Keyence (Japan)

In science education, building models of dynamical systems is a promising method for understanding various natural phenomena and artifacts with scientific concepts. It is, however, difficult to learn skills and concepts necessary for modeling. Though several model-building learning environments (MBEs) have been developed with potentially useful methods for assisting students, the verification of them has been limited so far. Most studies evaluated their effectiveness by measuring the degree of model completion by students, or total learning effect that consists of several types of assistance. In this study, we investigated how students learn modeling skills and concepts of system dynamics through modeling dynamical systems, focusing on how students’ behavior and understanding are influenced by the type of assistance and students’ prior knowledge. We implemented the function that detects the difference of a model by students from the correct model and gives one of the two types of feedback: structural explanation indicates structurally erroneous parts of a model by students to promote students’ model completion, while behavioral explanation suggests erroneous behavior of a model by students to promote students’ understanding about the cause of error. Our experiment revealed the following: (1) Students assigned to structural explanation showed high model completion, but their understanding depended on whether they used the feedback appropriately or not. (2) Students assigned to behavioral explanation showed less model completion, but once they completed models, they acquired a deeper understanding.

The western blotting technique is widely used to analyze protein expression levels and protein molecular weight. The chemiluminescence method is mainly used for detection due to its high sensitivity and ease of manipulation, but it is unsuitable for detailed analyses because it cannot be used to detect multiple proteins simultaneously. Recently, more attention has been paid to the fluorescence detection method because it is more quantitative and is suitable for the detection of multiple proteins simultaneously. However, fluorescence detection can be limited by poor image resolution and low detection sensitivity. Here, we describe a method to detect fluorescence in western blots using fluorescence microscopy to obtain high-resolution images. In this method, filters and fluorescent dyes are optimized to enhance detection sensitivity to a level similar to that of the chemiluminescence method.

We propose a fast algorithm for nonlinear moving horizon state estimation (MHSE). An optimization problem to be solved at each time step is formulated in a deterministic setting to estimate the unknown state and the unknown disturbance over a finite past, which leads to a nonlinear two-point boundary-value problem (TPBVP) to be solved at each time. Instead of solving the nonlinear TPBVP with an iterative method, the estimate is updated by integrating a differential equation to trace the time-varying solution of the TPBVP, which is a kind of continuation method and needs to solve a linear algebraic equation only once at each sampling time. Moreover, the linear algebraic equation involved in the differential equation is solved efficiently by the generalized minimum-residual method, one of the Krylov subspace methods. The proposed algorithm is evaluated by a numerical simulation and experiment with a hovercraft model the dynamics of which are nonlinear. MHSE by the proposed algorithm generates reasonable estimates even when the extended Kalman filter fails, and the proposed algorithm is sufficiently fast for real-time implementation with a sampling period in the order of milliseconds.

We present the numerical analysis of the growth of a silicon (Si) single crystal. In the MCZ (Magnetic-field-applied Czochralski) method, two magnetic fields that stand opposite to each other generate a cusp magnetic field. In this work, the three cusp magnetic fields used for the analysis are an external magnetic field, a surface magnetic field and an internal magnetic field. Each case was evaluated mainly as to the degree of stirring, shaft symmetry and the stability of the flow. As a result , the cusp magnetic field that yielded to best conditions was the internal magnetic field.