Niklas Johansson

A Distributed Scheduling Algorithm for a Bluetooth Scatternet

This paper deals with bandwidth allocation in a Bluetooth scatternet. the proposed assignment of transmission rights provides a controlled traffic transfer between bluetooth piconets and represents a key component in an ad-hoc wireless Bluetooth network in order to provide with efficient data packet passing within and across piconets. This assignment is obtained by executing a distributed algorithm in each node. The algorithm works for unrestricted topologies of both stationary and mobile networks and also deals with assignment changes caused by network re-configurations without the use of a centralized factor. The effect of this re-assignment can be limited to the locality of that topology change. It is also shown that the construction of a link schedule of minimum length in a Bluetooth scatternet is NP-complete.

TCP/IP over the Bluetooth Wireless Ad-hoc Network

Bluetooth is a wireless ad-hoc network concept that was presented in February 1998 by its five original promoters Ericsson, Nokia, IBM, Toshiba and Intel. With Bluetooth, mobile terminals within range of each other can set up ad-hoc connections for both synchronous traffic, e.g. voice, and asynchronous traffic, e.g. IP-based data traffic. In this paper we analyse how well Bluetooth can carry TCP/IP traffic and in particular we show that though the radio channel is very disturbed the TCP Vegas protocol with its flow control mechanism can be carried very well. With ARQ handled at the Bluetooth level, retransmissions are made immediately after a packet error and thus the delays, normally introduced are kept acceptably short. In our model important mechanisms in TCP Vegas as well as Bluetooth mechanisms are modelled in detail and we show that TCP throughput is quite high and delays are kept short for packet error probabilities up to 50% and moderate loads.

Motivated language change : processes involved in the growth and conventionalization of onomatopoeia and sound symbolism.

This paper takes its basis in onomatopoeia and sound symbolism and investigates the processes of language change that create these phenomena. Data have mainly been taken from the Germanic branch of the Indo-European language family in which the origin of onomatopoeic expressions, as well as sound symbolic clusters, or phonaesthemes, can be traced historically to Proto-Germanic and Proto-Indo-European. Two main types of motivated connections between expression and content are distinguished: iconic and indexical. Iconic connections basically embrace onomatopoeic expression, in which there is an attempt towards creating a likeness between the sound created by the content and the linguistic form of the expression. These types of motivated expressions behave differently from the indexical, even though the boundaries to some extent are floating. Phonaesthemes are regarded as predominantly indexically motivated and analysed synchronically in the Germanic languages, in which there is considerable agreement on the meaning connected to some of them, e.g. fl-, gl-, bl- which are connected to light and similar semantic associations. Other phonaesthemes, such as fj-, are restricted to individual languages only. The all-Germanic phonaesthemes are traced back historically as well as into reconstructed stages of the proto-language, and the origin of words and groups of words are taken into consideration. The later phonaesthemes, occurring in individual languages only, are traced back historically, taking older sources and first occurrences into consideration. The study shows that a number of different mechanisms of change, both on the form and the meaning side, are involved when sound symbolic clusters grow in a language. This shows that the general principles of change are disrupted or distorted by synchronically operative linguistic mechanisms, involving iconicity and indexicality. Finally, motivated language change is compared to other similar changes such as analogical change, and the consequences for the classification of various types of iconicity are discussed.

The De-Iconization and Rebuilding of Iconicity in Spatial Deixis

This paper investigates iconicity as a possible driving force behind the rebuilding of deictic systems and forms in individual languages. A comparison of a reconstructed Proto-Indo-European deictic system (based mainly on Beekes, Comparative Indo-European Linguistics: An Introduction, 1995) compared with the systems of attested Indo-European languages makes it clear that both systems and forms have undergone change, may it be through sound change, analogy, and/or semantic change. Based on the assumptions by Ultan (Universals of Human Language 2, Phonology, 1978), Woodworth (1991), Traunmüller (Tongues and Texts Unlimited. Studies in Honour of Tore Jansson on the Occasion of his Sixtieth Anniversary, 1994), and Johansson and Zlatev (Motivations for Sound Symbolism in Spatial Deixis: A Typological Study of 101 languages. The Public Journal of Semiotics, 2013), iconicity obviously plays a role in the synchronic systems of spatial deixis, which in turn indicates the iconicity has played a role on the process of change, both of the forms themselves and the systems as such. Data from 13 contemporary and 17 historical languages, belonging to 12 Indo-European branches was used. Vowels and consonants were divided into voiceless sounds as being more proximal, and voiced sounds being more distal (see the explanation below). The voiced sounds were divided according to the frequency of their f2, with [i] and voiced palatal consonants as more proximal and [u] as more distal (Ohala, Sound Symbolism, 1994). Results were divided into motivated (fulfilling the expected relation between deictic form and sound value), non-motivated (arbitrary), and reversed-motivated (the reverse of motivated). Five strategies of rebuilding deictic systems and forms were identified. None of the languages investigated have used a system identical to the Proto-Indo-European reconstructed system. Mostly internal material from the Proto-Indo-European deictic system was used in the forms of the systems of the daughter languages. Generally, a statistically significant motivated support was found: 70.2% of the forms of the languages used were identified as motivated, 9.2–10.4% were non-motivated and 19.4–20.7% reversed-motivated. Due to the different strategies of rebuilding systems and forms, generative explanations for the motivated support should be excluded. Hence, iconicity seemed to be reintroduced after the decay, by means of language change, of a former (motivated) deictic system. Therefore, it turned out as a very likely conclusion that iconicity has been and is involved in the rebuilding of deictic material, relating to the systems as such.

Diachronic Atlas of Comparative Linguistics (DiACL)—A database for ancient language typology

Feature stability, time and tempo of change, and the role of genealogy versus areality in creating linguistic diversity are important issues in current computational research on linguistic typology. This paper presents a database initiative, DiACL Typology, which aims to provide a resource for addressing these questions with specific of the extended Indo-European language area of Eurasia, the region with the best documented linguistic history. The database is pre-prepared for statistical and phylogenetic analyses and contains both linguistic typological data from languages spanning over four millennia, and linguistic metadata concerning geographic location, time period, and reliability of sources. The typological data has been organized according to a hierarchical model of increasing granularity in order to create datasets that are complete and representative.

Goal-Based Filtering of Service Interactions

In order to assure short time-to-market and high quality of new services, effective and efficient pre-deployment service interaction handling is necessary. Service creators and service providers need mechanisms for assessing the impact of newly introduced services on the existing ones. In particular, efficient methods for detecting undesired interactions are required. To satisfy these needs, the EURESCOM1 Project P509, “Handling Service Interactions in the Service Life Cycle” created the concept of interaction filtering which is a step up towards interaction detection. Filtering identifies service and feature combinations which are interaction-prone and to eliminate those which are unlikely to cause any interactions, which simplifies the actual interaction detection. Filtering uses a number of complementary methods which analyse different aspects of services. The paper presents and evaluates one of such methods called goal-based filtering. The method identifies interaction-prone combinations by analysing the relations between service properties and users goals.