Microstructure of the juvenile sheep aortic valve hinge region and the trilamellar sliding hypothesis.

Background: The aortic valve mechanism performs extremely sophisticated functions which depend on the microstructure of its component parts. The hinge mechanism of the aortic leaflets plays a crucial part in the overall function. However, the detailed microstructure and its relation to function has not been adequately studied. Methods: The aortic roots of juvenile sheep were fixed under physiologic pressure. Sections through all three sinuses were then performed to illustrate the microstructure of the hinge mechanism in different regions of the aortic root. Results: The hinge region in the different sinuses showed unique microstructure with a trilamellar topology with a dominant core consisting of glycosaminoglycans. The exact arrangement of the trilamellar structures varies around the aortic sinuses, which could have functional implications. These features allow the hinge to perform its complex functions through what we have described as "the trilamellar sliding hypothesis". Conclusion: The microstructure of the hinge mechanism is unique and enables it to perform it sophisticated functions

NbSe3: Effect of Uniaxial Stress on the Threshold Field and Fermiology

We have measured the effect of uniaxial stress on the threshold field ET for the motion of the upper CDW in NbSe3. ET exhibits a critical behavior, ET ~ (1 - e/ec)^g, wher e is the strain, and ec is about 2.6% and g ~ 1.2. This ecpression remains valid over more than two decades of ET, up to the highest fields of about 1.5keV/m. Neither g nor ec is very sensitive to the impurity concentraction. The CDW transition temperature Tp decreases linearly with e at a rate dTp/de = -10K/%, and it does not show any anomaly near ec. Shubnikov de-Haas measurements show that the extremal area of the Fermi surface decreases with increasing strain. The results suggest that there is an intimate relationship between pinning of the upper CDW and the Fermiology of NbSe3.Comment: 4 pages, 5 figure

Neural net diagnostics for VLSI test

This paper discusses the application of neural network pattern analysis algorithms to the IC fault diagnosis problem. A fault diagnostic is a decision rule combining what is known about an ideal circuit test response with information about how it is distorted by fabrication variations and measurement noise. The rule is used to detect fault existence in fabricated circuits using real test equipment. Traditional statistical techniques may be used to achieve this goal, but they can employ unrealistic a priori assumptions about measurement data. Our approach to this problem employs an adaptive pattern analysis technique based on feedforward neural networks. During training, a feedforward network automatically captures unknown sample distributions. This is important because distributions arising from the nonlinear effects of process variation can be more complex than is typically assumed. A feedforward network is also able to extract measurement features which contribute significantly to making a correct decision. Traditional feature extraction techniques employ matrix manipulations which can be particularly costly for large measurement vectors. In this paper we discuss a software system which we are developing that uses this approach. We also provide a simple example illustrating the use of the technique for fault detection in an operational amplifier

Smart subtitles for vocabulary learning

Language learners often use subtitled videos to help them learn. However, standard subtitles are geared more towards comprehension than vocabulary learning, as translations are nonliteral and are provided only for phrases, not vocabulary. This paper presents Smart Subtitles, which are interactive subtitles tailored towards vocabulary learning. Smart Subtitles can be automatically generated from common video sources such as subtitled DVDs. They provide features such as vocabulary definitions on hover, and dialog-based video navigation. In our pilot study with intermediate learners studying Chinese, participants correctly defined over twice as many new words in a post-viewing vocabulary test when they used Smart Subtitles, compared to dual Chinese-English subtitles. Learners spent the same amount of time watching clips with each tool, and enjoyed viewing videos with Smart Subtitles as much as with dual subtitles. Learners understood videos equally well using either tool, as indicated by self-assessments and independent evaluations of their summaries

Effects of Preheated Clusters on the CMB Spectrum

Mounting evidence from $x$-ray observations reveals that bound objects should receive some form of energy in the past injected from non-gravitaional sources. We report that an instantaneous heating scheme, for which gases in dense regions were subjected to a temperature jump of 1keV at $z=2$ whereas those in rarified regions remained intact, can produce bound objects obeying the observed mass-temperature and luminosity-temperature relations. Such preheating lowers the peak Sunyaev-Zeldovich (SZ) power by a factor of 2 and exacerbates the need for the normalization of matter fluctuations $\sigma_8$ to assume an extreme high value $(\sim 1.1)$ for the SZ signals to account for the excess anisotropy on 5-arcminute scale detected by the Cosmic Background Imager in the cosmic microwave background radiation.Comment: 6 pages, 3 figs, submitted to ApJL. Corrected for a normalization problem and one more simulation result is included. Conclusion has been reversed. Motion pictures of simulations can be found at http://asweb.phys.ntu.edu.tw/~tseng/MEMO/SZE.htm

Noncommutative Solitons and Intersecting D-Branes

We construct intersecting D-branes as noncommutative solitons in bosonic and type II string theory. ``Defect'' branes which are D-branes containing bubbles of the closed string vacuum play an important role in the construction.Comment: 17 pages, harvmac; published version with added clarification

Determining the representative factors affecting warning message dissemination in VANETs

In this paper, we present a statistical analysis based on the 2k factorial methodology to determine the representative factors affecting traffic safety applications in Vehicular ad hoc networks (VANETs). Our purpose is to determine what are the key factors affecting Warning Message Dissemination (WMD) in order to concentrate on such parameters, thus reducing the amount of required simulation time when evaluating VANETs. Simulation results show that the key factors affecting warning messages delivery are: (i) the transmission range, (ii) the radio propagation model used, and (iii) the density of vehicles. Based on this statistical analysis, we evaluate a compound key factor: neighbor density. This factor combines the above-mentioned factors into a single entity, reducing the number of factors that must be taken into account for VANET researchers to evaluate the benefits of their proposals.This work was partially supported by the Ministerio de Educacion y Ciencia, Spain, under Grant TIN2008-06441-C02-01, and by the Fundacion Antonio Gargallo, under Grant 2009/B001.Martínez Domínguez, FJ.; Toh, CK.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.; Manzoni, P. (2012). Determining the representative factors affecting warning message dissemination in VANETs. Wireless Personal Communications. 67(2):295-314. https://doi.org/10.1007/s11277-010-9989-4S295314672Eichler, S. (2007). Performance evaluation of the IEEE 802.11p WAVE communication standard. In Proceedings of the vehicular technology conference (VTC-2007 Fall), USA.Fall, K., & Varadhan, K. (2000). ns notes and documents. The VINT Project. UC Berkeley, LBL, USC/ISI, and Xerox PARC. Available at http://www.isi.edu/nsnam/ns/ns-documentation.html .Fasolo, E., Zanella, A., & Zorzi, M. (2006). An effective broadcast scheme for alert message propagation in vehicular ad hoc networks. In Proceedings of the IEEE International Conference on Communications, Istambul, Turkey.Korkmaz, G., Ekici, E., Ozguner, F., & Ozguner, U. (2004). Urban multi-hop broadcast protocols for inter-vehicle communication systems. In Proceedings of First ACM Workshop on Vehicular Ad Hoc Networks (VANET 2004).Martinez, F. J., Toh, C.-K., Cano, J.-C., Calafate, C. T., & Manzoni, P. (2009). Realistic radio propagation models (RPMs) for VANET simulations. In IEEE wireless communications and networking conference (WCNC), Budapest, Hungary.Martinez, F. J., Cano, J.-C., Calafate, C. T., & Manzoni, P. (2008). CityMob: A mobility model pattern generator for VANETs. In IEEE vehicular networks and applications workshop (Vehi-Mobi, held with ICC), Beijing, China.Martinez, F. J., Cano, J.-C., Calafate, C. T., & Manzoni, P. (2009). A performance evaluation of warning message dissemination in 802.11p based VANETs. In IEEE local computer networks conference (LCN 2009), Zürich, Switzerland.Torrent-Moreno, M., Santi, P., & Hartenstein, H. (2005). Fair sharing of bandwidth in VANETs. In Proceedings of the 2nd ACM international workshop on vehicular ad hoc networks, Germany.Tseng Y.-C., Ni S.-Y., Chen Y.-S., Sheu J.-P. (2002) The broadcast storm problem in a mobile ad hoc network. Wireless Networks 8: 153–167Wisitpongphan N., Tonguz O., Parikh J., Mudalige P., Bai F., Sadekar V. (2007) Broadcast storm mitigation techniques in vehicular ad hoc networks. Wireless Communications IEEE 14(6): 84–94. doi: 10.1109/MWC.2007.4407231Yang, X., Liu, J., Zhao, F., & Vaidya, N. H. (2004). A vehicle-to-vehicle communication protocol for cooperative collision warning. In Proceedings of the first annual international conference on mobile and ubiquitous systems: Networking and services (MobiQuitous’04).Yoon, J., Liu, M., & Noble, B. (2003). Random waypoint considered harmful. Proceedings of IEEE INFOCOMM 2003, San Francisco, California, USA.Zang, Y., Stibor, L., Cheng, X., Reumerman, H.-J., Paruzel, A., & Barroso, A. (2007). Congestion control in wireless networks for vehicular safety applications. In Proceedings of the 8th European Wireless Conference, Paris, France