Creating and retargetting motion by the musculoskeletal human body model

Recently, optimization has been used in various ways to interpolate or retarget human body motions obtained by motion-capturing systems. However, in such cases, the inner structure of a human body has rarely been taken into account, and hence there have been difficulties in simulating physiological effects such as fatigue or injuries. In this paper, we propose a method to create/retarget human body motions using a musculoskeletal human body model. Using our method, it is possible to create dynamically and physiologically feasible motions. Since a muscle model based on Hill's model is included in our system, it is also possible to retarget the original motion by changing muscular parameters. For example, using the muscle fatigue model, a motion where a human body gradually gets tired can be simulated. By increasing the maximal force exertable by the muscles, or decreasing it to zero, training or displacement effects of muscles can also be simulated. Our method can be used for biomechanically correct inverse kinematics, interpolation of motions, and physiological retargetting of the human body motion.     

ANIMENGINE: An Engineering Animation System

CIM animation systems are designed to provide exact and unambiguous displays of moving objects. This system also offers a special geometric model for almost real-time display.     

Calculation and visualization of the dynamic ability of the human body

There is a great demand for data on the mobility and strength capability of the human body in many areas, such as ergonomics, medical engineering, biomechanical engineering, computer graphics (CG) and virtual reality (VR). This paper proposes a new method that enables the calculation of the maximal force exertable and acceleration performable by a human body during arbitrary motion. A musculoskeletal model of the legs is used for the calculation. Using our algorithm, it is possible to evaluate whether a given posture or motion is a feasible one. A tool to visualize the calculated maximal feasibility of each posture is developed. The obtained results can be used as criteria of manipulability or strength capability of the human body, important in ergonomics and human animation. Since our model is muscle‐based, it is possible to simulate and visualize biomechanical effects such as fatigue and muscle training. The solution is based on linear programming and the results can be obtained in real time. Copyright © 1999 John Wiley & Sons, Ltd.     

Negative-chirp electroabsorption modulator using low-wavelengthdetuning

The negative chirp of an electroabsorption modulator having an α-parameter value of 0 to -0.5, at an input light wavelength of 1.55-1.56 μm, has been developed by optimizing the bandgap energy of an InGaAsP bulk absorption layer. We have demonstrated successful transmission with 10 Gb/s NRZ modulation over a 100-km span of standard fiber without resort to dispersion compensation     

Surface coding based on Morse theory

Coding system requirements are briefly discussed. Classical Morse theory, which was primarily motivated by the calculus of variations, is reviewed. The limits of the theory are examined, and an extension that enables 3-D surfaces to be accurately reconstructed from cross sections is presented. The resulting coding works interactively with a range of surface reconstruction systems. The prototype coding system is applied to representing the hierarchical structure of contours     

Tuning characteristics of monolithic passively mode-lockeddistributed Bragg reflector semiconductor lasers

Tuning characteristics of multicontact passively mode-locked distributed Bragg reflector (DBR) semiconductor lasers are investigated in terms of center wavelengths and pulse repetition frequencies. It is shown that the center wavelength of the pulses can be tuned over a wide range by changing the refractive index of the Bragg reflector section either by means of carrier injection or by thermal effects while maintaining the pulses to be nearly transform-limited. Tuning of the pulse repetition rates is realized by using four different approaches, i.e., current injection to a passive phase-control section, varying of the reverse bias to the absorber, varying of the injection current to the gain region, and thermal effects. Injecting current into the phase-control region results in a tuning range of more than 400 MHz while maintaining the pulses at transform-limited condition. Varying the reverse bias voltage to the absorber is shown to be an alternative to achieve large repetition rate tuning, by which a tuning range of 600 MHz is obtained. By combining these tuning schemes, a total tuning range of more than 1 GHz is realized     

Crystallographic defects in thermally oxidized wafer bonded silicon on insulator (SOI) substrates

The crystalline quality of wafer bonded (WB) silicon on insulator (SOI) structures thermal treated in dry oxygen ambients has been investigated by means of transmission electron microscopy and defect etching. The main crystallographic defects present in the SOI layers are dislocations, amorphous precipitates, and oxidation induced stacking faults (OISF). The evolution of the OISFs with time and temperature has also been investigated. The main feature observed is that the OISF in WB SOI structures undergo a retrogrowth process at temperatures around T = 1195°C for times of t = 2h. This result is very similar to that recently reported for oxygen implanted SOI (SIMOX) but considerably different from that observed in bulk silicon. The experimental data fits nicely a model recently proposed for the retrogrowth of OISF in thin SOI layers. This model considers that the self-interstitial supersaturation is considerably reduced compared to bulk silicon due to the relative fast point defect recombination inside the top silicon layer.     

Effects of Cu, Ag and Sb on the creep-rupture strength of lead-free solder alloys

The materials used in the present research are pure Sn metal and Sn-0.5% Cu, Sn-3.5%Ag, Sn-0.3%Sb, and Sn-3.5%Ag-0.5%Cu alloys. Effects of Cu, Ag and Sb on the creep-rupture strength of lead-free solder alloys have been investigated. Creep tests are performed at the stress and temperature range of 3 to 12 MPa and 378 to 403 K, respectively. A 3.5% addition of Ag had the largest contribution to the creep-rupture strength of Sn metal among the single addition of 0.5%Cu, 3.5%Ag, and 0.3%Sb. The combined addition of 3.5%Ag and 0.5%Cu makes the largest creep-rupture strength. The effects of these elements on the microstructure of the lead-free alloys are also investigated with optical microscope (OM) and transmission electron microscope (TEM) observations.