Hello? Is Anybody Out There?

Well, here we are in the Year 2000, at least by one calendar — but we won’t go through that again. So, has the Y2K bug bitten you? I know it’s the last thing you probably want to hear right now. A combination of New Year’s celebrating and Y2K is enough to give anyone enough migraines to last until the next century.     

Such a Beautiful Disease

奈奈是一家网络游戏公司的小MM。有句话叫做“命悬一线”，像我这样一天超过12个小时面对电脑的人，工作、生活就寄托在那根小小的网线上。     

User’s manual as a requirements specification: case studies

This paper argues that a users manual makes an excellent software requirements specification. It describes several experiences, including one in industry, of writing users manuals as requirements specifications. Finally, it discusses several lessons learned from the experiences.

Is active sitting as active as we think?

The aim of this study was to compare the biomechanical characteristics of sitting on a stool without a backrest (so as to encourage active sitting), sitting on a conventional office chair and standing in healthy participants. Thirteen healthy participants performed a keyboard-writing task during four (stable and unstable) sitting conditions and standing. Body segment positions and posture, postural sway and muscle activity of neck and trunk muscles were assessed with a motion capture system, a force plate and surface electromyography. The results showed that body segment positions, postural sway and trunk muscle activity were relatively similar for the stools without backrests compared with standing. All sitting conditions showed lower vertical upper body alignment, less anterior pelvic tilt and larger hip angles, compared with standing (p = 0.000). Unexpectedly, the muscle activity levels and total postural sway, sway velocity and sway in M/L and A/P directions were lower (p = 0.000) for the conditions that encouraged active sitting and standing, compared with the conventional office chair conditions.

Practitioner Summary: Thirteen healthy participants performed a keyboard-writing task during different sitting conditions and standing and were analysed regarding posture, postural sway and trunk muscle activity. Surprisingly, less postural sway and less muscle activity were observed during the conditions that encourage active sitting, compared with sitting on a conventional office chair.     

Linking Classical and Quantum Key Agreement: Is There a Classical Analog to Bound Entanglement?

Abstract. After carrying out a protocol for quantum key agreement over a noisy quantum channel, the parties Alice and Bob must process the raw key in order to end up with identical keys about which the adversary has virtually no information. In principle, both classical and quantum protocols can be used for this processing. It is a natural question which type of protocol is more powerful. We show that the limits of tolerable noise are identical for classical and quantum protocols in many cases. More specifically, we prove that a quantum state between two parties is entangled if and only if the classical random variables resulting from optimal measurements provide some mutual classical information between the parties. In addition, we present evidence which strongly suggests that the potentials of classical and of quantum protocols are equal in every situation. An important consequence, in the purely classical regime, of such a correspondence would be the existence of a classical counterpart of so-called bound entanglement, namely ``bound information' that cannot be used for generating a secret key by any protocol. This stands in contrast to what was previously believed.     

Is a GigaLIP Fast Enough?

The capability of large, data-intensive expert systems is determined not only by the cleverness and expertise of their knowledge manipulation algorithms and methods but also by the fundamental speeds of the computer systems upon which they are implemented. To date, logical inferences per second (LIPS) is used as the power metric of the knowledge processing capacity of an expert system implementation. We show why this simplistic metric is misleading. We relate the power metrics for conventional computer systems to LIPS and demonstrate wide discrepancies. We review the power of today's largest conventional mainframes, such as the IBM 3090/400 and the Cray Research Cray-2 and forecast the expected power of mainframes and specialized processors in the coming decade.     

Is Cybersecurity a Public Good?

Minds and Machines -     

Is a Semantic Web Agent a Knowledge-Savvy Agent?

The issue of knowledge sharing has permeated the field of distributed AI and, in particular, its successor, multiagent systems. Through the years, many research and engineering efforts have tackled the problem of encoding and sharing knowledge without the need for a single, centralized knowledge base. The proposed solutions to this problem are based, more or less, on stringent assumptions, such as static, shared ontological models, or the existence of a common blackboard (or "Linda Space") environment where entities can share knowledge. However, the uptake of the World Wide Web and the emergence of modern computing paradigms, such as distributed, open systems, have highlighted the importance of sharing distributed and heterogeneous knowledge on a larger scale-possibly on the scale of the Internet.     

Is Echo a complex adaptive system?

We evaluate whether John Holland's Echo model exemplifies his theory of complex adaptive systems. After reviewing Holland's theory of complex adaptive systems and describing his Escho model, we describe and explain the characteristic evolutionary behavior observed in a series of Echo model runs. We conclude that Echo lacks the diversity of hierarchically organized aggregates that typify complex adaptive systems, and we explore possible explanations for this failure.     

Is electronic money a disruptive technology?

Good companies can fail, even when management makes apparently logical and competent decisions. The reason for their downfall can be the impact of new technology that disrupts established markets. Consultant Richard Emsley examines electronic money to see if it is a disruptive technology.     

Virtuality as a basis for problem solving?

This paper is an attempt to develop a paradigm in problem solving where the notion of virtuality plays a central role. Following a brief discussion on virtual simulation, the paper attempts to identify a notion of virtuality based on the identification of the self (man or computer) with the problem solver. It is shown that such an identification/distinction possibly violates some general principle of the problem environment.To deal with this violation, a new problem is generated and a new virtualization act is required, in order to attain a correspondence between virtuality and reality. A better understanding of this approach requires a combination of analog and digital reasoning: the analog being related to the environment in which the problem solving is required, and the digital to the problem solver's mental activities.We will briefly analyze the recursive approach to problem solving and suggest a possible problem solving methodology based on virtuality. The paper concludes with comments on the relation between etnology and virtual reality.     

‘Requirements-Uncertainty’: Is it best formulated as a latent,aggregate or profile construct?

This paper identifies the strategies that experienced information systems (IS) project managers say they use to cope with requirements-uncertainty (RU) when managing development projects for external clients. It is shown that project managers (PMs) claim to use different strategies for coping with the different dimensions of requirements-uncertainty, as this notion has been formulated in IS literature. Based on this finding, it is proposed that perhaps requirements-uncertainty should be formulated as a profile construct, and not as a latent or aggregate construct, if it is to have pragmatic validity as a guide to action for project managers.     

Is computational complexity a barrier to manipulation?

When agents are acting together, they may need a simple mechanism to decide on joint actions. One possibility is to have the agents express their preferences in the form of a ballot and use a voting rule to decide the winning action(s). Unfortunately, agents may try to manipulate such an election by mis-reporting their preferences. Fortunately, it has been shown that it is NP-hard to compute how to manipulate a number of different voting rules. However, NP-hardness only bounds the worst-case complexity. In this survey article, we summarize the evidence for and against computational complexity being a barrier to manipulation. We look both at techniques identified to increase complexity (for example, hybridizing together two or more voting rules), as well as other features that may change the computational complexity of computing a manipulation (for example, if votes are restricted to be single peaked then some of the complexity barriers fall away). We discuss recent theoretical results that consider the average case, as well as simple greedy and approximate methods. We also describe how computational ??phase transitions??, which have been fruitful in identifying hard instances of propositional satisfiability and other NP-hard problems, have provided insight into the hardness of manipulating voting rules in practice. Finally, we consider manipulation of other related problems like stable marriage and tournament problems.