University of Piraeus

About: University of Piraeus is a education organization based out in Piraeus, Attiki, Greece. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1731 authors who have published 6209 publications receiving 106699 citations.

Modelling the investment decision of the entrepreneur in the tanker sector: choosing between a second-hand vessel and a newly built one

Abstract: It is often the case that the investor in the shipping sector faces the dilemma of investing in a second-hand vessel or building a new one. This happens because an active second-hand market for almost all kinds of vessels exists. We argue that one of the prime considerations for the investment decision should not be the price of the vessel per se, second-hand (SH) or newly built (NP) but (a) the relative price ratio (SH/NP) second-hand price over the new building price and (b) the movement of this ratio. We investigate the determinants of this ratio across different vessel sizes in the tanker sector and show that it can be used as an effective tool in investment decision as well as in asset appraisal. We employ monthly data between 1995 and 2006 for four different ship sizes–VLCC, Suezmax, Aframax and Handysize–and implement an error correction model. The investment decision depends on a number of risk and return variables as well as the perceived speed of adjustment of the price ratio to its equilibriu...

Student Modelling in an Intelligent Tutoring System for the Passive Voice of English Language

Abstract: This paper describes an intelligent multimedia tutoring system for the passive voice of the English grammar. The system may be used to present theoretical issues about the passive voice and to provide exercises that the student may solve. The main focus of the tutor is on the student's error diagnosis process, which is performed by the student modelling component. When the student types the solution to an exercise, the system examines the correctness of the answer. If the student's answer has been erroneous it attempts to diagnose the underlying misconception of the mistake. In order to provide individualised help, the system holds a profile for every student, the long term student model. The student’s progress and his/her usual mistakes are recorded to this long term student model. This kind of information is used for the individualised error diagnosis of the student in subsequent sessions. In addition, the information stored about the student can also be used for the resolution of an arising ambiguity, as to what the underlying cause of a student error has been.