In this paper, analog and digital optical pulse synthesizers using high-resolution arrayed-waveguide gratings (AWG) have been developed. The analog type of optical synthesizer consists of an AWG with ...an integrated 45deg, curved-surfaced mirror, a 4-f lens system, and an optically addressable spatial light modulator. The effective frequency resolution is 14.5 GHz. A dispersion compensation experiment is successfully carried out and a transform-limited short pulse has been obtained. This digital type of optical synthesizer comprises 30 frequency separated channels with a spacing of 12.5 GHz, where each channel includes an amplitude modulator and a phase modulator. The rectangular-shaped pulse is generated with this pulse synthesizer, together with a 12.5-GHz-spacing, optical frequency comb. The synthesizer can generate an optical pulse with any waveform. Moreover, using periodic characteristics of the pulse synthesizer, a 250-GHz repetition rate pulse train was generated, in combination with an ultrawideband, waveguide type of Fabry-Perot electrooptic modulator.
A novel interferometry technique using a frequency-comb light source is proposed for surface profilometry and tomography of discontinuous objects. Surface profile measurement is performed by sweeping ...the comb interval frequency without mechanical scanning. Step heights of 0.5 and 1.0 mm are successfully measured by use of the scheme with 9 mum accuracy.
In this paper, we investigated the imaging condition of asymmetric pulses on a temporal imaging (TI) system comprising two optical fibers and a phase modulator. We introduced a fitness function to ...evaluate the difference between target and output waveforms to quantitatively estimate TI characteristics. We successfully determined the optimal combination of phase modulation index and phase deviation to provide good TI by simulating the fitness function. We generated chirp-free pulses with symmetric and asymmetric waveforms using an in-line waveguide pulse synthesizer, i.e., an optical pulse synthesizer, based on pulse shaping and experimentally confirmed the TI condition in a time lens system. Moreover, TI was achieved not only at a theoretical value of the modulation index satisfying the TI condition but at a much smaller value than the theoretical value for a time-reversal mode as well. Measured waveforms of the experimental output agreed with simulation results. This may be important for practical applications because a TI system requires a much smaller modulation power.
We realized a long-scanning-range and high-resolution interferometry in a time-domain full-field microscopic scheme by adopting a simple configuration. A reference mirror was synchronously scanned ...with an objective lens, which was installed in a common path, to prevent lateral resolution degradation due to defocus at the mirror. High axial resolution was obtained using a broadband supercontinuum (SC) generated by a 1.55 µm pump. The SC was generated by propagating a femtosecond pulse at 1.55 µm through a highly nonlinear dispersion shifted fiber with a small dispersion slope. We designed and constructed an interferometer carefully to utilize the entire bandwidth. The broad bandwidth of the interferometer achieved an axial resolution of 2.50 µm in air. The synchronous scanning maintained a lateral resolution longer than 1 mm. The system successfully yielded a cross-sectional image of two layers of scotch tape along the 400-µm-depth and 90-nm-step surface profiles.
Background The subcallosal artery is a proximal branch of the anterior communicating artery and has been recognized as the vessel responsible for fornix infarction. Fornix infarction caused by ...vascular damage to the posterior circulation has not been reported previously. Results A 26-year-old woman suffered from fornix infarction due to artery-to-artery embolism after vertebral artery dissection. Cerebral infarctions were also found in the left thalamus, body of the left caudate nucleus, and the left occipital lobe other than the fornix. Conclusions Occlusion of the subcallosal artery results in cerebral infarction of fornix, anterior cingulate cortex, and genu of the corpus callosum. However, in our case, lesions were restricted to the territory of posterior circulation. In addition to subcallosal artery, lateral posterior choroidal artery, a perforating branch of the posterior cerebral artery, has been described to send branches to the fornix, so we speculated that the left lateral posterior choroidal artery was actually responsible for fornix infarction.
7-2 Analysis System (XPIA) Kurokawa, Takashi; Nojima, Ryo; Moriai, Shiho
Journal of the National Institute of Information and Communications Technology,
03/2017, Letnik:
63, Številka:
2
Journal Article
Secure Socket Layer(SSL)/Transport Layer Security(TLS) are cryptographic protocols widely used from e-government systems to network services immediately surrounding people, for example, internet ...banking and online shopping. At the same time, the cryptographic attacks against SSL/ TLS have constantly been evolved and sophisticated in step with the development and popularization of online services. In this paper, we show an outline of our research and development for the recent attacks.
This study investigated 1 class in the 5th grade of elementary school (12 boys and 16 girls) who received coaching in endurance running using 3 methods : the all-out method, in which children ran at ...almost full exertion; the inner/outer track (I/OT) method, in which the duration of exercise was equalized by having slower/faster runners use the inner/outer running tracks, respectively; and the rate of perceived exertion (RPE) method, in which children ran at a "fairly light - somewhat hard" intensity. We compared the changes in awareness regarding endurance running and explored the factors responsible for these changes based on exercise intensity and pace strategy. Our results were as follows: 1) Before implementation of the coaching methods, the percentage of those who perceived endurance running favorably was significantly higher for boys (83.3%) than for girls (43.8%) (p ＝ .046) and for other question items, scores for boys were generally higher. 2) After implementation of the coaching methods, favorable responses remained high at 91.7% for boys and increased to 62.5 - 75.0% for girls, irrespective of coaching method. However, there were no significant differences among the 3 methods, and no tendency for the positivity rate to increase for any particular method. 3) For each coaching method, running speed showed a U-shaped curve, with no apparent gender difference. However, the running speed and stride length that contributed to it were significantly higher in boys than in girls. 4) Regardless of gender, the heart rate (HR) observed for each coaching method rose rapidly immediately after the start, and HRs at the 40% and 100% time points had increased to 180.9 -186.5 bpm and 182.1 - 195.3 bpm, respectively, there being no differences among the 3 methods. 5) The RPE taught before running and the RPE just after running almost matched. However, the RPE just after running was 6 (HR 60 beats/min) lower than the HR at the end of running. 6) In conclusion, there were no significant differences between the 3 coaching methods for both sexes in terms of favorable attitudes, irrespective of the type of endurance running, pace pattern or HR. However, endurance running ability and attitude towards endurance running were less favorable for girls than for boys, suggesting that a coaching method designed to develop a favorable attitude is particularly desirable for girls.
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