Mehdi Abbasi

Analyzing the Operations Strategies of Manufacturing Firms Using a Hybrid Grey DEA approach – A case of Fars Cement Companies in Iran

In competitive markets, the operations strategies of companies are normally formulated based on their competitive advantages. An effective operations strategy should maintain and improve competitive advantages based on the capabilities of the corporate operations resources. Considering the market requirements and the operational performance of the rivals is the key for success and survival of a company in the competition. Therefore, recognizing where a company stands in comparison with its rivals and adopting the appropriate operations strategy plays vital roles in the success of companies. This paper proposes a method for comparing and ranking operations strategies of companies based on the concept of efficient frontier using data envelopment analysis (DEA) in grey environment. In the aforementioned method, DEA is used to evaluate the efficiency of operations strategies of manufacturing firms. Also, grey theory is used to support the uncertainty of the experts’ opinions regarding the inputs and outputs of the DEA model. Then the respective units are ranked, and analyses are performed. The proposed approach is applied for the entire nine cement factories of Fars Province in Iran, and the units are ranked, respective analyses are presented regarding the efficient and inefficient units.

Operational efficiency-based ranking framework using uncertain DEA methods

Purpose – Competition in dynamic markets requires operational excellence and effective operations strategy. Hence, organizations have to evaluate their operational performance in comparison to their rivals. The purpose of this paper is to present an operational performance evaluation framework for analyzing and ranking the organizations based on the effectiveness of their operations strategies. Design/methodology/approach – In this study three uncertain data envelopment analysis (DEA) models consist of fuzzy DEA (FDEA), imprecise DEA (IDEA) and Grey DEA are applied to assess the performance of organizations in terms of the operations. The applicability of the proposed framework is demonstrated through a case study at Fars province cement manufacturers of Iran. Findings – The ranking results assist the mangers of service and manufacturing enterprises in finding out the current positions of their companies and the effectiveness of their operations strategies in comparison to their rivals. Accordingly they c...

A path fuzzy planner for autonomous underwater vehicles to avoid moving unknown obstacles

A fuzzy approach is used for AUVs in this paper to avoid fixed or moving unknown obstacles. In this approach, the line of sight guidance is used. AUV travels towards a target without any collision with fixed or moving unknown obstacles. By considering experience, a fuzzy logic planner is used to generate steering commands for an AUV to avoid obstacles. Speed of the moving obstacle is considered as one of the inputs of the proposed fuzzy planner. By considering this input, a fuzzy planner acquires a better path for an AUV movement. Finally by considering the available information, an algorithm is designed and simulated for AUVs path in the presence of fixed and moving unknown obstacles. The simulation results show that the fuzzy planner allows the Vehicle to navigate safely and travel toward the target on its path without collision.

A New Automated Approach for Semantic Caching on XML Queries

This research presents a semantic approach for XML queries in ORM. XML has been emerging as a standard structure to communicate data through applications. The object-oriented software uses the ORM to store and retrieve persistent objects from relational database. XML is used as a metadata for mapping an object to a relation in ORM. There are two algorithms, one for Recognition Conflict between two XML schemas and the other for integration of schemas. Using the proposed algorithms, semantic caching determines the antonym schema from the cached schema and the schema derived from the new query. The resulted schema is the remainder query schema submitted to the data server. This approach reduces the response time for queries and improves performance of ORM.