bluuebunny/crossref_metadata_2025 huggingface dataset:
Algorithm Improvement of Two-Way Merge Sort Based on OpenMP
Authors: Zhang Jun , Gao Yong Ping , He Yue Shun , Wang Xue Yuan
Published: December 2014

Two-way merge sort algorithm has a good time efficiency which has been used widely. The sort algorithm can be improved on speed and efficient based on its own potential parallelism via the parallel processing capacity of multi-core processor and the convenient programming interface of OpenMP. The time complexity is improved to O(nlog2n/TNUM) and inversely proportional to the number of parallel threads. The experiment results show that the improved two-way merge sort algorithm become much more efficient compared to the traditional one.
Penalty Method Involving Electric Sliding Contact Problem
Authors: Tan Sai , Lu Jun Yong , Long Xin Lin , Zhang Xiao
Published: December 2014

Basing on governing Maxwell and energy equation of rail gun considering armature movement in two dimension, The total domain to be solved is divided into two subdomains: moving (armature) part and static (rail) part, finite element formulations of two subdomains are built independently, then using the interface condition of two subdomains, formulations are connected by coupled equation which is derived out by penalty method. Shifted physical quantity is used to simulate movement. The final magnetic-thermal coupled fields finite element formulations of rail gun are established by these methods. Numerical calculation results compared by theoretical and other numerical results verify that penalty method is an effective way to deal with electric sliding contact problem associating with Shifted physical quantity method.
A Novel Background Subtraction Method Using Multiclass Support Vector Machine
Authors: Zhou Shao Na , Xu Shao Rui , Xiao Hua
Published: December 2014

Background subtraction, where the foreground is segmented from the background, is the first step of data analysis and processing in automated visual surveillance. Aiming to solve the problems associated with dynamic, multi-modal background, we explore a new approach which can handle the unconstrained environment. Based on multiclass support vector machines, a new MSVM is proposed for the classification of the background and the foreground. The simulation indicates our proposed algorithm is feasible.
A Novel Model Based on LBP and Meanshift for UAV Image Segmentation
Authors: Hou Peng , Xu Jing Wen , Zhao Jun Fang , Zhan Xin , Fan Ge
Published: December 2014

This paper propose a hybrid model which combine LBP and Meanshift for unmanned aerial vehicle image segmentation. In order to take full advantage of UAV image,The segmentation start with the over-segmentation regions,where the image divided into many regions by Mean shift. Then the small regions are merge with their neighbors by the hybrid distance with spectral, spatial and LBP histogram.
Background Subtraction Based on Pulse Coupled Neural Network
Authors: Cai Xi , Han Guang , Wang Jin Kuan
Published: December 2014

Dynamic environments often bring great challenges to moving object detection. Solving this problem will promote expansion of application fields of moving object detection. Unlike those background subtraction methods using local feature-based background models, inspired by integrity of human visual perception, we present a background subtraction method for moving object detection in dynamic environments, building its background models based on global features extracted by pulse coupled neural network. We employ the pulse coupled neural network to take good advantage of their global coupling characters, in order to imitate the human biological visual activity. After sensing images via the pulse coupled neural network, we extract global information of the scenes and then build background models robust to background disturbances based on the global features. Experimental results prove that, our method behaves well in terms of visual and quantitative evaluations for dynamic environments.
Research of Image Segmentation Based on Iterative Threshold
Authors: Shao Lei , Mu Yi , Guo Peng , Liu Jun , Dong Guo Ling , Liu Hong Li
Published: December 2014

Image segmentation is the key step in image recognition,the result of segmentation affects the one of recognition directly.The article introduces the concept and detailed definition of the image segmentation. The segmentation algorithm of iterative threshold in detail. According to the intrinsic characteristics of weed images, just can use the iteration threshold segmentation method, and implements them by Matlab programme, then processes three weed images, respectively to obtain effective results , and establishes a good base for the pick-up of the target character.
The Improved Hybrid MAP-POCS Based Algorithm for Super-Resolution Image Restoration Research
Authors: Shao Le Tu , Zhang Hong Gang , Zhang Guo Hua
Published: December 2014

Super-resolution image restoration technique can certainly increase the resolution of the obtained images without altering the system hardware conditions, which has become a research hotspot in the fields of remote sensing, military surveillance, public safety and medical imaging. The spatial domain algorithm has been studied widely and deeply, but it still has shortcomings and limitations. This paper studies the image degradation mechanism, establishes a precise image degradation process model, proposes an improved hybrid MAP-POCS restoration algorithm with using the Huber-Markov random field model as the priori probability model, which adds the convex sets constraints to the MAP estimation process and uses the peak signal to noise ratio (PSNR) to evaluate the recovery image quality. The simulation results show that the improved hybrid algorithm combines the only solution solving feature and noise reduction ability of the MAP method and strong prior knowledge utilized feature and flexibility of the POCS method, effectively ensures the convergence stability of the restoration and maintains the edge details of the restored image, enhances the effect of the super-resolution restoration.
The Review of Automatic Chinese Word Segmentation
Authors: Ren Xiao Yan , Fu Yun Xia
Published: December 2014

As the fundamental work of Chinese information processing, Chinese word segmentation has achieved great progress since its birth. This paper reviews the research status of the CWS, discusses the formal model of automatic word segmentation, and analyzes the difficulties of word segmentation.
The Research of Word Similarity in Semantic Retrieval
Authors: Ran Jie , Huang Ji Ya , Xiao Zu
Published: December 2014

Word similarity computing is a crucial question in information processing technology. In this paper, an integrated word similarity computing method is proposed by analyzed morpheme's similarity, word order's similarity and word length's similarity, and parameters of the method are decided by experiments. The experiments show that this method has high efficiency.
Two-Dimensional Weighted and Locality Preserved Discriminant Analysis for Face Recognition
Authors: Qi Yong Feng , Yang Hong Wei , Huo Yuan Lian
Published: December 2014

In this paper, a novel method for face recognition, called two-dimensional weighted and locality preserved discriminant analysis (2D-WLPDA) is proposed. The new algorithm is developed based on three techniques: (1) locality preserved embedding, by embedding nearest-neighbor graphs which characterize the within-class compactness of the same class samples, 2D-WLPDA discovers the submanifold of images space; (2) image based projection which can avoids the small sample problem and improves the computation efficiency;(3) weighting contributions of individual class pairs which alleviates the overlap of neighboring classes in Fisher criterion for a k-class problem with k>2. We experimentally compare 2D-WLPDA to other feature extraction methods, such as 2D-LDA, 2D-PCA and 2D-DLPP, 2D-WLPDA has better recognition performance.
The Research about Technology of Client Data Real-Time Dynamic Based on JMX
Authors: Cai Ai Ping , Gao Cheng Zhen
Published: December 2014

When the client thread try to process massive amounts of unstructured data such as video, images, text, the traditional architecture is difficult to deal with. The main task of data processing is how to process real-time data efficiently based on requirement of applications. In this paper, dynamic loading method is adopted based on JMX, and taking management component Mbean as core component to realize a synchronous, real-time processing to data. This only committed data is required for submitting your application for subscription, then wait for system reply patiently. Make connections to the primary database, then, begin working through the data, so as to realize rapid real-time processing. Experiments show that on high through put of data access, and more practical then deferred data synchronization.
Key Technology for Wireless Sensor Data Fusion
Authors: Kang Zhi Qiang , Cheng Rui Feng , Chu Wei
Published: December 2014

Using wireless sensors network (WSN) to collect coal mine hydraulic support pressure data , the method to solve the drawbacks of wired sensors . But the lack of WSN transmission performance in the coal mine : the transmission distance is short , large power consumption , short life cycle . Improve working methods for WSN : DIGI low-power sensor nodes ; using low-power single-chip Wake and Sleep MPS430149 at checking time ; core is a data fusion process , in the process of collecting data from all nodes , the use of local computing and storage nodes the ability to process the data , removing redundant data and minimize the amount of data transmitted within the network , improve data collection efficiency , achieve energy saving role in enhancing the network of life . The results show that the method is effective in improving the life and efficiency of WSN .
Measurement of the Armature Speed in Electromagnetic Launching Process Using B-Dot Probes
Authors: Li Yu , Long Xin Lin , Lu Jun Yong
Published: December 2014

In this paper, the sensing principle of a B-dot probe to measure the armature position was analyzed. The output waveforms of the probe for two different orientations were given after mathematical deduction. An electromagnetic launching experiment was conducted, and the result shows that the output waveforms of the probes can present the velocity trend of the armature. After data fitting, the velocity of the armature moving in the bore was given, and combined with the waveform of the muzzle voltage, the muzzle velocity was obtained, which matched the measurement result by a high speed camera well.
Optimal Uncorrelated Unsupervised Discriminant Projection
Authors: Lin Yu E , Guo Yong Cun
Published: December 2014

Unsupervised Discriminant Projection (UDP) is a typical manifold-based dimensionality reduction method, and has been successfully applied in face recognition. However, UDP suffers from the small sample size problem and usually deteriorates because the basis vectors of UDP are statistically correlated. In order to resolve these problems, we propose an Optimal Uncorrelated Unsupervised Discriminant Projection (OUUDP).The aim of OUUDP is to seek a feature submanifold such that the local scatter is minimized and non-local scatter scatter is maximized simultaneously in the embedding space by using a difference-based optimization objective function. Moreover, we impose an appropriate constraint to make the extracted features statistically uncorrelated. As a result, OUUDP can solve the small sample size problem and exploit statistically uncorrelated features. Experimental results on ORL databases demonstrate the effectiveness of the proposed algorithm.
The Research of Nitrile Gloves Visual On-Line Automatic Surface Defect Inspection System
Authors: Liu Hui , Ren You Zhi , Wang Lu , Zeng Qian , Yang Ya Wei , Xu Rong Jun
Published: December 2014

This paper describes an automatic line detection system which is based on mechanical vision technology to detect the defects of the nitrile gloves’ surface, and mainly discusses the extraction methods and the recognition algorithms about the gloves image features. Finally, the last part gives the methods to design an easy-operation, friendly-interface, full-functions interface software system. The automatic line detection system about nitrile gloves surface defects not only lets the gloves detection line to be automated, but also improves the production efficiency and the quality of the products.
The Research of the Quality Testing Technology for Solder Paste Coating of the PCB Solder
Authors: Ren Hao , Sun Jie , Li Yue Feng
Published: December 2014

This paper proposed a welding quality detection method with the computer vision technology for PCB of IC chip. This method is better than the normal one by human examines in the precision and in speed. It is suitable for welding quality automatic detection in the printing process of the SMT solder paste for IC chips mount on PCB board. This method is implemented in lab. Theoretical analysis and experimental results show that the accuracy of this method is high; the capture error is small and is easy to operate.
The Structure Design and Analysis of Vibration Sensor
Authors: Tian Bian , Zhao Yu Long , Niu Zhe , Jiang Zhuang De , Zhang Tian Yi
Published: December 2014

In order to establish monitoring systems for micro vibration due to electric spark occurs in the faulty cable, a novel acceleration sensing structure utilizing the piezoresistive principle is presented. The mechanical model and its mathematical solution are established, which have been developed in order to calculate the sensitivity and frequency behaviour of an acceleration sensor. The sensor is built up as a sense beam and a supplement beam is supposed to have high sensitivity, low resonant frequency and minimized lateral effect. For the designed sensor structure, the formula of stress, natural frequency and damping was derived in theory, and the optimized structure is confirmed through adjust the beams size.
Study on the New Intelligent Monitoring System of ATM
Authors: Yin Qing Yong
Published: December 2014

In the mid-1980s, in order to enhance the image of modern banks, the banks in China began to introduce ATM (automated teller machine), which has become an important tool for cash flow of the financial system. ATM has brought us convenience, meanwhile,security issue has become the most concerned issue of the financial system. How to realize ATM’s digitization, networking, and intelligence? Since the late 1990s, China has begun to invest a lot of manpower and materials to conduct research on ATM, but there are still many problems. From the existing disadvantages of ATM’s system, this article introduces a full range of vision sensor to ATM intelligent monitoring field, which overcomes the defects of existing monitoring systems, such as small scope,low intelligence level, image information fusion problems, etc..
Configuration Design and Simulation of Exoskeleton for Upper Limb Rehabilitation Train
Authors: Zhang Yuan , Liu Qiang , Jiang Ji Liang , Zhang Li Yuan , Shen Rui Rui
Published: December 2014

A new upper limb exoskeleton mechanical structure for rehabilitation train and electric putters were used to drive the upper limb exoskeleton and kinematics simulation was carried. According to the characteristics of upper limb exoskeleton, program control and master - slave control two different ways were presented. Motion simulation analysis had been done by Pro/E Mechanism, the motion data of electric putter and major joints had been extracted. Based on the analysis of the movement data it can effectively guide the electric putter control and analysis upper limb exoskeleton motion process.
Design of Wireless Logistic Automated Guided Vehicles Control System with Swarm Intelligence
Authors: Zhang Guo Qing , Cheng Wen Bin , Liu Bao Jun
Published: December 2014

A new design of automated guided vehicles control system is presented, which applies wireless sensor network (WSN) communication technology to make vehicles work as mobile robots with distributed sensing ability, meanwhile uses swarm intelligence algorithms to coordinate the vehicles. Compared to the traditonal system, this system is more flexible because that it is an infrastructure-free system with WSN to assist locating and navigating, and it is suitable for the dynamic industrial applications with self-organization network communication and swarm intelligence control.
Developing of a Wheel-Paddle Integrated Propeller for Amphibious Robot Based on Moving Webbed Paddle Wheels
Authors: Zha Fu Sheng , Bing Zhen Shan , Wang Jun , Wang Peng Fei , Li Man Tian , Guo Wei , Cheng Long , Xia Yu
Published: December 2014

With wheeled amphibious robot as the research object, for the adaptability of amphibious robot to amphibious environment such as sandy, muddy, or rocky land, we have proposed a new wheel-paddle integrated propeller based on moving webbed paddle wheels. This propeller made the robot functional well in the water and on land, and made it a good adaptability to amphibious environment. Considering the specific situations of the amphibious robot, the design process was proposed to design this integrated wheel-paddle integrated propeller. The angles of the paddles in water were analyzed for stability through simulations. Finally, a wheel-paddle integrated propeller based on moving webbed paddle wheels was made according to virtual model. To test the prototype propeller’s performance on speed, turning and switching ability both on land and in water, several experiments were carried out. Results showed that the prototype propeller achieved the desired design specifications.
Modeling and Simulation of Electro-Hydraulic Compound Regenerative Braking Control Strategy for Electric Vehicle
Authors: Kong Chen Lu , Wan Mao Song , Chen Ning , Lv Li Ya , Li Bing Lin
Published: December 2014

This paper mainly discusses the dynamic distribution of regenerative braking system and conventional friction braking system of EV.In order to meet the requirements of vehicle braking stability and recycle the braking energy whenever possible, the paper proposes a control strategy which based on ECE regulation and I curve.Then the proposed control strategy is embedded into the simulation software ADVISOR.The result shows that the control strategy of regenerative braking the paper presented is better than ADVISOR’s own on braking energy recovery, and is especially suitable for frequent braking city conditions.
The Kinematics Analysis of the 3-PTT Parallel Machine Tools
Authors: Hu Ming , Shi Jia Shun
Published: December 2014

This paper presents the kinematics for 3-PTT parallel machine tools, the kinematic is analytically performed, the forward and inverse position kinematic equations are explicit functions and workspace is derived and there is no singularity configuration and kinematic coupling in the whole workspace. The manipulability analytical of the parallel machine tool is investigated by the Jacobian matrix.
The Discretization of Continuous Attributes Based on Improved SOM Clustering
Authors: Tao Gang , Yan Yong Gang , Zou Jiao , Liu Jun
Published: December 2014

In order to solve the problem of continuous attribute discretization, a new improved SOM clustering algorithm was proposed. The algorithm uses the SOM to achieve the initial cluster and get the clustering up limit, then treats the initial cluster centers as samples and use the BIRCH hierarchical clustering algorithm to get secondary clustering, then solves the problems of inflated clusters and identifies discrete breakpoints set. Finally, find the nearest neighbors of each cluster center among these any samples of Breakpoints sets which belong to its attribute, and use it as a basis of discrete trimming. The experimental results show that the proposed algorithm outperforms the conventional discrete SOM clustering algorithm in the breakpoints set (contour factor to enhance 75%) and discrete accuracy (incompatible degrees closer to 0) aspects.
A New Method for Eliminating False Lock in TT&C
Authors: Li Cheng Yi , Wang Chun Hui , Jin Xiao Jun , Jin Zhong He
Published: December 2014

False lock is a fatal problem in TT&C due to the inevitable excessive delay.It can lead to false carrier acquisition.Based on the knowledge that false lock will not occur in the fast capture bandwidth,a new method for eliminating false lock is proposed.The carrier recovery loop closes only when the uplink carrier signal is detected in fast capture bandwidth by using signal detector and lock detector,then the false lock can be avoid.Compared with traditional methods,this solution is easier to realize and suitable for any type of loop. The experimental results reveal that the proposed method can eliminate false lock effectively.
A New Method for Security Isolation and Data Transfer
Authors: Xu Xian Cheng , Yuan Chuan You
Published: December 2014

This paper presents both physical and logical methods that are completely one-way transmission without feedback. The imposed hardware isolation is achieved based on the light transmission property with low cost optic components, while the efficiency and accuracy of data transmission is guaranteed by defining new protocol structure based on UDP. Experiments demonstrate that high performance have been achieved after using our proposed protocol mechanism.
An Energy-Saving Algorithm of Wireless Sensor Network for the Internet of Things
Authors: Zhu Kai , Liang Yin Cheng , Xu Xin Jun
Published: December 2014

The internet of things (IoT) is developing very speedily. Wireless Sensor Networks (WSNs) are the perception foundation. It is inconvenience to recharge sensor batteries frequently and the sensor power resource is limited in the WSNs. Therefore, one of the most important problems about a WSN is to save energy. To overcome this challenge, a great deal of algorithms was developed in the last few years such as DYCTC. In this paper, we propose RD-LEACH algorithm. Data transmission depends on the residual energy and the distance between the nodes. It can reduce the number of data sent. It solves effectively the energy saving caused by the invalid send and avoids cluster heads concentrate in a small network. Tests show that this algorithm can save approximately 18% of the energy and prolong the network lifetime under the premise of the network connectivity.
Coding Algorithms and Network Plan for Context-Aware Data Collection Based on Internet of Things in Large Marine Ships
Authors: Xie Feng
Published: December 2014

The equipment maintenance in large marine ships may rely on Internet of Things to provide monitoring of equipment status instantly. The data volume of sensing data is huge as the number of equipments is large. It is critical to decrease the communication overhead of uploading sensing data for efficiently and timely monitoring. In this paper, we propose several coding algorithms by using data context that is modeled by our normal forms on the base of our observations. The communication efficiency is improved, which is justified by formal analysis and rigorous proof. We also propose several network plan policies for further improvement of the communication efficiency by using data context and cluster head deployment.
Data Transmission of Ground Penetrating Radar over Wireless Network
Authors: Li Tao Tao , Yang Feng , Liu Ming Chu
Published: December 2014

A wireless data transmission system used to realize data transmission of ground penetrating radar (GPR) is designed. It including data receiver and sender overcomes the disadvantages of traditional GPR cable transmission system. STM32F407 chip and ATK-RM04 are core components of data sender. PC with a wireless network card is data receiver. System is designed with reference to C/S network model. Data receiver and sender are respectively developed with VC++ socket and RAW API of Lwip TCP/IP protocol stack. CP protocol is chosen as network transport protocol. Practical applications show that system can stably transmit data within 0m-20m and maximum loss rate is 0.005%. It is reliable and convenient for GPR’s application.
Multiuser Detection for Mobile Communication Signals in Urban Architecture
Authors: Chen Bo
Published: December 2014

Aim to the problem of code-division multiple-access (CDMA) with both multiple-access interference (MAI) and intersymbol interference (ISI) in dispersive channels of cellular mobile communication under urban architecture’s influence, low-complexity multiuser detection is proposed to suppress MAI and ISI jointly. This technique is considered to base on a blind linear filter detector with the subspace-based and auxiliary vector incorporated the desired user's signature waveform. It is showed that the performance of newly proposed detector outperforms the conventional detectors.
Factors Affecting Physical Properties of Prednisolone Loaded Nanoparticles Fabricated by Eletrohydrodynamic Atomization Technique
Authors: Huanbutta Kampanart , Sangnim Tanikan , Limmatvapirat Sontaya , Nunthanid Jurairat , Sriamornsak Pornsak
Published: December 2014

Recently, nanoparticulate system has been applied to deliver drug to colon because this system can increase drug absorption, prolong drug staying in gastrointestinal tract and also minimize chance of dose dumping effect. In this study, nanoparticles (NPs) developed for colonic drug delivery were fabricated via electrohydrodynamic atomization (EHDA) to find suitable formulation and preparation conditions. The NPs were prepared by dissolving prednisolone (model drug) and Eudragit® S100 (EDS100) in methanol, ethanol, isopropanol, butanol and mixtures of ethanol with purified water in various drug/polymer weight ratio and polymer concentrations. After that, the prepared solution was injected using the EHDA machine. The preparation condition and the instrument parameters such as applied voltage, injected distance, feed rate, and drum collector rolling rate were delicately adjusted again to obtain blank and drug loaded NPs. The NPs papered from methanol offered spherical particles with diameter size of 422 nm. The products of isopropanol and butanol were shrinkage particles. The sprayed products were changed from particle to fiber when using the spraying solution prepared from high concentration of EDS100. More fiber product was obtained when high applied voltage (20kV) was utilized. Prednisolone loaded NPs were also fabricated by EHDA. SEM and zeta-potential results reveal that prednisolone was entrapped in the NPs. All the drug loaded NPs products were in spherical shape with average diameter size of 448.60-660.98 nm and the maximum drug encapsulation was 92.65%. From the preliminary result, this nanoparticulate system expresses possibility to fabricate specific colonic drug delivery.
Effect of Various Types of Hydroxypropyl Methylcellulose (HPMC) Films on Surface Free Energy and Contact Angle
Authors: Kraisit Pakorn , Luangtana-Anan Manee , Sarisuta Narong
Published: December 2014

The aim of this study was to investigate the physicochemical characteristics of various viscosity grades of hydroxypropyl methylcellulose (HPMC) for mucoadhesive buccal films. The HPMC used in this study was K4M, K15M and K100M which their viscosity were 4000, 15000 and 100000 mPas respectively. Using HPMC as film forming base matrix, all intrinsic characteristics of each HPMC grade is required as basic knowledge for the development of mucoadhesive buccal films. To understand the primary essential parameters, surface free energy and contact angle of various HPMC grades were determined. Sessile drop technique was used in this study to determine contact angle of HPMC and surface free energy was then evaluated by using the Wu’s equation. The results showed that the increase in viscosity of HPMC film tended to decrease the polar force and total surface free energy but increased the contact angle. These parameters indicated that the hydrophilic character of HPMC was influenced by its viscosity. Our study suggested that the polar and dispersive force detected by sessile drop technique could be beneficial for the further design and development of mucoadhesive buccal films.
Effect of Various Nonionic Surfactants Incorporated in Liposomes on Dermal Delivery of Hydrophilic Compound
Authors: Rangsimawong Worranan , Opanasopit Praneet , Rojanarata Theerasak , Ngawhirunpat Tanasait
Published: December 2014

Various surfactants-containing vesicles have been widely used as a carrier in drug delivery to enhance skin penetration of encapsulated therapeutic agents. The purpose of this study was to investigate the effect of nonionic surfactants-containing liposome vesicles on the penetration of hydrophilic compounds through the porcine skin. Ultradeformable liposomes composed of phosphatidylcholine (PC), cholesterol (Chol) and various surfactants e.g. Tween 20, Labrasol and Gelucire 44/14) were prepared as NaFI carrier. The physicochemical characteristic of liposomes and in vitro skin penetration were investigated. The particle size of surfactant-containing liposome vesicles showed smaller particle sizes (36 to 54 nm) than conventional liposome (CLs) and had negative surface charge. The EE% and LE% order of surfactants incorporated in liposome formulations were: Labrasol liposomes (LALs) > Gelucire 44/14 liposomes (GELs) > Tween20 liposomes (TWLs) > CLs. The flux of NaFI from ultradeformable liposomes was significantly higher than from CLs. Among various liposomes, Labrasol containing ultradeformable liposomes showed the highest skin permeation in 24 h, and their flux was significantly higher (p < 0.05) than the flux of CLs. The result suggests that the surfactant-containing liposomes were small and deformable vesicles due to incorporating of an edge activators. In addition, surfactants could act as a penetration enhancer to promote dermal delivery of NaFI.
Comparative Molecular Similarity Indices Analysis Studies on Chromone Derivatives as Topoisomerase I Inhibitors
Authors: Phosrithong Narumol , Songmuang Pinatthida , Prapaipak Chinnapat , Khawsuk Hataichanok
Published: December 2014

DNA Topoisomerase I is an enzyme, which is involved in DNA replication, transcription and chromosome segregation in cellular processes. Inhibitors of Topoisomerase I are designed to interrupt DNA replication in cancer cells, resulting in cell death. The goal of these studies was to identify structural features necessary for increasing inhibitory effect of Topoisomerase I and further use these features for designing novel anticancer agents. 3D-QSAR method was performed for 15 chromone derivatives using Comparative Molecular Similarity Indices Analysis (CoMSIA) method. The best CoMSIA model was obtained from AM1 geometry optimization and align database alignment. The satisfactory CoMSIA model based on steric, electrostatic, hydrophobic and hydrogen bond acceptor fields gave a leave-one-out cross-validation q2 = 0.753 and a non-cross-validation r2 = 0.987. Therefore, the resulting contour maps produced by the best CoMSIA models could be used to understand the important structural features responsible for the design and development of new highly active topoisomerase I inhibitors.
Chemometric and Experimental Investigations of Organogelation Based on β-Cyclodextrin
Authors: Klaewklod Amornrat , Tantishaiyakul Vimon , Sangfai Tanatchaporn , Hirun Namon , Rugmai Supagorn
Published: December 2014

The evaluation of PEG as a gelation solvent for an organogel based on β-cyclodextrin (β-CyD) was investigated using principal component analysis (PCA). The test tube tilting method was performed to examine the gel formation experimentally. The important descriptors used in the PCA included the Hansen partial solubility parameters. LogP may be able to be used as an additional descriptor for this system. According to PCA analysis, PEG was in a cluster of gelation solvents. Subsequently, various PEG liquid state grades were tested for their ability to gel the system and PEG400 was found to be able to produce a gel. This verifies that PCA can be successfully used to evaluate the role of PEG. Accordingly, this PCA method may be an effective tool to evaluate the role of any solvent for other low molecular weight gelators (LMWGs). Afterwards, the optimal components in the system were explored, and it was found to be 0.1M β-CyD, 0.5M K2CO3 in PEG400. Based on WAXS, the gel fiber of this organogel was demonstrated to be amorphous. This forming organogel will be further characterized in details and investigated for use in a drug delivery system.
Application of Artificial Neural Networks for Prediction of Ibuprofen Yield from Ultrasound-Assisted Anti-Solvent Crystallization
Authors: Minphimai Rattanawich , Piriyaprasarth Suchada , Sriamornsak Pornsak
Published: December 2014

The aim of the study was to develop neural network model to predict the yield obtained from ultrasound-assisted anti-solvent crystallization of ibuprofen in terms of formulation and processing factors. The different factors of anti-solvent crystallization method, such as type of additive, concentration of additive, sonication time and harvesting time, were used as independent variables. The ibuprofen yield was used as response variable. The correlation between independent and response variables was investigated using feed forward-back propagation neural networks. The goodness of fit test and predictability were used for optimization of in silico models. The results revealed that the type of polyethylene glycol (PEG) was a critical factor that affected the response variable in different patterns. The best artificial neural networks (ANNs) model with a configuration of 3-4-1 for input, hidden, and output layers gave the r2 of 0.7067 and 0.8729 and the root mean square error of 0.3693 and 0.2667 for the model using PEG 400 and PEG 4000, respectively. The predictive ability of these models was validated by a set of 4 formulations that were not included in the training set. The predicted and experimental of ibuprofen yields were correlated.
Solid-State Grafting of Poly(ethylene glycol) onto Alginic Acid
Authors: Mohamad Ismail Siti Salimah , Han Chan Chin , Wong Tin Wui
Published: December 2014

Melt reaction of poly (ethylene glycol) and alginic acid (guluronate-rich and mannuronate-rich) was studied. The poly (ethylene glycol) was end-capped with reactive amino group while the sodium alginate was converted to alginic acid before melt reaction. The melt reaction kinetics of poly (ethylene glycol) and alginic acid were monitored by differential scanning calorimetry. The reaction temperatures were ranged between 75 and 96 °C, below the degradation temperature of both parent polymers. The reactive amino group of poly (ethylene glycol) reacted with carboxyl group of alginic acid. The rate of reaction increased with reaction temperature.
Role of Temperature Change on Poly(DL-lactic acid) Porous Matrix Film Fabrication by Solvent Casting Method
Authors: Chitrattha Sasiprapa , Phaechamud Thawatchai
Published: December 2014

Poly(lactic acid) (PLA) has a variety of applications. It has been widely used in the biomedical and pharmaceutical fields due to its biocompatibility and biodegradability. Polyethylene glycol (PEG) is used as an inactive ingredient in the pharmaceutical industry as a solvent, plasticizer, surfactant, ointment base, suppository base, tablet lubricant and capsule lubricant. The aim of this study was to determine the effect of temperature change on PLA porous matrix film fabricating by solvent casting method with an addition of PEG400 to improve and increase the pore interconnectivity. Their mechanical properties such as tensile strength (TS) and % elongation at break (%E) and morphology were investigated. Porous films were prepared at 4 °C for 24 h and dry at room temperature for 24 h (4CRT), 4 °C for 24 h and dry at 60 °C for 24 h (4C60C), -20 °C for 24 h and dry at room temperature for 24 h (-20CRT), -20 °C for 24 h and dry at 60 °C for 24 h (-20C60C), -80 °C for 24 h and dry at room temperature for 24 h (-80CRT), and -80 °C for 24 h and dry at 60 °C for 24 h (-80C60C). 4C60C exhibited the highest strength and toughest, however all of samples showed the quite soft behavior. From topography study they displayed the different porous structure which sample of 4C60C displayed the smallest porous structure. Therefore, the temperature change between the fabrication processes affected the TS, %E and morphology structure of PLA porous matrix films.
Borneol as Sublimable Agent in Floating Matrix Tablet
Authors: Kriangkrai Worawut , Puttipipatkhachorn Satit , Sriamornsak Pornsak , Sungthongjeen Srisagul
Published: December 2014

To avoid unpredictable time to float due to variable pH of the gastric fluid in each subject, sublimation technique is the new interesting approach to prepare non-effervescent floating drug delivery system (FDDS). In this study, a floating matrix tablet using borneol as sublimable agent was developed. The system consists of drug, matrix-forming polymer and sublimable agent. The highly porous and low-density floating matrix tablet was obtained when borneol was sublimated. The floating matrix tablets immediately floated and maintained buoyancy over 8 h. The sublimation of borneol increased with increasing sublimation temperature and incubation time. Increasing amount of sublimable agent exhibited lower density of the floating tablet because of higher porous structure. The results demonstrated that boneol was one of good candidates to be used as sublimable agent for non-effervescent floating tablets. However, physical properties of the matrix floating tablets were needed to be concerned.
Effect of Lipophilicity of Drugs on Dissolution Profiles of Self-Nanoemulsifying Drug Delivery System
Authors: Weerapol Yotsanan , Limmatvapirat Sontaya , Sriamornsak Pornsak
Published: December 2014

The low solubility of poorly water-soluble drug is a major problem of oral drug adsorption. The self-emulsifying system can be applied to eliminate the drug dissolution step and improve the drug absorption. In this research, liquid self-nanoemulsifying drug delivery system (SNEDDS) composing of polyethoxylated castor oil, caprylic/capric glyceride and diethylene glycol monoethyl ether was developed. The drugs with similar structure but different lipophilicity (log P), nifedipine (NDP), felodipine (FDP) and manidipine (MDP), were investigated. Size and size distribution of emulsion after dilution in acid medium and in vitro drug dissolution were determined. The results showed that the size of emulsions obtained from dilution of SNEDDS in acidic medium ranged from 100-150 nm. Drug dissolution from SNEDDS was different depending on lipophilicity of drug, i.e., 98.6, 74.3 and 52.5% for NDP (log P 2.50), FDP (log P 4.46) and MDP (log P 5.46), respectively. The results suggested that the difference in lipophilicity may influence the drug dissolution from SNEDDS.
Fabrication of Shellac-Zein Based Matrix Tablet as a Carrier for Controlling of Drug Release
Authors: Chongcherdsak Noppadol , Aekthammarat Direk , Prathumchat Teerayuth , Limmatvapirat Chutima , Limmatvapirat Sontaya
Published: December 2014

The aim of research was to fabricate shellac-zein composite polymer-based matrix tablets by using theophylline as a model drug. The tablets were prepared by direct compression process. The initial weight and hardness of tablets were controlled within the range of 300±5 mg and 60±10 N, respectively. The tablets were annealed at 80 °C for 24 h and kept in the ambient temperature before evaluation. Drug release profile and kinetics of drug release in 0.1 N HCl and buffer pH 6.8 were investigated. The result showed that the annealing process and shellac:zein ratio, affected drug release characteristic in both media.The delayed released in acid medium of formulation containg shellac-zein composite polymer at the ratio from 30:70 was extended to over 120 min. In addition, the more sustained drug released in buffer was observed after increasing shellac:zein ratio. The good acid resistance of shellac and the swollen characteristic of zein in buffer might be a good explanation for the specific release. For the analysis of drug release data, drug release profiles were fitted into Higuchi model suggesting that the main mechanism of drug release from matrix tablets was super case II transport.
Preparation of Centella Extracts Loaded Aloe Vera Transdermal Patches for Wound Healing Purpose
Authors: Puttarak Panupong , Pichayakorn Wiwat , Sripoka Kanchana , Chaimud Khwanrudee , Panichayupakaranant Pharkphoom
Published: December 2014

Transdermal patch is a drug delivery system using a polymer for controlling the drug release. In this study, polysaccharides from aloe vera gel were used as polymer in transdermal patches because they are compatible, biodegradable, and safe to apply on skin without any side effect. Pentacyclic triterpenoids rich (asiatic acid, madecassic acid, asiaticoside and madecassoside) Centella asiatica extracts were added as active ingredients. Both polymer and active ingredients show pharmacological effects as wound healing. It was found that the optimized formulation contained polysaccharides from aloe vera gel blended with 20% glycerine and 15% sodium alginate calculated based on aloe vera mass could produce the good films. These films could be controlled with respect to physical properties thickness (0.509±0.015 mm), tensile strength (1.391±0.131 MPa), elongation at break (116.2±13.15%), peel strength (0.116±0.044 N), the highest swelling times (20 minutes), and the percentage of degradation at 30 minutes (51.57±5.96%). About 0.34 % centella extracts (57% pentacyclic triterpenoids) could be found in these films. After stability studies at 4, 25 and 45 °C for 10 weeks, films stored at 45 °C were loss of flexibility and brittleness that could not be further evaluated. While films stored at 4 and 25 °C were good physiochemical properties and stable as same as films base.
Modification of Starch Extracted from Black Glutinous Rice (Oryza sativa L, Variety Leum Pua) as Tablet Filler
Authors: Patomchaiviwat Vipaluk , Piriyaprasarth Suchada , Chaisomboonphan Bunyarit , Limpoemwuttiporn Chitatharinth , Nuamnoi Pornsuda
Published: December 2014

The aim of this study was to investigate the modification of black glutinous rice starch (BGRS) as tablet filler. The black glutinous rice was treated with NaCl and NaOH to obtain BGRS. The native BGRS was modified by pregelatinizaion and prepared as co-composite and used as filler in tablet formulation compared with Starch 1500®. Propranolol was used as a model drug. The properties of tablets including disintegration time were evaluated. Interestingly, the disintegration times of the native BGRS was less than 90s which was faster than Starch 1500®. The results suggest that the native BGRS would be used in fast disintegrating tablets. While the disintegration times of pregelatinized BGRS was more than 30 min. Thus, the pregelatinized BGRS might be used for sustained release tablet. For the co-composite method, PVP K90 in the concentration of 1, 3, 5, 7 and 9 % w/w was incorporated with BGRS. The tablets of the co-composite producing by direct compression method were compared with tablets producing by wet granulation method using PVP K90 as binder. In concentration of 3% w/w PVP K90, the co-composite was comparable to wet granulation method in term of hardness and disintegration time. Thus, it could be used as direct compression filler in pharmaceutical field.
Development of In Situ Gel for Oral Application
Authors: Panomsuk Suwannee , Nakprasong Pimchanok , Tanpichai Suthi On , Chin-Aramrungruang Sasithorn
Published: December 2014

In situ gel, a new concept of medical product for oral applications was developed using Poloxamer 407 (P) and Carbopol 934 (C) which are thermo-and pH-sensitive sol-gel polymers, respectively. The formulations were evaluated for the physical appearance, pH, viscosity, sol-gel temperature, gel strength and buccal mucoadhesive (adhesion to porcine buccal mucosa). Benzalkonium chloride (BzCl) 0.1% w/v was added in the suitable formulations as a model drug. Formulations containing 20% P (pH = 7.1) and 20% P + 0.6% C (pH = 5.0) showed good physical appearances which turned to gels in buccal conditions. Their mucoadhesive force to porcine buccal mucosa were higher than formulations containing 10 and 15 % P(p<0.05). The present of 0.6 % C in the formulation did not affect gel strength but tended to increase mucoadhesive properties. The release of BzCl from the formulations was performed using Franz diffusion cell at 37°C for 1 hour. There were no different in drug release from both formulations(p<0.05), the amount of drug release was 11.7% ± 4.4 and 10.9% ± 0.8, respectively. In conclusion, formulation containing 20% P and 0.6% C has revealed the most suitable properties as in situ gel for buccal mucosa applications, the release of BzCl was 10.9% ± 0.8 within 1 hour.
Preparation Process and Properties of Crosslinked Gelatin Beads for Drug Loading
Authors: Pichayakorn Wiwat , Wannaphatchaiyong Suchipha , Saisin Wanlapha
Published: December 2014

This study aimed to develop the preparation process of stable gelatin beads for drug loading. Gelatin beads were prepared by either ionotropic gelation or emulsification techniques. Hardening of gelatin beads were done by both cooling and chemical treatments. For ionotropic gelation techniques, aqueous gelatin solution was continuously dropped into cool calcium chloride (CaCl2) or sodium tripolyphosphate (TPP) solution. However, the stable bead particles could not be formed. For emulsification techniques, water in oil (w/o) system was performed using aqueous gelatin solution as dispersed phase and cool soybean oil as dispersion medium, and glutaraldehyde (GAL) might also be used as chemical crosslinking agent. Gelatin type, amount of GAL, and crosslinking time slightly affected the characters of beads formation. Propranolol HCl could be loaded in gelatin beads.
Lipid-Based Implants: Impact of Formulation Parameters
Authors: Nicolai Marisa , Amaral Vanessa , Antunes Cátia , Shuwisitkul Duangratana , Portugal Mota Joana
Published: December 2014

Lipid implants have been attracting attention in recent years. However, to better understand these systems, more fundamental studies are required. The objective of this work was to evaluate the effect of some formulation parameters, namely lipid and drug type, implant shape/surface area and lipid blend ratio, on drug release rate. The developed implants were cylindrical or spherical in shape with an even surface. Caffeine release from glycerol-trimyristate implant was very fast when compared with glycerol-tristerate matrix. The latter allowed a 4 month controlled release in contrast with glycerol-trimyristate matrix (~ 5 days). Caffeine and theophylline presented similar release rates, despite their different aqueous solubilities. In addition, different lipid blend ratios provided different release profiles for caffeine.
Formulation of Cold Pressed-Coconut Oil Dry Emulsion
Authors: Chomto Parichat , Chansiri Gaysorn , Tepsukon Khaw-on , Yodwandee Pawitra , Laovanichkul Porntipa , Kongmuang Somlak
Published: December 2014

Development of stable dry emulsion capable to self- reform into emulsion by reconstitution in water is presented. The major compositions of oil in water (o/w) emulsion were cold pressed-coconut oil (or virgin coconut oil from four different companies) as oil phase and water as phase containing an emulsifier [hydroxypropylmethylcellulose (HPMC)] and a densifier or solid [tapioca starch (T)]. Dry emulsions were prepared by placing liquid emulsion in condition at 60 °C. The percentage yield of dry emulsion was between 59-62%. After sieving, the most flowability data of dry emulsion granules were passable as a result of some oily parts appeared in particles. The moisture contents in dry emulsion granule were relatively low. The antioxidant activity of oil, primary emulsion (PE) and reconstitute emulsion (RE) were also investigated with Trolox as standard. It was found that the order of antioxidant activity of coconut oil as decrease as following: oil, emulsion and reconstitute emulsion respectively. After 2 freeze-thaw cycles, all reconstituted emulsions were shown to be unstable. The four different brands of virgin coconut oil showed no significant different physical and antioxidant properties of PE and RE. Thus, the process of making a virgin coconut oil dry emulsion might not be affected by any different sources of virgin coconut oil.