The mismatched multiple-access channel: General alphabets

This paper considers channel coding for the memoryless multiple-access channel with a given (possibly suboptimal) decoding rule. Non-asymptotic bounds on the error probability are given, and a cost-constrained random-coding ensemble is used to obtain an achievable error exponent. The achievable rate region recovered by the error exponent coincides with that of Lapidoth in the discrete memoryless case, and remains valid for more general alphabets. © 2013 IEEE.

4-channel polymeric optical bus module for board-level optical interconnections

A 4-channel polymeric optical bus module suitable for use in board-levelinterconnections is presented. Low-loss and low-crosstalk module performance is achieved, while-1 dB alignment tolerances better than ± 8 μm are demonstrated. © OSA 2012.

Developing ISO 14649-based conversational programming system for multi-channel complex machine tools

A multi-channel complex machine tool (MCCM) is a versatile machining system equipped with more than two spindles and turrets for both turning and milling operations. Despite the potential of such a tool, the value of the hardware is largely dependent on how the machine tools are effectively programmed for machining. In this paper we consider a shop-floor programming system based on ISO 14649 (called e-CAM), the international standard for the interface between computer-aided manufacture (CAM) and computer numerical control (CNC). To be deployed in practical industrial usage a great deal of research has to be carried out. In this paper we present: 1) Design consideration for an e-CAM system, 2) The architecture design of e-CAM, 3) Major algorithms to fulfill the modules defined in the architecture, and 4) Implementation details.

Second-order rate region of constant-composition codes for the multiple-access channel

This paper presents an achievable second-order rate region for the discrete memoryless multiple-access channel. The result is obtained using a random-coding ensemble in which each user's codebook contains codewords of a fixed composition. It is shown that this ensemble performs at least as well as i.i.d. random coding in terms of second-order asymptotics, and an example is given where a strict improvement is observed. © 2013 IEEE.

A derivation of the source-channel error exponent using nonidentical product distributions

This paper studies the random-coding exponent of joint source-channel coding for a scheme where source messages are assigned to disjoint subsets (referred to as classes), and codewords are independently generated according to a distribution that depends on the class index of the source message. For discrete memoryless systems, two optimally chosen classes and product distributions are found to be sufficient to attain the sphere-packing exponent in those cases where it is tight. © 2014 IEEE.

Cell types, network homeostasis, and pathological compensation from a biologically plausible ion channel expression model.

How do neurons develop, control, and maintain their electrical signaling properties in spite of ongoing protein turnover and perturbations to activity? From generic assumptions about the molecular biology underlying channel expression, we derive a simple model and show how it encodes an "activity set point" in single neurons. The model generates diverse self-regulating cell types and relates correlations in conductance expression observed in vivo to underlying channel expression rates. Synaptic as well as intrinsic conductances can be regulated to make a self-assembling central pattern generator network; thus, network-level homeostasis can emerge from cell-autonomous regulation rules. Finally, we demonstrate that the outcome of homeostatic regulation depends on the complement of ion channels expressed in cells: in some cases, loss of specific ion channels can be compensated; in others, the homeostatic mechanism itself causes pathological loss of function.

Channel formation and intermediate range order in sodium silicate melts and glasses

Kargl, Florian; Meyer, A.; Horbach, J.; Kob, W., (2004) 'Channel formation and intermediate range order in sodium silicate melts and glasses', Physical Review Letters 93(2) pp.027801 RAE2008

A fully integrated multi-channel detector for electron spectroscopy

Langstaff, David; Bushell, A.; Chase, T.; Evans, D.A., (2005) 'A fully integrated multi-channel detector for electron spectroscopy', Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 238 pp.219-223 RAE2008 Synchrotron Radiation in Materials Science ? Proceedings of the 4th Conference on Synchrotron Radiation in Materials Science 4th Conference on Synchrotron Radiation in Materials Science

A whole-cell and single-channel study of the voltage-dependent outward potassium current in avian hepatocytes.

Voltage-dependent membrane currents were studied in dissociated hepatocytes from chick, using the patch-clamp technique. All cells had voltage-dependent outward K+ currents; in 10% of the cells, a fast, transient, tetrodotoxin-sensitive Na+ current was identified. None of the cells had voltage-dependent inward Ca2+ currents. The K+ current activated at a membrane potential of about -10 mV, had a sigmoidal time course, and did not inactivate in 500 ms. The maximum outward conductance was 6.6 +/- 2.4 nS in 18 cells. The reversal potential, estimated from tail current measurements, shifted by 50 mV per 10-fold increase in the external K+ concentration. The current traces were fitted by n2 kinetics with voltage-dependent time constants. Omitting Ca2+ from the external bath or buffering the internal Ca2+ with EGTA did not alter the outward current, which shows that Ca2+-activated K+ currents were not present. 1-5 mM 4-aminopyridine, 0.5-2 mM BaCl2, and 0.1-1 mM CdCl2 reversibly inhibited the current. The block caused by Ba was voltage dependent. Single-channel currents were recorded in cell-attached and outside-out patches. The mean unitary conductance was 7 pS, and the channels displayed bursting kinetics. Thus, avian hepatocytes have a single type of K+ channel belonging to the delayed rectifier class of K+ channels.

The influence of transforming growth factor-beta1 gene polymorphisms on the severity of gingival overgrowth associated with concomitant use of cyclosporin A and a calcium channel blocker

The purpose of this study was to determine whether the prevalence and severity of gingival overgrowth in renal transplant recipients concomitantly treated with cyclosporin and a calcium channel blocker was associated with functional polymorphisms within the signal sequence of the transforming growth factor-(TGF)beta1 gene.

Phylogeographic analysis of the red seaweed Palmaria palmata reveals a Pleistocene marine glacial refugium in the English Channel

Phylogeography has provided a new approach to the analysis of the postglacial history of a wide range of taxa but, to date, little is known about the effect of glacial periods on the marine biota of Europe. We have utilized a combination of nuclear, plastid and mitochondrial genetic markers to study the biogeographic history of the red seaweed Palmaria palmata in the North Atlantic. Analysis of the nuclear rDNA operon (ITS1-5.8S-ITS2), the plastid 16S-trnI-trnA-23S-5S, rbcL-rbcS and rpl12-rps31-rpl9 regions and the mitochondrial cox2–3 spacer has revealed the existence of a previously unidentified marine refugium in the English Channel, along with possible secondary refugia off the southwest coast of Ireland and in northeast North America and/or Iceland. Coalescent and mismatch analyses date the expansion of European populations from approximately 128 000 bp and suggest a continued period of exponential growth since then. Consequently, we postulate that the penultimate (Saale) glacial maximum was the main event in shaping the biogeographic history of European P. palmata populations which persisted throughout the last (Weichselian) glacial maximum (c. 20 000 bp) in the Hurd Deep, an enigmatic trench in the English Channel.