86 research outputs found
Syria's predicament : state (de-) formation and international rivalries
No full textSyria’s war raises important questions about the interaction between the domestic and external dimensions of the conflict. What are the main areas of contention, and how do they relate to regional and international dynamics? Why has the conflict developed into a regional and international battle, and who are the main actors in this rivalry? And, finally, what are the realistic options for ending the Syrian war? The aim of this paper is to answer these questions. In the first, the author examines the domestic origins of the Syrian crisis by focusing on the process of state formation and deformation in Syria. Then, he considers the main areas of contention that shape the Syrian civil war and its regional and international dimensions. Finally, he assesses the conditions under which Syria – as a divided state in a polarised region – can end the war. He argues that in the absence of a military solution to the war in Syria, a political solution may be the only hope for ending the crisis; but such a solution is fraught by varying domestic and external interests in Syria.Peer reviewe
Cooperative localisation in underwater robotic swarms for ocean bottom seismic imaging.
No full textSpatial information must be collected alongside the data modality of interest in wide variety of sub-sea applications, such as deep sea exploration, environmental monitoring, geological and ecological research, and samples collection. Ocean-bottom seismic surveys are vital for oil and gas exploration, and for productivity enhancement of an existing production facility. Ocean-bottom seismic sensors are deployed on the seabed to acquire those surveys. Node deployment methods used in industry today are costly, time-consuming and unusable in deep oceans. This study proposes the autonomous deployment of ocean-bottom seismic nodes, implemented by a swarm of Autonomous Underwater Vehicles (AUVs). In autonomous deployment of ocean-bottom seismic nodes, a swarm of sensor-equipped AUVs are deployed to achieve ocean-bottom seismic imaging through collaboration and communication. However, the severely limited bandwidth of underwater acoustic communications and the high cost of maritime assets limit the number of AUVs that can be deployed for experiments. A holistic fuzzy-based localisation framework for large underwater robotic swarms (i.e. with hundreds of AUVs) to dynamically fuse multiple position estimates of an autonomous underwater vehicle is proposed. Simplicity, exibility and scalability are the main three advantages inherent in the proposed localisation framework, when compared to other traditional and commonly adopted underwater localisation methods, such as the Extended Kalman Filter. The proposed fuzzy-based localisation algorithm improves the entire swarm mean localisation error and standard deviation (by 16.53% and 35.17% respectively) at a swarm size of 150 AUVs when compared to the Extended Kalman Filter based localisation with round-robin scheduling. The proposed fuzzy based localisation method requires fuzzy rules and fuzzy set parameters tuning, if the deployment scenario is changed. Therefore a cooperative localisation scheme that relies on a scalar localisation confidence value is proposed. A swarm subset is navigationally aided by ultra-short baseline and a swarm subset (i.e. navigation beacons) is configured to broadcast navigation aids (i.e. range-only), once their confidence values are higher than a predetermined confidence threshold. The confidence value and navigation beacons subset size are two key parameters for the proposed algorithm, so that they are optimised using the evolutionary multi-objective optimisation algorithm NSGA-II to enhance its localisation performance. Confidence value-based localisation is proposed to control the cooperation dynamics among the swarm agents, in terms of aiding acoustic exteroceptive sensors. Given the error characteristics of a commercially available ultra-short baseline system and the covariance matrix of a trilaterated underwater vehicle position, dead reckoning navigation - aided by Extended Kalman Filter-based acoustic exteroceptive sensors - is performed and controlled by the vehicle's confidence value. The proposed confidence-based localisation algorithm has significantly improved the entire swarm mean localisation error when compared to the fuzzy-based and round-robin Extended Kalman Filter-based localisation methods (by 67.10% and 59.28% respectively, at a swarm size of 150 AUVs). The proposed fuzzy-based and confidence-based localisation algorithms for cooperative underwater robotic swarms are validated on a co-simulation platform. A physics-based co-simulation platform that considers an environment's hydrodynamics, industrial grade inertial measurement unit and underwater acoustic communications characteristics is implemented for validation and optimisation purposes
TINDAK TUTUR DALAM WACANA RESEP MASAKAN ASYHA AL-ALAWIYYAT KARYA KAUSAR AL-ADHAM ISMA�IL: ANALISIS PRAGMATIK
No full textThe research regarding a study of speech act in recipes of Asyha> al-
H}alawiyya>t by Kausar al-Adham Isma> 'i>l is conducted because in the author not
only using command line mode, but also the mode of declarative sentences. The
purpose of this research is to describe the types of speech acts uttered by the author
of Asyha> al-H}alawiyya>t recipe with pragmatics analysis. The method applied in this
study is pragmatic-comparative method, a method in which the determining tool is
the audience or the reader. Based on the analysis, it was found that in functional
aspect of the sentence in the Asyha> al-H}alawiyya>t, there are two types of speech
acts: illocutionary and perlocutionary act. Locutionary act is not found in this study
because the sentences in the recipes are not intended to give any particular
information, but order and predispose the subject to follow the ways of cooking
explained strictly. Illocutionary act in this study consists of assertive and directive
act. Based on sentence mode, there are five types of speech acts found in this recipe:
direct speech act, indirect speech act, literal speech act, direct literal speech act, and
indirect literal speech act
Accessibility impact analysis of new public transit projects in Cairo, Egypt
No full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M. in Urban Planning, Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2019Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 77-80).The New Urban Communities (NUC), built around Cairo, developed to relieve congestion and pull away residents from the crowded core, have not successfully attracted a significant number of residents. Since NUCs are not well connected by official public transport to the inner city, their residents rely on private cars and informal or expensive private mass transit to reach the job markets of inner Cairo. Although in official strategy plans, no direct link is drawn between the difficulty of moving between and within NUCs and their low occupancy rates, NUCs can be attractive places to live for diverse socio-economic groups if their accessibility to jobs and points of interest were improved. There is growing interest from the World Bank and the Egyptian government to invest in public transport routes in the Greater Cairo Region to improve job accessibility and relieve traffic congestion.Applying existing methods to measure the impact of different routes on job accessibility requires data on the location and density of jobs which is not readily available in many data-poor cities in the global south. A novel method was applied to produce a job density data set, combining scraped location and categorical data on businesses from online directories with official census and survey data on job numbers and industry types. This thesis explores the locations of employment opportunities in the absence of official data and the accessibility of the population to these opportunities in the Greater Cairo Region in order to assess the different levels of accessibility to jobs by public transport and inform the priorities of future investment in public transport provision. The research results in recommendations on where 3 routes, out of 10 given corridors, should be placed based on the impact of these new transit lines towards job accessibility.Using location-based accessibility models combined with a novel approach to developing job location data, the work identifies bus routes that performed the best in getting the largest number of people to jobs given considerations of socio-economic equity.by Adham Kalila.S.M. in Urban PlanningS.M.inUrbanPlanning Massachusetts Institute of Technology, Department of Urban Studies and Plannin
Corrigendum to “The 2016 update of the International Study Group (ISGPF) definition and grading of postoperative pancreatic fistula: eleven years after.” Surgery 2017. Mar; 161 (3):584–591. Epub Dec 28, 2016 (Surgery (2017) 161(3) (584–591), (S0039606016307577), (10.1016/j.surg.2016.11.014))
No full textThe authors regret that the name of author Charles R. Vollmer MD is incorrect in the final published version. The correct name Charles Vollmer. The authors would like to apologise for any inconvenience caused. Below is the correct order of authors: Claudio Bassi, MDa, Giovanni Marchegiani, MDa, Christos Dervenis, MD,b, Micheal Sarr, MDc, Mohammad Abu Hilal, MDd, Mustapha Adham, MDe, Peter Allen, MDf, Roland Andersson, MDg, Horacio J. Asbun, MDh, Marc G. Besselink, MDi, Kevin Conlon, MDj, Marco Del Chiaro, MDk, Massimo Falconi, MDl, Laureano Fernandez-Cruz, MDm, Carlos Fernandez-del Castillo, MDn, Abe Fingerhut, MDo, Helmut Friess, MDp, Dirk J Gouma, MDi, Thilo Hackert, MDq, Jakob Izbicki, MDr, Keith D. Lillemoe, MDn, John P. Neoptolemos, MDs, Attila Olah, MDt, Richard Schulick, MDu, Shailesh V. Shrikhande, MDv, Tadahiro Takada, MDw, Kyoichi Takaori, MDx, William Traverso, MDy, Charles Vollmer, MDz, Christopher L. Wolfgang, MDaa, Charles J. Yeo, MDbb, Roberto Salvia, MDa, Marcus Buchler, MDq, from the International Study Group on Pancreatic Surgery (ISGPS
Dynamic localization plan for underwater mobile sensor nodes using fuzzy decision support system.
No full textUnderwater mobile sensor node localization is a key enabling technology for several subsea missions. A novel scalable underwater localization scheme, called Best Suitable Localization Algorithm (BLSA), is proposed to dynamically fuse multiple position estimates of sensor nodes using fuzzy logic, aiming at improving localization accuracy and availability along the whole trajectory in missions. Numerical simulation has been conducted to demonstrate significant improvement in localization accuracy and availability by using the proposed fuzzy inference system. The proposed method provides a costeffective localization system by harnessing all available localization methods on-board
A Fuzzy Cooperative Localisation Framework for Underwater Robotic Swarms
No full textThis article proposes a holistic localisation framework for underwater robotic swarms to dynamically fuse multiple position estimates of an autonomous underwater vehicle while using fuzzy decision support system. A number of underwater localisation methods have been proposed in the literature for wireless sensor networks. The proposed navigation framework harnesses the established localisation methods in order to provide navigation aids in the absence of acoustic exteroceptive sensors navigation aid (i.e., ultra-short base line) and it can be extended to accommodate newly developed localisation methods by expanding the fuzzy rule base. Simplicity, flexibility, and scalability are the main three advantages that are inherent in the proposed localisation framework when compared to other traditional and commonly adopted underwater localisation methods, such as the Extended Kalman Filter. A physics-based simulation platform that considers environment’s hydrodynamics, industrial grade inertial measurement unit, and underwater acoustic communications characteristics is implemented in order to validate the proposed localisation framework on a swarm size of 150 autonomous underwater vehicles. The proposed fuzzy-based localisation algorithm improves the entire swarm mean localisation error and standard deviation by 16.53% and 35.17%, respectively, when compared to the Extended Kalman Filter based localisation with round-robin scheduling
Confidence-based underwater localization scheme for large-scale mobile sensor networks.
No full textThe absence of Global Positioning System in underwater environment predominates in the challenges of underwater vehicles navigation or sensor nodes tracking. Localization of single or few underwater vehicles has been fostered in recent years. However, online simultaneous tracking of large-scale mobile sensor network is still a very challenging research area due to the high cost and the very limited number of vehicles that can be simultaneously localized using Ultra-Short Base Line (USBL) system. We propose a confidence-based localization algorithm for large-scale underwater mobile sensor networks that employs high precision localized sensor nodes in neighboring sensor nodes localization. Numerical simulation shows that a swarm of 100 sensor nodes can be tracked using a single USBL system, range measurement sensors and communication modems
A Fuzzy Cooperative Localisation Framework for Underwater Robotic Swarms
No full textThis article proposes a holistic localisation framework for underwater robotic swarms to dynamically fuse multiple position estimates of an autonomous underwater vehicle while using fuzzy decision support system. A number of underwater localisation methods have been proposed in the literature for wireless sensor networks. The proposed navigation framework harnesses the established localisation methods in order to provide navigation aids in the absence of acoustic exteroceptive sensors navigation aid (i.e., ultra-short base line) and it can be extended to accommodate newly developed localisation methods by expanding the fuzzy rule base. Simplicity, flexibility, and scalability are the main three advantages that are inherent in the proposed localisation framework when compared to other traditional and commonly adopted underwater localisation methods, such as the Extended Kalman Filter. A physics-based simulation platform that considers environment’s hydrodynamics, industrial grade inertial measurement unit, and underwater acoustic communications characteristics is implemented in order to validate the proposed localisation framework on a swarm size of 150 autonomous underwater vehicles. The proposed fuzzy-based localisation algorithm improves the entire swarm mean localisation error and standard deviation by 16.53% and 35.17%, respectively, when compared to the Extended Kalman Filter based localisation with round-robin scheduling
HISTORICAL FOLKLORE AND HISTORICAL REALITY (ABOUT LEGENDS AND PARABLES ABOUT HISTORICAL MONUMENTS IN USTYURT)
No full textThe article talks about the historical reality in legends and parables about the historical monuments of Ustyurt. The author conducts a historical and linguistic analysis of why historical places called Pulzhai, Tengeshashkan and Dzhezkempir received such a name. Readers are also offered interesting information about the sacred place in the southeastern part of Ustyurt – the mausoleum and cemetery of King Ibrahim Adham
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