scholarly journals Optimising a Euclidean Colour Space Transform for Colour Order and Perceptual Uniformity

2021 ◽  
Vol 2021 (29) ◽  
pp. 282-287
Author(s):  
Luvin Munish Ragoo ◽  
Ivar Farup

In this paper, we attempt to optimise a colour space transform for colour order and perceptual uniformity to verify if a trade-off could be achieved between the two. The IPT colour space is used as basis for the optimisation. An optimisation model consisting of a modified XYZ-to-LMS matrix, a nonlinearity factor, and two geometric transformation matrices is proposed. Two objective functions are constructed based on the optimisation model, where one would improve perceptual uniformity primarily and the other would improve colour order instead. Finally, the two objective functions are combined, in an attempt to optimise both simultaneously and see if a trade-off between the seemingly incompatible features can be achieved. The performance of the optimised IPT transform is then compared to the original IPT transform, in terms of relative improvements in perceptual uniformity and colour order. Finally, the results show that there is indeed an inverse relationship between the two objectives. However, by adjusting the bias of the optimisation, a balance could be achieved between the two, where both colour order and perceptual uniformity was improved with respect to the original IPT transform.

2020 ◽  
Vol 12 (7) ◽  
pp. 2767 ◽  
Author(s):  
Víctor Yepes ◽  
José V. Martí ◽  
José García

The optimization of the cost and CO 2 emissions in earth-retaining walls is of relevance, since these structures are often used in civil engineering. The optimization of costs is essential for the competitiveness of the construction company, and the optimization of emissions is relevant in the environmental impact of construction. To address the optimization, black hole metaheuristics were used, along with a discretization mechanism based on min–max normalization. The stability of the algorithm was evaluated with respect to the solutions obtained; the steel and concrete values obtained in both optimizations were analyzed. Additionally, the geometric variables of the structure were compared. Finally, the results obtained were compared with another algorithm that solved the problem. The results show that there is a trade-off between the use of steel and concrete. The solutions that minimize CO 2 emissions prefer the use of concrete instead of those that optimize the cost. On the other hand, when comparing the geometric variables, it is seen that most remain similar in both optimizations except for the distance between buttresses. When comparing with another algorithm, the results show a good performance in optimization using the black hole algorithm.


2021 ◽  
Vol 15 (2) ◽  
pp. 183-204
Author(s):  
Pankaj Sinha ◽  
Naina Grover

This study analyses the impact of competition on liquidity creation by banks and investigates the dynamics between diversification, liquidity creation and competition for banks operating in India during the period from 2005 to 2018. Using the broad and narrow measures of liquidity creation, an inverse relationship is determined between liquidity creation and competition. The study also indicates a trade-off between pro-competitive policies to improve consumer welfare and the liquidity-destroying effects of competition, and it highlights how diversification affects liquidity creation. Highly diversified banks in India create less liquidity compared with less-diversified banks, both public and private. The liquidity-destroying effects of competition is intensified among highly diversified private banks, which suggest that diversification has not moderated the adverse impact of competition. JEL Codes: G01, G18, G21, G28


2016 ◽  
Vol 24 (2) ◽  
pp. 12-25 ◽  
Author(s):  
Samo Drobne ◽  
Mitja Lakner

Abstract The use of different objective functions in hierarchical aggregation procedures is examined in this paper. Specifically, we analyse the use of the original Intramax objective function, the sum-of-flows objective function, the sum-of-proportions-to-intra-regional-flows objective function, Smart’s weighted interaction index, the first and second CURDS weighted interaction indices, and Tolbert and Killian’s interaction index. The results of the functional regionalisation have been evaluated by self-containment statistics, and they show that the use of the original Intramax procedure tends to delineate operationally the most persuasive and balanced regions that, regarding the intra-regional flows, homogeneously cover the analysed territory. The other objective functions give statistically better but operationally less suitable results. Functional regions modelled using the original Intramax procedure were compared to the regions at NUTS 2 and NUTS 3 levels, as well as to administrative units in Slovenia. We conclude that there are some promising directions for further research on functional regionalisation using hierarchical aggregation procedures.


2018 ◽  
Vol 47 (2) ◽  
pp. 150-159 ◽  
Author(s):  
Emerta Aragie

By developing a model that describes the Kenyan coffee value chain, this study evaluates opportunities emanating from four scenarios representing productivity gains in the various value chain stages of the coffee sector and additional three scenarios reflecting shifts in market situations. Results show that productivity-enhancing policies have stronger effects on coffee output and export performance if they target the milling stage of the value chain. Export subsidy and favourable external marketing conditions also have stronger effects, distributed comparably across the various value chain stages. We, however, found that these gains in the coffee sector come at the expense of other cash crops such as cotton, tea, sugar and tobacco. The approach followed in this study is relevant as this trade-off between coffee and the other cash crop sectors may not be visibly shown using standard value chain approaches.


2021 ◽  
Author(s):  
Kyriakos Avgouleas ◽  
Emmanouil Sarris ◽  
George Gougoulidis

The economical and operational implications of poor alignment are indisputable for the propulsion shafting system of a commercial vessel. This holds true for naval vessels as well, although far less documented in the technical literature. This paper addresses some of the challenges associated with the proper alignment of a high-speed naval craft, which has been in service for many years. Laser bore-sighting was performed on a Guided Missile Fast Patrol Boat resting on a docking cradle. The measured bearing offsets were input to a FEA model of the shafting system to calculate bearing reactions and detect potential misalignment issues. Subsequent decisions regarding corrective measures take into account the results computed by the numerical model, experience from sister ships, the available documentation from the building yard and several other factors which are discussed in the paper. The solutions proposed are targeted towards a balanced trade-off between cost effectiveness and out-of-service time on one hand, and the risk of potential damage from misalignment on the other hand, which would seriously disrupt the ship’s operational availability. Practical aspects and lessons identified in the process are also presented, which demonstrate the distinct differences in alignment strategy of a high-speed naval craft compared to a typical commercial vessel.


2010 ◽  
Vol 21 (03) ◽  
pp. 311-319 ◽  
Author(s):  
AYSUN AYTAC ◽  
ZEYNEP NIHAN ODABAS

The rupture degree of an incomplete connected graph G is defined by [Formula: see text] where w(G - S) is the number of components of G - S and m(G - S) is the order of a largest component of G - S. For the complete graph Kn, rupture degree is defined as 1 - n. This parameter can be used to measure the vulnerability of a graph. Rupture degree can reflect the vulnerability of graphs better than or independent of the other parameters. To some extent, it represents a trade-off between the amount of work done to damage the network and how badly the network is damaged. Computing the rupture degree of a graph is NP-complete. In this paper, we give formulas for the rupture degree of composition of some special graphs and we consider the relationships between the rupture degree and other vulnerability parameters.


1988 ◽  
Vol 16 (4) ◽  
pp. 277-282 ◽  
Author(s):  
Sonja Vaglum ◽  
Per Vaglum ◽  
Øivind Larsen

95 non alcoholic female employees were personally interviewed and divided into three drinking pattern groups with an increasing level of alcohol consumption: the traditional feminine drinking group (TF) ( n=28), the new feminine drinking group (NF) ( n=37), and the masculine drinking group (M) ( n=30). The groups were compared on family variables which may be regarded as risk factors of alcoholism. The results show an inverse relationship between family risk factors and consumption level, the TF-group having significantly more risk factors than the other two groups. The TF-women more often came from families where the mother and her parents were abstainers, while the father and his parents were more often alcohol abusers or not abstainers. The TF-women were more often attached to their alcoholic fathers as children, while the M-women were more often attached to their mothers. The choice of drinking pattern may be inversely related to the frequency of family risk factors among non alcoholic women.


2017 ◽  
Vol 9 (4) ◽  
pp. 277-302 ◽  
Author(s):  
Thomas Hellmann ◽  
Veikko Thiele

We develop a new theory of the dynamic boundary of the firm where asset owners may want to change partners ex post. We identify a fundamental trade-off between (i) a “displacement externality” under non-integration, where a partner leaves a relationship even though his benefit is worth less than the loss to the displaced partner, and (ii) a “retention externality” under integration, where a partner inefficiently retains the other. With more asset specificity, displacement externalities matter more and retention externalities less, so that integration becomes more attractive. Wealth can resolve ex post inefficient partner arrangements, but may weaken ex ante incentives for specific investments. (JEL D21, D23, D25, D62, D86, G31)


1993 ◽  
Vol 27 (1) ◽  
pp. 59-64 ◽  
Author(s):  
F. S. Venter ◽  
H. Cloete ◽  
J. V. Seier ◽  
M. J. Faber ◽  
J. E. Fincham

Plasma and red blood cell (RBC) folic acid levels, as well as plasma vitamin B12 levels were determined in Vervet monkeys ( Cercopithecus aethiops). All the vervets were apparently healthy and without symptoms or lesions typical of folic acid and/or vitamin B12 deficiencies. Competitive protein binding radioassays were used to determine folate and vitamin B12 values in animals fed 4 different diets. The B12 levels for all the groups ranged between 866 and 5867 pg/ml and showed an inverse relationship with the FA measurements. The lowest mean RBC folic acid content in a group fed an atherogenic diet for 3 years was 12·8 ng/ml. For the other 3 diets, mean RBC folic acid levels were 90·7, 132·3 and 152·8 ng/ml, respectively. A megadose of 25·6 mg of folic acid per day for 99 days was given to 3 adult males. No obvious toxic effects were observed in these animals although mean RBC folic acid levels increased to 1013 ng/ml.


2016 ◽  
Vol 38 (4) ◽  
pp. 307-317
Author(s):  
Pham Hoang Anh

In this paper, the optimal sizing of truss structures is solved using a novel evolutionary-based optimization algorithm. The efficiency of the proposed method lies in the combination of global search and local search, in which the global move is applied for a set of random solutions whereas the local move is performed on the other solutions in the search population. Three truss sizing benchmark problems with discrete variables are used to examine the performance of the proposed algorithm. Objective functions of the optimization problems are minimum weights of the whole truss structures and constraints are stress in members and displacement at nodes. Here, the constraints and objective function are treated separately so that both function and constraint evaluations can be saved. The results show that the new algorithm can find optimal solution effectively and it is competitive with some recent metaheuristic algorithms in terms of number of structural analyses required.


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