Switching Diffusions: Applications To Ecological Models, And Numerical Methods For Games In Insurance

Recently, a class of dynamic systems called ``hybrid systems containing both continuous dynamics and discrete events has been adapted to treat a wide variety of situations arising in many real-world situations. Motivated by such development, this dissertation is devoted to the study of dynamical systems involving a Markov chain as the randomly switching process. The systems studied include hybrid competitive Lotka-Volterra ecosystems and non-zero-sum stochastic differential games between two insurance companies with regime-switching. The first part is concerned with competitive Lotka-Volterra model with Markov switching. A novelty of the contribution is that the Markov chain has a countable state space. Our main objective is to reduce the computational complexity by using the two-time-scale formulation. Because the existence and uniqueness as well as continuity of solutions for Lotka-Volterra ecosystems with Markovian switching in which the switching takes place in a countable set are not available, such properties are studied first. The two-time scale feature is highlighted by introducing a small parameter into the generator of the Markov chain. When the small parameter goes to 0, there is a limit system or reduced system. It is established in this work that if the reduced system possesses certain properties such as permanence and extinction, etc., then the complex original system also has the same properties when the parameter is sufficiently small. These results are obtained by using the perturbed Lyapunov function methods. The second part develops an approximation procedure for a class of non-zero-sum stochastic differential games for investment and reinsurance between two insurance companies. Both proportional reinsurance and excess-of-loss reinsurance policies are considered. We develop numerical algorithms to obtain the approximation to the Nash equilibrium by adopting the Markov chain approximation methodology. We establish the convergence of the approximation sequences and the approximation to the value functions. Numerical examples are presented to illustrate the applicability of the algorithms

EFFECT OF ANION GROUPS ON CORROSION INHIBITION BEHAVIOURS OF VIETNAM ORANGE PEEL ESSENTIAL OIL FOR MILD STEEL IN THE ACIDIC MEDIA

This paper deals with the effect of anion groups (SO42- and Cl-) on inhibition behaviours of Vietnam orange peel essential oil (OPE) for corrosion process of mild steel in acidic media. The electrochemical techniques (potentiodynamic, electrochemical impedance spectroscopy (EIS)), weight loss and scanning electron microscopy (SEM) analyses are used in this study. The results show that anion groups do not affect the inhibition mechanism of OPE. The OPE ­behaves as mixed inhibitor for mild steel corrosion in both 1N HCl and H2SO4 acid. The inhibition efficiency of OPE in 1N HCl is greater than that in 1N H2SO4 which implies that the adsorption of the inhibitor is influenced by the nature of anions in acidic solutions. Moreover, the OPE inhibits both general and pitting corrosion for mild steel in the acidic media.

Russia’s Pivot to Asia and Russia-Vietnam Economic Relations in the Early 21st Century

Russia began to refocus its attention on the Asia-Pacific region in 1994, but the policy of pivoting toward Asia was implemented dramatically in the second decade of the 21st century. Adjustments made by Russia to its foreign policy and practical activities carried out by Russia in the region have impacted Russia-Vietnam relations generally and their economic ties in particular. Based on a qualitative approach and analysis of secondary data collected from previously conducted research works, this paper focuses on the following issues: (1) Adjustments made by Russia to its foreign policy towards Asia-Pacific over the first two decades of the 21st century; (2) Position of Vietnam in Russia’s foreign policy towards Asia–Pacific; and (3) Impacts of Russia’s new foreign policy on the economic ties between Russia and Vietnam over the first two decades of the 21st century. Based on the results of the analysis and evaluation, Russia's Asia-Pacific policy has been adjusted, particularly in the second decade of the 21stcentury, when the country turned its attention to Southeast Asia. Due to the importance of this region, Russia is implementing a comprehensive Asia policy and promoting Russia's interests in this region. The Russian Federation considers Vietnam an important partner in its "Look to the East" policy and plays a leading role because Vietnam is a country with an important geostrategic position to connect both land and sea between Northeast Asia and Southeast Asia. This is reflected in the Russian Federation's upgrading of its strategic partnership with Vietnam from 2001 to a comprehensive strategic partnership in 2012. The adjustment of the Asia-Pacific policy of the Russian Federation has positively affected the relationship between Vietnam and Russia in the economic fields (trade and investment). Doi: 10.28991/ESJ-2022-06-06-017 Full Text: PD

JAPANESE COINS AND BANKNOTES RECOGNITION FOR VISUALLY IMPAIRED PEOPLE

Recent deep learning techniques are successfully integrated into devices to assist visually impaired people in their daily lives, particularly detecting coins/banknotes. Previous works have focused on well captured devices and examined high-quality images. In this work, we design a framework to recognize Japanese Coin/Banknote (JCB) for low-quality images under various criteria. Discriminate features usually disappear in low-quality images. Consequently, using the depth image in addition to RGB image in processing can be enhanced the accuracy of our system. In this work, we first leverage depth information by using a Monocular Depth Prediction network. Additionally, a pre-trained Deep Convolutional Neural Network process RGB and Depth images, respectively. At last, we combine two networks by an ensemble method to produce more accurate detections. By processing depth images in addition to RGB images, the detection results are thus accurate. As a result, our work achieves 74.1% mean Average Precision (mAP)

Factor substitution in rice production function: the case of Vietnam

Vietnamese rice production has achieved remarkable success over the last couple of decades. This is due to land and market reforms, known as ‘Doi Moi’. There were noticeable changes in policies, such as land and production systems, which were transformed from a collective to an individual contract system in the 1980s. Vietnam made progress in rice production through the legalisation of the privatisation of farm properties and a huge investment in irrigation systems. The country not only ensured its domestic demand, but also started exporting rice and gradually became the second largest exporter in the world. An estimate of the Constant Elasticity of Substitution function (CES) for Vietnam’s rice production is essential for the government to design effective policy on agricultural production. This study makes the first attempt to estimate the nested CES model for Vietnamese rice production in 2012. The paper finds that the elasticity of substitution of Vietnam’s nested CES model lies between 0.44 and 0.46. The results indicate the weak substitutability between land and the capital-labour composite in the nested CES model. This also suggests that it is impossible to take labour as the substitutable factor for land and capital

The Value Chain of White Leg Shrimp Exported to the U.S Market: The Case of Khanh Hoa Province, Vietnam

Three years since 2008, white leg shrimp have exhibited fabulous growth rate and become a popular livestock along with black tiger shrimp and pangasius. This gives rise to the interest to investigate the value chain of frozen white leg shrimp exported to the U.S from Khanh Hoa Province, Vietnam. Research findings showed that before exported to the U.S, white leg shrimp undergo farming, procurement, and processing. Shrimp farming comprises of pond cleaning, seed release, and caring. As shrimp attain harvestable size, middlemen come to perform the procurement including harvesting, preserving, and transporting. At the processing plants, shrimp are transformed into final products, packed, labeled preserved and stored waiting to be exported. During farming, farmers incur costs like seed, feed, labor, and other miscellaneous expenses. At the procurement stage, addition to purchasing shrimp from farmers, middlemen add some other costs like transport, labor, ice, and other inputs to transfer shrimp to the next stage. At the processing stage, direct material, labor, overhead, and other costs are added in accordance with the accounting format. Farmers, middlemen and processors experience positive profit in the 2008-2010 period. Based on costs and earnings data, some calculations were made to reveal the distributions of revenue, cost and profit of 1 kg frozen shrimp exported to the U.S. Revenue and profits were distributed in sync with incurred costs. The research also revealed reasons why farmers depend on middlemen to sell their harvest, that is, lack of facilities, delayed payment policy and risk aversion.Keywords: Special Topics, Posters and Game Demonstration Session and Reception, Fisheries EconomicsKeywords: Special Topics, Posters and Game Demonstration Session and Reception, Fisheries Economic

FTIR Combined with Chemometrics for Fast Simultaneous Determination of Penicillin and Cephalexin in Pharmaceutical Tablets

In this research, the potential of combining chemometrics with FTIR techniques to provide a rapid and simultaneous quantitative analyses method for determination penicillin, cephalexin is studied. Unlike other methods, FTIR is considered as a time saving method due to its non-destructive and simple sample preparation. Due to the similarity of infrared spectral, PLS and PCR couples with spectral treatment techniques are applied to make the calibration model for penicillin and cephalexin determination at the same time. The result is also validated in term of RMSEP and R2 value using validation set. The FTIR combined with PLS method shows the best results

Impact of trained human resources, adoption of technology and international standards on the improvement of accounting and auditing activities in the agricultural sector in Viet Nam

Recently, the adoption of accounting and auditing standards in the agricultural sector has been a global phenomenon that has gained increasing trend due to the significant role of the agricultural industry in the country's economy. Thus, the present study examines the impact of trained human resources, technology adoption, and international standards on improving accounting and auditing activities in the agricultural sector in Vietnam. The present research investigates the moderating impact of agricultural, institutional support among the linkage of trained human resources, technology adoption, international standards, and improvement of accounting and auditing activities in the agricultural sector. The present article has adopted the questionnaires to gather the primary data from selected respondents. The current research has applied the smart-PLS to test the study's hypotheses. The results revealed that trained human resources, technology adoption, and international standards positively impact the improvement of accounting and auditing activities in the agricultural sector. The findings also indicated that the agricultural institutional support significantly moderates the linkage of trained human resources, technology adoption, international standards, and improved accounting and auditing activities in the agricultural sector.Nguyen Van Hoa (University of Kinh Bac (UKB)), Nguyen Thi Hanh Duyen (Vinh University), Vu Ngoc Huyen (Viet Nam National University of Agriculture (VNUA)), Hoang Vu Quang (Researcher at Institute of Policy and Strategy for Agriculture and Rural Development (IPSARD)), Nguyen Van Huong (Hung Yen University of Technology and Education (UTEHY)), Nguyen Thi Cam Tu (National Economics University (NEU)), Bui Thi Minh Nguyet (Vietnam National University of Forestry (VNUF))Includes bibliographical references