Search

Recently, a concept of virtual emotion barrier by wireless signal gained a lot of interests because it supports human emotion recognition within given IoT environment. If detection of human emotion can be made with possibly high detection accuracy by virtual emotion barrier, it can be utilized to an extensive scope of emotion-based applications and communication software services. But, some IoT devices failures in the barrier may cause emotion-based system performance degradation critically. Also, thanks to recent advent of technology, intelligent smart UAVs with rapid speed are considered as promising devices when existing infrastructures are recovered. In this study, fault-tolerant mutual assisted virtual emotion barrier system is introduced with intelligent autonomous UAVs in convergent smart cities. Moreover, we present a formal definition of the problem whose goal is maximizing entire total accuracy of emotion detection where the failed locations are recovered by UAVs’ movement from initial locations without any potential conflicts among UAVs. A greedy UAV movement scheme that constructs resilient virtual emotion barriers is proposed by handling those failed parts in the barriers continuously. Moreover, the proposed schemes are executed by comprehensive simulations with useful scenarios and we evaluate the earned outcome.

In this letter, we introduce a multiplex cumulative virtual emotion detection system for two-way enabled multi domain IoT environment, which avoids detection holes in all IoT domains. Formally, we define a problem whose objective is to maximize cumulative accuracy of detection holes on condition that perpendicular barriers or horizontal barriers are constructed in every domain area. After presenting the defined problem with ILP formulation, we devise a novel scheme to solve the problem. Moreover, we evaluate the obtained results through extensive experiments.

Since a long time, the integrity of physical borders is seen as a challenging concern. Indeed, governments have to facilitate travelling and trade so that economies continue to grow while preventing the entry of dangerous entities. To this aim, several conventional techniques were enforced to secure borders in the recent past. However, due to the immensity of the area to be monitored, such solutions require an intensive human involvement and high maintenance costs. This advocated to use new technologies, such as Wireless Sensor Networks (WSN), to reduce the costs and improve the efficiency of the border surveillance system. Although using and combining these technologies has been already addressed in different existing solutions, it still some key points to be considered like energy efficiency, load balancing, and redundancy elimination. In this paper, we first propose a multilayer hybrid architecture based on cameras, scalar sensors, radars, and UAVs to design a border surveillance system. Then, a detailed deployment strategy is discussed. Finally, an activation scheduling strategy based on load balancing and energy saving is addressed. The simulation results show that our solution could not only detect the intrusion in border areas, but also outperforms the other solutions by managing efficiently the network and extending its lifetime.

With a recent advent of technology, it is possible to recognize human emotion through various schemes which cover audio, visual data, facial expression and wireless signal and its reflection. When we design a virtual emotion system with an applicability of replaceable barrier concept in IoT environment, it is a critical issue to avoid the weak hole in the barriers. In this article, we introduce a continuous virtual emotion detection system toward suitable emotion-based services in advanced intelligent smart cities. Then, we formally define a MaxContLDA problem whose objective is to maximize the continuous lowest emotion detection accuracy to avoid weak detection holes in replaceable barriers. To solve the problem, we propose a novel approach using lowest edge replacement and implement it through extensive simulations with different scenarios. Also, we analyze the performance of the proposed approach which returns possible maximum lowest emotion detection accuracy value for those various simulation settings and scenarios. Furthermore, we discuss future research challenges, issues and plans with expanded perspectives.

A barrier coverage has been studied widely because it provides guaranteed detection of mobile objects after a barrier is constructed. Also, many researchers have investigated the recognition of human emotion by facial expression and human gesture or motion with possible high accuracy. In particular, thanks to recent remarkable advancements of technology, it is possible to recognize human emotion by wireless signal. In this article, we introduce a new emotion-detectable framework in advanced smart cities with a concept of barrier coverage in IoT-enabled environments. The proposed framework allows IoT devices to create a virtual emotion barrier, called a VEmoBar, which is able to sense human emotion through a wireless signal and its reflection. Also, we define a problem whose goal is to form a specific number of VEmoBars which returns a maximum cumulative accuracy. To solve the problem, we propose a novel approach as well as a system initialization and then evaluate them through extensive simulations with various scenarios. Moreover, we discuss future issues and challenges toward future promising smart cities based on this virtual emotion framework.

Securing physical borders is a critical task and a real concern for all the countries over the world. Conventional techniques which have been largely investigated to secure borders over the past, are progressively abandoned due to the intensive human involvement and high maintenance costs. Recently, new technologies, such as Wireless Sensor Networks (WSN), have been implemented to reduce the costs and improve the efficiency of the border surveillance system. One of the critical issue in WSN it to define an efficient activation strategy of the different sensors to reduce the resource consumption and enhance the lifetime of the network. We propose in this paper to study the effectiveness of adapting the activation period of scalar sensors and cameras on the lifetime of the network. Simulation results show that this period should be reduced in crisis time to enhance the fault tolerance of the network while it should be augmented in peacetime to extend the network lifetime.

Recently, a barrier-coverage has gained much interest due to potentiality of various applications. In this letter, we introduce a reinforced barrier-coverage in heterogeneous wireless sensor networks, which guarantees that any penetration variation of intruder is detected by at least one sensor with a consideration of heterogeneous sensors with different capabilities. Also, we formally define a problem whose objective is to maximize the lifetime of heterogeneous reinforced barriers and propose two novel approaches, including a creation of base graph. Then, the performances of the proposed schemes are analyzed through various scenarios.

In a wireless sensor network, a subset of sensor nodes provides a barrier-coverage over an area of interest if the sensor nodes are dividing the area into two regions such that any object moving from one region to another is guaranteed to be detected by a sensor node. Recently, Kumar et?al. introduced scheduling algorithms for the maximum lifetime barrier-coverage problem. The algorithms achieved the optimal lifetime by identifying a collection of disjoint subsets of nodes such that each subset in the collection can provide barrier-coverage over the area, and by activating each subset in turn. This introduces a new security problem of these scheduling algorithms called barrier-breach. We show there could be a way to penetrate the area protected by barrier-covers when one barrier-cover is replaced by another. To deal with this issue, we propose three different remedies for the algorithms. In addition, we compare the performance of the three approaches against an upper bound via extensive simulation and make a discussion on the results.

Thanks to advancement of vehicle technologies, Unmanned Aerial Vehicle (UAV) now widely spread over practical services and applications affecting daily life of people positively. Especially, multiple heterogeneous UAVs with different capabilities should be considered since UAVs can play an important role in Internet of Things (IoT) environment in which the heterogeneity and the multi domain of UAVs are indispensable. Also, a concept of barrier-coverage has been proved as a promising one applicable to surveillance and security. In this paper, we present collision-free reinforced barriers by heterogeneous UAVs to support multi domain. Then, we define a problem which is to minimize maximum movement of UAVs on condition that a property of collision-free among UAVs is assured while they travel from current positions to specific locations so as to form reinforced barriers within multi domain. Because the defined problem depends on how to locate UAVs on barriers, we develop a novel approach that provides a collision-free movement as well as a creation of virtual lines in multi domain. Furthermore, we address future research topics which should be handled carefully for the barrier-coverage by heterogeneous UAVs.

Recently, Unmanned Aerial Vehicle (UAV) networks attracts a lot of interest as one of promising research areas since it can be used for a large portfolio of relevant applications. Among several issues in UAV networks, a collision avoidance among multiple UAVs should be addressed due to its significance. Furthermore, a barrier-coverage is considered as an important coverage concept because it is also appropriate for various applications such as intrusion detection and border surveillance. In this paper, we introduce a barrier-coverage system in UAV networks to construct collision-free UAV reinforced barrier. Then, we formally define a problem whose objective is to minimize total moving distance of UAVs such that collision-free is guaranteed among multiple UAVs when they move from initial locations to positions of constructing a reinforced barrier. To solve the problem, we introduce a novel strategy based on dividing a region into zones and describe our proposed approach. Moreover, we discuss future issues for barrier-coverage of UAV networks.

A barrier-coverage in wireless sensor networks (WSN), which is able to detect a mobile object from one side to another opposite side, is a critical problem for lots of applications. Because it is highly appropriate to consider a barrier-coverage in event-driven environment, Kim et al. recently introduced k-event-driven partial barriers (k-EP barriers) with static sensor nodes, which at least k sensors can detect or monitor every movement of mobile objects on paths among multiple hubs in event-driven environment. But, in case of failures of sensors, k-EP barriers should be recovered from those failures. In this paper, we introduce resilient event-driven partial barriers with mobile sensors, which can maintain k-EP barriers continuously as well as can recover from a failed status when there exist failed sensors on initially constructed k-EP barriers due to energy depletion of those sensors. Also, we formally define a problem whose objective is to minimize total moving distance of mobile sensors such that k-EP are maintained continuously by considering movements of mobile sensors. To solve the problem, we propose a novel approach to minimize total movement distance of mobile sensors to form k-EP barriers continuously. Then, we address future issues and directions for resilient event-driven partial barriers.

Recently a barrier-coverage in wireless sensor networks (WSN), which detects a moving object from one side to another opposite side, has attracted lots of attention. Although it is highly desirable to consider a barrier-coverage which can detect any moving objects for multiple sides simultaneously in event-driven environment, an existing barrier does not support those properties. In this paper, we introduce a new type of barrier, event-driven partial barrier, which can detect or monitor every movement of mobile objects on paths among multiple hubs in event-driven environment. Based on the new barrier concept, we define k-EP barriers that a motion by mobile objects is guaranteed to be detected by at least k sensors. Also, we formally define a problem whose objective is to minimize the number of sensors in order to construct k-EP barriers for every hub. To solve the problem, we propose two novel approaches to maximize a network lifetime by minimizing the number of sensors with satisfying requirements of k-EP barriers. Then, we evaluate their relative performances through extensive simulations.

Summary Recently, barrier-coverage in wireless sensor networks is a critical issue because it can be used for various applications (e.g., intrusion detection and border protection). Many existing works for barrier-coverage assume that an intruder penetrates through two opposite sides such as from top to bottom or from bottom to top and focus on constructing barriers to detect those penetrations. However, in many practical scenarios, it should be desirable to detect an intruder that enters the area of interest through any of its sides and passes through any other of its sides. In this paper, we introduce a new barrier-coverage problem whose goal is maximizing the network lifetime such that any penetration variation of the attacker is guaranteed to be detected. In order to solve the problem, we create a new type of sensor barriers, which is referred as reinforced barriers, that can sense any movement variation of the intruder. Also, we propose four different approaches to construct reinforced barriers from a given layout of sensors and we compare their relative performances for maximum number of reinforced barriers through extensive simulations by various scenarios.

A subset of sensors in wireless sensor networks provides barrier-coverage over an area of interest if the sensor nodes are dividing the area into two regions such that any object moving from one region to another is guaranteed to be detected by a sensor. In many practical scenarios, it may be desirable to detect an intruder that enters the region through any of its sides and exits through any other of its sides. That is, not only detect top-down movement, but also side-to-side, and even turn from one side to another. In this paper, we introduce a new barrier-coverage problem whose objective is to maximize the network lifetime such that any penetration of the intruder is detected. To solve the problem, we create a new form of sensor barriers, which we refer to as reinforced barriers, which can detect any movement variation of the attacker. Also, we propose three approaches to obtain these barriers from a given layout of sensor nodes, and we then compare their relative performances through extensive simulations.

Wireless sensor and actor networks (WSANs) are composed of static sensor nodes and mobile actor nodes. We assume actors have a random initial location in the two-dimensional sensing area. The objective is to move each actor to a location such that every sensor node is within a bounded number of hops from some actor. Because sensor nodes have limited energy, the new actor locations are chosen as to minimize the transmission range required from the sensor nodes. However, actors also have a limited (although larger) power supply, and their movement depletes their resources. It follows that by carefully choosing the new actor locations, the total actor movement can be minimized. In this paper, we study the trade-off between minimizing sensor transmission radius and minimizing actor movement. Due to the complexity of the problem, we introduce an optimal ILP formulation, and compare its results against a proposed heuristic. For the ILP solution to be feasible, we introduce a finite set of potential actor positions such that an optimal solution is guaranteed to be found within this set.

Wireless sensor and actor networks (WSANs) are composed of static sensor nodes and movable actors. We assume actors have a random initial location in the field. The objective is to move each actor to a location such that every sensor node is within one transmission hop from some actor. Because sensor nodes have limited energy, finding actor locations that minimize the transmission range required from the sensor nodes may significantly increase network lifetime. However, actors also have a limited (although larger) power supply, and their movement depletes their resources. It follows that an optimal pairing of actors with the chosen new locations may also provide energy savings for the actors. In this paper, we address the problem that simultaneously minimizes sensor transmission radius and total actor movement. Due to its complexity, we present a heuristic and compare it against an optimial ILP solution. More importantly, we consider two approaches for both the heuristic and the ILP. First, actor locations that minimize transmission range are found, and then the assignment of actors to locations is performed (double-step approach). Second, a joint-optimization (single-step) approach is proposed in which transmission range and actor movement are considered simultaneously. We show that the single-step approach outperforms the double-step approach.

Wireless sensor and actor networks (WSANs) consist of fixed sensor nodes and mobile actor nodes. Data is generated at the sensor nodes, and collected at the more powerful actor nodes. We consider the problem of finding the location for K actor nodes such that every sensor node is within d-hop from an actor node, where K and d are parameters of the problem. Our approach distinguishes itself in obtaining the minimum transmission radius necessary for such coverage to be possible. We provide an exact solution by via an integer-linear-programming formulation (ILP), and evaluate two heuristic approaches.

We consider the design of wireless sensor and actor networks. Sensors are network nodes with a fixed location and limited transmission power. Actors are mobile nodes that may relocate their position to provide coverage to the sensor nodes. We consider the problem of relocating K actors from initial random locations to locations where every sensor node is able to communicate directly with at least one actor node. The new actor locations are chosen to minimize the transmission power that is necessary for the sensor nodes. Also, the pairing of actors to their new locations is such that the cost of relocating the actors is minimized.