106 research outputs found
On the Interference Alignment Designs for Secure Multiuser MIMO Systems
In this paper, we propose two secure multiuser multiple-input multiple-output
transmission approaches based on interference alignment (IA) in the presence of
an eavesdropper. To deal with the information leakage to the eavesdropper as
well as the interference signals from undesired transmitters (Txs) at desired
receivers (Rxs), our approaches aim to design the transmit precoding and
receive subspace matrices to minimize both the total inter-main-link
interference and the wiretapped signals (WSs). The first proposed IA scheme
focuses on aligning the WSs into proper subspaces while the second one imposes
a new structure on the precoding matrices to force the WSs to zero. When the
channel state information is perfectly known at all Txs, in each proposed IA
scheme, the precoding matrices at Txs and the receive subspaces at Rxs or the
eavesdropper are alternatively selected to minimize the cost function of an
convex optimization problem for every iteration. We provide the feasible
conditions and the proofs of convergence for both IA approaches. The simulation
results indicate that our two IA approaches outperform the conventional IA
algorithm in terms of average secrecy sum rate.Comment: Updated version, updated author list, accepted to be appear in IEICE
Transaction
VFFINDER: A Graph-based Approach for Automated Silent Vulnerability-Fix Identification
The increasing reliance of software projects on third-party libraries has
raised concerns about the security of these libraries due to hidden
vulnerabilities. Managing these vulnerabilities is challenging due to the time
gap between fixes and public disclosures. Moreover, a significant portion of
open-source projects silently fix vulnerabilities without disclosure, impacting
vulnerability management. Existing tools like OWASP heavily rely on public
disclosures, hindering their effectiveness in detecting unknown
vulnerabilities. To tackle this problem, automated identification of
vulnerability-fixing commits has emerged. However, identifying silent
vulnerability fixes remains challenging. This paper presents VFFINDER, a novel
graph-based approach for automated silent vulnerability fix identification.
VFFINDER captures structural changes using Abstract Syntax Trees (ASTs) and
represents them in annotated ASTs. VFFINDER distinguishes vulnerability-fixing
commits from non-fixing ones using attention-based graph neural network models
to extract structural features. We conducted experiments to evaluate VFFINDER
on a dataset of 36K+ fixing and non-fixing commits in 507 real-world C/C++
projects. Our results show that VFFINDER significantly improves the
state-of-the-art methods by 39-83% in Precision, 19-148% in Recall, and 30-109%
in F1. Especially, VFFINDER speeds up the silent fix identification process by
up to 47% with the same review effort of 5% compared to the existing
approaches.Comment: Accepted by IEEE KSE 202
Controlled Synthesis of Titania using Water-soluble Titanium Complexes: A Review
The development of human society has led to the increase in energy and resources consumption as well as the arising problems of environmental damage and the toxicity to the human health. The development of novel synthesis method which tolerates utilization of toxic solvents and chemicals would fulfill the demand of the society for safer, softer, and environmental friendly technologies. For the past decades, a remarkable progress has been attained in the development of new water-soluble titanium complexes (WSTC) and their use for the synthesis of nanocrystalline titanium dioxide materials by aqueous solution-based approaches. The progress of synthesis of nanocrystalline titanium dioxide using such WSTCs is reviewed in this work. The key structural features responsible for the successfully controlled synthesis of TiO2 are discussed to provide guidelines for the morphology-controlled synthesis. Finally, this review ends with a summary and some perspectives on the challenges as well as new directions in this fascinating research
CONTRIBUTION ESTIMATE OF PAHS TOXIC COMPOUNDS IN AIR ENVIRONMENT AT MAJOR TRAFFIC JOINTS OF HANOI, VIETNAM
Joint Research on Environmental Science and Technology for the Eart
Development of Daphnia magna under exposure to the xenobiotic octylphenol: Research article
Xenobiotics are of human and environmental concerns due to their potential toxicity. Octylphenol is one of the very common and daily used xenobiotics in door and out door activities of human beings. Toxicity of octylphenol to aquatic organisms, especially to zooplankton (e.g. Daphnia magna) was investigated but not fully understood. In this study we evaluated the chronic effects of octylphenol at the concentrations of 5, 50 and 500 μg L-1 on Daphnia magna over a period of 14 days. The results showed that low concentration of octylphenol (5 μg L-1) stimulated the maturation while high concentrations of the chemical (50 and 500 μg L-1) caused a significant mortality to the Daphnia. Besides, all the tested concentrations of octylphenol had serious impacts on fecundity and growth of the animals. Investigations on the presence, distribution, fate and toxicity of xonobiotics including octylphenol in the developing country environment are suggested for human, environmental and ecological health protection.Những hợp chất tổng hợp đang là mối quan ngại cho con người và môi trường vì khả năng gây độc của chúng. Octylphenol là một trong những hợp chất tổng hợp được sử dụng phổ biến và thường xuyên trong những hoạt động của con người trong nhà và ngoài trời. Độc tính của octylphenol đối với thủy sinh vật, đặc biệt đối với động vật phù du (vd. Daphnia magna) mặc dù đã được nghiên cứu nhưng vẫn chưa được hiểu biết đầy đủ. Trong nghiên cứu này, chúng tôi đánh giá ảnh hưởng mãn tính của octylphenol ở các nồng độ 5, 50 và 500 μg/lít lên Daphnia magna trong thời gian 14 ngày. Kết quả cho thấy ở nồng độ octylphenol thấp (5 μg/lít) kích thích sự thành thục của sinh vật trong khi ở nồng độ cao hơn (50 và 500 μg/lít) gây chết đáng kể Daphnia. Bên cạnh đó, tất cả các nồng độ ocytlphenol dùng trong thí nghiệm gây ảnh hưởng nghiêm trọng lên sức sinh sản và sinh trưởng của sinh vật. Nghiên cứu về sự hiện diện, phân bố, phát tán và độc tính của những chất tổng hợp bao gồm octylphenol ở các nước đang phát triển nên được tiến hành vì mục tiêu bảo vệ sức khỏe con người, môi trường và hệ sinh thái
The results of deep magnetotelluric sounding for studying the Nha Trang - Tanh Linh fault
The profile of deep magnetotelluric sounding (MT) from Duc Trong - Tuy Phong has been carried out in Lam Dong and Binh Thuan provinces. The length of the Duc Trong - Tuy Phong profile is about 80 km with 15 stations and the distance between the stations measures about 5 km. Two-dimensional MT inversion was used to find a resistivity model that fits the data. The 2D resistivity model allows determining position and development formation of the Nha Trang - Tanh Linh fault. This is the deep fault, which is showed by the boundaries of remarkable change of resistivity. In the near surface of the Earth (from ground to the depth of 6 km), the angle of inclination of this fault is about 60o; in the next part, the direction of the Nha Trang - Tanh Linh faut is vertical. Geoelectrical section of the Nha Trang - Tanh Linh profile shows that the resistivity of mid-crust is higher than that of lower-crust and of upper-crust
ANTECEDENTS OF TOURISTS’ LOYALTY: THE ROLE AND INFLUENCE OF TOURISM PRODUCTS, DESTINATION IMAGE IN HOIAN WORLD CULTURAL HERITAGE SITE
The study’s aim is to examine the antecedents of destination loyalty, and considers the role and influence of tourism
products and destination image to international tourisms’ loyalty in case of HoiAn World Cultural Heritage Site. The study
suggested an integrated approach to understand tourists’ loyalty model and investigate the empirical evidence about the
relationship among tourism products, destination image, risk perception, tourist experience, destination satisfaction and tourists’
loyalty. This study also mentions important questions concerning how tourism products, destination image, tourist experience,
risk perception, and tourists’ satisfaction affect tourists’ loyalty. Smart PLS3 is used to estimate and test the relationships in the
research model. Mediation analysis and importance performance matrix analysis are also used to consider clearly the relationship
between the constructs of research model. The study’s results indicate that tourism products, destination image, tourism
experience, risk perception, and satisfaction are antecedents of international tourists’ loyalty in Hoi An World Cultural Heritage
Site. And in them, tourism products affect significantly positively to destination imagine and satisfaction, beside destination
image and satisfaction hold the role of mediator in this relationship. Implementing IPMA to identify the predecessors that have
relatively high importance for loyalty but also a relatively low performance. The results pointed out that the constructs as
satisfaction, tourism product, risk perception and image have a high importance for the tourist loyalty. The study added the
antecedent of tourism products and risk perception to the model and could enrich the literature, pointing to be possibility of a
destination loyalty model that can be applied to various contexts, especially after COVID- 19 pandemic. The study also discussed
theoretical and managerial implications for marketing tourism
Selective breeding of saline-tolerant striped catfish (Pangasianodon hypophthalmus) for sustainable catfish farming in climate vulnerable Mekong Delta, Vietnam
peer reviewedStriped catfish (Pangasianodon hypophthalmus), a freshwater species cultured mainly in the Mekong Delta region in Southern Vietnam, is facing a significant challenge due to salinity intrusion as a result of climatic changes. Given these evolving environmental conditions, selecting new strains with a higher salinity tolerance could make production of striped catfish economically feasible in brackish environments. In this study, we carried out a selection program aimed at developing a striped catfish strain able to survive and grow fast in a saline environment. To implement the selection program, we first collected males and females from different provinces in the Mekong delta. We next performed a factorial cross of these breeders to produce half- and full-sib families. When fish reached fry stage (47 dph), we put them in a saline environment (10 ppt) and subsequently kept 50 % of the fastest-growing fish after 143 days post hatching (dph). We repeated this mass selection procedure after 237 dph and 340 dph. We maintained in parallel a randomly selected group in saline conditions and a group of fish reared in freshwater to serve as controls. After crossing the selected individuals, we performed several tests on the next generation of fish to evaluate the effectiveness of selection after one generation in saline conditions. Average direct responses to selection were 18.0 % for growth and 11.4 % for survival rate after one generation of selection. We estimated a moderate realized heritability (0.29) for body weight. The genetic gains obtained in our study for body weight and survival rate after one generation of selection under saline conditions suggest that selection can be effective to improve ability of striped catfish to cope with saline stress. We conclude that our selection program has succeeded in developing a productive strain of striped catfish with better tolerance to salinity. © 2022 The Author
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