Yamaha (Japan)

Additive manufacturing (AM) has become the subject of attention because it can build parts with structures that cannot be achieved by conventional methods. However, one hindrance that has been pointed out to the widespread use of the laser powder bed fusion (L-PBF) method, a type of AM technology, is its high manufacturing costs. An effective method of reducing these costs is reducing manufacturing times and using inexpensive powder. In this research, specimens were built through the L-PBF method by varying the layer thickness using aluminum alloy (AlSi10Mg) broad powder, which included unused coarse powder. Furthermore, we investigated the effects of the particle size distribution of powders and the layer thickness at the time of manufacturing on the relative density of the as-built specimens. As a result, the relative density of the as-built specimen using broad powder was higher than that of a specimen using the existing powder. Although the fabrication conditions of the high-density specimens were limited if the layer was thick, by increasing the layer thickness from 60 µm (conventional value) to 120 µm and adjusting the fabrication conditions, the building speed was increased by 45% while obtaining high-density specimens.

This study examined whether or not the coexistence of smoking and metabolic syndrome synergistically increases the risk of cardiovascular disease (CVD) beyond their individual effects. This prospective cohort study included 68,743 workers from the Japan Epidemiology Collaboration on Occupational Health Study. The participants were categorized into four groups based on their smoking status and metabolic syndrome. Biological interactions were evaluated using relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (S). During a mean follow-up of 7.2 (range: 0.1-10.9) years, 346 participants developed CVD. Current smokers with metabolic syndrome had the highest CVD risk (hazard ratio: 6.45, 95% confidence interval [CI]: 4.73-8.80). Approximately 35% of CVD cases among individuals exposed to both factors were attributed to their biological interactions (RERI: 2.27, 95% CI: 0.56-3.98; AP: 0.35, 95% CI: 0.15-0.55; S: 1.71, 95% CI: 1.16-2.52). An analysis of CVD subtypes revealed a significant biological interaction for myocardial infarction (RERI: 5.14, 95% CI: 0.65-9.62; AP: 0.52, 95% CI: 0.26-0.78; S: 2.38, 95% CI: 1.22-4.62) but not for stroke (RERI: 1.34, 95% CI: -0.46-3.13; AP: 0.25, 95% CI: -0.03-0.53; S: 1.44, 95% CI: 0.89-2.34). Smoking and metabolic syndrome interact synergistically to elevate CVD risk, particularly for myocardial infarction. Targeting both factors is essential for CVD prevention.

Abstract Patient-derived-organoids (PDOs) are valuable tools for predicting individual responses to cancer treatments. However, current screening methods require large numbers of PDOs, resulting in long turnaround times and limiting clinical use. This study aimed to streamline the process by automating PDO seeding with the Yamaha Cell Handler™ (YCH). We optimized the YCH to pick and place up to 10 PDOs per well, significantly reducing sample requirements compared to conventional methods. Assay optimization included evaluating seeding densities, devices, readouts, and measurement techniques. We validated the miniaturized assay by comparing it to standard screens and correlating organoid responses with patient outcomes. Our proof-of-concept demonstrated that mCRC PDOs respond to chemotherapy and targeted treatments in a way that closely matches results from traditional assays. This miniaturized automated platform enables efficient, high-quality drug screening with fewer cells, offering promising potential for faster, personalized cancer treatment predictions in clinical settings.

This study aims to determine the effect of public speaking skills on the quality of group presentations among students in the History of Religion course. The background of this research is the low ability of students to deliver presentation material effectively, even though they have mastered the content. The study used an experimental method with a pre-test post-test control group design. The sample consisted of 20 students divided into two groups: an experimental group given public speaking training and a control group without training. Data were collected through observation, presentation rubrics, and self-confidence questionnaires. The results showed a significant increase in clarity of delivery, argument structure, and students’ confidence in the experimental group compared to the control group. These findings indicate that public speaking training positively influences the quality of student presentations in the History of Religion course.

<div class="section abstract"><div class="htmlview paragraph">This study focused on the effects of hydrogen on the flame propagation characteristics and combustion characteristics of a small spark-ignition engine. The combustion flame in the cylinder was observed using a side-valve engine that allowed optical access. The fundamental characteristics of hydrogen combustion were investigated based on combustion images photographed in the cylinder with a high-speed camera and measured cylinder pressure waveforms. Experiments were conducted under various ignition timings and equivalence ratios and comparisons were made with the characteristics of an existing hydrocarbon liquid fuel. The hydrogen flame was successfully photographed, although it has been regarded as being difficult to visualize, thus enabling calculation of the flame propagation speed. As a result, it was found that the flame propagation speed of hydrogen was much faster than that of the existing hydrocarbon fuel. On the other hand, it was difficult to photograph the hydrogen flame directly in the lean region. In future studies, it will be necessary to reduce the shooting speed or to conduct investigations based on spectroscopic measurements.</div><div class="htmlview paragraph">Regarding hydrogen combustion, it was found that the combustible range of hydrogen was broad even when the experimental conditions were substantially varied. It was also found that the combustible period was much shorter than that of the existing hydrocarbon fuel. Misfiring and after-firing were observed in hydrogen combustion where the ignition timing was close to top dead center as well as under a lean condition. This confirmed that there are issues concerning hydrogen combustion stability under such conditions.</div></div>

Characterizing and modeling the spatial radiation of musical instruments is a challenging task in acoustics due to the complex and high-dimensional nature of their directivities. In this paper, we address this challenge by presenting a comprehensive analysis of musical instrument directivities using Spatial Complexity, a novel metric that quantitatively describes how energy is distributed across spherical harmonics coefficients. Lower Spatial Complexity values indicate a concentration of energy in lowerorder spherical harmonic components, corresponding to nearly isotropic radiation patterns, while higher values reflect energy distributed across higher-order harmonics, denoting highly directional and intricate beam patterns. To demonstrate the utility of this metric, we analyze an extensive dataset of measured instrument directivities, uncovering systematic correlations between complexity and physical radiation properties. Further, we train a rotation-equivariant neural network designed to preserve the geometric symmetries of spherical harmonics representations. The model's latent space organizes directivities along gradients tightly aligned with complexity, showing the metric's ability to capture fundamental attributes of spatial radiation. These findings highlight the effectiveness of complexity as a concise and interpretable analytical tool for comparing and categorizing instrument directivities, with potential applications in acoustic research, instrument design, and spatial audio technologies.

<div class="section abstract"><div class="htmlview paragraph">In this study, an initial approach using deep reinforcement learning to replicate the complex behaviors of motorcycle riders was presented. Three learning examples were demonstrated: following a target velocity, maintaining stability at low speeds, and following a target trajectory. These examples serve as a starting point for further research. Additionally, the proficiency of the constructed models was examined using rider proficiency evaluation methods developed in previous studies. Initial results indicated that the models have the potential to mimic real rider behaviors; however, challenges such as differences between the model’s output and what humans can produce were also identified for future work.</div></div>

Real-time performance tracking is the core component of automatic accompaniment systems. Previous methods typically require full information on the performance score (the human part) and also assume very limited improvisations off the score, otherwise, the tracker will get lost. In this paper, we aim to track a fully improvised performance for automatic accompaniment, in which the only reference is the accompaniment score (the machine part). The key idea is to incorporate semantic-level alignment to model the correspondence between the user performance and the accompaniment. Our system contains two real-time components: The first component is an accompaniment-conditioned quantization model using a Long Short-Term Memory (LSTM) layer. For each performance note onset, we first compute its rough projected score position using previously estimated performance-to-score mapping and then refine the mapping using the quantization results. The second component is a playback control system, which updates the performance-to-score mapping via the performance-quantized time pair (similar to the performance-score alignment pair in traditional automatic accompaniment systems). Experiments show the system achieves better tracking results on expressive piano performance than baselines, allowing score-free tracking on both texture and tempo variations. Video demos are accessible on our demo page<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>.