Applied Mechanics and Materials Vol. 311

Abstract: In this paper, we proposed a method to fabricate a D-shaped optical fiber of Bragg surface grating filter component by D-shaped fiber polishing along with photolithography、holographic interference lithography technologies and micro-molding process. The optical fiber was side-polished until it reaches the core of fiber. The master Bragg grating was first fabricated on the positive photoresister by using the holography interference lithography, then the patterned resist was used as a mother mold to transfer the pattern onto a hard polydimethylsiloxane (hPDMS)/ polydimethylsiloxane (PDMS) mold. The gratings pattern on hPDMS/PDMS was then transferred onto the UV polymer on the surface of a D-shaped fiber using a UV replication process. The transmission spectra of the resulting gratings were measured, with test results showing the transmission dip of -17dB , and 3-dB-transmission bandwidth of 9nm.

Abstract: The bad quality of machining surfaces caused by the micro wear of pressing parts has been a very big trouble for the engineers over the past decades. In order to decrease the surface wear, the technology of heat treatment is used popular. Many papers about the heat treatment technology had been proposed. Especially, the deep cryogenic treatment has been used widely for the purpose of wear-resistance in the industry. Moreover, the method of using variations of surface magnetization to monitor the dynamic tribological properties between the metal pairs has been applied successfully by the author. Therefore, this paper is base on the above statements to further investigate the tribological properties of the tool steel by deep cryogenic treatment. It can be clarified for effects of different deep cryogenic treatment temperatures on wear-resistance of the tool steel DC53. Besides, the purpose of better quality and faster product speed of the pressing process can then be obtained.

Abstract: This article is to design and develop a programming electrocardiogram (ECG) generator. It can be used to test the efficiency of algorithms and to calibration and maintenance of electrocardiograph equipment. We simplified and modified the three coupled ordinary differential equations of McSharry’s model to single differential equation to generate the synthetic ECG waveforms. This generator can provide the adjusted amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters. The system can set the rage of the average gear rate from 20 to 120 beat per minute (BPM) with an adjustable variation of 1 BPM. The parameters of the adjusted synthetic ECG model can be stored in Flash memory of the system through Universal Serial Bus (USB) 2.0 interface. The results were generated four different ECG waveforms for test which are Lead I, Lead II, hyperkalaemia and left bundle branch block. According to the experimental results, the system can not only generate the ECG waveforms of the setting heart rate but also can adjust the different types of ECG waveforms. ECG generator will generate the synthetic electrocardiograms for testing the electrocardiogram analytic algorithms. ECG generator will generate the synthetic electrocardiograms for testing the electrocardiogram analytic algorithms.

Abstract: Auditory phase-synchronization near 40Hz is reportedly related to sensory stimulation. This study applied the phase synchrony analysis and Bi-coherence analyses to analyze the electroencephalographic measurements. Four experimental stages were conducted with 34 healthy high school students to collect the data: (A) resting with eyes closed, (B) listening to the classical music, (C) resting with eyes closed, and (D) listening to popular music. The result shows that the whole brain phase-synchronization occurs at 40Hz and lasts about 400 ms, which is quite different from the estimated 40Hz phase-coupling lasting about 20–25 ms in previous studies and seems to play an important role in inducing auditory attention loss. Additionally, the result also shows that hypersynchronous states may affect perceptual processing. This study develops an original nonlinear time serial analytical approach and suggests that 40Hz phase-synchronization might be an important indicator in perceptual process.

Abstract: Mental rotation is an important psychological process for identifying rotated or misoriented objects. In this study, ERPs were recorded while 18 participants responded to two types of two-dimensional (2D) pictures. The participants matched the pictures of a blank Task without using mental rotation, but used mental rotation to match the pictures of Task A. The ERPs data were analyzed using spatial complexity analysis. The results showed: a) the rotation-related negativity of the ERPs data was shown when mental rotation was performed; b) the EEG data showed a significantly greater synchronization in the fast frequency bands (> 20 Hz) when the participants used their mental rotation ability.

Abstract: Frontal EEG asymmetry has been recognized as a useful method in determining emotional states and psychophysiological conditions. For the current research, resting prefrontal EEG was measured before, during and after listening to sad music video. Data were recorded and analyzed using a wireless EEG module with digital results sent via Bluetooth to a remote computer for further analysis. The relative alpha power was utilized to determine EEG asymmetry indexes. The results indicated that even if a person had a stronger right hemisphere in the initial phase a significant shift first occurred during audio-video stimulation and was followed by a further inclination to left EEG asymmetry as measured after the stimulation. Furthermore the current research was able to use prefrontal EEG to produce results that were mostly measured at the frontal lobe. It was also able to provide significant changes in results using audio and video stimulation as to previous experiments that made use of audio stimulation. In the future, more experiments can be conducted to obtain a better understanding of a person’s appreciation or dislike toward a certain video, commercial or other multimedia contents through the aid of convenient EEG module.

Abstract: The purpose of this study was to utilize prefrontal EEG to discuss the theta EEG on the sleep quality of good and poor sleepers. Prefrontal EEG was chosen as it was positively correlated with reduced performance on neuropsychological tasks during total sleep deprivation. Hence, two test groups of ten volunteers were taken as test groups of good and poor sleepers. In addition, six tasks were performed using single channel forehead EEG. Results showed that audio stimulation provided the largest difference in theta amplitude between good and poor sleepers. Second, a large difference in the theta amplitude could be observed before and after the audio stimulation for poor sleepers. Third, it was also proven that prefrontal EEG could be conveniently applied for studying poor sleep qualities as it exhibited significant changes in the subject’s prefrontal EEG after biofeedback stimulation. In conclusion, the current research was able to provide significant differences between good and poor sleepers using prefrontal EEG through measuring and analyzing EEG theta wave.

Abstract: Because of stress and sleeping obstacle for 21th century people, the purpose of this study is to design a home decorative fabric which has the function of releasing from stress and enhancing sleeping quality. The optical fiber were sewn on the surface of optical fabric in form of three kinds of curvature patterns. Guiding the LED light into the optical fiber, the light will emit out of the optical fiber and stimulate our visual system in order to change the form of brain wave. Afterwards, the EEG instrument was used to evaluate the function of stress relaxation of such fabrics. The results were shown that human’s brain wave can be changed from relaxed and sober status to shallow-sleeping status after the stimulation of light emitting from the optical fiber fabrics. For the effect of causing shallow-sleeping status, female is more significant than male. Therefore, the light stimulating visual system by using the optical fiber fabrics can change the form of brain wave and achieve the effect of stress relaxation.

Abstract: In Taiwan, breast cancer has become the second leading type of cancerous diseases among women. The incidence and mortality rates keep rising, and mammography remains to be the only effective screening technique which is capable of detecting breast cancer at an early stage. High mammographic density is a strong risk factor for breast cancer. Based on BI-RADS categories, mammograms are classified into four categories (D1-D4) based on the percentage of dense area (PDA). However, reporting of breast density suffers from high inter and intra observer variability. Because the risk of breast cancer is at least three times greater in women with density (D3&D4) than in women with density D1, this paper proposes a local entropy method to identify the higher density (D3&D4) from (D1&D2) by two features. There are 406 mammograms with four categories collected for the test. The higher density (D3&D4) can be identified from lower density (D1&D2) in the correction of 100%. The Az of receiver operating characteristic curve of 0.9996 can be achieved.

Abstract: Climate change has increased the vulnerability of physical environments and natural disasters can cause serious loses. Climate change and the plight of the world's indigenous people of Taiwan, the South Island nation and other aboriginal peoples of the world has been a very popular topic and the similarities and differences of both situations are being discussed; it has been suggested that each country should develop its own system to evaluate the disaster risk caused by climate change. Therefore, this study is based on the climate circumstance that drafts evaluation indexes through literature and now saves the most completed existing slabstone houses as the case, review and experts workshop. Furthermore, this study sorts evaluation indexes through the Fussy Delphi method. Finally, the entire evaluation system includes three themes: climate change factor, physical environment condition, and social economic condition. Indictors include: typhoon season, rainy season, summer, geological hazards sensitive area, awaiting migration of the settlements, and slabstone house renovation system.