7,373 research outputs found
The Company You Keep: The Effects of Family and Neighborhood on Disadvantaged Youths
We examine the effects of family background variables and neighborhood peers on the behaviors of inner-city youths in a tight labor market using data from the 1989 NBER survey of youths living in low-income Boston neighborhoods. We find that family adult behaviors are strongly related to analogous youth behaviors. The links between the behavior of older family members and youths are important for criminal activity, drug and alcohol use, childbearing out of wedlock, schooling, and church attendance. We also find that the behaviors of neighborhood peers appear to substantially affect youth behaviors in a manner suggestive of contagion models of neighborhood effects. Residence in a neighborhood in which a large proportion of other youths are involved in crime is associated with a substantial increase in an individual's probability of the being involved in crime. Significant neighborhood peer effects are also apparent for drug and alcohol use, church attendance, and the propensity of youths to be out of school and out of work. Our results indicate that family and peer influences both operate in manner such that "like begets like."
Finite temperature superfluid density in very underdoped cuprates
The combination of a large superconducting gap, low transition temperature,
and quasi two-dimensionality in strongly underdoped high temperature
superconductors severely constrains the behavior of the ab-plane superfluid
density \rho with temperature T. In particular, we argue that the contribution
of nodal quasiparticles to \rho(T) is essential to account both for the
amplitude of, and the recently observed deviations from, the Uemura scaling. A
relation between T_c and \rho(0) which combines the effects of quasiparticle
excitations at low temperatures and of vortex fluctuations near the critical
temperature is proposed and discussed in light of recent experiments.Comment: 5 RevTex pages, 4 figures (one new); more discussion and comparison
with experiment; version to appear in Phys. Rev.
Results of Millikan Library Forced Vibration Testing
This report documents an investigation into the dynamic properties of Millikan Library under forced excitation. On July 10, 2002, we performed frequency sweeps from 1 Hz to 9.7 Hz in both the East-West (E-W) and North-South (N-S) directions using a roof level vibration generator. Natural frequencies were identified at 1.14 Hz (E-W fundamental mode), 1.67 Hz (N-S fundamental mode), 2.38 Hz (Torsional fundamental mode), 4.93 Hz (1st E-Wovertone), 6.57 Hz (1st Torsional overtone), 7.22 Hz (1st N-S overtone), and at 7.83 Hz (2nd E-Wovertone). The damping was estimated at 2.28% for the fundamental E-W mode and 2.39% for the N-S fundamental mode. On August 28, 2002, a modal analysis of each natural frequency was performed using the dense instrumentation network located in the building. For both the E-W and N-S fundamental modes, we observe a nearly linear increase in displacement with height, except at the ground floor which appears to act as a hinge. We observed little basement movement for the E-W mode, while in the N-S mode 30% of the roof displacement was due to basement rocking and translation. Both the E-W and N-S fundamental modes are best modeled by the first mode of a theoretical bending beam. The higher modes are more complex and not well represented by a simple structural system
Are bonuses compatible with the Deming philosophy?
This paper examines the philosophy of Dr. W. Edwards Deming to determine what principles of that philosophy should apply to selecting a bonus compensation plan. All types of bonus plans, including the following incentive bonus plans individual incentive, group incentive, gain sharing, profit sharing and pay-for-knowledge are examined to determine which meet the Deming principles
Complex and Connected Lives: Voices of “English Language Learners” in Middle School
In addition to the typical ups and downs of middle school (MS), English language learners (ELLs) in the middle grades also grapple with learning English, straddling multiple cultures, and adapting to the realities of immigration. While school systems tend to focus on linguistic and academic development, MS ELLs exercise agency, creativity, judgment, and resilience as they navigate hybrid identities, complex and context-specific social and cultural expectations, and home/school connections and disconnections. This article reports on an interview study of middle school ELLs from a variety of backgrounds. Using self-selected artifacts representing their in-school and out-of-school lives, participants discussed their in- and out-of-school lives, social networks, impressions of school, and goals for the future. Themes of navigating complexity and forging connection point to a portrait of middle school ELLs with initiative, purpose, and dimensionality that challenges the narrow focus on language often prominent in the professional discourse about ELLs
An Experimental Examination of Equivalence Failures in Multi-Cultural Comparative Research
As the global economy integrates, there is an increased need to understand international business phenomena. This forces a reliance upon multi-cultural marketing research, which is evidenced by a marked increase in international studies, particularly multi-cultural comparative research (Sin, Cheung & Lee 1999). Central to the usefulness of this research is the question of the validity and comparability of results, which is greatly affected by a property known as equivalence of test instruments; or the degree to which the scales and the items in them are seen to be the same across cultures.
To date, no research exists that approaches the problem of equivalence from a position of knowledge, or beginning with a known equivalence error and then tracing its psychometric effects. The dissertation fills that need by experimentally manipulating a translation error in a scale and then using conjoint analysis to decompose respondents\u27 choice patterns for items or attributes that cause equivalence failures.
Results from a probability sample of American consumers indicate that: (1) current techniques to diagnose equivalence failure can adequately identify items that are inequivalent, but also (2) that items failing equivalence have a pronounced tendency to attenuate other items in the scale. Conjoint results were similarly affected by translation error. The presents serious implications for international researchers and global marketing managers, including some question as to the usefulness of existing scales in multi-cultural contexts. In addition, theoretical development regarding response behaviors in needed to explain the differences between control and experiment groups with respect to non-manipulated items. Further research is also needed to systematically examine the effect of translation error across response formats and scale types
Production study of gadolinium-153
Production of gadolinium-153 for use in atmospheric density gages based on gamma backscatter measurement
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