Inapproximability Results for Maximum Edge Biclique, Minimum Linear Arrangement, and Sparsest Cut

2011 ◽  
Vol 40 (2) ◽  
pp. 567-596 ◽  
Author(s):  
Christoph Ambühl ◽  
Monaldo Mastrolilli ◽  
Ola Svensson
Keyword(s):  
Linear Arrangement ◽  
Sparsest Cut

scholarly journals ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament

2021 ◽  
Vol 502 (3) ◽  
pp. 3294-3311
Author(s):  
Yuanming Wang ◽  
Artem Tuntsov ◽  
Tara Murphy ◽  
Emil Lenc ◽  
Mark Walker ◽  
...  
Keyword(s):  
Physical Properties ◽  
Angular Width ◽  
Scattering Medium ◽  
Central Frequency ◽  
Linear Arrangement ◽  
Plasma Filament ◽  
Kinematic Models ◽  
Tidal Stream ◽  
First Time ◽  
Insight Into

ABSTRACT We present the results from an Australian Square Kilometre Array Pathfinder search for radio variables on timescales of hours. We conducted an untargeted search over a 30 deg2 field, with multiple 10-h observations separated by days to months, at a central frequency of 945 MHz. We discovered six rapid scintillators from 15-min model-subtracted images with sensitivity of $\sim\! 200\, \mu$Jy/beam; two of them are extreme intra-hour variables with modulation indices up to $\sim 40{{\ \rm per\ cent}}$ and timescales as short as tens of minutes. Five of the variables are in a linear arrangement on the sky with angular width ∼1 arcmin and length ∼2 degrees, revealing the existence of a huge plasma filament in front of them. We derived kinematic models of this plasma from the annual modulation of the scintillation rate of our sources, and we estimated its likely physical properties: a distance of ∼4 pc and length of ∼0.1 pc. The characteristics we observe for the scattering screen are incompatible with published suggestions for the origin of intra-hour variability leading us to propose a new picture in which the underlying phenomenon is a cold tidal stream. This is the first time that multiple scintillators have been detected behind the same plasma screen, giving direct insight into the geometry of the scattering medium responsible for enhanced scintillation.

scholarly journals Engineering Mathematical Analysis Method for Productivity Rate in Linear Arrangement Serial Structure Automated Flow Assembly Line

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Tan Chan Sin ◽  
Ryspek Usubamatov ◽  
M. A. Fairuz ◽  
Mohd Fidzwan B. Md. Amin Hamzas ◽  
Low Kin Wai
Keyword(s):  
Mathematical Model ◽  
Failure Rate ◽  
Mathematical Analysis ◽  
Assembly Line ◽  
Flow Line ◽  
Analysis Method ◽  
Machining Time ◽  
Linear Arrangement ◽  
Final Assembly ◽  
Productivity Rate

Productivity rate (Q) or production rate is one of the important indicator criteria for industrial engineer to improve the system and finish good output in production or assembly line. Mathematical and statistical analysis method is required to be applied for productivity rate in industry visual overviews of the failure factors and further improvement within the production line especially for automated flow line since it is complicated. Mathematical model of productivity rate in linear arrangement serial structure automated flow line with different failure rate and bottleneck machining time parameters becomes the basic model for this productivity analysis. This paper presents the engineering mathematical analysis method which is applied in an automotive company which possesses automated flow assembly line in final assembly line to produce motorcycle in Malaysia. DCAS engineering and mathematical analysis method that consists of four stages known as data collection, calculation and comparison, analysis, and sustainable improvement is used to analyze productivity in automated flow assembly line based on particular mathematical model. Variety of failure rate that causes loss of productivity and bottleneck machining time is shown specifically in mathematic figure and presents the sustainable solution for productivity improvement for this final assembly automated flow line.

Dioxazine pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Christie ◽  
Adrian Abel
Keyword(s):  
High Performance ◽  
Industrial Applications ◽  
Textile Dye ◽  
Linear Arrangement ◽  
Natural Colorant ◽  
X Ray ◽  
Organic Pigments ◽  
Tyrian Purple ◽  
Violet Color ◽  
The Individual

Abstract This chapter provides an overview of the structural and synthetic chemistry, and the industrial applications, of dioxazine pigments, a small group of high performance organic pigments. The color violet (or purple) has frequently assumed a prominent position in history, on account of its rarity and cost. The natural colorant Tyrian purple and the first synthetic textile dye, Mauveine, are prime examples of this unique historical feature. CI Pigment Violet 23, also referred to as Dioxazine Violet or Carbazole Violet, is one of the most universally used organic pigments, by far the most important industrial pigment in the violet shade area. Dioxazine Violet is also unique as the dominant industrial violet pigment providing a brilliant, intense violet color and an excellent all-round set of fastness properties. The pigment has a polycyclic molecular structure, originally described wrongly as a linear arrangement, and later shown to adopt an S-shaped arrangement on the basis of X-ray structural analysis. Two other dioxazine pigments are of rather lesser importance. The synthesis and manufacturing route to CI Pigment Violet 23 is described in the review. Finally, a survey of the principal current applications of the individual dioxazine pigments is presented.

scholarly journals On the Hardness of Approximating Multicut and Sparsest-Cut

2005 ◽  
Author(s):  
S. Chawla ◽  
R. Krauthgamer ◽  
R. Kumar ◽  
Y. Rabani ◽  
D. Sivakumar
Keyword(s):  
Sparsest Cut

Bronze Age Cremation Cemeteries in the East Midlands

1987 ◽  
Vol 53 (1) ◽  
pp. 187-221 ◽  
Author(s):  
Carol S. M. Allen ◽  
Mary Harman ◽  
Hazel Wheeler
Keyword(s):  
Bronze Age ◽  
Direct Relationship ◽  
Small Cluster ◽  
Linear Arrangement ◽  
Thin Sections ◽  
Probable Function ◽  
East Midlands ◽  
Materials Used ◽  
First Time ◽  
Organic Remains

Two Bronze Age cremation cemeteries excavated between 1968 and 1975 are reported and discussed. At Coneygre Farm, Notts., fifty-one cremations were excavated, thirty-one in pots, six in cists, and fourteen uncontained. Cremations were deposited in a roughly linear arrangement and no barrow was found. At Pasture Lodge Farm, Lincs., twenty-seven pots were found, of which twenty-five had associated cremations, and fifteen further sherds could represent burials. Vessels in this cemetery form a small cluster. Pottery from these two cemeteries is broadly similar to Deverel-Rimbury ware and with vessels from other sites in the region is considered to form an East Midlands group of Bronze Age pottery. Vessels of this type from Frieston and Grantham, Lincs., are illustrated for the first time. Examination of thin sections of the pottery from the two cemeteries suggests that most, although not all, of the materials used could have been found locally. Organic remains found in thin sections provide environmental information. The effect of soils on durability of pots and their probable function is discussed. A direct relationship is noticed for the first time between the age of the cremated individual and the capacity of the pot in which the cremation was deposited.

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