Thyroid-Associated Orbitopathy: Evaluating Microstructural Changes of Extraocular Muscles and Optic Nerves Using Readout-Segmented Echo-Planar Imaging-Based Diffusion Tensor Imaging

Huan-Huan Chen,Hao Hu,Wen Chen,Dai Cui,Xiao-Quan Xu,Fei-Yun Wu,Tao Yang 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.3

Objective: We aimed to investigate the ability of readout-segmented echo-planar imaging (rs-EPI)-based diffusion tensor imaging (DTI) in assessing the microstructural change of extraocular muscles (EOMs) and optic nerves in patients with thyroidassociated orbitopathy (TAO) as well as in evaluating disease activity. Materials and Methods: We enrolled 35 TAO patients and 22 healthy controls (HCs) who underwent pre-treatment rs-EPIbased DTI. Mean, axial, and radial diffusivity (MD, AD, and RD) and fractional anisotropy (FA) of the medial and lateral EOMs and optic nerve for each orbit were calculated and compared between TAO and HC groups and between active and inactive TAO groups. Factors such as age, sex, disease duration, mediation, and smoking history between groups were also compared. Logistic regression analysis was used to evaluate the predictive value of significant variables for disease activity. Results: Disease duration was significantly shorter in active TAOs than in inactive ones (p < 0.001). TAO patients showed significantly lower FA and higher MD, AD, and RD than HCs for both medial and lateral EOMs (p < 0.001), but not the AD value of lateral EOMs (p = 0.619). Active patients had significantly higher FA, MD, and AD than inactive patients for medial EOMs (p < 0.005), whereas only FA differed significantly in the lateral EOMs (p = 0.018). The MD, AD, and RD of optic nerves were significantly lower in TAO patients than HCs (p < 0.05), except for FA (p = 0.129). Multivariate analysis showed that the MD of medial EOMs and disease duration were significant predictors for disease activity. The combination of these two parameters showed optimal diagnostic efficiency for disease activity (area under the curve, 0.855; sensitivity, 68.4%; specificity, 96.9%). Conclusion: rs-EPI-based DTI is promising in assessing microstructural changes of EOMs and optic nerves and can help to indicate the disease activity of TAO, especially through the MD of medial EOMs.

Chlorophyll a fluorescence as an indicator of establishment of Zostera marina transplants on the southern coast of Korea

Wen-Tao Li,박정임,박상률,Xiu-mei Zhang,이근섭 한국조류학회I 2010 ALGAE Vol.25 No.2

To test the feasibility of using chlorophyll a fluorescence to assess the establishment success of seagrass transplants,photosynthetic characteristics of eelgrass Zostera marina transplants were measured using a Diving-pulsed amplitude modulation fluorometer in Jindong Bay on the southern coast of Korea. Maximum quantum yield (Fv/Fm),photosynthetic efficiency (α), saturating irradiance (Ek) and maximum electron transport rate (ETRmax) of transplants and reference plants in a nearby transplant site were measured using the fluorometer for 5 months. Additionally, shoot morphology, individual shoot weight and productivity of transplants and reference plants were also monitored. Shoot height, leaf weight and productivity of transplants were significantly reduced during the first two or three months after transplantation compared to those of reference plants, and then increased to the levels of reference plants. Characteristics of chlorophyll a fluorescence, including Fv/Fm, α, Ek and ETRmax of transplants were also significantly reduced in the initial period, but recovered slightly sooner than shoot morphology or leaf productivity. These results indicated that after transplantation, Z. marina transplant photosynthesis recovered faster than shoot morphology, biomass or productivity. Thus, chlorophyll a fluorescence can be used as an indicator for early assessment of the status of eelgrass transplants without destructive sampling.

Adaptation success of Zostera marina to a new transplant environment

Wen-Tao Li,이근섭 한국조류학회I 2010 ALGAE Vol.25 No.1

Marked declines in seagrass meadows are increasingly being reported from coasts around Korea and many regions of the world. The transplantation of seagrasses has been attempted to mitigate and control their degradation from a range of anthropogenic factors. In this study, Zostera marina shoots, which were collected from a donor bed in Koje Bay, were transplanted in Jindong Bay in December 2004. In 2008, a comparative investigation of shoot morphology, growth, and reproduction strategy of Z. marina was carried out between the donor and transplant sites to assess their adaptation success. Shoot height, individual shoot weight, and leaf productivity at the transplant site were significantly greater than those at the donor site. However, below-/aboveground tissue ratio was significantly lower at the transplant site compared to the donor site. Z. marina survival was maintained through vegetative reproduction, while peak season for lateral shoot recruitment was late winter for both donor and transplant site populations. However, vegetative reproduction mainly occurred during late winter and spring at the transplant site, whereas lateral shoots were evident across all seasons except late spring in the donor site. More pronounced seasonal variations were found at the transplant site compared to the donor site. These results indicate that Z. marina populations at the two sites possess distinct phenotypic variations induced by different environmental conditions, and Z. marina transplants have adapted well to the new transplant environment.

Deformation and Failure Mechanism of Brittle Rocks under Loading and Unloading Conditions in High Stress Area

( Tao Wen ),( Huiming Tang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Excavation of rock mass slope engineering is a complex loading and unloading process. The rock’s strength, deformation and failure are greatly different under loading and unloading conditions. This study presents the research on the deformation and failure mechanism of rock under loading and unloading and its application in high stress area, choosing Dabenliu high slope in the Jinping hydropower station as the typical research object, analyzing the deformation mechanism of the slope based on geotechnical investigation, acquiring the mechanical parameters of rock based on the laboratorical tests, building rock damage constitutive model, determining the mechanical parameters of rock masses based on quality evaluation system of rock mass, finally analyzing the deformation mechanism and the slope stability considering the unloading and damage effects based on numerical simulation. The research output will provide theoretical guarantee to the successful construction and safe operation of similar projects and have important theoretical significance as well as engineering practical value.

FINITE LOGARITHMIC ORDER SOLUTIONS OF LINEAR q-DIFFERENCE EQUATIONS

Wen, Zhi-Tao Korean Mathematical Society 2014 대한수학회보 Vol.51 No.1

During the last decade, several papers have focused on linear q-difference equations of the form ${\sum}^n_{j=0}a_j(z)f(q^jz)=a_{n+1}(z)$ with entire or meromorphic coefficients. A tool for studying these equations is a q-difference analogue of the lemma on the logarithmic derivative, valid for meromorphic functions of finite logarithmic order ${\rho}_{log}$. It is shown, under certain assumptions, that ${\rho}_{log}(f)$ = max${{\rho}_{log}(a_j)}$ + 1. Moreover, it is illustrated that a q-Casorati determinant plays a similar role in the theory of linear q-difference equations as a Wronskian determinant in the theory of linear differential equations. As a consequence of the main results, it follows that the q-gamma function and the q-exponential functions all have logarithmic order two.

Reconfigurable DDP-type transmitter coil for electric vehicle wireless charging under misaligned conditions

Wen, Feng,Li, Qiang,Li, Rui,Liu, Ling,Wang, Tao,Liu, Li,Wu, Tao,Li, Yuxiao The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

This paper presents a new type of a transmitter coil for wireless power transfer (WPT) to assist in the achievement of a constant output power and in the reduction of magnetic field leakage under misaligned electric vehicle (EV) wireless-charging conditions. The proposed DDP coil is an improvement upon the conventional DD coil and can be adaptively reconfigured depending on the misalignment of different sizes or types of receiver coils. The reconfigurable resonant circuit is designed to compensate various coil structures and to maintain a high-energy efficiency. The reconfiguration strategy is presented by studying the characteristics of the magnetic field and mutual inductance of the coils. A precise human anatomic model and a full-scale Tesla EV model are built to evaluate the magnetic field leakage and human exposure to the WPT system. Simulation results show that the power transfer efficiency (PTE) reaches 99.16% and that the maximum electric field induced in humans is -1.11 dBV/m, while the transfer power is 6.6 kW with a 12 cm lateral offset on both the x-axis and y-axis. The effectiveness of the proposed type of transmitter coil is verified through simulation and experimental results.

Energy analysis of the deformation and failure process of sandstone and damage constitutive model

Tao Wen,Huiming Tang,Junwei Ma,Junwei Ma 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

The damage theory was introduced to clarify and simulate the strain softening property of rocks. On the basis of the theory, an energy method was utilized to portray the rock mechanical properties from microscopic perspective. Firstly, from the perspective of rock microstructure, damage variable (expressed as D) was redefined by dividing the rock into three portions: undamaged materials, damaged materials and micro-defects, and an impact factor was introduced as the connection between the damaged material and the micro-defects. Meanwhile, the method for determining the impact factor was presented. Secondly, the damage variable was redefined in light of energy dissipation, then damage evolution analysis was conducted based on triaxial tests. An improved rock damage constitutive model was further obtained in another expression to reflect the energy change law. Subsequently, the relationship between D and the deformation and failure process of rocks was analyzed on account of the damage evolution equation formularized by fitting to a logistic function, which can measure the influence of energy dissipation on the propagation of micro-defects. By comparing between experimental results and theoretical results of illustrative examples, the effectiveness of the improved model was validated, and the its application was also discussed.

A Study on the Role of Music in Documentary Films

Wen Tao,고정훈 한국상품문화디자인학회 2022 상품문화디자인학연구 Vol.71 No.-

The art of film is a comprehensive art. With the lens as the basic unit, with the picture and sound as the main form of expression, through the means of picture editing and audio-visual montage, create a variety of screen images to reflect the material reality of the world and human spiritual life. Film art is made up of visual parts, auditory parts and associative parts. Documentary video art, known as documentary by the general audience, is the art form closest to the real life state in the film art. Music plays an important role in the expression of documentary image art. However, compared with people's attention to visual effects, ordinary people as audiences often ignore the role of music. This phenomenon will feed back to the creators and affect the creators' creation of music in the process of creation. In fact, music is one of the oldest and most abundant ideographic elements. In the primitive stage, the expression of all thoughts and opinions in human society is based on sound, and music plays a greater role in the expression of sound. In the process of documentary image art creation, the role of music goes far beyond the general sense of showing plot and rendering atmosphere. Through the analysis of music in the process of documentary image art creation, the paper studies the rich functional performance of music in documentary image art, in-depth analysis of the diversified role music can play in the process of documentary image art creation, so as to explore more possibilities of music creation and use in documentary image art creation. And summarize the role of music in the creation of documentary video art.

Chaotic dynamic characteristics of pressure fluctuation signals in hydro-turbine

Wen-Tao Su,Xiao-Bin Li,Chao-Feng Lan,Shi An,Jiansheng Wang,Feng-Chen Li 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

The pressure fluctuation characteristics in a Francis hydro-turbine running at partial flow conditions were studied based on the chaotic dynamic methods. Firstly, the experimental data of pressure fluctuations in the draft tube at various flow conditions was de-noised using lifting wavelet transformation, then, for the de-noised signals, their spectrum distribution on the frequency domain, the energy variation and the energy partition accounting for the total energy was calculated. Hereby, for the flow conditions ranging from no cavitation to severe cavitation, the chaos dynamic features of fluctuation signals were analyzed, including the temporal-frequency distribution, phase trajectory, Lyapunov exponent and Poincaré map etc. It is revealed that, the main energy of pressure fluctuations in the draft tube locates at low-frequency region. As the cavitation grows, the amplitude of power spectrum at frequency domain becomes larger. For all the flow conditions, all the maximal Lyapunov exponents are larger than zero, and they increase with the cavitation level. Therefore, it is believed that there indeed exist the chaotic attractors in the pressure fluctuation signals for a hydro-turbine.

SiO₂/ZnS:Cu /ZnS Triplex Layer Coatings for Phosphorescence Enhancement

Wen-Tao Zhang,Hong-Ro Lee 한국표면공학회 2008 한국표면공학회지 Vol.41 No.4

The objective of this study is to coat the SiO₂ layer uniformly on the ZnS:Cu phosphors by using Sol-Gel method. From results of SEM micrographs observation, XRD and XPS analysis, it could be confirmed that SiO₂ layer was relatively well coated on ZnS:Cu particles. Ag2S was used as a decoding chemical to analyze the dense and uniform coating performance of SiO₂ layer on phosphor particles. It could be concluded that phosphors synthesized from our two step replacement method showed strong blue peak comparing to other method and rather weak green peak also. Obtained particle size of phosphors were about 20m diameter. Luminescence properties of the phosphors were examined by photoluminescence spectra at the excitation wavelength of 270 ㎚.