<p>With the increased use of social media as a marketing tool, marketing strategies and the way brands communicate with customers is changing. Due to its low cost and characteristic short length of messages, Twitter is an especially beneficial marketing tool. Twitter is free and consists of making posts that are easy to compose and easy to consume, which makes it an ideal way for companies, such as startups, to reach customers without having to use many resources. However, companies should be strategic in their use of Twitter and no data exists on the best practices for startup companies as they develop Twitter marketing plans. This study sought to address this issue and explored different methods for engaging followers and which of these methods were the most effective for technology-oriented startups to use. A content analysis revealed that engagement tools, such as media, hashtags, URLs, and mentions serve their intended purpose for tech startups and were related to engagement. However, using conversational, two-way communication, as suggested by marketing companies and literature, proved to not be positively related to engagement rates. One-way, promotional language that is typically advised against was more related to higher engagement. Thus, startup tech companies should continue to prioritize engaging followers with engagement tools but should focus on non-conversational topics, such as their products, events, news, and updates.</p>

In this work, the problem of relay selection and resource power allocation in one- way and two-way cognitive relay networks using half duplex channels with different relaying protocols is investigated. Optimization problems for both single and multiple relay selection that maximize the sum rate of the secondary network without degrading the quality of service of the primary network by respecting a tolerated interference threshold were formulated. Single relay selection and optimal power allocation for two-way relaying cognitive radio networks using decode-and-forward and amplify-and-forward protocols were studied. Dual decomposition and subgradient methods were used to find the optimal power allocation. The transmission process to exchange two different messages between two transceivers for two-way relaying technique takes place in two time slots. In the first slot, the transceivers transmit their signals simultaneously to the relay. Then, during the second slot the relay broadcasts its signal to the terminals. Moreover, improvement of both spectral and energy efficiency can be achieved compared with the one-way relaying technique. As an extension, a multiple relay selection for both one-way and two-way relaying under cognitive radio scenario using amplify-and-forward were discussed. A strong optimization tool based on genetic and iterative algorithms was employed to solve the 
formulated optimization problems for both single and multiple relay selection, where discrete relay power levels were considered. Simulation results show that the practical and low-complexity heuristic approaches achieve almost the same performance of the optimal relay selection schemes either with discrete or continuous power distributions while providing a considerable saving in terms of computational complexity.

This dissertation explores the development of America’s infantry forces between 1918-1945. While doing so, it challenges and complicates the traditional narrative that highlights the fierceness of the rivalry between the U.S. Army and Marine Corps. During the First World War, both commissioned and enlisted Marines attended U.S. Army schools and served within Army combat formations, which brought the two closer together than ever before. Both services became bonded by a common warfighting paradigm, or way of battle, that centered upon the infantry as the dominant combat arm. All other arms and services were subordinated to the needs and requirements of the infantry. Intelligent initiative, fire and maneuver by the smallest units, penetrating hostile defenses while bypassing strong points, and aggressive, not reckless, leadership were all salient characteristics of that shared infantry way of battle. After World War I, Army and Marine officers constructed similar intellectual proposals concerning the ways to fight the next war. Although there were differences in organizational culture, the two were more alike in their respective values systems than historians have realized. There was mutual admiration, and targeted attempts to replicate each other’s combat thinking and spirit. They prepared for battle by observing each other’s doctrine, and sharing each other’s conception of modern combat. When preparation turned to execution in World War II, they created solutions for battlefield problems that evolved from their near-identical way of battle. At the conclusion of the war, the common bonds between the Army and Marine Corps were all but forgotten. This, ultimately, led to increased friction during the Congressional defense unification battles in 1946. / History

The widespread application of wireless services and the requirements of ubiquitous access have recently triggered rapidly booming energy consumption in wireless communications networks. Such escalation of energy consumption in wireless networks causes high operational expenditure from electricity bills for operators, unsatisfactory user experience due to limited battery capacity of wireless devices, and a large amount of greenhouse gas emission. Green radio (GR), which emphasizes both energy efficiency (EE) and spectral efficiency (SE), has been proposed as an effective solution and is becoming the mainstream for future wireless network design. Unfortunately, EE and SE do not always coincide and may even sometimes conflict. In this dissertation, we focus on energy-efficient transmission and resource allocation techniques for orthogonal frequency division multiple access (OFDMA) networks and the joint energy-efficient design of OFDMA and other promising wireless communications techniques, such as cognitive radio (CR) and two-way relay. Firstly, we investigate the principles of energy-efficient design for pure OFDMA networks. As the first step, we study the fundamental interrelationship between EE and SE in downlink OFDMA networks and analyze the impacts of channel gain and circuit power on the EE-SE relationship. We establish a general EE-SE optimization framework, where the overall EE, SE and per-user quality-of-service (QoS) are all considered. Under this framework, we find that EE is quasiconcave in SE and decreases with SE when SE is large enough. These findings are very helpful guidelines for designing energy- and spectral-efficient OFDMA. To facilitate the application of energy-efficient resource allocation, we then investigate the energy-efficient resource allocation in both downlink and uplink OFDMA networks. For the downlink transmission, the generalized EE is maximized while for the uplink case the minimum individual EE is maximized, both under prescribed per-user minimum data rate requirements. For both transmission scenarios, we first provide the optimal solution and then develop an computationally efficient suboptimal approach by exploring the inherent structure and property of the energy-efficient design. Then we study energy-efficient design in downlink OFDMA networks with effective capacity-based delay provisioning for delay-sensitive traffic. By integrating information theory with the concept of effective capacity, we formulate and solve an EE optimization problem with statistical delay provisioning. We also analyze the tradeoff between EE and delay, the relationship between spectral-efficient and energy-efficient designs, and the impact of system parameters, including circuit power and delay exponents, on the overall performance. Secondly, we consider joint energy-efficient design of OFDMA and CR and two-way relay, respectively, to further enhance the EE and SE of wireless networks. We study energy-efficient opportunistic spectrum access strategies for an OFDMA-based CR network with multiple secondary users (SUs). Both worst EE and average EE of the SUs are considered and optimized subject to constraints including maximum transmit power and maximum interference to primary user (PU) system. For both cases, we first find the optimal solution and then propose a low-complexity suboptimal alternative. The results show that the energy-efficient CR strategies significantly boost EE compared with the conventional spectral-efficient CR ones while the low-complexity suboptimal approaches can well balance the performance and complexity. Then we study energy-efficient resource allocation for OFDMA-based two-way relay, which aims at maximizing the aggregated EE utility while provisioning proportional fairness in EE among different terminal pairs. Different from most exist energy-efficient design, we consider a new circuit power model, where the dynamic circuit power is proportional to the number of active subcarrier. For low-complexity solution, we propose an EE-oriented sequential subchannel assignment policy and discover the sufficient condition for early termination of the sequential subchannel assignment without losing the EE optimality. It is found that the energy-efficient transmission does not necessarily make all the subcarriers active, which is another useful principle for practical energy-efficient system design.

This essay is about the change of the Swedish party Socialdemokraterna (S). It is a very current subject, since many political newspapers write about that the party moves into the political middle. Apparently the party is not what it used to be and that is what this essay will explore and analyze. My purpose is to explore what ideal type answers best to the Social democrats change. The chosen ideal types are neo-liberalism, reformist socialism and the third way. And the materials I use are political programs from 1990, 2001 and 2013. To achieve my purpose I’ve chosen two different methods: 1. Content analysis 2. Idea analysis. Each of them has been very useful and to combine them has proved efficient. The results of the content analysis show that the party in 2001 and 2013 is using a different vocabulary than in 1990. The results of the idea analysis are that the political program from 2013 show that some of the ideas are divergent. For example, a traditional social democratic value is that the working hours should be shorter. But in 2013, the party doesn’t suggest shorter working days and weeks.

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The effectiveness of an emergency response during an incident is often affected by the lack of information provided to the people within the situation about the current conditions. Deaths in large-scale fires are often likely to have been caused by delays in the occupants receiving relevant information on the fire and egress routes. This is why pre-movement behaviour, which is defined as the behaviour which occurs before an alarm is sounded and includes the activities which occur between the alarm sounding and the occupants beginning to move towards an exit, is believed to be generally more important to survival than the actual movement speed. It is the unpredictability and complexity of human behaviour that is the most influential factor on the success / failure of an evacuation plan. Unfortunately, evacuation plans rely on the use of purposely designed egress routes which often are not the common everyday exits. These specifically designed egress routes, which an engineer may assume will be used during an evacuation, are often ignored by occupants due to the lack of information and noticeable distinguishing features. Having occupants moving in directions away from these intended routes may result in the increasing possibility of occupants finding themselves in a dangerous situation, ultimately leading to potential loss of life. The value of a sensor-linked fire model has been demonstrated and the potential for interpretation of human behaviour shown. However, there are many challenges in representing and interpreting data on human behaviour. Within most emergency evacuation situations, occupants will often walk past emergency exits without using them and exit through the main entrance or main exit, as displayed during an evacuation experiment held in IKEA in 1996. Problems occur because occupants will rely on the familiar exits over the closest emergency exit, which could be potentially overcome by the use of an information driven evacuation system. The main function of the Information Driven Evacuation System or I.D.E.S. is to provide occupants with information on the most appropriate egress paths within a building based on the development of the fire and the movement of other occupants. The system is a combination of real-time sensor data, a prediction modelling tool and the information driven way-finding tools. However, as all three processes are independent systems, a central server will be required in order to ensure that all the different processes are speaking the same language and that the information from one system can be understood by another. of the components within the system interact with each other. The basis of the system will combine the use of sensors within a building and specific way-finding tools to give the I.D.E.S. the ability to change the information provided by the way-finding tools by having the sensors within the building interfacing with a computer server. This server will incorporate a modelling program that will have ability to assess the data gathered by the sensors, and use the servers “intelligence” (i.e. predicting capabilities) to alter the information provided by the way-finding tools. The server will also have the ability to use the sensor data to predict the development of the fire and the movement / behaviours of the occupants. The way-finding tools used within the I.D.E.S. would have the primary goal of relaying the information to the occupants within the building through the use of both audio (e.g. directional speakers) and visual (e.g. flashing lights) capabilities. Basic audio and visual tools are already used as common features of an evacuation plan [9] and include exit signage and alarm bell/sirens. The computer model used as part of the “intelligence” of the server will need to have predicative capabilities that incorporate information provided in real time. It is believed that the combination of these tools will be able to provide the occupants with the information required to evacuate the building in a safe and efficient way without causing confusion, thus reducing the possibility of stress and anxiety. However, the solution will only work if the combination of the tools, sensors and systems are able to be integrated into a central control panel that can be understood and used effectively by fire service and/or security staff. The following is the Chapter breakdown of the thesis: Chapter 1 discusses the nature of the problem that is to be addressed by the I.D.E.S. as well as the proposed solution and the overall concept of the system. Chapter 2 provides an overview of the system to be developed as part of this thesis, via a graphical overview as well discussing the current status of the system and an higher level summary. Chapters 3, 4 and 5 discusses the background research and information gathered on the current code requirements for an evacuation design, the current theories and completed research focusing on the human behaviour of occupants during an evacuation, and the development of computer modelling programs and their historical implementation. Chapter 6 focuses and describes the development of predictive modelling, the limitations that dictates the modelling process, the requirements of the I.D.E.S. modelling programme and a review of the possible programmes for their ability to be used as part of the system. Chapter 7 covers each of the three evacuation experimental series that were conducted as part of this thesis. The purpose of each of the relevant experiment is covered, the results gathered, the analysis of the research, and how the results influenced the development of the simulation methodology. Chapter 8 focuses on the development of the modelling programme, based on the experimental data gathered, and presents a feasibility study that will demonstrate how the system would work during a simulated real life evacuation based on the information gathered from the experiments using the updated CRISP program and the hypothetical installation of the system within an existing building, located in Auckland, New Zealand. The possible further evolution of the system is discussed in Chapter 10.

Relay techniques have the potential to enhance capacity and coverage of a wireless network. Due to rapidly increasing number of smart phone subscribers and high demand for data intensive multimedia applications, the useful radio spectrum is becoming a scarce resource. For this reason, two way relay network and cognitive radio technologies are required for better utilization of radio spectrum. Compared to the conventional one way relay network, both the uplink and the downlink can be served simultaneously using a two way relay network. Hence the effective bandwidth efficiency is considered to be one time slot per transmission. Cognitive networks are wireless networks that consist of different types of users, a primary user (PU, the primary license holder of a spectrum band) and secondary users (SU, cognitive radios that opportunistically access the PU spectrum). The secondary users can access the spectrum of the licensed user provided they do not harmfully affect to the primary user. In this thesis, various resource allocation and optimization techniques have been investigated for wireless relay and cognitive radio networks.

For the Texas Department of Transportation (TxDOT), accurately predicting durations for right-of-way (R/W) acquisition and utility adjustment on highway projects has been deemed as one of the most important capabilities that regional districts should possess. Because this need is so pressing, TxDOT has sought to establish an effective methodology for predicting the durations of these two pre-construction processes. The “Right-of-Way Acquisition and Utility Adjustment Process Duration Information (RUDI) tool” was developed, which is an Excel-based tool that takes into consideration user inputs regarding project circumstances such as schedule urgency and levels of uncertainty. In this study, the accuracy of RUDI and the key drivers that affect the durations of R/W acquisition and utility adjustment have been examined in order to assess RUDI’s effectiveness in implementation on projects, to identify critical needs for enhancing RUDI, and to understand how practitioners can better predict durations needed for R/W acquisition and utility adjustment. RUDI proved useful in predicting durations with better accuracy in spite of limited data availability. Specifically, RUDI provided practitioners with reasonable duration ranges that can be used in better forecasting the durations of utility adjustment. Moreover, the study revealed that practitioners with more than 13 years of experience and R/W acquisition specialization showed better performance in estimating durations for R/W acquisition. Accurately estimated durations for utility adjustment were mostly provided by practitioners working at districts located in urban or metropolitan areas in Texas. The drivers identified significantly influential in predicting durations for R/W acquisition by the practitioners include “TxDOT Project Type,” “District R/W Annual Budget,” “Dedication of Funds to the Project,” “Funding Limitations for the Project,” “Level of Political Pressure,” “Need for Residential Relocation,” “Level of Local Availability of Replacement Housing Facilities,” and “Likelihood of Title Curative Actions,” “Status of Environmental Clearance,” “Status of Right-of-Way Map,” “Frequency of Eminent Domain,” “Right-of-Way and Utility Scope,” and “Number of Parcels for Acquisition.” Likewise, for estimating utility adjustment durations, the drivers deemed highly influential and important by the practitioners include “Dedication of Funds to the Project (R/W and Construction),” “Funding Limitations for the Project,” “Have Subsurface Utility Engineering (SUE) Investigations been Performed,” “Adjustment is Reimbursable Utility or Non-Reimbursable Utility,” “Status of Environmental Clearance,” “Status of Right-of-Way Map,” “Right-of-Way and Utility Scope,” “Number of Utilities Located in Private Easement,” and “Responsiveness of Utility Companies to TxDOT Needs.” These drivers should be considered key data points in RUDI because they can provide users with more duration ranges that can be useful in forecasting actual durations of R/W acquisition and utility adjustment on highway projects. The study also revealed that further research is needed to maximize the benefits of the RUDI tool, although validating the study’s findings was restricted due to a lack of data. Additional studies for improving the RUDI tool should focus both on collecting more recent data and reconstructing the tool in terms of function and structure. / text

Massive stars play a key role in the evolution of the Galaxy; hence they are important objects of study in astrophysics. Although they are rare compared to low mass stars, they are the principal source of heavy elements and UV radiation, affecting the process of formation of stars and planets, and the physical, chemical, and morphological structure of galaxies. Star clusters form in dense "clumps" (~few parsecs in size) within giant molecular clouds, while individual stars form in cores (subparsec scale). An important step in the observational study of massive star formation is the identification and characterization of clumps. More detailed studies can then show how these clumps fragment into cores. Studies of clumps in our Galaxy will provide fundamental guidelines for the analysis of other galaxies, where individual clumps and cores cannot be resolved, and provide a catalog of interesting sources for observations of the Milky Way with a new generation of instruments, such as the Atacama Large Millimeter/Submillimeter Array. Large-scale blind surveys of the Galactic plane at millimeter and submillimeter wavelengths have recently been completed, allowing us to identify star forming clumps and improve our understanding of the early stages of massive stars. One of these studies, the Bolocam Galactic Plane Survey (BGPS), mapped the continuum emission at 1.1 mm over a large region of the northern Galactic plane at a resolution of 33'', identifying 8559 compact sources throughout the Galaxy. In this dissertation, I present observations of a sample of sources from the BGPS catalog, obtained with the Submillimeter High Angular Resolution Camera II (SHARC-II). I present in this work 107 continuum emission maps at 350 microns at high angular resolution (8.5'') toward clump-like sources and construct a catalog of BGPS substructures. I estimate clump properties such as temperatures and multiplicity of substructures, and compare my results with 350 microns continuum maps from the Hi-GAL survey. I also present a detailed analysis, using molecular line and dust continuum observations, of the region G331.5-0.1, one of the most luminous regions of massive star formation in the Milky Way, located at the tangent region of the Norma spiral arm. Molecular line and millimeter continuum emission maps reveal the presence of six compact and luminous molecular clumps, with physical properties consistent with values found toward other massive star forming sources. This work includes the discovery of one of the most energetic and luminous molecular outflows known in the Galaxy, G331.512-0.103. For this high-speed outflow, I present ALMA observations that reveal a very compact, extremely young bipolar outflow and a more symmetric outflowing shocked shell surrounding a very small region of ionized gas. The source is one of the youngest examples of massive molecular outflows associated with the formation of a high-mass star. / text