Hong-Hsu Yen

Shih Hsin University · Department of Information Management

Because of toxic gases and fast propagation speed, smoke causes the major injuries and deaths than burns in the fire. Deploying IoT enabled smoke sensors can help to sense, collect, and transmit the smoke data to the control station, it enables a dynamic and real-time evacuation approach to increase the evacuation success probability. In this paper...

Temperature sensors with a communication capability can help monitor and report temperature values to a control station, which enables dynamic and real-time evacuation paths in fire emergencies. As compared to traditional approaches that identify a one-shot fire evacuation path, in this paper, we develop an intelligent algorithm that can identify t...

The rapid advancements of Micro/NanoBOTs (MNBOTs) introduce a new research opportunity in routing multiple MNBOTs to perform practical biomedical applications. In this paper, leveraging on existing group communication and motion control schemes for MNBOTs, we propose an Activation Based Molecular Routing (ABMR) scheme in MNBOT networks to coordinat...

In this paper, we consider the visual sensor deployment algorithm in Pan-Tilt-Zoom (PTZ) Wireless Visual Sensor Networks (WVSNs). With PTZ capability, a sensor’s visual coverage can be extended to reduce the number of visual sensors that need to be deployed. The coverage zone of a visual sensor in PTZ WVSN is composed of two regions, a Direct Cover...

With the development of new networking paradigms and wireless protocols, nodes with different capabilities are used to form a heterogeneous network. The performance of this kind of networks is seriously deteriorated because of the bottlenecks inside the network. In addition, because of the application requirements, different routing schemes are req...

Molecular Nanoscale Sensor Networks (MNSNs) introduce a new molecular routing paradigm where the molecular communication is enabled by activating the nanosensors on the routing path to release the molecules. This new molecular activation mechanism is a new many-to-many scheme where the transmitting nanosensors transmits molecules to multiple receiv...

In this paper, the visual sensor coverage and deployment problem in occluded wireless visual sensor network (WVSN) is studied. A new occlusion probability model is proposed to compute the occlusion probability from the fixed obstacles and the moving obstacles. Based on this occlusion probability model, an optimization formulation is developed, and...

By equipping the Pan-Tilt-Zoom (PTZ) capable visual sensor in Wireless Visual Sensor Networks (WVSN), the visual sensor could move the camera to increase its coverage area. Then, fewer visual sensors will be needed on deploying the WVSN. Because of the PTZ, the Field of View (FoV) of the sensor is divided into two regions, namely Direct Coverage Re...

In this paper, we consider the visual sensor deployment algorithm in Pan-Tilt-Zoom (PTZ) Wireless Visual Sensor Networks (WVSN). With the capability of panning, tilting and zooming, the sensor visual coverage can be enlarged and fewer visual sensors are needed as compared to the traditional WVSN. We divide the Field of View (FoV) of the PTZ sensor...

Wireless Visual Sensor Networks (WVSNs) where camera-equipped sensor nodes can capture, process and transmit image/video information have become an important new research area. As compared to the traditional wireless sensor networks (WSNs) that can only transmit scalar information (e.g., temperature), the visual data in WVSNs enable much wider appl...

One of the important applications in Wireless Sensor Networks (WSNs) is video surveillance that includes the tasks of video data processing and transmission. Processing and transmission of image and video data in WSNs has attracted a lot of attention in recent years. This is known as Wireless Visual Sensor Networks (WVSNs). WVSNs are distributed in...

Traditional Wireless Sensor Networks (WSN) transmits the scalar data (e.g., temperature, irradiation) to the sink node. A new Wireless Visual Sensor Network (WVSN) that can transmit images is a more promising solution than the WSN on sensing, detecting and monitoring the environment to enhance awareness of the cyber, physical, and social contexts o...

Traditional wireless sensor networks (WSNs) transmit the scalar data (e.g., temperature and irradiation) to the sink node. A new wireless visual sensor network (WVSN) that can transmit images data is a more promising solution than the WSN on sensing, detecting, and monitoring the environment to enhance awareness of the cyber, physical, and social c...

Power-efficient multicast routing is an active research field in wireless networks because most network nodes are powered by battery. However, this kind of multicast routing only considers the transmission radius coverage without addressing whether the signal quality is able to meet bandwidth requirement of the users. In this article, by leveraging...

3D transmission is a new and challenging research issue in wireless network. Basically, 3D video stream is composed of multiple 2D video streams to create 3D viewing experience at the receiver. As compared to the 2D video stream, 3D video stream requires significant bandwidth requirements. However, in wireless networks, due to the limited frequency...

Multicast routing in wireless networks that possess the wireless multicast advantage could significantly reduce the power and energy consumption. However, this kind of multicast routing that only addresses the transmission radius coverage might not be able to meet the bandwidth requirement of the users. As a result, additional transmissions are req...

D video transport methods have been the most intriguing and interesting research topic due to the recent popular 3D movie and 3DTV. Basically, D video stream is different from the 2D video stream that requires additional video streams to create 3D viewing experience. These additional video streams require significant transmission bandwidth so that...

VSN is different from traditional WSN that collect and transmit images/video instead of scalar data to the sink. Images provide richer information than scalar data that enable VSN to be a promising technology on security monitoring and surveillance. Image transmission in VSN is expansive due to its large image size and significant energy consumptio...

The issues of survivability of networks, especially to some open year round services have increased rapidly over the last few years. To address this topic, the effective survivability metric is mandatory for managerial responsibility. In this paper, we provide a survivability mechanism called Degree of Disconnectivity (DOD) for the network operator...

It is impossible for a system or network to keep completely safe with the possibility of many new threats occurring at any moment. To analyze and solve these kinds of problems, this paper presents a mathematical programming problem, which adopts a novel metric called Degree of Disconnectivity (DOD) to evaluate the damage level and survivability of...

In this paper, we formulate the minimum power multicast problem in wireless networks as a mixed integer linear programming problem and then propose a Lagrangean relaxation based algorithm to solve this problem. By leveraging on the information from the Lagrangean multiplier, we could construct more power efficient routing paths. Numerical results d...

In this paper, we consider one light-path based and two light-tree based traffic grooming schemes for supporting IP multicast services. We made performance comparisons for call blocking probability and bandwidth blocking probability on those schemes. Simulation results reveal that light-path scheme has lower blocking probability and less consumes b...

By eliminating redundant data flows, data aggregation capabilities in wireless sensor networks could transmit less data to reduce the total energy consumption. However, additional data collisions incur extra data retransmissions. These data retransmissions not only increase the system energy consumption, but also increase link transmission delays....

The concept of a hybrid wireless-optical broadband access network (WOBAN) is a very attractive one. This is because it may be costly in several situations to run fiber to every home (or equivalent end-user premises) from the telecom central office (CO); also, providing wireless access from the CO to every end user may not be possible because of lim...

Many future Internet applications supported over optical networks may require large amounts of guaranteed bandwidth between two remote end hosts, but this bandwidth may not necessarily be needed immediately. To ensure a deterministic service, Internet customers may prefer to reserve network resources, e.g., lightpaths, in advance and may indicate a...

In wireless sensor networks, data aggregation routing could reduce the number of data transmissions so as to achieve energy efficient transmission. However, data aggregation introduces data retransmission that is caused by co-channel interference from neighboring sensor nodes. This kind of co-channel interference could result in extra energy consum...

In wireless sensor networks, data aggregation routing could reduce the number of data transmission so as to achieve efficient total energy consumption. However, this kind of data aggregation introduces data retransmission that is caused by co-channel interference from neighbouring sensor nodes. Hence, more data aggregation leads to more extra energ...

Network design for sliding scheduled traffic is a highly-complex task that has been dealt by multistep approaches. We propose a scalable method, based on Lagrangean Relaxation, which can perform integrated scheduling, routing and wavelength assignment.

Embedding data-aggregation capabilities into sensor nodes of wireless networks could save energy by reducing redundant data flow transmissions. Existing research describes the construction of data aggregation trees to maximize data aggregation times in order to reduce data transmission of redundant data. However, aggregation of more nodes on the sa...

Energy efficient multicast routing has been a blooming research field in wireless networks. However, this kind of multicast routing only addresses the transmission radius coverage might not be able to meet the bandwidth requirement of the users. In this paper, for the first time, we address the bandwidth aware minimum power multicast routing proble...

In a WOBAN, the back end is a wired optical network, the front end is managed by wireless connectivity, and, in between, the tail ends of the optical part [known as optical network unit (ONU)] communicate directly with wireless access points (AP). We study a WOBAN deployment scenario and investigate an algorithm to optimize the placement of multipl...

A hybrid wireless-optical broadband access network (WOBAN) is a promising architecture for future access networks. Recently, the WOBAN has been gaining increasing attention, and early versions are being deployed as municipal access solutions. This architecture saves on network deployment cost because fiber need not penetrate to each end user. Howev...

In this paper, we investigate delay constrained multicast routing for supporting QoS guaranteed point to multi-point communications in IP over WDM networks. To achieve high bandwidth utilization, packets coming from different multicast connections are groomed and carried together over a single wavelength. Lightpath scheme is adopted in this paper t...

In this article, we consider traffic grooming and integrated routing in IP over WDM networks. The challenges of this problem come from jointly considering traffic grooming, IP routing, and lightpath routing and wavelength assignment (RWA). Due to the high bandwidth of optical fiber, there exists a mismatch between the capacity needed by an IP flow...

Multigranular optical WDM network aims to reduce network cost by grouping multiple wavelengths and then switching those wavelengths together at waveband or fiber levels. To configure such multi-granular network, we have two choices-homogeneous network and heterogeneous network. The former applies only a single type of optical cross connect (OXC) wh...

Hybrid wireless-optical broadband access network (WOBAN) is a promising architecture for future network operations. Recently, the wireless part of WOBAN has been gaining increasing attention and early versions are being deployed as a municipal access solution to eliminate the wired backhaul to every wireless router. This architecture saves on netwo...

We propose "risk-and-delay aware routing algorithm" (RADAR) for WOBAN. RADAR minimizes packet delay in the wireless front end of WOBAN and reduces packet loss for multiple failure scenarios: gateway failure, ONU failure, and OLT failure.

The concept of a hybrid wireless-optical broadband access network (referred to as WOBAN here) is a very attractive one. This is because it may be costly in several situations to run fiber to every home from the telecom central office (CO); also, providing wireless access from the CO to every end user may not be possible because of limited spectrum....

We consider optical impairment and investigate wavelength grooming strategies in multi-granular WDM networks. The strategy that allows lightpaths to share waveband paths holds better call blocking and port usage performance than that without sharing.

Incorporating sensor nodes with data aggregation capability to transmit less data flow in wireless sensor networks could reduce the total energy consumption. However, the penalty from data retransmissions due to collision could jeopardize the advantages from data aggregation. In this paper, for the first time, we consider the energy consumption tra...

Incorporating sensor nodes with data aggregation capability to transmit less data flow in wireless sensor networks could reduce the total energy consumption. This calls for the efficient and effective data-centric routing algorithm to facilitate this advantage. In this paper, we model the data-centric routing problem by a rigorous mixed integer and...

An essential issue in designing, operating and managing a modern network is to assure end-to-end QoS from users perspective, and in the meantime to optimize a certain average performance objective from the systems perspective. So in the first part of this paper, we address the above issue by using the rerouting approach, where the objective is to m...

Protected working capacity envelope concept has been proposed to simplify network management and operation in survivable WDM networks. Dynamic lightpath provisioning within working capacity envelope is only required to perform shortest path routing algorithm. Based on PWCE concept, we propose an efficient approximation approach, called Lagrangean r...

Among various access network topologies, the tree topology is the most popular due to its simplicity and relatively low cost. A salient example is the CATV network. In this paper, we consider the tree-based access network design problem where the operational cost and the fixed installation cost are jointly minimized. The problem is formulated as a...

An essential issue in designing, operating and managing a modern network is to assure end-to-end QoS from users perspective, and in the meantime to optimize a certain average performance objective from the systems perspective. So in the first part of this paper, we address the above issue by using the rerouting approach, where the objective is to m...

An essential issue in designing, operating and managing a modern network is to assure end-to-end Quality-ofService (QoS) from users perspective, and in the meantime to optimize a certain average performance objective from the system s perspective. In this paper, we consider the problem of minimizing the average cross-network packet delay in virtual...

In this paper, we consider the backbone network design problem with a full set of QoS requirements. Unlike previous researches, we consider both the transmission line cost and the switch cost. And the QoS requirements that we considered include the average packet delay, end-to-end packet delay and node disjoint paths. We formulate the problem as a...

This paper proposes the optimal design of lightpath Routing and Wavelength Assignment (RWA) problem in Wavelength Division Multiplexing (WDM) networks without wavelength conversion. We formulate RWA as a mixed Integer Linear Programming (ILP) problem where the objective is to minimize the cost of wavelength assignment to the fiber links in the netw...

The Internet has brought about several threats of information security to individuals and cooperates. It is difficult to keep a network completely safe because cyber attackers can launch attacks through networks without limitations of time and space. As a result, it is an important and critical issue be able to efficiently evaluate network survivab...

Good service network design is important to service providers in modern business environment. It will improve customer satisfaction by quick customer response, and in the same time to minimize the total service center installation cost. In this paper, we consider the service network design problem where the objective is to minimize the total facili...

An efficient supply chain network is crucial to the logistics of a modern business. Careful design of the supply chain network will lead to enormous cost saving and market opportunity. In the supply chain network design, how to determine the best location and capacity configurations of the Distribution Centers (DCs) and the distribution paths is a...