641 research outputs found
Stabilizing machine learning models with Age-Period-Cohort inputs for scoring and stress testing
Machine learning models have been used extensively for credit scoring, but the architectures employed suffer from a significant loss in accuracy out-of-sample and out-of-time. Further, the most common architectures do not effectively integrate economic scenarios to enable stress testing, cash flow, or yield estimation. The present research demonstrates that providing lifecycle and environment functions from Age-Period-Cohort analysis can significantly improve out-of-sample and out-of-time performance as well as enabling the model's use in both scoring and stress testing applications. This method is demonstrated for behavior scoring where account delinquency is one of the provided inputs, because behavior scoring has historically presented the most difficulties for combining credit scoring and stress testing. Our method works well in both origination and behavior scoring. The results are also compared to multihorizon survival models, which share the same architectural design with Age-Period-Cohort inputs and coefficients that vary with forecast horizon, but using a logistic regression estimation of the model. The analysis was performed on 30-year prime conforming US mortgage data. Nonlinear problems involving large amounts of alternate data are best at highlighting the advantages of machine learning. Data from Fannie Mae and Freddie Mac is not such a test case, but it serves the purpose of comparing these methods with and without Age-Period-Cohort inputs. In order to make a fair comparison, all models are given a panel structure where each account is observed monthly to determine default or non-default
SUBJECTIVE WELL-BEING OF THE STAFF OF ENTERPRISES WITH DIFFERENT INVOLVEMENT IN INNOVATIVE PROCESSES: AGE ASPECT
The results of empirical investigations of subjective well-being of multi-age engineering staff at successful innovative enterprise and the enterprise with long-term problems of transition to innovative development format have been presented. Subjective well-being has been сonsidered as emotional regulator of labor activity and staff acceptance of innovations factor. Readiness for innovative changes, self-esteem of fatigue, health status, stress and age state of health has been studied as indicators of well-being. It has been shown that at ordinary enterprise the most unpleasant indicators of subjective well-being are typical for young staff, but at the innovative enterprise the staff regardless of age have a high level of subjective well-being which is manifested in a commitment to innovative values and personal involvement in the labor process
Orientation, substructure, and optical properties of rutile films
The orientation, optical properties, and substructure of rutile films prepared by thermal and pulsed photon assisted oxidation of single crystal Ti films were investigated by transmission electron micros copy, optical spectroscopy, and high energy electron diffractionyesBelgorod State Universit
Charged Particles Evaporation in the Stopped Pion Absorption Reactions
In the present work we have analyzed evaporation spectra and yields of p,d,t formed in the reaction of stopped pion absorption. It is shown that the values of equilibrium temperature obtained through the usage of proposed model are in agreement with the values obtained in various other experiments. We also discuss the A-dependences of the evaporation yields and consider possible contributions of the “indirect” evaporation processes
APATITE SHELLS OF THE DEVONIAN FORAMINIFERS (SAFYANOVSKY COPPER-SULPHIDE DEPOSIT, MIDDLE URAL)
Relevance of the work is due to the possibility of a detailed study of Devonian foraminifers with apatite shells and the reconstruction of specific conditions for their formation. Foraminifer shells are morphologically similar to Parathurammina aff. tamarae L. Petrova, 1981, the Eifelian-the Givetian, which were found in thin sections of samples of carboniferous and chiselly aleuropelites of the ore-bearing strata of the Safyanovsky copper-sulphide deposit (Middle Urals) for the first time.
Purpose of work. Detailed study of the shells of Devonian foraminifers similar to Parathurammina aff. tamarae L. Petrova, 1981, as well as reconstruction of sedimentation conditions for carboniferous and chiselly rocks of the ore-bearing strata of the Safyanovsky copper-sulphide deposit.
Research methodology. Shells were studied in thin sections of carboniferous and chiselly aleuropelite samples. The detailed study of morphology and composition of the shells was carried out using a scanning electron microscope JSM-6390LV (JEOL) with an energy-dispersive spectrometer Inca Energy 450, an electron microscope Tescan and an electron probe microanalyzer Cameca SX100.
Results. Size and morphology of the shells were determined; it was also found that the walls of the shells of the studied foraminifers were represented by fluorapatite. It was assumed that initially they were calcareous, and subsequently were replaced by apatite and quartz. However, more detailed studies did not reveal traces of substitution of carbonate rock for apatite.
Conclusions. Compared with Parathurammina aff. tamarae L. Petrova, 1981, shells have a reduced size and a smaller number of fauces, which can be explained by unfavorable habitats in a shallow sea basin, where carbonate sedimentation was suppressed by a significant influx of volcanic material. The presence of sulfide minerals in nucleus of shells may indicate to the specific habitat (pH of the environment, salinity of supra-bottom water) of foraminifers. Findings of fossils of green, siphon algae together with studied foraminifers indicate that formation of the original substrate took place in near-surface layers (up to 200 m) of the photic zone of seas
Automated search for star clusters in large multiband surveys: II. Discovery and investigation of open clusters in the Galactic plane
Automated search for star clusters in J,H,K_s data from 2MASS catalog has
been performed using the method developed by Koposov et. al (2008). We have
found and verified 153 new clusters in the interval of the galactic latitude
-24 < b < 24 degrees. Color excesses E(B-V), distance moduli and ages were
determined for 130 new and 14 yet-unstudied known clusters. In this paper, we
publish a catalog of coordinates, diameters, and main parameters of all the
clusters under study. A special web-site available at http://ocl.sai.msu.ru has
been developed to facilitate dissemination and scientific usage of the results.Comment: 9 pages, 3 tables, 5 figures, accepted to Astronomy Letter
Crecimiento empresarial post-recesión:impacto en ROE a corto y largo plazo
A principios del presente siglo, la economía mundial experimentó varios eventos de crisis que afectaron negativamente el desempeño empresarial. Muchas empresas han atravesado largos períodos de reducción de las ventas. Este artículo continúa la serie de trabajos científicos sobre el estudio del reinicio del crecimiento, es decir, el crecimiento de las empresas después de un largo período de estancamiento o caída de las ventas, y contribuye con la literatura mediante el análisis del impacto de diferentes tipos de reactivación del crecimiento en el desempeño de las empresas (rendimiento sobre el capital de la empresa-ROE). Los datos de panel incluyen 7528 observaciones (1882 empresas * 4 años). Para el análisis de datos se utilizan modelos de regresión con efectos fijos. El estudio reveló un impacto positivo del crecimiento a largo plazo sobre el ROE, pero no confirmó el impacto del crecimiento a corto plazo sobre el ROE. Los máximos beneficios los obtienen las empresas jóvenes con un rápido crecimiento de las ventas a largo plazo. Los estudios empíricos arrojan resultados variables sobre el impacto del crecimiento en la rentabilidad de las empresas. Nuestro enfoque muestra que el crecimiento sostenible a largo plazo permite a las empresas lograr una mayor rentabilidad. Estos resultados serán de interés para los inversores que deberían centrarse en encontrar empresas que puedan demostrar un crecimiento anual de las ventas durante varios años. También se recomienda que los propietarios y gerentes se esfuercen por lograr un crecimiento anual a largo plazo en las ventas de la empresa
Features of epigenetic dolomite transformations in the Syukeyevskoye bitumen field
Syukeyevskoye bitumen field is one of perspective for development of open pit mining in western part of the Republic of Tatarstan. Basically two predominant stages in the process of epigenetic rock transformations were discriminated on the basis of field and laboratory data. The first stage associates with the fluids penetration in biomicritic dolomites and the hydrocarbon accumulation. The second stage associates with hydrocarbon oxidation. One can resume that leaching processes dominate at the stage of hydrocarbons penetration within dolomite rocks, and metasomatic processes dominate at hydrocarbon oxidation stage. These features can be used as key for understanding rock formation history in other similar cases
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