Biểu diễn phụ thuộc hàm xấp xỉ theo phân hoạch, ma trận phân biệt được và luật kết hợp

Approximate Functional Dependencies (AFD) and Association Rules are really meaningful knowledge in data mining. In this article, we first recall some basic concepts of rough set theory, error measures $g_1$, $g_2$ and $g_3$ for functional dependencies. Then, based on the method of partitions and expectation in probability theory, we propose an error measure $g_4$ to construct the discernibility matrix in a different way, defined error measures $g_1$, $g_2$, dependency degree $\gamma$ and significance of Attributes $\sigma$ from the discernibility matrix. Finally, a relationship between AFD and Association Rules via error measure $g_4$ and confidence is presented.Các phụ thuộc hàm xấp xỉ và luật kết hợp là những tri thức thực sự có ý nghĩa trong khai phá dữ liệu. Trong bài báo này, đầu tiên, chúng tôi nhắc lại một số khái niệm cơ bản của lý thuyết tập thô, các độ đo lỗi $g_1, g_2, g_3$ của phụ thuộc hàm. Sau đó, chúng tôi đề xuất độ đo lỗi $g_4$ dựa trên phân hoạch. Phần tiếp theo chúng tôi xây dựng ma trận phân biệt theo một cách khác và biểu diễn các độ đo lỗi $g_1, g_2$ độ phụ thuộc $\gamma$ và ý nghĩa thuộc tính $\sigma$ theo ma trận phân biệt được. Cuối cùng, chúng tôi đưa ra mối liên hệ giữa phụ thuộc hàm xấp xỉ và luật kết hợp thông qua độ đo lỗi $g_4$ và độ tin cậy Confidence

Conditional Support Alignment for Domain Adaptation with Label Shift

Unsupervised domain adaptation (UDA) refers to a domain adaptation framework in which a learning model is trained based on the labeled samples on the source domain and unlabelled ones in the target domain. The dominant existing methods in the field that rely on the classical covariate shift assumption to learn domain-invariant feature representation have yielded suboptimal performance under the label distribution shift between source and target domains. In this paper, we propose a novel conditional adversarial support alignment (CASA) whose aim is to minimize the conditional symmetric support divergence between the source's and target domain's feature representation distributions, aiming at a more helpful representation for the classification task. We also introduce a novel theoretical target risk bound, which justifies the merits of aligning the supports of conditional feature distributions compared to the existing marginal support alignment approach in the UDA settings. We then provide a complete training process for learning in which the objective optimization functions are precisely based on the proposed target risk bound. Our empirical results demonstrate that CASA outperforms other state-of-the-art methods on different UDA benchmark tasks under label shift conditions

Approximation Measures for Conditional Functional Dependencies Using Stripped Conditional Partitions

Conditional functional dependencies (CFDs) have been used to improve the quality of data, including detecting and repairing data inconsistencies. Approximation measures have significant importance for data dependencies in data mining. To adapt to exceptions in real data, the measures are used to relax the strictness of CFDs for more generalized dependencies, called approximate conditional functional dependencies (ACFDs). This paper analyzes the weaknesses of dependency degree, confidence and conviction measures for general CFDs (constant and variable CFDs). A new measure for general CFDs based on incomplete knowledge granularity is proposed to measure the approximation of these dependencies as well as the distribution of data tuples into the conditional equivalence classes. Finally, the effectiveness of stripped conditional partitions and this new measure are evaluated on synthetic and real data sets. These results are important to the study of theory of approximation dependencies and improvement of discovery algorithms of CFDs and ACFDs

MÔ PHỎNG ẢNH HƯỞNG CỦA MỰC NƯỚC BIỂN DÂNG ĐẾN BIẾN ĐỘNG ĐỊA HÌNH ĐÁY VÙNG VEN BỜ CỬA SÔNG MÊ KÔNG

This paper presents some study results on morphological change in the coastal region of Mekong River under the influences of sea level rise. In order to set up the models, measured data were collected, systematically and homogeneously processed to create open boundary conditions (time-serial data) for the model. Open sea boundary conditions of the model were created by NESTING method. The model (Delft3D model) was set up with 4 layers in Sigma coordinate. The results of model were validated, showing a fairly good agreement with measured data (water elevation, currents, and suspended sediment concentration) at some places in the study area. Results of some scenarios of simulation (dry and flood season) show the sea level rise due to climate change could make a reduction in the seaward sediment transport and increase its settling around estuaries. As a result, sea level rise causes an increase in the accreted rate of sandbars in southern estuary of Mekong river coastal area. The influences of sea level rise on Mekong river coastal bed topography are prevailing in the region of about 7 - 10 km seawards. Further 10 km from the coast, influences of sea level rise on coastal morphology are not significant.Bài báo trình bày các kết quả nghiên cứu dự báo biến động địa hình ở vùng ven bờ châu thổ sông Mê Kông dưới ảnh hưởng của nước biển dâng. Để thiết lập mô hình tính, các chuỗi số liệu quan trắc đã được thu thập, xử lý hệ thống và đồng bộ cho các điều kiện biên (sông, biển) của mô hình dạng chuỗi số liệu (time serial data). Các biên mở phía biển của mô hình được tạo ra bằng phương pháp lưới lồng (NESTING) từ mô hình có miền tính rộng hơn ở phía ngoài. Mô hình Delft3D với 4 lớp độ sâu theo hệ tọa độ Sigma đã được thiết lập và kiểm chứng cho thấy có sự phù hợp với số liệu đo đạc. Kết quả dự báo trong mùa cạn và mùa lũ đã cho thấy sự dâng cao mực nước biển do biến đổi khí hậu làm hạn chế sự phát tán của dòng trầm tích về phía biển và tập trung di chuyển quanh các cửa sông. Qua đó làm tăng tốc độ bồi tại các bãi bồi khu vực phía ngoài các cửa sông phía nam của vùng ven bờ châu thổ sông Mê Kông. Những ảnh hưởng do dâng cao mực nước biển đến địa hình đáy ven bờ châu thổ sông Mê Kông phổ biến diễn ra trong phạm vi khoảng 7 -       10 km từ cửa sông ra phía ngoài. Ở phía ngoài 10 km từ bờ ra, ảnh hưởng do dâng cao mực nước đến địa hình đáy hầu như không đáng kể

Effects of protein levels of commercial diets on the growth performance and survival rate of rabbitfish (Siganus guttatus) at the nursing stage

This study aimed to determine the effect of a commercial diet's protein level on the fry-to-fingerling stage. Thirty days-old fries having the initial length and weight of 18.25 ± 0.15 mm fish-1 and 0.036 ± 0.50 g fish-1 respectively have been used in this study. Diet having three protein levels i.e. 30% (trial 1 as control), 35% (trial 2), 40% (trial 3), and 45% (trial 4), respectively, have been used to evaluate the effect of protein, and each trial has been repeated three times. During the study, stocking density was allocated to 1000 fish per composite tank with a volume of 1 m3. After 30 days of rearing, the weight of fingerlings in trial 1 reached up to 1.50 ± 0.02 g fish-1 and it was recorded as 1.52 ± 0.01g for trial 2, these two were lower than that of trials 3 and 4, where fingerling weight was reported 1.69 ± 0.01 and 1.58g fish-1 respectively and obtained the best weight compared to others. The length of fingerlings at the end of the experimental period was also changed in different trials and it was recorded 47.12; 46.92; 50.97; and 48.89 mm fish-1 for trail 1, 2, 3, and 4 respectively, among the tested combinations lower fingerlings length was recorded for trial 2 (35% CP), but it is not significantly different for trial 1 and 2 and a significant difference (P < 0.05) was reported for trail 2, 3, and 4. The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVW) in the treatment using 40% protein (trial 3) was the highest at 72.33% (p < 0.05). The results of the study can be concluded that the level of protein has a significant effect on the various growth parameters of fingerlings

Disinfection performance of an ultraviolet lamp: a CFD investigation

Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls

LAKESCAPE UNDER URBAN DEVELOPMENT IN DONG DA DISTRICT, HANOI CITY

Joint Research on Environmental Science and Technology for the Eart

The acceptance of mobile applications for accommodation booking in Vietnam: Case of gen Z

The development of technology and smart mobile devices such as phones and tablets has changed the behavior of tourists when booking tourism services. Based on the technology acceptance model, this study aims to explore the factors influencing the intention to use mobile applications for accommodation booking among GENZ in Vietnam. The analysis of 218 users revealed that four factors influence the behavior of using mobile applications for booking: performance expectancy, effort expectancy, social influence, and hedonic motivation. In addition to identifying the factors affecting usage intention, this study also proposes implications to assist developers and providers in improving their applications and developing suitable product strategies for the future

LAND USE CHANGE AND RELATED PROBLEMS UNDER URBANIZATION IN SUBURBAN AREA OF HANOI CITY (A CASE STUDY OF HOANG LIET COMMUNE, THANH TRI DISTRICT)

Joint Research on Environmental Science and Technology for the Eart