Error statistics for concatenated systems on non-renewal time-varying channels, Journal of Telecommunications and Information Technology, 2001, nr 3

The statistics of the error process generated by a discrete super channel formed by the concatenation of a constrained encoder, a non-renewal finite state channel (FSC), and a constrained decoder is studied in this paper. First, recursions are developed for the error weight distribution. This statistics is relevant to the design of coding schemes and interleaving in concatenated systems. We also study the renewal nature of the residual error process as modified by the constrained decoder. Ferreira et al. conjectured that if the channel model is a renewal FSC, the super channel can be modeled as a similar renewal model. We use a statistics called the multigap distribution to analytically disprove this hypothesis. Furthermore, the effect of interleaving is investigated from a new perspective using the variance of the multigap distribution

Computational cytometer based on magnetically modulated coherent imaging and deep learning.

Detecting rare cells within blood has numerous applications in disease diagnostics. Existing rare cell detection techniques are typically hindered by their high cost and low throughput. Here, we present a computational cytometer based on magnetically modulated lensless speckle imaging, which introduces oscillatory motion to the magnetic-bead-conjugated rare cells of interest through a periodic magnetic force and uses lensless time-resolved holographic speckle imaging to rapidly detect the target cells in three dimensions (3D). In addition to using cell-specific antibodies to magnetically label target cells, detection specificity is further enhanced through a deep-learning-based classifier that is based on a densely connected pseudo-3D convolutional neural network (P3D CNN), which automatically detects rare cells of interest based on their spatio-temporal features under a controlled magnetic force. To demonstrate the performance of this technique, we built a high-throughput, compact and cost-effective prototype for detecting MCF7 cancer cells spiked in whole blood samples. Through serial dilution experiments, we quantified the limit of detection (LoD) as 10 cells per millilitre of whole blood, which could be further improved through multiplexing parallel imaging channels within the same instrument. This compact, cost-effective and high-throughput computational cytometer can potentially be used for rare cell detection and quantification in bodily fluids for a variety of biomedical applications

Journal of Telecommunications and Information Technology, 2001, nr 3

kwartalni

Voltage-gating and assembly of split Kv10.1 channels

Voltage-gated ion channels allow ions to pass cell membrane upon changes of transmembrane electrical potential. Conformational changes in the voltage-sensing domain of the channel (VSD) are assumed to be transmitted to the pore domain (PD) through an alpha-helical linker between them (S4-S5 linker). We have previously shown that expression of VSD and PD as separate fragments results in functional Kv10.1 channels that retain voltage-dependence. Here we used such ‘split’ channels to investigate functional interactions between VSD and PD. We found that their electrophysiological properties greatly depend on where the S4-S5 linker is interrupted. Remarkably, wild-type-like channel behavior could be fully or largely restored by mutations of crucial linker amino acids, indicating that precise functional interactions between VSD and PD remain when they are not covalently bound. Voltage-Clamp Fluorometry measurements revealed that VSD motion is alerted in specific split channels, but these changes were subtler. Finally, the increased separation between VSD activation and channel opening in the split channel carrying a large deletion in the S4-S5 linker, as well as the failure of the PD expressed alone to give currents, suggest that the role of the VSD in the is to open the channel pore and prevent it from closing

Voltage-gating and assembly of split Kv10.1 channels

Voltage-gated ion channels allow ions to pass cell membrane upon changes of transmembrane electrical potential. Conformational changes in the voltage-sensing domain of the channel (VSD) are assumed to be transmitted to the pore domain (PD) through an alpha-helical linker between them (S4-S5 linker). We have previously shown that expression of VSD and PD as separate fragments results in functional Kv10.1 channels that retain voltage-dependence. Here we used such ‘split’ channels to investigate functional interactions between VSD and PD. We found that their electrophysiological properties greatly depend on where the S4-S5 linker is interrupted. Remarkably, wild-type-like channel behavior could be fully or largely restored by mutations of crucial linker amino acids, indicating that precise functional interactions between VSD and PD remain when they are not covalently bound. Voltage-Clamp Fluorometry measurements revealed that VSD motion is alerted in specific split channels, but these changes were subtler. Finally, the increased separation between VSD activation and channel opening in the split channel carrying a large deletion in the S4-S5 linker, as well as the failure of the PD expressed alone to give currents, suggest that the role of the VSD in the is to open the channel pore and prevent it from closing

Thirty Years of Machine Learning: The Road to Pareto-Optimal Wireless Networks

Future wireless networks have a substantial potential in terms of supporting a broad range of complex compelling applications both in military and civilian fields, where the users are able to enjoy high-rate, low-latency, low-cost and reliable information services. Achieving this ambitious goal requires new radio techniques for adaptive learning and intelligent decision making because of the complex heterogeneous nature of the network structures and wireless services. Machine learning (ML) algorithms have great success in supporting big data analytics, efficient parameter estimation and interactive decision making. Hence, in this article, we review the thirty-year history of ML by elaborating on supervised learning, unsupervised learning, reinforcement learning and deep learning. Furthermore, we investigate their employment in the compelling applications of wireless networks, including heterogeneous networks (HetNets), cognitive radios (CR), Internet of things (IoT), machine to machine networks (M2M), and so on. This article aims for assisting the readers in clarifying the motivation and methodology of the various ML algorithms, so as to invoke them for hitherto unexplored services as well as scenarios of future wireless networks.Comment: 46 pages, 22 fig

Microfabricated Devices for Adherent Stem Cell Culture

This thesis details the development of a system of microfabricated devices for the adherent culture of stem cells. The multipotency and self renewal of stem cells make them a potentially abundant source of valuable human cells, for both drug screening and regenerative medicine. However, processing stem cells is challenging due to the complexity of whole cell products, the number of process parameters, and the typical use of adherent culture. It is hypothesised that a microfabricated adherent culture system could facilitate process development with minimal use of resources. Furthermore, microfluidic systems offer advantages in spatial and temporal control over the microenvironment that would benefit process development. An existing prototype culture system is critically evaluated by: assessing the design, modelling fluid flow and dissolved oxygen, and successfully co-culturing human embryonic stem cells, on inactivated mouse embryonic fibroblasts, under perfused conditions. The utilisation of reversible seals facilitates the use of standard tissue-culture polystyrene culture surfaces and manual seeding techniques. The evaluation of the prototype system is used to inform improvements to the design, making it easier to use, increasing the robustness, allowing monitoring of whole culture chambers by microscopy, and improving control over mean pericellular dissolved oxygen. Modelling shows the improved culture system also achieves more uniform distribution of both pericellular dissolved oxygen and fluid velocity. The improved culture system shows similar mouse embryonic stem cell seeding behaviour to tissue culture flasks, but, with medium perfused at 300 μl.h 1, mouse embryonic stem cells reach full confluency in less than 48 h, compared with 72 hours for cells maintained statically in flasks. There is also inconclusive data suggesting that the growth rate is limited by pericellular dissolved oxygen and is, therefore, increased and made more uniform by the inclusion of a gas permeable lid system. The reliability, ease of use, comparability with traditional culture systems, and control over process parameters of the improved system should make it a useful tool for stem cell process development

LHCb VELO Upgrade: Technical Design Report

The upgraded LHCb VELO silicon vertex detector is a lightweight hybrid pixel detector capable of 40 MHz readout at a luminosity of 2×10^33 cm^−2 s^−1. The track reconstruction speed and precision is enhanced relative to the current VELO detector even at the high occupancy conditions of the upgrade, due to the pixel geometry and a closest distance of approach to the LHC beams of just 5.1 mm for the first sensitive pixel. Cooling is provided by evaporative CO2 circulating in microchannel cooling substrates. The detector contains 41 million 55μ×55μ pixels, read out by the custom developed VeloPix front end ASIC. The detector will start operation together with the rest of the upgraded LHCb experiment after the LHC LS2 shutdown, currently scheduled to end in 2019. This Technical Design Report describes the upgraded VELO system, planned construction and installation, and gives an overview of the expected detector performanc

Neutronics analysis and thermodynamics studies of several DEMO breeding blankets for the development of the AINA safety code

By 2050 the energy consumption is expected to increase considerably.The production might be mostly based on renewable energy mix driven by the nuclear fusion which could potentially deliver continuous, large-scale power for the long-term without harming the environment. Regrettably, the nuclear fusion still requires numerous developments, which are undergoing around the word, to prove the design feasibility and to evaluate the safety relatad aspects which are to sorne extent embraced this thesis. In light of this, during the last ten years the Nuclear Engineering Research Group (NERG-UPC) has being developing a safety code callad AJNA (acron of Analyses of IN-vessel Accidents) to evaluate the magnetic fusion reactor plasma-wall transients in case of ex-vessel LOCA and overfuelling , determining thermal wall profiles as well as checking the integrity of in-vessel components (melting). Considering the e'v'Olution of technologies and related methodologies, a substantial renewal/improvement plan for AJNA were established. Two specific development tasks are part of this PhD thesis. (i) The definition, standardization and validation of an enhanced methodology to develop new AJNA versions in order to obtain robust models, estimating as accurately as possible the behaviour of the studied systems. (ii) The re-design, generalization and optimization of thermal-hydraulics routines for the determination of the AJNA thermal-wall distributions both in normal and accident scenarios in substitution of the former unverified/unqualified ones. In addition, the thermal­ hydraulic routines have been validated against commercial software as ANSYS Fluent. Consequently, the code has been almost rewritten, improved and consolidated giving special attention on document, comment and V&Vaccording to the current software standard requirements . lndeed, severa! novel features have been introduced to extend the modelling capacity of the AJNA application solver and to estimate the errors . Afterward, two specific AJNA blanket thermal-wall models have been developed: the Water Cooled Pebble Sed JAPANESE­ DEMO and the Helium Cooled Pebble Bed EUROPEAN-DEMO. According to the established methodology, the complete process of design, improvement and validation has included the complete set of compulsory radiation transport analyses , thermal-hydraulic studies and AJNA thermal-wall model tuning. Furthermore, preliminary assessments of the transient accident scenarios and sensibility studies haw been also performed. So, starting from fully detailed neutronics and thermal­ hydraulic results, a simplified and conservatiw wall model has been implemented in AJNA obtaining reliable results in a short calculation time validating the approach proposed. lndeed, simplified models haw been iteratiwly built and adjusted, achieving a good agreement with the fully detailed simulation and yielding a maximum absolute temperature differences around 10%. The determination and coherence of the temperature distribution obtained using independenttool s and approaches, ANSYS® Fluent® vs AJNA thermal-hydraulic routines, supports the proposed methodology, hence validating the whole results obtained. Newrtheless, the 1D non-conservatiw temperature field, where present, could be compensated by the application of scaling functions , obtaining a perfect match with the most conservative 30 distribution. In this innovative approach, the scaling functions correspond to the ratios between the most conservatiw radial distribution in the fully detailed and the 10 simulations . Moreowr, thanks to the simplified and endorsed model, sensitivities and screening assessment can be easily perforrned showing how the system reacts as consequences of loads, boundary conditions and perturbations. In light of this, the detailed number of study can be extensively reduced. To conclude, this multidisciplinary activity has requested the establishment of a specific framework , including skills and tools.En el año 2050 la producción de energía podría estar distribuida principalmente entre fuentes renovables lideradas por la fusión nuclear que potencialmente puede proveer grande cantidades de energías para largos tiempos, sin afectar considerablemente el ambiente. Desafortunadamente, la fusión nuclear requiere aun numerosos desarrollos para demostrar entre otros la validez del diseño y la seguridad nuclear, argumentos que son tratados en esta tesis doctoral. Durante los últimos diez años, el Nuclear Engineering Research Group (NERG-UPC) ha estado desarrollando un código de seguridad nuclear denominado AINA (Analyses of IN-vessel Accidents) para evaluar los transitorios de plasma-pared en los TOKAMAK, reactores de fusión nuclear a confinamiento magnético, en caso LOCA ex-vessel y accidentes de combustible. El programa determina las consecuencias en componentes in-vessel como la temperatura de los mismos y su integridad. Teniendo en cuenta la ewlución de las tecnologías, un plan de renovación para AINA ha sido puesto en marcha incluyendo dos tareas específicas en esta tesis.(i) La definición, estandarización y validación de una metodología para el desarrollo de nuevas versiones de AINA para obtener modelos simplificados y fiables que puedan estimar de manera precisa el comportamiento de los componentes estudiados. (ii) El rediseño, generalización y optimización de las rutinas termo-hidráulicas para la determinación de los perfiles de temperatura evaluados por AINA, en caso estacionario o transitorios con el fin de remplazar las anteriores. Así mismo, dichas funciones han sido evaluadas y verificadas a través de comparaciones directas a software comerciales como ANSYS Fluent. De esta manera, AINA ha sido casi completamente replanteado, mejorado y consolidado con especial atención a la documentación, comentarios y verificación en línea con los estándares de software actuales. Novedosas técnicas han sido introducidas para añadir la capacidad de modelación y su capacidad