Using 2-Opt based evolution strategy for travelling salesman problem

Harmony search algorithm that matches the (µ+ 1) evolution strategy, is a heuristic method simulated by the process of music improvisation. In this paper, a harmony search algorithm is directly used for the travelling salesman problem. Instead of conventional selection operators such as roulette wheel, the transformation of real number values of harmony search algorithm to order index of vertex representation and improvement of solutions are obtained by using the 2-Opt local search algorithm. Then, the obtained algorithm is tested on two different parameter groups of TSPLIB. The proposed method is compared with classical 2-Opt which randomly started at each step and best known solutions of test instances from TSPLIB. It is seen that the proposed algorithm offers valuable solutions

Generalized formulae for the periodic fixed and geometric-gradient series payment models in a skip payment loan with rhythmic skips

Nowadays, the periodic level payment model is the most widely used loan payment model by the banks. In addition, the periodic geometric and linear gradient payment models are available in the financial mathematics books. The arbitrary skip periodic level (or equal) loan payment model was firstly developed by Formato (1992). Formato’s model was extended to the geometric gradient loan payment model by Moon (1994) and the linear gradient model by Eroglu and Karaoz (2002). This loan payment models that have periodic level and geometric gradient series payment with rhythmic skips instead of arbitrary skips have beendiscussed. General formulae have been derived for these models. Numerical examples are solved to show the practical application of the developed payment models on home financing

Heterojen Filolu Yeşil Araç Rotalama Probleminin Tavlama Benzetimi Yöntemi ile Çözümü

Araç rotalama problemi, müşterilere siparişlerini ulaştırmak için minimum maliyetli rota kümesinin belirlendiği optimizasyon problemidir. Son yıllarda çevresel duyarlılıktaki artışla beraber, uygulayıcılar ve araştırmacılar fosil yakıtların çevreye olan etkilerini azaltmak için taşıma faaliyetlerinin çevre ile ilgili özelliklerine odaklanmaya başlamıştır. Araç rotalama probleminin bu duyarlılığı dikkate alan türü ise yeşil araç rotalama problemi olarak adlandırılmaktadır. Yeşil araç rotalama problemi son yıllarda üzerinde oldukça yoğun çalışılan bir konudur. Çalışmanın ana motivasyonu, güncel hayatta doğal olarak karşılaşılan heterojen araç filoları için yük toplama/dağıtma rotalarının işlemesi sonucu ortaya çıkan emisyon gazlarının minimize edilmesi amacıyla bir yaklaşım geliştirmektir. Çalışmada, bölge distribütörü olarak faaliyet gösteren bir firmanın dağıtım faaliyetleri heterojen filolu yeşil araç rotalama problemi olarak ele alınmış ve tavlama benzetimi yöntemiyle daha düşük emisyon değerleri sağlayan çevreci çözümler elde edilmeye çalışılmıştır. Çözüm yaklaşımında heterojen bir filo için emisyon değerleri araçların taşıdığı yük miktarı ve yüklerin taşındığı mesafe üzerinden hesaplanmıştır. Yeşil Araç Rotalama çözümleri, standart araç rotalama problemi olarak elde edilen çözümler üzerinden hesaplanan emisyon değerleri ile kıyaslanmıştır. Sonuç olarak, yük miktarı, taşıma mesafesi ve emisyon salınımı ilişkileri nedeniyle önerilen yaklaşım bazı veri setlerinde daha yüksek dolaşım mesafesine karşın daha düşük emisyon miktarı içeren çözümler sağlamıştır. Bütün çözümlerin toplam değeri göz önüne alındığında, seyahat mesafesi bakımından %38,5 ve emisyon değeri bakımından ise %86,7 oranında daha iyi çözümler elde edilmiştir

Physics-inspired optimization algorithm for obtaining initial routes of capacitated vehicle routing problem

Capacitated vehicle routing problem (CVRP) is NP-Hard and computing exact solutions in real life situations is mostly infeasible. Therefore, heuristic methods are used as an alternative. In heuristic methods the quality of the final solution is directly related with the initial solution space. In this study, artificial physics based optimization algorithm is applied to CVRP in order to obtain the initial population pool of a heuristic method. The A, B and P group 74 test instances of Augerat et al are considered. The group average deviations of the initial solutions from best known solutions is calculated as 37.95%, 32.10% and 31.45% for A, B and P groups respectively. Then, a conventional genetic algorithm (GA) with one point crossover and one point mutation is chosen as a heuristic search algorithm and the initial solutions obtained are used for the first generation of the GA. The GA is executed 1000 generations with crossover and mutation rates as 0.9 and 0.1, respectively. For each problem, GA is executed 10 times and best output is recorded. As a result, 7.15%, 4.37% and 6.33% group average deviations are obtained after heuristic search

Investigation of the effects of IMPULS Maturity model with a simulation-based analysis

International Symposium onIntelligent Manufacturing and Service Systems (10. : 2019 : Sakarya, Turkey)Industry 4.0 enables to produce products that are complex in production in a short time and in high quality by entering factories and making our production environments smarter. Industry 4.0 is defined as the digitization of all work processes of a company, not just a production line or an activity. In the scope of these definitions, the current situation was determined with IMPULS Industry 4.0 maturity model with a previous study and then as-is model was stated by using ARIS which is one of the business process model software in a solar panel production company in this study. The next step is to design and run a simulation model based on current innovations and improvements. As a result of the simulation analysis, the results were compared by the view of operations, waiting times and resources usage in the current situation and the new situation. A total of 20 panels will be produced by using 120 cells. 110 minutes of waiting time is decreased to 70 minutes. So, the improvement rate of outcome is 36%. Waiting time’s improvement rate is 14% as well. The conclusion of this study, via analyzing the current situation of the company, as a managerial decision determining which stages of the production line will apply transformation to Industry 4.0 processes. Also, this study can be considered as a pioneer applied study for the next transformation cases on the other maturity models with more effectively in a shorter time by making different additions appropriate for the similar purposes.No sponso

CARGO DISTRIBUTION PROBLEMS: A CASE STUDY OF ISPARTA CITY

The vehicle routing problem (vrp) is related to service a number of customers with a fleet of vehicles. In real life, the applications of transportation, distribution and logistics are mostly studied as a research area for scientists and industrial practioners. In this study, the cargo distribution problem has been presented by using vrp procedures for a cargo company in Isparta City, Turkiye. The 400 customer points and their requirements are only served from two branch offices of a cargo company. Firstly, the customer points are clustered to Euclidean distance matrices and in the second phase, the distribution plans are computed via vrp approach. As a result, the solutions are obtained and the distribution plans are offered to the cargo company under cost and fleet minimization

A Financial Ratio Analysis on BIST Information and Technology Index (XUTEK) Using AHP-weighted Grey Relational Analysis

The financial ratio analysis is an important issue for the stock exchange markets which have many sub-sectoral indexes. During Industry 4.0 revolution and transition, the sector of information and technology is shown as one of the sectors that have great strategic importance in the global change and development process. So, the performance of the information and technology sector provides a significant added value to the economies. In this study, multi-criteria decision-making (MCDM) approaches will be used to determine the weights of the criteria with considering the experts’ opinions used in the evaluation of the financial performance of the companies operating in the field of Information and Technology Sector of BIST Stock Index (XUTEK). In order to measure the financial performance of companies with MCDM methods, the ratios of the liquidity, operational/activity, financial structure, and profitability are obtained from the financial statements are frequently applied in the scientific literature. In the study, criteria weights were determined by using the pairwise comparison feature of the analytical hierarchy process method and expert opinions. Then, the smallest and largest values of the financial ratio values in quarterly periods in 2020 and the uncertainty formed were evaluated with the gray relational analysis method. After all; XUTEK stocks to be included in the priority investment portfolio in terms of financial performance have been determined

ERP software selection using intuitionistic fuzzy and interval grey number-based MACBETH method

Purpose – Enterprise Resource Planning (ERP) software which is a knowledge-based design on the interconnective communication of business units and information share, ensures that business processes such as finance, production, purchasing, sales, logistics and human resources, are integrated and gathered under one roof. This integrated system allows the company to make fast and accurate decisions and increases its competitiveness. Therefore, for an enterprise, choosing the suitable ERP software is extremely important. The aim of this study is to present new research on the ERP software selection process by clarifying the uncertainties and find suitable software in a computational way. Design/methodology/approach – ERP selection problem design includes uncertainties on the expert opinions and the criteria values using intuitionistic fuzzy set theory and interval grey-numbers to MACBETH multi criteria decision making method. In this paper, a new interval grey MACBETH method approach is proposed, and the degree of greyness approach is used for clarifying the uncertainties. Using this new approach in which grey numbers are used, it is aimed to observe the changes in the importance of the alternatives. Moreover, the intuitionistic fuzzy set method is applied by considering the importance of expert opinions separately. Findings – The proposed method is based on quantitative decision making derived from qualitative judgments. The results given under uncertain conditions are compared with the results obtained under crisp conditions of the same methods. With the qualitative levels of experts reflected in the decision process, it is clearly seen that ERP software selection problem area has more effective alternative decision solutions to the uncertain environment, and decision makers should not undervalue the unsteadiness of criteria during ERP software selection process.No sponso