Reliability of feedback fechanism based on root cause defect analysis - case study

The case study presented in this article focuses on the common pitfall in which many defect prevention activities fall, caused by inconsistency of data. Before any collected Root Cause Defect Analysis (RCA) data can be used reliably, an analysis of the variation due to the measurement system itself such as a Gauge R&R study, should be performed. This allows to understand of the integrity of the data in terms of data consistency and validity. The RCA data collection process chosen for this case study concentrates on the RCA assessment performed by engineers independently

On Unbounded Composition Operators in L2L^2-Spaces

Fundamental properties of unbounded composition operators in $L^2$-spaces are studied. Characterizations of normal and quasinormal composition operators are provided. Formally normal composition operators are shown to be normal. Composition operators generating Stieltjes moment sequences are completely characterized. The unbounded counterparts of the celebrated Lambert's characterizations of subnormality of bounded composition operators are shown to be false. Various illustrative examples are supplied

Spectroscopic and kinetic evidence for redox cycling, catalase and degradation activities of MnIII(TPPS) in a basic aqueous peroxide medium

MnIII(TPPS) was found to react rapidly with hydrogen peroxide in basic aqueous solution to form intermediate (TPPS)MnV[double bond, length as m-dash]O and (TPPS)MnIV[double bond, length as m-dash]O species which, in the presence of excess H2O2, are reduced fully back to MnIII(TPPS) with clear evidence for redox cycling of MnIII(TPPS). The system shows very strong catalase and degradation activities

Tritolylporphyrin dimer as a new potent hydrophobic sensitizer for photodynamic therapy of melanoma

We report the synthesis, photochemical and photophysical properties and preliminary studies on biological effect of a new tritolylporphyrin dimer (T-D). Absorption and emission properties of T-D suggest its possible use in photodynamic therapy. T-D is capable of singlet oxygen production with 0.8 quantum yield. It also has a high photostability. The photodynamic properties of the dimer were examined following the growth of SKMEL 188 (human melanoma) cells irradiated with red light (cut off vs. non-irradiated cells) for an 81 J/cm2 dose. Our results suggest that tritolylporphyrine dimer T-D may be an interesting hydrophobic sensitizer for photodynamic therapy

A moment problem for pseudo-positive definite functionals

A moment problem is presented for a class of signed measures which are termed pseudo-positive. Our main result says that for every pseudo-positive definite functional (subject to some reasonable restrictions) there exists a representing pseudo-positive measure. The second main result is a characterization of determinacy in the class of equivalent pseudo-positive representation measures. Finally the corresponding truncated moment problem is discussed.Comment: 23

Photoredox Reactions of Hg(CN)₂/[Fe(CN)₆]⁴⁻ and [HgCo₂(CN)₁o]⁶⁻ induced by Inner-Sphere Metal to Metal Charge Transfer Excitation

In complexes of the type [(NC)2HgIINCFeII(CN)5]4- which are formed in aqueous mixtures of Hg(CN)2 and [Fe(CN)6]4- both metals are weakly coupled. Optical metal to metal charge transfer (MMCT) excitation from FeII to HgII leads to the reduction of HgII to Hg0 and the oxidation of [Fe(CN)6]4- to [Fe(CN)6]3-. In the complex [(NC)5CoI-HgII-CoI(CN)5]6- the metals are strongly coupled by direct but polar metal metal bonds. MMCT (CoI -> HgII) excitation induces the photoredox reaction: [HgCo2(CN)10]6- -> Hg0 + 2[Co(CN)5]3-

Technical Debt Prioritization in Telecommunication Applications: Why the Actual Refactoring Deviates from the Plan and How to Remediate It? Case Study in the COVID Era

This paper focuses on application of a technical debt prioritisation technique in telecommunication software managing a fleet of devices for a video surveillance system. Technical debt for this application was gathered, categorised and prioritised according to the Continuous Debt Valuation Approach (CoDVA), previously proposed by the authors. The following research question was posed: Is prioritising technical debt reduction based on CoDVA effective (i.e., executed as per plan, bringing tangible benefits)? The outbreak of COVID-19 pandemic caused unprecedented disturbance to the engineering organisations worldwide, therefore the technical debt identification phase had to be adapted to cope with a switch to forced working-from-home mode. This was achieved by applying the Wisdom of Crowds method, ensuring broad participation of engineers, and providing a fairly complete picture of the accrued technical debt. Nevertheless, the actual technical debt reduction activities did not follow exactly the expected guidelines. The three main causes of this phenomenon were discovered: continuous refactoring approach, sizing of technical debt items, and the broadened scope of refactoring activities. Therefore, as a result of this case study we propose to adopt a specific broadened definition of technical debt and follow a few rules for defining its scope and granularity

Technical Debt Prioritization in Telecommunication Applications: Why the Actual Refactoring Deviates from the Plan and How to Remediate It? Case Study in the COVID Era

This paper focuses on application of a technical debt prioritisation technique in telecommunication software managing a fleet of devices for a video surveillance system. Technical debt for this application was gathered, categorised and prioritised according to the Continuous Debt Valuation Approach (CoDVA), previously proposed by the authors. The following research question was posed: Is prioritising technical debt reduction based on CoDVA effective (i.e., executed as per plan, bringing tangible benefits)? The outbreak of COVID-19 pandemic caused unprecedented disturbance to the engineering organisations worldwide, therefore the technical debt identification phase had to be adapted to cope with a switch to forced working-from-home mode. This was achieved by applying the Wisdom of Crowds method, ensuring broad participation of engineers, and providing a fairly complete picture of the accrued technical debt. Nevertheless, the actual technical debt reduction activities did not follow exactly the expected guidelines. The three main causes of this phenomenon were discovered: continuous refactoring approach, sizing of technical debt items, and the broadened scope of refactoring activities. Therefore, as a result of this case study we propose to adopt a specific broadened definition of technical debt and follow a few rules for defining its scope and granularity