Learning Technological Capability for Vietnam's Industrial Upgrading: Challenges of the Globalization.

The paper discusses technological capabilities in Vietnamese industry considering mainly the role of foreign companies. The support of technological change is limited by specific disadvantages of Vietnamese environment, mainly insufficient organizational and legal shortcomings. Thus the connections between foreign and local companies did not produce expected results. The diffusion of technological skills takes place via training process, transfer of tacit and codified knowledge, spillover to local partners and influence absorption capacity of the local market. The cases of ten foreign companies from five different countries are presented. Major conclusions underline the threats of global operations of international companies when they are not supported by enlightened policies of companies and governments in host countries on one side and present the opportunities for these countries economy on the other.FDI; Joint-ventures; technology spillover; technological capabilities; tacit knowledge; low-cost-labor-trap; value chain; technical change

Performance of cluster-based cognitive multihop networks under joint impact of hardware noises and non-identical primary co-channel interference

In this paper, we evaluate outage probability (OP) of a cluster-based multi-hop protocol operating on an underlay cognitive radio (CR) mode. The primary network consists of multiple independent transmit/receive pairs, and the primary transmitters seriously cause co-channel interference (CCI) to the secondary receivers. To improve the outage performance for the secondary network under the joint impact of the CCI and hardware imperfection, we employ the best relay selection at each hop. Moreover, the destination is equipped with multiple antennas and uses the selection combining (SC) technique to enhance the reliability of the data transmission at the last hop. For performance evaluation, we first derive an exact formula of OP for the primary network which is used to calculate the transmit power of the secondary transmitters. Next, an exact closed-form expression of the end-to-end OP for the secondary network is derived over Rayleigh fading channels. We then perform Monte-Carlo simulations to validate the derivations. The results present that the CCI caused by the primary operations significantly impacts on the outage performance of the secondary network

An overview of 5G technologies

Since the development of 4G cellular networks is considered to have ended in 2011, the attention of the research community is now focused on innovations in wireless communications technology with the introduction of the fifth-generation (5G) technology. One cycle for each generation of cellular development is generally thought to be about 10 years; so the 5G networks are promising to be deployed around 2020. This chapter will provide an overview and major research directions for the 5G that have been or are being deployed, presenting new challenges as well as recent research results related to the 5G technologies. Through this chapter, readers will have a full picture of the technologies being deployed toward the 5G networks and vendors of hardware devices with various prototypes of the 5G wireless communications systems

On the energy efficiency of NOMA for wireless backhaul in multi-tier heterogeneous CRAN

This paper addresses the problem of wireless backhaul in a multi-tier heterogeneous cellular network coordinated by a cloud-based central station (CCS), namely heterogeneous cloud radio access network (HCRAN). A non-orthogonal multiple access (NOMA) is adopted in the power domain for improved spectral efficiency and network throughput of the wireless downlink in the HCRAN. We first develop a power allocation for multiple cells of different tiers taking account of the practical power consumption of different cell types and wireless backhaul. By analysing the energy efficiency (EE) of the NOMA for the practical HCRAN downlink, we show that the power available at the cloud, the propagation environment and cell types have significant impacts on the EE performance. In particular, in a large network, the cells located at the cloud edge are shown to suffer from a very poor performance with a considerably degraded EE, which accordingly motivates us to propose an iteration algorithm for determining the maximal number of cells that can be supported in the HCRAN. The results reveal that a double number of cells can be covered in the urban environment compared to those in the shadowed urban environment and more than 1.5 times of the number of microcells can be deployed over the macrocells, while only a half number of cells can be supported when the distance between them increases threefol

On the performance of regenerative relaying for SWIPT in NOMA Systems

As a potential access strategy in 5G mobile communication systems, non-orthogonal multiple access (NOMA) has been proposed as a supplement to the traditional orthogonal multiple access (OMA). This paper investigates simultaneous wireless information and power transfer (SWIPT) in a NOMA relaying system. The data is transferred from a source to two end terminals among which the one close to the source acts as a relay employing decode-and-forward protocol to assist the far-end one. In order to simultaneously harvest the energy and information processing at relay node, power-splitting relaying (PSR) and time switching-based relaying (TSR) protocols are sequentially considered. Outage probability and ergodic rate of both protocols are firstly analyzed to realize the impacts of various parameters including energy harvesting time, power splitting ratio, energy harvesting efficiency, source data rate, and the distance between the source and the relay node. Numerical results are then provided to validate the analytical findings. It is shown that the PSR outperforms the TSR at normal SNR regime in terms of throughput and ergodic rate

Hepatitis B prevalence, risk factors, infection awareness and disease knowledge among inmates: A cross-sectional study in Switzerland's largest pre-trial prison

© 2018, Journal of Health Global. Background Hepatitis B virus (HBV) is a major health concern in prison, but data are scarce in European prisons. This study aims to measure the prevalence of HBV infection, risk factors, awareness about infection, and HBV knowledge among inmates in Switzerland's largest pre-trial prison. Methods Serological blood tests (HBsAg, anti-HBs, and anti-HBc) and a standardized socio-demographic and sexual health survey were offered to consenting prisoners in 2009 and 2011. HBV knowledge was assessed using a standardized questionnaire among participants recruited in 2009. Findings A total of 273 male participants were included in the study (116 participants answered the HBV knowledge survey), with 38.1% originating from Eastern Europe, 28.2% from sub-Saharan Africa, 14.3% from North Africa, and 9.5% from Latin America. The prevalence of anti-HBc (resolved/chronic infection) was 38.2% and the prevalence of HBsAg (chronic infection) was 5.9%; 14% of participants had vaccine-acquired immunity (anti-HBs positive/anti- HBc negative). We estimated that 15.5% of people living in Geneva having chronic infection go through the Geneva's prison. Region of origin was significantly associated with chronic/resolved HBV infection (P < 0.001): 72.2% of participants from sub-Saharan African, 34.6% from Eastern Europe and 13.2% from other regions. In terms of chronic infection, 15.6% of participants from sub-Saharan Africa were positive for HBsAg, vs 2% of those from other regions (P < 0.001). In stratified analyses, region of origin remained significantly associated with HBV infection. Among those with chronic infection, only 12.5% were aware of their status. A minority of inmates knew how HBV could be transmitted. Conclusions The primary factor associated with HBV infection in this study was the geographical region of origin of participants. Given the high HBV prevalence found in this prison population, a targeted testing and vaccination approach based on prisoners' region of origin would be a cost-effective strategy when resources are limited. Additionally, identification of at-risk people should not rely on sensitive questions nor self-reported history of HBV. An inclusive approach to global health needs to incorporate prison population, as incarcerated people have a disproportionate burden of HBV infection and because an important proportion of hard-to-reach chronic HBV infected people go through the incarceration system