bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects and mechanisms of anacardium occidentale and glochidion zeylanicum leaf extracts on neuroprotective, neuritogenesis, oxidative stress resistance and anti-aging properties.
Authors:   , Duangjan Chatrawee
Published: September 2023

Aging is the primary risk factor for most neurodegenerative diseases and can negatively affect the quality of life. Neurodegenerative diseases are linked to neuronal cell death and neurite outgrowth impairment that are often caused by oxidative stress. As people want to live longer and healthier, healthy nutrition has been increasingly received much attention in recent years. Several studies reported a positive correlation between antioxidants in foods and longevity. Natural products from food supplements and medicinal plants with antioxidant properties could be promising candidates for fighting against various aging-related diseases and promoting longevity. Leaf extracts from A. occidentale (AO) and G. zeylanicum (GZ) have been of great interest due to their pronounced antioxidant effects. However, the anti-oxidant and anti-aging effects of AO and GZ leaf extracts still have not been reported. The current study aims to document beneficial effects of leaf extracts from AO and GZ extracts with neuroprotective, neuritogenesis, oxidative stress resistance properties and lifespan extension in the cultured neuronal (HT22 and Neuro-2a) cells and the C. elegans model. In cultured neuronal cell models, the AO and GZ extracts have a protective effect against glutamate/H2O2-mediated oxidative stress-induced cell death via inhibition of ROS accumulation, up-regulation of endogenous antioxidant enzymes, and the increase of the SIRT1-Nrf2 signaling pathway. The AO and GZ extracts increase neurite outgrowth mediated Ten-4 transmembrane protein. In C.elegans models, the AO and GZ extracts mediated the survival rate of nematodes under oxidative stress by stimulation stress-response genes (SOD-3 and GST-4), attenuating intracellular reactive oxygen species (ROS) accumulation via DAF-16/FoxO and SKN-1/Nrf-2 signaling pathway. The AO and GZ extracts exhibited anti-aging activities and enhanced longevity by improving pharyngeal pumping function, attenuation of pigment accumulation (lipofuscin) and a lifespan extension in wild-type worm. Collectively, this study is the first report about the phytochemical composition of A. occidentale and G. zeylanicum along with neuroprotective, neuritogenesis, antioxidant and anti-aging effects in cultured neuronal cells (In vitro) and C. elegans models (In vivo). Our novel findings could initiate further applications of AO and GZ leaf extracts as natural products beneficial to humans for developing new treatment and protection aging-related diseases in the future.
A peer-to-peer protocol for prioritized software updates on wireless sensor networks
Authors:   , Nuntanirund Natchanon
Published: September 2023

Software updating is essential for devices in wireless sensor networks for adding new features, improving performance, or patching vulnerabilities. But since some deployed devices are unable to be accessed directly, data dissemination protocol is used for distributing the update to those devices. However, each software updating may have different priority, for instance, an update that adds an optional feature does not have to be applied as fast as an update that patches severe vulnerabilities. This research presents a reliable data dissemination protocol which is configurable for energy-speed trade-off deriving some concepts from BitTorrent such as Handshaking, Segmented File Transfer, and Choking Algorithm.
Thai scene text recognition
Authors:   , Kobchaisawat Thananop
Published: September 2023

Automatic scene text detection and recognition can benefit a large number of daily life applications such as reading signs and labels, and helping visually impaired persons. Reading scene text images becomes more challenging than reading scanned documents in many aspects due to many factors such as variations of font styles and unpredictable lighting conditions. The problem can be decomposed into two sub-problems: text localization and text recognition. The proposed scene text localization works at the pixel level combined with a new text representation and a fully-convolutional neural network. This method is capable of detecting arbitrary shape texts without language limitations. The experimental results on the standard benchmarks show the performance in terms of accuracy and speed compared to the existing works. The cropped text instances are passed into the proposed text recognition algorithm, which consists of four stages: transformation, feature extraction, sequence modeling, and prediction. The proposed method is designed based on a fully-learnable deep learning-based model in combination with multi-level attention, which inspires from Thai writing system. The training data is purely synthesized from various fonts and novel techniques to make the generated images looked sensible. The experimental results on the test dataset show excellent accuracy and inference time.
Access to higher education, job mismatch, and wage penalties in Thailand
Authors:   , Saripan Palita
Published: September 2023

This study considers whether close proximity to higher education institutions increases the probability of earning a bachelor’s degree, overeducation, and horizontal mismatch between degree and occupation. Using data from the 2015 and 2016 Labor Force Survey of the National Statistical Office of Thailand, and jobs data from the Ministry of Labor, we find that individuals living in provinces with research or Rajabhat universities are more likely to earn a bachelor’s degree, but does not increase the probability of being overeducated for their job. In addition, we find larger overeducation penalties in provinces with universities. Finally, qualitative analysis shows that demand for bachelor's degree fields is relatively consistent with the supply of graduates in some regions. But in Bangkok, there is a horizontal mismatch problem.
Patient preference and cost-effectiveness analysis of colorectal cancer screening and treatment
Authors:   , Phisalprapa Pochamana
Published: September 2023

Background/Aims: Colorectal cancer (CRC) screening and treatment have been reported to be cost-effective in many high-income countries. However, there was no such study in low- and middle-income countries (LMICs). This study aimed to assess the factors determine individuals’ preferences and cost-effectiveness of CRC screening and treatment.

Methods: This study consists of three parts. The first part focused on the factors determine individuals’ preferences for CRC screening using discrete choice experiment and multinomial logit model. The second part investigated the cost-effectiveness and budget impact analyses of CRC screening comparing between annual fecal immunochemical test (FIT) and colonoscopy every 10 years. The results from the first part can be used to improve patients’ participation rate which is the key factor for the cost-effectiveness analysis of the screening tests. Finally, the last part evaluated the cost-effectiveness and budget impact analyses of CRC stage III treatment. This part aimed to identify the most cost-effective treatment regimen in Thailand. The input parameters were obtained from Siriraj CRC screening and treatment projects, health care costs and databases of Thailand, and systematic literature review.

Results: A total of 400 respondents preferred screening with high risk reduction of CRC-related mortality, no complication, 5-year interval, less bowel preparation, and lower cost. FIT is the preferred choice of screening with the highest willingness-to-pay and uptake rate. From cost-effectiveness analysis results, both FIT and colonoscopy were cost-effective when compared to no screening. Colonoscopy was cost-effective when compared to FIT. However, colonoscopy required 8-times higher budget and more human resource than FIT. In addition, for CRC stage III, the new regimens of capecitabine and irinotecan will be cost-effective if the prices were reduced about 50-80%. The budget impact of early screening was lower than treatment due to the preventing of premature deaths.

Conclusions: This study provides real-world patients’ preference and cost-effectiveness evidence of CRC screening and treatment. Annual FIT was preferred to other screening tests and it could be implemented with no human resource and financial constraint. The new drugs for CRC stage III treatment were not cost-effective. Policy makers can use these findings to improve the success rate of CRC screening and appropriate treatment in Thailand.
Application of battery energy storage system for frequency regulation of Mae Hong Son microgrid
Authors:   , Teawnarong Arnon
Published: September 2023

Mae Hong Son microgrid in an isolated mode has low inertia. Therefore, when a disturbance occurs, the system frequency is subjected to a large deviation, which may lead to a blackout. The installation of a battery energy storage system (BESS) will improve the frequency response performance of the microgrid system in both islanding and grid-connected modes. The objective of this thesis is to investigate and compare BESS control methods for providing primary and secondary frequency response. The results show that the control of BESS for providing primary frequency response using virtual droop and virtual inertia approaches can reduce the frequency deviation in the microgrid. Moreover, the control of BESS for providing secondary frequency response can bring the system frequency to standard values.
Simulation studies in ferroresonant phenomena on distribution transformers
Authors:   , Phomvongsy Phinnakhone
Published: September 2023

Ferroresonance phenomena often appear in any typical distribution systems consisting of drop-out fuse cutouts, overhead lines or power cables and a distribution transformer. Single-pole energization and fuse operation may lead to ferroresonance overvoltages, resulting in electrical equipment damage. The occurrence of ferroresonance depends on several factors including size and length of line, power rating and type of distribution transformer. This thesis presents two case studies involving ferroresonance phenomena.

The first case studies the lengths of overhead lines and underground cables which create enough capacitive reactance for ferroresonance. The critical lengths are estimated by hand calculation and computer simulation. The obtained results show that the system with underground cables has much lower critical length in comparison with that of overhead lines. The critical length decreases with increasing conductor size and decreasing power rating of transformer.

The second case studies the effect of low-loss transformer in comparison with the conventional one. It is found that using the low-loss transformer has more chance to face ferroresonane phenomena.
Process improvement of housing loan product in Thailand commercial bank
Authors:   , Santitrakulvech Araya
Published: September 2023

According to digital disruption has become key factor that stimulates changing in business nowadays including banking business. To respond through rapid change in customer behavior and become competitive among rivals, this research is aimed to improve business process of housing loan product in one of commercial banks in Thailand which is mainly operated in manual operation and paper process and believed to be main symptoms of bottleneck in lending process. 

The main objective of this research is to reduce lead time of housing loan business by going through the detail of business process to reveal wastes or non-value-added activities using appropriate lean tools and find possible solution to assess for improvement. By approach of lean tool known as Value Stream Mapping that being used as a key tool in research methodology, it revealed that majority of wastes were from long waiting time and long query time causing from unneccesary tasks and noncontinuous of traditional process. Therefore, possible solution from lean concept including method of simplifying and streamling of process and standardization were considered.

In addition, gathering with the concept of digital transformation in banking industry which were also revealed as the final solution in the form of new system implementation that was conducted in the studied bank, it showed improvement in shorter lead time by contribution of key capabilities from the new system implementation including electronic credit bureau check, automated credit decision management. The result revealed 62.3% improvement from reduction of cycle time in pre-screening stage that contributed lead time to reduce from 11 days to 6 days which can imply that by enhancement of transforming the process to be digitalized, it can contribute the process to be more efficient, seamless, and respond to the rapid changing in banking business decently.
Architectural joinery design to prevent water leakage in a precast concrete detached house
Authors:   , Vataniyobol Prokchol
Published: September 2023

The precast concrete construction is widely used in Thailand by customers and developers for residential development. For many decades of building with the precast concrete wall system, the common problems of water leakage are the most pressing concerns. This thesis aims to find the issues that lead to the causes of water penetration and propose a solution to prevent water leakage. From the literature review, the sources of water leakage are at the connection location between the precast modules. The water can penetrate through the opening with the four forces: a momentum of the raindrop, capillary action, gravity, and air pressure. This thesis categorized the precast concrete joinery into three types of a one-stage joint, a two-stage joint, and a drain joint. The experiment on water infiltration was conducted based on the two leading forces of water leakage with water on the surface test for gravity force and a water spray test for the raindrop momentum (wind-driven rains). The six precast concrete wall modules are setup where three modules do not have a scarf detail, and three modules had a one-way scarf detail. The result shows that the most efficient joinery types are the one-stage joint but, due to the high chance of defection, make the joint more likely to cause water leakage. The second useful joinery is a drain joint with scarfs details with the lowest change of temperature on the two water tests. The research finding of this thesis is used for redesigns the Centro Rangsit village(phase 2) which is a two-story detached house. The project used a precast concrete wall system. The redesign had implemented the modularity in space planning, the panels division that reduces the point of connection, and incorporates the additional element to deflect and discharge the water away from the building surface. Based on the water infiltration experiment, the redesign integrates the scarf drain joinery types. This thesis proposed a redesign that improves the three house modules of the Centro Rangsit village(phase 2) that increases the water leakage prevention mechanism.
Strategic supplier selection:the case of international food trading company
Authors:   , Paramaporn Natchanok
Published: September 2023

The objective of the research project is to develop strategic supplier selection system for an international food trading company using the Analytic Hierarchy Process (AHP). The products involved are canned food for worldwide export. The decision makers consist of a president and two marketing managers. The chosen decision criteria listed by weight of important are ‘Export Capability’ (54%), ’Pricing Policy’ (28%), ‘Technological Catch-up’ (10%), ‘Ethical Practices’ (5%), and ‘Environmental Management’ (3%). The sub-criteria chosen are ‘Number of Food Safety Certificate’ (54%), ‘Net Selling Price’ (23%), ‘Automation in Production Process’ (8%), ‘Payment Terms’ (5%), ‘Worker’s Safety and Health’ (4%), ‘Adverse Weather Control‘ (2%), ‘Packaging Varieties‘ (2%), ‘Stop Child and forced labor’ (1%), and ‘Environmental Compliances’(1%).

According to the company existing choice of supplier using cheap price as the criterion for selection that supplier C for pineapple products, supplier F for sweet corn products, and supplier L for baby corn products. After the proposed strategic selection system is applied, the optimal suppliers for pineapple are found to be Supplier B (with a score of 33.6%) and Supplier D (32.8%), for sweet corn product are Supplier F (29.35%) and Supplier E (29.22%), and for baby corn product are Supplier I (32.33%) and Supplier K (26.55%).

It may be concluded from the present thesis research that strategic criteria involved with current business environments obtained substantial weight from expert’s opinion. This confirmed that Strategic Supplier Selection should obtain a lot of attention from business sector.
A study of price elasticity of demand and its application in first mile/last mile service collaboration between mass transit and ride sharing providers
Authors:   , Warapiankul Voragorn
Published: September 2023

Since today, Bangkok faces the big pollution and low mobility. One main reason is Bangkok people tend to travel by automobiles instead of the transit. The main problem of Bangkok transit especially Bangkok metro is the low accessibility to travel to/from the transit nodes and between nodes or as called First Mile Last Mile problem. Moreover, Bangkok metro transit fare is claimed that is too expensive compared to the cost of living and minimum wages in Bangkok. This research aims to study the price elasticity of demand for Bangkok metro which is the indicator of fare demand management in Bangkok metro transit that is important to have the public opinion on the fare with their range of acceptable price. Following to analyse the approach for the collaboration between Bangkok metro transit and ride sharing providers, in order to find the solution to improve the First Mile Last Mile of Bangkok metro transit and the accepted service fare strategy. The research methods are surveying the Bangkok metro users for the accepted fare opinion and interviewing the metro operators and ride sharing providers for the collaborative approach with their fare strategies. The results show the metro routes which is operated by Bangkok Mass Transit System Public Company Limited (BTSC) is elastic to demand and should discount its current fare base on users opinion. While the metro routes which is operated by Bangkok Expressway and Metro Public Limited Company (BEM) is inelastic to demand that its current fare is already in the accepted range. Moreover, the Bangkok metro operator and ride sharing provider accept the collaborative approach that is able to gain the mutual benefit for the transport providers to increase its service demand and for the Bangkok people to increase the conveniences and decrease cost of travelling in their daily life.
Big data analytics for improving customer win-back rate in townhome segment
Authors:   , Lilahajiva Warot
Published: September 2023

Thailand’s real-estate market is now facing with negative growth, where most developers are encountered with challenges in generating satisfactory revenue, particularly from new customers. In order to improve the revenue stream, customer win-back approach that focuses on current customers in the sales funnel and re-engages them by offering more attractive residential projects is therefore initiated. In particular, we focus on the development of predictive analytics model that potentially increases customer win-back rate by exploring the current databases, identifying significance for win-back (based on past performance), and testing the resulting predictions via several machine learning algorithms. The proposed method returns a propensity model that ranks customers based on likelihood to purchase if contacted. We test the proposed method by running an A/B test for 3 weeks and then compare (1) average number of refer cases to sales department and (2) average customer referral rate with the base case. We find that the propensity model impressively helps increase average number of refer cases to sales department by 11.8% and increase referral rate by 13.5%. In terms of finance, these significant improvements lead to a revenue uplift of 20.9% year-on-year, valued at THB 253.5 million.
An interlanguage study of L2 perception and production of english word stress by L1 Thai learners.
Authors:   , Jaiprasong Sawaros
Published: September 2023

The aim of this study was to investigate L1 Thai learners’ English word stress perception and production of two different groups of English words: English words with different suffixes (suffixes affecting stress shift and neutral suffixes) and compound words (compound nouns and compound verbs). Three objectives were 1) to compare and contrast the perception of English word stress focusing on words, 2) to compare and contrast the production of English word stress focusing on words and 3) to investigate whether there is a relationship between L1 Thai learners’ perception and production of English word stress. Two groups of L1 Thai first-year undergraduate learners participated in this study: 30 L1 Thai beginners and 30 L1 Thai intermediate learners from Srinakharinwirot University. They completed two tasks: “Marking English Word Stress in Sentences” and “Reading English Word Stress in Sentences”.  The results showed the L1 Thai intermediate learners significantly outperformed the L1 Thai beginners in both perception and production. Moreover, a relationship between the learners’ perception and production of English word stress was observed from the L1 Thai beginners and the L1 Thai intermediate learners. It was assumed that the problems of English stress assignment were caused by both interlingual and intralingual factors (Ellis, 2003; Haryani, 2016). Word stress placement rules in English and Thai differ substantially. Based on the Interlanguage Hypothesis, strategies of second language learning possibly have a negative impact on the problems (Selinker, 1972; Corder, 1999). The results contributed to second language acquisition and provided pedagogical implications for teaching and learning English pronunciation with respect to English word stress by L2 learners.
The effect of control-ownership disparity on earnings management: evidence from Korean large business groups
Authors:   , Kim Jaehyeok
Published: September 2023

This study examines the difference in the use of earnings management at family-controlled firms belonging to Korean large business groups (chaebol) versus non-chaebol firms belonging to Korean large business groups from 2002 to 2016. Firms belonging to large business groups are subject to similar regulations by authorities. This study also tests whether a divergence between voting rights and cash flow rights affects earnings management by controlling shareholders. This study examines both accrual-based earnings management (AEM) and real-activities earnings management (REM), using two measures of accrual-based earnings management and three measures of real-activities earnings management. This study finds that chaebol firms have better earnings quality compared to non-chaebol when an earnings quality measure is used as an AEM proxy. However, there is no significant difference between chaebol and non-chaebol firms when a second AEM proxy, measuring discretionary accruals, is employed. These mixed results indicate that there is no difference between family-controlled firms (chaebol) and non-family firms (non-chaebol) in the use of accrual-based earnings management. Second, this paper provides evidence that there is no significant difference between chaebol firms and non-chaebol firms with respect to all three measures of real-activities earnings management. This study finds stronger evidence of overproduction as a means of real-activities earnings management at a subsample of firms in manufacturing industries, compared with the full sample containing firms in both manufacturing and non-manufacturing industries. This study shows that a control-ownership disparity by controlling insiders of large business groups does not have an impact on accrual-based earnings management or real-activities earnings management. This is because a variety of regulations imposed on large business group make the use of earnings management costly regardless of the presence of a control-ownership wedge. In additional analyses, this paper finds that chaebol firms with greater control-ownership disparity are associated with poor earnings quality. Lastly, this study finds that chaebol firms engage less in overproduction as a means of real-activities earnings management, as the families which control the chaebol have a greater disparity between control rights and ownership rights.
A neural network-based method for solving a dynamic investment and consumption problem with transaction costs and stochastic volatility
Authors:   , Noonoi Kittipong
Published: September 2023

Optimal investment and consumption problem with proportional transaction costs known as Davis \& Norman problem is a challenging portfolio free-boundary problem to solve. According to the HJB equation, see Davis and Norman (1990), there are three optimal regions i.e. no-trade region, buy region, and sell region in which different actions are prescribed. However, the two boundaries separating the three regions are unknown and it is crucial to discover them in order to obtain the optimal policy. Nonetheless, under a special class of model in which the excess return of stock is assumed to be positively linear in variance reflecting the principle of risk-return tradeoff, the increase of two boundaries in variance suggests the investor to over-invest in a high-risk/high-return stock and to under-invest in a low-risk/low-return stock. This becomes contradictory to the principle eventually and reflects the incompleteness of the model setup. In this study, we aim to extend the model setup of the Davis \& Norman problem to include stochastic variance by assuming that it follows Heston stochastic volatility model. The problem becomes solving a two dimensional free-boundary partial differential equation problem which is different from the one in the Davis \& Norman problem, therefore, numerical methods for approximating boundaries of the Davis \& Norman problem are no longer applicable. As a result, we propose a neural network-based method inspired by the original Deep Galerkin Method (DGM) proposed by Sirignano and Spiliopoulos (2018). Unlike the solution of the Davis \& Norman problem, the neural network approximated solution implies that the stochastic variance can reduce the domination of excess return on the buy boundary resulting the boundary to be less steep i.e. less positively sensitive to initial variance compared to that of the Davis \& Norman problem. Moreover, stochastic variance completely gains the dominance over excess mean return on the sell boundary making it downward-sloping i.e. decreases when the initial variance level is increased for the set of parameters that we used. However, in the presence of a negative correlation between the stochastic variance and stock returns, the buy boundary barely transforms while the sell boundary is no longer downward-sloping and becomes almost insensitive to initial variance. Therefore, under the Heston model with this set of parameters, the investor can implement roughly the same policy for every level of initial variance.
Correlation development of wax deposition prediction from fang oil field
Authors:   , Aye Aung
Published: September 2023

In petroleum industry, wax deposition is a critical operational challenge. It occurs in various locations in the petroleum production chain including well tubing. Hexane, chemical inhibitor, is used to prevent the wax problem of oil from Fang oilfield by the measurement of pour point, wax appearance temperature (WAT) and wax deposition. An increasing shear rate can reduce WAT and the deposited amount increases with lowering the temperature in Fang crude oil. Moreover, the non-linear regression analysis of Fang crude oil with and without hexane in different conditions are done for all three tests. Those regression analysis equations can predict WAT at different shear rates and wax deposited weight amount at different temperature of crude oil in Fang. The effects of parameters such as hexane concentration, temperature and shear rate on pour point, WAT and wax deposition are studied. The higher hexane concentration can reduce pour point. The more hexane concentration was used, the higher WAT reduction was observed. Both higher hexane concentration and temperature give the less amount of wax deposit. The calculated WAT is attained from intersection point between equations and modified Ronningsen’s correlation is used for wax deposition prediction. The percent difference between the experimental and calculated results are compared. Both increasing hexane concentration percent and shear rate make calculated WAT decrease and the selected equations can be applied in both concentration and shear rate perceptive. Increasing hexane concentration and decreasing temperature can lower wax deposition amount in Modified Ronningsen’s correlation and this correlation works well with both different solvent concentrations and temperatures.
Pre-feasibility study on granite quarry for aggregate: a case study at Kanchanaburi province, Thailand
Authors:   , Ziyivang Bee
Published: September 2023

This study aims to develop long term mine planning and design, equipment requirement calculation, and financial model analysis of mining and crushing plant. The ore reserve estimation and pit design carried out by using MineSight software (Ver. 9.50). A discounted cash flow model (DCF) and sensitivity analysis used to evaluate the financial project. Based on our study, the open-pit mining method was advisable for mine planning and design. Ore reserve estimated to 48.4 Mtons under the mining operation of 2.4 Mtos per year. The project time frame is 22 years which spends 21 years for operation and one year for preparation and development. The project required of 598 million baht for capital cost, spent 148 million baht for operating costs annually. The financial model indicated that NPV13.4% is 2,335 million baht, MIRR obtained 22.41%, and 1.6 years of payback period. The sensitivity analysis of the financial model shown that the most sensitive value was the aggregate price. For example, a 30% increase in aggregate price leading to raised NPV13.4% up from 2,335 million baht to 3,442 million baht. In contrast, a decrease of 30% in aggregate price resulted in NPV13.4%  reduced by 53.62%.
A market-based probabilistic risk assessment of As concentration in raw and cooked rice in Bangkok
Authors:   , Hensawang Supanad
Published: September 2023

Rice is a staple food of human and can be a main source of arsenic (As) exposure. This study was conducted to i) investigate the concentrations of total, inorganic and bioaccessible of As in raw rice, ii) investigate the effects of rice processing before human consumption on the concentrations of As in rice, and iii) evaluate the potential health impacts of As exposure through rice consumption. A total of 208 polished and non-polished samples sold in the local markets of Bangkok were collected. The total As concentrations in polished (0.0878 to 0.2949 mg kg-1, n = 154) and non-polished (0.1187 to 0.51722 mg kg-1, n = 54) were determined. The percentages of inorganic As to total As in rice were 58% and 52% in polished and non-polished rice, respectively. Approximately 25% of total As in 8% DOP rice grain were significantly reduced compared to the total As in non-polished rice (0% DOP) (p < 0.01). Only 3-time washing could significantly decrease total As concentration in polished rice (p < 0.05) by approximately 29%. Washing did not effectively remove As from non-polished rice grain. Rice washed for 3 times and then cooked with the traditional and modern cooking method using an aluminum pot and an electric rice cooker, respectively, had approximately 60% and 21% of total As reduction comparing to the raw rice. Cooked rice from both cooking methods had significantly lower As bioaccessibility than the raw rice. The deterministic and probabilistic risk assessment results of bioaccessible As exposure through the consumption of modern cooked rice indicated a negligible non-carcinogenic effects in the majority of children, adolescents, and adults as the hazard quotients in all groups were less than 1. Adults were susceptible population to carcinogenic effects especially from the non-polished rice consumption. The average cancer risk which was approximately 1.12×10-4 exceeded the acceptable cancer risk of 1×10-4. Three important factors affecting the health risk levels were rice ingestion rate, individual body weight, and As concentration in cooked rice.
Phospholipid- and gold-induced gelation of Thai silk fibroin
and its applications for cell and drug delivery
Authors:   , Laomeephol Chavee
Published: September 2023

Recently, an in situ gelation, which is a rapid sol-to-gel transition under mild conditions, has been employed, allowing an entrapment of cells or substances in 3D structures as well as tailorable geometries and point-of-care uses. Silk fibroin (SF), a natural polymer from Bombyx mori silkworm cocoons, was chosen in this study as a substrate for the in situ hydrogel fabrication, due to self-assembly characteristic and a presence of modifiable functional groups. However, regenerated SF solution poses a slow gelation (several days or weeks) which is impractical for an in situ application. Therefore, a phospholipid, dimyristoyl glycerophosphoglycerol (DMPG), and a gold salt (Au3+) were introduced as chemical inducers to accelerate the gelation process of SF.

SF hydrogels induced by DMPG can be obtained within 10-40 min depending on the concentration of DMPG. Electrostatic and hydrophobic interactions were proposed as driving forces for inducing SF structural transition. Encapsulated L929 and NIH/3T3 fibroblasts in the hydrogel displayed a normal proliferation, confirming the cytocompatibility of DMPG-induced SF hydrogel. Subsequently, DMPG-based liposomes were prepared and loaded with an anticancer drug, curcumin. The liposomes can enhance loading amount and extend curcumin stability as well as induce the rapid gelation of SF. Curcumin released from liposome-SF hydrogels can inhibit the growth of cancer cells. When using the hydrogel as a substrate for cell culture, low cell survival was observed, possibly due to the combination of low cell attachment on SF and cytotoxicity of curcumin. Moreover, an addition of a gold salt (Au3+) in regenerated and thiolated SF solutions can accelerate the sol-to-gel transition. Dityrosine formation was proposed as an underlying mechanism of gelation for regenerated SF, while the formation of disulfide and Au-S bonds was proposed for thiolated SF. The obtained hydrogels exhibited good cytocompatibility with L929 fibroblasts.

In summary, the rapid gelation of SF can be achieved by the addition of DMPG or Au3+ salt. Different gelation mechanisms were proposed, and the obtained hydrogels showed the in vitro cytocompatibility, indicating the potential uses as a biomaterial for different biomedical applications.
Argonaute 4 promotes genomic methylation
Authors:   , Chalertpet Kanwalat
Published: September 2023

RNA-directed DNA methylation (RdDM) is the major small RNA-mediated epigenetic pathway in plants. Similar to genome and epigenome editing with the CRISPR-Cas9 system, RdDM is composed of a regulatory protein and a “guide” RNA (gRNA), which recruits the complex to specific genomic locations containing DNA sequences homologous to the RNA sequence. In humans, we found that Argonaute-4 (AGO4) colocalization has a strong correlation to promoter methylation of AGO4-binding genes. Here, we engineered cell-penetrating tagged oligoarginines (R9) tagged AGO4 (R9-AGO4) or xentry tagged AGO4 (X-AGO4) loaded with single guided-RNA (sgRNA) as a tool to  specifically add methylation at genome locations where sgRNA is homologous to. We uncovered that only R9-AGO4-sgRNA complex can methylate both repetitive sequences (Alu and LINE-1) and unique copy gene (EML2 and CCNA1) while X-AGO4-sgRNA can penetrate into cells, but did not provide methylation change. The induction of methylation by R9-AGO4-LINE-1 or R9-AGO4-CCNA1 also contributes to down-regulation of their own gene expression. Moreover, R9-AGO4-LINE-1 can delay proliferation rate of transfected cells compared with their control counterparts. Therefore, our study is the first time reported that the engineered R9-AGO4  protein can be transfected to cells with sgRNA and can be used as an alternative tool for epigenomic editing at any specific genes or DNA sequences in humans.
Predicting market crashes using systemic risk and volatility spillovers : a deep learning approach
Authors:   , Mahutchariyakul Kornprarun
Published: September 2023

We develop a model for predicting market crashes in the Stock Exchange of Thailand using a deep learning-based anomaly detection approach (LSTM-VAE). The model aims to detect market behavior before each market crash. Apart from the common stock market variables, we feed the model with the indices of systemic risk, and of volatility spillovers. With these two indices, the model takes into account the influences from both inside and outside the particular stock market. We find that in large crashes our model gives the crash warning signals shortly after the SET index reaches its peaks and long before the index reaches its troughs. And our model outperforms the existing models in the literature. Besides, when compared with a buy-and-hold strategy, our strategy incorporated signal from the model also leads to a higher return, because it helps us evade from large crashes.
Characteristics and mechanisms of coastal upwelling in the gulf of Thailand
Authors:   , Sripoonpan Pacharamon
Published: September 2023

The characteristics and mechanisms of coastal upwelling in the Gulf of Thailand was investigated through 2 approaches; 1) Ekman transport upwelling index (UIET) and sea surface temperature upwelling index (UISST), and 2) Hydrodynamics model DELFT3D-FLOW under the influences of tide, spatially varying wind, water temperature, salinity and river discharge. The UIET indicated favorable upwelling conditions along the west coast of the GoT mostly during northeast monsoon in January and 1st inter-monsoon in March, while the favorable upwelling condition indicated by UISST was found along the east coast during southwest monsoon in August and 2nd inter-monsoon in October. The model expressed the favorable upwelling conditions along the west coast of the upper gulf and the west coast of Ca Mau Cape during northeast monsoon and southwest monsoon. Besides, the model results shown the upwelling with the obvious cooler coastal water along the west coast of the upper gulf and the central gulf and along the west coast of Ca Mau Cape during northeast monsoon and southwest monsoon, and with slightly cooler coastal water during 1st inter-monsoon in March and 2nd inter-monsoon in October. The coastal upwelling associated with UIET was different from UISST and the model simulation. The UIET indicated the wind-driven coastal upwelling directly connecting with directions of Ekman transport and wind. In contrast, the UISST was estimated using the satellite-observed sea surface temperature. Also, the upwelling found in the model simulation was generated using different forces, e.g., tide, wind, temperature, salinity, river discharge and heat. The tracked coastal upwelling in this study might be vital for fisheries resources managements and conservation, and to complete the knowledge of nutrient distributions in the Gulf of Thailand.
Classification of aircraft with shadow using keypoint descriptor from remote sensing images
Authors:   , Meeboonmak Natnicha
Published: September 2023

Presently, aircraft classification from remote sensing images is widely used in military and civilian. However, aircraft type classification is still challenging to discriminate. The reason is that the aircraft displayed in the image has different in color, shape, size, and orientation. Moreover, there is the shadow appeared over and behind the aircraft that obscures some details of aircraft. Therefore, this work proposes the classification of aircraft with shadow method. This method modifies the deeply supervised salient object detection with short connections to make the aircraft be outstanding from the shadow and other objects in the background and then segment it. The segmentation experiment performs on our dataset, which is divided into two categories: simple case and difficult case. The results show that our proposed method performs well in both cases. In order to classify the types of aircraft, we extract features from each keypoint of aircraft segmented image by using the Fourier descriptor based on centroid contour distance, which is invariant to position, scale, and rotation. After that, we use the random forest algorithm to classify the aircraft types into six classes in the classification experiment. The result shows that the method can efficiently classify the aircraft and work well on aircraft images with shadow.
Pointwise dimension of archimedean copulas
Authors:   , Yanpaisan Noppawit
Published: September 2023

In this thesis, we introduce the pointwise dimension of a bivariate copula C at (u,v) in [0, 1]2 via its C-volume. This quantity gives a broader view of probability mass distribution than the support of a copula, the smallest closed set on which the whole mass lies. We would like to study some fundamental properties of pointwise dimension, including the equality to pointwise exponent whenever both of them exist. After that, we investigate the behavior of the pointwise dimension of copulas constructed by various methods. In the last part, we compute the pointwise dimension of Archimedean copulas, an important class of copulas used widely in many branches.
Solving interval-valued returns mean absolute deviation portfolio selection model under basis stability
Authors:   , Chaiyakan Songkomkrit
Published: September 2023

This work discusses a portfolio selection model with interval linear programming arising from the uncertainty of future rates of return and the disagreement over their estimates. The risk of the overall portfolio is proposed as an objective function to obtain a well-diversified portfolio with a certain threshold rate of return. The optimization problem employs mean absolute deviation as a risk measure for the sake of risk diversification and time complexity. The possible ranges of optimal portfolio returns and associated risks are derived. The duality theory contributes to an enclosure of the optimal portfolios. When the bounds on future rates of return are sufficiently tight, the ambiguity of optimal portfolio compositions can significantly be reduced by basis stability. A theoretical framework for the study of the interval linear programming is also provided. The use of this method is illustrated with the historical returns of S&P 500 stocks, for which the negative correlation condition empirically holds, with a 6-month investment horizon from November 2018 to April 2019. The historical data is collected monthly over the past four years from November 2014 to October 2018. Compared to the bilevel optimization method, our proposed algorithms produce better results in both empirical and theoretical aspects.
Covers for Leo Moser's worm problem
Authors:   , Kanchai Thitipong
Published: September 2023

Leo Moser’s worm problem was posted in 1966 stating that “What is the region of the smallest area that can cover every unit are?”. In 2018, N. Ploymaklam and W. Wichiramala illustrated a new cover, which is currently smallest. Their cover was adapted from the cover of R. Norwood and G. Poole. In this work, we modify the region from the work of R. Norwood and G. Poole and the work of N. Ploymaklam and W. Wichiramala. Our regions are modified by changing their upper boundary. However, the regions remain satisfying properties in the work of R. Norwood and G. Poole. In addition, we construct the region using cosine function as the upper boundary. This region can cover every unit are which has area approximately 0.26009. Moreover, we try to construct the region starting from the lower boundary. However, we confront with the complex numerical computation. Thus, we cannot construct the region using this idea.
Effects of non-albicans Candida species on biofilm formation and acidogenicity of dual-species biofilms and on cariogenic virulence gene expression of streptococcus mutans
Authors:   , Sansanoa Wirunphat
Published: September 2023

Early childhood caries is a common oral disease found in children which could affect their general health. Streptococcus mutans is an important cariogenic pathogen since it possesses cariogenic properties, which are acid production, acid tolerance and biofilm formation. Recent studies showed that Candida albicans, which is frequently found together with S. mutans in plaques of children with dental caries, enhances cariogenicity. At the same time, increasing prevalence of non-albicans Candida species (NACs) in children and immune-compromised patients has been reported. Therefore, this study aims to investigate the effects of NACs when co-cultured with S. mutans on cariogenic properties and virulence gene expression of S. mutans. The results showed that C. albicans and NACs, especially Candida tropicalis,  increased biofilm mass and cell viability of dual species biofilm, but did not increase acid production. For S. mutans gene expression, the genes related to exopolysaccharides synthesis (gtfBCD), sugar transportation (scrAB) and sugar utilization (pdhA and pfl) were up-regulated in dual species biofilm when co-culture with C. albicans, C. tropicalis and Candida krusei. In contrast, the expression levels of genes related to acid stress tolerance (atpD and fabM) in all dual-species biofilm were similar to S. mutans in single-species biofilm. In addition, the expression of genes involved in the signal transduction system (ciaRH) were upregulated in dual-species biofilms of S. mutans and C. albicans or NACs, except C. dubliniensis. In conclusion, the presence of NACs, especially C. tropicalis and C. krusei, could enhance cariogenic virulence factors of S. mutans similarly to C. albicans.
Removal of trace olefins from aromatics with modified USY zeolite and clays
Authors:   , Lertprapaporn Sirawit
Published: September 2023

Naphtha reforming is an important raw material for aromatic hydrocarbon products in petrochemical processes. However, aromatic hydrocarbon streams obtained from refinery contain unavoidable trace amounts of olefins as an impurity. The trace olefins must be removed because these undesirable olefins are harmful to the following separation processes. Alkylation reaction has been used to remove olefins with acid catalysts. In this study, clays and zeolites were screened for further modification in order to enhance the catalytic activity of olefins removal. The catalytic activity testing was studied in a batch reactor at 195 ℃ for 6 h under 12 barg. USY was modified by dealumination with 0.075 – 0.3 M citric acid, and bentonite was modified by acid activation with 1–6 M hydrochloric acid. The properties of catalysts were determined by XRD, XRF, N₂ adsorption, TPD-NH₃, and STA. The results showed that the modification of USY with 0.15 M citric acid increased the surface area and proportion of strong acid sites to total acid sites resulting in the increase in the initial and final olefins removal from 76 to 87% and 84 to 90%, respectively. Likewise, the modification of bentonite with 1 M hydrochloric acid increased the acidity leading to the increase in the initial and final olefins removal from 74 to 81% and 86 to 90%, respectively.