Problem-based leadership: nurturing managers during turbulent times

Purpose – The paper explores problem-based learning (PBL) as a useful methodology in leadership development during turbulent times. It identifies several pertinent action points for managers to lead through problems while understanding their capacity to empower themselves and others to face challenges at work. Design/methodology/approach – Broad concepts of PBL are used to distil the characteristics of this methodology and how they might be applicable to leadership development. An actual case of PBL in leadership education and training is employed to illustrate the processes of problem solving and reflective action-taking. Findings – When confronted by problems, managers should adopt a learning-oriented mindset and draw on the strengths of others to generate immediate solutions for experimentation. In doing so, they need to accept failure as a prerequisite for creative tensions to be generated and applied in messy circumstances. Until they think out of the box, they will continue to solve problems in tried-and-tested ways obstructing the emergence of revolutionary solutions. Practical implications – In order for managers to make an impact on organizational process and improvement, they need to focus on the action and learn components of PBL. They should be given the space to listen to their own “voice” and internalize the “voice” of others through reflection and dialogue. They should also be recognized for their courage and boldness in confronting problems even if more problems are generated in the process. It is facing the goliath that managers truly grow to become real leaders. Originality/value – Although the concept of PBL has been around for a long while, its applicability to leadership development has not been sufficiently explored in both theory and practice. This paper brings another dimension to the common idea of problem solving where solution seeking is not an end it itself. At best, it is a means to discovering the potential of true leadership in those whose mindset is focused on learning and reflective decision-making

Local noise can enhance entanglement teleportation

Recently we have considered two-qubit teleportation via mixed states of four qubits and defined the generalized singlet fraction. For single-qubit teleportation, Badziag {\em et al.} [Phys. Rev. A {\bf 62}, 012311 (2000)] and Bandyopadhyay [Phys. Rev. A {\bf 65}, 022302 (2002)] have obtained a family of entangled two-qubit mixed states whose teleportation fidelity can be enhanced by subjecting one of the qubits to dissipative interaction with the environment via an amplitude damping channel. Here, we show that a dissipative interaction with the local environment via a pair of time-correlated amplitude damping channels can enhance fidelity of entanglement teleportation for a class of entangled four-qubit mixed states. Interestingly, we find that this enhancement corresponds to an enhancement in the quantum discord for some states.Comment: 10 page

EMPIRE: A robust empirical reconstruction of solar irradiance variability

We present a new empirical model of total and spectral solar irradiance (TSI and SSI) variability entitled EMPirical Irradiance REconstruction (EMPIRE). As with existing empirical models, TSI and SSI variability is given by the linear combination of solar activity indices. In empirical models, UV SSI variability is usually determined by fitting the rotational variability in activity indices to that in measurements. Such models have to date relied on ordinary least squares regression, which ignores the uncertainty in the activity indices. In an advance from earlier efforts, the uncertainty in the activity indices is accounted for in EMPIRE by the application of an error-in-variables regression scheme, making the resultant UV SSI variability more robust. The result is consistent with observations and unprecedentedly, with that from other modelling approaches, resolving the long-standing controversy between existing empirical models and other types of models. We demonstrate that earlier empirical models, by neglecting the uncertainty in activity indices, underestimate UV SSI variability. The reconstruction of TSI and visible and IR SSI from EMPIRE is also shown to be consistent with observations. The EMPIRE reconstruction is of utility to climate studies as a more robust alternative to earlier empirical reconstructions.Comment: J. Geophys. Res. (2017

Solar cycle variation in solar irradiance

The correlation between solar irradiance and the 11-year solar activity cycle is evident in the body of measurements made from space, which extend over the past four decades. Models relating variation in solar irradiance to photospheric magnetism have made significant progress in explaining most of the apparent trends in these observations. There are, however, persistent discrepancies between different measurements and models in terms of the absolute radiometry, secular variation and the spectral dependence of the solar cycle variability. We present an overview of solar irradiance measurements and models, and discuss the key challenges in reconciling the divergence between the two

First-Order Transition and Critical End-Point in Vortex Liquids in Layered Superconductors

We calculate various thermodynamic quantities of vortex liquids in a layered superconductor by using the nonperturbative parquet approximation method, which was previously used to study the effect of thermal fluctuations in two-dimensional vortex systems. We find there is a first-order transition between two vortex liquid phases which differ in the magnitude of their correlation lengths. As the coupling between the layers increases,the first-order transition line ends at a critical point. We discuss the possible relation between this critical end-point and the disappearance of the first-order transition which is observed in experiments on high temperature superconductors at low magnetic fields.Comment: 9 pages, 5 figure

Physical condition and spin-resolved exchange correlation kernels in an inhomogeneous many electron system

We first exploit the spin symmetry relation $f^{\rm xc}_{s\bar s} (\zeta)=f^{\rm xc}_{\bar s s}(-\zeta)$ for the exact exchange correlation kernel $f^{\rm xc}_{s\bar s}(\zeta)$ in an inhomogeneous many electron system with arbitrary spin polarization $\zeta$. The physical condition required to satisfy the specific symmetry relation $f^{\rm xc}_{s\bar s}(\zeta) = f^{\rm xc}_{\bar s s}(\zeta)$ is derived and examined for simple ferromagnetic-nonmagnetic structure by taking the electrochemical potential into account. The condition is then applied to several composite systems useful in spintronics applications such as the magnetic system with net spin polarization.Comment: 5 pages, 1 figur

LABOR MARKET BEHAVIOR IN WASHINGTON: A COINTEGRATION APPROACH

In recent years, the research that investigates impact of employment on other labor related variables has a prominent place in regional science. Generally, it is well understood that new business investment brings changes in population, increased labor force participation rate and migration of new residents. There is mixed research results regarding the extent that new migrants tend to account for new employment. Bartik (1993) found that about one-quarter of the new jobs go to local workers because of the increase in the labor force participation rates of local residents in the long run. He considered the long run effects by estimating the effects of 1% job growth in a certain period on the labor force participation rate seventeen years after the period. In contrast Blanchard and Katz's (1992) research reaches the opposite conclusion - in five to seven years the employment response consists entirely of the migration of new migrants. Their finding is that long-run effect of the job growth on the labor force participation rate is negligible. In this study, from the cointegration time series analysis, we found a long run equilibrium relationship among population, labor force participation rate and employment, in which population is positively related to employment and negatively related to labor force participation rate. The long run effect of a unit change of labor force participation rate (1%) is a decrease of 73,880 in population and the long run effect of a unit change in employment (1000) is an increase of 2,190 in population. We decomposed the time series into stationary components and non-stationary components. The pattern of the stationary component of population is quite similar to that of labor force participation rate while that of employment shows a different fluctuation. From the decomposition, it was obvious that the pattern of stationary component of employment and net migration is quite similar, which means net migration is the short run, temporary response to employment change. The patterns of three years delayed stationary components of population are similar to that of employment and net migration, and the plots correspond to changing economic conditions. According to the change in economic conditions population responds three years later than employment and net migration. We interpreted the non-stationary component of labor force participation rate as reflecting the increasing trend of labor force participation rate in Washington mainly due to a considerable increase in the female labor force participation. The impulse responses of population, employment and labor force participation rate to a one standard deviation shock in employment show permanent increase effects. They settle at different equilibrium value after long term periods. The response of the labor force participation rate to an impulse in employment supports Bartik's finding. Obviously the result is the opposite of Blanchard-Katz's finding that the long-run effect of job growth on the labor force participation rate is negligible. However, since the effect of population is also significantly high, we doubt that the effect of increase in labor force participation rate according to the employment shock covers only local resident labor force.Labor and Human Capital,

Analysis and modeling of solar irradiance variations

A prominent manifestation of the solar dynamo is the 11-year activity cycle, evident in indicators of solar activity, including solar irradiance. Although a relationship between solar activity and the brightness of the Sun had long been suspected, it was only directly observed after regular satellite measurements became available with the launch of Nimbus-7 in 1978. The measurement of solar irradiance from space is accompanied by the development of models aimed at describing the apparent variability by the intensity excess/deficit effected by magnetic structures in the photosphere. The more sophisticated models, termed semi-empirical, rely on the intensity spectra of photospheric magnetic structures generated with radiative transfer codes from semi-empirical model atmospheres. An established example of such models is SATIRE-S (Spectral And Total Irradiance REconstruction for the Satellite era). One key limitation of current semi-empirical models is the fact that the radiant properties of network and faculae are not adequately represented due to the use of plane-parallel model atmospheres (as opposed to three-dimensional model atmospheres). This thesis is the compilation of four publications, detailing the results of investigations aimed at setting the groundwork necessary for the eventual introduction of three-dimensional atmospheres into SATIRE-S and a review of the current state of the measurement and modelling of solar irradiance. Also presented is an update of the SATIRE-S model. We generated a daily reconstruction of total and spectral solar irradiance, covering 1974 to the present, that is more reliable and, in most cases, extended than similar reconstructions from contemporary models.Comment: Doctoral thesis, ISBN 978-3-944072-07-

Beef flavor and fatty acids in different carcass sites as affected by grass and corn diets up to 140 days

Ninety-one Angus steers which were wintered on fescue pasture and allowed unlimited grazing on an orchard grass, fescue and clover pasture during the spring and summer of 1980 were assigned to 5 groups of 15 steers each and one group of 16 steers on the basis of frame size. One group was slaughtered off pasture (0 days on corn), and the rest were adjusted to a whole shelled corn diet for 2 weeks. After adjustment, a group of corn-fed steers was slaughtered every 28 days up to 140 days. For each steer, the fatty acid composition of total intramus-cular lipids of the longissimus, brisket fat and intermuscular fat was determined, the volatile fatty acid (VFA) content of the longissimus was measured, and the flavor of the cooked longissimus was evaluated by Quantitative Descriptive Analysis. Most of the fatty acids in each fat site were affected by days steers were fed corn. As days steers were fed corn increased, the percentages of saturated fatty acids in the brisket and intramuscular fat decreased, the percentages of monounsaturated fatty acids of all three fat sites increased, and the percentages of the polyunsaturated fatty acids of the brisket fat and intramuscular lipid decreased. Frame size of steers did not affect the fatty acid composition of any fat site very much. Of the three fat sites, the intramuscular lipid had the greatest concentration of polyunsaturated fatty acids, the seam fat had the most monounsaturated fatty acids, and the brisket fat had the highest amount of saturated fatty acids. The VFA content of the longissimus muscle also was affected by days steers were fed corn. Steers fed corn for any time generally had greater concentration of acetic, isobutyric, butyric and caproic acids and lower amounts of valeric acid in the longissimus than steers off pasture. Of all frame sizes, steers with the largest frame size had the lowest levels of isocaproic acids and highest levels of acetic acid. As corn was fed steers from 0 to 140 days, the intensity of an undesirable milky-oily aroma and flavor decreased linearly and the intensity of a desirable cooked beef fat aroma and flavor increased linearly. Long chain polyunsaturated fatty acids (C18:3, C20:3, C20:4, and C22:5), αC15:0 and C18:0 were positively correlated with the milky-oily aroma and C10:0, C12:0, C14:0, C14:1 and C18:1 were negatively correlated. The polyunsaturated fatty acids are more labile to oxidation during storage and cooking of meat, and probably contribute to the off-flavors in beef produced by grass and to its reduced storage life