Tokyo, Japan
Tokyo, Japan

Tamagawa University is a Japanese university in Machida, Tokyo, Japan. The university consists of 16 departments in seven faculties , as well as seven programs leading to a master’s degree and four programs leading to a doctorate degree. Part of the Tamagawa Gakuen campus, the school was founded by influential Japanese education reformer Kuniyoshi Obara. Wikipedia.


Time filter

Source Type

Patent
IHI Corporation and Tamagawa University | Date: 2010-11-03

The present invention relates to a hydrogen supply device which supplies hydrogen by selectively permitting permeation of hydrogen contained in a hydrogen containing gas (G1). This device includes: a first metal layer (2) which dissociates hydrogen molecules into hydrogen ions by a catalytic reaction and has hydrogen permeability; a second metal layer (3) which creates hydrogen molecules by bonding hydrogen ions to each other using electrons and has hydrogen permeability; a hydrogen permeation layer (1) which is interposed between the first metal layer (2) and the second metal layer (3) and permits permeation of the hydrogen ions from the first metal layer (2) to the second metal layer (3) by the application of a voltage; and a voltage application (7) for applying the voltage to the hydrogen permeation layer (1) by setting the first metal layer (2) as an anode and setting the second metal layer (3) as a cathode. According to this device, even when the concentration of hydrogen is low, it is possible to dissociate hydrogen from a hydrogen containing gas, and to suppress noise during the operation of the device.


Takiyama K.,Tamagawa University | Hirashima M.,Osaka University | Nozaki D.,University of Tokyo
Nature Communications | Year: 2015

Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the models novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. © 2015 Macmillan Publishers Limited. All rights reserved.


The functions of juvenile hormone in the physiological and behavioral maturation in Apis mellifera males (drones) were investigated by application of a juvenile hormone analog, methoprene. No evidence was found for the stimulation of maturation of male reproductive organs by methoprene. The dry weight of the seminal vesicle and reproductive accessory gland was slightly but significantly lighter in drones treated with a high dose (100 or 500 μg/male) of methoprene than drones treated either with a low dose (1 or 10 μg/male) or solvent control only. Methoprene accelerated in-colony male movement from the center to the periphery. It also induced earlier diet transition from pollen and jelly-like materials to honey. These results suggest that juvenile hormone acts as a behavioral pacemaker rather than as a gonadotropin in drones. © 2013 INRA, DIB and Springer-Verlag France.


Shirasaki H.,Tamagawa University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

In this paper, we show the 2D and 3D scatterometry simulation software which has spectroscopy calculation and optimization algorithm systems. The scatterometry analysis for 3D-structure requires a lot of memory and along calculation time. The calculation is sped up by parallel computing using the GPU (Graphics Processor Unit). Here, we use the programming language CUDA (Compute Unified Device Architecture) and CULA (CULApack) for the NVIDIA GPU. Then, we use the real-coded GA (RCGA) to increase the population, to make a more sensitive solution and to get better fitting groove figures. The scatterometry characteristic is examined by choosing the n-th power cosine type period groove. © 2013 SPIE.


The idea of planned production of vegetables using a factory has been suggested for many years as a technology extending the application of greenhouse horticulture. However, it has not been a very long time since the world's first systematized vegetable factory appeared for commercial production. Development of vegetable factories in Japan was started in the second half of the 1970s, and subsequently many companies like manufacturers of electrical appliances, food producers, and electric power companies and so on began technology development work in this field. Currently, Japan is one of the most active countries in the world in technology development in this field. If the goals of vegetable production in factory are fully planned production and cultivation management, then in terms of lighting, a fully controlled system using artificial light only is superior to a sunlight/artificial light combined system. However, one issue with artificial lighting is the running cost, especially the cost of electricity for lighting and air conditioning. Estimates based on high pressure sodium lamps and fluorescent light indicate that lighting accounts for approximately 40% of the total running cost for vegetable production. Therefore, it is essential that electricity costs for lighting and air conditioning should be lowered in order to develop a practical vegetable factory that uses fully controlled artificial light. Light-emitting diodes (LEDs) are featured with a narrow light-emitting spectrum, enabling them to focus light on plants with just the required wavelength of light. In addition, it is possible to completely reduce thermal infrared radiation. This means the light source can be positioned very close to plants. Furthermore, the lack of infrared radiation is an important cost advantage in terms of managing the temperature of a closed vegetable cultivation system. This article will overview the history and technology development of the light-controlled plant cultivation system in Japan, especially comparing the performance and characteristics of lighting devices for vegetable cultivation.


Shirasaki H.,Tamagawa University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

In this paper, we examine the sensitivity of scatterometry for the isolation mounts on the substrate by applying PML in RCWA. We analyze the reflectance from the silicon and resist single mount and the silicon double mounts on the silicon substrate. First, we investigate the mode convergences and the beam width dependences of reflectance. Second, we show the propagation properties of the electromagnetic fields propagating for the isolation mounts on the silicon substrate. Finally, we examine the wavelength properties of reflectance calculated by changing the beam width, the mount width and the mount height for single mount and the silicon mount positions for the double silicon mounts. Then, we understand that the scatterometry observation is possible in several decade microns beam width. © 2014 SPIE.


Kato K.,Tamagawa University
IEEE International Symposium on Information Theory - Proceedings | Year: 2012

The necessary and sufficient conditions for the minimax strategy of a finite number of decisions in quantum signal detection are derived in the case that the average Bayes cost is used as a quality function. This is a simple extension of the result of Hirota and Ikehara [1]. Applying the necessary and sufficient conditions, a closed-form expression of the minimax strategy for binary pure state signal is shown. Furthermore, the minimax strategy for a discrimination problem of the quasi-Bell states is considered. In this case, the square-root measurement consisting of the quasi-Bell states yields the minimax strategy. © 2012 IEEE.


Futami F.,Tamagawa University
Quantum Information Processing | Year: 2014

Quantum Enigma Cipher is an epoch-making concept in the cryptography that may break the Shannon limit of the cryptography. Yuen-2000 (Y-00) protocol is a first generation toward the Quantum Enigma Cipher that overcomes the Shannon limit in cryptography relying on macroscopic quantum effects. Current Y-00 cipher is an encryption scheme where noise masking blocks an eavesdropper’s reading of the physical ciphertext consisting of the mathematical structure. No such masking effect is realized only by using the mathematical encryption, because mathematical ciphertexts are composed of binary signals, “0” or “1” or deterministic symbols, and they are correctly discriminated. Y-00 cipher is one of the candidates to provide high transmission performance and a provable security simultaneously in the real world. In our present, Y-00 cipher, mathematical cipher and physical phenomena are combined. It features multi-level signaling by mathematical cipher and noise masking to hide the ciphertext in the quantum noise and other channel noise. In the paper, transmission performance of Y-00 cipher is experimentally investigated. A running test for 60 days of Y-00 cipher transceiver at 2.5 Gbit/s is demonstrated. In addition, a trial of a current direct modulation scheme using 4096 signal levels for realizing a compact Y-00 transceiver is demonstrated. Furthermore, a wavelength-division multiplexing transmission of Y-00 cipher is experimentally demonstrated, and 100-Gbit/s Y-00 cipher transmission is successfully transmitted over 120 km. © 2014, Springer Science+Business Media New York.


A configuration method of an optical signal, an encryption device, and an encryption system makes it possible for a legitimate communicating party to ensure information-theoretic security against a known plain text attack and to communicate long-distance. By adding a transmission information data sequence randomization device to the Yuen encrypted communications device according to the present information, which divides transmission information data into blocks, appends sequence numbers thereto, randomly switches the sequence of the blocks with a digitized signal of output of an electrical noise generator, and inputs same into a transmission data generator of a conventional Yuen encrypted optical transmitter, the relation between a known transmission information data sequence (plain text) and an optical signal which is outputted from the transmitter is randomized, allowing forcibly making even a circumstance wherein a known-plain text attack would be possible into a cipher-text-only attack, realizing information-theoretic security against a known-plain text attack.


Provided are a configuration method of an optical signal, an encryption device, and an encryption system whereby it is possible for a legitimate communicating party to ensure information-theoretic security against a known plain text attack as well as to communicate long-distance. By adding a transmission information data sequence randomization device to the Yuen encrypted communications device according to the present information, which divides transmission information data into blocks, appends sequence numbers thereto, randomly switches the sequence of the blocks with a digitized signal of output of an electrical noise generator, and inputs same into a transmission data generator of a conventional Yuen encrypted optical transmitter, the relation between a known transmission information data sequence (plain text) and an optical signal which is outputted from the transmitter is randomized, allowing forcibly making even a circumstance wherein a known-plain text attack would be possible into a cipher-text-only attack, realizing information-theoretic security against a known-plain text attack.

Loading Tamagawa University collaborators
Loading Tamagawa University collaborators