Input validation analysis and testing

This research addresses the problem of statically analyzing input command syntax as defined in interface and requirements specifications and then generating test cases for dynamic input validation testing. The IVAT (Input Validation Analysis and Testing) technique has been developed, a proof-of-concept tool (MICASA) has been implemented, and a case study validation has been performed. Empirical validation on large-scale industrial software (from the Tomahawk Cruise Missile) shows that as compared with senior, experienced analysts and testers, MICASA found more syntactic requirement specification defects, generated test cases with higher syntactic coverage, and found additional defects. The experienced analysts found more semantic defects than MICASA, and the experienced testers’ cases found 7.4 defects per test case as opposed to an average of 4.6 defects found by MICASA test cases. Additionally, the MICASA tool performed at less cost.

Bridging the physical and virtual worlds by local connectivity-based physical selection

The prevalent visions of ambient intelligence emphasise natural interaction between user and functions and services embedded in the environment or available through mobile devices. In these scenarios the physical and virtual worlds seamlessly gear into each other, making crossing the border between these worlds natural or even invisible to the user. The bottleneck in reaching these scenarios appear in the natural mapping between the physical objects and their virtual counterparts. The emergence of local connectivity in mobile devices opens possibilities for implementing novel user interface paradigms to enhance this mapping. We present physical selection paradigm for implementing an intuitive human technology interaction for mobile devices. In order to demonstrate the feasibility of the paradigm we implemented two experimental set-ups using commercially available smart phones with IrDA connectivity. The experiments involved selecting a website by physically pointing at its symbol and making a phone call by pointing at an icon representing the person to be called. In tentative user experiments the physical selection method was more time-efficient and it was perceived more positively by the users than a conventional method.

The Racket virtual machine and randomized testing

We present a PLT Redex model of a substantial portion of the Racket virtual machine and bytecode verifier (formerly known as MzScheme), along with lessons learned in developing the model. Inspired by the “warts-and-all” approach of the VLISP project, in which Wand et al. produced a verified implementation of Scheme, our model reflects many of the realities of a production system. Our methodology departs from the VLISP project’s in its approach to validation; instead of producing a proof of correctness, we explore the use of QuickCheck-style randomized testing, finding it a cheap and effective technique for discovering a variety of errors in the model—from simple typos to more fundamental design mistakes.     

The virtual world gets physical: perspectives on personalization

MusicFX and GroupCast illustrate some benefits possible from extending the personalization of electronic content in the virtual world to applications in the physical world. Utilizing individual preferences in the physical world, particularly in public spaces, infringes on people's privacy more than it does in the virtual world, where it is easier to maintain different addresses and aliases that can shield or mask personal details from online interactions. However, the use of these preferences in a group context, where some degree of plausible deniability exists, may diminish people's concerns. If sufficient benefits are provided - think of a world without "elevator music" - people might even embrace the technologies that will make adaptive environments possible     

How to model and implement connections between physical and virtual models for digital twin application

Digital twin (DT) is a virtual mirror (representation) of a physical world or a system along its lifecycle. As for a complex discrete manufacturing system (DMS), it is a digital model for emulating or reproducing the functions or actions of a real manufacturing system by giving the system simulation information or directly driven by a real system with proper connections between the DT model and the real-world system. It is a key building block for smart factory and manufacturing under the Industry 4.0 paradigm. The key research question is how to effectively create a DT model during the design stage of a complex manufacturing system and to make it usable throughout the system’s lifecycle such as the production stage. Given that there are some existing discussions on DT framework development, this paper focuses on the modeling methods for rapidly creating a virtual model and the connection implementation mechanism between a physical world production system at a workshop level and its mirrored virtual model. To reach above goals, in this paper, the discrete event system (DES) modeling theory is applied to the three-dimension DT model. First, for formally representing a manufacturing system and creating its virtual model, seven basic elements: controller, executor, processor, buffer, flowing entity, virtual service node and logistics path of a DMS have been identified and the concept of the logistics path network and the service cell is introduced to uniformly describe a manufacturing system. Second, for implementing interconnection and interaction, a new interconnection and data interaction mechanism between the physical system and its virtual model for through-life applications has been designed. With them, each service cell consists of seven elements and encapsulates input/output information and control logic. All the discrete cells are constructed and mapped onto different production-process-oriented digital manufacturing modules by integrating logical, geometric and data models. As a result, the virtual-physical connection is realized to form a DT model. The proposed virtual modeling method and the associated connection mechanism have been applied to a real-world workshop DT to demonstrate its practicality and usefulness.     

虚拟维修模型的校验方法研究

介绍了虚拟雏修与建模仿真的关系,分析了虚拟维修模型校验的特点,研究了虚拟维修模型校验的方法,分别应用置信区间法、假设检验法、Bayes法、TIC法、频谱分析法从静态性能和动态性能两个方面对模型实施校验,从而为虚拟维修模型准确性、实时性提供了较为可靠的验证方法.为虚拟维修模型的校验提供一套系统的理论和方法,有利于虚拟维修模型得到更好应用.     

Quantifying software validation: when to stop testing?

The authors explain how to use reliability models to determine how much system testing to do and how to allocate resources among the components to be tested. They begin by discussing the basic concepts of software reliability. They examine the functions, presuppositions, and basic procedures of system testing, as well as testing comparison and the use of calendar-time component to predict when testing will be completed. They then discuss acceptance testing. The authors conclude with examples of actual applications     

Assessing and improving state-based class testing: a series of experiments

This work describes an empirical investigation of the cost effectiveness of well-known state-based testing techniques for classes or clusters of classes that exhibit a state-dependent behavior. This is practically relevant as many object-oriented methodologies recommend modeling such components with statecharts which can then be used as a basis for testing. Our results, based on a series of three experiments, show that in most cases state-based techniques are not likely to be sufficient by themselves to catch most of the faults present in the code. Though useful, they need to be complemented with black-box, functional testing. We focus here on a particular technique, Category Partition, as this is the most commonly used and referenced black-box, functional testing technique. Two different oracle strategies have been applied for checking the success of test cases. One is a very precise oracle checking the concrete state of objects whereas the other one is based on the notion of state invariant (abstract states). Results show that there is a significant difference between them, both in terms of fault detection and cost. This is therefore an important choice to make that should be driven by the characteristics of the component to be tested, such as its criticality, complexity, and test budget.     

Using smartphone technology to deliver a virtual pedestrian environment: usability and validation

Various programs effectively teach children to cross streets more safely, but all are labor- and cost-intensive. Recent developments in mobile phone technology offer opportunity to deliver virtual reality pedestrian environments to mobile smartphone platforms. Such an environment may offer a cost- and labor-effective strategy to teach children to cross streets safely. This study evaluated usability, feasibility, and validity of a smartphone-based virtual pedestrian environment. A total of 68 adults completed 12 virtual crossings within each of two virtual pedestrian environments, one delivered by smartphone and the other a semi-immersive kiosk virtual environment. Participants completed self-report measures of perceived realism and simulator sickness experienced in each virtual environment, plus self-reported demographic and personality characteristics. All participants followed system instructions and used the smartphone-based virtual environment without difficulty. No significant simulator sickness was reported or observed. Users rated the smartphone virtual environment as highly realistic. Convergent validity was detected, with many aspects of pedestrian behavior in the smartphone-based virtual environment matching behavior in the kiosk virtual environment. Anticipated correlations between personality and kiosk virtual reality pedestrian behavior emerged for the smartphone-based system. A smartphone-based virtual environment can be usable and valid. Future research should develop and evaluate such a training system.     

一种基于时频控制方法的控制器设计与实验

为提升被控系统在整个工作频域内的动态性能,本文提出一种时频(time-frequency,TF)控制方法的理论框架,该框架通过应用小波分析技术以提高传统控制器性能的方式达到上述目标.在阐述了此框架下TF控制机理的基础上,结合传统PI控制方法设计了一种时频PI(time-frequency PI,TFPI)控制器,并对TFPI控制器中时频参数的设计原理进行了分析.针对TFPI控制器中参数众多所导致的整定工作量增大的问题,结合最优控制理论中积分型性能指标的概念,建立了以单纯形优化方法为手段的参数自动寻优策略.最后以电磁阀控制液压缸系统模型为例进行了控制器硬件在环仿真测试.阶跃响应结果显示,在超调量不超过1%的要求下,相对传统PI控制器0.15s左右的响应时间,TFPI控制器响应时间可达0.06s,在不失稳定性的情况下显著提升系统的动态性能;此外,与文献中其他两种TF控制算法亦进行了仿真比较,结果进一步证明了该控制方法在系统动态性能提升方面的有效性.     

Single-channel EEG measurement of engagement in virtual rehabilitation: a validation study

Virtual Reality - Stroke rehabilitation suffers from low levels of patient engagement, impeding recovery. Virtual rehabilitation (VR) approaches can improve patient outcomes; however, there is...     

Multi-station equipment for physical training: design and validation of a prototype

The design of a prototype multi-station exercise machine is described. Resistance models and muscle groups used varied between stations which were constructed to accommodate a wide range of individual differences. The apparatus was validated using time-motion analysis, anthropometry, subjective user responses and physiological methods. Problems at the man-machine interface were identified, and risk and discomfort factors minimised. The equipment is recommended for use both to athletes for specific conditioning and to recreational users for endurance and strength training.     

Strategic channel alignment: an analysis of the configuration of physical and virtual marketing channels

Extensive integration of online and offline channels is often described as the most preferable strategy for multi channel retailing. However, empirical findings challenge this assumption by showing that retailers choose a variety of disparate multi channel strategies. Given this variety, we conjecture that there is no single best approach to multi channel retailing, but that, depending on the general marketing strategy, different multi channel strategies can be suitable for retailers. We develop a model of strategic channel alignment and identify four different paths of channel alignment, which we use to reconstruct and interpret multi channel strategies as an alignment of general marketing strategy and online strategy. An application of the model to four prominent and successful cases from the grocery retailing industry shows that although the companies pursue fundamentally different multi channel strategies, they can all be considered as examples of successful alignment and mature multi channel strategies.     

Integrating virtual and physical context to support knowledge workers

The Kimura system augments and integrates independent tools into a pervasive computing system that monitors a user's interactions with the computer, an electronic whiteboard, and a variety of networked peripheral devices and data sources.     

Application of machine vision in improving safety and reliability for gear profile measurement

This research presents a camera-based measurement system which is developed to improve the safety and reliability for gear profile measurement system. Gear profile measurement is vital in precision engineering. To increase the safety and reliability of the precision measurement, application of camera or vision is very useful. Automatic control is also necessary to increase reliability of the measurement system. Normally, gear profiles are measured using contact-based stylus system. During gear profile measurement, human monitoring is required to avoid accident and sometimes we may face great danger regarding safety of our body especially eyes. The stylus is sharp and thin and if it is collided to the gear teeth there is high probability of breaking and scattering the stylus tip. To save time, if the measurement probe scans the gear shape with a speed of 10 mm/s then the issue of safety should be considered highly. The traditional methods for gear measurement are either time consuming or expensive. This paper presents the successful implementation of the camera system in precision measurement which saves time and increases safety and reliability of the measurement with the increment of the measurement performance by increasing production rate. Color-based stylus tracking algorithm is implemented to acquire better reliability of the complete system. Thus, the developed system with vision enhances safety and reliability of the precision measurement.     

Differences in virtual and physical head orientation predict sickness during active head-mounted display-based virtual reality

Virtual Reality - During head-mounted display (HMD)-based virtual reality (VR), head movements and motion-to-photon-based display lag generate differences in our virtual and physical head pose...     

The influence of self-discrepancy between the virtual and real selves in virtual communities

Virtual communities enable one to pretend to be a different person or to possess a different self-identity at little or no cost. Despite the ubiquity of such communities, there is limited theoretical and empirical research regarding the effect of taking on a different self-identity associated with one’s psychological and behavioral functioning in those communities. To address this issue, drawing on the self-concept rooted in sociopsychology, this study employs the self-discrepancy index, which assesses the degree of differences between one’s virtual and real selves; the study goes onto develop a theoretical framework that links self-discrepancy, psychological states (i.e., autonomy, recovery, and catharsis), and behavior (i.e., contribution quality and quantity). The results of an analysis involving 299 survey participants show that self-discrepancy has a significant influence on autonomy and recovery and that this, in turn, influences levels of contribution quality and quantity. It is of note that the results of this study indicate that catharsis is inversely related to contribution quality. Furthermore, subgroup analysis reveals that the effects of self-discrepancy on contribution vary depending on whether the virtual community is utilitarian or hedonic.     

Subjective visual vertical in virtual reality (Curator SVV): validation and normative data

Subjective visual vertical (SVV) assesses the ability to perceive verticality, which is a measure of vestibular otolithic function. Vestibular lesions influence this perception of verticality. We developed a method using virtual reality (VR) display and an Android software application named ‘Curator SVV’. The virtual reality SVV (Curator SVV) consisted of ten readily identifiable artworks projected by a Samsung phone S6 which is inserted into a virtual reality headset. In the first study, 20 patients had there SVV assessed with two devices: (1) a commercially available SVV measurement device (VestiTest^®) and (2) a virtual reality SVV using the Curator SVV application. In a second study, 32 healthy subjects had their SVV assessed by the Curator SVV application whilst sitting in a chair. In the first study, there was no significant difference (p = 0.44, paired t test and p = 0.01, test of equivalence) between results obtained by Curator SVV and the commercially available device. In the second study, the average angle measured for healthy subjects was 0.00° ± 0.85°. The normal range (mean ± 2 SD) was ± 2° in standard upright position. We were able to demonstrate that the Curator SVV can be readily employed as an objective, non-invasive and affordable means of assessing otolith function in the clinical context. We validated this novel methodology by finding strong quantitative parity between a standard commercial SVV unit and the VR Curator SVV method. Our very lightweight and mobile device can be employed in clinical contexts including at the bedside and in different head and body positions.