bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary Lysine Affect Carcass Characteristics and Myostatin Gene Exon 1 Region Methylation in Muscle Tissue of Broilers
Authors: Liu Guo Qing , Yang Xiao Jiao , Zong Kai , Xu Jing
Published: September 2012

Amino acids emerged in various biochemical cycles in vivo, affecting the performance and carcass characteristics of broilers. In this study, the contents of dietary lysine and their effects on carcass performance of broiler were investigated. Experimental results showed that deficient dietary lysine significantly reduced live weight, carcass weight, eviscerated yield with gihlet (EYG) and eviscerated yield (EY) of broilers. Whereas, the percentage of slaughter yield, the percentage of eviscerated yield (PEY) and the percentage of eviscerated yield with giblet (PEG) were slightly affected. Many CpG sites were found at the myostatin exon 1 region (nucleotides 2360-2980 bp). At the myostatin exon 1 region where CpG sites enriched (nucleotides 2360-2980 bp), we found significantly lower methylation rate of 18% in low-lysine group of 55-day-old broilers, compared with methylation rate of 87% in control group, which suggested the deficient dietary lysine may lead to demethylation of their original methylated sites. In muscle tissues, the exon1 hypermethylation status of myostatin gene was detected, which was negative correlated with the expression of this gene. These results suggested that methylation of this gene was a dynamic process, which plays a dominant role in regulation of gene expression for development of individuals.
The Heartbeat Classification Based on PCA
Authors: Chen Xue Qin , Wang Rui Ping
Published: September 2012

Classify the electrocardiogram (ECG) into different pathophysiological categories is a complex pattern recognition task which has been tried in lots of methods. This paper will discuss a method of principal component analysis (PCA) in exacting the heartbeat features, and a new method of classification that is to calculate the error between the testing heartbeat and reconstructed heartbeat. Training and testing heartbeat is taken from the MIT-BIH Arrhythmia Database, in which 8 types of arrhythmia signals are selected in this paper. The true positive rate (TPR) is 83%.
Evaluation of Causal Influences in Model of Motor Control in Left Hands Movement-Readiness State
Authors: Wang Yu Qing , Chen Hua Fu , Zeng Ling
Published: September 2012

The previous research revealed some functional coupling among nodes in model of motor control in human brain, which described nondirectional synchronous actions among these nodes during movement-readiness state. However, causal relationships among these nodes were still lack, which represented some directional interactions among these nodes in movement-readiness state. In the present study, we used functional magnetic resonance imaging (fMRI) and conditional Granger causality (CGC) method to investigate the interactions in model of motor control in movement-readiness state. Our result showed that upper precuneus and cingulate motor area revealed net causal influences with contralateral supplementary motor areas and contralateral caudate nucleus during the left hands movement-readiness state. Moreover, the results of Out-In degrees indicated that bilateral primary sensorimotor areas revealed competitive relationship during left hands movement-readiness.
The Influence of UVB Radiation on Proliferation and Youngs Modulus of Dermal Fibroblasts
Authors: Lien Cheng Chang , Wu Meng Chien , Chang Hsin I
Published: September 2012

The aim of this research is using different dose of UVB radiation to study the influence on dermal fibroblasts. These studies include cell viability analysis, proliferation rate and Youngs modulus measurement using Atomic force microscope (AFM). Results have exhibited that the cell viability was 100%, 89.46%, 73.76% and 70.75% when the exposed dose of UVB radiation on dermal fibroblasts was 0, 540, 1080 and 2160mJ/cm2. After 24 hours of incubation, dermal fibroblasts without exposure to UVB radiation increased cell growth to 183.5% but cells exposed to UVB radiation between 216 and 2160 mJ/cm2 reduced cell growth rate to 131% and 47.7%. Moreover, the Youngs modulus of dermal fibroblasts measured by AFM ranged from 24.12 to 9.40 kPa depending on the UVB exposed dose (0-2160 mJ/cm2). Therefore, UVB radiation showed a dose-dependent inhibitory effect on cell viability, proliferation rate and Youngs modulus.
Modification of PK-15 Cells Proteome in the early Stage of Classical Swine Fever Virus Infection
Authors: Sun Jin Fu
Published: September 2012

To uncover host cellular responses in the early stage of classical swine fever virus infection, a proteomic analysis was conducted using 2D electrophoresis followed by MALDI-TOF-TOF identification. Altered expression of 21 protein spots in infected pk-15 cells at 24 h p.i. were identified in 2D gels, with 13 of these being characterized by MALDI-TOF-TOF. These proteins function in cytoskeletal, energy metabolism, nucleic acid/processing, and cellular stress. The expression alteration of these proteins presents the changes in physiological functions of host cells and provides a clue for further understanding of the mechanisms of CSFV infection and pathogenesis.
Stability of Wind Power Turbines Magnetic Bearing
Authors: Yu Wei Jun , Qian Xian Yi
Published: September 2012

We first have analyzed the magnetic bearing systems stability conditions, and then we have built the magnetic bearing systems stability operation module and equations. We also have analyzed the lowest speed which can sustain systems stable operation and confirmed the critical damp conditions. At last, we have designed the critical damping system.
Calcium Ion and Protocorm Differentiation for Cymbidium Hybrid Cymbidium Lucky Gloria × Cymbidium Lovely Moon 'Crescent'
Authors: Yang Chuan Gui , Gao Bao , Liu Jing Ran
Published: September 2012

The low protocorm rate of the hybrid Cymbidium Lucky Gloria × Cymbidium Lovely Moon Crescent (LLC) has long been a detriment to its propagation. In this paper, we describe the thorough research about the effects of calcium ion concentration on the protocorm differentiation for Cymbidium hybrid LLC in vitro through 4 levels of Ca2+ concentration in MS medium based on the trial test including medium experiment with different calcium concentrations and the use of calcium inhibitor La3+. Our studies revealed that Ca2+ played a key role in protocorm differentiation of LLC, which was against the generally accepted idea about the function of 6-benzyl aminopurine (6-BA) and indole-3-butyric acid (IBA) in hybrid cymbidium protorcorm differentiation in vitro. The Chain reaction constituted by cytokinin, calcium, and auxin is submitted to exloringly explain the function mechanism of Ca2+.
Application of Fuzzy Enhancement in the Diagnosis of Liver Cancer from Ultrasound Images
Authors: Qiu Wu , Xiao Feng , Yang Xin , Ye Mao Lin , Ming Yu Chi , Ding Ming Yue
Published: September 2012

Fuzzy enhancement is applied in computer aided diagnosis of liver cancer from B mode ultrasound images as a pre-processing procedure in this paper. It was evaluated with three classifiers including K means, back propagation neural network and support vector machine using 25 features from single gray-level statistic, gray-level co-occurrence matrix (GLCM), and gray-level run-length matrix (GLRLM). The results show that the fuzzy enhancement algorithm can improve classification accuracy of normal liver, liver cancer and Hemangioma from B mode ultrasound images for three classifiers. It is proved that fuzzy enhancement as an efficient preprocessing procedure could be used in the computer aided diagnosis system of liver cancer.
Wavelet-Based Medical Image Denoising and Enhancement
Authors: Jiang Hui Qin , Wang Zhong Yong , Ma Ling , Liu Yu Min , Li Ping
Published: September 2012

The visual quality of medical images is an important aspect in PACS implementation. In this study, on the basis of wavelet analysis, a denoising and enhancement algorithm for medical image is proposed. The algorithm mainly includes six steps. At first, an effcient method is investigated for Poisson Noise remove. Second, diagnosis features of the denoised image are enhanced by compressing the dynamic range. Third, we extract the high frequency component of the original image by the designed lowpass filter. Fourth, the extracted high frequency component are segment into diagnosis feature component in the high signal range, the diagnosis feature component in the low signal range, and the noise component. Five, we reconstruct an image using image fusion. Finally, we make DICOM calibration for used display and decide parameters of the image fusion, resulting in the diagnosis image. Experimental results show that this new scheme offers effective noise removal in medical images and enhancing sharpness. More importantly, this scheme can improve the diagnostic value of the display image on the commercial display successfully.
A Medical Image Fusion Method Based on Contourlet Transformation and Region Sensitivity
Authors: Li Jun Li , Qiu Yi Na , Lou Yang
Published: September 2012

The traditional wavelet-based image fusion method has some problems, in order to further satisfy the requirements of image fusion on the right direction, this paper studies the principle and performance contourlet transformation based on the proposed sensitivity analysis. In this method, contourlet multi-resolution, locality and direction effectively capture the source image in detail, texture, direction of information, enhance the visibility of the fused image and obtain the higher quality medical images.
An Energy Saving Scheme Based on Evolutionary Potential Power Allocation
Authors: Lu Zhao Ming , Zhao Yan Kun , Wen Xiang Ming , Zheng Wei
Published: September 2012

According to SMART 2020, Internet and ICT (Information and communication technology) could reduce emissions by 15 percent in annual energy costs by 2020. One of the main methods to reduce the energy costs in communication system is to reduce the transmitting power of eNBs. In our study, we explore the problem of downlink energy saving for LTE/LTE-A network based on Orthogonal Frequency Division Multiplexing (OFDM). We propose an adaptive eNB transmitting power allocation scheme based on inter-eNB coordination. This power allocation scheme works in distributive way by being formulated as an evolutionary potential game. Numerical results prove that our proposed algorithm notably reduces the overall transmitting power, while throughputs of either overall or edge users are guaranteed at the same time.
Cryptograph Index Technology Based on Bucket Partitioning and B+ Tree
Authors: Chen Zhuo , Li Shi Qi , Lu Nan Nan , Han Tao
Published: September 2012

Database encryption is the last defense to ensure data security, resolving the problem of insecurity caused by unencrypted data directly stored in database. At the same time, Database encryption has brought a new troubleencryption makes query efficiency become obviously slow. Cryptograph index is an effective method. In the DAS(Database as a service) model, a method based on bucket partitioning and B+ tree, which utilizes B+ tree to sort data in the bucket and improves the efficiency due to reduce the amount of processing data, is put forth in this paper. Finally, the paper has made an analysis on its performance.
Accurate Computation of Zernike Moments in Cartesian Coordinates
Authors: Fu Bo , Fan Xiu Xiang , Cheng Qiong , Li Li , Li Bo , Zhang Guo Jun
Published: September 2012

In this paper, a novel algorithm is proposed to accurately calculate Zernike moments in Cartesian Coordinates. We connect the corners of an image pixel with the origin to construct four triangles and then assign the intensity function value of the pixel to these triangles. The Fourier Mellin moment integration of the pixel is converted to a summation of four integrations within domains of these constructed triangles. By using the trigonometric resolution, we derive the analytic equations of the four integrations of these triangles. Then, the analytic expressions of the Fourier Mellin moments and Zernike moments are obtained. The algorithm eliminates the geometric and discretization errors theoretically. Finally, a set of efficient computational recursive relations is proposed. An experiment is designed to verify the performance of the proposed algorithm.
Simulation and Implementation of 2D DOA Estimation in Wireless Location
Authors: Tan Ping , Zhou Zhi Yao , Zhang Yu Feng , Luo Ye , Ma Hong
Published: September 2012

It is needed to realize high resolution two dimensional (2D) direction of arrivals (DOA) estimation in determining the location of the mobile with high accuracy. In this paper, the problem of estimating the 2D DOA using uniform circular array (UCA) is investigated. Performance of 2D DOA estimation based on the real-valued unitary transformation MUSIC algorithm for UCA is presented, especially focusing on DOA estimation of multiple correlated signals.Then the validations of Unitary Transformation MUSIC algorithm are performed based on the measurement data in a wireless location system.
Design and Simulation of Feedback Interference Cancellation Repeater
Authors: Zhang Fu Hong , Zhu Ye
Published: September 2012

Stability and output signal quality are two important indicators to evaluate the performance of a repeater.A high gain is also the basic requirement of repeater.This paper first proposes a feedback interference cancellation repeater scheme, and then the scheme is simulated on simulink.The result shows that the proposed scheme is able to cancel the feedback interference and guarantee the stability and output signal quality of repeater. Besides, it confirms that stability and output signal quality have some relation with the repeater gain G, the order of estimated channel filter N and the introduced delay. Finally, the approach of variable gain effectively increases the repeater gain, and appropriate selection of the gain makes it possible to avoid the output signal quality deterioration.
Simulation of Cantilever Column under the Isolation Device Considering Additional Moment
Authors: Zhang Hua Ying , Li Hui , Zhang Xin , Pan Rui Song
Published: September 2012

To accurately simulate the second-order bending moment caused by the superstructure shift in the isolation system is difficult. A simulation method of considering the second-order moment is put forward in this paper, and which is used to obtain the push-over curve of the cantilever column. Comparison of the push-over curves that with or without considering the additional moment is shown in this paper. The comparison presents evidence reduction, and embodies the decrease of stiffness. This simulation method can effectively balance the affection of the upper structure shift to the vertical bearing member under the isolator.
A Hybrid Process Modeling Method and its Application in Equipment Support System
Authors: Wang Ya Bin , Liu Hong Bo
Published: September 2012

In this paper, a hybrid process modeling method for equipment support system was presented. Combining with the advantages of ARENA and UML, the models of equipment support process were constructed by the means of UML, which include function models, dynamic models and object models. The frame work of UML-ARENA simulation software was designed, and the mapping relations between UML object classes and ARENA models were founded. The equipment support process was simulated by ARENA. At last, an example was given, which proves that this hybrid modeling method is feasible and significant for its can optimize the support process, shorten the support time, and improve the usage ratio of resources.
The Existence of Homoclinic Solutions for Second Order Differential Equation
Authors: Gao Jie
Published: September 2012

The research for Hamilton system is a classical problem, it has valuable applications in celestial mechanics, plasma physics, and biological engineering. But in actual management, Hamilton system can be changed into solving homoclinic solutions of differential equation or system. This paper studies the existence of homoclinic solutions for a class of second order differential equation, we will prove this equation exists at least one nontrivial homoclinic solution.
Simulation for Mixture of Archimedean Copulas
Authors: Ou Shi De
Published: September 2012

Many dependence structures can consist of mixed copulas. In order to analyze the dependence of stock, we present the method of estimation for mixed copula models. Via generating random samples and using maximum likelihood estimation, the parameters of mixture of Archimedean copulas are estimated. Numerical results show that this method estimates effectively the parameters and tail dependence coefficients. Therefore we can use the method to analyze dependence structure for stocks.
Modeling of CNC Machine Tool Energy Consumption and Optimization Study Based on Neural Network and Genetic Algorithm
Authors: Xie Dong , Chen Guo Rong , Wang Feng , Zhu Jian Qu
Published: September 2012

The issue of CNC machine tool energy consumption and environmental protection plays an important role on manufacturing technology research since CNC machine tool energy is consumed during motor racing or cutting process. The paper analyzes CNC machine tool energy consumption influence by cutting parameters of cutting speed, feed speed, cutting depth. Based on nonlinear mapping ability of neural network, the model of CNC machine tool energy consumption related to cutting parameters is established by using experimental data, and then the optimal combination of cutting parameters are searched by using global optimization of genetic algorithm, and verified in CNC machine tool cutting experiment. The proposed method provides a good energy control proposal for CNC machine tool roughing process. The experimental results show that the energy consumption is optimal.
Performance Analysis of LFM Signal Parameter Estimation through FrFT Transform
Authors: Wang Ze Zhong , Huang Yu , Liu Feng
Published: September 2012

The fractional Fourier transform (FrFT) used to process linearly frequency modulated (LFM) signals is applied in the differentiation and parameters estimation of LFM radar signals. The performance of the LFM signals detection and parameters estimation through FrFT are studied when the signal-noise ratio (SNR) is low. The situation is set and the demonstration routine through simulations is made so that the performance on the chirp rate estimation and the central frequency estimation of LFM signals through FrFT is tested, the time used to obtain parameter estimation results through computer simulations is compared. The simulation results demonstrate that the method through FrFT could be used to differentiate LFM radar signals and to estimate parameters of LFM radar signals when the SNR is low.
An Energy-Efficient Receiver for Human Body Communication
Authors: Zhang Da Hui , Nie Ze Dong , Guan Feng , Wang Lei
Published: September 2012

A low-power, wideband signaling receiver for data transmission through a human body was presented in this paper. The receiver utilized a novel implementation of energy-efficient wideband impulse communication that uses the human body as the transmission medium, provides low power consumption, high reception sensitivity. The receiver consists of a low-noise amplifier, active balun, variable gain amplifier (VGA) Gm-C filter, comparator, and FSK demodulator. It was designed with 0.18um CMOS process in an active area of 1.54mm0.414mm. Post-simulation showed that the receiver has a gain range of-2dB~40dB. The receiver consumes 4mW at 1.8V supply and achieves transmission bit energy of 0.8nJ/bit.
Modeling and Analysis of Planning and Process Workflow to Obtain Luban Award
Authors: Wei Zhi Hua , Meng Min
Published: September 2012

As the highest honor in the project quality aspect of the domestic construction industry, Luban Award has a strict appraisal condition and standard. When determining the plan of applying Luban Award, construction unit must design a set of perfect planning mentality and detailed implementation process plan. This article proposed one kind of planning and process workflow model to apply Luban Award, according to the appraisal request of applying Luban Award, Analyzed the nodes in each stage of a project, carried on the formal description to the project activity using the Petri net modeling method, established a mapping mechanism from each service to the workflow model, and analyzed the model reliability.
A Systematic Measurement of CSP Based on Fuzzy Analytical Hierarchy Process
Authors: Chen Shou Ming , Fan Jia Si
Published: September 2012

With increasing social awareness on the issue of corporate social performance (CSP), the measurement of CSP has received considerable attention in both academic literature and managerial practice. Though earlier literature provides several methods for measuring corporate social activities, almost all of them have some limitations. In this paper, we propose a methodology for the development of a systematic measure of CSP based on fuzzy analytical hierarchy process (FAHP). In addition, a preliminary investigation is presented to explain how the approach can help in evaluating CSP in practice.
Study on Model Validation of Logistics System Based on Petri Nets
Authors: Zhang Guan Xiang , He Shan , Zhang Zhi Yong
Published: September 2012

Simulation is a better method than traditional analytic mathematics method for the analysis and description of complex logistics system, which can preview the result of decision and simulate the system operation process. But a accurate model is the foundation of it. All analytical studies of the system are based on the model. Unfortunately, it is an unsolved problem that how to evaluate and verify a model quality. The article add the mathematics analysis of model in modeling by object-oriented theory. It studies the conversion rules among the UML, OOPN and eM-Plant model. At last, a relative case is included to verify the feasibility.
Study on the Design of a Magnetic Started Wireless Capsule Endoscopy
Authors: Wang Ya Zhen , Chen Ying Jun , Ping Huang
Published: September 2012

Based on the minimal CMOS image sensor OV6920, a magnetic controlled wireless capsule endoscopy has been designed in principles of micromation and low power consumption. The peripheral circuit of OV6920 is designed. With optical design, the power consumption of transmitting circuit is cut down according to the relationships between the resistance in series and the voltage, current, and transmitting power consumption. The total size of the system is only φ13×29mm, and the power consumption is about 100mW when all modules are connected altogether. The clear captured images in the imaging experiments prove the system design is feasible.
Physics Teaching Based on the In-Class Interaction System
Authors: Feng Xiu Mei , Pi Yuan , Wang Jian Zhong , Zhou Xiang , Zhou Si Qi
Published: September 2012

The in-class interaction system (clicker) has been used in the physics class recently in China. It dramatically changes the normal lectures in large classes and enhances the class interaction. In this paper the improvements of this system on the traditional physics teaching are summarized. We illustrate how to integrate this system to the physics class to design teaching process. Some suggestions about teaching effectively and assessment of this system are also given.
A New Type of the Research and Deployment Strategy for Web-Page Tamper-Resistant
Authors: Yang Mian Rong , Zhang Xin
Published: September 2012

This paper presents a system architecture through a new type of strategy for web-page tamper-resistant. The new strategy emphasizes the following points: by using of file filter technology timely find out and block the malicious tampering so that the illegal malicious tampering is prevented; the tamper-resistant module and digital watermark module are distributed in two different servers and the servers are separated by a firewall to strengthen the overall security of the system; to ensure the security of the tamper-resistant process, it is necessary to deployment a single chip machine to protect the tamper-resistant process.
Study on Coal Mine Safety Monitoring System with Emergency Voice Communication Based on Wireless Sensor Network
Authors: Chen Jun Hua , Chen Xiao Zhou
Published: September 2012

The drawback of the current voice communication for coal mine is that only the wired scheduling telephone or a small flexible phone for mine is used for voice contact. According to the existing coal mine environment monitoring systems, a more secure coal mine monitoring system with emergency voice communication is designed based on wireless sensor network (WSN). By introducing voice module which achieves voice, the sensor nodes and sink nodes of the monitor system are redeveloped on the Imote2 and Stargate platforms respectively. This system gives consideration to the real-time of environment data monitor and voice communication reliability in coal mine, and the key technologies of hardware design and software of sensor nodes with voice and their tasks scheduler algorithm with priority are given. This system conquers the defect of wired networks and avoids the high-energy cost of other wireless technology. The experiment results show that the designed system is simple, reliable, and economic and has a great application prospect for coal mine.
Study of FCLSD Algorithm Performance Based on LTE System
Authors: Liu Ke Wen , Liu Quan
Published: September 2012

Soft-output complex list sphere decoding algorithm is a low-complexity MIMO detection algorithm and its BER performance approximates that of Maximum-Likelihood. However, it has a problem of not fixed complexity, and which make it very difficult to implement. To resolve this and try best to retain the advantages of the algorithm, a modified algorithmfixed complex list sphere decoding algorithm was proposed. Based on LTE TDD system, this paper studies the performance of the FCLSD algorithm. The simulation results show that: the BER performance of the FCLSD algorithm is close to that of the CLSD algorithm. However, when the number of antennas and modulation order increasing, the FCLSD algorithm is non-constrained of spherical radius and has fixed complexity. In addition, hardware implementation of the FCLSD algorithm could be carried out by parallel processing, thereby greatly reducing the algorithm complexity. So it is a high-performance algorithm of great potential.
Solid-Phase Mechanical Alloying of BCC Iron Alloys by Nitrogen in Ball Mills
Authors: Shabashov V.A. , Kozlov K.A. , Lyashkov K.A. , Litvinov A.V. , Dorofeev G.A. , Titova S.G.
Published: September 2012

The methods of Mössbauer spectroscopy and X-ray diffraction analysis have been used to study the processes of a solid-phase alloying of the iron alloys with a bcc lattice by nitrogen that occur upon ball-mill mechanical activation in the presence of chromium nitrides. It is shown that a deformation-induced dissolution of chromium nitrides in the matrix of pure iron and in that of the alloys Fe–3Al and Fe–6V results in the formation of the substitutional chromium and interstitial nitrogen bcc solid solutions. An additional alloying of iron with aluminum or vanadium under the deformation dissolution of nitrides leads to the escape of aluminum and vanadium from the matrix and to a decrease in the nitrogen content characteristic of the interstitial solid solution proper due to the strong chemical bonding of alloying elements with nitrogen. The subsequent annealing leads to the decomposition of already formed solid solutions with the formation of aluminum, vanadium, and chromium nitrides of extreme dispersion.
Characterization of H-Plasma Treated ZnO Crystals by Positron Annihilation and Atomic Force Microscopy
Authors: Čížek Jakub , Procházka I. , Kuriplach J. , Anwand W. , Brauer Gerhard , Cowan T.E. , Grambole D. , Schmidt H. , Skorupa W.
Published: September 2012

Nominally undoped, hydrothermally grown ZnO single crystals have been investigated before and after exposure to remote H-plasma. Defect characterization has been made by two complementary techniques of positron annihilation: positron lifetime spectroscopy and coincidence Doppler broadening. The high-momentum parts of the annihilation photon momentum distribution have been calculated from first principles in order to assist in defect identification. The positron annihilation results are supplemented by Atomic Force Microscopy for characterization of the crystal surface. It was found that virgin ZnO crystal contains Zn-vacancies associated with hydrogen. H-plasma treatment causes a significant reduction in concentration of these complexes. Physical mechanism of this effect is discussed in the paper.
Design and Construction of a Slow Positron Beam for Solid and Surface Investigations
Authors: Anwand Wolfgang , Brauer Gerhard , Butterling Maik , Kissener Hans Rainer , Wagner Andreas
Published: September 2012

On the basis of the design and construction of the slow positron beam SPONSOR at the Helmholtz-Centre Dresden-Rossendorf an example is given how to build-up a simple slow positron beam for solid surface investigations within a short time and without high financial costs. The system uses a 22Na source and consists of three main parts: (1) the source chamber with a thin film tungsten moderator used in transmission, and a pre-accelerator stage, (2) the vacuum system with magnetic transport, a bent tube for energy selection and an accelerator, (3) the sample chamber with a sample holder, Ge detectors and (4) facilities for remote control and data acquisition. These parts are described in detail. The paper is preferentially addressed to beginners in the field of slow positron beam techniques and other readers being generally interested in positron annihilation spectroscopy.
Applications of Positron Annihilation Spectroscopy to Life Science
Authors: Chen Hong Min , van Horn J. David , Jean Yan Ching
Published: September 2012

Positron annihilation spectroscopy (PAS) is a novel method that can provide molecular-level information about complex biological and macromolecular structure in a manner which is different, but complementary, to conventional medical and biochemical research methodology. Positron annihilation lifetime spectroscopy (PALS) and Doppler broadening energy spectroscopy (DBES), coupled with a slow positron beam have been extensively applied to the life science research recently. These techniques provide new information about the atomic and molecular level free-volume and void sizes, and their distributions 0.1 nm to a few nm, molecular bonding, structures at depth-layers, and phase transitions. This paper is to review recent research on positron annihilation spectroscopy applied to the area of life science and also focus on current bioscience-related work in the positron group at the University of MissouriKansas City (UMKC).
Low Background Digital Coincidence Spectrometer – A Tool for Investigation of Positron Annihilation in Flight
Authors: Čížek Jakub , Vlček M. , Lukáč F. , Melikhova O. , Procházka I. , Anwand W. , Butterling M. , Wagner A. , Brauer Gerhard
Published: September 2012

A digital spectrometer for low background gamma ray spectroscopy equipped with two high purity Ge detectors and a 12-bit two channel digitizer was employed for the investigation of positron annihilation-in-flight. Measurements were performed for positrons emitted by 68Ge/68Ga and 22Na radioisotopes and annihilated in Cu and Mg targets. The contribution of the two-quantum positron annihilation-in-flight was clearly resolved in coincidence two-dimensional gamma ray energy spectra. The contribution of positrons annihilated in flight has a hyperbolic shape described well by the relativistic theory.
Atomic Force Microscopy and Scanning Tunneling Microscopy of Aluminum Nanoislands
Authors: Nedilko S.G. , Prorok V. , Rozouvan Stanislav
Published: September 2012

Aluminum nanoislands deposited on silicon substrate were studied by a scanning tunnelling microscopy technique. Measurements completed with spatial resolution up to 1 nm revealed a complex nanoisland structure-rhomboidally ordered near the border of the aluminum-silicon and porous structure in the islands upper parts. Volt-ampere curves demonstrated strong dependency from the film thickness and were interpreted as nanoscale effects. Kelvin probe microscopy was used for simultaneous aluminum-alumina and alumina-air surface scanning.
Extension Education for Dryland Cropping Systems in Iraq
Authors: Abi‐Ghanem Rita , Carpenter‐Boggs Lynne , Koenig Richard , Pannkuk Chris , Pan William , Parker Robert
Published: September 2012

Iraq, formerly known as Mesopotamia, is the birthplace of agriculture. The recent war and instability have significantly impacted the country's agricultural production and knowledge support systems. To support revitalization of the Iraqi agricultural system, the USDA funded a consortium of five U.S. universities (Washington State University, University of California‐Davis, New Mexico State University, Utah State University, and Texas A&M University as the lead institution) to provide training to agricultural extension personnel from Iraq. Each university had a specific training area. Washington State University was responsible for training in dryland cropping systems and delivered five separate sessions to Iraqis in several Middle East locations. Questionnaires distributed during each session guided subsequent training agendas and enhanced our understanding of extension and dryland cropping systems information needs in Iraq. There is great demand for training, technology, basic farm equipment, seed, and fertilizers, since current access to resources is insufficient to satisfy the country's needs. In addition to supplying inputs and equipment, further training should introduce methods for utilizing on‐farm resources. There is also a clear need for better cooperation between Iraq's universities and extension agency, administered by the Iraq Ministry of Agriculture, in order to maximize the efficiency of research information transfer to farmers.
The Impact of Professional Development in Natural Resource Investigations Using Geospatial Technologies
Authors: Hanley Carol D. , Davis Hilarie B. , Davey Bradford T.
Published: September 2012

As use of geospatial technologies has increased in the workplace, so has interest in using these technologies in the K–12 classroom. Prior research has identified several reasons for using geospatial technologies in the classroom, such as developing spatial thinking, supporting local investigations, analyzing changes in the environment, and interesting students in technology and geography. The National Research Council (NRC) advocates spatial thinking instruction across the K–12 curriculum and instruction in geospatial technologies, such as geographic information systems (GIS), is one way to increase understanding in spatial thinking. Many educators agree that GIS can be a useful tool for student learning; however, if GIS is going to be successfully integrated into the classroom, many issues need to be addressed, including those related to professional development. Many of the characteristics of effective professional development apply to professional development in geospatial technologies but researchers continue to identify best practices. The professional development objectives for the NSF ITEST (Innovative Technology Experiences for Students and Teachers) program at the University of Kentucky were threefold: (1) to increase knowledge of geospatial technologies, including GIS, GPS, and remote sensing; (2) to develop spatial thinking; and (3) to apply that knowledge to community‐based natural resource investigations, a localized form of project‐based learning (PBL). The UK team hypothesized that the unique components of this professional development program would be an effective way to increase teachers’ knowledge of new technologies and spatial thinking and to instruct teachers how to apply that knowledge to community‐based investigations.
Relevance of a New Integral Keratoconus Grading System for the Outcomes of Intracorneal Ring Segment Implantation
Authors: Burguera-Gimenez Neus
Published: September 2012

Purpose

To report a new grading system of Keratoconus according to visual limitation and to provide the intrastromal corneal ring segments (ICRS) outcomes that can be expected based on preoperative visual impairment.

How to cite this article

Alio JL, Burguera-Gimenez N, Vega- Estrada A. Relevance of a New Integral Keratoconus Grading System for the Outcomes of Intracorneal Ring Segment Implantation. Int J Kerat Ect Cor Dis 2012;1(2):79-86.
MyoRing for Central and Noncentral Keratoconus
Authors: Daxer Albert
Published: September 2012

Purpose

To demonstrate treatment options for keratoconus using MyoRing intracorneal implant in central and noncentral cones.

Materials and methods

Five eyes with central and noncentral cones were compared in a retrospective study.

Results

In central cones the maximum of the flattening effect is in the corneal center while in noncentral cones the maximum of the flattening is in area of the cone.

Conclusion

No matter where the cone location is the implantation of MyoRing intracorneal implants always results in a regularization of the central cornea.

How to cite this article

Daxer A. MyoRing for Central and Noncentral Keratoconus. Int J Kerat Ect Cor Dis 2012;1(2):117-119.
Cross-linking for the Management of Pellucid Marginal Degeneration in a Case of an Unsuccessful Implantation of Intracorneal Ring Segments
Authors: Tuffaha Bader Tarek , Piñero David P
Published: September 2012

We present a case of progressive pellucid marginal degeneration (PMD) treated with cross-linking (CXL) after a previous unsuccessful implantation of intracorneal ring segments. One year after surgery, an increase in the corneal biomechanical properties accompanied by an improvement in corrected visual acuity and a decrease in the magnitude of corneal coma-like aberrations was observed. However, the magnitude of the refractive cylinder and keratometry increased whereas the internal astigmatism was reduced by 3.93 D. CXL in a cornea with a progressive PMD seems to induce not only changes in the anterior corneal surface, but also in the posterior corneal surface.

How to cite this article

Tuffaha BT, Alio JL, Piñero DP. Cross- linking for the Management of Pellucid Marginal Degeneration in a Case of an Unsuccessful Implantation of Intracorneal Ring Segments. Int J Kerat Ect Cor Dis 2012;1(2):120-124.
Collagen Corneal Cross-linking in a Keratoconic Eye with Diffuse Corneal Edema
Authors: Garzozi Hanna , Pickel Yossef , Barua Ankur
Published: September 2012

Corneal cross-linking has proven safety and efficacy in arresting the progression of keratoconus. Its use has been extended to resolution of corneal edema. We present a case report and review of literature on the treatment of corneal edema using corneal cross-linking. Corneal cross-linking seems to be an effective method in reducing corneal edema at least as a temporary measure till definitive solution, such as penetrating keratoplasty (PKP) or Descemet's stripping automated endothelial keratoplasty (DASEK) is preformed.

How to cite this article

Barbara R, Garzozi H, Barbara A, Pickel Y, Barua A. Collagen Corneal Cross-linking in a Keratoconic Eye with Diffuse Corneal Edema. Int J Kerat Ect Cor Dis 2012;1(2):134-139.
Analyse der Störfestigkeit nichtlinearer Schaltungen gegenüber leitungsgebundenen elektromagnetischen Störungen mit multi-input Wiener/Hammerstein-Modellen
Authors: Stegemann S. , John W. , Mathis W.
Published: September 2012

Abstract. In dieser Arbeit wird der Einfluss von leitungsgebundenen Störungen untersucht, welche in einen beliebigen Eingang (Signaleingang, Spannungsversorgung, Masse-Potenzial, etc.) einer Analogschaltung einkoppeln. Die zu untersuchende Schaltung wird dazu durch einen Wiener/Hammerstein-Ansatz als nichtlineares System mit zwei Eingängen modelliert. Mit Hilfe dieses Blockmodells werden analytische Ausdrücke derjenigen Frequenzanteile bestimmt, die durch Intermodulationen zwischen Stör- und Eingangssignal am Ausgang einer Schaltung entstehen.
Traceable electric and magnetic field calibrations of radiation monitors for amateur radio inside a parallel plate transmission line up to 30 MHz
Authors: Kootz T. , Schrader T. , Münter K.
Published: September 2012

Abstract. In many countries the electromagnetic field strength in the proximity of licensed amateur radio stations is limited to ensure public safety. If the station antenna(s) and/or the environmental situation are complex, only measurement results are acceptable as proof, and proper calibration of the field strength meters ("radiation monitors") is mandatory. A system and a procedure are described here, enabling calibration of such "radiation monitors" at a high quality level and traceable to the SI units, but with low-budget amateur equipment.
Signalparameter zur Ortung von HPEM-Quellen
Authors: Kanyou Nana R. , Kranzpiller W. , Sonnenberg N. , Nguete Tsamo R.
Published: September 2012

Abstract. In diesem Beitrag wird anhand von Signalproben untersucht, mit welchen geeigneten Signalparametern die Ortung von aktiven leistungsstarken elektromagnetischen Quellen (sog. HPEM-Quellen) optimal durchgeführt werden kann. Da sich die Positionsberechnung durch die Verarbeitung von Laufzeitdifferenzen ergibt, beschränkt sich die Untersuchung auf die Bestimmung der Laufzeitdifferenzen. Betrachtet werden sowohl Signalausschnitte definierter Länge sowie eindeutig identifizierbare Ereigniszeitpunkte. Im ersten Fall werden aus der Korrelation der Signalausschnitte im Frequenzbereich die Laufzeitdifferenzen bestimmt. Hierbei wird durch Variation der Anzahl der Abtastwerte eines Signalausschnitts die erforderliche Signaldauer ermittelt. Im zweiten Fall werden zuerst aus den direkt erfassten Signaldaten die Einhüllenden gewonnen. Bezüglich eines vordefinierten Referenzwertes werden diese Einhüllenden dann korrigiert. Mit Hilfe eines festgelegten Schwellwertes wird abschließend aus den korrigierten Hüllkurven die Differenz der Ereigniszeitpunkte gebildet und somit die Laufzeitdifferenz im Zeitbereich bestimmt.
Area- and energy-efficient CORDIC accelerators in deep sub-micron CMOS technologies
Authors: Vishnoi U. , Noll T. G.
Published: September 2012

Abstract. The COordinate Rotate DIgital Computer (CORDIC) algorithm is a well known versatile approach and is widely applied in today's SoCs for especially but not restricted to digital communications. Dedicated CORDIC blocks can be implemented in deep sub-micron CMOS technologies at very low area and energy costs and are attractive to be used as hardware accelerators for Application Specific Instruction Processors (ASIPs). Thereby, overcoming the well known energy vs. flexibility conflict. Optimizing Global Navigation Satellite System (GNSS) receivers to reduce the hardware complexity is an important research topic at present. In such receivers CORDIC accelerators can be used for digital baseband processing (fixed-point) and in Position-Velocity-Time estimation (floating-point). A micro architecture well suited to such applications is presented. This architecture is parameterized according to the wordlengths as well as the number of iterations and can be easily extended for floating point data format. Moreover, area can be traded for throughput by partially or even fully unrolling the iterations, whereby the degree of pipelining is organized with one CORDIC iteration per cycle. From the architectural description, the macro layout can be generated fully automatically using an in-house datapath generator tool. Since the adders and shifters play an important role in optimizing the CORDIC block, they must be carefully optimized for high area and energy efficiency in the underlying technology. So, for this purpose carry-select adders and logarithmic shifters have been chosen. Device dimensioning was automatically optimized with respect to dynamic and static power, area and performance using the in-house tool. The fully sequential CORDIC block for fixed-point digital baseband processing features a wordlength of 16 bits, requires 5232 transistors, which is implemented in a 40-nm CMOS technology and occupies a silicon area of 1560 μm2 only. Maximum clock frequency from circuit simulation of extracted netlist is 768 MHz under typical, and 463 MHz under worst case technology and application corner conditions, respectively. Simulated dynamic power dissipation is 0.24 uW MHz−1 at 0.9 V; static power is 38 uW in slow corner, 65 uW in typical corner and 518 uW in fast corner, respectively. The latter can be reduced by 43% in a 40-nm CMOS technology using 0.5 V reverse-backbias. These features are compared with the results from different design styles as well as with an implementation in 28-nm CMOS technology. It is interesting that in the latter case area scales as expected, but worst case performance and energy do not scale well anymore.
Reconfigurable ultra-wideband transmitter for generation of arbitrary impulse shapes and modulation schemes
Authors: Ott A. T. , Eisner C. J. , Blech M. D. , Eibert T. F.
Published: September 2012

Abstract. In this paper a reconfigurable ultra-wideband (UWB) impulse radio (IR) transmitter is presented. The IR signal is synthesized at an intermediate frequency (IF) by employing a multi-Nyquist digital-to-analog converter (DAC) with 12 bit resolution and an update rate of 2.3 GHz. Digital generation of signals in a field programmable gate array (FPGA) guarantees very high flexibility of the reconfigurable design. For upconversion to the radio frequency (RF) band, a first order bandpass (BP) sampling concept and an alternative conventional concept with mixer stages, have been realized. The system enables to generate signals with arbitrary modulation schemes and techniques at an external host personal computer (PC) employing MATLAB. Different measurements using a digitizing oscilloscope have been conducted to demonstrate the performance of the transmitter.
Fixed Dilated Pupilla as a Common Complication of Deep Anterior Lamellar Keratoplasty Complicated with Descemet Membrane Perforation
Authors: Bozkurt Kansu Tahir , Acar Banu Torun , Acar Suphi
Published: September 2012

Purpose.

To report 8 cases of fixed dilated pupilla (FDP) (Urrets-Zavalia syndrome) following deep anterior lamellar keratoplasty (DALK) with Descemet membrane (DM) perforation and change of management to avoid FDP.

Methods.

Retrospective analysis of 106 eyes of 94 patients who underwent DALK for various diagnoses was performed. Intraoperative and postoperative details of eyes that developed DM detachment, FDP, as well as change of management to prevent rise of intraocular pressure (IOP) (as a common trait of these eyes) were evaluated.

Results.

Descemet membrane perforation developed in 17 (16%) eyes. Fixed dilated pupilla was diagnosed in 8 (7.5%) eyes. Seven of the eyes with FDP experienced DM perforation and air bubble was left in anterior chamber (AC) to tamponade DM perforation at the end of the surgeries. Five eyes developed FDP in the early postoperative period and the remaining 2 eyes, which were diagnosed as double AC and managed by repeated air injections, developed FDP in the third postoperative week. The last patient who experienced intense postoperative inflammation had a fixed dilated pupil in the third postoperative week.

Conclusions.

Fixed dilated pupilla is an uncommon but well-known complication of keratoplasty. The exact mechanism remains unknown but postoperative high IOP seems to be an important risk factor following complicated DALK. Rise in IOP during the management of complications following DALK related to DM was found to be important in the development of FDP in this series.