Combined adaptive lattice reduction-aided detection and antenna shuffling for DSTTD-OFDM systems

In this paper, we consider lattice reduction (LR) aided linear detection in a DSTTD-OFDM (double space-time transmit diversity- orthogonal frequency division multiplexing) system with antenna shuffling. We first derive an antenna shuffling criterion for the LR-aided DSTTD-OFDM system. Next, we propose a combined reduced-feedback and adaptive LR algorithm by exploiting the correlation between OFDM subcarriers in the frequency domain. The LR-aided DSTTD OFDM system with this algorithm requires low computational effort for the LR operation and small feedback information. Simulation results show that a significant improvement could be achieved in the proposed system compared to previous (non-LR-aided) systems under spatially correlated channels. Also, the proposed complexity-reduced approach could greatly lower the system complexity while exhibiting a slight performance loss

ASSESSING THE STATUS OF BUILDING COLLECTIVE MARKS FOR CRAFT VILLAGE PRODUCTS IN THUA THIEN HUE PROVINCE

Abstract: Thua Thien Hue is a locality with many potentials to develop craft village products. In the context of deep integration, the use of intellectual property tools, namely collective mark, is one of the prerequisites for craft villages to show their strength and value of brands and better export products to international markets. This study clarifies the status of building collective marks for craft village products in Thua Thien Hue province. The research analyzes the secondary data, uses the descriptive statistics of primary data obtained from in-depth interviews with 5 experts and surveys 28 collective mark owners in the locality. The results reflect the status of collective marks for craft products in Thua Thien Hue province through two aspects: (i) the status of collective mark registration and (ii) support activities for building and managing collective marks for craft village products of management agencies in Thua Thien Hue province. Thereby, the study points out outstanding issues and proposes solutions to building and developing collective marks for craft village products in Thua Thien Hue.Keywords: collective mark, craft village product, Thua Thien Hu

Understanding of cervical cancer and screening among Vietnamese female sex workers in Ho Chi Minh City

Objective and methodology: The objectives of this study are to explore how Vietnamese female sex workers (FSWs) explained about cervical cancer and screening which have profound effects on their attendance in cervical cancer screening. To gain objectives, a qualitative study was designed with in-depth interviews. Total 15 FSWs working in different venues were recruited through a non-government group. Findings: We found that although FSWs considered themselves to be risk for cervical cancer due to their sexual lives, they still postponed going for cervical cancer screening. Some FSWs in this study believed that cervical cancer was a specific genital infection which resulted from white blood, poor hygiene and multiple sexual partners. Other FSWs believed that cervical cancer comes from God. Based on these beliefs, FSWs thought that the best way to prevent cervical cancer is treating white blood, practicing good hygiene, having safe sex with condoms and limiting sex work. As a result, they postpone going for cervical cancer screening. Recommendation: The findings suggest that health education about cervical cancer and cervical cancer screening for FSWs should be improved not only to increase knowledge but also to rebuild their beliefs and existing knowledge in a creative way. Besides, physician and clients have to understand how the other perceives cancer, its prevention and its treatment. This mutual understanding may create a good foundation for physicians and clients to cooperate in healthcare setting

FACTORS AFFECTING WORK MOTIVATION OF CIVIL SERVANTS IN THUA THIEN HUE PROVINCIAL PEOPLE'S COMMITTEE

Abstract: The purpose of this study is to examine the factors affecting the motivation of civil servants at the People's Committee of Thua Thien Hue province. Based on data collected from 181 officers at the People's Committee of Thua Thien Hue Province,  researchers processed all data by SPSS with some techniques such as: descriptive statistics, Cronbach's Alpha, Exploratory Factor Analysis (EFA) and Multivariate Regression Analysis... The research results show that there are 6 factors affecting the motivation of officers at the People's Committee of Thua Thien Hue province, including: (i) Working conditions; (ii) Nature of work; (iii) Career development opportunities; (iv) Income and benefits; (v) Relationship with leaders and (vi) Relationships with colleagues. Based on the research results, a number of solutions have been proposed to improve the work motivation in the People's Committee of Thua Thien Hue.Keywords: work motivation, civil servants, Thua Thien Hue Provincial People's Committe

Vietnamese female sex workers’ perception of the healthcare quality in cervical cancer screening in Ho Chi Minh city

The objectives of this paper are to explore issues relating to the quality of care received in reproductive health service, especially cervical cancer screening from perspective of Vietnamese female sex workers (FSWs) in Ho Chi Minh City (HCMC). From the findings, we make recommendations to improve the quality of reproductive health care service. This is a qualitative study using observation and in-depth interview with 15 female sex workers aged 18-44 years. The research findings indicate that physician-client relationship, gender of doctor, information, privacy and technique competency are elements influencing their decision on cervical cancer screening

Grid search of multilayer perceptron based on the walk-forward validation methodology

Multilayer perceptron neural network is one of the widely used method for load forecasting. There are hyperparameters which can be used to determine the network structure and used to train the multilayer perceptron neural network model. This paper aims to propose a framework for grid search model based on the walk-forward validation methodology. The training process will specify the optimal models which satisfy requirement for minimum of accuracy scores of root mean square error, mean absolute percentage error and mean absolute error. The testing process will evaluate the optimal models along with the other ones. The results indicated that the optimal models have accuracy scores near the minimum values. The US airline passenger and Ho Chi Minh city load demand data were used to verify the accuracy and reliability of the grid search framework

Adaptive antenna selection for energy-efficient MIMO-OFDM wireless systems

In this paper, we investigate energy-efficiency in antenna selection OFDM-based systems. We show that an OFDM system with conventional antenna selection approaches, including per-subcarrier selection (i.e., selecting antennas independently for each subcarrier) and bulk-selection (i.e., choosing the same antennas for all subcarriers), suffers from a significant loss in energy-efficiency. To achieve a better energy-efficiency performance, we propose an adaptive antenna selection scheme where both the number of active RF (radio frequency) chains and the antenna indices are selected depending on the channel condition. This selection scheme could be implemented by exhaustive search. Moreover, we develop an algorithm that achieves a near-optimal performance with much lower complexity when the number of antennas is large, compared to the (optimal) exhaustive search method. Simulation results demonstrate a significant improvement in terms of energy-efficiency in the proposed system compared to the conventional counterparts

Transmit antenna subset selection with power balancing for high data rate MIMO-OFDM UWB systems

This paper proposes per-subcarrier transmit antenna subset selection with power balancing for MIMO-OFDM UWB systems to simultaneously improve the system error performance and increase data rates. The deployment of the per-subcarrier antenna subset selection may result in a power unbalance across antennas, which could cause power amplifiers (PAs) to operate in their non-linear regions. To overcome this disadvantage, we formulate a linear optimization problem for the optimal allocation of data subcarriers under a constraint that all antennas have the same number of assigned data symbols. This optimization problem could be applied to systems with an arbitrary number of multiplexed data streams, antennas, and with different selection criteria. The efficacy of the proposed allocation scheme from the PA linearity perspective is validated by analyzing the distribution of the peak amplitude of timedomain signals. Simulation results demonstrate that the proposed system outperforms the system without a balancing constraint

Patent Signals of IPO Performance: Evidence from High- and Low-Tech Industries in Japan

Abstract: Prior studies pointed to evidence that startups and venture capital (VC) companies tended to use different measures to provide signals to outsiders. This study adds to those previous insights by focusing on established firms’ patenting behaviors and their effect on the amount of money raised at the initial public offering (IPO). Since technology intensity may differ considerably between high and low-tech companies, our main interest in this paper lies on whether the significance of pre-IPO patenting activities as a predictor of IPO performance also varies between these two industry categories. Using cross-sectional data representing 308 Japanese industrial firms’ IPO commitments between 2000 and 2015, we find a robust positive correlation between patent applications and IPO performance. Contrary to the conventional wisdom proposing that high-tech firms with more patenting activities achieve better IPO performance, we show that the signaling power of patenting is stronger for the low-tech companies in our sample: While the high-tech firms do not seem to have significantly benefited from a patent signal, the low-tech firms seem to have attracted external investors more easily due to patenting at the IPO. Keywords:  Patent, signal, initial public offering (IPO), high-tech industries, low-tech industrie