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The backpropagation method is modified by replacing sigmoid function by sinusoidal function. The leaving law is also modified. The modified procedure shows great improvement over the original BP in terms of the number of neurons and the learning time. © 1992 IEEE.

In Experiment 1, the choice responses of 8 pigeons were observed during 50 periods of transition. Each condition began with equal probabilities of reinforcement on 2 response keys and switched to unequal probabilities. With the ratio of the 2 probabilities held constant, preference for the higher probability developed more rapidly when the 2 probabilities were high than when they were low. In Experiment 2, each condition began with 2 equal variable-interval schedules, but later 1 key delivered 60%, 75%, or 90% of the reinforcers. The rate of approach to asymptotic performance was roughly the same with all 3 reinforcement percentages. These and previous results pose difficulties for some well-known models of acquisition, but the results are well described by a simple model that states that the strength of each response is independently increased by reinforcement and decreased by nonreinforcement.

New systolic architectures are proposed for the computation of the Fourier transform based on the generation of the coefficients of the transform during the computation. These architectures require less input/output pins on the chip. The new architectures are also extremely modular and cascadeable, thus, amenable for efficient VLSI implementation. VLSI complexity of the architectures are compared with the existing parallel architectures. © 1992 IEEE.

This study investigated the outcomes of a demonstration project that provided free medical coverage to former Aid to Families with Dependent Children (AFDC) recipients who were holding jobs with limited or no health benefits. Data were collected on the Medicaid expenditures of 54 eligible participants and their dependents for up to two years before they exited welfare; the expenditures averaged 56 percent less for adults and 45 percent less for children than the respective AFDC averages for the county. Because only 22 percent of the eligible participants took advantage of the program, telephone interviews also were conducted with 24 people who did not participate in or dropped out of the health plan. The main reasons cited for not enrolling were a misunderstanding of the program, a claim that no notification of the program was received, and a lack of interest. These results and their policy implications are presented in the context of the Family Support Act's mandate that states extend medical assistance coverage to AFDC recipients whose cases are closed because of employment. © 1991 by the National Association of Social Workers, Inc.

There is no abstract available for the item entitled The impact of local tape databases on the library: The M(I)das touch.

To study the effect of teaching decision-making to inmates in a maximum security facility on locus of control 19 adult male inmates who were incarcerated at a community correctional center were pre- and posttested on the Rotter Internal-External Locus of Control Scale. In this preliminary study there was no statistically significant difference at pretest or posttest so teaching decision-making skills in group settings versus teaching in a group combined and one-to-one contact did not affect locus of control as measured. This personality trait appears stable over time and a more thorough means of intervention is required to effect change.

A total of 28 Swainson's Hawk (Buteo swainsoni) and 30 Red-tailed Hawk (B. jamaicensis) nests were found in Cache Valley. Utah, during the summers of 1992 and 1993. All nests were in trees, but only Red-tailed Hawks nested in dead trees (30%). In the intensive study area, nesting densities were 0.10 nests/km2 for Swainson's Hawk and 0.08 nests/km2 for Red-tailed Hawk. Nearest-neighbor nest distances were significantly shorter among Swainson's Hawks (1.74 km) than among Red-tailed Hawks (2.83 km). Congeneric nearest- neighbor distances were significantly shorter than conspecific distances for Red-tailed Hawks (1.59 vs. 2.83 km) but not for Swainson's Hawks (1.52 vs. 1.74 km). GIS analysis of habitat types was made for 2-km radii around nest sites. Cropland was the dominant land cover type of nest sites of both species and no significant difference was found between species. Swainson's Hawk nest sites contained significantly more pasture, whereas Red-tailed nest sites contained significantly more juniper, maple, and sagebrush. Only Red- tailed Hawk nests (n=8; 27%) were found on the periphery of the valley at the base of foothills of the Cache Mountains. This preference resulted in a significantly higher elevation for Red-tailed Hawk nest sites. Swainson's Hawk nests occurred only on the valley floor on level terrain. Distance to the nearest paved road and building was very similar for both species, implying that little difference exists in tolerance levels for human activities. Overall, multivariate niche overlap for habitat was high (0.89), indicating a lack of habitat partitioning between these 2 Buteos in Cache Valley.

The social interactions of a wintering population of Northern Harriers (Circus cyaneus) were studied in the Hackensack Meadowlands tidal marshes in New Jersey. Juvenile harriers were numerically dominant in the population and participated in hunting groups significantly more often than adult males or females. Group sizes varied from 2-4 birds (total groups observed = 66 duets, five trios and two quartets). The occasional inclusion of adults in a foraging group was usually the result of juveniles following the adult, presumably for the parasitic benefits of grabbing flushed prey or exploiting high yield foraging patches. Our observations suggested a non-territorial wintering harrier population documented by observations of 3-6 different individuals frequently hunting the same 12-ha area each day as well as random use of our study quadrats (3-ha) by individuals of all sexes and ages. Territorial defense was observed in only one adult female, which infrequently attempted to defend a territory. Overall, the prevalence of group-foraging behavior is consistent with the general lack of winter territory in this population.

This study breaks from traditional adult-centered models of interpersonal conflict by privileging children’s experiences. As part of an assessment for establishing a school-based peer mediation program, focus group interviews were conducted with second graders through high school students. Analysis focuses on the sites (causes), signs, and aftermath (or responses) of conflict. Children’s impressions regarding fairness and gender differences are also addressed. With respect to the sites and signs of conflict, the main themes that were found include conflict as a product of the spoken word and conflict as a dirty look. Additionally, a symbolic representation of these intrusions emerged in the metaphor of conflict as an explosion. Analysis of the children's discussions concerning the aftermath of conflicts revealed four general themes: confronting, seeking involvement of third parties, ignoring others, and treating others with kindness. Differences in the children’s perceptions of gender-based differences are explored as are their perceptions of the construct of “fairness” and its associated dictates in favor of equality of treatment, struggles with inferiority/superiority, and expression of conflict as a betrayal. © 1996, Taylor & Francis Group, LLC. All rights reserved.

Five types of depersonalization experiences based on scales developed by Jacobs and Bovasso (1992) were used to cluster subjects into six groups. Four relatively small groups which had regular depersonalization experiences were identified: the Derealized, the Self-negating, the Body-detached, and the Profoundly Depersonalized. The fifth group, the Fleetingly Depersonalized, and the sixth group, the Non-depersonalized, constituted 25% and 50% of the population, respectively. A profile analysis indicated qualitative differences between the six groups in their pathological traits, which fell along a continuum of pathological severity. The results support the validity of a multidimensional depersonalization construct which may clarify some of the contradictions and inconsistencies in the literature on depersonalization. Further, the results may facilitate clinicians' differentiation of their patients along a continuum of pathological severity based on the type and frequency of depersonalization experiences which they report.