BOARD STRUCTURE AND AGENCY COSTS

Bing sheng Yi,Chia Wei Chen,T Chotigeat People&Global Business Association 2007 Global Business and Finance Review Vol.12 No.1

Several features are used to measure board structure: board size. leadership. inside director ownership. outside director ownership, and proportion of outside directors. Among these features. only inside director ownership significantly affects agency costs. and its effect is non-linear. In addition, the paper shows that small firms tend to have lower agency costs than large firms when the CEO also acts as chairperson of the board. Direct evidence on the relationship between hoard structure and agency costs is provided: the findings have important implications to shareholders and policy makers

Fractal kinetic characteristics of uranium leaching from low permeability uranium-bearing sandstone

Sheng Zeng,Yuan Shen,Bing Sun,Kaixuan Tan,Shuwen Zhang,Wenhao Ye 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uraniumleaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, wastaken as the research object. The fractal characteristics of the pore structure of the uranium-bearingsandstone were studied using mercury intrusion experiments and fractal theory, and the fractaldimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics wasstudied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that therate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant(K) is linearly related to the pore specific surface fractal dimension (DS) and the pore volume fractaldimension (DV). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics wereestablished using the unreacted shrinking core model, and the linear relationship between the fractaldimension of the sample's pore structure and the dissolution rate during the leaching was fitted.

Ship information system: overview and research trends

Sheng Liu,Bowen Xing,Bing Li,Mingming Gu 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.3

Ship Information Systems (SISs) have been one of the main research focuses in ship design and become a multidisciplinary area. With these growing research trends, it is important to consolidate the latest knowledge and in-formation to keep up with the research needs. In this paper, the SIS and its different forms are introduced and discussed. The beginning of this paper discusses the history and evolution of SIS. The next part of this paper focuses on different fields and research areas such as networking technology, information fusion, information decision, message display, ship control in real-time SISs. A Semi-Physical Simulation Platform (SPSIM) designed for SIS research and its running effect through a new Fuzzy-PID fusion algorithm are introduced in this paper then. A brief literature survey and po-ssible future direction concerning each topic is included.

Ultra-precision Ductile Grinding of Off-Axis Biconical Free-Form Optics with a Controllable Scallop Height Based on Slow Tool Servo with Diamond Grinding Wheels

Sheng Wang,Qingliang Zhao,Bing Guo 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.5

Free-form optics made of hard and brittle materials possesses the reflection and imaging functions that are difficult to be achieved by traditional optics and are widely used in various high energy space optical systems. However, free-form optics made of hard and brittle materials poses great challenges to ultra-precision machining due to its extreme demands of complex surface shapes with nonrotational asymmetric, submicron profile accuracy, controllable scallop height, nanometer surface roughness and ductile grinding surfaces. The freeform generation technique of the slow tool servo with diamond grinding wheel (STS-DGW) previously proposed by us was used to manufacture free-form optics made of hard and brittle materials. First, a theoretical model of scallop height during grinding of biconical free-form surface was established, and the effects of curvature changes on scallop height were studied. Subsequently, the profile error caused by the centering error of diamond wheel was calculated theoretically, and an accurate adjustment method of the grinding wheel position was proposed. Then, an undeformed chip thickness model for achieving ductile grinding was established, and the simulation calculation of critical grinding parameters was carried out. Ultimately, a typical off-axis biconical free-form optics with submicron profile accuracy, a controllable scallop height, nanometer surface roughness, and ductile grinding surfaces was successfully fabricated on single-crystal silicon using the proposed STS-DGW. Compared with the previous research, the profile accuracy was further improved, a controllable scallop height and ductile grinding surface was achieved.

Pore structure evolution characteristics of sandstone uranium ore during acid leaching

Sheng Zeng,Yuan Shen,Bing Sun,Ni Zhang,Shuwen Zhang,Song Feng 한국원자력학회 2021 Nuclear Engineering and Technology Vol.53 No.12

To better understand the permeability of uranium sandstone, improve the leaching rate of uranium, andexplore the change law of pore structure characteristics and blocking mechanism during leaching, wesystematically analyzed the microstructure of acid-leaching uranium sandstone. We investigated thevariable rules of pore structure characteristics based on nuclear magnetic resonance (NMR). The resultsshowed the following: (1) The uranium concentration change followed the exponential law duringuranium deposits acid leaching. After 24 h, the uranium leaching rate reached 50%. The uranium leachingslowed gradually over the next 4 days. (2) Combined with the regularity of porosity variation, Stages Iand II included chemical plugging controlled by surface reaction. Stage I was the major completion phaseof uranium displacement with saturation precipitation of calcium sulfate. Stage II mainly precipitatediron (III) oxide-hydroxide and aluminum hydroxide. Stage III involved physical clogging controlled bydiffusion. (3) In the three stages of leaching, the permeability of the leaching solution changed with thepore structure, which first decreased, then increased, and then decreased

MicroRNA Let-7c inhibits Bcl-xl expression and regulates ox-LDL-induced endothelial apoptosis

( Bing Qin ),( Bo Xiao ),( De Sheng Liang ),( Ye Li ),( Ting Jiang ),( Huan Yang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.8

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl. [BMB Reports 2012; 45(8): 464-469]

Simple denoising method for novel speckle-shifting ghost imaging with connected-region labeling

Sheng Yuan,Xuemei Liu,Pibin Bing 한국광학회 2019 Current Optics and Photonics Vol.3 No.3

A novel speckle-shifting ghost imaging (SSGI) technique is proposed in this paper. This method can effectively extract the edge of an unknown object without achieving its clear ghost image beforehand. However, owing to the imaging mechanism of SSGI, the imaging result generally contains serious noise. To solve the problem, we further propose a simple and effective method to remove noise from the speckle-shifting ghost image with a connected-region labeling (CRL) algorithm. In this method, two ghost images of an object are first generated according to SSGI. A threshold and the CRL are then used to remove noise from the imaging results in turn. This method can retrieve a high-quality image of an object with fewer measurements. Numerical simulations are carried out to verify the feasibility and effectiveness.

Ship information system: overview and research trends

Liu, Sheng,Xing, Bowen,Li, Bing,Gu, Mingming The Society of Naval Architects of Korea 2014 International Journal of Naval Architecture and Oc Vol.6 No.3

Ship Information Systems (SISs) have been one of the main research focuses in ship design and become a multidisciplinary area. With these growing research trends, it is important to consolidate the latest knowledge and information to keep up with the research needs. In this paper, the SIS and its different forms are introduced and discussed. The beginning of this paper discusses the history and evolution of SIS. The next part of this paper focuses on different fields and research areas such as networking technology, information fusion, information decision, message display, ship control in real-time SISs. A Semi-Physical Simulation Platform (SPSIM) designed for SIS research and its running effect through a new Fuzzy-PID fusion algorithm are introduced in this paper then. A brief literature survey and possible future direction concerning each topic is included.

Sperm-mediated Gene Transfer in the Chinese Honeybee, Apis cerana cerana (Hymenoptera: Apidae)

Dong-Sheng Guo,Liang-Xian Sun,Zhi-Jiang Zeng,Xian-Bing Xie 한국응용곤충학회 2007 Journal of Asia-Pacific Entomology Vol.10 No.4

Transgenic Apis cerana cerana were produced by sperm-mediated gene transfer (SMGT). In the experiment, the foreign DNA was linearized and introduced with sperm during the instrumental insemination of virgin queen. The descendants of the experimental colonies were analyzed. In the green fluorescent-positive offspring, green fluorescence was observed for 1- to 2-day-old larvae, the predicted fragment was isolated by means of PCR amplification of genomic DNA and the expression of transferred genes was confirmed at transcriptional level by reverse transcription-polymerase chain reaction. These results showed that the exogenous gene could be integrated in a fraction of the germ line cells of the queen Apis cerana cerana and transmitted to offspring by SMGT.

Reconfiguring Second-order Dynamic Systems via P-D Feedback Eigenstructure Assignment : A Parametric Method

Guo-Sheng Wang,Bing Liang,Guang-Ren Duan 대한전기학회 2005 International Journal of Control, Automation, and Vol.3 No.1