Volume 3 Issue 4
Authors: Jan O. Jonson
Abstract: This paper demonstrates that Coulomb’s Law can account for the attractive force between two electromagnets, provided the respective currents have the same direction of rotation, the electromagnets being aligned along the same axis. The work is based on earlier research showing that Coulomb’s law can account for the forces between collinear currents in Ampère’s bridge. This was done by recognising the need for analysing the delay of action that can be ascribed the different propagation time for the action between parts of two currents due to their relative distance. This will cause the stationary positive ions bound to the metal lattice in an electric conductor to give rise to a different strength of the force field than the moving electrons. The difference between these fields constitutes the so-called magnetic force. It is also necessary to take into account the Lorentz transformation of lengths according to the Special Relativity theory in order to predict the attractive force between two parallel currents. This result explains why two electromagnets carrying currents with the same rotational direction attract each other. This is shown for the simplistic case of one-winding coils.
Keywords: AmpÈRe’S Law; Coulomb’s Law; Propagation Delay; Electromagnets; AmpÈRe´S Bridge; Lorentz Force; Retarded Action; Special Relativity Theory; Lorentz Transformation
Authors: Yuko Yuko Ichiyanagi; Jun Utsumi
Abstract: We studied Cu/Cu direct bonding by surface activated bonding at room temperature for the application in 3D integration. The Cu film surfaces were activated by irradiating with an Ar fast atom beam in a high vacuum. For the successful bonding, it is necessary to sufficiently remove the native oxide layer and contaminants on the sample surface. The microstructure of the Cu/Cu direct bonding interface was investigated by transmission electron microscopy, and no intermediate layers or voids were visible at the bonding interface. The absence of oxide at the bonding interface was confirmed by energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. Tensile testing revealed that the bonding strength of the Cu-Cu interface was higher than 8 MPa. The current-voltage characteristic of the bonding was linear.
Keywords: Surface Activated Bonding; Room Temperature Bonding; Cu Film; Bonding Interface; Transmission Scanning Microscope (TEM); Energy Dispersion Spectroscopy (EDS); Electron Energy Loss Spectroscopy (EELS)
Authors: Koji Abe; Hiroyoshi Masaki; Haiyan Tian
Abstract: This paper presents a method for extracting features of real sound data from time-frequency images. The features are used for a sound classification equipped for hearing aids. As an application of hearing aids in mind, four classes of “classical music”, “speech”, “multi-talker noise”, and “speech in the noise” are prepared in order to classify the input signal of a hearing aid into useful classes. Although there are several possible ways to figure out which class the current input signal belongs to, an approach from image processing is utilized to find out appropriate features because 2D image (time-frequency image) can contain multifaceted information compared to 1D information (waveform or frequency response of sound), and can be regarded as comprehensive data. It is found that eight features are required to meet a certain quality of sound classification according to our investigation. Experimental results of the sound classification by some clustering machines using the proposed features have shown that accuracy of the classification was more than 95% with every clustering machine.
Keywords: Hearing Aids; Sound Classification; Auditory Scene Analysis; Time-Frequency Image