Information Technology and Sustained Competitive Advantage: A Resource-Based Analysis

This is the published version. Copyright 1995 MIS Quarterly.The concept of IT as a powerful competitive weapon has been strongly emphasized in the literature, yet the sustainability of the competitive advantage provided by IT applications is not well-explained. This work discusses the resource-based theory as a means of analyzing sustainability and develops a model founded on this resource-based view of the firm. This model is then applied to four attributes of IT -- capital requirements, proprietary technology, technical IT skills, and managerial IT skills -- which might be sources of sustained competitive advantage. From this resource-based analysis, we conclude that managerial IT skills is the only one of these attributes that can provide sustainability

Parental support, student motivational orientation and achievement : the impact of emotions

This paper investigates the potential effects of parental involvement at home on student motivational orientation in school work and achievement and how such effects may be mediated by the perceived emotional quality of parent-student interactions (positive and negative). The participants in the study included 631 students in the 2nd and 3rd cycle of compulsory education (5th to 9th grade) from 6 schools in the Lisbon area in Portugal. Students‟ age ranged from 10 to 16 years (M=12.8; SD=1.64) with 53% being female. Hierarchical analysis using structural equation modeling was carried out, taking into consideration three sets of variables (background, perceived parental involvement and emotions) to predict schoolwork self-regulation and academic achievement. Results emphasized the role of emotions, highlighting the importance of affective components in parent-child interactions in order to understand the students‟ motivational orientation and academic achievement.peer-reviewe

Positional trueness of three removable die designs with different root geometries manufactured using stereolithographic 3D printing.

STATEMENT OF PROBLEM Three-dimensional (3D) printed casts are a suitable alternative to dental stone casts. Contemporary dental design computer programs permit designing definitive casts with removable dies with different root geometries and retention mechanisms. Studies on the positional trueness of 3D-printed removable dies with different root geometries are lacking. PURPOSE The purpose of this in vitro study was to investigate the 3D displacements of three 3D-printed removable die designs with different root geometries. MATERIAL AND METHODS The digital file of a dental stone alveolar cast with root-form removable dies (MOD UJ IV Fixed Prosthetics; Ivoclar AG) was used as a reference to create 3 removable die and alveolar cast designs (Root Form, RF; Conical, CON; Cylindric, CYL) with different root geometries in 2 dental design computer programs (DentalCAD 3.1 Rijeka; exocad; GmbH; InLab CAD 22.0; Dentsply Sirona). 3 equidistant Ø1-mm spheres (C, Cervical; M, Middle; O, Occlusal) were designed on the buccal surface of the coronal portion of the removable die to evaluate their displacement. A total of 45 alveolar casts with 45 removable dies were fabricated using a stereolithographic 3D printer (Form 3; Formlabs); each die group consisted of 15 specimens. After fabrication and postprocessing, the specimens were scanned, and their digital files were analyzed in a metrology-grade computer program to evaluate the displacement of the removable dies with respect to the position of the die in the master reference file. Subsequently, the data were analyzed using a 3-way analysis of variance (ANOVA) followed by step-down Bonferroni-corrected pairwise comparisons (α=.05). RESULTS Two statistically significant 2-way interactions were detected between the independent variables, die design and direction (P<.001), and location and direction (P<.001). The post hoc analysis identified significant differences between the displacement values of RF and CYL (P<.001) and RF and the CON (P<.001) designs on the Y axis. The measured displacements were statistically different between the C and O locations on the Y axis (P=.001) and the M and O locations on the Z axis (P=.006). CONCLUSIONS The root geometry of a 3D-printed removable die and alveolar cast can affect seating, and variable degrees of tipping of the removable die can be seen. The seating and congruence of the removable die with the interocclusal space and relationships observed intraorally should be confirmed before adjusting indirect restorations

Los estilos de aprendizaje y su aplicación en la formación para el emprendimiento

El trabajo cuestiona la detección de estilos de aprendizaje, el sistema de ámbitos y escenarios educativos cerrados y las competencias del saber reproductivo sólo basado en contenidos. Propone contrastar cuestionarios sobre estilos, con el universitario como participante consciente. Presenta otro itinerario de aprendizaje basado en el modelo de Kolb, que comienza imaginando expectativas, actuando para reflexionar y teorizar, para practicar y acabar creando nuevos procesos de solución a los problemas: Imaginativo-Creativo (I-C). Fundamenta la utilidad práctica de interactuar abriendo los espacios educativos del estudiante a su realidad profesional, mediante el aprendizaje colaborativo; con redes y herramientas para organizar equipos de trabajo, que diseñen y ejecuten proyectos de emprendimiento social, como medio real de intervención, aprendizaje y servicio a la comunidad. Para dicho emprendimiento se ofrece un plan de intervención socioeducativa, diseñado desde el modelo CANVAS, modificado y completado para acciones de emprendimiento social y aprendizaje mediante el itinerario I-C.Tesis vinculada al Proyecto coordinado: "De los tiempos educativos a los tiempos sociales: la construcción cotidiana de la condición juvenil en una sociedad de redes. Problemáticas específicas y alternativas pedagógico-sociales" financiado por el Ministerio de Economía y Competitividad a través del Plan Nacional de I+D+i (2012-2015), Subprograma de Proyectos de Investigación Fundamental No Orientada, con la aportación de los Fondos Europeos FEDER (EDU 2012-39080-C07-00 a 07). Subproyecto: De los tiempos educativos a los tiempos sociales: Impacto de la educación en la red de emprendimiento en los jóvenes. Competencias e innovaciones curriculares (Referencia EDU 2012-39080-C07-06)

Synthesis and reactivity of new silyl-substituted monocyclopentadienyl molybdenum and tungsten complexes

The functionalized silylated cyclopentadienyl molybdenum and tungsten complexes [MCpCl(CO)3H] (M=Mo, W; CpCl=η5-C5H4SiMe2Cl) are prepared easily from the reaction of [M(CO)3(NCMe)3] with C5H5SiMe2Cl in refluxing THF, via C–H activation and H transfer to the metal centre. Metathetical replacement of hydride by chloride is readily achieved when their methylene chloride solutions are treated with a few milliliters of CCl4 to give the chloro complexes [MCpCl(CO)3Cl] (M=Mo, W). The chloro–molybdenum complexes react with 1/2 equivalent of deoxygenated water to give the corresponding dinuclear complexes [{Mo(CO)3X}2(μ-CpOCp)], (X=H, Cl; CpOCp=η5-C5H4-SiMe2-O-SiMe2-η5-C5H4), whereas their reaction with one equivalent of anhydrous LiOH in toluene leads to selective substitution of the silicon-bonded chlorine atom to give the hydroxo complexes [MoCpOH(CO)3X] (X=H, Cl; CpOH=η5-C5H4SiMe2OH). These hydroxosilyl complexes can be transformed into the dinuclear compounds [{Mo(CO)3X}2(μ-CpOCp)] by heating (50°C, 2 h) or by their reaction with one equivalent of the respective hydrido and chloro derivatives [MoCpCl(CO)3X]. Total decarbonylation of the hydrido compounds results from oxidation with a stoichiometric amount of PCl5 to give the paramagnetic molybdenum(V) and tungsten(V) complexes [MCpClCl4] (M=Mo, W). Reactions of these complexes with one equivalent of NH2R in the presence of NEt3 yield the imido derivatives [MCpCl(NR)Cl2] (M=Mo, R=2,6-Me2-Ph; M=W, R=tBu) and subsequent oxidation of the tungsten complex with 1/2 equivalent of PCl5 gives [WCpCl(NtBu)Cl3]. Reduction of [MoCpClCl4] with two equivalents of Na/Hg gives the dinuclear molybdenum(III) complex [MoCpCl]2(μ-Cl)4. All of the reported compounds were characterized by elemental analysis and 1H- and 13C NMR-spectroscopy.The authors acknowledge DGICYT (project PB92-0178-C) for financial support

Modelos estadísticos para el análisis de la maquinabilidad de materiales compuestos de matriz poli (éter-éter-cetona)

En este artículo se recurre a métodos estadísticos para analizar la maquinabilidad de  mate-riales compuestos de matriz termoplástica.Se aplicará el análisis ANOVA para cuantificar la influencia de los parámetros funcionales de corte sobre la evolución de las fuerzas de corte y del acabado superficial.Se proponen modelos de predicción, basados en técnicas de regresión múltiple, que permi-tan anticipar el comportamiento de estos materiales ante unas condiciones de corte dadas. Finalmente, se presentan los resultados de los tests de confirmación para validar los modelos propuestos.In this paper statistic techniques are employed to analyze the machinability of thermoplastic composite materials. Analysis of variance (ANOVA) is used to quantify the influence of cutting parameters on cutting forces and surface finish.Predictive models, based on multiple analysis regression, are carried out to predict the be-haviour before cutting conditions. Finally, the results of confirmation test are presented, to validate the proposed models

Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain

Although recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than have been previously reported, their significance for paleomagnetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain). Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization, which we term a bio-depositional remanent magnetization. Some studied polarity reversals record paleomagnetic directions with an apparent 60-70 kyr recording delay. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes coincides broadly with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC), an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our results highlight the importance of magnetofossils as carriers of high-quality paleomagnetic and paleoenvironmental signals even in dominantly terrigenous sediments.This study was funded by the Guadaltyc project (MINECO, CGL2012–30875), ARC grant DP120103952, and NSFC grant 41374073

Restoring the buyer–seller relationship through online return shipping: The role of return shipping method and return shipping fee

Relationships with consumers are critical to the success of online sellers. Online returns can detrimentally influence buyer–seller relationships and, thus, online sellers should carefully approach online returns to restore their relationship with consumers. Returns due to consumer satisfaction-related reasons are a significant and inevitable part of e-commerce. This article focuses on how online sellers deal with the method and the fee aspects of their return shipping policy to improve buyer–seller relationships. We also studied the effects of return shipping policies on several pivotal consumer perceptions and repurchase intentions. A two-factor (integrated return shipping vs. separated return shipping; free return shipping vs. fee return shipping), between-subject experiment was conducted. This research revealed that both using an integrated return shipping method and offering free return shipping can lead to a better buyer–seller relationship and improve other consumer responses. No interaction effect was found between the two factors

Corona discharge characteristics of narrow coaxial wire- pipe discharge tubes with gas flow

An experimental investigation has been conducted to study corona discharge in a narrow tube. Narrow or capillary corona discharge (dis- charge tube diameter d = 1 to 20 mm) is used for many industrial applications such as flue gas cleaning corona induced plasma reactors, ion sources and electrohydrodynamic heat exchangers. In this work, corona discharge characteristics of narrow coaxial wire-pipe discharge tubes with gas flow are experimentally investigated. The results show that, unlike normal corona discharge, a hysteresis in the corona discharge current-voltage characteristics were observed for narrow tube discharges. The on-set of the corona discharge observed to be significantly depends on the gas temperature and gas flow rates 1.588 cm 0.d. copper tube was placed coaxially outside the system. Entrance and exit gas temperature of the wire-pipe corona discharge zone and outer-grounded pipe gas cooling zone were measured by T-type thermocouples. Time-averaged current was measured by the Keithly electrometer, and air flow rate in both flow channels was measured by a rotameter. The air flow flowing through the corona discharge zone was electrically heated at upstream of the system. Experiments are conducted for the gas flow rate from 0 to 20 [/min., the inlet gas temperature from 10 to 60°C, and the applied voltage from 0 to It 10 k

Gait recognition and fall detection with inertial sensors

In contrast to visual information that is recorded by cameras placed somewhere, inertial information can be obtained from mobile phones that are commonly used in daily life. We present in this talk a general deep learning approach for gait and soft biometrics (age and gender) recognition. Moreover, we also study the use of gait information to detect actions during walking, specifically, fall detection. We perform a thorough experimental evaluation of the proposed approach on different datasets: OU-ISIR Biometric Database, DFNAPAS, SisFall, UniMiB-SHAR and ASLH. The experimental results show that inertial information can be used for gait recognition and fall detection with state-of-the-art results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech