Rajamangala University of Technology at Srivijaya

Songkhla, Thailand
Time filter
Source Type

Ukritchon B.,Chulalongkorn University | Yingchaloenkitkhajorn K.,Rajamangala University of Technology at Srivijaya | Keawsawasvong S.,Chulalongkorn University
Computers and Geotechnics | Year: 2017

The undrained tunnel face stability in clay with a linearly increasing shear strength with depth was investigated by three-dimensional finite element analysis. Three parametric studies were performed to study the effects of the cover depth ratio, overburden stress factor and linear strength gradient ratio on the load factor of the undrained tunnel face stability. The influence of the linear strength gradient ratio on the predicted failure mechanism of the undrained face stability was discussed and examined. An approximate closed-form solution was proposed for three-dimensional undrained tunnel face stability in clays with constant or linearly increasing shear strength profiles with depth. © 2017 Elsevier Ltd

Thongprajukaew K.,Prince of Songkla University | Rodjaroen S.,Rajamangala University of Technology at Srivijaya
Aquatic Living Resources | Year: 2017

Cyclical starvation and refeeding in order to induce compensatory growth were investigated in juvenile yellow mystus (Hemibagrus nemurus). The fish (7.12 ± 0.14 g initial body weight and 8.87 ± 0.04 cm initial length) were starved for one (1DPW), two (2DPW), three (3DPW) or four (4DPW) days per week and otherwise fed ad libitum, while the control group was fed every day (no starvation, 0DPW). The indoor experiments lasted six weeks and followed a completely randomized design (5 treatments × 3 replications × 10 fish per replication). Growth performance, feed utilization, specific activity of digestive enzymes, carcass composition and muscle quality were used to compare the treatment effects. The fish in the 3DPW group exhibited clear compensation for the reduced number of feeding days and had increased body weight towards the end of the experiment. However, this compensation was insufficient to match the specific growth rate in the control group that was fed to satiation daily. The 3DPW treatment also maintained feed utilization parameters, specific activities of protein-, carbohydrate- and lipid-digesting enzymes, carcass composition and muscle quality, relative to the 0DPW control group. The remaining treatments gave some inferior characteristics when compared to 3DPW and 0DPW; the ranking of these feeding treatments was unexpected within the studied period. These findings suggest that cyclical starvation for three days per week (3DPW treatment) and refeeding could be used for rearing juvenile yellow mystus. The intermittent feeding schedule scheme is useful for labor management in the aquaculture production of yellow mystus. However, since partial compensatory growth was observed in the 2DPW and 4DPW groups, as indicated by the compensation coefficient, prolonged experiments on the accelerated growth rate should be conducted in further studies. © EDP Sciences 2017.

Montakarntiwong K.,King Mongkut's University of Technology Thonburi | Chusilp N.,Rajamangala University of Technology at Srivijaya | Tangchirapat W.,King Mongkut's University of Technology Thonburi | Jaturapitakkul C.,King Mongkut's University of Technology Thonburi
Materials and Design | Year: 2013

Two different sources of bagasse ash with low and high loss on ignition (LOI) were used in this experiment. Ordinary Portland cement was replaced by bagasse ash at the levels of 20%, 30%, and 40% by weight of binder. The effects of LOI, fineness, and cement replacement of bagasse ash on the compressive strength of concrete were investigated. Additionally, the heat evolution of concrete mixed with ground bagasse ash with low LOI was also measured. The results revealed that the compressive strength of concrete containing unground bagasse ash was much lower than that of control concrete (CON). Concrete mixed with low LOI ground bagasse ash had a slightly higher compressive strength than the mixture with high LOI ground bagasse ash. The replacement of cement by ground bagasse ash with low and high LOI at 30% and 20% by weight of binder, respectively, result in a compressive strength at 28. days as high as that of CON concrete. Finally, the temperature of bagasse ash concretes could be reduced by 13-37% relative to CON concrete, depending on the level of cement replacement by ground bagasse ash with low LOI. © 2013 Elsevier Ltd.

Inthavisas K.,Rajamangala University of Technology at Srivijaya | Lopresti D.,Lehigh University
IET Biometrics | Year: 2012

The security of biometrics against attacks is a serious concern in biometric personal authentication systems. In particular, the security of biometric templates is a topic of rapidly growing importance in the area of user authentication. The authors first demonstrate the security of a protected speech biometric template and devised an algorithm to attack a speech biometric user authentication system where templates are protected by a cryptographic framework. The experimental result showed an improvement for attackers in gaining access to the system. Then, a way to combine a password with a speech biometric cryptosystem is proposed. The authors present two schemes to enhance verification performance in a biometric cryptosystem using a password. Both can resist a password brute-force search if the biometrics are not compromised. Even if the biometrics are compromised, the attackers have to make many more attempts in searching for cryptographic keys in the system described in this study, compared to a traditional password-based approach. Finally, it is shown that the error rate of the proposed scheme is the same as in a traditional password-based approach even when genuine biometrics or templates are compromised. © 2012 The Institution of Engineering and Technology.

Bunsanit C.,Rajamangala University of Technology at Srivijaya
2014 11th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology, ECTI-CON 2014 | Year: 2014

This article presents beamforming algorithm of wideband smart antenna using Only Spatial Signal Processing in which its operation relies on the use of two-dimensional Inverse Discrete Fourier Transformer (IDFT) technique. The required weights at individual antenna elements are represented by real number which in practice can be realized by amplifiers or attenuators. Then we designed and constructed a full prototype of a smart antenna systems for wideband wireless communication in order to validate this algorithm. After that, the results of radiation pattern are compared between simulation and measurement. © 2014 IEEE.

Samakee C.,Rajamangala University of Technology at Srivijaya
2016 8th International Conference on Knowledge and Smart Technology, KST 2016 | Year: 2016

In general, a single-input-single-output (SISO) Volterra series cannot be used for modeling component of ultraharmonic frequency from ultrasound echo signal. In this paper we present a new method for modeling the ultraharmonic component based on a SISO Volterra filter with exciting input signal at half-fundamental frequency. Results from the approach of the SISO Volterra show capability for successful modeling of the ultraharmonic. We have investigated the accuracy of predicting the ultrasound echo signal under different noise levels. In addition, the SISO Volterra can be still modeled subharmonic frequency component. This is significant solution for separating the ultraharmonic only or adding both the sub- and ultraharmonic for contrast imaging by the system identification of the SISO Volterra filter. © 2016 IEEE.

Bunnoon P.,Rajamangala University of Technology at Srivijaya
International Journal of Electrical and Computer Engineering | Year: 2016

One of most important elements in electric power system planning is load forecasts. So, in this paper proposes the load demand forecasts using denoising wavelet transform (DNWT) integrated with neural network (NN) methods. This research, the case study uses peak load demand of Thailand (Electricity Generating Authority of Thailand: EGAT). The data of demand will be analyzed with many influencing variables for selecting and classifying factors. In the research, the de-noising wavelet transform uses for decomposing the peak load signal into 2 components these are detail and trend components. The forecasting method using the neural network algorithm is used. The work results are shown a good performance of the model proposed. The result may be taken to the one of decision in the power systems operation. Copyright © 2016 Institute of Advanced Engineering and Science. All rights reserved.

Chooklin S.,Rajamangala University of Technology at Srivijaya
International Food Research Journal | Year: 2014

This research aimed to determine optimum condition of the phenolic compounds from brown rice extract from Sung Yod Phatthalung and to determine their applications as an antioxidant in refined palm olein. Brown rice was extracted with solvent concentration (40-80% ethanol, vv-1), pH (2-8) and extraction time (5-60 min). Total phenolic content and antioxidant activities as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) of brown rice extract were measured. The optimum conditions were as follows: ethanol concentration, 60% (vv-1); pH 6 and extraction time, 25 min. Under the above-mentioned conditions, the experimental total phenolic content and DPPH of brown rice was 1.30 mg ferulic acid equivalents/g of dry sample and 86.55%, respectively. The oxidation properties (peroxide value, PV and thiobarbutitutic acid reactive substance, TBARS) of antioxidant in refined palm oil were compared with other synthetic antioxidants (butylated hydroxyanisole, BHA and butylated hydroxytoluene, BHT) at different concentration. It has been observed that the highest efficiency of BHT, followed by brown rice extract, BHA and control. The results revealed that the brown rice extract to be a potential antioxidant for stabilization of refined palm olein. © All Rights Reserved.

Kittiphoom S.,Rajamangala University of Technology at Srivijaya
International Food Research Journal | Year: 2012

Mango (Mangifera indica Linn.) is one of the most important tropical fruits in the world. During processing of mango, by-products such as peel and kernel are generated. Kernels take up about 17-22% of the fruit. The major components of mango seed are starch, fat and protein. The oil of mango seed kernel consist of about 44-48% saturated fatty acids (majority stearic) and 52-56% unsaturated. Mango seed kernels have a low content of protein but they contain the most of the essential amino acids, with highest values of leucine, valine and lysine. Mango seed kernels were shown to be a good source of polyphenols, phytosterols as campesterol, sitosterol and tocopherols. In addition, mango seed kernel could be used as a potential source for functional food ingredients, antimicrobial compounds and cosmetic due to its high quality of fat and protein as well as high levels of natural antioxidants. The mango stone obtained after decortication of mango seed can be utilized as adsorbent.

Kittiphoom S.,Rajamangala University of Technology at Srivijaya | Sutasinee S.,Rajamangala University of Technology at Srivijaya
International Food Research Journal | Year: 2013

Mango seed kernel oil was extracted using soxhlet extraction with petroleum ether, ethanol and hexane. The physicochemical properties (acid value, iodine value, peroxide value and saponification value), the fatty acid composition and phenolic contents, of mango seed kernel oil were examined. Oil extracted with hexane has better overall quality. Its acid, peroxide, iodine saponification values and phenolic content were 0.10 mg KOH/g oil, 8.72 mg/g oil, 38.50 mg/100 g oil, 207.5 mg KOH/g oil and 98.7 mg/g, respectively. The main fatty acids found in the mango seed kernel oil were steric acid and oleic acid. The results suggested that mango seed kernel oil is a good source of the unsaturated fatty acid, phenolic compounds and has the potential to be used as nutrient rich food oil or as ingredients for functional or enriched foods. © 2008 IFRJ.

Loading Rajamangala University of Technology at Srivijaya collaborators
Loading Rajamangala University of Technology at Srivijaya collaborators