Voice quality evaluation in wireless packet communication systems: a tutorial and performance results for RHC

As wireless systems evolve toward supporting a wide array of services, including traditional voice service, using packet-switched transport, it becomes increasingly important to assess the impact of packet-switched transport protocols on voice quality, in this article we present a tutorial on voice quality evaluation for wireless packet-switched systems. We introduce an evaluation methodology that combines elementary objective voice quality metrics with a frame synchronization mechanism. The methodology allows networking researchers to conduct effective and accurate quality evaluation of packet voice. To illustrate the use of the described evaluation methodology and interpretation of the results, we conduct a case study of the impact of robust header compression (ROHC) on the voice quality achieved with real-time transmission of GSM encoded voice over a wireless link.     

Method for assessing remaining life in electronic assemblies

A physics-of-failure based methodology is presented for determining the remaining life in electronic assemblies. The methodology has three steps. The first step is to conduct an analysis of the degradation in electronic assemblies resulting from their storage or use, in order to determine the potential failure mechanisms. The second step is to use physics-of-failure models for these mechanisms to define test conditions and durations that produce similar damage as that expected in the intended application but in a much shorter time. The third step is to perform these accelerated tests on used and unused assemblies and to conduct subsequent failure/degradation analysis of the tested assemblies. This third step provides the information needed to determine if the assembly has sufficient life to survive in the intended application. This methodology is demonstrated by determining the remaining life of electronic assemblies operated intermittently in refrigerators.     

Performance‐based evaluations of the tangible benefits of information networks with applications

This paper provides a new methodology for the evaluation of the tangible benefits of information networks, based on their utilization and performance. The methodology enables the evaluation of different tangible benefits including those resulting from time, movement, paper, and space savings. Copyright © 2000 John Wiley & Sons, Ltd.     

电子信息装备体系贡献率综合集成法评估

体系贡献率是电子信息装备体系效能评估的一项重要指标。以一个典型的电子信息装备体系为例,研究电子装备体系的基本内涵,分析电子装备体系的开放性、动态演化性等基本特性,提出运用系统论的方法来研究电子信息装备体系贡献率评估的问题。基于系统论的综合集成方法,以雷达装备为例研究了典型电子信息装备体系贡献率评估的综合集成法流程,详细给出流程中的3个重要步骤,主要包括电子信息装备体系贡献率的内涵、本质特点、作用模式等的定性综合集成形成初步判断和认识,体系贡献率定性与定量相结合评估指标选取与评估,以及体系贡献率评估指标分析验证实现从定性到定量的综合集成方法论,为电子装备试验体系贡献率试验与评估提供借鉴和参考。     

Journal quality assessment: an integrated subjective and objectiveapproach

Many universities, research institutions, and government funding agencies are continuously attempting to grade or rank journals for their academic value. Such grading is needed both for funding and resource allocation purposes and for personnel decisions. In grading journals, objective information, such as the impact factors (the most commonly used journal citation information provided by Journal Citation Reports) and/or subjective information, such as experts' judgments about the journals, are used. Grading of journals is typically done by a committee. Most of the existing approaches only consider either the subjective or the objective information. While such approaches work in many cases, they may not work in many others. Complaints about politics, inconsistencies and unfairness are common in many situations. This paper presents a methodology that integrates both types of information, providing a comprehensive method for assessing the quality of journals. The method employs a fuzzy set approach that also deals with the imprecise and missing information frequently inherited in the evaluation process. The proposed evaluation model is implemented in a Web-based system. A pilot evaluation study indicated that participants clearly preferred the system and its major features     

MaRMI‐III: A Methodology for Component‐Based Development

As component‐based development (CBD) rapidly spread throughout the software industry, a comprehensive methodology is needed to apply it more systematically. For this purpose, a new CBD methodology named Magic & Robust Methodology Integrated III (MaRMI‐III) has been developed. The purpose of this paper is to present MaRMI‐III by its constituent processes and claim that it can be used to support system developers conduct CBD in a consistent manner. First, we review the CBD approach to system development and the role of CBD methodology, and then we explain the several characteristics of MaRMI‐III which are considered necessary to the CBD environment. Next, we explain a process model of MaRMI‐III which separates the development process from the project management process and prescribes well‐ordered activities and tasks that the developer should conduct. Each phase forming the Process Model is explained in terms of its objectives and main constituent activities. Some techniques and workproducts related to each phase are also explained. Finally, to examine the usefulness of MaRMI‐III, an analytical comparison with other CBD methodologies and the results of a questionnaire survey are described.     

Capacity of full frame DCT image watermarks

The evaluation of the number of bits that can be hidden within an image through digital watermarking is a crucial topic, which has been addressed only for additive watermarks. The evaluation of watermark capacity is very important because it allows to put a theoretical upper bound on the amount of information that can be hidden into an image by a given watermarking procedure, regardless of the watermark extraction technique. It is the purpose of this work to suggest a methodology for the evaluation of the watermark capacity in a nonadditive, non-Gaussian framework, and to discuss the results we obtained by applying it to a set of standard images.     

Adaptive appearance modeling for video tracking: survey and evaluation

Long-term video tracking is of great importance for many applications in real-world scenarios. A key component for achieving long-term tracking is the tracker's capability of updating its internal representation of targets (the appearance model) to changing conditions. Given the rapid but fragmented development of this research area, we propose a unified conceptual framework for appearance model adaptation that enables a principled comparison of different approaches. Moreover, we introduce a novel evaluation methodology that enables simultaneous analysis of tracking accuracy and tracking success, without the need of setting application-dependent thresholds. Based on the proposed framework and this novel evaluation methodology, we conduct an extensive experimental comparison of trackers that perform appearance model adaptation. Theoretical and experimental analyses allow us to identify the most effective approaches as well as to highlight design choices that favor resilience to errors during the update process. We conclude the paper with a list of key open research challenges that have been singled out by means of our experimental comparison.     

On quality of experience of scalable video adaptation

In this paper, we study the quality of experience (QoE) issues in scalable video coding (SVC) for its adaptation in video communications. A QoE assessment database is developed according to SVC scalabilities. Based on the subjective evaluation results, we derive the optimal scalability adaptation track for the individual video and further summarize common scalability adaptation tracks for videos according to their spatial information (SI) and temporal information (TI). Based on the summarized adaptation tracks, we conclude some general guidelines for the effective SVC video adaptation. A rate-QoE model for SVC adaptation is derived accordingly. Experimental results show that the proposed QoE-aware scalability adaptation scheme significantly outperforms the conventional adaptation schemes in terms of QoE. Moreover, the proposed QoE model reflects the rate and QoE relationship in SVC adaptation and thus, provides a useful methodology to estimate video QoE which is important for QoE-aware scalable video streaming.     

基于粗糙孤立点检测的安全风险分析方法

Security is a nonfunctional information system attribute that plays a crucial role in wide sensor network application domains. Security risk can be quantified as the combination of the probability that a sensor network system may fail and the evaluation of the severity of the damage caused by the failure. In this paper, we devise a methodology of Rough Outlier Detection (ROD) for the detection of security-based risk factor, which originates from violations of attack requirements ( namely, attack risks). The methodology elaborates dimension reduction method to analyze the attack risk probability from high dimensional and nonlinear data set, and combines it with rough redundancy reduction and the distance measurement of kernel function which is obtained using the ROD. In this way, it is possible to determine the risky scenarios, and the analysis feedback can be used to improve the sensor network system design. We illustrate the methodology in the DARPA case set study using step-by-step approach and then prove that the method is effective in lowering the rate of false alarm.     

Explicit incorporation of prior anatomical information into a nonrigid registration of thoracic and abdominal CT and 18-FDG whole-body emission PET images

The aim of this paper is to develop a registration methodology in order to combine anatomical and functional information provided by thoracic/abdominal computed tomography (CT) and whole-body positron emission tomography (PET) images. The proposed procedure is based on the incorporation of prior anatomical information in an intensity-based nonrigid registration algorithm. This incorporation is achieved in an explicit way, initializing the intensity-based registration stage with the solution obtained by a nonrigid registration of corresponding anatomical structures. A segmentation algorithm based on a hierarchically ordered set of anatomy-specific rules is used to obtain anatomical structures in CT and emission PET scans. Nonrigid deformations are modeled in both registration stages by means of free-form deformations, the optimization of the control points being achieved by means of an original vector field-based approach instead of the classical gradient-based techniques, considerably reducing the computational time of the structure registration stage. We have applied the proposed methodology to 38 sets of images (33 provided by standalone machines and five by hybrid systems) and an assessment protocol has been developed to furnish a qualitative evaluation of the algorithm performance.     

Standardized evaluation methodology for 2-D-3-D registration

In the past few years, a number of two-dimensional (2-D) to three-dimensional (3-D) (2-D-3-D) registration algorithms have been introduced. However, these methods have been developed and evaluated for specific applications, and have not been directly compared. Understanding and evaluating their performance is therefore an open and important issue. To address this challenge we introduce a standardized evaluation methodology, which can be used for all types of 2-D-3-D registration methods and for different applications and anatomies. Our evaluation methodology uses the calibrated geometry of a 3-D rotational X-ray (3DRX) imaging system (Philips Medical Systems, Best, The Netherlands) in combination with image-based 3-D-3-D registration for attaining a highly accurate gold standard for 2-D X-ray to 3-D MR/CT/3DRX registration. Furthermore, we propose standardized starting positions and failure criteria to allow future researchers to directly compare their methods. As an illustration, the proposed methodology has been used to evaluate the performance of two 2-D-3-D registration techniques, viz. a gradient-based and an intensity-based method, for images of the spine. The data and gold standard transformations are available on the internet (http://www.isi.uu.nl/Research/Databases/).     

Classification and evaluation of IoT brokers: A methodology

Since the term Internet of Things (IoT) was coined by Kevin Ashton in 1999, a number of middleware platforms have been developed to cope with important challenges such as the integration of different technologies. In this context of heterogeneous technologies, IoT message brokers become critical elements for the proper function of smart systems and wireless sensor networks (WSN) infrastructures. There are several evaluations made on IoT messaging middleware performance. Nevertheless, most of them ignore crucial aspects of the IoT context that also need to be included, such as reliability and other qualitative aspects. Thus, in this article, we propose a methodology for classification and evaluation of IoT brokers to help the scientific community and technology industry on evaluating them according to their interests, without leaving out important aspects for the context of smart environments. Our methodology bases its qualitative evaluations on the ISO/IEC 25000 (SQuaRE) set of standards and its quantitative evaluations on Jain's process for performance evaluation. We developed a case study to illustrate our proposal with 12 different open-source brokers, validating the feasibility of our methodological approach.     

Continuous equipment diagnosis using evidence integration: an LPCVDapplication

A diagnostic system that employs the Dempster-Shafer (D-S) evidential reasoning technique to conduct malfunction diagnosis on semiconductor manufacturing equipment has been developed. This is accomplished by combining the continuous stream of information that originates from maintenance status records, from real-time sensor measurements, and from the differences between inline measurements and values predicted by equipment models. Using this information, equipment malfunctions are analyzed and their causes are inferred through the resolution of qualitative and quantitative constraints. The qualitative constraints describe the normal operation of the equipment. The quantitative constraints are numerical models that apply to the manufacturing step in question. These models are specifically created and characterized through experimentation and statistical analysis, and they can be updated to reflect equipment aging. The violation of these constraints is linked to the evaluation of continuous belief functions for the calculation of the belief associated with the various types of failure. The belief functions encapsulate the experience of many equipment maintenance specialists. Once created, the belief functions can be fine-tuned automatically, drawing from historical maintenance records. These records are stored in symbolic form to facilitate this task, and they must be updated to track equipment changes over time. A prototype of this diagnostic system was implemented in an object-oriented programming environment. The effectiveness of this technique was demonstrated on a low-pressure chemical vapor deposition (LPCVD) reactor used for the deposition of undoped polysilicon     

一种分布式网络环境下基于挑战-响应模型的可信评估方法

运用信任模型进行可信评估是解决分布式网络安全问题的重要手段。然而,目前大部分研究工作把研究重点放在如何收集更完整的信任证据,以及如何利用一些新手段如机器学习、区块链等评估节点信任值,很少对如何获取节点可靠的初始信任值进行研究。实际上,针对分布式网络提出的很多信任模型都依赖于历史信任证据,而初次对网络进行可信评估时并不具备相关历史信息。基于此,该文面向分布式网络环境的安全问题,提出了基于挑战-响应模型的可信评估方法。首先利用挑战-响应模型获取节点可靠的初始信任值,并利用此初始信任值对网络中的节点进行分簇,在簇内进行信任值计算和信任值更新,完成分布式网络环境下完整的可信评估流程。仿真结果表明,相较于统一设置初始信任值的方式,该文所提方法能对恶意节点、自私节点的信任值有较准确的预测,同时对恶意节点的检测率也更高。     

Increasing the accuracy of thermal transient measurements

Recent developments in the methodology of thermal transient measurements and evaluation are discussed in the paper. All of them are aimed at increasing the accuracy of these measurements and their evaluation. After a short summary of the evaluation methodology a procedure is presented for the correction of the nonconstant powering. New methods are presented for the compensation, evaluation and modeling of the nonlinearities. Various aspects of pulsed powering are discussed in detail.     

Quantitative spectrum occupancy evaluation in China: based on a large scale concurrent spectrum measurement

Due to the usable frequency becomes more and more crowed,dynamic spectrum access (DSA) is a new hope to solve this problem.However,DSA in China requires a quantitative analysis of the current spectrum ...     

Changeover Improvement: Reinterpreting Shingo's “SMED” Methodology

A rapid changeover capability is widely acknowledged as an essential prerequisite to flexible, responsive small batch manufacturing. Its importance in mass customization is recognized, where minimal losses need to be incurred as manufacture switches between differing products. Retrospective improvement of existing changeover practice is often undertaken, arising from pressure to respond better to customer demands, wherein improvement personnel frequently engage Shigeo Shingo's Single Minute Exchange of Die (SMED) methodology to achieve better performance. Irrespective of the improvement methodology that is employed this paper assesses two fundamental mechanisms by which better changeovers might be achieved. First, improvement can occur by altering when tasks are conducted. Better allocation of tasks to the resources necessary to conduct them is sought, where the tasks themselves remain essentially unchanged. The second mechanism is to seek structural change to existing tasks, thereby intrinsically enabling them to be completed more quickly. These two mechanisms are described in relation to use of the SMED methodology, where it is argued that, by reinterpreting Shingo's work, greater clarity of potential improvement options can be gained     

Real-time channel emulation for mobile communcation test beds

This article describes a methodology to model in real-time the channel quality variations for mobile communication systems. This method was used to implement a GSM hardware test bed employed to demonstrate the improved perceived voice quality obtained with link adaptation. Real-time operation is achieved by use of a large error pattern database, derived for time varying channel models. The modular design of the demonstrator and the reusability of the database enable a relatively straightforward extension to conduct novel multi-channel link level investigations. The proposed methodology can be adapted for a range of radio interfaces.     

军事电子信息系统测试评估工具的研究与实践

结合测试评估工具的研究与软件开发实践,对军事电子信息系统测试评估工具的设计与开发进行了分析研究,总结出军事电子信息系统测试评估软件的特点、设计原则和开发策略.归纳了反映军事电子信息系统典型指标统计特性的各种图表的功能及作用,提出了设计军用测评软件的完整方法.最后结合具体实例说明军用测评软件在测试评估中的功能以及达到的效果.