FQMaP: Towards a Framework Quantitative Management of Processes in Small Software Development Organizations

Software development organizations need to control and improve their practices, seeking to reduce variability when executing the necessary processes to elaborate software; therefore, these organizations implement improvement plans to identify factors that affect the processes. Quantitative Management deals with identification, tracing, and control of those incident factors, using data proactively to predict performance and the effect of possible changes in a process. Reference models in software processes development such as CMMI V2.0 and ISO/IEC 33061:2021 address Quantitative Management, but are aimed at big enterprises. Other models such as MoProSoft, COMPETISOFT, and MPS.BR are aimed at small enterprises, but do not include enough elements on Quantitative Management. Execution of a systematic literature review permitted searching for works on Quantitative Management intended for small software development enterprises, indicating necessary practices and how to perform them. This search showed that a proposal is not available that incorporates Quantitative Management practices for software processes aimed small software development enterprises. The referred aspects make it difficult to adopt a Quantitative Management culture within these organizations, it which has become a problem, consisting in that small software development enterprises that do not execute quantitative management practices will have difficulty identifying and focusing on the factors that impact the process performance and, therefore, on the results of their projects. This work sought to tackle this problem by proposing the “framework for quantitative management of processes in small software development organizations” (FQMaP), which allows incorporating practices and techniques that support Quantitative Management of software development processes in these kinds of enterprises. From the evaluation of FQMaP, carried out by following Focus Group technique guidelines, it can be demonstrated that it is a simple proposal and with elements that can serve a company to quantitatively manage software development processes. Also, it has clearly specified its components, showing that its structure is familiar with other process patterns, that would facilitate their interpretation

Does Sb2Se3 admit nonstoichiometric conditions? How modifying the overall se content affects the structural, optical, and optoelectronic properties of Sb2Se3 thin films

Sb2Se3 is a quasi-one-dimensional (1D) semiconductor, which has shown great promise in photovoltaics. However, its performance is currently limited by a high Voc deficit. Therefore, it is necessary to explore new strategies to minimize the formation of intrinsic defects and thus unlock the absorber’s whole potential. It has been reported that tuning the Se/Sb relative content could enable a selective control of the defects. Furthermore, recent experimental evidence has shown that moderate Se excess enhances the photovoltaic performance; however, it is not yet clear whether this excess has been incorporated into the structure. In this work, a series of Sb2Se3 thin films have been prepared imposing different nominal compositions (from Sb-rich to Se-rich) and then have been thoroughly characterized using compositional, structural, and optical analysis techniques. Hence, it is shown that Sb2Se3 does not allow an extended range of nonstoichiometric conditions. Instead, any Sb or Se excesses are compensated in the form of secondary phases. Also, a correlation has been found between operating under Se-rich conditions and an improvement in the crystalline orientation, which is likely related to the formation of a MoSe2 phase in the back interface. Finally, this study shows new utilities of Raman, X-ray diffraction, and photothermal deflection spectroscopy combination techniques to examine the structural properties of Sb2Se3, especially how well-oriented the material is.Postprint (published version

Cu₂SiSe₃ as a promising solar absorber: harnessing cation dissimilarity to avoid killer antisites

Copper-chalcogenides are promising candidates for thin film photovoltaics due to their ideal electronic structure and potential for defect tolerance. To this end, we have theoretically investigated the optoelectronic properties of Cu₂SiSe₃, due to its simple ternary composition, and the favourable difference in charge and size between the cation species, limiting antisite defects and cation disorder. We find it to have an ideal, direct bandgap of 1.52 eV and a maximum efficiency of 30% for a 1.5 μm-thick film at the radiative limit. Using hybrid density functional theory, the formation energies of all intrinsic defects are calculated, revealing the p-type copper vacancy as the dominant defect species, which forms a perturbed host state. Overall, defect concentrations are predicted to be low and have limited impact on non-radiative recombination, as a consequence of the p–d coupling and antibonding character at the valence band maxima. Therefore, we propose that Cu₂SiSe₃ should be investigated further as a potential defect-tolerant photovoltaic absorber

Analiza občutljivosti HDM-4 modelov propadanja vozišč

Občutljivost HDM-4 modelov propadanja vozišč je sicer že prikazana v dokumentaciji HDM-4 paketa, a zgolj na kvalitativnem nivoju. Namen te naloge pa je, da kvantitativno ocenimo elastičnost modelov na spremembe nekaterih ključnih parametrov. V tej nalogi sem analiziral občutljivost parametrov, ki so bili v dokumentaciji HDM-4 modela razvrščeni v I. razred. Kot je opisal Mrawire et al (1998), obstajajo različni pristopi, ki se lahko uporabljajo za izvedbo analize občutljivosti. V nalogi sem uporabil tradicionalni pristop “Ceteris paribus”, kjer opazujemo spremembe izhodnih rezultatov v primeru spremembe enega od vhodnih podatkov, pri čemer pa ostali ostanejo nespremenjeni. Iz rezultatov izračunamo elastičnost kot razmerje med procentom spremembe rezultatov in procentom spremembe vhodnega podatka. Ta študija je bila izvedena z uporabo projektne analize v paketu HDM-4. Parametri, ki so bili izbrani za analizo občutljivosti so naslednji: Prilagojeno Strukturno število (SNP) Neravnost vozišča Vse strukturne razpoke Vsak parameter smo preučevali ločeno na primerih realnih cestnih odsekov ceste Kabul – Kandahar v Afganistanu.The sensitivity of road deterioration and maintenance prediction to variation of individual input parameters, are classified according to their impact elasticity in “Highway Development and Maintenance Management Model” HDM-4 version 2 Volume, which was developed by World Bank. As classification presented in the documentation is more or less qualitative the aim of this thesis is to quantify elasticity of some of the most important parameters. In this research sensitivity analyzed of the deterioration parameters which have been already classified in HDM-4 Volume 5 Sensitivity Class I, is provided. As described by Mrawire et al. (1998), there are different approaches which can be used for undertaking sensitivity analysis. The way we are following here is the Traditional Ceteris Paribus (TCP) method in which by changing single input parameters and holding other parameters to be unchanged, the impact elasticity will be calculated. Impact elasticity is the ratio of the percentage change of specific result by the percentage change to individual input parameters of the pavement deterioration models. (HDM-4 V5) This study is executed by the using of the project analysis of the HDM-4 application using TCP method, and then the results are used to find the impact elasticity which is used for sensitivity ranking. The parameters which are chosen from the sensitivity class-I for the deterioration sensitivity analysis are as follows: Adjusted Structural Number (SNP) Pavement Roughness All Structural Cracking Each parameter was studied separately in a real road section which was chosen form the Afghanistan Rind road, Kabul – Kandahar region

Electronic properties of solution-processed Cu(In,Ga)(S,Se)2 solar cells using metal chalcogenides and amine-thiol solvent mixtures

This work examines the effects of post-deposition air-annealing on the electronic properties of solution-processed heterojunction CIGS solar cells. The annealing in air of the CIGS/CdS interface was found to have positive effects on the device performance with an increase in all PV parameters even after annealing times as short as 5 min. A VOC increase of <; 130 mV was caused by the reduced surface and grain boundary recombination through passivation of surface Se deficiencies with oxygen atoms. Prolonged annealing causes charge redistribution and diffusion of mobile elements such as Cu and Cd deeper into the absorber bulk however, resulting in lower carrier density and deeper defects with increased annealing time. These were observed through capacitance-voltage profiling and admittance spectroscopy

Boosting the sodium storage performance of iron selenides by a synergetic effect of vacancy engineering and spatial confinement

Recently, iron selenides have been considered as one of the most promising candidates for the anodes of sodium-ion batteries (SIBs) due to their cost-effectiveness and high theoretical capacity; however, their practical application is limited by poor conductivity, large volume variation and slow reaction kinetics during electrochemical reactions. In this work, spatially dual-carbon-confined Vₛₑ-Fe₃Se₄₋ₓSₓ/FeSe₂₋ₓSₓ nanohybrids with abundant Se vacancies (Vₛₑ-Fe₃Se₄₋ₓSₓ/FeSe₂₋ₓSₓ@NSC@rGO) are constructed via anion doping and carbon confinement engineering. The three-dimensional crosslinked carbon network composed of the nitrogen-doped carbon support derived from polyacrylic acid (PAA) and reduced graphene enhances the electronic conductivity, provides abundant channels for ion/electron transfer, ensures the structure integrity, and alleviates the agglomeration, pulverization and volume change of active material during the chemical reactions. Moreover, the introduction of S into iron selenides induces a large number of Se vacancies and regulates the electron density around iron atoms, synergistically improving the conductivity of the material and reducing the Na+ diffusion barrier. Based on the aforementioned features, the as-synthesized Vₛₑ-Fe₃Se₄₋ₓSₓ/FeSe₂₋ₓSₓ@NSC@rGO electrode possesses excellent electrochemical properties, exhibiting the satisfactory specific capacity of 630.1 mA h g−¹ after 160 cycles at 0.5 A/g and the reversible capacity of 319.8 mA h g−¹ after 500 cycles at 3 A/g with the low-capacity attenuation of 0.016 % per cycle. This investigation provides a feasible approach to develop high-performanc

Perspectives of chalcopyrite-based CIGSe thin-film solar cell: a review

Solar photovoltaic (PV) is empowering, reliable, and ecofriendly technology for harvesting energy which can be assessed from the fact that PV panels with total electricity generation capacity of 505 GW have been installed by the end of 2018. Thin-film solar cells based on copper indium gallium selenide (CIGSe) are promising photovoltaic absorber material owing to an alternative to crystalline silicon (c-Si)-based solar cells because of the huge potential for low-cost solar electricity production with minimal usage of raw materials. The efficiency record of 23.4% was achieved recently in CIGSe solar cells, which was comparable to c-Si solar cells (27.6%). The manufacturing cost of $0.34/W is expected for 15% efficient CIGSe module. The present review article discusses the perspectives of CISe/CIGSe-based thin-film solar cells with the focus on absorber material. Different vacuum and non-vacuum techniques for fabricating these materials are discussed along with the operation of solar cells and their manufacturability. The working mechanism of CIGSe solar cells with the characteristic features of the open-circuit voltage and current density as well as the factors influencing the efficiency in different fabrication techniques are reviewed. Moreover, some strategies toward the improvement of solar cells performance contemplating modified deposition are reviewed. Furthermore, how these strategies can be executed in order to make it cost effective methods is also discussed in detail. Prevailing constrictions for the commercial maturity are deliberated, and future perspectives for improvement at lab as well as industrial scalabilities are outlined