SCOPUS 2010-2014
Permanent URI for this collection
Browse
Recent Submissions
Item An optical buffer manipulation using a microring array(2011) Suphanchai Punthawanunt; Chat Teeka; Rangsan Jomtarak; Preecha P. Yupapin; S. Punthawanunt; Faculty of Science and Technology, Kasem Bundit University, Bangkok 10250, Thailand; email: suphanchai@kbu.ac.thWe present design and FDTD simulations of microring resonator array optical buffer. The proposed buffer consists of six microring array coupled via upper MZI arm and one microring coupled via lower MZI arm all coupled with 105 nm gap coupling. Results obtained have shown that the delay signals can be available for the use for optical memory and applications.Item Meta-analysis and sensitivity analysis for multi-arm trials with selection bias(2011) Hathaikan Chootrakool; Jian Qing Shi; Rongxian Yue; J.Q. Shi; School of Mathematics and Statistics, University of Newcastle, Newcastle NE1 7RU, United Kingdom; email: j.q.shi@ncl.ac.ukMulti-arm trials meta-analysis is a methodology used in combining evidence based on a synthesis of different types of comparisons from all possible similar studies and to draw inferences about the effectiveness of multiple compared-treatments. Studies with statistically significant results are potentially more likely to be submitted and selected than studies with non-significant results; this leads to false-positive results. In meta-analysis, combining only the identified selected studies uncritically may lead to an incorrect, usually over-optimistic conclusion. This problem is known asbiselection bias. In this paper, we first define a random-effect meta-analysis model for multi-arm trials by allowing for heterogeneity among studies. This general model is based on a normal approximation for empirical log-odds ratio. We then address the problem of publication bias by using a sensitivity analysis and by defining a selection model to the available data of a meta-analysis. This method allows for different amounts of selection bias and helps to investigate how sensitive the main interest parameter is when compared with the estimates of the standard model. Throughout the paper, we use binary data from Antiplatelet therapy in maintaining vascular patency of patients to illustrate the methods. © 2011 John Wiley & Sons, Ltd.Item SRL-GSM: A hybrid approach based on semantic role labeling and general statistic method for text summarization(Asian Network for Scientific Information, 2010) L. Suanmali; N. Salim; M.S. BinwahlanSentence extraction techniques are commonly used to produce extraction summaries. The goal of text summarization based on extraction approach is to identify the most important set of sentences for the overall understanding of a given document. One of the methods to obtain suitable sentences is to assign some numerical measure of a sentence for summary called sentence weighting and then select the best ones. In this study, we propose Semantic Role Labeling (SRL) approach to improve the quality of the summary created by the general statistic method. We calculate a couple of sentence semantic similarity based on the similarity of the pair of words using WordNet thesaurus to discover the word relationship between sentences. We perform text summarization based on General Statistic Method (GSM) and then combine it with the SRL method. We compare our results with the baseline summarizer and Microsoft Word 2007 summarizers. The results show that SRL-GSM and GSM give the best average precision, recall and f-measure for creation of summaries. © 2010 AsianNetwork for Scientific Information.Item Antimicrobial and antioxidant activities of traditional Thai herbal remedies for aphthous ulcers(2010) Chantana Mekseepralard; Narisa Kamkaen; Jenny M. Wilkinson; C. Mekseepralard; Department of Microbiology, Faculty of Medicine, Srinakharinwirot University, Klongtoei, Wattana, Bangkok 10110, Thailand; email: chantana@swu.ac.thFour medicinal plants (Quercus infectoria, Kaempferia galanga, Coptis chinensis and Glycyrrhiza uralensis) as well as one traditional Thai treatment for aphthous ulcers based on these four plants were tested for antimicrobial activity. MIC values for a range of bacteria and Candida albicans were determined, with both type strains and clinical isolates being used. Antioxidant activity was determined using the ABTS radical scavenging assay. Among the four plants, Q. infectoria showed antimicrobial activity against Staphylococcus aureus with an MIC of 0.41 mg/mL, while C. chinensis showed antifungal activity against C. albicans with an MIC of 6.25 mg/mL. Activity was also shown against a range of other organisms including Salmonella typhi, Serratia marcescens, Vibrio cholerae, Vibrio parahaemolyticus, Pseudomonas aeruginosa and Enterococcus faecalis. The antimicrobial activity of the traditional aphthous ulcer preparation (a powder) was comparable to that for the individual plant extracts, however, incorporation of the powder into a gel formulation resulted in the loss of almost all activity. All extracts, with the exception of K. galanga, also showed good antioxidant activity. This study supports the traditional use of these plants and suggests that they may also be useful in the treatment of other infections. © 2010 John Wiley & Sons, Ltd.Item Biodegradation of paraquat by the novel bacterial strain aeromonas Veronii NK67 from cassava fields in Thailand(EM International, 2014) Nuttabodee Viriyawattana; S. SurachatThe herbicide paraquat residues in Cassava field have been shown to cause adverse human health effects and soil degradation, leading to decreased crop productivity. Bioremediation is the effective way to solve this problem. This study focused on selecting soil bacteria that are capable to degrade paraquai The 283 soil samples were collected from Cassava field in Nakhon Ratcha Sima provinces, because of paraquat is one of the most widely used chemical herbicides in this area. All 112 isolates have been isolated. Among them, there were 6 isolates tolerance to paraquat concentration 1 mM, including 4 and 2 strains of Clostridium spp. and Aeromonas spp., respectively. The isolates were further tested for their efficacy to degrade paraquat. The results showed that only two strains of Aeromonas spp. (strain NK 66 and MC 67) were able to degrade paraquat. It was found that levels of paraquat decreased to 4.9 ppm (24.36%) and 10.68 ppm (53.4%) after exposed to Aeromonas spp. Strain MC 66 and MC 67, respectively. Molecular Methods to Identify Aeromonas spp. strain NK 67 using PCR-amplified 16S rRNA genes sequencing were employed. Nucleotide sequence of 16S rRNA from Aeromonas spp. strain NK 67 was compared with nucleotide sequences from GenBank database by using BLAST program. The results showed that 99% similar to 16S rRNA from A. veronii strain ATCC 35624, according to the results of classification by Bergey's Manual of Systematic Bactedology Then it can be conclude that this bacteria is A. veronii N1C67 (JN880412). This is the first report that A. veronii exhibited high efficiency to degrade paraquat which can be further applied for remediation of paraquat in contaminated areas and going for commercial production. © Global Science Publications.Item RASSF1A promoter hypermethylation as a prognostic marker for hepatocellular carcinoma(Asian Pacific Organization for Cancer Prevention, 2010) Pensri Saelee; Sopit Wongkham; Sunanta Chariyalertsak; Songsak Petmitr; Ubol Chuensumran; P. Saelee; Research Division, National Cancer Institute, Bangkok, Thailand; email: saelee@health.moph.go.thThis study was performed to determine whether epigenetic aberrant methylation of RASSF1A might be associated with hepatocarcinogenesis. Methylation specific-PCR was performed to identify RASSF1A promoter hypermethylation in 29 tumors and corresponding normal liver tissues. In addition, RASSF1A mRNA levels were analyzed by quantitative real-time reverse transcription-PCR. Aberrant methylation of RASSF1A was detected in 25 of 29 cases (86%), with loss of RASSF1A expression evident in 8 of 22 cases (36%). No correlation between loss of RASSF1A mRNA and promoter hypermethylation of the RASSF1A gene was observed. There was a significant correlation between the methylation status of RASSF1A and hepatocellular carcinoma (HCC) patients who did not undergo chemotherapy (P = 0.03). Multivariate analysis, adjusted for tumor size, treatment, RASSF1A hypermethylation, and RASSF1A under-expression, showed RASSF1A hypermethylation to be assocaited with a better prognosis for HCC patients (HR= 0.089, 95%CI = 0.013-0.578; P = 0.012). Our findings showed that RASSF1A promoter hypermethylation occurs frequently, and may serve as a good prognostic factor.Item Development of a Community-based Pre-hospital Care Management Model for Emergency Volunteers(2011) Taweewun Chaleekrua; Supavan Phlainoi; Pragai Jirojanakul; Adisak PlitponkarnpimUsing Community Action Research (CAR), this study constructed a model for community-based pre- hospital care management for emergency volunteers (EVs). The study was conducted in three phases: exploration of the community context including a needs assessment; capacity building and evaluation of the management of EVs; and evaluation of the previous two phases. There were 126 participants in the study who provided data through group interviews, in-depth interviews, workshops, forums and from lessons learned. Data analysis was conducted by content analysis, free-list analysis, concurrent analysis, and mean difference methods. Findings were as follows: (1) people in a remote rural community practiced reciprocity in pre-hospital care within a hybrid of functional and interpretive management paradigms and in doing so took the major responsibility to organize and manage a system to respond to emergencies that includes informal organization, flexible rules, communications, and budgeting, but with some support from government; (2) the management of emergency volunteers was within a Hybrid model composed of the functional and interpretive paradigms and this affected recruitment and retention of emergency volunteers; and (3) evaluation of emergency volunteers depended on the paradigm with evaluation in the functional paradigm depending on a quantitative approach but in the interpretive approach it depended on qualitative methods. Results also showed that the Hybrid model was effective for managing emergency volunteers, and built self-confidence among the participants. This model can be used in similar remote rural areas with policy to be formulated for the management of emergency volunteers.Item Technology of Dv_ravat_ pottery: A view from petrographic analysis(Indo-Pacific Prehistory Association, 2011) Duangkamol Aussavamas; D. Aussavamas; Rajabhat Suan Dusit University, Bangkok, Thailand; email: aussa@hotmail.comThis study focuses on the examination of aspects of the carinated pottery of the Dv_ravat_ period. This type of pottery is one of the most prominent types found in a large number of Dv_ravat_ sites in Thailand. Samples used for this study were collected from excavations at archaeological sites located in several regions of Thailand, including Northern, Northeastern and Central Thailand. The carinated potteries were analyzed using petrographic analysis. The objective of this work was to examine the pottery fabric. This method is used to establish sources of raw materials and whether production techniques, decorations, and firing temperature show patterns associated with the raw material source distributions. It is also possible to reconstruct the production technology of the vessels. Knowing the source of raw materials source of clay and temper and understanding the patterns of manufacturing and decorative processes help us better understand material distribution patterns of the Dv_ravat_ period. Analysis shows that Dv_ravat_ earthenware pottery raw materials include both primary and secondary clays, and that temper used was both organic matter (rice chaff) and grogs (fired clay mixed with iron oxide). Evidence for wheel-thrown production was associated with all decoration styles, and finishing techniques included plain, polishing, incising, cord marking, red slip and black burnishing. The firing temperatures were as low as 400-550¡ C. These samples indicate there was general homogeneity over a wide area, but also the presence of regional groups of pottery. This suggests the widespread circulation of pottery styles among various production centers during the Dv_ravat_ period.Item Spin-polarization array generation for spin transport use(2011) S. Mitatha; W. Sangiamsak; K. Kulsirirat; C. Teeka; P.P. YupapinSpin-polarization can be formed by the two components of soliton (electromagnetic wave) within the metallic waveguide. Under the resonant condition, the random transverse electric and magnetic fields of the solitons corresponding to the left-hand and right hand photons can be generated. Whenever a photon is absorbed by an object, an angular momentum of either +_ or -_ is imparted to the object, in which two possible spin states known as optoelectronic spins are exhibited. Furthermore, the array of optoelectronic spins, i.e., many particles can be generated and controlled by using the modified add-drop filter, in which the broad spectrum soliton can be generated and used to form large scale spin transport applications. © 2011 World Scientific Publishing Company.Item A generalized E-learning usage behaviour model by data mining technique(Universiti Utara Malaysia Press, 2014) Songsakda Chayanukro; Massudi Mahmuddin; Husniza HusniCurrent study on e-Learning user's behaviour model obtained the specific models. In many cases, the e-Learning user's behaviour model for open source e-Learning system such as Moodle, which can predict learning outcome or learning performance is still deficient and cannot generally apply in many institutions due to the fact that the majority of prediction models were developed particularly for certain institutions. This study proposes to produce a general model that can make a prediction of learning outcome inspired by Skinner's theory, which explains the relationship between learner, achievement, and learner reinforcement. This study proposes similar patterns in e-Learning user's behaviour models of different institutions by the data-mining technique based on the learning environment theory. Therefore, this research is conducted in three main phases; include data preparation from weblog of different institutions with the same e-Learning system, data extraction by the accurate classifier model finding process and model verification for generating a verification pattern. The research outcome will be a similar pattern that could be used as a direction for creating a more appropriate e-Learning users' behaviour model and could be used broadly in other higher institutions.Item Single electron-hole pair generation using dark-bright solitons conversion control(2011) S. Punthawanunt; R. Jomtarak; C. Teeka; P.P. Yupapin; J. Ali; S. Punthawanunt; Faculty of Science and Technology, Kasem Bundit University, Bangkok 10250, Thailand; email: suphanchai@kbu.ac.thIn this paper, we present the new concept of single electron-hole pair generation by using dark-bright solitons conversion control based on microring resonator coupled to one arm MZI. By using some suitable parameters and found that the single electron-hole pair are seen, therefore, the single electron-hole pair generate can be storage and controll within the design system.Item Single electron-hole pair generation using dark-bright solitons conversion control(2010) R. Jomtarak; C. Teeka; P.P. Yupapin; J. Ali; R. Jomtarak; Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand; email: rangsan_jom@dusit.ac.thRecently, the electron-hole pair generated in 1.06-_m separate-absorber-avalanche (multiplier) InP-based devices [1], SiGe/Si planar waveguides [2] fabricated with a Ge concentration ranging from 2% to 6% and different thicknesses ranging from 200 nm to 2 _m, generating electron-hole pairs with a 100 fs laser pulse emitted at 810 nm, and monitoring the free-carrier absorption transient with a c.w. probe beam at 1.55 _m, bipolar transistors [3], CMOS process [4], InAs-GaSb superlattice (SL) photodiodes [5], resonant microcavity [6], A cavity-QED using a single InAs quantum dot and a high-Q whispering gallery mode [7]. ©2010 IEEE.Item Using "activated carbon from bagasse" for color removal(Nova Science Publishers, Inc., 2011) Paitip Thiravetyan; Parinda Suksabye; P. Thiravetyan; Division of Biotechnology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Thakham, Bangkhuntien, Bangkok, Thailand; email: paitip.thi@kmutt.ac.th[No abstract available]Item Managerial ownership and firm performance in Thailand: An empirical analysis(Virtus Interpress, 2010) Wanachan Singhchawla; Robert T. Evans; John EvansThis study investigates whether managerial share ownership serves to enhance or detract from firm performance in listed companies in Thailand. The convergence-of-interest hypothesis asserts that firm value increases as management ownership rises. On the other hand, when managers own a substantial fraction of the firm shares, then voting power or other influence may satisfy other non-value- maximizing objectives without endangering other positions. This gives rise to the entrenchment hypothesis, which suggests that excessive insider ownership has a negative impact on corporate performance. The results of this study support both the alignment and entrenchment efforts and therefore the existence of a non-linear relationship between firm performance and managerial ownership. Firm size and industry are also shown to impact significantly on firm performance in Thailand.Item Index financial time series based on zigzag-perceptually important points(2010) Chawalsak Phetchanchai; Ali Selamat; Amjad Rehman; Tanzila SabaProblem statement: Financial time series were usually large in size, unstructured and of high dimensionality. Since, the illustration of financial time series shape was typically characterized by a few number of important points. These important points moved in zigzag directions which could form technical patterns. However, these important points exhibited in different resolutions and difficult to determine. Approach: In this study, we proposed novel methods of financial time series indexing by considering their zigzag movement. The methods consist of two major algorithms: first, the identification of important points, namely the Zigzag-Perceptually Important Points (ZIPs) identification method and next, the indexing method namely Zigzag based M-ary Tree (ZM-Tree) to structure and organize the important points. Results: The errors of the tree building and retrieving compared to the original time series increased when the important points increased. The dimensionality reduction using ZM-Tree based on tree pruning and number of retrieved points techniques performed better when the number of important points increased. Conclusion: Our proposed techniques illustrated mostly acceptable performance in tree operations and dimensionality reduction comparing to existing similar technique like Specialize Binary Tree (SB-Tree). © 2010 Science Publications.Item Phosphoproteomic analysis of apoptotic hematopoietic stem cells from hemoglobin E/_-thalassemia(2011) Saranyoo Ponnikorn; Tasanee Panichakul; Kitima Sresanga; Chokdee Wongborisuth; Sittiruk Roytrakul; Suradej Hongeng; Sumalee Tungpradabkul; S. Hongeng; Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; email: rashe@mahidol.ac.thBackground: Hemoglobin E/_-thalassemia is particularly common in Southeast Asia and has variable symptoms ranging from mild to severe anemia. Previous investigations demonstrated the remarkable symptoms of _-thalassemia in terms of the acceleration of apoptotic cell death. Ineffective erythropoiesis has been studied in human hematopoietic stem cells, however the distinct apoptotic mechanism was unclear.Methods: The phosphoproteome of bone marrow HSCs/CD34+ cells from HbE/_-thalassemic patients was analyzed using IMAC phosphoprotein isolation followed by LC-MS/MS detection. Decyder MS software was used to quantitate differentially expressed proteins in 3 patients and 2 normal donors. The differentially expressed proteins from HSCs/CD34+ cells were compared with HbE/_-thalassemia and normal HSCs.Results: A significant change in abundance of 229 phosphoproteins was demonstrated. Importantly, the analysis of the candidate proteins revealed a high abundance of proteins that are commonly found in apoptotic cells including cytochrome C, caspase 6 and apoptosis inducing factors. Moreover, in the HSCs patients a significant increase was observed in a specific type of phosphoserine/threonine binding protein, which is known to act as an important signal mediator for the regulation of cell survival and apoptosis in HbE/_-thalassemia.Conclusions: Our study used a novel method to investigate proteins that influence a particular pathway in a given disease or physiological condition. Ultimately, phosphoproteome profiling in HbE/_-thalassemic stem cells is an effective method to further investigate the cell death mechanism of ineffective erythropoiesis in _-thalassemia. Our report provides a comprehensive phosphoproteome, an important resource for the study of ineffective erythropoiesis and developing therapies for HbE/_-thalassemia. © 2011 Ponnikorn et al; licensee BioMed Central Ltd.Item Fuzzy genetic semantic based text summarization(2011) Ladda Suanmali; Naomie Salim; Mohammed Salem Binwahlan; L. Suanmali; Faculty of Science and Technology, Suan Dusit Rajabhat University, Bangkok, 10300, Thailand; email: ladda_sua@dusit.ac.thAutomatic text summarization is a data reduction process to exclude unnecessary details and present important information in a shorter version. One way to summarize document is by extracting important sentences in the document. To select suitable sentences, a numerical rank is assigned to each sentence based on a sentence scoring approach. Highly ranked sentences are used for the summary. This paper proposed an automatic text summarization approach based on sentence extraction using fuzzy logic, genetic algorithm, semantic role labeling and their combinations to generate high quality summaries. This study explored the benefits of the genetic algorithm in the optimization problem in for feature selection during the training phase and adjusts feature weights during the testing phase. Fuzzy IF-THEN rules were used to balance the weights between important and unimportant features. Conventional extraction methods cannot capture semantic relations between concepts in a text. Therefore, this research investigates the use of the semantic role labeling to capture the semantic contents in sentences and incorporate it into the summarization method. This paper is evaluated in terms of performance using ROUGE toolkit. Experimental results showed that the summaries produced by the proposed approaches are better than other approaches produced by Microsoft Word 2007, Copernic Summarizer, and MANYASPECTS summarizers. © 2011 IEEE.Item A reinvestigation of EXAFS and EPR spectroscopic measurements of chromium(VI) reduction by coir pith(2010) Parinda Suksabye; Niramon Worasith; Paitip Thiravetyan; Akira Nakajima; Bernard A. Goodman; B.A. Goodman; Health and Environment Department, Unit of Environmental Resources and Technologies, Austrian Institute of Technology, Seibersdorf A-2444, Austria; email: bernard_a_goodman@yahoo.comNew measurements using extended X-ray absorption fine structure (EXAFS) and electron paramagnetic resonance (EPR) techniques are consistent with Cr in the Cr(III) oxidation state as the main product from the adsorption of Cr(VI) on coir pith. These confirm the previous X-ray measurements, but differ from the results of previous EPR studies, which indicated that Cr(V) was the main form of Cr. The reason for this discrepancy is the presence of a broad signal from Cr(III) in an unsymmetrical environment that was missed previously; the Cr(V) component is in fact only a minor reaction product. As a result of this problem with spectral acquisition and interpretation, some simple recommendations are presented for conducting EPR investigations on natural systems. © 2010.Item ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm(2011) C. Tanaram; C. Teeka; R. Jomtarak; P.P. Yupapin; M.A. Jalil; I.S. Amiri; J. Ali; C. Tanaram; Faculty of Science and Technology, Kasem Bundit University, Bangkok 10250, Thailand; email: tchanapk@gmail.comWe present a new concept of ASK-to-PSK generation based on nonlinear microring resonators coupled to one MZI arm by using OptiWave FDTD method. By microring resonator increase from one to three microring (SR to TR), we found that the amplitude shift keying (ASK) are increase exactly and the phase shift keying (PSK) is equal to ¹.Item Effect of reducing fat and using fat replacers in the crust of flaky chinese pastry(2011) Teeranuch Chysirichote; Anchanee Utaipatanacheep; Warunee Varanyanond; T. Chysirichote; Curriculum of Home Economics, Suan Dusit School of Culinary Arts, Suan Dusit Rajabhat University, Bangkok 10300, Thailand; email: Chtnuch@hotmail.comFlaky Chinese pastry (Pia), is a small Chinese pastry filled with mungbean conserve and is a popular bakery product. Its crust is made from wheat flour, fat, water, sugar and salt, with mungbean conserve stuffed inside. This research aimed to lower the fat content in Pia by using fat replacers in the outer crust that had high liking scores from untrained panelists. Maltodextrin gel and inulin gel were used as fat replacers. The results indicated that the hardness of the product increased slightly with the reduction in fat content, while the extension and puffiness decreased. Panelists liked products in which the fat content in the outer crust was reduced by 45% and replaced by 50% of its weight with inulin gel in the formula. The overall liking of the developed product was at a moderate level, which was not significantly (p > 0.05) different from the control. The chemical composition of this formula was analyzed and showed that the fat, total calories and calories from fat could be reduced by 10.5, 3.02 and 10.05%, respectively.