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Hoang Nguyen

Abstract

The paper presents the fuzzy methods in failure modes and effects analysis (FMEA) for estimating the risk of the ship system failures based on the expert judgments. It provides an appropriate representation of the uncertain and ambiguous notions expressed in the natural language. An example of fuzzy intuitionistic FMEA analysis is illustrated in estimating the risk of tanker system failures. The results show that the proposed method in comparison with the traditional FMEA is more effective and useful in estimating the risk of ship system failures based on the expert opinions, available in such cases.

Open access

Hoang Nguyen

The application of the ahp method in ship system risk estimation

The article presents procedures of application of the AHP method for estimating risks of ship systems. The estimation of system risk function parameters is done based on the data obtained from experts and processed using the pairwise comparative method.

Open access

Nguyen Quy Hoang

Abstract

Anattā or the Not-Self is a very important concept of Buddhism, which distinguishes it from other religions. there are some ways to explain this doctrine and many debates were happened between Buddhist schools and between Buddhists and the Brahmanists on this issue. Early Buddhism analyse that self is the combination of five aggregates (skandhas), and each of them is not the self. Based on this explanation, Buddhists think wrongly that anattā is ‘No-self. Deeply understand and practice of the not-self concept will help practitioners of Buddhism to be free from all sufferings. So, one needs to have a clear understanding on this concept. The purpose of this paper is to present a comprehensive view of Not-self (anattā) doctrine in Early Buddhism. All its related aspects are presented in succession. This article investigates the doctrine of anattā, it is also examined with other related doctrines in Early Buddhism. By analyzing method, the meaning of Not-self (anattā) in Early Buddhism is proposed by the author. (//https:www.abebooks.de/buchsuchen/titel/anatta/)

Open access

Hvedri Inassaridze, Le Hoang Mai and Nguyen Xuan Tuyen

Abstract

Based on the concept of accessible subhemirings and inspired by the work on the general Kurosh-Amitsur radical theory for rings, this paper studies the lower radical classes and the hereditary radical classes of hemirings. We characterize radical classes of hemirings, and con- struct a lower radical class from a homomorphically closed class. We provide a necessary and sufficient condition under which an upper radical class of hemirings becomes hereditary and prove that an upper radical class of a regular class of semirings is hereditary. Besides, we show that the Brown-McCoy radical class and a Jacobson-type radical class are hereditary.

Open access

Alfred Brandowski, Andrzej Mielewczyk, Hoang Nguyen and Wojciech Frąckowiak

A Fuzzy - Neuron Model of the Ship Propulsion Risk Prediction

A prediction model is presented of the ship propulsion risk, i.e. a risk of the consequences of loss of the ship propulsion capability. This is an expert model based on opinions elicited by the ship power plant operators. The risk level depends, among other things, on the reliability state of the ship propulsion system components. This state is defined by operators in a linguistic form. The formal risk model parameters are determined by means of a neural network.

Open access

A. Brandowski, Hoang Nguyen and Wojciech Frąckowiak

ABSTRACT

The neural network tuning procedure applied to reliability analyses of anthrop technical systems, based on judgements of experts - experienced operating practicians. Numerical and linguistic elicitation of the judgements, analyses of the network input and output data correlation and of the AHP method processing deviation are presented. Example of data elicitation and correlation analysis of a reliability arrangement of the seagoing ship propulsion system are included to the article.

Open access

Cong Tien Nguyen, Ha Manh Bui and Duyen Hoang My Nguyen

Abstract

The A new benzothiazepine’s derivative names N-(p-tolyl)-2-(2-(4-phenyl-2,3-dihydrobenzo[b][1,4]thiazepin-2-yl)phenoxy)acetamide was synthesized by reaction of o-aminothiophenol and N-(p-tolyl)-2-(2-(3-oxo-3-phenylprop-1-en-1-yl)phenoxy)acetamide, which was prepared from salicylaldehyde and acetophenone through (E)-3-(2-hydroxyphenyl)-1-phenylprop-2-en-1-one. The structures of the compounds were determined by IR, 1H-NMR, 13C-NMR and HR-MS spectral data.

Open access

Q. Nguyen, D. Quyen and T. Hoang

Abstract

A new route of emulsifier-free emulsion polymerization based on the homogenous mechanism was investigated to prepare magnetic nanoparticles coated by poly (methyl methacrylate) (PMMA). The experimental results confirm the formation of PMMA thin and unique layers covering magnetite cores. The polymer layer thickness, determined from transmission electron microscopy (TEM) images, increases from 4.3 nm to 6.8 nm with increasing mass ratio of MMA to magnetite from 3:1 to 11:1. The increase of the polymer thickness results in the decrease in magnetization saturation of polymeric coated magnetic particles. However, this reduction, no more than 13 emu g−1, is much lower compared to that in other studies with the presence of surfactants or emulsifiers. Besides, the dispersion stability of the prepared particles is significantly improved.

Open access

Tran Hoang Quang Minh, Nguyen Huu Khanh Nhan, Nguyen Doan Quoc Anh and Hsiao-Yi Lee

Abstract

This paper investigates a method for improving the lighting performance of white light-emitting diodes (WLEDs), packaged using two separating remote phosphor layers, yellow-emitting YAG:Ce phosphor layer and red-emitting α-SrO·3B2O3:Sm2+ phosphor layer. The thicknesses of these two layers are 800 μm and 200 μm, respectively. Both of them have been examined at average correlated color temperatures (CCT) of 7700 K and 8500 K. For this two-layer model, the concentration of red phosphor has been varied from 2 % to 30 % in the upper layer, while in the lower layer the yellow phosphor concentration was kept at 15 %. It was found interesting that the lighting properties, such as color rendering index (CRI) and luminous flux, are enhanced significantly, while the color uniformity is maintained at a level relatively close to the level in one-layer configuration (measured at the same correlated color temperature). Besides, the transmitted and reflected light of each phosphor layer have been revised by combining Kubelka-Munk and Mie-Lorenz theories. Through the analysis, it is demonstrated that the packaging configuration of two-layered remote phosphor that contains red-emitting α-SrO·3B2O3:Sm2+ phosphor particles provides a practical solution to general WLEDs lighting.

Open access

Nguyen Thuy Lan Chi, Phan Dao and Hoang Khanh Hoa

Abstract

Wisely using natural water resources to serve human needs plays a decisive role in ensuring water and food security. In the natural water cycle, rainwater is considered as a valuable renewable resource. Rainwater harvesting (RWH) for daily life and production is a simple but effective and also environmentally sound measure. It is also a positive solution in a climate change adaptation strategy. However, this resource is being wasted in our country in general and in the HCM City in particular. This paper provides an overview of the status of rainwater use in the world; the general situation, the potential of rainwater collection and a number of issues related to the potential of rainwater harvesting in the city. Some solutions to enhance the use of rainwater and improve water supply for city residents are also suggested in this discussion.