Bangkok, Thailand

Ramkhamhaeng University
Bangkok, Thailand

Ramkhamhaeng University is one of two open universities in Thailand. The university was named in honour of King Ramkhamhaeng the Great of Sukhothai, who traditionally is credited for creating the Thai alphabet.Before the establishment of Ramkhamhaeng University in 1971, Thailand had what has been described as "a crisis in the quest for higher education", since the number of high school graduates seeking competitive place in the government universities far outnumbered the capacity of all universities combined. Parliament finally passed a law authorizing the establishment of Ramkhamhaeng University, the kingdom's first open-admission university.The university is composed of the Faculties of Law, Business Administration, Humanities, Education, Science, Political Science, Economics, Engineering, and Education Technology. The Faculty of Engineering admits a limited number of students, while other faculties are open to anyone who wishes to enroll.Ramkhamhaeng University has two major campuses, both in Bangkok. Freshman classes are held at Bang Na campus in Phra Khanong District. Most others classes are conducted at the main campus at Hua Mak, Bang Kapi District. Wikipedia.

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Kalb K.,Lichenologisches Institute Neumarkt | Kalb K.,University of Regensburg | Buaruang K.,Ramkhamhaeng University | Mongkolsuk P.,Ramkhamhaeng University | Boonpragob K.,Ramkhamhaeng University
Phytotaxa | Year: 2012

Eight lichenized ascomycetes and one lichenicolous non-lichenized fungus are described as new to science, namely Coniocarpon coralloideum from Venezuela and Ecuador, Crustospathula khaoyaiana from Thailand, Cryptolechia pittieriana from Venezuela, Cryptothecia napoensis from Ecuador, Malmidea incrassata from Brazil, Malmidea reunionis from Réunion, Malmidea tratiana from Thailand, Stirtonia rhizophorae from Thailand and the nonlichenized fungus Melaspilea lekae from Thailand. The following ten taxa are new additions to the lichen biota of the countries given in brackets: Agonimia pacifica (China), Bactrospora myriadea (Thailand), Brigantiaea phaeomma (China), Brigantiaea sorediata (Tanzania), Coenogonium pineti (Thailand), Cratiria vioxanthina (Brazil), Cryptothecia eungellae(Thailand), Eschatogonia dissecta (Brazil), Malmidea badimioides (Mexico) and Porpidia albocaerulescens var. polycarpiza (Thailand). Buellia vioxanthina is transferred to the genus Cratiria, and a new chemotype of Eschatogonia prolifera was found in Thailand. © 2012 Magnolia Press.

Thongmee S.,Ramkhamhaeng University | Yupapin P.P.,King Mongkut's University of Technology Thonburi
Procedia Engineering | Year: 2011

We propose a new design of all-optical circuit using microring and nanoring devices, in which the simultaneous operation of half adder/subtractor arithmetic can be formed by using dark-bright soliton conversion control within the system. The input logic "0" and "1" are performed by using dark and bright soliton pulses, respectively. By using the dark-bright soliton conversion behavior with in the π/2 phase shift device, the arithmetic unit can perform simultaneously at the drop and though port, respectively. In application, the proposed scheme is simple and flexible for performing the logic switching system, which can be used for advanced logical system.

Foithong S.,King Mongkut's University of Technology Thonburi | Pinngern O.,Ramkhamhaeng University | Attachoo B.,King Mongkut's University of Technology Thonburi
Expert Systems with Applications | Year: 2012

In this paper, we introduced a novel feature selection method based on the hybrid model (filter-wrapper). We developed a feature selection method using the mutual information criterion without requiring a user-defined parameter for the selection of the candidate feature set. Subsequently, to reduce the computational cost and avoid encountering to local maxima of wrapper search, a wrapper approach searches in the space of a superreduct which is selected from the candidate feature set. Finally, the wrapper approach determines to select a proper feature set which better suits the learning algorithm. The efficiency and effectiveness of our technique is demonstrated through extensive comparison with other representative methods. Our approach shows an excellent performance, not only high classification accuracy, but also with respect to the number of features selected. © 2011 Elsevier Ltd. All rights reserved.

Seeka C.,Ramkhamhaeng University | Sutthivaiyakit S.,Ramkhamhaeng University
Chemical and Pharmaceutical Bulletin | Year: 2010

Two 15β-hydroxycardenolides (1,2) and a 16α-hydroxycalactinic acid methyl ester (3) along with eleven known compounds including 16α-hydroxycalotropagenin, coroglaucigenin, 16α-hydroxycalotropin, calactinic acid, calotoxin, 6′-O-(E-4-hydroxycinnamoyl)desglucouzarin, 12β-hydroxycoroglaucigenin, frugoside, calotropagenin, 9,12,13- trihydroxyoctadeca-10(E),15(Z)-dienoic acid and R-(-)-mevalonolactone were isolated from the polar fraction of the CH2Cl2 extract, and n-BuOH extract of the leaves of this plant. The isolated compounds were evaluated for their inhibitory activities against a panel of cell lines. © 2010 Pharmaceutical Society of Japan.

Rodtook A.,Ramkhamhaeng University | Makhanov S.S.,Thammasat University
Journal of Visual Communication and Image Representation | Year: 2013

Segmentation of ultrasound (US) images of breast cancer is one of the most challenging problems of the modern medical image processing. A number of popular codes for US segmentation are based on a generalized gradient vector flow (GGVF) method proposed by Xu and Prince. The GGVF equations include a smoothing term (diffusion) applied to regions of small gradients of the edge map and a stopping term to fix and extend large gradients appearing at the boundary of the object. The paper proposes two new directions. The first component is diffusion as a polynomial function of the intensity of the edge map. The second component is the orientation score of the vector field. The new features are integrated into the GGVF equations in the smoothing and the stopping term. The algorithms, having been tested by a set of ground truth images, show that the proposed techniques lead to a better convergence and better segmentation accuracy with the reference to conventional GGVF snakes. The adaptive multi-feature snake does not require any hand-tuning. However, it is as efficient as the standard GGVF with the parameters selected by the "brutal force approach". Finally, proposed approach has been tested against recent modifications of GGVF, i.e. the Poisson gradient vector flow, the mixed noise vector flow and the convolution vector flow. The numerical tests employing 195 synthetic and 48 real ultrasound images show a tangible improvement in the accuracy of segmentation. © 2013 Elsevier Inc. All rights reserved.

Surapong P.,Ramkhamhaeng University
BMEiCON 2015 - 8th Biomedical Engineering International Conference | Year: 2016

A small current through low frequency is able to treat patients by attenuating or malfunctioning mechanism of microbes which flow through the blood. In addition, the performance delivery of oxygen and nutrients in blood are improved. With the advance, blood viscosity and hematocrit are coincidentally approached to normal level, adaptive flow-rate. This paper proposes the conceptual design of an electrotherapeutic device used for modality application. The design is based on a certain square wave varied from 4 to 5 Hz with a stimulating current and voltage adapted from 0.241mA to 1.027mA and from 15Vpp to 64Vpp, respectively. Applying the wave form to blood model in testing environment, the experimental results show that the viscosity is reduced to satisfy level. © 2015 IEEE.

Changtam C.,Ramkhamhaeng University | Hongmanee P.,Mahidol University | Suksamrarn A.,Ramkhamhaeng University
European Journal of Medicinal Chemistry | Year: 2010

Curcumin (1), demethoxycurcumin (2) and bisdemethoxycurcumin (3), the curcuminoid constituents of the medicinal plant Curcuma longa L., have been structurally modified to 55 analogs and antimycobacterial activity against Mycobacterium tuberculosis has been evaluated. Among the highly active curcuminoids, the isoxazole analogs are the most active group, with mono-O-methylcurcumin isoxazole (53) being the most active compound (MIC 0.09 μg/mL). It was 1131-fold more active than curcumin (1), the parent compound, and was approximately 18 and 2-fold more active than the standard drugs kanamycin and isoniazid, respectively. Compound 53 also exhibited high activity against the multidrug-resistant M. tuberculosis clinical isolates, with the MICs of 0.195-3.125 μg/mL. The structural requirements for a curcuminoid analog to exhibit antimycobacterial activity are the presence of an isoxazole ring and two unsaturated bonds on the heptyl chain. The presence of a suitable para-alkoxyl group on the aromatic ring which is attached in close proximity to the nitrogen function of the isoxazole ring and a free para-hydroxyl group on another aromatic ring enhances the biological activity. © 2010 Elsevier Masson SAS. All rights reserved.

Yeemin T.,Ramkhamhaeng University
Phuket Marine Biological Center Research Bulletin | Year: 2012

We examined the survival of juvenile coral colonies following the 2010 coral bleaching event at eight study sites in the Similan Islands, the Andaman Sea. Density of juvenile corals differed significantly between time, location and major genera. The lowest bleaching impact on juvenile coral colonies was recorded at Christmas Point Rock, a deep study site (20-25m) on the west of the Similan Islands.Most juvenile coral colonies of Pavona spp., Diploastrea heliopora, Leptastrea spp. and Cyphastrea spp. were the least impacted. There was also high survival of juvenile coral colonies of Goniastrea spp., Fungia spp., Acropora spp. and Porites spp. and large coral colonies (>5 cm diameter) of Dendrophyllia micranthus, Fungia fungites and Porites lutea. The findings of this study suggest a high potential for coral recovery at temporarily closed diving sites because of the large number of juvenile colony survivors. It is necessary to implement science-based management plans for marine protected areas to cope with climate change and anthropogenic disturbances.

Sutthacheep M.,Ramkhamhaeng University
Phuket Marine Biological Center Research Bulletin | Year: 2012

The impact of elevated water temperatures in May-August 2010 on coral assemblages at Kut Island, in the eastern Gulf of Thailand was assessed by quantifying the changes of live coral cover before and after the 2010 bleaching phenomenon at three study sites. The coral mortality as a result of the bleaching varied significantly among the three study sites. Corals at Ao Kralang had the highest percentage mortality (45%) whereas Ao Phrao had the lowest (26%), the latter site being subject to relatively high water-flow. Substantial differences in mortality were found among coral taxa. Fungiids showed the lowest percentage mortality (<5%) while all observed colonies of Montipora spp., Acropora spp. and Pocillopora damicornis completely died. Recovery of these corals will depend on recruitment from neighboring reefs where some surviving colonies were observed.

Rodtook A.,Ramkhamhaeng University | Makhanov S.S.,Thammasat University
Pattern Recognition | Year: 2010

We propose a modification of the generalized gradient vector flow field techniques based on a continuous force field analysis. At every iteration the generalized gradient vector flow method obtains a new, improved vector field. However, the numerical procedure always employs the original image to calculate the gradients used in the source term. The basic idea developed in this paper is to use the resulting vector field to obtain an improved edge map and use it to calculate a new gradient based source term. The improved edge map is evaluated by new continuous force field analysis techniques inspired by a preceding discrete version. The approach leads to a better convergence and better segmentation accuracy as compared to several conventional gradient vector flow type methods. © 2010 Elsevier Ltd. All rights reserved.

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