964 research outputs found
Peacock Bundles: Bundle Coloring for Graphs with Globality-Locality Trade-off
Bundling of graph edges (node-to-node connections) is a common technique to
enhance visibility of overall trends in the edge structure of a large graph
layout, and a large variety of bundling algorithms have been proposed. However,
with strong bundling, it becomes hard to identify origins and destinations of
individual edges. We propose a solution: we optimize edge coloring to
differentiate bundled edges. We quantify strength of bundling in a flexible
pairwise fashion between edges, and among bundled edges, we quantify how
dissimilar their colors should be by dissimilarity of their origins and
destinations. We solve the resulting nonlinear optimization, which is also
interpretable as a novel dimensionality reduction task. In large graphs the
necessary compromise is whether to differentiate colors sharply between locally
occurring strongly bundled edges ("local bundles"), or also between the weakly
bundled edges occurring globally over the graph ("global bundles"); we allow a
user-set global-local tradeoff. We call the technique "peacock bundles".
Experiments show the coloring clearly enhances comprehensibility of graph
layouts with edge bundling.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Motions and world-line deviations in Einstein-Maxwell theory
We examine the motion of charged particles in gravitational and
electro-magnetic background fields. We study in particular the deviation of
world lines, describing the relative acceleration between particles on
different space-time trajectories. Two special cases of background fields are
considered in detail: (a) pp-waves, a combination of gravitational and
electro-magnetic polarized plane waves travelling in the same direction; (b)
the Reissner-Nordstr{\o}m solution. We perform a non-trivial check by computing
the precession of the periastron for a charged particle in the
Reissner-Nordstr{\o}m geometry both directly by solving the geodesic equation,
and using the world-line deviation equation. The results agree to the order of
approximation considered.Comment: 23 pages, no figure
Examples of D=11 S-supersymmetric actions for point-like dynamical systems
A non standard super extensions of the Poincare algebra (S-algebra [1,2]),
which seems to be relevant for construction of various D=11 models, are
studied. We present two examples of actions for point-like dynamical systems,
which are invariant under off-shell closed realization of the S-algebra as well
as under local fermionic -symmetry. On this ground, an explicit form of
the S-algebra is advocated.Comment: 18 pages, LaTex fil
Twisted N=8, D=2 super Yang-Mills theory as example of a Hodge-type cohomological theory
It is shown that the dimensional reduction of the N_T=2, D=3 Blau-Thompson
model to D=2, i.e., the novel topological twist of N=8, D=2 super Yang-Mills
theory, provides an example of a Hodge-type cohomological theory. In that
theory the generators of the topological shift, co-shift and gauge symmetry,
together with a discrete duality operation, are completely analogous to the de
Rham cohomology operators and the Hodge *-operation.Comment: 8 pages, Late
Green-Schwarz type formulation of D=11 S - invariant superstring and superparticle actions
A manifestly Poincare invariant formulations for and SO(2,9)
superstring actions are proposed. The actions are invariant under a local
fermionic -symmetry as well as under a number of global symmetries,
which turn out to be on-shell realization of the known ``new supersymmetry``
S-algebra. Canonical quantization of the theory is performed and relation of
the quantum state spectrum with that of type IIA Green-Schwarz superstring is
discussed. Besides, a mechanical model is constructed, which is a zero tension
limit of the D=11 superstring and which incorporates all essential features of
the latter. A corresponding action invariant under off-shell closed realization
of the S-algebra is obtained.Comment: Revised version, in particular, discussion of SO(2,9) case is
included. To be published in Int. J. Mod. Phys.
Considerations on Super Poincare Algebras and their Extensions to Simple Superalgebras
We consider simple superalgebras which are a supersymmetric extension of
\fspin(s,t) in the cases where the number of odd generators does not exceed
64. All of them contain a super Poincar\'e algebra as a contraction and another
as a subalgebra. Because of the contraction property, some of these algebras
can be interpreted as de Sitter or anti de Sitter superalgebras. However, the
number of odd generators present in the contraction is not always minimal due
to the different splitting properties of the spinor representations under a
subalgebra. We consider the general case, with arbitrary dimension and
signature, and examine in detail particular examples with physical implications
in dimensions and .Comment: 16 pages, AMS-LaTeX. Version to appear in the Reviews in Mathematical
Physic
PENGARUH PENAMBAHAN LENSA NOZZLE DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415 TERHADAP HASIL DAYA LISTRIK TURBIN ANGIN SUMBU HORISONTAL
Danur Lambang Pristiandaru. PENGARUH PENAMBAHAN LENSA NOZZLE
TURBIN ANGIN DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415
TERHADAP HASIL DAYA LISTRIK. Skripsi, Fakultas Keguruan dan Ilmu
Pendidikan Universitas Sebelas Maret Surakarta. Januari 2016
Tujuan penelitian ini adalah: (1) Menyelidiki pengaruh jumlah blade pada
turbin angin non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang
dihasilkan. (2) Menyelidiki pengaruh penambahan lensa nozzle pada turbin angin
non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang dihasilkan
turbin angin. (3) Menyelidiki pengaruh bersama (interaksi) antara penambahan
lensa nozzle dan jumlah blade terhadap daya listrik yang dihasilkan turbin angin.
Penelitian ini menggunakan metode deskriptif kuantitatif. Sampel dalam
penelitian ini adalah Turbin Angin Sumbu Horisontal (TASH) dengan desain blade
airfoil NACA 4415 non-twisted. 3 desain lensa nozzle digunakan untuk mengetahui
pengaruhnya terhadap peningkatan daya listrik TASH. Terdapat 3 variasi jumlah
blade yaitu jumlah blade 2, jumlah blade 3, dan jumlah blade 4. Variasi kecepatan
angin yang digunakan dalam penelitian ini adalah 2,5 m/s, 3,5 m/s, dan 4,5 m/s.
Data diperoleh dengan melakukan pengujian TASH menggunakan angin rekayasa,
daya listrik yang dihasilkan dibaca dan direkam oleh data logger. Data yang
diperoleh dari hasil penelitian dimasukkan ke dalam tabel dan ditampilkan dalam
bentuk grafik, kemudian dianalisis.
Berdasarkan hasil penelitian dapat disimpulkan bahwa: (1) Adanya
pengaruh variasi jumlah blade terhadap daya listrik turbin angin. TASH 3 blade
menghasilkan daya listrik yang paling besar yaitu 0,7222 W pada kecepatan angin
4,5 m/s. (2) Adanya pengaruh penambahan lensa nozzle terhadap turbin angin.
Lensa nozzle mampu meningkatkan hasil daya listrik turbin angin semua jenis
variasi jumlah blade dibandingkan turbin angin tanpa lensa nozzle. (3) Ada
pengaruh bersama yang signifikan antara variasi jumlah blade dan variasi jenis
lensa terhadap daya listrik turbin angin. TASH 3 blade dengan lensa C pada
kecepatan angin 4,5 m/s memiliki daya listrik tertinggi yaitu sebesar 0,82041 W.
Daya listrik tersebut meningkat 13,60% dibanding TASH 3 blade tanpa
penambahan lensa, yaitu 0,7222 W.
Kata kunci: Turbin Angin, Lensa Nozzle, Daya Listrik, Data Logge
Presence and fate of priority substances in domestic greywater treatment and reuse systems
A wide range of household sources may potentially contribute to contaminant loads in domestic greywater. The ability of greywater treatment systems to act as emission control barriers for household micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of xenobiotic micropollutants in on-site greywater treatment systems. All of the investigated compounds are listed under the European Water Framework Directive as either "Priority Substances" (PS) or "Priority Hazardous Substances" (PHS). Significant knowledge gaps are identified. A wide range of potential treatment trains are available for greywater treatment and reuse but treatment efficiency data for priority substances and other micropollutants is very limited. Geochemical modelling indicates that PS/PHS removal during treatment is likely to be predominantly due to sludge/solid phase adsorption, with only minor contributions to the water phase. Many PS/PHS are resistant to biodegradation and as the majority of automated greywater treatment plants periodically discharge sludge to the municipal sewerage system, greywater treatment is unlikely to act as a comprehensive PS/PHS emission barrier. Hence, it is important to ensure that other source control options (e.g. eco-labeling, substance substitution, and regulatory controls) for household items continue to be pursued, in order that PS/PHS emissions from these sources are effectively reduced and/or phased out as required under the demands of the European Water Framework Directive
- …