Time Versus Cost Tradeoffs for Deterministic Rendezvous in Networks

Two mobile agents, starting from different nodes of a network at possibly different times, have to meet at the same node. This problem is known as $\mathit{rendezvous}$. Agents move in synchronous rounds. Each agent has a distinct integer label from the set $\{1,\dots,L\}$. Two main efficiency measures of rendezvous are its $\mathit{time}$ (the number of rounds until the meeting) and its $\mathit{cost}$ (the total number of edge traversals). We investigate tradeoffs between these two measures. A natural benchmark for both time and cost of rendezvous in a network is the number of edge traversals needed for visiting all nodes of the network, called the exploration time. Hence we express the time and cost of rendezvous as functions of an upper bound $E$ on the time of exploration (where $E$ and a corresponding exploration procedure are known to both agents) and of the size $L$ of the label space. We present two natural rendezvous algorithms. Algorithm $\mathtt{Cheap}$ has cost $O(E)$ (and, in fact, a version of this algorithm for the model where the agents start simultaneously has cost exactly $E$) and time $O(EL)$. Algorithm $\mathtt{Fast}$ has both time and cost $O(E\log L)$. Our main contributions are lower bounds showing that, perhaps surprisingly, these two algorithms capture the tradeoffs between time and cost of rendezvous almost tightly. We show that any deterministic rendezvous algorithm of cost asymptotically $E$ (i.e., of cost $E+o(E)$) must have time $\Omega(EL)$. On the other hand, we show that any deterministic rendezvous algorithm with time complexity $O(E\log L)$ must have cost $\Omega (E\log L)$

City Clustering Tool at iFood - Data-driven approach to design online experiments

Internship Report presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Business AnalyticsOne of the many ways innovation occurs in big tech companies is due to A/B testing in order to achieve reliable results the design of these online experiments needs to be well thought. There are some business constraints that might hinder some key requirements of the design such as the fact that some tests can’t be done under the granularity of users and most be done under the granularity of cities which might happen due to ethical and judicial constraints. In those cases in order to make sure that the chosen sample is a good representation of the population it’s proposed a cientific approach of city clustering so that the test cities all together represent a bigger portion of the county plus a best matching city function in order to choose the control cities. With the assumption that the introduction of a city clustering tool would improve the city A/B testing design consistency within the profitability department. The present document reports the descriptive details of the research, discovery, development and validation phase. Results show that new experiments done using said tool are more reliable than the ones done prior. Although results are positive, future steps are proposed, which includes a better UI/UX in order to facilitate stakeholder’s interaction with the tool

Trajectory-Oriented Approach to Managing Traffic Complexity: Operational Concept and Preliminary Metrics Definition

This document describes preliminary research on a distributed, trajectory-oriented approach for traffic complexity management. The approach is to manage traffic complexity in a distributed control environment, based on preserving trajectory flexibility and minimizing constraints. In particular, the document presents an analytical framework to study trajectory flexibility and the impact of trajectory constraints on it. The document proposes preliminary flexibility metrics that can be interpreted and measured within the framework

A Decade of Experimental Research on Spatial Models of Elections and Committees

The Euclidean representation of political issues and alternative outcomes, and the associated representation of preferences as quasi-concave utility functions is by now a staple of formal models of committees and elections. This theoretical development, moreover, is accompanied by a considerable body of experimental research. We can view that research in two ways: as a test of the basic propositions about equilibria in specific institutional settings, and as an attempt to gain insights into those aspects of political processes that are poorly understood or imperfectly modeled, such as the robustness of theoretical results with respect to procedural details and bargaining environments. This essay reviews that research so that we can gain some sense of its overall import

Automated anomaly recognition in real time data streams for oil and gas industry.

There is a growing demand for computer-assisted real-time anomaly detection - from the identification of suspicious activities in cyber security, to the monitoring of engineering data for various applications across the oil and gas, automotive and other engineering industries. To reduce the reliance on field experts' knowledge for identification of these anomalies, this thesis proposes a deep-learning anomaly-detection framework that can help to create an effective real-time condition-monitoring framework. The aim of this research is to develop a real-time and re-trainable generic anomaly-detection framework, which is capable of predicting and identifying anomalies with a high level of accuracy - even when a specific anomalous event has no precedent. Machine-based condition monitoring is preferable in many practical situations where fast data analysis is required, and where there are harsh climates or otherwise life-threatening environments. For example, automated conditional monitoring systems are ideal in deep sea exploration studies, offshore installations and space exploration. This thesis firstly reviews studies about anomaly detection using machine learning. It then adopts the best practices from those studies in order to propose a multi-tiered framework for anomaly detection with heterogeneous input sources, which can deal with unseen anomalies in a real-time dynamic problem environment. The thesis then applies the developed generic multi-tiered framework to two fields of engineering: data analysis and malicious cyber attack detection. Finally, the framework is further refined based on the outcomes of those case studies and is used to develop a secure cross-platform API, capable of re-training and data classification on a real-time data feed

Fire and Life Safety Analysis: Robert E Kennedy Library, Cal Poly San Luis Obispo Campus

This report provides a fire safety analysis on the Robert E. Kennedy Library located on the Cal Poly University campus San Luis Obispo, California. In the course of this analysis, a prescriptive and performance-based approached was used. The goal was to review and obtain an understanding of the features of the building’s design and use that provide fire safety. During the analysis, areas of deficiency will be identified. Recommendations will be made based on the analysis and the nature of the deficiencies. The overall goal is to abide by the NPFA Life Safety standard: (1) Protection of occupants not intimate with the initial fire development, and (2) Improvement of the survivability of occupants, intimate with the initial fire development. These goals can be accomplished by both prescriptive and performance-based codes. Since the library is an existing building, the prescriptive-based codes will apply and the performance analysis will be used to review areas of safety concern. In the prescriptive analysis, the buildings classification and use were established and the rated structural elements were assessed. This included structural typing, egress components, suppression systems, and alarm functions. On the prescriptive side, the library was built according to the 1976 Uniform Building Code. Any requirements would be held to that code. The use of the International Building Code is only for reference. However, it should be noted that if any changes to the structure or use of the building would require a new code review and possible update to the current code. The library is a five-story Type I-A building classified as a Group A-2.1 (Group A-3 per IBC). It has a calculated occupant load capacity of 2725 people. While the primary building elements comply with the code, there were some areas of deficiencies. These are mainly egress issue for occupant loads. The two main ones, are a single exit point in the first-floor open courtyard and the lack of egress width capacity on the second-floor. As recommended, a simple fix would be to reduce occupancy capacity or add a second exit to the courtyard. Since the library is not fully equipped with an automatic sprinkler system, it has some water demand issue. Hydrant flow tests show a water supply of 2590 GPM. The current water supply is well under the IBC and ISO recommendations. While not a requirement for existing buildings, if a sprinkler system was installed, the current water demand would then be able to meet the IBC and ISO recommendations. For the performance-based analysis, the following tenability criterion was established to meet the defined goals: (1) Smoke Obscuration of 13-feet horizontal view or vertical smoke level dropping below 6-feet above floor, (2) Asphyxiant gas: Ct exposure dose of CO at 30,000 ppm-min, and (3) Thermal – ambient air temperature at 6 feet of 140° F. Three different design fires were developed trying to meet the guidelines in the NFPA Life Safety Code. The first was a fire in the bookstack area of the fourth-floor. The second was a desk fire located at the main entrance causing the front exit and main staircase to be unusable. These two fires are fuel limited fires and not expected to cause flashover. The third fire is one in a smaller room on the fourth-floor. This fire was designed to reach flashover. After modeling the three fires, the fire progression was compared to the tenability criterion. This was used to determine if RSET met ASET for each of the three different design fires. For design fire 1 (fire in the bookstack area) the ASET was 460 seconds to evacuate the floor while the RSET with a safety margin was 429 seconds. The fire in the bookstack area did not meet the safe egress requirements. For design fire 2 (fire in the front lobby) the ASET was 900 seconds to evacuate the first and second floors while the RSET with a safety margin was 810 seconds. For design fire 3 (fire in study room on fourth floor) the ASET was not established, but it was expected to exceed the RSET with a safety margin value of 612 seconds. After the performance analysis there were further recommendations in addition to the recommendations for the prescriptive aspects. These include installing additional smoke detectors, equipping the library with an emergency voice alert system, and implementing a written safety plan that includes staff training