Non-invasive imaging of subsurface paint layers with optical coherence tomography

Optical coherence tomography (OCT) systems are fast scanning infrared Michelson interferometers designed for the non-invasive examination of the interiors of the eye and subsurface structures of biological tissues. OCT has recently been applied to the non-invasive examinations of the stratigraphy of paintings and museum artefacts. So far this is the only technique capable of imaging non-invasively the subsurface structure of paintings and painted objects. Unlike the traditional method of paint cross-section examination where sampling is required, the non-invasive and non-contact nature of the technique enables the examination of the paint cross-section anywhere on a painting, as there is no longer an issue with conservation ethics regarding the taking of samples from historical artefacts. A range of applications of the technique including the imaging of stratigraphy of paintings and painted artefacts, the imaging of underdrawings to the analysis of the optical properties of paint and varnish layers is presented. Future projects on the application of OCT to art conservation are discussed

Navigation Pattern Discovery from Internet Data

Electronic commerce sites need to learn as much as possible about their customers and those browsing their virtual premises, in order to maximize their marketing effort. The discovery of marketing related navigation patterns requires the development of data mining algorithms capable of discovering sequential access patterns from web logs. This paper introduces a new algorithm called MiDAS that extends traditional sequence discovery with a wide range of web-specific features. Domain knowledge is described as flexible navigation templates that can specify navigational behavior, as network structures for the capture of web site topologies, in addition to concept hierarchies and syntactic constraints. Unlike existing approaches, field dependency has been implemented, which allows the detection of sequences across monitored attributes, such as URLs and http referrers. Three different types of contained-in relationships are supported, which express different types of browsing behavior. The carried out experimental evaluation have shown promising results in terms of functionality as well as scalability.

PENGARUH LAMA PERENDAMAN DALAM LARUTAN BUBUR BLACK MULBERRY (Morus nigra) DAN SUHU PENGERINGAN TERHADAP KARAKTERISTIK BERAS IR 64

PT. Electric Wire Indonesia atau lebih dikenal dengan PT. EWINDO (persero) merupakan perusahaan yang bergerak di bidang manufaktur dengan produk yang dihasilkan, yaitu Kabel Elektrik & Kabel Otomotif, Power Supply Cord, dan Kawat Pengaman. Saat ini PT. EWINDO sedang menghadapi permasalahan kualitas. Kegagalan terhadap fungsi terlihat pada saat uji fungsional tes produk power supply cord. Saat ini perbaikan yang dilakukan perusahaan hanya melakukan perbaikan ulang produk dan pemeriksaan ditahap manufakturing, tanpa mengetahui faktor-faktor yang berpengaruh terhadap kegagalan suatu produk sehingga dikemudian hari dapat terulang kembali kegagalan yang sama. Oleh sebab itu, diperlukan suatu rencana perbaikan berkelanjutan. Jenis kegagalan fungsional pada power supply cord terjadi akibat beberapa modus kegagalan proses sehingga dilakukan perbaikan proses dengan merancang ulang proses. Perlu diketahui faktor prioritas perbaikan terhadap kegagalan proses dengan menggunakan analisis FMEA (Failure Mode and Effect Analysis) untuk menghilangkan potensial kegagalan. Didalam melakukan perbaikan kualitas, dilihat dari perhitungan nilai RPN (Risk Priority Number). Nilai RPN didasarkan kepada faktor severity, occurance, detection. Diketahui nilai RPN Wall thickness sebesar 360, Injection rate 280, kerapihan hasil crimping 160, holding pressure 140, stripper 120. Rancangan ulang proses produksi dapat mengurangi nilai RPN dari setiap modus kegagalan berupa penambahan proses pembersihan cavity, penambahan waktu untuk injection rate, pembersihan selang hidrolik, penambahan waktu tahan pada holding pressure, penggantian pegas untuk stripper. Perbaikan menghasilkan nilai estimasi berdasarkan pendapat para ahli. Perbaikan secara berkelanjutan dilakukan dengan melihat faktor mana saja yang belum diteliti. Kata kunci : Quality Improvement, Failure Mode and Effect Analysis (FMEA), prinsip 5W+1H, reliabilit

Neurochemistry-enriched dynamic causal models of magnetoencephalography, using magnetic resonance spectroscopy

We present a hierarchical empirical Bayesian framework for testing hypotheses about neurotransmitters’ concertation as empirical prior for synaptic physiology using ultra-high field magnetic resonance spectroscopy (7T-MRS) and magnetoencephalography data (MEG). A first level dynamic causal modelling of cortical microcircuits is used to infer the connectivity parameters of a generative model of individuals’ neurophysiological observations. At the second level, individuals’ 7T-MRS estimates of regional neurotransmitter concentration supply empirical priors on synaptic connectivity. We compare the group-wise evidence for alternative empirical priors, defined by monotonic functions of spectroscopic estimates, on subsets of synaptic connections. For efficiency and reproducibility, we used Bayesian model reduction (BMR), parametric empirical Bayes and variational Bayesian inversion. In particular, we used Bayesian model reduction to compare alternative model evidence of how spectroscopic neurotransmitter measures inform estimates of synaptic connectivity. This identifies the subset of synaptic connections that are influenced by individual differences in neurotransmitter levels, as measured by 7T-MRS. We demonstrate the method using resting-state MEG (i.e., task-free recording) and 7T-MRS data from healthy adults. Our results confirm the hypotheses that GABA concentration influences local recurrent inhibitory intrinsic connectivity in deep and superficial cortical layers, while glutamate influences the excitatory connections between superficial and deep layers and connections from superficial to inhibitory interneurons. Using within-subject split-sampling of the MEG dataset (i.e., validation by means of a held-out dataset), we show that model comparison for hypothesis testing can be highly reliable. The method is suitable for applications with magnetoencephalography or electroencephalography, and is well-suited to reveal the mechanisms of neurological and psychiatric disorders, including responses to psychopharmacological interventions

Comets, historical records and vedic literature

A verse in book I of Rigveda mentions a cosmic tree with rope-like aerial roots held up in the sky. Such an imagery might have ensued from the appearance of a comet having `tree stem' like tail, with branched out portions resembling aerial roots. Interestingly enough, a comet referred to as `heavenly tree' was seen in 162 BC, as reported by old Chinese records. Because of weak surface gravity, cometary appendages may possibly assume strange shapes depending on factors like rotation, structure and composition of the comet as well as solar wind pattern. Varahamihira and Ballala Sena listed several comets having strange forms as reported originally by ancient seers such as Parashara, Vriddha Garga, Narada and Garga. Mahabharata speaks of a mortal king Nahusha who ruled the heavens when Indra, king of gods, went into hiding. Nahusha became luminous and egoistic after absorbing radiance from gods and seers. When he kicked Agastya (southern star Canopus), the latter cursed him to become a serpent and fall from the sky. We posit arguments to surmise that this Mahabharata lore is a mythical recounting of a cometary event wherein a comet crossed Ursa Major, moved southwards with an elongated tail in the direction of Canopus and eventually went out of sight. In order to check whether such a conjecture is feasible, a preliminary list of comets (that could have or did come close to Canopus) drawn from various historical records is presented and discussed.Comment: This work was presented in the International Conference on Oriental Astronomy held at IISER, Pune (India) during November, 201