School Principals' Emotional Coping Process

Science.gov (United States)

Poirel, Emmanuel; Yvon, Frédéric

2014-01-01

The present study examines the emotional coping of school principals in Quebec. Emotional coping was measured by stimulated recall; six principals were filmed during a working day and presented a week later with their video showing stressful encounters. The results show that school principals experience anger because of reproaches from staff…

Aerobic Physical Activity and the Leadership of Principals

Science.gov (United States)

Kiser, Kari

2016-01-01

The purpose of this study was to explore if there was a connection between regular aerobic physical activity and the stress and energy levels of principals as they reported it. To begin the research, the current aerobic physical activity level of principals was discovered. Additionally, the energy and stress levels of the principals who do engage…

Principal Leadership in the Accountability Era: Influence of Expanding Job Responsibilities on Functional Work Performance, Stress Management, and Overall Job Satisfaction

Science.gov (United States)

Andreyko, Tammy A.

2010-01-01

This study examined the relationship of stress, burnout, and coping strategies among middle school principals in Western Pennsylvania. This study assessed coping skill preferences among middle school principals, especially regarding their age, gender, marital status, experience, and school enrollment. A review of the literature included studies…

True Triaxial Strength and Failure Modes of Cubic Rock Specimens with Unloading the Minor Principal Stress

Science.gov (United States)

Li, Xibing; Du, Kun; Li, Diyuan

2015-11-01

True triaxial tests have been carried out on granite, sandstone and cement mortar using cubic specimens with the process of unloading the minor principal stress. The strengths and failure modes of the three rock materials are studied in the processes of unloading σ 3 and loading σ 1 by the newly developed true triaxial test system under different σ 2, aiming to study the mechanical responses of the rock in underground excavation at depth. It shows that the rock strength increases with the raising of the intermediate principal stress σ 2 when σ 3 is unloaded to zero. The true triaxial strength criterion by the power-law relationship can be used to fit the testing data. The "best-fitting" material parameters A and n ( A > 1.4 and n plastic deformation. The maximum extension strain criterion Stacey (Int J Rock Mech Min Sci Geomech Abstr 651 18(6):469-474, 1981) can be used to explain the change of failure mode from shear to slabbing for strong and hard rocks under true triaxial unloading test condition.

Cardiorespiratory Coordination in Repeated Maximal Exercise

Directory of Open Access Journals (Sweden)

Sergi Garcia-Retortillo

2017-06-01

Full Text Available Increases in cardiorespiratory coordination (CRC after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1 were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax, maximal oxygen consumption (VO2 max, or ventilatory threshold (VT, an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08 was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43 in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC

Maximizing Lipid Yield in Neochloris oleoabundans Algae Extraction by Stressing and Using Multiple Extraction Stages with N-Ethylbutylamine as Switchable Solvent

NARCIS (Netherlands)

Du, Ying; Schuur, Boelo; Brilman, Derk W.F.

2017-01-01

(Graph Presented) The extraction yield of lipids from nonbroken Neochloris oleoabundans was maximized by using multiple extraction stages and using stressed algae. Experimental parameters that affect the extraction were investigated. The study showed that with wet algae (at least) 18 h extraction

Administrative Stressors and Islamic Coping Strategies Among Muslim Primary Principals in Malaysia: A Mixed Method Study.

Science.gov (United States)

Tahir, Lokman Mohd; Khan, Aqeel; Musah, Mohammed Borhandden; Ahmad, Roslee; Daud, Khadijah; Al-Hudawi, Shafeeq Hussain Vazhathodi; Musta'Amal, Aede Hatib; Talib, Rohaya

2017-11-18

Principals are school leaders who experienced stress while leading their schools towards excellence. However, principals stress experiences are always ignored and least studied. This mixed-methods study investigates primary principals' stress experiences and their Islamic coping strategies used in incapacitating the stress experiences. A total of 216 Muslim primary principals across different gender, types of schools and years of experiences as school leaders responded to the administrative stress and the Islamic coping strategies items. In addition, seven primary principals were purposefully selected and interviewed in exploring their reasons of using Islamic coping strategies for their relieving process. Results discovered that primary principals experienced fairly stress level and they perceived managing students' academic achievement was the most stressor followed by managing teachers' capabilities. Although findings revealed that no significant differences in terms primary principals' demographics; male primary principals, and experienced between 6 and 10 years and positioned in schools with least students (SLS) category have slightly higher level of stress. In terms of Islamic coping strategies used by primary principals, saying dhua to Allah, performing dhikir and reciting the Yassen are selected coping approaches employed in handling their stress. From interviews, primary principals also revealed that they used Islamic religious approaches as part of meaningful activities not just to overcoming their stress but also as part of religious approaches in remembering Allah, thinking back their past mistakes as part of the Muhasabah process. Therefore, we believed that religious approaches should be taken into consideration in principals' training as it provides peaceful and treatment in managing principals' stress issue.

Conceptual development of a method to determine the principal stresses around coal mine workings to ensure safe mine design

CSIR Research Space (South Africa)

Coetzer, S

1997-06-01

Full Text Available The objective of this project is to identify or to develop methods or procedures for the determination of the principal stresses in coal mine workings, which in turn would provide improved criteria for mine design layouts in coal mines. To address...

Principal bundles on the projective line

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

LetX be a complete nonsingular curve over the algebraic closurek ofk andGa reductive group over k. Let E → X be a principal G-bundle on X. E is said to be semistable if, for every reduction of structure group EP ⊂ E to a maximal parabolic subgroup P of G, we have degree EP (p) ≤ 0, where p is the Lie algebra of P and EP ...

Optimal interface between principal deterrent systems and material accounting

International Nuclear Information System (INIS)

Deiermann, P.J.; Opelka, J.H.

1983-01-01

The purpose of this study is to find an optimal blend between three safeguards systems for special nuclear material (SNM), the material accounting system and the physical security and material control systems. The latter two are denoted as principal deterrent systems. The optimization methodology employed is a two-stage decision algorithm, first an explicit maximization of expected diverter benefits and subsequently a minimization of expected defender costs for changes in material accounting procedures and incremental improvements in the principal deterrent systems. The probability of diverter success function dependent upon the principal deterrents and material accounting system variables is developed. Within the range of certainty of the model, existing material accounting, material control and physical security practices are justified

On Maximally Dissipative Shock Waves in Nonlinear Elasticity

OpenAIRE

Knowles, James K.

2010-01-01

Shock waves in nonlinearly elastic solids are, in general, dissipative. We study the following question: among all plane shock waves that can propagate with a given speed in a given one-dimensional nonlinearly elastic bar, which one—if any—maximizes the rate of dissipation? We find that the answer to this question depends strongly on the qualitative nature of the stress-strain relation characteristic of the given material. When maximally dissipative shocks do occur, they propagate according t...

Generalized principal resonance in oscillatory systems of second order; Resonancia principal generalizada en sistemas oscilatorios de segundo orden

Energy Technology Data Exchange (ETDEWEB)

Munoz Aguirre, E. [Universidad Autonoma de Puebla, Oaxaca (Mexico); Alexandrov, V. V. [Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

2001-02-01

This paper will describe the generalized principal resonance of systems as described by the second order of ordinary differential equations and proved by the Pontriaguin maximal principle to coincide with the lengthened solution of an external problem of the same system. The results are verified in special cases of general resonance and parametric resonance for the Mathieu equation. [Spanish] En el presente articulo se estudia la resonancia principal generalizada para sistemas descritos por ecuaciones diferenciales ordinarias de segundo orden y se demuestra con ayuda del principio del maximo de Pontriaguin, la coincidencia de esta con la solucion prolongada de un problema extremal para el mismo sistema. Ademas se verifican estos resultados en los casos particulares de resonancia general y resonancia parametrica para la ecuacion de Mathieu.

Combined approach based on principal component analysis and canonical discriminant analysis for investigating hyperspectral plant response

Directory of Open Access Journals (Sweden)

Anna Maria Stellacci

2012-07-01

Full Text Available Hyperspectral (HS data represents an extremely powerful means for rapidly detecting crop stress and then aiding in the rational management of natural resources in agriculture. However, large volume of data poses a challenge for data processing and extracting crucial information. Multivariate statistical techniques can play a key role in the analysis of HS data, as they may allow to both eliminate redundant information and identify synthetic indices which maximize differences among levels of stress. In this paper we propose an integrated approach, based on the combined use of Principal Component Analysis (PCA and Canonical Discriminant Analysis (CDA, to investigate HS plant response and discriminate plant status. The approach was preliminary evaluated on a data set collected on durum wheat plants grown under different nitrogen (N stress levels. Hyperspectral measurements were performed at anthesis through a high resolution field spectroradiometer, ASD FieldSpec HandHeld, covering the 325-1075 nm region. Reflectance data were first restricted to the interval 510-1000 nm and then divided into five bands of the electromagnetic spectrum [green: 510-580 nm; yellow: 581-630 nm; red: 631-690 nm; red-edge: 705-770 nm; near-infrared (NIR: 771-1000 nm]. PCA was applied to each spectral interval. CDA was performed on the extracted components to identify the factors maximizing the differences among plants fertilised with increasing N rates. Within the intervals of green, yellow and red only the first principal component (PC had an eigenvalue greater than 1 and explained more than 95% of total variance; within the ranges of red-edge and NIR, the first two PCs had an eigenvalue higher than 1. Two canonical variables explained cumulatively more than 81% of total variance and the first was able to discriminate wheat plants differently fertilised, as confirmed also by the significant correlation with aboveground biomass and grain yield parameters. The combined

Non-invasive coronary angiography for patients with acute atypical chest pain discharged after negative screening including maximal negative treadmill stress test. A prospective study.

Science.gov (United States)

Bonello, L; Armero, S; Jacquier, A; Com, O; Sarran, A; Sbragia, P; Panuel, M; Arques, S; Paganelli, F

2009-05-01

Among patients admitted in the emergency department for acute atypical chest pain those with an acute coronary syndrome (ACS) who are mistakenly discharged home have high mortality. A recent retrospective study has demonstrated that multislice computed tomography (MSCT) coronary angiography could improve triage of these patients. We aimed to prospectively confirm these data on patients with a negative screening including maximal treadmill stress. 30 patients discharged from the emergency department after negative screening for an ACS were included. All patients underwent MSCT angiography of the coronary artery. Patients with coronary atheroma on MSCT had an invasive coronary angiography to confirm these findings. Seven patients (23%) had obstructive coronary artery disease on MSCT. Invasive coronary angiography (ICA) confirmed the diagnosis in all patients. In patients with no previously known coronary artery disease admitted to the emergency department with atypical acute chest pain and discharged after negative screening, including maximal treadmill stress test, MSCT coronary angiography is useful for the diagnosis of obstructive coronary artery disease.

Maximizing Lipid Yield in Neochloris oleoabundans Algae Extraction by Stressing and Using Multiple Extraction Stages with N-Ethylbutylamine as Switchable Solvent

Science.gov (United States)

2017-01-01

The extraction yield of lipids from nonbroken Neochloris oleoabundans was maximized by using multiple extraction stages and using stressed algae. Experimental parameters that affect the extraction were investigated. The study showed that with wet algae (at least) 18 h extraction time was required for maximum yield at room temperature and a solvent/feed ratio of 1:1 (w/w). For fresh water (FW), nonstressed, nonbroken Neochloris oleoabundans, 13.1 wt % of lipid extraction yield (based on dry algae mass) was achieved, which could be improved to 61.3 wt % for FW stressed algae after four extractions, illustrating that a combination of stressing the algae and applying the solvent N-ethylbutylamine in multiple stages of extraction results in almost 5 times higher yield and is very promising for further development of energy-efficient lipid extraction technology targeting nonbroken wet microalgae. PMID:28781427

Tri-maximal vs. bi-maximal neutrino mixing

International Nuclear Information System (INIS)

Scott, W.G

2000-01-01

It is argued that data from atmospheric and solar neutrino experiments point strongly to tri-maximal or bi-maximal lepton mixing. While ('optimised') bi-maximal mixing gives an excellent a posteriori fit to the data, tri-maximal mixing is an a priori hypothesis, which is not excluded, taking account of terrestrial matter effects

A Note on McDonald's Generalization of Principal Components Analysis

Science.gov (United States)

Shine, Lester C., II

1972-01-01

It is shown that McDonald's generalization of Classical Principal Components Analysis to groups of variables maximally channels the totalvariance of the original variables through the groups of variables acting as groups. An equation is obtained for determining the vectors of correlations of the L2 components with the original variables.…

Activation of AMPK by Buddleja officinalis Maxim. Flower Extract Contributes to Protecting Hepatocytes from Oxidative Stress.

Science.gov (United States)

Jung, Ji Yun; Lee, Chul Won; Park, Sang Mi; Jegal, Kyung Hwan; Kim, Jae Kwang; Park, Chung A; Cho, Il Je; Jung, Dae Hwa; An, Won G; Ku, Sae Kwang; Zhao, Rongjie; Kim, Sang Chan

2017-01-01

The Buddleja officinalis Maxim. flower is used in traditional Chinese and Korean medicine to treat inflammation, vascular diseases, headache, and stroke, as well as enhance liver function. This research investigated the effects of B. officinalis Maxim. flower extract (BFE) on hepatotoxicity. The cytoprotective effects and mechanism of BFE against severe mitochondrial dysfunction and H 2 O 2 production in hepatotoxicity induced by coadministration of arachidonic acid (AA) and iron were observed in the HepG2 cell line. In addition, we performed blood biochemical, histopathological, and histomorphometric analyses of mice with carbon tetrachloride- (CCl 4 -) induced acute liver damage. BFE inhibited the AA + iron-mediated hepatotoxicity of HepG2 cells. Moreover, it inhibited mitochondrial dysfunction, H 2 O 2 production, and glutathione depletion mediated by AA + iron in the same cells. Meanwhile, the cytoprotective effects of BFE against oxidative stress were associated with the activation of AMP-activated protein kinase (AMPK). In particular, based on the histopathological observations, BFE (30 and 100 mg/kg) showed clear hepatoprotective effects against CCl 4 -induced acute hepatic damage. Furthermore, it inhibited 4-hydroxynonenal and nitrotyrosine immunoreactivity in hepatocytes. These results provide evidence that BFE has beneficial hepatoprotective effects against hepatic damage via the activation of AMPK pathway. Accordingly, BFE may have therapeutic potential for diverse liver disorders.

Activation of AMPK by Buddleja officinalis Maxim. Flower Extract Contributes to Protecting Hepatocytes from Oxidative Stress

Directory of Open Access Journals (Sweden)

Ji Yun Jung

2017-01-01

Full Text Available The Buddleja officinalis Maxim. flower is used in traditional Chinese and Korean medicine to treat inflammation, vascular diseases, headache, and stroke, as well as enhance liver function. This research investigated the effects of B. officinalis Maxim. flower extract (BFE on hepatotoxicity. The cytoprotective effects and mechanism of BFE against severe mitochondrial dysfunction and H2O2 production in hepatotoxicity induced by coadministration of arachidonic acid (AA and iron were observed in the HepG2 cell line. In addition, we performed blood biochemical, histopathological, and histomorphometric analyses of mice with carbon tetrachloride- (CCl4- induced acute liver damage. BFE inhibited the AA + iron-mediated hepatotoxicity of HepG2 cells. Moreover, it inhibited mitochondrial dysfunction, H2O2 production, and glutathione depletion mediated by AA + iron in the same cells. Meanwhile, the cytoprotective effects of BFE against oxidative stress were associated with the activation of AMP-activated protein kinase (AMPK. In particular, based on the histopathological observations, BFE (30 and 100 mg/kg showed clear hepatoprotective effects against CCl4-induced acute hepatic damage. Furthermore, it inhibited 4-hydroxynonenal and nitrotyrosine immunoreactivity in hepatocytes. These results provide evidence that BFE has beneficial hepatoprotective effects against hepatic damage via the activation of AMPK pathway. Accordingly, BFE may have therapeutic potential for diverse liver disorders.

The Principal's Role in Leading Instructional Change: A Case Study in New Program Adoption

Science.gov (United States)

Breon, Amy

2016-01-01

The noise in generating an agreed upon definition of instructional leadership that extends beyond theory to the practice of principals has been almost deafening in the last few decades. Many emphasize the need for the role of the principal to adapt to meet the demands of leadership that maximizes student achievement, but lack the specificity to…

Identifying and Addressing Themes of Job Dissatisfaction for Secondary Principals

Science.gov (United States)

De Jong, David; Grundmeyer, Trent; Yankey, Julie

2017-01-01

Secondary principals serve in important roles that are complex, high-stress, and include demanding job responsibilities. Key stakeholders such as superintendents, school board members, and legislators must understand the challenges facing secondary principals in order to address the current themes of job dissatisfaction. Using new survey data…

Tolerance to oxidative stress is required for maximal xylem colonization by the xylem-limited bacterial phytopathogen, Xylella fastidiosa.

Science.gov (United States)

Wang, Peng; Lee, Yunho; Igo, Michele M; Roper, M Caroline

2017-09-01

Bacterial plant pathogens often encounter reactive oxygen species (ROS) during host invasion. In foliar bacterial pathogens, multiple regulatory proteins are involved in the sensing of oxidative stress and the activation of the expression of antioxidant genes. However, it is unclear whether xylem-limited bacteria, such as Xylella fastidiosa, experience oxidative stress during the colonization of plants. Examination of the X. fastidiosa genome uncovered only one homologue of oxidative stress regulatory proteins, OxyR. Here, a knockout mutation in the X. fastidiosa oxyR gene was constructed; the resulting strain was significantly more sensitive to hydrogen peroxide (H 2 O 2 ) relative to the wild-type. In addition, during early stages of grapevine infection, the survival rate was 1000-fold lower for the oxyR mutant than for the wild-type. This supports the hypothesis that grapevine xylem represents an oxidative environment and that X. fastidiosa must overcome this challenge to achieve maximal xylem colonization. Finally, the oxyR mutant exhibited reduced surface attachment and cell-cell aggregation and was defective in biofilm maturation, suggesting that ROS could be a potential environmental cue stimulating biofilm development during the early stages of host colonization. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Crystallographic cut that maximizes of the birefringence in photorefractive crystals

OpenAIRE

Rueda-Parada, Jorge Enrique

2017-01-01

The electro-optical birefringence effect depends on the crystal type, cut crystal, applied electric field and the incidence direction of light on the principal crystal faces. It is presented a study of maximizing the birefringence in photorefractive crystals of cubic crystallographic symmetry, in terms of these three parameters. General analytical expressions for the birefringence were obtained, from which birefringence can be established for any type of cut. A new crystallographic cut was en...

Phenomenology of maximal and near-maximal lepton mixing

International Nuclear Information System (INIS)

Gonzalez-Garcia, M. C.; Pena-Garay, Carlos; Nir, Yosef; Smirnov, Alexei Yu.

2001-01-01

The possible existence of maximal or near-maximal lepton mixing constitutes an intriguing challenge for fundamental theories of flavor. We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other (x=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter ε(equivalent to)1-2sin 2 θ ex and quantify the present experimental status for |ε| e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 -8 eV 2 ∼ 2 ∼ -7 eV 2 . In the mass ranges Δm 2 ∼>1.5x10 -5 eV 2 and 4x10 -10 eV 2 ∼ 2 ∼ -7 eV 2 the full interval |ε| e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay

(stress) testing

African Journals Online (AJOL)

However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01). Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, ...

Teaching Principal Components Using Correlations.

Science.gov (United States)

Westfall, Peter H; Arias, Andrea L; Fulton, Lawrence V

2017-01-01

Introducing principal components (PCs) to students is difficult. First, the matrix algebra and mathematical maximization lemmas are daunting, especially for students in the social and behavioral sciences. Second, the standard motivation involving variance maximization subject to unit length constraint does not directly connect to the "variance explained" interpretation. Third, the unit length and uncorrelatedness constraints of the standard motivation do not allow re-scaling or oblique rotations, which are common in practice. Instead, we propose to motivate the subject in terms of optimizing (weighted) average proportions of variance explained in the original variables; this approach may be more intuitive, and hence easier to understand because it links directly to the familiar "R-squared" statistic. It also removes the need for unit length and uncorrelatedness constraints, provides a direct interpretation of "variance explained," and provides a direct answer to the question of whether to use covariance-based or correlation-based PCs. Furthermore, the presentation can be made without matrix algebra or optimization proofs. Modern tools from data science, including heat maps and text mining, provide further help in the interpretation and application of PCs; examples are given. Together, these techniques may be used to revise currently used methods for teaching and learning PCs in the behavioral sciences.

Maximal Bell's inequality violation for non-maximal entanglement

International Nuclear Information System (INIS)

Kobayashi, M.; Khanna, F.; Mann, A.; Revzen, M.; Santana, A.

2004-01-01

Bell's inequality violation (BIQV) for correlations of polarization is studied for a product state of two two-mode squeezed vacuum (TMSV) states. The violation allowed is shown to attain its maximal limit for all values of the squeezing parameter, ζ. We show via an explicit example that a state whose entanglement is not maximal allow maximal BIQV. The Wigner function of the state is non-negative and the average value of either polarization is nil

Principal Investigator-in-a-Box

Science.gov (United States)

Young, Laurence R.

1999-01-01

Human performance in orbit is currently limited by several factors beyond the intrinsic awkwardness of motor control in weightlessness. Cognitive functioning can be affected by such factors as cumulative sleep loss, stress and the psychological effects of long-duration small-group isolation. When an astronaut operates a scientific experiment, the performance decrement associated with such factors can lead to lost or poor quality data and even the total loss of a scientific objective, at great cost to the sponsors and to the dismay of the Principal Investigator. In long-duration flights, as anticipated on the International Space Station and on any planetary exploration, the experimental model is further complicated by long delays between training and experiment, and the large number of experiments each crew member must perform. Although no documented studies have been published on the subject, astronauts report that an unusually large number of simple errors are made in space. Whether a result of the effects of microgravity, accumulated fatigue, stress or other factors, this pattern of increased error supports the need for a computerized decision-making aid for astronauts performing experiments. Artificial intelligence and expert systems might serve as powerful tools for assisting experiments in space. Those conducting space experiments typically need assistance exactly when the planned checklist does not apply. Expert systems, which use bits of human knowledge and human methods to respond appropriately to unusual situations, have a flexibility that is highly desirable in circumstances where an invariably predictable course of action/response does not exist. Frequently the human expert on the ground is unavailable, lacking the latest information, or not consulted by the astronaut conducting the experiment. In response to these issues, we have developed "Principal Investigator-in-a-Box," or [PI], to capture the reasoning process of the real expert, the Principal

Maximizing and customer loyalty: Are maximizers less loyal?

Directory of Open Access Journals (Sweden)

Linda Lai

2011-06-01

Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.

Principal Pressure in the Middle of Accountability

Science.gov (United States)

Derrington, Mary Lynne; Larsen, Donald E.

2012-01-01

When a new superintendent is hired, Tom Thompson, middle school principal, is squeezed between complying with the demands of the district and cultivating a positive culture in his school. He wrestles with the stress of facing tough leadership choices that take a toll on his physical and mental health. Tom realizes that a career-ending move might…

PEM-PCA: A Parallel Expectation-Maximization PCA Face Recognition Architecture

Directory of Open Access Journals (Sweden)

Kanokmon Rujirakul

2014-01-01

Full Text Available Principal component analysis or PCA has been traditionally used as one of the feature extraction techniques in face recognition systems yielding high accuracy when requiring a small number of features. However, the covariance matrix and eigenvalue decomposition stages cause high computational complexity, especially for a large database. Thus, this research presents an alternative approach utilizing an Expectation-Maximization algorithm to reduce the determinant matrix manipulation resulting in the reduction of the stages’ complexity. To improve the computational time, a novel parallel architecture was employed to utilize the benefits of parallelization of matrix computation during feature extraction and classification stages including parallel preprocessing, and their combinations, so-called a Parallel Expectation-Maximization PCA architecture. Comparing to a traditional PCA and its derivatives, the results indicate lower complexity with an insignificant difference in recognition precision leading to high speed face recognition systems, that is, the speed-up over nine and three times over PCA and Parallel PCA.

PEM-PCA: a parallel expectation-maximization PCA face recognition architecture.

Science.gov (United States)

Rujirakul, Kanokmon; So-In, Chakchai; Arnonkijpanich, Banchar

2014-01-01

Principal component analysis or PCA has been traditionally used as one of the feature extraction techniques in face recognition systems yielding high accuracy when requiring a small number of features. However, the covariance matrix and eigenvalue decomposition stages cause high computational complexity, especially for a large database. Thus, this research presents an alternative approach utilizing an Expectation-Maximization algorithm to reduce the determinant matrix manipulation resulting in the reduction of the stages' complexity. To improve the computational time, a novel parallel architecture was employed to utilize the benefits of parallelization of matrix computation during feature extraction and classification stages including parallel preprocessing, and their combinations, so-called a Parallel Expectation-Maximization PCA architecture. Comparing to a traditional PCA and its derivatives, the results indicate lower complexity with an insignificant difference in recognition precision leading to high speed face recognition systems, that is, the speed-up over nine and three times over PCA and Parallel PCA.

Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction.

Science.gov (United States)

Pexa, Brett S; Ryan, Eric D; Myers, Joseph B

2018-04-01

Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis. To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo. Controlled laboratory study. Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition. The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous

Principles of maximally classical and maximally realistic quantum ...

Indian Academy of Sciences (India)

Principles of maximally classical and maximally realistic quantum mechanics. S M ROY. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2N-dimensional phase space, ...

Biomechanical characteristics of handballing maximally in Australian football.

Science.gov (United States)

Parrington, Lucy; Ball, Kevin; MacMahon, Clare

2014-11-01

The handball pass is influential in Australian football, and achieving higher ball speeds in flight is an advantage in increasing distance and reducing the chance of interceptions. The purpose of this study was to provide descriptive kinematic data and identify key technical aspects of maximal handball performance. Three-dimensional full body kinematic data from 19 professional Australian football players performing handball pass for maximal speed were collected, and the hand speed at ball contact was used to determine performance. Sixty-four kinematic parameters initially obtained were reduced to 15, and then grouped into like components through a two-stage supervised principal components analysis procedure. These components were then entered into a multiple regression analysis, which indicated that greater hand speed was associated with greater shoulder angular velocity and separation angle between the shoulders and pelvis at ball contact, as well as an earlier time of maximum upper-trunk rotation velocity. These data suggested that in order to increase the speed of the handball pass in Australian football, strategies like increased shoulder angular velocity, increased separation angle at ball contact, and earlier achievement of upper-trunk rotation speed might be beneficial.

Profit maximization mitigates competition

DEFF Research Database (Denmark)

Dierker, Egbert; Grodal, Birgit

1996-01-01

We consider oligopolistic markets in which the notion of shareholders' utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price...... competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution...... of profits among consumers fully into account and partial equilibrium analysis suffices...

Implications of maximal Jarlskog invariant and maximal CP violation

International Nuclear Information System (INIS)

Rodriguez-Jauregui, E.; Universidad Nacional Autonoma de Mexico

2001-04-01

We argue here why CP violating phase Φ in the quark mixing matrix is maximal, that is, Φ=90 . In the Standard Model CP violation is related to the Jarlskog invariant J, which can be obtained from non commuting Hermitian mass matrices. In this article we derive the conditions to have Hermitian mass matrices which give maximal Jarlskog invariant J and maximal CP violating phase Φ. We find that all squared moduli of the quark mixing elements have a singular point when the CP violation phase Φ takes the value Φ=90 . This special feature of the Jarlskog invariant J and the quark mixing matrix is a clear and precise indication that CP violating Phase Φ is maximal in order to let nature treat democratically all of the quark mixing matrix moduli. (orig.)

Maximizers versus satisficers

Directory of Open Access Journals (Sweden)

Andrew M. Parker

2007-12-01

Full Text Available Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007. Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002, we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions, more avoidance of decision making, and greater tendency to experience regret. Contrary to predictions, self-reported maximizers were more likely to report spontaneous decision making. However, the relationship between self-reported maximizing and worse life outcomes is largely unaffected by controls for measures of other decision-making styles, decision-making competence, and demographic variables.

Managing Stress in the Principalship.

Science.gov (United States)

Lyons, James E.

1990-01-01

The principal's office is frequently a collection point for problems and demands. Secondary school principals often average 1,000 interactions daily. Principals can manage stress by declining to solve every problem, delegating responsibility, reexamining their supervisory role, developing networks of trusted friends, and engaging in…

Maximizing opto‐mechanical interaction using topology optimization

DEFF Research Database (Denmark)

Gersborg, Allan Roulund; Sigmund, Ole

2011-01-01

is performed on a periodic cell and the periodic modeling of the optical and mechanical fields have been carried out using transverse electric Bloch waves and homogenization theory in a plane stress setting, respectively. Two coupling effects are included being the photoelastic effect and the geometric effect......This paper studies topology optimization of a coupled opto‐mechanical problem with the goal of finding the material layout which maximizes the optical modulation, i.e. the difference between the optical response for the mechanically deformed and undeformed configuration. The optimization...

Applicability of initial stress measurement methods to Horonobe Siliceous rocks and initial stress state around Horonobe Underground Research Laboratory

International Nuclear Information System (INIS)

Sanada, Hiroyuki; Niunoya, Sumio; Matsui, Hiroya; Fujii, Yoshiaki

2009-01-01

Understanding initial stress condition in deep underground is important for such construction as rock cavern for geological disposal of HLW and underground power plant. Neogene sedimentary rock is widely distributed in Japan. There are only a few studies of initial stress measurement in Neogene sedimentary rock mass in Japan due to difficulty of measurement. Evaluation of initial stress condition around Horonobe Underground Research Laboratory Project was carried out in order to understand initial stress condition and applicability of AE, DSCA and hydraulic fracturing (HF) methods to Neogene sedimentary rock. Initial stress values obtained from AE method is smaller than overburden pressure due to time dependency of Kaizer effect. It would be difficult to use AE method as initial stress measurement method for Horonobe Siliceous rocks. Principal stress values by DSCA are similar to those by HF tests. Directions of maximum horizontal principal stresses are approximately in E-W and corresponded to HF results. In HF, rod type and wire-line type systems were compared. Workability of rod type was much better than wire-line type. However, re-opening pressure were not able to be precisely measured in case of rod type system due to the large compliance of the packers and rods. Horizontal maximum and minimum principal stresses increase linearly in HF results. Deviatoric stress is acting at shallow depth. Initial stress condition approaches hydrostatic condition with depth. Direction of maximum horizontal principal stress was in E-W direction which was similar to tectonic movement around Horonobe URL by triangular surveying. (author)

Mapping Tectonic Stress Using Earthquakes

International Nuclear Information System (INIS)

Arnold, Richard; Townend, John; Vignaux, Tony

2005-01-01

An earthquakes occurs when the forces acting on a fault overcome its intrinsic strength and cause it to slip abruptly. Understanding more specifically why earthquakes occur at particular locations and times is complicated because in many cases we do not know what these forces actually are, or indeed what processes ultimately trigger slip. The goal of this study is to develop, test, and implement a Bayesian method of reliably determining tectonic stresses using the most abundant stress gauges available - earthquakes themselves.Existing algorithms produce reasonable estimates of the principal stress directions, but yield unreliable error bounds as a consequence of the generally weak constraint on stress imposed by any single earthquake, observational errors, and an unavoidable ambiguity between the fault normal and the slip vector.A statistical treatment of the problem can take into account observational errors, combine data from multiple earthquakes in a consistent manner, and provide realistic error bounds on the estimated principal stress directions.We have developed a realistic physical framework for modelling multiple earthquakes and show how the strong physical and geometrical constraints present in this problem allow inference to be made about the orientation of the principal axes of stress in the earth's crust

Developing maximal neuromuscular power: Part 1--biological basis of maximal power production.

Science.gov (United States)

Cormie, Prue; McGuigan, Michael R; Newton, Robert U

2011-01-01

This series of reviews focuses on the most important neuromuscular function in many sport performances, the ability to generate maximal muscular power. Part 1 focuses on the factors that affect maximal power production, while part 2, which will follow in a forthcoming edition of Sports Medicine, explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability of the neuromuscular system to generate maximal power is affected by a range of interrelated factors. Maximal muscular power is defined and limited by the force-velocity relationship and affected by the length-tension relationship. The ability to generate maximal power is influenced by the type of muscle action involved and, in particular, the time available to develop force, storage and utilization of elastic energy, interactions of contractile and elastic elements, potentiation of contractile and elastic filaments as well as stretch reflexes. Furthermore, maximal power production is influenced by morphological factors including fibre type contribution to whole muscle area, muscle architectural features and tendon properties as well as neural factors including motor unit recruitment, firing frequency, synchronization and inter-muscular coordination. In addition, acute changes in the muscle environment (i.e. alterations resulting from fatigue, changes in hormone milieu and muscle temperature) impact the ability to generate maximal power. Resistance training has been shown to impact each of these neuromuscular factors in quite specific ways. Therefore, an understanding of the biological basis of maximal power production is essential for developing training programmes that effectively enhance maximal power production in the human.

Stress measurements in the Stripa granite. Technical project report No. 4

International Nuclear Information System (INIS)

Carlsson, H.

1978-08-01

Rock stress measurements at the 348 m level of the Stripa Mine have been carried out with the Leeman tri-axial equipment. The largest principal stress is found to be 20.0 MPa and directed parallel with the strike of the contact between the granite and the orebody. The intermediate principal stress is 11.4 MPa and directed almost horizontal and perpendicular to the contact. The minor principal stress has a magnitude of 5.4 MPa. The deduced vertical stress is approximately of the same value as can be theoretically calculated

Combined shape and topology optimization for minimization of maximal von Mises stress

DEFF Research Database (Denmark)

Lian, Haojie; Christiansen, Asger Nyman; Tortorelli, Daniel A.

2017-01-01

This work shows that a combined shape and topology optimization method can produce optimal 2D designs with minimal stress subject to a volume constraint. The method represents the surface explicitly and discretizes the domain into a simplicial complex which adapts both structural shape and topology....... By performing repeated topology and shape optimizations and adaptive mesh updates, we can minimize the maximum von Mises stress using the p-norm stress measure with p-values as high as 30, provided that the stress is calculated with sufficient accuracy....

Flux-pinning-induced stresses in a hollow superconducting cylinder with flux creep and viscosity properties

International Nuclear Information System (INIS)

Feng, W.J.; Gao, S.W.

2014-01-01

Highlights: • Magnetoelastic problem for a superconducting cylinder with a hole is investigated. • The effects of both flux creep and viscous flux flow on stresses are analyzed. • For the FC case, the maximal hoop tensile stress always occurs at hole edge. • For the ZFC case, the maximal hoop stress is not certain to occur at hole edge. - Abstract: The magnetoelastic problem for a superconducting cylinder with a concentric hole placed in a magnetic field is investigated, where the flux creep and viscous flux flow have been considered. The stress distributions are derived and numerical calculated for the descending field in both the zero-field cooling (ZFC) and field cooling (FC) processes. The effects of applied magnetic field, flux creep and viscous flux flow on the maximal radial and hoop stresses are discussed in detail, and some novel phenomena are found. Among others, for the FC case, the maximal hoop tensile stress always occurs at the hole edge, whist for the ZFC case, the maximal stresses including both hoop and radial stresses either occur in the vicinity of the hole or occur at the position of flux frontier in the remagnetization process. For the descending field, in general, both the flux creep and viscosity parameters have important effects on the maximal radial and hoop stresses. All these phenomena are perhaps of vital importance for the application of superconductors

Visible Leading: Principal Academy Connects and Empowers Principals

Science.gov (United States)

Hindman, Jennifer; Rozzelle, Jan; Ball, Rachel; Fahey, John

2015-01-01

The School-University Research Network (SURN) Principal Academy at the College of William & Mary in Williamsburg, Virginia, has a mission to build a leadership development program that increases principals' instructional knowledge and develops mentor principals to sustain the program. The academy is designed to connect and empower principals…

Combined shape and topology optimization for minimization of maximal von Mises stress

International Nuclear Information System (INIS)

Lian, Haojie; Christiansen, Asger N.; Tortorelli, Daniel A.; Sigmund, Ole; Aage, Niels

2017-01-01

Here, this work shows that a combined shape and topology optimization method can produce optimal 2D designs with minimal stress subject to a volume constraint. The method represents the surface explicitly and discretizes the domain into a simplicial complex which adapts both structural shape and topology. By performing repeated topology and shape optimizations and adaptive mesh updates, we can minimize the maximum von Mises stress using the p-norm stress measure with p-values as high as 30, provided that the stress is calculated with sufficient accuracy.

A comparative meta-analysis of maximal aerobic metabolism of vertebrates: implications for respiratory and cardiovascular limits to gas exchange.

Science.gov (United States)

Hillman, Stanley S; Hancock, Thomas V; Hedrick, Michael S

2013-02-01

Maximal aerobic metabolic rates (MMR) in vertebrates are supported by increased conductive and diffusive fluxes of O(2) from the environment to the mitochondria necessitating concomitant increases in CO(2) efflux. A question that has received much attention has been which step, respiratory or cardiovascular, provides the principal rate limitation to gas flux at MMR? Limitation analyses have principally focused on O(2) fluxes, though the excess capacity of the lung for O(2) ventilation and diffusion remains unexplained except as a safety factor. Analyses of MMR normally rely upon allometry and temperature to define these factors, but cannot account for much of the variation and often have narrow phylogenetic breadth. The unique aspect of our comparative approach was to use an interclass meta-analysis to examine cardio-respiratory variables during the increase from resting metabolic rate to MMR among vertebrates from fish to mammals, independent of allometry and phylogeny. Common patterns at MMR indicate universal principles governing O(2) and CO(2) transport in vertebrate cardiovascular and respiratory systems, despite the varied modes of activities (swimming, running, flying), different cardio-respiratory architecture, and vastly different rates of metabolism (endothermy vs. ectothermy). Our meta-analysis supports previous studies indicating a cardiovascular limit to maximal O(2) transport and also implicates a respiratory system limit to maximal CO(2) efflux, especially in ectotherms. Thus, natural selection would operate on the respiratory system to enhance maximal CO(2) excretion and the cardiovascular system to enhance maximal O(2) uptake. This provides a possible evolutionary explanation for the conundrum of why the respiratory system appears functionally over-designed from an O(2) perspective, a unique insight from previous work focused solely on O(2) fluxes. The results suggest a common gas transport blueprint, or Bauplan, in the vertebrate clade.

Maximizers versus satisficers

OpenAIRE

Andrew M. Parker; Wandi Bruine de Bruin; Baruch Fischhoff

2007-01-01

Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions...

Positive exercise thallium-201 test responses in patients with less than 50% maximal coronary stenosis: angiographic and clinical predictors

International Nuclear Information System (INIS)

Brown, K.A.; Osbakken, M.; Boucher, C.A.; Strauss, H.W.; Pohost, G.M.; Okada, R.D.

1985-01-01

The incidence and causes of abnormal thallium-201 (TI-201) myocardial perfusion studies in the absence of significant coronary artery disease were examined. The study group consisted of 100 consecutive patients undergoing exercise TI-201 testing and coronary angiography who were found to have maximal coronary artery diameter narrowing of less than 50%. Maximal coronary stenosis ranged from 0 to 40%. The independent and relative influences of patient clinical, exercise and angiographic data were assessed by logistic regression analysis. Significant predictors of a positive stress TI-201 test result were: (1) percent maximal coronary stenosis (p less than 0.0005), (2) propranolol use (p less than 0.01), (3) interaction of propranolol use and percent maximal stenosis (p less than 0.005), and (4) stress-induced chest pain (p . 0.05). No other patient variable had a significant influence. Positive TI-201 test results were more common in patients with 21 to 40% maximal stenosis (59%) than in patients with 0 to 20% maximal stenosis (27%) (p less than 0.01). Among patients with 21 to 40% stenosis, a positive test response was more common when 85% of maximal predicted heart rate was achieved (75%) than when it was not (40%) (p less than 0.05). Of 16 nonapical perfusion defects seen in patients with 21 to 40% maximal stenosis, 14 were in the territory that corresponded with such a coronary stenosis. Patients taking propranolol were more likely to have a positive TI-201 test result (45%) than patients not taking propranolol (22%) (p less than 0.05)

Maximal power output during incremental exercise by resistance and endurance trained athletes.

Science.gov (United States)

Sakthivelavan, D S; Sumathilatha, S

2010-01-01

This study was aimed at comparing the maximal power output by resistance trained and endurance trained athletes during incremental exercise. Thirty male athletes who received resistance training (Group I) and thirty male athletes of similar age group who received endurance training (Group II) for a period of more than 1 year were chosen for the study. Physical parameters were measured and exercise stress testing was done on a cycle ergometer with a portable gas analyzing system. The maximal progressive incremental cycle ergometer power output at peak exercise and carbon dioxide production at VO2max were measured. Highly significant (P biofeedback and perk up the athlete's performance.

Entropy maximization

Indian Academy of Sciences (India)

Abstract. It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf f that satisfy. ∫ fhi dμ = λi for i = 1, 2,...,...k the maximizer of entropy is an f0 that is pro- portional to exp(. ∑ ci hi ) for some choice of ci . An extension of this to a continuum of.

Biomarkers of Risk for Post-Traumatic Stress Disorder (PTSD)

Science.gov (United States)

2008-05-01

post - traumatic stress disorder ( PTSD ),” Principal Investigator, 4/07-4/10, $276,422. 12. R01 MH0687670-01 “DEX/CRH Response... Stress Disorder ( PTSD ) PRINCIPAL INVESTIGATOR: Audrey R. Tyrka, M.D., Ph.D. CONTRACTING ORGANIZATION: Butler Hospital... Stress Disorder ( PTSD ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-07-1-0269 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Audrey R.

Entropy Maximization

Indian Academy of Sciences (India)

It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf that satisfy ∫ f h i d = i for i = 1 , 2 , … , … k the maximizer of entropy is an f 0 that is proportional to exp ⁡ ( ∑ c i h i ) for some choice of c i . An extension of this to a continuum of ...

Endogenous Market Structures and Contract Theory. Delegation, principal-agent contracts, screening, franchising and tying

OpenAIRE

Etro Federico

2010-01-01

I study the role of unilateral strategic contracts for firms active in markets with price competition and endogenous entry. Traditional results change substantially when the market structure is endogenous rather than exogenous. They concern 1) contracts of managerial delegation to non-profit maximizers, 2) incentive principal-agent contracts in the presence of moral hazard on cost reducing activities, 3) screening contracts in case of asymmetric information on the productivity of the managers...

Burnout And Lifestyle Of Principals And Entrepreneurs

Directory of Open Access Journals (Sweden)

Jasna Lavrenčič

2014-12-01

Full Text Available Research Question (RQ: What kind of lifestyle do the principals and entrepreneurs lead? Does the lifestyle of principals and entrepreneurs influence burnout? Purpose: To find out, based on the results of a questionnaire, what kind of lifestyle both researched groups lead. Does lifestyle have an influence on the occurrence of the phenomenon of burnout. Method: We used the method of data collection by questionnaire. Acquired data were analyzed using SPSS, descriptive and inference statistics. Results: Results showed, that both groups lead a similar lifestyle and that lifestyle influences burnout with principals, as well as entrepreneurs. Organization: School principals and entrepreneurs are the heads of individual organizations or companies, the goal of which is success. To be successful in their work, they must adapt their lifestyle, which can be healthy or unhealthy. If their lifestyle is unhealthy, it can lead to burnout. Society: With results of the questionnaire we would like to answer the question about the lifestyle of both groups and its influence on the occurrence of burnout. Originality: The study of lifestyle and the occurrence of burnout in these two groups is the first study in this area. Limitations/Future Research: In continuation, research groups could be submitted to the research fields of effort physiology and tracking of certain haematological parameters, such as cholesterol, blood sugar and stress hormones - adrenaline, noradrenalin, cortisol. Thus, we could carry out an even more in depth research of the connection between lifestyle and burnout.

Effect of material strength on the relationship between the principal Hugoniot and quasi-isentrope of beryllium and 6061-T6 aluminum below 35 GPa

International Nuclear Information System (INIS)

Moss, W.C.

1985-01-01

Quasi-isentropic (QI) compression can be achieved by loading a specimen with a low strain rate, long rise time uniaxial strain wave. Recent experimental data show that the quasi-isentrope of 6061-T6 aluminum lies a few percent above the principal Hugoniot, that is, at a given specific volume, the QI stress exceeds the principal Hugoniot stress. It has been suggested that this effect is due to material strength. Using Hugoniot data, shock-reshock, and shock-unload data for beryllium and 6061-T6 aluminum, we have constructed the quasi-isentropes as functions of specific volume. Our results show that the QI stress exceeds the principal Hugoniot stress above a Hugoniot stress of 8.4 GPa in beryllium, and between Hugoniot stresses of 3.8 and 21.4 GPa in aluminum. The effect is due to strength and implies that the QI yield strength can be large. Our calculations show that the QI yield strength is 0.9 GPa in aluminum at a QI stress of 9 GPa, and 5.2 GPa in beryllium at a QI stress of 35 GPa

A comparison of maximal exercise and dipyridamole thallium-201 planar gated scintigraphy

International Nuclear Information System (INIS)

Martin, W.; Tweddel, A.C.; Main, G.; Hutton, I.

1992-01-01

Both symptom-limited maximal exercise and intravenously given dipyridamole stress (0.56 mg/kg over 4 min with a 2 min walk) gated thallium scans were performed in 22 patients undergoing coronary arteriography for the assessment of chest pain. All scans were acquired gated to the electrocardiogram in 3 projections and were reported for the presence and extent of defects in 5 myocardial segments in each view. In addition, left and right ventricular myocardial uptake and estimates of right and left lung and liver to left ventricular uptake were assessed relative to the injected dose of thallium-201. Overall, 190/310 segments were abnormal with exercise compared with 169/310 with dipyridamole. Segments were scored greater in extent in 90/310 cases with exercise, compared with 46/310 in which the defect was more extensive with dipyridamole. Non-attenuation corrected percentage myocardial thallium uptakes were similar for both stresses. Left and right lung and liver to left ventricle ratios were all significantly higher with dipyridamole than with exercise. High right and left lung uptakes with dipyridamole were strongly correlated with high exercise values. The liver uptake was weakly correlated between the 2 different stress tests. These results demonstrate that dipyridamole induces fewer and less extensive thallium perfusion defects than maximal exercise, and that liver and lung to myocardial ratios are higher with dipyridamole than with exercise. (orig./MG)

Maximally incompatible quantum observables

Energy Technology Data Exchange (ETDEWEB)

Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

2014-05-01

The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

Maximally incompatible quantum observables

International Nuclear Information System (INIS)

Heinosaari, Teiko; Schultz, Jussi; Toigo, Alessandro; Ziman, Mario

2014-01-01

The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

Effects of composite adherend properties on stresses in double lap bonded joints

International Nuclear Information System (INIS)

Mokhtari, M.; Madani, K.; Belhouari, M.; Touzain, S.; Feaugas, X.; Ratwani, M.

2013-01-01

Highlights: ► We analysis the maximal stresses distribution in the adhesive and the adherend for double lap joint. ► We modified the mechanical properties of adherend layer to decreases the stresses in adhesive layer. ► Then, we analysis the influence of modifying the types of fibers on maximal stresses distributions. ► We analysis the thickness modifications of some layers on maximal stresses distribution. ► In last, we analysis the combination of different modifications on maximal stresses distribution. -- Abstract: The effects of composite layer stiffness, thickness and ply orientations on stresses in the adhesive layer of a double lap bonded joint are investigated using three-dimensional finite element analysis code ABAQUS. A special 3-layer modelling technique is used in the finite element analysis. The non-linear behaviour of adhesive is also considered. Six composite laminates with different ply orientations are used in the lap-joint analysis. The composite materials considered in the analysis are – carbon epoxy, boron epoxy, T300/934 graphite-epoxy, and aramid epoxy. The analysis results indicate that the maximum stress in the adhesive can be significantly reduced by changing the stiffness and fibre orientations in the composite layer. Also, the use of hybrid composite (changing the nature of the fibres in two layers which are near the adhesive layer) results in reducing adhesive shear stresses.

Maximal combustion temperature estimation

International Nuclear Information System (INIS)

Golodova, E; Shchepakina, E

2006-01-01

This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

Developing maximal neuromuscular power: part 2 - training considerations for improving maximal power production.

Science.gov (United States)

Cormie, Prue; McGuigan, Michael R; Newton, Robert U

2011-02-01

This series of reviews focuses on the most important neuromuscular function in many sport performances: the ability to generate maximal muscular power. Part 1, published in an earlier issue of Sports Medicine, focused on the factors that affect maximal power production while part 2 explores the practical application of these findings by reviewing the scientific literature relevant to the development of training programmes that most effectively enhance maximal power production. The ability to generate maximal power during complex motor skills is of paramount importance to successful athletic performance across many sports. A crucial issue faced by scientists and coaches is the development of effective and efficient training programmes that improve maximal power production in dynamic, multi-joint movements. Such training is referred to as 'power training' for the purposes of this review. Although further research is required in order to gain a deeper understanding of the optimal training techniques for maximizing power in complex, sports-specific movements and the precise mechanisms underlying adaptation, several key conclusions can be drawn from this review. First, a fundamental relationship exists between strength and power, which dictates that an individual cannot possess a high level of power without first being relatively strong. Thus, enhancing and maintaining maximal strength is essential when considering the long-term development of power. Second, consideration of movement pattern, load and velocity specificity is essential when designing power training programmes. Ballistic, plyometric and weightlifting exercises can be used effectively as primary exercises within a power training programme that enhances maximal power. The loads applied to these exercises will depend on the specific requirements of each particular sport and the type of movement being trained. The use of ballistic exercises with loads ranging from 0% to 50% of one-repetition maximum (1RM) and

Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room

Directory of Open Access Journals (Sweden)

Ballinger Michelle R

2008-01-01

Full Text Available Abstract Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR. It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

Hydraulic fracturing stress measurements at Yucca Mountain, Nevada, and relationship to the regional stress field

International Nuclear Information System (INIS)

Stock, J.M.; Healy, J.H.; Hickman, S.H.; Zoback, M.D.

1985-01-01

Hydraulic fracturing stress measurements and acoustic borehole televiewer logs were run in holes USW G-1 and USW G-2 at Yucca Mountain as part of the Nevada Nuclear Waste Storage Investigations for the U. S. Department of Energy. Eight tests in the saturated zone, at depths from 646 to 1288 m, yielded values of the least horizontal stress S/sub h/ that are considerably lower than the vertical principal stress S/sub v/. In tests for which the greatest horizontal principal stress S/sub H/ could be determined, it was found to be less than S/sub v/, indicating a normal faulting stress regime. The borehole televiewer logs showed the presence of long (in excess of 10 m), vertical, drilling-induced fractures in the first 300 m below the water table. These are believed to form by the propagation of small preexisting cracks under the excess downhole fluid pressures (up to 5.2 MPa) applied during drilling. The presence of these drilling-induced hydrofractures provides further confirmation of the low value of the least horizontal stresses. A least horizontal principal stress direction of N60 0 W--N65 0 W is indicated by the orientation of the drilling-induced hydrofractures (N25 0 E--N30 0 E), and the orientation of stress-induced well bore breakouts in the lower part of USW G-2 (N65 0 W). This direction is in good agreement with indicators of stress direction from elsewhere at the Nevada Test Site. The observed stress magnitudes and directions were examined for the possibility of slip on preexisting faults. Using these data, the Coulomb criterion for frictional sliding suggests that for coefficients of friction close to 0.6, movement on favorably oriented faults could be expected

Principal Component Analysis - A Powerful Tool in Computing Marketing Information

Directory of Open Access Journals (Sweden)

Constantin C.

2014-12-01

Full Text Available This paper is about an instrumental research regarding a powerful multivariate data analysis method which can be used by the researchers in order to obtain valuable information for decision makers that need to solve the marketing problem a company face with. The literature stresses the need to avoid the multicollinearity phenomenon in multivariate analysis and the features of Principal Component Analysis (PCA in reducing the number of variables that could be correlated with each other to a small number of principal components that are uncorrelated. In this respect, the paper presents step-by-step the process of applying the PCA in marketing research when we use a large number of variables that naturally are collinear.

Principals as Leaders of School and Community Revitalization: A Phenomenological Study of Three Urban Schools in Morocco

Science.gov (United States)

Elmeski, Mohammed

2015-01-01

This article explores leadership of place in the context of three urban middle schools in Morocco. School reform means that principals are changing from agents of authority to leaders with school improvement responsibilities. This shift in mission can be stressful for principals who are called to lead, but are often constrained by bureaucratic and…

Patterns of stress responses shift during seasonal life-history transitions: An analysis comparing baseline, maximal and integrated corticosterone in female red-sided garter snakes (Thamnophis sirtalis parietalis).

Science.gov (United States)

Dayger, Catherine A; Lutterschmidt, Deborah I

2017-05-15

Glucocorticoids often rise and fall with a variety of external and internal cues and frequently vary among life-history stages. This suggests that changing glucocorticoids may coordinate life-history transitions. To explore this hypothesis, we asked if the time-course of stress-induced glucocorticoid levels differ between two life-history transitions (i.e., spring and fall migration) in female red-sided garter snakes (Thamnophis sirtalis parietalis). We collected non-migratory females from a communal den and migratory females from a road along the migration route and treated them with 4h of capture stress; plasma corticosterone was measured before, during and after capture stress. During the spring, den-collected females exhibited a stress-induced peak in corticosterone at an earlier sampling time than migrating, road-collected females. Because the pattern of corticosterone responses varied with migratory state, negative feedback on and/or sensitivity of the hypothalamus-pituitaryadrenal (HPA) axis may be linked to spring migration. During the fall, capture stress elicited an increase in corticosterone in den-collected females but not in migrating, road-collected females. Baseline corticosterone was higher and both maximal and integrated corticosterone responses were lower during the fall compared to spring, indicating that stress responses are smaller when baseline corticosterone is elevated, perhaps due to a "ceiling effect". These data suggest that HPA axis regulation changes during seasonal migration, possibly via altering negative feedback, HPA axis sensitivity, or some other mechanism. This study supports the hypothesis that glucocorticoids coordinate life-history events and suggests that examining a suite of stress response characteristics is most informative for understanding the function of HPA modulation. Copyright © 2017 Elsevier Inc. All rights reserved.

AUC-Maximizing Ensembles through Metalearning.

Science.gov (United States)

LeDell, Erin; van der Laan, Mark J; Petersen, Maya

2016-05-01

Area Under the ROC Curve (AUC) is often used to measure the performance of an estimator in binary classification problems. An AUC-maximizing classifier can have significant advantages in cases where ranking correctness is valued or if the outcome is rare. In a Super Learner ensemble, maximization of the AUC can be achieved by the use of an AUC-maximining metalearning algorithm. We discuss an implementation of an AUC-maximization technique that is formulated as a nonlinear optimization problem. We also evaluate the effectiveness of a large number of different nonlinear optimization algorithms to maximize the cross-validated AUC of the ensemble fit. The results provide evidence that AUC-maximizing metalearners can, and often do, out-perform non-AUC-maximizing metalearning methods, with respect to ensemble AUC. The results also demonstrate that as the level of imbalance in the training data increases, the Super Learner ensemble outperforms the top base algorithm by a larger degree.

Female Traditional Principals and Co-Principals: Experiences of Role Conflict and Job Satisfaction

Science.gov (United States)

Eckman, Ellen Wexler; Kelber, Sheryl Talcott

2010-01-01

This paper presents a secondary analysis of survey data focusing on role conflict and job satisfaction of 102 female principals. Data were collected from 51 female traditional principals and 51 female co-principals. By examining the traditional and co-principal leadership models as experienced by female principals, this paper addresses the impact…

Chronic Stress and Limbic-Hypothalamopituitary-Adrenal Axis (LHPA Response in Female Reproductive system

Directory of Open Access Journals (Sweden)

Farideh Zafari Zangeneh

2009-12-01

Full Text Available The hypothalamo-pituitary-adrenocortical (HPA axis is a critical adaptive system that maximizes survival potential in the face of physical or psychological challenge. The principal end products of the HPA axis, glucocorticoid hormones, act on multiple organ systems, including the brain, to maintain homeostatic balance. The brain is a target of stress, and the hippocampus is the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. These anatomical areas in brain are limbic system, and in particular the hippocampus, medial prefrontal cortex (mPFC and amigdal that have multiple control points in regulation of the hypothalamic–pituitary–adrenal (HPA axis. The studies show the prefrontal cortex (PFC plays an important role in the regulation of stress-induced hypothalamic–pituitary–adrenal (HPA activity and regulation of gonadal function in men and women is under the control of the HPA. This regulation is complex and sex steroids are important regulators of GnRH and gonadotropin release through classic feedback mechanisms in the hypothalamus and pituitary gland. Chronic stress can have a deleterious effect on the reproductive axis that, for females, is manifested in reduced pulsatile gonadotropin secretion and increased incidence of ovulatory abnormalities and infertility. The limbic–hypothalamic–pituitary–adrenal (LHPA axis suggests a functional role for gonadal steroids in the regulation of a female’s response to stress.

Is CP violation maximal

International Nuclear Information System (INIS)

Gronau, M.

1984-01-01

Two ambiguities are noted in the definition of the concept of maximal CP violation. The phase convention ambiguity is overcome by introducing a CP violating phase in the quark mixing matrix U which is invariant under rephasing transformations. The second ambiguity, related to the parametrization of U, is resolved by finding a single empirically viable definition of maximal CP violation when assuming that U does not single out one generation. Considerable improvement in the calculation of nonleptonic weak amplitudes is required to test the conjecture of maximal CP violation. 21 references

Shareholder, stakeholder-owner or broad stakeholder maximization

OpenAIRE

Mygind, Niels

2004-01-01

With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating stakeholder-owner. Maximization of shareholder value is a special case of owner-maximization, and only under quite re-strictive assumptions shareholder maximization is larger or equal to stakeholder-owner...

Task-oriented maximally entangled states

International Nuclear Information System (INIS)

Agrawal, Pankaj; Pradhan, B

2010-01-01

We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.

Multistage principal component analysis based method for abdominal ECG decomposition

International Nuclear Information System (INIS)

Petrolis, Robertas; Krisciukaitis, Algimantas; Gintautas, Vladas

2015-01-01

Reflection of fetal heart electrical activity is present in registered abdominal ECG signals. However this signal component has noticeably less energy than concurrent signals, especially maternal ECG. Therefore traditionally recommended independent component analysis, fails to separate these two ECG signals. Multistage principal component analysis (PCA) is proposed for step-by-step extraction of abdominal ECG signal components. Truncated representation and subsequent subtraction of cardio cycles of maternal ECG are the first steps. The energy of fetal ECG component then becomes comparable or even exceeds energy of other components in the remaining signal. Second stage PCA concentrates energy of the sought signal in one principal component assuring its maximal amplitude regardless to the orientation of the fetus in multilead recordings. Third stage PCA is performed on signal excerpts representing detected fetal heart beats in aim to perform their truncated representation reconstructing their shape for further analysis. The algorithm was tested with PhysioNet Challenge 2013 signals and signals recorded in the Department of Obstetrics and Gynecology, Lithuanian University of Health Sciences. Results of our method in PhysioNet Challenge 2013 on open data set were: average score: 341.503 bpm 2 and 32.81 ms. (paper)

Functional Principal Components Analysis of Shanghai Stock Exchange 50 Index

Directory of Open Access Journals (Sweden)

Zhiliang Wang

2014-01-01

Full Text Available The main purpose of this paper is to explore the principle components of Shanghai stock exchange 50 index by means of functional principal component analysis (FPCA. Functional data analysis (FDA deals with random variables (or process with realizations in the smooth functional space. One of the most popular FDA techniques is functional principal component analysis, which was introduced for the statistical analysis of a set of financial time series from an explorative point of view. FPCA is the functional analogue of the well-known dimension reduction technique in the multivariate statistical analysis, searching for linear transformations of the random vector with the maximal variance. In this paper, we studied the monthly return volatility of Shanghai stock exchange 50 index (SSE50. Using FPCA to reduce dimension to a finite level, we extracted the most significant components of the data and some relevant statistical features of such related datasets. The calculated results show that regarding the samples as random functions is rational. Compared with the ordinary principle component analysis, FPCA can solve the problem of different dimensions in the samples. And FPCA is a convenient approach to extract the main variance factors.

Numerical modeling of tectonic stress field and fault activity in North China

Directory of Open Access Journals (Sweden)

Li Yan

2012-02-01

Full Text Available On the basis of a 3-dimension visco-elastic finite element model of lithosphere in North China, we numerically simulate the recent mutative figures of tectonic stress field. Annual change characteristics of stress field are; 1 Maximum principal tensile stress is about 3–9 kPaa−1 and its azimuth lie in NNW-SSE. 2 Maximum principal compressive stress is about 1–6 kPaa−1 and its azimuth lie in NEE-SWW. 3 Maximum principal tensile stress is higher both in the west region and Liaoning Province. 4 Variation of tectonic stress field benefits fault movement in the west part and northeast part of North China. 5 Annual accumulative rates of Coulomb fracture stress in Tanlu fault belt have segmentation patterns: Jiashan-Guangji segment is the highest (6 kPaa−1, Anshan-Liaodongwan segment is the second (5 kPaa−1, and others are relatively lower (3–4 kPaa−1.

Sparse principal component analysis in medical shape modeling

Science.gov (United States)

Sjöstrand, Karl; Stegmann, Mikkel B.; Larsen, Rasmus

2006-03-01

Principal component analysis (PCA) is a widely used tool in medical image analysis for data reduction, model building, and data understanding and exploration. While PCA is a holistic approach where each new variable is a linear combination of all original variables, sparse PCA (SPCA) aims at producing easily interpreted models through sparse loadings, i.e. each new variable is a linear combination of a subset of the original variables. One of the aims of using SPCA is the possible separation of the results into isolated and easily identifiable effects. This article introduces SPCA for shape analysis in medicine. Results for three different data sets are given in relation to standard PCA and sparse PCA by simple thresholding of small loadings. Focus is on a recent algorithm for computing sparse principal components, but a review of other approaches is supplied as well. The SPCA algorithm has been implemented using Matlab and is available for download. The general behavior of the algorithm is investigated, and strengths and weaknesses are discussed. The original report on the SPCA algorithm argues that the ordering of modes is not an issue. We disagree on this point and propose several approaches to establish sensible orderings. A method that orders modes by decreasing variance and maximizes the sum of variances for all modes is presented and investigated in detail.

FLOUTING MAXIMS IN INDONESIA LAWAK KLUB CONVERSATION

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Rahmawati Sukmaningrum

2017-04-01

Full Text Available This study aims to identify the types of maxims flouted in the conversation in famous comedy show, Indonesia Lawak Club. Likewise, it also tries to reveal the speakers‘ intention of flouting the maxim in the conversation during the show. The writers use descriptive qualitative method in conducting this research. The data is taken from the dialogue of Indonesia Lawak club and then analyzed based on Grice‘s cooperative principles. The researchers read the dialogue‘s transcripts, identify the maxims, and interpret the data to find the speakers‘ intention for flouting the maxims in the communication. The results show that there are four types of maxims flouted in the dialogue. Those are maxim of quality (23%, maxim of quantity (11%, maxim of manner (31%, and maxim of relevance (35. Flouting the maxims in the conversations is intended to make the speakers feel uncomfortable with the conversation, show arrogances, show disagreement or agreement, and ridicule other speakers.

In situ stress measurements at 250m gallery off the ventilation shaft

International Nuclear Information System (INIS)

Nakamura, Takahiro; Sanada, Hiroyuki; Sugita, Yutaka; Kato, Harumi

2011-06-01

boreholes. Shut-in pressure of inclined transverse cracks and the circumferential position of longitudinal cracks on the wellbore surface were used to determine the magnitude and orientation of principal stress around the 250m gallery on the assumption that all of the target zones of hydraulic fracturing were in a uniform stress state. The determined in situ stress state showed a little difference of magnitude between intermediate stress and minimum stress. The vertical component of the in situ stress was evaluated to be about a half of the overburden at the test site. The maximum principal stress was inclined to about 40 degrees from the level with azimuth of NE orientation. The reason why the evaluated state of stress at 140m niches and 250m gallery are different would be attributed to geological environment. (2) Stress relief method by conical-ended borehole overcoring. Stress relief method by conical-ended borehole overcoring was successfully conducted at the depths of 17.25m and 17.72m of the borehole 09-V250-M02. Orientation of the evaluated principal stresses at the two depths showed a good agreement. The maximum principal stress inclined about 60 degrees from the level with azimuth of NNE and the intermediate principal stress was almost horizontal with WNW orientation. The orientation of the maximum principal stress was almost perpendicular to the plane of sedimentation of Koetoi formation and Wakkanai formation. The magnitude of the maximum principal stress was comparable to the uniaxial compressive strength of Wakkanai formation. The estimated ratio of the principal stresses σ 1 /σ 3 was 11.6 and 6.0 at the depth of 17.25m and 17.72m, respectively. No spalling of the walls of the boreholes due to the stress concentration was detected while both the magnitude and the ratio of principal stress were large enough to cause borehole breakout. The inconsistency would be explained by microcracks in the boring core formed during the drilling process or/and by elastic

VIOLATION OF CONVERSATION MAXIM ON TV ADVERTISEMENTS

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Desak Putu Eka Pratiwi

2015-07-01

Full Text Available Maxim is a principle that must be obeyed by all participants textually and interpersonally in order to have a smooth communication process. Conversation maxim is divided into four namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner of speaking. Violation of the maxim may occur in a conversation in which the information the speaker has is not delivered well to his speaking partner. Violation of the maxim in a conversation will result in an awkward impression. The example of violation is the given information that is redundant, untrue, irrelevant, or convoluted. Advertisers often deliberately violate the maxim to create unique and controversial advertisements. This study aims to examine the violation of maxims in conversations of TV ads. The source of data in this research is food advertisements aired on TV media. Documentation and observation methods are applied to obtain qualitative data. The theory used in this study is a maxim theory proposed by Grice (1975. The results of the data analysis are presented with informal method. The results of this study show an interesting fact that the violation of maxim in a conversation found in the advertisement exactly makes the advertisements very attractive and have a high value.

Finding Maximal Quasiperiodicities in Strings

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Pedersen, Christian N. S.

2000-01-01

of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...... in the suffix tree that have a superprimitive path-label....

Stress analysis of the HFIR HB-2 and HB-3 beam tube nozzles

International Nuclear Information System (INIS)

Williams, P.T.

1998-08-01

The results of three-dimensional linear elastic stress analyses of the HFIR HB-2 and HB-3 nozzles are presented in this report. Finite element models were developed using the PATRAN pre-processing code and translated into ABAQUS input file format. A scoping analysis using simple geometries with internal pressure loading was carried out to assess the capabilities of the ABAQUS/Standard code to calculate maximum principal stress distributions within cylinders with and without holes. These scoping calculations were also used to provide estimates for the variation in tangential stress around the rim of a nozzle using the superposition of published closed-form solutions for the stress around a hole in an infinite flat plate under uniaxial tension. From the results of the detailed finite element models, peak stress concentration factors (based on the maximum principal stresses in tension) were calculated to be 3.0 for the HB-2 nozzle and 2.8 for the HB-3 nozzle. Submodels for each nozzle were built to calculate the maximum principal stress distribution in the weldment region around the nozzle, where displacement boundary conditions for the submodels were automatically calculated by ABAQUS using the results of the global nozzle models. Maximum principal stresses are plotted and tabulated for eight positions around each nozzle and nozzle weldment

Shareholder, stakeholder-owner or broad stakeholder maximization

DEFF Research Database (Denmark)

Mygind, Niels

2004-01-01

With reference to the discussion about shareholder versus stakeholder maximization it is argued that the normal type of maximization is in fact stakeholder-owner maxi-mization. This means maximization of the sum of the value of the shares and stake-holder benefits belonging to the dominating...... including the shareholders of a company. Although it may be the ultimate goal for Corporate Social Responsibility to achieve this kind of maximization, broad stakeholder maximization is quite difficult to give a precise definition. There is no one-dimensional measure to add different stakeholder benefits...... not traded on the mar-ket, and therefore there is no possibility for practical application. Broad stakeholder maximization instead in practical applications becomes satisfying certain stakeholder demands, so that the practical application will be stakeholder-owner maximization un-der constraints defined...

On the maximal superalgebras of supersymmetric backgrounds

International Nuclear Information System (INIS)

Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

2009-01-01

In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

Preliminary analysis on the tectonic stress level in the source region of Tangshan earthquake

Science.gov (United States)

Jian-Tao, Zhao; Cui, Xiao-Feng; Xie, Fu-Ren

2002-05-01

The abundant data of focal mechanism solutions in Tangshan region, China, are inverted for the tectonic stress field. Combined with tectonophysical consideration, the magnitude of the three principal stresses, as well as their vertical variation under the average crustal rock property, in the source region of the 1976 Tangshan earthquake is estimated. The relationship between crustal stress and friction μ c, pore pressure P 0 and stress shape factor Φ is studied. The paper draws the conclusion that the vertical increasing rate of the maximum principal stress σ is directly proportional to friction, and inversely to pore pressure P 0 and stress shape factor Φ; while the vertical increasing rate of the minimum principal tress σ is directly proportional to pore pressure P 0, inversely to friction μ c and stress shape factor Φ. This study is a try to invert the data of focal mechanism solutions for the complete stress tensor.

Structural biomechanics of the craniomaxillofacial skeleton under maximal masticatory loading: Inferences and critical analysis based on a validated computational model.

Science.gov (United States)

Pakdel, Amir R; Whyne, Cari M; Fialkov, Jeffrey A

2017-06-01

The trend towards optimizing stabilization of the craniomaxillofacial skeleton (CMFS) with the minimum amount of fixation required to achieve union, and away from maximizing rigidity, requires a quantitative understanding of craniomaxillofacial biomechanics. This study uses computational modeling to quantify the structural biomechanics of the CMFS under maximal physiologic masticatory loading. Using an experimentally validated subject-specific finite element (FE) model of the CMFS, the patterns of stress and strain distribution as a result of physiological masticatory loading were calculated. The trajectories of the stresses were plotted to delineate compressive and tensile regimes over the entire CMFS volume. The lateral maxilla was found to be the primary vertical buttress under maximal bite force loading, with much smaller involvement of the naso-maxillary buttress. There was no evidence that the pterygo-maxillary region is a buttressing structure, counter to classical buttress theory. The stresses at the zygomatic sutures suggest that two-point fixation of zygomatic complex fractures may be sufficient for fixation under bite force loading. The current experimentally validated biomechanical FE model of the CMFS is a practical tool for in silico optimization of current practice techniques and may be used as a foundation for the development of design criteria for future technologies for the treatment of CMFS injury and disease. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Maximally multipartite entangled states

Science.gov (United States)

Facchi, Paolo; Florio, Giuseppe; Parisi, Giorgio; Pascazio, Saverio

2008-06-01

We introduce the notion of maximally multipartite entangled states of n qubits as a generalization of the bipartite case. These pure states have a bipartite entanglement that does not depend on the bipartition and is maximal for all possible bipartitions. They are solutions of a minimization problem. Examples for small n are investigated, both analytically and numerically.

Maximally Symmetric Composite Higgs Models.

Science.gov (United States)

Csáki, Csaba; Ma, Teng; Shu, Jing

2017-09-29

Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

Stress measurements in the Naesliden Mine

Energy Technology Data Exchange (ETDEWEB)

Leijon, B. [Univ. of Luleaa, Sweden; Carlsson, H.; Myrvang, A.

1980-05-15

Determinations of virgin stresses were performed at an early stage of the Naesliden Project in order to obtain input data for the finite element models of the mine. The Leeman three-dimensional overcoring technique was used at five locations on levels ranging from 210 m to 460 m below surface. Stress data were obtained at four of these locations. The results show an excess of horizontal stresses whilst the vertical stress is in accordance with the gravitational load from the overburden. The major and intermediate principal stresses are sub-horizontal and directed respectively perpendicular and parallel to the schisotsity of the wall rock and the strike of the tabular ore body. The minor principal stress is directed almost vertically. Stresses were also measured close to a stope on 300 m level in the mine. Biaxial and triaxial overcoring measurements were made at eighteen points between 0.25 m and 7.2 m above the roof of the stope. The stresses were found to have magnitudes of about 70 MPa close to the roof and to decrease rapidly with the distance from the roof. Stress measurements were made in connection with slot blastings in the foot wall, the latter measure being made in an attempt to de-stress the roof of stope 3. Two methods were used for stress monitorings, both showing that expected stress changes did not take place. Long-term stress guages have been installed in the ore body in order to monitor expected re-distributions of stresses due to mining. So far, the recorded stress changes are below 5 MPa.

Maximal quantum Fisher information matrix

International Nuclear Information System (INIS)

Chen, Yu; Yuan, Haidong

2017-01-01

We study the existence of the maximal quantum Fisher information matrix in the multi-parameter quantum estimation, which bounds the ultimate precision limit. We show that when the maximal quantum Fisher information matrix exists, it can be directly obtained from the underlying dynamics. Examples are then provided to demonstrate the usefulness of the maximal quantum Fisher information matrix by deriving various trade-off relations in multi-parameter quantum estimation and obtaining the bounds for the scalings of the precision limit. (paper)

Understanding Violations of Gricean Maxims in Preschoolers and Adults

Directory of Open Access Journals (Sweden)

Mako eOkanda

2015-07-01

Full Text Available This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants’ understanding of the following maxims was assessed: be informative (first maxim of quantity, avoid redundancy (second maxim of quantity, be truthful (maxim of quality, be relevant (maxim of relation, avoid ambiguity (second maxim of manner, and be polite (maxim of politeness. Sensitivity to violations of Gricean maxims increased with age: 4-year-olds’ understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner, and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.

The effects of location, thermal stress, and residual stress on corner cracks in nozzles with cladding

International Nuclear Information System (INIS)

Besuner, P.M.; Cohen, L.M.; McLean, J.L.

1977-01-01

The stress intensity factors (Ksub(I)) for corner cracks in a boiling water reactor feedwater nozzle with stainless steel cladding are obtained for loading by internal pressure, and a fluid quench in the nozzle. Conditions with and without residual stress in the component are considered. The residual stress is simulated by means of a reference temperature change. The stress distribution for the uncracked structure is obtained from a three-dimensional finite element model. A three-dimensional influence function (IF) method, in conjunction with the boundary-integral equation method for structural analysis, is employed to compute Ksub(I) values from the uncracked structure's stress distribution. For each type of loading Ksub(I) values are given for cracks at 15 nozzle locations and for six crack depths. Reasonable agreement is noted between calculated and previously published pressure-induced Ksub(I) values. Comparisons are made to determine the effect on Ksub(I) of crack location, thermal stress, and residual stress as compared to pressure stress. For the thermal transient it is shown that Ksub(I) for small crack depths is maximized early in the transient while Ksub(I) for large cracks is maximized later, under steady state conditions. Ksub(I) computations should, therefore, be made for several transient time points and the maximum Ksub(I) for a given crack depth should be used for design analysis. It is concluded that the effects on Ksub(I) of location, thermal stresses, and residual stresses are significant and generally too complex to evalute without advanced numerical procedures. The utilized combination of finite element analysis of the uncracked structure and three-dimensional influence function analysis of the cracked structure is demonstrated

Stress Managment and Health Promotion

Directory of Open Access Journals (Sweden)

Asghar Dadkhah

2004-09-01

Full Text Available Health promotion approach is utilized to address the prevention, management and early intervention for stress management and also to promote positive mental and psychological health. Stress affects everyone and must be managed effectively to reduce its chronic and deleterious effects this study consists of two sections: in first section the principals of health promotion in different human existence levels, prevention of disease related to stress, the effect of stress on human well-being, and stress management were discussed. In second section the role of rehabilitation specialists (Medical technologist, nurses, occupational therapists, physiotherapists, respiratory therapists, and social workers in stress management were counted.

Analytical model and application of stress distribution on mining coal floor

Institute of Scientific and Technical Information of China (English)

ZHU Shu-yun; JIAN Zhen-quan; HOU Hong-liang; XIAO Wei-guo; YAO Pu

2008-01-01

Given the analysis of underground pressure, a stress calculation model of coal floor stress has been established based on a theory of elasticity. The model presents the law of stress distribution on the relatively fixed position of the mining coal floor: the extent of stress variation in a fixed floor position decreases gradually along with depth, the decreasing rate of the vertical stress is clearly larger than that of the horizontal stress at a specific depth. The direction of the maximum principal stress changes gradually from a vertical direction to a horizontal direction with the advance of the working face. The deformation and permeability of the rock mass of the coal floor are obtained by contrasting the difference of the principal stress established from theoretical calculations with curves of stress-strain and permeability-strain from tests, which is an important mechanical basis for preventing water inrush from confined aquifers.

Demonstration of over core stress measurement from surface using the Sigra IST tool

CSIR Research Space (South Africa)

Gray, I

2003-01-01

Full Text Available are consistent in magnitude and direction. The major principal effective stress is in the region of 4 to 5 Mpa, which is small in the context of a rock UCS of 100 MPa. Of more concern if long wall mining were being considered is the minor principal stress which...

29 CFR 1471.995 - Principal.

Science.gov (United States)

2010-07-01

... SUSPENSION (NONPROCUREMENT) Definitions § 1471.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or... 29 Labor 4 2010-07-01 2010-07-01 false Principal. 1471.995 Section 1471.995 Labor Regulations...

On maximal massive 3D supergravity

OpenAIRE

Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K

2010-01-01

ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...

Portraits of Principal Practice: Time Allocation and School Principal Work

Science.gov (United States)

Sebastian, James; Camburn, Eric M.; Spillane, James P.

2018-01-01

Purpose: The purpose of this study was to examine how school principals in urban settings distributed their time working on critical school functions. We also examined who principals worked with and how their time allocation patterns varied by school contextual characteristics. Research Method/Approach: The study was conducted in an urban school…

31 CFR 19.995 - Principal.

Science.gov (United States)

2010-07-01

... SUSPENSION (NONPROCUREMENT) Definitions § 19.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Principal. 19.995 Section 19.995...

22 CFR 208.995 - Principal.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Principal. 208.995 Section 208.995 Foreign...) Definitions § 208.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory responsibilities related to a...

22 CFR 1006.995 - Principal.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Principal. 1006.995 Section 1006.995 Foreign... § 1006.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory responsibilities related to a...

2 CFR 180.995 - Principal.

Science.gov (United States)

2010-01-01

... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Principal. 180.995 Section 180.995 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS... § 180.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator...

22 CFR 1508.995 - Principal.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Principal. 1508.995 Section 1508.995 Foreign...) Definitions § 1508.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory responsibilities related to a...

Principal stratification in causal inference.

Science.gov (United States)

Frangakis, Constantine E; Rubin, Donald B

2002-03-01

Many scientific problems require that treatment comparisons be adjusted for posttreatment variables, but the estimands underlying standard methods are not causal effects. To address this deficiency, we propose a general framework for comparing treatments adjusting for posttreatment variables that yields principal effects based on principal stratification. Principal stratification with respect to a posttreatment variable is a cross-classification of subjects defined by the joint potential values of that posttreatment variable tinder each of the treatments being compared. Principal effects are causal effects within a principal stratum. The key property of principal strata is that they are not affected by treatment assignment and therefore can be used just as any pretreatment covariate. such as age category. As a result, the central property of our principal effects is that they are always causal effects and do not suffer from the complications of standard posttreatment-adjusted estimands. We discuss briefly that such principal causal effects are the link between three recent applications with adjustment for posttreatment variables: (i) treatment noncompliance, (ii) missing outcomes (dropout) following treatment noncompliance. and (iii) censoring by death. We then attack the problem of surrogate or biomarker endpoints, where we show, using principal causal effects, that all current definitions of surrogacy, even when perfectly true, do not generally have the desired interpretation as causal effects of treatment on outcome. We go on to forrmulate estimands based on principal stratification and principal causal effects and show their superiority.

Inclusive fitness maximization: An axiomatic approach.

Science.gov (United States)

Okasha, Samir; Weymark, John A; Bossert, Walter

2014-06-07

Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of quasi-inclusive fitness maximization can be derived from axioms on an individual׳s 'as if preferences' (binary choices) for the case in which phenotypic effects are additive. Our results help integrate evolutionary theory and rational choice theory, help draw out the behavioural implications of inclusive fitness maximization, and point to a possible way in which evolution could lead organisms to implement it. Copyright © 2014 Elsevier Ltd. All rights reserved.

Principals' Salaries, 2007-2008

Science.gov (United States)

Cooke, Willa D.; Licciardi, Chris

2008-01-01

How do salaries of elementary and middle school principals compare with those of other administrators and classroom teachers? Are increases in salaries of principals keeping pace with increases in salaries of classroom teachers? And how have principals' salaries fared over the years when the cost of living is taken into account? There are reliable…

21 CFR 1404.995 - Principal.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Principal. 1404.995 Section 1404.995 Food and...) Definitions § 1404.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory responsibilities related to a...

34 CFR 85.995 - Principal.

Science.gov (United States)

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Principal. 85.995 Section 85.995 Education Office of...) Definitions § 85.995 Principal. Principal means— (a) An officer, director, owner, partner, principal investigator, or other person within a participant with management or supervisory responsibilities related to a...

Principal Self-Efficacy and Work Engagement: Assessing a Norwegian Principal Self-Efficacy Scale

Science.gov (United States)

Federici, Roger A.; Skaalvik, Einar M.

2011-01-01

One purpose of the present study was to develop and test the factor structure of a multidimensional and hierarchical Norwegian Principal Self-Efficacy Scale (NPSES). Another purpose of the study was to investigate the relationship between principal self-efficacy and work engagement. Principal self-efficacy was measured by the 22-item NPSES. Work…

Myocardial functional responses do not contribute to maximal exercise performance in the heat.

Science.gov (United States)

Smith, Denise L; DeBlois, Jacob P; Wharton, Margaret; Rowland, Thomas

2015-01-01

Both the extent and means by which maximal oxygen uptake ([Formula: see text]) is depressed by elevated ambient temperature are uncertain. Particularly, information is currently unavailable regarding the possible influence of alterations in myocardial function on [Formula: see text] and performance during exercise in the heat. This study investigated the effects of environmental heat on [Formula: see text], peak work capacity, and myocardial function during a standard, progressive cycle test to exhaustion. Twelve euhydrated men (aged 20.7 ± 1.7 years) performed a maximal cycle test in an environmental chamber in both heat stress [35°C, 30% relative humidity (RH)] and temperate (20°C, 30% RH) conditions with measurement of standard gas exchange variables, core temperature, and echocardiographic measures of cardiac function. A small but statistically significant reduction of peak work capacity was observed in the heat stress versus temperate conditions (253 ± 30 and 259 ± 30 W, respectively, p = 0.02). Mean [Formula: see text] was not statistically different in the two conditions (p = 0.16) but values were 3.4% lower in the heat, and 9 of 12 participants demonstrated lower values in the heat stress trial. No differences in responses of heart rate, cardiac output, stroke volume, core temperature, hydration status, or myocardial systolic or diastolic function were observed between the two conditions, but perceived body temperature was higher in the heat. The small, negative impact of heat on exercise performance and [Formula: see text] could not be explained by disturbances in myocardial functional responses to exercise in young adult males.

Maximal Entanglement in High Energy Physics

Directory of Open Access Journals (Sweden)

Alba Cervera-Lierta, José I. Latorre, Juan Rojo, Luca Rottoli

2017-11-01

Full Text Available We analyze how maximal entanglement is generated at the fundamental level in QED by studying correlations between helicity states in tree-level scattering processes at high energy. We demonstrate that two mechanisms for the generation of maximal entanglement are at work: i $s$-channel processes where the virtual photon carries equal overlaps of the helicities of the final state particles, and ii the indistinguishable superposition between $t$- and $u$-channels. We then study whether requiring maximal entanglement constrains the coupling structure of QED and the weak interactions. In the case of photon-electron interactions unconstrained by gauge symmetry, we show how this requirement allows reproducing QED. For $Z$-mediated weak scattering, the maximal entanglement principle leads to non-trivial predictions for the value of the weak mixing angle $\\theta_W$. Our results are a first step towards understanding the connections between maximal entanglement and the fundamental symmetries of high-energy physics.

Maximal Inequalities for Dependent Random Variables

DEFF Research Database (Denmark)

Hoffmann-Jorgensen, Jorgen

2016-01-01

Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

An ethical justification of profit maximization

DEFF Research Database (Denmark)

Koch, Carsten Allan

2010-01-01

In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing...... behaviour. It is argued that some form of consequential ethics must be applied, and that both profit seeking and profit maximization can be defended from a rule-consequential point of view. It is noted, however, that the result does not apply unconditionally, but requires that certain form of profit (and...... utility) maximizing actions are ruled out, e.g., by behavioural norms or formal institutions....

New Computer Automated Holo-Photoelastic Method For Measuring Planar Principal Stress Magnitudes And Orientation

Science.gov (United States)

Brown, G. M.; Sullivan, J. L.

1987-09-01

A complete experimental determination of the stress and strain fields in an arbitrary deformed structure is generally unavailable. However, for two dimensional elasticity problems, such determinations are possible since in those cases one needs only to solve for three stresses (two normal and one shear). In fact, such determinations have been conducted quite often. By using isochromatic and isoclinic photoelastic data, the shear difference and numerical iteration techniques (1) and the least squares techniques (2) have been successfully used for complete stress field determinations of two dimensional elasticity problems. Though the shear difference technique can be particularly sensitive to cumulative errors resulting from numerical integration, the least squares technique is not affected by this and appears to yield better accuracy. The methods just cited use both experimental data and one or more mechanics conditions(e.g., the equations of equilibrium) to determine the stress field. However, the stress field can also be obtained from experimental data alone for planar elasticity problems, if there is enough of it to solve for the three stresses. For example, the Moire* technique or the combination of isochromatic, isoclinic, and isopachic data (for transparent models) can be used for such determinations. Further, with the marriage of advanced image processing equipment to computers, such analyses using this type of data can be conveniently conducted. It is even possible that such analyses could be more accurate than those using the combined experimental/numerical techniques cited above. The purposes of this report are two fold: i) to describe a single apparatus for obtaining isochromatic, isopachic, and isoclinic results for complete stress field determinations of two dimensional transparent models, and ii) to compare experimental and theoretical stress field values for an antisymmetrically loaded beam obtained using that apparatus.

Simultaneous maximal exercise radionuclide angiography and thallium stress perfusion imaging

International Nuclear Information System (INIS)

Narahara, K.A.; Mena, I.; Maublant, J.C.; Brizendine, M.; Criley, J.M.

1984-01-01

Gold-195m is a new ultra-short-lived radionuclide that can be used for cardiac studies. Accurate, reproducible ejection fraction and ventricular wall motion studies can be obtained from first-transit angiography using commercially available imaging and image-processing equipment. The short half-life of gold-195m (30.5 seconds) makes simultaneous dual isotope imaging possible and substantially reduces the radiation exposure from the isotope angiography. The feasibility and possible benefits of performing dual radionuclide studies were evaluated during a single exercise stress test in 24 subjects with known coronary artery disease (CAD) and in 20 normal volunteers. High-quality first-transit angiograms were obtained in all subjects. An 83% sensitivity and 95% specificity for detecting CAD with thallium-201 imaging was noted in this investigation, suggesting that its diagnostic accuracy was not altered by simultaneous dual isotone imaging. When segmental left ventricular (LV) wall motion was compared with thallium-201 perfusion imaging, divergent results were noted in 15 of 44 subjects. An analysis of the ejection fraction (EF) results at rest and stress provided additional information that could be useful in assessing the clinical significance of such differences in segmental wall motion and perfusion. Simultaneous dual isotope imaging appears to be appropriate for situations in which both LV perfusion and function require evaluation. The use of gold-195m allows such information to be obtained from a single exercise test and can thereby reduce the cost and time required for noninvasive evaluations of patients for CAD

An Investigation of Teacher, Principal, and Superintendent Perceptions on the Ability of the National Framework for Principal Evaluations to Measure Principals' Leadership Competencies

Science.gov (United States)

Lamb, Lori D.

2014-01-01

The purpose of this qualitative study was to investigate the perceptions of effective principals' leadership competencies; determine if the perceptions of teachers, principals, and superintendents aligned with the proposed National Framework for Principal Evaluations initiative. This study examined the six domains of leadership outlined by the…

Comparison of myocardial 201Tl clearance after maximal and submaximal exercise: implications for diagnosis of coronary disease: concise communication

International Nuclear Information System (INIS)

Massie, B.M.; Wisneski, J.; Kramer, B.; Hollenberg, M.; Gertz, E.; Stern, D.

1982-01-01

Recently the quantitation of regional 201 Tl clearance has been shown to increase the sensitivity of the scintigraphic detection of coronary disease. Although 201 Tl clearance rates might be expected to vary with the degree of exercise, this relationship has not been explored. We therefore evaluated the rate of decrease in myocardial 201 Tl activity following maximal and submaximal stress in seven normal subjects and 21 patients with chest pain, using the seven-pinhole tomographic reconstruction technique. In normals, the mean 201 Tl clearance rate declined from 41% +/- 7 over a 3-hr period with maximal exercise to 25% +/- 5 after 3 hr at a submaximal level (p less than 0.001). Similar differences in clearance rates were found in the normally perfused regions of the left ventricle in patients with chest pain, depending on whether or not a maximal end point (defined as either the appearance of ischemia or reaching 85% of age-predicted heart rate) was achieved. In five patients who did not reach these end points, 3-hr clearance rates in uninvolved regions averaged 25% +/- 2, in contrast to a mean of 38% +/- 5 for such regions in 15 patients who exercised to ischemia or an adequate heart rate. These findings indicate that clearance criteria derived from normals can be applied to patients who are stressed maximally, even if the duration of exercise is limited, but that caution must be used in interpreting clearance rates in those who do not exercise to an accepted end point

Thermal stresses at nozzles of nuclear steel containments under LOCA-conditions

International Nuclear Information System (INIS)

Sanchez Sarmiento, G.; Bergmann, A.N.

1986-01-01

During a loss of coolant accident (LOCA) of a PWR-nuclear power plant, a considerable heating of the containment atmosphere is expected to occur. Transient thermal stresses will appear at the containment as a consequence of a non-uniform rise of its temperature. Applying computer codes based on the finite element method, dimensionless general thermal stresses at nozzles of spherical steel containment have been calculated, varying the principal geometrical parameters and the Biot number for the containment internal surface. Atmosphere temperature and Biot number are assumed constant after the accident. Several plots of the maximum principal stresses are provided, which constitute general results applicable to stress analysis of any particular containment of this kind. (orig.)

Residual stresses

International Nuclear Information System (INIS)

Sahotra, I.M.

2006-01-01

The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

Inclusive Fitness Maximization:An Axiomatic Approach

OpenAIRE

Okasha, Samir; Weymark, John; Bossert, Walter

2014-01-01

Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of qu...

Does mental exertion alter maximal muscle activation?

Directory of Open Access Journals (Sweden)

Vianney eRozand

2014-09-01

Full Text Available Mental exertion is known to impair endurance performance, but its effects on neuromuscular function remain unclear. The purpose of this study was to test the hypothesis that mental exertion reduces torque and muscle activation during intermittent maximal voluntary contractions of the knee extensors. Ten subjects performed in a randomized order three separate mental exertion conditions lasting 27 minutes each: i high mental exertion (incongruent Stroop task, ii moderate mental exertion (congruent Stroop task, iii low mental exertion (watching a movie. In each condition, mental exertion was combined with ten intermittent maximal voluntary contractions of the knee extensor muscles (one maximal voluntary contraction every 3 minutes. Neuromuscular function was assessed using electrical nerve stimulation. Maximal voluntary torque, maximal muscle activation and other neuromuscular parameters were similar across mental exertion conditions and did not change over time. These findings suggest that mental exertion does not affect neuromuscular function during intermittent maximal voluntary contractions of the knee extensors.

Digital model analysis of the principal artesian aquifer, Savannah, Georgia area

Science.gov (United States)

Counts, H.B.; Krause, R.E.

1977-01-01

A digital model of the principal artesian aquifer has been developed for the Savannah, Georgia, area. The model simulates the response of the aquifer system to various hydrologic stresses. Model results of the water levels and water-level changes are shown on maps. Computations may be extended in time, indicating changes in pumpage were applied to the system and probable results calculated. Drawdown or water-level differences were computed, showing comparisons of different water management alternatives. (Woodard-USGS)

Characteristic gene selection via weighting principal components by singular values.

Directory of Open Access Journals (Sweden)

Jin-Xing Liu

Full Text Available Conventional gene selection methods based on principal component analysis (PCA use only the first principal component (PC of PCA or sparse PCA to select characteristic genes. These methods indeed assume that the first PC plays a dominant role in gene selection. However, in a number of cases this assumption is not satisfied, so the conventional PCA-based methods usually provide poor selection results. In order to improve the performance of the PCA-based gene selection method, we put forward the gene selection method via weighting PCs by singular values (WPCS. Because different PCs have different importance, the singular values are exploited as the weights to represent the influence on gene selection of different PCs. The ROC curves and AUC statistics on artificial data show that our method outperforms the state-of-the-art methods. Moreover, experimental results on real gene expression data sets show that our method can extract more characteristic genes in response to abiotic stresses than conventional gene selection methods.

PIPE STRESS and VERPIP codes for stress analysis and verifications of PEC reactor piping

International Nuclear Information System (INIS)

Cesari, F.; Ferranti, P.; Gasparrini, M.; Labanti, L.

1975-01-01

To design LMFBR piping systems following ASME Sct. III requirements unusual flexibility computer codes are to be adopted to consider piping and its guard-tube. For this purpose PIPE STRESS code previously prepared by Southern-Service, has been modified. Some subroutine for detailed stress analysis and principal stress calculations on all the sections of piping have been written and fitted in the code. Plotter can also be used. VERPIP code for automatic verifications of piping as class 1 Sct. III prescriptions has been also prepared. The results of PIPE STRESS and VERPIP codes application to PEC piping are in section III of this report

On maximal surfaces in asymptotically flat space-times

International Nuclear Information System (INIS)

Bartnik, R.; Chrusciel, P.T.; O Murchadha, N.

1990-01-01

Existence of maximal and 'almost maximal' hypersurfaces in asymptotically flat space-times is established under boundary conditions weaker than those considered previously. We show in particular that every vacuum evolution of asymptotically flat data for Einstein equations can be foliated by slices maximal outside a spatially compact set and that every (strictly) stationary asymptotically flat space-time can be foliated by maximal hypersurfaces. Amongst other uniqueness results, we show that maximal hypersurface can be used to 'partially fix' an asymptotic Poincare group. (orig.)

Maximal exercise testing of men with prostate cancer being treated with androgen deprivation therapy.

Science.gov (United States)

Wall, Bradley A; Galvão, Daniel A; Fatehee, Naeem; Taaffe, Dennis R; Spry, Nigel; Joseph, David; Newton, Robert U

2014-12-01

Exercise is being increasingly established as a key adjuvant therapy in clinical oncology. As research has demonstrated the beneficial effect of exercise for cancer management, a growing number of patients with cancer are undertaking structured exercise programs. This study aimed to determine the safety and feasibility of formal exercise testing in clinical settings as it is becoming increasingly used as a screening tool and for exercise prescription purposes. One hundred and twelve patients with prostate cancer undergoing androgen deprivation therapy (ADT) took part in a physician-supervised multistage maximal stress test (Bruce protocol). Sixty patients had been on ADT for 3 months (chronic). Of these men, 85% were able to meet the criteria for the attainment of V˙O2max, whereas three positive tests (3.2%) were observed. The three participants who recorded a positive stress test underwent further medical examination and were subsequently cleared of clinically significant cardiovascular disease. Apart from the relatively low V˙O2max (24.7 ± 6.0 mL·kg·min, 10th-15th percentile), compared with normative data in healthy age-matched controls, the cardiovascular response to exercise was similar in this cancer population. Moreover, treatment duration did not seem to influence cardiovascular responses to exercise. This early evidence suggests that risk of adverse events during maximal exercise testing is relatively low in this population and certainly no higher than that in ages-matched, apparently healthy individuals. Maximal exercise testing was demonstrated to be feasible and safe, providing a direct assessment of V˙O2max. The relatively low number of positive tests in this study suggests that the risk of adverse events is relatively low in this population and certainly no higher than that in age-matched, apparently healthy individuals.

Latitude-Time Total Electron Content Anomalies as Precursors to Japan's Large Earthquakes Associated with Principal Component Analysis

Directory of Open Access Journals (Sweden)

Jyh-Woei Lin

2011-01-01

Full Text Available The goal of this study is to determine whether principal component analysis (PCA can be used to process latitude-time ionospheric TEC data on a monthly basis to identify earthquake associated TEC anomalies. PCA is applied to latitude-time (mean-of-a-month ionospheric total electron content (TEC records collected from the Japan GEONET network to detect TEC anomalies associated with 18 earthquakes in Japan (M≥6.0 from 2000 to 2005. According to the results, PCA was able to discriminate clear TEC anomalies in the months when all 18 earthquakes occurred. After reviewing months when no M≥6.0 earthquakes occurred but geomagnetic storm activity was present, it is possible that the maximal principal eigenvalues PCA returned for these 18 earthquakes indicate earthquake associated TEC anomalies. Previously PCA has been used to discriminate earthquake-associated TEC anomalies recognized by other researchers, who found that statistical association between large earthquakes and TEC anomalies could be established in the 5 days before earthquake nucleation; however, since PCA uses the characteristics of principal eigenvalues to determine earthquake related TEC anomalies, it is possible to show that such anomalies existed earlier than this 5-day statistical window.

Insulin resistance and maximal oxygen uptake

DEFF Research Database (Denmark)

Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

2003-01-01

BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

Stress-constrained topology optimization for compliant mechanism design

DEFF Research Database (Denmark)

de Leon, Daniel M.; Alexandersen, Joe; Jun, Jun S.

2015-01-01

This article presents an application of stress-constrained topology optimization to compliant mechanism design. An output displacement maximization formulation is used, together with the SIMP approach and a projection method to ensure convergence to nearly discrete designs. The maximum stress...... is approximated using a normalized version of the commonly-used p-norm of the effective von Mises stresses. The usual problems associated with topology optimization for compliant mechanism design: one-node and/or intermediate density hinges are alleviated by the stress constraint. However, it is also shown...

Synthesis of magnetic systems producing field with maximal scalar characteristics

International Nuclear Information System (INIS)

Klevets, Nickolay I.

2005-01-01

A method of synthesis of the magnetic systems (MSs) consisting of uniformly magnetized blocks is proposed. This method allows to synthesize MSs providing maximum value of any magnetic field scalar characteristic. In particular, it is possible to synthesize the MSs providing the maximum of a field projection on a given vector, a gradient of a field modulus and a gradient of a field energy on a given directing vector, a field magnitude, a magnetic flux through a given surface, a scalar product of a field or a force by a directing function given in some area of space, etc. The synthesized MSs provide maximal efficiency of permanent magnets utilization. The usage of the proposed method of MSs synthesis allows to change a procedure of projecting in principal, namely, to execute it according to the following scheme: (a) to choose the sizes, a form and a number of blocks of a system proceeding from technological (economical) reasons; (b) using the proposed synthesis method, to find an orientation of site magnetization providing maximum possible effect of magnet utilization in a system obtained in (a). Such approach considerably reduces a time of MSs projecting and guarantees maximal possible efficiency of magnets utilization. Besides it provides absolute assurance in 'ideality' of a MS design and allows to obtain an exact estimate of the limit parameters of a field in a working area of a projected MS. The method is applicable to a system containing the components from soft magnetic material with linear magnetic properties

POLITENESS MAXIM OF MAIN CHARACTER IN SECRET FORGIVEN

Directory of Open Access Journals (Sweden)

Sang Ayu Isnu Maharani

2017-06-01

Full Text Available Maxim of Politeness is an interesting subject to be discussed, since politeness has been criticized from our childhood. We are obliques to be polite to anyone either in speaking or in acting. Somehow we are manage to show politeness in our spoken expression though our intention might be not so polite. For example we must appriciate others opinion although we feel objection toward the opinion. In this article the analysis of politeness is based on maxim proposes by Leech. He proposed six types of politeness maxim. The discussion shows that the main character (Kristen and Kami use all types of maxim in their conversation. The most commonly used are approbation maxim and agreement maxim

Measuring general and specific stress causes and stress responses among beginning secondary school teachers in the Netherlands

OpenAIRE

Harmsen, R; Helms-Lorenz, M.; Maulana, R; van Veen, K; van Veldhoven, M.J.P.M.

2018-01-01

The main aim of this study was to adjust the Questionnaire on the Experience and Evaluation of Work (QEEW) in order to measure stress causes and stress responses of beginning secondary school teachers in the Netherlands. First, the suitability of the original QEEW stress scales for use in the beginning teachers (BTs) context was investigated using a sample of 356 beginning teachers from 52 different secondary school locations in the Netherlands. Confirmatory Factor Analyses, Principal Compone...

Measuring general and specific stress causes and stress responses among beginning secondary school teachers in the Netherlands.

OpenAIRE

Harmsen, Ruth; Helms-Lorenz, Michelle; Maulana, Ridwan; van Veen, Klaas; van Veldhoven, M.J.P.M.

2018-01-01

The main aim of this study was to adjust the Questionnaire on the Experience and Evaluation of Work (QEEW) in order to measure stress causes and stress responses of beginning secondary school teachers in the Netherlands. First, the suitability of the original QEEW stress scales for use in the beginning teachers (BTs) context was investigated using a sample of 356 beginning teachers from 52 different secondary school locations in the Netherlands. Confirmatory Factor Analyses, Principal Compone...

Combining Earthquake Focal Mechanism Inversion and Coulomb Friction Law to Yield Tectonic Stress Magnitudes in Strike-slip Faulting Regime

Science.gov (United States)

Soh, I.; Chang, C.

2017-12-01

The techniques for estimating present-day stress states by inverting multiple earthquake focal mechanism solutions (FMS) provide orientations of the three principal stresses and their relative magnitudes. In order to estimate absolute magnitudes of the stresses that are generally required to analyze faulting mechanics, we combine the relative stress magnitude parameter (R-value) derived from the inversion process and the concept of frictional equilibrium of stress state defined by Coulomb friction law. The stress inversion in Korean Peninsula using 152 FMS data (magnitude≥2.5) conducted at regularly spaced grid points yields a consistent strike-slip faulting regime in which the maximum (S1) and the minimum (S3) principal stresses act in horizontal planes (with an S1 azimuth in ENE-WSW) and the intermediate principal stress (S2) close to vertical. However, R-value varies from 0.28 to 0.75 depending on locations, systematically increasing eastward. Based on the assumptions that the vertical stress is lithostatic, pore pressure is hydrostatic, and the maximum differential stress (S1-S3) is limited by Byerlee's friction of optimally oriented faults for slip, we estimate absolute magnitudes of the two horizontal principal stresses using R-value. As R-value increases, so do the magnitudes of the horizontal stresses. Our estimation of the stress magnitudes shows that the maximum horizontal principal stress (S1) normalized by vertical stress tends to increase from 1.3 in the west to 1.8 in the east. The estimated variation of stress magnitudes is compatible with distinct clustering of faulting types in different regions. Normal faulting events are densely populated in the west region where the horizontal stress is relatively low, whereas numerous reverse faulting events prevail in the east offshore where the horizontal stress is relatively high. Such a characteristic distribution of distinct faulting types in different regions can only be explained in terms of stress

RE Rooted in Principal's Biography

NARCIS (Netherlands)

ter Avest, Ina; Bakker, C.

2017-01-01

Critical incidents in the biography of principals appear to be steering in their innovative way of constructing InterReligious Education in their schools. In this contribution, the authors present the biographical narratives of 4 principals: 1 principal introducing interreligious education in a

Natural maximal νμ-ντ mixing

International Nuclear Information System (INIS)

Wetterich, C.

1999-01-01

The naturalness of maximal mixing between myon- and tau-neutrinos is investigated. A spontaneously broken nonabelian generation symmetry can explain a small parameter which governs the deviation from maximal mixing. In many cases all three neutrino masses are almost degenerate. Maximal ν μ -ν τ -mixing suggests that the leading contribution to the light neutrino masses arises from the expectation value of a heavy weak triplet rather than from the seesaw mechanism. In this scenario the deviation from maximal mixing is predicted to be less than about 1%. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Gaussian maximally multipartite-entangled states

Science.gov (United States)

Facchi, Paolo; Florio, Giuseppe; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio

2009-12-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7 .

Gaussian maximally multipartite-entangled states

International Nuclear Information System (INIS)

Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio; Lupo, Cosmo; Mancini, Stefano

2009-01-01

We study maximally multipartite-entangled states in the context of Gaussian continuous variable quantum systems. By considering multimode Gaussian states with constrained energy, we show that perfect maximally multipartite-entangled states, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of these states and their frustration for n≤7.

Utility maximization and mode of payment

NARCIS (Netherlands)

Koning, R.H.; Ridder, G.; Heijmans, R.D.H.; Pollock, D.S.G.; Satorra, A.

2000-01-01

The implications of stochastic utility maximization in a model of choice of payment are examined. Three types of compatibility with utility maximization are distinguished: global compatibility, local compatibility on an interval, and local compatibility on a finite set of points. Keywords:

Redesigning Principal Internships: Practicing Principals' Perspectives

Science.gov (United States)

Anast-May, Linda; Buckner, Barbara; Geer, Gregory

2011-01-01

Internship programs too often do not provide the types of experiences that effectively bridge the gap between theory and practice and prepare school leaders who are capable of leading and transforming schools. To help address this problem, the current study is directed at providing insight into practicing principals' views of the types of…

The Future of Principal Evaluation

Science.gov (United States)

Clifford, Matthew; Ross, Steven

2012-01-01

The need to improve the quality of principal evaluation systems is long overdue. Although states and districts generally require principal evaluations, research and experience tell that many state and district evaluations do not reflect current standards and practices for principals, and that evaluation is not systematically administered. When…

Preparing Principals as Instructional Leaders: Perceptions of University Faculty, Expert Principals, and Expert Teacher Leaders

Science.gov (United States)

Taylor Backor, Karen; Gordon, Stephen P.

2015-01-01

Although research has established links between the principal's instructional leadership and student achievement, there is considerable concern in the literature concerning the capacity of principal preparation programs to prepare instructional leaders. This study interviewed educational leadership faculty as well as expert principals and teacher…

Inclusions and inhomogeneities under stress

CSIR Research Space (South Africa)

Nabarro, FRN

1996-02-01

Full Text Available Some general theorems, new and old, concerning the behaviour of elastic inclusions and inhomogeneities in bodies without or with external stress, are assembled. The principal new result is that arbitrary external tractions cannot influence the shape...

Activity versus outcome maximization in time management.

Science.gov (United States)

Malkoc, Selin A; Tonietto, Gabriela N

2018-04-30

Feeling time-pressed has become ubiquitous. Time management strategies have emerged to help individuals fit in more of their desired and necessary activities. We provide a review of these strategies. In doing so, we distinguish between two, often competing, motives people have in managing their time: activity maximization and outcome maximization. The emerging literature points to an important dilemma: a given strategy that maximizes the number of activities might be detrimental to outcome maximization. We discuss such factors that might hinder performance in work tasks and enjoyment in leisure tasks. Finally, we provide theoretically grounded recommendations that can help balance these two important goals in time management. Published by Elsevier Ltd.

Principal Self-Efficacy, Teacher Perceptions of Principal Performance, and Teacher Job Satisfaction

Science.gov (United States)

Evans, Molly Lynn

2016-01-01

In public schools, the principal's role is of paramount importance in influencing teachers to excel and to keep their job satisfaction high. The self-efficacy of leaders is an important characteristic of leadership, but this issue has not been extensively explored in school principals. Using internet-based questionnaires, this study obtained…

Basolateral amygdala and stress-induced hyperexcitability affect motivated behaviors and addiction.

Science.gov (United States)

Sharp, B M

2017-08-08

The amygdala integrates and processes incoming information pertinent to reward and to emotions such as fear and anxiety that promote survival by warning of potential danger. Basolateral amygdala (BLA) communicates bi-directionally with brain regions affecting cognition, motivation and stress responses including prefrontal cortex, hippocampus, nucleus accumbens and hindbrain regions that trigger norepinephrine-mediated stress responses. Disruption of intrinsic amygdala and BLA regulatory neurocircuits is often caused by dysfunctional neuroplasticity frequently due to molecular alterations in local GABAergic circuits and principal glutamatergic output neurons. Changes in local regulation of BLA excitability underlie behavioral disturbances characteristic of disorders including post-traumatic stress syndrome (PTSD), autism, attention-deficit hyperactivity disorder (ADHD) and stress-induced relapse to drug use. In this Review, we discuss molecular mechanisms and neural circuits that regulate physiological and stress-induced dysfunction of BLA/amygdala and its principal output neurons. We consider effects of stress on motivated behaviors that depend on BLA; these include drug taking and drug seeking, with emphasis on nicotine-dependent behaviors. Throughout, we take a translational approach by integrating decades of addiction research on animal models and human trials. We show that changes in BLA function identified in animal addiction models illuminate human brain imaging and behavioral studies by more precisely delineating BLA mechanisms. In summary, BLA is required to promote responding for natural reward and respond to second-order drug-conditioned cues; reinstate cue-dependent drug seeking; express stress-enhanced reacquisition of nicotine intake; and drive anxiety and fear. Converging evidence indicates that chronic stress causes BLA principal output neurons to become hyperexcitable.

Lifestyle and metabolic approaches to maximizing erectile and vascular health.

Science.gov (United States)

Meldrum, D R; Gambone, J C; Morris, M A; Esposito, K; Giugliano, D; Ignarro, L J

2012-01-01

Oxidative stress and inflammation, which disrupt nitric oxide (NO) production directly or by causing resistance to insulin, are central determinants of vascular diseases including ED. Decreased vascular NO has been linked to abdominal obesity, smoking and high intakes of fat and sugar, which all cause oxidative stress. Men with ED have decreased vascular NO and circulating and cellular antioxidants. Oxidative stress and inflammatory markers are increased in men with ED, and all increase with age. Exercise increases vascular NO, and more frequent erections are correlated with decreased ED, both in part due to stimulation of endothelial NO production by shear stress. Exercise and weight loss increase insulin sensitivity and endothelial NO production. Potent antioxidants or high doses of weaker antioxidants increase vascular NO and improve vascular and erectile function. Antioxidants may be particularly important in men with ED who smoke, are obese or have diabetes. Omega-3 fatty acids reduce inflammatory markers, decrease cardiac death and increase endothelial NO production, and are therefore critical for men with ED who are under age 60 years, and/or have diabetes, hypertension or coronary artery disease, who are at increased risk of serious or even fatal cardiac events. Phosphodiesterase inhibitors have recently been shown to improve antioxidant status and NO production and allow more frequent and sustained penile exercise. Some angiotensin II receptor blockers decrease oxidative stress and improve vascular and erectile function and are therefore preferred choices for lowering blood pressure in men with ED. Lifestyle modifications, including physical and penile-specific exercise, weight loss, omega-3 and folic acid supplements, reduced intakes of fat and sugar, and improved antioxidant status through diet and/or supplements should be integrated into any comprehensive approach to maximizing erectile function, resulting in greater overall success and patient

Maximizing Entropy over Markov Processes

DEFF Research Database (Denmark)

Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis

2013-01-01

The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... as a reward function, a polynomial algorithm to verify the existence of an system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code....

Maximizing entropy over Markov processes

DEFF Research Database (Denmark)

Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis

2014-01-01

The channel capacity of a deterministic system with confidential data is an upper bound on the amount of bits of data an attacker can learn from the system. We encode all possible attacks to a system using a probabilistic specification, an Interval Markov Chain. Then the channel capacity...... as a reward function, a polynomial algorithm to verify the existence of a system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...... to use Interval Markov Chains to model abstractions of deterministic systems with confidential data, and use the above results to compute their channel capacity. These results are a foundation for ongoing work on computing channel capacity for abstractions of programs derived from code. © 2014 Elsevier...

PRESENTDAY STRESS STATE OF THE SHANXI TECTONIC BELT

Directory of Open Access Journals (Sweden)

Wang Kaiying

2012-01-01

Full Text Available The Shanxi tectonic belt is a historically earthquakeabundant area. For the majority of strong earthquakes in this area, the distribution of earthquake foci was controlled by the N–S oriented local structures on the tectonic belt. Studies of the present stress state of the Shanxi tectonic belt can contribute to the understanding of the relationship between strong earthquakes’ occurrence and their structural distribution and also facilitate assessments of regional seismic danger and determination of the regions wherein strong earthquakes may occur in future. Using the Cataclastic Analysis Method (CAM, we performed stress inversion based on the focal mechanism data of earthquakes which took place in the Shanxi tectonic belt from 1967 to 2010. Our results show that orientations of the maximum principal compressive stress axis of the Shanxi tectonic belt might have been variable before and after the 2001 Kunlun MS=8.1 strong earthquake, with two different superior trends of the NW–SE and NE–SW orientation in different periods. When the maximum principal compressive stress axis is oriented in the NE–SW direction, the pattern of the space distribution of the seismic events in the Shanxi tectonic belt shows a trend of their concentration in the N–S oriented tectonic segments. At the same time, the stress state is registered as horizontal shearing and horizontal extension in the N–S and NE–SW oriented local segments in turn. When the maximum principal compressive stress axis is NW–SE oriented, the stress state of the N–S and NE–SW oriented tectonic segments is primarily registered as horizontal shearing. Estimations of plunges of stress axes show that seismicity in the Shanxi belt  corresponds primarily to the activity of lowangle faults, and highangle stress sites are located in the NE–SW oriented extensional tectonic segments of the Shanxi belt. This indicates that the stress change of the Shanxi belt is

Evaluation of Bending Strength of Carburized Gears Based on Inferential Identification of Principal Surface Layer Defects

Science.gov (United States)

Masuyama, Tomoya; Inoue, Katsumi; Yamanaka, Masashi; Kitamura, Kenichi; Saito, Tomoyuki

High load capacity of carburized gears originates mainly from the hardened layer and induced residual stress. On the other hand, surface decarburization, which causes a nonmartensitic layer, and inclusions such as oxides and segregation act as latent defects which considerably reduce fatigue strength. In this connection, the authors have proposed a formula of strength evaluation by separately quantifying defect influence. However, the principal defect which limits strength of gears with several different defects remains unclarified. This study presents a method of inferential identification of principal defects based on test results of carburized gears made of SCM420 clean steel, gears with both an artificial notch and nonmartensitic layer at the tooth fillet, and so forth. It clarifies practical uses of presented methods, and strength of carburized gears can be evaluated by focusing on principal defect size.

HEALTH INSURANCE: CONTRIBUTIONS AND REIMBURSEMENT MAXIMAL

CERN Document Server

HR Division

2000-01-01

Affected by both the salary adjustment index on 1.1.2000 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maximal, has changed significantly. An adjustment of the amounts of the reimbursement maximal and the fixed contributions is therefore necessary, as from 1 January 2000.Reimbursement maximalThe revised reimbursement maximal will appear on the leaflet summarising the benefits for the year 2000, which will soon be available from the divisional secretariats and from the AUSTRIA office at CERN.Fixed contributionsThe fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions):voluntarily insured member of the personnel, with complete coverage:815,- (was 803,- in 1999)voluntarily insured member of the personnel, with reduced coverage:407,- (was 402,- in 1999)voluntarily insured no longer dependent child:326,- (was 321...

On the maximal diphoton width

CERN Document Server

Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo

2016-01-01

Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.

Legal Problems of the Principal.

Science.gov (United States)

Stern, Ralph D.; And Others

The three talks included here treat aspects of the law--tort liability, student records, and the age of majority--as they relate to the principal. Specifically, the talk on torts deals with the consequences of principal negligence in the event of injuries to students. Assurance is given that a reasonable and prudent principal will have a minimum…

Preventing work-related stress among staff working in children's cancer Principal Treatment Centres in the UK: a brief survey of staff support systems and practices.

Science.gov (United States)

Beresford, B; Gibson, F; Bayliss, J; Mukherjee, S

2018-03-01

Growing evidence of the association between health professionals' well-being and patient and organisational outcomes points to the need for effective staff support. This paper reports a brief survey of the UK's children's cancer Principal Treatment Centres (PTCs) regarding staff support systems and practices. A short on-line questionnaire, administered in 2012-2013, collected information about the availability of staff support interventions which seek to prevent work-related stress among different members of the multi-disciplinary team (MDT). It was completed by a member of staff with, where required, assistance from colleagues. All PTCs (n = 19) participated. Debriefs following a patient death was the most frequently reported staff support practice. Support groups were infrequently mentioned. There was wide variability between PTCs, and between professional groups, regarding the number and type of interventions available. Doctors appear to be least likely to have access to support. A few Centres routinely addressed work-related stress in wider staff management strategies. Two Centres had developed a bespoke intervention. Very few Centres were reported to actively raise awareness of support available from their hospital's Occupational Health department. A minority of PTCs had expert input regarding staff support from clinical psychology/liaison psychiatry. © 2016 The Authors. European Journal of Cancer Care Published by John Wiley & Sons Ltd.

Principals Who Think Like Teachers

Science.gov (United States)

Fahey, Kevin

2013-01-01

Being a principal is a complex job, requiring quick, on-the-job learning. But many principals already have deep experience in a role at the very essence of the principalship. They know how to teach. In interviews with principals, Fahey and his colleagues learned that thinking like a teacher was key to their work. Part of thinking the way a teacher…

Trust Me, Principal, or Burn Out! The Relationship between Principals' Burnout and Trust in Students and Parents

Science.gov (United States)

Ozer, Niyazi

2013-01-01

The purpose of this study was to determine the primary school principals' views on trust in students and parents and also, to explore the relationships between principals' levels of professional burnout and their trust in students and parents. To this end, Principal Trust Survey and Friedman Principal Burnout scales were administered on 119…

Full-field stress determination in photoelasticity with phase shifting technique

Science.gov (United States)

Guo, Enhai; Liu, Yonggang; Han, Yongsheng; Arola, Dwayne; Zhang, Dongsheng

2018-04-01

Photoelasticity is an effective method for evaluating the stress and its spatial variations within a stressed body. In the present study, a method to determine the stress distribution by means of phase shifting and a modified shear-difference is proposed. First, the orientation of the first principal stress and the retardation between the principal stresses are determined in the full-field through phase shifting. Then, through bicubic interpolation and derivation of a modified shear-difference method, the internal stress is calculated from the point with a free boundary along its normal direction. A method to reduce integration error in the shear difference scheme is proposed and compared to the existing methods; the integration error is reduced when using theoretical photoelastic parameters to calculate the stress component with the same points. Results show that when the value of Δx/Δy approaches one, the error is minimum, and although the interpolation error is inevitable, it has limited influence on the accuracy of the result. Finally, examples are presented for determining the stresses in a circular plate and ring subjected to diametric loading. Results show that the proposed approach provides a complete solution for determining the full-field stresses in photoelastic models.

Failure of Sierra White granite under general states of stress

Science.gov (United States)

Ingraham, M. D.; Dewers, T. A.; Lee, M.; Holdman, O.; Cheung, C.; Haimson, B. C.

2017-12-01

The effect of the intermediate principal stress on the failure of Sierra White granite was investigated by performing tests under true triaxial states of stress. Tests were performed under constant Lode angle conditions with Lode angles ranging from 0 to 30°, pure shear to axisymmetric compression. Results show that the failure of Sierra White granite is heavily dependent on the intermediate principal stress which became more dramatic as the mean stress increased. An analysis of the shear bands formed at failure was performed using an associated flow rule and the Rudnicki and Rice (1975) localization criteria. The localization analysis showed excellent agreement with experimental results. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

Principal component regression analysis with SPSS.

Science.gov (United States)

Liu, R X; Kuang, J; Gong, Q; Hou, X L

2003-06-01

The paper introduces all indices of multicollinearity diagnoses, the basic principle of principal component regression and determination of 'best' equation method. The paper uses an example to describe how to do principal component regression analysis with SPSS 10.0: including all calculating processes of the principal component regression and all operations of linear regression, factor analysis, descriptives, compute variable and bivariate correlations procedures in SPSS 10.0. The principal component regression analysis can be used to overcome disturbance of the multicollinearity. The simplified, speeded up and accurate statistical effect is reached through the principal component regression analysis with SPSS.

A biomonitoring program of the coastal area of the Principality of Monaco

International Nuclear Information System (INIS)

Tambutte, S.; Tambutte, E.; Rolland, P.; Van Klaveren, M.C.

1999-01-01

The laboratory of ecotoxicology of the 'Service de l'Environnement de Monaco' has set up a biomonitoring program in three areas of the littoral of the Principality of Monaco. This program belongs to the general monitoring program on the quality of the Environment. At a subregional level, this program is part of the programs of the tripartite agreement 'RAMOGE', between the three countries France, Italy and the Principality of Monaco; the aim of this agreement being to build a pilot zone of fight against pollution in Mediterranean. At an international level, this program goes in the scope of the 'MEDPOL' biomonitoring program intending to establish or to intensify programs for the continuous monitoring of marine pollution in the mediterranean zone. Our biomonitoring program consists in assessing the effects of pollutants on two marine organisms (Dicentrarchus labrax and Mytilus galloprovincialis) by using general and specific stress indices

Imaging shear stress distribution and evaluating the stress concentration factor of the human eye

Science.gov (United States)

Joseph Antony, S.

2015-03-01

Healthy eyes are vital for a better quality of human life. Historically, for man-made materials, scientists and engineers use stress concentration factors to characterise the effects of structural non-homogeneities on their mechanical strength. However, such information is scarce for the human eye. Here we present the shear stress distribution profiles of a healthy human cornea surface in vivo using photo-stress analysis tomography, which is a non-intrusive and non-X-ray based method. The corneal birefringent retardation measured here is comparable to that of previous studies. Using this, we derive eye stress concentration factors and the directional alignment of major principal stress on the surface of the cornea. Similar to thermometers being used for monitoring the general health in humans, this report provides a foundation to characterise the shear stress carrying capacity of the cornea, and a potential bench mark for validating theoretical modelling of stresses in the human eye in future.

Determination of near surface in-situ stresses

International Nuclear Information System (INIS)

Garritty, P.; Irvin, R.

1983-06-01

One of the major unknowns affecting aspects of underground construction and the geohydrology of rock masses is the magnitude and direction of the geostatic principal stresses in the earth's crust. This is particularly the case in near surface rocks where there are indications that high horizontal stresses may exist. The techniques, experiences and results of a preliminary rock stress measurement programme conducted at shallow depth in the Carnmenellis Granite, Cornwall, using C.S.I.R.O. triaxial hollow inclusion cells are described. (author)

Exploring the Impact of Applicants' Gender and Religion on Principals' Screening Decisions for Assistant Principal Applicants

Science.gov (United States)

Bon, Susan C.

2009-01-01

In this experimental study, a national random sample of high school principals (stratified by gender) were asked to evaluate hypothetical applicants whose resumes varied by religion (Jewish, Catholic, nondenominational) and gender (male, female) for employment as assistant principals. Results reveal that male principals rate all applicants higher…

The influence of stress state on the reorientation of hydrides in a zirconium alloy

International Nuclear Information System (INIS)

Cinbiz, Mahmut N.; Koss, Donald A.; Motta, Arthur T.

2016-01-01

Hydride reorientation can occur in spent nuclear fuel cladding when subjected to a tensile hoop stress above a threshold value during cooling. Because in these circumstances the cladding is under a multiaxial stress state, the effect of stress biaxiality on the threshold stress for hydride reorientation is investigated using hydrided CWSR Zircaloy-4 sheet specimens containing ∼180 wt ppm of hydrogen and subjected to a two-cycle thermo-mechanical treatment. The study is based on especially designed specimens within which the stress biaxiality ratios range from uniaxial (σ_2/σ_1 = 0) to “near-equibiaxial” tension (σ_2/σ_1 = 0.8). The threshold stress is determined by mapping finite element calculations of the principal stresses and of the stress biaxiality ratio onto the hydride microstructure obtained after the thermo-mechanical treatment. The results show that the threshold stress (maximum principal stress) decreases from 155 to 75 MPa as the stress biaxiality increases from uniaxial to “near-equibiaxial” tension.

Investigations of some rock stress measuring techniques and the stress field in Norway

Energy Technology Data Exchange (ETDEWEB)

Hanssen, Tor Harald

1998-12-31

Rock stresses are important to the safe construction and operation of all man-made structures in rock, whether In mining, civil or petroleum engineering. The crucial issue is their relative magnitude and orientation. This thesis develops equipment and methods for further rock stress assessment and reevaluates existing overcoring rock stress measurements, and relates this information to the present geological setting. Both laboratory work and field work are involved. In the field, rock stresses are measured by the overcoring and the hydraulic fracturing technique. An observation technique for assessing likely high stresses is developed. The field data refer to several hydropower projects and to some offshore hydrocarbon fields. The principal sections are: (1) Tectonic setting in the western Fennoscandia, (2) Triaxial rock stress measurements by overcoring using the NTH cell (a strain gauge cell developed at the Norwegian technical university in Trondheim and based on the CSIR cell of the South African Council for Scientific and Industrial Research), (3) Laboratory testing of the NTH cell, (4) Quality ranking of stresses measured by the NTH cell, (4) Recalculated rock stresses and implications to the regional stress field, (5) Hydraulic fracturing stress measurements. 113 refs., 98 figs., 62 tabs.

Investigations of some rock stress measuring techniques and the stress field in Norway

Energy Technology Data Exchange (ETDEWEB)

Hanssen, Tor Harald

1997-12-31

Rock stresses are important to the safe construction and operation of all man-made structures in rock, whether In mining, civil or petroleum engineering. The crucial issue is their relative magnitude and orientation. This thesis develops equipment and methods for further rock stress assessment and reevaluates existing overcoring rock stress measurements, and relates this information to the present geological setting. Both laboratory work and field work are involved. In the field, rock stresses are measured by the overcoring and the hydraulic fracturing technique. An observation technique for assessing likely high stresses is developed. The field data refer to several hydropower projects and to some offshore hydrocarbon fields. The principal sections are: (1) Tectonic setting in the western Fennoscandia, (2) Triaxial rock stress measurements by overcoring using the NTH cell (a strain gauge cell developed at the Norwegian technical university in Trondheim and based on the CSIR cell of the South African Council for Scientific and Industrial Research), (3) Laboratory testing of the NTH cell, (4) Quality ranking of stresses measured by the NTH cell, (4) Recalculated rock stresses and implications to the regional stress field, (5) Hydraulic fracturing stress measurements. 113 refs., 98 figs., 62 tabs.

Principals' Perceptions of Politics

Science.gov (United States)

Tooms, Autumn K.; Kretovics, Mark A.; Smialek, Charles A.

2007-01-01

This study is an effort to examine principals' perceptions of workplace politics and its influence on their productivity and efficacy. A survey was used to explore the perceptions of current school administrators with regard to workplace politics. The instrument was disseminated to principals serving public schools in one Midwestern state in the…

Method for stress determination in N, E, and T tunnels, Nevada Test Site, by hydraulic fracturing, with a comparison of overcoring methods

International Nuclear Information System (INIS)

Miller, C.H.

1976-01-01

Twenty-nine intervals in 10 core holes were hydraulically fractured in N, E, and T tunnels, Nevada Test Site, during 1974. Certain pressures were determined and related to the ambient stress field, but the orientation of the hydraulic fractures was not measured. These data and data from previous investigations in G tunnel indicated that both the magnitude of the hydraulic pressures and the direction of fracturing are independent of the orientation of the core holes. The maximum and minimum principal compressive stresses determined by the hydraulic fracturing methods are good approximations of those determined by nearby overcore methods. The data show that a good approximation of the magnitudes of the maximum and minimum principal stress axes can be obtained from several hydrofractured intervals in one core hole. Furthermore, if fracture orientation can be measured, then the direction of minimum principal compressive stress can be determined and the orientation of the plane of the maximum and intermediate principal compressive stresses can also be determined

Evaluation of Residual Stresses using Ring Core Method

Directory of Open Access Journals (Sweden)

Holý S.

2010-06-01

Full Text Available The method for measuring residual stresses using ring-core method is described. Basic relations are given for residual stress measurement along the specimen depth and simplified method is described for average residual stress estimation in the drilled layer for known principal stress directions. The estimation of calculated coefficients using FEM is described. Comparison of method sensitivity is made with hole-drilling method. The device for method application is described and an example of experiment is introduced. The accuracy of method is discussed. The influence of strain gauge rosette misalignment to the evaluated residual stresses is performed using FEM.

A Criterion to Identify Maximally Entangled Four-Qubit State

International Nuclear Information System (INIS)

Zha Xinwei; Song Haiyang; Feng Feng

2011-01-01

Paolo Facchi, et al. [Phys. Rev. A 77 (2008) 060304(R)] presented a maximally multipartite entangled state (MMES). Here, we give a criterion for the identification of maximally entangled four-qubit states. Using this criterion, we not only identify some existing maximally entangled four-qubit states in the literature, but also find several new maximally entangled four-qubit states as well. (general)

Vacua of maximal gauged D=3 supergravities

International Nuclear Information System (INIS)

Fischbacher, T; Nicolai, H; Samtleben, H

2002-01-01

We analyse the scalar potentials of maximal gauged three-dimensional supergravities which reveal a surprisingly rich structure. In contrast to maximal supergravities in dimensions D≥4, all these theories possess a maximally supersymmetric (N=16) ground state with negative cosmological constant Λ 2 gauged theory, whose maximally supersymmetric groundstate has Λ = 0. We compute the mass spectra of bosonic and fermionic fluctuations around these vacua and identify the unitary irreducible representations of the relevant background (super)isometry groups to which they belong. In addition, we find several stationary points which are not maximally supersymmetric, and determine their complete mass spectra as well. In particular, we show that there are analogues of all stationary points found in higher dimensions, among them are de Sitter (dS) vacua in the theories with noncompact gauge groups SO(5, 3) 2 and SO(4, 4) 2 , as well as anti-de Sitter (AdS) vacua in the compact gauged theory preserving 1/4 and 1/8 of the supersymmetries. All the dS vacua have tachyonic instabilities, whereas there do exist nonsupersymmetric AdS vacua which are stable, again in contrast to the D≥4 theories

Renewing the Principal Pipeline

Science.gov (United States)

Turnbull, Brenda J.

2015-01-01

The work principals do has always mattered, but as the demands of the job increase, it matters even more. Perhaps once they could maintain safety and order and call it a day, but no longer. Successful principals today must also lead instruction and nurture a productive learning community for students, teachers, and staff. They set the tone for the…

Principal Ports

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Principal Ports are defined by port limits or US Army Corps of Engineers (USACE) projects, these exclude non-USACE projects not authorized for publication. The...

Perceptions of Beginning Public School Principals.

Science.gov (United States)

Lyons, James E.

1993-01-01

Summarizes a study to determine principal's perceptions of their competency in primary responsibility areas and their greatest challenges and frustrations. Beginning principals are challenged by delegating responsibilities and becoming familiar with the principal's role, the local school, and school operations. Their major frustrations are role…

Andragogical Practices of School Principals in Developing the Leadership Capacities of Assistant Principals

Science.gov (United States)

McDaniel, Luther

2017-01-01

The purpose of this mixed methods study was to assess school principals' perspectives of the extent to which they apply the principles of andragogy to the professional development of assistant principals in their schools. This study was conducted in school districts that constitute a RESA area in a southeastern state. The schools in these…

Study of Characters in Story of School Principal (Modir Madrese

Directory of Open Access Journals (Sweden)

Ghadamzli Sarrami

2013-05-01

Full Text Available Abstract It is concluded from the story that the reader to be briefed on the writer that he is fully aware of the education system process, furthermore it signifies that the inefficiency and distortion virtually experienced in the field of education affect the life cycle of the author as well.  Modir Madrese or School Principal is a fiction composed by Jalale Aleahmad a writer with genre of third person addressee, he narrates the biography of a teacher that he got tired of his job therefore he got his mind to assume the post of school principal, he reached to the favorite post by bribery as a result the previous teacher turned to school principal, the school situated at the slope of mountain.  The principal encountered with seven teachers, a janitor and 235 student who were mostly poor, geographical status, hygienic Services, yard, pond and school insufficient facilities which outlined as major shortcomings in the story.  Cognizance of students` parents, local council and establishment of school and home association, pornographies carried by a student, injury of 4th grade class teacher by car of an American citizen, jail of 3 grade class teacher due to sympathy toward socialists, appearing the accountant of education dept at the school asking for bribery and finally sexual scandal by 5th grade student counted as the major parts of the story , the whole incidences forced the principal to resign.  The current story represented in three perspectives like prose, simplicity and motive.  Motive signifies the text of story in social style it means realism fad while the prose depicts soft and colloquial by contribution of simile, explanations, proverbs and folkloric idioms, the stressed discourses, sarcasms and mockery including intensive and expressive prose manifested by representation of samples drawn out from the text.  The prominent part of the criticism revealed by analysis of story characters, as a result criticism of individual characters

Study of Characters in Story of School Principal (Modir Madrese

Directory of Open Access Journals (Sweden)

Dr Ghadamzli Sarrami , Mohammad Moghiseh

2013-01-01

Full Text Available It is concluded from the story that the reader to be briefed on the writer that he is fully aware of the education system process, furthermore it signifies that the inefficiency and distortion virtually experienced in the field of education affect the life cycle of the author as well. Modir Madrese or School Principal is a fiction composed by Jalale Aleahmad a writer with genre of third person addressee, he narrates the biography of a teacher that he got tired of his job therefore he got his mind to assume the post of school principal, he reached to the favorite post by bribery as a result the previous teacher turned to school principal, the school situated at the slope of mountain. The principal encountered with seven teachers, a janitor and 235 student who were mostly poor, geographical status, hygienic Services, yard, pond and school insufficient facilities which outlined as major shortcomings in the story. Cognizance of students` parents, local council and establishment of school and home association, pornographies carried by a student, injury of 4th grade class teacher by car of an American citizen, jail of 3 grade class teacher due to sympathy toward socialists, appearing the accountant of education dept at the school asking for bribery and finally sexual scandal by 5th grade student counted as the major parts of the story , the whole incidences forced the principal to resign. The current story represented in three perspectives like prose, simplicity and motive. Motive signifies the text of story in social style it means realism fad while the prose depicts soft and colloquial by contribution of simile, explanations, proverbs and folkloric idioms, the stressed discourses, sarcasms and mockery including intensive and expressive prose manifested by representation of samples drawn out from the text. The prominent part of the criticism revealed by analysis of story characters, as a result criticism of individual characters demonstrate symbol of

41 CFR 105-68.995 - Principal.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Principal. 105-68.995 Section 105-68.995 Public Contracts and Property Management Federal Property Management Regulations System...-GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 105-68.995 Principal. Principal means— (a...

Sex differences in autonomic function following maximal exercise.

Science.gov (United States)

Kappus, Rebecca M; Ranadive, Sushant M; Yan, Huimin; Lane-Cordova, Abbi D; Cook, Marc D; Sun, Peng; Harvey, I Shevon; Wilund, Kenneth R; Woods, Jeffrey A; Fernhall, Bo

2015-01-01

Heart rate variability (HRV), blood pressure variability, (BPV) and heart rate recovery (HRR) are measures that provide insight regarding autonomic function. Maximal exercise can affect autonomic function, and it is unknown if there are sex differences in autonomic recovery following exercise. Therefore, the purpose of this study was to determine sex differences in several measures of autonomic function and the response following maximal exercise. Seventy-one (31 males and 40 females) healthy, nonsmoking, sedentary normotensive subjects between the ages of 18 and 35 underwent measurements of HRV and BPV at rest and following a maximal exercise bout. HRR was measured at minute one and two following maximal exercise. Males have significantly greater HRR following maximal exercise at both minute one and two; however, the significance between sexes was eliminated when controlling for VO2 peak. Males had significantly higher resting BPV-low-frequency (LF) values compared to females and did not significantly change following exercise, whereas females had significantly increased BPV-LF values following acute maximal exercise. Although males and females exhibited a significant decrease in both HRV-LF and HRV-high frequency (HF) with exercise, females had significantly higher HRV-HF values following exercise. Males had a significantly higher HRV-LF/HF ratio at rest; however, both males and females significantly increased their HRV-LF/HF ratio following exercise. Pre-menopausal females exhibit a cardioprotective autonomic profile compared to age-matched males due to lower resting sympathetic activity and faster vagal reactivation following maximal exercise. Acute maximal exercise is a sufficient autonomic stressor to demonstrate sex differences in the critical post-exercise recovery period.

Eccentric exercise decreases maximal insulin action in humans

DEFF Research Database (Denmark)

Asp, Svend; Daugaard, J R; Kristiansen, S

1996-01-01

subjects participated in two euglycaemic clamps, performed in random order. One clamp was preceded 2 days earlier by one-legged eccentric exercise (post-eccentric exercise clamp (PEC)) and one was without the prior exercise (control clamp (CC)). 2. During PEC the maximal insulin-stimulated glucose uptake...... for all three clamp steps used (P maximal activity of glycogen synthase was identical in the two thighs for all clamp steps. 3. The glucose infusion rate (GIR......) necessary to maintain euglycaemia during maximal insulin stimulation was lower during PEC compared with CC (15.7%, 81.3 +/- 3.2 vs. 96.4 +/- 8.8 mumol kg-1 min-1, P maximal...

Principal-Counselor Collaboration and School Climate

Science.gov (United States)

Rock, Wendy D.; Remley, Theodore P.; Range, Lillian M.

2017-01-01

Examining whether principal-counselor collaboration and school climate were related, researchers sent 4,193 surveys to high school counselors in the United States and received 419 responses. As principal-counselor collaboration increased, there were increases in counselors viewing the principal as supportive, the teachers as regarding one another…

12 CFR 561.39 - Principal office.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Principal office. 561.39 Section 561.39 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY DEFINITIONS FOR REGULATIONS AFFECTING ALL SAVINGS ASSOCIATIONS § 561.39 Principal office. The term principal office means the home...

Teacher Supervision Practices and Principals' Characteristics

Science.gov (United States)

April, Daniel; Bouchamma, Yamina

2015-01-01

A questionnaire was used to determine the individual and collective teacher supervision practices of school principals and vice-principals in Québec (n = 39) who participated in a research-action study on pedagogical supervision. These practices were then analyzed in terms of the principals' sociodemographic and socioprofessional characteristics…

The Root Cause of Post-traumatic and Developmental Stress Disorder

Science.gov (United States)

2013-03-01

Post - traumatic and Developmental Stress Disorder PRINCIPAL INVESTIGATOR: Keith A...28 Feb 2013 4. TITLE AND SUBTITLE The Root Cause of Post - traumatic and Developmental Stress Disorder 5a. CONTRACT NUMBER W81XWH-­‐07-­‐1-­‐0244...goal of Project 1 is to describe the progression of post -deployment stress disorders ( PTSD , major depression, suicidality) in active duty troops

Maximize x(a - x)

Science.gov (United States)

Lange, L. H.

1974-01-01

Five different methods for determining the maximizing condition for x(a - x) are presented. Included is the ancient Greek version and a method attributed to Fermat. None of the proofs use calculus. (LS)

Developing Principal Instructional Leadership through Collaborative Networking

Science.gov (United States)

Cone, Mariah Bahar

2010-01-01

This study examines what occurs when principals of urban schools meet together to learn and improve their instructional leadership in collaborative principal networks designed to support, sustain, and provide ongoing principal capacity building. Principal leadership is considered second only to teaching in its ability to improve schools, yet few…

Principal Stability and the Rural Divide

Science.gov (United States)

Pendola, Andrew; Fuller, Edward J.

2018-01-01

This article examines the unique features of the rural school context and how these features are associated with the stability of principals in these schools. Given the small but growing literature on the characteristics of rural principals, this study presents an exploratory analysis of principal stability across schools located in different…

A principal-agent Model of corruption

NARCIS (Netherlands)

Groenendijk, Nico

1997-01-01

One of the new avenues in the study of political corruption is that of neo-institutional economics, of which the principal-agent theory is a part. In this article a principal-agent model of corruption is presented, in which there are two principals (one of which is corrupting), and one agent (who is

Stress analysis of glass-ceramic insulator and molybdenum cylinders in vacuum tube subassembly

International Nuclear Information System (INIS)

Spears, R.K.

1980-01-01

This study determined the state of stress between molybdenum cylinders and a glass-ceramic insulator of a vacuum tube during cooling when the glass-ceramic coefficient of expansion differed from molybdenum by +-2 x 10 -7 / 0 C. A thermoelastic stress analysis was performed on the vacuum tube subassembly using the finite element method. Two cases, which examined the effect of cooling over a 700 0 C range, were considered. In Case One, the expansion coefficient of the glass-ceramic was 2 x 10 -7 / 0 C less than that of molybdenum while for Case Two, it was 2 x 10 -7 / 0 C greater. For Case One, it was found that the tangential stresses in the insulator were entirely compressive but the maximum principal stresses in the r-z plane were mainly tensile. For Case Two, the tangential stresses were tensile in the insulator as were most of the maximum principal stresses in the r-z plane except for stress in the upper regions of the insulator. The magnitude of the stress at the maximum principal stress location appears to be substantially lower than what has been observed in practice (i.e., cracking of this design had never been a major problem, but it has been observed that if the coefficient of expansion of the glass-ceramic was 2 x 10 -7 / 0 C lower than molybdenum, cracking usually resulted). This analysis showed that the expansion coefficient of the glass-ceramic could be varied quite liberally from molybdenum before the ultimate strength (13,000 lb/in. 2 ) of the glass-ceramic was exceeded

Elastic-plastic stress distributions near the endcap of a fuel element

International Nuclear Information System (INIS)

Tayal, M.; Hallgrimson, K.D.; Sejnoha, R.; Singh, P.N.

1993-06-01

This paper discusses the stress patterns in and near the endcap of a CANDU fuel element from the perspective of stress corrosion cracking. Simulations of out-reactor burst tests suggest that local plastic strains stay comparatively low for internal pressures below 26-30 MPa. Photoelastic measurements as well as analytical assessments show that the reentrant corner at the sheath/endcap junction results in high concentration of stresses and strains. Analytical assessments show that the in-reactor stresses and strains at the reentrant corner are highly multiaxial, and well into the plastic range. The maximum principal stress correlates well with the location and the direction of circumferential endcap cracks observed in fuel that failed in the Bruce reactor. Thus the maximum principal stress appears promising in ranking various geometries of the sheath/endcap junction with respect to their relative susceptibility to stress corrosion cracking. Design studies suggest that the most effective practical ways of lowering the stresses near the weld, in order of decreasing importance, are to provide a larger interference-free length between the ridge and the endcaps; to increase the pellet/sheath radial gap; to increase the pellet/endcap axial gap; and to keep the gas pressure low. (author). 16 refs., 16 figs

Hydrocortisone at stress-associated concentrations helps maintain human heart rate variability during subsequent endotoxin challenge.

Science.gov (United States)

Rassias, Athos J; Guyre, Paul M; Yeager, Mark P

2011-12-01

We evaluated the differential impact of stress-associated vs high pharmacologic concentrations of hydrocortisone pretreatment on heart rate variability (HRV) during a subsequent systemic inflammatory stimulus. Healthy volunteers were randomized to receive placebo (Control) and hydrocortisone at 1.5 μg/kg per minute (STRESS) or at 3.0 μg/kg per minute (PHARM) as a 6-hour infusion. The STRESS dose was chosen to replicate the condition of physiologic adrenal cortical output during acute systemic stress. The PHARM dose was chosen to induce a supraphysiologic concentration of cortisol. The next day, all subjects received 2 ng/kg Escherichia coli endotoxin (lipopolysaccharide). Heart rate variability was analyzed with the statistic approximate entropy (ApEn). A lower ApEn correlates with decreased HRV. At the 3-hour nadir, the decrease in ApEn in the STRESS group was significantly less compared to placebo (P statistically different. We also found that the maximal decrease in ApEn preceded maximal increase in heart rate in all groups. The decrease in R-R interval was maximal at 4 hours, whereas the ApEn nadir was 1 hour earlier at 3 hours. Pretreatment with a stress dose of hydrocortisone but not a higher pharmacologic dose maintained a significantly higher ApEn after endotoxin exposure when compared to a placebo. In addition, decreases in ApEn preceded increases in heart rate. Copyright © 2011 Elsevier Inc. All rights reserved.

Principal Curves on Riemannian Manifolds.

Science.gov (United States)

Hauberg, Soren

2016-09-01

Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

Overcoring rock stress measurements in drillholes ONK-PP169 and ONK-PP170 Olkiluoto

International Nuclear Information System (INIS)

Berg, S.; Sjoeberg, J.

2009-03-01

Three-dimensional overcoring rock stress measurements were conducted in drillholes ONK-PP169 and ONK-PP170 at the 230 m depth level in the ONKALO site ramp. The measurements were performed during the spring of 2008. The objective of the measurements was to obtain better understanding of the in situ stress field for the measured depth levels. Another objective was to increase the confidence and reliability and to diminish the uncertainties concerning the state of stress at shallow depth of ONKALO. Due to problems with bonding of strain gauges, which may have been caused by a thin layer/coating of unknown material on the pilot hole wall, stress measurements results were only achieved in drillhole ONK-PP170 at -230 m level. The initial plan was to conduct measurements at three depth levels, -120 m, -180 m and -220 m levels, in the ONKALO ramp. Two (2) of the conducted measurements could be rated as successful (rating a) two (2) measurement were partly successful (rating b). The results from the measurements assuming isotropic condition, the major principal stress is plunging between 18deg and 35deg and trending between S and WSW. Stress magnitudes (for σ 1 ) varied between 12 and 16 MPa except for test 2:3:3 where a much higher value (47 MPa) was obtained. The orientation of the major principal stress are similar for test 2:3:3 and 2:4:3 (WSW), but are different from the orientation of the major principal stress for test 2:5:1 and 2:6:1 (S). Likewise, the horizontal stresses have the highest values for test 2:3:3 but in this case the orientation is similar to test 2:5:1 and 2:4:3. The horizontal stress magnitudes of test 2:4:3, 2:5:1 and 2:6:1 are similar but the orientation for test 2:6:1 are different from the other three tests. The results from two of the measurements assuming transversely isotropic conditions, the major principal stress is 12.3 MPa and 12.7 MPa, trending WSW and S, plunging 30 deg. (orig.)

Principal Leadership for Technology-enhanced Learning in Science

Science.gov (United States)

Gerard, Libby F.; Bowyer, Jane B.; Linn, Marcia C.

2008-02-01

Reforms such as technology-enhanced instruction require principal leadership. Yet, many principals report that they need help to guide implementation of science and technology reforms. We identify strategies for helping principals provide this leadership. A two-phase design is employed. In the first phase we elicit principals' varied ideas about the Technology-enhanced Learning in Science (TELS) curriculum materials being implemented by teachers in their schools, and in the second phase we engage principals in a leadership workshop designed based on the ideas they generated. Analysis uses an emergent coding scheme to categorize principals' ideas, and a knowledge integration framework to capture the development of these ideas. The analysis suggests that principals frame their thinking about the implementation of TELS in terms of: principal leadership, curriculum, educational policy, teacher learning, student outcomes and financial resources. They seek to improve their own knowledge to support this reform. The principals organize their ideas around individual school goals and current political issues. Principals prefer professional development activities that engage them in reviewing curricula and student work with other principals. Based on the analysis, this study offers guidelines for creating learning opportunities that enhance principals' leadership abilities in technology and science reform.

Study of the characteristics of crust stress field in East China by inversion of stress tensor

International Nuclear Information System (INIS)

Huilan, Z.; Rugang, D.

1991-12-01

This paper combines the search procedure with the optimization procedure to inverse the average stress tensor, and applies this method to study the crustal stress field using data of the solution of P wave first motion. By dealing with the data of Haicheng, Tangshan, Xingtai, Anyang, Liyang, Taiwan, Fujian and Guangdong areas, we obtain the characteristics of crust stress field of East China. The directions of the principal pressure stress always possess a small dip angle, but the azimuths vary from NEE (in north part of East China) to SEE (in the south part). This frame probably is related to the push-extrusive effects of the northwestern Pacific plate from NEE and the Philippine plate from SEE. (author). 5 refs, 8 figs, 4 tabs

Utility Maximization in Nonconvex Wireless Systems

CERN Document Server

Brehmer, Johannes

2012-01-01

This monograph formulates a framework for modeling and solving utility maximization problems in nonconvex wireless systems. First, a model for utility optimization in wireless systems is defined. The model is general enough to encompass a wide array of system configurations and performance objectives. Based on the general model, a set of methods for solving utility maximization problems is developed. The development is based on a careful examination of the properties that are required for the application of each method. The focus is on problems whose initial formulation does not allow for a solution by standard convex methods. Solution approaches that take into account the nonconvexities inherent to wireless systems are discussed in detail. The monograph concludes with two case studies that demonstrate the application of the proposed framework to utility maximization in multi-antenna broadcast channels.

Analysis of rock stress and rock stress measurements with application to Aespoe HRL

International Nuclear Information System (INIS)

Lundholm, Beatrice

2000-11-01

the opening where no influence from the openings can be expected. Since the magnitudes of the rock stresses differ between overcoring and hydraulic fracturing, some efforts have been made to find possible causes for this. The rock stresses when conducting overcoring gave higher values overall, which could be explained by high Poisson's ratios and a minor influence from the opening as the stress measurements might have been done in the disturbed zone. The high Poisson's ratio may depend on the stress-induced microcracks, which might be initiated during the overcoring of the cell, during the drilling of the pilot borehole, in which the cell is installed, and during biaxial testing. Statistical analysis showed that there is significant differences between the mean values of Poisson's ratio obtained from biaxial tests of cores containing the CSIRO HI-cell and the SSPB-cell. Poisson's ratio is about 0.34 for CSIRO HI-cell while the SSPB-cell gave a Poisson's ratio of 0.23. The analysis also showed that Young's modulus does not differ between the techniques. The modelling in FLAC was made to simulate the overcoring and biaxial testing. The result show that it is possible to obtain extensional strain in the core during overcoring if the major principal stress is perpendicular to the borehole axis. This may lead to microcracking occurring in the core causing high Poisson's ratio, which results in higher stresses. It can also be seen from the simulation of the biaxial testing that extensional strain is achieved even if the hollow core is not damaged during overcoring. The analyses using UDEC was made to study the effect of different properties of a discontinuity, such as the dip angle, Young's modulus, Poisson's ratio, density and the normal and shear stiffness. The analyses showed that an inclined discontinuity affects the stresses especially if sliding occurs. So, the dip angle does not solely, determine the amount of disturbance of the state of stress around a discontinuity

Aging and loss decision making: increased risk aversion and decreased use of maximizing information, with correlated rationality and value maximization.

Science.gov (United States)

Kurnianingsih, Yoanna A; Sim, Sam K Y; Chee, Michael W L; Mullette-Gillman, O'Dhaniel A

2015-01-01

We investigated how adult aging specifically alters economic decision-making, focusing on examining alterations in uncertainty preferences (willingness to gamble) and choice strategies (what gamble information influences choices) within both the gains and losses domains. Within each domain, participants chose between certain monetary outcomes and gambles with uncertain outcomes. We examined preferences by quantifying how uncertainty modulates choice behavior as if altering the subjective valuation of gambles. We explored age-related preferences for two types of uncertainty, risk, and ambiguity. Additionally, we explored how aging may alter what information participants utilize to make their choices by comparing the relative utilization of maximizing and satisficing information types through a choice strategy metric. Maximizing information was the ratio of the expected value of the two options, while satisficing information was the probability of winning. We found age-related alterations of economic preferences within the losses domain, but no alterations within the gains domain. Older adults (OA; 61-80 years old) were significantly more uncertainty averse for both risky and ambiguous choices. OA also exhibited choice strategies with decreased use of maximizing information. Within OA, we found a significant correlation between risk preferences and choice strategy. This linkage between preferences and strategy appears to derive from a convergence to risk neutrality driven by greater use of the effortful maximizing strategy. As utility maximization and value maximization intersect at risk neutrality, this result suggests that OA are exhibiting a relationship between enhanced rationality and enhanced value maximization. While there was variability in economic decision-making measures within OA, these individual differences were unrelated to variability within examined measures of cognitive ability. Our results demonstrate that aging alters economic decision-making for

Aging and loss decision making: increased risk aversion and decreased use of maximizing information, with correlated rationality and value maximization

Directory of Open Access Journals (Sweden)

Yoanna Arlina Kurnianingsih

2015-05-01

Full Text Available We investigated how adult aging specifically alters economic decision-making, focusing on examining alterations in uncertainty preferences (willingness to gamble and choice strategies (what gamble information influences choices within both the gains and losses domains. Within each domain, participants chose between certain monetary outcomes and gambles with uncertain outcomes. We examined preferences by quantifying how uncertainty modulates choice behavior as if altering the subjective valuation of gambles. We explored age-related preferences for two types of uncertainty, risk and ambiguity. Additionally, we explored how aging may alter what information participants utilize to make their choices by comparing the relative utilization of maximizing and satisficing information types through a choice strategy metric. Maximizing information was the ratio of the expected value of the two options, while satisficing information was the probability of winning.We found age-related alterations of economic preferences within the losses domain, but no alterations within the gains domain. Older adults (OA; 61 to 80 years old were significantly more uncertainty averse for both risky and ambiguous choices. OA also exhibited choice strategies with decreased use of maximizing information. Within OA, we found a significant correlation between risk preferences and choice strategy. This linkage between preferences and strategy appears to derive from a convergence to risk neutrality driven by greater use of the effortful maximizing strategy. As utility maximization and value maximization intersect at risk neutrality, this result suggests that OA are exhibiting a relationship between enhanced rationality and enhanced value maximization. While there was variability in economic decision-making measures within OA, these individual differences were unrelated to variability within examined measures of cognitive ability. Our results demonstrate that aging alters economic

TensorCalculator: exploring the evolution of mechanical stress in the CCMV capsid

Science.gov (United States)

Kononova, Olga; Maksudov, Farkhad; Marx, Kenneth A.; Barsegov, Valeri

2018-01-01

A new computational methodology for the accurate numerical calculation of the Cauchy stress tensor, stress invariants, principal stress components, von Mises and Tresca tensors is developed. The methodology is based on the atomic stress approach which permits the calculation of stress tensors, widely used in continuum mechanics modeling of materials properties, using the output from the MD simulations of discrete atomic and C_α -based coarse-grained structural models of biological particles. The methodology mapped into the software package TensorCalculator was successfully applied to the empty cowpea chlorotic mottle virus (CCMV) shell to explore the evolution of mechanical stress in this mechanically-tested specific example of a soft virus capsid. We found an inhomogeneous stress distribution in various portions of the CCMV structure and stress transfer from one portion of the virus structure to another, which also points to the importance of entropic effects, often ignored in finite element analysis and elastic network modeling. We formulate a criterion for elastic deformation using the first principal stress components. Furthermore, we show that von Mises and Tresca stress tensors can be used to predict the onset of a viral capsid’s mechanical failure, which leads to total structural collapse. TensorCalculator can be used to study stress evolution and dynamics of defects in viral capsids and other large-size protein assemblies.

Focal mechanisms in the southern Aegean from temporary seismic networks - implications for the regional stress field and ongoing deformation processes

Science.gov (United States)

Friederich, W.; Brüstle, A.; Küperkoch, L.; Meier, T.; Lamara, S.; Egelados Working Group

2014-05-01

The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 well-constrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini-Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW-SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE-SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east-west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW-SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except in volcanic areas, where both

Maximally Informative Observables and Categorical Perception

OpenAIRE

Tsiang, Elaine

2012-01-01

We formulate the problem of perception in the framework of information theory, and prove that categorical perception is equivalent to the existence of an observable that has the maximum possible information on the target of perception. We call such an observable maximally informative. Regardless whether categorical perception is real, maximally informative observables can form the basis of a theory of perception. We conclude with the implications of such a theory for the problem of speech per...

Triangulating Principal Effectiveness: How Perspectives of Parents, Teachers, and Assistant Principals Identify the Central Importance of Managerial Skills. Working Paper 35

Science.gov (United States)

Grissom, Jason A.; Loeb, Susanna

2009-01-01

While the importance of effective principals is undisputed, few studies have addressed what specific skills principals need to promote school success. This study draws on unique data combining survey responses from principals, assistant principals, teachers and parents with rich administrative data to identify which principal skills matter most…

BANK CAPITAL AND MACROECONOMIC SHOCKS: A PRINCIPAL COMPONENTS ANALYSIS AND VECTOR ERROR CORRECTION MODEL

Directory of Open Access Journals (Sweden)

Christian NZENGUE PEGNET

2011-07-01

Full Text Available The recent financial turmoil has clearly highlighted the potential role of financial factors on amplification of macroeconomic developments and stressed the importance of analyzing the relationship between banks’ balance sheets and economic activity. This paper assesses the impact of the bank capital channel in the transmission of schocks in Europe on the basis of bank's balance sheet data. The empirical analysis is carried out through a Principal Component Analysis and in a Vector Error Correction Model.

Principal components

NARCIS (Netherlands)

Hallin, M.; Hörmann, S.; Piegorsch, W.; El Shaarawi, A.

2012-01-01

Principal Components are probably the best known and most widely used of all multivariate analysis techniques. The essential idea consists in performing a linear transformation of the observed k-dimensional variables in such a way that the new variables are vectors of k mutually orthogonal

Anxiety and Stress--How They Affect Teachers, Teaching.

Science.gov (United States)

Youngs, Bettie Burres

1978-01-01

Principals can play an important role in the interpersonal relationships within a school building by exploring and assessing issues regarding cause and effect of the anxiety, stress, and tension that exist among personnel. (Author/MLF)

Measuring Principal Performance: How Rigorous Are Commonly Used Principal Performance Assessment Instruments? A Quality School Leadership Issue Brief

Science.gov (United States)

Condon, Christopher; Clifford, Matthew

2010-01-01

This brief reviews the publicly available principal assessments and points superintendents and policy makers toward strong instruments to measure principal performance. Specifically, the measures included in this review are expressly intended to evaluate principal performance and have varying degrees of publicly available evidence of psychometric…

Cycle counting procedure for fatigue failure preditions for complicated multi-axial stress histories

International Nuclear Information System (INIS)

Jones, D.P.; Friedrich, C.M.; Hoppe, R.G.

1977-12-01

A procedure has been developed to determine the cumulative fatigue damage in structures experiencing complicated multi-axial stress histories. The procedure is a generalization of the rainflow method developed by Matsuishi and Endo for one-dimensional situations. It provides a consistent treatment of three-dimensional stress states that is especially suited to computer programming applications for the post-processing of finite element stress data. The procedure includes a unique method to account for the rotation of principal stresses with time during the stress history and for the cumulative fatigue damage resulting from partial stress reversals within a stress cycle. The general procedure and necessary equations for programming are presented. Comparisons are made with life predictions using Section III of the ASME Boiler and Pressure Vessel Code for two hypothetical multi-axial stress histories for which the principal stresses are rotating with time. These comparisons show that the cycle counting method provides a consistent unambiguous interpretation of the fatigue design procedure in the ASME Code for these cases. Finally, the fatigue life of a perforated plate, as analyzed by finite elements, is computed for the combination of several hypothetical stress histories. This example demonstrates the utility of the proposed method when used in conjunction with finite element programs

Study of Characters in Story of School Principal (Modir Madrese

Directory of Open Access Journals (Sweden)

Ghadamzli Sarrami

2013-04-01

Full Text Available  Abstract It is concluded from the story that the reader to be briefed on the writer that he is fully aware of the education system process, furthermore it signifies that the inefficiency and distortion virtually experienced in the field of education affect the life cycle of the author as well.  Modir Madrese or School Principal is a fiction composed by Jalale Aleahmad a writer with genre of third person addressee, he narrates the biography of a teacher that he got tired of his job therefore he got his mind to assume the post of school principal, he reached to the favorite post by bribery as a result the previous teacher turned to school principal, the school situated at the slope of mountain.  The principal encountered with seven teachers, a janitor and 235 student who were mostly poor, geographical status, hygienic Services, yard, pond and school insufficient facilities which outlined as major shortcomings in the story.  Cognizance of students` parents, local council and establishment of school and home association, pornographies carried by a student, injury of 4th grade class teacher by car of an American citizen, jail of 3 grade class teacher due to sympathy toward socialists, appearing the accountant of education dept at the school asking for bribery and finally sexual scandal by 5th grade student counted as the major parts of the story , the whole incidences forced the principal to resign.  The current story represented in three perspectives like prose, simplicity and motive.  Motive signifies the text of story in social style it means realism fad while the prose depicts soft and colloquial by contribution of simile, explanations, proverbs and folkloric idioms, the stressed discourses, sarcasms and mockery including intensive and expressive prose manifested by representation of samples drawn out from the text.  The prominent part of the criticism revealed by analysis of story characters, as a result criticism of

Usefulness and safety of dobutamine stress thallium myocardial scintigraphy

International Nuclear Information System (INIS)

Imai, Kamon; Araki, Yasushi; Horiuchi, Kouichi; Saito, Satoshi; Ozawa, Yukio; Yasugi, Tadao.

1993-01-01

Pharmaceutical stress test is performed for diagnosis of coronary artery disease in patients who can not perform exercise test. We studied whether high dose dobutamine stres test is useful and safe. Subjects consisted of 133 patients (pts) in dobutamine stress test and 45 pts in exercise test. Dobutamine stres test was initiated by 10 μg/kg/min, followed by 10 μ/gkg/min increment every 3 minutes. Maximal dobutamine dose was 40 μg/kg/min for 3 minutes. Endpoints of dobutamine stress were as follows: ST depression equal to or more than (≥) 0.2 mV: 30 pts, ≥75% predictive maximum heart rate: 20 pts, ≥20 mmHg systolic blood pressure fallen: 10 pts, 40 μg/kg/min for 3 minutes: 10 pts, chest pain: 7 pts, pressure rate product (PRP) ≥25,000: 1 pt. Side effects of dobutamine stress test were as follows: palpitation: 52%, arhythmia: 13%, angina and dyspnea: 7%, headache: 6%. These symptoms disappeared within 2 minutes. One patient, who underwent dobutamine test 2 days after PTCA, had myocardial infarction. At peak of dobutamine stress test, systolic blood pressure, heart rate and PRP were increased similar to exercise test. However, diastolic blood pressure was not changed. The concentration at peak of dobutamine was 25.5±7.8 μg/kg/min. The duration of dobutamine stress test was 7.3±2.3 minutes. The 65 patients (49%) need more than 20 μg/kg/min of dobutamine which was maximal loading dose in previous reports. For diagnosis of coronary artery disease, sensitivity was 91% (31/34) and specificity was 70% (7/10). From these data, high dose dobutamine stress test is useful and relatively safe stress method for diagnosis of coronary disease. This stress test would be performed in patients who cannot undergo exercise test. (author)

Maximally Entangled Multipartite States: A Brief Survey

International Nuclear Information System (INIS)

Enríquez, M; Wintrowicz, I; Życzkowski, K

2016-01-01

The problem of identifying maximally entangled quantum states of a composite quantum systems is analyzed. We review some states of multipartite systems distinguished with respect to certain measures of quantum entanglement. Numerical results obtained for 4-qubit pure states illustrate the fact that the notion of maximally entangled state depends on the measure used. (paper)

Corporate Social Responsibility and Profit Maximizing Behaviour

OpenAIRE

Becchetti, Leonardo; Giallonardo, Luisa; Tessitore, Maria Elisabetta

2005-01-01

We examine the behavior of a profit maximizing monopolist in a horizontal differentiation model in which consumers differ in their degree of social responsibility (SR) and consumers SR is dynamically influenced by habit persistence. The model outlines parametric conditions under which (consumer driven) corporate social responsibility is an optimal choice compatible with profit maximizing behavior.

Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

Directory of Open Access Journals (Sweden)

Shazlin Shaharudin

2014-12-01

Full Text Available The slides ergometer (SE was an improvisation from fixed ergometer (FE to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE and fixed ergometers (FE. The laterality of muscle synergy was also examined. Surface electromyography activity, power output, heart rate, stroke length and stroke rate were analyzed from nine physically active subjects to assess the rowing performance. Physically active subjects, who were not specifically trained in rowing, were chosen to exclude the training effect on muscle synergy. Principal component analysis (PCA with varimax rotation was applied to extract muscle synergy. Three muscle synergies were sufficient to explain the majority of variance in SE (94.4 ± 2.2 % and FE (92.8 ± 1.7 %. Subjects covered more rowing distance, exerted greater power output and attained higher maximal heart rate during rowing on SE than on FE. The results proved the flexibility of muscle synergy to adapt to the mechanical constraints. Rowing on SE emphasized on bi-articular muscles contrary to rowing on FE which relied on cumulative effect of trunk and upper limb muscles during propulsive phase.

Deformation and Stress Response of Carbon Nanotubes/UHMWPE Composites under Extensional-Shear Coupling Flow

Science.gov (United States)

Wang, Junxia; Cao, Changlin; Yu, Dingshan; Chen, Xudong

2018-02-01

In this paper, the effect of varying extensional-shear couple loading on deformation and stress response of Carbon Nanotubes/ ultra-high molecular weight polyethylene (CNTs/UHMWPE) composites was investigated using finite element numerical simulation, with expect to improve the manufacturing process of UHMWPE-based composites with reduced stress and lower distortion. When applying pure extensional loading and pure X-Y shear loading, it was found that the risk of a structural breakage greatly rises. For identifying the coupling between extensional and shear loading, distinct generations of force loading were defined by adjusting the magnitude of extensional loading and X-Y shear loading. It was shown that with the decrement of X-Y shear loading the deformation decreases obviously where the maximal Mises stress in Z-direction at 0.45 m distance is in the range from 24 to 10 MPa and the maximal shear stress at 0.61 m distance is within the range from 0.9 to 0.3 MPa. In addition, all the stresses determined were clearly below the yield strength of CNTs/UHMWPE composites under extensional-shear couple loading.

Innovation Management Perceptions of Principals

Science.gov (United States)

Bakir, Asli Agiroglu

2016-01-01

This study is aimed to determine the perceptions of principals about innovation management and to investigate whether there is a significant difference in this perception according to various parameters. In the study, descriptive research model is used and universe is consisted from principals who participated in "Acquiring Formation Course…

Principal modes of rupture encountered in expertise of advanced components

International Nuclear Information System (INIS)

Tavassoli, A.A.; Bougault, A.

1986-10-01

Failure of many metallic components investigated can be classified into two categories: intergranular or transgranular according to their principal mode of rupture. Intergranular ruptures are often provoked by segregation of impurities at the grain boundaries. Three examples are cited where this phenomenon occured, one of them is a steel (A 508 cl 3) used for PWR vessel. Intergranular failures are in general induced by fatigue in the advanced components operating under thermal or load transients. One example concerning a sodium mixer which was subjected to thermal loadings is presented. Examples of stress corrosion and intergranular sensitization failures are cited. These examples show the importance of fractography for the determination of rupture causes [fr

Metabolomic Profiling of the White, Violet, and Red Flowers of Rhododendron schlippenbachii Maxim.

Science.gov (United States)

Park, Chang Ha; Yeo, Hyeon Ji; Kim, Nam Su; Park, Ye Eun; Park, Soo-Yun; Kim, Jae Kwang; Park, Sang Un

2018-04-04

Rhododendron schlippenbachii Maxim. is a garden plant that is also used for natural medicines as a consequence of the biological activities of its diverse metabolites. We accordingly profiled two anthocyanins and 40 primary and secondary metabolites in the three different colored flowers. The major anthocyanins found in the flowers were cyanidins. The red flowers exhibited the highest accumulation of anthocyanins (1.02 ± 0.02 mg/g dry weight). Principal component analysis was applied to the GC‒TOFMS data. The levels of key tricarboxylic acid cycle intermediates in red flowers, such as succinic acid, fumaric acid, and malic acid, were found to be highly significantly different ( p < 0.0001) from those in the flowers of other colors. In this study, we aimed to determine metabolite interactions and phenotypic variation among white, violet, and red flowers of R. schlippenbachii by using gas chromatography time-of-flight mass spectrometry (GC‒TOFMS) and high-performance liquid chromatography (HPLC).

Guinea pig maximization test

DEFF Research Database (Denmark)

Andersen, Klaus Ejner

1985-01-01

Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...

Modelo de contrato de terceirização de manutenção: uma abordagem principal-agente Model contract for outsourcing of maintenance: a principal-agent approach

Directory of Open Access Journals (Sweden)

Jonas Alves de Paiva

2012-12-01

Full Text Available A terceirização é uma das soluções utilizadas para se reduzir esforços em atividades não relacionadas com a atividade de produção. Na terceirização da manutenção, modelos de contratos de incentivos existentes na literatura focam como principais indicadores de controle apenas o tempo de reparo e o custo das atividades de manutenção. O principal objetivo desse trabalho consiste em apresentar um modelo de incentivos considerando também outras variáveis que são afetadas pela manutenção e que afetam fortemente o lucro, que são a qualidade dos produtos produzidos e a redução da capacidade de produção. O trabalho utiliza a teoria principal-agente para modelar um contrato de incentivos que conduz a um aumento do lucro da empresa, forçando o agente a desenvolver atividades que maximizem esse lucro. É apresentada uma exemplificação numérica, que evidencia o impacto positivo nos resultados da empresa, além da generalização e adequação do modelo.The outsourcing is being used to reduce work on activities not related to production activities. Nowadays, the models of contracts of maintenance use the repair time and the cost of maintenance activities as main control indicator to estimate the political of incentives. The main objective of this paper is to introduce a model of incentives considering other variables that affect substantially the profit and that they are affected by the maintenance activities as the quality of products produced and the reduction of production capacity. The paper uses the Principal-Agent Theory to develop an incentive contract that leads the agent to execute activities that maximize the profit. It is used a numerical example in order to highlight the positive impact on company results, in addition to the generalization and adaptation of the model.

Paraheliotropism can protect water-stressed bean (Phaseolus vulgaris L.) plants against photoinhibition.

Science.gov (United States)

Pastenes, Claudio; Porter, Victor; Baginsky, Cecilia; Horton, Peter; González, Javiera

2004-12-01

In order to estimate the importance of leaf movements on photosynthesis in well-watered and water-stressed field grown bean cultivars (Arroz Tuscola (AT), Orfeo INIA (OI), Bayos Titan (BT), and Hallados Dorado (HD)), CO2 assimilation, leaf temperature, and capacity for the maximum quantum yield recovery, measured as Fv/Fm, were assessed. Leaf water potential was lower in water-stressed compared to control plants throughout the day. Water status determined a decrease in the CO2 assimilation and stomatal conductance as light intensity and temperature increased up to maximal intensities at midday. Both parameters were lower in stressed compared to control plants. Even though high light intensity and water-stress induced stomatal closure is regarded as a photoinhibitory condition, the recovery of variable to maximal fluorescence (Fv/Fm) after 30min of darkness was nearly constant in both water regimes. In fact, higher values were observed in OI and AT when under stress. Photochemical and non-photochemical fluorescence quenching resulted in minor changes during the day and were similar between watered and stressed plants. It is concluded that paraheliotropism, present in the four bean cultivars, efficiently protects stressed plants from photoinhibition in the field and helps maintain leaf temperatures far below the ambient temperatures, however, it may also be responsible for low CO2 assimilation rates in watered plants.

Stress Response and Artemisinin Resistance in Malaria Parasite

Science.gov (United States)

2017-07-01

AWARD NUMBER: W81XWH-16-1-0241 TITLE: Stress Response and Artemisinin Resistance in Malaria Parasite PRINCIPAL INVESTIGATOR: Juan C. Pizarro...SUBTITLE Stress Response and Artemisinin Resistance in Malaria Parasite 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-16-1-0241 5c. PROGRAM ELEMENT...13. SUPPLEMENTARY NOTES 14. ABSTRACT In malaria , drug resistance is a major treat to disease control efforts. Unfortunately, there is a significant

Gradient Dynamics and Entropy Production Maximization

Science.gov (United States)

Janečka, Adam; Pavelka, Michal

2018-01-01

We compare two methods for modeling dissipative processes, namely gradient dynamics and entropy production maximization. Both methods require similar physical inputs-how energy (or entropy) is stored and how it is dissipated. Gradient dynamics describes irreversible evolution by means of dissipation potential and entropy, it automatically satisfies Onsager reciprocal relations as well as their nonlinear generalization (Maxwell-Onsager relations), and it has statistical interpretation. Entropy production maximization is based on knowledge of free energy (or another thermodynamic potential) and entropy production. It also leads to the linear Onsager reciprocal relations and it has proven successful in thermodynamics of complex materials. Both methods are thermodynamically sound as they ensure approach to equilibrium, and we compare them and discuss their advantages and shortcomings. In particular, conditions under which the two approaches coincide and are capable of providing the same constitutive relations are identified. Besides, a commonly used but not often mentioned step in the entropy production maximization is pinpointed and the condition of incompressibility is incorporated into gradient dynamics.

Time Management for New Principals

Science.gov (United States)

Ruder, Robert

2008-01-01

Becoming a principal is a milestone in an educator's professional life. The principalship is an opportunity to provide leadership that will afford students opportunities to thrive in a nurturing and supportive environment. Despite the continuously expanding demands of being a new principal, effective time management will enable an individual to be…

Estimation of the controlling stress in creep fracture

International Nuclear Information System (INIS)

Henderson, J.; Ferguson, F.R.

1975-01-01

The implementation of correct criterion in creep design, has been shown to be of fundamental significance in the assessment of component life. The present report considers the problem of the means whereby the criterion may be derived for a particular metal without the availability of sophisticated complex-stress testing equipment and procedures such as the combined tension and torsion tests on thin walled tubular specimens employed in the earlier fundamental researches on the subject. By investigating a wide spectrum of engineering metals it was established that for homogeneous stress conditions two criteria appeared to be sufficient to cover all the metals studied for complex-stress creep fracture, either the maximum principal stress or the octahedral shear stress criterion. Further, it was found that those metals which developed random and continuous cracking during creep were controlled with respect to fracture time by the maximum principal stress, while metals which showed virtually no cracking were governed by the octahedral shear stress or second order invariant. The physical nature of the final fracture (transcrystalline or inter-crystalline), contrary to considerable current concepts, was found to be unrelated to which criterion was operative. Having reduced the possible fracture criteria to two, it only remained to develop a simple test method exploiting this finding to achieve the precise identification for a particular metal. Seven metals including aluminium, copper, titanium, cast iron and three steels have been investigated in the present report at temperatures where creep conditions are operative. The results have shown that the method leads to sufficiently accurate prediction of the complex stress creep fracture criterion for the metals studied

Lithology-dependent In Situ Stress in Heterogeneous Carbonate Reservoirs

Science.gov (United States)

Pham, C. N.; Chang, C.

2017-12-01

Characterization of in situ stress state for various geomechanical aspects in petroleum development may be particularly difficult in carbonate reservoirs in which rock properties are generally heterogeneous. We demonstrate that the variation of in situ stress in highly heterogeneous carbonate reservoirs is closely related to the heterogeneity in rock mechanical property. The carbonate reservoir studied consists of numerous sequential layers gently folded, exhibiting wide ranges of porosity (0.01 - 0.29) and Young's modulus (25 - 85 GPa) depending on lithology. Wellbore breakouts and drilling-induced tensile fractures (DITFs) observed in the image logs obtained from several wells indicate that the in situ state of stress orientation changes dramatically with depth and location. Even in a wellbore, the azimuth of the maximum horizontal stress changes by as much as 60° within a depth interval of 500 m. This dramatic change in stress orientation is inferred to be due to the contrast in elastic properties between different rock layers which are bent by folding in the reservoir. The horizontal principal stress magnitudes are constrained by back-calculating stress conditions necessary to induce the observed wellbore failures using breakout width and the presence of DITFs. The horizontal stresses vary widely, which cannot be represented by a constant stress gradient with depth. The horizontal principal stress gradient increases with Young's modulus of layer monotonically, indicating that a stiffer layer conveys a higher horizontal stress. This phenomenon can be simulated using a numerical modelling, in which the horizontal stress magnitudes depend on stiffness of individual layers although the applied far-field stress conditions are constant. The numerical results also suggest that the stress concentration at the wellbore wall is essentially higher in a stiffer layer, promoting the possibility of wellbore breakout formation. These results are in agreement with our

On Maximal Non-Disjoint Families of Subsets

Directory of Open Access Journals (Sweden)

Yu. A. Zuev

2017-01-01

Full Text Available The paper studies maximal non-disjoint families of subsets of a finite set. Non-disjointness means that any two subsets of a family have a nonempty intersection. The maximality is expressed by the fact that adding a new subset to the family cannot increase its power without violating a non-disjointness condition. Studying the properties of such families is an important section of the extreme theory of sets. Along with purely combinatorial interest, the problems considered here play an important role in informatics, anti-noise coding, and cryptography.In 1961 this problem saw the light of day in the Erdos, Ko and Rado paper, which established a maximum power of the non-disjoint family of subsets of equal power. In 1974 the Erdos and Claytman publication estimated the number of maximal non-disjoint families of subsets without involving the equality of their power. These authors failed to establish an asymptotics of the logarithm of the number of such families when the power of a basic finite set tends to infinity. However, they suggested such an asymptotics as a hypothesis. A.D. Korshunov in two publications in 2003 and 2005 established the asymptotics for the number of non-disjoint families of the subsets of arbitrary powers without maximality condition of these families.The basis for the approach used in the paper to study the families of subsets is their description in the language of Boolean functions. A one-to-one correspondence between a family of subsets and a Boolean function is established by the fact that the characteristic vectors of subsets of a family are considered to be the unit sets of a Boolean function. The main theoretical result of the paper is that the maximal non-disjoint families are in one-to-one correspondence with the monotonic self-dual Boolean functions. When estimating the number of maximal non-disjoint families, this allowed us to use the result of A.A. Sapozhenko, who established the asymptotics of the number of the

Focal mechanisms in the southern Aegean from temporary seismic networks – implications for the regional stress field and ongoing deformation processes

Directory of Open Access Journals (Sweden)

W. Friederich

2014-05-01

Full Text Available The lateral variation of the stress field in the southern Aegean plate and the subducting Hellenic slab is determined from recordings of seismicity obtained with the CYCNET and EGELADOS networks in the years from 2002 to 2007. First motions from 7000 well-located microearthquakes were analysed to produce 540 well-constrained focal mechanisms. They were complemented by another 140 derived by waveform matching of records from larger events. Most of these earthquakes fall into 16 distinct spatial clusters distributed over the southern Aegean region. For each cluster, a stress inversion could be carried out yielding consistent estimates of the stress field and its spatial variation. At crustal levels, the stress field is generally dominated by a steeply dipping compressional principal stress direction except in places where coupling of the subducting slab and overlying plate come into play. Tensional principal stresses are generally subhorizontal. Just behind the forearc, the crust is under arc-parallel tension whereas in the volcanic areas around Kos, Columbo and Astypalea tensional and intermediate stresses are nearly degenerate. Further west and north, in the Santorini–Amorgos graben and in the area of the islands of Mykonos, Andros and Tinos, tensional stresses are significant and point around the NW–SE direction. Very similar stress fields are observed in western Turkey with the tensional axis rotated to NNE–SSW. Intermediate-depth earthquakes below 100 km in the Nisyros region indicate that the Hellenic slab experiences slab-parallel tension at these depths. The direction of tension is close to east–west and thus deviates from the local NW-oriented slab dip presumably owing to the segmentation of the slab. Beneath the Cretan sea, at shallower levels, the slab is under NW–SE compression. Tensional principal stresses in the crust exhibit very good alignment with extensional strain rate principal axes derived from GPS velocities except

Inquiry in bibliography some of the bustan`s maxim

Directory of Open Access Journals (Sweden)

sajjad rahmatian

2016-12-01

Full Text Available Sa`di is on of those poets who`s has placed a special position to preaching and guiding the people and among his works, allocated throughout the text of bustan to advice and maxim on legal and ethical various subjects. Surely, sa`di on the way of to compose this work and expression of its moral point, direct or indirect have been affected by some previous sources and possibly using their content. The main purpose of this article is that the pay review of basis and sources of bustan`s maxims and show that sa`di when expression the maxims of this work has been affected by which of the texts and works. For this purpose is tried to with search and research on the resources that have been allocated more or less to the aphorisms, to discover and extract traces of influence sa`di from their moral and didactic content. From the most important the finding of this study can be mentioned that indirect effect of some pahlavi books of maxim (like maxims of azarbad marespandan and bozorgmehr book of maxim and also noted sa`di directly influenced of moral and ethical works of poets and writers before him, and of this, sa`di`s influence from abo- shakur balkhi maxims, ferdowsi and keikavus is remarkable and noteworthy.

Can monkeys make investments based on maximized pay-off?

Directory of Open Access Journals (Sweden)

Sophie Steelandt

2011-03-01

Full Text Available Animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. We investigated whether monkeys can use different investment strategies in an exchange task. We tested eight capuchin monkeys (Cebus apella and thirteen macaques (Macaca fascicularis, Macaca tonkeana in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. One, the doubling partner, returned a reward that was twice the amount given by the subject, whereas the other, the fixed partner, always returned a constant amount regardless of the amount given. To maximize pay-offs, subjects should invest a maximal amount with the first partner and a minimal amount with the second. When tested with the fixed partner only, one third of monkeys learned to remove a maximal amount of food for immediate consumption before investing a minimal one. With both partners, most subjects failed to maximize pay-offs by using different decision rules with each partner' quality. A single Tonkean macaque succeeded in investing a maximal amount to one experimenter and a minimal amount to the other. The fact that only one of over 21 subjects learned to maximize benefits in adapting investment according to experimenters' quality indicates that such a task is difficult for monkeys, albeit not impossible.

Ketamine as a Rapid Treatment for Post-Traumatic Stress Disorder

Science.gov (United States)

2011-10-01

Post - traumatic stress disorder ( PTSD ) is a debilitating anxiety disorder characterized by intrusive re-experiences of the traumatic events...08-1-0602 TITLE: Ketamine as a Rapid Treatment for Post - Traumatic Stress Disorder PRINCIPAL INVESTIGATOR: Dennis Charney...dissociative effects of ketamine but not have any sustained anxiolytic and antidepressant effects. Forty individuals diagnosed with post - traumatic

What Motivates Principals?

Science.gov (United States)

Iannone, Ron

1973-01-01

Achievement and recognition were mentioned as factors appearing with greater frequency in principal's job satisfactions; school district policy and interpersonal relations were mentioned as job dissatisfactions. (Editor)

Towards the prediction of pre-mining stresses in the European continent. [Estimates of vertical and probable maximum lateral stress in Europe

Energy Technology Data Exchange (ETDEWEB)

Blackwood, R. L.

1980-05-15

There are now available sufficient data from in-situ, pre-mining stress measurements to allow a first attempt at predicting the maximum stress magnitudes likely to occur in a given mining context. The sub-horizontal (lateral) stress generally dominates the stress field, becoming critical to stope stability in many cases. For cut-and-fill mining in particular, where developed fill pressures are influenced by lateral displacement of pillars or stope backs, extraction maximization planning by mathematical modelling techniques demands the best available estimate of pre-mining stresses. While field measurements are still essential for this purpose, in the present paper it is suggested that the worst stress case can be predicted for preliminary design or feasibility study purposes. In the Eurpoean continent the vertical component of pre-mining stress may be estimated by adding 2 MPa to the pressure due to overburden weight. The maximum lateral stress likely to be encountered is about 57 MPa at depths of some 800m to 1000m below the surface.

Maximal lattice free bodies, test sets and the Frobenius problem

DEFF Research Database (Denmark)

Jensen, Anders Nedergaard; Lauritzen, Niels; Roune, Bjarke Hammersholt

Maximal lattice free bodies are maximal polytopes without interior integral points. Scarf initiated the study of maximal lattice free bodies relative to the facet normals in a fixed matrix. In this paper we give an efficient algorithm for computing the maximal lattice free bodies of an integral m...... method is inspired by the novel algorithm by Einstein, Lichtblau, Strzebonski and Wagon and the Groebner basis approach by Roune....

Disk Density Tuning of a Maximal Random Packing.

Science.gov (United States)

Ebeida, Mohamed S; Rushdi, Ahmad A; Awad, Muhammad A; Mahmoud, Ahmed H; Yan, Dong-Ming; English, Shawn A; Owens, John D; Bajaj, Chandrajit L; Mitchell, Scott A

2016-08-01

We introduce an algorithmic framework for tuning the spatial density of disks in a maximal random packing, without changing the sizing function or radii of disks. Starting from any maximal random packing such as a Maximal Poisson-disk Sampling (MPS), we iteratively relocate, inject (add), or eject (remove) disks, using a set of three successively more-aggressive local operations. We may achieve a user-defined density, either more dense or more sparse, almost up to the theoretical structured limits. The tuned samples are conflict-free, retain coverage maximality, and, except in the extremes, retain the blue noise randomness properties of the input. We change the density of the packing one disk at a time, maintaining the minimum disk separation distance and the maximum domain coverage distance required of any maximal packing. These properties are local, and we can handle spatially-varying sizing functions. Using fewer points to satisfy a sizing function improves the efficiency of some applications. We apply the framework to improve the quality of meshes, removing non-obtuse angles; and to more accurately model fiber reinforced polymers for elastic and failure simulations.

Bureaucratic Control and Principal Role.

Science.gov (United States)

Bezdek, Robert; And Others

The purposes of this study were to determine the manner in which the imposition of increased bureaucratic control over principals influenced their allocation of time to tasks and to investigate principals' perceptions of the changes in their roles brought about by this increased control. The specific bureaucratic control system whose effects were…

Thermal stresses in long prisms by relaxation methods

International Nuclear Information System (INIS)

Cummins, J.D.

1959-07-01

A general method is presented for calculating the elastic thermal stresses in long prisms which are producing heat and are not solvable by simple analytical methods. The problem of an inverted lattice i.e. an hexagonal coolant passage surrounded by hexagonal fuel elements is considered and the temperature and principal thermal stress distributions evaluated for the particular case of 20% coolant. The maximum thermal stress for this type of fuel element is about the same as the maximum thermal stress in a cylindrical fuel element surrounded by a sea of coolant assuming the existence of the same maximum temperature drop and material properties. (author)

Thermal stresses in long prisms by relaxation methods

Energy Technology Data Exchange (ETDEWEB)

Cummins, J D [Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

1959-07-15

A general method is presented for calculating the elastic thermal stresses in long prisms which are producing heat and are not solvable by simple analytical methods. The problem of an inverted lattice i.e. an hexagonal coolant passage surrounded by hexagonal fuel elements is considered and the temperature and principal thermal stress distributions evaluated for the particular case of 20% coolant. The maximum thermal stress for this type of fuel element is about the same as the maximum thermal stress in a cylindrical fuel element surrounded by a sea of coolant assuming the existence of the same maximum temperature drop and material properties. (author)

Modelling of thermal stress in vapor generator supports

International Nuclear Information System (INIS)

Halpert, S.; Vazquez, L.

1997-01-01

To assure safety and availability of a nuclear power plant components or equipment stress analysis are done. When thermal loads are involved it's necessary to know the temperature field of the component or equipment. This paper describes the structural analysis of a steam generator lug with thermal load including the model used for computer simulation and presents the evolution of the temperature profile, the stress intensity and principal stress during start up and shut down of a nuclear power reactor. Temperature field obtained from code calculation show good agreement with the experimental data while stress analysis results are in agreement with a preview estimation. (author) [es

Utility of atropine in patients under beta-blocker effect during exercise stress echocardiography

International Nuclear Information System (INIS)

Munera, Ana G; Restrepo, Gustavo; Aristizabal, Dagnovar; Cubides, Carlos A

2006-01-01

The objective is to assess the usefulness of adding atropine 0.5 to 1.0 mg by intravenous injection during peak exercise in patients under beta-blocker effect that are subjected to exercise stress echocardiography. Population: exercise stress echocardiography was performed in 73 patients receiving beta-blocking agents with basal heart rate below 60 beats per minute (BPM). Two groups were established at random: group I (18 patients that did not receive atropine during maximal exercise) and group II (50 patients from whom 28 received 0.5 mg atropine IV 30 seconds to one minute before concluding the exercise and 22 patients who received 1.0 mg atropine IV 30 seconds to one minute before its conclusion). From a demographic point of view, there were no differences between the two groups. Mean age was 59 ± 10.8 years (57% male). Most of the patients received metoprolol (87%) and no significant statistical differences in relation with the doses were found in these two groups. At the end of the exercise, the patients had a mean heart rate of 84% from their maximal heart rate (MHR). The values post-exercise were 76% at 30 seconds, 68% at 60 sec., 62% at 90 sec., and 59% of the maximal heart rate at 120 sec. When comparing the percentage of the maximal heart rate achieved in maximal exercise and the one observed during the first 120 sec. after exercise, no statistically significant difference was observed between the two groups (p > 0.05). Conclusion: during the performance of stress exercise echocardiography, the administration of intravenous atropine was of no use for incrementing the peak heart rate post-exercise in patients with significant beta-blocker effect (basal heart rate < 60 BPM)

Petroselinum Crispum is Effective in Reducing Stress-Induced Gastric Oxidative Damage

OpenAIRE

Ayşin Akıncı; Mukaddes Eşrefoğlu; Elif Taşlıdere; Burhan Ateş

2017-01-01

Background: Oxidative stress has been shown to play a principal role in the pathogenesis of stress-induced gastric injury. Parsley (Petroselinum crispum) contains many antioxidants such as flavanoids, carotenoids and ascorbic acid. Aims: In this study, the histopathological and biochemical results of nutrition with a parsley-rich diet in terms of eliminating stress-induced oxidative gastric injury were evaluated. Study Design: Animal experimentation. Methods: Forty male Wistar albino...

Petroselinum Crispum is Effective in Reducing Stress-Induced Gastric Oxidative Damage

OpenAIRE

Ak?nc?, Ay?in; E?refo?lu, Mukaddes; Ta?l?dere, Elif; Ate?, Burhan

2017-01-01

Background: Oxidative stress has been shown to play a principal role in the pathogenesis of stress-induced gastric injury. Parsley (Petroselinum crispum) contains many antioxidants such as flavanoids, carotenoids and ascorbic acid. Aims: In this study, the histopathological and biochemical results of nutrition with a parsley-rich diet in terms of eliminating stress-induced oxidative gastric injury were evaluated. Study Design: Animal experimentation Methods: Forty male Wistar albino rats were...

An information maximization model of eye movements

Science.gov (United States)

Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

2005-01-01

We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

Microscopic creep models and the interpretation of stress-dip tests during creep

International Nuclear Information System (INIS)

Poirier, J.P.

1976-09-01

A critical analysis is made of the principal divergent view points concerning stress-dip tests. The raw data are examined and interpreted in the light of various creep models. The following problems are discussed: is the reverse strain anelastic or plastic; is the zero creep rate periodic due to recovery or is it spurious; can the existence or inexistence of an internal stress be deduced from stress-dip tests; can stress-dip tests allow to determine whether glide is jerky or viscous; can the internal stress be measured by stress-dip tests

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of an approach to modelling the state of stress

Energy Technology Data Exchange (ETDEWEB)

Hakami, Eva; Hakami, Hossein [Itasca Geomekanik AB, Solna (Sweden); Cosgrove, John [Imperial College of Science and Technology, London (United Kingdom)

2002-05-01

The overall objective of this project has been to develop, test and establish a method for creating a Rock Mechanics Site Descriptive Model for a site considered in the site investigation programme. The work was divided into three parts, the empirical and theoretical 'property models' and the 'stress model'. The work on the stress model is presented in this report. The work consisted of i) a literature review about geological factors controlling in situ stress and a review about the use of numerical models for this subject, ii) the development of recommendations on the methodology to be applied during a site investigation and iii) the Test Case exercise, where the suggested methods were tested. The main mechanism controlling the in situ stress magnitudes in Sweden is plate tectonics causing the stress field to show similarities in most parts of north-western Europe, having a NW-SE trend of the maximum principal stress. The orientation of the stress field is largely determined by the relative movements by the plates. However, the stress orientation may also be influenced by the presence of large regional weak zones, such as the Tornquist deformation zone that lies between Sweden and Denmark. The strike of the Tornquist deformation zone is parallel to the maximum principal stress as observed in central and southern Sweden. The magnitude of the stress is more difficult to estimate, but the general pattern is an increase in magnitude with depth, at least for the upper kilometres. To determine the stress magnitude at a certain site and depth, with reasonable certainty, stress measurement should be used. A methodology for building a stress model has been proposed. It involves different steps starting with a preliminary stress estimation, followed by steps for interpreting site-specific information. If the stress pattern and structural geology of the site are complex, including major fracture zones intersecting the area, numerical analyses of the

Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of an approach to modelling the state of stress

International Nuclear Information System (INIS)

Hakami, Eva; Hakami, Hossein; Cosgrove, John

2002-05-01

The overall objective of this project has been to develop, test and establish a method for creating a Rock Mechanics Site Descriptive Model for a site considered in the site investigation programme. The work was divided into three parts, the empirical and theoretical 'property models' and the 'stress model'. The work on the stress model is presented in this report. The work consisted of i) a literature review about geological factors controlling in situ stress and a review about the use of numerical models for this subject, ii) the development of recommendations on the methodology to be applied during a site investigation and iii) the Test Case exercise, where the suggested methods were tested. The main mechanism controlling the in situ stress magnitudes in Sweden is plate tectonics causing the stress field to show similarities in most parts of north-western Europe, having a NW-SE trend of the maximum principal stress. The orientation of the stress field is largely determined by the relative movements by the plates. However, the stress orientation may also be influenced by the presence of large regional weak zones, such as the Tornquist deformation zone that lies between Sweden and Denmark. The strike of the Tornquist deformation zone is parallel to the maximum principal stress as observed in central and southern Sweden. The magnitude of the stress is more difficult to estimate, but the general pattern is an increase in magnitude with depth, at least for the upper kilometres. To determine the stress magnitude at a certain site and depth, with reasonable certainty, stress measurement should be used. A methodology for building a stress model has been proposed. It involves different steps starting with a preliminary stress estimation, followed by steps for interpreting site-specific information. If the stress pattern and structural geology of the site are complex, including major fracture zones intersecting the area, numerical analyses of the stress field is

School Principals' Sources of Knowledge

Science.gov (United States)

Perkins, Arland Early

2014-01-01

The purpose of this study was to determine what sources of professional knowledge are available to principals in 1 rural East Tennessee school district. Qualitative research methods were applied to gain an understanding of what sources of knowledge are used by school principals in 1 rural East Tennessee school district and the barriers they face…

On the way towards a generalized entropy maximization procedure

International Nuclear Information System (INIS)

Bagci, G. Baris; Tirnakli, Ugur

2009-01-01

We propose a generalized entropy maximization procedure, which takes into account the generalized averaging procedures and information gain definitions underlying the generalized entropies. This novel generalized procedure is then applied to Renyi and Tsallis entropies. The generalized entropy maximization procedure for Renyi entropies results in the exponential stationary distribution asymptotically for q element of (0,1] in contrast to the stationary distribution of the inverse power law obtained through the ordinary entropy maximization procedure. Another result of the generalized entropy maximization procedure is that one can naturally obtain all the possible stationary distributions associated with the Tsallis entropies by employing either ordinary or q-generalized Fourier transforms in the averaging procedure.

Violating Bell inequalities maximally for two d-dimensional systems

International Nuclear Information System (INIS)

Chen Jingling; Wu Chunfeng; Oh, C. H.; Kwek, L. C.; Ge Molin

2006-01-01

We show the maximal violation of Bell inequalities for two d-dimensional systems by using the method of the Bell operator. The maximal violation corresponds to the maximal eigenvalue of the Bell operator matrix. The eigenvectors corresponding to these eigenvalues are described by asymmetric entangled states. We estimate the maximum value of the eigenvalue for large dimension. A family of elegant entangled states |Ψ> app that violate Bell inequality more strongly than the maximally entangled state but are somewhat close to these eigenvectors is presented. These approximate states can potentially be useful for quantum cryptography as well as many other important fields of quantum information

Wellness Intervention Effects on Lifestyle, Attitudes and Stress.

Science.gov (United States)

Horowitz, Stephen M.; And Others

The effect of an on-site health promotion program on lifestyle behavior, health, attitude, and stress was studied with 41 university faculty and nonacademic administrators. The participants were administered a maximal graded exercise tolerance test, hydrostatic weighing, and the Lifestyle Analysis Questionnaire. While 32 staff were assigned to an…

Reduction of symplectic principal R-bundles

International Nuclear Information System (INIS)

Lacirasella, Ignazio; Marrero, Juan Carlos; Padrón, Edith

2012-01-01

We describe a reduction process for symplectic principal R-bundles in the presence of a momentum map. These types of structures play an important role in the geometric formulation of non-autonomous Hamiltonian systems. We apply this procedure to the standard symplectic principal R-bundle associated with a fibration π:M→R. Moreover, we show a reduction process for non-autonomous Hamiltonian systems on symplectic principal R-bundles. We apply these reduction processes to several examples. (paper)

New Principal Coaching as a Safety Net

Science.gov (United States)

Celoria, Davide; Roberson, Ingrid

2015-01-01

This study examines new principal coaching as an induction process and explores the emotional dimensions of educational leadership. Twelve principal coaches and new principals--six of each--participated in this qualitative study that employed emergent coding (Creswell, 2008; Denzin, 2005; Glaser & Strauss, 1998; Spradley, 1979). The major…

Modelling Monthly Mental Sickness Cases Using Principal ...

African Journals Online (AJOL)

The methodology was principal component analysis (PCA) using data obtained from the hospital to estimate regression coefficients and parameters. It was found that the principal component regression model that was derived was good predictive tool. The principal component regression model obtained was okay and this ...

Importance of an Effective Principal-Counselor Relationship

Science.gov (United States)

Edwards, LaWanda; Grace, Ronald; King, Gwendolyn

2014-01-01

An effective relationship between the principal and school counselor is essential when improving student achievement. To have an effective relationship, there must be communication, trust and respect, leadership, and collaborative planning between the principal and school counselor (College Board, 2011). Principals and school counselors are both…

Management Of Indiscipline Among Teachers By Principals Of ...

African Journals Online (AJOL)

This study compared the management of indiscipline among teachers by public and private school principals in Akwa Ibom State. The sample comprised four hundred and fifty (450) principals/vice principals randomly selected from a population of one thousand, four hundred and twenty eight (1,428) principals. The null ...

What Do Effective Principals Do?

Science.gov (United States)

Protheroe, Nancy

2011-01-01

Much has been written during the past decade about the changing role of the principal and the shift in emphasis from manager to instructional leader. Anyone in education, and especially principals themselves, could develop a mental list of responsibilities that fit within each of these realms. But research makes it clear that both those aspects of…

Real-time topic-aware influence maximization using preprocessing.

Science.gov (United States)

Chen, Wei; Lin, Tian; Yang, Cheng

2016-01-01

Influence maximization is the task of finding a set of seed nodes in a social network such that the influence spread of these seed nodes based on certain influence diffusion model is maximized. Topic-aware influence diffusion models have been recently proposed to address the issue that influence between a pair of users are often topic-dependent and information, ideas, innovations etc. being propagated in networks are typically mixtures of topics. In this paper, we focus on the topic-aware influence maximization task. In particular, we study preprocessing methods to avoid redoing influence maximization for each mixture from scratch. We explore two preprocessing algorithms with theoretical justifications. Our empirical results on data obtained in a couple of existing studies demonstrate that one of our algorithms stands out as a strong candidate providing microsecond online response time and competitive influence spread, with reasonable preprocessing effort.

The Principal as Academician: The Renewed Voice.

Science.gov (United States)

McAvoy, Brenda, Ed.

This collection of essays was written by principals who participated in the 1986-87 Humanities Seminar sponsored by the Principals' Institute of Georgia State University. The focus was "The Evolution of Intellectual Leadership." The roles of the principal as philosopher, historian, ethnician, writer and team member are examined through…

Comparison in muscle damage between maximal voluntary and electrically evoked isometric contractions of the elbow flexors.

Science.gov (United States)

Jubeau, Marc; Muthalib, Makii; Millet, Guillaume Y; Maffiuletti, Nicola A; Nosaka, Kazunori

2012-02-01

This study compared between maximal voluntary (VOL) and electrically stimulated (ES) isometric contractions of the elbow flexors for changes in indirect markers of muscle damage to investigate whether ES would induce greater muscle damage than VOL. Twelve non-resistance-trained men (23-39 years) performed VOL with one arm and ES with the contralateral arm separated by 2 weeks in a randomised, counterbalanced order. Both VOL and ES (frequency 75 Hz, pulse duration 250 μs, maximally tolerated intensity) exercises consisted of 50 maximal isometric contractions (4-s on, 15-s off) of the elbow flexors at a long muscle length (160°). Changes in maximal voluntary isometric contraction torque (MVC), range of motion, muscle soreness, pressure pain threshold and serum creatine kinase (CK) activity were measured before, immediately after and 1, 24, 48, 72 and 96 h following exercise. The average peak torque over the 50 isometric contractions was greater (P < 0.05) for VOL (32.9 ± 9.8 N m) than ES (16.9 ± 6.3 N m). MVC decreased greater and recovered slower (P < 0.05) after ES (15% lower than baseline at 96 h) than VOL (full recovery). Serum CK activity increased (P < 0.05) only after ES, and the muscles became more sore and tender after ES than VOL (P < 0.05). These results showed that ES induced greater muscle damage than VOL despite the lower torque output during ES. It seems likely that higher mechanical stress imposed on the activated muscle fibres, due to the specificity of motor unit recruitment in ES, resulted in greater muscle damage.

Leadership Coaching for Principals: A National Study

Science.gov (United States)

Wise, Donald; Cavazos, Blanca

2017-01-01

Surveys were sent to a large representative sample of public school principals in the United States asking if they had received leadership coaching. Comparison of responses to actual numbers of principals indicates that the sample represents the first national study of principal leadership coaching. Results indicate that approximately 50% of all…

El culto de Maximón en Guatemala

OpenAIRE

Pédron‑Colombani, Sylvie

2009-01-01

Este artículo se enfoca en la figura de Maximón, deidad sincrética de Guatemala, en un contexto de desplazamiento de la religión católica popular por parte de las iglesias protestantes. Esta divinidad híbrida a la cual se agregan santos católicos como Judas Iscariote o el dios maya Mam, permite la apropiación de Maximón por segmentos diferenciados de la población (tanto indígena como mestiza). Permite igualmente ser símbolo de protestas sociales enmascaradas cuando se asocia Maximón con figur...

The Response of Photosynthetic Functions of F1 Cutting Seedlings From Physocarpus amurensis Maxim (♀ × Physocarpus opulifolius “Diabolo” (♂ and the Parental Seedlings to Salt Stress

Directory of Open Access Journals (Sweden)

Xu Nan

2018-06-01

Full Text Available This paper selected clonal cutting seedlings from the F1 hybrid varieties of Physocarpus amurensis Maxim (♀ × P. opulifolius “Diabolo” (♂ as research material to study the response of the photosynthetic gas exchange parameters and chlorophyll fluorescence parameters of P. amurensis hybrids and their parental leaves to NaCl stress (with concentrations of 0, 50, 100, and 200 mmol⋅L-1. The results showed that under salt stress, the stomatal conductance (Gs, transpiration rate (Tr, and net photosynthetic rate (Pn of the three kinds of P. amurensis all significantly decreased. When the NaCl concentration was below 100 mmol⋅L-1, the intercellular CO2 concentration (Ci of leaves of the three samples declined with the increase of salt concentration; however, when the concentration increased to 200 mmol⋅L-1, Ci did not decrease significantly, especially when the Ci of P. opulifolius “Diabolo” presented a slight increase. This indicated that the decline of photosynthetic carbon assimilation capacity induced by salt stress was the consequence of interaction between stomatal factors and non-stomatal factors, and the stomatal factors played an important role when the salt concentration was below 200 mmol⋅L-1. Compared with P. amurensis, the photosynthetic gas exchange capability of P. opulifolius “Diabolo” leaves was more sensitive to salt stress, and the limitation of non-stomatal factors was relatively evident. However, the photosynthetic capacity of hybrid P. amurensis leaves with the desired purple color was improved compared with P. amurensis. Under salt stress, the PSII activity of the three kinds of P. amurensis leaves declined, the electron transfer was inhibited, and obvious signs of photoinhibition were present. The PSII activity of P. opulifolius “Diabolo” leaves was more sensitive to salt stress than that in P. amurensis. Under salt stress, the NPQ of P. opulifolius “Diabolo” leaves decreased greatly, while under

Riccati transformations and principal solutions of discrete linear systems

International Nuclear Information System (INIS)

Ahlbrandt, C.D.; Hooker, J.W.

1984-01-01

Consider a second-order linear matrix difference equation. A definition of principal and anti-principal, or recessive and dominant, solutions of the equation are given and the existence of principal and anti-principal solutions and the essential uniqueness of principal solutions is proven

Self-consistent collective-coordinate method for ''maximally-decoupled'' collective subspace and its boson mapping: Quantum theory of ''maximally-decoupled'' collective motion

International Nuclear Information System (INIS)

Marumori, T.; Sakata, F.; Maskawa, T.; Une, T.; Hashimoto, Y.

1983-01-01

The main purpose of this paper is to develop a full quantum theory, which is capable by itself of determining a ''maximally-decoupled'' collective motion. The paper is divided into two parts. In the first part, the motivation and basic idea of the theory are explained, and the ''maximal-decoupling condition'' on the collective motion is formulated within the framework of the time-dependent Hartree-Fock theory, in a general form called the invariance principle of the (time-dependent) Schrodinger equation. In the second part, it is shown that when the author positively utilize the invariance principle, we can construct a full quantum theory of the ''maximally-decoupled'' collective motion. This quantum theory is shown to be a generalization of the kinematical boson-mapping theories so far developed, in such a way that the dynamical ''maximal-decoupling condition'' on the collective motion is automatically satisfied

Principals' Collaborative Roles as Leaders for Learning

Science.gov (United States)

Kitchen, Margaret; Gray, Susan; Jeurissen, Maree

2016-01-01

This article draws on data from three multicultural New Zealand primary schools to reconceptualize principals' roles as leaders for learning. In doing so, the writers build on Sinnema and Robinson's (2012) article on goal setting in principal evaluation. Sinnema and Robinson found that even principals hand-picked for their experience fell short on…

Principals as Assessment Leaders in Rural Schools

Science.gov (United States)

Renihan, Patrick; Noonan, Brian

2012-01-01

This article reports a study of rural school principals' assessment leadership roles and the impact of rural context on their work. The study involved three focus groups of principals serving small rural schools of varied size and grade configuration in three systems. Principals viewed assessment as a matter of teacher accountability and as a…

Principals: Learn P.R. Survival Skills.

Science.gov (United States)

Reep, Beverly B.

1988-01-01

School building level public relations depends on the principal or vice principal. Strategies designed to enhance school public relations programs include linking school and community, working with the press, and keeping morale high inside the school. (MLF)

Phenylethanoid glycosides of Pedicularis muscicola Maxim ameliorate high altitude-induced memory impairment.

Science.gov (United States)

Zhou, Baozhu; Li, Maoxing; Cao, Xinyuan; Zhang, Quanlong; Liu, Yantong; Ma, Qiang; Qiu, Yan; Luan, Fei; Wang, Xianmin

2016-04-01

Exposure to hypobaric hypoxia causes oxidative stress, neuronal degeneration and apoptosis that leads to memory impairment. Though oxidative stress contributes to neuronal degeneration and apoptosis in hypobaric hypoxia, the ability for phenylethanoid glycosides of Pedicularis muscicola Maxim (PhGs) to reverse high altitude memory impairment has not been studied. Rats were supplemented with PhGs orally for a week. After the fourth day of drug administration, rats were exposed to a 7500 m altitude simulation in a specially designed animal decompression chamber for 3 days. Spatial memory was assessed by the 8-arm radial maze test before and after exposure to hypobaric hypoxia. Histological assessment of neuronal degeneration was performed by hematoxylin-eosin (HE) staining. Changes in oxidative stress markers and changes in the expression of the apoptotic marker, caspase-3, were assessed in the hippocampus. Our results demonstrated that after exposure to hypobaric hypoxia, PhGs ameliorated high altitude memory impairment, as shown by the decreased values obtained for reference memory error (RME), working memory error (WME), and total error (TE). Meanwhile, administration of PhGs decreased hippocampal reactive oxygen species levels and consequent lipid peroxidation by elevating reduced glutathione levels and enhancing the free radical scavenging enzyme system. There was also a decrease in the number of pyknotic neurons and a reduction in caspase-3 expression in the hippocampus. These findings suggest that PhGs may be used therapeutically to ameliorate high altitude memory impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

Principal minors and rhombus tilings

International Nuclear Information System (INIS)

Kenyon, Richard; Pemantle, Robin

2014-01-01

The algebraic relations between the principal minors of a generic n × n matrix are somewhat mysterious, see e.g. Lin and Sturmfels (2009 J. Algebra 322 4121–31). We show, however, that by adding in certain almost principal minors, the ideal of relations is generated by translations of a single relation, the so-called hexahedron relation, which is a composition of six cluster mutations. We give in particular a Laurent-polynomial parameterization of the space of n × n matrices, whose parameters consist of certain principal and almost principal minors. The parameters naturally live on vertices and faces of the tiles in a rhombus tiling of a convex 2n-gon. A matrix is associated to an equivalence class of tilings, all related to each other by Yang–Baxter-like transformations. By specializing the initial data we can similarly parameterize the space of Hermitian symmetric matrices over R,C or H the quaternions. Moreover by further specialization we can parametrize the space of positive definite matrices over these rings. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Cluster algebras mathematical physics’. (paper)

Stress and strain provide positional and directional cues in development.

Directory of Open Access Journals (Sweden)

Behruz Bozorg

2014-01-01

Full Text Available The morphogenesis of organs necessarily involves mechanical interactions and changes in mechanical properties of a tissue. A long standing question is how such changes are directed on a cellular scale while being coordinated at a tissular scale. Growing evidence suggests that mechanical cues are participating in the control of growth and morphogenesis during development. We introduce a mechanical model that represents the deposition of cellulose fibers in primary plant walls. In the model both the degree of material anisotropy and the anisotropy direction are regulated by stress anisotropy. We show that the finite element shell model and the simpler triangular biquadratic springs approach provide equally adequate descriptions of cell mechanics in tissue pressure simulations of the epidermis. In a growing organ, where circumferentially organized fibers act as a main controller of longitudinal growth, we show that the fiber direction can be correlated with both the maximal stress direction and the direction orthogonal to the maximal strain direction. However, when dynamic updates of the fiber direction are introduced, the mechanical stress provides a robust directional cue for the circumferential organization of the fibers, whereas the orthogonal to maximal strain model leads to an unstable situation where the fibers reorient longitudinally. Our investigation of the more complex shape and growth patterns in the shoot apical meristem where new organs are initiated shows that a stress based feedback on fiber directions is capable of reproducing the main features of in vivo cellulose fiber directions, deformations and material properties in different regions of the shoot. In particular, we show that this purely mechanical model can create radially distinct regions such that cells expand slowly and isotropically in the central zone while cells at the periphery expand more quickly and in the radial direction, which is a well established growth pattern

Stress and strain provide positional and directional cues in development.

Science.gov (United States)

Bozorg, Behruz; Krupinski, Pawel; Jönsson, Henrik

2014-01-01

The morphogenesis of organs necessarily involves mechanical interactions and changes in mechanical properties of a tissue. A long standing question is how such changes are directed on a cellular scale while being coordinated at a tissular scale. Growing evidence suggests that mechanical cues are participating in the control of growth and morphogenesis during development. We introduce a mechanical model that represents the deposition of cellulose fibers in primary plant walls. In the model both the degree of material anisotropy and the anisotropy direction are regulated by stress anisotropy. We show that the finite element shell model and the simpler triangular biquadratic springs approach provide equally adequate descriptions of cell mechanics in tissue pressure simulations of the epidermis. In a growing organ, where circumferentially organized fibers act as a main controller of longitudinal growth, we show that the fiber direction can be correlated with both the maximal stress direction and the direction orthogonal to the maximal strain direction. However, when dynamic updates of the fiber direction are introduced, the mechanical stress provides a robust directional cue for the circumferential organization of the fibers, whereas the orthogonal to maximal strain model leads to an unstable situation where the fibers reorient longitudinally. Our investigation of the more complex shape and growth patterns in the shoot apical meristem where new organs are initiated shows that a stress based feedback on fiber directions is capable of reproducing the main features of in vivo cellulose fiber directions, deformations and material properties in different regions of the shoot. In particular, we show that this purely mechanical model can create radially distinct regions such that cells expand slowly and isotropically in the central zone while cells at the periphery expand more quickly and in the radial direction, which is a well established growth pattern in the meristem.

Assessment of the Maximal Split-Half Coefficient to Estimate Reliability

Science.gov (United States)

Thompson, Barry L.; Green, Samuel B.; Yang, Yanyun

2010-01-01

The maximal split-half coefficient is computed by calculating all possible split-half reliability estimates for a scale and then choosing the maximal value as the reliability estimate. Osburn compared the maximal split-half coefficient with 10 other internal consistency estimates of reliability and concluded that it yielded the most consistently…

Learning curves for mutual information maximization

International Nuclear Information System (INIS)

Urbanczik, R.

2003-01-01

An unsupervised learning procedure based on maximizing the mutual information between the outputs of two networks receiving different but statistically dependent inputs is analyzed [S. Becker and G. Hinton, Nature (London) 355, 161 (1992)]. For a generic data model, I show that in the large sample limit the structure in the data is recognized by mutual information maximization. For a more restricted model, where the networks are similar to perceptrons, I calculate the learning curves for zero-temperature Gibbs learning. These show that convergence can be rather slow, and a way of regularizing the procedure is considered

Statewide Data on Supply and Demand of Principals after Policy Changes to Principal Preparation in Illinois

Science.gov (United States)

Haller, Alicia; Hunt, Erika

2016-01-01

Research has demonstrated that principals have a powerful impact on school improvement and student learning. Principals play a vital role in recruiting, developing, and retaining effective teachers; creating a school-wide culture of learning; and implementing a continuous improvement plan aimed at increasing student achievement. Leithwood, Louis,…

Breakdown of maximality conjecture in continuous phase transitions

International Nuclear Information System (INIS)

Mukamel, D.; Jaric, M.V.

1983-04-01

A Landau-Ginzburg-Wilson model associated with a single irreducible representation which exhibits an ordered phase whose symmetry group is not a maximal isotropy subgroup of the symmetry group of the disordered phase is constructed. This example disproves the maximality conjecture suggested in numerous previous studies. Below the (continuous) transition, the order parameter points along a direction which varies with the temperature and with the other parameters which define the model. An extension of the maximality conjecture to reducible representations was postulated in the context of Higgs symmetry breaking mechanism. Our model can also be extended to provide a counter example in these cases. (author)

Maximizers versus satisficers: Decision-making styles, competence, and outcomes

OpenAIRE

Andrew M. Parker; Wändi Bruine de Bruin; Baruch Fischhoff

2007-01-01

Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al.\\ (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decision...

IMNN: Information Maximizing Neural Networks

Science.gov (United States)

Charnock, Tom; Lavaux, Guilhem; Wandelt, Benjamin D.

2018-04-01

This software trains artificial neural networks to find non-linear functionals of data that maximize Fisher information: information maximizing neural networks (IMNNs). As compressing large data sets vastly simplifies both frequentist and Bayesian inference, important information may be inadvertently missed. Likelihood-free inference based on automatically derived IMNN summaries produces summaries that are good approximations to sufficient statistics. IMNNs are robustly capable of automatically finding optimal, non-linear summaries of the data even in cases where linear compression fails: inferring the variance of Gaussian signal in the presence of noise, inferring cosmological parameters from mock simulations of the Lyman-α forest in quasar spectra, and inferring frequency-domain parameters from LISA-like detections of gravitational waveforms. In this final case, the IMNN summary outperforms linear data compression by avoiding the introduction of spurious likelihood maxima.

Neutrino mass textures with maximal CP violation

International Nuclear Information System (INIS)

Aizawa, Ichiro; Kitabayashi, Teruyuki; Yasue, Masaki

2005-01-01

We show three types of neutrino mass textures, which give maximal CP violation as well as maximal atmospheric neutrino mixing. These textures are described by six real mass parameters: one specified by two complex flavor neutrino masses and two constrained ones and the others specified by three complex flavor neutrino masses. In each texture, we calculate mixing angles and masses, which are consistent with observed data, as well as Majorana CP phases

Protective effects of flavonoids isolated from Korean milk thistle Cirsium japonicum var. maackii (Maxim.) Matsum on tert-butyl hydroperoxide-induced hepatotoxicity in HepG2 cells.

Science.gov (United States)

Jung, Hyun Ah; Abdul, Qudeer Ahmed; Byun, Jeong Su; Joung, Eun-Ji; Gwon, Wi-Gyeong; Lee, Min-Sup; Kim, Hyeung-Rak; Choi, Jae Sue

2017-09-14

Milk thistle leaves and flowers have been traditionally used as herbal remedy to alleviate liver diseases for decades. Korean milk thistle, Cirsium japonicum var. maackii (Maxim.) Matsum has been employed in traditional folk medicine as diuretic, antiphlogistic, hemostatic, and detoxifying agents. The aim of current investigation was to evaluate hepatoprotective properties of the MeOH extract of the roots, stems, leaves and flowers of Korean milk thistle as well as four isolated flavonoids, luteolin, luteolin 5-O-glucoside, apigenin and apigenin 7-O-glucuronide during t-BHP-induced oxidative stress in HepG2 cells. Hepatoprotective potential of the MeOH extracts and flavonoids derived from Korean milk thistle against t-BHP-induced oxidative stress in HepG2 cells were evaluated following MTT method. Incubating HepG2 cells with t-BHP markedly decreased the cell viability and increased the intracellular ROS generation accompanied by depleted GSH levels. Protein expression of heme oxygenase (HO-1) and nuclear factor-E2-related factor 2 (Nrf-2) was determined by Western blot. Our findings revealed that pretreating HepG2 cells with MeOH extracts and bioactive flavonoids significantly attenuated the t-BHP-induced oxidative damage, followed by increased cell viability in a dose-dependent manner. The results illustrate that excess ROS generation was reduced and GSH levels increased dose-dependently when HepG2 cells were pretreated with four flavonoids. Moreover, Western blotting analysis demonstrated that protein expressions of Nrf-2 and HO-1 were also up-regulated by flavonoids treatment. These results clearly demonstrate that the MeOH extracts and flavonoids from Korean milk thistle protected HepG2 cells against oxidative damage triggered by t-BHP principally by modulating ROS generation and restoring depleted GSH levels in addition to the increased Nrf-2/HO-1 signaling cascade. These flavonoids are potential natural antioxidative biomarkers against oxidative stress

Effect of constraint condition and internal medium on residual stress under overlay welding for dissimilar metal welding

International Nuclear Information System (INIS)

Song, Tae Kwang; Kim, Yun Jae; Lee, Kyoung Soo; Park, Chi Yong; Kim, Jong Sung; Kim, Jin Weon

2007-01-01

In nuclear power plants, residual stress of dissimilar metal weld propagates cracks in the weld metal which is susceptible to stress corrosion cracking. Overlay welding is a process widely used to mitigate residual stress replacing inside tensile stress by compression stress. However, according to the result of this study the effect of overlay welding on residual stress depends on both internal medium and constraint condition. The purpose of this study is to maximize the positive effect of overlay welding by finite element analyses

Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction

OpenAIRE

Jung, Halim; Jung, Sangwoo; Joo, Sunghee; Song, Changho

2016-01-01

[Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility...

The Deputy Principal Instructional Leadership Role and Professional Learning: Perceptions of Secondary Principals, Deputies and Teachers

Science.gov (United States)

Leaf, Ann; Odhiambo, George

2017-01-01

Purpose: The purpose of this paper is to report on a study examining the perceptions of secondary principals, deputies and teachers, of deputy principal (DP) instructional leadership (IL), as well as deputies' professional learning (PL) needs. Framed within an interpretivist approach, the specific objectives of this study were: to explore the…

Measuring Principals' Effectiveness: Results from New Jersey's First Year of Statewide Principal Evaluation. REL 2016-156

Science.gov (United States)

Herrmann, Mariesa; Ross, Christine

2016-01-01

States and districts across the country are implementing new principal evaluation systems that include measures of the quality of principals' school leadership practices and measures of student achievement growth. Because these evaluation systems will be used for high-stakes decisions, it is important that the component measures of the evaluation…

A Model of Anisotropic Property of Seepage and Stress for Jointed Rock Mass

Directory of Open Access Journals (Sweden)

Pei-tao Wang

2013-01-01

Full Text Available Joints often have important effects on seepage and elastic properties of jointed rock mass and therefore on the rock slope stability. In the present paper, a model for discrete jointed network is established using contact-free measurement technique and geometrical statistic method. A coupled mathematical model for characterizing anisotropic permeability tensor and stress tensor was presented and finally introduced to a finite element model. A case study of roadway stability at the Heishan Metal Mine in Hebei Province, China, was performed to investigate the influence of joints orientation on the anisotropic properties of seepage and elasticity of the surrounding rock mass around roadways in underground mining. In this work, the influence of the principal direction of the mechanical properties of the rock mass on associated stress field, seepage field, and damage zone of the surrounding rock mass was numerically studied. The numerical simulations indicate that flow velocity, water pressure, and stress field are greatly dependent on the principal direction of joint planes. It is found that the principal direction of joints is the most important factor controlling the failure mode of the surrounding rock mass around roadways.

Principals' Perceptions of School Public Relations

Science.gov (United States)

Morris, Robert C.; Chan, Tak Cheung; Patterson, Judith

2009-01-01

This study was designed to investigate school principals' perceptions on school public relations in five areas: community demographics, parental involvement, internal and external communications, school council issues, and community resources. Findings indicated that principals' concerns were as follows: rapid population growth, change of…

Principal-vector-directed fringe-tracking technique.

Science.gov (United States)

Zhang, Zhihui; Guo, Hongwei

2014-11-01

Fringe tracking is one of the most straightforward techniques for analyzing a single fringe pattern. This work presents a principal-vector-directed fringe-tracking technique. It uses Gaussian derivatives for estimating fringe gradients and uses hysteresis thresholding for segmenting singular points, thus improving the principal component analysis method. Using it allows us to estimate the principal vectors of fringes from a pattern with high noise. The fringe-tracking procedure is directed by these principal vectors, so that erroneous results induced by noise and other error-inducing factors are avoided. At the same time, the singular point regions of the fringe pattern are identified automatically. Using them allows us to determine paths through which the "seed" point for each fringe skeleton is easy to find, thus alleviating the computational burden in processing the fringe pattern. The results of a numerical simulation and experiment demonstrate this method to be valid.

Whose Perception of Principal Instructional Leadership? Principal-Teacher Perceptual (Dis)agreement and Its Influence on Teacher Collaboration

Science.gov (United States)

Park, Joo-Ho; Ham, Seung-Hwan

2016-01-01

This study examines teacher collaboration across three Asia-Pacific countries (Australia, Malaysia, and South Korea), focusing on the possibility that principal-teacher perceptual disagreement regarding principal instructional leadership performance may impede progress toward a school organizational condition conducive to collaborative teacher…

High Stakes Principalship--Sleepless Nights, Heart Attacks and Sudden Death Accountabilities: Reading Media Representations of the United States Principal Shortage.

Science.gov (United States)

Thomson, Pat; Blackmore, Jill; Sachs, Judyth; Tregenza, Karen

2003-01-01

Subjects a corpus of predominantly United States news articles to deconstructive narrative analysis and finds that the dominant media representation of principals' work is one of long hours, low salary, high stress, and sudden death from high stakes accountabilities. Notes that the media picture may perpetuate the problem, and that it is at odds…

Maximally-localized position, Euclidean path-integral, and thermodynamics in GUP quantum mechanics

Science.gov (United States)

Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.

2018-04-01

In dealing with quantum mechanics at very high energies, it is essential to adapt to a quasiposition representation using the maximally-localized states because of the generalized uncertainty principle. In this paper, we look at maximally-localized states as eigenstates of the operator ξ = X + iβP that we refer to as the maximally-localized position. We calculate the overlap between maximally-localized states and show that the identity operator can be expressed in terms of the maximally-localized states. Furthermore, we show that the maximally-localized position is diagonal in momentum-space and that the maximally-localized position and its adjoint satisfy commutation and anti-commutation relations reminiscent of the harmonic oscillator commutation and anti-commutation relations. As application, we use the maximally-localized position in developing the Euclidean path-integral and introduce the compact form of the propagator for maximal localization. The free particle momentum-space propagator and the propagator for maximal localization are analytically evaluated up to quadratic-order in β. Finally, we obtain a path-integral expression for the partition function of a thermodynamic system using the maximally-localized states. The partition function of a gas of noninteracting particles is evaluated. At temperatures exceeding the Planck energy, we obtain the gas' maximum internal energy N / 2 β and recover the zero heat capacity of an ideal gas.

Why firms should not always maximize profits

OpenAIRE

Kolstad, Ivar

2006-01-01

Though corporate social responsibility (CSR) is on the agenda of most major corporations, corporate executives still largely support the view that corporations should maximize the returns to their owners. There are two lines of defence for this position. One is the Friedmanian view that maximizing owner returns is the corporate social responsibility of corporations. The other is a position voiced by many executives, that CSR and profits go together. This paper argues that the first position i...

Myocardial 201Tl washout after combined dipyridamole submaximal exercise stress: Reference values from different patient groups

International Nuclear Information System (INIS)

Fridrich, L.

1989-01-01

Dipyridamole stress is favorable in patients unable to exercise maximally for 201 Tl myocardial scintigraphy. Aside from an analysis of uptake defects, proper washout analysis can be limited by heart rate variations when isolated dipyridamole stress is used. Heart rate standardized 201 Tl washout kinetics after a combined dipyridamole and submaximal exercise stress protocol (CDSE), feasible in elderly patients as well as in patients with peripheral artery disease, were therefore studied to investigate the 201 Tl washout after CDSE in differently defined patient groups: Group I comprised 19 patients with documented heart disease and angiographically excluded coronary artery disease (CAD); group II contained 17 patients with a very low likelihood of CAD determined by both normal exercise radionuclide ventriculography and normal 201 Tl uptake. Group III comprised 56 patients with a 50% pretest likelihood of CAD but normal 201 Tl uptake. Mean washout values were nearly identical in all groups. Despite similar uptake patterns, however, washout standardized by CDSE was significantly lower than the normal washout values after maximal treadmill exercise. Thus an obviously lower 201 Tl washout after CDSE than after maximal treadmill exercise must be considered if washout analysis criteria after dipyridamole are applied to evaluate ischemic heart disease. Nevertheless, heart rate elevation achieved by additional submaximal exercise stress seems necessary, adequate and clinically safe for standardisation of washout analysis in dipyridamole 201 Tl scintigraphy. (orig.)

Temporal stress changes caused by earthquakes: A review

Science.gov (United States)

Hardebeck, Jeanne L.; Okada, Tomomi

2018-01-01

Earthquakes can change the stress field in the Earth’s lithosphere as they relieve and redistribute stress. Earthquake-induced stress changes have been observed as temporal rotations of the principal stress axes following major earthquakes in a variety of tectonic settings. The stress changes due to the 2011 Mw9.0 Tohoku-Oki, Japan, earthquake were particularly well documented. Earthquake stress rotations can inform our understanding of earthquake physics, most notably addressing the long-standing problem of whether the Earth’s crust at plate boundaries is “strong” or “weak.” Many of the observed stress rotations, including that due to the Tohoku-Oki earthquake, indicate near-complete stress drop in the mainshock. This implies low background differential stress, on the order of earthquake stress drop, supporting the weak crust model. Earthquake stress rotations can also be used to address other important geophysical questions, such as the level of crustal stress heterogeneity and the mechanisms of postseismic stress reloading. The quantitative interpretation of stress rotations is evolving from those based on simple analytical methods to those based on more sophisticated numerical modeling that can capture the spatial-temporal complexity of the earthquake stress changes.

Coping Patterns and Stress in Women Teachers.

Science.gov (United States)

McMurray, J. G.

Popular opinion suggests that teaching is a stressful profession. A dissenting view is supported in this investigation of women teachers in five Canadian provinces. Self-report attitudinal questionnaires containing 26 items were mailed to a sample of 940 elementary and secondary school principals in eight Western and Eastern Canadian provinces.…

Overexpression of a cytosolic abiotic stress responsive universal stress protein (SbUSP mitigates salt and osmotic stress in transgenic tobacco plants

Directory of Open Access Journals (Sweden)

Pushpika eUdawat

2016-04-01

Full Text Available The Universal Stress Protein (USP is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologues of intron less SbUSP gene which encodes for salt and osmotic responsive universal stress protein. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control (wild type and vector control plants under different abiotic stress condition. Transgenic lines (T1 exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability and lower electrolyte leakage and lipid peroxidation (malondialdehyde content under stress treatments than control (WT and VC plants. Lower accumulation of H2O2 and O2- radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis (PCA exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant.

Maximizing band gaps in plate structures

DEFF Research Database (Denmark)

Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard

2006-01-01

periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated......Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...... theoretically and experimentally and the issue of finite size effects is addressed....

Finding Maximal Pairs with Bounded Gap

DEFF Research Database (Denmark)

Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.

1999-01-01

. In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

The key kinematic determinants of undulatory underwater swimming at maximal velocity.

Science.gov (United States)

Connaboy, Chris; Naemi, Roozbeh; Brown, Susan; Psycharakis, Stelios; McCabe, Carla; Coleman, Simon; Sanders, Ross

2016-01-01

The optimisation of undulatory underwater swimming is highly important in competitive swimming performance. Nineteen kinematic variables were identified from previous research undertaken to assess undulatory underwater swimming performance. The purpose of the present study was to determine which kinematic variables were key to the production of maximal undulatory underwater swimming velocity. Kinematic data at maximal undulatory underwater swimming velocity were collected from 17 skilled swimmers. A series of separate backward-elimination analysis of covariance models was produced with cycle frequency and cycle length as dependent variables (DVs) and participant as a fixed factor, as including cycle frequency and cycle length would explain 100% of the maximal swimming velocity variance. The covariates identified in the cycle-frequency and cycle-length models were used to form the saturated model for maximal swimming velocity. The final parsimonious model identified three covariates (maximal knee joint angular velocity, maximal ankle angular velocity and knee range of movement) as determinants of the variance in maximal swimming velocity (adjusted-r2 = 0.929). However, when participant was removed as a fixed factor there was a large reduction in explained variance (adjusted r2 = 0.397) and only maximal knee joint angular velocity continued to contribute significantly, highlighting its importance to the production of maximal swimming velocity. The reduction in explained variance suggests an emphasis on inter-individual differences in undulatory underwater swimming technique and/or anthropometry. Future research should examine the efficacy of other anthropometric, kinematic and coordination variables to better understand the production of maximal swimming velocity and consider the importance of individual undulatory underwater swimming techniques when interpreting the data.

Kinetic theory in maximal-acceleration invariant phase space

International Nuclear Information System (INIS)

Brandt, H.E.

1989-01-01

A vanishing directional derivative of a scalar field along particle trajectories in maximal acceleration invariant phase space is identical in form to the ordinary covariant Vlasov equation in curved spacetime in the presence of both gravitational and nongravitational forces. A natural foundation is thereby provided for a covariant kinetic theory of particles in maximal-acceleration invariant phase space. (orig.)

Half-maximal supersymmetry from exceptional field theory

Energy Technology Data Exchange (ETDEWEB)

Malek, Emanuel [Arnold Sommerfeld Center for Theoretical Physics, Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen (Germany)

2017-10-15

We study D ≥ 4-dimensional half-maximal flux backgrounds using exceptional field theory. We define the relevant generalised structures and also find the integrability conditions which give warped half-maximal Minkowski{sub D} and AdS{sub D} vacua. We then show how to obtain consistent truncations of type II / 11-dimensional SUGRA which break half the supersymmetry. Such truncations can be defined on backgrounds admitting exceptional generalised SO(d - 1 - N) structures, where d = 11 - D, and N is the number of vector multiplets obtained in the lower-dimensional theory. Our procedure yields the most general embedding tensors satisfying the linear constraint of half-maximal gauged SUGRA. We use this to prove that all D ≥ 4 half-maximal warped AdS{sub D} and Minkowski{sub D} vacua of type II / 11-dimensional SUGRA admit a consistent truncation keeping only the gravitational supermultiplet. We also show to obtain heterotic double field theory from exceptional field theory and comment on the M-theory / heterotic duality. In five dimensions, we find a new SO(5, N) double field theory with a (6 + N)-dimensional extended space. Its section condition has one solution corresponding to 10-dimensional N = 1 supergravity and another yielding six-dimensional N = (2, 0) SUGRA. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Transcriptional Profiling in Cotton Associated with Bacillus Subtilis (UFLA285) Induced Biotic-Stress Tolerance

Science.gov (United States)

Abstract Lint yield and quality in cotton is greatly affected by water-deficit stress. The principal aim of this study was to identify cotton genes associated metabolic pathways involved in the water-deficit stress response. Gene expression profiles were developed for leaf and root tissues subject...

Composite resin reinforced with pre-tensioned fibers: a three-dimensional finite element study on stress distribution.

Science.gov (United States)

Jie, Lin; Shinya, Akikazu; Lassila, Lippo V J; Vallittu, Pekka K

2013-01-01

Pre-tensioned construction material is utilized in engineering applications of high strength demands. The purpose of this study was to evaluate the effect of the pre-tensioning fibers of fiber-reinforced composite (FRC) using three-dimensional finite element (FE) analysis. The 3D FE models of particulate composite resin (CR), FRC and composite resin reinforced with pre-tensioned fibers (PRE-T-FRC) were constructed. The uniaxial three-point bending test was simulated using FE analysis to calculate the principal stress distribution. In the FRC and PRE-T-FRC, stresses were higher than CR, and they were located in the fiber. However, the maximum principal stress value at the composite of PRE-T-FRC was lower than the FRC and CR. Composite resin reinforced with pre-tensioned fibers was advantageous for stress distribution and lowering the stress at the composite itself. Experimental studies on physical properties of pre-tensioned FRC are encouraged to be conducted.

Maximal slicing of D-dimensional spherically symmetric vacuum spacetime

International Nuclear Information System (INIS)

Nakao, Ken-ichi; Abe, Hiroyuki; Yoshino, Hirotaka; Shibata, Masaru

2009-01-01

We study the foliation of a D-dimensional spherically symmetric black-hole spacetime with D≥5 by two kinds of one-parameter families of maximal hypersurfaces: a reflection-symmetric foliation with respect to the wormhole slot and a stationary foliation that has an infinitely long trumpetlike shape. As in the four-dimensional case, the foliations by the maximal hypersurfaces avoid the singularity irrespective of the dimensionality. This indicates that the maximal slicing condition will be useful for simulating higher-dimensional black-hole spacetimes in numerical relativity. For the case of D=5, we present analytic solutions of the intrinsic metric, the extrinsic curvature, the lapse function, and the shift vector for the foliation by the stationary maximal hypersurfaces. These data will be useful for checking five-dimensional numerical-relativity codes based on the moving puncture approach.

New pulser for principal PO power

International Nuclear Information System (INIS)

Coudert, G.

1984-01-01

The pulser of the principal power of the PS is the unit that makes it possible to generate the reference function of the voltage of the principal magnet. This function depends on time and on the magnetic field of the magnet. It also generates various synchronization and reference pulses

An Examination of Principal Job Satisfaction

Science.gov (United States)

Pengilly, Michelle M.

2010-01-01

As education continues to succumb to deficits in budgets and increasingly high levels of student performance to meet the federal and state mandates, the quest to sustain and retain successful principals is imperative. The National Association of School Boards (1999) portrays effective principals as "linchpins" of school improvement and…

The Succession of a School Principal.

Science.gov (United States)

Fauske, Janice R.; Ogawa, Rodney T.

Applying theory from organizational and cultural perspectives to succession of principals, this study observes and records the language and culture of a small suburban elementary school. The study's procedures included analyses of shared organizational understandings as well as identification of the principal's influence on the school. Analyses of…

Social Media Strategies for School Principals

Science.gov (United States)

Cox, Dan; McLeod, Scott

2014-01-01

The purpose of this qualitative study was to describe, analyze, and interpret the experiences of school principals who use multiple social media tools with stakeholders as part of their comprehensive communications practices. Additionally, it examined why school principals have chosen to communicate with their stakeholders through social media.…

Left ventricle expands maximally preceding end-diastole. Radionuclide ventriculography study

International Nuclear Information System (INIS)

Horinouchi, Osamu

2002-01-01

It has been considered that left ventricle (LV) expands maximally at the end-diastole. However, is it exactly coincident with this point? This study was aimed to determine whether the maximal expansion of LV coincides with the peak of R wave on electrocardiogram. Thirty-three angina pectoris patients with normal LV motion were examined using radionuclide ventriculography. Data were obtained from every 30 ms backward frame from the peak of R wave. All patients showed the time of maximal expansion preceded the peak of R wave. The intervals from the peak of R wave and the onset of P wave to maximal expansion of LV was 105±29 ms and 88±25 ms, respectively. This period corresponds to the timing of maximal excurtion of mitral valve by atrial contraction, and the centripetal motion of LV without losing its volume before end-diastole may be interpreted on account of the movement of mitral valve toward closure. These findings suggest that LV expands maximally between P and R wave after atrial contraction, preceding the peak of R wave thought conventionally as the end-diastole. (author)

Overexpression of a Cytosolic Abiotic Stress Responsive Universal Stress Protein (SbUSP) Mitigates Salt and Osmotic Stress in Transgenic Tobacco Plants

Science.gov (United States)

Udawat, Pushpika; Jha, Rajesh K.; Sinha, Dinkar; Mishra, Avinash; Jha, Bhavanath

2016-01-01

The universal stress protein (USP) is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologs of intron less SbUSP gene which encodes for salt and osmotic responsive USP. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control [wild-type (WT) and vector control (VC)] plants under different abiotic stress condition. Transgenic lines (T1) exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability, and lower electrolyte leakage and lipid peroxidation (malondialdehyde content) under stress treatments than control (WT and VC) plants. Lower accumulation of H2O2 and O2− radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant. PMID:27148338

Quantification of Applied Stresses of C-Ring Specimens for Stress Corrosion Cracking Tests

International Nuclear Information System (INIS)

Kim, Woo Gon; Kim, Sun Jae; Rhee, Chang Kyu; Kuk, Il Hiun; Choi, Jong Ho

1997-01-01

For comparing their resistances for stress-corrosion cracking(SCC) in the K600-MA, K690-MA, and K600-TT tubes, C-ring specimens were fabricated with the various thermal-treatments to control the distributions of the precipitates like Cr-carbides. The bending stresses were analyzed to determine the amounts to make the stress quantitatively to all the C-ring samples, and then the stresses were calculated with the relation to the outer diameter(O.D) deflection(δ) of the C-rings. To measure accurately the bending strains of the C-ring specimens, the strain gauges were used and the compression test was also carried out. In the elastic region, the stresses in both the transverse and the circumferential directions were different with the locations of the strain gauges as attached at α= 30 .deg., 45 .deg., and 90 .deg. to the principal stress direction, but those in the longitudinal direction were independent of their attached locations. Calculated stresses from the strains obtained using the strain gauges were well agreed with the theoretical. In the plastic region over δ=1.0mm, the stresses for the TT tubes showed lower values of about 400MPa than those for the MA tubes. However, the stresses among the TT tubes showed almost the similar values in this region. Therefore, the states of the stresses applied to the C-ring specimens would be different with the material conditions, i.e, the chemical compositions, the thermal treatments such as MA and TT

Connection between tectonic stresses and well fracturing data

Energy Technology Data Exchange (ETDEWEB)

Scheidegger, A E [Imperial Oil Res. Lab., Calgary, CA

1961-01-01

Theoretical considerations of hydraulic well fracturing normally utilize a model in which the borehole is assumed to be a cylinder of infinite length. This leads to treatment of the induced stress state in two dimensions. The two-dimensional model is obviously an oversimplification. Therefore, a three-dimensional model is proposed in which the well pressure is assumed to be equivalent to a spherical pressure center. The bottom hole pressure during fracturing is determined by 4 variables; i.e., the 3 principal geological stresses and the rock strength. The response to fracturing is determined primarily by the prevailing stress state and to a lesser degree by the rock strength. The fracture condition is formulated and the model is used in the calculation of geological stresses from well data.

The Interdependence of Principal School Leadership and Student Achievement

Science.gov (United States)

Soehner, David; Ryan, Thomas

2011-01-01

This review illuminated principal school leadership as a variable that impacted achievement. The principal as school leader and manager was explored because these roles were thought to impact student achievement both directly and indirectly. Specific principal leadership behaviors and principal effectiveness were explored as variables potentially…

Aerobic exercise increases resistance to oxidative stress in sedentary older middle-aged adults. A pilot study.

Science.gov (United States)

Done, Aaron J; Traustadóttir, Tinna

2016-12-01

Older individuals who exercise regularly exhibit greater resistance to oxidative stress than their sedentary peers, suggesting that exercise can modify age-associated loss of resistance to oxidative stress. However, we recently demonstrated that a single bout of exercise confers protection against a subsequent oxidative challenge in young, but not older adults. We therefore hypothesized that repeated bouts of exercise would be needed to increase resistance to an oxidative challenge in sedentary older middle-aged adults. Sedentary older middle-aged men and women (50-63 years, n = 11) participated in an 8-week exercise intervention. Maximal oxygen consumption was measured before and after the intervention. The exercise intervention consisted of three sessions per week, for 45 min at an intensity corresponding to 70-85 % maximal heart rate (HR max ). Resistance to oxidative stress was measured by F 2 -isoprostane response to a forearm ischemia/reperfusion (I/R) trial. Each participant underwent the I/R trial before and after the exercise intervention. The intervention elicited a significant increase in maximal oxygen consumption (VO 2max ) (P exercise intervention (time-by-trial interaction, P = 0.043). Individual improvements in aerobic fitness were associated with greater improvements in the F 2 -isoprostane response (r = -0.761, P = 0.011), further supporting the role of aerobic fitness in resistance to oxidative stress. These data demonstrate that regular exercise with improved fitness leads to increased resistance to oxidative stress in older middle-aged adults and that this measure is modifiable in previously sedentary individuals.

District Leadership for Effective Principal Evaluation and Support

Science.gov (United States)

Kimball, Steven M.; Arrigoni, Jessica; Clifford, Matthew; Yoder, Maureen; Milanowski, Anthony

2015-01-01

Research demonstrating principals' impact on student learning outcomes has fueled the shift from principals as facilities managers to an emphasis on instructional leadership (Hallinger & Heck, 1996; Leithwood, Louis, Anderson, & Wahlstrom, 2004; Marzano, Waters, & McNulty, 2005). Principals are under increasing pressure to carry out…

School Restructuring and the Dilemmas of Principals' Work.

Science.gov (United States)

Wildy, Helen; Louden, William

2000-01-01

The complexity of principals' work may be characterized according to three dilemmas: accountability, autonomy, and efficiency. Narrative vignettes of 74 Australian principals revealed that principals were fair and inclusive. When faced with restructuring dilemmas, however, they favored strong over shared leadership, efficiency over collaboration,…

Do Principals Fire the Worst Teachers?

Science.gov (United States)

Jacob, Brian A.

2011-01-01

This article takes advantage of a unique policy change to examine how principals make decisions regarding teacher dismissal. In 2004, the Chicago Public Schools (CPS) and Chicago Teachers Union signed a new collective bargaining agreement that gave principals the flexibility to dismiss probationary teachers for any reason and without the…

Revising the Role of Principal Supervisor

Science.gov (United States)

Saltzman, Amy

2016-01-01

In Washington, D.C., and Tulsa, Okla., districts whose efforts are supported by the Wallace Foundation, principal supervisors concentrate on bolstering their principals' work to improve instruction, as opposed to focusing on the managerial or operational aspects of running a school. Supervisors oversee fewer schools, which enables them to provide…

The Principal's Guide to Grant Success.

Science.gov (United States)

Bauer, David G.

This book provides principals of public and private elementary and middle schools with a step-by-step approach for developing a system that empowers faculty, staff, and the school community in attracting grant funds. Following the introduction, chapter 1 discusses the principal's role in supporting grantseeking. Chapter 2 describes how to…

Principals, agents and research programmes

OpenAIRE

Elizabeth Shove

2003-01-01

Research programmes appear to represent one of the more powerful instruments through which research funders (principals) steer and shape what researchers (agents) do. The fact that agents navigate between different sources and styles of programme funding and that they use programmes to their own ends is readily accommodated within principal-agent theory with the help of concepts such as shirking and defection. Taking a different route, I use three examples of research programming (by the UK, ...

Maximization of regional probabilities using Optimal Surface Graphs

DEFF Research Database (Denmark)

Arias Lorza, Andres M.; Van Engelen, Arna; Petersen, Jens

2018-01-01

Purpose: We present a segmentation method that maximizes regional probabilities enclosed by coupled surfaces using an Optimal Surface Graph (OSG) cut approach. This OSG cut determines the globally optimal solution given a graph constructed around an initial surface. While most methods for vessel...... wall segmentation only use edge information, we show that maximizing regional probabilities using an OSG improves the segmentation results. We applied this to automatically segment the vessel wall of the carotid artery in magnetic resonance images. Methods: First, voxel-wise regional probability maps...... were obtained using a Support Vector Machine classifier trained on local image features. Then, the OSG segments the regions which maximizes the regional probabilities considering smoothness and topological constraints. Results: The method was evaluated on 49 carotid arteries from 30 subjects...

Negligence--When Is the Principal Liable? A Legal Memorandum.

Science.gov (United States)

Stern, Ralph D., Ed.

Negligence, a tort liability, is defined, discussed, and reviewed in relation to several court decisions involving school principals. The history of liability suits against school principals suggests that a reasonable, prudent principal can avoid legal problems. Ten guidelines are presented to assist principals in avoiding charges of negligence.…

Temperature and thermal stress analysis of a switching tube anode

International Nuclear Information System (INIS)

Sutton, S.B.

1979-01-01

In the design of high power density switching tubes which are subjected to cyclic thermal loads, the temperature induced stresses must be minimized in order to maximize the life expectancy of the tube. Following are details of an analysis performed for the Magnetic Fusion Program at the Lawrence Livermore Laboratory on a proposed tube. The tube configuration is given. The problem was simplified to one-dimensional approximations for both the thermal and stress analyses. The underlying assumptions and their implications are discussed

The Principal and the Law. Elementary Principal Series No. 7.

Science.gov (United States)

Doverspike, David E.; Cone, W. Henry

Developments over the past 25 years in school-related legal issues in elementary schools have significantly changed the principal's role. In 1975, a decision of the U.S. Supreme Court established three due-process guidelines for short-term suspension. The decision requires student notification of charges, explanation of evidence, and an informal…

Singularity Structure of Maximally Supersymmetric Scattering Amplitudes

DEFF Research Database (Denmark)

Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy

2014-01-01

We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....

Identities on maximal subgroups of GLn(D)

International Nuclear Information System (INIS)

Kiani, D.; Mahdavi-Hezavehi, M.

2002-04-01

Let D be a division ring with centre F. Assume that M is a maximal subgroup of GL n (D), n≥1 such that Z(M) is algebraic over F. Group identities on M and polynomial identities on the F-linear hull F[M] are investigated. It is shown that if F[M] is a PI-algebra, then [D:F] n (D) and M is a maximal subgroup of N. If M satisfies a group identity, it is shown that M is abelian-by-finite. (author)

Adaptive maximal poisson-disk sampling on surfaces

KAUST Repository

Yan, Dongming

2012-01-01

In this paper, we study the generation of maximal Poisson-disk sets with varying radii on surfaces. Based on the concepts of power diagram and regular triangulation, we present a geometric analysis of gaps in such disk sets on surfaces, which is the key ingredient of the adaptive maximal Poisson-disk sampling framework. Moreover, we adapt the presented sampling framework for remeshing applications. Several novel and efficient operators are developed for improving the sampling/meshing quality over the state-of-theart. © 2012 ACM.

Validating the Copenhagen Psychosocial Questionnaire (COPSOQ-II) Using Set-ESEM: Identifying Psychosocial Risk Factors in a Sample of School Principals.

Science.gov (United States)

Dicke, Theresa; Marsh, Herbert W; Riley, Philip; Parker, Philip D; Guo, Jiesi; Horwood, Marcus

2018-01-01

School principals world-wide report high levels of strain and attrition resulting in a shortage of qualified principals. It is thus crucial to identify psychosocial risk factors that reflect principals' occupational wellbeing. For this purpose, we used the Copenhagen Psychosocial Questionnaire (COPSOQ-II), a widely used self-report measure covering multiple psychosocial factors identified by leading occupational stress theories. We evaluated the COPSOQ-II regarding factor structure and longitudinal, discriminant, and convergent validity using latent structural equation modeling in a large sample of Australian school principals ( N = 2,049). Results reveal that confirmatory factor analysis produced marginally acceptable model fit. A novel approach we call set exploratory structural equation modeling (set-ESEM), where cross-loadings were only allowed within a priori defined sets of factors, fit well, and was more parsimonious than a full ESEM. Further multitrait-multimethod models based on the set-ESEM confirm the importance of a principal's psychosocial risk factors; Stressors and depression were related to demands and ill-being, while confidence and autonomy were related to wellbeing. We also show that working in the private sector was beneficial for showing a low psychosocial risk, while other demographics have little effects. Finally, we identify five latent risk profiles (high risk to no risk) of school principals based on all psychosocial factors. Overall the research presented here closes the theory application gap of a strong multi-dimensional measure of psychosocial risk-factors.

Particularidades estructurales y determinación del stress principal a partir de la información de un perfil en la parte oriental de la Sierra del Rosario, Pinar del Río, Cuba

Directory of Open Access Journals (Sweden)

Dámaso Cáceres-Govea

2003-03-01

Full Text Available A partir de las descripciones de afloramientos y mediciones estructurales de estructuras disyuntivas y plicativas, con la utilización de sistemas que permiten el procesamiento de la información, se llega a resultados que sirven de base para el análisis y determinación de la posible orientación del stress principal σ1 en el momento en que ocurrieron los movimientos tectónicos que afectaron el corte en el occidente de Cuba. Se reporta y explica la presencia y posición de restos de hidrocarburos en vetas y grietas en las secuencias carbonatadas del corte en la porción más oriental de la Sierra.

Utility Of Stress-Texture Characteristics Of Structural Materials By X-Ray Technique

Directory of Open Access Journals (Sweden)

Bonarski J.T.

2015-09-01

Full Text Available The article presents the results of residual stress analysis in selected metal-metal joints manufactured by conventional welding and explosive merging. The X-ray diffraction technique applied for advanced stress-texture measurements and data processing revealed directions and values of the principal stresses and their configuration on the surface of the examined structural elements. The obtained stress topography of the joint intersections indicates a possible path of potential cracking formed during the exploitation process and thus it becomes a very useful tool in the diagnostics of structural elements.

Fracture criteria of reactor graphite under multiaxial stresses

International Nuclear Information System (INIS)

Sato, S.; Kawamata, K.; Kurumada, A.; Oku, T.

1987-01-01

New fracture criteria for graphite under multiaxial stresses are presented for designing core and support materials of a high temperature gas cooled reactor. Different kinds of fracture strength tests are carried out for a near isotropic graphite IG-11. Results show that, under the stress state in which tensile stresses are predominant, the maximum principal stress theory is seen as applicable for brittle fracture. Under the stress state in which compressive stresses are predominant there may be two fracture modes for brittle fracture, namely, slipping fracture and mode II fracture. For the former fracture mode the maximum shear stress criterion is suitable, but for the latter fracture mode a new mode II fracture criterion including a restraint effect for cracks is verified to be applicable. Also a statistical correction for brittle fracture criteria under multiaxial stresses is discussed. By considering the allowable stress values for safe design, the specified minimum ultimate strengths corresponding to a survival probability of 99% at the 95% confidence level are presented. (orig./HP)

Should Principals Know More about Law?

Science.gov (United States)

Doctor, Tyrus L.

2013-01-01

Educational law is a critical piece of the education conundrum. Principals reference law books on a daily basis in order to address the wide range of complex problems in the school system. A principal's knowledge of law issues and legal decision-making are essential to provide effective feedback for a successful school.

Is the β phase maximal?

International Nuclear Information System (INIS)

Ferrandis, Javier

2005-01-01

The current experimental determination of the absolute values of the CKM elements indicates that 2 vertical bar V ub /V cb V us vertical bar =(1-z), with z given by z=0.19+/-0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase β is approximately the maximum allowed by the measured absolute values of the CKM elements. This is β=(π/6-z/3) for γ=(π/3+z/3), which implies α=π/2. Alternatively, assuming that β is exactly maximal and using the experimental measurement sin(2β)=0.726+/-0.037, the phase γ is predicted to be γ=(π/2-β)=66.3 o +/-1.7 o . The maximality of β, if confirmed by near-future experiments, may give us some clues as to the origin of CP violation

User's guide to MITRE, a stress analysis program for Mitred pipe bends

International Nuclear Information System (INIS)

Beveridge, D.C.; Carmichael, G.D.T.

1977-12-01

The MITRE computer program calculates the flexibility factor, circumferential and longitudinal inside and outside surface bending stress ratio, pressure stresses, and total stresses around the mitre section at both the mid and edge section locations of a pressurised multimitred bend under in and/or out of plane bending. Additionally, the circumferential and longitudinal strains, equivalent stress (Mises and Tresca), principal stresses, and total stresses perpendicular and parallel to the edge section at the inside and outside surfaces are calculated for the edge section. The stresses sustained by single mitres subjected to internal pressure can also be evaluated for bends with either 'long' or 'short' leg lengths. Results are tabulated and plotted in graphical form on the line printer. (author)

A New Augmentation Based Algorithm for Extracting Maximal Chordal Subgraphs.

Science.gov (United States)

Bhowmick, Sanjukta; Chen, Tzu-Yi; Halappanavar, Mahantesh

2015-02-01

A graph is chordal if every cycle of length greater than three contains an edge between non-adjacent vertices. Chordal graphs are of interest both theoretically, since they admit polynomial time solutions to a range of NP-hard graph problems, and practically, since they arise in many applications including sparse linear algebra, computer vision, and computational biology. A maximal chordal subgraph is a chordal subgraph that is not a proper subgraph of any other chordal subgraph. Existing algorithms for computing maximal chordal subgraphs depend on dynamically ordering the vertices, which is an inherently sequential process and therefore limits the algorithms' parallelizability. In this paper we explore techniques to develop a scalable parallel algorithm for extracting a maximal chordal subgraph. We demonstrate that an earlier attempt at developing a parallel algorithm may induce a non-optimal vertex ordering and is therefore not guaranteed to terminate with a maximal chordal subgraph. We then give a new algorithm that first computes and then repeatedly augments a spanning chordal subgraph. After proving that the algorithm terminates with a maximal chordal subgraph, we then demonstrate that this algorithm is more amenable to parallelization and that the parallel version also terminates with a maximal chordal subgraph. That said, the complexity of the new algorithm is higher than that of the previous parallel algorithm, although the earlier algorithm computes a chordal subgraph which is not guaranteed to be maximal. We experimented with our augmentation-based algorithm on both synthetic and real-world graphs. We provide scalability results and also explore the effect of different choices for the initial spanning chordal subgraph on both the running time and on the number of edges in the maximal chordal subgraph.

Mechanisms Underlying Stress Fracture and the Influence of Sex and Race/Ethnicity

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-16-1-0652 TITLE: Mechanisms Underlying Stress Fracture and the Influence of Sex and Race/Ethnicity PRINCIPAL INVESTIGATOR...5a. CONTRACT NUMBER W81XWH-16-1-0652 Mechanisms Underlying Stress Fracture and the Influence of Sex and Race/Ethnicity 5b. GRANT NUMBER W81XWH...to stress fracture risk. In particular, in Study 1, we will perform advanced skeletal imaging along with gait-assessments in subjects with history of

Posttraumatic Stress and Cognitive Processes in Patients with Burns

OpenAIRE

Sveen, Josefin

2011-01-01

A severe burn is one of the most traumatic injuries a person can experience. Posttraumatic stress disorder (PTSD) is relatively common after burns, and can be devastating for the individual’s possibilities for recovery. The principal aims were to gain knowledge regarding posttraumatic stress symptoms and cognitive processes after burn and to evaluate methods for assessing symptoms of PTSD up to one year after burn. The psychometric properties of a Swedish version of the Impact of Event Scale-...

Principal Ports and Facilities

Data.gov (United States)

California Natural Resource Agency — The Principal Port file contains USACE port codes, geographic locations (longitude, latitude), names, and commodity tonnage summaries (total tons, domestic, foreign,...

Principal Ports and Facilities

Data.gov (United States)

California Department of Resources — The Principal Port file contains USACE port codes, geographic locations (longitude, latitude), names, and commodity tonnage summaries (total tons, domestic, foreign,...

Promoting principals' managerial involvement in instructional improvement.

Science.gov (United States)

Gillat, A

1994-01-01

Studies of school leadership suggest that visiting classrooms, emphasizing achievement and training, and supporting teachers are important indicators of the effectiveness of school principals. The utility of a behavior-analytic program to support the enhancement of these behaviors in 2 school principals and the impact of their involvement upon teachers' and students' performances in three classes were examined in two experiments, one at an elementary school and another at a secondary school. Treatment conditions consisted of helping the principal or teacher to schedule his or her time and to use goal setting, feedback, and praise. A withdrawal design (Experiment 1) and a multiple baseline across classrooms (Experiment 2) showed that the principal's and teacher's rates of praise, feedback, and goal setting increased during the intervention, and were associated with improvements in the academic performance of the students. In the future, school psychologists might analyze the impact of involving themselves in supporting the principal's involvement in improving students' and teachers' performances or in playing a similar leadership role themselves.

Primary School Principals' Self-Monitoring Skills

Science.gov (United States)

Konan, Necdet

2015-01-01

The aim of the present study is to identify primary school principals' self-monitoring skills. The study adopted the general survey model and its population comprised primary school principals serving in the city of Diyarbakir, Turkey, while 292 of these constituted the sample. Self-Monitoring Scale was used as the data collection instrument. In…

How Not to Prepare School Principals

Science.gov (United States)

Davis, Stephen H.; Leon, Ronald J.

2011-01-01

Instead of focusing on how principals should be trained, an contrarian view is offered, grounded upon theoretical perspectives of experiential learning, and in particular, upon the theory of andragogy. A brief parable of the DoNoHarm School of Medicine is used as a descriptive analog for many principal preparation programs in America. The…

Evaluating the Effectiveness of Traditional and Alternative Principal Preparation Programs

Science.gov (United States)

Pannell, Summer; Peltier-Glaze, Bernnell M.; Haynes, Ingrid; Davis, Delilah; Skelton, Carrie

2015-01-01

This study sought to determine the effectiveness on increasing student achievement of principals trained in a traditional principal preparation program and those trained in an alternate route principal preparation program within the same Mississippi university. Sixty-six Mississippi principals and assistant principals participated in the study. Of…

Principal Turnover: Upheaval and Uncertainty in Charter Schools?

Science.gov (United States)

Ni, Yongmei; Sun, Min; Rorrer, Andrea

2015-01-01

Purpose: Informed by literature on labor market and school choice, this study aims to examine the dynamics of principal career movements in charter schools by comparing principal turnover rates and patterns between charter schools and traditional public schools. Research Methods/Approach: This study uses longitudinal data on Utah principals and…

Principal succession: The socialisation of a primary school principal in South Africa

Directory of Open Access Journals (Sweden)

Gertruida M. Steyn

2013-04-01

Full Text Available This study focussed on the socialisation of a new principal in a South African primary school with a strong Christian culture. He was appointed when the predecessor retired after more than two decades. The conceptual framework focuses on the three phases of socialisation: professional socialisation, organisational socialisation and occupational identity, which are used to interpret the study. A qualitative study, which occurred during two phases, investigated the phenomenon, principal succession, in the particular school. The data collection methods included a number of interviews with the principal, a focus group interview with staff members who experienced the previous principal’s leadership practice, and individual interviews with staff members. The following categories emerged from the data analysis: Recalling the previous principal: ‘One sees Mr X [the predecessor] everywhere’; Entry and orientation: ‘I found it intimidating initially’; and Immersion and reshaping: ‘Reins that previously were a bit slack, he is now pulling tight’.Die sosialisering van ’n primêre skoolhoof in Suid-Afrika. Hierdie studie het gefokus op die sosialisering van ’n nuwe skoolhoof in ’n Suid-Afrikaanse primêre skool met ’n sterk Christelike kultuur. Hy is aangestel toe sy voorganger ná meer as twee dekades afgetree het. Die konseptuele raamwerk, wat gebruik is om die bevindinge te interpreteer, het op die drie fases van sosialisering gefokus, naamlik professionele sosialisering, organisatoriese sosialisering en beroepsidentiteit. ’n Kwalitatiewe ondersoek na die skoolhoofopvolgingverskynsel in die bepaalde skool is in twee fases gedoen. Die data-insamelingsmetodes het ’n aantal onderhoude met die skoolhoof, ’n fokusgroeponderhoud met personeellede wat ook onder leierskap van die vorige skoolhoof gewerk het en individuele onderhoude met personeellede ingesluit. Tydens die data-analise het die volgende kategorieë na vore gekom

Looked after or Left Behind: The Effectiveness of Principal Preparation Programs as Perceived by Generation Y Principals

Science.gov (United States)

Sledge, Chandra

2013-01-01

This research study intended to discover the perceptions of 10 Illinois Generation Y novice high school principals pertaining to the effectiveness of their principal preparation programs in terms of how well it prepared them to lead in the first three years of their principalship, and what subsequent professional development they deemed necessary…

Study of residual stresses in CT test specimens welded by electron beam

Science.gov (United States)

Papushkin, I. V.; Kaisheva, D.; Bokuchava, G. D.; Angelov, V.; Petrov, P.

2018-03-01

The paper reports result of residual stress distribution studies in CT specimens reconstituted by electron beam welding (EBW). The main aim of the study is evaluation of the applicability of the welding technique for CT specimens’ reconstitution. Thus, the temperature distribution during electron beam welding of a CT specimen was calculated using Green’s functions and the residual stress distribution was determined experimentally using neutron diffraction. Time-of-flight neutron diffraction experiments were performed on a Fourier stress diffractometer at the IBR-2 fast pulsed reactor in FLNP JINR (Dubna, Russia). The neutron diffraction data estimates yielded a maximal stress level of ±180 MPa in the welded joint.

Quantum speedup in solving the maximal-clique problem

Science.gov (United States)

Chang, Weng-Long; Yu, Qi; Li, Zhaokai; Chen, Jiahui; Peng, Xinhua; Feng, Mang

2018-03-01

The maximal-clique problem, to find the maximally sized clique in a given graph, is classically an NP-complete computational problem, which has potential applications ranging from electrical engineering, computational chemistry, and bioinformatics to social networks. Here we develop a quantum algorithm to solve the maximal-clique problem for any graph G with n vertices with quadratic speedup over its classical counterparts, where the time and spatial complexities are reduced to, respectively, O (√{2n}) and O (n2) . With respect to oracle-related quantum algorithms for the NP-complete problems, we identify our algorithm as optimal. To justify the feasibility of the proposed quantum algorithm, we successfully solve a typical clique problem for a graph G with two vertices and one edge by carrying out a nuclear magnetic resonance experiment involving four qubits.

Stepping stones: Principal career paths and school outcomes.

Science.gov (United States)

Béteille, Tara; Kalogrides, Demetra; Loeb, Susanna

2012-07-01

More than one out of every five principals leaves their school each year. In some cases, these career changes are driven by the choices of district leadership. In other cases, principals initiate the move, often demonstrating preferences to work in schools with higher achieving students from more advantaged socioeconomic backgrounds. Principals often use schools with many poor or low-achieving students as stepping stones to what they view as more desirable assignments. We use longitudinal data from one large urban school district to study the relationship between principal turnover and school outcomes. We find that principal turnover is, on average, detrimental to school performance. Frequent turnover of school leadership results in lower teacher retention and lower student achievement gains. Leadership changes are particularly harmful for high poverty schools, low-achieving schools, and schools with many inexperienced teachers. These schools not only suffer from high rates of principal turnover but are also unable to attract experienced successors. The negative effect of leadership changes can be mitigated when vacancies are filled by individuals with prior experience leading other schools. However, the majority of new principals in high poverty and low-performing schools lack prior leadership experience and leave when more attractive positions become available in other schools. Copyright © 2012 Elsevier Inc. All rights reserved.

Muscle mitochondrial capacity exceeds maximal oxygen delivery in humans

DEFF Research Database (Denmark)

Boushel, Robert Christopher; Gnaiger, Erich; Calbet, Jose A L

2011-01-01

Across a wide range of species and body mass a close matching exists between maximal conductive oxygen delivery and mitochondrial respiratory rate. In this study we investigated in humans how closely in-vivo maximal oxygen consumption (VO(2) max) is matched to state 3 muscle mitochondrial respira...

Methods for evaluation of mechanical stress condition of materials

Directory of Open Access Journals (Sweden)

Mirchev Yordan

2018-01-01

Full Text Available Primary attention is given to the following methods: method by drilling cylindrical holes (drill method and integrated ultrasonic method using volume (longitudinal and transverse, surface, and sub-surface waves. Drill method allows determination of residual mechanical stress in small depth of material surfaces, assessing type, size, and orientation of principal stresses. For the first time, parallel studies are carried out of mechanical stress in materials using the electroacoustic effect of volume, surface and sub-surface waves on the one hand, and effective mechanical stresses on the other. The experimental results present electroacoustic coefficients for different types of waves in the material of gas pipeline tube of 243 mm diameter and 14 mm thickness. These are used to evaluate mechanical stresses in pipelines, according to active GOST standards.

Blood pressure and heart rate during stress in children born small for gestational age.

Science.gov (United States)

Pirojsakul, Kwanchai; Thanapinyo, Apinya; Nuntnarumit, Pracha

2017-06-01

Increased sympathetic nervous system activity has been proposed as a potential mechanism for the blood pressure (BP) elevation seen in individuals born small for gestational age (SGA). This study was carried out to detect the changes in BP and heart rate (HR) in children born SGA during exposure to stress and to assess for changes in urinary catecholamine excretion. Nineteen children aged 6-14 years born SGA and 17 age- and gender-matched healthy controls were included in the study. The stress test included a mathematical test and venipuncture. BP and HR were monitored during the test. Spot urine samples were collected at baseline and after the stress test to determine dopamine, epinephrine and norepinephrine levels. At baseline, there was no difference in BP and HR between the SGA and control groups, but mean urinary norepinephrine levels were slightly higher in the SGA group (55.7 ± 16.1 vs. 43.4 ± 3.8 mcg/gCr; P = 0.10). Compared to the control group, mean maximal HR increase was higher in the SGA group (31.3 ± 3.1 vs. 19.2 ± 3.8%; P = 0.008), and mean duration of maximal HR to baseline HR was longer (186 ± 23 vs. 97 ± 13 s, respectively; P = 0.003). There was a significant negative correlation between birth weight and maximal HR increase (r = -0.497, P = 0.003). Children born SGA showed significantly greater increases in HR and significantly longer periods of tachycardia during exposure to stress than did healthy controls. The rise in HR was inversely correlated with birth weight. These findings suggest that children born SGA have a greater increase in sympathetic response when exposed to stress than do healthy individuals.

Simulation investigation of thermal phase transformation and residual stress in single pulse EDM of Ti-6Al-4V

Science.gov (United States)

Tang, Jiajing; Yang, Xiaodong

2018-04-01

The thermal phase transformation and residual stress are ineluctable in the electrical discharge machining (EDM) process, and they will greatly affect the working performances of the machined surface. This paper presents a simulation study on the thermal phase transformation and residual stress in single-pulse EDM of Ti-6Al-4V, which is the most popular titanium alloy in fields such as aircraft engine and some other leading industries. A multi-physics model including thermal, hydraulic, metallography and structural mechanics was developed. Based on the proposed model, the thickness and metallographic structure of the recast layer and heat affected layer (HAZ) were investigated. The distribution and characteristics of residual stress around the discharge crater were obtained. The recast layer and HAZ at the center of crater are found to be the thinnest, and their thicknesses gradually increase approaching the periphery of the crater. The recast layer undergoes a complete α‧ (martensitic) transformation, while the HAZ is mainly composed by the α  +  β  +  α‧ three-phase microstructure. Along the depth direction of crater, the Von Mises stress increases first and then decreases, reaching its maximal value near the interface of recast layer and HAZ. In the recast layer, both compressive stress component and tensile stress component are observed. ANOVA results showed that the influence of discharge current on maximal tensile stress is more significant than that of pulse duration, while the pulse duration has more significant influence on average thickness of the recast layer and the depth location of the maximal tensile stress. The works conducted in this study will help to evaluate the quality and integrity of EDMed surface, especially when the non-destructive testing is difficult to achieve.

Temperature field and thermal stress analysis of the HT-7U vacuum vessel

International Nuclear Information System (INIS)

Song Yuntao; Yao Damao; Wu Songtao; Weng Peide

2000-01-01

The HT-7U vacuum vessel is an all-metal-welded double-wall interconnected with toroidal and poloidal stiffening ribs. The channels formed between the ribs and walls are filled with boride water as a nuclear shielding. On the vessel surface facing the plasma are installed cable-based Ohmic heaters. Prior to plasma operation the vessel is to be baked out and discharge cleaned at about 250 degree C. During baking out the non-uniformity of temperature distribution on the vacuum vessel will bring about serious thermal stress that can damage the vessel. In order to determine and optimize the design of the HT-7U vacuum vessel, a three-dimensional finite element model was performed to analyse its temperature field and thermal stress. the maximal thermal stress appeared on the round of lower vertical port and maximal deformation located just on the region between the upper vertical port and the horizontal port. The results show that the reinforced structure has a good capability of withstanding the thermal loads

A Review of the Literature on Principal Turnover

Science.gov (United States)

Snodgrass Rangel, Virginia

2018-01-01

Among the many challenges facing public schools are high levels of principal turnover. Given the important role that principals play and are expected to play in the improvement process, concerns about principal turnover have resulted in a growing body of research on its causes and consequences. The purpose of this review is to take stock of what…

Stress measurement by x-ray diffractometry

Energy Technology Data Exchange (ETDEWEB)

Mitchell, C M

1985-10-22

This invention relates to x-ray diffractometry and more particularly to apparatus and methods for the measurement of residual stress in polycrystalline, e.g. metallic, specimens. The procedure is based on measurement of the lattice strain of crystals by x-ray diffraction, in which change in the interplanar spacing of a set of crystal lattice planes due to strain causes a change in the diffraction angle of the scattered x-ray beam, from which latter change the magnitude of the strain can be determined. In a polycrystalline specimen, from well know relations for elastic behaviour in isotropic materials, the stress on a plane normal to a given direction in the surface has a component in the given direction which can be calculated from measurement of lattice strain in two directions in a plane containing the given direction and the normal to the specimen surface. In general three such stress components in three directions in the surface are required to determine the principal stresses and thus express the state of stress in the surface. (author). 2 tabs., 9 figs.

3D geomechanical modeling and numerical simulation of in-situ stress fields in shale reservoirs: A case study of the lower Cambrian Niutitang formation in the Cen'gong block, South China

Science.gov (United States)

Liu, Jingshou; Ding, Wenlong; Yang, Haimeng; Wang, Ruyue; Yin, Shuai; Li, Ang; Fu, Fuquan

2017-08-01

An analysis of the in-situ state of stress in a shale reservoir was performed based on comprehensive information about the subsurface properties from wellbores established during the development of an oil and gas field. Industrial-level shale gas production has occurred in the Niutitang formation of the lower Cambrian Cen'gong block, South China. In this study, data obtained from hydraulic fracturing, drilling-induced fractures, borehole breakout, global positioning system (GPS), and well deviation statistics have been used to determine the orientation of the maximum horizontal principal stress. Additionally, hydraulic fracturing and multi-pole array acoustic logging (XMAC) were used to determine the vertical variations in the in-situ stress magnitude. Based on logging interpretation and mechanical experiments, the spatial distributions of mechanical parameters were obtained by seismic inversion, and a 3D heterogeneous geomechanical model was established using a finite element stress analysis approach to simulate the in-situ stress fields. The effects of depth, faults, rock mechanics, and layer variations on the principal stresses, horizontal stress difference (Δσ), horizontal stress difference coefficient (Kh), and stress type coefficient (Sp) were determined. The results show that the direction of the maximum principal stress is ESE 120°. Additionally, the development zones of natural fractures appear to correlate with regions with high principal stress differences. At depths shallower than 375 m, the stress type is mainly a thrust faulting stress regime. At depths ranging from 375 to 950 m, the stress type is mainly a strike-slip faulting stress regime. When the depth is > 950 m, the stress type is mainly a normal faulting stress regime. Depth, fault orientation, and rock mechanics all affect the type of stress. The knowledge regarding the Cen'gong block is reliable and can improve borehole stability, casing set point determination, well deployment

Enumerating all maximal frequent subtrees in collections of phylogenetic trees.

Science.gov (United States)

Deepak, Akshay; Fernández-Baca, David

2014-01-01

A common problem in phylogenetic analysis is to identify frequent patterns in a collection of phylogenetic trees. The goal is, roughly, to find a subset of the species (taxa) on which all or some significant subset of the trees agree. One popular method to do so is through maximum agreement subtrees (MASTs). MASTs are also used, among other things, as a metric for comparing phylogenetic trees, computing congruence indices and to identify horizontal gene transfer events. We give algorithms and experimental results for two approaches to identify common patterns in a collection of phylogenetic trees, one based on agreement subtrees, called maximal agreement subtrees, the other on frequent subtrees, called maximal frequent subtrees. These approaches can return subtrees on larger sets of taxa than MASTs, and can reveal new common phylogenetic relationships not present in either MASTs or the majority rule tree (a popular consensus method). Our current implementation is available on the web at https://code.google.com/p/mfst-miner/. Our computational results confirm that maximal agreement subtrees and all maximal frequent subtrees can reveal a more complete phylogenetic picture of the common patterns in collections of phylogenetic trees than maximum agreement subtrees; they are also often more resolved than the majority rule tree. Further, our experiments show that enumerating maximal frequent subtrees is considerably more practical than enumerating ordinary (not necessarily maximal) frequent subtrees.

Softly Broken Lepton Numbers: an Approach to Maximal Neutrino Mixing

International Nuclear Information System (INIS)

Grimus, W.; Lavoura, L.

2001-01-01

We discuss models where the U(1) symmetries of lepton numbers are responsible for maximal neutrino mixing. We pay particular attention to an extension of the Standard Model (SM) with three right-handed neutrino singlets in which we require that the three lepton numbers L e , L μ , and L τ be separately conserved in the Yukawa couplings, but assume that they are softly broken by the Majorana mass matrix M R of the neutrino singlets. In this framework, where lepton-number breaking occurs at a scale much higher than the electroweak scale, deviations from family lepton number conservation are calculable, i.e., finite, and lepton mixing stems exclusively from M R . We show that in this framework either maximal atmospheric neutrino mixing or maximal solar neutrino mixing or both can be imposed by invoking symmetries. In this way those maximal mixings are stable against radiative corrections. The model which achieves maximal (or nearly maximal) solar neutrino mixing assumes that there are two different scales in M R and that the lepton number (dash)L=L e -L μ -L τ 1 is conserved in between them. We work out the difference between this model and the conventional scenario where (approximate) (dash)L invariance is imposed directly on the mass matrix of the light neutrinos. (author)

Surface analysis the principal techniques

CERN Document Server

Vickerman, John C

2009-01-01

This completely updated and revised second edition of Surface Analysis: The Principal Techniques, deals with the characterisation and understanding of the outer layers of substrates, how they react, look and function which are all of interest to surface scientists. Within this comprehensive text, experts in each analysis area introduce the theory and practice of the principal techniques that have shown themselves to be effective in both basic research and in applied surface analysis. Examples of analysis are provided to facilitate the understanding of this topic and to show readers how they c

Stress field modelling from digital geological map data

Science.gov (United States)

Albert, Gáspár; Barancsuk, Ádám; Szentpéteri, Krisztián

2016-04-01

To create a model for the lithospheric stress a functional geodatabase is required which contains spatial and geodynamic parameters. A digital structural-geological map is a geodatabase, which usually contains enough attributes to create a stress field model. Such a model is not accurate enough for engineering-geological purposes because simplifications are always present in a map, but in many cases maps are the only sources for a tectonic analysis. The here presented method is designed for field geologist, who are interested to see the possible realization of the stress field over the area, on which they are working. This study presents an application which can produce a map of 3D stress vectors from a kml-file. The core application logic is implemented on top of a spatially aware relational database management system. This allows rapid and geographically accurate analysis of the imported geological features, taking advantage of standardized spatial algorithms and indexing. After pre-processing the map features in a GIS, according to the Type-Property-Orientation naming system, which was described in a previous study (Albert et al. 2014), the first stage of the algorithm generates an irregularly spaced point cloud by emitting a pattern of points within a user-defined buffer zone around each feature. For each point generated, a component-wise approximation of the tensor field at the point's position is computed, derived from the original feature's geodynamic properties. In a second stage a weighted moving average method calculates the stress vectors in a regular grid. Results can be exported as geospatial data for further analysis or cartographic visualization. Computation of the tensor field's components is based on the implementation of the Mohr diagram of a compressional model, which uses a Coulomb fracture criterion. Using a general assumption that the main principal stress must be greater than the stress from the overburden, the differential stress is

Subjective performance evaluations and reciprocity in principal-agent relations

DEFF Research Database (Denmark)

Sebald, Alexander Christopher; Walzl, Markus

2014-01-01

. In contrast to existing models of reciprocity, we find that agents tend to sanction whenever the feedback of principals is below their subjective self-evaluations even if agents' pay-offs are independent of it. In turn, principals provide more positive feedback (relative to their actual performance assessment......We conduct a laboratory experiment with agents working on, and principals benefiting from, a real effort task in which the agents' performance can only be evaluated subjectively. Principals give subjective performance feedback to agents, and agents have an opportunity to sanction principals...... of the agent) if this does not affect their pay-off....

Maximal heart rate does not limit cardiovascular capacity in healthy humans

DEFF Research Database (Denmark)

Munch, G D W; Svendsen, J H; Damsgaard, R

2014-01-01

In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function...... and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax...... and RAP (P healthy...

Power Converters Maximize Outputs Of Solar Cell Strings

Science.gov (United States)

Frederick, Martin E.; Jermakian, Joel B.

1993-01-01

Microprocessor-controlled dc-to-dc power converters devised to maximize power transferred from solar photovoltaic strings to storage batteries and other electrical loads. Converters help in utilizing large solar photovoltaic arrays most effectively with respect to cost, size, and weight. Main points of invention are: single controller used to control and optimize any number of "dumb" tracker units and strings independently; power maximized out of converters; and controller in system is microprocessor.

No Mikheyev-Smirnov-Wolfenstein Effect in Maximal Mixing

OpenAIRE

Harrison, P. F.; Perkins, D. H.; Scott, W. G.

1996-01-01

We investigate the possible influence of the MSW effect on the expectations for the solar neutrino experiments in the maximal mixing scenario suggested by the atmospheric neutrino data. A direct numerical calculation of matter induced effects in the Sun shows that the naive vacuum predictions are left completely undisturbed in the particular case of maximal mixing, so that the MSW effect turns out to be unobservable. We give a qualitative explanation of this result.

Single maximal versus combination punch kinematics.

Science.gov (United States)

Piorkowski, Barry A; Lees, Adrian; Barton, Gabor J

2011-03-01

The aim of this study was to determine the influence of punch type (Jab, Cross, Lead Hook and Reverse Hook) and punch modality (Single maximal, 'In-synch' and 'Out of synch' combination) on punch speed and delivery time. Ten competition-standard volunteers performed punches with markers placed on their anatomical landmarks for 3D motion capture with an eight-camera optoelectronic system. Speed and duration between key moments were computed. There were significant differences in contact speed between punch types (F(2,18,84.87) = 105.76, p = 0.001) with Lead and Reverse Hooks developing greater speed than Jab and Cross. There were significant differences in contact speed between punch modalities (F(2,64,102.87) = 23.52, p = 0.001) with the Single maximal (M+/- SD: 9.26 +/- 2.09 m/s) higher than 'Out of synch' (7.49 +/- 2.32 m/s), 'In-synch' left (8.01 +/- 2.35 m/s) or right lead (7.97 +/- 2.53 m/s). Delivery times were significantly lower for Jab and Cross than Hook. Times were significantly lower 'In-synch' than a Single maximal or 'Out of synch' combination mode. It is concluded that a defender may have more evasion-time than previously reported. This research could be of use to performers and coaches when considering training preparations.

Formation Control for the MAXIM Mission

Science.gov (United States)

Luquette, Richard J.; Leitner, Jesse; Gendreau, Keith; Sanner, Robert M.

2004-01-01

Over the next twenty years, a wave of change is occurring in the space-based scientific remote sensing community. While the fundamental limits in the spatial and angular resolution achievable in spacecraft have been reached, based on today s technology, an expansive new technology base has appeared over the past decade in the area of Distributed Space Systems (DSS). A key subset of the DSS technology area is that which covers precision formation flying of space vehicles. Through precision formation flying, the baselines, previously defined by the largest monolithic structure which could fit in the largest launch vehicle fairing, are now virtually unlimited. Several missions including the Micro-Arcsecond X-ray Imaging Mission (MAXIM), and the Stellar Imager will drive the formation flying challenges to achieve unprecedented baselines for high resolution, extended-scene, interferometry in the ultraviolet and X-ray regimes. This paper focuses on establishing the feasibility for the formation control of the MAXIM mission. MAXIM formation flying requirements are on the order of microns, while Stellar Imager mission requirements are on the order of nanometers. This paper specifically addresses: (1) high-level science requirements for these missions and how they evolve into engineering requirements; and (2) the development of linearized equations of relative motion for a formation operating in an n-body gravitational field. Linearized equations of motion provide the ground work for linear formation control designs.

Perceptions of Kentucky High School Principals and Superintendents on the Role of the Superintendent Influencing Principal Instructional Leadership

Science.gov (United States)

Hamilton, Charles L., Jr.

2011-01-01

This exploratory study surveyed the promotion of instructional leadership of high school principals by superintendents, as perceived by self and the principals they supervise. The two-phased study included an initial questionnaire administered to both study groups and comparisons of responses analyzed. All superintendents (N = 173), except the…

Characterizing the Role of Hep27 in Liver and Colorectal Cancer Stress Tolerance

Science.gov (United States)

2018-01-01

AWARD NUMBER: W81XWH-16-1-0402 TITLE: Characterizing the Role of Hep27 in Liver and Colorectal Cancer Stress Tolerance PRINCIPAL INVESTIGATOR...Sep 2016 – 14 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Characterizing the Role of Hep27 in Liver and Colorectal Cancer Stress Tolerance...project has not demonstrated that Hep27 plays a role in ROS tolerance in liver cancer cells. 15. SUBJECT TERMS Hep27, ROS, stress , cancer 16. SECURITY

Conversational Implicature of Peanuts Comic Strip Based on Grice’s Maxim Theory

Directory of Open Access Journals (Sweden)

Muhartoyo Muhartoyo

2013-04-01

Full Text Available This article discusses about conversational implicature that occurs in Peanuts comic strips. The objectives of this study are to find out the implied meaning in the conversation between Charlie Brown with Lucy van Pelt and Lucy van Pelt with Linus van Pelt to evaluate the existence of maxim flouting and maxim violating in those conversations in relation to the four maxims such as quantity, quality, relation, and manner. Likewise, this study attempts to find out the reason for using conversational implicature in a comic strip. The writers uses a qualitative method with library research concerning to Grice’s maxim theory to analyze the conversational implicature. Based on the analysis, it can be concluded that all the comics that comprise 14 comics generate conversational implicature since all the characters breach rules of maxim. The result of this analysis shows that flouting maxim of manner has the highest occurrence of conversational implicature and the least occurrences belong to flouting maxim of relation and violating maxim of quantity. Moreover, the writers concludes that to make a successful communication ideally the speaker and the hearer to cooperate in the conversation by saying explicitly so the hearer can grasp the meaning as the goal of communication is to deliver a message to the hearer.  

Comparison of changes in the mobility of the pelvic floor muscle on during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction.

Science.gov (United States)

Jung, Halim; Jung, Sangwoo; Joo, Sunghee; Song, Changho

2016-01-01

[Purpose] The purpose of this study was to compare changes in the mobility of the pelvic floor muscle during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. [Subjects] Thirty healthy adults participated in this study (15 men and 15 women). [Methods] All participants performed a bridge exercise and abdominal curl-up during the abdominal drawing-in maneuver, maximal expiration, and pelvic floor muscle maximal contraction. Pelvic floor mobility was evaluated as the distance from the bladder base using ultrasound. [Results] According to exercise method, bridge exercise and abdominal curl-ups led to significantly different pelvic floor mobility. The pelvic floor muscle was elevated during the abdominal drawing-in maneuver and descended during maximal expiration. Finally, pelvic floor muscle mobility was greater during abdominal curl-up than during the bridge exercise. [Conclusion] According to these results, the abdominal drawing-in maneuver induced pelvic floor muscle contraction, and pelvic floor muscle contraction was greater during the abdominal curl-up than during the bridge exercise.

Deformation quantization of principal fibre bundles

International Nuclear Information System (INIS)

Weiss, S.

2007-01-01

Deformation quantization is an algebraic but still geometrical way to define noncommutative spacetimes. In order to investigate corresponding gauge theories on such spaces, the geometrical formulation in terms of principal fibre bundles yields the appropriate framework. In this talk I will explain what should be understood by a deformation quantization of principal fibre bundles and how associated vector bundles arise in this context. (author)

Descriptive Analysis on Flouting and Hedging of Conversational Maxims in the “Post Grad” Movie

Directory of Open Access Journals (Sweden)

Nastiti Rokhmania

2012-11-01

Full Text Available This research is focused on analyzing flouting and hedging of conversational maxim of utterances used by the main characters in “Post Grad” movie. Conversational maxims are the rules of cooperative principle categorized into four categories; Maxim of Quality, Maxim of Quantity, Maxim of Relevance, and Maxim of Manner. If these maxims are used in conversations, the conversations can go smoothly. However, people often break the maxims overtly (flouting maxim and sometimes break the maxims secretly (hedging maxims when they make a conversation. This research is conducted using descriptive qualitative method based on the theory known as Grice’s Maxims. The data are in form of utterances used by the characters in “Post Grad” movie. The data analysis reveals some finding covering the formulated research question. The maxims are flouted when the speaker breaks some conversational maxims when using the utterances in the form of rhetorical strategies, such as tautology, metaphor, hyperbole, irony, and rhetorical question. On the other hand, conversational maxims are also hedged when the information is not totally accurate or unclearly stated but seems informative, well-founded, and relevant.

Maximal and anaerobic threshold cardiorespiratory responses during deepwater running

Directory of Open Access Journals (Sweden)

Ana Carolina Kanitz

2014-12-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p41   Aquatic exercises provide numerous benefits to the health of their practitioners. To secure these benefits, it is essential to have proper prescriptions to the needs of each individual and, therefore, it is important to study the cardiorespiratory responses of different activities in this environment. Thus, the aim of this study was to compare the cardiorespiratory responses at the anaerobic threshold (AT between maximal deep-water running (DWR and maximal treadmill running (TMR. In addition, two methods of determining the AT (the heart rate deflection point [HRDP] and ventilatory method [VM] are compared in the two evaluated protocols. Twelve young women performed the two maximal protocols. Two-factor ANOVA for repeated measures with a post-hoc Bonferroni test was used (α < 0.05. Significantly higher values of maximal heart rate (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 and maximal oxygen uptake (TMR: 33.7 ± 3.9; DWR: 22.5 ± 4.1 ml.kg−1.min−1 in TMR compared to the DWR were found. Furthermore, no significant differences were found between the methods for determining the AT (TMR: VM: 28.1 ± 5.3, HRDP: 26.6 ± 5.5 ml.kg−1.min−1; DWR: VM: 18.7 ± 4.8, HRDP: 17.8 ± 4.8 ml.kg−1.min−1. The results indicate that a specific maximal test for the trained modality should be conducted and the HRDP can be used as a simple and practical method of determining the AT, based on which the training intensity can be determined

Artful Dodges Principals Use to Beat Bureaucracy.

Science.gov (United States)

Ficklen, Ellen

1982-01-01

A study of Chicago (Illinois) principals revealed many ways principals practiced "creative insubordination"--avoiding following instructions but still getting things done. Among the dodges are deliberately missing deadlines, following orders literally, ignoring channels to procure teachers or materials, and using community members to…

Stress field reconstruction in an active mudslide

Science.gov (United States)

Baroň, Ivo; Kernstocková, Markéta; Melichar, Rostislav

2017-07-01

Meso-scale structures from gravitational slope deformation observed in landslides and deep-seated gravitational slope failures are very similar to those of endogenous ones. Therefore we applied palaeostress analysis of fault-slip data for reconstructing the stress field of an active mudslide in Pechgraben, Austria. This complex compound landslide has developed in clayey colluvium and shale and was activated after a certain period of dormancy in June 2013. During the active motion on June 12, 2013, 73 fault-slip traces at 9 locations were measured within the landslide body. The heterogeneous fault-slip data were processed in term of palaeostresses, the reconstructed palaeostress tensor being characterized by the orientations of the three principal stress axes and the stress ratio (which provides the shape of the stress ellipsoid). The results of the palaeostress analysis were compared to airborne laser scan digital terrain models that revealed dynamics and superficial displacements of the moving mass prior and after our survey. The results were generally in good agreement with the observed landslide displacement pattern and with the anticipated stress regime according to Mohr-Coulomb failure criteria and Anderson's theory. The compressional regime was mostly registered at the toe in areas, where a compressional stress field is expected during previous mass-movement stages, or at margins loaded by subsequent landslide bodies from above. On the other hand, extension regimes were identified at the head scarps of secondary slides, subsequently on bulged ridges at the toe and in the zone of horst-and-graben structures in the lower central part of the main landslide body, where the basal slip surface probably had locally convex character. Strike-slip regimes, as well as oblique normal or oblique reverse regimes were observed at the lateral margins of the landslide bodies. The directions of principal stresses could be used as markers of landslide movement directions

Principal spectra describing magnetooptic permittivity tensor in cubic crystals

Energy Technology Data Exchange (ETDEWEB)

Hamrlová, Jana [Nanotechnology Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Legut, Dominik [IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Veis, Martin [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague, 121 16 Czech Republic (Czech Republic); Pištora, Jaromír [Nanotechnology Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Hamrle, Jaroslav, E-mail: jaroslav.hamrle@vsb.cz [IT4Innovations Centre, VSB – Technical University of Ostrava, listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague, 121 16 Czech Republic (Czech Republic); Department of Physics, VSB – Technical University of Ostrava, 17. listopadu 15, Ostrava, 708 33 Czech Republic (Czech Republic)

2016-12-15

We provide unified phenomenological description of magnetooptic effects being linear and quadratic in magnetization. The description is based on few principal spectra, describing elements of permittivity tensor up to the second order in magnetization. Each permittivity tensor element for any magnetization direction and any sample surface orientation is simply determined by weighted summation of the principal spectra, where weights are given by crystallographic and magnetization orientations. The number of principal spectra depends on the symmetry of the crystal. In cubic crystals owning point symmetry we need only four principal spectra. Here, the principal spectra are expressed by ab initio calculations for bcc Fe, fcc Co and fcc Ni in optical range as well as in hard and soft x-ray energy range, i.e. at the 2p- and 3p-edges. We also express principal spectra analytically using modified Kubo formula.

Stress and PTSD Mechanisms as Targets for Pharmacotherapy of Alcohol Abuse, Addiction and Relapse

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-13-1-0126 TITLE: Stress and PTSD Mechanisms as Targets for Pharmacotherapy of Alcohol Abuse, Addiction and Relapse PRINCIPAL...10/27/2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 — 29 Sep 2017 4. TITLE AND SUBTITLE Stress and PTSD Mechanisms as Targets for...insights into mechanism; (2) suppression of noradrenergic signaling decreases alcohol drinking in rats with a history of traumatic stress , but not in

Quantization with maximally degenerate Poisson brackets: the harmonic oscillator!

International Nuclear Information System (INIS)

Nutku, Yavuz

2003-01-01

Nambu's construction of multi-linear brackets for super-integrable systems can be thought of as degenerate Poisson brackets with a maximal set of Casimirs in their kernel. By introducing privileged coordinates in phase space these degenerate Poisson brackets are brought to the form of Heisenberg's equations. We propose a definition for constructing quantum operators for classical functions, which enables us to turn the maximally degenerate Poisson brackets into operators. They pose a set of eigenvalue problems for a new state vector. The requirement of the single-valuedness of this eigenfunction leads to quantization. The example of the harmonic oscillator is used to illustrate this general procedure for quantizing a class of maximally super-integrable systems

Maximally flat radiation patterns of a circular aperture

Science.gov (United States)

Minkovich, B. M.; Mints, M. Ia.

1989-08-01

The paper presents an explicit solution to the problems of maximizing the area utilization coefficient and of obtaining the best approximation (on the average) of a sectorial Pi-shaped radiation pattern of an antenna with a circular aperture when Butterworth conditions are imposed on the approximating pattern with the aim of flattening it. Constraints on the choice of admissible minimum and maximum antenna dimensions are determined which make possible the synthesis of maximally flat patterns with small sidelobes.

The Large Margin Mechanism for Differentially Private Maximization

OpenAIRE

Chaudhuri, Kamalika; Hsu, Daniel; Song, Shuang

2014-01-01

A basic problem in the design of privacy-preserving algorithms is the private maximization problem: the goal is to pick an item from a universe that (approximately) maximizes a data-dependent function, all under the constraint of differential privacy. This problem has been used as a sub-routine in many privacy-preserving algorithms for statistics and machine-learning. Previous algorithms for this problem are either range-dependent---i.e., their utility diminishes with the size of the universe...

Effect of Preoperative Low Maximal Flow Rate on Postoperative Voiding Trials after the Midurethral Sling Procedure in Women with Stress Urinary Incontinence.

Science.gov (United States)

Chae, Ji Y; Bae, Jae H; Lee, Jeong G; Park, Hong S; Moon, Du G; Oh, Mi M

2017-06-02

To evaluate the effects of preoperative low maximal flow rate (Qmax) on voiding trials after the midurethral sling (MUS) procedure in women with stress urinary incontinence (SUI). One hundred and sixty-eight women who underwent MUS procedure were enrolled. Preoperative free uroflowmetry was performed and patients were divided by Qmax. Low Qmax was defined as a Qmax under 15 mL/sec with voided volume at least 150 mL. Surgical results, failure of voiding trial, and postoperative uroflowmetry parameters were compared between the groups. Failure of voiding trial was defined by a PVR more than 100 mL on postoperative uroflowmetry. At the discharge day, there were 42 cases showing failure of voiding trial and 33 cases requiring CIC, but only one patient showed failure of voiding trial at 12 months postoperatively. Overall, 48 patients had preoperative low Qmax. Low Qmax group showed lower Qmax in all of postoperative uroflowmetry, but there were no significant differences in the rate of postoperative voiding trial failure or CIC. The low Qmax group was then divided into two groups according to the preoperative detrusor pressure at Qmax over and under 20 cmH 2 O in pressure flow study. Comparing the two groups, no significant differences were observed in the cure rate, voiding trial failure or CIC. Our results suggest that women with preoperative low Qmax experienced no definite unfavorable voiding problem from the MUS procedure compared to those with normal voiding function. MUS procedure may be regarded as a safe and successful procedure in SUI women with low Qmax. © 2017 John Wiley & Sons Australia, Ltd.

Enumerating all maximal frequent subtrees in collections of phylogenetic trees

Science.gov (United States)

2014-01-01

Background A common problem in phylogenetic analysis is to identify frequent patterns in a collection of phylogenetic trees. The goal is, roughly, to find a subset of the species (taxa) on which all or some significant subset of the trees agree. One popular method to do so is through maximum agreement subtrees (MASTs). MASTs are also used, among other things, as a metric for comparing phylogenetic trees, computing congruence indices and to identify horizontal gene transfer events. Results We give algorithms and experimental results for two approaches to identify common patterns in a collection of phylogenetic trees, one based on agreement subtrees, called maximal agreement subtrees, the other on frequent subtrees, called maximal frequent subtrees. These approaches can return subtrees on larger sets of taxa than MASTs, and can reveal new common phylogenetic relationships not present in either MASTs or the majority rule tree (a popular consensus method). Our current implementation is available on the web at https://code.google.com/p/mfst-miner/. Conclusions Our computational results confirm that maximal agreement subtrees and all maximal frequent subtrees can reveal a more complete phylogenetic picture of the common patterns in collections of phylogenetic trees than maximum agreement subtrees; they are also often more resolved than the majority rule tree. Further, our experiments show that enumerating maximal frequent subtrees is considerably more practical than enumerating ordinary (not necessarily maximal) frequent subtrees. PMID:25061474

Temperature rise and stress induced by microcracks in accelerating structures

Directory of Open Access Journals (Sweden)

W. Zhu

2010-12-01

Full Text Available The temperature rise and induced stress due to Ohmic heating in the vicinity of microcracks on the walls of high-gradient accelerating structures are considered. The temperature rise and induced stress depend on the orientation of the crack with respect to the rf magnetic field, the shape of the crack, and the power and duration of the rf pulse. Under certain conditions the presence of cracks can double the temperature rise over that of a smooth surface. Stress at the bottom of the cracks can be several times larger than that of the case when there are no cracks. We study these effects both analytically and by computer simulation. It is shown that the stress in cracks is maximal when the crack depth is on the order of the thermal penetration depth.

Reel Principals: A Descriptive Content Analysis of the Images of School Principals Depicted in Movies from 1997-2009

Science.gov (United States)

Wolfrom, Katy J.

2010-01-01

According to Glanz's early research, school principals have been depicted as autocrats, bureaucrats, buffoons, and/or villains in movies from 1950 to 1996. The purpose of this study was to determine if these stereotypical characterizations of school principals have continued in films from 1997-2009, or if more favorable images have emerged that…

The relative influence of body characteristics on humid heat stress response

NARCIS (Netherlands)

Havenith, G.; Luttikholt, V. G.; Vrijkotte, T. G.

1995-01-01

The present study was designed to determine the relative importance of individual characteristics such as maximal oxygen uptake (VO2max), adiposity, DuBois body surface area (AD), surface to mass ratio (AD: mass) and body mass, for the individual's reaction to humid heat stress. For this purpose 27

Pace's Maxims for Homegrown Library Projects. Coming Full Circle

Science.gov (United States)

Pace, Andrew K.

2005-01-01

This article discusses six maxims by which to run library automation. The following maxims are discussed: (1) Solve only known problems; (2) Avoid changing data to fix display problems; (3) Aut viam inveniam aut faciam; (4) If you cannot make it yourself, buy something; (5) Kill the alligator closest to the boat; and (6) Just because yours is…

The DRE-Principal Partnership: Making It Work.

Science.gov (United States)

Davis, Barbara; Elliott, Karen

1995-01-01

Discusses the roles of the director of religious education (DRE) and the school principal at Catholic schools, viewing them as complimentary rather than competitive. Provides examples of positive cooperation between the principal and DRE at Most Pure Heart of Mary Parish, in Shelby, Ohio. (KP)

New Principals' Perspectives of Their Multifaceted Roles

Science.gov (United States)

Gentilucci, James L.; Denti, Lou; Guaglianone, Curtis L.

2013-01-01

This study utilizes Symbolic Interactionism to explore perspectives of neophyte principals. Findings explain how these perspectives are modified through complex interactions throughout the school year, and they also suggest preparation programs can help new principals most effectively by teaching "soft" skills such as active listening…

Leading Learning: First-Year Principals' Reflections on Instructional Leadership

Science.gov (United States)

O'Doherty, Ann; Ovando, Martha N.

2013-01-01

This qualitative study examined the instructional leadership perceptions of four first-year principals. Findings illuminate five themes drawn from the data: definitions of instructional leadership, challenges that first-year principals faced, how these principals addressed these challenges, how the novice principals plan to enact their…

Gravitational collapse of charged dust shell and maximal slicing condition

International Nuclear Information System (INIS)

Maeda, Keiichi

1980-01-01

The maximal slicing condition is a good time coordinate condition qualitatively when pursuing the gravitational collapse by the numerical calculation. The analytic solution of the gravitational collapse under the maximal slicing condition is given in the case of a spherical charged dust shell and the behavior of time slices with this coordinate condition is investigated. It is concluded that under the maximal slicing condition we can pursue the gravitational collapse until the radius of the shell decreases to about 0.7 x (the radius of the event horizon). (author)

A definition of maximal CP-violation

International Nuclear Information System (INIS)

Roos, M.

1985-01-01

The unitary matrix of quark flavour mixing is parametrized in a general way, permitting a mathematically natural definition of maximal CP violation. Present data turn out to violate this definition by 2-3 standard deviations. (orig.)

Stress, satisfaction and burnout amongst Australian and New Zealand radiation oncologists.

Science.gov (United States)

Leung, John; Rioseco, Pilar; Munro, Philip

2015-02-01

The aim of this study was to determine the self-reported prevalence of stress, job satisfaction and burnout among radiation oncologists in Australia and New Zealand. A secondary aim was to determine the association between stress and satisfaction parameters with burnout. An anonymous online survey was distributed to all radiation oncologists listed on Royal Australian and New Zealand College of Radiologists membership database. There were 37 Likert scale questions on stress, 17 Likert scale questions on job satisfaction and burnout assessed by the Maslach Burnout Inventory - Human Services Survey (MBI-HSS). A principal component analysis was done for stress and satisfaction to identify specific areas. Independent samples t-tests and analysis of variances were done. There were 220 responses out of 348 eligible respondents (63.2% response rate).For stress, a principal component analysis identified five areas: delivery demands, demands on time, continuing professional development (CPD), value and security, and interpersonal/teaching demands. Specialist radiation oncologists were more stressed by value and security than generalists (P stress associated with delivery demands, demands on time and CPD compared with others (P = 0.01). Those over 60 years were less stressed by delivery demands (P = 0.02), demands on time (P = 0.01) and CPD (P = 0.01) than their younger colleagues. Four satisfaction factors were identified in the principal component analysis: resources/remuneration, status/security, delivery of services and professional activities. [Correction added on 15 August 2014, after first online publication: stress/security was replaced with status/security.] Males and Australian radiation oncologists were more satisfied with professional activities (P = 0.02). Brachytherapy specialists were more satisfied with status/security (P = 0.01) while those interested in urology were more satisfied with resources/renumeration (P = 0.01) and

Stress and radioresistance (genetic aspects)

International Nuclear Information System (INIS)

Lyubaschevsky, N.M.; Grigorkina, E.B.

1995-01-01

Inbred mice and randomly bred stock were exposed to long-term adrenaline and hypothermia stress effects for unification of their functional status, followed by acute total gamma irradiation by equal-effect doses (LD 50/30 ). The significant reduction of lethality distribution in inbred mice after combined stress and radiation effects was observed. The spread of lethality in random bred stock was increased as compared to the control group. The post-irradiation mortality in experimental animals differed only slightly from the values in the control groups. Conclusions are drawn about the principal meaning of genotype in radiosensitivity, about the role of an organism's functional status in determination of death date and about the possible epigenetic structuralisation of linear mice by radioresistance. (Author)

The effect of ergonomic training and intervention on reducing occupational stress among computer users

Directory of Open Access Journals (Sweden)

T. Yektaee

2014-05-01

Result: According to covariance analysis, ergonomic training and interventions lead to reduction of occupational stress of computer users. .Conclusion: Training computer users and informing them of the ergonomic principals and also providing interventions such as correction of posture, reducing duration of work time, using armrest and footrest would have significant implication in reducing occupational stress among computer users.

Deconstructing facts and frames in energy research: Maxims for evaluating contentious problems

International Nuclear Information System (INIS)

Sovacool, Benjamin K.; Brown, Marilyn A.

2015-01-01

In this article, we argue that assumptions and values can play a combative, corrosive role in the generation of objective energy analysis. We then propose six maxims for energy analysts and researchers. Our maxim of information asks readers to keep up to date on trends in energy resources and technology. Our maxim of inclusivity asks readers to involve citizens and other public actors more in energy decisions. Our maxim of symmetry asks readers to keep their analysis of energy technologies centered always on both technology and society. Our maxim of reflexivity asks readers to be self-aware of one's assumptions. Our maxim of prudence asks readers to make energy decisions that are ethical or at least informed. Our maxim of agnosticism asks readers to look beyond a given energy technology to the services it provides and recognize that many systems can provide a desired service. We conclude that decisions in energy are justified by, if not predicated on, beliefs—beliefs which may or may not be supported by objective data, constantly blurring the line between fact, fiction, and frames. - Highlights: • Assumptions and values can play a combative, corrosive role in the generation of objective energy analysis. • Decisions in energy are justified by, if not predicated on, beliefs. • We propose six maxims for energy analysts and researcher.

Honouring Roles: The Story of a Principal and a Student

Directory of Open Access Journals (Sweden)

Jerome Cranston

2012-11-01

Full Text Available The importance of the teacher-student relationship in educational practice is well established, as is the idea of principal leadership in relationship to staff. Even though principal leadership is regarded as a factor in student success, the principal’s effect is usually assumed to take place via the teaching staff. There is an absence of research about the “lived experience” of direct principal-student relationships that shed lights on the ways in which these relationships play a role in student success and principal transformation. This paper presents two narratives written about a particular set of principal-student interactions experienced by the researcher (principal and participant (student.  The analysis uses a narrative inquiry approach to explore both the individual and collective meanings of this principal-student relationship. The stories and their derived meanings have the potential to enliven and  influence educational practice as they explore the subtleties of the principal-student relationship.

Maximal isometric strength of the cervical musculature in 100 healthy volunteers

DEFF Research Database (Denmark)

Jordan, A; Mehlsen, J; Bülow, P M

1999-01-01

A descriptive study involving maximal isometric strength measurements of the cervical musculature.......A descriptive study involving maximal isometric strength measurements of the cervical musculature....

The Principal's Role in Site-Based Management.

Science.gov (United States)

Drury, William R.

1993-01-01

In existing school-based management models, the principal's role ranges from chairing the local council to being a coach/facilitator. With teachers and parents assuming greater control over governance, curriculum, and budgeting, paranoid principals may establish more formal bargaining relationships with district boards. Caution is advised, because…

An expression relating breaking stress and density of trabecular bone

DEFF Research Database (Denmark)

Rajapakse, C.S.; Thomsen, J.S.; Ortiz, J.S.E.

2004-01-01

Bone mineral density (BMD) is the principal diagnostic tool used in clinical settings to diagnose and monitor osteoporosis. Experimental studies on ex vivo bone samples from multiple skeletal locations have been used to propose that their breaking stress bears a power-law relationship to volumetric...

The measurement of in-situ stress in near surface environments

International Nuclear Information System (INIS)

Garritty, P.; Irvin, R.A.

1984-04-01

One of the major unknowns affecting aspects of underground construction and the geohydrology of rock masses is the magnitude and direction of the geostatic principal stresses in the earth's crust. This is particularly the case in near surface rocks where there are indications that high horizontal stresses may exist. The measurement of stress in near surface environments is particularly difficult. The techniques, experience and results of a geostatic stress measurement programme using four commercially available devices at shallow depth in the Carnmenellis Granite are critically discussed and compared. This report also brings together some of the conclusions of two previous reports in the series, Garritty (1983) and Garritty and Irvin (1983), and emphasises the fundamental relationship between the state of stress in the earth's crust and the geohydrology of rock masses. (author)

Leadership Standards in Action: The School Principal as Servant-Leader

Science.gov (United States)

Brumley, Cade

2011-01-01

"Leadership Standards In Action: The School Principal as Servant-Leader" is a powerful resource for aspiring principals, practicing principals, district leadership, and university faculty. The book responsibly unpacks the metaphor of principal as servant leader to the school's people and purpose. As a framework, the six ISLLC Standards of…

Nonadditive entropy maximization is inconsistent with Bayesian updating

Science.gov (United States)

Pressé, Steve

2014-11-01

The maximum entropy method—used to infer probabilistic models from data—is a special case of Bayes's model inference prescription which, in turn, is grounded in basic propositional logic. By contrast to the maximum entropy method, the compatibility of nonadditive entropy maximization with Bayes's model inference prescription has never been established. Here we demonstrate that nonadditive entropy maximization is incompatible with Bayesian updating and discuss the immediate implications of this finding. We focus our attention on special cases as illustrations.

Les Ambivalences du Silence: Les "Maximes" de la Rochefoucauld Par Quatre Chemins

Science.gov (United States)

Turcat, Eric

2012-01-01

Maxims are famous for their moral pronouncements, yet La Rochefoucauld's "Maximes" (1678) have become infamous for offering little moral guidance. Morally ambivalent at best, the "Maximes" are also less known for their other forms of ambivalence, whether rhetorical, psychological, anthropological or linguistic. Such are…

Do Qualification, Experience and Age Matter for Principals Leadership Styles?

OpenAIRE

Muhammad Javed Sawati; Saeed Anwar; Muhammad Iqbal Majoka

2013-01-01

The main focus of present study was to find out the prevalent leadership styles of principals in government schools of Khyber Pakhtunkhwa and to find relationship of leadership styles with qualifications, age and experience of the principals. On the basis of analyzed data, four major leadership styles of the principals were identified as Eclectic, Democratic, Autocratic, and Free-rein. However, a small proportion of the principal had no dominant leadership style. This study shows that princip...

FLOUTS OF THE COOPERATIVE PRINCIPLE MAXIMS IN SBY’S PRESIDENTIAL INTERVIEWS

Directory of Open Access Journals (Sweden)

Fahrus Zaman Fadhly

2012-12-01

Full Text Available This paper analyzed the presidential interviews of the President of Republic of Indonesia, Susilo Bambang Yudoyono (SBY, based on Grice’s theory of the Cooperative Principles (CP. This study employed a qualitative research design and the data were three transcripts of interview discourse between SBY and eight Indonesian journalists obtained through the presidential official website: http://www.presidentsby.info. The research investigated the ways of SBY in flouting the CP maxims in his presidential interviews and the functions of the flouts were. The research revealed that SBY flouted all the CP maxims and the maxim of Quantity was frequently flouted. Meanwhile, there were four ways used by SBY in flouting the CP maxims, i.e. hedging, indirectness, open answer and detailed element. The function of the flouts, i.e. face saving acts (FSA, self-protection, awareness, politeness, interestingness, control of information, elaboration and ignorance. This research also revealed that CP maxims of Grice are not universal.

Avoiding Optimal Mean ℓ2,1-Norm Maximization-Based Robust PCA for Reconstruction.

Science.gov (United States)

Luo, Minnan; Nie, Feiping; Chang, Xiaojun; Yang, Yi; Hauptmann, Alexander G; Zheng, Qinghua

2017-04-01

Robust principal component analysis (PCA) is one of the most important dimension-reduction techniques for handling high-dimensional data with outliers. However, most of the existing robust PCA presupposes that the mean of the data is zero and incorrectly utilizes the average of data as the optimal mean of robust PCA. In fact, this assumption holds only for the squared [Formula: see text]-norm-based traditional PCA. In this letter, we equivalently reformulate the objective of conventional PCA and learn the optimal projection directions by maximizing the sum of projected difference between each pair of instances based on [Formula: see text]-norm. The proposed method is robust to outliers and also invariant to rotation. More important, the reformulated objective not only automatically avoids the calculation of optimal mean and makes the assumption of centered data unnecessary, but also theoretically connects to the minimization of reconstruction error. To solve the proposed nonsmooth problem, we exploit an efficient optimization algorithm to soften the contributions from outliers by reweighting each data point iteratively. We theoretically analyze the convergence and computational complexity of the proposed algorithm. Extensive experimental results on several benchmark data sets illustrate the effectiveness and superiority of the proposed method.

Evaluation of anti-hyperglycemic effect of Actinidia kolomikta (Maxim. etRur.) Maxim. root extract.

Science.gov (United States)

Hu, Xuansheng; Cheng, Delin; Wang, Linbo; Li, Shuhong; Wang, Yuepeng; Li, Kejuan; Yang, Yingnan; Zhang, Zhenya

2015-05-01

This study aimed to evaluate the anti-hyperglycemic effect of ethanol extract from Actinidia kolomikta (Maxim. etRur.) Maxim. root (AKE).An in vitro evaluation was performed by using rat intestinal α-glucosidase (maltase and sucrase), the key enzymes linked with type 2 diabetes. And an in vivo evaluation was also performed by loading maltose, sucrose, glucose to normal rats. As a result, AKE showed concentration-dependent inhibition effects on rat intestinal maltase and rat intestinal sucrase with IC(50) values of 1.83 and 1.03mg/mL, respectively. In normal rats, after loaded with maltose, sucrose and glucose, administration of AKE significantly reduced postprandial hyperglycemia, which is similar to acarbose used as an anti-diabetic drug. High contents of total phenolics (80.49 ± 0.05mg GAE/g extract) and total flavonoids (430.69 ± 0.91mg RE/g extract) were detected in AKE. In conclusion, AKE possessed anti-hyperglycemic effects and the possible mechanisms were associated with its inhibition on α-glucosidase and the improvement on insulin release and/or insulin sensitivity as well. The anti-hyperglycemic activity possessed by AKE maybe attributable to its high contents of phenolic and flavonoid compounds.

Integrating Technology: The Principals' Role and Effect

Science.gov (United States)

Machado, Lucas J.; Chung, Chia-Jung

2015-01-01

There are many factors that influence technology integration in the classroom such as teacher willingness, availability of hardware, and professional development of staff. Taking into account these elements, this paper describes research on technology integration with a focus on principals' attitudes. The role of the principal in classroom…

Constructing principals' professional identities through life stories ...

African Journals Online (AJOL)

The Life History approach was used to collect data from six ... experience as the most significant leadership factors that influence principals' ... ranging from their entry into the teaching profession to their appointment as ..... teachers. I think I learnt from my principal to be strict but accommodating ..... Teachers College Press.

Women principals' reflections of curriculum management challenges ...

African Journals Online (AJOL)

This study reports the reflections of grade 6 rural primary principals in Mpumalanga province. A qualitative method of inquiry was used in this article, where data were collected using individual interviews with three principals and focus group discussions with the school management teams (SMTs) of three primary schools.

What Effective Principals Do to Improve Instruction and Increase Student Achievement

Science.gov (United States)

Turner, Elizabeth Anne

2013-01-01

The purposes of this mixed method study were to (a) Examine the relationships among principal effectiveness, principal instructional leadership, and student achievement; (b) examine the differences among principal effectiveness, principal instructional leadership and student achievement; and (c) investigate what effective principals do to improve…

Bipartite Bell Inequality and Maximal Violation

International Nuclear Information System (INIS)

Li Ming; Fei Shaoming; Li-Jost Xian-Qing

2011-01-01

We present new bell inequalities for arbitrary dimensional bipartite quantum systems. The maximal violation of the inequalities is computed. The Bell inequality is capable of detecting quantum entanglement of both pure and mixed quantum states more effectively. (general)

Maximally efficient protocols for direct secure quantum communication

Energy Technology Data Exchange (ETDEWEB)

Banerjee, Anindita [Department of Physics and Materials Science Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India); Department of Physics and Center for Astroparticle Physics and Space Science, Bose Institute, Block EN, Sector V, Kolkata 700091 (India); Pathak, Anirban, E-mail: anirban.pathak@jiit.ac.in [Department of Physics and Materials Science Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP-201307 (India); RCPTM, Joint Laboratory of Optics of Palacky University and Institute of Physics of Academy of Science of the Czech Republic, Faculty of Science, Palacky University, 17. Listopadu 12, 77146 Olomouc (Czech Republic)

2012-10-01

Two protocols for deterministic secure quantum communication (DSQC) using GHZ-like states have been proposed. It is shown that one of these protocols is maximally efficient and that can be modified to an equivalent protocol of quantum secure direct communication (QSDC). Security and efficiency of the proposed protocols are analyzed and compared. It is shown that dense coding is sufficient but not essential for DSQC and QSDC protocols. Maximally efficient QSDC protocols are shown to be more efficient than their DSQC counterparts. This additional efficiency arises at the cost of message transmission rate. -- Highlights: ► Two protocols for deterministic secure quantum communication (DSQC) are proposed. ► One of the above protocols is maximally efficient. ► It is modified to an equivalent protocol of quantum secure direct communication (QSDC). ► It is shown that dense coding is sufficient but not essential for DSQC and QSDC protocols. ► Efficient QSDC protocols are always more efficient than their DSQC counterparts.

Focus On Impact for a Profit-Driven Medical Practice. Part II: Six Processes You Can Use to Maximize and Capitalize on the Uniqueness of Your Practice.

Science.gov (United States)

Lipton-Dibner, Wendy

2015-01-01

This article presents the second part of the proven Focus on Impact strategic model for practice growth. It spotlights six specific processes you can use to maximize and capitalize on the uniqueness of your practice to increase revenues, enhance patient care and service, improve executive team alignment and intra- and interdepartmental teamwork, and dramatically reduce conflict and stress among practice personnel.

Chamaebatiaria millefolium (Torr.) Maxim.: fernbush

Science.gov (United States)

Nancy L. Shaw; Emerenciana G. Hurd

2008-01-01

Fernbush - Chamaebatiaria millefolium (Torr.) Maxim. - the only species in its genus, is endemic to the Great Basin, Colorado Plateau, and adjacent areas of the western United States. It is an upright, generally multistemmed, sweetly aromatic shrub 0.3 to 2 m tall. Bark of young branches is brown and becomes smooth and gray with age. Leaves are leathery, alternate,...

Generalized Yosida Approximations Based on Relatively A-Maximal m-Relaxed Monotonicity Frameworks

Directory of Open Access Journals (Sweden)

Heng-you Lan

2013-01-01

Full Text Available We introduce and study a new notion of relatively A-maximal m-relaxed monotonicity framework and discuss some properties of a new class of generalized relatively resolvent operator associated with the relatively A-maximal m-relaxed monotone operator and the new generalized Yosida approximations based on relatively A-maximal m-relaxed monotonicity framework. Furthermore, we give some remarks to show that the theory of the new generalized relatively resolvent operator and Yosida approximations associated with relatively A-maximal m-relaxed monotone operators generalizes most of the existing notions on (relatively maximal monotone mappings in Hilbert as well as Banach space and can be applied to study variational inclusion problems and first-order evolution equations as well as evolution inclusions.

Burnout, stress and satisfaction among Australian and New Zealand radiation oncology trainees.

Science.gov (United States)

Leung, John; Rioseco, Pilar

2017-02-01

To evaluate the incidence of burnout among radiation oncology trainees in Australia and New Zealand and the stress and satisfaction factors related to burnout. A survey of trainees was conducted in mid-2015. There were 42 Likert scale questions on stress, 14 Likert scale questions on satisfaction and the Maslach Burnout Inventory-Human Services Survey assessed burnout. A principal component analysis identified specific stress and satisfaction areas. Categorical variables for the stress and satisfaction factors were computed. Associations between respondent's characteristics and stress and satisfaction subscales were examined by independent sample t-tests and analysis of variance. Effect sizes were calculated using Cohens's d when significant mean differences were observed. This was also done for respondent characteristics and the three burnout subscales. Multiple regression analyses were performed. The response rate was 81.5%. The principal component analysis for stress identified five areas: demands on time, professional development/training, delivery demands, interpersonal demands and administration/organizational issues. There were no significant differences by demographic group or area of interest after P-values were adjusted for the multiple tests conducted. The principal component analysis revealed two satisfaction areas: resources/professional activities and value/delivery of services. There were no significant differences by demographic characteristics or area of interest in the level of satisfaction after P-values were adjusted for the multiple tests conducted. The burnout results revealed 49.5% of respondents scored highly in emotional exhaustion and/or depersonalization and 13.1% had burnout in all three measures. Multiple regression analysis revealed the stress subscales 'demands on time' and 'interpersonal demands' were associated with emotional exhaustion. 'Interpersonal demands' was also associated with depersonalization and correlated negatively

[Effects of water stress and temperature on gas exchange and chlorophyll fluorescence of Sinocalycanthus chinensis leaves].

Science.gov (United States)

Ke, Shi-sheng; Jin, Ze-xin

2008-01-01

Sinocalycanthus chinensis is an endangered species in Sinocalycanthus, and only distributed in Zhejiang Province of China. This paper studied the photosynthetic responses of 2-year-old pot-cultured S. chinensis to different levels of water stress and temperature. The results indicated that under mild and moderate water stress, the net photosynthetic rate (Pn) of S. chinensis leaves was decreased to 92.3% and 74.3% of the control, respectively, which was mainly attributed to stomatal limitation; and under severe water stress, the Pn was decreased to 44.4% of the control, which might be mainly linked to non-stomatal limitation. The appropriate temperature for S. chinensis photosynthesis was from 20 degrees C to 28 degrees C. At 39 degrees C, the Pn, water use efficiency (WUE), and maximal photochemistry efficiency (Fv/Fm) were decreased significantly, while the dark respiration rate (Rd) and transpiration rate (Tr) were enhanced significantly. With increasing water stress and temperature, some photosynthetic parameters including light saturation point (LSP), apparent quantum yield (AQY) and maximal CO2 assimilation rate (Pmax) decreased to certain extents, while light compensation point (LCP) increased, suggesting that both severe water stress and higher temperature were the important environmental factors affecting the survival of S. chinensis.

Hubungan Efikasi Diri dengan Coping Stress pada Mahasiswa Angkatan 2012 Fakultas Kedokteran Universitas Riau

OpenAIRE

Rizky, Elsavina; ", Zulharman

2014-01-01

Student in education life will face many obstacles where good self adapted and readiness is needed. Coping stress is a good principal for students to face their problems. Coping stress can be influenced by internal factors and external factors, one of internal factor is self efficacy. This research conducted to discover correlation between self efficacy and coping stress on medical students of Riau University on year 2012. This is an analytic correlation study with cross sectional approachmen...

Spall behaviour of single crystal aluminium at three principal orientations

Science.gov (United States)

Owen, G. D.; Chapman, D. J.; Whiteman, G.; Stirk, S. M.; Millett, J. C. F.; Johnson, S.

2017-10-01

A series of plate impact experiments have been conducted to study the spall strength of the three principal crystallographic orientations of single crystal aluminium ([100], [110] and, [111]) and ultra-pure polycrystalline aluminium. The samples have been shock loaded at two impact stresses (4 GPa and 10 GPa). Significant differences have been observed in the elastic behaviour, the pullback velocities, and the general shape of the wave profiles, which can be accounted for by considerations of the microscale homogeneity, the dislocation density, and the absence of grain boundaries in the single crystal materials. The data have shown that there is a consistent order of spall strength measured for the four sample materials. The [111] orientation has the largest spall strength and elastic limit, followed closely by [110], [100], and then the polycrystalline material. This order is consistent with both quasi-static data and geometrical consideration of Schmid factors.

Tectonic stress orientations and magnitudes, and friction of faults, deduced from earthquake focal mechanism inversions over the Korean Peninsula

Science.gov (United States)

Soh, Inho; Chang, Chandong; Lee, Junhyung; Hong, Tae-Kyung; Park, Eui-Seob

2018-05-01

We characterize the present-day stress state in and around the Korean Peninsula using formal inversions of earthquake focal mechanisms. Two different methods are used to select preferred fault planes in the double-couple focal mechanism solutions: one that minimizes average misfit angle and the other choosing faults with higher instability. We invert selected sets of fault planes for estimating the principal stresses at regularly spaced grid points, using a circular-area data-binning method, where the bin radius is optimized to yield the best possible stress inversion results based on the World Stress Map quality ranking scheme. The inversions using the two methods yield well constrained and fairly comparable results, which indicate that the prevailing stress regime is strike-slip, and the maximum horizontal principal stress (SHmax) is oriented ENE-WSW throughout the study region. Although the orientation of the stresses is consistent across the peninsula, the relative stress magnitude parameter (R-value) varies significantly, from 0.22 in the northwest to 0.89 in the southeast. Based on our knowledge of the R-values and stress regime, and using a value for vertical stress (Sv) estimated from the overburden weight of rock, together with a value for the maximum differential stress (based on the Coulomb friction of faults optimally oriented for slip), we estimate the magnitudes of the two horizontal principal stresses. The horizontal stress magnitudes increase from west to east such that SHmax/Sv ratio rises from 1.5 to 2.4, and the Shmin/Sv ratio from 0.6 to 0.8. The variation in the magnitudes of the tectonic stresses appears to be related to differences in the rigidity of crustal rocks. Using the complete stress tensors, including both orientations and magnitudes, we assess the possible ranges of frictional coefficients for different types of faults. We show that normal and reverse faults have lower frictional coefficients than strike-slip faults, suggesting that

Contemporary Challenges and Changes: Principals' Leadership Practices in Malaysia

Science.gov (United States)

Jones, Michelle; Adams, Donnie; Joo, Mabel Tan Hwee; Muniandy, Vasu; Perera, Corinne Jaqueline; Harris, Alma

2015-01-01

This article outlines the findings from a contemporary study of principals' leadership practices in Malaysia as part of the 7 System Leadership Study. Recent policy developments within Malaysia have increased principals' accountability and have underlined the importance of the role of the principals in transforming school performance and student…

Mutually Unbiased Maximally Entangled Bases for the Bipartite System Cd⊗ C^{dk}

Science.gov (United States)

Nan, Hua; Tao, Yuan-Hong; Wang, Tian-Jiao; Zhang, Jun

2016-10-01

The construction of maximally entangled bases for the bipartite system Cd⊗ Cd is discussed firstly, and some mutually unbiased bases with maximally entangled bases are given, where 2≤ d≤5. Moreover, we study a systematic way of constructing mutually unbiased maximally entangled bases for the bipartite system Cd⊗ C^{dk}.

Maximal near-field radiative heat transfer between two plates

Science.gov (United States)

Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

2013-09-01

Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

3D face recognition with asymptotic cones based principal curvatures

KAUST Repository

Tang, Yinhang

2015-05-01

The classical curvatures of smooth surfaces (Gaussian, mean and principal curvatures) have been widely used in 3D face recognition (FR). However, facial surfaces resulting from 3D sensors are discrete meshes. In this paper, we present a general framework and define three principal curvatures on discrete surfaces for the purpose of 3D FR. These principal curvatures are derived from the construction of asymptotic cones associated to any Borel subset of the discrete surface. They describe the local geometry of the underlying mesh. First two of them correspond to the classical principal curvatures in the smooth case. We isolate the third principal curvature that carries out meaningful geometric shape information. The three principal curvatures in different Borel subsets scales give multi-scale local facial surface descriptors. We combine the proposed principal curvatures with the LNP-based facial descriptor and SRC for recognition. The identification and verification experiments demonstrate the practicability and accuracy of the third principal curvature and the fusion of multi-scale Borel subset descriptors on 3D face from FRGC v2.0.

3D face recognition with asymptotic cones based principal curvatures

KAUST Repository

Tang, Yinhang; Sun, Xiang; Huang, Di; Morvan, Jean-Marie; Wang, Yunhong; Chen, Liming

2015-01-01

The classical curvatures of smooth surfaces (Gaussian, mean and principal curvatures) have been widely used in 3D face recognition (FR). However, facial surfaces resulting from 3D sensors are discrete meshes. In this paper, we present a general framework and define three principal curvatures on discrete surfaces for the purpose of 3D FR. These principal curvatures are derived from the construction of asymptotic cones associated to any Borel subset of the discrete surface. They describe the local geometry of the underlying mesh. First two of them correspond to the classical principal curvatures in the smooth case. We isolate the third principal curvature that carries out meaningful geometric shape information. The three principal curvatures in different Borel subsets scales give multi-scale local facial surface descriptors. We combine the proposed principal curvatures with the LNP-based facial descriptor and SRC for recognition. The identification and verification experiments demonstrate the practicability and accuracy of the third principal curvature and the fusion of multi-scale Borel subset descriptors on 3D face from FRGC v2.0.

Stress Analysis of an Edge-Cracked Plate by using Photoelastic Fringe Phase Shifting Method

International Nuclear Information System (INIS)

Baek, Tae Hyun; Kim, Myung Soo; Cho, Sung Ho

2000-01-01

The method of photoelasticity allows one to obtain principal stress differences and principal stress directions in a photoelastic model. In the classical approach, the photoelastic parameters are measured manually point by point. The previous methods require much time and skill in the identification and measurement of photoelastic data. Fringe phase shifting method has been recently developed and widely used to measure and analyze fringe data in photo-mechanics. This paper presents the test results of photoelastic fringe phase shifting technique for the stress analysis of a circular disk under compression and an edge-cracked plate subjected to tensile load. The technique used here requires four phase stepped photoelastic images obtained from a circular polariscope by rotating the analyzer at 0 .deg. ,45 .deg. ,90 .deg. ,and 135 .deg. . Experimental results are compared with those or FEM. Good agreement between the results can be observed. However, some error may be included if the technique is used to general direction which is not parallel to isoclinic fringe

Principal bundles the classical case

CERN Document Server

Sontz, Stephen Bruce

2015-01-01

This introductory graduate level text provides a relatively quick path to a special topic in classical differential geometry: principal bundles.  While the topic of principal bundles in differential geometry has become classic, even standard, material in the modern graduate mathematics curriculum, the unique approach taken in this text presents the material in a way that is intuitive for both students of mathematics and of physics. The goal of this book is to present important, modern geometric ideas in a form readily accessible to students and researchers in both the physics and mathematics communities, providing each with an understanding and appreciation of the language and ideas of the other.

Taking a Distributed Perspective to the School Principal's Workday

Science.gov (United States)

Spillane, James P.; Camburn, Eric M.; Pareja, Amber Stitziel

2007-01-01

Focusing on the school principal's day-to-day work, we examine who leads curriculum and instruction- and administration-related activities when the school principal is not leading but participating in the activity. We also explore the prevalence of coperformance of management and leadership activities in the school principal's workday. Looking…

Principal Preparation in Special Education: Building an Inclusive Culture

Science.gov (United States)

Hofreiter, Deborah

2017-01-01

The importance of principal preparation in special education has increased since the Education for All Handicapped Children Act was passed in 1975. There are significant financial reasons for preparing principals in the area of special education. Recent research also shows that all children learn better in an inclusive environment. Principals who…

Urban School Principals and Their Role as Multicultural Leaders

Science.gov (United States)

Gardiner, Mary E.; Enomoto, Ernestine K.

2006-01-01

This study focuses on the role of urban school principals as multicultural leaders. Using cross-case analysis, the authors describe what 6 practicing principals do in regard to multicultural leadership. The findings suggest that although multicultural preparation was lacking for these principals, some did engage in work that promoted diversity in…

Maximally entangled mixed states of two atoms trapped inside an optical cavity

International Nuclear Information System (INIS)

Li Shangbin; Xu Jingbo

2009-01-01

In some off-resonant cases, the reduced density matrix of two atoms symmetrically coupled with an optical cavity can very approximately approach maximally entangled mixed states or maximal Bell violation mixed states in their evolution. The influence of a phase decoherence on the generation of a maximally entangled mixed state is also discussed

Principals: Human Capital Managers at Every School

Science.gov (United States)

Kimball, Steven M.

2011-01-01

Being a principal is more than just being an instructional leader. Principals also must manage their schools' teaching talent in a strategic way so that it is linked to school instructional improvement strategies, to the competencies needed to enact the strategies, and to success in boosting student learning. Teacher acquisition and performance…

IIB solutions with N>28 Killing spinors are maximally supersymmetric

International Nuclear Information System (INIS)

Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

2007-01-01

We show that all IIB supergravity backgrounds which admit more than 28 Killing spinors are maximally supersymmetric. In particular, we find that for all N>28 backgrounds the supercovariant curvature vanishes, and that the quotients of maximally supersymmetric backgrounds either preserve all 32 or N<29 supersymmetries

The Effects of Reform in Principal Selection on Leadership Behavior of General and Vocational High School Principals in Taiwan

Science.gov (United States)

Hsiao, Hsi-Chi; Lee, Ming-Chao; Tu, Ya-Ling

2013-01-01

Deregulation has formed the primary core of education reform in Taiwan in the past decade. The principal selection system was one of the specific recommendations in the deregulation of education. The method of designation of senior high school principals has changed from being "appointed" to being "selected." The issue as to…

Principal Holistic Judgments and High-Stakes Evaluations of Teachers

Science.gov (United States)

Briggs, Derek C.; Dadey, Nathan

2017-01-01

Results from a sample of 1,013 Georgia principals who rated 12,617 teachers are used to compare holistic and analytic principal judgments with indicators of student growth central to the state's teacher evaluation system. Holistic principal judgments were compared to mean student growth percentiles (MGPs) and analytic judgments from a formal…

Job Satisfaction of Elementary Principals in Large Urban Communities

Science.gov (United States)

Mitchell, Cathryn M.

2010-01-01

The purpose of this study was to determine job satisfaction levels of elementary principals in "major urban" districts in Texas and to identify strategies these principals used to cope with the demands of the position. Additionally, the project sought to find structures and supports needed to attract and retain principals in the…

Leadership Behaviors and Its Relation with Principals' Management Experience

Science.gov (United States)

Mehdinezhad, Vali; Sardarzahi, Zaid

2016-01-01

This paper aims at studying the leadership behaviors reported by principals and observed by teachers and its relationship with management experience of principals. A quantitative method was used in this study. The target population included all principals and teachers of guidance schools and high schools in the Dashtiari District, Iran. A sample…

Violations of Grice`s Maxims in The Prince and the Pauper Movie

Directory of Open Access Journals (Sweden)

Antonius Waget

2016-12-01

Full Text Available Proper responses must be provided interlocutors to make onversation productive and meaningful. However, interlocutors do not always provide proper responses because they do not even know conversation rules. Grice coins 4 maxims as general rules to govern daily conversation. The maxims are Quantity, Quality, Relevance, and Manner. Conversation occurs in the real daily interaction also in arts including movies. The Prince and the Pauper movie is one of the media for human daily conversation. Some parts of the movie contains violations of Grice`s maxims by the characters. Based on this background, the writer intends to explore violations ofGrice’s maxims in the movie and analyze the purposes of the violations. To achieve these objectives, the writer formulates two research problems: (1 Which of Grice`s maxims are violated by the addressees in The Prince and the Pauper movie? (2 For what purposes do the addressees violate the maxims? The base of this research is a movie script as document. Thus, the writer uses document analysis as the method of this research. Grounded on the analysis, the writer finds that the characters, especially Prince, Tom Canty, King, and the Earl of Hertford in the movie dialogues violate the four of Grice`s maxims. When failing to provide sufficient information, telling lie to their addressers, providing irrelevant glosses, and failing to be true, brief, univocal, and orderly, they respectively violate maxims of Quantity, Quality, Relevance, and Manner. Moreover, the writer finds that the characters violate the maxims in order to mislead the counterparts, be polite, save face, avoid discussion, and communicate self-interest.   DOI: https://doi.org/10.24071/llt.2015.180101

Environmental heat stress, hyperammonemia and nucleotide metabolism during intermittent exercise

DEFF Research Database (Denmark)

Mohr, Magni; Rasmussen, Peter; Drust, Barry

2006-01-01

) followed by five 15 s all-out sprints. Control trials were conducted in a 20°C environment while heat stress trials were performed at an ambient temperature of 40°C. Muscle biopsies and venous blood samples were obtained at rest, after 40 min of exercise and following the maximal sprints. Following......Abstract  This study investigated the influence of environmental heat stress on ammonia (NH3) accumulation in relation to nucleotide metabolism and fatigue during intermittent exercise. Eight males performed 40 min of intermittent exercise (15 s at 306±22 W alternating with 15 s of unloaded cycling...... exercise with heat stress, the core and muscle temperatures peaked at 39.5±0.2 and 40.2±0.2°C to be ~ 1°C higher (Pheat stress trial (P

Improvement of residual stress in stainless steel by cavitating jet; Cavitation funryu ni yoru stainless ko no zanryu oryoku kaizen

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