Trends in the Solution of Distributed Data Placement Problem

Data placement for optimal performance is an old problem. For example the problem dealt with the placement of relational data in distributed databases, to achieve optimal query processing time. Heterogeneous distributed systems with commodity processors evolved in response to requirement of storage and processing capacity of enormous scale. Reliability and availability are accomplished by appropriate level of data replication, and efficiency is achieved by suitable placement and processing techniques. Where to place which data, how many copies to keep, how to propagate updates so as to maximize the reliability, availability and performance are the issues addressed. In addition to processing costs, the network parameters of bandwidth limitation, speed and reliability have to be considered. This paper surveys the state of the art of published literature on these topics. We are confident that the placement problem will continue to be a research problem in the future also, with the parameters changing. Such situations will arise for example with the advance of mobile smart phones both in terms of the capability and applications

Co-refolding denatured-reduced hen egg white lysozyme with acidic and basic proteins

Refolding of denatured-reduced lysozyme and the effect of co-refolding it with other proteins such as RNase A, bovine serum albumin, histone, myelin basic protein, alcohol dehydrogenase and DNase I on the renaturation yield and the aggregation of lysozyme have been studied. Basic proteins consistently increase the renaturation yield of the basic protein lysozyme (10–20% more than in their absence) with little or no aggregation. On the other hand, co-refolding of lysozyme with acidic proteins leads to aggregation and a significant decrease in renaturation yields. Our results show that hetero-interchain interactions (non-specific interactions) occur when the basic protein lysozyme is refolded together with acidic proteins such as bovine serum albumin, alcohol dehydrogenase or DNase I. Our results also suggest that the net charge on proteins plays a significant role in such non-specific aggregation. These results should prove useful in understanding the hetero-interchain interactions between folding polypeptide chains

Redox-regulated chaperone function and conformational changes of Escherichia coli Hsp33

We have studied the chaperone activity and conformation of Escherichia coli heat shock protein (Hsp)33, whose activity is known to be switched on by oxidative conditions. While oxidized Hsp33 completely prevents the heat-induced aggregation of ζ-crystallin at 42°C at a ratio of 1:1 (w/w), the reduced form exhibits only a marginal effect on the aggregation. Far UV–circular dichroism (CD) spectra show that reduced Hsp33 contains a significant α-helical component. Oxidation results in significant changes in the far UV–CD spectrum. Near UV–CD spectra show changes in tertiary structural packing upon oxidation. Polarity-sensitive fluorescent probes report enhanced hydrophobic surfaces in the oxidized Hsp33. Our studies show that the oxidative activation of the chaperone function of Hsp33 involves observable conformational changes accompanying increased exposure of hydrophobic pockets

MultiPoseNet: Fast Multi-Person Pose Estimation using Pose Residual Network

In this paper, we present MultiPoseNet, a novel bottom-up multi-person pose estimation architecture that combines a multi-task model with a novel assignment method. MultiPoseNet can jointly handle person detection, keypoint detection, person segmentation and pose estimation problems. The novel assignment method is implemented by the Pose Residual Network (PRN) which receives keypoint and person detections, and produces accurate poses by assigning keypoints to person instances. On the COCO keypoints dataset, our pose estimation method outperforms all previous bottom-up methods both in accuracy (+4-point mAP over previous best result) and speed; it also performs on par with the best top-down methods while being at least 4x faster. Our method is the fastest real time system with 23 frames/sec. Source code is available at: https://github.com/mkocabas/pose-residual-networkComment: to appear in ECCV 201

Statistics of Impedance, Local Density of States, and Reflection in Quantum Chaotic Systems with Absorption

We are interested in finding the joint distribution function of the real and imaginary parts of the local Green function for a system with chaotic internal wave scattering and a uniform energy loss (absorption). For a microwave cavity attached to a single-mode antenna the same quantity has a meaning of the complex cavity impedance. Using the random matrix approach, we relate its statistics to that of the reflection coefficient and scattering phase and provide exact distributions for systems with beta=2 and beta=4 symmetry class. In the case of beta=1 we provide an interpolation formula which incorporates all known limiting cases and fits excellently available experimental data as well as diverse numeric tests.Comment: 4 pages, 1 figur

Optimal control theory for unitary transformations

The dynamics of a quantum system driven by an external field is well described by a unitary transformation generated by a time dependent Hamiltonian. The inverse problem of finding the field that generates a specific unitary transformation is the subject of study. The unitary transformation which can represent an algorithm in a quantum computation is imposed on a subset of quantum states embedded in a larger Hilbert space. Optimal control theory (OCT) is used to solve the inversion problem irrespective of the initial input state. A unified formalism, based on the Krotov method is developed leading to a new scheme. The schemes are compared for the inversion of a two-qubit Fourier transform using as registers the vibrational levels of the $X^1\Sigma^+_g$ electronic state of Na$_2$. Raman-like transitions through the $A^1\Sigma^+_u$ electronic state induce the transitions. Light fields are found that are able to implement the Fourier transform within a picosecond time scale. Such fields can be obtained by pulse-shaping techniques of a femtosecond pulse. Out of the schemes studied the square modulus scheme converges fastest. A study of the implementation of the $Q$ qubit Fourier transform in the Na$_2$ molecule was carried out for up to 5 qubits. The classical computation effort required to obtain the algorithm with a given fidelity is estimated to scale exponentially with the number of levels. The observed moderate scaling of the pulse intensity with the number of qubits in the transformation is rationalized.Comment: 32 pages, 6 figure