Tomasz Nowak

Towards Formal Specification and Verification in Cyberspace

A formal framework for specification and verification of multi-agent systems is developed. Specification of an infrastructure created by a mobile agent platform is presented. On the basis of the specification, the notions of common ontology core, and agents knowledge are introduced. A simple agent architecture is presented. Given agents knowledge and decision mechanisms, model checking method is applied to verify whether the agents can realize their goals.

Agentspace as a Middleware for Service Integration

Agentspace is an emerging environment resulting from process automation in the Internet and the Web. It is supposed that autonomous software (mobile) agents provide the automation. The agents realize goals delegated to them by their human masters. Interoperability is crucial to assure meaningful interaction, communication and cooperation between heterogeneous agents and heterogeneous services. In order to realize the goals, the agents must create, manage and reconfigure complex workflows. Usually, a workflow integrates a number of heterogeneous services. Our research aims at extracting a minimum that is necessary and sufficient for providing transparency between users and services, i.e. for joining applications as services to agentspace on the one hand and for using and integrating them by heterogeneous agents (on behalf of their users) on the other hand. For this very purpose we introduce a new concept of agent architecture as well as the new agent mobility form called soul migration.

LITHIUM FLUORIDE CRYSTALS AS FLUORESCENT NUCLEAR TRACK DETECTORS

Radiophotoluminescence signal of LiF crystals was found to be sufficiently strong to visualize tracks of a single charged particle. This was achieved with a wide-field fluorescent microscope equipped with a ×100 objective and LiF single crystals grown with the Czochralski method at IFJ PAN. The tracks of alpha particles, protons, as well as products of 6Li(n,α)3H reaction with thermal neutrons (moderated Pu/Be source), were observed. These encouraging results are the first steps towards practical use of LiF as fluorescent nuclear track detectors. The most promising dosimetric application seems to be neutron measurements.

Modeling Agent Organizations

We present a formal specification of an environment created by our mobile platform Pegaz [17]. Since all existing mobile agent platform create more or less the same infrastructure on a computer network, this formal specification may be seen as a formal representation of the cyberspace Then, we present a concept of agent organizations in a model of production environment. It is argued that such organizations can be applied in the cyberspace. Agents are supposed to form enterprises producing the commodity specified by the system designer, and then sell the commodity at the market. The goal of the designer is to create efficient enterprises producing the desired commodity. The market is modeled as the price oligopoly. The price oligopoly serves to eliminate enterprises that are not efficient.

Radiation exposure at the proton eye therapy facility at IFJ in Kraków

The proton radiotherapy facility for the treatment of eye tumors is under development at the Institute of Nuclear Physics (IFJ) in Kraków. The optical line installed at the treatment room is applied to form and monitor the 60 MeV proton beam provided by the AIC-144 isochronous cyclotron. Typical proton dose rates measured at the isocentre varied between 0.01 and 0.5 Gy/s. The intensities of the secondary radiation field inside and around the treatment room have been measured with a stationary monitoring system. Four sets of radiation monitors provide the continuous monitoring of gamma and neutron radiation during the operation of the facility. Monte Carlo calculations have been performed for understanding the structure of the radiation field inside the treatment room. Typical ambient dose equivalent rates inside the treatment room vary between 100 and 800 μSv/h for neutrons and between 10 and 130 μSv/h for gamma rays. The maximum values were found to be 2.5 mSv/h and 0.3 mSv/h respectively. The ambient dose equivalent rates outside the therapy room were not higher than 2.5 μSv/h for neutrons and 0.35 μSv/h for gamma rays. The end of the beam line, the optical line and the beam scattering system are main sources of the secondary radiation. Optimisation and shielding of these elements will reduce the patient and facility personnel exposure to the secondary radiation.

RADIOTHERAPY PROTON BEAM PROFILOMETRY WITH scCVD DIAMOND DETECTOR IN SINGLE PARTICLE MODE

Proton radiotherapy requires precise knowledge of the volumetric dose distribution. In proton beam delivery systems, based on narrow pencil beams, a contribution from small doses in low-intensity regions, consisting mainly of scattered protons, may have not negligible influence on total dose delivered to patient. Insufficient information about dose profile can cause underestimation of dose and potential delivery of inflated dose during hadrontherapy treatment. Presented work aims to verify applicability of diamond detectors, produced by Chemical Vapor Deposition method, for therapeutic proton beam profilometry at large fields. This requires the capability of measuring the core of the beam intensity profile (wide dynamic range) as well as its lateral spread (very high sensitivity) with a single device.

IMAGING OF PROTON BRAGG PEAKS IN LiF

Lithium fluoride (LiF) is one of the most common thermoluminescent phosphors routinely used in radiation protection services. Another advantageous property of LiF is radiophotoluminescence, whose occurs after its irradiation due to the creation of color centers. Excitation of LiF samples with a blue light causes the emission of photoluminescence, which spectrum consists of two peaks at ~520 and ~670 nm. The work was focused on imaging of Bragg peaks of proton beams routinely applied at the proton eye radiotherapy facility operating at the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN) in Krakow by the measurement of the fluorescence light in LiF crystals excited with a 445 nm blue light after their previous irradiation with the proton beams of energies of 28, 30, 40 and 50 MeV. The range of proton beams in LiF crystals for different energies was calculated by Monte Carlo simulations.

OSL dosimetric properties and efficiency of Brazilian natural calcium fluoride pellets

Calcium fluoride (CaF2), in both natural and synthetic forms, has been exhaustively studied and explored as thermoluminescent (TL) detector. However its sensitivity to ambient light points to the applicability of CaF2 as OSL (Optically Stimulated Luminescence) detector, increasing the research about its luminescent properties. Although some properties to employ CaF2 detectors with OSL technique have been already demonstrated, there is a lack of some essential information as the OSL response to different types and energy of ionizing radiation. In order to extend the use of Brazilian natural CaF2 with OSL technique, we evaluated the efficiency and dosimetric properties of cold pressed CaF2:NaCl pellets. The CaF2 detectors presented good reproducibility and negligible fading of the signal over one month after irradiation. The dose response using OSL, TL and residual TL showed linear behavior for different radiation beams (protons, photons and alpha and beta particles), being equivalent to the results obtained with BeO and MTS (LiF) detectors through OSL and TL technique respectively. Moreover, differences were observed in OSL efficiency according the beam type and energy; CaF2 detectors presented a higher OSL and TL sensitivities to protons, photons and beta particles than to alpha particles. The energy response to photons obtained using OSL and residual TL intensities present an over response at lower photon energy similar to TL energy response. In addition, differences in the OSL curve shapes were observed according to radiation type and energy, pointing to the possibility of applying this material in mixed radiation fields and to estimate average LET (Linear Energy Transfer).

A Concept of Agent Language in Agentspace

Agentspace is an emerging environment resulting from process automation in the Internet and Web. It is supposed that autonomous software (mobile) agents provide the automation. The agents realize the goals delegated to them by their human masters. Interoperability is crucial to assure meaningful interaction, communication and cooperation between heterogeneous agents and services. In order to realize the goals, the agents must create, manage and reconfigure complex workflows. The presentation is focused on language layer of agentspace architecture.