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Applying a Step Approach Method in Solving the Multi-Frequency Radiation From a Complex Obstacle

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Computer Modeling in Engineering & Sciences 2016年第7期112卷 59-73页

作者： jui-Hsiang Kao Department of Systems Engineering and Naval Architecture National Taiwan Ocean UniversityKeelungTaiwanR.O.C

In this paper,a step approach method in the time domain is developed to calculate the radiated waves from an arbitrary obstacle pulsating with multiple *** computing scheme is based on the Boundary Integral Equation and derived in the time domain;thus,the time-harmonic Neumann boundary condition can be *** the present method,the values of the initial conditions are set to zero,and the approach process is carried forward in a loop from the first time step to the *** each time step,the radiated pressure on each element is *** several loops,the correct radiated pressures can be obtained.A sphere pulsating with a monopole frequency in an infinite acoustic domain is calculated *** result is compared with the analytical solution,and both of them are in good ***,a complex-shaped radiator is taken as the studied *** pulsating frequency of this case is multiple,and the waves propagate in half *** is shown that the present method can treat multiple-frequency pulsation well,even when the radiator is a complex shape,and a robust convergence can be attained quickly.

关键词： Step approach method Time domain Radiated waves Multiple frequencies Boundary integral equation Neumann boundary condition

Applying AHP-Based CBR to Estimate Pavement Maintenance Cost

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Tsinghua Science and Technology 2008年第S1期13卷 114-120页

作者： jui-Sheng Chou Department of Construction Engineering Taiwan Tech (NTUST)

The cost-efficacy control of maintenance operations in developing countries has become critical to the infrastructure asset management after highway construction. To effectively manage numerous projects annually with limited resources, it is necessary to reasonably estimate costs during the process of making maintenance project selection decisions. This study outlines the modeling of case-based reasoning (CBR) estimation that compares and retrieves the most similar instance across the case library. Four CBR approaches were presented and assessed in terms of their mean absolute prediction error rates. The resulting model demonstrates the ability of estimating the pavement maintenance project costs with the satisfactory accuracy at the early stages.

关键词： case-based reasoning analytical hierarchy process cost estimation project management

Kernel Entropy Based Extended Kalman Filter for GPS Navigation Processing

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Computers, Materials & Continua 2021年第7期68卷 857-876页

作者： Dah-Jing Jwo jui-Tao Lee Department of Communications Navigation and Control EngineeringTaiwan Ocean UniversityKeelung202301Taiwan

This paper investigates the kernel entropy based extended Kalman filter(EKF)as the navigation processor for the Global Navigation Satellite Systems(GNSS),such as the Global Positioning System(GPS).The algorithm is effective for dealing with non-Gaussian errors or heavy-tailed(or impulsive)interference errors,such as the *** kernel minimum error entropy(MEE)and maximum correntropy criterion(MCC)based filtering for satellite navigation system is involved for dealing with non-Gaussian errors or heavy-tailed interference errors or outliers of the *** standard EKF method is derived based on minimization of mean square error(MSE)and is optimal only under Gaussian assumption in case the system models are precisely *** GPS navigation algorithm based on kernel entropy related principles,including the MEE criterion and the MCC will be performed,which is utilized not only for the time-varying adaptation but the outlier type of interference *** kernel entropy based design is a new approach using information from higher-order signal *** information theoretic learning(ITL),the entropy principle based measure uses information from higher-order signal statistics and captures more statistical information as compared to *** improve the performance under non-Gaussian environments,the proposed filter which adopts the MEE/MCC as the optimization criterion instead of using the minimum mean square error(MMSE)is utilized for mitigation of the heavy-tailed type of multipath *** assessment will be carried out to show the effectiveness of the proposed approach for positioning improvement in GPS navigation processing.

关键词： GPS satellite navigation extended Kalman filter entropy correntropy multipath non-Gaussian

Experimental study of the separated joint of an underground pipeline rehabilitated by cured-in-place pipe

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Underground Space 2022年第4期7卷 543-563页

作者： jui-Min Hsu Keh-Jian Shou Department of Civil Engineering Chung-Hsing UniversityTaiwanChina

Reinforced concrete pipes(RCPs)were commonly used in older underground pipelines in Taiwan,***,their joints are prone to damage,including fracture and separation,from problems such as overloading,poor backfilling,and *** the rehabilitation of such aged pipelines,trenchless methods are preferred to minimize the impact on *** cured-in-place-pipe(CIPP)rehabilitation could be one of the most popular trenchless methods suitable for the cases with angular alignment and changing ***,according to the existing standards,no details are available on the performance of the rehabilitated parts of the damaged pipeline,including the effect of separated *** study designed and conducted laboratory testing on the composite pipe joint(the CIPP rehabilitated RCPs with a separated joint)with different scenarios,including radial and longitudinal loading *** radial test results indicated that,for a small separation distance,CIPP rehabilitation can restore the original function of a pipeline and improve its hoop *** longitudinal test revealed that the damage due to bending was controlled by the tensile strength of the liner *** ultimate flexural strength decreased as the separation distance ***,pipelines may be subjected to additional loads due to flotation or subsidence,for which the longitudinal loading capacity is often the limiting *** such conditions,it is necessary to confirm,by more research,whether the wall thickness is sufficient.

关键词： Reinforced concrete pipes Pipe joint Rehabilitation Cured-in-place pipe Trenchless technology

Discussion of the Fluid Acceleration Quality of a Ducted Propulsion System on the Propulsive Performance

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Computer Modeling in Engineering & Sciences 2022年第3期130卷 1325-1348页

作者： jui-Hsiang Kao Yi-Fan Liao Department of Systems Engineering and Naval Architecture Taiwan Ocean UniversityKeelung202301Taiwan

This paper focuses on the ducted propulsion with the accelerating nozzle,and discusses the influence of its fluid acceleration quality on its propulsive performances,including the hull efficiency,the relative rotative efficiency,the effective wake,and the thrust deduction *** actual ducted propulsion system is used as an example for computational *** computational conditions are divided into four combinations,which are provided with different propeller pitches,cambers,and duct *** applied in this study is the Computational Fluid Dynamics(CFD)technology,and the contents of the calculation include the hull’s viscous resistance,the wave-making resistance,the propeller performance curve,and the self-propulsion simulation in order to obtain the ship’s effective wake,thrust deduction factor,hull efficiency,and relative rotative *** performance curve of the propeller and resistance estimation results are compared with the experimental values for determining the correctness of the self-propulsion *** to the computational analysis,it is known that increasing the propeller pitch cannot effectively increase the hull *** duct acceleration quality can be reduced by shortening the duct length;hence,when the effective wake fraction and thrust deduction factor decrease,the hull efficiency is *** addition,the pressure inside the duct is relatively low if the acceleration quality of the duct is too high,which is unfavorable for controlling the propeller ***,if the hull bottom in front of the propeller is tapered up from the front to the back at an overly steep angle,the thrust deduction factor will be too large and lead to a relatively low hull efficiency.

关键词： Ducted propellers accelerating nozzle hull efficiency relative rotative efficiency effective wake thrust deduction factor

Atrial fibrillation and prediabetes:Interplay between left atrium and systemic diseases

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World Journal of Diabetes 2024年第11期15卷 2242-2244页

作者： Ming-jui Hung Department of Internal Medicine Section of Cardiovascular ImagingDivision of CardiologyChang Gung Memorial Hospital at KeelungChang Gung University College of MedicineKeelung 204201Taiwan

Atrial fibrillation(AF)is associated with multiple other comorbidities,*** is one of the multiple comorbidities observed in patients with AF,whereby these two disease entities share the same pathophysiological mechanisms,namely oxidative stress and *** prediabetes is reported to have a negative impact on major adverse cardiac or cerebrovascular events in hospitalized AF patients,information about the interactions between prediabetes and AF remains inconsistent.A more in-depth exploration of pathophysiology and more comprehensive prospective clinical studies of AF and diabetes would provide a thorough understanding of the timing of events and further treatment *** investigations are needed to clarify the interactions and causal relationships between AF and prediabetes.

关键词： Atrial fibrillation Endothelial dysfunction Inflammation Prediabetes Stroke

The Optimization Design of the Nozzle Section for theWater Jet Propulsion System Applied in Jet Skis

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2277-2304页

作者： Cheng-Yeh Li jui-Hsiang Kao Department of Systems Engineering and Naval Architecture Taiwan Ocean UniversityKeelungTaiwanChina

The performance of a water jet propulsion system is related to the inlet duct,rotor,stator,and ***,the flow inlet design must fit the bottom line of the hull,and the design of the inlet duct is often limited by stern *** entire section,from the rotor to the nozzle through the stator,must be designed based on system integration in that the individual performance of these three components will influence each ***,the section from the rotor to the nozzle significantly impacts the performance of a water jet propulsion *** study focused on nozzle design and established referable analysis results to facilitate subsequent integrated studies on the design parameters regarding nozzle *** existing studies concentrate on discussions on rotor design and the tip leakage flow of rotors or have replaced the existing complex computational domain with a simple flow ***,research has yet to implement an integrated,optimal design of the section from the rotor to the *** the above,our program conducted preliminary research on this system integration design issue,discussed the optimal nozzle for this section in-depth,and proposed design suggestions based on the *** program used an existing model as the design *** study referred to the actual trial data as the design conditions for the proposed *** prior references’simple flow field form,this study added a jet ski geometry and free surface to the computational *** the linear hull shape was considered,the inflow in the inlet duct would be closer to the actual *** on the numerical calculation result,this study recommends that the optimal nozzle outlet area should be 37%of the inlet area and that the nozzle contour should be ***,for the pump head,static pressure had a more significant impact than dynamic pressure.

关键词： Water jet propulsion system rotor nozzle outlet area nozzle contour

Endoscopic fibrin sealant closure of duodenal perforation after endoscopic retrograde cholangiopancreatography

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World Journal of Gastroenterology 2015年第45期21卷 12976-12980页

作者： Hsin-Yeh Yang jui-Hao Chen Division of Gastroenterology Department of Internal Medicine Shin Kong Wu Ho-Su Memorial Hospital Faculty of Medicine Taipei Medical University

Traditionally, perivaterian duodenal perforation can be managed conservatively or surgically. If a large volume of leakage results in fluid collection in the retroperitoneum, surgery may be necessary. Our case met the surgical indication for perivaterian duodenal perforation after endoscopic retrograde cholangiopancreatography(ERCP) with sphincterotomy and endoscopic papillary balloon dilatation. The patient developed a retroperitoneal abscess after the procedures, and a perivaterian perforation was suggested on computed tomography(CT). CT-guided abscess drainage was performed immediately. We unsuccessfully attempted to close the perforation with hemoclips initially. Subsequently, we used fibrin sealant(Tisseel) injection to occlude the perforation. Fibrin sealant injections have been previously used during endoscopy for wound closure and fistula repair. Based on our report, fibrin sealant injection can be considered as an alternative method for the treatment of ERCPrelated type Ⅱ perforations.

关键词： Perivaterian duodenal perforation Endoscopic retro

Layered double hydroxide using hydrothermal treatment： morphology evolution, intercalation and release kinetics of diclofenac sodium

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Frontiers of Materials Science 2017年第4期11卷 395-409页

作者： Mathew JOY SrividhyaJ. IYENGAR jui CHAKRABORTY Swapankumar GHOSH Project Management Division CSIR-Central Glass & Ceramic Research Institute Kolkata-700032 India Bioceramics & Coating Division CSIR-Central Glass & Ceramic Research Institute Kolkata-700032 India

The present work demonstrates the possibilities of hydrothermal trans- formation of Zn-AI layered double hydroxide （LDH） nanostructure by varying the synthetic conditions. The manipulation in washing step before hydrothermal treatment allows control over crystal morphologies, size and stability of their aqueous solutions. We examined the crystal growth process in the presence and the absence of extra ions during hydrothermal treatment and its dependence on the drug （diclofenac sodium （Dic- Na）） loading and release processes. Hexagonal plate-like crystals show sustained release with -90% of the drug from the matrix in a week, suggesting the applicability of LDH nanohybrids in sustained drug delivery systems. The fits to the release kinetics data indicated the drug release as a diffusion-controlled release process. LDH with rod-like morphology shows excellent colloidal stability in aqueous suspension, as studied by photon correlation spectroscopy.

关键词： layered double hydroxide crystal morphology hydrothermal treatment drug loading