocol design are considered, and several design heuristics for control protocols are proposed