@conference {
	title = {Collaborative Sequential Detection of Gaussian Models from Observed Data and The Value of Information Exchanged},
	author = {Raghavan, Aneesh., Baras, John S.},
	year = {2017},
	month = {12/2017},
	abstract = {We consider the problem of detecting which Gaussian model generates an observed time series data. We consider as possible generative models two linear systems driven by white Gaussian noise with Gaussian initial conditions. We also consider two collaborating observers. The observers observe a function of the state of the systems. Using these observations, the aim is to find which one of the two Gaussian models has generated the observations. For each observer we formulate a sequential hypothesis testing problem. Each observer computes its own likelihood ratio based on its own observations.Using the likelihood ratio, each observer performs sequential probability ratio test (SPRT) to arrive at its decision on the hypothesis. Taking into account the random and asymmetric stopping times of the two observers, we present a consensus algorithm which guarantees asymptotic convergence to the true hypothesis. The consensus algorithm involves exchange of information, i.e., the decision of the observers. Through simulations, the {\textquotedblleft}value{\textquotedblright} of the information exchanged, probability of error and average time to consensus are computed.~},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)},
	pages = {pp. 15-20}
}
@conference {
	title = {Networked H$\infty$ Control with Minimum Directed Information},
	author = {Soleymani, Touraj., Hirche, Sandra., Baras, John S.},
	year = {2017},
	month = {12/2017},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)}
}
@conference {
	title = {Crowdsourcing with Multi-Dimensional Trust and Active Learning},
	author = {Liu, Xiangyang., Baras, John S.},
	year = {2017},
	month = {12/2017},
	abstract = {We consider a typical crowdsourcing task that aggregates input from multiple workers as a problem in information fusion. To cope with the issue of noisy and sometimes malicious input from users, trust is used to model workers expertise. We propose a probabilistic model to jointly infer multi-dimensional trust of workers, multi-domain properties of questions,and true labels of questions.Our model is flexible and extensible to incorporate metadata associated with questions. To show that, we further propose two extended models, one of which handles input tasks with real-valued features and the other handles tasks with text features by incorporating topic models. In order to decrease entropies and reduce error rates more quickly with fewer annotations from workers, we further propose strategies for selecting which questions to ask and which workers to assign the questions to based on multidimension characteristics of questions and workers trust values in those dimensions. We evaluate our models and algorithms on real-world data sets. These results can be applied for fusion of information from multiple data sources like sensors, human input, machine learning results, or a hybrid of them.~},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)},
	pages = {pp. 3224-3231}
}
@conference {
	title = {Event-Triggered Output-Feedback H$\infty$ Control with Minimum Directed Information},
	author = {Soleymani, Touraj., Hirche, Sandra., Baras, John S.},
	year = {2017},
	month = {12/2017},
	abstract = {In this paper, the H$\infty$ control problem with minimum information exchange between a plant and a remote controller is considered. For transmission of the measured outputs, an event-triggering mechanism is proposed. We measure the transferred information satisfying the causality condition by the directed information, and measure the H$\infty$ control performance by the L2-gain. We achieve the minimum directed information required for a guaranteed level of control performance. In particular, corresponding to the worst case disturbances, we develop a filter with a recursive variable, and show that the optimal control policy is a linear function of this recursive variable. Finally, we define the value of information, and determine the structure of the optimal sampling policy based on the value of information.
~},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)},
	pages = {pp. 6088-6094}
}
@conference {
	title = {Linear Quadratic Games with Costly Measurements},
	author = {Maity, Dipankar., Anastasopoulos, Achilleas. , Baras, John S.},
	year = {2017},
	month = {12/2017},
	abstract = {In this work we consider a stochastic linear quadratic two-player game.The state measurements are observed through a switched noiseless communication link. Each player incurs a finite cost every time the link is established to get measurements. Along with the usual control action, each player is equipped with a switching action to control the communication link. The measurements help to improve the estimate and hence reduce the quadratic cost, but at the same time the cost is increased due to switching. We study the subgame perfect equilibrium control and switching strategies for the players. We show that the problem can be solved in a two-step process by solving two dynamic programming problems. The first step corresponds to solving a dynamic programming for the control strategy and the second step involves solving another dynamic programming for the switching strategy.},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)},
	pages = {pp. 6223-6228}
}
@conference {
	title = {Algebraic-Graphical Approach for Signed Dynamical Networks},
	author = {Shi, Guodong., Altafini, Claudio., Baras, John S.},
	year = {2017},
	month = {12/2017},
	abstract = {A signed network is a network with each link associated with a positive or negative sign. Models for nodes interacting over such signed networks, where two types of interactions are defined along the positive and negative links, respectively, arise from various biological, social, political, and economical systems. Starting from standard consensus dynamics, there are two basic types of negative interactions along negative links, namely state flipping or relative-state flipping. In this paper, we provide an algebraic-graphical method serving as a systematic tool of studying these dynamics over signed networks. Utilizing generalized Perron-Frobenius theory, graph theory, and elementary algebraic recursions, we show this method is useful to establish a series of basic convergence results for dynamics over signed networks.
~},
	address = {Melbourne, Australia},
	booktitle = {56th IEEE Conference on Decision and Control (CDC 2017)},
	pages = {pp. 2009-2014}
}
@conference {
	title = {An Approximate Dynamic Programming Approach for Patient and Process Prioritization in A Hospital Environment},
	author = {Apergi, Lida A., Baras, John S., Golden, Bruce L., Wood, Kenneth.},
	year = {2017},
	month = {10/2017},
	abstract = {This research tackles the problem of patient and process prioritization in a healthcare environment with limited resources. Considering the medical cardiology department of a large medical center, a holistic model is designed and developed towards optimizing the decisions of allocating the available resources to the patients in order to minimize patients{\textquoteright} waiting costs. Approximate Dynamic Programming techniques are applied to optimize the aforementioned decisions over time, as well as capture the heterogeneity of the patients.},
	address = {Houston Texas},
	booktitle = {INFORMS Annual Meeting 2017}
}
@conference {
	title = {IoT and 5G as enablers for Networked Human-Cyber-Physical Systems},
	author = {Baras, John S., Papagianni, Chrysa. },
	year = {2017},
	month = {08/2017},
	abstract = {Cyber-Physical Systems (CPS) are transformative technologies for managing interconnected systems between a system{\textquoteright}s physical assets and computational capabilities. Several novel opportunities and research challenges emerge in CPS from the core domains of CPS, the physical and the cyber world and their interdependencies, as well as other domains such as networking and distributed systems. Specifically, CPS are frequently distributed and often they are either large-scale or require elasticity of scale as utilization fluctuates. Most of CPS are networked, typically via the Internet or the cloud, or via special logical or physical networks, leading s to networked CPS (Net-CPS). Examples include modern factories, modern enterprises, heterogeneous wireless networks, heterogeneous wireless sensor networks, social networks over the Internet, the Industrial Internet Consortium (IIC), the Internet of Things (IoT). Furthermore, we now live and work in a networked immersed world. That is humans are now important components of these networked systems. We call the resulting systems networked human-cyber- physical systems (Net-HCPS). The main thesis of the presentation is that the emerging technologies of IoT and 5G are indispensable enablers of both Net-CPS and Net-HCPS. We illustrate with several ubiquitous examples. The requirements for Net-HCPS design and performance evaluation suggest that a promising idea is to make the communication networks linking the components in Net-CPS, both programmable and flexible to changing operating conditions. This is precisely where Software Defined Networks (SDN) offers exciting new opportunities. SDN is a new paradigm that provides unprecedented flexibility via dynamic, programmatic (re) configuration of network resources using open standard interfaces. Neither 5G or IoT can be efficiently and predictably implemented without Software Defined Wireless Networks (SDWN) and Network Function Virtualization (NFV). We describe how these interdependencies lead us to a Software-Defined Architecture for Net-CPS and Net-HCPS. We describe critical implications of this work for the Industrial Internet and Industrie 4.0. Our work is in line with major shifts and R\&amp;amp;D interests in major communication companies (including Nokia Bell labs, Qualcomm, Ericsson, AT\&amp;amp;T). Finally, it has huge implications on smart cities viewed as Net-HCPS.},
	address = {Reston, VA},
	booktitle = {IEEE 5G Summit}
}
@conference {
	title = {Value of Information in Minimum-Rate LQG Control},
	author = {Soleymani, Touraj., Hirche, Sandra., Baras, John S.},
	year = {2017},
	month = {07/2017},
	abstract = {This study concerns fundamental limitations in control of mobile cyber-physical systems. In these systems, communication between a node and its base station due to limited power of the node is asymmetrical in terms of bandwidth and signal-to-noise ratio. The framework we develop in this paper is for partially observed linear quadratic Gaussian (LQG) control over communication networks in which the forward channel transporting measurements is modeled by a zero-delay packet-deletion channel and the feedback channel transporting control inputs is assumed ideal. Making use of dynamic programming, we characterize the optimal control and the optimal sampling policies that achieve the minimum data rate required for a guaranteed level of control performance. In particular, we prove that in the presence of event driven sampling the adopted filter is optimal and the separation principle between control and estimation holds. We show that the optimal control policy is a certainty equivalent policy and the optimal sampling policy is a threshold policy expressed in terms of the value of information. Furthermore, we prove that the value of information is a quadratic function of the innovation.},
	address = {Toulouse, France},
	booktitle = {IFAC 2017 World Conference}
}
@conference {
	title = {Linear Quadratic Stochastic Differential Games under Asymmetric Value of Information},
	author = {Maity, Dipankar., Baras, John S.},
	year = {2017},
	month = {07/2017},
	abstract = {This paper considers a variant of two-player linear quadratic stochastic differential games. In this framework, none of the players have access to the state observations for all the time, which restricts the possibility of continuous feedback strategies. However, they can observe the state intermittently at discrete time instances by paying some finite cost. Having on demand costly measurements ensure that open-loop strategy is not the only strategy for this game. The individual cost functions for each player explicitly incorporate the value of information and the asymmetry that comes along with different costs of state observation for different players. We study the structural properties of the Nash equilibrium for this particular class of problems when the cost of observation is finite and positive. We show that the game problem simplifies into two decoupled game problems: one for deciding the control strategies, and the other for deciding the observation acquisition times. The study also reveals that under two extreme cases -cost of observation being 0 or $\infty$- the strategies coincide with feedback and open-loop strategies respectively.},
	address = {Toulouse, France},
	booktitle = {IFAC 2017 World Conference},
	pages = {pp. 9287-9292}
}
@conference {
	title = {Detection of Markov Chain Models from Observed Data Using Binary Hypothesis Testing and Consensus:},
	author = {Raghavan, Aneesh., Baras, John S.},
	year = {2017},
	month = {07/2017},
	abstract = {In this paper, we consider the problem of detecting which Markov chain model generates observed time series data. We consider two Markov chains. The state of the Markov chain cannot be observed directly, only a function of the state can be observed. Using these observations, the aim is to find which of the two Markov chains has generated the observations. We consider two observers. Each observer observes a function of the state of the Markov chains. We formulate a binary hypothesis testing problem for each observer. Each observer makes a decision on the hypothesis based on its observations. Then Observer 1 communicates its decision to Observer 2 and vice-versa. If the decisions are the same, then a consensus has been achieved. If their decisions are different then the binary hypothesis testing problem is continued. This process is repeated until consensus has been achieved. We solve the binary hypothesis testing problem and prove the convergence of the consensus algorithm. The {\textquotedblleft}value{\textquotedblright} of the information gained through 1-bit communication is discussed along with simulation results.},
	address = {Toulouse, France},
	booktitle = {IFAC 2017 World Conference},
	pages = {pp. 3944-3949}
}
@conference {
	title = {Optimization and Resource Management in NOMA Wireless Networks Supporting Real and Non-real Time Service Bundling},
	author = {Vamvakas, Panagiotis, Tsiropoulou, Eirini Eleni., Papavassiliou, Symeon., Baras, John S.},
	year = {2017},
	month = {07/2017},
	abstract = {In this paper, the problem of joint users{\textquoteright} uplink transmission power and rate allocation in NOMA wireless networks is studied, under the scenario that each user is simultaneously requesting multiple services. Each user is associated with a twovariable utility function that represents his satisfaction from his allocated resources (i.e., power and rate). In order to appropriately reflect the combined needs of the user for bundling different types of services under the same common umbrella, user{\textquoteright}s utility function consists of two parts while different percentages are adopted by each user for each part in order to express his need for real and nonreal-time services. The joint resource allocation problem is directly confronted as a two-variable optimization problem and formulated as a non-cooperative game. The theory of S-modular multivariable games is adopted towards determining the Nash equilibrium point of the game. A distributed, iterative and low complexity algorithm for computing game{\textquoteright}s Nash equilibrium is introduced, while updating user{\textquoteright}s uplink transmission power and rate at the same step. Detailed numerical results exhibit the ability of the proposed framework to simultaneously satisfy diverse multiple services requested by the same user.},
	address = {Crete, Greece},
	booktitle = {22nd IEEE Symposium on Computers and Communication (ISCC 2017)},
	pages = {pp. 699-705}
}
@conference {
	title = {Asymptotic Policies for Stochastic Differential Linear Quadratic Games with Intermittent State Feedback},
	author = {Maity, Dipankar., Baras, John S.},
	year = {2017},
	month = {07/2017},
	abstract = {In this paper, we consider infinite horizon linear quadratic stochastic differential games where the games are neither open-loop nor closed-loop. The state of the game dynamics is measured only when a certain switch is closed. The switch requires unanimous operation by the players, and continuum state measurements are not possible. There is an upper bound on the number of times the switch can be closed. Each player is given a quadratic cost function and the objective of each player is to design a switching strategy and a control strategy in order to optimize their respective cost function. We investigate the Nash control strategy and optimal switching policy for this game with two different cost structures: discounted cost and average-time cost.},
	address = {Valletta, Malta},
	booktitle = {25th Mediterranean Conference on Control and Automation (MED 2017)},
	pages = {pp. 117-122}
}
@conference {
	title = {Fast Task-Specific Target Detection via Graph Based Constraints Representation and Checking},
	author = {Luan, Wentao., Yang, Yezhou., Fermuller, Cornelia., Baras, John S.},
	year = {2017},
	month = {05/2017},
	abstract = {We present a framework for fast target detection in real-world robotics applications. Considering that an intelligent agent attends to a task-specific object target during execution, our goal is to detect the object efficiently. We propose the concept of early recognition, which influences the candidate proposal process to achieve fast and reliable detection performance. To check the target constraints efficiently, we put forward a novel policy which generates a sub-optimal checking order, and we prove that it has bounded time cost compared to the optimal checking sequence, which is not achievable in polynomial time. Experiments on two different scenarios: 1) rigid object and 2) non-rigid body part detection validate our pipeline. To show that our method is widely applicable, we further present a human-robot interaction system based on our non-rigid body part detection.},
	address = {Singapore},
	booktitle = {2017 IEEE International Conference on Robotics and Automation},
	pages = {pp.  3984-3991},
	organization = {Marina Bay Sands Convection Center}
}
@conference {
	title = {Stochastic Differential Linear-Quadratic Games with Intermittent Asymmetric Observations},
	author = {Maity, Dipankar., Raghavan, Aneesh., Baras, John S.},
	year = {2017},
	month = {05/2017},
	abstract = {In this paper, we consider a two-players stochastic linear quadratic game framework. The game is partially observed and each player has their own private observation. The challenge is that none of the players has access to the continuum observations, rather they can access their respective observations at discrete time instances by operating a switch unanimously. The operation of the switch is costly and hence the gathering of the observations are costly. Each player is equipped with finite memory and she can only use the latest observation to construct the control strategy. The private observations of the players lead to a source of asymmetry in this game. Moreover, the players have different costs for operating the switch, which is another source of asymmetry. We study the structural properties of the Nash equilibrium for this particular class of problems and then we finally show that the switching problem simplifies to a bi-objective optimization problem.},
	address = {Seattle, WA},
	booktitle = {2017 American Control Conference},
	pages = {pp. 3670-3675},
	organization = {Sheraton Seattle Hotel}
}
@conference {
	title = {Reachability Analysis for Linear Hybrid Set-Dynamics Driven by Random Convex Compact Sets},
	author = {Matei, Ion., Baras, John S.},
	year = {2017},
	month = {05/2017},
	abstract = {This paper studies linear set-dynamics driven by random convex compact sets (RCCSs), where the parameter matrix evolves according to an underlying Markovian random process taking values in a finite set. We derive dynamics of the expectations of the associated reach sets. We establish that such expectations evolve according to coupled deterministic set{\textendash}dynamics. We provide sufficient conditions for the convergence of the reach sets expectations. We also give conditions under which the reach sets remain asymptotically bounded with probability one. As an illustrative example, we apply our results to evaluate the expectations of the reach sets associated to the position of a quadrotor},
	address = {Seattle, WA},
	booktitle = {2017 American Control Conference},
	pages = {pp.  1765-1770},
	organization = {Sheraton Seattle Hotel}
}
@conference {
	title = {Autonomous Relocation Strategies for Cells on Wheels in Environments with Prohibited Areas},
	author = {Rabieekenari, Ladan., Sayrafian, Kamran., Baras, John S.},
	year = {2017},
	month = {05/2017},
	abstract = {Public safety organizations increasingly rely on wireless technology for their mission critical communication during disaster response operations. In such situations, a communication network could face much higher traffic demands compared to its normal operation. Given the limited capacity of base stations in the network, such peak traffic scenarios could lead to high blocking probability or equivalently service interruptions during critical communications. At the same time, networking infrastructure can breakdown during a disaster. Proper deployment of mobile cells - Cells on Wheels - can help to enhance the network coverage or accommodate excess traffic in areas with high concentration of users. In addition, an intelligent relocation strategy can be used to efficiently adapt the cell locations to match variations in the spatial distribution of the traffic. In practical scenarios, these mobile base stations may not be able to relocate to all positions within the target field. Such prohibited areas introduce additional constraints on designing an intelligent relocation strategy. In this paper, we propose a decentralized relocation algorithm that enables mobile cells to adapt their positions in response to potentially changing traffic patterns in a field with prohibited areas. Extensive simulations show considerable improvement in supporting spatially variable traffic throughout the target field.},
	address = {Paris, France},
	booktitle = {IEEE International Conference on Communications (ICC 2017)},
	pages = {pp.1-6}
}
@conference {
	title = {Interest, Energy and Physical-Aware Coalition Formation and Resource Allocation in Smart IoT Applications},
	author = {Tsiropoulou, Eirini Eleni., Paruchuri, S.T, Baras, John S.},
	year = {2017},
	month = {03/2017},
	abstract = {In this paper, the problem of coalition formation among Machine-to-Machine (M2M) communication type devices and the resource management problem is addressed. Each M2M device is characterized by its energy availability, as well as by differentiated interests to communicate with other devices based on the Internet of Things (IoT) application that they jointly serve. Physical ties among devices also exist based on their physical distance proximity and communication channel quality. Those three factors: energy availability, interest, and physical ties, are considered into the coalition formation process and the coalition-head selection. Each M2M device is associated with a holistic utility function, which appropriately represents its degree of satisfaction with respect to Quality of Service (QoS) pre requisites fulfillment. Given the created coalitions among the M2M devices, a distributed power control framework is proposed towards determining each M2M device{\textquoteright}s optimal transmission power in order to fulfill its QoS prerequisites. The performance of the proposed approach is evaluated via modeling and simulation and its superiority compared to other state of the art approaches is illustrated.},
	address = {Baltimore, MD},
	booktitle = {The 51st Conference on Information Sciences and Systems (CISS 2017)},
	pages = {pp. 1-6},
	organization = {Johns Hopkins University}
}
@conference {
	title = {Autonomous Relocation Strategies for Cells on Wheels in Public Safety Networks},
	author = {Rabieekenari, Ladan., Sayrafian, Kamran., Baras, John S.},
	year = {2017},
	month = {01/2017},
	abstract = {Lack of network availability or limited access to~communication services are among the challenges that public~safety officials and first responders could face during disasters~or emergency scenarios. Networking infrastructure can partially~(or sometimes fully) breakdown during a catastrophe. At the~same time, unusual peaks in traffic load could lead to much~higher blocking probability or service interruptions for critical~communication. Lack of adequate communication among emergency~responders or public safety personnel could put many~lives at risks. A possible solution to deal with such scenarios~is through the use of mobile/portable infrastructures commonly~referred to as Cells on Wheels (COW) or Cells on Light~Trucks (COLT). These mobile cells can effectively complement~the existing undamaged infrastructure or enable a temporary~emergency network by themselves. Given the limited capacity of~each cell, variable and spatially non-uniform traffic across the~disaster area can make a big impact on the network performance.~Not only judicious deployment of the cells can help to meet~the coverage and capacity demands across the area, but also~intelligent relocation strategies can optimally match the network~resources to potentially changing traffic demands. Assuming that~each cell can autonomously change its location, in this paper, we~propose a decentralized relocation algorithm that adapts network~coverage in order to increase the supported users traffic. Our~simulations show an average improvement of approximately 35\%~in the supported traffic compared to static uniform deployment.},
	address = {Las Vegas, Nevada},
	booktitle = {The 14th Annual IEEE Consumer Communications \& Networking Conference (CCNC 2017)},
	pages = {pp. 41-44}
}
@conference {
	title = {Network Function Placement on Virtualized Cellular Cores},
	author = {Dietrich, David., Papagianni, Chrysa. , Panagiotis, Papadimitriou., Baras, John S.},
	year = {2017},
	month = {01/2017},
	abstract = {The proliferation of mobiles devices, application sprawl, and the ever-increasing data volume generates significant~stress on cellular networks and particularly on the cellular~core, also known as the Evolved Packet Core (EPC). This is~further exacerbated by the deployment of hardware appliances~for the implementation of a wide range of network functions~(e.g., gateways, mobility management, firewalls, network address~translation), hindering any opportunity for elastic provisioning,~and eventually leading to high operational costs and a significant~degree of load imbalance across the EPC.~Network Function Virtualization (NFV) has been seen a ~promising solution in order to enable elasticity in the cellular core. Applying NFV to the EPC raises the need for network~function (NF) placement, which in turn entails significant challenges,~due to the stringent delay budgets among cellular core components and the coexistence of communicating data and~control plane elements. To address these challenges, we present a~linear programming (LP) formulation for the computation of NF~placements that strikes a balance between optimality and time
complexity. Our evaluation results show that the LP achieves~significantly better load balancing, request acceptance rate,~and resource utilization compared to a greedy algorithm that~performs NF placement inline with carriers{\textquoteright} common practice~today.~},
	address = {Bengaluru, India},
	booktitle = {9th International Conference on COMmunication Systems \& NETworkS (COMSNETS 2017)},
	pages = {pp. 259-266}
}
