单片机应用系统综合实验装置的设计

单片机原理与应用作为电子技术类学科中的必修课程具有很强实践性,要求学生掌握实际应用能力,为此研制了基于单片机系统通信为基础的实验板,依据单片机应用系统特点,可完成SPI、I^2C、UART串行通信以及并行总线方式通信。实验板有利于学生更好地了解和掌握单片机应用系统设计的方法,有利于学生进行自主设计和内容拓展。做到培养学生的学习能力、提高学生的学习兴趣、发挥学生的创造性。     

Policing of realistic VBR video traffic in an ATM network

ATM has been accepted by CCITT as the transport mechanism for the future BISDN and will also be widely used in future customer premises networks. Networks based on the ATM principle are expected to provide a very flexible communications infrastructure allowing customers to make effective use of a wide variety of offered services. To provide this flexibility with an acceptable quality of service while operating the network in an economic way, elaborate traffic management functions will be necessary to control the traffic flows within the network. This paper will study one of these functions—the so-called ‘usage parameter control’ or ‘policing’ function—in some detail to illustrate some of the problems that arise and point out possible solutions. The mechanisms chosen to implement the policing function will be the ‘leaky bucket’ mechanism, the ‘jumping window’ mechanism and the ‘moving window’ mechanism. The input streams used to assess the mechanisms represent different types of video communication—videophone, video conference and entertainment video—coded according to different variable bit-rate (VBR) algorithms. In contrast to most of the previous studies, where artificial, statistical traffic sources have been used, the sources used in this paper are directly based on measured ‘real-life’ video data. This ensures that all the statistical properties of the actual traffic stream are preserved and allows identification of the different factors that influence the dimensioning and the performance of the policing mechanism. The results of this study show that the uncertainty about the key parameters at call set-up and the considerable impact of single scenes make the proper dimensioning of policing mechanisms difficult. Furthermore, it seems not to be practical to use the long term mean bit-rate as the key traffic control parameter for these sources. Results indicating that the long-term cell loss ratio is not a sufficient measure for the quality of service are also presented. A comparison of the mechanisms shows that from a performance perspective, the ‘leaky bucket’ mechanism is superior to the two window mechanisms. This work is relevant to evolving standards for both BISDN traffic management and variable bit-rate video coding.     

Terms of Choice: Uncertainty,Journalism, and Crisis

This article considers whether thinking about journalism's present set of challenges is best served by the notion of “crisis.” It argues that adopting such a notion to explain a diverse set of technological, political, economic, social, occupational, moral, and legal circumstances misses an opportunity to recognize how contingent and differentiated the futures of journalism might be. It also raises critical questions about how institutions deal with uncertainty at their core, obscuring a fuller understanding of the permutations that get eclipsed by perceiving crisis as a unitary phenomenon.     

A Mobile App Search Engine

With the popularity of mobile apps on mobile devices based on iOS, Android, Blackberry and Windows Phone operating systems, the numbers of mobile apps in each of the respective native app stores are increasing in leaps and bounds. Currently there are close to one million mobile apps across these four major native app stores. Due to the enormous number of apps, both the constituents in the app ecosytem, consumers and app developers, face problems in ‘app discovery’. For consumers, it is a daunting task to discover the apps they like and need among the huge number of available apps. Likewise, for developers, enabling their apps to be discovered is a challenge. To address these issues, Mobilewalla (MW) an app search engine provides an independent unbiased search for mobile apps with semantic search capabilities. It has also developed an objective scoring mechanism based on user and developer involvement with an app. The scoring mechanism enables MW to provide a number of other ways to discover apps—such as dynamically maintained ‘hot’ lists and ‘fast rising’ lists. In this paper, we describe the challenges of developing the MW platform and how these challenges have been mitigated. Lastly, we demonstrate some of the key functionalities of MW.     

Blended learning: Investigating the influence of engagement in multiple learning delivery modes on students’ performance

The current reliance on different modes for delivering learning materials and establishing connections among peers can be significantly attributed to the teaching and learning practices in higher education. Here, the possible effects of students’ engagement in multiple learning delivery modes on their academic performance were examined. This study specifically examined the effects of students’ engagement in three learning delivery modes—face-to-face (F2F) learning, learning management system (LMS)-based learning, and web-based learning (WBL)—on their learning experience and performance. A total of 196 questionnaires were administrated to university students (104 male; 92 female) to assess their perception of the three modes. Log records were also obtained to investigate the mediation effect of students’ learning experience in LMS-based learning (by access, time spent, tools usage) and WBL (by web tools usage and self-learning time) on their learning performance. Results of a partial least-squares structural equation modeling (PLS-SEM) analysis revealed that students’ engagement in the F2F mode had a significant positive effect on their engagement in the LMS and WBL modes. Moreover, LMS time and tools usage had a positive influence on students’ learning performance in the blended learning environment. Thus, the study results evince the effectiveness of multiple learning delivery modes on the learning development of students in higher education.     

Integration and control

In the Semiconductor 2003 meeting in Edinburgh in June, the prime message for the compound sector from both Bookham’s Andy Carter and Intense Photonics’ John Marsh was ‘integration.’ From Prof Gabriel Aeppli of University College London, the nano technology message was that μ-scale electronics is already a working science; revolutionised by scan probe microscopy and e-beam litho, it cannot be distinguished from modern materials science; but the trick will be in ‘learning to control it.’     

PCB企业设备维修管理系统的开发

介绍PCB企业设备维修管理系统产生的背景,并结合我司设备[1]维修管理的运作特点,分析其设备维修管理的需求,研究和开发了以预防为主的设备维修管理系统,通过无纸化的管理作业实现了提升设备维修效率、减少停机时间保证生产不间断运行、严格控制备件消耗的设备管理的目标。     

Budget-constraint mechanism for incremental multi-labeling crowdsensing

Machine learning techniques require an enormous amount of high-quality data labeling for more naturally simulating human comprehension. Recently, mobile crowdsensing, as a new paradigm, makes it possible that a large number of instances can be often quickly labeled at low cost. Existing works only focus on the single labeling for supervised learning problems of traditional machine learning, where one instance associates with only label. However, in many real world applications, an instance may have more than one label. To the end, in this paper, we explore an incremental multi-labeling issue by incentivizing crowd users to label instances under the budget constraint, where each instance is composed of multiple labels. Considering both uncertainty and diversity of the number of each instance’s labels, this paper proposes two mechanisms for incremental multi-labeling crowdsensing by introducing both uncertainty and diversity. Through extensive simulations, we validate their theoretical properties and evaluate the performance.     

Building-integrated PV activities within the IEA framework: Going from task 16 to task VII

Early in 1997 a new task will be launched within the scope of the International Energy Agency (IEA) Photovoltaic Power Systems Implementing Agreement. This new task, Task VII, aims to develop building-integrated photovoltaic (BIPV) technology, consider ing technical viability, economics and aesthetic quality. The task concentrates strongly on the involvement of architects, building engineers and urban planners, and the ability to increase their interest in BIPV. Task VII succeeds Task 16, ‘Photovoltaics in Buildings’ of the IEA Solar Heating and Cooling Program, completed in March 1996. It has proved to be very effective in developing and demonstrating new concepts for building-integrated photovoltaics, with t he international cooperation in the task assisting in advancing and promoting the application of photovoltaics in both residential and commercial buildings. Task 16 played a pioneering role in obtaining the World's attention for BIPV. It is expected that Task VII will provide accelerated development and market acceptance of this promising technology.     

Filthy lucre: gold,language, and exchange anxiety

This essay examines the discourse among newly emerging American right-wing groups around gold currency and the gold standard to develop the concept of exchange anxiety, a discomfort about the terms of subjects’ participation in social economies of exchange. Gold is a common thread linking many otherwise disparate conservative groups, and examining this continuity may demonstrate an underlying connective logic among newly emerging right-wing ideologies. Using Jacques Lacan’s notions of anxiety and psychosis, I argue that anxiety over the gold standard bears a metaphorical relationship to both language and excrement. This anxiety can be further illuminated with Lacan’s concept of the “yieldable object,” an intermediary between subject and Other that may serve as the object of the Other’s demand. Ultimately, the gold standard represents an insistence on intrinsic value that compensates for uncertainty about subjects’ participation in highly complex and rapidly changing social systems. Rather than directly refuting specific claims, engaged scholarship might profit by insisting on rhetoric’s traditional embrace of ambiguity and messiness to disrupt the delusional certainty advanced by extremist ideologies.     

Client Science: Bad News and the Fully Informed ADR Client

Professor Aaron comments that this piece, excerpted from: “Bad News and the Fully Informed Client,” the first chapter of her book, Client Science, addresses the lawyer's challenge when counseling clients where “bad” news—negative, pessimistic or unwelcome developments or analysis—must be conveyed, whether or not within an ADR process. “As a mediator of civil cases, I suspect that mediation involves a higher than average percentage of cases involving ill‐counseled clients or ‘difficult clients’ who may fairly be characterized as ‘counseling‐resistant’ despite the best efforts of skilled lawyers. When the lawyer explains ‘bad news’ about case developments or likely outcomes, he risks the client's suspicion or accusation of less than zealous advocacy. While a mediator can assist with client communication when legal circumstances are grim, counsel are obligated to ensure their clients are well informed of realistic expectations when exercising autonomy and self determination.”     

Shakra: Tracking and Sharing Daily Activity Levels with Unaugmented Mobile Phones

This paper explores the potential for use of an unaugmented commodity technology—the mobile phone—as a health promotion tool. We describe a prototype application that tracks the daily exercise activities of people, using an Artificial Neural Network (ANN) to analyse GSM cell signal strength and visibility to estimate a user’s movement. In a short-term study of the prototype that shared activity information amongst groups of friends, we found that awareness encouraged reflection on, and increased motivation for, daily activity. The study raised concerns regarding the reliability of ANN-facilitated activity detection in the ‘real world’. We describe some of the details of the pilot study and introduce a promising new approach to activity detection that has been developed in response to some of the issues raised by the pilot study, involving Hidden Markov Models (HMM), task modelling and unsupervised calibration. We conclude with our intended plans to develop the system further in order to carry out a longer-term clinical trial.     

Uptake,polymorphism, and the construction of networked events on Twitter

This study conceptualises networked events as a platform-oriented view of media events by initiating a taxonomy of bottom-up construction. Focusing on computer-mediated event construction that may involve live delivery, permeate digital platforms, and attract user engagement prior to, during, and after the occurrence of ceremonial or disruptive events, the study argues that networked events can be characterised by polymorphism— i.e., presence of distinct patterns of uptake and different interactional orientations within the same space of interactions, such as hashtags. For analysis, a network dataset was created using 221,105 retweets that included the hashtag #HimToo. This hashtag was used extensively during the US Senate judiciary committee hearing that investigated claims of sexual harassment against President Trump’s Supreme Court nominee Brett Kavanaugh. The study demonstrates that three types of construction— i.e., actor-centric, memetic, and metaconstruction— causes polymorphism in Twitter engagement related to the event.     

Contentious Actions and Communication for Social Change: The Public Hearing (Jan Sunwai) as Process

This article explores the relationship between ‘contentious actions’ and communication processes in communication for social change (CSC) theory. Beginning with an analysis of the contributions made by Charles Tilly to the understanding of the methods and repertoires of popular protest and E. P. Thompson's interpretation of the moral economy of protests, it explores the history of contentious action in India, before focusing on the empowerment potential of the ‘Public Hearing’ as contentious action, specifically in the context of the Right to Information Movement in India. It argues that contentious actions such as public hearings need to become a focus for study in CSC theory precisely because it contributes to the validation of Voice, and to individual and collective empowerment.     

A global perspective on an emotional learning model proposal

Existing literature argues that emotions have a significant impact on the majority of human activities and functions. The learning process is one of the activities on which emotions have a direct influence. Thus, understanding the manner in which emotions change the students’ learning process is not only very important but it can also allow to improve the existing learning models.Currently, in the majority of situations, the teacher serves as a facilitator between the student and the learning course, and through a constant analysis of the student’s behaviour, emotions and achievements, he constantly performs adjustments to the teaching process in order to meet the students’ needs and goals. Thus far, in online learning environments there is no easy way for teachers to analyse students’ behaviour and emotions. A possible solution to this problem can be the development of mechanisms that enable computers to automatically detect students’ emotions and adapt the learning process in order to meet students’ real needs.An emotional learning model was described and a software prototype was developed and tested, in order to find out whether it performs live identification of the students’ emotions, by using affective computing techniques, and whether it automatically performs adjustments to their individual learning process. Through a deeper analysis and multidisciplinary discussion of the achieved results it is possible to acknowledge that not only emotions impact students’ learning, but also that an application that performs live emotion recognition and which integrates this feature with adjustable online learning environments will trigger improvements in students’ learning.     

Impurity ‘Hot Spots’ in MBE HgCdTe/CdZnTe

In this work, impurity ‘hot spot’ macro-defects—high impurity level macro-defect contaminates were examined. ‘Hot spots’ have very high localized concentrations of: K, Mg, Ni, Cr, Mn, Ca, Al, Na, Fe, and Cu. For example, these ‘hot spot’ macro-defects can have Cu concentrations >?1?×?10¹⁸ cm^?3. Focused ion beam scanning transmission electron microscopy analysis of four ‘hot spots’ was performed. The origin of ‘hot spot’ defects is unresolved—however, our analysis has shown ‘hot spots’ can arise due to molecular beam epitaxy spit defects and CdZnTe substrate defects. The estimated ‘hot spot’ density is ～?30 cm^?2. The presence of impurity ‘hot spot’ macro-defects in HgCdTe/CdZnTe is confirming evidence for the occurrence of L. Bubulac’s impurity ‘pipe’ mechanism.     

一种组网雷达的抗干扰效能评估方法

组网雷达的抗干扰能力是整体作战效能的一个重要指标,然而其具有参数的不确定性,应用灰色层次分析法对组网雷达的抗干扰效能进行综合的评估。通过建立层次评价指标体系,采用专家评分法来确定评估指标权重,运用灰色聚类来评估模型,计算出组网雷达抗干扰效能的代数值。研究结果表明,该方法具有客观性,能够有效地降低人为因素的影响,为决策者提供比较可靠的数量依据。     

Theory Comparison: Uncertainty Reduction, Problematic Integration, Uncertainty Management, and Other Curious Constructs

This paper compares 3 theories examining the role of communication in producing and coping with subjective uncertainty. Uncertainty reduction theory offers axioms and derived theorems that describe communicative and noncommunicative causes and consequences of uncertainty. The narrow scope of the theory and its axiomatic form are both advantageous and disadvantageous. Problematic integration and uncertainty management theories are comparatively broad, and they exhibit an open, web-like structure. The former theory scrutinizes the complex intersection of probability assessments and evaluations of the objects of these assessments, whereas the latter examines the various ways in which people cope with uncertainty, including sometimes attempting to increase it. The paper also compares meanings of "uncertainty" in the 3 theories as well as the roles played by natural language in the communication-uncertainty interface.     

基于嵌入式Qtopia汽车BCM自动检测系统设计

汽车BCM在车身功能控制系统中起着举足轻重的作用,因此汽车BCM出厂前的功能检测一直得到企业和消费者的高度重视。目前多数企业仍使用人工测试的方法,而本次自动检测系统是采用三星公司的S3C2440作为核心控制器,在嵌入式Linux系统下使用Qtopia应用开发平台搭建控制界面添加检测控制程序,通过接口板连接汽车BCM从而实现自动检测功能。