What makes a space invader? Passenger perceptions of personal space invasion in aircraft travel

Abstract

The invasion of personal space is often a contributory factor to the experience of discomfort in aircraft passengers. This paper presents a questionnaire study which investigated how air travellers are affected by invasions of personal space and how they attempt to adapt to, or counter, these invasions. In support of recent findings on the factors influencing air passenger comfort, the results of this study indicate that the invasion of personal space is not only caused by physical factors (e.g. physical contact with humans or objects), but also other sensory factors such as noise, smells or unwanted eye contact. The findings of this study have implications for the design of shared spaces.

Practitioner Summary: This paper presents a questionnaire study which investigated personal space in an aircraft environment. The results highlight the factors which affect the perception of personal space invasion in aircraft and can therefore inform the design of aircraft cabin environments to enhance the passenger experience.     

Detecting ground fog from space – a microphysics-based approach

The detection of ground fog from satellite data is of interest in operational nowcasting applications, as well as in studies of the climate system. A discrimination between fog at the ground and other low-stratus situations from satellite data requires information on cloud vertical geometry to establish whether the cloud touches the ground. This article introduces a technique that allows for the discrimination between low stratus and (ground) fog on the basis of geostationary satellite imagery. The cloud-base height is derived using a subadiabatic model of cloud microphysics. In this model, the cloud base is varied until model liquid–water path matches that retrieved from satellite data. The performance of this technique is shown to be good in a comparison with METeorological Aerodrome Report data comprising 1030 satellite scenes. With a hit rate of 81% and a threat score of 0.62, the skill is satisfactory.     

Bearing fault diagnosis with cascaded space projection and a CNN

Fault diagnosis is essential for the normal and safe operation of dynamic systems. To improve the spatial resolution among multiple channels and the discriminability among categories of the original data collected from actual operating equipments and to further achieve high diagnostic accuracy, this paper proposes a method for fault diagnosis by cascaded space projection (CSP) and a convolutional neural network (CNN) model. First, one of every kind of sample is selected from the original data to calculate the PCA transformation matrices. Second, the original data are expanded to 10 dimensions by the W2C projection matrix provided by Google-image searching, which is the main part of CSP. Third, the ten-dimensional matrix is multiplied by the PCA transformation matrix, which corresponds to its fault type, to make the data more representative by reducing unnecessary dimensions. Finally, the processed data are converted into images to input into a CNN, the backbone structure for fault diagnosis. To verify the effectiveness and reliability of the proposed method, the Case Western Reserve University (CWRU) and Xi’an Jiaotong University (XJTU-SY) rolling bearing datasets are used to perform experiments. Comparison with other methods is carried out to show the superiority of the proposed method. The experimental results demonstrate that the method proposed in this paper can effectively achieve 100% accuracy.     

H-infinity deconvolution filtering： a Krein space approach in state-space setting

This note is concerned with the H-infinity deconvolution filtering problem for linear time-varying discretetime systems described by state space models, The H-infinity deconvolution filter is derived by proposing a new approach in Krein space. With the new approach, it is clearly shown that the central deconvolution filter in an H-infinity setting is the same as the one in an H2 setting associated with one constructed stochastic state-space model. This insight allows us to calculate the complicated H-infinity deconvolution filter in an intuitive and simple way. The deconvolution filter is calculated by performing Riccati equation with the same order as that of the original system.     

Sense and sidedness in the graphics pipeline via a passage through a separable space

Computer graphics is ostensibly based on projective geometry. The graphics pipeline—the sequence of functions applied to 3D geometric primitives to determine a 2D image—is described in the graphics literature as taking the primitives from Euclidean to projective space, and then back to Euclidean space. This is a weak foundation for computer graphics. An instructor is at a loss: one day entering the classroom and invoking the established and venerable theory of projective geometry while asserting that projective spaces are not separable, and then entering the classroom the following week to tell the students that the standard graphics pipeline performs clipping not in Euclidean, but in projective space—precisely the operation (deciding sidedness, which depends on separability) that was deemed nonsensical. But there is no need to present Blinn and Newell’s algorithm (Comput. Graph. 12, 245–251, 1978; Commun. ACM 17, 32–42, 1974)—the crucial clipping step in the graphics pipeline and, perhaps, the most original knowledge a student learns in a fourth-year computer graphics class—as a clever trick that just works. Jorge Stolfi described in 1991 oriented projective geometry. By declaring the two vectors and distinct, Blinn and Newell were already unknowingly working in oriented projective space. This paper presents the graphics pipeline on this stronger foundation.

Distributed identification of the lineality space of a cone

A distributed approach is described for solving lineality (or linearity) space (LS) problems with large cardinalities and a large number of dimensions. The LS solution has applications in engineering, science, and business, and includes a subset of solutions of the more general extended linear complementarity problem (ELCP). A parallel MATLAB framework is employed and results are computed on an 8-node Rocks based cluster computer using Remote Procedure Calls (RPCs) and the MPICH2 Message Passing Interface (MPI). Results show that both approaches perform comparably when solving distributed LS problems. This indicates that when deciding which parallel approach to use, the implementation details particular to the method are the decisive factors, which in this investigation give MPICH2 MPI the advantage.

Design space exploration of on-chip ring interconnection for a CPU–GPU heterogeneous architecture

Incorporating a GPU architecture into CMP, which is more efficient with certain types of applications, is a popular architecture trend in recent processors. This heterogeneous mix of architectures will use an on-chip interconnection to access shared resources such as last-level cache tiles and memory controllers. The configuration of this on-chip network will likely have a significant impact on resource distribution, fairness, and overall performance.     

The EM algorithm in a distributed computing environment for modelling environmental space–time data

Statistical models for spatio-temporal data are increasingly used in environmetrics, climate change, epidemiology, remote sensing and dynamical risk mapping. Due to the complexity of the relationships among the involved variables and dimensionality of the parameter set to be estimated, techniques for model definition and estimation which can be worked out stepwise are welcome. In this context, hierarchical models are a suitable solution since they make it possible to define the joint dynamics and the full likelihood starting from simpler conditional submodels. Moreover, for a large class of hierarchical models, the maximum likelihood estimation procedure can be simplified using the Expectation–Maximization (EM) algorithm.In this paper, we define the EM algorithm for a rather general three-stage spatio-temporal hierarchical model, which includes also spatio-temporal covariates. In particular, we show that most of the parameters are updated using closed forms and this guarantees stability of the algorithm unlike the classical optimization techniques of the Newton–Raphson type for maximizing the full likelihood function. Moreover, we illustrate how the EM algorithm can be combined with a spatio-temporal parametric bootstrap for evaluating the parameter accuracy through standard errors and non-Gaussian confidence intervals.To do this a new software library in form of a standard R package has been developed. Moreover, realistic simulations on a distributed computing environment allow us to discuss the algorithm properties and performance also in terms of convergence iterations and computing times.     

The space of EDF deadlines: the exact region and a convex approximation

It is well known that the performance of computer controlled systems is heavily affected by delays and jitter occurring in the control loops, which are mainly caused by the interference introduced by other concurrent activities. A common approach adopted to reduce delay and jitter in periodic task systems is to decrease relative deadlines as much as possible, but without jeopardizing the schedulability of the task set. In this paper, we formally characterize the region of admissible deadlines so that the system designer can appropriately select the desired values to maximize a given performance index defined over the task set. Finally we also provide a sufficient region of feasible deadlines which is proved to be convex.

Linear parameter varying switching attitude control for a near space hypersonic vehicle with parametric uncertainties

This paper deals with the problem of linear parameter varying (LPV) switching attitude control for a near space hypersonic vehicle (NSHV) with parametric uncertainties. First, due to the enormous complexity of the NSHV nonlinear attitude dynamics, a slow–fast loop polytopic LPV attitude model is developed by using Jacobian linearisation and the tensor product model transformation approach. Second, for the purpose of less conservative attitude controller design, the flight envelope is divided into four subregions. For each parameter subregion, slow-loop and fast-loop LPV controllers are designed. By the defined switching character function, these slow–fast loop LPV controllers are then switched in order to guarantee the closed-loop NSHV system to be asymptotically stable and satisfy a specified tracking performance criterion. The condition of LPV switching attitude controller synthesis is given in terms of linear matrix inequalities, which can be readily solved via standard numerical software, and the robust stability analysis of the closed-loop NSHV system is verified based on multiple Lypapunov functions. Finally, numerical simulations have demonstrated the effectiveness of the proposed approach.     

“Solving” ambiguity in the virtual space: communication strategies in a collaborative virtual environment

Collaborative virtual environments (CVE) face the challenge of succeeding in incorporating critical dimensions of cooperation and communication in everyday working situations. One of these dimensions, situation ambiguity, is scarcely considered in studies on CVE although it can prove a key factor in future use of CVE in real work situations. Many computer-supported cooperative environments and telecommunication systems, like those currently used in telemedicine, would benefit from the incorporation of some degree of situation ambiguity allowing users to deploy their diagnostic and interpretive abilities. In the perspective adopted in this study, ambiguity is the contingent outcome of the ongoing interaction taking place between the environment and the interests of social actors. The research focuses on the cooperation within couples of participants facing situation ambiguity in a virtual environment: a simulated city named Babylon. Participants moved in the city through an avatar and could communicate in one of the following conditions: face-to-face, phone or chat. Their goal was that of meeting somewhere in the city, in a place that they did not know previously. Babylon contained elements designed to allow both production and detection of ambiguity. Ambiguity emerged when participants realized the presence of inconsistencies in the way they perceived the situations they had to face. The moments in which ambiguity was perceived—called “critical events” (CE)—were measured and described through qualitative (ethnographically oriented) methods. The different strategies that participants used to “solve” ambiguity were characterized as: looking for environmental cues, narrowing the focus of attention and investing on cooperation. Both CEs and strategies were analyzed with respect to the three communication conditions: face-to-face, phone and chat. All the communication conditions allowed the emergence of ambiguity and the negotiation of strategies to solve ambiguity between partners: according to literature, chat is very costly in terms of time spent on writing but this disadvantage did not block completely the emergence of ambiguity and the development of adequate strategies of solution. All navigations but three (on a total of 18 couples) succeeded: the partners did meet in a short time (less than 15 min) relying on their pragmatic resources in a new virtual place. Further research is required to clarify the possible factors influencing the choice of one strategy over the others, the order in which strategies follow each other and the role of leadership in ambiguity detection and solution.     

Java内存不足PermGen space错误探究

Java程序运行时可能会遇到java.lang.OutOfMemoryError:PermGen space错误;JavaEE服务器(如tomcat、jboss等)在加载war包或ear包时也可能会出现这种错误,这些都是由于永久保存区域内存不足导致的。本文分析了Java程序的运行机制和JVM的内存结构,解释了什么是permanent generation space,分析了PermGen space错误的常见原因,并给出避免这一错误的解决办法。     

The lattice structure and refinement operators for the hypothesis space bounded by a bottom clause

Searching the hypothesis space bounded below by a bottom clause is the basis of several state-of-the-art ILP systems (e.g. Progol, Aleph). These systems use refinement operators together with search heuristics to explore a bounded hypothesis space. It is known that the search space of these systems is limited to a sub-graph of the general subsumption lattice. However, the structure and properties of this sub-graph have not been properly characterised. In this paper firstly, we characterise the hypothesis space considered by the ILP systems which use a bottom clause to constrain the search. In particular, we discuss refinement in Progol as a representative of these ILP systems. Secondly, we study the lattice structure of this bounded hypothesis space. Thirdly, we give a new analysis of refinement operators, least generalisation and greatest specialisation in the subsumption order relative to a bottom clause. The results of this study are important for better understanding of the constrained refinement space of ILP systems such as Progol and Aleph, which proved to be successful for solving real-world problems (despite being incomplete with respect to the general subsumption order). Moreover, characterising this refinement sub-lattice can lead to more efficient ILP algorithms and operators for searching this particular sub-lattice. For example, it is shown that, unlike for the general subsumption order, efficient least generalisation operators can be designed for the subsumption order relative to a bottom clause.     

Brain–computer interfaces for space applications

Recent experiments have shown the possibility to use the brain electrical activity to directly control the movement of robots. Such a kind of brain–computer interface is a natural way to augment human capabilities by providing a new interaction link with the outside world and is particularly relevant as an aid for paralysed humans, although it also opens up new possibilities in human–robot interaction for able-bodied people. One of these new fields of application is the use of brain–computer interfaces in the space environment, where astronauts are subject to extreme conditions and could greatly benefit from direct mental teleoperation of external semi-automatic manipulators—for instance, mental commands could be sent without any output/latency delays, as it is the case for manual control in microgravity conditions. Previous studies show that there is a considerable potential for this technology onboard spacecraft.     

新世代3D浏览器space time DETA

随着技术的发展，现在的电脑普遍采用了海量内存，而软件的发展趋势就是更充分地利用那些内存。由于电脑的运算能力随着处理器的更新换代而稳步增强，因此软件设计师们可以设计出更加生动活泼的应用软件。在图形处理技术一日千里的世界，还有很多人不能像游戏发烧友那样享受到这种进步带来的好处，因为桌面应用和视频编解码要么用不到这么强的功能，要么要用的功能它没提供。以前我们上网游戏网页，显示的都是平面的网页；在3D技术不断成熟的时期，浏览器也有3D的了。任何用过微软最新操作系统Vista的用户都知道，在电脑上观看三维内容并不是什么新鲜事儿。在Vista系统中，窗口都是以三维模式进行排列，用户可以翻阅那些窗口，然后选择想看的窗口。苹果公司推出的OSX操作系统也将采用类似的三维效果即“时间机器”，它可以展示和保存电脑创建文件的所有版本。SpaceTime与它们的三维概念是相同的，而且它不需要嵌入操作系统，它的导航机制更为灵活有为。SpaceTime就是一个另类的3D浏览器，它试图打破常规二维分页式浏览模式，充分发挥现代先进电脑的强大图形功能，将我们的网络冲浪浏览进行了3D时代！下面我们就来一起体验一下吧。[编者按]     

熊猫谈技巧msn space进阶教程

在安装CustomHTML隐藏模块后，这期熊猫谈技巧，熊猫将教你们如何把MSN中没用的模块名称全部删除掉，这就要用到CustomHTML模块的HTML语言编辑功能了，熊猫会深入浅出地为FANS们——解释。[编者按]     

The new HCI? navigation of information space

When we use the term ‘human–computer interaction’ (HCI), the image that is conjured up is of a person sitting at a visual display unit staring in at the world of ‘information’; the person is very much outside the space of information. But when we think of other activities such as going shopping, having a meeting or driving across town, we do not think of the person as outside this space. On the contrary, we see the person as inside a space of activities, surrounded by, and interacting with, assorted artefacts and people. Navigation of Information Space is an alternative conceptualisation of HCI that sees people as existing inside information spaces. Looking at HCI in this way means looking at HCI design as the creation of information spaces. This paper explores these ideas in more detail, arguing that Navigation of Information Space is not just a metaphor for HCI; it is a ‘paradigm shift’. The paper illustrates how Semiotics has informed this conception and discusses why such a paradigm shift is needed.