Quality-aware Tasking in Mobile Opportunistic Networks - Distributed Information Retrieval and Processing utilizing Opportunistic Heterogeneous Resources.

Advances in wireless technology have facilitated direct communication among mobile devices in recent years, enabling opportunistic networks. Opportunistic networking among mobile devices is often utilized to offload and save cellular network traffic and to maintain communication in case of impaired communication infrastructure, such as in emergency situations. With a plethora of built-in capabilities, such as built-in sensors and the ability to perform even intensive operations, mobile devices in such networks can be used to provide distributed applications for other devices upon opportunistic contact. However, ensuring quality requirements for such type of distributed applications is still challenging due to uncontrolled mobility and resource constraints of devices. Addressing this problem, in this thesis, we propose a tasking methodology, which allows for assigning tasks to capable mobile devices, considering quality requirements. To this end, we tackle two fundamental types of tasks required in a distributed application, i.e., information retrieval and distributed processing. Our first contribution is a decentralized tasking concept to obtain crowd collected data through built-in sensors of participating mobile devices. Based on the Named Data Networking paradigm, we propose a naming scheme to specify the quality requirements for crowd sensing tasks. With the proposed naming scheme, we design an adaptive self-organizing approach, in which the sensing tasks will be forwarded to the right devices, satisfying specified quality requirements for requested information. In our second contribution, we develop a tasking model for distributed processing in opportunistic networks. We design a task-oriented message template, which enhances the definition of a complex processing task, which requires multiple processing stages to accomplish a predefined goal. Our tasking concept enables distributed coordination and an autonomous decision of participating device to counter uncertainty caused by the mobility of devices in the network. Based on this proposed model, we develop computation handover strategies among mobile devices for achieving quality requirements of the distributed processing. Finally, as the third contribution and to enhance information retrieval, we integrate our proposed tasking concept for distributed processing into information retrieval. Thereby, the crowd-collected data can be processed by the devices during the forwarding process in the network. As a result, relevant information can be extracted from the crowd-collected data directly within the network without being offloaded to any remote computation entity. We show that the obtained information can be disseminated to the right information consumers, without over-utilizing the resource of participating devices in the network. Overall, we demonstrate that our contributions comprise a tasking methodology for leveraging resources of participating devices to ensure quality requirement of applications built upon an opportunistic network

MÔ PHỎNG PHÂN BỐ VÀ KHẢ NĂNG CHỊU TẢI ĐỐI VỚI CHẤT LƠ LỬNG KHU VỰC ĐẦM CẦU HAI - TỈNH THỪA THIÊN-HUẾ BẰNG MÔ HÌNH TOÁN

By applying of regression methods to assimilate data for suspended particulate matter as the input data to mathematical model, the paper presents the results on the distribution and carrying capacity of suspended particulate matter in Cau Hai lagoon, Thua Thien-Hue province during the dry season (7/2013) and rainy season (10/2013). The initial simulation show that the water exchange in Cau Hai lagoon is weak in comparsion with that in Thuy Tu lagoon as well as Tam Giang lagoon, leading the distribution of suspended particulate matter to be dominated by seasonal and the suspended particulate matter from Truoi river. The overall mean concentration of suspended particulate matter is 30 g/m3 during dry season and 48 g/m3 in the rainy season. Notably, the carrying capacity of suspended particulate matter in Cau Hai lagoon is very low in the rainy season, with the remaining capacity of receiving being only 4%. Therefore, a small increase in the suspended particulate matter can result in the overload of suspended particulate matter in Cau Hai region.Ứng dụng phương pháp hồi quy đơn trong việc đồng hóa số liệu đối với chất lơ lửng làm đầu vào cho mô hình toán, bài báo đã đưa ra những kết quả về phân bố và khả năng chịu tải chất lơ lửng tại khu vực đầm Cầu Hai tỉnh Thừa Thiên-Huế trong mùa khô (7/2013) và mùa mưa (10/2013). Các kết quả mô phỏng ban đầu cho thấy, sự trao đổi nước trong khu vực đầm Cầu Hai là yếu so với sự trao đổi nước ở đầm Thủy Tú cũng như đầm Tam Giang, dẫn tới sự phân bố chất lơ lửng trong đầm chủ yếu bị chi phối theo mùa và phụ thuộc vào nguồn chất lơ lửng từ sông Truồi đưa ra. Hàm lượng chất lơ lửng trung bình toàn đầm đạt 30 g/m3 vào mùa khô và 48 g/m3 vào mùa mưa. Đáng chú ý là khả năng chịu tải chất lơ lửng đối với đầm Cầu Hai trong mùa mưa là rất thấp, khả năng tiếp nhận chỉ còn 4%. Bởi vậy chỉ cần một tác động nhỏ làm gia tăng hàm lượng chất lơ lửng vào đầm cũng dẫn đến kết quả quá tải chất lơ lửng trong khu vực đầm Cầu Hai

Neutron Yield from (γ, n) and (γ, 2n) Reactions following 100 MeV Bremsstrahlung in a Tungsten Target

The photonuclear reactions of (γ, xn) or (γ, xnp) types can be used to produce high-intensity neutron sources for research and applied purposes. In this work a Monte-Carlo calculation has been used to evaluate the production yield of neutrons from the (γ, n) and (γ, 2n) reactions following the bremsstrahlung produced by a 100 MeV electron beam on a tungsten target

Effect of fertilizer on lead (Pb) accumulation ability of Polygonum hydropiper L.

Polygonum hydropiper L. was cultivated on alluvial soil (Pb = 2.6 mg/kg, dry weight) and Pb contaminated soil (Pb = 1,380 mg/kg dry weight) without and with amendment of 2 g organic fertilizer/kg soil and 2.5; 5.0; 10.0 g NPK fertilizer/1kg soil. After 45 days of cultivation, the growth in height and biomass of P. hydropiper in Pb contaminated soil without amendment of fertilizer was lower than that in alluvial soil, but the Pb content in the above-ground part of the P. hydropiper was higher. In the formula 4, on Pb contaminated soil (Pb = 1,380 mg/kg dry weight), when amending 2 g of microbiological organic fertilizer + 5 g NPK fertilizer per 1 kg of soil (with the total nutrients amended were: N = 0.25, P2O5= 0.52, K2O = 0.15, and organic matter = 0.21 g/kg soil), growth of P. hydropiper was optimal (its height and biomass were up to 244.0% and 284.9% in comparison to that of before experiment) and their Pb extraction potential was promoted to the highest level among the formulae used. The average level of Pb accumulated in the above-ground part of P. hydropiper cultivated at formula 4 was 1,098.3 mg/kg dry weight (DW) after 45 days of cultivation that was 1.6 time higher than the one of formula 2 without fertilizer amendment (687.8 mg/kg DW). The potential of Pb extracted and stored in the above-ground part of P. hydropiper cultivated at formula 4 after 45 days was 479.2 g/ha that was 2.85 time higher than the one of formula 2 without fertilizer amendment (168.02 g/ha).Nghể răm Polygonum hydropiper L. được trồng theo 5 công thức trên đất phù sa không ô nhiễm chì (Pb = 2,6 mg/kg khô) và đất ô nhiễm chì (Pb = 1380 mg/kg khô)không bón phân và có bón phân với các liều lượng 2 g phân hữu cơ vi sinh/1 kg đất và 2,5; 5,0; 10,0 g phân NPK /1 kg đất. Sau 45 ngày thí nghiệm trồng cây, tăng trưởng về chiều cao và sinh khối của cây trên đất ô nhiễm Pb không bón phân thấp hơn trên đất phù sa, nhưng hàm lượng Pb trong phần trên mặt đất của cây cao hơn. Ở công thức (CT) 4, trên đất ô nhiễm chì (Pb = 1380 mg/kg khô) khi bón phân với liều lượng 2 g hữu cơ + 5 g NPK/1 kg đất (với tổng hàm lượng dinh dưỡng được bón là: N = 0,25, P2O5= 0,52, K2O = 0,15, và chất hữu cơ = 0,21 g/kg đất) thì tăng trưởng của câynghể răm đạt tối ưu (chiều cao và khối lượng đạt 244,0 % và 284, 9% so với trước thí nghiệm) và tiềm năng hút thu Pb của chúng cũng được thúc đẩy cao nhất trong số các công thức được sử dụng. Lượng Pb trung bình tích lũy trong phần trên mặt đất của nghể răm ở CT 4 đạt 1.098,3 mg/kg khô sau 45 ngày trồng, cao gấp 1,6 lần so với cây ở công thức 2 không bón phân (687,8 mg/kg khô). Khả năng loại bỏ Pb từ đất ô nhiễm của nghể răm khi được bón phân ở CT4 đạt 479,2 g/ha sau 45 ngày trồng, cao gấp 2,85 lần so với cây ở CT 2 không bón phân (168,02 g/ha)

Groundwater simulation in Dak Lak province based on MODFLOW model and climate change scenarios

Purpose – Groundwater plays a critical part in both natural and human existence. When surface water is scarce in arid climates, groundwater becomes an immensely valuable resource. Dak Lak is an area that frequently lacks water resources for everyday living and production, and the scarcity of water resources is exacerbated during the dry season. As a result, it is critical to do study and understand about groundwater to meet the region's water demand. This study aims to extend the use of the MODFLOW model for groundwater simulation and assess the overall groundwater reserves and water demand in the highland province Dak Lak. Design/methodology/approach – The MODFLOW model is used in this work to compute and analyze the flow, prospective reserves of groundwater from which to plan extraction and estimate groundwater variation in the future. Findings – The application of the MODFLOW model to Dak Lak province demonstrates that, despite limited data, particularly drilling hole data for subterranean water research, the model's calculation results have demonstrated its reliability and great potential for use in other similar places. The use of the model in conjunction with other data extraction modules is a useful input for creating underground flow module maps for various time periods. The large impact of recharge and evaporation on groundwater supplies and water balance in the research area is demonstrated by simulations of climate change scenarios RCP4.5 and RCP8.5. Originality/value – None of the studies has been done previously to analyze water resources of Dak Lak and the scarcity of water resources is exacerbated during the dry season. Therefore, this study will provide useful insights in the water resource management and the conservation of Dak Lak. The groundwater in Dak Lak can meet the area's water demand, according to the results obtained and water balance in the study area. However, the management of water resources and rigorous monitoring of groundwater extraction activities in the area should receive more attention

Rodents and risk in the Mekong delta of Vietnam: seroprevalence of selected zoonotic viruses in rodents and humans

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Redondoviridae: High Prevalence and Possibly Chronic Shedding in Human Respiratory Tract, But No Zoonotic Transmission

Redondoviridae is a recently discovered DNA virus family consisting of two species, vientovirus and brisavirus. Here we used PCR amplification and sequencing to characterize redondoviruses in nasal/throat swabs collected longitudinally from a cohort of 58 individuals working with animals in Vietnam. We additionally analyzed samples from animals to which redondovirus DNA-positive participants were exposed. Redondoviruses were detected in approximately 60% of study participants, including 33% (30/91) of samples collected during episodes of acute respiratory disease and in 50% (29/58) of baseline samples (with no respiratory symptoms). Vientovirus (73%; 24/33) was detected more frequently in samples than brisaviruses (27%; 9/33). In the 23 participants with at least 2 redondovirus-positive samples among their longitudinal samples, 10 (43.5%) had identical redondovirus replication-gene sequences detected (sampling duration: 35–132 days). We found no identical redondovirus replication genes in samples from different participants, and no redondoviruses were detected in 53 pooled nasal/throat swabs collected from domestic animals. Phylogenetic analysis described no large-scale geographical clustering between viruses from Vietnam, the US, Spain, and China, indicating that redondoviruses are highly genetically diverse and have a wide geographical distribution. Collectively, our study provides novel insights into the Redondoviridae family in humans, describing a high prevalence, potentially associated with chronic shedding in the respiratory tract with lack of evidence of zoonotic transmission from close animal contacts. The tropism and potential pathogenicity of this viral family remain to be determined

Redondoviridae: High Prevalence and Possibly Chronic Shedding in Human Respiratory Tract, But No Zoonotic Transmission

Redondoviridae is a recently discovered DNA virus family consisting of two species, vientovirus and brisavirus. Here we used PCR amplification and sequencing to characterize redondoviruses in nasal/throat swabs collected longitudinally from a cohort of 58 individuals working with animals in Vietnam. We additionally analyzed samples from animals to which redondovirus DNA-positive participants were exposed. Redondoviruses were detected in approximately 60% of study participants, including 33% (30/91) of samples collected during episodes of acute respiratory disease and in 50% (29/58) of baseline samples (with no respiratory symptoms). Vientovirus (73%; 24/33) was detected more frequently in samples than brisaviruses (27%; 9/33). In the 23 participants with at least 2 redondovirus-positive samples among their longitudinal samples, 10 (43.5%) had identical redondovirus replication-gene sequences detected (sampling duration: 35–132 days). We found no identical redondovirus replication genes in samples from different participants, and no redondoviruses were detected in 53 pooled nasal/throat swabs collected from domestic animals. Phylogenetic analysis described no large-scale geographical clustering between viruses from Vietnam, the US, Spain, and China, indicating that redondoviruses are highly genetically diverse and have a wide geographical distribution. Collectively, our study provides novel insights into the Redondoviridae family in humans, describing a high prevalence, potentially associated with chronic shedding in the respiratory tract with lack of evidence of zoonotic transmission from close animal contacts. The tropism and potential pathogenicity of this viral family remain to be determined