Iskanje po katalogu digitalne knjižnice

Opis: This study deals with berth allocation for Maritime Autonomous Surface Ships (MASSs) in the context of the mixed operation of MASSs and manned vessels from the perspective of port-shipping companies’ collaboration. Two berth allocation strategies, namely the separated-type and the mixed-type, are proposed in this article. Two mixed integer nonlinear programming models aimed at minimizing the total docking cost of the vessels in the port and the waiting time for berths are developed and solved using Gurobi, respectively. A large-scale simulation of the mixed-type berth allocation model is carried out using an improved simulated annealing algorithm. Several experiments are conducted to test the effectiveness of the model and to draw insights for commercializing autonomous vessels. The presented results show that multi-objective modeling and optimization should be conducted from the collaboration of port-shipping companies, which is more efficient from the perspective of shipping companies or ports, respectively. When berth resources are limited or there is a high requirement for operational safety, the separated-type berth allocation strategy is more efficient. When the number of MASS-dedicated berths reaches a certain proportion, the total docking cost of the vessel no longer changes, indicating that more dedicated berths are not better.
Ključne besede: maritime autonomous surface ship (MASS), mixed operation scenarios, berth allocation, mixed integer programming, simulated annealing algorithm, port-shipping companies’ collaboration
Objavljeno v DKUM: 18.06.2025; Ogledov: 0; Prenosov: 0
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Opis: “Einstein’s riddle” is a popular example of constraints satisfaction problem. Since its introduction, different forms and variations of the riddle have been presented. Regardless of the variant of the riddle, its solution is considered a tough challenge for humans. Researchers have developed and are still developing mathematical models, as well as computational simulation models for solving it. In this article, the authors have modified a previously published mathematical model and developed a computational spreadsheet model for solving the riddle, which provides a unique solution for the riddle. The model was also tested in a small and medium-scaled form for solving constraint satisfaction problems regarding the allocation of construction machines. The authors have also highlighted the model’s limitations for solving such problems and made suggestions regarding necessary modifications in the model to solve more complex problems in the same domain.
Ključne besede: Einstein's riddle, zebra riddle, construction, machine allocation, combinatorial optimization
Objavljeno v DKUM: 02.08.2017; Ogledov: 1282; Prenosov: 430
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Opis: It is possible to participate in the PE industry in different ways. Direct investment, co-investments, alongside specialized investors, indirect investments through limited partnership, and indirect investments through fund of funds. Big institutional investors usually make direct investments. For this approach to PE it is required to invest in a fund management team, which has an intensive relationship and due diligence skills to select the appropriate PE investments. For medium or small size investors, who do not have such high amount to invest, direct investment might not be achievable and it is recommended to invest in funds. Investing in PE funds also gives a higher level of diversification, and is managed by a specialized fund management team. From a PE backed company perspective, fund managers do not only provide capital, but also offer management support, take an active role, where they contribute their skills, network, and experience. Besides the opportunity to get exposure to unlisted PE funds with Limited Partnership, it is also possible to invest in exchange-traded PE companies or LPE. These PE investments are done either directly, indirectly or through the capital of their customers. Investments are conducted in the same way as Limited Partnerships, through various investment horizons (venture, buyout and growth) and financing styles (equity, mezzanine and debt). These exchange-traded PE companies offer the investor an immediate, liquid exposure to the PE investment class. The problem with investing in unlisted PE funds is the minimum required capital to participate in the PE investment class, which is usually too high for smaller or individual investors. It is also difficult to determine the price, which is determined on a illiquid and not transparent secondary market. While the LPE is traded on an organized exchange market, that is liquid, has transparent market prices available and the possibility to get access to the investment class even for smaller institutional or individual investors with a minimum initial investment volume. Another advantage is the capability to rebalance their PE allocation in a flexible way. From analytic perspective it is also much easier to compare LPE to other public traded asset classes using common standard analysing tools. In the analysis with the efficient frontier the portfolios with the additional asset class PE has a clear improvement of the risk, and return characteristics. Over the standard deviation range from 3.28% to 11.90%, the average improvement in return in the optimization framework is 0.48%. For big institutional, smaller or even individual investors, the LPE gives a liquid, transparent and immediate exposure to PE. In the environment of low interest rate, the PE mode is working well. If these kind conditions will continue in 2017, the asset class will continue to contribute a high absolute return and portfolio diversification.
Ključne besede: Private Equity, diversification, institutional and individual investors, strategic asset allocation.
Objavljeno v DKUM: 26.05.2017; Ogledov: 1305; Prenosov: 81
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Ključne besede: capacitor bank allocation, distributive network, evolutionary algorithm, fuzzy logic, optimization
Objavljeno v DKUM: 05.06.2012; Ogledov: 2078; Prenosov: 58
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Ključne besede: projects, project management, management, manager, project organization, planning, project planning, conflicts, bargaining, negotiation, budgeting, costs, information systems, information resources, allocation, monitoring, control, auditing, statistics, probability, case study, textbooks
Objavljeno v DKUM: 01.06.2012; Ogledov: 2391; Prenosov: 116
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