The Loading–Unloading Model of Contact Between Fractal Rough Surfaces

Yuan Yuan,Kuo Xu,Ke Zhao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.6

A loading–unloading elastic–plastic model of contact between three dimensional fractal rough surfaces has been presented in this paper. During loading process, the mechanical properties of a single asperity follow Hertzian theory. During unloading process, the load-area relationships of a single asperity are obtained by EK model. The truncation size distribution functions for diff erent levels of asperities are deduced. And total true contact area and total contact load are obtained during a loading–unloading process. The results show as the rough surface is in elastic deformation, the load-area relationships during loading and unloading process are identical. As the rough surface is in inelastic deformation, the total true contact area during unloading process is greater than that during loading process. An experiment is designed to verify the validity of the present model.

Buckling behavior of functionally graded porous plates integrated with laminated composite faces sheets

Kuo Xu,Yuan Yuan,Mingyang Li 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.5

In this work, lightweight sandwich plates consisting of a functionally graded porous (FGP) core and two laminated composite face sheets resting on elastic foundation have been proposed. Three different profiles are considered for the distributions of porosities along core thickness. The main aim of this paper is the investigation of the buckling behavior of the proposed porous sandwich plates (PSPs) by reporting their critical mechanical loads and their corresponding mode shapes. A finite element method (FEM) based on first order shear deformation theories (FSDT) is developed to discretize governing equations for the buckling behavior of the proposed sandwich plates. The effects of porosity dispersion and volume, the numbers and angles of laminated layers, sandwich plate geometrical dimensions, elastic foundation coefficients, loading and boundary conditions are studied. The results show that the use of FGP core can offer a PSP with half weight core and only 5% reduction in critical buckling loads. Moreover, stacking sequences with only ±45 orientation fibers offer the highest values of buckling loads.

Enhancing the static behavior of laminated composite plates using a porous layer

Yuan Yuan,Ke Zhao,Kuo Xu 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.6

The main aim of this paper is enhancing design of traditional laminated composite plates subjected to static loads. In this regard, this paper suggests embedding a lightweight porous layer in the middle of laminated composite as the core layer of the resulted sandwich plate. The static responses of the suggested structures with uniform, symmetric and non-symmetric porosity distributions are compared to optimize their design. Using the first order shear deformation theories, the static governing equations of the suggested laminated composite plates with a porous layer (LCPPL) rested on two-parameter foundation are obtained. A finite element method is also utilized to solve the governing equations of LCPPLs. Effects of laminated composite and porosity characteristics as well as geometry dimension, edges’ boundary conditions and foundation coefficients on the static deflection and stress distribution of the suggested composite plates have been investigated. The results reveal that the use of core between the layers of laminated composites leads to a sharp reduction in the static deflections of LCPPLs. Furthermore, in compare with perfect cores, the use of porous core between the layers of laminated composite plates can offer a considerable reduction in structural weight without a significant difference in their static responses.

Relationship of Forecast Encompassing to Composite Forecasts with Simulations and an Application

Kuo-yuan Liang,Keunkwan Ryu 서울대학교 경제연구소 2003 Seoul journal of economics Vol.16 No.3

This paper examines the role of forecast-encompassing principles in model-specification searches through the use of linear composite forecasts. Based on the results of the pairwise forecast-encompassing test, this paper outlines a conceptual framework to provide some useful insights on cross-model evaluations in econometrics and the selection of predictors in composite forecasts. Second, it offers three different ways of performing the encompassing test and compares their finite sample performance through a Monte Carlo simulation study. Test results guide researchers to choose component forecasts and thus to avoid blind pooling in the combining regression.

Effects of Caponization and Testosterone on Bone and Blood Parameters of SCWL Male Chickens

Chen, Kuo-Lung,Tsay, Shiow-Min,Lo, Dan-Yuan,Kuo, Feng-Jui,Wang, Jiann-Hsiung,Chiou, Peter Wen-Shyg Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.5

This study was to investigate the caponization effects on bone characteristics in male chickens, and the optimum testosterone implantation dosage on bone characteristics improvement. Healthy Single Comb White Leghorn cockerels were caponized at 12-wk-old and selected at 16-wk-old for a 10-wk feeding experiment. Fifteen intact male and caponized male chickens (capon) respectively were assigned to trial 1. Ten sham-operated chickens and 40 capons (randomly allocated into four treatments) were implanted with cholesterol (1.62 mm i.d., 3.16 mm o.d., $9.24{\pm}0.36$ mg), low (1 mm i.d., 3 mm o.d., $5.88{\pm}0.23$ mg), medium (1.62 mm i.d., 3.16 mm o.d., $9.81{\pm}0.17$ mg) or high dose (2 mm i.d., 4 mm o.d., $16.7{\pm}0.24$ mg) of testosterone in trial 2. The results from trial 1 showed that the tibia length, relative tibia weight, breaking strength, bending moment and stress in intact males were higher than capons (p<0.05). The blood phosphorus concentration in capons was higher than the intact male chickens (p<0.05). Caponization also resulted in more antrums and osteoclasts within periosteum and cortical bone from histological observation. In trial 2, the adverse impact of caponization on the bone breaking strength, bending moment and stress could be alleviated through medium dose testosterone implantation. It appears that caponization reduced androgen secretion hence influenced the biomechanical characteristics of bone (tibia) and these adverse effects could be alleviated through appropriate dose of testosterone implantation.

A 30 MeV-cyclotron-based quasi-monoenergetic neutron source

Chu Kuo-Yuan,Kuo Weng-Sheng,Lee How-Ming,Fuh Yiin-Kuen 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5

This study developed a quasi-monoenergetic neutron source (QMN) for the semiconductor device's soft error rate test (SER). Quasi-monoenergetic neutrons are generated by 9Beðp; nÞ 9B nuclear reaction with a 1 mm beryllium target and 30 MeV protons from a cyclotron. An 8 mm water in the back of the beryllium target is used for avoiding proton penetration. The neutron spectra simulated by MCNP showed that the peak energy was around 26.5 MeV. The heat flow and mechanical properties are numerically analyzed, and the safe operating conditions are therefore determined.

Effects of Fiber Characteristics on the Greaseproofing Property of Paper

YUAN-SHING PERNG,EUGENE I-CHEN WANG,LAN-SHENG KUO,YU-CHUN CHEN 한국펄프·종이공학회 2006 한국펄프종이학회 기타 간행물 Vol.- No.-

Grease barrier food containers are commonly used for packaging of fast food, cooked food, and food in general. Greaseproofing is also used for certificate paper and label paper etc. Different pulp raw materials, due to their different fiber morphology and chemical compositions, produce papers of varying characteristics. We used optical photomicroscopy and fiber analysis data to evaluate fiber morphology and traits under various beating conditions in order to understand which pulp raw materials produced superior greaseproofing property when a fluorinated greaseproofing agent was added internally. The experiment studied 9 species of pulps, including 2 softwood (northern pine and radiata pine) bleached kraft pulps which were beaten to 550 and 350 mL CSF, respectively; 3 hardwoods (eucalypts, acacia, mixed Indonesian hardwoods) bleached kraft pulps which were beaten to 450 and 250 mL CSF, respectively; and nonwood fibers of reed, bagasse, and abaca. A fluorinated greaseproofing chemical at 0.12% dosage with respect to dry pulp was added to each pulp preparation and formed handsheets. A total of 67 sets of handsheets were prepared, and their basis weights, thickness, bulks, opacities, wet opacities, air resistance, water absorption and degrees of greaseproofing were measured for an overall evaluation of pulp and freeness on greaseproofing papers. The experimental fiber length, coarseness and distribution characteristics and the greaseproofing results suggest that softwood pulps (radiate pine < northern pine) were superior to hardwood pulps (eucalypts > acacia > mixed Indonesian hardwoods). The unbeaten pulps gave papers with high porosities and nearly devoid of greaseproofing property. Greaseproofing is proportional to air resistance. Among the nonwood fibers, bagasse had the best greaseproofing property, followed by reed and abaca was the poorest. With regards to waterproofing property, hardwood pulps (mixed Indonesian hardwoods > acacia > eucalypts) were better than softwood pulps (northern pine > radiate pine). Among the Nonwood fibers, reed had the highest waterproofing property, and it was followed by abaca, while bagasse had the poorest waterproofing characteristic. In summary, bleached kraft northern pine, eucalypts and reed pulps were best suited for making greaseproofing papers, Freeness of the pulps should be kept at 200~280 mL CSF for optimal performance.

Frontiers in the Clinical Applications of Botulinum Toxin A as Treatment for Neurogenic Lower Urinary Tract Dysfunction

Yuan-Hong Jiang,Sheng-Fu Chen,Hann-Chorng Kuo 대한배뇨장애요실금학회 2020 International Neurourology Journal Vol.24 No.4

Patients with neurogenic lower urinary tract dysfunction (NLUTD) experience urinary incontinence with or without difficult urination, which might promote recurrent urinary tract infection (UTI) and exacerbate upper urinary tract function. Nonetheless, appropriate bladder management has been shown to reduce urological complications and improve quality of life. In addition to pharmacological therapy and surgical intervention, botulinum toxin A (BoNT-A) has been widely utilized in NLUTD. The therapeutic efficacy of detrusor BoNT-A injections for neurogenic detrusor overactivity due to spinal cord injury (SCI), multiple sclerosis, or other central nervous system lesions, such as cerebrovascular accident, Parkinson disease, early dementia, and pediatric NLUTD due to myelomeningocele, has been well established, with repeated BoNT-A injections every 6 to 9 months being necessary to maintain its therapeutic effects. Urethral BoNT-A injection can decrease urethral sphincter resistance and facilitate efficient voiding in patients with NLUTD who wish to preserve self-voiding. Detrusor BoNT-A injection can also decrease the occurrence of autonomic dysreflexia in patients with SCI, even after failed augmentation enterocystoplasty, with additional benefits including reduced UTI episodes and preserved renal function with repeated injections. However, this treatment does have some side effects. Complete informed consent for BoNT-A injection therapy with full disclosure of its potential complications should therefore be obtained before this procedure is undertaken.

Moldable Job Scheduling for HPC as a Service with Application Speedup Model and Execution Time Information

Kuo-Chan Huang,Tse-Chi Huang,Mu-Jung Tsaia Hsi-Ya Chang,Yuan-Hsin Tung 한국정보기술융합학회 2013 JoC Vol.4 No.4

Self-organizing Map Network for Automatically Recognizing Color Texture Fabric Nature

Kuo, Chung-Feng Jeffrey,Kao, Chih-Yuan The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.2

The method of recognizing color texture brought forth in the present study is to employ unsupervised learning network to automatically recognize the fabric type and the main texture types. Firstly, the color scanner is adopted to extract fabric image which is afterwards saved as the digital image. Secondly, CIE-Lab color model is taken to obtain the feature value and wavelet transform is utilized to display the texture of the fabric image. Thirdly, co-occurrence matrix is employed to figure out the feature values of the texture structure such as angular second moment, entropy, homogeneity, contrast. Finally, self-organizing map (SOM) network is used as the classifier. The experiment result shows that the study can automatically and accurately classify the fabric types (including shuttle-woven fabric, jersey fabric and non-woven fabric) and main texture type of the fabric (such as plain weave, twill weave, satin weave, single jersey, double jersey and non-woven fabric).