Sprachwissenschaftliche Veröffentlichungen von Prof. Dr. G.J. Ramstedt

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Preprocessing Greek Papyri for Linguistic Annotation

Greek documentary papyri form an important direct source for Ancient Greek. It has been exploited surprisingly little in Greek linguistics due to a lack of good tools for searching linguistic structures. This article presents a new tool and digital platform, “Sematia”, which enables transforming the digital texts available in TEI EpiDoc XML format to a format which can be morphologically and syntactically annotated (treebanked), and where the user can add new metadata concerning the text type, writer and handwriting of each act of writing. An important aspect in this process is to take into account the original surviving writing vs. the standardization of language and supplements made by the editors. This is performed by creating two different layers of the same text. The platform is in its early development phase. Ongoing and future developments, such as tagging linguistic variation phenomena as well as queries performed within Sematia, are discussed at the end of the article.Peer reviewe

Greek Meter : An Approach Using Metrical Grids and Maxent

Standard presentations of ancient Greek poetic meter typically focus on identifying and classifying the repeatable syllable-weight-based patterns found in Greek poetry. This dissertation, by contrast, seeks to understand why selected Greek poets arranged their words in just those patterns instead of some others. Counter to the prevailing approach in classics, which defines meters as strings of short and long positions, meters are here viewed as abstract rhythmic patterns, made concrete by the phonological representations of verses. A main goal is to explicitly characterize the well-formedness conditions on the correspondences between these abstract patterns and actual lines. The study is couched in the framework of generative metrics. Chapter 1 sets the scope and context of the study and provides a brief rationale for the proposed approach by comparing it with traditional Greek metrics and demonstrating the built-in limitations of the latter in explaining the metrical choices of Greek poets. In addition, the chapter examines some basic features of Greek meter from the perspective of comparative metrics. Chapter 2 discusses the key background assumptions about the structure of meter and defends the view that poetic meters are musical objects rather than purely phonological ones, as some scholars have suggested. Chapter 3 presents the statistical method used in the dissertation to model the metrical intuitions of poets (maximum entropy density estimation). The chapter also introduces a new method for examining the extent to which the inherent rhythms of the relevant language explain the regularities observed in verses. Chapters 4-6 contain the main contributions to the study of Greek meter and the theory of metrics. Chapter 4 presents statistical analyses of four different meters (trochaic tetrameter, archaic and tragic iambic trimeter, comic iambic trimeter, and anapestic dimeter). According to the analyses, the quantitative patterns in these meters can be plausibly described using hierarchical metrical grids and natural metrical constraints. Chapter 5 examines the rhythmically more complex verses of Sappho and Alcaeus in the light of Paul Kiparsky’s recent proposal that the rhythmic aperiodicity that characterizes much early Greek verse is due to syncopation. It is shown that Kiparsky's theory, with some revisions, can be applied to the analysis of the metrical forms used by Sappho and Alcaeus. Chapter 6 argues against the theory of “Prosodic metrics”, which seeks to analyze Greek meters (and those of other languages) by using phonological markedness constraints alone. Chapter 7 summarizes the main results of the dissertation, places them in the context of the recent history of metrical scholarship, and considers directions for further research.Antiikin kreikkalaisen metriikan yleisesitykset tyypillisesti keskittyvät teksteissä esiintyvien rytmikuvioiden tunnistamiseen ja luokitteluun. Tämä väitöskirja pyrkii sen sijaan ymmärtämään, miksi eräät kreikkalaiset runoilijat käyttivät juuri näitä kuvioita joidenkin toisten asemesta. Vastoin antiikintutkimuksessa vallitsevaa lähestymistapaa, jossa runomittoja kuvaillaan lyhyiden ja pitkien tavupositioiden muodostamina jonoina, tässä väitöskirjassa mittoja tarkastellaan abstrakteina rytmisinä skeemoina, joita runoilijat konkretisoivat kielen sommitelmilla. Työn päätavoite on kuvata täsmällisesti tällaisten mitta-säe-vastaavuusparien hyvinmuodostuneisuutta koskevia ehtoja. Tutkimus nivoutuu generatiiivisen metriikan tutkimustraditioon. Väitöskirja koostuu seitsemästä luvusta. Luvussa 1 määritellään työn tausta ja tavoitteet sekä motivoidaan valittu lähestymistapa vertaamalla sitä traditionaaliseen metriikkaan ja osoittamalla jälkimmäisen lähestymistavan sisäänrakennetut rajoitteet säemuotojen valikoitumisen selittämisessä. Lisäksi luvussa kuvaillaan joitakin kreikkalaisen metriikan peruspiirteitä komparatiivisen metriikan näkökulmasta. Luvussa 2 tarkastellaan työn keskeisiä taustaoletuksia mittojen rakenteesta ja puolustetaan näkemystä, että runomitat ovat musiikillisia eivätkä puhtaasti fonologisia konstruktioita, kuten eräät tutkijat ovat esittäneet. Luvussa 3 esitellään tilastollinen menetelmä, jota työssä sovelletaan runoilijoiden mitallisten intuitioiden mallintamiseen (ns. suurimman uskottavuuden estimointi). Luvussa myös esitellään uusi menetelmä sen tutkimiseen, miltä osin kielen ominaisrytmit selittävät säkeissä havaittavia säännönmukaisuuksia. Luvut 4-6 sisältävät työn keskeisen kotribuution kreikan metriikan ja metriikan teorian tutkimukseen. Luvussa 4 esitetään tilastollinen analyysi neljästä eri runomitasta (trokeinen tetrametri, arkaainen ja traaginen jambinen trimetri, koominen jambinen trimetri ja anapestinen dimetri). Analyysien mukaan näissä mitoissa sommiteltua kielenainesta voidaan uskottavasti kuvailla hierarkkisten metristen kaavojen ja yksinkertaisten mittarajoitteiden avulla. Luvussa 5 tarkastellaan Sapfon ja Alkaioksen rytmisesti monimutkaisempia säkeitä analysoiden niitä Paul Kiparskyn viimeaikaisen ehdotuksen näkökulmasta, jonka mukaan kreikan varhaisten säemuotojen näennäinen aperiodisuus johtuu yksinkertaisen perussykkeen synkopoinnista. Luvussa osoitetaan, että Kiparskyn teoriaa voidaan muutamin muutoksin soveltaa myös Sapfon ja Alkaioksen käyttämien runomittojen analysointiin. Luvussa 6 argumentoidaan näkemystä vastaan, jonka mukaan kreikan (ja muiden kielten) mittoja voidaan uskottavasti kuvata pelkkien fonologisten tunnusmerkkirajoitteiden avulla. Luvussa 7 esitetään yhteenveto väitöskirjan tärkeimmistä tuloksista, kontekstualisoidaan niitä suhteessa metriikan tutkimuksen lähihistoriaan sekä hahmotellaan suuntaviivoja jatkotutkimukselle

Multiple Loop Self-Triggered Model Predictive Control for Network Scheduling and Control

We present an algorithm for controlling and scheduling multiple linear time-invariant processes on a shared bandwidth limited communication network using adaptive sampling intervals. The controller is centralized and computes at every sampling instant not only the new control command for a process, but also decides the time interval to wait until taking the next sample. The approach relies on model predictive control ideas, where the cost function penalizes the state and control effort as well as the time interval until the next sample is taken. The latter is introduced in order to generate an adaptive sampling scheme for the overall system such that the sampling time increases as the norm of the system state goes to zero. The paper presents a method for synthesizing such a predictive controller and gives explicit sufficient conditions for when it is stabilizing. Further explicit conditions are given which guarantee conflict free transmissions on the network. It is shown that the optimization problem may be solved off-line and that the controller can be implemented as a lookup table of state feedback gains. Simulation studies which compare the proposed algorithm to periodic sampling illustrate potential performance gains.Comment: Accepted for publication in IEEE Transactions on Control Systems Technolog

TrueTime: Real-time Control System Simulation with MATLAB/Simulink

Traditional control design using MATLAB/Simulink, often disregards the temporal effects arising fromthe actual implementation of the controllers. Nowadays, controllersare often implemented as tasks in a real-time kernel and communicatewith other nodes over a network. Consequently, the constraints of thetarget system, e.g., limited CPU speed and network bandwidth, must betaken into account at design time.For this purpose we have developed TrueTime, a toolbox forsimulation of distributed real-time control systems. TrueTimemakes it possible to simulate the timely behavior of real-time kernelsexecuting controller tasks. TrueTime also makes it possibleto simulate simple models of network protocols and their influence onnetworked control loops.TrueTime consists of a kernel block and a network block, bothvariable-step S-functions written in C++. TrueTimealso provides a collection of MATLAB functions used to, e.g., do A/Dand D/A conversion, send and receive network messages, set up timers,and change task attributes. The TrueTime blocks are connectedwith ordinary continuous Simulink blocks to form a real-time controlsystem.The TrueTime kernel block simulates a computer with anevent-driven real-time kernel, A/D and D/A converters, a networkinterface, and external interrupt channels. The kernel executesuser-defined tasks and interrupt handlers, representing, e.g., I/Otasks, control algorithms, and communication tasks. Execution isdefined by user-written code functions (C++ functions orm-files) or graphically using ordinary discrete Simulink blocks. Thesimulated execution time of the code may be modeled as constant,random or even data-dependent. Furthermore, the real-time schedulingpolicy of the kernel is arbitrary and decided by the user.The TrueTime network block is event driven and distributesmessages between computer nodes according to a chosen network model.Currently five of the most common medium access control protocols aresupported (CSMA/CD (Ethernet), CSMA/CA (CAN), token-ring, FDMA, andTDMA). It is also possible to specify network parameters such astransmission rate, pre- and post-processing delays, frame overhead,and loss probability.TrueTime is currently used as an experimental platform forresearch on flexible approaches to real-time implementation andscheduling of controller tasks. One example is feedback schedulingwhere feedback is used in the real-time system to dynamicallydistribute resources according to the current situation in the system

Resource-Constrained Embedded Control Systems: Possibilities and Research Issues

A survey that points out research issues and open problems in the area of integrated control and real-time scheduling. Issues that are discussed include temporal robustness, schedulability margin, optimal and direct feedback scheduling, quality-of-control, and tools

Severity as a Priority Setting Criterion: Setting a Challenging Research Agenda

Priority setting in health care is ubiquitous and health authorities are increasingly recognising the need for priority setting guidelines to ensure efficient, fair, and equitable resource allocation. While cost-effectiveness concerns seem to dominate many policies, the tension between utilitarian and deontological concerns is salient to many, and various severity criteria appear to fill this gap. Severity, then, must be subjected to rigorous ethical and philosophical analysis. Here we first give a brief history of the path to today’s severity criteria in Norway and Sweden. The Scandinavian perspective on severity might be conducive to the international discussion, given its long-standing use as a priority setting criterion, despite having reached rather different conclusions so far. We then argue that severity can be viewed as a multidimensional concept, drawing on accounts of need, urgency, fairness, duty to save lives, and human dignity. Such concerns will often be relative to local mores, and the weighting placed on the various dimensions cannot be expected to be fixed. Thirdly, we present what we think are the most pertinent questions to answer about severity in order to facilitate decision making in the coming years of increased scarcity, and to further the understanding of underlying assumptions and values that go into these decisions. We conclude that severity is poorly understood, and that the topic needs substantial further inquiry; thus we hope this article may set a challenging and important research agenda

Simulation of Wireless Networked Control Systems

Embedded systems are becoming increasingly networked and are deployed in application areas that require close interaction with their physical environment. Examples include distributed mobile agents and wireless sensor/actuator networks. The complexity of these applications make co-simulation a necessary tool during system development. This paper presents a simulation environment that facilitates simulation of computer nodes and communication networks interacting with the continuous-time dynamics of the real world. Features of the simulator include interrupt handling, task scheduling, wired and wireless communication, local clocks, dynamic voltage scaling, and battery-driven operation. Two simulation case studies are presented: a simple communication scenario and a mobile robot soccer game

SYSTEMS AND METHODS FOR PREDICTING ONLINE VIDEO METRICS

A low-latency reporting mechanism that runs as a layer on top of an analytics engine is described. The analytics engine runs a predictive model to generate one or more metrics related to online content usage in near future. The predictive model is based on artificial intelligence and machine learning. The predictive model can be trained with low-latency real-time event data as well as canonical data obtained from historical event logs