A New Algorithm for Privacy-Preserving Horizontally Partitioned Linear Programs

In a linear programming for horizontally partitioned data, the equality constraint matrix is divided into groups of rows. Each group of the matrix rows and the corresponding right-hand side vector are owned by different entities, and these entities are reluctant to disclose their own groups of rows or right-hand side vectors. To calculate the optimal solution for the linear programming in this case, Mangasarian used a random matrix of full rank with probability 1, but an event with probability 1 is not a certain event, so a random matrix of full rank with probability 1 does not certainly happen. In this way, the solution of the original linear programming is not equal to the solution of the secure linear programming. We used an invertible random matrix for this shortcoming. The invertible random matrix converted the original linear programming problem to a secure linear program problem. This secure linear programming will not reveal any of the privately held data.

Equilibrium Pricing with Duality-Based Method: Approach for Market-Oriented Capacity Remuneration Mechanism

The crucial design elements of a good capacity remuneration mechanism are market orientation, insurance of long-term power system adequacy, and optimal cross-border generation capacity utilization. Having in mind these design elements, this research aims to propose a financially fair pricing mechanism that will guarantee enough new capacity and will not present state aid. The proposed capacity remuneration mechanism is an easy-to-implement linear program problem presented in its primal and dual form. The shadow prices in the primal problem and dual variables in the dual problem are used to calculate the prices of firm capacity which is capacity needed for long-term power system adequacy under capacity remuneration mechanism. In order to test if the mechanism ensures sufficient new capacity under fair prices, the mechanism is tested on the European Network of Transmission System Operators for Electricity (ENTSO-E) regional block consisting of Austria, Slovenia, Hungary, and Croatia with simulation conducted for a period of one year with a one-hour resolution and for different scenarios of the credible critical events from a standpoint of security of supply; different amounts of newly installed firm capacity; different short-run marginal costs of newly installed firm capacity; and different capacity factors of newly installed firm capacity. Test data such as electricity prices and electricity load are referred to the year 2018. The results show that the worst-case scenario for Croatia is an isolated system scenario with dry hydrology that results with high values of indicators expected energy not served (EENS), loss of load expectation (LOLE), and loss of load probability (LOLP) for Croatia. Therefore, new capacity of several hundred MW is needed to stabilize these indicators at lower values. Price for that capacity depends on the range of installed firm capacity and should be in range of 1000–7000 €/MW/year for value of lost load (VoLL) in Croatia of 1000 €/MWh and 3000–22,000 €/MW/year for VoLL of 3100 €/MWh that correlates with prices from already established capacity markets. The presented methodology can assist policymakers, regulators, and market operators when determining capacity remuneration mechanism rules and both capacity and price caps. On the other hand, it can help capacity market participants to prepare the most suitable and near-optimal bids on capacity markets.

Improvement of megacity ecological conditions with the use of a clever SmartBoxCity container-tranformer

Introduction. The paper proposes an option for improving the environmental situation in Rostov-on-Don. That is the optimization of the way of cargo delivery to the customer using the clever SmartBoxCity container-tranformer and the Dispatcher RD program. Problem Statement. It is necessary to improve the ecological situation of the city by reducing the number of traffic jams and the time spent in them. The task was to develop and implement technical and information support, on which the driver's ability to get up-to-date information and reduce the delivery time of products to consumers depends. Theoretical Part. The optimization of traffic within the city must be solved using the existing traffic scheme. Due to the optimization, you can significantly reduce the number of traffic jams and the time spent in them, and, accordingly, improve the environmental situation in the city. The way how the driver gets up-to-date information depends entirely on the information support. It is proposed to use a smart folding cargo container-transformer SmartBoxCity, which includes elements of intelligent urban mobility. To optimize the delivery path in the absence of the Internet, the Dispatcher RD software product can be used. Conclusion. The effective management, monitoring and integrated planning of the movement is carried out with the use of mobile and server applications. To improve the professional competence of students of the relevant specialties, it is proposed to use the current SmartBoxCity layout, a developed mobile application and a computer program for optimizing the delivery path.

MEMAKSIMALKAN KEUNTUNGAN HARIAN PADA INDUSTRI RUMAHAN “NANDA JAYA” DENGAN PENERAPAN METODE SIMPLEKS

The home industry "Nanda Jaya" produces banana chips, cassava chips and tempe chips daily. From preliminary observations, information is obtained that in determining the composition of the number of units for each type of chips produced, and determining the selling price of the product per unit, is carried out on the basis of experience while running the business, so there is no optimal way to determine it. With this condition, the company's profit needs to be reviewed whether it is optimal or not. The purpose of this research is to determine the number of production units of each type of chips, in order to obtain maximum profit and also determine the efficiency that occurs in the utilization of cost and time resources. Data collection was carried out by observation and interviews. The mathematical model of the research problem is a linear program problem with three variables that can be solved by the simplex method. From the results of data analysis, it was concluded that in order to obtain maximum profit, the company had to produce 74 units of Banana Chips, 161 units of Cassava Chips and Tempe Chips not to be produced. Maximum profit is Rp. 285,387, - (previously Rp. 247,000, -), Production Capital was reduced to Rp. 889,613, - (previously Rp. 928,000, -), while the total available time was used up.

Finding orthologous gene blocks in bacteria: the computational hardness of the problem and novel methods to address it

Motivation The evolution of complexity is one of the most fascinating and challenging problems in modern biology, and tracing the evolution of complex traits is an open problem. In bacteria, operons and gene blocks provide a model of tractable evolutionary complexity at the genomic level. Gene blocks are structures of co-located genes with related functions, and operons are gene blocks whose genes are co-transcribed on a single mRNA molecule. The genes in operons and gene blocks typically work together in the same system or molecular complex. Previously, we proposed a method that explains the evolution of orthologous gene blocks (orthoblocks) as a combination of a small set of events that take place in vertical evolution from common ancestors. A heuristic method was proposed to solve this problem. However, no study was done to identify the complexity of the problem. Results Here, we establish that finding the homologous gene block problem is NP-hard and APX-hard. We have developed a greedy algorithm that runs in polynomial time and guarantees an O(ln⁡n) approximation. In addition, we formalize our problem as an integer linear program problem and solve it using the PuLP package and the standard CPLEX algorithm. Our exploration of several candidate operons reveals that our new method provides more optimal results than the results from the heuristic approach, and is significantly faster. Availability and implementation The software and data accompanying this paper are available under the GPLv3 and CC0 license respectively on: https://github.com/nguyenngochuy91/Relevant-Operon.

Optimal Pressure Management for Large-Scale Water Distribution Systems Using Smoothing Model

Optimal pressure management in water distribution systems (WDSs) is one of the most efficient approaches to control water leakage for water utilities worldwide. The optimal pressure management can be accomplished through regulating operations of pressure reducing valves (PRVs) to ensure that the excessive pressure in the WDS is minimized. This engineering task can be casted into a nonlinear program problem (NLP) with non-smooth constraints. Until now, the non-smooth constraints have been approximated by the smoothing function of Chen Harker-Kanzow-Smale (CHKS). In this paper, instead of using the CHKS function, we propose to apply the uniform smoothing function for formulation of the NLP. Numerical simulations using two smoothing functions will be carried out for optimal pressure managements of a benchmark WDS and a real-world WDS in Thainguyen City, in Vietnam. The comparison results reveal that the NLP formulated with the uniform smoothing function outperforms the existing NLP formulated with the CHKS in terms of optimal solution accuracy.

Do Pragmatismo Ao Universalismo: A Mudança De Estratégia Da Política Externa Brasileira Para A América Latina No Governo Figueiredo (1979-1985)

Este artigo busca identificar e qualificar as mudanças da política externa brasileira para a América Latina no governo de João Figueiredo (1979-1985) em relação ao governo de Ernesto Geisel (1974-1979). O artigo é baseado no modelo proposto por Charles Hermann para mudanças em política externa. Serão considerados os quatro níveis graduados de mudança – ajuste, programa, objetivo e orientação internacional – e as quatro fontes de mudança – guiada pelo líder, burocracia, reestruturação doméstica, e choques externos – propostos pelo autor. Testaremos o modelo a partir de uma revisão de literatura que versa sobre as linhas gerais e específicas da política “universalista”. Os dados indicam que ocorreu uma mudança de ajuste nas linhas gerais da política externa, mas, nas relações com a América Latina, houve uma mudança de objetivo. Argumenta-se também que tais mudanças foram impulsionadas pelo processo de redemocratização e gradual substituição do modelo de desenvolvimento econômico; além do impacto de choques externos.Palavras-chave: Política externa brasileira; Mudanças em Política Externa; Governo Figueiredo. ABSTRACTThis paper aims to identify and qualify the changes that occurred in the Brazilian Foreign Policy in João Figueiredo’s presidency (1979-1985) in comparison to Ernesto Geisel’s tenure as president (1979-1985). Our analysis is based upon Charles Hermann’s framework to analyze changes in foreign policy. We consider his four graduated levels of change – adjustment, program, problem/goal, and international orientation – and his four sources of change – leader driven, bureaucratic advocacy, domestic restructuring, and external shocks. We test his framework through a literature revision about the “universalismo” general and specific lines. Our analysis points to adjustment changes in the foreign policy’s general lines, but objective changes towards Latin America. We also argue that the sources of such changes were twofold: the domestic re-democratization process and the gradual replacement of the national economic development strategy; and external shocks impact.Keywords: Brazilian foreign policy; changes in foreign policy; Figueiredo government.