The mass function of nearby black hole candidates

The mass function of super-massive black holes in our cosmic neighborhood is required to understand the statistics of their activity and consequently the origin of the ultra high energy particles. We determine a mass function of black hole candidates from the entire sky except for the Galactic plane. Using the 2MASS catalogue as a starting point, and the well established correlation between black hole mass and the bulge of old population of stars, we derive a list of nearby black hole candidates within the redshift range z < 0.025, then do a further selection based on the Hubble-type, and give this as a catalogue elsewhere. The final list of black hole candidates above a mass of M_BH > 3*10^{6} M_sol has 5,829 entries; moreover doing a further Hubble type correction to account for the selection effects cuts down the number to 2,919 black hole candidates. We also correct for volume, so that this mass function is a volume limited distribution to redshift 0.025 The differential mass function of nearby black hole candidates is a curved function, with a straight simple power-law of index -3 above 10^{8} M_sol, growing progressively flatter towards lower masses, turning off towards a gap below 3*10^{6} M_sol, and then extending into the range where nuclear star clusters replace black holes. The shape of this mass function can be explained in a simple merger picture. Integrating this mass function over the redshift range, from which it has been derived, gives a total number of black holes with z 10^{7} M_sol of about 2.4*10^{4}, or, if we just average uniformly, 0.6 for every square degree on the sky. In different models many of these are candidates for ultra high energy particles sources. If a very small fraction of the super-massive black holes produces ultra high energy cosmic rays, this should be enough to observe the highly inhomogeneous distribution of the galaxies.Comment: 12 pages, 6 figures, resubmitted to A&

The Ordered Latent Transition Analysis Model for the Measurement of Learning

Several statistical models have been developed in educational measurement to determine and track the performance of students in longitudinal studies. An example of a model designed for such purpose is the latent transition analysis (LTA) model. The LTA model (Graham, Collins, Wugalter, Chung, & Hansen 1991) is a type of autoregressive model specifically designed to model transitions between class membership from Time t to Time t+1. The model however makes no assumption of ordering of the latent statuses and the transition probabilities. This project extends the LTA model by using the ordering technique proposed by Croon (1990) to introduce inequality constraints on the response probabilities of the LTA model. This new approach, referred to as the ordered latent transition analysis (OLTA) model, ensures ordering of the students' learning levels (known as statuses under LTA), and the transition probabilities. Simulation study was conducted in order to determine the adequacy of parameter recovery by OLTA as well as to evaluate the performance of the information criterion (AIC and BIC) in selecting the appropriate number of levels in the model. The simulation results showed good parameter recovery overall. Additionally, the AIC and BIC performed comparably well in selecting the correct transition model, but the AIC outperformed the BIC for the selection of optimal number of levels. An example of OLTA analysis of empirical data on reading skill development is presented

The IIUM: internationalizing higher education

Introduction: The hallmark of the new millennium is the ever-increasing interdependence of people of various cultures. People, capital, ideologies, media images, and cultural impulses travel around the world more rapidly and efficiently than ever before. Responding to the needs of global man, higher education policies have become increasingly internationalized. Policy-makers and educators stress internationalization as a principal goal for higher education. This required them to bring about changes in the research agenda, alter the curricula, establish linkages with other centres of learning, and make the composition of professional staff and student bodies more pluralistic. The policies and practices undertaken by academic systems and institutions to cope with the global academic environment is generally referred to as internationalization

Toward a Career Anchor Structure: An Empirical Investigation of Engineers

Contrary to Schein’s theory of career anchors, which rests on the dominance of a single career anchor, the present study proposes an original career anchor structure that captures multiple dominant anchors. The analysis of data from a sample of 880 Quebec engineers supports this reconceptualization based on a circular model of career anchors. The new dynamics of career anchors shows that several anchors are complementary (e.g., creativity and challenge) while others are conflictual (e.g., challenge and security). In particular, the correlational analysis at the axial level indicates that the “self-enhancement” pole (managerial competence, identity) is negatively correlated with the “self-transcendence” (service/dedication to a cause, technical competence), whereas the pole “openness to change” (challenge, entrepreneurial creativity) is negatively correlated with the “conservation” pole (security, lifestyle). These findings can lead to more research in career management.Le modèle des ancres de carrière de Schein (1978) propose que les individus ne possèdent qu’une seule ancre dominante, celle-ci reflétant les habiletés, les valeurs et les besoins fondamentaux privilégiés par une personne au cours de sa carrière. Un tel phénomène de dominance, souvent opérationnalisé en identifiant l’ancre ayant obtenu le score le plus élevé chez un individu, est appelé « différenciation ». Récemment, plusieurs chercheurs ont remis en question la différenciation. Selon Martineau, Wils et Tremblay (2005), certains individus intériorisent en fait plusieurs ancres élevées, ce qui fait référence à « l’indifférenciation ».Contrairement au modèle de Schein, celui de Feldman et Bolino (1996) aide à comprendre l’indifférenciation parce qu’il repose sur une structuration des ancres organisée selon une dynamique octogonale. En effet, il existerait une proximité de certaines ancres dites « compatibles » (ancres connexes de l’octogone) ainsi qu’une opposition entre d’autres ancres dites « incompatibles » (ancres diamétralement opposées de l’octogone). L’idée de structuration des ancres selon une dynamique circulaire est théoriquement intéressante, car elle pourrait expliquer pourquoi un individu n’afficherait que quelques ancres dominantes données. Vu que la justification avancée par Feldman et Bolino pour articuler les ancres ne découle pas d’une preuve empirique probante, leur modèle a besoin d’être peaufiné d’un point de vue théorique en faisant appel à un autre modèle de structuration. Les ancres étant essentiellement des valeurs qui guident les décisions de carrière et, par le fait même, l’évolution de la carrière et du travail des individus, il est logique de mobiliser le modèle de structuration des valeurs de Schwartz. En particulier, un modèle de structuration circulaire des ancres émerge d’un parallèle entre les valeurs et les ancres de carrière.Plusieurs études empiriques ont montré soit des corrélations positives, soit des corrélations négatives entre des ancres de carrière. Sans un modèle de structuration circulaire des ancres, il devient difficile d’interpréter ces corrélations d’autant plus qu’elles proviennent de données n’ayant pas été normalisées sur une base individuelle comme le recommande Schwartz (1992). Aussi l’objectif de cette étude est-il de vérifier l’existence d’une telle structuration des ancres en mettant à jour la dynamique corrélationnelle entre les ancres. Pour ce faire, cette recherche a adopté la méthodologie développée par Schwartz. Les données, qui proviennent d’un échantillon de 880 ingénieurs québécois, sont soumises à des analyses multidimensionnelles (de type SSA « Smallest Space Analysis » de Guttman-Lingoes, disponible uniquement avec SYSTAT) ainsi qu’à des analyses corrélationnelles (SPSS) afin de vérifier six hypothèses.Les résultats des analyses multidimensionnelles sont représentés sur une carte composée de quatre quadrants. Un premier quadrant correspond au pôle « affirmation de soi ». Ce quadrant regroupe des items reliés aux domaines du pouvoir (richesse, autorité, pouvoir social et reconnaissance sociale) et d’accomplissement (réussite, influence). Ainsi, l’ancre de gestion et l’ancre d’identité font partie d’une même famille d’ancres managériales. Opposé à ce quadrant, se situe le domaine associé au pôle « dépassement de soi » composé des items reliés au domaine de la quête de savoir (ancre de compétence technique) et de la bienveillance (ancre service/dévouement à une cause). D’autre part, deux autres quadrants s’opposent. Un troisième quadrant rassemble l’item associé au domaine de la sécurité (ancre de sécurité) auquel s’ajoute les items ayant trait à la QVT, aux conditions de travail et au climat de travail (ancre style de vie); il s’agit donc du pôle « continuité ». Enfin, un quatrième quadrant, celui de l’ouverture au changement, englobe des items reliés à l’auto-orientation (ancre de créativité) et à la stimulation (ancre de défi) auxquels s’ajoutent les items reliés au changement d’emploi, au changement géographique et au changement de projet. De ces résultats il en découle que les quatre premières hypothèses reçoivent un fort appui empirique.Les deux dernières hypothèses de cette étude portent sur la dynamique corrélationnelle. À partir des items identifiés dans chacun des quadrants, quatre variables composites ont été calculées après avoir normalisé les données par individu. Ces quatre variables correspondent aux quatre pôles, à savoir l’affirmation de soi, le dépassement de soi, l’ouverture au changement et la continuité. L’analyse corrélationnelle au niveau axial indique que le pôle « affirmation de soi » est négativement corrélé au pôle de dépassement de soi (r = -0,44 significatif à p < 0,01) tandis que le pôle « ouverture au changement » est négativement corrélé au pôle « continuité » (r = -0,49 significatif à p < 0,01). Les hypothèses 5 et 6 sont donc vérifiées.Cette recherche apporte une contribution importante au domaine des carrières en proposant un modèle original de structuration des ancres de carrière qui est non seulement décliné selon une logique théorique (la structuration des valeurs de Schwartz), mais aussi vérifié par une preuve empirique probante. Les résultats de cette étude militent en faveur de la thèse de l’indifférenciation et suggèrent une reconceptualisation du concept « d’ancres de carrière ». En effet, plusieurs auteurs ont avancé l’idée que certaines ancres se repoussent alors que d’autres s’attirent. Ce phénomène de répulsion et d’attraction, qui fut expliqué dans Martineau, Wils et Tremblay (2005), a été vérifié par la dynamique corrélationnelle au niveau axial présentée dans cette recherche.Il est important de souligner qu’une limite de cette recherche a trait à la spécificité de l’échantillon qui se compose uniquement d’ingénieurs. D’autres recherches sont requises afin de pouvoir généraliser nos résultats à d’autres professions. De plus, la construction et la validation d’un nouvel instrument de mesure est essentiel pour l’avancement des connaissances sur les ancres de carrière, du fait que les instruments de mesure actuels, ne mesurent pas adéquatement les ancres de carrière.Contrariamente a la teoría de anclaje de carreras de Schein, que se queda en el campo de un anclaje único de carrera, el presente estudio propone una estructura de anclaje de carrera original que incluye múltiples anclajes dominantes. El análisis de datos a partir de una muestra de 880 ingenieros de Quebec sostiene esta re-conceptualización basada en un modelo circular de anclajes de carrera. Las nuevas dinámicas de anclaje de carrera muestran que varios anclajes son complementarios (por ejemplo, creatividad y reto) mientras otros son conflictivos (por ejemplo, reto y seguridad). En particular, el análisis de correlación al nivel axial indica que el polo “auto-mejora” (dedicación a la causa, competencia técnica) está en correlación negativa con la “auto-trascendencia”, mientras el polo “apertura al cambio” (reto, creatividad empresarial) está en correlación negativa con el polo “conservador” (seguridad, estilo de vida). Estos resultados pueden llevar a otras investigaciones sobre la carrera de gestión

A CONCEPT PAPER OF GREEN SUPPLY CHAIN MANAGEMENT PRACTICES IN KENYA

Green supply chain has emerged as proactive area in healthcare. The study examinesrelevant literature review that explains green supply chain practices especially in health in Kenya.The health sector is often a key sector in a developing society .This is due to its contribution towellbeing among its citizens. The paper shall also propose a conceptual framework based on theliterature to explain the relationship between greening practices in the supply chain andorganizational performance. Firms involved in the supply chain of medical related supply arecurrently under pressure to supply environmentally conducive and biodegradable products.Findings from the paper indicate, that a firm’s commitment to conserve the environment is drivenby suppliers and consumers needs of the same.Key words: Green supply chain management, green procurement, green packaging, eco design,waste management reverse logistics and practices

Preparing Teachers for Integrating Visual Arts for Academic Success of Elementary School Students

The majority of people agree that students’ education should provide them with the essential skills to be successful in the 21st-century workforce. Although these same sets of skills are commonly practiced through the process of making art, art education continues to hold an inferior status in schools. This disconnection raises the question, what has led to the devaluation of art in academics? This senior capstone will explore how teachers are prepared to integrate visual arts into the classroom. Through the use of a literature review, interviews with three in-service teachers, and a survey of students majoring in Liberal Studies at CSUMB, the result findings indicate that there is a lack of adequate teacher preparation and professional development in visual art integration that has contributed to the academic success of elementary school students

Dennis Holme Robertson (1890–1963)

Dennis Robertson played an important role in the history of Cambridge economics, through his contributions to monetary and business cycle theory, and to utility and welfare. As a macroeconomist, Robertson investigated the dynamic relationship between monetary flows and economic fluctuations. His main contributions to monetary macroeconomics were written between 1915 and 1934. During that period (especially in the 1920s), he and Maynard Keynes interacted extensively. However, after the publication of Keynes’s General Theory in 1936, Robertson became critical of what he perceived as the shortcomings of Keynesian liquidity preference and equilibrium unemployment theories. From a microeconomic perspective, Robertson made a sustained effort to keep alive the Cambridge Marshallian cardinalist approach to utility, especially after the ordinalist revolution in welfare economics in the 1940s. Robertson claimed that economic theory and policy necessarily involve interpersonal comparisons of utility and welfare

Conceptual Framework for Designing Virtual Field Trip Games

This thesis aimed to provide designing models to explore an alternative solution for a field trip when it becomes impossible for several reasons such as the limitation of cost and time. Virtual field trip games are relatively new means to create virtual field trips in game environments through adding game aspects to learning aspects to enhance the learning experience. The simple combining of game and learning aspects will not guarantee the desired effect of virtual field trips. Theoretical and logical connections should be established to form interweave between both aspects. This thesis proposes a designing framework by establishing three links between game design aspects and learning aspects. The three links are constructed by modelling: the experiential learning theory (ELT), the gameplay, and the game world. ELT modelling quantifies the theory into the internal economy mechanic and balances the levels of game task difficulty with the player’s ability through game machinations, game modelling links the learning process to gameplay, and world modelling connects field environment to game environment. The internal economy mechanic and its components (resources, internal mechanic, feedback loop), formulating equations to define generic player’s interactions and identify indicators to capture evidence of achievements via a mathematical (evaluation) model. The game modelling includes skill models to design two important high-order skills (decision-making and teamwork) and connects them to the evaluation model. The game world is modelled through defining its variables and relationships’ rules to connect both environments (game and field) expanding the evaluation model. The framework is supported by essential learning theories (ELT, task-based learning, some aspects of social learning) and pedagogical aspects (assessment, feedback, field-based structure, high-order skills) and connected to the key game elements (interaction, multimodal presentation, control of choice…etc) of field-based learning along with suitable game mechanics. The two research studies that were conducted as part of this thesis found that the designing framework is useful, usable, and provides connections between learning and game aspects and the designed VFTG based on the framework improved learning performance along with providing motivation and presence. This suggests the effectiveness of the framework

Investigation of FACTS devices to improve power quality in distribution networks

Flexible AC transmission system (FACTS) technologies are power electronic solutions that improve power transmission through enhanced power transfer volume and stability, and resolve quality and reliability issues in distribution networks carrying sensitive equipment and non-linear loads. The use of FACTS in distribution systems is still in its infancy. Voltages and power ratings in distribution networks are at a level where realistic FACTS devices can be deployed. Efficient power converters and therefore loss minimisation are crucial prerequisites for deployment of FACTS devices. This thesis investigates high power semiconductor device losses in detail. Analytical closed form equations are developed for conduction loss in power devices as a function of device ratings and operating conditions. These formulae have been shown to predict losses very accurately, in line with manufacturer data. The developed formulae enable circuit designers to quickly estimate circuit losses and determine the sensitivity of those losses to device voltage and current ratings, and thus select the optimal semiconductor device for a specific application. It is shown that in the case of majority carrier devices (such as power MOSFETs), the conduction power loss (at rated current) increases linearly in relation to the varying rated current (at constant blocking voltage), but is a square root of the variable blocking voltage when rated current is fixed. For minority carrier devices (such as a pin diode or IGBT), a similar relationship is observed for varying current, however where the blocking voltage is altered, power losses are derived as a square root with an offset (from the origin). Finally, this thesis conducts a power loss-oriented evaluation of cascade type multilevel converters suited to reactive power compensation in 11kV and 33kV systems. The cascade cell converter is constructed from a series arrangement of cell modules. Two prospective structures of cascade type converters were compared as a case study: the traditional type which uses equal-sized cells in its chain, and a second with a ternary relationship between its dc-link voltages. Modelling (at 81 and 27 levels) was carried out under steady state conditions, with simplified models based on the switching function and using standard circuit simulators. A detailed survey of non punch through (NPT) and punch through (PT) IGBTs was completed for the purpose of designing the two cascaded converters. Results show that conduction losses are dominant in both types of converters in NPT and PT IGBTs for 11kV and 33kV systems. The equal-sized converter is only likely to be useful in one case (27-levels in the 33kV system). The ternary-sequence converter produces lower losses in all other cases, and this is especially noticeable for the 81-level converter operating in an 11kV network