Numerical Analysis of Consolidation of Soft Soils Fully-penetrated by Deep-mixed Columns

Yan Jiang,Jie Han,Gang Zheng 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

Deep mixing is a common ground improvement technology that can be used to increase bearing capacity and stability and reduce total and differential settlements of foundations constructed on soft soils. Field data have shown that deep mixed column foundations had a higher consolidation rate than untreated foundations even though deep mixed columns had similar or lower permeability than untreated soils. The consolidation mechanisms and behavior of deep mixed column foundations have not been well understood. In this study, the consolidation of soft soils fully penetrated by deep mixed columns was investigated using a mechanically and hydraulically coupled three-dimensional finite element method. One quarter of a unit cell was used considering its symmetry and the column and the surrounding soil were modeled as elastic materials. A case study for a stone column foundation in the literature was first used to verify the numerical model and then this model was adopted to analyze the stress transfer, settlement, and consolidation of the soft soil fully penetrated by a deep mixed column. A parametric study was conducted to evaluate the influence of four key factors, soft soil thickness, area replacement ratio, column modulus, and column permeability, on the stress concentration ratio (the ratio of the average vertical stress on the column to that on the soil), settlement, and average degree of consolidation of the deep mixed column foundation. The numerical results show that the average degree of consolidation calculated based on the settlement or the excess pore water pressure was identical. The stress concentration ratio increased with the column modulus and time, but the effect of the soft soil thickness, area replacement ratio, and column permeability was not significant. The simplified method based on a composite foundation concept could conservatively estimate the consolidation settlement. An increase of the column modulus, area replacement ratio, and/or column permeability increased the rate of consolidation.

Global Practical Tracking for a Class of Switched Nonlinear Systems with Quantized Input and Output via Sampled-data Control

Yan Jiang,Junyong Zhai 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.5

In this paper, we study the global practical output tracking problem for a class of switched nonlinearsystems via sampled-data output feedback control. Both the input signal and the output signal are quantized forthe sake of less communication burden. The Filippov solution and differential inclusion are adopted to analyzethe resulting discontinuous system. Accordingly, an observer is designed to estimate the unmeasurable states atthe sampling points. Then, a linear sampled-data output feedback controller is designed with a proper choice ofthe sampling period, the quantization parameter and the design parameters. Finally, a numerical example and apractical example are presented to verify the effectiveness of the proposed scheme.

The Pilot Study for Waste Oil Removal from Oilfields by Acinetobacter johnsonii Using a Specialized Batch Bioreactor

Yan Jiang,Xianming Zhang,Guoxu Chen,Yu Shen,Liang Zhou 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.6

The batch bioreactor with a maximum capacity of 0.28 m3 was designed and manufactured according to oilfield conditions Acinetobacter johnsonii ioslated from waste oil in an aerobic environment was employed to cleanse waste oil and wash-down water using the bioreactor in a pilot scale. The aerating process was optimized from 2 to 4 m3/h corresponding to the different cell growth phases, ensuring sufficient dissolved oxygen and avoiding cell damage from the shearing forces due to strong aeration. The bio-treatment of waste oil underwent two stages:one was the wettability reversal of inorganic admixtures from oil phase into waster phase through enlarged wetting angles, and the other was the bio-flocculation in waster phase by intermediate metabolites excreted by cells. Finally,inorganic admixtures were effectively removed from waste oil and wash-down water at the optimal conditions, with the content less than 0.5% in oil phase and turbidity and sulfide less than 100 NTU and 1 mg/L in the water phase,respectively. Such bio-treatment made the oil-water interface clear against oil and water emulsification and in favor of smooth reclamations for waste oil and wash-down water.

A note on the value distribution of $f^2(f')^n$ for $n\geq 2$

Yan Jiang 대한수학회 2016 대한수학회보 Vol.53 No.2

Let $f$ be a transcendental meromorphic function in the complex plane $\mathbb{C}$, and $a$ be a nonzero constant. We give a quantitative estimate of the characteristic function $T(r,f)$ in terms of $N(r,1/(f^2(f')^n-a))$, which states as following inequality, for positive integers $n\geq 2$, $$T(r,f)\leq \left(3+\frac{6}{n-1}\right)N\left(r,\frac{1}{af^2(f')^n-1}\right)+S(r,f).$$

Electric Control of Friction on Silicon Studied by Atomic Force Microscope

Yan Jiang,Lili Yue,Boshen Yan,Xi Liu,Xiaofei Yang,Guoan Tai,Juan Song 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.3

We investigated friction on an n-type silicon surface using an atomic force microscope when a bias voltage was applied to the sample. Friction forces on the same track line were measured before and after the bias voltages were applied and it was found that the friction forces in n-type silicon can be tuned reversibly with the bias voltage. The dependence of adhesion forces between the silicon nitride tip and Si sample on the bias voltages approximately follows a parabolic law due to electrostatic force, which results in a significant increase in the friction force at an applied electric field.

Efficient Three-Party Password Authenticated Key Exchange for Client-to-Client Applications

Yanjiang Yang,Feng Bao 한국정보보호학회 2008 정보보호학회논문지 Vol.18 No.b6

Nowadays, client-to-client applications such as online chat (e.g. MSN) and SMS (Short Message Services) are becoming increasingly prevalent. These client-to-client applications are revolutionizing the way we communicate. Three-party PAKE (password authenticated key exchange) protocols provide a means for the two communicating parties holding passwords to establishment a secure channel between them with the help of a common server. In this paper, we propose an efficient three-party PAKE protocol for the client-to-client applications, which has much better performance than the existing generic constructions. We also show that the proposed protocol is secure in a formal security model.

Efficient Three-Party Password Authenticated Key Exchange for Client-to-Client Applications

Yanjiang Yang,Feng Bao 한국정보보호학회 2008 정보보호학회논문지 Vol.18 No.6

Nowadays, client-to-client applications such as online chat (e.g. MSN) and SMS (Short Message Services) are becoming increasingly prevalent. These client-to-client applications are revolutionizing the way we communicate. Three-party PAKE (password authenticated key exchange) protocols provide a means for the two communicating parties holding passwords to establishment a secure channel between them with the help of a common server. In this paper, we propose an efficient three-party PAKE protocol for the client-to-client applications, which has much better performance than the existing generic constructions. We also show that the proposed protocol is secure in a formal security model.

The Clinical Manifestation of p.Asp50Asn Heterozygous Mutation of GJB2 Gene in 3 Members of a Family Is Similar to That of Clouston Syndrome

Yanjiang Xu,Minhua Wang,Ling Huang,Jie Hu 대한피부과학회 2022 Annals of Dermatology Vol.34 No.5

Keratitis-ichthyosis-deafness (KID) syndrome has genetic heterogeneity, and the clinicalmanifestations of some patients may overlap with Clouston syndrome. A 34-year-old femalepatient came to our department with a complain of “sparse hair, rough skin, photophobiaand deafness for more than 30 years.” We found that the proband and two other familymembers (57-year-old mother and 4-year-old daughter) had similar clinical manifestations:systemic hair loss, generalized skin hyperkeratosis, especially in the metacarpophalangealarea. Subungual hyperkeratosis, finger/toenail dystrophy, as well as photophobia andepiphora. According to the investigation, one of the family members also had similar clinicalmanifestations (grandfather of the proband) and he’s died. The other three members of thefamily had no hearing impairment, and all patients had typical nail dystrophy, hair loss andpalmoplantar hyperkeratosis, similar like as seen in Clouston syndrome, so we suspected todiagnose the case as Clouston syndrome. However, after genetic testing, it was found that theproband, his mother and daughter all had p.Asp50Asn heterozygous mutations in the GJB2gene, and no mutation was detected in GJB6. The modified diagnosis was KID syndrome.

Efficient Three-Party Password Authenticated Key Exchange for Client-to-Client Applications

Yang, Yanjiang,Bao, Feng Korea Institute of Information Security and Crypto 2008 정보보호학회논문지 Vol.18 No.b6

Nowadays, client-to-client applications such as online chat (e.g. MSN) and SMS (Short Message Services) are becoming increasingly prevalent. These client-to-client applications are revolutionizing the way we communicate. Three-party PAKE (password authenticated key exchange) protocols provide a means for the two communicating parties holding passwords to establishment a secure channel between them with the help of a common server. In this paper, we propose an efficient three-party PAKE protocol for the client-to-client applications, which has much better performance than the existing generic constructions. We also show that the proposed protocol is secure in a formal security model.

Needle Deflection during Insertion into Soft Tissue Based on Virtual Spring Model

Haiyan Du,Yongde Zhang,Jingang Jiang,Yanjiang Zhao 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

Needle insertion is the most common procedure of minimally invasive interventions. During insertion into a soft tissue, the needle with bevel tip can deflect due to the asymmetric forces acting on the tip of the needle. In this paper, a mechanics-based model is developed to predict the needle deflection. In the model, the needle is considered as a cantilever beam supported by a series of nonlinear springs each of which has stiffness different from each other. The value of stiffness can be calculated by cutting force acting on the needle tip. Based on the model and the analysis of cutting force and friction force, Rayleigh-Ritz method is used to estimate the amount of needle deflection. Experiment shows that the simulation model can accurately predict the deflection of the bevel-tipped needle.