Narrow Results

Given an undirected graph $G$ and a real edge-weight vector, the connected subgraph problem consists of finding a maximum-weight subset of edges which induces a connected subgraph of $G$. In this paper, we establish a link between the complexity of the connected subgraph problem and the matching number. We study the separation problem associated with the so-called matching-partition inequalities, which were introduced by Didi Biha, Kerivin and Ng [Polyhedral study of the connected subgraph problem, Discr. Math.338 (2015) 80–92] for the connected subgraph polytope.

In this paper we propose the generalized mirrored scheme for scheduling double round robin tournaments (DRRTs), a common topic in sports scheduling, to deal with the conflicting constraints of breaks and separation. In practice, usually a small number of breaks and a large separation are desirable, but typical methods of scheduling DRRTs cannot obtain both a minimum number of breaks and a positive separation. We firstly consider DRRTs by this scheme with a separation of two slots and a minimum number of breaks. In case the number of teams is a multiple of four, we show that such DRRTs could be generated by a constructive method; we also propose a model and find such DRRTs for any other numbers of teams up to 90. Secondly, we consider those with a separation of more than two. We show that if a minimum number of breaks is required, DRRTs with a separation of any number of slots could be obtained by a constructive method, for some large number of teams; otherwise, a tradeoff for a large separation at the cost of only four additional breaks exists for any number of teams.

Water permeation across a carbon nanotube is important in carbon-based nanodevices. Water transfer rate is closely related to the radius of a carbon nanotube. It is hard to change water transfer rate by interior methods once the radius of the entrance of a carbon nanotube is chosen. In this paper, water transfer across a tandem carbon nanotube with a separation is investigated by molecular dynamics simulations. We find that water transfer rate experiences two different transfer behaviors: an increasing behavior and a decreasing behavior by changing the separation length. The result is important in designing a controllable carbon-based nanodevice.

In switching algebra, there exist standard forms of Boolean functions such as the disjunctive or conjunctive form. This paper discusses the theory of the extended standard forms of Boolean functions. In addition to the four existing standard forms, two further forms are introduced and thus expanded to six basic forms. On the one hand, the existence of the extended forms is presented and on the other hand new formulas and equations are illustrated. Equations relating to the resolution and/or solution of conjunction/disjunctions are detailed and proven to be valid. In addition, equations for conversion between forms are exemplified. Finally, certain formal relations between the basic forms that are valid under certain conditions are featured.

We consider the separability of two point sets inside a polygon by means of chords or geodesic lines. Specifically, given a set of red points and a set of blue points in the interior of a polygon, we provide necessary and sufficient conditions for the existence of a chord and for the existence of a geodesic path that separate the two sets; when they exist we also derive efficient algorithms for their obtention. We also study the separation of the two sets using the minimum number of pairwise non-crossing chords.

We propose a natural scheme to measure the joint separation of a cluster of objects in general geometric settings. In particular, here the measure is developed for finite sets of planes in ℝ³ in terms of extreme configurations of vectors on the planes of a given set. We prove geometric and graph-theoretic results about extreme configurations on arbitrary finite plane sets. We then specialize to the planes bounding a regular polyhedron in order to exploit the symmetries. However, even then results are non-trivial and surprising – extreme configurations on regular polyhedra may turn out to be highly irregular.

We obtain lower bounds in the algebraic computation tree model for deciding the separability of two disjoint point sets. In particular, we show Ω(n log n) time lower bounds for separability by means of strips, wedges, wedges with apices on a given line, fixed-slopes double wedges, and triangles, which match the complexity of the existing algorithms, and therefore prove their optimality.

Given simple polygons P and Q, their separation, denoted by σ(P, Q), is defined to be the minimum distance between their boundaries. We present a parallel algorithm for finding a closest pair among all pairs (p, q), p ∈ P and q ∈ Q. The algorithm runs in O (log n) time using O(n) processors on a CREW PRAM, where n = |P| + |Q|. This algorithm is time-optimal and improves by a factor of O (log n) on the time complexity of previous parallel methods. The algorithm can be implemented serially in Θ (n) time, which gives the first optimal sequential algorithm for determining the separation of simple polygons. Our results are obtained by providing a unified treatment of the separation and the closest visible vertex problems for simple polygons.

This paper investigates computational aspects of the well-known convexity theorem due to Helly, which states that the existence of a point in the common intersection of n convex sets is guaranteed by the existence of points in the common intersection of each combination of d+1 of these sets. Given an oracle which accepts d+1 convex sets and either returns a point in their common intersection, or reports its non-existence, we give two algorithms which compute a point in the common intersection of n such gets. The first algorithm runs in O(n^d+1T) time and O(n^d) space, where T is the time required for a single call to the oracle. The second algorithm is a multi-stage variant of the first by which the space complexity may be reduced to O(n) at the expense of an increase in the time complexity by a factor independent of n. We also show how these algorithms may be adapted to construct linear and spherical separators of a collection of sets, and to construct a translate of a given object which either contains, is contained by, or intersects a collection of convex sets.

The ability to transform between distinct geometric representations is the key to success of multiple-representation modeling systems. But the existing theory of geometric modeling does not directly address or support construction, conversion, and comparison of geometric representations. A study of classical problems of CSG ↔ b-rep conversions, CSG optimization, and other representation conversions suggests a natural relationship between a representation scheme and an appropriate decomposition of space. We show that a hierarchy of space decompositions corresponding to different representation schemes can be used to enhance the theory and to develop a systematic approach to maintenance of geometric representations.

In this paper, we study a gang territorial model consisting of two parabolic and two ordinary differential equations, where a taxis-type mechanism models that the two rivaling gangs are repelled by each other’s graffiti. Our main analytical finding shows the existence of global, bounded classical solutions. By making use of quantitative global estimates, we prove that these solutions converge to homogeneous steady states if the initial data are sufficiently small.

Moreover, we perform numerical experiments which show that for different choices of parameters, the system may become diffusion- or convection-dominated, where in the former case the solutions converge toward constant steady states while in the latter case nontrivial asymptotic behavior such as segregation is observed. In order to perform these experiments, we apply a nonlinear finite element flux-corrected transport method (FEM-FCT) which is positivity-preserving. Then we treat the nonlinearities in both the system and the proposed nonlinear scheme simultaneously using fixed-point iteration.

The main result is that the Vassiliev invariants are dense in the set of numeric knot invariants if and only if they separate knots.

This paper examines two fundamental issues in sound field analysis: acoustic sources localization and separation. Algorithms are developed to locate and separate acoustic signals on the basis of plane-wave decomposition. In the localization stage, directions of plane waves are determined using either minimum variance distortionless response (MVDR) method or multiple signal classification (MUSIC) method. For broadband scenarios, coherent and incoherent techniques are utilized in the localization procedure. In the separation stage, two approaches with overdetermined and underdetermined settings can be employed. In the overdetermined approach, Tikhonov regularization (TIKR) is utilized to recover the source signals. In the underdetermined approach, the steering matrix is augmented by including the directions that have been determined in the localization stage. Hence, the separation problem is formulated into a compressive sensing (CS) problem which can be effectively solved by using convex (CVX) optimization. Simulation and experiments are conducted for a 24-element circular array. Objective tests using perceptual evaluation of speech quality (PESQ) tests and subjective listening tests demonstrate that the proposed methods yield speech signals with well separated and improved quality, as compared to the mixed signals.

In this work, total 1592 individual leakage-free polymethylmethacrylate (PMMA) microfluidic devices as laboratory-on-a-chip systems are fabricated by maskless lithography, hot embossing lithography, and direct bonding technique. Total 1094 individual Audio Video Interleave Files as experimental outputs related to the surface-driven capillary flow have been recorded and analyzed. The influence of effective viscosity, effect of surface wettability, effect of channel aspect ratio, and effect of centrifugal force on the surface-driven microfluidic flow of aqueous microparticle suspensions have been successfully and individually investigated in these laboratory-on-a-chip systems. Also, 5 micron polystyrene particles have been separated from the aqueous microparticle suspensions in the microfluidic lab-on-a-chip systems of modified design with 98% separation efficiency, and 10 micron polystyrene particles have been separated with 100% separation efficiency. About the novelty of this work, the experimental investigations have been performed on the surface-driven microfluidic flow of aqueous microparticle suspensions with the investigations on the separation time in particle-size based separation mechanism to control these suspensions in the microfluidic lab-on-a-chip systems. This research work contains a total of 10,112 individual experimental outputs obtained using total 30 individual instruments by author’s own hands-on completely during more than three years continuously. Author has performed the experimental investigations on both the fluid statics and fluid dynamics to develop an automated fluid machine.

The cuplike structure of calix[4]arenes is one of the most attractive features, which has been observed both in the solid state and in solution. The newly synthesized 5,11,17,23-tetrakis(3-mercaptopropyl)calix[4]arene (1) and 25,26,27,28-tetrakis(5-mercaptopenthoxy)calix[4]arene containing aryl sulfide rings (2), have four alkyl thiol linkages, which allow the calixarenes to attach onto the gold surface. Surface plasmon resonance (SPR) spectroscopy allows us to monitor the binding of calixarene derivatives on the gold surface. The 1 and 2 bind very effectively on the gold surface and self-assembled layers of 1 and 2 produce significant change in SPR signals in 30 min. Calixarenes layers are used as platforms for molecular recognition, where complementary binding sites are easily and selectively introduced. The aromatic molecules used in this study are anthracene, pyrene, coronene and rubrene. The host-guest properties of these aromatic molecules and the calixarene cavity exhibit selectivity of these aromatic molecules. The anthracene, pyrene and coronene have moderate binding affinity to the cavity, and the rubrene does not bind at all.

In a general semi-martingale financial market with possibly nonlinear wealth dynamics, incomplete information, and ambiguity, we show that the optimal consumption decision of an agent with logarithmic preferences can be separated from the agent's investment decisions. Using minimal assumptions and mathematical machinery, we demonstrate that the optimal consumption/wealth ratio is deterministic, and we derive an explicit formula for it.

Combining Modern Life Sciences Toolbox to Tackle Current Bottlenecks for Algal Biofuels.

Biodiesel: From Lab to Industry.

Biofuels from Microorganisms.

Membranes for Biofuel Separation.

Carbon Dioxide Bio-mitigation and Third Generation Biofuel - The Way Forward.

APTAR PHARMA Provides Unit-Dose Nasal Spray Technology for Treatment of Opioid Overdose

Cloudera, Broad Institute Collaborate on the Next Generation of the Genome Analysis Toolkit

Singapore-based Luye Medical Group Completes Acquisition of Healthe Care, Australia's Third Largest Private Healthcare Group

FEI Launches Apreo – Industry-Leading Versatile, High-Performance SEM

BOGE Publishes New Guide on Specifying Compressed Air for Healthcare

Takara Bio USA, Inc. and Integrated DNA Technologies Announce Collaboration to Support Targeted RNA Sequencing

Pelican BioThermal Announces Launch of New Asia Headquarters in Singapore

A Faster Way to Separate Proteins with Electrophoresis

Biosensors Announces Strategic Agreement with Cardinal Health

BGI and Clearbridge BioMedics Partner to Develop China CTC Liquid Biopsy Market towards Precision Medicine

Certain separation problems in descriptive set theory correspond to a forcing preservation property, with a fusion type infinite game associated to it. As an application, it is consistent with the axioms of set theory that the circle 𝕋 can be covered by ℵ₁ many closed sets of uniqueness while a much larger number of H-sets is necessary to cover it.

We consider the quasilinear equation of the form