The aim of this paper is to present the main results arisen from the joint efforts of the public-private partnership in being between CCII (Centro Cultura Innovativa d'Impresa) of University of Salento and Apphia s...The aim of this paper is to present the main results arisen from the joint efforts of the public-private partnership in being between CCII (Centro Cultura Innovativa d'Impresa) of University of Salento and Apphia s.r.l.. This paper will focus on the results of the core of the OBSS (on board stability system) module that, starting from the exact 3D geometry of a ship hull, described by a discrete model in a standard format, the distribution of all weights onboard and the data acquired by the system, calculates ship floating conditions (in draught, heel and trim). The proposed approach is based on geometry meshes represented by an universally accepted file format (named OBJ) first developed by Wavefront Technologies. Demonstration of the validity of the results is done by the authors using as hull model a simple rectangular box.展开更多
A ship's crew plays an important role in the maritime transportation sector and their performance is paramont in the shipping industry. On this account, an impartial evaluation of the crew's performance is an import...A ship's crew plays an important role in the maritime transportation sector and their performance is paramont in the shipping industry. On this account, an impartial evaluation of the crew's performance is an important issue. In this paper, the ship officer's performance evaluation problem is studied. The performance evaluation criteria that shipping companies take into account are determined and a performance evaluation process is modelled by using the FAHP (Fuzzy Analytic Hierarchy Process) based on Chang's Algorithm. Linguistic variables and fuzzy numbers are used in the assessment process. The results of the proposed model demonstrate that the FAHP method is effective and helps managers make better and more reliable decisions under fuzzy circumstances.展开更多
The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system...The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system consists of three independent loops. During the normal operation, the primary sodium in the EVST is circulated by natural convection and the secondary circulation in the EVST sodium cooling system is powered by electromagnetic pumps. When an SBO (station blackout) occurs, all the pumps and blowers are tripped. Therefore, it was necessary to evaluate the cooling ability by the natural circulation of sodium in the EVST sodium cooling system and air through the air cooler during the SBO. In this study, an analysis and evaluation of the plant dynamics for the spent fuel and the EVSS structural integrity during an SBO were performed. When the number of cooling loops was not changed and natural circulation occurred in only two loops, the sodium temperature in the EVST increased to approximately 450 ~C. However, the structural integrity of the EVSS was maintained. The analytical results, therefore, help clarify the number of necessary cooling loops for efficient decay heat removal and sodium temperature behavior in an SBO.展开更多
文摘The aim of this paper is to present the main results arisen from the joint efforts of the public-private partnership in being between CCII (Centro Cultura Innovativa d'Impresa) of University of Salento and Apphia s.r.l.. This paper will focus on the results of the core of the OBSS (on board stability system) module that, starting from the exact 3D geometry of a ship hull, described by a discrete model in a standard format, the distribution of all weights onboard and the data acquired by the system, calculates ship floating conditions (in draught, heel and trim). The proposed approach is based on geometry meshes represented by an universally accepted file format (named OBJ) first developed by Wavefront Technologies. Demonstration of the validity of the results is done by the authors using as hull model a simple rectangular box.
文摘A ship's crew plays an important role in the maritime transportation sector and their performance is paramont in the shipping industry. On this account, an impartial evaluation of the crew's performance is an important issue. In this paper, the ship officer's performance evaluation problem is studied. The performance evaluation criteria that shipping companies take into account are determined and a performance evaluation process is modelled by using the FAHP (Fuzzy Analytic Hierarchy Process) based on Chang's Algorithm. Linguistic variables and fuzzy numbers are used in the assessment process. The results of the proposed model demonstrate that the FAHP method is effective and helps managers make better and more reliable decisions under fuzzy circumstances.
文摘The prototype fast breeder reactor "MONJU" has an EVSS (ex-vessel fuel storage system) which consists mainly of an EVST (ex-vessel fuel storage tank) and an EVST sodium cooling system. EVST sodium cooling system consists of three independent loops. During the normal operation, the primary sodium in the EVST is circulated by natural convection and the secondary circulation in the EVST sodium cooling system is powered by electromagnetic pumps. When an SBO (station blackout) occurs, all the pumps and blowers are tripped. Therefore, it was necessary to evaluate the cooling ability by the natural circulation of sodium in the EVST sodium cooling system and air through the air cooler during the SBO. In this study, an analysis and evaluation of the plant dynamics for the spent fuel and the EVSS structural integrity during an SBO were performed. When the number of cooling loops was not changed and natural circulation occurred in only two loops, the sodium temperature in the EVST increased to approximately 450 ~C. However, the structural integrity of the EVSS was maintained. The analytical results, therefore, help clarify the number of necessary cooling loops for efficient decay heat removal and sodium temperature behavior in an SBO.