Bitcoin as an alternative investment vehicle

This paper documents time series momentum in Bitcoin returns. The paper finds persistence in returns for one to 8 weeks that partially reverses over longer horizons, consistent with sentiment theories of initial under-reaction and delayed over-reaction. The time series momentum in Bitcoin returns is similar to that of the other asset returns while the time span is much shorter. This may be due to much quicker nature and shorter term memory of Bitcoin investors. A combined portfolio of S&P500 and Bitcoin momentum strategy shows enhanced expected return, skewness, kurtosis and Value at Risk for given levels of portfolio return volatility.     

The segment method as an alternative to minimax in hypothesis testing

An alternative approach to the design of hypothesis tests within modeling uncertainty is proposed. This approach is based on a design technique known as the segment method, which has been established previously as a favorable alternative to the minimax concept in the context of optimal control. The general segment concept is discussed here as it applies to binary decisions made in the presence of unknown prior distribution or parametric uncertainty. In the latter context, several aspects of the design of hypothesis tests on Gaussian data are considered in detail.     

Browsers to support awareness and social interaction

Information sharing and social interaction are the Web's main features that have enabled online communities to abound and flourish. However, the Web is lacking cues and browsing mechanisms for the online social spaces. The challenge of creating social browsing tools to access such social information and patterns is of interest as a visual analytic problem for two reasons. Browsers that combine social visualizations and tools let newcomers and visitors explore information and patterns. Here we present social browsers for two Web communities. In addition to the novel visualizations and representation of two facets of a group's identity, our work has three other notable contributions.     

Two types of single-peaked data: Correspondence analysis as an alternative to principal component analysis

It has been argued that principal component analysis (PCA) is not appropriate for analyzing data conforming to single-peaked response models, also referred to as unfolding models. An overview of these findings is given, which relates them to the distinction between two types of unfolding models; namely, models that are either a quadratic function of the person-to-item distances or an exponential function of these distances. This distinction is easy to recognize empirically because the inter-item correlation matrix for the two types of data typically shows different patterns. Furthermore, for both types of unfolding models, correspondence analysis (CA), which is a rival method for dimensionality reduction, outperforms PCA in terms of representation of both person and item locations, especially for the exponential unfolding model. Finally, it is shown that undoubled CA outperforms doubled CA for both types of unfolding models. It is argued that performing CA on the raw data matrix is an unconventional, but meaningful approach to scaling items and persons on an underlying unfolding scale. A real data example on personality assessment is given, which shows that for this type of data (undoubled) CA is to be preferred over PCA.     

Automating knowledge acquisition: a propositional approach torepresenting expertise as an alternative to repertory gridtechnique

Repertory grid technique plays a central role in the elicitation methodology of many well-reported knowledge acquisition tools or workbenches. However, the dependability of these systems is low where the technique breaks down or proves inadequate due to limited expressive power and other problems. The paper introduces an alternate approach based on Personal Construct Theory that elicits an expert's knowledge as a network of terms that constitutes a propositional formalism. An extended example is used to both highlight the difficulties encountered using repertory grids and illustrate how these are overcome using the proposed approach. The results of an empirical study are presented where an experienced clinician compared the knowledge structures that she constructed for a diagnostic task using each elicitation technique. Furthermore, although the network representation is amenable to inductive learning methods for generating production rules, an inference method is demonstrated which reveals the formalism's categorical reasoning potential. The authors conclude that it is more appropriate to classify such methods as either mediating or immediate rather than the knowledge structures they employ. The paper contributes to a better understanding of constructivist formalisms developed for knowledge acquisition     

Measurement as an alternative to bureaucracy for the achievement of software quality

In this paper we discuss the two dominant modes of thought on the problem of software quality: the bureaucratic approach and the technical approach. The aim of the paper is to pursue the issues of how these approaches affect people, in our case software developers, and how we can assess the effectiveness of each approach in actually achieving quality software. An outline of the main aspects of the organizational approach — process modelling and software standards — is given. In order to address the effects of each of these modes of thought on people we take a psychological perspective. The implications for software engineering, in terms of formalism and mechanization, are discussed. The paper argues that overzealous structure, control and automation can negatively affect the creative process of developing software. A perspective on each of the components of the technical approach in terms of their effectiveness in achieving quality objectives is provided. From recent work we find that process modelling and many software standards do not provide an adequate assessment of the benefits derived from their application. The paper argues that measurement goes some way to addressing these problems. Measurement should form the core of the software development process, especially with respect to product quality assessment. The main conclusion is that by focusing on measurable objectives and results we can best achieve quality software products and highlight the processes which are likely to create them in a repeatable and manageable fashion. Additionally, by adopting measurement in practice we should expect to increase the freedom and creativity of software developers.     

Multiple two-dimensional displays as an alternative to three-dimensional displays in telerobotic tasks

In this study a multiple-view two-dimensional (2D) display was compared with a three-dimensional (3D) monocular display and a 3D stereoscopic display using a simulated telerobotic task. As visual aids, three new types of visual enhancement cues were provided and evaluated for each display type. The results showed that the multiple-view 2D display was superior to the 3D monocular and the 3D stereoscopic display in the absence of the visual enhancement depth cues. When participants were provided with the proposed visual enhancement cues, the stereoscopic and monocular displays became equivalent to the multiple-view 2D display. Actual or potential applications of this study include the design of visual displays for teleoperation systems.     

Linking the lonely: an exploration of a communication technology designed to support social interaction among older adults

This article explores mixed methods data gathered from a pilot of a communication system prototype in the homes of 19 older adults over a period of 10?weeks. The system has been designed to enhance communication among both friends and strangers and has been developed as a possible tool to increase interaction in older adults suffering from social isolation and loneliness. The paper uses remote logging data to inform discussion of how such a technology was received and utilised over time in a home setting. Qualitative data gathered via entry and exit interviews, and weekly checkpoint calls were used to provide deeper insight into patterns and practices identified via the logs.     

Minimization of the expected compliance as an alternative approach to multiload truss optimization

We show that a problem of finding the truss of minimum expected compliance under stochastic loading conditions is equivalent to the dual of a special convex minimax problem, and therefore may be efficiently solved. This equivalence makes it possible to provide classic multiload compliance minimization problems with interpretations in a probabilistic setting. In fact, we prove that minimizing the expected compliance amounts to solving a multiload-like problem associated with a particular finite set of loading scenarios, which depend on the mean and the variance of the perturbations.     

Java distributed object models: an alternative to Corba?

Remote method invocation and RMI over IIOP relieve developers of many Corba complexities. Companies looking for a simpler way to achieve interoperability should strongly consider these models     

Classification trees: an alternative to traditional land cover classifiers

Classification trees are a powerful alternative to more traditional approaches of land cover classification. Trees provide a hierarchical and nonlinear classification method and are suited to handling non-parametric training data as well as categorical or missing data. By revealing the predictive hierarchical structure of the independent variables, the tree allows for great flexibility in data analysis and interpretation. In this Letter, we compare a tree' s performance to that of a maximum likelihood classifier using a 1° by 1° global data sel. The tree's accuracy in classifying a validation dala set is comparable to that when using maximum likelihood (82 per cent). The tree also may be used to reduce the dimensionality of data sets and to find those metrics that are most useful for discriminating among cover types.     

Email-based identification and authentication: an alternative to PKI?

E-mail-based identification and authentication is an emerging alternative to public-key infrastructure. It overcomes many problems inherent with traditional authentication techniques, such as social security numbers, and. provides functional security when used within a limited context.     

Environments to support context and emotion aware visual interaction

The interaction with software systems is often affected by many types of hurdles that induce users to make errors and mistakes, and to break the continuity of their reasoning while carrying out a working task with the computer. As a consequence, negative emotional states, such as frustration, dissatisfaction, and anxiety, may arise. In this paper, we illustrate how the Software Shaping Workshop (SSW) methodology can represent a solution to the problem of developing interactive systems that are correctly perceived and interpreted by end-users, thus becoming more acceptable and favouring positive emotional states. In the methodology, a key role is played by domain-expert users, that is, experts in a specific domain, not necessarily experts in computer science. Domain-expert users’ skills and background, including their knowledge of the domain and users’ needs and habits, are exploited to create context and emotion aware visual interactive systems. Examples of these systems are illustrated by referring to a case study in the automation field.     

Multi-scale lacunarity as an alternative to quantify and diagnose the behavior of prostate cancer

Prostate cancer is a serious public health problem accounting for up to 30% of clinical tumors in men. The diagnosis of this disease is made with clinical, laboratorial and radiological exams, which may indicate the need for transrectal biopsy. Prostate biopsies are discerningly evaluated by pathologists in an attempt to determine the most appropriate conduct. This paper presents a set of techniques for identifying and quantifying regions of interest in prostatic images. Analyses were performed using multi-scale lacunarity and distinct classification methods: decision tree, support vector machine and polynomial classifier. The performance evaluation measures were based on area under the receiver operating characteristic curve (AUC). The most appropriate region for distinguishing the different tissues (normal, hyperplastic and neoplasic) was defined: the corresponding lacunarity values and a rule’s model were obtained considering combinations commonly explored by specialists in clinical practice. The best discriminative values (AUC) were 0.906, 0.891 and 0.859 between neoplasic versus normal, neoplasic versus hyperplastic and hyperplastic versus normal groups, respectively. The proposed protocol offers the advantage of making the findings comprehensible to pathologists.     

Social interaction in online support groups: Preference for online social interaction over offline social interaction

The purpose of the current study was to identify potential factors leading to preference for social interaction in online support groups (OSGs) over offline interaction. By identifying such factors, the current study advances understanding of the way patients use the Internet as a supportive resource and integrate support from offline and online relationships. An online survey was conducted with current users of health-related OSGs (N = 158). Findings show that those who were dissatisfied with the support they received from their current offline contacts were more likely to prefer social interaction in OSGs. Such a preference was prominent among those who built deeper social relationships in OSGs. Results suggest that some people develop a preference for social interaction in OSGs over offline interaction and use computer-mediated relationships as a possible alternative to offline support networks. Healthcare professionals and users as well as designers of OSGs must acknowledge the limits of online support and caution against the possibility of developing excessive reliance on online support resources.     

C — an alternative to assembly programming

The recent increase in popularity of the programming language c is explained, and similarities between c and both high- and low-level languages are pointed out. In particular, a comparison is drawn with assembly language programming. Advantages and disadvantages of programming in c are highlighted. The c compiler written by Whitesmiths is treated in some detail. Various examples of its use are given.     

Data-dependent dissimilarity measure: an effective alternative to geometric distance measures

Nearest neighbor search is a core process in many data mining algorithms. Finding reliable closest matches of a test instance is still a challenging task as the effectiveness of many general-purpose distance measures such as \(\ell _p\)-norm decreases as the number of dimensions increases. Their performances vary significantly in different data distributions. This is mainly because they compute the distance between two instances solely based on their geometric positions in the feature space, and data distribution has no influence on the distance measure. This paper presents a simple data-dependent general-purpose dissimilarity measure called ‘\(m_p\)-dissimilarity’. Rather than relying on geometric distance, it measures the dissimilarity between two instances as a probability mass in a region that encloses the two instances in every dimension. It deems two instances in a sparse region to be more similar than two instances of equal inter-point geometric distance in a dense region. Our empirical results in k-NN classification and content-based multimedia information retrieval tasks show that the proposed \(m_p\)-dissimilarity measure produces better task-specific performance than existing widely used general-purpose distance measures such as \(\ell _p\)-norm and cosine distance across a wide range of moderate- to high-dimensional data sets with continuous only, discrete only, and mixed attributes.     

PNNARMA model: an alternative to phenomenological models in chemical reactors

This paper is focused on the development of non-linear neural models able to provide appropriate predictions when acting as process simulators. Parallel identification models can be used for this purpose. However, in this work it is shown that since the parameters of parallel identification models are estimated using multilayer feed-forward networks, the approximation of dynamic systems could be not suitable. The solution proposed in this work consists of building up parallel models using a particular recurrent neural network. This network allows to identify the parameter sets of the parallel model in order to generate process simulators. Hence, it is possible to guarantee better dynamic predictions. The dynamic behaviour of the heat transfer fluid temperature in a jacketed chemical reactor has been selected as a case study. The results suggest that parallel models based on the recurrent neural network proposed in this work can be seen as an alternative to phenomenological models for simulating the dynamic behaviour of the heating/cooling circuits.     

Process improvement: an alternative to BPR for software development organizations

Whereas BPR (Business Process Re-engineering or Business Process Re-design) is being offered as a means by which organizations may be able to respond to the challenge of increased competition, Process Improvement, on the other hand aims to improve productivity, product quality and competitive advantage. Fundamentally, both activities offer a means by which organizations may be able to deal with a rapidly changing business environment, through internal change. BPR extends the concept of process change (albeit rapid change through innovation) to include changes to the basic assumptions and principles of management. The results, however are not positive: estimates of between 50 and 70% of firms fail to achieve the expected dramatic gains from BPR. An alternative to BPR for software development organizations is Process Assessment and Process Improvement. This paper presents a Process/Product Quality Model which incorporates three separate evaluations: process conformance, process effectiveness and product quality as a means of evaluating what is, i.e. the current status of activities, within a software development organization. The model aims to identify possible areas for process improvement and to uncover all relevant issues which may affect attempts to implement improvement initiatives. Preliminary findings from a set of case studies conducted within software development organizations in Australia are presented in support of the usefulness of the model.