scholarly journals Lexicographic Unranking of Combinations Revisited

Algorithms ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 97
Author(s):  
Antoine Genitrini ◽  
Martin Pépin
Keyword(s):  
Time Complexity ◽  
Complexity Analysis ◽  
Lexicographic Order ◽  
Familiar Word ◽  
Integer Arithmetic ◽  
Combinatorial Objects ◽  
New Strategy ◽  
High Level ◽  
The Cost ◽  
Multinomial Coefficients

In the context of combinatorial sampling, the so-called “unranking method” can be seen as a link between a total order over the objects and an effective way to construct an object of given rank. The most classical order used in this context is the lexicographic order, which corresponds to the familiar word ordering in the dictionary. In this article, we propose a comparative study of four algorithms dedicated to the lexicographic unranking of combinations, including three algorithms that were introduced decades ago. We start the paper with the introduction of our new algorithm using a new strategy of computations based on the classical factorial numeral system (or factoradics). Then, we present, in a high level, the three other algorithms. For each case, we analyze its time complexity on average, within a uniform framework, and describe its strengths and weaknesses. For about 20 years, such algorithms have been implemented using big integer arithmetic rather than bounded integer arithmetic which makes the cost of computing some coefficients higher than previously stated. We propose improvements for all implementations, which take this fact into account, and we give a detailed complexity analysis, which is validated by an experimental analysis. Finally, we show that, even if the algorithms are based on different strategies, all are doing very similar computations. Lastly, we extend our approach to the unranking of other classical combinatorial objects such as families counted by multinomial coefficients and k-permutations.

scholarly journals Computing the Exact Number of Similarity Classes in the Longest Edge Bisection of Tetrahedra

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1447
Author(s):  
Jose P. Suárez ◽  
Agustín Trujillo ◽  
Tania Moreno
Keyword(s):  
Data Structure ◽  
Stability Condition ◽  
Open Problem ◽  
Integer Arithmetic ◽  
Exact Number ◽  
Similarity Class ◽  
The Stability ◽  
High Level ◽  
The Cost

Showing whether the longest-edge (LE) bisection of tetrahedra meshes degenerates the stability condition or not is still an open problem. Some reasons, in part, are due to the cost for achieving the computation of similarity classes of millions of tetrahedra. We prove the existence of tetrahedra where the LE bisection introduces, at most, 37 similarity classes. This family of new tetrahedra was roughly pointed out by Adler in 1983. However, as far as we know, there has been no evidence confirming its existence. We also introduce a new data structure and algorithm for computing the number of similarity tetrahedral classes based on integer arithmetic, storing only the square of edges. The algorithm lets us perform compact and efficient high-level similarity class computations with a cost that is only dependent on the number of similarity classes.

Complexity Research on B Algorithm

2010 ◽  
Vol 20-23 ◽  
pp. 173-177
Author(s):  
Ai Li Han
Keyword(s):  
Time Complexity ◽  
Complexity Analysis ◽  
Search Algorithms ◽  
Heuristic Function ◽  
Worst Case ◽  
Intelligent Search ◽  
The Cost

The time complexity of B algorithm, one of the intelligent search algorithms, is discussed. By anatomizing some instances, it is pointed out that the cost of calculating the value of heuristic function should be included in the range of time complexity analysis for B algorithm. And then, an algorithm of calculating the value of heuristic function is presented. By analyzing the cost of calculating the value of heuristic function, it is pointed out that the number of recursions in B algorithm is O(n!) in the worst case. Therefore, the time complexity of B algorithm is exponential instead of O(n2).

Changing Role of Agriculture in Income and Employment, and Trends of Agricultural Worker Productivity in Indian States

2020 ◽  
pp. 183-189
Keyword(s):  
Green Revolution ◽  
Positive Trend ◽  
Worker Productivity ◽  
Indian States ◽  
Agricultural Worker ◽  
The Sixties ◽  
High Level ◽  
The Cost ◽  
Changing Role

The productivity of land has been often discussed and deliberated by the academia and policymakers to understand agriculture, however, very few studies have focused on the agriculture worker productivity to analyze this sector. This study concentrates on the productivity of agricultural workers from across the states taking two-time points into consideration. The agriculture worker productivity needs to be dealt with seriously and on a time series basis so that the marginal productivity of worker can be ascertained but also the dependency of worker on agriculture gets revealed. There is still disguised unemployment in all the states and high level of labour migration, yet most of the states showed the dependency has gone down. Although a state like Madhya Pradesh is doing very well in terms of income earned but that is at the cost of increased worker power in agriculture as a result of which, the productivity of worker has gone down. States like Mizoram, Meghalaya, Nagaland and Tripura, though small in size showed remarkable growth in productivity and all these states showed a positive trend in terms of worker shifting away from agriculture. The traditional states which gained the most from Green Revolution of the sixties are performing decently well, but they need to have the next major policy push so that they move to the next orbit of growth.

scholarly journals Determining the critical period for weed control in high-yielding cotton using common sunflower as a mimic weed

2019 ◽  
Vol 33 (6) ◽  
pp. 800-807 ◽  
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Field Studies ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Density ◽  
High Level ◽  
The Cost ◽  
Planting Season

AbstractField studies were conducted over six seasons to determine the critical period for weed control (CPWC) in high-yielding cotton, using common sunflower as a mimic weed. Common sunflower was planted with or after cotton emergence at densities of 1, 2, 5, 10, 20, and 50 plants m−2. Common sunflower was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 growing degree days (GDD) after planting. Season-long interference resulted in no harvestable cotton at densities of five or more common sunflower plants m−2. High levels of intraspecific and interspecific competition occurred at the highest weed densities, with increases in weed biomass and reductions in crop yield not proportional to the changes in weed density. Using a 5% yield-loss threshold, the CPWC extended from 43 to 615 GDD, and 20 to 1,512 GDD for one and 50 common sunflower plants m−2, respectively. These results highlight the high level of weed control required in high-yielding cotton to ensure crop losses do not exceed the cost of control.

One-IPC high-level simulation of microthreaded many-core architectures

2016 ◽  
Vol 31 (2) ◽  
pp. 152-162 ◽  
Author(s):  
Irfan Uddin
Keyword(s):  
Design Space Exploration ◽  
Instruction Set ◽  
Efficient Design ◽  
Simulation Framework ◽  
Fine Grained ◽  
Detailed Simulation ◽  
High Level ◽  
Many Core ◽  
The Cost ◽  
Multiple Clusters

The microthreaded many-core architecture is comprised of multiple clusters of fine-grained multi-threaded cores. The management of concurrency is supported in the instruction set architecture of the cores and the computational work in application is asynchronously delegated to different clusters of cores, where the cluster is allocated dynamically. Computer architects are always interested in analyzing the complex interaction amongst the dynamically allocated resources. Generally a detailed simulation with a cycle-accurate simulation of the execution time is used. However, the cycle-accurate simulator for the microthreaded architecture executes at the rate of 100,000 instructions per second, divided over the number of simulated cores. This means that the evaluation of a complex application executing on a contemporary multi-core machine can be very slow. To perform efficient design space exploration we present a co-simulation environment, where the detailed execution of instructions in the pipeline of microthreaded cores and the interactions amongst the hardware components are abstracted. We present the evaluation of the high-level simulation framework against the cycle-accurate simulation framework. The results show that the high-level simulator is faster and less complicated than the cycle-accurate simulator but with the cost of losing accuracy.

Criteria for the Evaluation of Social Policy Effectiveness of States

2014 ◽  
pp. 87-97
Author(s):  
V. Sautkina
Keyword(s):  
Developed Countries ◽  
Legal Aspects ◽  
Educational Services ◽  
State Control ◽  
National Education ◽  
Current State ◽  
The Usa ◽  
The Government ◽  
High Level ◽  
The Cost

The following article is devoted to the study of current state of national education and healthcare systems. The cost of services in these areas constantly increases, there for even developed countries are forced to make significant efforts in order to maintain earlier achieved results. Due to this reason countries entered into the period of constant reforms with the purpose of maintaining that high level of health and educational services for all segments of population with a constant reduction of its volume of financing. The legal aspects of these changes are requiring manifestation of the will of politicians in order to overcome the opposition of parties which are defending their interests. As an example, the main opponents of the healthcare reforms proposed by Barak Obama in the USA are Republicans who are concerned about a significant increase of a state control over the entire national insurance system. The author comes to the conclusion that only joint actions of the government and every segment of population might actually improve the quality of medical and educational services.

Cost Effectiveness Analysis in Short Sea Shipping: Evidence from Northeast Asian Routes

2021 ◽  
Vol 9 (12) ◽  
pp. 1340
Author(s):  
Xue-Bin Zheng ◽  
Yul-Seong Kim ◽  
Young-Ran Shin
Keyword(s):  
Supply Chain ◽  
Cost Effectiveness ◽  
Short Sea Shipping ◽  
Effectiveness Analysis ◽  
Transportation Modes ◽  
Lift Off ◽  
Cooperative Relationship ◽  
High Level ◽  
Northeast Asian ◽  
The Cost

Nowadays, roll-on/roll-off (Ro-Ro) is an important mode for short sea shipping (SSS) due to its advantages of fast and convenient load and unloading system. Despite the advantages, the market share of Ro-Ro is insignificant compared with lift-on/lift-off (Lo-Lo) in the Northeast Asian region that is geographically suitable for fostering SSS. Therefore, it is of utmost importance to have a better understanding of the effectiveness or Ro-Ro and Lo-Lo in the regional SSS market. For this purpose, this paper develops a model to estimate the total logistics cost of the two transportation modes. The total logistics costs of Ro-Ro and Lo-Lo are calculated on three major SSS routes between Korea and Japan. The results show that Lo-Lo outperforms Ro-Ro on most routes in terms of the cost effectiveness, and Ro-Ro is competitive only for high-priced and time-sensitive cargo. However, it is also documented that Ro-Ro transport has a significant impact on reduction in the total logistics costs when companies integrate the supply chain and improve the cooperative relationship to a high level.

Application of transfer pricing as a management accounting tool in the project management system

2021 ◽  
pp. 43-53
Author(s):  
N. P. Agafonova
Keyword(s):  
Project Management ◽  
Management Accounting ◽  
Transfer Pricing ◽  
Information Support ◽  
Sufficient Information ◽  
Project Management System ◽  
Management Concept ◽  
Modern Economic ◽  
High Level ◽  
The Cost

Modern economic conditions, due to the high level of competition, lead to the need to search for internal reserves to improve the efficiency of economic entities, one of the solutions to this problem can be considered the application of the management concept “project management”. However, its full implementation is impossible without sufficient information support, which is eliminated as a result of the use of various management accounting tools, one of which is transfer pricing. The article presents the results of a study on the use of transfer education in determining the cost of implementing an agricultural project.

scholarly journals The Impact of CEOs' Compensations on Cost Stickiness in Industrial Companies Listed on the Amman Stock Exchange

2021 ◽  
Vol 15 (1) ◽  
pp. 152
Author(s):  
Lina Fuad Hussien
Keyword(s):  
Stock Exchange ◽  
Industrial Companies ◽  
Level Of Activity ◽  
Cost Behavior ◽  
Study Population ◽  
The Difference ◽  
High Level ◽  
The Cost ◽  
The Impact ◽  
Cost Stickiness

The purpose of this study is to analyze the asymmetry in cost behavior (cost stickiness) and to identify the impact of CEOs' compensation on the degree of cost stickiness behavior. The study population consists of the public shareholding companies listed on the ASE, which number (56) industrial company. Data were collected from (35) industrial companies for the period (2009 - 2019). To measure the degree of costs stickiness, The Model of Weiss (2010) was used. The Model of Weiss (2010) takes into account the costs and changes in the level of activity (sales) for the last four quarters of the company, Weiss (2010) model constructs the difference in logarithmic ratios of changes in cost. The study found that the CEO's compensation in Jordanian industrial companies consists of two forms. The companies pay fixed salaries or performance-related bonuses. The study found that the form of compensation that is paid to the CEO affects the behavior of managers. The results indicated that the performance-related rewards are accompanied by a decrease in the level of cost stickiness, and the compensation paid in the form of fixed salaries are accompanied by a high level of cost stickiness. The study recommends that companies should understand the role of the compensation form in administrative decisions, especially with regard to resource modifications, as management motives in relation to resource modifications must be taken into account because of their clear and direct impact on the cost structure of companies.

scholarly journals Economic Models of Higher Education: An International Perspective

2015 ◽  
Vol 2 (2) ◽  
Author(s):  
Pierre-Bruno Ruffini
Keyword(s):  
Higher Education ◽  
Cost Sharing ◽  
Economic Models ◽  
State Intervention ◽  
Developed Countries ◽  
International Perspective ◽  
Tuition Fees ◽  
Market Mechanisms ◽  
High Level ◽  
The Cost

As other sectors, higher education can be characterized by the combination of market mechanisms and state intervention in its funding and organization. Although higher education systems of developed countries pursue similar goals (provide high-level manpower, meet individual and social demands, etc.) and face similar challenges (massive expansion, internationalization, MOOCs, etc.) their economic models differ significantly. In some countries, universities are public and charge no or very low tuition fees, whereas in other countries, the cost-sharing with parents and students is much more demanding. The paper will try to underscore and explain these differences by drawing on the lessons of economic analysis and on the historical and cultural background of countries.

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