Robust and accurate prediction of thermal error of machining centers under operations with cutting fluid supply

A novel temperature measuring system named LATSIS was proposed to realize a robust and accurate prediction of the thermal deformation of machining centers, even under external disturbances such as cutting fluid supply. LATSIS enables a drastic increase in the number of sensors employed for measuring the temperature of the machine tool. Thus, the entire temperature distribution can be obtained by interpolating the measured temperature 3-dimensionally without calculating the heat conduction. A set of experiments was conducted in which the LATSIS was employed to predict the TCP error. A total of 284 sensors were placed on the machining center, and the TCP error was predicted based on the measured temperature for the situation with/without the cutting fluid supply. The results of the prediction showed good agreement with the measured TCP error even during the initial transient temperature change as well as in the cooling phase after the machine halt. The TCP error with the cutting fluid supply is accurately predicted. LATSIS was proven to be a robust and accurate method for predicting the thermal deformation of machine tools, and is a promising technology for future manufacturing systems.     

Investigation report of geotechnical disaster on river area due to typhoon landfall three times on Okhotsk region,Hokkaido, Japan

For one week from August 17 to 23, 2016, three consecutive typhoons made landfall in Hokkaido for the first time on record. These typhoons and the front they stimulated brought record-breaking torrential rain over the eastern part of Hokkaido. To investigate the damage to grounds and rivers resulting from this rainfall, the Japan Society of Civil Engineers (JSCE) and the Japanese Geotechnical Society (JGS) formed a disaster research group to conduct an investigation. This report provides the results of the investigation into damage to the grounds of areas along the Tokoro River of the Okhotsk region, Hokkaido, that suffered from this tremendous and diverse disaster. Specifically, the report describes the situation of the levees which were broken and eroded by the overflowing water, the shape of the levee bodies, the levee body soil properties examined by observation of the sections, as well as the occurrence of sand boiling and air blows. The washout of road embankments as well as damage to road bridge mounting fills and abutment backfills were also investigated. The investigation has demonstrated the need to clarify the resistance of the abutment backfills and levee bodies to flowing water as well as the geotechnical predominant factors in order to clarify the mechanisms behind erosion and washout, the need to review new measures that allow for the scale of sand boiling and resultant changes in levee body stability, and the fact that the existing embankments were able to temporarily suppress the flooding water which had spilled over from the river. Furthermore, although it has been identified that the findings of a study on an embankment washout associated with a tsunami can be applied to measures taken against the overflowing water, it has also been found necessary to clarify the predominant geotechnical factors using model tests and to use a more sophisticated analytical approach to establish a geotechnical stability review as soon as possible in order to prevent the levees and embankments from being eroded and washed out due to overflowing water.     

Trap Levels in Eu and other Rare‐Earth Ions Codoped CaAl2O4 Phosphors

Photoluminescence spectrum, trap depths, and densities of trapped carriers of CaAl₂O₄:Eu phosphor crystals doped with rare‐earth elements were studied using the thermally stimulated luminescence technique. Trap depths and densities of the specimens vary with rare‐earth elements doped as the auxiliary activators. Tm and Nd are found to be effective for the strong afterglow phosphorescence peaking at λ = 442 nm for several hours after the excitation. CaAl₂O₄:Eu phosphor crystals doped with Nd and Tm include high density of carriers trapped at E = 0.59 and 0.52 eV, respectively.     

Role of interfacial potential in coagulation of cuprammonium cellulose solution

The electric potential, copper ion flux, and ammonia flux across the interface of cuprammonium cellulose solution (CCS) and various 1.0 equiv/Lelectrolyte solutions (ES) at 25°C were measured. The interfacial potentials were strongly negative (–10 to –35 mV) with H₂SO_4, HCI, and (NH₄)₂SO₄ as ES, weakly positive (6 to 8 mV) with NaCl, KCl, LiCl, CsCL, and RbCl as ES, and strongly positive (19 to 34 mV) with KOH and NaOH as ES, generally showing values similar to the diffusion potentials for electrolyte solutions comprising ions of the same absolute charge. The ammonia flux (about 1 X 10^-4 mol/cm₂/s) was relatively unaffected by the interfacial potential, but the copper ion flux was clearly dependent on it. These results, together with the observed rates of CCS coagulation, indicate that the mechanism of the coagulation was largely determined by the interfacial potential, with strongly negative potential gradients accelerating the Cu²⁺ flux into the ES and CCS coagulation proceeding rapidly by Cu²⁺ removal, strongly positive potential gradients accelerating the Na⁺ flux into the CCS and coagulation proceeding rapidly via the formation of cellulose-Na⁺ complex, and the absence of a strong potential gradient capable of accelerating the ion flux resulting in slow coagulation by ammonia removal. It may therefore be possible to control the interfacial potential and the ion flux by the ES composition, and thus to influence the structure of regenerated cellulosic fibers and membranes. © 1996 John Wiley & Sons, Inc.     

Multilayered reasoning by means of conceptual fuzzy sets

The real world consists of instances of events and continuous numeric values, while people represent and process their knowledge in terms of symbols. Fuzzy sets provide a strong notation connecting the symbolic representation to the real world. In previously proposed Conceptual Fuzzy Sets (CFS), the meaning of a concept is represented by the distribution of activations of labels in a bidirectional associative memory. In particular, a multilayered structured CFS represents the meaning of the same concept as it is used in various expressions in each layer. The propagation of activations corresponds to reasoning. Therefore, we propose a multilayered reasoning method associated to a multilayered structured CFS, which has the following features: (1) capable of simultaneous symbolic and quantitative processing, (2) capable of simultaneous top-down and bottom-up processing. The effectiveness of the proposed method is illustrated by practical examples of decision regarding the amount of steering in the task of parking a car, and recognition of facial expressions for an image understanding system. © 1996 John Wiley & Sons, Inc.     

新一代超小型DIP-IPM

为了满足空调、洗衣机、冰箱等白色家电对高效、高性能的需要,三菱电机开发了新一代超小型第四代(Ver.4)双列直插封装的智能功率模块(Dual-In-linePackageIntelligentPowerModule,简称DIP-IPM)。本文首先分析了第四代超小型DIP-IPM内部电路的构成和功能,然后详细介绍了第四代DIP-IPM生产过程中的关键技术,包括无铅化、高热传导性绝缘片、chip-to-chip导线直接连接以及ASIC技术,最后与第三代(Ver.3)DIP-IPM进行了比较。     

Development of a new heterojunction structure (ACJ -HIT) and its application to polycrystalline silicon solar cells

A new solar cell structure named HIT (Heterojunction with Intrinsic Thin layer) has been developed based on new artificially constructed junction (ACJ) technology. In this structure a non-doped a-Si thin layer was inserted between the p(a-Si)/n(c-Si) heterojunction, improving the output characteristics and achieving a conversion efficiency of 18.1%. This structure was applied to cast polycrystalline silicon solar cells of a practical size. A high conversion efficeincy of 13.6% was obtained with a cell size of 10 cm × 10 cm using various technologies, including hydrogen plasma passivation.     

Interactive visualization of three-dimensional magnetic fields

In order to observe the physical values (magnetic flux density and eddy current) in 3D magnetic field analysis, an interactive and highly manipulative visualization system depicting stereo images is intalled in a graphics workstation with high functional graphic processors. The system has the following characteristics:

• 1 An interactive and highly manipulative menu window with many functions: it enables visualization of complex phenomena in a 3D field through observation of various combinations of physical values from various viewpoints.
• 2 Simultaneous display of both magnetic flux density and eddy current by using the appropriate use of two colour display methods for stream lines and distribution maps of density: this function facilitates observation of the mutual relations between two physical values in a 3D field.
• 3 Animations and stereo displays: since they give extremely distinct images, observers can easily understand even highly complex 3D phenomena.

In this paper, the calculation method of density vectors, their display methods, and interactive functions are described. Some examples are also illustrated.