Search results for: Minh Trang Nguyen
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 318

Search results for: Minh Trang Nguyen

258 The Light-Effect in Cylindrical Quantum Wire with an Infinite Potential for the Case of Electrons: Optical Phonon Scattering

Authors: Hoang Van Ngoc, Nguyen Vu Nhan, Nguyen Quang Bau

Abstract:

The light-effect in cylindrical quantum wire with an infinite potential for the case of electrons, optical phonon scattering, is studied based on the quantum kinetic equation. The density of the direct current in a cylindrical quantum wire by a linearly polarized electromagnetic wave, a DC electric field, and an intense laser field is calculated. Analytic expressions for the density of the direct current are studied as a function of the frequency of the laser radiation field, the frequency of the linearly polarized electromagnetic wave, the temperature of system, and the size of quantum wire. The density of the direct current in cylindrical quantum wire with an infinite potential for the case of electrons – optical phonon scattering is nonlinearly dependent on the frequency of the linearly polarized electromagnetic wave. The analytic expressions are numerically evaluated and plotted for a specific quantum wire, GaAs/GaAsAl.

Keywords: the light–effect, cylindrical quantum wire with an infinite potential, the density of the direct current, electrons-optical phonon scattering

Procedia PDF Downloads 307
257 Information on Financial Statements for Loan Decision-Making of Commercial Banks in Vietnam

Authors: Mai Hoang Minh

Abstract:

Financial statements (FS) are tools which provide information to users for making business decisions. This article is going to present the survey which clarifies the role of financial statement to Commercial Banks’ loan decisions in Vietnam. Moreover, this also discusses about financial statement’s quality currently, thereby making suggestions for enterprises to enhance the usefulness of accounting information in borrowing activities.

Keywords: usefulness of financial statement, accounting information quality, loan decisions

Procedia PDF Downloads 247
256 Study of the Antimicrobial Activity of Aminoreductone against Pathogenic Bacteria in Comparison with Other Antibiotics

Authors: Vu Thu Trang, Lam Xuan Thanh, Samira Sarter, Tomoko Shimamura, Hiroaki Takeuchi  

Abstract:

Antimicrobial activities of aminoreductone (AR), a product formed in the initial stage of Maillard reaction, were screened against pathogenic bacteria. A significant growth inhibition of AR against all 7 isolates (Staphylococcus aureus ATCC® 25923™, Salmonella Typhimurium ATCC® 14028™, Bacillus cereus ATCC® 13061™, Bacillus subtilis ATCC® 11774™, Escherichia coli ATCC® 25922™, Enterococcus faecalis ATCC® 29212™, Listeria innocua ATCC® 33090™) were observed by the standard disc diffusion methods. The inhibition zone for each isolate by AR (2.5 mg) ranged from 15±0 mm to 28.3±0.4 mm in diameter. The minimum inhibitory concentration (MIC) of AR ranging from 20 mM to 26 mM was proven in the seven isolates tested. AR also showed the similar effect of growth inhibition in comparison with antibiotics frequently used for the treatment of infections bacteria, such as amikacin, ciprofloxacin, meropennem, and levofloxacin. The results indicated that foods containing AR are valuable sources of bioactive compounds towards pathogenic bacteria.

Keywords: pathogenic bacteria, aminoreductone, Maillard reaction, antimicrobial activity

Procedia PDF Downloads 349
255 Blind Speech Separation Using SRP-PHAT Localization and Optimal Beamformer in Two-Speaker Environments

Authors: Hai Quang Hong Dam, Hai Ho, Minh Hoang Le Ngo

Abstract:

This paper investigates the problem of blind speech separation from the speech mixture of two speakers. A voice activity detector employing the Steered Response Power - Phase Transform (SRP-PHAT) is presented for detecting the activity information of speech sources and then the desired speech signals are extracted from the speech mixture by using an optimal beamformer. For evaluation, the algorithm effectiveness, a simulation using real speech recordings had been performed in a double-talk situation where two speakers are active all the time. Evaluations show that the proposed blind speech separation algorithm offers a good interference suppression level whilst maintaining a low distortion level of the desired signal.

Keywords: blind speech separation, voice activity detector, SRP-PHAT, optimal beamformer

Procedia PDF Downloads 253
254 Using Deep Learning Neural Networks and Candlestick Chart Representation to Predict Stock Market

Authors: Rosdyana Mangir Irawan Kusuma, Wei-Chun Kao, Ho-Thi Trang, Yu-Yen Ou, Kai-Lung Hua

Abstract:

Stock market prediction is still a challenging problem because there are many factors that affect the stock market price such as company news and performance, industry performance, investor sentiment, social media sentiment, and economic factors. This work explores the predictability in the stock market using deep convolutional network and candlestick charts. The outcome is utilized to design a decision support framework that can be used by traders to provide suggested indications of future stock price direction. We perform this work using various types of neural networks like convolutional neural network, residual network and visual geometry group network. From stock market historical data, we converted it to candlestick charts. Finally, these candlestick charts will be feed as input for training a convolutional neural network model. This convolutional neural network model will help us to analyze the patterns inside the candlestick chart and predict the future movements of the stock market. The effectiveness of our method is evaluated in stock market prediction with promising results; 92.2% and 92.1 % accuracy for Taiwan and Indonesian stock market dataset respectively.

Keywords: candlestick chart, deep learning, neural network, stock market prediction

Procedia PDF Downloads 402
253 Evaluation of E-Government Service Quality

Authors: Nguyen Manh Hien

Abstract:

Service quality is the highest requirement from users, especially for the service in electronic government. During the past decades, it has become a major area of academic investigation. Considering this issue, there are many researches that evaluated the dimensions and e-service contexts. This study also identified the dimensions of service quality but focused on a new conceptual and provides a new methodological in developing measurement scales of e-service quality such as information quality, service quality and organization quality. Finally, the study will suggest a key factor to evaluate e-government service quality better.

Keywords: dimensionality, e-government, e-service, e-service quality

Procedia PDF Downloads 502
252 Directional Ground Improvement Technique for Urban Tunnel Projects in Vietnam

Authors: Le Quang Hanh

Abstract:

Almost all big cities in Vietnam are often located in the river deltas. Therefore the ground condition on these cities is mostly soft soil. As a result, the soil strengthen works are mandatory in order to prevent the harmful to the third parties and tunnel structure itself in urban tunnel projects in Vietnam. This paper will particularly introduce the large diameter jet-grouted column technique that is recently being successfully applied in Ho Chi Minh City in Vietnam. The success application of this technique for protecting the historical sensitive building and for water cutoff objective of launching and arriving shafts in the urban tunnel project, will be analyzed from construction process, quality control and lessons learnt. From this situation, the large diameter jet-grouted column technique can extend to another urban tunnel projects in Vietnam and other countries which have similar soft soil conditions.

Keywords: large diameter, jet grouting, ground improvement, urban tunnel

Procedia PDF Downloads 182
251 Failure Analysis Using Rtds for a Power System Equipped with Thyristor-Controlled Series Capacitor in Korea

Authors: Chur Hee Lee, Jae in Lee, Minh Chau Diah, Jong Su Yoon, Seung Wan Kim

Abstract:

This paper deals with Real Time Digital Simulator (RTDS) analysis about effects of transmission lines failure in power system equipped with Thyristor Controlled Series Capacitance (TCSC) in Korea. The TCSC is firstly applied in Korea to compensate real power in case of 765 kV line faults. Therefore, It is important to analyze with TCSC replica using RTDS. In this test, all systems in Korea, other than those near TCSC, were abbreviated to Thevenin equivalent. The replica was tested in the case of a line failure near the TCSC, a generator failure, and a 765-kV line failure. The effects of conventional operated STATCOM, SVC and TCSC were also analyzed. The test results will be used for the actual TCSC operational impact analysis.

Keywords: failure analysis, power system, RTDS, TCSC

Procedia PDF Downloads 92
250 A Review of End-of-Term Oral Tests for English-Majored Students of HCMC Open University

Authors: Khoa K. Doan

Abstract:

Assessment plays an essential role in teaching and learning English as it aims to measure the learning outcomes. Designing appropriate test types and procedures for four skills, especially productive skills, is a very challenging task for teachers of English. The assessment scheme is supposed to provide precise measures and fair opportunities for students to demonstrate what they can do with their language skills. This involves content domains, measurement techniques, administrative feasibility, target populations, and potential sources of testing bias. Based on these elements, a review of end-of-term speaking tests for English-majored students at Ho Chi Minh City Open University (Viet Nam) was undertaken for the purpose of analyzing the strengths and limitations of the testing tool for the speaking assessment. It helped to identify what could be done to facilitate the process of teaching and learning in that context.

Keywords: assessment, oral tests, speaking, testing

Procedia PDF Downloads 291
249 A Comparative Study of the Modeling and Quality Control of the Propylene-Propane Classical Distillation and Distillation Column with Heat Pump

Authors: C. Patrascioiu, Cao Minh Ahn

Abstract:

The paper presents the research evolution in the propylene – propane distillation process, especially for the distillation columns equipped with heat pump. The paper is structured in three parts: separation of the propylene-propane mixture, steady state process modeling, and quality control systems. The first part is dedicated to state of art of the two distillation processes. The second part continues the author’s researches of the steady state process modeling. There has been elaborated a software simulation instrument that may be used to dynamic simulation of the process and to design the quality control systems. The last part presents the research of the control systems, especially for quality control systems.

Keywords: absorption, distillation, heat pump, Unisim design

Procedia PDF Downloads 307
248 Persistent Homology of Convection Cycles in Network Flows

Authors: Minh Quang Le, Dane Taylor

Abstract:

Convection is a well-studied topic in fluid dynamics, yet it is less understood in the context of networks flows. Here, we incorporate techniques from topological data analysis (namely, persistent homology) to automate the detection and characterization of convective/cyclic/chiral flows over networks, particularly those that arise for irreversible Markov chains (MCs). As two applications, we study convection cycles arising under the PageRank algorithm, and we investigate chiral edges flows for a stochastic model of a bi-monomer's configuration dynamics. Our experiments highlight how system parameters---e.g., the teleportation rate for PageRank and the transition rates of external and internal state changes for a monomer---can act as homology regularizers of convection, which we summarize with persistence barcodes and homological bifurcation diagrams. Our approach establishes a new connection between the study of convection cycles and homology, the branch of mathematics that formally studies cycles, which has diverse potential applications throughout the sciences and engineering.

Keywords: homology, persistent homolgy, markov chains, convection cycles, filtration

Procedia PDF Downloads 103
247 Improving the Supply Chain of Vietnamese Coffee in Buon Me Thuot City, Daklak Province, Vietnam to Achieve Sustainability

Authors: Giang Ngo Tinh Nguyen

Abstract:

Agriculture plays an important role in the economy of Vietnam and coffee is one of most crucial agricultural commodities for exporting but the current farming methods and processing infrastructure could not keep up with the development of the sector. There are many catastrophic impacts on the environment such as deforestation; soil degradation that leads to a decrease in the quality of coffee beans. Therefore, improving supply chain to develop the cultivation of sustainable coffee is one of the most important strategies to boost the coffee industry and create a competitive advantage for Vietnamese coffee in the worldwide market. If all stakeholders in the supply chain network unite together; the sustainable production of coffee will be scaled up and the future of coffee industry will be firmly secured. Buon Ma Thuot city, Dak Lak province is the principal growing region for Vietnamese coffee which accounted for a third of total coffee area in Vietnam. It plays a strategically crucial role in the development of sustainable Vietnamese coffee. Thus, the research is to improve the supply chain of sustainable Vietnamese coffee production in Buon Ma Thuot city, Dak Lak province, Vietnam for the purpose of increasing the yields and export availability as well as helping coffee farmers to be more flexible in an ever-changing market situation. It will help to affirm Vietnamese coffee brand when entering international market; improve the livelihood of farmers and conserve the environment of this area. Besides, after analyzing the data, a logistic regression model is established to explain the relationship between the dependent variable and independent variables to help sustainable coffee organizations forecast the probability of farmer will be having a sustainable certificate with their current situation and help them choose promising candidates to develop sustainable programs. It investigates opinions of local farmers through quantitative surveys. Qualitative interviews are also used to interview local collectors and staff of Trung Nguyen manufacturing company to have an overview of the situation.

Keywords: supply chain management, sustainable agricultural development, sustainable coffee, Vietnamese coffee

Procedia PDF Downloads 419
246 Taxonomic Classification for Living Organisms Using Convolutional Neural Networks

Authors: Saed Khawaldeh, Mohamed Elsharnouby, Alaa Eddin Alchalabi, Usama Pervaiz, Tajwar Aleef, Vu Hoang Minh

Abstract:

Taxonomic classification has a wide-range of applications such as finding out more about the evolutionary history of organisms that can be done by making a comparison between species living now and species that lived in the past. This comparison can be made using different kinds of extracted species’ data which include DNA sequences. Compared to the estimated number of the organisms that nature harbours, humanity does not have a thorough comprehension of which specific species they all belong to, in spite of the significant development of science and scientific knowledge over many years. One of the methods that can be applied to extract information out of the study of organisms in this regard is to use the DNA sequence of a living organism as a marker, thus making it available to classify it into a taxonomy. The classification of living organisms can be done in many machine learning techniques including Neural Networks (NNs). In this study, DNA sequences classification is performed using Convolutional Neural Networks (CNNs) which is a special type of NNs.

Keywords: deep networks, convolutional neural networks, taxonomic classification, DNA sequences classification

Procedia PDF Downloads 404
245 Modelling Dengue Disease With Climate Variables Using Geospatial Data For Mekong River Delta Region of Vietnam

Authors: Thi Thanh Nga Pham, Damien Philippon, Alexis Drogoul, Thi Thu Thuy Nguyen, Tien Cong Nguyen

Abstract:

Mekong River Delta region of Vietnam is recognized as one of the most vulnerable to climate change due to flooding and seawater rise and therefore an increased burden of climate change-related diseases. Changes in temperature and precipitation are likely to alter the incidence and distribution of vector-borne diseases such as dengue fever. In this region, the peak of the dengue epidemic period is around July to September during the rainy season. It is believed that climate is an important factor for dengue transmission. This study aims to enhance the capacity of dengue prediction by the relationship of dengue incidences with climate and environmental variables for Mekong River Delta of Vietnam during 2005-2015. Mathematical models for vector-host infectious disease, including larva, mosquito, and human being were used to calculate the impacts of climate to the dengue transmission with incorporating geospatial data for model input. Monthly dengue incidence data were collected at provincial level. Precipitation data were extracted from satellite observations of GSMaP (Global Satellite Mapping of Precipitation), land surface temperature and land cover data were from MODIS. The value of seasonal reproduction number was estimated to evaluate the potential, severity and persistence of dengue infection, while the final infected number was derived to check the outbreak of dengue. The result shows that the dengue infection depends on the seasonal variation of climate variables with the peak during the rainy season and predicted dengue incidence follows well with this dynamic for the whole studied region. However, the highest outbreak of 2007 dengue was not captured by the model reflecting nonlinear dependences of transmission on climate. Other possible effects will be discussed to address the limitation of the model. This suggested the need of considering of both climate variables and another variability across temporal and spatial scales.

Keywords: infectious disease, dengue, geospatial data, climate

Procedia PDF Downloads 347
244 Instruct Students Effective Ways to Reach an Advanced Level after Graduation

Authors: Huynh Tan Hoi

Abstract:

Considered as one of the hardest languages in the world, Japanese is still the language that many young people choose to learn. Today, with the development of technology, learning foreign languages in general and Japanese language, in particular, is not an impossible barrier. Learning materials are not only from paper books, songs but also through software programs of smartphones or computers. Especially, students who begin to explore effective skills to study this language need to access modern technologies to improve their learning much better. When using the software, some students may feel embarrassed and challenged, but everything would go smoothly after a few days. After completing the course, students will get more knowledge, achieve a higher knowledge such as N2 or N1 Japanese Language Proficiency Test Certificate. In this research paper, 35 students who are studying at Ho Chi Minh City FPT University were asked to complete the questionnaire at the beginning of July up to August of 2018. Through this research, we realize that with the guidance of lecturers, the necessity of using modern software and some effective methods are indispensable in term of improving quality of teaching and learning process.

Keywords: higher knowledge, Japanese, methods, software, students

Procedia PDF Downloads 192
243 Trions in Semiconductor Quantum Dot System

Authors: Jayden Leonard, Nguyen Que Huong

Abstract:

In this work, we study the Trion state in a spherical quantum dot of a direct band gap semiconductor with a shell of organic material. The electronic structure of the Trion due to degenerate valence band will be considered. The coupling between the wannier exciton inside the dot and the Frenkel exciton in the shell will make the Trion state become hybrid. The competition between “semiconductor” and “organic” phases of the Trion and the transitions between them depend on Parameters of the system such as the materials, the size of the dot and the thickness of the shell, etc… and could be manipulated using those parameters.

Keywords: trion, exciton, quantum dot, heterostructure

Procedia PDF Downloads 147
242 Co-integration for Soft Commodities with Non-Constant Volatility

Authors: E. Channol, O. Collet, N. Kostyuchyk, T. Mesbah, Quoc Hoang Long Nguyen

Abstract:

In this paper, a pricing model is proposed for co-integrated commodities extending Larsson model. The futures formulae have been derived and tests have been performed with non-constant volatility. The model has been applied to energy commodities (gas, CO2, energy) and soft commodities (corn, wheat). Results show that non-constant volatility leads to more accurate short term prices, which provides better evaluation of value-at-risk and more generally improve the risk management.

Keywords: co-integration, soft commodities, risk management, value-at-risk

Procedia PDF Downloads 524
241 Induction of Innovation (Districts) in (Spatial) Planning and Policy

Authors: Meera Prajapati

Abstract:

Technological innovation is important for economic and spatial rejuvenation. Innovation districts from the last decades around university towns offer interesting examples. Planning directs the interplay between economic and urban development in these innovation districts that appear in particular regions with economic benefits as a result of incentives to attract multinational industries in innovation centres, research parks, universities, bio incubator assets, etc. The inclination of the OECED towards developing entrepreneurship and innovation to harness a boost in growth requires sustainable living conditions. This research aims to understand ‘how innovation or knowledge centres affected development policies and helped cities to become a high-tech region?’ Therefore, the economic policies of cities are investigated as well as the location logic of centres and their intertwining with supporting services (health, education, living environment, etc.). Case studies (Eindhoven (The Netherlands) and Ho Chi Minh City (Viet Nam)) position Pune (India) in terms of the planning components of innovation.

Keywords: innovation districts, high-tech regions, smart cities, urban planning and policies

Procedia PDF Downloads 116
240 Existential Feeling in Contemporary Chinese Novels: The Case of Yan Lianke

Authors: Thuy Hanh Nguyen Thi

Abstract:

Since 1940, existentialism has penetrated into China and continued to profoundly influence contemporary Chinese literature. By the method of deep reading and text analysis, this article analyzes the existential feeling in Yan Lianke’s novels through various aspects: the Sisyphus senses, the narrative rationalization and the viewpoint of the dead. In addition to pointing out the characteristics of the existential sensation in the writer’s novels, the analysis of the article also provides an insight into the nature and depth of contemporary Chinese society.

Keywords: Yan Lianke, existentialism, the existential feeling, contemporary Chinese literature

Procedia PDF Downloads 115
239 The Effect of Computer-Based Formative Assessment on Learning Outcome

Authors: Van Thien NGO

Abstract:

The purpose of the study is to examine the effect of student response systems in computer-based formative assessment on learning outcomes. The backward design course is a tool to be applied for collecting necessary assessment evidence. The quasi-experimental research design involves collecting pre and posttest data on students assigned to the control group and the experimental group. The sample group consists of 150 college students randomly selected from two of the eight classes of electrical and electronics students at Cao Thang Technical College in Ho Chi Minh City, Vietnam. Findings from this research revealed that the experimental group, in which student response systems were applied, got better results than the controlled group, who did not apply them. Results show that using student response systems for technology-based formative assessment is vital and meaningful not only for teachers but also for students in the teaching and learning process.

Keywords: student response system, computer-based formative assessment, learning outcome, backward design course

Procedia PDF Downloads 107
238 The Interrelationship between Formal and Informal Institutions and Its Impacts on the Autonomy of Public Service Delivery Units: The Case of Vietnam

Authors: Minh Thi Hai Vo

Abstract:

This article draws on in-depth interviews with state employees at public hospitals and universities in its institutional analysis of the autonomy practices of public service delivery units in Vietnam. Unlike many empirical and theoretical studies that view formal and informal institutions as complements or substitutes, this article finds no evidence of complementary or substitutive relationships. Instead, the article finds that formal institutions accommodate informal ones and that informal institutions tend to compete and interfere, with the existing and ineffective formal institutions. The result of such conflicting relationship is that the actual autonomy of public service delivery units is, in most cases, perceived to be greater than the formal autonomy they are given. In the condition of poor regulation, the informal autonomy may result in unethical practices including rent-seeking and corruption. The implication of the study finding is policy-makers need to redesign and reorganize the autonomisation of public service delivery units to make informal institutions support and reinforce formal ones in a complementary manner.

Keywords: autonomy, formal institutions, informal institutions, public service delivery units, Vietnam

Procedia PDF Downloads 174
237 Framework for Improving Manufacturing "Implicit Competitiveness" by Enhancing Monozukuri Capability

Authors: Takahiro Togawa, Nguyen Huu Phuc, Shigeyuki Haruyama, Oke Oktavianty

Abstract:

Our research focuses on a framework which analyses the relationship between product/process architecture, manufacturing organizational capability and manufacturing "implicit competitiveness" in order to improve manufacturing implicit competitiveness. We found that 1) there is a relationship between architecture-based manufacturing organizational capability and manufacturing implicit competitiveness, and 2) analysis and measures conducted in manufacturing organizational capability proved effective to improve manufacturing implicit competitiveness.

Keywords: implicit competitiveness, QCD, organizational capacity, architectural strategy

Procedia PDF Downloads 262
236 Study on Clarification of the Core Technology in a Monozukuri Company

Authors: Nishiyama Toshiaki, Tadayuki Kyountani, Nguyen Huu Phuc, Shigeyuki Haruyama, Oke Oktavianty

Abstract:

It is important to clarify the company’s core technology in product development process to strengthen their power in providing technology that meets the customer requirement. QFD method is adopted to clarify the core technology through identifying the high element technologies that are related to the voice of customer, and offer the most delightful features for customer. AHP is used to determine the importance of evaluating factors. A case study was conducted by using this approach in Japan’s Monozukuri Company (so called manufacturing company) to clarify their core technology based on customer requirements.

Keywords: core technology, QFD, voices of customer, analysis procedure

Procedia PDF Downloads 355
235 Modern Saigon Drag Queen Show: Voice of the Trans Vietnamese for Gender Equality

Authors: Ly Quyet Tien

Abstract:

Starting in the 1990s and growing in tandem with the LGBTQI movement in Vietnam, Modern Saigon Lottery Show is one of the most popular Vietnamese drag queen shows in Ho Chi Minh City, Vietnam. Transgender by nature, underprivileged by status, avoided by the family, and despised by society for decades, these queer artists came out of the closet and decided to change their own destiny by organizing lottery music shows. Unprofessionally in the start, they gradually appeared professionally on stage in big cities and won the heart of the larger public. Their success affirms themself, promotes their gender right, and assures their life in a proud way: honest, independent, and sustainable. This paper aims to give the readers a full portrait of Modern Saigon’s activities through musical bingo. It examines the background into which the drag queen show was born and developed: its styles, themes as well as own particularity. It also studies its identity, diversity in the entertainment industry, and its revolutionary role in the promotion of the welfare of Vietnamese transgender citizens and the local popular queer culture in Vietnam and Asia.

Keywords: transgender, lottery show, equality, culture

Procedia PDF Downloads 71
234 Numerical Simulation for Self-Loosening Phenomenon Analysis of Bolt Joint under Vibration

Authors: Long Kim Vu, Ban Dang Nguyen

Abstract:

In this paper, the finite element method (FEM) is utilized to simulate the comprehensive process including tightening, releasing and self-loosening of a bolt joint under transverse vibration. Following to the accurate geometry of helical threads, an absolutely hexahedral meshing is implemented. The accuracy of simulation process is verified and validated by comparison with the experimental results on clamping force-vibration relationship, which shows the sufficient correlation. Further analysis with different amplitude and frequency of transverse vibration is done to determine the dominant factor inducing the failure.

Keywords: bolt self-loosening, contact state, finite element method, FEM, helical thread modeling

Procedia PDF Downloads 173
233 Effects of Rice Plant Extracts and Phenolic Allelochemicals on Seedling Growth of Radish

Authors: Mohammad Shamim Hasan Mandal, Phu Minh, Do Tan Khang, Phung Thi Tuyen, Tran Dang Xuan

Abstract:

Rice (Oryza sativa L.) is one of the major crops of Vietnam which has more than thousands of varieties. Many of the local varieties have greater potentiality but they are in danger of extinct. Rice plant contains many secondary metabolites that are allelopathic to other plants. Seven rice varieties were cultivated in the field condition at Hiroshima University, Japan; stems and leaves from each variety were collected later, they were extracted with methanol, hexane, ethyl acetate, butanol, and water. Total phenolic content and total flavonoid contents were high in ethyl acetate extracts. DPPH antioxidant assay results showed that the ethyl acetate extracts had the higher IC50 value. Therefore, the ethyl acetate extracts were selected for laboratory experimentation through petri dish assay. Results showed that the two-local variety Re nuoc and Nan chon completely inhibited the germination of radish seedlings. Further laboratory bioassay and field experimentation will be conducted to validate the laboratory bioassay findings.

Keywords: allelopathy, bioassay, Oryza sativa, Raphanus sativus

Procedia PDF Downloads 323
232 Application of 1-MCP on ‘Centro’ Melon at Different Days after Harvest

Authors: L. P. L. Nguyen, G. Hitka, T. Zsom, Z. Kókai

Abstract:

This study is aimed to investigate the influence of postharvest delays of 1-Methylcyclopropene (1-MCP) treatment on prolonging the storage potential of melon. Melons were treated with 625-650 ppb 1-MCP at 10 °C for 24 hours on the 1st, 3rd and 5th day after harvest. Decreased ethylene production and retarded softening of melon fruits after 7 days of storage at 10 °C plus 3 days of shelflife were obtained by 1-MCP applications. 1-MCP strongly affected the chlorophyll fluorescence characteristics and hue angle values of melon. After shelf-life, the peel color of treated melon was slow in turning to yellow compared to the control. Additionally, firmness of melons treated on the first day after harvest was 38% higher than that of the control fruit. Results showed that fruits treated on the 1st and the 3rd day after harvest could maintain the quality of melon.

Keywords: 1-MCP, muskmelon, storage, treatment.

Procedia PDF Downloads 203
231 Age and Population Structure of the Goby Parapocryptes Serperaster in the Mekong Delta, Vietnam, Based on Length-Frequency and Otolith Analyses

Authors: Quang Minh Dinh, Jian Guang Qin, Sabine Dittmann, Dinh Dac Tran

Abstract:

The age and population structure the dermal gopy Parapocryptes serperaster were studied using length distributions, otolith and von Bertalanffy model in the Mekong Delta over a whole year through monthly sampling. The sex ratio of P. serperaster was near 1:1, and von Bertalanffy growth parameters were L∞= 25.2 cm, K = 0.74 yr-1, and t0 = -0.22 yr-1. Fish size at first entry to fishery was 14.6 cm, and fishing mortality (1.57 yr-1) and natural mortality (1.51 yr-1) accounted for 51% and 49% of the total mortality (3.07 yr-1), respectively. Relative yield-per-recruit and biomass-per-recruit analyses revealed the levels of maximum exploitation yield (Emax = 0.83), maximum economic yield (E0.1 = 0.71) and the yield at 50% reduction of exploitation (E0.5 = 0.37). Otoliths from 164 female and 196 male gobies were readable, and the otolith morphometry data were used for age identification. The mean age estimated by reading otolith annual rings and by analysing length frequency distribution was consistent. This study shows that the otolith morphometry is a reliable method for aging this goby and possibly also applicable for other tropical gobies. The fishery analysis indicates that this goby stock has not been overexploited in the Mekong Delta.

Keywords: Parapcryptes serperaster, otolith, age, pulation structure, Vietnam

Procedia PDF Downloads 618
230 Factors Influencing the Voluntary Disclosure of Vietnamese Listed Companies

Authors: Pham Duc Hieu, Do Thi Huong Lan

Abstract:

The aim of this paper is to investigate the factors affecting the extent of voluntary disclosure by examining the annual reports of 205 industrial and manufacturing companies listing on Ho Chi Minh Stock Exchange (HSX) and Hanoi Stock Exchange (HNX) for the year end of 2012. Those factors include company size, profitability, leverage, state ownership, managerial ownership, and foreign ownership, board independence, role duality and type of external auditors. Evidence from this study suggests two main findings. (1) Companies with high foreign ownership have a high level of voluntary disclosure. (2) The company size is an important factor related to the increased level of voluntary disclosure in annual reports made by Vietnamese listed companies. The larger the company, the higher the information is disclosed. However, no significant associations are found between profitability, leverage, state ownership, managerial ownership, board independence, role duality and type of external auditors as hypothesized in this study.

Keywords: voluntary disclosure, Vietnamese listed companies, voluntary, duality

Procedia PDF Downloads 383
229 The Effects of Subsidised Irrigation Service Fees on Irrigation Performance in Vietnam

Authors: Trang Pham

Abstract:

Approximately 70% of the Vietnamese population lives in rural areas where the main livelihood is farming. For many years, the Vietnamese Government has been working towards improving farmers’ quality of life. In 2008, the Government issued the decree 115/2008/ND-CP to subsidize farmers’ water fees. The subsidy covers operation and management costs of major water infrastructure. Water users have only to pay for the operation and management of minor or tertiary canal systems. But the “subsidized water fee” has become contentious; there are two opposing schools of thought. One view is that the subsidy lessens the burden on farmers in terms of reducing their production costs, at the same time generating a sufficient budget for Irrigation Management Companies (IMCs) and Water User Association (WUAs). The alternate point of view is that the subsidy negatively effects irrigation performance, especially in tertiary canals. The aim of this study was to gain clear awareness of the perceptions of farmers, WUA members, and IMC staffs in regard to irrigation performance and management since the introduction of subsidies and local water fees. In order to find out how the government intervention has affected local farming communities, a series of questionnaires and interviews were administered in 2013. Four case studies were chosen which represent four different agricultural areas and four different irrigation systems in Vietnam. Interviews were conducted with IMC staffs and WUA members and questionnaires were used to gather information from farmers. The study compares the difference in operation and management costs across the four case studies both before and after the implementation of the decree. The results disclose factors behind the subsidized water fee that either allow or hinder improved irrigation performance and better irrigation management.

Keywords: water fee, irrigation performance, local farming, tertiary canal systems

Procedia PDF Downloads 285