Exploring and calibrating local curvature effect of cortical bone for quantitative ultrasound (QUS)

Chen, Jiangang,Su, Zhongqing,Cheng, Li,Ta, De-An Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.4

Apart from thinning of cortical layers, the local bone curvature, varying along bone periphery, modulates ultrasound waves as well, which is however often underestimated or overlooked in clinical quantitative ultrasound (QUS). A dedicated three-dimensional finite element modelling technique for cortical bones was established, for quantitatively exploring and calibrating the effect of local curvature of cortical bone on ultrasound. Using a correlation-based mode extraction technique, high-velocity group (HVG) and low-velocity group (LVG) wave modes in a human radius were examined. Experimental verification using acrylic cylinders and in vitro testing using a porcine femur were accomplished. Results coherently unravelled the cortical curvature exerts evident influence on bone-guided ultrasound when RoC/${\lambda}$ <1 for HVG mode and RoC/${\lambda}$ <2 for LVG mode (RoC/${\lambda}$: the ratio of local bone curvature radius to wavelength); the sensitivity of LVG mode to bone curvature is higher than HVG mode. It has also been demonstrated the local group velocity of an HVG or LVG mode at a particular skeletal site is equivalent to the velocity when propagating in a uniform cylinder having an outer radius identical to the radius of curvature at that site. This study provides a rule of thumb to compensate for the effect of bone curvature in QUS.

An Imaging System for Monitoring the Feeding Behavior of Dairy Cows

( Cheng-yu Kuan ),( Yu-chi Tsai ),( Chen-yu Cheng ),( Jih-tay Hsu ),( Shih-torng Dnig ),( Ta-te Lin ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In sub-tropical countries, dairy cows tend to experience heat stress problems. This phenomenon may lead to declines in feed intake, milk production, and fertility. Under normal conditions, the dairy cows have a regular feeding and drinking time. For this reason, changes in feeding behavior can be a possible indicator to detect heat stress phenomena that can help farm owners monitor dairy cow health. In order to monitor and record the feeding behavior of dairy cows, an imaging system is proposed herein. The imaging system uses Raspberry Pi 3, as the embedded system, and a camera module to acquire images for dairy cow face detection in front of the feeding area to confirm if the dairy cow is eating. The dairy cow faces are detected through cascade-AdaBoost algorithms which can automatically select weak classifiers to form a strong classifier with fast processing speed in an embedded system. The factors affecting the performance of the dairy cow face detection algorithm have been tested and optimized. The system has been tested in a feeding area in National Taiwan University’s dairy farm, which has 25 dairy cows in total. By converting the frequency of dairy cow face detection into feeding time, the feeding behavior of grouped dairy cows can be analyzed. Furthermore, combining the temperature humidity index (THI) and feeding behavior can provide the farm owners with an index to evaluate the level heat stress of dairy cows.

Exploring and calibrating local curvature effect of cortical bone for quantitative ultrasound (QUS)

Jiangang Chen,Zhongqing Su,Li Cheng,De-an Ta 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.4

Apart from thinning of cortical layers, the local bone curvature, varying along bone periphery,modulates ultrasound waves as well, which is however often underestimated or overlooked in clinical quantitative ultrasound (QUS). A dedicated three-dimensional finite element modelling technique for cortical bones was established, for quantitatively exploring and calibrating the effect of local curvature of cortical bone on ultrasound. Using a correlation-based mode extraction technique, high-velocity group (HVG) and low-velocity group (LVG) wave modes in a human radius were examined. Experimental verification using acrylic cylinders and in vitro testing using a porcine femur were accomplished. Results coherently unravelled the cortical curvature exerts evident influence on bone-guided ultrasound when RoC/λ<1 for HVG mode and RoC/λ<2 for LVG mode (RoC/λ: the ratio of local bone curvature radius to wavelength); the sensitivity of LVG mode to bone curvature is higher than HVG mode. It has also been demonstrated the local group velocity of an HVG or LVG mode at a particular skeletal site is equivalent to the velocity when propagating in a uniform cylinder having an outer radius identical to the radius of curvature at that site. This study provides a rule of thumb to compensate for the effect of bone curvature in QUS.

Research on Three-Component Geomagnetic Field Differential Measurement Method for Underwater Vehicle

Zhao Ta,Chen Yu Wei,Zhou Zhi Jian,Cheng De Fu 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.2

The precise measurement of the geomagnetic element is the key to realize navigation and positioning with the development of geomagnetic navigation technology. In this paper, a kind of underwater vehicle three-component geomagnetic field differential measurement method is presented based on the ideas of the difference. The threecomponent geomagnetic field mathematical model of traditional measurement method is improved and new differential measurement model(DMM) is established. Difference expressions of measurement magnetic field in the DMM obviously reduce the impact of interference magnetic field in the process of geomagnetic field measurement and improve the measuring precision of the three-component geomagnetic field. Finally, the method’s effectiveness is validated by simulation. The precision of DMM method is 10 ± 5nT which is about two times that of traditional measurement model (TMM) method under the condition of ± 25nT stray outside interference magnetic field. The method effectively improves the geomagnetic field measurement precision and has stronger antiinterference ability. It is of significance for practical application of underwater geomagnetic navigation method.

Shear strength and shear behaviour of H-beam and cruciform-shaped steel sections for concrete-encased composite columns

Keng-Ta Lin,Cheng-Cheng Chen 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.3

In this research, we tested 10 simply supported concrete-encased composite columns under monotonic eccentric loads and investigated their shear behaviour. The specimens tested were two reinforced concrete specimens, three steelreinforced concrete (SRC) specimens with an H-shaped steel section (also called a beam section), and five SRC specimens with a cruciform-shaped steel section (also called a column section). The experimental variables included the transverse steel shape’s depth and the longitudinal steel flange’s width. Experimental observations indicated the following. (1) The ultimate loadcarrying capacity was controlled by web compression failure, defined as a situation where the concrete within the diagonal strut’s upper end was crushed. (2) The composite effect was strong before the crushing of the concrete outside the steel shape. (3) We adjusted the softened strut-and-tie SRC (SST-SRC) model to yield more accurate strength predictions than those obtained using the strength superposition method. (4) The MSST-SRC model can more reasonably predict shear strength at an initial concrete softening load point. The rationality of the MSST-SRC model was inferred by experimentally observing shear behaviour, including concrete crushing and the point of sharp variation in the shear strain.

Animal Exposure Study to Investigate the Impact of Electronic Cigarette Aerosols on Atherosclerosis

Tsai-Ling Chen,Shih-Hsin Cheng,Kai-Chien Yang,Ta-Chih Hsiao 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

The in vivo photothermal treatment of gold nanorod in the mouse ear model

Liu, Bruce Yao Wen,Chen, Cheng-Lung,Lee, Shin-Yu,Chang, Fu-Hsiung,Lin, Win-Li,Chia, Chih-Ta,Chen, Yang-Yuan Techno-Press 2014 Biomaterials and Biomechanics in Bioengineering Vol.1 No.1

Gold nanorod's exceptional light to heat transduction is a robust phonomenon that has been extensively verified. The phenomenon is a trait from which many novel applications across disciplines have been proposed. In this investigation, the feasibility of utilizing heat harvested from such photothermal method to combat cancer is presented. Using non-invasive laser methods, an in vivo study is conducted on mouse ear tumors administered with gold nanorods (Au NRs). An emphasis is placed on monitoring the tumor developments after photothermal treatments, over time. The findings reveal significant tumor growth surpression at a threshold laser power of $0.6W/cm^2$ lasting 2 minutes; this energy also brought about dramatic size reduction in treated tumors. Furthermore, the apparent formation of an eschar over the laser treated region indicates extensive hemorrhagic necrosis of the tumor tissue; a phenomenon implicative to the inhibition of angiogenesis.

The in vivo photothermal treatment of gold nanorod in the mouse ear model

Liu, Bruce Yao Wen,Chen, Cheng-Lung,Lee, Shin-Yu,Chang, Fu-Hsiung,Lin, Win-Li,Chia, Chih-Ta,Chen, Yang-Yuan Techno-Press 2014 Biomaterials and biomedical engineering Vol.1 No.1

Gold nanorod's exceptional light to heat transduction is a robust phonomenon that has been extensively verified. The phenomenon is a trait from which many novel applications across disciplines have been proposed. In this investigation, the feasibility of utilizing heat harvested from such photothermal method to combat cancer is presented. Using non-invasive laser methods, an in vivo study is conducted on mouse ear tumors administered with gold nanorods (Au NRs). An emphasis is placed on monitoring the tumor developments after photothermal treatments, over time. The findings reveal significant tumor growth surpression at a threshold laser power of $0.6W/cm^2$ lasting 2 minutes; this energy also brought about dramatic size reduction in treated tumors. Furthermore, the apparent formation of an eschar over the laser treated region indicates extensive hemorrhagic necrosis of the tumor tissue; a phenomenon implicative to the inhibition of angiogenesis.

An Automatic Environmental Monitoring and Cooling System to Reduce Heat Stress in Dairy Cows

( Yu-chi Tsai ),( Chen-yu Cheng ),( Jih-tay Hsu ),( Shih-torng Dnig ),( Ta-te Lin ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In tropical and subtropical regions with high temperature and humidity conditions, one of the problems in dairy farm management is the effect of heat stress on animal productivity. Due to this problem, the utilization of an automatic environmental monitoring system for cooling, labor-saving and heat stress reduction is necessary. In this study, an environmental monitoring and automatic cooling system based on an embedded system for dairy farms was designed. The system aims to regulate the environmental condition by means of direct feedback depending on the monitoring of heat stress index (HSI) augmented by dairy cow drinking behavior. The system is composed of two sub-systems: data acquisition and environmental control. The data acquisition module collects images, temperature and humidity data. The cooling system is controlled based on the real-time environmental data, and the historical data are recorded and uploaded to the server for display and analysis. The data are analyzed on the environmental monitoring panel on the farm and on the website, which can be remotely accessed. The control parameters are adjusted using the image results from the dairy cow drinking behavior with a fixed time interval. The results of the conducted experiments show that there is labor saving improvement and an increment in milk production compared to the same period in the previous year when the system was not installed. The automatic environmental monitoring cooling system exhibits high efficiency and can perform real-time control and self-adjustment. The system can be used for fully automated dairy cow system application, as well as dairy cow behavior analysis through both environmental and image information.

Evaluating Extreme Rainfall Changes over Taiwan Using a Standardized Index

Tung, Yu-Shiang,Chen, Cheng-Ta,Min, Seung-Ki,Lin, Lee-Yaw Chinese Geoscience Union 2016 TAO Vol.27 No.5

<P>The annual daily maximum precipitation (rx1day) is widely used to represent extreme events and is an important parameter in climate change studies. However, the climate variability in rx1day is sensitive to outliers and has difficulty representing the characteristics of large areas. We propose to use the probability index (PI), based on the cumulative density function (CDF) of a generalized extreme value (GEV) distribution to fit and standardize the rx1day to represent extreme event records in this study. A good correlation between the area-averaged PIs of the observed stations and those of the gridded dataset can be found over Taiwan. From the past PI records, there is no distinct trend in western Taiwan before the end of the 20th century, but a climate regime change happened during 2002 - 2003. The dual change effects from both the variance and linear trend of extreme events are identified over the northeastern and southern parts of Taiwan, along with the island's central and southern regions, showing different abrupt changing trends and intensity. The PI can also be calculated using climate projection data to represent the characteristics of future extreme changes. The climate variability of PIs on the present (ALL) and future (RCP4.5 and RCP8.5) scenarios were evaluated using the 16 Couple Model Intercomparison Projects Phase-5 models (CMIP5). The simulated present fluctuations in PIs are smaller than those of actual observations. In the 21st century, the RCP8.5 scenario shows that the PI significantly increases by 10% during the first half of the century, and 14% by the end of the century.</P>