Thesis (M. Phil.)--University of Hong Kong, 1977. / Photocopy of typecript.

Thesis (Ph. D.)--Ohio State University, 1971. / Includes vita. Includes bibliographical references (leaves 215-222). Available online via OhioLINK's ETD Center.

Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references.

Positioning systems for trains are traditionally based on track-side infrastructure, implying costs for both installation and maintenance. A reliable on-board system would therefore be attractive. Sufficient reliability for on-board systems is likely going to require a multi-sensor solution. This thesis investigates how measurements from bogie-mounted inertial and magnetic sensors can contribute to such a system. The first part introduces and compares two different methods for estimating the speed. The first one estimates the fundamental frequency of the variations in the magnetic field, and the second one analyses the mechanical vibrations using the accelerometer and gyro, where one mode is due to the wheel irregularities. The second part introduces and evaluates a method for train localization using magnetic signatures. The method is evaluated both as a solution for localization along a given track and at switchways. Overall, the results in both parts show that bogie-mounted inertial and magnetic sensors provide accurate estimates of both speed (within 0.5 m/s typically) and location (3-5 m accuracy typically).

Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

published_or_final_version / Housing Management / Master / Master of Housing Management

High speed trains are very popular in Europe. In Sweden there has been a long political debate about the necessity of them. In 2008 there was a strong political no to the idea. However after some years of debate the government decided to build a new high speed railway between Järna (south of Stockholm) and Linköping, called “Ostlänken”. This study is about the decision-making process of an investment of 35 billion SEK involving a new railway during 2017 up to 2028. This study includes interviews with prominent politicians from different parties. The first issue concerns what arguments were used to promote the new railway, and how the local and regional politicians work to agree on a common stand point. Special interest is focused on the Right party (Moderaterna), who lead the coalition that governed Sweden from 2006 to 2014. In sum, four main issues were in focus. One conclusion is that a lack of railway-capacity between Stockholm and Linköping is important for the decision. Another issue is that “arbetslinjen” played an important role. The political interest in investments in infrastructure has raised sharply which also is positive for “Ostlänken”. A fourth issue is that globalization requires better connections to big airports.

published_or_final_version / abstract / toc / Comparative Literature / Master / Master of Philosophy

The principal of works means and reception of the solution, used for the investigation of rails flaw do not change. Even the newest microprocessor systems of rails’ flaw detection which is found in the latest year uses the simplest criteria’s, that are the amplitude of the reflected ultrasound signal and delaying time. While computer and microprocessor technology improves, the means of numerical measurement and possibilities of processing data, that is signals capable to measure the large majority of the more difficult structure and the algorithm or functions, are found out. The widest classification of the objects is used for identifications’ solution based on separating random processes. The acoustic diagnostic of engines and mechanics, sound and ultrasound defectoscopy, and objects’ identification in accordance with spread signals’ of noise that are in the random background and etc. are named in all those areas where the method of random processes’ classification is suitable.

Šiame darbe nagrinėjama geležinkelio vagonų, reikalingų tam tikros apimties krovinių vežimams, poreikio problema. Ypatingas dėmesys atkreipiamas į vagonų parko rezervo sudarymą. Pagal pateiktas matematines formules, įvertinus visas vagonų eksploatavimo sąnaudas, nustatomas reikalingų vagonų skaičius. Taip pat yra aprašomas „MS Excel“ programa sudarytas matematinis modelis operatyviniam bei planiniam vagonų poreikiui apskaičiuoti. Šiuo modeliu apskaičiuota reikšmė yra optimali ir yra 1,4 % mažesnė, negu vagono poreikio reikšmė, apskaičiuota remiantis praėjusių metų statistiniais rezultatais. Siekiant visapusiškai išnagrinėti problemą, papildomai buvo tiriamas prekinių vagonų parko amžius, atlikta vagonų prastovų laiko analizė, nustatyti prekinių vagonų poreikio ekonominiai aspektai. / This paper considers the need of the rail cars for the determined volume of the freight traffic. The special attention is drawn to the composition of the railway wagon reserve park. The mathematical equations evaluating the operational elements of the wagons are determined. An experimental mathematical model which describes the operational need of wagons is calculated using supportive software Excel; the model estimates that the optimized need for wagons are by 1.4 % lower then the need has been calculated by last year statistical data. Furthermore the work also observes the performance and the age of the freight Wagon Park. The analysis performed to analyze the wagons idle time and other economic issues concerning the matter of the freight wagons are observed.