Unbiased Pairwise Approach toward Learning-to-Rank: An Empirical Study

With the bloom of information technology in recent decades, people are constantly being exposed to a huge amount of information. Learning-to-rank comes out as one of the solutions to ease out the mentioned obstacle by trying to rearrange objects according to their degrees of importance or relevance. This solution usually applies machine learning techniques to construct ranking models in information retrieval systems. The aim of this study is to explore and experiment the existing learning-to-rank approaches with real-life logs data. The study also includes estimating and minimizing the bias noise found in the click-through data of the recorded logs. Evaluation results have presented the advantage and disadvantage of the experimented approaches in realistic settings

Effect of land-use changes resulting from shrimp farming on acid sulfate soils in the Can Gio coastal wetland area (Vietnam)

Acid sulfate soils in coastal wetland areas are particularly vulnerable to land-use changes. We identifid the potential impacts of land-use changes in the Can Gio coastal wetland area in Vietnam due to the reclamation of acid sulfate soils from shrimp farms. Our study applied the support of vector machine algorithm in ENVI software to observe land-use changes from 1995 to 2015, using Landsat Thematic Mapper and Operational Land Imager data. We classifid the land use of the study area into four major classes including vegetation, bare land, dedicated land and aquaculture land. Our study successfully met the overall classifiation accuracy requirement above 95% and kappa statistics above 0.95. Between 1995 and 2006, about 2,938.05 ha of bare land and 1,464.66 ha of vegetation (mangrove forest) were converted to aquaculture land. In contrast, between 2006 and 2015, 2,423.88 ha of aquaculture land converted back to bare land, mainly related to the abandonment of shrimp ponds due to crop failure and disease. The disturbance of acid sulfate soils through initial soil reclamation and subsequent fallowing is considered a key reason for hastening and extending soil acidifiation in the study area. We collected 144 topsoil samples from 17 fallowed ponds in two batches, and 142 of these were acidic: 128 samples were extremely and strongly acidic (pH < 5.5), 14 samples were moderately and slightly acid (pH between 5.5 and 6.5), and only two samples were neutral (pH over 6.5)

Application of the Fenton-like agent based on magnetic iron and manganese oxide in the degradation process of paracetamol in water

A Fenton-like catalyst MnO2-Fe3O4/SiO2 is synthesized via a two-step approach. The prepared composite has a mesoporous structure and a high surface area of 190 m2/g. The XRD pattern describes a specific peak of Fe3O4 magnetite on the baseline of amorphous silica. Furthermore, the FTIR spectra not only show the height assigned to stretching vibrations of Si-O-Si bonds, and Fe–O–Fe connections but also exhibit a small peak that matches the Mn–O bonds. SEM images exhibit a porous network structure of the composites with some holes among 30 – 100 nm clusters. The activity of the catalyst is determined in a paracetamol degradation as a Fenton oxidation. The paracetamol removal efficiency is at 85.6% with the optimal condition as initial pH 3, catalyst dosage of 0.15 g/50mL and H2O2 concentration of 1 mL/50 mL. In addition, the catalyst can be reused at least 5 times with a low reduction of the catalytic activity from 85.6% to 80.8%. The experiment results open a direction that has high efficiency in the treatment process of excess paracetamol in pharmacy wastewater

Automatic Crack Detection in Built Infrastructure Using Unmanned Aerial Vehicles

This paper addresses the problem of crack detection which is essential for health monitoring of built infrastructure. Our approach includes two stages, data collection using unmanned aerial vehicles (UAVs) and crack detection using histogram analysis. For the data collection, a 3D model of the structure is first created by using laser scanners. Based on the model, geometric properties are extracted to generate way points necessary for navigating the UAV to take images of the structure. Then, our next step is to stick together those obtained images from the overlapped field of view. The resulting image is then clustered by histogram analysis and peak detection. Potential cracks are finally identified by using locally adaptive thresholds. The whole process is automatically carried out so that the inspection time is significantly improved while safety hazards can be minimised. A prototypical system has been developed for evaluation and experimental results are included.Comment: In proceeding of The 34th International Symposium on Automation and Robotics in Construction (ISARC), pp. 823-829, Taipei, Taiwan, 201

Review of Impacts of Leadership Competence of Project Managers on Construction Project Success

Leadership - Human endeavors play an important role in all areas of socio-economic development for any country in the world. Construction investment projects need more leadership role by their own characteristics. This research aims to give an overview of the theories of project manager leadership competence, the viewpoints of evaluation of the project's success, and the views on the influence of leadership competences and the success of the project. Research on the use of reliable secondary document sources in the world is synthesized from research works, scientific reports in the field of project management. The results of this study show that there is a great deal of research literature on project manager leadership competence and the success of the project in general but not many research papers on construction projects. This research is intended to suggest further studies to determine the specific influences, from that the training direction will increase the project management competence in the field of construction

Determinants Influencing Consumers’ Attitude Towards Online Shopping: An Extension of the Technology Acceptance Model

This research is conducted for investigating determinants influencing consumers’ attitude towards online shopping. The survey was based on 423 Vietnamese Internet users. Data collected was analyzed in accordance with the process from Cronbach's Alpha to EFA and multiple regression technique. The results show that consumers’ attitude towards online shopping was impacted by perceived usefulness, compatibility and trust. Based on the findings, some recommendations are given for retailers to improve customers’ attitude toward online shopping in the context of Vietnam in particular and in emerging countries in general. Keywords: Attitude, Online shopping, Perceived usefulness, Trust

NGUỒN GIỐNG TÔM, CÁ VÙNG NƯỚC VEN CÁC ĐẢO THUỘC QUẦN ĐẢO TRƯỜNG SA

Belonging to the Indo - Pacific tropical marine biodiversity Central, marine living communities at the coastal waters of Islands of Truong Sa Archipelago plays the important roles in conservation and cover distribution the breeds of marine living resources (including larva forms of shrimp, fish anf others) not only in this areas but also in the neughbour waters. However, due to far from mainlands, the studies on them is limited to now. Samples was collected at the 3 - 7 transects with long 100m to 30 - 50m deepth, where is around some island such as Nam Yet, Da Nam, big Truong Sa, Song Tu Tay ... There are two stations was located on every transect for sampling the species composition and individual numbers of larva. Samples was catched by net with 200µ diameter in the vertical drawing following the water colum. This primary results that were identified including 46 taxons of fish, shrimp and others larva. Most of them are belonging to the coral fish anh shrimp and the widely distribution ecological groups having high econimic value such as: Labridae, Scaridae, Nemipteridae, Nephridae, Palinuridae ... The spatial taxon of larva diversity distribution is not very regular every island. The taxon diversity at the big Truong Sa, Nam Yet, Da Nam ones is higher than the others with 18 - 31 taxons/island. The others is have only about 10 taxons/islands. The medium individual number of larva is rather higher than that in the other sites which is in nearshore water with about 300 inds/100m3. The highest concentration of inds number of fish and shrimp larva is at the stations having good coral reefs.Nằm trong vùng biển nhiệt đới là một trong những trung tâm đa dạng sinh học và phát sinh các loài thuộc vùng địa động vật Ấn Độ - Thái Bình Dương, nên quần xã sinh vật vùng biển và ven  các đảo Trường Sa có vai trò rất quan trọng trong việc duy trì và phát tán nguồn giống các loài sinh vật thuỷ sinh  cho  các vùng biển lân cận. Tuy nhiên do điều kiện địa lý xa cách, nên những nghiên cứu về sinh vật phù du nói chung và  nguồn giống các loại động vật thuỷ sản như tôm, cua, cá và thân mềm nói riêng ở vùng nước quanh các đảo vùng biển Trường Sa còn rất hạn chế. Kết quả trong bài báo thống kê từ kết quả khi thu mẫu các loại ấu trùng tôm, cá trên 3 - 7 mặt cắt (mỗi mặt cắt 2 trạm) thuộc 9 đảo tại quần đảo Trường Sa trong năm 2007 - 2008 do đề tài nghiên cứu cơ sở khoa học xây dựng các khu bảo tồn biển quần đảo Trường Sa tổ chức. Kết quả nghiên cứu cho thấy thành phần nguồn giống gồm 46 taxon là ấu trùng các giai đoạn của tôm, cua, cá và thân mềm. Trong đó có 26 taxon là ấu trùng cá, 16 taxon là ấu trùng tôm, 5 taxon ấu trùng cua và thân mềm. Hầu hết đều là các loại cá, tôm có giá trị kinh tế và chỉ thị tốt cho rạn san hô (RSH) như: Labridae, Scaridae, Nemipteridae, Nephridae, Palinuridae. Kết quả cũng xác định khu vực quanh đảo Trường Sa lớn, Nam Yết và Đá Nam thành phần nguồn giống đa dạng nhất với 18 - 31 đơn vị taxon. Mật độ trung bình của  ấu trùng tôm, cá khá cao tới hơn 300 con/100m3, cao hơn một số khu vực ven các đảo gần bờ và có sự tập trung mật độ cao nhất tại các nơi có RSH phát triển tốt nhất

How scientific research changes the Vietnamese higher education landscape: Evidence from social sciences and humanities between 2008 and 2019

Background: In the context of globalization, Vietnamese universities, whose primary function is teaching, there is a need to improve research performance. Methods: Based on SSHPA data, an exclusive database of Vietnamese social sciences and humanities researchers’ productivity, between 2008 and 2019 period, this study analyzes the research output of Vietnamese universities in the field of social sciences and humanities. Results: Vietnamese universities have been steadily producing a high volume of publications in the 2008-2019 period, with a peak of 598 articles in 2019. Moreover, many private universities and institutions are also joining the publication race, pushing competitiveness in the country. Conclusions: Solutions to improve both quantity and quality of Vietnamese universities’ research practice in the context of the industrial revolution 4.0 could be applying international criteria in Vietnamese higher education, developing scientific and critical thinking for general and STEM education, and promoting science communication