STUDY OF THE PHYSICAL EQUATIONS UNDERLYING THE MOTION THE PHENOMENA AROUND US: PERCOLLATION IN TRAFFIC FLOW AND OSCILLATION OF KITES' LONG TAIL

• Main Author: Dian Utami, Fisca
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79100
• Institution: Institut Teknologi Bandung

The phenomenon of motion is all around us, from macroscale to nanoscale. Understanding how objects move in nature is of particular interest and inspires applications in various modern technologies. One of the interesting motion phenomena that is part of this dissertation is the motion model in traffic or transportation systems. Transportation inefficiency is one of the common problems that need to be addressed. The increase in travel needs as well as the growth in economic potential and population density will burden the road infrastructure. The increase in the total of vehicles which far exceeds the expansion of the road has led to a high level of congestion in various traffic lanes, causing inconvenience in various aspects such as energy inefficiency, air pollution and noise, increased travel costs and time, and reduce travel safety. Traffic transition from a free flow to a seriously congested state occurs on a daily basis in populous cities and deteriorates the system’s efficiency. Various policies in each region have been implemented to achieve efficient transportation, including one-way traffic rules, constructing flyovers and smart vehicles under consideration to deal with increasing congested and inefficient traffic. This research aims to built an alternative concept to describe the average traffic congestion in several populous cities around the world from a new concept, namely landscape percolation. Seeing the importance of spatial information (geometry, topology, and morphology), several researchers have explored spatial information and related it to road network, network topology and motivated to provide a new element in an effective urban planning system. In addition to the required spatial information, the percolation approach is a solution to answer and study the network formation and separation. So far, percolation has been widely studied to predict the failure of traffic management, in order to plan and build an effective traffic network. As a scientific input, it can be very useful for planners and policy makers in urban planning and land management. Against this background, urban landscape-based percolation becomes an interesting discussion in the study of its effect on traffic congestion. In this study, the ratio between the residential area size and the road width is a fundamental parameter that controls traffic congestion. The developed model have been compared with the data extracted from several populous cities around the world (data extracted from Google Earth images) and demonstrated very consistent results. In addition, the model is also compared to recognized annual average traffic congestion data, namely Tomtom congestion level data and Numbeo traffic index. The result obtained is to find urban landscape criteria that make cities considered congested or deserted. It was identified from the research results that the congestion conditions in a city strongly depend on the ratio of residential area to road width. After defining the road surface fraction, a criterion is obtained that separates congested and non-congested cities, namely the surface fraction of about 0.1. Cities with an area fraction less than 0.1 are classified as congested cities, while cities with an area fraction greater than 0.1 are classified as empty cities. The model also describes very well the consistency of data measured by various reports on congestion levels (such as the level of congestion recognized by Tomtom or the Numbeo traffic index) of several densely populated cities around the world. These results can help to design new cities or to redesign the infrastructure of densely populated cities, for example to decide the maximum size of the residential area and the width of the roads. The second part of this dissertation discusses how the phenomenon of motion in the long tail oscillation of a kite from a physics point of view. When looking at a very long kite tail such as during festival season, sometimes the tail oscillates in the wind and sometimes it also maintains a static shape. There is a similarity of the Bessel function formulation to the kite tail profile and the deviation angle as the tail moves towards the free (bottom) end. The kite tail profile can be approximated from a zero-order Bessel function where the coordinate origin is at the bottom of the tail. In this paper, we derive a simple equation to qualitatively describe the tail profile under horizontal wind. We consider three possible states: static bending, oscillation with small deviation around the vertical axis, and oscillation with small deviation around the static bending state. We find that the deviations from small oscillations satisfy zeroth-order Bessel functions of the first kind. The phenomenon of kite motion is interesting to discuss because it has a wide potential application, in addition to being physics knowledge, it also has the potential to generate electric power.