The effect of a market factor on information flow between stocks using minimal spanning tree

We empirically investigated the effects of market factors on the information flow created from N(N-1)/2 linkage relationships among stocks. We also examined the possibility of employing the minimal spanning tree (MST) method, which is capable of reducing the number of links to N-1. We determined that market factors carry important information value regarding information flow among stocks. Moreover, the information flow among stocks evidenced time-varying properties according to the changes in market status. In particular, we noted that the information flow increased dramatically during periods of market crises. Finally, we confirmed, via the MST method, that the information flow among stocks could be assessed effectively with the reduced linkage relationships among all links between stocks from the perspective of the overall market

Development and application of a self-referencing glucose microsensor for the measurement of glucose consumption by pancreatic ?-cells

Glucose gradients generated by an artificial source and ?-cells were measured using an enzyme-based glucose microsensor, 8-?m tip diameter, as a self-referencing electrode. The technique is based on a difference measurement between two locations in a gradient and thus allows us to obtain real-time flux values with minimal impact of sensor drift or noise. Flux values were derived by incorporation of the measured differential current into Fick's first equation. In an artificial glucose gradient, a flux detection limit of 8.2 ± 0.4 pmol·cm-2·s-1 (mean ± SEM, n = 7) with a sensor sensitivity of 7.0 ± 0.4 pA/mM (mean ± SEM, n = 16) was demonstrated. Under biological conditions, the glucose sensor showed no oxygen dependence with 5 mM glucose in the bulk medium. The addition of catalase to the bulk medium was shown to ameliorate surface-dependent flux distortion close to specimens, suggesting an underlying local accumulation of hydrogen peroxide. Glucose flux from ?-cell clusters, measured in the presence of 5 mM glucose, was 61.7 ± 9.5 fmol·nL-1·s-1 (mean ± SEM, n = 9) and could be pharmacologically modulated. Glucose consumption in response to FCCP (1 ?M) transiently increased, subsequently decreasing to below basal by 93 ± 16 and 56 ± 6%, respectively (mean ± SEM, n = 5). Consumption was decreased after the application of 10 ?M rotenone by 74 ± 5% (mean ± SEM, n = 4). These results demonstrate that an enzyme-based amperometric microsensor can be applied in the self-referencing mode. Further, in obtaining glucose flux measurements from small clusters of cells, these are the first recordings of the real-time dynamic of glucose movements in a biological microenvironment. <br/

Optimal Control Methods for PV-integrated Shading Devices.

The main reason for the under-utilization of natural light is glare caused by excessive admission of daylight into interior spaces. Absence of a dynamic and effective shading control system entails leaving shading devices at a closed position for glare prevention. For increasing building energy efficiency, it is imperative to develop shading control methods that provide both visual comfort and electric lighting energy savings. A tracking PV system has higher light-to-electricity conversion efficiency than its fixed counterpart. Previous studies on louver controls indicate that louver slat surfaces blocking sunlight receive higher solar radiation than a vertical or tilted-up position. As such, a louver coated with photovoltaics cells, when appropriately controlled, has potentials to achieve high energy production efficiency and visual comfort simultaneously. This is the motivation of the development of a novel hybrid of PV system and shading device: a PV-integrated shading device (PVIS). The performance of a PVIS, whose louvers are coated with photovoltaic cells, was evaluated in terms of electricity production, daylight admission, and occupant visual comfort. Three different shading control methods were developed and tested: 1) maximizing the louver PV output only, 2) maximizing the PV output while meeting an indoor daylight level requirement, and 3) maximizing the PV output while satisfying an indoor daylight level and daylight glare criteria. An artificial neural network was developed to predict the effect of solar radiation and slat tilt angle on PV output and visual comfort. Through experimental testings, it was found that artificial neural network can effectively incorporated in the optimization of shading control. It was also found that the control method with the visual comfort criteria resulted in 9% reduction of PV output compared to that without them. The total building energy benefits of the control method with visual comfort criteria was at least 36% higher than that without due to the reduction of electric lighting energy consumption. Due to the PV-output criterion, the daylight glare remained within the comfortable range. For this reason, the glare criterion made no difference in louver tilt angle control.PHDArchitectureUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/110457/1/jskstrm_1.pd

Delayed rupture of a pseudoaneurysm in the brachial artery of a burn reconstruction patient

A brachial artery pseudoaneurysm is a rare but serious condition that can be limb threatening. A number of reports have found that it may be the result of damage to the blood vessels around the brachial artery, either directly or indirectly, due to trauma or systemic diseases. We present our experience of delayed pseudoaneurysm rupture of the brachial artery in a rehabilitation patient with burns of the upper extremity who underwent fasciotomy and musculocutaneous flap coverage. We also provide a review of the brachial artery pseudoaneurysm

SimpleSSD: Modeling Solid State Drives for Holistic System Simulation

Existing solid state drive (SSD) simulators unfortunately lack hardware and/or software architecture models. Consequently, they are far from capturing the critical features of contemporary SSD devices. More importantly, while the performance of modern systems that adopt SSDs can vary based on their numerous internal design parameters and storage-level configurations, a full system simulation with traditional SSD models often requires unreasonably long runtimes and excessive computational resources. In this work, we propose SimpleSSD, a highfidelity simulator that models all detailed characteristics of hardware and software, while simplifying the nondescript features of storage internals. In contrast to existing SSD simulators, SimpleSSD can easily be integrated into publicly-available full system simulators. In addition, it can accommodate a complete storage stack and evaluate the performance of SSDs along with diverse memory technologies and microarchitectures. Thus, it facilitates simulations that explore the full design space at different levels of system abstraction.Comment: This paper has been accepted at IEEE Computer Architecture Letters (CAL