Some fast finite-difference solvers for Dirichlet problems on special domains

summary:The author proves the existence of the multi-parameter asymptotic error expansion to the usual five-point difference scheme for Dirichlet problems for the linear and semilinear elliptic PDE on the so-called uniform and nearly uniform domains. This expansion leads, by Richardson extrapolation, to a simple process for accelerating the convergence of the method. A numerical example is given

Social Housing for Workers in Industrial Zones in Vietnam - Concepts and Practical Solutions towards Sustainable Development. The Case Studies of Hanoi City

Economic growth associated with the rapid industrialization and urbanization over the past 30 years since Doi Moi (Reform) has facilitated the establishment and development of many industrial zones (IZs) in major cities of Vietnam. The high concentration of IZs in the largest cities has attracted millions of industrial laborers and created large migration waves from rural to urban areas. Establishing and improving the living environment of workers have become a huge pressure for the Government and local authorities across the country to deal with. Although the Government has issued numerous policies and incentives to encourage and support housing development for factory workers, there are still many conflicts and challenges in policy implementation. Through observational and questionnaire surveys supported with in-depth interviews of experts in urban planning and management, the research aims to understand clearly the context of social housing development for IZ workers in Vietnam recently, to demonstrate outstanding characters of different types of housing for factory workers as well as crucial issues related to social housing and informal housing for factory workers. Furthermore, the research proposes solutions including legal institutions, management mechanisms, industrial worker housing database establishment, and basic technical solutions (planning and spatial organization) in order to find out some appropriate concepts for social housing targeted at industrial workers and then to achieve social sustainable development

Positioning precision of GPS/Galileo integration in Vietnam

The design of Galileo has been conceived so as to facilitate its possible joint use with GPS thus contributing to a favorable multi-GNSS environment. Evaluating the performances of such multi-GNSS combination is crucial for end users to assess the quality of obtainable PVT and the easiness of interoperability of the two systems. In this paper, we evaluate the GPS/Galileo integration performances in terms of estimated precision in position determination and in terms of availability of the service. Results obtained from real data are presented and show that there is an improvement of both these criteria when the two systems are jointly used

Financial Sector Reforms in Vietnam: Selected Issues and Problems

The purpose of this report is to concentrate on performing in-depth analyses of selected issues of prominence and importance for the future success of the reform process rather than describing the current day-to-day operations and procedures in the financial sector. This eclectic approach implies that other important issues such as the development of a payment system, the state and prospects for the inter-bank markets, and the human capital and organisational issues in the state-owned banks are neglected and/or not analysed in depth. They are, however, omissions due to constraints imposed by funds and time available rather than a failure to comprehend their importance. In this context, the present report should thus be viewed as a first step towards establishing an open dialogue about the nature and speed of the financial sector reforms in Vietnam based on recurrent independent assessments of financial sector issues and problems.Financial Sector Reforms, Vietnam

Brain oscillations differentially encode noxious stimulus intensity and pain intensity

Noxious stimuli induce physiological processes which commonly translate into pain. However, under certain conditions, pain intensity can substantially dissociate from stimulus intensity, e.g. during longer-lasting pain in chronic pain syndromes. How stimulus intensity and pain intensity are differentially represented in the human brain is, however, not yet fully understood. We therefore used electroencephalography (EEG) to investigate the cerebral representation of noxious stimulus intensity and pain intensity during 10 min of painful heat stimulation in 39 healthy human participants. Time courses of objective stimulus intensity and subjective pain ratings indicated a dissociation of both measures. EEG data showed that stimulus intensity was encoded by decreases of neuronal oscillations at alpha and beta frequencies in sensorimotor areas. In contrast, pain intensity was encoded by gamma oscillations in the medial prefrontal cortex. Contrasting right versus left hand stimulation revealed that the encoding of stimulus intensity in contralateral sensorimotor areas depended on the stimulation side. In contrast, a conjunction analysis of right and left hand stimulation revealed that the encoding of pain in the medial prefrontal cortex was independent of the side of stimulation. Thus, the translation of noxious stimulus intensity into pain is associated with a change from a spatially specific representation of stimulus intensity by alpha and beta oscillations in sensorimotor areas to a spatially independent representation of pain by gamma oscillations in brain areas related to cognitive and affective-motivational processes. These findings extend the understanding of the brain mechanisms of nociception and pain and their dissociations during longer-lasting pain as a key symptom of chronic pain syndromes

Utilization of services provided by village based ethnic minority midwives in mountainous villages of Vietnam

Introduction: Since 2011, the Vietnam’s Ministry of Health implemented the ethnic minority midwives (EMMs) scheme in order to increase the utilization of maternal health services by women from ethnic minorities and those living in hard-to-reach mountainous areas. This paper analyzes the utilization of antenatal, delivery, and postpartum care provided by EMMs and reports the key determinants of utilization of EMM services as perceived by service users. Methods: A structured questionnaire was administered in 2015 to all mothers (n=320) who gave birth to a live-born during a 1-year period in 31 villages which had EMM in two provinces, Dien Bien and Kon Tum. A multivariate logistic regression model was used to examine the association between all potential factors and the use of services provided by EMMs. Results: We found that EMMs provided more antenatal care and postnatal care as compared with delivery services, which corresponded to their job descriptions. The results also showed that utilization of antenatal care provided by EMMs was lower than that of postnatal care. The proportion of those who never heard about EMM was high (24%). Among the mothers who knew about EMM services, 33.4% had antenatal checkups, 20.1% were attended during home deliveries, and 57.3% had postnatal visits by an EMM. Key factors that determined the use of EMM services included knowledge of the location of EMM’s house, being aware about EMMs by health workers, trust in services provided by EMMs, and perception that many others mothers in a village also knew about EMM services. Conclusion: EMM seems to be an important mechanism to ensure assistance during home births and postnatal care for ethnic minority groups, who are often resistant to attend health facilities. Building trust and engaging with communities are the key facilitators to increase the utilization of services provided by EMMs. Communication campaigns to raise awareness about EMMs and to promote their services in the village, particularly by other health workers, represent an important strategy to further improve effectiveness of EMM scheme

Magneto-transport properties of monolayer borophene in perpendicular magnetic field: influence of electron-phonon interaction

The magneto-transport properties of a borophene monolayer in a perpendicular magnetic field B are studied via calculating the conductivity tensor and resistance under electron-optical phonon interaction by using the linear response theory. Numerical results are obtained and discussed for some specific parameters. The magnetic field-dependent longitudinal conductivity shows the magneto-phonon resonance effect that describes the transition of electrons between Landau levels by absorbing/emitting an optical phonon. The Hall conductivity increases first and then decreases with the magnetic field strength. Also, the longitudinal resistance increases significantly with increasing temperature, which shows the metal behaviour of the material. Practically, the observed magneto-phonon resonance can be applied to experimentally determine some material parameters, such as the distance between Landau levels and the optical phonon energy

Proposal of MIMO Ultra-Wide Band Antenna with Low Mutual Coupling

In this paper, a new ultra-wide band (UWB) MIMO antenna is proposed. A MIMO antenna set consists of two single ultra-wide band antennas. This simple and compact MIMO antenna, which is designed to work from 3.1 GHz to 10.6 GHz, has a broad bandwidth with the VSWR ≤ 2. In addition, MIMO antenna characteristics such as radiation pattern, maximal gain are thoroughly investigated

Photoconductive UV Detectors Based on ZnO Films Prepared by R.F. Magnetron Sputtering Method

Highly c-axis oriented zinc oxide (ZnO) thin films were deposited on glass substrates by radio frequency (r.f.) sputtering. The photoconductor UV detector based on ZnO films, having a metal-semiconductor-metal (MSM) structure with interdigitation configuration, were fabricated by using aluminium (Al) as a contact metal. The characteristics of dark and photocurrent of the ultraviolet (UV) detector and the UV photo-response of the detector were investigated. The linear current-voltage (I-V) characteristics under both forward and reverse bias exhibit ohmic metal-semiconductor contacts. Under illumination by monochromatic light at a wavelength of 365~nm, the photo-generated current was measured to be 0.56 $\mu$A at a bias of 6 V. The photo-response decay in these devices is slow