Knowledge visualization for evaluation tasks

Although various methods for the evaluation of intelligent systems have been proposed in the past, almost no techniques are present that support the manual inspection of knowledge bases by the domain specialist. Manual knowledge base inspection is an important and frequently applied method in knowledge engineering. Since it can hardly be performed in an automated manner, it is a time-consuming and costly task. In this paper, we discuss a collection of appropriate visualization techniques that help developers to interactively browse and analyze the knowledge base in order to find deficiencies and semantic errors in their implementation. We describe standard visualization methods adapted to specifically support the analysis of the static knowledge base structure, but also of the usage of knowledge base objects such as questions or solutions. Additionally, we introduce a novel visualization technique that supports the validation of the derivation and interview behavior of a knowledge system in a semi-automatic manner. The application of the presented methods was motivated by the daily practice of knowledge base development.     

Synthese von 2,4-Bisalky(aryl)amino-6-cyanamino-1,3,5-triazinen

Synthesis of 2,4-Bisalkyl(aryl)amino-6-cyanamino-s-triazines Reaction of 2,4-bisalkyl(aryl)amino-6-chloro-s-triazines with disodiumcyanamide to 2,4-bisalkyl(aryl)amino-6-cyanamino-s-triazines ( 3a – g ) strongly depends on the solvent used. In dimethylformamide by-products predominate. The best results are found in dimethylsulphoxide.     

Protonierung und Solvatation schwacher organischer Basen. I. Zur Basizität von ω-Chloracetophenonen

Protonation and Solvation of Weak Organic Bases. I. Basicity of ω-Chloroacetophenones The protonation equilibria of ω-chloroacetophenone and some p-substituted derivates have been studied in the acid system H₂O/H²SO⁴/SO₃ by u.v. and ¹H-n.m.r. spectroscopy. From the determined H₀ values for half-protonation _pK_BH+ values were calculated by means of the solvation parameters m of YATES and McCLELLAND . The (H₀)_1/2 and the _pK_BH+ values were successfully correlated with σ_p and σ_p⁺ substituent constants.     

Zur heterogenkatalytischen Oxydation und Ammoxydation von Isobuten. IV. Über die Beeinflussung der heterogenkatalytischen Oxydation von Isobuten zu Methacrolein durch n-Buten

On the Heterogeneous-Catalytic Oxidation and Ammoxidation of Isobutene. IV. Influence of n-Butene on the Heterogeneous-Catalytic Oxidation of Isobutene to Methacroleine The influence of n-butenes 2 on the oxidation of isobutenes 1 to methacroleine 3 has been investigated in presence of a catalyst containing Bi, Mo, P, Fe, Mg, Mn, Si and O. Addition of 2 to the gas mixture increase the selectivity and yield of 3 . This fact can be correlated by decrease of oxygen partial pressure in consequence of the dehydrogenation of 2 to butadiene 4 .     

Protonierung und Solvatation schwacher organischer Basen. IV. H-NMR-spektroskopische Bestimmung der Basizität aliphatischer Ketone

Protonation and Solvation of Weak Organic Bases. IV. ¹H-N.M.R. Spectroscopic Determination of the Basicity of Aliphatic Ketones From protonation ratios for a series of methyl and ethyl alkyl ketones 1—13 with gradually branched alkyl groups in the H₂O–H₂SO₄ system, determined by ¹H-n.m.r. spectroscopy, basicity and solvation parameters are systematically estimated by application of extrapolation procedures based on the Hammett acidity function H₀ or the excess acidity X.     

Extensible Prototyping for pragmatic engineering of knowledge-based systems

Knowledge-based systems (KBSs) have been built and practically applied in various contexts for decades. Yet, they still challenge developers by their complexity: Apart from a sound knowledge base they likewise require comprehensive user interface (UI) and interaction design for supporting the task at hand optimally. However, current KBS-Engineering methodologies still mostly focus on knowledge base development, regarding UI/interaction design a more incidental, low priority task. Thus, the UI often is developed in a rather ad hoc manner, thereby neglecting the potential of experimental design and creating reusable solutions. The integration of (rapid) evolutionary prototyping activities with KBS Engineering offers the chance for incorporating UI/interaction design more prominently into the process while at the same time leveraging the overall development task; specifically, we propose Extensible Prototyping as a tailored prototyping approach and we suggest its integration with the Agile Process Model for knowledge-based systems in this paper. For practical support, we further introduce the customized prototyping and knowledge systems engineering tool ProKEt, and we report on practical experiences with applying both the approach and the tool.     

Experimental and theoretical study on the effectiveness of vacuum in osmotic membrane distillation

The possibility of creating a vacuum in a membrane and maintaining the vacuum for many days during the osmotic membrane distillation (OMD) process has been experimentally shown. The limiting parameters of OMD with a vacuum have been evaluated as functions of external pressure, temperature, and temperature differential across the membrane. Equations and plots for calculation of the osmotic pressure and the temperature difference that stops the OMD process are presented.     

Picosecond spectrochronography

The general problem of extracting complete (amplitude and phase) information out of an optical signal is discussed. We have shown that the best one can do to determine all essential features of light pulses is to apply simultaneous temporal and spectral analysis to take spectrochronograms with the appropriate shape of the resolution cell on theomegat-plane. We use the term "spectrochronogram" instead of the much broader term "time-resolved spectrum" for a specific measurement result where the resolutionsDeltaomegaandDeltatused are transform correlated. A novel subtractive mount of monochromators has been proposed to overcome the obstacles to experimental realization of uncertainty-principle-limited setups for high spectral resolution picosecond spectrochronography. For the examples of perylene and anthracene molecules, experimental spectrochronograms revealing temporal behavior of hot luminescence lines and, correspondingly, picosecond kinetics of intramolecular vibrational relaxation have been presented. Some further applications of picosecond spectrochronography have been discussed.