Optimal periodic and random inspections with first,last and overtime policies

It has been assumed for a standby unit that periodic inspection is performed more easily to detect failures, but such a strict periodic mode would be impractical if the unit is executing some procedures without stops. From the above viewpoint, this paper first optimises a random inspection policy in accordance with random procedure times, compares it with periodic inspection and computes a modified checking cost for random inspection to determine the case where such a random inspection would be adopted. Second, this paper proposes three new inspection models in which inspections with deterministic policies are scheduled strategically while their performances need to be limited by completion times of operation procedures. These policies are called inspection first, inspection last and inspection overtime. The total expected inspection and downtime costs of each model until failure detection are obtained, and optimal policies which minimise them are derived analytically. Furthermore, the three inspection policies are compared with periodic inspection, inspection first and last are compared with each other, and a modified checking cost for inspection overtime is discussed when the policy would be better than periodic inspection.     

Robot motion design using bunraku emotional expressions – focusing on Jo-Ha-Kyū in sounds and movements*

One of the UNESCO intangible cultural heritages Bunraku puppets can play one of the most beautiful puppet motions in the world. The Bunraku puppet motions can express emotions without the so-called ‘Uncanny Valley.’ We try to convert these emotional motions into robot affective motions so that robots can interact with human beings more comfortable. In so doing, in the present paper, we present a robot motion design framework using Bunraku affective motions that are based on the so-called ‘Jo-Ha-Kyū,’ and convert a few simple Bunraku motions into a robot motions using one of deep learning methods. Our primitive experiments show that Jo-Ha-Kyū can be incorporated into robot motion design smoothly, and some simple affective robot motions can be designed using our proposed framework.     

A Nom historical document recognition system for digital archiving

A Nom historical document recognition system is being developed for digital archiving that uses image binarization, character segmentation, and character recognition. It incorporates two versions of off-line character recognition: one for automatic recognition of scanned and segmented character patterns (7660 categories) and the other for user handwritten input (32,695 categories). This separation is used since including less frequently appearing categories in automatic recognition increases the misrecognition rate without reliable statistics on the Nom language. Moreover, a user must be able to check the results and identify the correct categories from an extended set of categories, and a user can input characters by hand. Both versions use the same recognition method, but they are trained using different sets of training patterns. Recursive X–Y cut and Voronoi diagrams are used for segmentation; k–d tree and generalized learning vector quantization are used for coarse classification; and the modified quadratic discriminant function is used for fine classification. The system provides an interface through which a user can check the results, change binarization methods, rectify segmentation, and input correct character categories by hand. Evaluation done using a limited number of Nom historical documents after providing ground truths for them showed that the two stages of recognition along with user checking and correction improved the recognition results significantly.     

Locally parallel cache design based on KL1 memory access characteristics

The parallel inference machine (PIM) is now being developed at ICOT. It consists of a dozen or more clusters, each of which is a tightly coupled multiprocessor (comprising about eight processing elements) with shared global memory and a common bus. Kernel language 1 (KL1), a parallel logic programming language based on Guarded Horn Clauses (GHC), is executed on each PIM cluster. This paper describes the memory access characteristics in KL1 parallel execution and a locally parallel cache mechanism with hardware lock. The most important issue of locally parallel cache design is how to reduce common bus traffic. A write-back cache protocol having five cache states specially optimized for KL1 execution on each PIM cluster is described. We introduced new software controlled memory access commands, named DW, ER, and RP. A hardware lock mechanism is attached to the cache on each processor. This lock mechanism enables efficient word-by-word locking, reducing common bus traffic by using the cache states.     

Enhancement of the Passive Direct Methanol Fuel Cells Performance by Modification of the Cathode Microporous Layer Using Carbon Nanofibers

Mass transfer is a key parameter affecting the performance of the passive direct methanol fuel cells (DMFCs), which work under natural convection. In this study, effect of carbon nanofibers (CNFs) addition to the cathode microporous layer (MPL) on the performance of the passive DMFCs was investigated. The results indicated that CNFs content has a significant influence on both of the mass transport and the electrochemical surface area (ECSA). Interestingly, addition of the CNFs (20 wt.%) leads to increase the power density of the passive DMFC to 160% compared to pristine carbon black MPL. At low current density, the CNFs content has no influence on the performance, while at high current density the maximum performance can be obtained at 20 wt.% CNFs then the performance decreases with further increase in the CNFs content. Although the highest catalyst utilization is observed at 40 wt.% CNFs, a maximum power density of 36 mW cm^–2 can be obtained at 20 wt.% CNFs and this is related to the significant effect of the mass transfer resistance under the passive operation conditions. Overall, addition of CNFs to the MPL can be considered an effective strategy to modify the passive DMFCs performance.     

The Impact of Duodenal Mucosal Vulnerability in the Development of Epigastric Pain Syndrome in Functional Dyspepsia

An unidentified cause of functional dyspepsia (FD) is closely associated with medication resistance. Acid suppression is a traditional and preferential method for the treatment of FD, but the efficacy of this treatment varies between epigastric pain syndrome (EPS) and postprandial syndrome (PDS): it is efficient in the former but not much in the latter. Transepithelial electrical resistance (TEER), a surrogate of mucosal barrier function, was measured under pH 3 and pH 5 acidic conditions using duodenal biopsy specimens obtained from the patients with EPS and PDS and asymptomatic healthy controls. The infiltration of inflammatory cells to the duodenal mucosa was accessed by immunohistochemical analysis. The duodenal mucosal TEER in EPS patients was decreased by exposure to the acidic solution compared to that of the controls and the PDS patients. The decrease in TEER of the EPS patients was observed even under pH 5 weak acidic condition and was correlated to degree of the epigastric pain. Moreover, the duodenal mucosa of EPS patients presented an increase in mast cells and plasma cells that expressed Ig-E. Duodenal mucosal vulnerability to acid is likely to develop EPS.     

Freeze-dried solid foams prepared from carbon nanotube aqueous suspension: Application to gas diffusion layers of a proton exchange membrane fuel cell

Freeze-dried macroporous solid foams were prepared from the multi-walled carbon nanotube (MWCNT) aqueous suspensions dispersed by chitosan. Thin film shaped CNT solid foams were prepared, and applied to the gas diffusion layers (GDLs) of a laboratory scale proton exchange membrane fuel cell (PEMFC). It was demonstrated that the prepared carbon foams in this study were useful to a fuel cell GDL material. The prepared cell performances were fairly comparable to the cell prepared with conventional carbon paper for GDL material. The microstructures of the prepared carbon foams were found to affect on the PEMFC performances. It was suggested that the interconnected carbon networks formed during the freezing step closely link to the cell performances. Hence, the defection of the interconnected microstructure lead degradation of the GDL quality. The impedance measurement made clear that the prepared foam materials were also advantageous for reducing the ohmic resistance in PEMFC assembly. The kinetic resistance values and the thermal conductive characteristics suggested that the freezing process would also control the degree of overlaps among single CNTs in a freeze-dried bulk that influenced on the electrochemical properties.     

Determination of Ring-OSF Position in Czochralski Silicon Single Crystals by Numerical Analysis of Distribution of Grown-in Defects

A numerical analysis technique that incorporates Voronkov's model were examined and used to estimate the distribution of defects during crystal growth. By comparisons of the distribution of the density of LSTD and the position of R-OSF in non-nitrogen-doped (non-N-doped) and nitrogen-doped (N-doped) silicon crystals, it is found that the results of the numerical analyses agree with practically evaluated data. The observations suggest that the R-OSF nucleus is a VO2 complex that is formed by bonds between oxygen atoms and residual vacancies consumed during the formation of void defects. This suggests that Voronkov's model can be used to accurately predict the generation and growth of defects in silicon crystals. This numerical analysis technique was also found to be an effective method of estimating the distribution of defects in silicon crystals during crystal growth.     

Calculation of Age-Replacement with Weibull Failure Times

An age-replacement policy with Weibull failure times is considered. It is troublesome to compute an optimum replacement time numerically. Upper and lower bounds of an optimum time are given in simple terms of replacement costs and parameters of a Weibull distribution. A numerical example shows that the approximation can be used when the ratio of the replacement cost for a failed unit to that for a nonfailed unit is large. The approximation is best when the optimum age of replacement is small.