1,734,280 research outputs found
Mertens conjecture counterexamples
No full text<p>This contains the best bounds known for the smallest Mertens conjecture counterexamples given in the manuscript</p>
<p>"On counterexamples to the Mertens conjecture" by Seungki Kim and Phong Nguyen. Source codes and data files are provided to reproduce the experiments. </p>
<p>The README file explains the meaning of the files. The libraries ARB and NTL are required.</p>
A dataset for the detection of mathematical expressions in camera captured document images acquired in Vietnam
No full textThe dataset consists of 6000 Vietnamese camera captured document images that containing mathematical expressions. The dataset can be used for the detection of mathematical expressions in camera document images issue. This is the first dataset for the detection of mathematical expressions in Vietnamese camera captured document images.The annotation files (in .json format) provides position information of mathematical expressions. Researcher can use the Intersection of Union (IoU) metric to determine if the detection is correct or not by using the dataset.Please, kindly refer the following articles when using the datasets:[1] Bui Hai Phong et al., "Mathematical Expression Detection in Camera Captured Document Images", Lecture Notes on Data Engineering and Communications Technologiesthis link is disabled, 2022, 148, pp. 98–109, 2022.[2] Bui Hai Phong et al., "An end-to-end framework for the detection of mathematical expressions in scientific document images",Expert Systemsthis link is disabled, 2022, 39(1), e12800, 2022
Mertens conjecture counterexamples
No full text<p>This contains the best bounds known for the smallest Mertens conjecture counterexamples given in the manuscript</p>
<p>"On counterexamples to the Mertens conjecture" by Seungki Kim and Phong Nguyen. Source codes and data files are provided to reproduce the experiments. </p>
<p>The README file explains the meaning of the files. The libraries ARB and NTL are required.</p>
Community Forestland Management, Outside Interventions and Local Responses: The case of the Thai ethnic group in the Hanh Dich commune, Que Phong district, Nghe An province, Vietnam
No full textIn an increasing interaction between indigenous or isolated ethnic communities and outside actors, a lack of confirmation of local forestland rights is seen as one of the most critical issues. Does the outsiders’ occupancy of land for rent seeking and authoritative patronage for forest management meet the dispossessed people’s aspirations? How and to what extent should local communities be involved in forestland management and play a determining role in their own future? To answer these questions, this research is based on in-depth interviews focusing on the folk traditions, cultural beliefs, customary laws, local knowledge, and comments and recommendations of the local Thai ethnic people and some outsiders residing in the Hanh Dich commune, Que Phong district, Nghe An province, Vietnam. In addition, a number of previous case studies and reports from the archive of SPERI (Social Policy Ecology Research Institute) and its alliance members have been synthesised and analysed.
The essential findings and arguments in this thesis comprise the local Thai people’s cultural traits, chronicles of outside interventions, local responses, and cognitive and methodological approaches to the study of indigenous cultures and their forestlands. It was found that local people have been upholding their holistic and unique perspectives, beliefs, customary laws, traditional organizational and institutional practices and that these inherent values and strengths can contribute effectively to forest protection and improvement of local people’s livelihood. However, it was also observed that the increasing imposition of the mainstream top-down approaches have not recognized or encouraged, that is to say, have undermined local strengths and values. In addition, on the basis of an ethnocentric view, superficial perceptions of the ethnic minority peoples and their values have pervaded in the Vietnamese media. These phenomena raise questions as to cultural rights, human rights, and the quality of the policy making process and law enforcement which are inevitably affected by these ethnocentric views and approaches.
To counteract the hurtful effects of mainstream interventions, local people have responded in a subtle and implicit way. As a result of outside interventions, they have had to find ways to adjust their productive and cultural settings. However, there remain wishes to recover traditional cultural values, especially in the minds of the elders. In an alternative bottom-up approach facilitated by SPERI, the people are stimulated to promote their own institutional and organizational strengths towards their brighter future. In a democratized and decentralized process, community’s land rights and customary rights should be officially recognized and confirmed. But official recognition should not be seen as the final goal, only as a supportive factor while the local community’s strengths and self-enforcement of their rights are determinant. To this end, indigenous peoples need further opportunities for networking, capacity building, and taking part in thorough socio-cultural ethnographic research in order to ensure that they are more truly and fairly represented
Oral History of Phong Duc Do
No full textAn oral history with Phong Duc Do, born in 1958 in Saigon, Vietnam. He grew up with 3 siblings and his interview focused on experiences with the education system in Vietnam as well as the social relations between friends in the 1960s and 1970s in Saigon. His father was sent to reeducation camp in 1975 and as the oldest brother, he had to work to support his family. He tried escaping Vietnam as a boat refugee but failed and then in 1991 his family left through the Humanitarian Operation under the Orderly Departure Program. He was sponsored to Washington state but eventually resettled in San Diego, California. After working in various jobs and attending school, he got a job as an aircraft engineer working for the US Navy.Recorded Digitall
A two-stage reduction for complex combustion chemistry
No full textThe combustion of hydrocarbon is a main energy resource for transportation. It is easy to start but very hard to understand and simulate. There have been several efforts to build detailed kinetic mechanisms from elementary reactions. Although they are highly accurate and well capture the complicated chemistry of combustion process, it is expensive to model with detailed mechanisms because their size is too large. Furthermore, it is not effective to apply detailed mechanism while there are only some of species and reactions involved in a typical condition. Therefore, a suitable reduced mechanism for such considered condition is a hot requirement. Recently, Petzold et al., and Androulakis suggested an automatic mechanism reduction based on the mathematical programming method. Following their approach, Banerjee et al. applied GA search to generate reduced mechanisms. The fruit of that work is a reduced mechanism library, which can govern combustion of air -- methane mixture with high accuracy. Nevertheless, the GA reduction method is hard to directly apply to the complex chemistry whose solution space is large. It, therefore, needs a first step of reduction, which can condense the search space of complex combustion mechanisms. Androulakis provided a method based on flux analysis to build a reduced mechanism with a suitable cut-off value of element flux accumulation. Although his method is flexible and very fast, the obtained mechanism can contain some species, which can be further eliminated. In this work, the two approaches mentioned above were combined to form a two-step reduction procedure on n-pentane and n-heptane mechanism. The flux analysis reduction was used first to obtain a skeleton reduced mechanism. Then the GA reduction considered the obtained mechanism as a detailed mechanism for parallel GA search. Nine conditions of n-pentane and nine conditions of n-heptane oxidation were investigated. Although the size of the final reduced mechanisms is much smaller than that of detailed mechanisms, they well estimate the oxidation process.M.S.Includes bibliographical references (p. 64-67)by Phong Tien Huyn
Solvent-free beta-carotene nanoparticles for food fortification
No full textMost nutraceutical compounds are poorly-water soluble. Their low solubility decreases the adsorption rate in living organisms leading to their low bioavailability. Utilization of nanoparticles is a promising way to improve the solubility of hydrophobic compounds. Nanoparticles increase the total surface area of the poorly-water soluble nutraceuticals making them more bioavailable. Some traditional methods for decreasing particle size include pearl or jet milling, where particles are broken down through grinding or collisions under high pressure. These mechanical processes not only require high energy input but also raise a concern of milling media residues. The high pressure homogenizer approach applies implosion forces and collision of particles to generate nanosuspensions. This method requires microsuspensions as starting material and consumes high energy. Among several emulsion-based techniques for preparing nanoparticles, solvent diffusion practice is a novel approach in which a poorly-water soluble compound is transferred into nanoemulsion droplets of a partially water-soluble organic solvent. The compound then crystallizes because the solvent diffuses out of the emulsion droplets. The key point of proposed emulsion-diffusion technology is that the phase transition occurs within an isolated nanoemulsion droplet. The main purpose of this study is to develop a “green” and scalable method for preparing nanosuspensions of highly hydrophobic compounds. We use FDA GRAS ingredients to create nanoparticles of poorly-water soluble nutraceuticals. β-carotene is selected as a model hydrophobic nutraceutical. Triacetin, a partially- water soluble triacetate compound, is used as the dispersed phase of nanoemulsions. The influence of surfactant, water concentration, and homogenization time on particle size and stability is investigated. The impact of surfactant on diffusion flux of triacetin is studied. Kolmogorov theory is applied to reveal the breakup mechanism of emulsion droplets under shear and predict their size. A mathematical model is built to discover the size of emulsion droplet during the formation of nanosuspensions. It is hoped that the this work will greatly advance the manufacture of nanoparticles of poorly-water soluble nutraceuticalsPh. D.Includes bibliographical referencesby Phong Tien Huyn
Optimized Phong and Blinn-Phong Glossy Highlights
No full textFigure 1 . Phong-illuminated teapot with shininess exponent α = 50. Blue color is used to visualize pixels where the glossy computation is skipped in a standard implementation (middle image) and using the proposed technique (right image). Abstract We describe a simple technique to compute the threshold at which glossy lobes in Phong or Blinn-Phong-like reflection models are negligible and thus avoid the cost of an exponentiation and a few other operations. The technique is trivial to incorporate into existing shaders. For existing shaders that already branch when the glossy term is zero, it introduces little overhead. SIMD or GPU shaders that do not already branch will incur the overhead of a branch and may experience divergence, which should be weighed against the potential advantages
PHONG CÁCH VÀ PHONG CÁCH TƯ DUY – MỘT SỐ VẤN ĐỀ CỐT YẾU
No full text Khái niệm phong cách và phong cách tư duy được đề cập rất nhiều trong các công trình nghiên cứu gần đây. Bài viết này, trên cơ sở của các công trình nghiên cứu trước đó, cố gắng nhận diện chính xác nội hàm khái niệm phong cách và phong cách tư duy. Trong đó, tập trung làm rõ bản chất, những yếu tố cấu thành của phong cách tư duy dưới góc nhìn khoa học, gợi mở một số vấn đề có tính chất phương pháp luận nhằm rèn luyện phong cách tư duy khoa học
Optimized Phong and Blinn-Phong Glossy Highlights
No full textFigure 1 . Phong-illuminated teapot with shininess exponent a = 50. Blue color is used to visualize pixels where the glossy computation is skipped in a standard implementation (middle image) and using the proposed technique (right image). Abstract We describe a simple technique to compute the threshold at which glossy lobes in Phong or Blinn-Phong-like reflection models are negligible and thus avoid the cost of an exponentiation and a few other operations. The technique is trivial to incorporate into existing shaders. For existing shaders that already branch when the glossy term is zero, it introduces little overhead. SIMD or GPU shaders that do not already branch will incur the overhead of a branch and may experience divergence, which should be weighed against the potential advantages
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