5,201 research outputs found

    Age-related differences in pointing accuracy in familiar and unfamiliar environments

    Get PDF
    This study aimed to investigate age-related differences in spatial mental representations of familiar and unfamiliar places. Nineteen young adults (aged 18\u201323) and 19 older adults (aged 60\u201374), all living in the same Italian town, completed a set of visuospatial measures and then pointed in the direction of familiar landmarks in their town and in the direction of landmarks in an unknown environment studied on a map. Results showed that older adults were less accurate in the visuospatial tasks and in pointing at landmarks in an unfamiliar environment, but performed as well as the young adults when pointing to familiar places. Pointing performance correlated with visuospatial tests accuracy in both familiar and unfamiliar environments, while only pointing in an unknown environment correlated with visuospatial working memory (VSWM). The spatial representation of well-known places seems to be well preserved in older adults (just as well as in young adults), while it declines for unfamiliar environments. Spatial abilities sustain the mental representations of both familiar and unfamiliar environments, while the support of VSWM resources is only needed for the latter

    Eigenstates of excitons near a surface

    Get PDF
    Journal ArticleThe exact eigenstates and energies of an electron and a hole of equal effective masses, with an attractive δ-function interaction and hard-wall repulsion at the surfaces of a solid, are classified and obtained explicitly for a solid of arbitrary thickness. Both bound and scattering states of the exciton are significantly quantized for thin films

    Pembuatan Karbon Aktif dari Kulit Durian sebagai Adsorbent Logam Fe

    Full text link
    Durian peel is known as the waste that can pollute the environment. One effort to improve the economic value of the durian skin can be done with the process into activated carbon. This study aims to obtain optimum conditions for the use of activators of Kaliaum Hidroksida on the quality of activated carbon and activated carbon absorption of Fe metal. Activated carbon is made via two processes, namely the process of carbonization and activation at 320oC temperature with a solution of Kalium Hidroksida by varying the massa aktif carbon1, 1.5, 2, 2.5, dan 3 gr and adsorb time30, 60, 90, dan 120 menit. To determine the quality of activated carbon, activated carbon characteristics tested, such as moisture content, ash content, and the absorption of iodine. The results showed that the characteristics of activated charcoal SNI 06-3730-1995 meets the standards the water content of 14.12%, 5.46% ash content and absorption of I2 solution of 580.27 mg / g in adsorbing metals Fe. Application of Fe metal adsorption by activated carbon from durian skin with 3 grams of carbon mass variation and contact time of 90 minutes where the adsorption efficiency is 96.75%

    Perancangan Sistem Pengolahan Data Jemaat Berbasis Web pada Gereja Gkpi Kota Jambi

    Full text link
    The data processing systems is a very necessary way to manipulate a data into useful information. The system makes data storage, adding, changing, scheduling to reporting well integrated, so that it can help parts to exchange information and make decisions quickly. The problems faced by GKPI Pal Merah Jambi are currently still using Microsoft Office Word and in disseminating information such as worship schedules, church activities and other worship routines through paper and wall-based worship services. To print worship and report reports requires substantial operational funds, in addition to data collection and storage there are still deficiencies including recording data on the book, difficulty in processing large amounts of data and stored in only one special place that is passive. Based on the above problems, the author is interested in conducting research with the title Designing Data Processing Systems for Web-Based Churches in the GKPI Pal Merah Church in Jambi. The purpose of this study is to design and produce a data processing system for the church. Using this system can facilitate data processing in the GKPI Pal Merah Jambi Church. This study uses a waterfall development method, a method that provides a systematic and sequential approach to system needs analysis, design, implementation and unit testing, system testing and care. Applications built using the web with MySQL DBMS database, PHP programming language and Laravel

    Scalable photonic platform for real-time quantum reservoir computing

    Full text link
    Quantum Reservoir Computing (QRC) exploits the information processing capabilities of quantum systems to solve non-trivial temporal tasks, improving over their classical counterparts. Recent progress has shown the potential of QRC exploiting the enlarged Hilbert space, but real-time processing and the achievement of a quantum advantage with efficient use of resources are prominent challenges towards viable experimental realizations. In this work, we propose a photonic platform suitable for real-time QRC based on a physical ensemble of reservoirs in the form of identical optical pulses recirculating through a closed loop. While ideal operation achieves maximum capacities, statistical noise is shown to undermine a quantum advantage. We propose a strategy to overcome this limitation and sustain the QRC performance when the size of the system is scaled up. The platform is conceived for experimental implementations to be viable with current technology

    Squeezing as a resource for time series processing in quantum reservoir computing

    Full text link
    Squeezing is known to be a quantum resource in many applications in metrology, cryptography, and computing, being related to entanglement in multimode settings. In this work, we address the effects of squeezing in neuromorphic machine learning for time series processing. In particular, we consider a loop-based photonic architecture for reservoir computing and address the effect of squeezing in the reservoir, considering a Hamiltonian with both active and passive coupling terms. Interestingly, squeezing can be either detrimental or beneficial for quantum reservoir computing when moving from ideal to realistic models, accounting for experimental noise. We demonstrate that multimode squeezing enhances its accessible memory, which improves the performance in several benchmark temporal tasks. The origin of this improvement is traced back to the robustness of the reservoir to readout noise as squeezing increases

    The flank eruption history of Etna (1610-2006) as a constraint on lava flow hazard

    Get PDF
    Data of the flank eruptions of Etna from over the last 400 years were extracted from the new geological map for the lava flow extensions and vent positions, and from the catalogs of historical eruptions for the eruption durations and lava volumes. The partially or widely hidden lava fields on the new geological map were retrieved from older geological maps. The distributions of the eruption durations and lava volumes were analyzed, with the definition of six eruptive classes for use in numerical simulations. The threshold values for the eruption durations and lava volumes were set at 45 days and at 35 Ă— 106 m3 and 100 Ă— 106 m3, respectively. A global analysis was performed on the whole volcano to evaluate the recurrence of the classes, and to estimate for each class the ranges, means and standard deviations of the durations, volumes and elevations of the main vent. The same analysis was repeated by subdividing the volcano into three sectors, which were defined on the basis of the distribution of the eruptive fissures over the last 15 ka. The classes have different recurrences across these various sectors, and different distributions of volumes, durations and elevations of the main vent. Finally, a lava flow resurfacing map that counts the number of lava flows on each given area of the volcano over the last 400 years was compiled and then normalized

    Evidence for age-related deficits in object-location binding during place recognition.

    Get PDF
    Deciding whether a place is the same or different than places encountered previously is a common task in daily navigation which requires to develop knowledge about the locations of objects (object-location binding) and to recognize places from different perspectives. These abilities rely on hippocampal functioning which is susceptible to increasing age. Thus, the question of the present study is how they both together impact on place recognition in aging. Forty people aged 20-29, 44 aged 60-69, and 32 aged 70-79 were presented with places consisting of four different objects during the encoding phase. In the test phase, they were then presented with a second place and had to decide whether it was the same or different. Test places were presented from different perspectives (0°, 30°, 60°) and with different object conditions (same, a swap of two objects, a substitution with a novel object). The sensitivity for detecting changes (d') decreased from 20-29 to 60-69 and to 70-79 years old, and with increasing perspective shifts. Importantly, older adults were less sensitive to object swapping than to object substitution, while young participants did not show any difference. Overall, these results suggest specific age-related difficulties in object-location binding in the context of place recognition
    • …
    corecore