Decision support for Cybersecurity risk planning

Security countermeasures help ensure the confidentiality, availability, and integrity of information systems by preventing or mitigating asset losses from Cybersecurity attacks. Due to uncertainty, the financial impact of threats attacking assets is often difficult to measure quantitatively, and thus it is difficult to prescribe which countermeasures to employ. In this research, we describe a decision support system for calculating the uncertain risk faced by an organization under cyber attack as a function of uncertain threat rates, countermeasure costs, and impacts on its assets. The system uses a genetic algorithm to search for the best combination of countermeasures, allowing the user to determine the preferred tradeoff between the cost of the portfolio and resulting risk. Data collected from manufacturing firms provide an example of results under realistic input conditions.     

Rapid scalar value classification and volume clipping for?interactive 3D medical image visualization

In many clinical scenarios, medical data visualization and interaction are important to physicians for exploring inner anatomical structures and extracting meaningful diagnostic information. Real-time high-quality volume rendering, artifact-free clipping, and rapid scalar value classification are important techniques employed in this process. Unfortunately, in practice, it is still difficult to achieve an optimal balance. In this paper, we present some strategies to address this issue, which are based on the calculation of segment-based post color attenuation and dynamic ray–plane intersection (RPI) respectively. When implemented within our visualization system, the new classification algorithm can deliver real-time performance while avoiding the “color over-accumulation” artifacts suffered by the commonly used acceleration algorithms that employ pre-integrated classification. Our new strategy can achieve an optimized balance between image quality and classification speed. Next, the RPI algorithm is used with opacity adjustment technique to effectively remove the “striping” artifacts on the clipping plane caused by the nonuniform integration length. Furthermore, we present techniques for multiple transfer function (TF) based anatomical feature enhancement and “keyhole” based endoscopic inner structure view. Finally, the algorithms are evaluated subjectively by radiologists and quantitatively compared using image power spectrum analysis.     

Dynamic Network User Equilibrium with State-Dependent Time Lags

This paper recasts the Friesz et al. (1993) measure theoretic model of dynamic network user equibrium as a controlled variational inequality problem involving Riemann integrals. This restatement is done to make the model and its foundations accessible to a wider audience by removing the need to have a background in functional analysis. Our exposition is dependent on previously unavailable necessary conditions for optimal control problems with state-dependent time lags. These necessary conditions, derived in an Appendix, are employed to show that a particular variational inequality control problem has solutions that are dynamic network user equilibria. Our analysis also shows that use of proper flow propagation constraints obviates the need to explicitly employ the arc exit time functions that have complicated numerical implementations of the Friesz et al. (1993) model heretofore. We close by describing the computational implications of numerically determining dynamic user equilibria from formulations based on state-dependent time lags.     

The BIOPHILE Sample Process Management System - Automated Sample Access at Ultra Low Temperatures

The genomics, proteomics, clinical, and drug discovery laboratories have a growing need to maintain valuable samples at ultra-low (−80°C) temperatures in a validated, secure environment. Automated sample processing systems have until now required manual (off-line) storage of samples at −80°C, reducing system reliability and speed. Both of these important needs are addressed by the Sample Process Management System being introduced by BIOPHILE Inc. Conventional sample management processes, such as storage, retrieval, and cataloging, are increasingly strained by the growing sample populations. There are variable sample types, access requirements and storage requirements. Security and inventory procedures are implemented manually. The evolving technologies present in the laboratory cannot interface with conventional manual storage techniques. Addressing these limitations, the primary benefits of BIOPHILE's solutions are:

• Fully validated sample management process that coordinates the life-cycles of samples and their related data.

• Robotic technology to securely store and retrieve samples, improving their accessibility and stability. Thermal shock is reduced, improving sample longevity and quality. The robotic technology allows integration with larger automation systems.

• A process program to develop a Sample Management Strategy. This strategy is developed by analyzing long-term research goals, current baseline processes, and identification of current sample life cycles. A full validation documentation package can be generated, providing a high level of quality assurance.

• Improved sample visibility and quality assurance - automated sample population cataloging; controlled sample management access and security.

     

Cross-talk induces bifurcations in nonlinear models of synaptic plasticity

Linear models of synaptic plasticity provide a useful starting-point for examining the dynamics of neuronal development and learning, but their inherent problems are well known. Models of synaptic plasticity that embrace the demands of biological realism are therefore typically nonlinear. Viewed from a more abstract perspective, nonlinear models of synaptic plasticity are a subset of nonlinear dynamical systems. As such, they may therefore exhibit bifurcations under the variation of control parameters, including noise and errors in synaptic updates. One source of noise or error is the cross-talk that occurs during otherwise Hebbian plasticity. Under cross-talk, stimulation of a set of synapses can induce or modify plasticity in adjacent, unstimulated synapses. Here, we analyze two nonlinear models of developmental synaptic plasticity and a model of independent component analysis in the presence of a simple model of cross-talk. We show that cross-talk does indeed induce bifurcations in these models, entirely destroying their ability to acquire either developmentally or learning-related patterns of fixed points. Importantly, the critical level of cross-talk required to induce bifurcations in these models is very sensitive to the statistics of the afferents' activities and the number of afferents synapsing on a postsynaptic cell. In particular, the critical level can be made arbitrarily small. Because bifurcations are inevitable in nonlinear models, our results likely apply to many nonlinear models of synaptic plasticity, although the precise details vary by model. Hence, many nonlinear models of synaptic plasticity are potentially fatally compromised by the toxic influence of cross-talk and other sources of noise and errors more generally. We conclude by arguing that biologically realistic models of synaptic plasticity must be robust against noise-induced bifurcations and that biological systems may have evolved strategies to circumvent their possible dangers.     

电力电子和未来的航海电气系统(上)

明天的航海电气系统将同今天的系统有极大的不同。电力电子给予船舶上包括推进、电力分配、备用电源、声纳和雷达等在内的各种系统的进展以重要的影响。刚刚出现的新材料、新器件和新的系统概念(诸如宽带半导体材料、碳化硅基的电力半导体器件、电力电子模组(PEBB),以及集成功率系统)正在使、并将持续地使未来的航海系统有别于今天的系统,如同内燃船舶有别于蒸汽船舶。但是,这些正在实现的技术和有关概念还未被大家所周知,而且还有难于理解的地方。本文就将介绍这些新概念和新技术,指出潜在的影响力,并揭示新的设计方法,以推动航海电气系统的发展。     

A unified approach to multistage frequency-response masking filter design using the WLS technique

This paper presents a unified approach to the optimal design of sharp linear-phase finite-impulse-response (FIR) digital filters synthesized using the multistage frequency-response masking (FRM) technique. In this approach, the design of a k-stage FRM filter is achieved in a recursive manner. The minimax design problem arising at each step of the synthesis process is converted into a corresponding weighted least-squares (WLS) problem. The WLS problem is highly nonlinear with respect to the coefficients of the filter. Consequently, it is decomposed into several linear least-squares (LS) problems, each of which can be solved analytically. It is then solved iteratively by using an alternating variable approach. Numerical design examples are included to demonstrate the effectiveness of the method.     

Factors Affecting Hydrogen Production from Food Wastes by Clostridium-Rich Composts

This study used the technique of response surface approach to analyze the combined effects of heat-shocking temperature and time on anaerobic grass composts. Results indicate that the grass composts under heat-shocking temperature and time of 80°C and 3?h, respectively, could yield high populations of hydrogen-producing microorganisms. Metabolic results demonstrate that the composts are reliable, having considerable hydrogen-producing Clostridia. The multivariate analysis with response surface by considering specific hydrogen-producing potential and rate simultaneously indicate that the cultural media with Fe2+ = 132?mg/L; NH4+ = 537?mg/L; and PO43? = 1,331?mg/L were optimal for the hydrogen-producing Clostridia-rich composts using high-solids food wastes. The specific hydrogen production potential and rate were 77±3?mL?H2/gTVS and 520±20?mL?H2/g?TVS/day, respectively. The former was 38% of theoretical hydrogen-producing potential of Clostridium sp. using glucose. Of these factors, ammonium and phosphate are nutrients for the hydrogen-producing Clostridia growth while iron exerts a synergistic influence on them in the conversion of the food wastes into hydrogen.     

The Nature of Struck-by Accidents

Construction accidents are broadly categorized into five basic groups, namely falls (from elevation), shock (electrical), caught in/between, struck-by, and other. “Struck-by” accidents accounted for 22% of all construction-related fatalities recorded by the Occupational Safety and Health Administration between 1985 and 1989. Recent (1997 to 2000) data show that the percentage of struck-by accidents constituted 24.6% of the fatalities and serious construction worker injuries. Struck-by accidents primarily involve workers struck by equipment, private vehicles, falling materials, vertically hoisted materials, horizontally transported materials, and trench cave ins. Determining possible causation factors of these accident types is often difficult, due to the broad categories utilized in the accident coding system. This study resulted in gaining insights about the root causes of the struck-by injuries. By finding the root causes, effective methods for accident prevention can be developed.     

Health Service Use Predictors Among Trauma Survivors: A Critical Review.

This article had 2 aims: (a) to comprehensively review and synthesize the literature on predictors of health service utilization in survivors of traumatic events and posttraumatic stress disorder (PTSD) patients and (b) to discuss methodological issues in examining service utilization in this population. PsycINFO was searched for relevant articles published through April 2004. Included studies had to primarily sample trauma survivors or PTSD patients and statistically explore health service use determinants. Although some findings conflicted across studies, increased mental health service use was generally related to being female, having a previous trauma history, and having a PTSD diagnosis. Increased medical service use was found among those with a PTSD diagnosis. Methodological recommendations are made for future health service use studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)