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How accurate are insights compared to analytical solutions? In four experiments, we investigated how participants’ solving strategies influenced their solution accuracies across different types of problems, including one that was linguistic, one that was visual and two that were mixed visual-linguistic. In each experiment, participants’ self-judged insight solutions were, on average, more accurate than their analytic ones. We hypothesised that insight solutions have superior accuracy because they emerge into consciousness in an all-or-nothing fashion when the unconscious solving process is complete, whereas analytic solutions can be guesses based on conscious, prematurely terminated, processing. This hypothesis is supported by the finding that participants’ analytic solutions included relatively more incorrect responses (i.e., errors of commission) than timeouts (i.e., errors of omission) compared to their insight responses.

This work is a study of DES-like ciphers where the bitwise exclusive-or (XOR) operation in the underlying Feistel network is replaced by an arbitrary group operation. The authors construct a two-round simplified version of DES that contains all the DES components and show that its set of encryption permutations is not a group under functional composition, it is not a pure cipher, and its set of encryption permutations does not generate the alternating group. They present a non-statistical proof that for n ≤ 4 the set of n-round Feistel permutations over an arbitrary group do not constitute a group under functional composition.

From a sample of 419 college students, 750 written recollections were obtained regarding their parental and nonparental childcare experiences. Vignettes were sorted and coded according to five emerging themes: emotional valence, play, TV, educational activities and holidays/birthdays. Several significant differences were found in remembered experience between parental and nonparental care. Emotionally positive recollections were significantly more prevalent in parental care. Emotionally negative recollections were significantly more prevalent in nonparental care. In addition, within context, emotional parental care memories were more often positive while emotional nonparental care memories were more often negative. Regarding the other four themes, memories of educational activities, play, and holiday/birthday celebrations were more often related to parental care. There were no between‐context differences in rates of recall for TV – related memories. Across contexts, play memories were most prevalent.

Conditions for strong refractive index enhancement (n ∼ 5 to 10) in the presence of complete absorption compensation are presented and discussed in terms of a generic model system composed of three-level atom inclusions in a dielectric host material.

Daycare parents ( N =37; mean age=30) were interviewed by phone about important aspects of their child's daycare center. Information about the daycare centers' structural and procedural characteristics was obtained through interviews with center directors. Comparisons between parental answers and the data provided by the directors revealed significant gaps in parental knowledge of daycare. On average, parents answered only 45% of questions correctly, and reported a lack of knowledge regarding both general center characteristics ( i.e. ,'turnover rates, caregiver training, and hiring practices) and specific group characteristics ( i.e. , group size, adult-child ratio, and child's daily schedule). Parental knowledge increased with length of involvement with the center, but other variables such as parent education and the number of hours the child spent in care per week did not contribute to prediction of parental knowledge.

Numerical and semi-analytical results of the propagation of high-power ultra-short near IR laser pulses propagating in ionizing air are presented.

We study numerically the effects of local-field corrections originating from near dipole—dipole interactions on the dynamics of a single mode, inhomogeneously broadened laser. Our analysis is based on a set of generalized Maxwell–Bloch equations in which the inhomogeneous nature of gain broadening is accounted for by introducing two new dynamical variables and a single parameter that governs the extent of inhomogeneous broadening. Our results show that local-field effects occurring in a dense gain medium reduce the range of continuous wave operation and lead to instabilities and chaos at much lower pumping levels.

It is shown that causality is not violated in the classical electrodynamic description of radiation reaction provided a physically appropriate form of the classical field is used. As a consequence the classical and quantum electrodynamic theories of a bound electron have a similar mathematical structure.

SYNOPSIS The application of solar power in the developed and developing world are reviewed and some practical and theoretical considerations, regarding collectors and cover plates, summarised. The object is to show that there are widespread uses and installation is simple. To overcome shortcomings in current absorber materials, attempts have been made to find alternative coatings. Tin coating systems which have been examined include tin oxide/black molybdenum, tin oxide on black enamel, tinplate/black chrome, tin-iron alloy layer/wax or lacquer, tin-nickel and tin-cobalt. The last two look particularly promising and a pilot unit using an electroplated selective black tin-nickel coating is described.

Research has shown that organization plays an important role in memory. This study applies these findings to the design of a command language. The concept of orthogonality was used to maximize the internal organization of a text-editing command language. In Experiments 1 and 2, this orthogonal language was compared to an organized, but nonorthogonal, and an antiorganized language on measures of predictability, recall, and performance. Subjects in the orthogonal language condition performed better than subjects in the other conditions on all measures. In a third experiment, steps were taken to eliminate possible confounding effects of mnemonics. The orthogonal language was compared to the organized language on measures of recall and performance. Even without the aid of mnemonics, subjects in the orthogonal language condition performed better on the recall test than subjects in the organized language condition. In addition, analysis of keystroke data revealed that subjects using the orthogonal language required less time to think of appropriate commands to accomplish their tasks. General steps necessary to design an orthogonal language are discussed.

Rapidly solidified ribbons of a variety of niobium-based alloys have been produced by electron beam melting and splat quenching (EBSQ) onto a rotating copper disc. Microstructural analysis of the beneficial effects of rapid solidification can be performed on the as-solidified and heat treated ribbons. Ribbons can be reduced to particulates and consolidated into a fully dense billet using conventional powder metallurgical techniques such as hot isostatic pressing (HIP).

The properties and processing methods of the niobium alumlnide intermetallics Al3Nb and Nb3Al are discussed. The AI3Nb phase has attractive properties as a high-temperature structural material, but its use is limited by poor ductility. The phase Nb3Al is superconducting and requires strict stoichiometric control during processing to optimize the critical temperature.

Primate research has a long history in the Soviet Union. As early as 1913, at The Darwin Museum in Moscow, Ladygina-Kots was studying the comparative behavioral development of young chimpanzees and of children. In 1927, one of the world's oldest and largest primate research centers was established at Sukhumi. Now known as the Institute of Experimental Pathology and Therapy, it makes available several thousand animals (including a dozen chimpanzees and two young gorillas) for study by several hundred scientific investigators. A second primate facility, which has been in use for more than three decades and from which a considerable number of interesting studies have come, is the Anthropoid House at Koltushi, a laboratory administered by the Pavlov Physiology Institute in Leningrad. Finally, just in the last two years, a new primate laboratory has been added to the Institute of Physiology in Tbilisi.