物件導向軟體之架構(Object-Oriented Software Construction)探討

The term ‘‘Internet-of-Things’’ is used as an umbrella keyword for covering various aspects related to the extension of the Internet and the Web into the physical realm, by means of the widespread deployment of spatially distributed devices with embedded identification, sensing and/or actuation capabilities. Internet-of-Things envisions a future in which digital and physical entities can be linked, by means of appropriate information and communication technologies, to enable a whole new class of applications and services. In this article, we present a survey of technologies, applications and research challenges for Internetof-Things.

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Internet of things: Vision, applications and research challenges

A mobile ad hoc network consists of wireless hosts that may move often. Movement of hosts results in a change in routes, requiring some mechanism for determining new routes. Several routing protocols have already been proposed for ad hoc networks. This report suggests an approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks.

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Location-aided routing (LAR) in mobile ad hoc networks

Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

Parallel discrete event simulation (PDES), sometimes called distributed simulation, refers to the execution of a single discrete event simulation program on a parallel computer. PDES has attracted a considerable amount of interest in recent years. From a pragmatic standpoint, this interest arises from the fact that large simulations in engineering, computer science, economics, and military applications, to mention a few, consume enormous amounts of time on sequential machines. From an academic point of view, parallel simulation is interesting because it represents a problem domain that often contains substantial amounts of parallelism (e.g., see [59]), yet paradoxically, is surprisingly difficult to parallelize in practice. A sufficiently general solution to the PDES problem may lead to new insights in parallel computation as a whole. Historically, the irregular, data-dependent nature of PDES programs has identified it as an application where vectorization techniques using supercomputer hardware provide little benefit [14].A discrete event simulation model assumes the system being simulated only changes state at discrete points in simulated time. The simulation model jumps from one state to another upon the occurrence of an event. For example, a simulator of a store-and-forward communication network might include state variables to indicate the length of message queues, the status of communication links (busy or idle), etc. Typical events might include arrival of a message at some node in the network, forwarding a message to another network node, component failures, etc.We are especially concerned with the simulation of asynchronous systems where events are not synchronized by a global clock, but rather, occur at irregular time intervals. For these systems, few simulator events occur at any single point in simulated time; therefore parallelization techniques based on lock-step execution using a global simulation clock perform poorly or require assumptions in the timing model that may compromise the fidelity of the simulation. Concurrent execution of events at different points in simulated time is required, but as we shall soon see, this introduces interesting synchronization problems that are at the heart of the PDES problem.This article deals with the execution of a simulation program on a parallel computer by decomposing the simulation application into a set of concurrently executing processes. For completeness, we conclude this section by mentioning other approaches to exploiting parallelism in simulation problems.Comfort and Shepard et al. have proposed using dedicated functional units to implement specific sequential simulation functions, (e.g., event list manipulation and random number generation [20, 23, 47]). This method can provide only a limited amount of speedup, however. Zhang, Zeigler, and Concepcion use the hierarchical decomposition of the simulation model to allow an event consisting of several subevents to be processed concurrently [21, 98]. A third alternative is to execute independent, sequential simulation programs on different processors [11, 39]. This replicated trials approach is useful if the simulation is largely stochastic and one is performing long simulation runs to reduce variance, or if one is attempting to simulate a specific simulation problem across a large number of different parameter settings. However, one drawback with this approach is that each processor must contain sufficient memory to hold the entire simulation. Furthermore, this approach is less suitable in a design environment where results of one experiment are used to determine the experiment that should be performed next because one must wait for a sequential execution to be completed before results are obtained.

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Parallel discrete event simulation

In Long Term Evolution (LTE), Voice over Internet Protocol (VoIP) is used for the delivery of the voice data. One of the major challenges for VoIP over LTE is to guarantee the Quality of Experience (QoE) of the VoIP calls. This paper uses an LTE base station emulator and a radio channel emulator to evaluate the impacts of different User Equipment (UE) velocities and Radio Link Control (RLC) parameter values on the QoE of the calls in the vehicular environment. Our study shows that LTE can provide acceptable VoIP quality in the high-speed scenarios (e.g., high-speed train). This paper provides the guidelines for the telecommunications operators to select the appropriate parameter values when deploying their VoIP services in LTE.

QoE-Aware LTE Radio Link Control Parameters for Voice over IP in Vehicular Environments

This paper describes a threshold-based wake-up mechanism to reduce the battery power consumption of a mobile data handset. The threshold approach switches the system into the sleep mode when the memory queue for arriving packets is empty, and switches on the system when the number of packets in the memory queue is above a threshold value. We propose several adaptive schemes capable of dynamically selecting the threshold value for the threshold approach. An adaptive algorithm adjusts the threshold value based on a pre-defined packet-dropping probability, for which the switch-on rate is kept reasonably small to maintain the actual packet-dropping probability as close as the pre-defined value. Two strategies are used in the adaptive algorithm to adjust the threshold value: binary-division and fixed-amount. Two calculation strategies are considered to measure the packet-dropping probability: window-averaging and leaky-bucket integration (LBI). Our study indicates that the binary-division strategy outperforms the fixed-amount strategy in adjusting the threshold value. Furthermore, with proper setting, the LBI strategy outperforms the window-averaging strategy.

Adaptive schemes for reducing power consumption of mobile data handsets

Due to climate change, Spodoptera litura has the potential to become an increasingly severe pest because of increased habitat suitability. To support precision agriculture, it is essential to accurately predict the life cycle of Spodoptera litura, and use the information for pest control. This paper proposes BugTalk to predict the life of Spodoptera litura (Common Cutworm). Based on the Internet of Things (IoT) technology, BugTalk is a real-time prediction version of modified Insect Life Cycle Modeling software (ILCYM), an open-source software package that implements the functions used in the four models of the four life stages of Spodoptera litura. In this paper, we significantly improve the ILCYM functions and several models of the previous studies to improve the accuracy of the prediction. We develop the first real-time prediction system that can predict the number of Spodoptera litura for the farm fields in real-time. The results are compared with the measurements during 2014-2020. We extend the temperature-based ILCYM model to accommodate humidity for the larvae emergence stage, which further improves the accuracy of the model. The Mean Arctangent Absolute Percentage Error (MAAPE) between the measurements and the BugTalk prediction is 24.593%. This result has been practically utilized in farm management.

BugTalk: Online Prediction for the Life of Spodoptera Litura (Common Cutworm)

This column describes ParadeTalk, an IoT based system that allows innovative interactions between parade floats and audiences By using the sensors and the actuators of AgriTalk, a commercially operated smart agriculture solution, we implement ParadeTalk in the Singpoli parade float of the Pasadena Tournament of Roses Parade in California, USA We describe how the sensors/controls are connected to the objects in the parade float We hope that parade audiences will learn basic ideas of smart farming in the rose decorated float when they enjoy interacting with the float We also analyze how the delays of the IoT messages affect the interaction between the parade flow and the audience members ParadeTalk is a success story that implements a sustainable IoT application commercially operated

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ParadeTalk: Innovative Interactions between Parade and Audiences Using IoT

A cordless telephone system (or as it is sometimes called a low power personal communications services system) provides telephone services to moving users. The Cordless Telephone Second generation (CT2) is a digital cordless telephone system developed in Europe in 1989. The CT2 system provides high speech quality (32 kb/s speech rate) with low power consumption (the maximum transmit power is 10 mW). While the radio aspect of CT2 has been extensively discussed, the network aspect is seldom mentioned in the literature. This article introduces the CT2 call control procedures (specifically, call origination and call delivery) from the network aspect. We first describe the call control procedures for a private CT2 system in a company building. Then we describe the procedures for a public CT2 system.

Yi-Bing Lin

Papers

QoE-Aware LTE Radio Link Control Parameters for Voice over IP in Vehicular Environments

Adaptive schemes for reducing power consumption of mobile data handsets

BugTalk: Online Prediction for the Life of Spodoptera Litura (Common Cutworm)

ParadeTalk: Innovative Interactions between Parade and Audiences Using IoT

Calling for control