Predicting freshwater habitat conditions by the distribution of macroinvertebrates using artificial neural network

Artificial Neural Networks were used to model the relationship between habitat conditions and macroinvertebrate assemblages in the Queensland river and stream system. The clean water approach was used to determine the relationship between presence and absence of macroinvertebrate taxa and physical predictor variables, studying data from reference sites in near pristine conditions. Trained models were applied to assess habitat conditions of impacted and test sites. The dirty water approach studied interrelationships between physical, chemical and biological processes. Sensitivity analyses were carried out by manipulating the values of input parameters and assessing the resulting changes in outputs. Artificial Neural Networks proved an effective computational approach to support bioassessment.Thesis (M.App.Sc.) -- University of Adelaide, Dept. of Soil and Water, 200

Bivariate modelling of precipitation and temperature using a non-homogeneous hidden Markov model

Aiming to generate realistic synthetic times series of the bivariate process of daily mean temperature and precipitations, we introduce a non-homogeneous hidden Markov model. The non-homogeneity lies in periodic transition probabilities between the hidden states, and time-dependent emission distributions. This enables the model to account for the non-stationary behaviour of weather variables. By carefully choosing the emission distributions, it is also possible to model the dependance structure between the two variables. The model is applied to several weather stations in Europe with various climates, and we show that it is able to simulate realistic bivariate time series

THE IMPACT OF DATA SECURITY ON THE INTENTION OF VIETNAMESE CONSUMERS TO USE E-WALLETS

E-wallets are used as a form of payment that brings many benefits to users. This article studies the impact of data security on consumer intentions to use e-wallets in the rapidly growing economy of Vietnam. The data consist of 236 observations from a survey of consumers in Vietnam. Covariance-based structural equation modeling (CB-SEM) was employed to test the proposed hypotheses. Research results show that security trust has the greatest impact on the intention to use e-wallets, followed by perceived privacy risk, social influence, and information sensitivity. The study also reveals the role of privacy policies and security concerns in consumer intentions to use e-wallets. Based on the research results, the study provides recommendations for consumers, e-wallet providers, and governmental agencies to increase awareness of and responsibility for information security among the consumers who use e-wallets

Stakeholder Involvement and the Attainment of SDGs at Local Tourism Destinations: A Case Study in Vietnam

This paper explores how the United Nations Sustainable Development Goals (SDGs) can be achieved at local tourism destinations through the collective efforts of stakeholders. A multiple-case study is conducted at Da Nang and Hue in Vietnam. These destinations experience a controversial concern between tourism development and natural/cultural preservation. A thematic analysis of qualitative data reveals the cooperation of various stakeholders to prevent the encroachment of tourism development in the natural environment in Da Nang or balance heritage preservation and tourism development in Hue. These collective efforts facilitate the achievement of the seventeen Sustainable Development Goal to attain various SDGs in each case. This research contributes to sustainability research by revealing the contribution and effects of collective actions in achieving the common goals related to the sustainable development of local destinations

Theoretical basis for reasonable population distribution in Tho Chu archipelago

Tho Chu archipelago is one of administrative units of Kien Giang province, Hon Nhan- one of its islands - is selected to become A1 base point of baseline for Vietnam territorial waters. If Tho Chau district is established, it will contribute to identifying sovereignty of Vietnam Southwest sea area following the United Nations Convention on the Law of the Sea, creating favourable conditions for islands’ socio-economic development, developing culture, enhancing effects of administration work and life quality of population in this island, firmly protecting sea border, securing island and sea sovereignty… However, the establishment of Tho Chu district appears in the context of streamlining administrative apparatus and limitation of capital for infrastructure construction in district level. This article focuses on the analysis of some factors affecting a reasonable population distribution in order to meet the requirement of building the Tho Chu into a district-level administrative unit in Kien Giang province

Do Parents Choose the Sex of their Children? Evidence from Vietnam

The paper finds imbalance of sex ratio at birth and analyzes some possible determinants on sex ratio at birth in Viet Nam by using the Vietnam Population Census 2009. This paper concentrates to analyze the parental interference of child sex. Although the magnitude of correlation between the parental characteristics and the gender of children is not high, this correlation is statistically significant. The result of this paper concludes that gender of the firstborn, birth order, ethnicity of parents, the age of parents as well as their education level are associated with the sex of children. More specifically, having the firstborn boy reduces the probability of having boys in the next birth. Children with higher birth order are more likely to be male. It implies that parents follow male-preferring stopping rule. Several households are more likely to have children until they get a boy. Kinh parents with higher education are more likely to have boys than ethnic minority parents with lower education

Do Parents Choose the Sex of their Children? Evidence from Vietnam

The paper finds imbalance of sex ratio at birth and analyzes some possible determinants on sex ratio at birth in Viet Nam by using the Vietnam Population Census 2009. This paper concentrates to analyze the parental interference of child sex. Although the magnitude of correlation between the parental characteristics and the gender of children is not high, this correlation is statistically significant. The result of this paper concludes that gender of the firstborn, birth order, ethnicity of parents, the age of parents as well as their education level are associated with the sex of children. More specifically, having the firstborn boy reduces the probability of having boys in the next birth. Children with higher birth order are more likely to be male. It implies that parents follow male-preferring stopping rule. Several households are more likely to have children until they get a boy. Kinh parents with higher education are more likely to have boys than ethnic minority parents with lower education

Application of hybrid control algorithm for the vehicle active suspension system to reduce the vibration

This research proposes a hybrid control algorithm to enhance smoothness in a vehicle’s motion. The control signal is synthesized from two separate controllers, Proportional Integral Derivative (PID) and Sliding Mode Control (SMC), to achieve superior control performance. The novelty of the proposed control algorithm lies in using a double-loop algorithm to determine the controller parameters. The algorithm proposed in this research involves two computational processes to determine the model's optimal values including the raw value and the acceptable value. The proposed control algorithm has been simulated considering three specific cases corresponding to the three types of road stimuli. The results demonstrate that the values of sprung mass displacement and acceleration dropped considerably with the application of the proposed algorithm. Moreover, the change in vertical force at the wheel is also reduced with the application of the algorithm particularly in the third case where the vertical force at the wheel has reached to zero. The average values of vehicle body displacement are found to be 166.17mm (for passive case), 54.20mm (for PID) and 42.52mm (for SMC). The proposed control algorithm managed to reduce this value to 8.95mm as evidenced by simulation results. Finally, the response of the control system when subjected to an excitation signal from the road surface further demonstrates efficacy of the proposed hybrid control algorithm

MACRO-ZOOPLANKTON ABUNDANCE IN RELATION TO METAL ACCUMULATION AND WATER QUALITY IN TRUC BACH LAKE

Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in Truc Bach lake and levels of two essential metals: copper (Cu), and zinc (Zn) and of three non-essential metals: arsenic (As), and lead (Pb) in water samples were determined. The results showed that Cladocerans and copepods are macro-zooplankton dominant species in Truc Bach Lake. Water temperature significantly affects the variety of copepod blooming. Arsenic concentration in water collected from the lake exceeded the safety level of current Vietnamese regulation. As concentration in macro-zooplankton positively correlated with metal concentrations in the water (p 0.05) while the concentration of Cu, Zn, and Pb in water has no significant correlation with the metal in zooplankton’s body. The relative abundance of adult copepods in Truc Bach lake had a negative correlation with As concentration in water (p = 0.01). The higher As concentration in water, the lower relative abundance of copepods was found in the sample