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We carried out the intensive observation for the GPM/DPR ground validation at Mt. Zao during 2014–2015 winter season, targeting the melting layer. For the better understanding of microphysics in the melting layer, we developed Ground-based Particle Image and Mass Measurement System (G-PIMMS). It can capture particle images by CCD cameras and measure particle weight by the electronic balance. G-PIMMSs...
Bone metabolism of temporomandibular joint (TMJ) induced by loss of unilateral occlusal support was evaluated using the high resolution positron emission tomography scanner. Highly enhanced metabolic activity of TMJ in the extracted side was observed in the early stage after tooth extraction, and it was gradually decreased.
The Tropical Rainfall Measuring Mission (TRMM) is a joint venture between the National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). The TRMM spacecraft was launched on November 27, 1997. In August 2001, TRMM was boosted to a higher operational altitude of 402.5 km from the initial one of 350 km, to save fuel and extend the mission life. On July 8, 2014,...
This paper presents an iron loss calculation by incorporating the Landau-Lifshitz-Gilbert (LLG) equation into a magnetic circuit model. In the proposed model, dc hysteresis loss is calculated by the LLG equation, and eddy current loss is calculated by a magnetic inductance. The validity is proved by comparing with the catalog values.
Switched reluctance (SR) motors attract attention as a machine without rare-earth materials. And it is a candidate technology for electric vehicle application. However, torque density of SR motors is smaller than that of Permanent Magnet Synchronous Machines (PMSMs). Recently, an axial-gap structure is attention on possibility of effective utilization of in-wheel flat motor space. In the paper, a...
Magnetic gears are becoming attractive since they offer advantages such as low vibration and acoustic noise, and low maintenance operation in comparison with conventional mechanical gears. Planetary type magnetic gears, especially, have larger transmission torque than the other types. Therefore, the planetary type magnetic gears are expected to be put into practical use. In this paper, first, torque...
This paper presents a method for calculating eddy current loss in a permanent magnet (PM) of a surface permanent magnet (SPM) motor based on electric and magnetic networks. First, a reluctance network analysis (RNA) model of the SPM motor and coupling between the RNA model and electric network model are described. To take account of the carrier harmonics caused by PWM switching, input current waveforms...
Both equivalent radar reflectivity factor (Ze) and specific attenuation (k) in several snow events are measured using a dual Ka-band radar system. Different k-Ze relations are obtained depending on surface air temperature. When surface air temperature is just above 0 °C, k-Ze relations scatter and larger k values than those of rain appear. On the other hand, when surface air temperature is below 0...
Information distribution is facilitated by data creation according to XML Schema. The definitions of a term are not uniquely defined between schemas in the same field because anyone can create a schema. Consequently, efforts are being made to share dictionaries of common terms and definitions of common XML Schema in each field as documents. However, in some cases a concept not defined in these documents...
This paper presents a novel magnetic circuit model incorporating micromagnetic simulation. The proposed magnetic circuit model consists of two elements; one is a dc hysteresis element given by the micromagnetic simulation, the other is an inductance element which denotes eddy current loss in silicon steels. In addition, the proposed model can be coupled with an external electric circuit model. The...
This paper presents a novel flux barrier type outer rotor interior permanent magnet (IPM) motor which has both rare-earth and ferrite magnets. The proposed IPM motor has two air layers in the outer rotor. The rare-earth magnets are inserted into the first layer, while the ferrite magnets are placed into the second one. The torque performance of the proposed IPM motor is larger than that of the conventional...
Switched reluctance motors (SR Motors) attract attention as motor that use no rare earth materials. And it is a candidate technology for electric vehicle application. In addition, axial-gap structure has possibility of effective utilization of in-wheel flat motor space. This paper mainly discusses the design and the characteristics of axial-gap SR motors. This study focuses on the volumetric constrains...
A dual Ka-band radar system was developed by the Japan Aerospace Exploration Agency for GPM/DPR algorithm development. The system consists of two identical Ka-band radars. Both the equivalent radar reflectivity factor (Ze) and specific attenuation (k) can be estimated at each range of the path. The estimated k-Ze relations of rain, snow, and the melting layer can be used for the GPM/DPR algorithm...
We have performed Monte Carlo simulation of photoexcited carriers in InAs thin films to investigate effects of the film thickness on the carrier dynamics. We find that the peak value of the time derivative of the current increases (decreases) as the film thickness decreases when the thickness is less than ∼200 nm, under the boundary condition that only holes (both electrons and holes) are confined...
Recently, a blog is well known as a tool for transmitting information easily. However, as the blog spam increases, the method of filtering spam is required to be efficient. In early researches, the method for detecting spam mails with Bayesian filter detects the spam from the characteristics of spam words appearing in spam mails with a high degree of accuracy. How-ever, there are some problems in...
Magnetic gears offer several advantages in comparison with conventional mechanical gears, such as reduced maintenance and acoustic noise, and improved reliability. Various types of magnetic gears have been introduced. Among them, a planetary type magnetic gear has attracted interest recently because its transmission torque is higher, which is expected to be put into practical use. This paper presents...
This paper presents a method for calculating eddy current loss in permanent magnets of a surface permanent magnet (SPM) motor based on electric and magnetic networks. First, an electric network model to calculate the eddy current loss is indicated. Then, to find the resistivity of a Nd-Fe-B magnet, eddy current loss in the magnet is measured by using a test core. Next, a reluctance network analysis...
Real-time burst detection over multiple window size is useful for analyzing data streams. Various burst detection methods have been proposed. However, they are not effective for real-time detection. This work proposes a new burst detection method that reduces computation by avoiding redundant data updates. It analyses an event on its occurrence, and detects the period where arrival frequency rises...
A dual Ka-band radar system is developed by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) dual-wavelength radar (DPR) algorithm development. The usage of the system is to measure backscattering and extinction cross sections by precipitation separately, and to provide testbed data for DPR algorithm. The parameters required in the DPR algorithm are raindrop...
This paper presents a method for calculating eddy current loss based on reluctance network analysis (RNA) considering the magnetic reaction field caused by the eddy current by using magnetic inductance. First, an electric network model for calculating eddy current is indicated. Next, RNA model considering the magnetic reaction field is presented. The validity of the proposed model is proved by comparing...
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