PathRank: Ranking nodes on a heterogeneous graph for flexible hybrid recommender systems

We present a flexible hybrid recommender system that can emulate collaborative-filtering, Content-based Filtering, context-aware recommendation, and combinations of any of these recommendation semantics. The recommendation problem is modeled as a problem of finding the most relevant nodes for a given set of query nodes on a heterogeneous graph. However, existing node ranking measures cannot fully exploit the semantics behind the different types of nodes and edges in a heterogeneous graph. To overcome the limitation, we present a novel random walk based node ranking measure, PathRank, by extending the Personalized PageRank algorithm. The proposed measure can produce node ranking results with varying semantics by discriminating the different paths on a heterogeneous graph. The experimental results show that our method can produce more diverse and effective recommendation results compared to existing approaches.     

Fixture modelling for an automotive assembly line

This paper proposes an efficient fixture modelling procedure for automotive body assembly lines. A fixture model consists of two sub-models; a geometric model and a kinetic model that should be remodelled frequently whenever design changes occur. We develop an algorithm extracting the kinetic model from the geometric model of a fixture to reduce the fixture modelling time and effort. Although the geometric models of fixtures used in automotive assembly lines vary, most follow the same kinetic mechanism, the so-called slider-crank mechanism; this is a four-axis system of three revolute and one prismatic joint. The prismatic axis of a fixture represents a pneumatic actuator involving a piston and a cylinder. It is very important to identify the prismatic axis from a given geometric model to extract the kinetic model of a fixture. We use the concept of the ‘moment of inertia’, which is a measure of an object's resistance to changes in its rotation rate, to identify the prismatic axis. Since the exact computation of the moment of inertia for an arbitrary solid model requires complicated computations, we introduce an approximating method for the moment of inertia. The proposed procedure has been implemented and tested with various examples.     

A reverse engineering approach to generate a virtual plant model for PLC simulation

A reverse engineering approach to generate a virtual plant model is proposed. The model can be used for programmable logical controller (PLC) simulation. The virtual plant model for the PLC simulation consists of virtual device models and must interact with the input and output signals of a PLC. The behavior of a virtual device model should be the same as that of real device. Conventionally, the discrete event system specifications (DEVS) formalism has been used to represent the behavior of a virtual device model. Modeling using DEVS formalism, however, requires in-depth knowledge of the simulation area, as well as a significant amount of time and effort. One of the key ideas of the proposed methodology is to provide a method to generate a virtual plant model using both log data (time-stamped signal history) and a PLC I/O signal table extracted from the existing production system. The proposed reverse engineering approach provides two major benefits: (1) significant reduction in the time and effort for the construction of a reliable virtual plant model of a current production system, which can be referenced for newly planned production systems, and (2) reduction in the stabilization time of a production system through PLC simulation. The proposed approach was implemented and applied to an automated production line.     

Performance Optimization of Parallel‐Like Ternary Organic Solar Cells through Simultaneous Improvement in Charge Generation and Transport

Ternary organic photovoltaic (OPV) devices with multiple light‐absorbing active materials have emerged as an efficient strategy for realizing further improvements in the power conversion efficiency (PCE) without building complex multijunction structures. However, the third component often acts as recombination centers and, hence, the optimization of ternary blend morphology poses a major challenge to improving the PCE of these devices. In this work, the performance of OPVs is enhanced through the morphological modification of nonfullerene acceptor (NFA)‐containing binary active layers. This modification is achieved by incorporating fullerenes into the layers. The uniformly dispersed fullerenes are sufficiently continuous and successfully mediate the ordering of NFA without charge or energy transfer. Owing to the simultaneous improvement in the charge generation and extraction, the PCE (12.1%) of these parallel‐linked ternary devices is considerably higher than those of the corresponding binary devices (9.95% and 7.78%). Moreover, the additional energy loss of the ternary device is minimized, compared with that of the NFA‐based binary device, due to the judicious control of the effective donor:acceptor composition of the ternary blends.     

Low-power functionality of silicon-nanowire-assembled inverters on bendable plastics

In this paper, we demonstrate the low-power functionality of silicon nanowire (SiNW)-assembled inverters on bendable plastics. Our bendable inverters are capable of operating at supply voltages as low as 0.8 V with a switching (or standby) power consumption of ～0.2 nW (or ～6.6 pW). The low-power inverting operation with a voltage gain of ～18 is attributable to the near-ideal characteristics of the component transistors that have selectively thinned SiNW channels and exhibit low, symmetrical threshold voltages of 0.40 and ?0.39 V and low sub-threshold swing values of 81 and 65 mV/dec. Moreover, mechanical bendability reveals that the inverting operation has good, stable fatigue properties.

Open image in new window

     

Lipopeptide‐Based Nanosome‐Mediated Delivery of Hyperaccurate CRISPR/Cas9 Ribonucleoprotein for Gene Editing

A transient cytosolic delivery system for accurate Cas9 ribonucleoprotein is a key factor for target specificity of the CRIPSR/Cas9 toolkit. Owing to the large size of the Cas9 protein and a long negative strand RNA, the development of the delivery system is still a major challenge. Here, a size‐controlled lipopeptide‐based nanosome system is reported, derived from the blood‐brain barrier‐permeable dNP2 peptide which is capable of delivering a hyperaccurate Cas9 ribonucleoprotein complex (HypaRNP) into human cells for gene editing. Each nanosome is capable of encapsulating and delivering ≈2 HypaRNP molecules into the cytoplasm, followed by nuclear localization at 4 h post‐treatment without significant cytotoxicity. The HypaRNP thus efficiently enacts endogenous eGFP silencing and editing in human embryonic kidney cells (up to 27.6%) and glioblastoma (up to 19.7% frequency of modification). The lipopeptide‐based nanosome system shows superior delivery efficiency, high controllability, and simplicity, thus providing biocompatibility and versatile platform approach for CRISPR‐mediated transient gene editing applications.     

Synchronized Cell Cycle Arrest Promotes Osteoclast Differentiation

Osteoclast progenitors undergo cell cycle arrest before differentiation into osteoclasts, induced by exposure to macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). The role of such cell cycle arrest in osteoclast differentiation has remained unclear, however. We here examined the effect of synchronized cell cycle arrest on osteoclast formation. Osteoclast progenitors deprived of M-CSF in culture adopted a uniform morphology and exhibited cell cycle arrest at the G₀–G₁ phase in association with both down-regulation of cyclins A and D1 as well as up-regulation of the cyclin-dependent kinase inhibitor p27^Kip1. Such M-CSF deprivation also promoted the differentiation of osteoclast progenitors into multinucleated osteoclasts expressing high levels of osteoclast marker proteins such as NFATc1, c-Fos, Atp6v0d2, cathepsin K, and integrin β3 on subsequent exposure to M-CSF and RANKL. Our results suggest that synchronized arrest and reprogramming of osteoclast progenitors renders them poised to respond to inducers of osteoclast formation. Further characterization of such effects may facilitate induction of the differentiation of heterogeneous and multipotent cells into desired cell lineages.     

Histomorphometric evaluation of an implant with a nanotubular surface treatment in a beagle femur

This study examined the effects of a nanotubular surface treatment on an implant by anodic oxidation. Forty two screw-shaped implants were classified into 3 groups; machined surface (control group), nanotube formation on the machined surface (group N) and nanotube formation on the RBM surface (group RN). A total of 36 implants were inserted into a beagle femur. Two implants from each group were observed by scanning electron microscopy. Histomorphometric analyses were performed after 4 and 12 weeks. After 4 weeks, the average bone to implant contact (BIC) ratio of groups N and RN was significantly higher than that of the control group (P < .05). After 12 weeks, a nanotubular surface treatment showed a significantly higher BIC ratio only in the marrow space adjacent to the implant apex (P < .05). This in vivo study revealed the enhanced osseointegration of nanotubes.     

Middle school improvement and reform: Development and validation of a school-level assessment of climate, cultural pluralism, and school safety.

The structure of perceived school climate and the relationship of climate dimensions to adaptation were examined in a large-scale multi-year investigation of students who attend middle-grade-level schools. Analyses of the structure, reliability, interrater convergence, and stability of school climate ratings were conducted in a large-scale sample of over 105,000 students in 188 schools. The climate scales exhibited a stable dimensional structure, high levels of internal consistency, and moderate levels of stability over 1- and 2-year time intervals. The relationship between climate ratings and students' adjustment was examined in 3 increasingly large samples of schools and students that were collected during successive years of this project. Ratings of multiple climate dimensions were associated consistently with indexes of academic, behavioral, and socioemotional adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)