Browsing by Issue Date, starting with "2020-01-22"

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Conformal Electrodeposition of Co-Ni to Improve the Mechanical Properties of Three-Dimensional Ordered Macroporous Ni Films
(2020-01-22)
Wang, Guang-Ren
;
Hung, Pei-Sung
;
Chang, Shou-Yi
;
Yang, Jenn-Ming
;
Tseng, Yuan-Chieh
Three-dimensional ordered macroporous Ni films, known as Ni inverse opals, are fabricated via a template approach in which polystyrene (PS) microspheres (820 nm in diameter) are assembled in closely-packed colloidal crystals via a vertical electrophoresis process, followed by electroplating of Ni into the interstitial voids within the colloidal crystals and the selective removal of PS microspheres. To improve its mechanical strength, a conformal Ni-Co layer (45 similar to 64 nm) is electrodeposited on the skeletons of the Ni inverse opals by cyclic voltammetry. After coating, from nano-indentation tests, the hardness and reduced elastic modulus are enhanced considerably (172 similar to 220% for hardness; 72 similar to 79% for reduced elastic modulus), as compared to those of pristine inverse opals. After an annealing treatment for the interdiffusion of Ni and Co, the sample reveals an even stronger hardness. X-ray diffraction patterns indicate that the finite thickness of the inverse opals skeletons induces preferential growth of the (111) plane. In short, a combined effect of solid solution alloying, thickening of inverse opals skeletons for greater load bearing, and a predominant (111) plane is responsible for the improved mechanical strength of the Ni inverse opals. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
Ballistic Impact Performance of SiC Ceramic-Dyneema Fiber Composite Materials
(2020-01-22)
Wu, Kai-Kuang
;
Chen, Yu-Liang
;
Yeh, Jau-Nan
;
Chen, Wei-Lun
;
Lin, Chia-Shih
This study investigated the ballistic resistance of a composite target plate fabricated by combining SiC ceramic with the Dyneema fiber. To achieve a light-weight target plate that conforms to the US National Institute of Justice level four (NIJ IV) standards, minimal areal density analysis was conducted to obtain the optimal SiC ceramic-Dyneema fiber thickness combination. This study used energy absorption to analyze the ballistic resistance of the target plates. To drastically reduce experimental costs, most of this work employed ANSYS/LS-DYNA software to conduct finite element numerical simulations. First, ballistic experiments that conformed to NIJ IV standards were conducted to verify the simulation parameter configurations. Subsequently, the correlation function of the relationship between the combined thickness of the composite material and its ballistic resistance was determined through the experimental design, which effectively reduced the simulation analysis time. According to simulation experiments and regression analysis, the equation for the relationship between the combined thickness of the composite material and its ballistic resistance was EA though there were limitations to its application. From the numerical analysis results, 8.1940 mm SiC ceramic and 6.9637 mm Dyneema fiber were determined to constitute the optimal thickness combination for a composite that features a minimal areal density and which conforms to NIJ IV standards. The combination was verified to be consistent with the numerical simulation analysis results.
Demographics of Pediatric OHCA Survivors With Postdischarge Diseases: A National Population-Based Follow-Up Study
(2020-01-24)
Lee, Tsung-Han
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Juan, I-Cheng
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Hsu, Hsiu-Ying
;
Chen, Wen-Liang
;
Huang, Cheng-Chieh
Background: Postdischarge diseases (PDDs) have been reported for adult survivors of out-of-hospital cardiac arrest (OHCA). However, the detailed demographics of pediatric OHCA survivors with PDDs are not well-documented, and information regarding functional survivors is particularly limited. We aimed to report detailed information on the PDDs of survivors of traumatic and non-traumatic pediatric OHCA using a national healthcare database. Methods: We retrospectively obtained data from the Taiwan government healthcare database (2011-2015). Information on the demographics of traumatic and non-traumatic pediatric OHCA survivors (<20 years) was obtained and reported. The patients who survived to discharge (survivors) and those classified as functional survivors were followed up for 1 year for the analysis of newly diagnosed PDDs. The time from discharge to PDD diagnosis was also reported. Results: A total of 2,178 non-traumatic and 288 traumatic OHCA pediatric cases were included. Among the non-traumatic OHCA survivors (n = 374, survival rate = 17.2%), respiratory tract (n = 270, 72.2%), gastrointestinal (n = 187, 50.0%), and neurological diseases (n = 167, 49.1%) were the three most common PDD categories, and in these three categories, the majority of PDDs were atypical/influenza pneumonia, non-infective acute gastroenteritis, and generalized/status epilepsy, respectively. Among the traumatic OHCA survivors (n = 21, survival rate = 7.3%), respiratory tract diseases (n = 17, 81.0%) were the most common, followed by skin or soft tissue (n = 14, 66.7%) diseases. Most functional survivors still suffered from neurological and respiratory tract diseases. Most PDDs, except for skin or soft tissue diseases, were newly diagnosed within the first 3 months after discharge. Conclusions: Respiratory tract (pneumonia), neurological (epilepsy), and skin or soft tissue (dermatitis) diseases were very common among both non-traumatic and traumatic OHCA survivors. More importantly, most PDDs, except for skin or soft tissue diseases, were newly diagnosed within the first 3 months after discharge.
Longitudinal and quantitative assessment platform for concurrent analysis of anti-tumor efficacy and cardiotoxicity of nano-formulated medication in vivo
(2020-01-25)
Tu, Wei-Ming
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Huang, Xin-Chun
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Chen, Yen-Ling
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Luo, Yun-Ling
;
Liau, Ian
Increasing nanomedicinal approaches have been developed to effectively inhibit tumor growth; however, critical questions such as whether a nanomedicinal approach can mitigate latent side effects are barely addressed. To this end, we established a zebrafish xenograft tumor model, combining pseudodynamic three-dimensional cardiac imaging and image analysis to enable simultaneous and quantitative determination of the change of tumor volume and cardiac function of zebrafish upon specific nanoformulation treatment. Doxorubicin (DOX), a well-known chemotherapeutic agent with cardiotoxicity, and a recently developed DOX-loaded nanocomposite were employed as two model drugs to demonstrate the effectiveness to utilize the proposed evaluation platform for rapid validation. The nanoformulation significantly mitigated DOX-associated cardiotoxicity, while retaining the efficacy of DOX in inhibiting tumor growth compared to administration of carrier-free DOX at the same dose. We anticipate that this platform possesses the potential as an efficient assessment system for nanoformulated cancer therapeutics with suspected toxicity and side effects to vital organs such as the heart. (C) 2019 Elsevier B.V. All rights reserved.
Analysis of the back-barrier effect in AlGaN/GaN high electron mobility transistor on free-standing GaN substrates
(2020-01-25)
Liu, Xinke
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Wang, Hao-Yu
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Chiu, Hsien-Chin
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Chen, Yuxuan
;
Li, Dabing
The effect of AlGaN back-barrier on AlGaN/GaN high electron mobility transistors (HEMTs) using freestanding GaN wafer has been investigated in this work. With the introducing back-barrier structure, the leakage path underneath the buffer (native nitrogen-vacancies and GaOx compounds of the HVPE-grown free-standing GaN surface) layer can be suppressed by lift-up the conduction band. As compared with AlGaN/GaN HEMTs on SiC wafer, AlGaN/GaN HEMTs on free-standing GaN wafer show enhanced drain current ( 700 mA/mm), improved transconductance (143 mS/mm), less current collapse (12%), higher current gain cut-off frequency (13 GHz), and maximum stable gain cut-off frequency (24 GHz), which is attributed to the higher epi quality layer on free-standing GaN wafer. (C) 2019 Elsevier B.V. All rights reserved.
Challenges in the design, planning and implementation of trials evaluating group interventions
(2020-01-29)
Biggs, Katie
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Hind, Daniel
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Gossage-Worrall, Rebecca
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Sprange, Kirsty
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White, David
Background Group interventions are interventions delivered to groups of people rather than to individuals and are used in healthcare for mental health recovery, behaviour change, peer support, self-management and/or health education. Evaluating group interventions in randomised controlled trials (RCTs) presents trialists with a set of practical problems, which are not present in RCTs of one-to-one interventions and which may not be immediately obvious. Methods Case-based approach summarising Sheffield trials unit's experience in the design and implementation of five group interventions. We reviewed participant recruitment and attrition, facilitator training and attrition, attendance at the group sessions, group size and fidelity aspects across five RCTs. Results Median recruitment across the five trials was 3.2 (range 1.7-21.0) participants per site per month. Group intervention trials involve a delay in starting the intervention for some participants, until sufficient numbers are available to start a group. There was no evidence that the timing of consent, relative to randomisation, affected post-randomisation attrition which was a matter of concern for all trial teams. Group facilitator attrition was common in studies where facilitators were employed by the health system rather than the by the grant holder and led to the early closure of one trial; research sites responded by training 'back-up' and new facilitators. Trials specified that participants had to attend a median of 62.5% (range 16.7%-80%) of sessions, in order to receive a 'therapeutic dose'; a median of 76.7% (range 42.9%-97.8%) received a therapeutic dose. Across the five trials, 75.3% of all sessions went ahead without the pre-specified ideal group size. A variety of methods were used to assess the fidelity of group interventions at a group and individual level across the five trials. Conclusion This is the first paper to provide an empirical basis for planning group intervention trials. Investigators should expect delays/difficulties in recruiting groups of the optimal size, plan for both facilitator and participant attrition, and consider how group attendance and group size affects treatment fidelity.
Structure-Dependent Photoluminescence in Low-Dimensional Ethylammonium, Propylammonium, and Butylammonium Lead Iodide Perovskites
(2020-01-29)
Lin, Chang-Wei
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Liu, Fangzhou
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Chen, Ting-Yang
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Lee, Kuan-Hua
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Chang, Chung-Kai
Hybrid organic-inorganic perovskites have attracted great attention as the next generation materials for photovoltaic and light-emitting devices. However, their environment instability issue remains as the largest challenge for practical applications. Recently emerging two-dimensional (2D) perovskites with Ruddlesden-Popper structures are found to greatly improve the stability and aging problems. Furthermore, strong confinement of excitons in these natural quantum-well structures results in the distinct and narrow light emission in the visible spectral range, enabling the development of spectrally tunable light sources. Besides the strong quasi-monochromatic emission, some 2D perovskites composed of the specific organic cations and inorganic layer structures emit a pronounced broadband emission. Herein, we report the light-emitting properties and the degradation of low-dimensional perovskites consisting of the three shortest alkylammonium spacers, mono-ethylammonium (EA), n-propylammonium (PA), and n-butylammonium (BA). While (BA)(2)PbI4 is known to form well-oriented 2D thin films consisting of layers of corner-sharing PbI6 octahedra separated by a bilayer of BA cations, EA with shorter alkyl chains tends to form other types of lower-dimensional structures. Nevertheless, optical absorption edges of asprepared fresh EAPbI(3), (PA)(2)PbI4, and (BA)(2)PbI4 are obviously blue-shifted to 2.4-2.5 eV compared to their 3D counterpart, methylammonium lead iodide (MAPbI(3)) perovskite, and they all emit narrow excitonic photoluminescence. Furthermore, by carefully optimizing deposition conditions, we have achieved a predominantly 2D structure for (PA)(2)PbI4. However, unlike (BA)(2)PbI4, upon exposure to ambient environment, (PA)(2)PbI4 readily transforms to a different crystal structure, exhibiting a prominently broadband light from similar to 500 to 800 nm and a gradual increase in intensity as structural transformation proceeds.
RiceTalk: Rice Blast Detection Using Internet of Things and Artificial Intelligence Technologies
(2020-02-01)
Chen, Wen-Liang
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Lin, Yi-Bing
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Ng, Fung-Ling
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Liu, Chun-You
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Lin, Yun-Wei
Rice blast is one of the most serious plant diseases. Many rice blast management approaches require know-how of experienced farmers or agronomists. Monitoring the farm for disease detection is labor intensive and time consuming. By using the Internet of Things (IoT) and artificial intelligence (AI), we are able to detect plant diseases more efficiently. Existing AI and IoT studies detect plant diseases by images or nonimage hyperspectral data, which require manual operations to obtain the photographs or data for analysis. Also, image detection typically is too late as rice blast may already spread to other plants. Based on an IoT platform for soil cultivation, we develop the RiceTalk project that utilizes nonimage IoT devices to detect rice blast. Unlike the image-based plant disease detection approaches, our agriculture sensors generate nonimage data that can be automatically trained and analyzed by the AI mechanism in real time. The beauty of RiceTalk is that the AI model is treated as an IoT device and is managed like other IoT devices. In this way, our approach significantly reduces the platform management cost to provide real-time training and predictions. We also propose an innovative spore germination mechanism as a new feature extraction model for agriculture. In the current implementation, the accuracy of the RiceTalk prediction on rice blast is 89.4%.
Discrimination of Severity of Alzheimer's Disease with Multiscale Entropy Analysis of EEG Dynamics
(2020-02-01)
Hsu, Chang Francis
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Chao, Hsuan-Hao
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Yang, Albert C.
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Yeh, Chih-Wei
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Hsu, Long
Multiscale entropy (MSE) was used to analyze electroencephalography (EEG) signals to differentiate patients with Alzheimer's disease (AD) from healthy subjects. It was found that the MSE values of the EEG signals from the healthy subjects are higher than those of the AD ones at small time scale factors in the MSE algorithm, while lower than those of the AD patients at large time scale factors. Based on the finding, we applied the linear discriminant analysis (LDA) to optimize the differentiating performance by comparing the resulting weighted sum of the MSE values under some specific time scales of each subject. The EEG data from 15 healthy subjects, 69 patients with mild AD, and 15 patients with moderate to severe AD were recorded. As a result, the weighted sum values are significantly higher for the healthy than the patients with moderate to severe AD groups. The optimal testing accuracy under five specific scales is 100% based on the EEG signals acquired from the T4 electrode. The resulting weighted sum value for the mild AD group is in the middle of those for the healthy and the moderate to severe AD groups. Therefore, the MSE-based weighted sum value can potentially be an index of severity of Alzheimer's disease.
Thermal Relaxation Spectra for Evaluating Luminescence Quantum Efficiency of CASN:Eu2+ Measured by Balanced-Detection Sagnac-Interferometer Photothermal Deflection Spectroscopy
(2020-02-01)
Chima, Hiromichi
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Shiokawa, Naoyuki
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Seto, Keisuke
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Takahashi, Kohsei
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Hirosaki, Naoto
Highly sensitive broadband photothermal spectroscopy with a white-light lamp as the excitation source was developed by combining a Sagnac interferometer and balanced detection with a photothermal deflection method. A probe beam was split by a birefringent crystal CaCO3 into signal and reference beams with a balanced intensity. This balanced detection enabled the measurement of photoexcited thermal relaxation spectra of materials in the air over the whole visible range in the weak excitation limit 50 mu W/cm(2). The photothermal excitation spectrum of Eu2+-doped CaAlSiN3 phosphors (CASN:Eu2+) with a high luminescent quantum efficiency was measured to be distinctly different from the photoluminescence excitation spectrum which reflects the absorption spectrum, revealing the thermal relaxation mechanism of the phosphor. Assuming a typical non-radiative relaxation from the higher excited states to the lowest excited state and successively to the ground state, it is demonstrated that the photoluminescence efficiency of the phosphors is readily evaluated simply by comparing the photothermal and photoluminescence excitation spectra.
Effects of surface inclination and type of surface roughness on the nucleate boiling heat transfer performance of HFE-7200 dielectric fluid
(2020-02-01)
Tran, Ngoctan
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Sajjad, Uzair
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Lin, Rick
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Wang, Chi-Chuan
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機械工程學系
In the present work, the effects of surface roughness (including roughness from machined roughness and sandblasted roughness), surface inclinations, and heat fluxes on the nucleate pool boiling heat transfer of HFE-7200 dielectric liquid at a working pressure of 1 atm. are examined in detail. Five aluminum surfaces, with different roughness from 0.45 mu m to 9 mu m, are employed as test samples. The nucleate boiling phenomenon is examined with the wall-superheat temperature ranging from 5 degrees C to 30 degrees C, and surface inclinations of 0 degrees, 90 degrees, and 180 degrees, respectively. SEM images and nucleate boiling bubbles captured by a high-speed camera are utilized for further analyses. For all cases in this study, it is found that the nucleate boiling heat transfer of the sandblasted rough surfaces is superior to those of the polished and machined rough surfaces. For instance, at a wall-superheat temperature of 30 degrees C and inclination angle of 0 degrees, the heat flux is augmented up to 69.7%, and 139.3% when compared to the polished surface for the sandblasted surfaces with the roughness of 6.2 mu m, and 9 mu m, respectively. In addition, novel correlations are also proposed for predicting the nucleate pool boiling heat transfer coefficient of HEF-7200 dielectric fluid with different surface roughness, inclinations and heat fluxes. (C) 2019 Elsevier Ltd. All rights reserved.
Highly efficient blue and white light-emitting electrochemical cells employing substrates containing embedded diffusive layers
(2020-02-01)
Chen, Yan-Zhi
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Luo, Dian
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Hsiang, Chi-Haw
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Yi, Rong-Huei
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Lin, Ching-Hsuan
Enhancing device efficiencies of the blue and white light-emitting electrochemical cells (LECs) is realized by employing substrates with embedded diffusive layers containing scattering TiO2 nanoparticles (NPs). The diffusive layers can eliminate the influence of microcavity effect on the output electroluminescence (EL) spectrum and recover the intrinsic EL spectrum of the emissive layer. The emission zone positions of the blue and white LECs are estimated by fitting the measured EL spectra with the simulated EL spectra based on precisely tuned emission zone positions. Incorporating red-emitting guest dopant in the white LEC results in shifted emission zone toward the cathode due to enhanced electron trapping. The external quantum efficiency (EQE) of the blue and white LECs employing proper diffusive substrates can be enhanced by 260 and 210%, respectively. The maximal EQE (power efficiency) of the blue and white LECs reach 35.4% (83.4 lm W-1) and 22.0% (41.6 lm W-1), respectively. These promising device efficiencies confirm the potential applications for the proposed diffusive substrates in enhancing light extraction from LECs. In addition, adjusting the effective refractive index of the diffusive layer has distinct effect on different EL emission color. With well confined optical field of blue EL in indium tin oxide layer, lower effective refractive index of the diffusive layer results in higher refractive index difference between the scattering TiO2 NPs and the host medium, rendering higher scattering efficiency and more light extraction. In contrast, higher effective refractive index of the diffusive layer leads to unguided red EL extending into the diffusive layer and more light can be outcoupled. These results show that the effective refractive index of the diffusive layer should be judiciously chosen according to the emission color of EL to be extracted.
Abnormal High Resistive State Current Mechanism Transformation in Ti/HfO2/TiN Resistive Random Access Memory
(2020-02-01)
Zhou, Kuan-Ju
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Chang, Ting-Chang
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Lin, Chih-Yang
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Chen, Chun-Kuei
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Tseng, Yi-Ting
In this letter, the electrical characteristics of Ti/HfO2/TiN resistive random access memory (RRAM) were thoroughly investigated. An abnormal current degradation was seen in the DC sweeping cycle. Both the on-state and off-state current clearly exhibited degradation with time. Next, current fitting analysis was used to investigate the carrier transport mechanisms. The results indicate that the on-state carrier transport mechanism changed from space-charge-limited current into hopping conduction after cycle sweeping. However, the off-state current changes from Schottky thermal emission to hopping conduction. Based on comparisons of different Schottky distances and Schottky barriers, physical models were proposed to explain the abnormal current degradation behavior. Finally, COMSOL electric field simulations were used to show the electric field distribution around the conducting filament (CF), and the conducting model was subsequently verified.
Strengthening long-term job performance: The moderating roles of sense of responsibility and leader's support
(2020-02-01)
Lin, Chieh-Peng
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Tsai, Meng-Keng
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交大名義發表
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National Chiao Tung University
Drawing upon human capital theory and attachment theory, this study develops a research model that examines how on-the-job training (OJT) effectiveness and work engagement play key mediating roles in the development of job performance. In the proposed model, job performance is indirectly influenced by cultural learning, professional learning, and mentorship learning via the full mediation of OJT effectiveness. At the same time, job performance is also influenced by social interaction, leader support, and self-efficacy via the full mediation of work engagement. Employees' sense of responsibility and leader support both play moderating roles in the research model. The hypotheses were empirically tested using both primary data from a survey on new employees of a leading financial holding company in Taiwan's banking industry and secondary data from the company's database of human resource management (HRM) regarding the training and education of the new employees. JEL Classification: D23, M53, O15
Spontaneously Micropatterned Silk/Gelatin Scaffolds with Topographical, Biological, and Electrical Stimuli for Neuronal Regulation
(2020-02-01)
Lin, Chun-Chang
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Chang, Jing-Jing
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Yung, Ming-Chi
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Huang, Wei-Chen
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Chen, San-Yuan
Effective integration of stimulation and direction in bionic scaffolds by materials and microstructure design has been the focus in the advancement of nerve regeneration. Hydrogels are the most promising biomimicked materials used in developing nerve grafts, but the highly hydrated networks limit the fabrication of hydrogel materials into complex biomedical devices. Herein, facile lithography-free and spontaneously micropatterned techniques were used to fabricate a smart protein hydrogel-based scaffold, which carried topographical, electrical, and chemical induction for neural regulation. The synthesized tissue-mimicked silk-gelatin (SG)/polylactic acid bilayer system can self-form three-dimensional ordered corrugation micropatterns with well-defined dimensions (wavelength, lambda) based on the stress-induced topography. Through magnetically and topographically guided deposition of the synthesized nerve growth factor-incorporated Fe3O4-graphene nanoparticles (GFPNs), a biologically and electrically conductive cell passage with one-dimensional directionality was constructed to allow for a controllable constrained geometric effect on neuronal adhesion, differentiation, and neurite orientation. Particularly, the SG with corrugation patterns of lambda approximate to 30 mu m resulted in the optimal cell adhesion and differentiation in response to the pattern guidance. Furthermore, the additional electrical stimulation applied on GFPN-deposited SG resulted in a 1.5-fold increase in the neurite elongation by day 7, finally leading to the neuronal connection by day 21. Such a hydrogel device with synergistic effects of physical and chemical enhancement on neuronal activity provides an expectable opportunity in the development of next-generation nerve conduits.
Multi-color optical microscopy using modulated excitation lasers and single-frequency demux
(2020-02-01)
Wang, Nan
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Kobayashi, Takayoshi
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Ruan, Shuangchen
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電機學院
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College of Electrical and Computer Engineering
Multi-color microscopy has been a powerful tool for industrial and biomedical applications. Traditionally, image acquisition through different color channels has to be carried out separately using a single detector for sequential detection or multi-detectors for simultaneous detection. This costly and complex process may introduce colocalization errors due to the alignment. This paper describes a compact multi-color microscope using modulated excitation lasers and a single electronic frequency demux for signal detection. To mark fluorescence from different labels in the sample separately, the excitation lasers are intensity modulated with different frequencies. After fluorescence is detected, the electronic signals are demultiplexed with a single spectrum analyzer. This method allows the realization of multi-color imaging with minimal amount of detection elements. Multi-color imaging of fluorescent spheres, gold nanoparticles, and biological tissues are carried out. A fiber-coupling system has also been used to simplify the optical alignments, while its focal chromatic aberration has been characterized.
Control of matrix stiffness promotes endodermal lineage specification by regulating SMAD2/3 via lncRNA LINC00458
(2020-02-01)
Chen, Yu-Fan
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Li, Yi-Shuan J.
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Chou, Chih-Hung
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Chiew, Men Yee
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Huang, Hsien-Da
During endoderm formation, cell identity and tissue morphogenesis are tightly controlled by cell-intrinsic and cell-extrinsic factors such as biochemical and physical inputs. While the effects of biochemical factors are well studied, the physical cues that regulate cell division and differentiation are poorly understood. RNA sequencing analysis demonstrated increases of endoderm-specific gene expression in hPSCs cultured on soft substrate (Young's modulus, 3 +/- 0.45 kPa) in comparison with hard substrate (Young's modulus, 165 +/- 6.39 kPa). Further analyses revealed that multiple long noncoding RNAs (lncRNAs) were up-regulated on soft substrate; among them, LINC00458 was identified as a stiffness-dependent lncRNA specifically required for hPSC differentiation toward an early endodermal lineage. Gain- and loss-of-function experiments confirmed that LINC00458 is functionally required for hPSC endodermal lineage specification induced by soft substrates. Our study provides evidence that mechanical cues regulate the expression of LINC00458 and induce differentiation of hPSC into hepatic lineage progenitors.
A Lucky Encounter that Triggered a Leap
(2020-02-01)
Tobe, Yoshito
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應用化學系
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Department of Applied Chemistry
A fast fused part-based model with new deep feature for pedestrian detection and security monitoring
(2020-02-01)
Cheng, Eric Juwei
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Prasad, Mukesh
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Yang, Jie
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Khanna, Pritee
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Chen, Bing-Hong
In recent years, pedestrian detection based on computer vision has been widely used in intelligent transportation, security monitoring, assistance driving and other related applications. However, one of the remaining open challenges is that pedestrians are partially obscured and their posture changes. To address this problem, deformable part model (DPM) uses a mixture of part filters to capture variation in view point and appearance and achieves success for challenging datasets. Nevertheless, the expensive computation cost of DPM limits its ability in the real-time application. This study propose a fast fused part-based model (FFPM) for pedestrian detection to detect the pedestrians efficiently and accurately in the crowded environment. The first step of the proposed method trains six Adaboost classifiers with Haar-like feature for different body parts (e.g., head, shoulders, and knees) to build the response feature maps. These six response feature maps are combined with full-body model to produce spatial deep features. The second step of the proposed method uses the deep features as an input to support vector machine (SVM) to detect pedestrian. A variety of strategies is introduced in the proposed model, including part-based to full-body method, spatial filtering, and multi-ratios combination. Experiment results show that the proposed FFPM method improves the computation speed of DPM and maintains the performance in detection. (C) 2019 Elsevier Ltd. All rights reserved.
Influence of Post-Annealing on the Structural and Nanomechanical Properties of Co Thin Films
(2020-02-01)
Hwang, Yeong-Maw
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Pan, Cheng-Tang
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Lu, Ying-Xu
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Jian, Sheng-Rui
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Chang, Huang-Wei
The correlations between the microstructure and nanomechanical properties of a series of thermal annealed Co thin films were investigated. The Co thin films were deposited on glass substrates using a magnetron sputtering system at ambient conditions followed by subsequent annealing conducted at various temperatures ranging from 300 degrees C to 800 degrees C. The XRD results indicated that for annealing temperature in the ranged from 300 degrees C to 500 degrees C, the Co thin films were of single hexagonal close-packed (hcp) phase. Nevertheless, the coexistence of hcp-Co (002) and face-centered cubic (fcc-Co (111)) phases was evidently observed for films annealed at 600 degrees C. Further increasing the annealing temperature to 700 degrees C and 800 degrees C, the films evidently turned into fcc-Co (111). Moreover, significant variations in the hardness and Young's modulus are observed by continuous stiffness nanoindentation measurement for films annealed at different temperatures. The correlations between structures and properties are discussed.