Performance Analysis of Hybrid ALOHA/CDMA RFID Systems with Quasi-decorrelating Detector in Noisy Channels

In this paper we investigate the performance of a hybrid Aloha/CDMA radio frequency identification (RFID) system with quasi-decorrelating detector (QDD). Motivated by the fact that the QDD outperforms the conventional decorrelating detector (DD) in noisy network scenarios, we study and propose using QDD as one of the most promising candidates for the structure of RFID readers. Performance analysis in terms of bit error rate and the RFID system efficiency is considered considering CDMA code collision and detection error. Computer simulations are also performed, and the obtained results of QDD-based structure are compared with those of DD-based one to confirm the correctness of the design suggestion in different practical applications of tag identification and missing-tag detection

Dietary patterns and risk factors for Type 2 diabetes mellitus in Fijian, Japanese and Vietnamese populations

Diabetes mellitus is now a serious and increasing problem in Asian countries, where dietary patterns have shifted toward Westernized foods and people are becoming more sedentary. In order to elucidate the relationship of dietary habits to the development of diabetic risk factors, the dietary patterns of 200 Fijian, 171 Japanese and 181 Vietnamese women of 30–39 years of age were investigated using 3 day–24 h recall or dietary records. Anthropometric measurements and glycosuria tests were also conducted. The dietary trends of Fijians and Japanese have changed drastically in the past 50 years, while Vietnamese have been minimally influenced by Western dietary habits. The mean 24 h dietary intake showed that Fijians had the highest energy intake. Energy intake from fat was only 13% for Vietnamese, but over 30% for Japanese and Fijians. Percentage of body fat was higher in Vietnamese than in Japanese, though there were no significant differences in body mass index (BMI). In the overweight and obese women, Vietnamese had higher abdominal obesity than Japanese. The prevalence of obesity (BMI � 30 kg/m2) was 63.0% for Fijians, 1.8% for Japanese and 1.1% for Vietnamese. Glycosuria testing yielded the most positive cases among Fijians. Dietary transition and dietary excess appear to be potential risk factors for diabetes in Fijian women

CÁC YẾU TỐ ẢNH HƯỞNG ĐẾN SỰ PHÂN BỐ ĐỘ MẶN CỦA NƯỚC LỖ RỖNG TRONG LỚP TRẦM TÍCH BIỂN TUỔI ĐỆ TỨ VÙNG NAM ĐỊNH

This paper presents the results of studies and analysis, assessment the controlling factors to the distribution of salinity (mainly NaCl) in the Quaternary marine sedimentary in Nam Dinh area by using a combination of different methods such as boreholes logging, undisturbed sediment sampling, pore water squeezing, analysis of chemical and stable isotope compositions of pore water.Based on the correlation between concentration of Cl-, Na+ ions and NaCl versus electrical conductivity of marine sediment at different depth according to geophysical borehole results determine the distribution of concentration of salinity (NaCl) of pore water at different depths. In addition, results from the analysis of stable isotopes δ18O and δ2H of porewater in the marine sedimentary layer show the mixing of marine water and meteoritic water in the sediments. Distribution of NaCl of marine sediments is due to difference in density and molecular diffusion.ReferencesCharles D. Shackelford, David E. Daniel, 1990. Diffusion in Saturated soil. Journal of Geotechnical Engineering 117, 467 - 484.Crooks, V. E. and Quigley, R. M., 1984. Saline leachate migration through clay: A comparative laboratory and field investigation. Can. Geotech. J., 21(2), 349 - 362.Đoàn Văn Cánh, Lê Thị Lài, Hoàng Văn Hưng, Nguyễn Đức Rỡi, Nguyễn Văn Nghĩa, 2005. Groundwater Resource Of Nam Định Province, J. of Geology, B/25, Hà Nội.Frank Wagner, Dang Tran Trung, Hoang Dai Phuc, Falk Lindenmaier, 2011. Assessment of Groundwater Resources in Nam Dinh Province. Final Technical Report of improvement of Groundwater Protection in Vietnam, Ha Noi.Hoàng Văn Hoan, Flemming Larsen, 2007. Phương pháp xác định độ lỗ hổng hiệu dụng, hệ số thấm của tầng chứa nước và TDS của nước bằng phương pháp địa vật lý lỗ khoan, lấy ví dụ vùng đồng bằng sông Hồng. TC KHKT Mỏ - Địa chất, 20/10-2007. Hà Nội, 101-107.Hoan V. Hoang, Nhan Q. Pham, Flemming Larsen, Long V. Tran, Frank Wagner And Anders V. Christiansen, 2011. Processes Controlling High Saline Groundwater in the Nam Dinh Province, Vietnam. 2nd Asia-Pacific Coastal Aquifer Management Meeting October 18-21, 2011, Jeju Island, Korea.Hoàng Văn Hoan, Phạm Quý Nhân, Flemming Larsen, Trần Vũ Long, Nguyễn Thế Chuyên, Trần Thị Lựu, 2012. Ảnh hưởng của quá trình khuếch tán tới sự phân bố độ mặn của nước lỗ rỗng trong lớp trầm tích biển tuổi Đệ tứ khu vực Nam Định. Báo cáo hội nghị khoa học lần thứ 20, ĐH Mỏ - Địa chất. Hà Nội.Nguyễn Kim Ngọc, Kiều Vân Anh, Nguyễn Thị Hạ, Hoàng Văn Hoan, Đỗ Tiến Hùng, Hoàng Văn Hưng, Nguyễn Văn Lâm, Phạm Quý Nhân, Nguyễn Thị Thanh Thủy, 2005. Thủy Địa Hóa học. Nhà xuất bản Giao thông vận tải, Hà Nội, 315tr.Kooi H., Groen J., Leijnse A., 2000. Modes of seawater intrusion during trangressions, Water resources research, Vol. 36, No. 12, phương pháp 3581-3589.Rowe, R. K., Caers, C. J., and Barone, F., 1988. Laboratory determination of diffusion and distribution coefficients of contanminants using undisturbed clayey soil. Can. Geotech. J., 25, 108-118.Schincariol RA, Schwartz FW, Mendoza CA., 1997. Instabilities in variable density flows: stability and sensitivity analyses for homogeneous and heterogeneous media. Water Resour Res; 33(1), 31-41.Simmons CT, Fenstemaker TR, Sharp JM., 2001. Variable-density groundwater flow and solute transport in heterogeneous media approaches resolutions and future challenges. J Contam Hydrol; 52(1-4), 245-75. 148.Tanabe, S., Hori, K., Saito, Y., Haruyama, S., Vu, V.P., Kitamura, A., 2003a. Song Hong (Red River) delta evolution related to millen-nium-scale Holocene sea-level changes. Quaternary Science Reviews 22, 2345-2361.Tanabe, S., Hori, K., Saito, Y., Haruyama, S., Doanh, L.Q., Sato, Y., Hiraide, S., 2003b. Sedimentary facies and radiocarbon dates of the Nam Dinh-1 core from the Song Hong (Red River) delta. Viet-nam. Journal of Asian Earth Science 21, 503-513.Tanabe, S., Hori, K., Saito, Quang Lan Vu, Till J. J. Hanebuth, Quang Lan Ngo, Akihisa Kitamura, 2006. Holocene evolution of Song Hong (Red River) delta system, north Vietnam. Sedimentary Geology 187, 29-61.Weixing Guo and Christian D. Langevin, 2002. User’s Guide to SEAWAT: A computer program for simulation of three-dimensional variable-density groundwater flow, USGS, Florida, USA.This paper presents the results of studies and analysis, assessment the controlling factors to the distribution ofsalinity (mainly NaCl) in the Quaternary marine sedimentary in Nam Dinh area by using a combination of differentmethods such as boreholes logging, undisturbed sediment sampling, pore water squeezing, analysis of chemical andstable isotope compositions of pore water.Based on the correlation between concentration of Cl-, Na+ ions and NaCl versus electrical conductivity of marinesediment at different depth according to geophysical borehole results determine the distribution of concentration ofsalinity (NaCl) of pore water at different depths. In addition, results from the analysis of stable isotopes δ18O and δ2H ofporewater in the marine sedimentary layer show the mixing of marine water and meteoritic water in the sediments.distribution of NaCl of marine sediments is due to difference in density and molecular diffusion

Low Profile Frequency Reconfigurable PIFA Antenna using Defected Ground Structure

In this paper, we design and implement a low profile frequency reconfigurable Planar Inverted-F Antenna (PIFA) for WLAN, m-WiMAX and UMTS applications. Dierent from several conventional designs, the air layer in our antenna is removed, while the radiator patches and ground plane are printed on two sides of the same substrate. This makes the antenna structure thin and lightweight. The defected ground structure (DGS) and coplanar sorting-trips are also designed for adjusting lower operating frequencies without increasing the antenna’s size. Three PIN-diodes are used in appropriate positions for accurate switches between frequency bands. Moreover, the three radiator patches’ parameters are optimally selected on all configurations using Genetic Algorithm (GA). Simulation results show that depending on the ON/OFF states of the PIN-diodes, the antenna can operate in three applicable frequency bands, i.e., 2.1 GHz, 2.4 GHz, and 3.5 GHz with the corresponding peak gains of 0.48 dBi, 3.55 dBi, and 4.33 dBi. The antenna occupies an overall size of 63.5x33.5x1.6 mm3, which can be easily fabricated and integrated into small wireless devices. Simulated and measured results are also compared to validate the correctness the antenna design

Spatial Variation of Rare Earth Elements (REEs) in Agricultural Soils Collected from Different Geographical Regions in Vietnam

Rare earth elements (REEs) exist commonly in minerals, such as carbonates, silicates, fluorides, and phosphates. REEs are also found in coals, animals, algae, and plants which were proven to increase the growth, development, yield, and quality of crops. In the present study, a preliminary assessment of REEs contents in soils collected from different areas in Vietnam was performed using the methods of Fe(OH)3 and Mg(OH)2 co-precipitation to exclude interferences from the sample matrix before analyzing REEs on ICP-MS system. The contents of REEs (mg kg-1) were in descending of Ce > Nd > La > Pr > Sm > Gd > Dy > Tb > Er > Yb > Lu. The light REEs contents were always higher than the heavy REEs, accounting for more than 70% of the total contents. In addition, the REEs also differed in total contents between areas. The contents of REEs were as follows Northwest > Northeast > Central Highland > Southeast. These differences could be related to influences during the natural weathering processes for soil formation and human activities such as mining and cultivation via fertilizers

Assessment of aflatoxin B1 contamination in rice and maize

Introduction: Aflatoxins B1 are among the most common poisonous mycotoxins produced by certain fungi that harm animals and crops. Mycotoxins can cause a variety of adverse health effects and pose a serious health threat to humans. The Maximum Residue Limits of aflatoxin B1 in processed cereals and ingredients are 2 parts per billion (ppb) and 5 ppb, respectively. Objectives: To evaluate the status of aflatoxin B 1 contamination in rice, corn and staple food produced in Ha Giang province compared with the maximum permitted levels. Methods: A total of 210 rice and maize samples were analyzed to quantify the level of aflatoxin B1. Analysis of mycotoxins was conducted by High Performance Liquid Chromatography using a fluorescence detector. Results: It was found that rice, rice products, maize, and maize products had a mean aflatoxin B1 content of 1.79 ppb, 2.55 ppb, 2.19 ppb, and 6.35 ppb, respectively. The results also showed that 71.9% of samples were contaminated with mycotoxins, and 14.28% of samples exceeded the maximum allowable limit. Conclusion: The concentration of aflatoxin B1 in 14.28% of the samples are over permissible limits by nationwide regulations

A Clinical and Epidemiological Investigation of the First Reported Human Infection With the Zoonotic Parasite Trypanosoma evansi in Southeast Asia.

BACKGROUND: Trypanosomais a genus of unicellular parasitic flagellate protozoa.Trypanosoma bruceispecies and Trypanosoma cruziare the major agents of human trypanosomiasis; other Trypanosomaspecies can cause human disease, but are rare. In March 2015, a 38-year-old woman presented to a healthcare facility in southern Vietnam with fever, headache, and arthralgia. Microscopic examination of blood revealed infection with Trypanosoma METHODS: Microscopic observation, polymerase chain reaction (PCR) amplification of blood samples, and serological testing were performed to identify the infecting species. The patient's blood was screened for the trypanocidal protein apolipoprotein L1 (APOL1), and a field investigation was performed to identify the zoonotic source. RESULTS: PCR amplification and serological testing identified the infecting species as Trypanosoma evansi.Despite relapsing 6 weeks after completing amphotericin B therapy, the patient made a complete recovery after 5 weeks of suramin. The patient was found to have 2 wild-type APOL1 alleles and a normal serum APOL1 concentration. After responsive animal sampling in the presumed location of exposure, cattle and/or buffalo were determined to be the most likely source of the infection, with 14 of 30 (47%) animal blood samples testing PCR positive forT. evansi. CONCLUSIONS: We report the first laboratory-confirmed case ofT. evansiin a previously healthy individual without APOL1 deficiency, potentially contracted via a wound while butchering raw beef, and successfully treated with suramin. A linked epidemiological investigation revealed widespread and previously unidentified burden ofT. evansiin local cattle, highlighting the need for surveillance of this infection in animals and the possibility of further human cases

The baseline characteristics and interim analyses of the high-risk sentinel cohort of the Vietnam Initiative on Zoonotic InfectiONS (VIZIONS)

The Vietnam Initiative for Zoonotic Infections (VIZIONS) includes community-based 'high-risk sentinel cohort' (HRSC) studies investigating individuals at risk of zoonotic infection due to occupational or residential exposure to animals. A total of 852 HRSC members were recruited between March 2013 and August 2014 from three provinces (Ha Noi, Dak Lak, and Dong Thap). The most numerous group (72.8%) corresponded to individuals living on farms, followed by slaughterers (16.3%) and animal health workers (8.5%). Nasal/pharyngeal and rectal swabs were collected from HRSC members at recruitment and after notifying illness. Exposure to exotic animals (including wild pigs, porcupine, monkey, civet, bamboo rat and bat) was highest for the Dak Lak cohort (53.7%), followed by Ha Noi (13.7%) and Dong Thap (4.0%). A total of 26.8% of individuals reported consumption of raw blood over the previous year; 33.6% slaughterers reported no use of protective equipment at work. Over 686 person-years of observation, 213 episodes of suspect infectious disease were notified, equivalent of 0.35 reports per person-year. Responsive samples were collected from animals in the farm cohort. There was noticeable time and space clustering of disease episodes suggesting that the VIZIONS set up is also suitable for the formal epidemiological investigation of disease outbreaks

Numerical Simulation of Turbulent Flow and Pollutant Dispersion in Urban Street Canyons

In this study, we have developed a numerical model based on an open source Computational Fluid Dynamics (CFD) package OpenFOAM, in order to investigate the flow pattern and pollutant dispersion in urban street canyons with different geometry configurations. In the new model, the pollutant transport driven by airflow is modeled by the scalar transport equation coupling with the momentum equations for airflow, which are deduced from the Reynolds Averaged Navier-Stokes (RANS) equations. The turbulent flow calculation has been calibrated by various two-equation turbulence closure models to select a practical and efficient turbulence model to reasonably capture the flow pattern. Particularly, an appropriate value of the turbulent Schmidt number has been selected for the pollutant dispersion in urban street canyons, based upon previous studies and careful calibrations against experimental measurements. Eventually, the numerical model has been validated against different well-known laboratory experiments in regard to various aspect ratios (a relationship between the building height and the width of the street canyon), and different building roof shapes (flat, shed, gable and round). The comparisons between the numerical simulations and experimental measurements show a good agreement on the flow pattern and pollutant distribution. This indicates the ability of the new numerical model, which can be applied to investigate the wind flow and pollutant dispersion in urban street canyons