Binary matrix factorization on special purpose hardware

Many fundamental problems in data mining can be reduced to one or more NP-hard combinatorial optimization problems. Recent advances in novel technologies such as quantum and quantum-inspired hardware promise a substantial speedup for solving these problems compared to when using general purpose computers but often require the problem to be modeled in a special form, such as an Ising or quadratic unconstrained binary optimization (QUBO) model, in order to take advantage of these devices. In this work, we focus on the important binary matrix factorization (BMF) problem which has many applications in data mining. We propose two QUBO formulations for BMF. We show how clustering constraints can easily be incorporated into these formulations. The special purpose hardware we consider is limited in the number of variables it can handle which presents a challenge when factorizing large matrices. We propose a sampling based approach to overcome this challenge, allowing us to factorize large rectangular matrices. In addition to these methods, we also propose a simple baseline algorithm which outperforms our more sophisticated methods in a few situations. We run experiments on the Fujitsu Digital Annealer, a quantum-inspired complementary metal-oxide-semiconductor (CMOS) annealer, on both synthetic and real data, including gene expression data. These experiments show that our approach is able to produce more accurate BMFs than competing methods.

HMB in DRAM-less NVMe SSDs: Their usage and effects on performance

Solid-state drives (SSDs) that do not have internal dynamic random-access memory (DRAM) are being widely spread for client SSD and embedded SSD markets in recent years because they are cheap and consume less power. Obviously, their performance is lower than conventional SSDs because they cannot exploit advantages of DRAM in the controller. However, this problem can be alleviated by using host memory buffer (HMB) feature of Non-Volatile Memory Express (NVMe), which allows SSDs to utilize the DRAM of host. In this paper, we show that commercial DRAM-less SSDs clearly exhibit worse I/O performance than SSDs with internal DRAM, but this can be improved by using the HMB feature. We also present methods that reveal how the host memory buffer is used in commercial DRAM-less SSDs to improve I/O performance. Through extensive experiments, we conclude that DRAM-less SSDs evaluated in this study mainly exploit the host memory buffer as an address mapping table cache rather than a read cache or write buffer to improve I/O performance.

New discretization method applied to NBV problem: Semioctree

This paper presents a discretization methodology applied to the NBV (Next Best View) problem, which consists of determining the heuristical best position of the next scan. This new methodology is a hybrid process between a homogenous voxelization and an octree structure that preserves the advantages of both methods. An octree structure is not directly applicable to the NBV problem: as the point cloud grows with every successive scanning, the limits and position of the discretization, octree structure must coincide, in order to transfer the information from one scan to the next. This problem is solved by applying a first coarse voxelization, followed by the division of each voxel in an octree structure. In addition, a previous methodology for solving the NBV problem has been adapted to make use of this novel approach. Results show that the new method is three times faster than the homogenous voxelization for a maximum resolution of 0.2m. For this target resolution of 0.2m, the number of voxels/octants in the discretization is reduced approximately by a 400%, from 35.360 to 8.937 for the study case presented.

Teledildonics and New Ways of "Being in Touch": A Phenomenological Analysis of the Use of Haptic Devices for Intimate Relations

The aim of this paper is to analyse teledildonics from a phenomenological perspective in order to show the possible effects they will have on ourselves and on our society. The new way of using digital technologies is to merge digital activities with our everyday praxes, and there are already devices which enable subjects to be digitally connected in every moment of their lives. Even the most intimate ones are becoming mediated by devices such as teledildonics which digitally provide a tactual stimulation allowing users to have sexual intercourse through them. The efforts made in order to provide such an intertwinement of our everyday lives and digital technologies are evident, but the effects produced by them are not clear at all. This paper will analyse these technologies from a phenomenological perspective in order to understand their effects on the constitution of the subjects and on our society at the intimate level.

Digital applications: the future in psychiatry?

Digital applications and new mobile technologies can change the nature of the psychiatrist-patient relationship and future clinical practice in terms of diagnosis, follow-up, and treatment, but need to be further studied. This issue explores these new approaches in psychiatry.

The Renewed Promise of Medical Informatics

The promise of the field of Medical Informatics has been great and its impact has been significant. In 1999, the Yearbook editors of the International Medical Informatics Association (IMIA) - also the authors of the present paper - sought to assess this impact by selecting a number of seminal papers in the field, and asking experts to comment on these articles. In particular, it was requested whether and how the expectations, represented by these papers, had been fulfilled since their publication several decades earlier. Each expert was also invited to comment on what might be expected in the future. In the present paper, these areas are briefly reviewed again. Where did these early papers have an impact and where were they not as successful as originally expected? It should be noted that the extraordinary developments in computer technology observed in the last two decades could not have been foreseen by these early researchers. In closing, some of the possibilities and limitations of research in medical informatics are outlined in the context of a framework that considers six levels of computer applications in medicine and health care. For each level, some predictions are made for the future, concluded with thoughts on fruitful areas for ongoing research in the field.

International Trends in Adolescent Screen-Time Behaviors From 2002 to 2010

PURPOSE

Engaging in prolonged screen-time behaviors (STBs) is detrimental for health. The objective of the present analyses was to examine temporal trends in TV viewing and computer use among adolescents across 30 countries.

METHODS

Data were derived from the cross-national Health Behaviour in School-aged Children study. Data on TV viewing and computer use for gaming and nongaming purposes were collected in 2002 (n = 139,725 [51.4% girls]), 2006 (n = 149,251 [51.3% girls]), and 2010 (n = 154,845 [51.2% girls]). The temporal trends in TV viewing and computer use were each tested for all countries combined and for each individual country by sex-specific univariate analysis of variance.

RESULTS

Between 2002 and 2010, TV viewing decreased slightly in most of the 30 countries among both boys and girls. This decrease was more than offset by a sharp increase in computer use, which was consistent across all countries. Overall, boys reported more hours of STBs. They also reported a slightly larger decrease in TV viewing and slightly larger increase in computer use. STBs were generally more frequent on weekend days.

CONCLUSIONS

The overall cross-national increases in STBs should be a call to action for public health practitioners, policy-makers, and researchers that interventions specifically focused on reducing STBs in youth are sorely needed. Because all countries experienced a trend in the same direction, it might be fruitful to learn more about the determinants of STBs among those countries in which hours of STBs are generally low as compared with other countries.

[Digitizing Human and Social Sciences Journals. Recent History and Perspectives]

Recent years have seen the emergence and the gradual rise of French journals digital offers in the fields of human and social sciences. In this article, we will both reconsider the conditions of occurrence of these services and discuss the evolution of their environment. Through the example of several emerging initiatives in the field of scientific publishing, in a context marked by continuity but also rupture, we will try to glimpse the role journals could play in the new digital world being created.

"Beards, Sandals, and Other Signs of Rugged Individualism": Masculine Culture within the Computing Professions

Over the course of the 1960s and 1970s, male computer experts were able to successfully transform the "routine and mechanical" (and therefore feminized) activity of computer programming into a highly valued, well-paying, and professionally respectable discipline. They did so by constructing for themselves a distinctively masculine identity in which individual artistic genius, personal eccentricity, anti-authoritarian behavior, and a characteristic "dislike of activities involving human interaction" were mobilized as sources of personal and professional authority. This article explores the history of masculine culture and practices in computer programming, with a particular focus on the role of university computer centers as key sites of cultural formation and dissemination.

Neuronal morphology goes digital: a research hub for cellular and system neuroscience

The importance of neuronal morphology in brain function has been recognized for over a century. The broad applicability of "digital reconstructions" of neuron morphology across neuroscience subdisciplines has stimulated the rapid development of numerous synergistic tools for data acquisition, anatomical analysis, three-dimensional rendering, electrophysiological simulation, growth models, and data sharing. Here we discuss the processes of histological labeling, microscopic imaging, and semiautomated tracing. Moreover, we provide an annotated compilation of currently available resources in this rich research "ecosystem" as a central reference for experimental and computational neuroscience.

Bioinspired principles for large-scale networked sensor systems: an overview

Biology has often been used as a source of inspiration in computer science and engineering. Bioinspired principles have found their way into network node design and research due to the appealing analogies between biological systems and large networks of small sensors. This paper provides an overview of bioinspired principles and methods such as swarm intelligence, natural time synchronization, artificial immune system and intercellular information exchange applicable for sensor network design. Bioinspired principles and methods are discussed in the context of routing, clustering, time synchronization, optimal node deployment, localization and security and privacy.

People and ideas in medical informatics - a half century review

OBJECTIVE. Reviewing the onset and the rapid changes to make realistic predictions on the future of medical informatics. METHODS. Pointing to the contributions of the early pioneers, who had their roots in other disciplines and by illustrating that from the onset an interdisciplinary approach was characteristic for our field. RESULTS. Some of the reasons for the changes in medical informatics are that nobody was able to predict the advent of the personal computer in the 1970s, the world-wide web in 1991, and the public start of the Internet in 1992, but foremost that nobody expected that it was not primarily the hardware or the software, but human factors that would be crucial for successful applications of computers in health care. In the past sometimes unrealistic expectations were held, such as on the impact of medical decision-support systems, or on the overly optimistic contributions of electronic health records. Although the technology is widely available, some applications appear to be far more complex than expected. Health care processes can seldom be fully standardized. Humans enter at least in two very different roles in the loop of information processing: as subjects conducting care - the clinicians - and as subjects that are the objects of care - the patients. CONCLUSIONS. Medical informatics lacks a specific methodology; methods are borrowed from adjacent disciplines such as physics, mathematics and, of course, computer science. Human factors play a major role in applying computers in health care. Everyone pursuing a career in biomedical informatics needs to be very aware of this. It is to be expected that the quality of health care will increasingly be assessed by computer systems to fulfill the requirements of medical evidence.

A survey of stimulation methods used in SSVEP-based BCIs

Brain-computer interface (BCI) systems based on the steady-state visual evoked potential (SSVEP) provide higher information throughput and require shorter training than BCI systems using other brain signals. To elicit an SSVEP, a repetitive visual stimulus (RVS) has to be presented to the user. The RVS can be rendered on a computer screen by alternating graphical patterns, or with external light sources able to emit modulated light. The properties of an RVS (e.g., frequency, color) depend on the rendering device and influence the SSVEP characteristics. This affects the BCI information throughput and the levels of user safety and comfort. Literature on SSVEP-based BCIs does not generally provide reasons for the selection of the used rendering devices or RVS properties. In this paper, we review the literature on SSVEP-based BCIs and comprehensively report on the different RVS choices in terms of rendering devices, properties, and their potential influence on BCI performance, user safety and comfort.

Use of the youth risk behavior survey to monitor trends for nutrition and physical activity in a Midwest city school district

BACKGROUND

The Youth Risk Behavior Survey (YRBS) was used by a city school district (approximately 11,000 students) in the upper Midwest to monitor trends for nutrition and physical activity (PA) behaviors both within and between years and to compare with national 2003 data.

METHODS

Independent random samples were obtained in 1999 (387 middle school [MS] and 931 high school [HS]), in 2001 (322 MS and 367 HS), and in 2003 (658 MS and 1026 HS). A two-sample test of proportions was used.

RESULTS

Within each survey year, a higher proportion of MS compared to HS reported positive behaviors with some exceptions: (1) an increased proportion of HS having daily physical education (PE) and (2) a reduced proportion of HS reporting media time. Within 2003, a lower proportion of district females compared to males (MS and HS) reported participation in many measured behaviors. District trends overtime indicated a reduced proportion: (1) drinking milk (MS and HS), (2) eating breakfast (HS), and (3) watching television (MS). Trends overtime indicated an increased proportion: (1) using computers for fun (MS and HS), (2) participating in moderate PA (MS), and (3) daily PE (HS). District HS compared to national (2003) indicated a higher proportion: (1) drinking milk, (2) getting moderate PA, and (3) taking daily PE. District HS compared to national indicated a lower proportion: (1) at risk of overweight, (2) overweight, and (3) watching television.

CONCLUSIONS

Analysis of district YRBS trends provides both a database for informed decisions by the school district and an assessment model for other districts.

The electronic, 'paperless' medical office; has it arrived?

Modern information technology offers efficiencies in medical practice, with a reduction in secretarial time in maintaining, filing and retrieving the paper medical record. Electronic requesting of investigations allows tracking of outstanding results. Less storage space is required and telephone calls from pharmacies, pathology and medical imaging service providers to clarify the hand-written request are abolished. Voice recognition software reduces secretarial typing time per letter. These combined benefits can lead to significantly reduced costs and improved patient care. The paperless office is possible, but requires commitment and training of all staff; it is preferable but not absolutely essential that at least one member of the practice has an interest and some expertise in computers. More importantly, back-up from information technology providers and back-up of the electronic data are absolutely crucial and a paperless environment should not be considered without them.

A strategy for computer-assisted mental practice in stroke rehabilitation

OBJECTIVE

To investigate the technical and clinical viability of using computer-facilitated mental practice in the rehabilitation of upper-limb hemiparesis following stroke.

DESIGN

A single-case study.

SETTING

Academic-affiliated rehabilitation center.

PARTICIPANT

A 46-year-old man with stable motor deficit of the upper right limb following subcortical ischemic stroke.

INTERVENTION

Three computer-enhanced mental practice sessions per week at the rehabilitation center, in addition to usual physical therapy. A custom-made virtual reality system equipped with arm-tracking sensors was used to guide mental practice. The system was designed to superimpose over the (unseen) paretic arm a virtual reconstruction of the movement registered from the nonparetic arm. The laboratory intervention was followed by a 1-month home-rehabilitation program, making use of a portable display device.

MAIN OUTCOME MEASURES

Pretreatment and posttreatment clinical assessment measures were the upper-extremity scale of the Fugl-Meyer Assessment of Sensorimotor Impairment and the Action Research Arm Test. Performance of the affected arm was evaluated using the healthy arm as the control condition.

RESULTS

The patient's paretic limb improved after the first phase of intervention, with modest increases after home rehabilitation, as indicated by functional assessment scores and sensors data.

CONCLUSION

Results suggest that technology-supported mental training is a feasible and potentially effective approach for improving motor skills after stroke.

BCI meeting 2005-workshop on technology: hardware and software

This paper describes the outcome of discussions held during the Third International BCI Meeting at a workshop to review and evaluate the current state of BCI-related hardware and software. Technical requirements and current technologies, standardization procedures and future trends are covered. The main conclusion was recognition of the need to focus technical requirements on the users' needs and the need for consistent standards in BCI research.