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The sensor nodes in Wireless Sensor Networks (WSNs) and Mobile Sensor Networks (MSNs) can be prone to failures due to limited resources and/or the harsh environments where they are deployed. The network may be subject to partitioning if such failures are experienced by the cut-vertex nodes in the system. In case of partitioning, connectivity of the nodes in disjoint partitions with the sink node is disrupted. This not only affects the data delivery but also the possible cooperation and coordination of the nodes in handling certain events. To restore the connectivity of a partition with the rest of the network, network topology should be adjusted through either exploiting existing mobile nodes in the network or introducing additional relay nodes (RNs) to the network. However, both solutions pose certain challenges. In the former case, the mobility of the nodes requires significant energy consumption and thus the movement distance should be minimized. In addition, if the scope of the damage is too wide, determining the nodes to be relocated and their final locations is another challenge. In the latter case, determining the number of RNs and a self-configuring scheme for their movement destinations need to be tackled. In case of unavailability of sufficient RNs to provide connectivity with stable links to the whole network, another solution can be providing intermittent connectivity to the partitions by employing RNs as Mobile Data Collectors (MDCs). A mixed solution where some of the RNs are employed as MDCs and some as stationary RNs raises the challenge of determining the number of stationary RNs and identifying their locations, assigning MDCs to serve partitions uniformly in such a way that the tour lengths of MDCs are minimized and the load among the MDCs are balanced. In this dissertation, we address the connectivity restoration problem in partitioned WNSs and MSNs due to large scale damages. We present centralized and distributed approaches while considering four cases: 1. Minimizing the movement cost of the nodes while utilizing existing nodes in the network in case of the availability of the mobile nodes/actors. 2. Minimizing the number of relay nodes to be used and their movement cost in case of the lack of mobile nodes/actors in the network. 3. Maximizing the number of nodes served with a stable link while not exceeding the maximum tour length defined on MDCs when a mixed solution is required where some or all of the RNs are employed as MDCs. 4. Considering QoS constraints and rendezvous waiting time when multiple MDCs are in use. The effectiveness of all proposed approaches are validated through extensive simulation experiments.

In this thesis, I study subnational and supranational institutional dynamics and their effects on international connectivity. In the second and third chapters, I focus on regulative harmonization within regional integration as a proxy to the changing institutions at the supranational level. I use process of Turkey’s candidacy to full membership in the European Union (EU) as a context of regional integration. In the second chapter, I adopt a network perspective to the international connectivity and track the progress in regulative harmonization by constructing a basic composite index using EU Commission annual progress reports. I utilized social network analysis on USPTO patent data to understand the effect of regulative harmonization on the centrality, complexity and resilience of Turkey’s innovation network. In the third chapter, I adopt a team perspective to the international connectivity. Using the same context, I construct a more sophisticated composite index by utilizing a combination of content analysis, principal component analysis (PCA) and linear aggregation methods to track the regulative harmonization in a robust way. In this chapter, I investigate the relationship between regulative harmonization and international connectivity in innovation using the same patent data supplemented by additional manually parsed company and country level data. I use a classic entropy-based measure, Shannon, to analyze the international connectivity of co-inventor teams in patents. Additionally, I explore asymmetrical impact of different regulation groups as well as a possible mediatory role of MNEs conditional on their origin using a signaling theory perspective. This chapter presents insights regarding the relationship between institutional fundamentals and international connectivity of a country. Finally, in the fourth chapter, I analyze the mechanisms through which national formal institutions interact with subnational informal institutions. More specifically, I use exploratory qualitative analysis supported by the fuzzy set qualitative comparative analysis to study how and under what conditions subnational informal institutional factors, that are represented by local business communities and local government-business relationships, exacerbate or ameliorate voids in national formal institutions. Export promotion programs represent the context for formal national institutions in this final chapter. My study contributes, first, to institutional theory by offering a deep analysis of how national formal and subnational informal institutions interact and result in different subnational responses to common institutional voids. Second, it contributes to the literature on economic geography and innovation by demonstrating the institutional fundamentals as antecedents of international connectivity in innovation from both network and team perspectives. My thesis also contributes to the IB literature by showing the asymmetrical effect of different groups of formal institutions on international connectivity and mediatory role of MNEs conditional on their origins in the relationship between regulative harmonization and international connectivity in innovation. I also contribute methodologically to analyses of complex social phenomenon by putting together a novel bundle that produces the Weighted Average Regulative Progress Index, WARP Index, and then combines it with Shannon’s Entropy Index and a recently published estimation method, ivmediate for Stata, that accounts both on endogeneity and mediation. / Business Administration/Strategic Management

In this dissertation, I evaluate questions related to the role of connectivity in economic and innovation-related processes. Specifically, I utilize conceptual frameworks from the economic geography literature to study the relevance of internal, external, and infrastructural connectivity at a city level.In the first essay, I examine the role of intra-metropolitan connectivity of inventors and evaluate the quality of the associated innovation outputs. I focus on the fact that there exist meaningful demographic differences between people domiciled in city centers and the suburban areas and claim that these heterogeneities serve as sources of diversity and creativity. I suggest empirical evidence that the collaboration of inventors from the two different sub-regions is associated with higher quality innovation outcomes. I further study how firm heterogeneity moderates the effects of this intra-metropolitan connectivity. The findings suggest that local firms and small to mid-sized firms (SMEs) enjoy more benefits because foreign firms and large firms are exploiting their own global network. This paper provides both managerial and practical implications that a metropolitan area may improve its quality of innovation outputs by taking advantage of the urban-suburban connectivity among the inventors. In the second essay, I provide specific guidelines to city planners to evaluate the external connectivity of the associated city. Cities are industry hotspots, playing vital roles as centers of economic development. Each city has different location-specific advantages that can foster different core industries and firms, participating in diverse activities within a global value chain system. Given the increasing rate of globalization at the metro level, it has become paramount for cities to establish and develop economic partnerships with other cities to further growing their regional economies. However, few city planners have clear directions in choosing partner cities, and the decisions are rarely based on appropriate data analysis. Based on the Brookings Institution’s Global City Initiative 2.0 project, and after enhancing it with additional data analyses, I introduce a set of step-by-step guidelines to city planners for finding global partner cities. To provide an actual case, I share our own anecdote regarding how Philadelphia chose potential partner cities in order to attract more FDI in its biopharmaceutical sector and foster innovation activities. I also present evidence that the inadequate ability of local firms to source knowledge from international markets associates with relatively weak economic performance. The comprehensive analyses of the city’s role in the global value chain include from the upstream (Research and Development) and the midstream (FDI, imports, international joint ventures) to the downstream (exports). This case-based paper provides practical implications to city planners by providing ways of understanding the broad global value chain with which the city is involved. In the third essay, I assess the relationship between soft networks and hard networks of global cities. Public transportation systems (PTS) have been developed along with the associated metropolitan area. Scholars in urban studies have emphasized the important roles of PTS in connecting diverse people, regions, activities, and socio-economic consequences. In this paper, I examine the relationship between public transportation systems and the innovation network in four major U.S. cities in the northeast - New York, Boston, Philadelphia, and Pittsburgh. I graphically show that inventor locations, as well as their connectivity, are established along with the city’s public transportation networks. I further stipulate that this relationship has been seriously undermined by the recent pandemic – COVID-19. Even though it is too early to draw a conclusion, I advance propositions that predict how the relationship between public transportation network and inventor connectivity will be changed followed by the pandemic. In conclusion, I claim that a metropolitan area’s internal, external, and infrastructural network significantly affects its competitiveness. Throughout this dissertation, I confirm that both hard networks and soft networks are key to enhancing the economic and innovative performance of the city. / Business Administration/International Business Administration

The comprehensive effect of sleep deprivation on biological and behavioral functions largely remains unknown. There is evidence to support that human sleep must be of sufficient duration and physiological continuity to ensure neurocognitive performance while we are waking. Insufficient sleep would lead to high risk of human-error related to accidents, injuries or even fatal outcomes. However, in modern society, more and more people suffer from sleep deprivation because of the increasing social, academic or occupational demand. It is important to study the effect of sleep deprivation, not only on task performance, but also on neurocognitive functions. Recent research that has explored brain effective connectivity has demonstrated the directed inference interaction among pairs of brain areas, which may bring important insight to understand how brain works to support neurocognitive function. This research aimed to identify the brain effective connectivity pattern associated with changes of a task performance, response time, following sleep deprivation. Experiments were conducted by colleagues at Neuroergonomics Department at Jagiellonian University, Krakow, Poland. Ten healthy young women, with an average age of 23-year-old, performed visual spatial sustained-attention tasks under two conditions: (1) the rest-wakeful (RW) condition, where participants had their usual sleep and (2) the sleep-deprived (SD) condition, where participants had 3 hours less sleep than their usual sleep, for 7 nights (amounting to 21 h of sleep debt). Measures included eye tracking performance and functional magnetic resonance imaging (fMRI). In each condition, each subject*s eye-position was monitored through 13 sessions, each with 46 trials, while fMRI data was recorded. There were two task performance measures, accuracy and response time. Accuracy measured the proportion of correct responses of all trials in each session. Response time measured the average amount of milliseconds until participants gazed at the target stimuli in each session. An experimental session could be treated as a short window. By splitting long trials of fMRI data into consecutive windows, Granger causality was applied based on short trials of fMRI data. This procedure helped to calculate pairwise causal influences with respect to time-varying property in brain causal interaction. Causal influence results were then averaged across sessions to create one matrix for each participant. This matrix was averaged within each condition to formulate a model of brain effective connectivity, which also served as a basis of comparison. In conclusion, significant effect of sleep deprivation was found on response time and brain effective connectivity. In addition, the change of brain effective connectivity after sleep deprivation was linked to the change of response time. First, an analysis of variance (ANOVA) showed significant difference for response time between the RW condition and the SD condition. No significant changes for accuracy were found. A paired t-test showed that response time was significantly shorter in sleep deprivation for the visual spatial sustained-attention task. Second, Granger causality analysis demonstrated a reduction of bidirectional connectivity and an increase of directed influences from low-level brain areas to high-level brain areas after sleep deprivation. This observation suggested that sleep deprivation provoked the effective connectivity engaged in salient stimuli processing, but inhibited the effective connectivity in biasing selection of attention on task and in maintaining self-awareness in day time. Furthermore, in the SD condition, attention at the visual spatial task seemed to be driven by a bottom-up modulation mechanism. Third, a relationship was found between brain effective connectivity with response time. Decreases of Granger causal influences in two directions, from medial frontal lobe to sub cortical gray nuclei and from medial parietal lobe to sub cortical gray nuclei, were associated with shorter response time in the SD condition. Additionally, an increase of Granger causal influence from medial parietal lobe to cerebellum was associated with longer response time in the SD condition.

Nearly two-thirds of Americans own a smart phone, and 19% of Americans rely on their smartphone for either accessing valuable information or staying connected with their friends and family across the globe [15]. Staying always-on and always-connected to the Internet is one of the most important and useful features of a smartphone. This connection is used by almost every single application on the device including web browsers, email clients, messaging applications, etc. Unfortunately, the cellular networks on our smartphones are not perfect and do not always have cellular signal. Our devices often lose Internet connection when users are on the go and traveling. This thesis presents a novel in-depth implementation and evaluation of what we can achieve when a user loses network connectivity. BleHttp, a library for Android, was developed that uses Bluetooth Low Energy to connect to other devices using a different carrier within close proximity of each other and make HTTP requests. In our results, we saw 100% success rates on HTTP requests with connected devices on a good connection. Average round trip times were tested to be as low as 1.5 seconds.

This decade will hopefully see the first human stepping on the Martian soil. Thus, supporting and enhancing the life quality of a future crew should be the driving theme for accomplishing manned missions on Mars. In this regard, an on-demand, ubiquitous, reliable, wideband, and low-latency connectivity seems of vital importance, both for in-situ and deep-space communications. Hence, this PhD dissertation aims to introduce innovation on this multi-faceted topic, to propose a new set of solutions which we refer to as Next Generation Communications on Mars (NGC-M). First, we discuss through extensive simulations the viability of an Extraterrestrial Long Term Evolution (E-LTE) porting, where a lander and a rover are re-allocated to compose a wireless local mobile network as the base station (BS) and user equipment (UE), respectively. Next, in order to model realistic Martian channels for further solid evaluations, we present a study on large and small-scale phenomena through a three-dimensional (3D) ray-tracing algorithm executed over 3D tile-based rendering of high-resolution Digital Elevation Model (DEM) of the ``Red Planet" surface. Then, we formulate a framework for the design of heterogeneous ground-to-space multi-layered (3D) networks implementing Cloud Radio Access Networks (C-RAN) for ``Towards 6G" Martian connectivity. The results will spread from simulations of the so-called splitting options, for the virtualization of baseband functionalities on non-dedicated hardware, to end-to-end (E2E) network emulations and on-hardware assessments. Finally, a decode-and-forward (DF) optical wireless multi-relay network (OWmRN), based on satellites orbiting the Lagrangian points (LPs), will be proposed for wideband exchanges of data between Mars and Earth. Data rate over time will be measured with respect to the selected shortest-path for relaying. The analysis of the various techniques, performed in a holistic and systemic view, focuses on viability and performance, taking into account trade-offs and constraints inherent to the unusual and challenging Martian application environment.

Yes

The default network (DN), and specifically its sub-networks default network A (DN A) and default network B (DN B), has been strongly implicated in social cognition. This study examined its role in predicting social behavior, and also differences that may exist across diagnostic groups that may explain discrepancies in social cognition and behavior. One of the popular methods of study is functional connectivity, or analyzing correlated activity in the brain. Autism Spectrum Disorder (ASD) is a disorder characterized by social impairment and abnormal social behavior. To date, much of the functional connectivity research in ASD has focused on global connectivity, or specific but large areas of the brain. This study adds to the body of that research in attempting to understand both global functional connectivity and the functional connectivity of specific networks (DN A and DN B) that are involved in social cognition and thus implicated in ASD. A sample of 75 individuals with ASD, 85 neurotypical individuals, and 505 individuals with varying other diagnoses was examined to determine the role of global functional connectivity and the role of DN A and DN B in social cognition by the predictive ability of brain features to determine behavioral outcomes. This analysis also aimed to determine if there are group differences in these same brain features. The features we examined included functional connectivity, or the comparison of timeseries of regions of interest, network surface area, and network similarity. This study found that there was no discernible difference across diagnostic group in global or network-specific functional connectivity for DN A. The majority of features for DN B did not differ across diagnostic group, but there was one connection that was significantly different between the autism group and the others. There was no global predictive ability of functional connectivity and brain topology for social cognition measures, nor was there predictive ability for DN A features. DN B features, however, were predictive of social cognition in the autism group, but not in the control group or the other diagnostic groups examined. This study adds to the current body of research by supporting findings already reported by others, and by adding new findings about the role of DN B in social cognition in autism.