La configurazione ottimale del magazzino

A dispetto della riconosciuta criticità del ruolo dei magazzini nel contesto di una rete logistica – e, in senso più ampio, nell’architettura e nella gestione dei sistemi produttivi manifatturieri – accade spesso di riscontrare, soprattutto presso le PMI, che costituiscono la parte strutturalmente più significativa del tessuto industriale del nostro paese, che per l’immagazzinamento non siano in realtà adottati criteri in tutto coerenti con la criticità anzidetta. È infatti ben ricorrente che i materiali vengano meramente accatastati, in assenza cioè di qualsiasi razionale attenzione a problemi – non certo irrilevanti – quali l’economia degli spazi, la rintracciabilità e l’accessibilità dei pallet, l’efficienza stessa della movimentazione. Sulla scorta di tali rilievi, nel presente lavoro verrà prospettata una procedura per ottimizzare la sistemazione a catasta di materiali pallettizzati in magazzini presso i quali i prodotti siano distinti per classi di stoccaggio (class based storage system). L’efficacia di tale metodologia è stata verificata dagli stessi scriventi presso il principale centro di stoccaggio in Italia di un’azienda di rilievo internazionale per prodotti di larghissimo consumo

Cardoon meal as alternative protein source to soybean meal for limousine bulls fattening period: Effects on growth performances and meat quality traits

SIMPLE SUMMARY: Beef cattle feeding strategies are commonly based on soybean meal utilization as a fundamental protein source. This feed, though, might have negative environmental impacts on the major areas of production and is becoming very expensive. Cardoon (Cynara cardunculus L.) is a resilient crop which represents a good opportunity in reclaiming and remediating unutilized lands. Cardoon seeds are rich in oil, which is extracted for industrial purposes, and the related by-products (press cake and meal) are characterized by high protein content and essential fatty acids. The aim of this study was to evaluate cardoon meal as a protein source during the Limousine bulls’ fattening period, in order to study a suitable alternative to develop and create low-input and low-emission feeding strategies. The results obtained in terms of growth performances showed no statistical difference between bulls fed the by control diet (containing soybean meal as main protein source) and animals fed by the experimental diet, where soybean meal was partially replaced by one containing cardoon meal. Meat quality traits were measured, and no differences between the groups were found. Hence, these by-products could be considered as a valuable solution in Limousine bulls’ fattening periods and could be used to represent a key factor to improve cattle-feeding sustainability. ABSTRACT: Soybean meal is the most important protein source in beef cattle feeding. The research of alternative protein sources to replace soy use, avoiding negative effects on in vivo performance and on the product’s quality, is an important issue. In this context, cardoon represents a non-OGM resilient crop that can be cultivated in marginal lands for extracting its seed oil (utilized for biodiesel and biodegradable bioplastic production) and whose and the residual meal from its seed oil (utilized for biodiesel and biodegradable bioplastic production) could be a suitable by-product for animal feeding, due to its fairly high protein content. The aim of this study was to evaluate the feasibility of using cardoon meal as an innovative protein source during the Limousine bulls’ fattening period. Thirty-two bulls were divided into two groups and fed with a diet containing soybean meal (SG) or partially replacing soybean meal with cardoon meal as a protein source (CG), respectively. The feeding trial lasted about 11 months. Growth performances and meat physical–chemical traits were evaluated. No statistical differences in feed efficiency, average daily gain, or in the main meat quality indicators, as well as in fatty acid profiles were found among the groups. Therefore, cardoon meal could be considered as an alternative to soybean meal in fattening Limousine bulls in order to enhance the sustainability of the farming system

Experimental Evaluation of Approximation and Heuristic Algorithms for the Dominating Paths Problem

Monitoring flows on networks is a research area for which a number of applications are waiting for models and algorithms to face new problems emerging with a very high pace. In this paper we analyze a particular optimization problem, namely the Dominating Paths Problem (DPP), that has application in this filed specially for urban transportation networks. Given an undirected graph G = (V; E) and a subset B ⊆ V of bound vertices, we look for a set of vertices M of minimum size such that each element of M is the origin of one or more paths, and, the set of all these paths dominates B. For this NP-hard problem, we present an approximation algorithm and new heuristic procedures extensively evaluated on a set of test instances. We defined two different sets of benchmarks: grid graphs and random graphs. Moreover, we included two test cases taken from real traffic networks. Computational results, discussed in the paper, give insights both on the problem and on algorithms’ performance

Orienting dart-free clique-Helly chordal graphs

In this paper we acyclic orient dart-free clique-Helly chordal graphs in which each directed path is contained in at most two maximal cliques. As shown by the authors in previous works, this allows to give performance guarantee approximation results on a wide class of optimization problems

Partitioning Cliques of Claw-free Strongly Chordal Graphs

In this paper we find a particular partition of the vertex set of claw-free strongly chordal graphs in which each element is a clique, and we show that the adjacency graph of these cliques is a tree. In particular, the presented results imply the existence of an ordering of the vertices, and a corresponding edge orientation, such that each directed path is contained in at most two maximal cliques. As shown by the authors in previous works, this allows to give performance guarantee approximation results on a wide class of optimization problems

A distributed simulation model for inventory management in a supply chain

One of the challenging issues faced by each enterprise of a supply chain is to determine the right production and/or stock levels in order to minimize costs while ensuring a given customer service. In a supply chain, each enterprise pursues its own goal and takes its own decisions in all independent way. However, the decisions are usually influenced by the actions or decisions of the others. One of the main factors influencing the decision process is the customer demand originated at the downstream layer of the supply chain and traveling tip the supply chain in terms of orders placed oil to upstream layers and becoming more and more altered. In order to achieve high efficiency in the whole system, an effective coordination between enterprises is needed. In this paper, all analysis of how supply chain actors interact with each other and how the communication and coordination improve the efficiency of the supply chain is presented; we propose a distributed simulation model for analyzing the effect of inventory policies and information sharing on changing customer demands. The proposed model is tested oil all Italian extended enterprise in which the actors cooperate to produce compressors for refrigerators