Un Squirrel Search Algorithm discreto aplicado al problema Job Shop con operadores calificados

Introduction: The Job Shop problem With Skilled Operators (JSSO) is an extension of the classic Job Shop in which, an operation must be executed by a limited set of workers, aiming to minimize jobs total termination time or Makespan. This situation can represent different applications in daily life. JSSO is a complex problem and its classified as NP-HARD.. Objective: In this article, the JSSO problem is addressed. It is made by adapting an algorithm known as Squirrel Search Algorithm (SSA). Method:  A discrete encoding scheme is proposed for the SSA algorithm and the Smallest Position Value (SPV) method are used. Also, solutions that can violate the precedent relationships are corrected with the Valid Particle Generator (VPG) method, which guarantees feasible solutions. Two versions of the algorithm were tested in 28 instances proposed in the literature to valid their performance. Results: Computer experiments show that the proposed algorithms reach optimal solutions in 25 and 28 analyzed instances. In addition, for the instances where optimality was not achieved, the average gap does not exceed the 2% for both versions of the proposed algorithms. Conclusions: The proposed encoding scheme guarantees the discretization of the algorithms, generating solutions that converge towards the optimum. In addition, the proposed encoding allows natural use of movement operators originally proposed for the algorithms used. Performance obtained by the algorithms is adequate and of high quality.Introducción: El problema Job Shop Con Operadores Calificados o Job Shop With Skilled Operators (JSSO) es una extensión del problema clásico Job Shop en el cual, una operación debe ser ejecutada por un conjunto limitados de trabajadores, con el objetivo de minimizar el tiempo de terminación total de los trabajos o Makespan, situación que puede representar distintas aplicaciones en la vida cotidiana. Es un problema complejo y es catalogado como NP-HARD. Objetivo: En este artículo, se aborda el problema JSSO desde la adaptación de un algoritmo conocido como Squirrel Search Algorithm (SSA). Metodología: Se propone un esquema de codificación discreto para el algoritmo SSA utilizando el método Smallest Position Value (SPV). Además, para evitar soluciones que violen las relaciones de precedencia; se corrigen con el método Valid Particle Generator (VPG), el cual garantiza soluciones factibles. Dos versiones del algoritmo se colocan a prueba en 28 instancias propuesta en la literatura para validar su rendimiento. Resultados: Los experimentos computacionales realizados muestran que los dos algoritmos propuestos alcanzan soluciones óptimas en 25 de las 28 instancias analizadas. Además, para las instancias en donde no se logró soluciones óptimas, el gap promedio no supera el 2% para ambas versiones de los algoritmos propuestos. Conclusiones: El esquema de codificación propuesto garantiza la discretización del algoritmo, generando soluciones que convergen hacia el óptimo. Además, la codificación propuesta, permite utilizar de manera natural los operadores de movimiento propuestos originalmente para el algoritmo utilizado. El rendimiento obtenido por los algoritmos es adecuado y de alta calidad

Intelligent algorithm for the optimization of assembly and handling systems and processes for in-line production

Povečanje konkurenčnosti podjetij je v veliki meri odvisno od učinkovitosti montažnih in strežnih sistemov ter procesov (MiSSP). Njihovo učinkovitost lahko povečamo z različnimi metodami optimizacije, predvsem z vidika zmanjševanja stroškov, skrajševanja pretočnih časov, dobavnih terminov, povečanja izkoriščenosti opreme itd. Ena najbolj učinkovitih metod optimiranja takšnih sistemov je optimiranje s sprotno simulacijo. Takšen pristop zahteva podrobne raziskave, študije in analizo vseh gradnikov ter parametrov, ki so potrebni, da se postavi ekspertni sistem sprotne oziroma "On-line" simulacije MiSSP linijske proizvodnje. V doktorski disertaciji je zato podrobno obravnavan razvoj inteligentnih algoritmov in uporaba le-teh za razvoj digitalnih agentov ter ekspertnih sistemov MiSSP linijske proizvodnje. Ekspertni sistem, razvit v okviru doktorske naloge, v povezavi z digitalnim dvojčkom in digitalnimi agenti nenehno nadzoruje in sproti optimira MiSSP linijske proizvodnje. Prav tako je v doktorskem delu razvit inteligentni algoritem, imenovan "premešaj in vstavi", ki npr. samodejno predlaga najboljše rešitve razporejanja naročil, strojev itd. v krajšem času kot uveljavljeni primerljivi algoritmi. Za potrebe validacije ekspertnega sistema z inteligentnim algoritmom je bil v laboratorijskem okolju zgrajen realni montažni in strežni sistem linijske proizvodnje. Digitalni MiSSP smo združili z realnim sistemom preko oblaka in s tem postavili vse potrebne okvire sprotne ali "On-line" simulacije in tako razvili ekspertni sistem, ki je v nenehni povezavi z realnim sistemom in ga sproti nadzoruje ter optimira. Postavljena metodologija zasnove inteligentnega algoritma, digitalnih agentov in digitalnih dvojčkov omogoča okvir za njihovo praktično uporabo v realnem proizvodnem okolju.Successful improvement of the competitiveness of enterprises depends to a large extent on the efficiency of assembly and handling systems and processes (AHSP). Their efficiency can be enhanced through various optimization methods, in particular in terms of the cost reduction, reduction of the throughput times, delivery times, increased utilization of equipment, etc. One of the most effective methods for optimizing such systems is optimization with on-line simulation. Such approach requires detailed research, study and analysis of all the building blocks and parameters needed to set up an expert system of on-line simulation of AHSP of the production line. Therefore, in the doctoral thesis, the development of intelligent algorithms and the use of them for the development of digital agents and expert systems of AHSP production line is discussed in detail. The expert system, developed in the doctoral thesis, in connection with the digital twin and digital agents, constantly monitors and continuously optimizes AHSP of the production line. In the doctoral thesis, an intelligent algorithm, called "flip and insert" is developed that can automatically suggest a very competitive schedule of orders, machines, etc. in a shorter time than well-established comparable algorithms. For the needs of validating the expert system with an intelligent algorithm, a real system of production line has been built in the laboratory environment. We combined the digital AHSP with the real system over the cloud, and thus set up all the necessary frameworks of the on-line simulation and thus develop an expert system that is in constant connection with the real system and is constantly monitoring and optimizing it. The methodology for intelligent algorithm, digital agents and digital twins provides a framework for their practical application in a real production environment

Pivot 2021: Dismantling/Reassembling

Pivot is a series of virtual conferences organized by the Pluriversal Design Special Interest Group (SIG) of the Design Research Society (DRS). Pivot’s first edition, PIVOT 2020: Designing a world of many centers, was hosted by the Phyllis M. Taylor Center for Social Innovation and Design Thinking at Tulane University. The 2021 edition was hosted by OCAD University (Toronto, Canada)

Proceedings of the 21st International Congress of Aesthetics, Possible Worlds of Contemporary Aesthetics Aesthetics Between History, Geography and Media

The Faculty of Architecture, University of Belgrade and the Society for Aesthetics of Architecture and Visual Arts of Serbia (DEAVUS) are proud to be able to organize the 21st ICA Congress on “Possible Worlds of Contemporary Aesthetics: Aesthetics Between History, Geography and Media”. We are proud to announce that we received over 500 submissions from 56 countries, which makes this Congress the greatest gathering of aestheticians in this region in the last 40 years. The ICA 2019 Belgrade aims to map out contemporary aesthetics practices in a vivid dialogue of aestheticians, philosophers, art theorists, architecture theorists, culture theorists, media theorists, artists, media entrepreneurs, architects, cultural activists and researchers in the fields of humanities and social sciences. More precisely, the goal is to map the possible worlds of contemporary aesthetics in Europe, Asia, North and South America, Africa and Australia. The idea is to show, interpret and map the unity and diverseness in aesthetic thought, expression, research, and philosophies on our shared planet. Our goal is to promote a dialogue concerning aesthetics in those parts of the world that have not been involved with the work of the International Association for Aesthetics to this day. Global dialogue, understanding and cooperation are what we aim to achieve. That said, the 21st ICA is the first Congress to highlight the aesthetic issues of marginalised regions that have not been fully involved in the work of the IAA. This will be accomplished, among others, via thematic round tables discussing contemporary aesthetics in East Africa and South America. Today, aesthetics is recognized as an important philosophical, theoretical and even scientific discipline that aims at interpreting the complexity of phenomena in our contemporary world. People rather talk about possible worlds or possible aesthetic regimes rather than a unique and consistent philosophical, scientific or theoretical discipline