Robust bin-picking system using tactile sensor

ABSTRACT

This paper presents a robust bin-picking system utilizing tactile sensors and a vision sensor. The object position and orientation are estimated using a fast template-matching method through the vision sensor. When a robot picks up an object, the tactile sensors detect the success or failure of the grasping, and a force sensor detects the contact with the environment. A weight sensor is also used to judge whether the lifting of the object has been successful. The robust and efficient bin-picking system presented herein is implemented through the integration of different sensors. In particular, the tactile sensors realize rope-shaped object picking that has yet to be made possible with conventional picking systems. The effectiveness of the proposed method was confirmed through grasping experiments and in a competitive event at the World Robot Challenge 2018.     

Sex hormonal modulation of hyperbolic discount factor in men.

Hormones in the brain have many types of visceral influences on social behavior and economic decision-making. Although hormone-associated visceral effects attract attention in neuroeconomics, little is known regarding the relationship between sex hormones and hyperbolic discounting. Furthermore, although the “discount factor” (a parameter indicating patience in intertemporal choice) is economically relevant and has neural correlates, most neuroeconomic studies on intertemporal choice have been focusing on neuromodulation of logged discount rates, which sometimes results in difficulty in interpretation. This study was aimed to examine linear correlations between chronic sex hormone levels and hyperbolic discount factors of gains and losses in healthy male students. Participants’ salivary sex hormone (testosterone) levels were also assessed. We observed a positive linear relationship between testosterone levels and hyperbolic discount factor of gains; while no linear relationship between testosterone levels and discount factor of losses was observed. The results indicate that (i) chronic elevation in testosterone may be associated with patience (indicated by a discount factor) in intertemporal choice on gains, (ii) testosterone is unrelated to discounting of delayed losses. Implications for sex hormone-related visceral effects on problematic decision-making (e.g. addiction) and possible neuroendocrinological mechanism (e.g. conversion of testosterone into female hormones in the brain) are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Minor actinide transmutation in fast reactor metal fuels irradiated for 120 and 360 equivalent full-power days

An irradiation experiment on uranium–plutonium–zirconium (U–Pu–Zr) alloys containing 5 wt% or less minor actinides (MAs) and rare earths was carried out in the Phénix fast reactor. The isotope compositions of the fuel alloys irradiated for 120 and 360 equivalent full-power days (EFPDs) were chemically analyzed by inductively coupled plasma–mass spectrometry after 3.3–5.3 years of cooling. The results of chemical analysis indicated that the discharged burnups of the fuel alloys irradiated for 120 and 360 EFPDs were 2.1–2.5 and 5.3–6.4 at%, respectively. The changes in the isotopic abundances of plutonium, americium, and curium during the irradiation experiment were assessed to discuss the transmutation performance of MA nuclides added to U–Pu–Zr alloy fuel. Multigroup three-dimensional diffusion and burnup calculations accurately predicted the changes in these isotopic abundances after fuel fabrication. An evaluation of the MA transmutation ratio based on the results of chemical analysis revealed that the quantity of MA elements in the U–19Pu–10Zr–5MA (wt%) alloy decreased by about 20% during the irradiation experiment for 360 EFPDs.     

Degradation of organophosphorus pesticides in aqueous extracts of young green barley leaves (Hordeum vulgare L)

The degradation of the organophosphorus pesticides malathion, chlorpyrifos, guthion, diazinon, methidathion and parathion in an aqueous extract of young green barley leaves (Hordeum vulgare L) was monitored by gas chromatography. Aqueous solutions of various amounts of freeze‐dried young barley leaves containing 5.75 mg l⁻¹ of malathion were incubated at 37 °C and pH 7.4 over prolonged time periods. Over 95% of the malathion degraded in 4 h in a 3% (30 g l⁻¹) solution of young green barley leaves. When the barley solution was autoclaved at 120 °C for 25 min prior to the addition of malathion, no degradation of malathion was observed. When 10 mg l⁻¹ each of the above six pesticides was incubated in a 15% (150 g l⁻¹) solution of young green barley leaves for 3 h at 37 °C and pH 7.4, malathion and chlorpyrifos degraded 100%, whereas parathion (75%), diazinon (54%), guthion (41%) and methidathion (23%) showed lesser degrees of degradation. © 1999 Society of Chemical Industry     

Critical role for p27Kip1 in cell cycle arrest after androgen depletion in mouse mammary carcinoma cells (SC-3)

The molecular mechanisms underlying androgen-regulated cancer growth and the frequent development of refractoriness to endocrine therapy remain unknown. In this study functional and quantitative alterations in cell cycle regulators after androgen depletion were examined in androgen-dependent mouse mammary carcinoma cells (SC-3) as a model system to clarify the initial response of cancer cells to anti-androgen therapy. FACS analysis of SC-3 cells cultured with or without 10(-7) M testosterone revealed that suppression of cell growth after hormone withdrawal was due to GI arrest. Although cyclin D1/Cdk4 activity decreased along with a reduced level of cyclin D1 protein, this was a later event (48-72 h) than the G1 arrest (24 h). Taken together with the results that constitutive expression of cyclin D1 in SC-3 cells did not overcome the growth suppression following androgen depletion, the existence of an alternative pathway(s) causing G1 arrest was suggested. Cyclin E/Cdk2 and cyclin A/Cdk2 activities decreased significantly at 24 h without apparent changes in the amounts of Cdk2, cyclin E or cyclin A. Among various Cdk inhibitors (CKIs) examined, p27Kip1 was upregulated at both mRNA and protein levels at 24 h after androgen depletion. In addition, immunoprecipitation-Western analysis showed that the amount of p27Kip1 associated with Cdk2 complexes increased as early as 24 h. These results suggest that p27Kip1 CKI is a critical target in the initial response of cancer cells to androgen depletion and plays a key role in Cdk2 inactivation through association with the kinase complex, leading to cell cycle arrest.     

Design of AVS/RS under group constraint

Distribution centers, which are essential to our society, are becoming increasingly important. Although the efficiency of an AVS/RS (Autonomous vehicle storage and retrieval system) makes it a promising system, there is still much to be studied regarding its effective use and design. This paper proposes a method of designing AVS/RSs through a quantitative consideration of group constraint by utilizing probability theory. The proposed algorithm also deals with the problem of designing the sizes of several buffers, and considers the effect of load fluctuations, which are important for real-world operation, by use of queuing network theory. Effectiveness of the proposed algorithm is shown with simulations of various number of groups, those of various safety factors for fluctuations, and those of various evasion rates for buffer overflow. The design results are shown to be much different from those which do not consider those factors. The results prove that the proposed method provides an accurate quantitative assessment of the AVS/RS’s constraints.     

Low‐frequency sound absorption of organic hybrid comprised of chlorinated polyethylene and N,N′‐dicyclohexyl‐2‐benzothiazolyl sulfenamide

We investigated the sound absorption characteristics of an organic hybrid material comprised of chlorinated polyethylene (CPE) as the matrix polymer and N,N′‐dicyclohexyl‐2‐benzothiazolyl sulfenamide (DBS) as the second component of an organic low‐molecular‐weight compound. We found specific crystallites, obtained by annealing, that generated new absorption for a low‐frequency sound in a CPE/DBS blend. We observed two sound absorption peaks, around 300 and 1000 Hz, in the annealed CPE/DBS (50 : 50 w/w) blends, whereas those peaks were not observed in the untreated sample. There were two kinds of crystals with different melting points in the annealed samples. It was confirmed that the crystals with the lower melting point brought about sound absorption at a low frequency. The crystals that had the lower melting point were smaller and/or more disordered than the crystals that had the higher melting point. We calculated the fraction of these two types of crystals from differential scanning calorimetry and wide‐angle X‐ray diffraction measurements. The annealing or reannealing temperature specified the fraction of the crystal with the lower melting point, and the obtained crystal fraction characterized sound absorption frequency. Therefore, it is possible to control the sound absorption frequency of an organic hybrid by heat treatment such as annealing. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Selective protein separation using siliceous materials with a trimethoxysilane-containing glycopolymer

A copolymer with α-D-mannose (Man) and trimethoxysilane (TMS) units was synthesized for immobilization on siliceous matrices such as a sensor cell and membrane. Immobilization of the trimethoxysilane-containing copolymer on the matrices was readily performed by incubation at high heat. The recognition of lectin by poly(Man-r-TMS) was evaluated by measurement with a quartz crystal microbalance (QCM) and adsorption on an affinity membrane, QCM results showed that the mannose-binding protein, concanavalin A, was specifically bound on a poly(Man-r-TMS)-immobilized cell with a higher binding constant than bovine serum albumin. The amount of concanavalin A adsorbed during permeation through a poly(Man-r-TMS)-immobilized membrane was higher than that through an unmodified membrane. Moreover, the concanavalin A adsorbed onto the poly(Man-r-TMS)-immobilized membrane was recoverable by permeation of a mannose derivative at high concentration.