Spectrum of Sizes for Perfect Deletion-Correcting Codes

One peculiarity with deletion-correcting codes is that perfect $t$-deletion-correcting codes of the same length over the same alphabet can have different numbers of codewords, because the balls of radius $t$ with respect to the Levenshte\u{\i}n distance may be of different sizes. There is interest, therefore, in determining all possible sizes of a perfect $t$-deletion-correcting code, given the length $n$ and the alphabet size~$q$. In this paper, we determine completely the spectrum of possible sizes for perfect $q$-ary 1-deletion-correcting codes of length three for all $q$, and perfect $q$-ary 2-deletion-correcting codes of length four for almost all $q$, leaving only a small finite number of cases in doubt.Comment: 23 page

Verification of Logs - Revealing Faulty Processes of a Medical Laboratory

Abstract. If there is a suspicion of Lyme disease, a blood sample of a patient is sent to a medical laboratory. The laboratory performs a number of dierent blood examinations testing for antibodies against the Lyme disease bacteria. The total number of dierent examinations depends on the intermediate results of the blood count. The costs of each examination is paid by the health insurance company of the patient. To control and restrict the number of performed examinations the health insurance companies provide a charges regulation document. If a health insurance company disagrees with the charges of a laboratory it is the job of the public prosecution service to validate the charges according to the regulation document. In this paper we present a case study showing a systematic approach to reveal faulty processes of a medical laboratory. First, files produced by the information system of the respective laboratory are analysed and consolidated in a database. An excerpt from this database is translated into an event log describing a sequential language of events performed by the information system. With the help of the regulation document this language can be split in two sets- the set of valid and the set of faulty words. In a next step, we build a coloured Petri net model corre-sponding to the set of valid words in a sense that only the valid words are executable in the Petri net model. In a last step we translated the coloured Petri net into a PL/SQL-program. This program can automat-ically reveal all faulty processes stored in the database.

Heat Transfer Through Plasma-Sprayed Thermal Barrier Coatings in Gas Turbines: A Review of Recent Work

A review is presented of how heat transfer takes place in plasma-sprayed (zirconia-based) thermal barrier coatings (TBCs) during operation of gas turbines. These characteristics of TBCs are naturally of central importance to their function. Current state-of-the-art TBCs have relatively high levels of porosity (~15%) and the pore architecture (i.e., its morphology, connectivity, and scale) has a strong influence on the heat flow. Contributions from convective, conductive, and radiative heat transfer are considered, under a range of operating conditions, and the characteristics are illustrated with experimental data and modeling predictions. In fact, convective heat flow within TBCs usually makes a negligible contribution to the overall heat transfer through the coating, although what might be described as convection can be important if there are gross through-thickness defects such as segmentation cracks. Radiative heat transfer, on the other hand, can be significant within TBCs, depending on temperature and radiation scattering lengths, which in turn are sensitive to the grain structure and the pore architecture. Under most conditions of current interest, conductive heat transfer is largely predominant. However, it is not only conduction through solid ceramic that is important. Depending on the pore architecture, conduction through gas in the pores can play a significant role, particularly at the high gas pressures typically acting in gas turbines (although rarely applied in laboratory measurements of conductivity). The durability of the pore structure under service conditions is also of importance, and this review covers some recent work on how the pore architecture, and hence the conductivity, is affected by sintering phenomena. Some information is presented concerning the areas in which research and development work needs to be focussed if improvements in coating performance are to be achieved

Dermal PK/PD of a lipophilic topical drug in psoriatic patients by continuous intradermal membrane-free sampling

Background: Methodologies for continuous sampling of lipophilic drugs and high-molecular solutes in the dermis are currently lacking. We investigated the feasibility of sampling a lipophilic topical drug and the locally released biomarker in the dermis of non-lesional and lesional skin of psoriatic patients over 25hrs by means of membrane-free dermal Open-Flow Microperfusion probes (dOFM) and novel wearable multi-channel pumps. Methods: Nine psoriatic patients received a topical p-38 inhibitor (BCT194, 0.5% cream) on a lesional and a non-lesional application site once daily for 8 days. Multiple dOFM sampling was performed for 25 hours from each site on day 1 and day 8. Patients were mobile as dOFM probes were operated by a novel light-weight Push-Pull pump. Ultrasound was used to verify intradermal probe placement, cap-LC-MS/MS for BCT194 and ELISA for TNFα analysis. Results: dOFM was well tolerated and demonstrated significant drug concentrations in lesional as well as non-lesional skin after eight days but did not show significant differences between tissues. On day 8 TNFα release following probe insertion was significantly reduced compared to day 1. Conclusions: Novel membrane-free probes and wearable multi-channel pumps allowed prolonged intradermal PK/PD profiling of a lipophilic topical drug in psoriatic patients. This initial study shows that dOFM overcomes limitations of microdialysis sampling methodology and it demonstrates the potential for PK/PD studies of topical products and formulations in a clinical setting

Using Colored Petri Nets to Construct Coalescent Hidden Markov Models: Automatic Translation from Demographic Specifications to Efficient Inference Methods

Abstract. Biotechnological improvements over the last decade has made it economically and technologically feasible to collect large DNA sequence data from many closely related species. This enables us to study the detailed evolutionary history of recent speciation and demographics. Sophisticated statistical methods are needed, however, to extract the information that DNA sequences hold, and a limiting factor in this is dealing with the large state space that the ancestry of large DNA sequences spans. Recently a new analysis method, CoalHMMs, has been developed, that makes it computationally feasible to scan full genome sequences – the complete genetic information of a species – and extract genetic histories from this. Applying this methodology, however, requires that the full state space of ancestral histories can be constructed. This is not feasible to do manually, but by applying formal methods such as Petri nets it is possible to build sophisticated evolutionary histories and automatically derive the analysis models needed. In this paper we describe how to use colored stochastic Petri nets to build CoalHMMs for complex demographic scenarios.