Showing papers in "Mobile Information Systems in 2008"

Efficient signature based malware detection on mobile devices

Abstract: The threat of malware on mobile devices is gaining attention recently It is important to provide security solutions to these devices before these threats cause widespread damage However, mobile devices have severe resource constraints in terms of memory and power Hence, even though there are well developed techniques for malware detection on the PC domain, it requires considerable effort to adapt these techniques for mobile devices In this paper, we outline the considerations for malware detection on mobile devices and propose a signature based malware detection method Specifically, we detail a signature matching algorithm that is well suited for use in mobile device scanning due to its low memory requirements Additionally, the matching algorithm is shown to have high scanning speed which makes it unobtrusive to users Our evaluation and comparison study with the well known Clam-AV scanner shows that our solution consumes less than 50% of the memory used by Clam-AV while maintaining a fast scanning rate

Performance evaluation of two fuzzy-based cluster head selection systems for wireless sensor networks

Abstract: Sensor networks supported by recent technological advances in low power wireless communications along with silicon integration of various functionalities are emerging as a critically important computer class that enable novel and low cost applications. There are many fundamental problems that sensor networks research will have to address in order to ensure a reasonable degree of cost and system quality. Cluster formation and cluster head selection are important problems in sensor network applications and can drastically affect the network's communication energy dissipation. However, selecting of the cluster head is not easy in different environments which may have different characteristics. In this paper, in order to deal with this problem, we propose two fuzzy-based systems for cluster head selection in sensor networks. We call these systems: FCHS System1 and FCHS System2. We evaluate the proposed systems by simulations and have shown that FCHS System2 make a good selection of the cluster head compared with FCHS System1 and another previous system.

A low-cost hybrid coordinated checkpointing protocol for mobile distributed systems

Abstract: Mobile distributed systems raise new issues such as mobility, low bandwidth of wireless channels, disconnections, limited battery power and lack of reliable stable storage on mobile nodes. In minimum-process coordinated checkpointing, some processes may not checkpoint for several checkpoint initiations. In the case of a recovery after a fault, such processes may rollback to far earlier checkpointed state and thus may cause greater loss of computation. In all-process coordinated checkpointing, the recovery line is advanced for all processes but the checkpointing overhead may be exceedingly high. To optimize both matrices, the checkpointing overhead and the loss of computation on recovery, we propose a hybrid checkpointing algorithm, wherein an all-process coordinated checkpoint is taken after the execution of minimum-process coordinated checkpointing algorithm for a fixed number of times. Thus, the Mobile nodes with low activity or in doze mode operation may not be disturbed in the case of minimum-process checkpointing and the recovery line is advanced for each process after an all-process checkpoint. Additionally, we try to minimize the information piggybacked onto each computation message. For minimum-process checkpointing, we design a blocking algorithm, where no useless checkpoints are taken and an effort has been made to optimize the blocking of processes. We propose to delay selective messages at the receiver end. By doing so, processes are allowed to perform their normal computation, send messages and partially receive them during their blocking period. The proposed minimum-process blocking algorithm forces zero useless checkpoints at the cost of very small blocking.

A speed-aware handover system for wireless cellular networks based on fuzzy logic

Abstract: Presently, the wireless mobile networks and devices are becoming increasingly popular to provide users the access anytime and anywhere. The mobile systems are based on cellular approach and the area is covered by cells that overlap each other. In mobile cellular systems the handover is a very important process, which refers to a mechanism that transfers an ongoing call from one Base Station (BS) to another. The performance of the handover mechanism is very important to maintain the desired Quality of Service (QoS). Many handover algorithms are proposed in the literature. However, to make a better handover and keep the QoS in wireless networks is very difficult. In this paper, we propose a speed-aware handover system based on fuzzy logic. The proposed system has 3 subsystems. The performance evaluation via simulations shows that proposed system has a good handover decision.

Home-Explorer: Ontology-based physical artifact search and hidden object detection system

Abstract: A new system named Home-Explorer that searches and finds physical artifacts in a smart indoor environment is proposed. The view on which it is based is artifact-centered and uses sensors attached to the everyday artifacts (called smart objects) in the real world. This paper makes two main contributions: First, it addresses, the robustness of the embedded sensors, which is seldom discussed in previous smart artifact research. Because sensors may sometimes be broken or fail to work under certain conditions, smart objects become hidden ones. However, current systems provide no mechanism to detect and manage objects when this problem occurs. Second, there is no common context infrastructure for building smart artifact systems, which makes it difficult for separately developed applications to interact with each other and uneasy for them to share and reuse knowledge. Unlike previous systems, Home-Explorer builds on an ontology-based knowledge infrastructure named Sixth-Sense, which makes it easy for the system to interact with other applications or agents also based on this ontology. The hidden object problem is also reflected in our ontology, which enables Home-Explorer to deal with both smart objects and hidden objects. A set of rules for deducing an object's status or location information and for locating hidden objects are described and evaluated.

Architecture for the development of context-sensitive mobile applications

Abstract: Recent advances in the development of mobile terminals and the appropriate communication infrastructures have the consequence that new kinds of applications arise. This trend leads to more and more complex mobile client applications as well. In this paper, we present a generic architecture, which can be used for the development of context-sensitive mobile applications.

EHeBby: An evocative humorist chat-bot

Abstract: A conversational agent, capable to have a "sense of humor" is presented. The agent can both generate humorous sentences and recognize humoristic expressions introduced by the user during the dialogue. EHeBby is an entertainment oriented conversational agent implemented using the ALICE framework embedded into an Yahoo! Messenger client. It is characterized by two areas: a rational, rule-based area and an evocative area. The first one is based on well founded techniques of computational humor and a standard AIML KB. The second one is based on a conceptual space, automatically induced by a corpus of funny documents, where KB items and user sentences are mapped. This area emulates an associative/evocative behavior of the conversational agent, making her more attractive. EHeBby includes also an avatar that changes the face expression according to humoristic content of the dialogue.

Secure authentication in heterogeneous wireless networks

Abstract: The convergence of cellular and IP technologies has pushed the integration of 3G and WLAN networks to the forefront. Gaining secure access to 3G services from 802.11 WLANs is a primary challenge for this new integrated wireless technology. Successful execution of 3G security algorithms can be limited to a specified area by encrypting a user's authentication challenge with spatial data defining his visited WLAN. With limited capacity to determine a user's location only to within a current cell and restrictions on accessing users' location due to privacy, 3G operators must rely on spatial data sent from visited WLANs to implement spatial authentication control. A potential risk is presented to 3G operators since no prior relationship or trust may exist with a WLAN owner. Algorithms to quantify the trust between all parties of 3G-WLAN integrated networks are presented to further secure user authentication. Ad-hoc serving networks and the trust relationships established between mobile users are explored to define stronger algorithms for 3G - WLAN user authentication.

Networked biomedical system for ubiquitous health monitoring

Abstract: We propose a distributed system that enables global and ubiquitous health monitoring of patients. The biomedical data will be collected by wearable health diagnostic devices, which will include various types of sensors and will be transmitted towards the corresponding Health Monitoring Centers. The permanent medical data of patients will be kept in the corresponding Home Data Bases, while the measured biomedical data will be sent to the Visitor Health Monitor Center and Visitor Data Base that serves the area of present location of the patient. By combining the measured biomedical data and the permanent medical data, Health Medical Centers will be able to coordinate the needed actions and help the local medical teams to make quickly the best decisions that could be crucial for the patient health, and that can reduce the cost of health service.

WIT: A wireless integrated traffic model

Abstract: Simulation is a common approach for designing ad hoc network applications, due to the slow deployment of these networks. The main building blocks of ad hoc network applications are the routing protocols, mobility, and traffic models. Several studies, which use synthetic models, show that mobility and traffic have a significant effect on protocol performance. Synthetic models do not realistically reflect the environment where the ad hoc networks will be deployed. In addition, mobility and traffic tools are designed independently of each other, however real trace data challenge that assumption. Indeed, recent protocol performance evaluation using real testbeds show that performance evaluations under real testbeds and simulations that use synthetic models differ significantly. In this paper we consider jointly both real mobility and traffic for protocol performance evaluation. The contributions of this work are as follows: (1) demonstrates that real mobility and traffic are interconnected; (2) announces the design and implementation of WIT -Wireless Integrated Traffic-, which includes the design of a real traffic generator; (3) shows that under real mobility and integrated traffic the performance metrics need to be re-thought, thus we propose availability as a new ad hoc network protocol performance metric; and, finally, (4) evaluates protocol performance under synthetic and real mobility models with integrated traffic. We believe that the results of our work constitute a step forward toward benchmarking of ad hoc network performance evaluations.

Tangible interfaces for interactive multimedia presentations

Abstract: This article is devoted to tangible interfaces for steering and control of interactive multimedia presentations. Various methods for digital encoding of physical objects are considered and their applicability in surface encoding for tangible interface components is discussed. Experiments with presentation controls, based on direct interaction with digitally encoded printed handouts are reported. An innovative approach for transferring presentation controls from printed handouts to surfaces of real physical objects is introduced. Consequently labels, digitally enhanced with CLUSPI codes are created and presentation control trials involving real products with digitally encoded surfaces are conducted. USB and wireless cameras are employed as CLUSPI readers for implementing surface based interactions and a portable communication device with an embedded camera is considered as a possible truly mobile solution.

Adaptive and fuzzy approaches for nodes affinity management in wireless ad-hoc networks

Abstract: In most of the ad-hoc routing protocols, a static link lifetime (LL) is used for a newly discovered neighbors. Though this works well for networks with fixed infrastructures, it is inadequate for ad-hoc networks due to nodes mobility and frequent breaks of links. To overcome this problem, routing protocols with estimated LL using nodes affinity were introduced. However, these protocols also used the static estimated LL during the connection time. In contrast to that, in this paper two methods are presented to estimate LL based on nodes affinity and then continually update those values depending on changes of the affinity. In the first method, linear function is used to map the relationship between the signal strength fluctuation and LL. In the second method, fuzzy logic system is used to map this relationship in a nonlinear fashion. Significance of the proposed methods is validated using simulation. Results indicate that fuzzy method provides the most efficient and robust LL values for routing protocols.

GAIML: A new language for verbal and graphical interaction in chatbots

Abstract: Natural and intuitive interaction between users and complex systems is a crucial research topic in human-computer interaction. A major direction is the definition and implementation of systems with natural language understanding capabilities. The interaction in natural language is often performed by means of systems called chatbots. A chatbot is a conversational agent with a proper knowledge base able to interact with users. Chatbots appearance can be very sophisticated with 3D avatars and speech processing modules. However the interaction between the system and the user is only performed through textual areas for inputs and replies. An interaction able to add to natural language also graphical widgets could be more effective. On the other side, a graphical interaction involving also the natural language can increase the comfort of the user instead of using only graphical widgets. In many applications multi-modal communication must be preferred when the user and the system have a tight and complex interaction. Typical examples are cultural heritages applications (intelligent museum guides, picture browsing) or systems providing the user with integrated information taken from different and heterogenous sources as in the case of the iGoogle™ interface. We propose to mix the two modalities (verbal and graphical) to build systems with a reconfigurable interface, which is able to change with respect to the particular application context. The result of this proposal is the Graphical Artificial Intelligence Markup Language (GAIML) an extension of AIML allowing merging both interaction modalities. In this context a suitable chatbot system called Graphbot is presented to support this language. With this language is possible to define personalized interface patterns that are the most suitable ones in relation to the data types exchanged between the user and the system according to the context of the dialogue.

Employ a mobile agent for making a payment

Abstract: The mobile agent paradigm offers flexibility and autonomy to e-commerce applications. But it is challenging to employ a mobile agent to make a payment due to the security consideration. In this paper, we propose a new agent-assisted secure payment protocol, which is based on SET payment protocol and aims at enabling the dispatched consumer-agent to autonomously sign contracts and make the payment on behalf of the cardholder after having found the best merchant, without the possibility of disclosing any secret to any participant. This is realized by adopting the Signature-Share scheme, and employing a Trusted Third Party (TTP). In the proposed protocol, the principle that each participant knows what is strictly necessary for his/her role is followed as in SET. In addition, mechanisms have been devised for preventing and detecting double payment, overspending and overpayment attacks. Finally the security properties of the proposed protocol are studied analytically. In comparison with other existing models, the proposed protocol is more efficient and can detect more attacks.

Design and evaluation of reliable data transmission protocol in wireless sensor networks

Abstract: A wireless sensor-actuator network (WSAN) is composed of sensor modes and actuator modes which are interconnected in wireless networks. A sensor node collects information on the physical world and sends a sensed value in a wireless network. Another sensor node forwards the sensed value to deliver to an actuator node. A sensor node can deliver messages with sensed values to only nearby nodes due to weak radio. Messages are forwarded by sensor nodes to an actuator node by a type of flooding protocol. A sensor mode senses an event and sends a message with the sensed value. In addition, on receipt of a message with a sensed value from another sensor mode, a sensor node forwards the sensed value. Messages transmitted by sensor nodes might be lost due to noise and collisions. In this paper, we discuss a redundant data transmission (RT) protocol to reliably and efficiently deliver sensed values sensed by sensor nodes to an actuator node. Here, a sensor node sends a message with not only its sensed value but also sensed values received from other sensor nodes. The more number of sensed values are included in a message, the more frequently the message is lost. Each message carries so many number of sensed values that the message loss ratio is not increased. Even if a message with a sensed value v is lost in the wireless network, an actuator node can receive the sensed value v from a message sent by another sensor node. Thus, each sensed value is redundantly carried in multiple messages. The redundancy of a sensed value is in nature increased since the sensed value is broadcast. In order to reduce the redundancy of sensed value, we take a strategy that the farther sensor nodes from an actuator node forward the fewer number of sensed values. We evaluate the RT protocol in terms of loss ratio, redundancy, and delay time of a sensed value. We show that about 80% of sensed values can be delivered to an actuator node even if 95% of messages are lost due to noise and collision.

QoS management and control for an all-IP WiMAX network architecture: Design, implementation and evaluation

Abstract: The IEEE 802.16 standard provides a specification for a fixed and mobile broadband wireless access system, offering high data rate transmission of multimedia services with different Quality-of-Service (QoS) requirements through the air interface. The WiMAX Forum, going beyond the air interface, defined an end-to-end WiMAX network architecture, based on an all-IP platform in order to complete the standards required for a commercial rollout of WiMAX as broadband wireless access solution. As the WiMAX network architecture is only a functional specification, this paper focuses on an innovative solution for an end-to-end WiMAX network architecture offering in compliance with the WiMAX Forum specification. To our best knowledge, this is the first WiMAX architecture built by a research consortium globally and was performed within the framework of the European IST project WEIRD (WiMAX Extension to Isolated Research Data networks). One of the principal features of our architecture is support for end-to-end QoS achieved by the integration of resource control in the WiMAX wireless link and the resource management in the wired domains in the network core. In this paper we present the architectural design of these QoS features in the overall WiMAX all-IP framework and their functional as well as performance evaluation. The presented results can safely be considered as unique and timely for any WiMAX system integrator.

Mobile systems and applications

Abstract: Leonard Barolli, Hui-Huang Hsu and Yoshitaka Shibata aDepartment of Information and Communication Engineering, Faculty of Information Engineering, Fukuoka Institute of technology (FIT), 3-30-1 Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan E-mail: barolli@fitacjp bDepartment of Computer Science and Information Engineering, Tamkang University, 151 Ying-Chuan Road, Tamsui, Taipei, 25137, Taiwan E-mail: hhsu@cstkuedutw cFaculty of Software and Information Science, Iwate Prefectural University, 152-52 Sugo, Takizawa, Takizawa-mura 020-0193, Iwate, Japan E-mail: shibata@iwate-puacjp

A skeleton based programming paradigm for mobile multi-agents on distributed systems and its realization within the MAGDA Mobile Agents platform

Abstract: Parallel programming effort can be reduced by using high level constructs such as algorithmic skeletons. Within the MAGDA toolset, supporting programming and execution of mobile agent based distributed applications, we provide a skeleton-based parallel programming environment, based on specialization of Algorithmic Skeleton Java interfaces and classes. Their implementation include mobile agent features for execution on heterogeneous systems, such as clusters of WSs and PCs, and support reliability and dynamic workload balancing. The user can thus develop a parallel, mobile agent based application by simply specialising a given set of classes and methods and using a set of added functionalities.

Novel directory service and message delivery mechanism enabling scalable mobile agent communication

Abstract: Mobile agent technology has emerged as a promising programming paradigm for developing highly dynamic and large-scale service-oriented computing middlewares due to its desirable features. For this purpose, first of all, scalable location-transparent agent communication issue should be addressed in mobile agent systems despite agent mobility. Although there were proposed several directory service and message delivery mechanisms, their disadvantages force them not to be appropriate to both low-overhead location management and fast delivery of messages to agents migrating frequently. To mitigate their limitations, this paper presents a scalable distributed directory service and message delivery mechanism. The proposed mechanism enables each mobile agent to autonomously leave tails of forwarding pointers on some few of its visiting nodes depending on its preferences. This feature results in low message forwarding overhead and low storage and maintenance cost of increasing chains of pointers per host. Also, keeping mobile agent location information in the effective binding cache of each sending agent, the sending agent can communicate with mobile agents much faster compared with the existing ones.

Emergent behavior in massively-deployed sensor networks

Abstract: The phenomenal advances in MEMS and nanotechnology make it feasible to build small devices, referred to as sensors that are able to sense, compute and communicate over small distances. The massive deployment of these small devices raises the fascinating question of whether or not the sensors, as a collectivity, will display emergent behavior, just as living organisms do. In this work we report on a recent effort intended to observe emerging behavior of large groups of sensor nodes, like living cells demonstrate. Imagine a massive deployment of sensors that can be in two states "red" and "blue". At deployment time individual sensors have an initial color. The goal is to obtain a uniform coloring of the deployment area. Importantly, the sensors can only talk to sensors that are one-hop away from them. The decisions to change colors are local, based on what the sensors can infer from collecting color information from their neighbors. We have performed extensive simulations involving 20,000 sensors in an area of 100 m × 100 m. Our simulation results show that the sensor network converges to a stable uniform coloring extremely fast.

Coordination protocols for a reliable sensor, actuator, and device network (SADN)

Abstract: A sensor, actuator, and device network (SADN) is composed of three types of nodes, which are sensor, actuator, and actuation device nodes. Sensor nodes and actuator nodes are interconnected in wireless networks as discussed in wireless sensor and actuator networks (WSANs). Actuator nodes and device nodes are interconnected in types of networks, i.e. wireless and wired network. Sensor nodes sense an physical event and send sensed values of the event to actuator nodes. An actuator node makes a decision on proper actions on receipt of sensed values and then issue the action requests to the device nodes. A device node really acts to the physical world. For example, moves a robot arms by performing the action on receipt of the action request. Messages may be lost and nodes may be faulty. Especially, messages are lost due to noise and collision in a wireless network. We propose a fully redundant model for an SADN where each of sensor, actuator, and device functions is replicated in multiple nodes and each of sensor-actuator and actuator-device communication is realized in many-to-many type of communication protocols. Even if some number of nodes are faulty, the other nodes can perform requested tasks. Here, each sensor node sends sensed values to multiple actuator nodes and each actuator node receives sensed values from multiple sensor nodes. While multiple actuator nodes communicate with multiple replica nodes of a device. Even if messages are lost and some number of nodes are faulty, device nodes can surely receive action requests required for sensed values and the actions are performed. In this paper, we discuss a type of semi-passive coordination (SPC) protocol of multiple actuator nodes for multiple sensor nodes. We discuss a type of active coordination protocol for multiple actuator nodes and multiple actuation device nodes. We evaluate the SPC protocol for the sensor-actuator coordination in terms of the number of messages exchanged among actuators.

Norms for modeling agents' interaction in ubiquitous environments

Abstract: In ubiquitous environments a vast amount of mobile human and software entities, each with limited resources and knowledge, needs to interact with each other to achieve common and/or individual goals within a specific context. Due to their autonomy, proactiveness, mobility, social capability, and the successful implementation of agent mediated applications and services over the Web, different scenarios have been proposed in literature for the use of agents in ubiquitous environments for a wide range of applications such as user interfaces, mobile computing, information retrieval and filtering, smart messaging, telecommunication and m-commerce. In this paper, we address the problem of modeling agents' interaction in ubiquitous environments. We argue agents' interactions can be modeled using norms, which are represented mathematically as zero set of n-variate functions. We utilize the barycentic coordinates to show how agents should behave based on established protocols, rules of conduct or accepted social practices.