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We present an algorithm that finds a maximum cardinality \(f\) -matching of a simple graph in time \(O(n^{2/3}m)\). Here, \(f:V\to\mathbb{N}\) is a given function and an \(f\) -matching is a subgraph wherein each vertex \(v\in V\) has degree \(\leq f(v)\). This result generalizes a string of algorithms that concentrate on simple bipartite graphs. The bipartite case is based on the notion of level graph, introduced by Dinic for network flow. In general graphs this notion breaks down: Vertices no longer have unique levels, and there are too many levels to analyze the corresponding level graph like bipartite graphs (\(\Theta(n^{2})\) vs. \(n\)). We use "natural" levels to prove properties of shortest augmenting trails (e.g., formulas for trail length). We use "shortened" levels to derive the algorithm's time bound. The algorithm, unmodified, is also efficient on multigraphs, achieving time \(O(\min\{\sqrt{f(V)},n\} m)\) for \(f(V)=\sum_{v}f(v)\). The special case \(f\equiv 1\) shows the algorithm duplicates the classic time bound for maximum cardinality matching, \(O(\sqrt{n} m)\). [ABSTRACT FROM AUTHOR]

Abstract The increasing adoption of electric vehicles is expected to substantially raise electricity demand. This could require significant grid investment to maintain secure electricity supply, which has traditionally been provided through infrastructure upgrades. The potential of smart technologies like Vehicle-to-Grid (V2G) to contribute to security of supply has prompted the need to quantify their impact. We hypothesize that the F-Factor methodology can effectively quantify V2G’s security of supply contribution. Applying F-Factor analysis to V2G through optimization modeling and sensitivity studies, we find that key parameters like V2G charger ratings, EV battery capacities, and load profile peakiness significantly influence the results. We conclude that the F-Factor provides a valuable tool for assessing V2G’s potential to enhance security of supply, with implications for more efficient grid planning in the context of transport electrification.

We prove that there exists an absolute constant C>0$$ C>0 $$ such that, for any positive integer k$$ k $$, every graph G$$ G $$ with minimum degree at least Ck$$ Ck $$ admits a vertex‐partition V(G)=S∪T$$ V(G)=S\cup T $$, where both G[S]$$ G\left[S\right] $$ and G[T]$$ G\left[T\right] $$ have minimum degree at least k$$ k $$, and every vertex in S$$ S $$ has at least k$$ k $$ neighbors in T$$ T $$. This confirms a question posted by Kühn and Osthus (J. Comb. Theory Ser. B. 88 (2003), 29–43.) and is tight up to a constant factor. Our proof combines probabilistic methods with structural arguments based on Ore's theorem on f$$ f $$‐factors of bipartite graphs. [ABSTRACT FROM AUTHOR]

The increasing adoption of electric vehicles is expected to substantially raise electricity demand. This could require significant grid investment to maintain secure electricity supply, which has traditionally been provided through infrastructure upgrades. The potential of smart technologies like Vehicle-to-Grid (V2G) to contribute to security of supply has prompted the need to quantify their impact. We hypothesize that the F-Factor methodology can effectively quantify V2G's security of supply contribution. Applying F-Factor analysis to V2G through optimization modeling and sensitivity studies, we find that key parameters like V2G charger ratings, EV battery capacities, and load profile peakiness significantly influence the results. We conclude that the F-Factor provides a valuable tool for assessing V2G's potential to enhance security of supply, with implications for more efficient grid planning in the context of transport electrification. [ABSTRACT FROM AUTHOR]

The structural parameters, optical properties, and dielectric constants at a frequency (f) range of 0.1–20 MHz, and temperature (T) range of 300–400 K of hydrothermally synthesized M/SnO 2 nanocomposites (for simplicity M denotes oxides of Al, Ni, or Mn) were compared. Rietveld refined X-ray powder diffraction (XRD) analysis demonstrated the formation of hexagonal, cubic, or spinel crystal structures of Al 2 O 3 , NiO, or Mn 3 O 4 phases, respectively, besides the tetragonal rutile crystal structure of SnO 2. The impact of Al addition on the optical band gap of SnO 2 is negligible while it decreased or increased by incorporation of Ni or Mn, respectively. The residual lattice dielectric constant of SnO 2 was increased, while the real part of the dielectric constant and the ac conductivity of SnO 2 were decreased by M incorporation. The dielectric parameters are remarkably affected by selected M, T, and f values and their changes agree with the Maxwell-Wagner model. The Q-factor of SnO 2 was increased by M addition while decreased with increasing T. The Ni/SnO 2 obeys the hole conduction at T ≤ 330 K, while Mn/SnO 2 and Ni/SnO 2 obey the electronic conduction at T > 330 K. The binding energy is independent of the chosen T for SnO 2 , whereas it sharply increases for Ni/SnO 2 and slightly decreases for Al/SnO 2 and Mn/SnO 2. The F-factor of SnO 2 was slightly decreased by M addition, but it was increased with T for SnO 2 , Al/SnO 2 , and Mn/SnO 2 while was decreased for Ni/SnO 2. The Cole-Cole plots for M/SnO 2 composites were analyzed, and the components of the equivalent circuit were determined. The electrical impedance, resistance of grains, resistance of grain boundaries, and equivalent resistance of SnO 2 were increased by M incorporation, whereas equivalent capacitance was decreased. The findings recommend the SnO 2 -based nanocomposites for applications in optoelectronics, lithium batteries, supercapacitors, and solar cell devices. [ABSTRACT FROM AUTHOR]

The challenge for graph matching algorithms is to extend known time bounds for bipartite graphs to general graphs. We discuss combinatorial algorithms for finding a maximum weight f-factor on an arbitrary multigraph, for given integral weights of magnitude at most W. (An f-factor is a subgraph whose degree function is the given function f : V → N .) For simple bipartite graphs the best-known time bound for combinatorial algorithms is O (n 2 / 3 m log n W) [Gabow and Tarjan, SIAM J Comput 18(5):1013–1036, 1989; n and m are respectively the number of vertices and edges.] A recent algorithm of Duan et al. [in: Proc. of the 47th International Colloquium on Automata, Languages, and Programming (ICALP 2020), 2020] for f-factors of simple general graphs comes within logarithmic factors of this bound, O ~ (n 2 / 3 m log W) . The best-known bound for bipartite multigraphs is O (Φ m log Φ W) ( Φ ≤ m is the size of the f-factor, Φ = ∑ v ∈ V f (v) / 2 ). This bound is more general than the restriction to simple graphs, and is even superior on "small" simple graphs, i.e., Φ = o (n 4 / 3) . We present an algorithm that comes within a log Φ factor of this bound, i.e., O (Φ log Φ m log Φ W) . The algorithm is a direct generalization of the algorithm of Gabow and Tarjan [J ACM 38(4):815–853, 1991] for the special case of ordinary matching ( f ≡ 1 ). We present that algorithm first. Our analysis is a simplified and more concrete version of Gabow and Tarjan [J ACM 38(4):815–853, 1991] and has independent interest. Furthermore the algorithm and analysis are both incorporated, without modification, into the f-factor algorithm. To extend these ideas to f-factors, the first step is "expanding" edges (i.e., replacing an edge by a length 3 alternating path). Duan et al. [in: Proc. of the 47th International Colloquium on Automata, Languages, and Programming (ICALP 2020), 2020] uses a one-time expansion of the entire graph. In contrast, our algorithm keeps the graph small by only expanding selected edges (edges incident to blossoms, in "I(B) sets"). Expanded edges get "compressed" back to their source when no longer needed. Expansion necessitates using an alternate graph model for blossoms (we call them "e-blossoms"). Compression requires coordinating e-blossoms with standard blossoms. [ABSTRACT FROM AUTHOR]

Blocking flows were introduced by Dinic (Soviet Math Doklady 11: 1277–1280, 1970) to speed up the computation of maximum network flows. They have been used in algorithms for problems such as maximum cardinality matching of bipartite graphs Hopcroft and Karp (SIAM J Comput 2(4), 225–231, 1973) and general graphs Micali and Vazirani (in: Proceedings of the 21st Annual Symposium on Foundations of Computer Science, 17–27, 1980), maximum weight matching of general graphs Gabow and Tarjan (J ACM 38(4), 815–853, 1991), and many others. The blocking algorithm of Gabow and Tarjan (1991) for matching is based on depth-first search. We extend the depth-first search approach to find f-factors of general multigraphs. Here f is an arbitrary integral-valued function on vertices, an f-matching is a subgraph where every vertex x has degree ≤ f (x) , an f-factor has equality in every degree bound. A set of blocking trails for an f-matching M is a maximal collection A of edge-disjoint augmenting trails such that M ⨁ A ∈ A A is a valid f-matching. Blocking trails are needed in efficient algorithms for maximum cardinality f-matching Huang and Pettie (Algorithmica 84(7): 1952–1992, 2022), maximum weight f-factors/matchings by scaling Duan et al. (In: Proceedings of the 47th International Colloquium on Automata, Languages, and Programming (ICALP 2020), Vol. 168 of LIPIcs, 41:1-41:17, 2020; Gabow (A weight-scaling algorithm for f-factors of multigraphs.arXiv:2010.01102, 2020), and approximate maximum weight f-factors and f-edge covers Huang and Pettie (2022). Since these algorithms find many sets of blocking trails, the time to find blocking trails is a dominant factor in the running time. Our blocking trail algorithm runs in linear time O(m). In independent work and using a different approach, Huang and Pettie (2022) present a blocking trails algorithm using time O (m α (m , n)) . As examples of the time bounds for the above applications, an approximate maximum weight f-factor is found in time O (m α (m , n)) using Huang and Pettie (2022), and our algorithm eliminates the factor α (m , n) . Similarly a maximum weight f-factor is found in time O (Φ log Φ m α (m , n) log (Φ W)) using Huang and Pettie (2022) , ( Φ = ∑ v ∈ V f (v) , W the maximum edge weight) and our algorithm eliminates the α (m , n) factor, making the time within a factor log Φ of the bound for bipartite multigraphs. The technical difficulty for this work stems from the fact that a fixed vertex can occur many times in a given search. This does not occur in ordinary matching or in algorithms for maximum cardinality or maximum weight f-matching. These multiple occurrences can create a new variant of blossom, the "skew blossom". Also they can make blossoms become "incomplete", i.e., partially processed yet still relevant in future searches. [ABSTRACT FROM AUTHOR]

Given k ≥ 2 and two k -graphs (k -uniform hypergraphs) F and H , an F-factor in H is a set of vertex disjoint copies of F that together covers the vertex set of H. Lenz and Mubayi studied the F -factor problems in quasi-random k -graphs with minimum degree Ω (n k − 1). In particular, they constructed a sequence of 1/8-dense quasi-random 3-graphs H (n) with minimum degree Ω (n 2) and minimum codegree Ω (n) but with no K 2 , 2 , 2 -factor. We prove that if p > 1 / 8 and F is a 3-partite 3-graph with f vertices, then for sufficiently large n , all p -dense quasi-random 3-graphs of order n with minimum codegree Ω (n) and f | n have F -factors. That is, 1/8 is the density threshold for ensuring all 3-partite 3-graphs F -factors in quasi-random 3-graphs given a minimum codegree condition Ω (n). Moreover, we show that one can not replace the minimum codegree condition by a minimum vertex degree condition. In fact, we find that for any p ∈ (0 , 1) and n ≥ n 0 , there exist p -dense quasi-random 3-graphs of order n with minimum degree Ω (n 2) having no K 2 , 2 , 2 -factor. In particular, we study the optimal density threshold of F -factors for each 3-partite 3-graph F in quasi-random 3-graphs given a minimum codegree condition Ω (n). In addition, we also study F -factor problems for k -partite k -graphs F with stronger quasi-random assumption and minimum degree Ω (n k − 1). [ABSTRACT FROM AUTHOR]

We report here the structural, FTIR, optical and dielectric properties of Zn1-xAlxO with x = 0.00 ≤ x ≤ 0.20)). The samples are synthesized by the solid state reaction method and the phase purity, structural morphology, and absorption spectra are examined by XRD, SEM, and FTIR techniques. The optical and dielectric measurements are obtained by a double beam spectrophotometer and an impedance analyzer. The wurtzite structure is confirmed for all samples, and the lattice parameters, crystallite diameter, and porosity are decreased by Al, whereas the Debye temperature and elastic modulus are increased. The residual stress is compressive for ZnO, but it is changed to tensile for the doped samples. Two different values of energy gap (Egh and Egl) are apparent for each sample. The Egh and Egl are, respectively, 3.60, 3.56, 3.43, 3.53, 3.68 eV and 3.02, 2.95, 2.85, 2.92, 3.07 eV for all samples such that ΔE = (Egh – Egl) ~ 0.60. The residual dielectric lattice constant is decreased by increasing x to 0.10, followed by a sharp increase at x = 0.20, while the opposite behavior is obtained for (N/m*). The dielectric constant and ac conductivity are slightly increased as x increases to 0.025, followed by a sharp increase with more increase of x to 0.20. The conduction is electronic for pure and x = 0.025 samples, but it changes to hole with increasing x to 0.20. The binding energy was decreased as x increased to 0.20, but there is no exact trend for the hopping distance and density of localized states against x. The F-factor for solar cell design was increased as x increased to 0.10, but it is almost constant at x = 0.20. The Cole–Cole plot is a straight line for x = 0.00, a semicircle arc for x = 0.025, and a complete semicircle for x ≥ 0.05. The impedance resistance of grain and grain boundaries decreases as x increases to 0.20. These outcomes indicate that the addition of Al to ZnO shifts the mechanical, optical, and dielectric medium to higher values, which is strongly recommended for the design of optoelectronic and solar cell instruments. [ABSTRACT FROM AUTHOR]

Ac dielectric measurements of Zn1−x−yFexMyO samples with different M, x and y were made against frequency (f) up to 10 MHz. It is found that addition of Cu beside Fe in ZnO decreased the porosity and average size of grains, whereas they are increased by addition of Ni in place of Cu. The real and imaginary parts of dielectric constant (ε′, ε″) and dielectric loss (tanδ) are generally decreased by Fe, followed by an increase/decrease for (Fe + Ni)/(Fe + Cu) samples. Furthermore, the conduction is electronic below 10 kHz for all samples, but it is changed to hole as f increases above 10 kHz. Generally, the binding energy Wm, minimum hopping distance (Rmin) and density of states at Fermi level N(EF) are slightly increased by Fe, followed by a decrease for the co-doped samples. Interestingly, the N(Ef) of the Zn0.9Fe.1O (S2) sample is sharply increased with f, goes to optimum at 28.7 Hz and then decreases. In addition, the F-factor, for solar cell design, was increased by increasing f, and it has the samples order of (Fe), (Fe + Ni), (Zn) and (Fe + Cu). A single semicircle could be obtained from the Cole–Cole plot and the impedance of grain Z\(G) and that of grain boundaries Z\(GB) are increased by Fe, followed by an increase/decrease for (Fe + Cu)/(Fe + Ni) samples. The radius of arc increases for Fe and (Fe + Cu) samples, revealing a decrease in capacitance, while vice versa for (Fe + Ni) samples. The arcs seem to be centered below the Z\ axis, indicating non-Debye relaxation of dipoles. These outcomes indicate that Fe and (Fe + Ni) samples shift the ZnO dielectric medium to higher values, and it is strongly recommended with Fe sample for solar cell design. In contrast, the (Fe + Cu) samples are recommended for high-frequency nonlinear optical devices due to their poor dielectric medium. To the best of our knowledge, the present systematic investigation may not be reported elsewhere. [ABSTRACT FROM AUTHOR]

In this article, proton, neutron, and gamma-ray shielding competences of six glasses with PbO or PbO/Bi 2 O 3 heavy metal oxides namely as Glass 1 to Glass 6 have been investigated via WinXcom and EXABCal computer codes. The maximum values of μ m were equal to 50.6, 53.06, 72.51, 80.67, 99.54, and 102.35 cm2 g-1 at 0.015 MeV for Glass 1 to Glass 6, respectively. The μ m of the glass's trend in ascending order for Glass 1 to Glass 6. Results of HVL and MFP of the glass's were trend in descending order for Glass 1 to Glass 6. The Z e f f of glasses varied from 14.49 (1.5 MeV) to 37.78 (0.1 MeV) and from 43.93 (2 MeV) to 65.62 (0.02 MeV) for Glass 1 and Glass 6, respectively. The f -factor of Glass 5 and Glass 6 was maximum for throughout the energy spectrum. The buildup factors are low and grow with the penetration depth rapidly up to the maximum depth of 40 mfp. The values of Σ R were varied from 0.0947 to 0.1155 cm−1 for Glass1 to Glass 6, respectively. Glass 2 and Glass 6 are preferred fast neutron shield when compared with ordinary concrete, water, and graphite. Generally, the molar concentration of PbO or PbO + Bi 2 O 3 improved the shielding capacity of the investigated glasses. [ABSTRACT FROM AUTHOR]

The National Oceanic and Atmospheric Administration (NOAA)-20 Visible Infrared Imaging Radiometer Suite (VIIRS) was launched on November 18, 2017, and it has been operational for more than two years and follows the first Joint Polar Satellite System (JPSS) series of the Suomi National Polar-orbiting Partnership (S-NPP) mission. VIIRS has 14 reflective solar bands (RSBs) covering a spectral range of 0.41– $2.3~\mu \text{m}$. The primary source of RSB calibration is the solar diffuser (SD), and the time-dependent SD degradation is monitored by the SD stability monitor (SDSM). The initial instability of the SD degradation (H-factor) was resolved by updating SDSM sun screen transmittance function combining yaw maneuver data and on-orbit SDSM data sets. After the H-factor improvements, the VIIRS RSB calibration coefficients (F-factors) are updated and applied to the operational Sensor Data Record (SDR) product generation. To validate the SD F-factors, the lunar F-factors are calculated by using a lunar irradiance model and comparing the trend differences between them. Over the two years of operation, decreasing trends have been calculated with the SD F-factors, whereas constant lunar F-factors were observed in bands M1–M4. With these discrepancies, the operational F-factors remained unchanged since April 2018 because the deep convective cloud (DCC) and cross-calibration comparison results did not show any further degradations in these bands. All the possible radiometric calibration sources, such as SD and lunar F-factors, DCC trends, and cross-calibration results, are monitored, compared, and applied by the NOAA VIIRS SDR science team for the best quality of the VIIRS SDR product. [ABSTRACT FROM AUTHOR]

This study provides an extensive analysis of the key parameters impacting the air-side heat transfer and frictional pressure drop performance in Finned Tube Heat Exchangers (FTHEs). The study considers parameters such as fin spacing, fin height, and different fin patterns and their role in shaping the thermal and hydraulic characteristics of the exchangers. Both experimental and numerical Colburn j -factor and f-factor correlations reported in the literature are compared for different fin types, and the most effective parameters are evaluated. Furthermore, new correlations were developed based on the fin spacing, tube pitches, and the number of tube rows based on the existing literatures. This review introduces a novel energy performance parameter (EPP) for each FTHE type. The EPP, which represents the ratio of the heat transfer rate to the pumping power, provides a useful tool for comparing various fin configurations under different operating conditions. The EPP analysis concludes that spiral fins display the highest EPP, whereas wavy fins exhibit the lowest EPP when compared to a plain fin reference. This comprehensive review not only provides a detailed understanding of FTHEs' performance but also introduces a new framework for optimizing heat exchanger design and operation for practical applications. • Conflicting results for the effect of fin spacing on the FTHEs are reviewed. • Colburn j -factor and friction f -factor correlations of FTHEs are compared. • Energy performance parameter is firstly evaluated for each FTHE. • According to the EPP, spiral and louver FTHEs are the most advantageous. [ABSTRACT FROM AUTHOR]

Socio-cultural changes bring about new demands to the psychotherapist who enters different social contexts or starts working with groups. The relationship between a psychoanalyst/psychotherapist and the social context is observed starting from the 'F-factor' concept proposed by Claudio Neri in his article The F-factor in psychoanalysis and group psychotherapy of 2011. [ABSTRACT FROM AUTHOR]

The Suomi NPP (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) performs the scheduled lunar roll maneuver on a monthly basis. The lunar calibration coefficients and lunar F-factor are calculated by taking the ratio of the lunar observed radiance to the simulated radiance from the Miller and Turner (MT) lunar model. The lunar F-factor is also validated against that derived from the VIIRS Solar Diffuser (SD). The MT model-based lunar F-factors in general agree with SD F-factors. The Lunar Band Ratio (LBR) is also derived from two channel lunar radiances and is implemented in the National Oceanic and Atmospheric Administration (NOAA) Integrated Calibration and Validation System (ICVS) to monitor the VIIRS long-term radiometric performance. The lunar radiances at pixels are summed for each of the VIIRS Reflective Solar Bands (RSBs) and normalized by the reference band M11 which has the most stable SD-based calibration coefficient. LBRs agree with the SD based F-factor ratios within one percent. Based on analysis with these two independent lunar calibration methods, SD-based and LBR-based calibrations show a lifetime consistency. Thus, it is recommended that LBR be used for both VIIRS radiometric calibration and lifetime stability monitoring. [ABSTRACT FROM AUTHOR]

Given integers $$n \ge k >l \ge 1$$ and a $$k$$ -graph $$F$$ with $$|V(F)|$$ divisible by $$n$$ , define $$t_l^k(n,F)$$ to be the smallest integer $$d$$ such that every $$k$$ -graph $$H$$ of order $$n$$ with minimum $$l$$ -degree $$\delta _l(H) \ge d $$ contains an $$F$$ -factor. A classical theorem of Hajnal and Szemerédi in (Proof of a Conjecture of P. Erdős, pp. 601-623, ) implies that $$t^2_1(n,K_t) = (1-1/t)n$$ for integers $$t$$ . For $$k \ge 3$$ , $$t^k_{k-1}(n,K_k^k)$$ (the $$\delta _{k-1}(H)$$ threshold for perfect matchings) has been determined by Kühn and Osthus in (J Graph Theory 51(4):269-280, ) (asymptotically) and Rödl et al. in (J Combin Theory Ser A 116(3):613-636, ) (exactly) for large $$n$$ . In this paper, we generalise the absorption technique of Rödl et al. in (J Combin Theory Ser A 116(3):613-636, ) to $$F$$ -factors. We determine the asymptotic values of $$t^k_1(n,K_k^k(m))$$ for $$k = 3,4$$ and $$m \ge 1$$ . In addition, we show that for $$t>k = 3$$ and $$\gamma >0, t^3_{2}(n,K_t^3) \le ( 1- \frac{2}{t^2-3t+4} + \gamma ) n$$ provided $$n$$ is large and $$t | n$$ . We also bound $$t^3_{2}(n,K_t^3)$$ from below. In particular, we deduce that $$t^3_2(n,K_4^3) = (3/4+o(1))n$$ answering a question of Pikhurko in (Graphs Combin 24(4):391-404, ). In addition, we prove that $$t^k_{k-1}(n,K_t^k) \le (1- \left( {\begin{array}{c}t-1\\ k-1\end{array}}\right) ^{-1} + \gamma )n$$ for $$\gamma >0, k \ge 6$$ and $$t \ge (3+ \sqrt{5})k/2$$ provided $$n$$ is large and $$t | n$$ . [ABSTRACT FROM AUTHOR]

Let G = G be a binomial random graph with n vertices and edge probability p = p( n), and f be a nonnegative integer-valued function defined on V( G) such that $$d_G^h (x) = \sum\limits_{x \in e} {h(e)}$$ for every x ∈ V( G). An fractional f-indicator function is an function h that assigns to each edge of a graph G a number h( e) in [0, 1] so that for each vertex x, we have d( x) = f( x), where 0 < a ≤ f( x) ≤ b < np − 2√ nplog n is the fractional degree of x in G. Set E = { e: e ∈ E( G) and h( e) ≠ 0}. If G is a spanning subgraph of G such that E( G) = E, then G is called an fractional f-factor of G. In this paper, we prove that for any binomial random graph G with $$p \geqslant n^{ - \tfrac{2} {3}}$$, almost surely G contains an fractional f-factor. [ABSTRACT FROM AUTHOR]

ABSTRACT Rapid fluctuations of wind shear hazard factor (or F-factor) calculated from the headwind profile measured by Doppler Light Detection and Ranging ( LIDAR) may make it difficult for use in wind shear alerting at an airport such as Hong Kong International Airport ( HKIA). Preprocessing by flight simulator or post-processing by averaging over a certain length are attempted in this study to smooth the F-factor and enhance its skills on wind shear alerting. The F-factor so obtained is used for alerting of wind shear (headwind change exceeding 15 knots) for departing flights. Through case studies and statistical studies, the LIDAR-based F-factors are found to have good correlation with the F-factor determined from flight data (the Quick Access Recorder, or QAR, data from the commercial jets). Using the relative operating characteristics ( ROC) curves, the LIDAR-based F-factor obtained by smoothing over a window size of 300-500 m is found to have good skills in wind shear alerting, and the performance is comparable with, or even better than, the LIDAR-based F-factor using the flight simulator approach. By choosing an optimal alerting threshold specific for each runway corridor, the F-factor successfully alerts 86% of pilot wind shear reports with the percentage of time on alert of 12%, which is found to be satisfactory for real-time use. The performance of the F-factor on stronger wind shear (headwind change of 25 knots or more) is also studied. [ABSTRACT FROM AUTHOR]

For analysis of low-level windshear, turbulence and wake vortex events at the Hong Kong International Airport (HKIA), besides pilot reports routinely received from Air Traffic Control, Quick Access Recorder (QAR) data are obtained from the local airlines by the Hong Kong Observatory (HKO). Instead of using directly the wind data recorded on the aircraft by the flight management system (FMS), there has been a collaborative study between HKO and the National Aerospace Laboratory (NLR) in The Netherlands to develop a QAR data analysis software to calculate the meteorological quantities. Such quantities include the three components of the wind, windshear hazard factor and turbulence intensity parameters, taking into account the aircraft's aerodynamic factors (e.g. sideslip angle, angle-of-attack). This paper describes the main features of the calculation software, named WINDSTURB, and illustrates its application to windshear, turbulence and wake vortex studies through selected cases at HKIA. [ABSTRACT FROM AUTHOR]

Let G be a graph with vertex set V( G) and let f be a nonnegative integer-valued function defined on V( G). A spanning subgraph F of G is called an f-factor if d F ( x)= f( x) for every x∈ V( F). In this paper we present some sufficient conditions for the existence of f-factors, connected ( f, f+1)-factors and connected ( f−2, f)-factors in graphs. The conditions involve the minimum degree and the stability number of graph G. Therefore we prove that the conjecture in Cai and Liu (Ars Comb. to appear, 2008) is true in some sense. [ABSTRACT FROM AUTHOR]

Abstract: Recently, András Sebő and Nicola Apollonio considered the following generalization of the problem to determine a matching of size k. Given a graph and an integer k, determine a subgraph of G that minimizes or more general , where is a separable convex function, and . They proved, that the problem is polynomially solvable in two ways. First, it admits “augmenting pairs of alternating paths” which, according to their analysis, yields a complexity of , if ℓ is a quadratic convex function. On the other hand they reduced the problem to a single minimum weight f-factor problem. Their reduction introduces quite a few new vertices and edges such that the resulting complexity is higher. We present a simpler reduction of “minconvex factor of prescribed size” to a single minimum weighted f-factor problem resulting in an overall complexity of . [Copyright &y& Elsevier]

Abstract: A relationship is considered between an f-factor of a graph and that of its vertex-deleted subgraphs. Katerinis [Some results on the existence of -factors in terms of vertex-deleted subgraphs, Ars Combin. 16 (1983) 271–277] proved that for even integer k, if has a k-factor for each , then G has a k-factor. Enomoto and Tokuda [Complete-factors and f-factors, Discrete Math. 220 (2000) 239–242] generalized Katerinis’ result to f-factors, and proved that if has an f-factor for each , then G has an f-factor for an integer-valued function f defined on with even. In this paper, we consider a similar problem to that of Enomoto and Tokuda, where for several vertices x we do not have to know whether has an f-factor. Let G be a graph, X be a set of vertices, and let f be an integer-valued function defined on with even, . We prove that if and if has an f-factor for each , then G has an f-factor. Moreover, if G excludes an isolated vertex, then we can replace the condition with . Furthermore the condition will be when . [Copyright &y& Elsevier]

Enterohemorrhagic Escherichia coli (EHEC) O157:H7, derived from an outbreak in Sakai city, Japan in 1996, possesses two kinds of plasmids: a 93-kb plasmid termed pO157, found in clinical EHEC isolates world-wide and a 3.3-kb plasmid termed pOSAK1, prevalent in EHEC strains isolated in Japan. Complete nucleotide sequences of both plasmids have been determined, and the putative functions of the encoded proteins and the cis-acting DNA sequences have been analyzed. pO157 shares strikingly similar genes and DNA sequences with F-factor and the transmissible drug-resistant plasmid R100 for DNA replication, copy number control, plasmid segregation, conjugative functions and stable maintenance in the host, although it is defective in DNA transfer by conjugation due to the truncation and deletion of the required genes and DNA sequences. In addition, it encodes several proteins implicated in EHEC pathogenicity such as an EHEC hemolysin (HlyA), a catalase-peroxidase (KatP), a serine protease (EspP) and type II secretion system. pOSAK1 possesses a ColE1-like replication system, and the DNA sequence is extremely similar to that of a drug-resistant plasmid, NTP16, derived from Salmonella typhimurium except that it lacks drug resistance transposons. [ABSTRACT FROM PUBLISHER]

The influence of density and molar concentration of Ag 2 O on photon, proton, neutron, and alpha particle shielding capacity of tellurite-vanadate-silver glass systems with the form 40TeO 2 +(60-x)V 2 O 5 +xAg 2 O: x = 0–50 mol% (encoded as TVAg0- TVAg50) was evaluated and analyzed in a wide range of energy (0.015–15 MeV). Linear and mass attenuation coefficients (μ , μ m), half value thickness (HVT), mean free path (MFP), and effective atomic number (Z eff) were evaluated via the free online program–Phy-X/PSD, while EBF and EABF were computed via EXABCal software. The maximum μ m was obtained at the least photon energy (15 keV) with values equal to 29.702, 31.371, 32.949, 34.443, 35.86, and 37.205 cm2g-1 for TVAg0, TVAg10, TVAg20, TVAg30, TVAg40, and TVAg50, respectively. Generally, The μ m of the glass's trends in the order: (μ m) TVAg0 < (μ m) TVAg10 < (μ m) TVAg20 < (μ m) TVAg30 < (μ m) TVAg40 < (μ m) TVAg50. The trend of μ amongst the glasses is like that of the mass attenuation coefficient. The values of the maximum MFP varied from 9.757 to 4.53 cm for TVAg0 and TVAg50, respectively. The HVT trend of TVAg-glasses obeys the order: (HVT) TVAg0 > (HVT) TVAg10 > (HVT) TVAg20 > (HVT) TVAg30 > (HVT) TVAg40 > (HVT) TVAg50. The range of Z e f f for the glasses varied from: 14.8 to 42.38 for TVAg0 glass and from 26.06 to 47.63 for TVAg50 glass. The f -factor of the TVAg-glasses were lower than unity except that of TVAg50 at 5 MeV. The variations in buildup factors with photon energy is alike for all glass materials and depth of penetration (mfp). The projected range (PR) followed the order: (PR) TVAg0 > (PR) TVAg10 > (PR) TVAg20 > (PR) TVAg30 > (PR) TVAg40 > (PR) TVAg50 for both proton and α-particle. Mass stopping power (MSP) is inversely proportional to the atomic number of the target (TAVg-glasses). Results confirmed that density and molar concentration of Ag 2 O plays an important role for improving the radiation shielding capacity of the investigated TAVg-glasses. • Samples of tellurite-vanadate-silver glasses were chosen. • Gamma radiation shielding features were evaluated via Phy-X/PSD program. • EBF and EABF were computed via EXABCal software. • Results were compared with previous ones. [ABSTRACT FROM AUTHOR]

Robust low-parasitic electrostatic discharge (ESD) protection is highly desirable for RF ICs. This letter reports design of a new low-parasitic polysilicon silicon controlled rectifier (SCR) ESD protection structure designed and implemented in a commercial 0.35-µm SiGe BiCMOS technology. The concept was verified by simulation and experiment with the results showing that the new structure has much lower parasitic capacitance (CESD) and higher F-factor than that of other ESD protection devices. A small polysilicon SCR structure of 750-µm² all-inclusive provides a high human body model ESD protection of 3.2 kV while featuring a high F-factor of ∼42 and a low CESD of ∼92.3 fF. The new polysilicon SCR ESD protection structure seems to be an attractive solution to high-GHz RF ICs. [ABSTRACT FROM AUTHOR]