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We show that the quantized flag manifold at a root of unity has natural affine open covering parametrized by the elements of the Weyl group. In particular, the quantized flag manifold turns out to be a quasi-scheme in the sense of Rosenberg [12] .

A partial flag variety P K of a Kac–Moody group G has a natural stratification into projected Richardson varieties. When G is a connected reductive group, a Bruhat atlas for P K was constructed in He et al. (2013): P K is locally modelled with Schubert varieties in some Kac–Moody flag variety as stratified spaces. The existence of Bruhat atlases implies some nice combinatorial and geometric properties on the partial flag varieties and the decomposition into projected Richardson varieties. A Bruhat atlas does not exist for partial flag varieties of an arbitrary Kac–Moody group due to combinatorial and geometric reasons. To overcome obstructions, we introduce the notion of Birkhoff–Bruhat atlas. Instead of the Schubert varieties used in a Bruhat atlas, we use the J -Schubert varieties for a Birkhoff–Bruhat atlas. The notion of the J -Schubert varieties interpolates Birkhoff decomposition and Bruhat decomposition of the full flag variety (of a larger Kac–Moody group). The main result of this paper is the construction of a Birkhoff–Bruhat atlas for any partial flag variety P K of a Kac–Moody group. We also construct a combinatorial atlas for the index set Q K of the projected Richardson varieties in P K . As a consequence, we show that Q K has some nice combinatorial properties. This gives a new proof and generalizes the work of Williams (2007) in the case where the group G is a connected reductive group.

We examine how consumer credit affects entrepreneurship by linking three million earnings and pass-through tax records to credit reports. In the cross-section, we show that self-employment without employees and employer firm ownership increase monotonically with credit limits and credit scores. We then isolate individuals who have had discrete increases in credit limits after the exogenous removal of bankruptcy flags to measure the effects of personal credit on entrepreneurship. Following bankruptcy flag removal, individuals are more likely to start a new employer business and borrow extensively. Those who own businesses with employees borrow $40,000 more after bankruptcy flag removal, a 33% gain relative to the sample average.

More than four decades ago, Eisenbud, Khim\v{s}ia\v{s}vili, and Levine introduced an analogue in the algebro-geometric setting of the notion of local degree from differential topology. Their notion of degree, which we call the EKL-degree, can be thought of as a refinement of the usual notion of local degree in algebraic geometry that works over non-algebraically closed base fields, taking values in the Grothendieck-Witt ring. In this note, we compute the EKL-degree at the origin of certain finite covers $f\colon \mathbb{A}^n\to \mathbb{A}^n$ induced by quotients under actions of Weyl groups. We use knowledge of the cohomology ring of partial flag varieties as a key input in our proofs, and our computations give interesting explicit examples in the field of $\mathbb{A}^1$-enumerative geometry., Comment: 15 pages

The new National Tuberculosis Elimination Program (NTEP) launched with its new logo in early 2020. Logo have been launched is circular with yellow and red colour. Name of program is in circular and with caption “TB Harega Desh Jeetega”. There is red colour joyful person surrounded by National Flag with image of lung in the logo. Present letter highlights observation and comments on the new NTEP logo.

This experimental study presents some aspects of the flapping dynamics and flow characteristics in the wake of small flags ( M * = 0.42 ) inserted in rectangular channels of various aspect (0.2 to 1.0) and confinement (1.0 to 5.0) ratios. The experiments were performed in the range of up to U * = 48 or R e d h = 44 , 000 . Results revealed that flag start-up characteristics were highly dependent on initial conditions. The hysteresis loop of the critical velocity ranged from 15% to 48% and was partially explained by the residual alternating pressure difference between the two sides of the flag. The flag flapping dynamics was largely affected by the confining walls. The flapping amplitude was constrained by the channel width and the oscillation modes shifted from simple shapes in low velocity, high confinement ratios to complex shapes in high velocity, low confinement ratios. The dimensionless oscillation frequency St initially decreased at low U* and Redh, and then converged to constant values in high U* and Redh. In addition, the presence of the flag substantially increased the flow unsteadiness and turbulence levels inside the channel, especially in the near wake. The measurements reveal a possible mechanism of vortex formation due to the flag’s oscillation. The shed vortices further interact with each other and the channel walls, then eventually decay. Confinement has a profound impact on wake behaviour. The size of the channel, which constrained the flag amplitude, largely dictated the structure of the vortex cores in the near wake and their eventual decay. The turbulence levels (I) inside the channel also depended on confinement: wider channels have higher I levels due to larger vortices produced which are convected farther before decaying. Narrow channels limit flag oscillation amplitude, leading to smaller vortex structures and their rapid decay.

Two experimental models are constructed, i.e. partially covered and fully covered, cantilevered plates with piezoelectric piezo patches and film sensors. Two different experimental methods are used to obtain large flapping vibrations, a mechanically forced vibration and a limit cycle oscillation from an aeroelastic responses. AC voltage outputs from the piezo patch or film sensors and a DC power extraction through a AC/DC converter circuit are obtained. These experiments are used to evaluate a new computational model and code for a piezoelectric-aeroelastic system.

This experimental work investigated the heat transfer characteristics of rectangular channels equipped with a flapping flag as a vortex generator. Specifically, it aimed to determine the influences of channel geometry, flag material properties and flow conditions on the resulting heat transfer behaviour of the system. Results showed that the inclusion of a flapping flag in the channel enhanced the flow unsteadiness and turbulence levels, leading to Nusselt number enhancement by as high as 1.34 to 1.62 times bare channel levels. As the turbulence decays in the streamwise direction, so does the thermal enhancement. The turbulence and heat transfer enhancements are accompanied by an increase in pressure drop due to the periodic blockage imposed by the flag during flapping. The friction factor, which is governed by the flag oscillation mode and frequency, was found to be as high as 1.39 to 3.56 times bare channel levels. The thermal enhancement benefit of the flag vortex generator varies with streamwise distance: a thermal enhancement factor as high as 1.14 was observed near the flag's free end. The blockage may be minimised through the use of a thicker flag which assumes a simpler oscillation mode that reduces the contact between the flag and the channel walls. The size of the channel (aspect ratios of 0.2–1.0) relative to the flag has profound effects on flag dynamics, turbulence levels and heat transfer. Wider channels allow wider flapping amplitudes and more complex oscillation modes, which lead to the creation of stronger vortices that decay slower inside the channel. Due to stronger vortices and delayed turbulence decay, thermal enhancement in wider channels are higher and sustained for longer distances.

Let D be a non-trivial 2– ( v , k , λ ) design with λ ≤ 4 , and G ≤ A u t ( D ) be flag-transitive, point-quasiprimitive, then G is of holomorph affine or almost simple type. As a corollary, we obtain that G cannot be an almost simple group if λ ≤ 3 , and also obtain a classification of flag-transitive, point-quasiprimitive and imprimitive 2- ( v , k , 4 ) designs.

In accordance with Article 91 of the United Nations Convention on the Law of the Sea, there should be a ‘genuine link’ between a vessel and its flag State. However, despite this provision and best-case scenario, maritime flags often bear little to no relationship to their flag State – either through the actual nationality of crew, captain, company, or beneficial owner of the vessel. With the advent of international agreements, such as the United Nations Port State Measure Agreement, attempting to address illegal activities at sea, identifying risk factors such as vessels flying flags of convenience (FOC) is essential to assist in addressing the lack of oversight by flag states, and prioritize vessels for further scrutiny. A novel approach to identifying the likelihood that a flag state is being used as a FOC is presented here, using a model-based scoring system that ranks countries according to their vessel ownership, vessel behaviour, and flag control patterns. This approach provides an accurate and transparent metric for ranking countries which can easily be updated as behaviour or information change. The metric compares favourably with the International Transport Federation classification of FOC and provides informative predictions for rates of inspections and detentions based on independent data. Two key reasons vessel owners use FOC are suggested – tax and reduction of oversight, which lead to different flagging preferences. This hypothesis aligns closely with the literature on international tax havens.

Scoring procedures for rater-mediated writing assessments often include checks for agreement between the raters who score students’ essays. When raters assign non-adjacent ratings to the same essay, a third rater is often employed to “resolve” the discrepant ratings. The procedures for flagging essays for score resolution are similar to person fit analyses based on item response theory (IRT). We used data from two writing performance assessments in science and social studies to explore the correspondence between traditional score resolution procedures and IRT person fit statistics. We observed that rater agreement criteria and person fit criteria flag many, but not all, of the same rating profiles for additional investigation. We also observed significantly different values of person fit statistics between students whose essays were and were not flagged for third ratings by the rater agreement criteria. Finally, when we used resolved ratings in place of the original ratings, we observed improvements in person fit for most, but not all, of the students whose essays were flagged for third ratings. These results suggest that person fit analyses may provide a complimentary approach to rater agreement criteria. We discuss these results in terms of their implications for research and practice.

International visitors are a particularly at-risk group when visiting Australian beaches due to poor knowledge of beach safety practices and hazards and typically comprise ∼10% of annual coastal drowning fatalities. This study examines beach safety knowledge and behaviour of visiting international Study Abroad students at UNSW Sydney, Australia in 2017. Data was obtained from online surveys of 254 students. The vast majority (92%) received no beach safety information prior to leaving for Australia, 85% arrived with no knowledge of the Australian beach safety flag system, and only 24% were able to correctly describe hazardous rip currents. A safety briefing soon after arrival in Australia, as well as visiting Australian beaches, improved knowledge and awareness: after these experiences only 20% were still unfamiliar with the flag system and correct description of rip currents rose to 60%. These findings have global implications for educating all types of international visitors about beach safety.

We investigate weighted floating bodies of polytopes. We show that the weighted volume depends on the complete flags of the polytope. This connection is obtained by introducing flag simplices, which translate between the metric and combinatorial structure. Our results are applied in spherical and hyperbolic space. This leads to new asymptotic results for polytopes in these spaces. We also provide explicit examples of spherical and hyperbolic convex bodies whose floating bodies behave completely different from any convex body in Euclidean space.

Does the term "flag" in Section 34(e) of R.A. No. 8491 exclusively refer to Philippine flag? The answer should be in the negative. Ms. Rabiya Mateo, representative of the Philippines to the Miss Universe Competition 2021, may have violated Republic Act No. 8491 or otherwise known as An Act Prescribing the Code of The National Flag, Anthem, Motto, Coat-of-Arms and Other Heraldic Items and Devices of The Philippines, particularly Section 34 (e) of the same law which provides: It shall be prohibited to wear the flag in whole or in part as a costume or uniform.

This article explores the negative implications of the current NCAA model on college athletes. The article also provides different ways in which the new name, image, and likeness policy should be implemented to best suit all parties.

Proximity complexes and filtrations are central constructions in topological data analysis. Built using distance functions, or more generally metrics, they are often used to infer connectivity information from point clouds. Here we investigate proximity complexes and filtrations built over the Chebyshev metric, also known as the maximum metric or l ∞ metric, rather than the classical Euclidean metric. Somewhat surprisingly, the l ∞ case has not yet been investigated thoroughly. In this paper, we examine a number of classical complexes under this metric, including the Cech, Vietoris-Rips, and Alpha complexes. We define two new families of flag complexes, which we call the Alpha flag and Minibox complexes, and prove their equivalence to Cech complexes in homological degrees zero and one. Moreover, we provide algorithms for finding Minibox edges of two, three, and higher-dimensional points. Finally, we present computational experiments on random points, which shows that Minibox filtrations can often be used to speed up persistent homology computations in homological degrees zero and one by reducing the number of simplices in the filtration.

Oscillating flexible flag due to the force exerted by periodic flow behind a cylinder is a significant technique to enhance mixing. To analyze its hydraulic and mixing performances, this paper numerically studies the pressure drop and mixing efficiency of fluid flow in a microchannel mounted with a cylinder and vertical flexible flag (CCFF) with different height and deformability in a wide range of Reynolds number Red based on the cylinder diameter. The simple channel without cylinder and flag (SC) and the channel with cylinder and rigid flag (CCRF) are also studied as comparisons. It is found that the mixing within CCFF occurs mainly due to the molecular diffusion at small and moderate Red, and its pressure drop and mixing efficiency increase with the increasing flag height. At large Red, the mixing in CCFF is highly enhanced by the vortices detached from the vibrating flag, and its pressure drop and mixing efficiency first increase and then reach a slight decrease or quasi-steady value with the increasing flag height. Compared with SC, the pressure drop of CCFF is always larger than that of SC, however, the mixing efficiency of CCFF is larger than that of SC only when Red or the flexible flag height is large enough. Comparing with CCRF, the pressure drop and mixing efficiency of CCFF are close to or smaller than those of CCRF at small and moderate Red, however, at large Red, CCFF has smaller pressure drop and larger mixing efficiency, and the maximum decrease of pressure drop could be up to 61.09% and the maximum increase of mixing efficiency could be up to 11.46% compared with CCRF.

The use of flags as vortex generators inside heat sinks has been successfully demonstrated as a heat transfer enhancement technique. However, their thermal-hydraulic performance is usually diminished by the blocking effect induced by the fluttering phenomenon. To tackle this problem, with the expectation to maximize the fluid mixing while minimizing the pressure drop, we report a simple and direct design by splitting a flag into multiple strips. Flags with different strip widths were compared with a full flag on the performance of pressure drop and heat transfer. A high-speed camera is used to investigate their fluttering motion. A piezoelectric plate is attached to the wall to measure the flag's flutter frequency. The results show that the performance of a flag with multiple strips outperforms that of the full flag for its lower pressure drop and higher heat dissipation effect. The performance of split flag is not linear with the strip number and the optimal way in our study is to split the full flag into 4 strips. The maximum thermal-hydraulic performance factor of the split flag is 1.91, which is 26% higher than that of the full flag. Besides, the split flag starts fluttering at a lower wind velocity. All these results demonstrate that the split strategy of a flag acting as a vortex generator is of great potential for improving the heat sink performance.

In this paper, we study the Kropina metrics as singular solutions of the Zermelo’s navigation problem with the navigation data ( h , W ) . We characterize the conformal vector fields on Kropina manifolds via navigation data. Further, we completely determine conformal vector fields on Kropina manifolds of weakly isotropic flag curvature in dimension greater than two.

Among the properties of homogeneity of incidence structures, flag-transitivity obviously is a particularly important and natural one. Originally, Buekenhout et al. reached a classification of flag-transitive Steiner 2-designs. Recently, Huber completely classified all flag-transitive Steiner t -designs with t ≤ 6 using the classification of the finite 2-transitive permutation groups. Hence the determination of all flag-transitive t -designs with λ ≥ 2 has remained of particular interest and has been known as a long-standing and still open problem.This article is a contribution to the study of the automorphism groups of 4-( v, k , 3) designs. Let S = ( P , B ) be a non-trivial 4- ( q + 1 , k , 3 ) design. If PSL (2, q ) acts flag-transitively on S , then S is a 4-(168,12,3) design and G B is conjugate to A 4 or Z 12 .

An $(\alpha,\beta)$-metric is defined by a Riemannian metric $\alpha$ and $1$-form $\beta$. In this paper, we study a known class of two-dimensional $(\alpha,\beta)$-metrics of vanishing S-curvature. We determine the local structure of those metrics and show that those metrics are Einsteinian (equivalently, isotropic flag curvature) but generally are not Ricci-flat., Comment: 11 pages

In this paper we consider the possibility that groups S n w r S 2 , 4 ≤ n ≤ 63 , act flag-transitively on block designs with n 2 points. We rule out n ∈ { 7 , 11 , 15 , 19 , 23 , 31 , 35 , 43 , 47 , 59 } and confirm the required action for other n in the given range through performing the construction of base blocks of the desired designs. Our construction makes use of flag-transitive incidence structures and weakly flag-transitive incidence structures.

Two side-by-side inverted flags in a uniform flow were simulated using the immersed boundary method. An energy harvesting system consisting of the two inverted flags was analyzed, and the flapping motions of the flags were investigated with consideration for the flow-mediated interactions between them. The flapping motions of the flags were determined from the spanwise gap distance between the trailing edges of the two flags. In-phase and out-of-phase flapping motions were observed by varying the gap distance and the initial configuration. The relative spanwise displacement of the leading edge from the trailing edge, the strain energy, and the flapping frequency was examined as a function of the gap distance and the bending rigidity. The large peak-to-peak amplitude was induced by placing an additional inverted flag. The large mean strain energy was achieved due to the intensified flapping motions of each flag. The vortical structures produced by the inverted flags, along with the pressure and velocity distributions along the center line were explored for different gap distances.

Let D be a quasi-residual design with an automorphism group G. In this paper, we classify flag-transitive, block-primitive or point-primitive quasi-residual designs with sporadic socle. Furthermore, we show that if G is flag-transitive block-primitive with sporadic socle, then G is point-primitive.

In the highly competitive shipping industry, flagging out has become an important operation strategy for shipowners. To attract vessels to use their national flags, the traditional maritime countries (TMCs) have adopted various incentive-based and rule-based marine policies. Among them, the establishment of second ship registers is one of the most effective, as shown by the success of EU countries. To understand the influence of the second ship register upon vessel registration and the mechanism of flag choice decisions, this study transforms binary and nested logit models with individual-level data into aggregate-level models. The empirical estimate suggests that the policy of establishing second ship registers significantly affects the number of vessels register back to their national countries, though this effect varies for different countries. The results of the nested logit model in analyzing the flag choice mechanism suggest that the second ship register is clustered to the nest of foreign ship registers. This suggests that the second register is more similar to open ship registers in function than to national registers, which indicates the convergence of maritime policies between the TMCs and open registers. This result has significant implications for China as it develops as an international maritime center. This study strongly recommends that China reorient its maritime policy by incorporating Hong Kong as its second ship register to provide a competitive operational environment for shipping companies and thereby foster a maritime cluster.

A Gelfand-Cetlin polytope is a convex polytope obtained as an image of certain completely integrable system on a partial flag variety. In this paper, we give an equivalent description of the face structure of a GC-polytope in terms of so called the face structure of a ladder diagram. Using our description, we obtain a partial differential equation whose solution is the exponential generating function of f-vectors of GC-polytopes. This solves the open problem (2) posed by Gusev, Kritchenko, and Timorin in [GKT]., 14 pages

The interaction and coupling between two inverted flags that are placed side-by-side in a uniform flow is investigated in an effort to determine the behavior of systems that are formed by arrays of cantilevered plates. Inverted flags are elastic plates that are free to move at their leading edge and clamped at their trailing edge. We show that placing two inverted flags of equal dimensions side-by-side will cause their motion to couple. In-phase, anti-phase, staggered, alternating and decoupled flapping modes are present, with the anti-phase mode being predominant at small flag distances and low wind speeds. Increases both in amplitude and frequency of flapping are observed in the two flag system with respect to a single flag. Two side-by-side inverted flags of different lengths are found to interact for small length differences, with the longer flag being able to induce a motion on the shorter flag even when the latter is outside of its flapping wind speed range.

Present study was undertaken to evaluate different morphological traits of rice advance lines. The experiment was laid out in randomized complete block design (RCBD) with ten rice advance lines replicated three times at National Tea and High Value Crops Research Institute (NTHRI) Shinkiari, Mansehra, Pakistan. Three plants per plot were selected randomly to record the important agro-morphological data viz. plant height, panicle length, number of tillers per plant, branches per panicle, flag leaf length, flag leaf width, flag leaf area, grain length, grain width and length/breadth (L/B) ratio were measured. All the recorded data was analyzed through SPSS 16.0 and Statistix 8.1. The results revealed that the vegetative growth attributes i.e. plant height was significantly increased in FH10-2 (152.7 cm), No. of tillers in FH4-1 (4.3), No. of branches in JP-6 (24.33), panicle length in Line 2(24) (49.6 cm), flag leaf length in FH10-2 (50.7 cm), flag leaf width in Super NPT-3 (4.3 cm) and flag leaf area in FH4-1 (143.6 cm), respectively. Furthermore, yield contributing attributes like grain length (8.5 mm) and Length/Breadth ratio (4.7) were significantly increased in FH4-1 and grain breadth in Super NPT-3 (2.8 mm). Among ten advance lines of rice, nine were recorded with slender grain shape while four advance lines were recorded with extra long slender and long slender grain size each.

In this paper we study spherically symmetric metrics on a symmetric space in R n with scalar and constant flag curvature and we also obtain families of this type of metrics. Many explicit examples are provided for Douglas metrics with scalar and constant flag curvature. Furthermore, new examples of locally projectively flat Finsler metrics are given. We also provide a family of spherically symmetric Finsler metrics which are not of Douglas type.

We use the theory of Mori dream spaces to prove that the global Okounkov body of a Bott–Samelson variety with respect to a natural flag of subvarieties is rational polyhedral. As a corollary, Okounkov bodies of effective line bundles over Schubert varieties are shown to be rational polyhedral. In particular, it follows that the global Okounkov body of a flag variety G / B is rational polyhedral. As an application we show that the asymptotic behaviour of dimensions of weight spaces in section spaces of line bundles is given by the volume of polytopes.

Let G / K be a generalized flag manifold with K = C ( S ) = S × K 1 , where S is a torus in a compact simple Lie group G and K 1 is the semisimple part of K. Then the associated M-space is the homogeneous space G / K 1 . These spaces were introduced and studied by H.C. Wang in 1954. We mainly investigate homogeneous geodesics in M-spaces which correspond to generalized flag manifolds with two isotropy summands and we also give some results for M-spaces corresponding to flag manifolds with at least three isotropy summands, thus extending some previous results. Finally, we prove that there are several M-spaces which admit nonnaturally reductive g.o. metrics.

On 2 April 2015, the International Tribunal for the Law of the Sea (ITLOS) rendered an advisory opinion in which it held that Articles 58(3), 62(4), 94(2), 192 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) laid down a responsibility of flag States for fishing activities undertaken by private actors in the Exclusive Economic Zones (EEZs) of coastal States. In interpreting these provisions of UNCLOS, the ITLOS made reference to specific clauses in fisheries access agreements (FAAs) concluded by coastal States and flag States. This article examines in more detail the contribution of FAAs to the concept of flag State responsibility. It will first offer a brief discussion of the framework for fisheries access under national jurisdiction provided by UNCLOS and will then take a closer look at how certain provisions contained in FAAs have contributed –and could contribute in the future– to the concept of flag State responsibility in international fisheries law. The article concludes that FAAs have contributed significantly to the development of the concept of flag State responsibility for fishing activities in the past and may do so to a more limited extent in the future.

By analyzing the Ricci star tensor Ri c * , we study the harmonic almost complex structure in maximal flag manifolds. We show that flag manifolds have diagonal Ri c * tensor. Using the concept of ⁎Einstein manifolds, we study the stability of the invariant almost complex structure and show examples of stables parabolic almost complex structures on maximal flag manifolds.

In this article, we consider the decoding problem of Grassmann codes using majority logic. We show that for two points of the Grassmannian, there exists a canonical geodesic between these points once a complete flag is fixed. These geodesics are used to construct a large set of parity checks orthogonal on a coordinate of the code, resulting in a majority decoding algorithm.

In this note, we show that the examples of non Berwaldian Landsberg surfaces with vanishing flag curvature, obtained in \cite{Zhou}, are in fact Berwaldian. Consequently, Bryant's claim is still unverified., 4 pages, LaTeX file

We generalize the Tutte polynomial of a matroid to a morphism of matroids via the K-theory of flag varieties. We introduce two different generalizations, and demonstrate that each has its own merits, where the trade-off is between the ease of combinatorics and geometry. One generalization recovers the Las Vergnas Tutte polynomial of a morphism of matroids, which admits a corank-nullity formula and a deletion-contraction recursion. The other generalization does not, but better reflects the geometry of flag varieties.

In this paper, we investigate the flag curvature of a special class of Finsler metrics called general spherically symmetric Finsler metrics, which are defined by a Euclidean metric and two related 1-forms. We find equations to characterize the class of metrics with constant Ricci curvature (tensor) and constant flag curvature. Moreover, we study general spherically symmetric Finsler metrics with the vanishing non-Riemannian quantity χ-curvature. In particular, we construct some new projectively flat Finsler metrics of constant flag curvature.

We study two-dimensional Finsler metrics of constant flag curvature and show that such Finsler metrics that admit a Killing field can be written in a normal form that depends on two arbitrary functions of one variable. Furthermore, we find an approach to calculate these functions for spherically symmetric Finsler surfaces of constant flag curvature. In particular, we obtain the normal form of the Funk metric on the unit disk D 2 .

Beach certification schemes, such as Blue Flag, have become prevalent in the current literature as a beach management tool is said to bridge the gap between recreation and conservation. Although there is evidence that Blue Flag has gained wide recognition globally, there has been limited research done to determine if Blue Flag is actually being successfully used as a tool for environmental protection. This study, therefore, investigates the effectiveness of Blue Flag as a management tool for environmental protection for beaches in Ontario, Canada. Semi-structured interviews were conducted with beach managers along the shoreline of the Great Lakes who represent a municipality involved in the Blue Flag program. The key findings of this research reveal that currently Blue Flag is not being used as an effective beach management tool for environmental protection as this study indicates that beach managers do not think that municipalities adopting Blue Flag will have a direct impact on improving the health and protection of the Great Lakes.

Numerical simulations using an improved version of the immersed boundary method are performed to explore a passive control concept for a single flexible flag in a viscous uniform flow. In order to control a single flag passively, we utilize the distinct dynamics of two side-by-side flags, characterized by in-phase and out-of-phase flapping modes depending on their spanwise gap distance. When the two side-by-side flags are in an in-phase flapping mode with a small spanwise gap distance, the flapping amplitude of a single downstream flag is highly enhanced due to synchronization between the vortices shed from the upstream and downstream flags. However, when the two upstream flags flap in an out-of-phase flapping mode with a large spanwise gap distance, the flapping of the single flag is significantly weakened with a reduction of the dominant flapping frequency. Because the upstream flags induce consecutive counter-rotating vortex pairs with a high frequency due to their flapping mode (out-of-phase state), relatively strong interaction with an upcoming vortex of the opposite rotational direction leads to flapping inhibition of the single flag. For an intermediate spanwise gap distance, the vortex-to-vortex interaction between the flags becomes more complicated, and a change of the flapping phases of the two side-by-side flags depending on streamwise gap distance between the upstream and downstream flags occurs. The interactions between coupled flags are documented through the root-mean-square cross-stream tail positions, frequency, drag coefficient, vorticity and pressure contours of the flags with varying non-dimensional parameters relevant to the problem. The proposed passive control concept of a single flag using two side-by-side flags is applicable to the development of energy harvesting systems to extract more energy and flapping control systems to suppress vibration.

Flow-induced vibration of an elastic structure such as a flag has drawn attention recently because of its complicated coupling mechanisms and potential application to energy harvesting. For both air and water flows, we experimentally investigate the effect of an upstream bluff body on the dynamics of two types of a downstream flag, a conventional flag and an inverted flag, on and off a midline. In contrast to the conventional flag, the trailing edge of the inverted flag is clamped, and its leading edge is free to move. By using smoke visualization and particle image velocimetry, the interaction of the flag with the vortices shedding from the bluff body was also identified. With the deployment of a bluff body, the conventional flag displays two distinct periodic flapping modes. While synchronization with the vortices shedding from the bluff body and a resultant fundamental mode appear in a low free-stream velocity range for the conventional flag lying on the midline behind the bluff body, the conventional flag off the midline shows a second harmonic mode by flutter instability in a higher free-stream velocity range. Meanwhile, the inverted flag reveals both small-amplitude flapping mode by a lock-in process and large-amplitude flapping mode by divergence stability at a given location on the midline and farther from the bluff body. However, only large-amplitude flapping mode is observed for the inverted flag off the midline. Even though the critical free-stream velocity when the inverted flag starts large-amplitude flapping depends on its relative streamwise and crosswise positions, the flag in flapping mode exhibits similar maximum amplitude and frequency pattern regardless of its relative locations.

The aim of this paper is to classify the non-symmetric 2 -designs with λ ź ( r , λ ) 2 admitting a flag-transitive automorphism group of almost simple type with sporadic socle. We prove that there are exactly such 33 non-isomorphic designs.

In this paper, we study equivariant vector bundles on partial flag varieties arising from Schur functors. We show that a partial flag variety with three or more steps does not admit an Ulrich bundle of this form with respect to the minimal ample class. We classify Ulrich bundles of this form on two-step flag varieties F(1,n-1;n), F(2,n-1;n), F(2,n-2;n), F(k,k+1;n) and F(k,k+2;n). We give a conjectural description of the two-step flag varieties which admit such Ulrich bundles., 36 pages, 11 figures. Merges and replaces arXiv:1507.00102 and arXiv:1506.03586

The Mingantu Ultrawide Spectral Radioheliograph (MUSER) has entered a test observation stage. After the construction of the data acquisition and storage system, it is urgent to automatically flag and eliminate the abnormal visibility data so as to improve the imaging quality. In this paper, according to the observational records, we create a credible visibility set, and further obtain the corresponding flag model of visibility data by using the support vector machine (SVM) technique. The results show that the SVM is a robust approach to flag the MUSER visibility data, and can attain an accuracy of about 86%. Meanwhile, this method will not be affected by solar activities, such as flare eruptions.

The classical Obata theorem in Riemannian space is generalized to the Randers spaces. It is proved that, if the generalized Obata equation on a closed Douglas Randers spaces admits a nontrivial solution, then M is weakly isometric to the Euclidean sphere ( S n ( 1 ) , h ) , where, h denotes the standard Riemannian metric of S n ( 1 ) . In particular, F is locally projectively flat with positive flag curvature.

In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861-2011), it was decided to analyse the artwork "The Italian Flag" (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907-1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork.