Advanced deep flux weakening operation control strategies for IPMSM

This paper proposes an advanced flux-weakening control method to enlarge the speed range of interior permanent magnet synchronous motor (IPMSM). In the deep flux weakening (FW) region, the flux linkage decreases as the motor speed increases, increasing instability. Classic control methods will be unstable when operating in this area when changing load torque or reference speed is required. The paper proposes a hybrid control method to eliminate instability caused by voltage limit violation and improve the reference velocity-tracking efficiency when combining two classic control methods. Besides, the effective zone of IPMSM in the FW is analyzed and applied to enhance stability and efficiency following reference velocity. Simulation results demonstrate the strength and effectiveness of the proposed method

BIẾN ĐỘNG THÀNH PHẦN LOÀI VÀ MẬT ĐỘ TRỨNG CÁ, CÁ CON HỌ CÁ MỐI (SYNODONTIDAE) Ở VÙNG BIỂN VỊNH BẮC BỘ, VIỆT NAM

Lizardfishes are one of the most common and primary fishes mainly caught by bottom trawls and set gillnets in the Gulf of Tonkin. According to the result of 16 species at early stage sampled from surveys between 2011 and 2013, 4 species and 1 species group were identified: Greater lizardfish (Saurida tumbil), brushtooth lizardfish (S. undosquamis), slender lizardfish (S. elongata), snakefish (Trachinocephalus myops) and lizardfish (Synodus spp. and Saurida sp.). There was an annual fluctuation in the number and encounter frequency of fish larvae and eggs. The density of fish larvae and eggs reduced steadily from 584 to 74 eggs/1,000 m3 seawater and from 30 to 1,785 fish larvae/1,000 m3 seawater. Variation in density was relatively obvious depending on monsoon. Lizardfish’s eggs and larvae were mainly distributed in the north of the Gulf of Tonkin. In Northeast monsoon, while lizardfish’s eggs were primarily concentrated around Bach Long Vi island and scattered around the center of the Gulf of Tonkin, fish larvae were often caught in the offshore areas of Thanh Hoa - Nghe An provinces and the southern sea of Bach Long Vi island. By contrast, in Southwest monsoon, fish larvae and eggs were mainly concentrated in inshore areas such as coastal areas of Quang Ninh and Thanh Hoa provinces and around Cat Ba island.Cá mối được khai thác chính bằng nghề lưới kéo đáy và nghề lưới rê đáy ở vùng biển vịnh Bắc Bộ. Qua 16 chuyến điều tra, thu mẫu giai đoạn sớm ở vùng biển Bắc Bộ từ năm 2011-2013, đã xác định được 4 loài và 1 nhóm loài trứng cá, cá con thuộc họ cá mối là: Loài cá mối thường (Saurida tumbil), loài cá mối vạch (S. undosquamis), loài cá mối ngắn (S. elongata), loài cá mối hoa (Trachinocephalus myops) và nhóm cá mối (Synodus spp. và Saurida sp.). Số lượng và tần suất bắt gặp trứng cá, cá con họ cá mối có sự biến động qua các năm. Mật độ trứng cá cá con có xu hướng giảm dần theo thời gian, dao động từ 584 trứng cá đến 74.272 trứng cá/1.000 m3 nước biển và từ 30 cá con đến 1.785 cá con/1.000 m3 nước biển. Biến động về mật độ thể hiện tương đối rõ theo mùa gió. Trứng cá, cá con thuộc họ cá mối phân bố chủ yếu ở vùng biển phía bắc vịnh Bắc Bộ. Trong mùa gió Đông Bắc, trứng cá thường tập trung ở khu vực Bạch Long Vĩ và rải rác ở khu vực gần giữa vịnh; cá con thì xuất hiện nhiều ở vùng ngoài khơi Thanh Hóa - Nghệ An và phía nam đảo Bạch Long Vĩ. Sang mùa gió Tây Nam, trứng cá, cá con có xu thế tập trung ở khu vực gần bờ: Vùng biển ven bờ Quảng Ninh, xung quanh đảo Cát Bà và ven bờ Thanh Hóa - Hà Tĩnh

A multi-criteria decision-making in relieving grinding process of surface of gear milling tooth based on the archimedean spiral using taguchi-ahp-topsis method

In this study, in order to optimize the quality criteria of the machined surface based on the Archimedean spiral, the relieving grinding process (RGP) was performed to machine the material of HSS P18 in a 1Б811 machine with four input parameters including graininess of grinding wheel (G), grinding wheel hardness (Hd), velocity of grinding wheel (V), and feed rate (s) and with three quality criteria including surface roughness (Ra), hardening of surface layer (∆HRC), and hardened layer thickness (∆L). Taguchi-AHP-Topsis method was successfully applied to solve the Multi-Criteria Decision Making (MCDM) problem in this case. The optimized results of the output parameters are surface roughness of 0.21 µm, surface hardening of 1.45 HRC, and hardened layer thickness of 34.18 µm. These results were determined at the set of the input parameters includes G, V, s with their values of 120, 24 m/s, 2.08 m/min, respectively, and Hd at level 1. The optimal results were verified through the comparison between the calculated and the experimental results using this set of optimal parameters. The differences between the calculated results and the experimental results were quite small (maximum different value was 4.8 %) Thus, the results of this study can be applied to solve the multi-objective optimization problems in RGP of the GMT surface based on the Archimedean spira

The Satisfaction of Corporate Customer at Agribank in Ho Chi Minh City

In this paper, the authors use analytical method of explore factor analysis to determining factors that are components of the corporate customer satisfaction in Ho Chi Minh City (HCMC). This paper conducted during the period from March 2012 to December 2014. The exploratory factor analysis result showed that there were five factors, which included of factors following the service behavior, the tangible and the competitive price, the reliance, the convenience and the Agribank Image that are components of the corporate customer satisfaction with significance level 5 %. In addition, the research result processed from SPSS 20.0 software. The research result showed that there were nearly 550 corporates of Agribank in HCMC interviewed but 503 corporates (47 samples mistaken) to be processed and answered about 30 questions. The researcher had analyzed KMO test. The corporate responses measured through an adapted questionnaire on a 5-point Likert scale. Hard copy and interview the corporate by questionnaire distributed among corporate of Agribank in HCMC. At the same time, the result was also a scientific evidence and important for researchers, and policy makers who apply them for improving the corporate customer satisfaction in HCMC. The researchers had obtained the main objectives of this study were to: 1. The first objective, the authors had to conduct a survey to find factors that are components of the corporate customer satisfaction of Agribank in HCMC. 2. The second objective, the authors had to identify some factors that are components in the corporate customer satisfaction in HCMC

The coexistence region in the Van der Waals fluid and the liquid-liquid phase transitions

Cellular membraneless organelles are thought to be droplets formed within the two-phase region corresponding to proteinaceous systems endowed with the liquid-liquid transition. However, their metastability requires an additional constraint—they arise in a certain region of density and temperature between the spinodal and binodal lines. Here, we consider the well-studied van der Waals fluid as a test model to work out criteria to determine the location of the spinodal line for situations in which the equation of state is not known. Our molecular dynamics studies indicate that this task can be accomplished by considering the specific heat, the surface tension and characteristics of the molecular clusters, such as the number of component chains and radius of gyration

Ultrasonic-Assisted Cathodic Plasma Electrolysis Approach for Producing of Graphene Nanosheets

In this chapter, we review on the production of graphene by ultrasonic-assisted cathodic plasma electrolysis approach which involves a combination process of conventional electrolysis and plasma at ambient pressure and moderate temperature. Firstly, we review on the techniques for electrochemical preparation of graphene. Then, we briefly describe plasma electrolysis approach for producing of graphene. The mechanism, advantages, and disadvantages of this technique are discussed in detail

Status Poles and Status Zoning to Model Residential Land Prices: Status-Quality Trade off Theory (Short Paper)

This study describes an approach for augmenting urban residential preference and hedonic house price models by incorporating Status-Quality Trade Off theory (SQTO). SQTO seeks explain the dynamic of urban structure using a multipolar, in which the location and strength of poles is driven by notions of residential status and dwelling quality. This paper presents in outline an approach for identifying status poles and for quantifying their effect on land and residential property prices. The results show how the incorporation of SQTO results in an enhanced understanding of variations in land / property process with increased spatial nuance. A number of future research areas are identified related to the status pole weights and the development of status pole index

Long-term outcomes of primary cardiac malignant tumors: Difference between African American and Caucasian population

BACKGROUND: The survival outcome for primary cardiac malignant tumors (PMCTs) based on race has yet to be fully elucidated in previously published literature. This study aimed to address the general long-term outcome and survival rate differences in PMCTs among African Americans and Caucasian populations. METHODS: The 18 cancer registries database from the Surveillance, Epidemiology, and End Results (SEER) Program from 1975 to 2016 were utilized. Ninety-four African American (AA) and 647 Caucasian (CAU) patients from the SEER registry were available for survival analysis. The log-rank test was used to compare the difference in mortality between two populations and presented by the Kaplan-Meier curves. A multivariate Cox proportional hazards regression was used to determine the independent predictors of all-cause mortality. RESULTS: The overall 30-day, 1-year, and 5-year survival rates were 74%, 44.3%, and 16.6%, respectively, with a median survival of 10 months. There was no significant difference in survival rate between the two races (p-value = 0.55). The 1-year survival rate improved significantly during the study timeline in the AA population (13.3% during 1975-1998, 40.9% during 1999-2004, 50% during 2005-2010, and 59.7% during 2011-2016, p-value = 0.0064). Age of diagnosis, type of tumor, disease stage, and chemotherapy administration are the main factors that predict survival outcomes of PMCT patients. Interactive nomogram was developed based on significant predictors. CONCLUSIONS: PMCTs have remained one of the most lethal diseases with poor survival outcome. Survival rate improved during the timeline in AA patients, but in general, racial differences in survival outcome were not observed

Crystal structure and Hirshfield surface analysis of 4-phenyl-3-(thio-phen-3-ylmeth-yl)-1<i>H</i>-1,2,4-triazole-5(4<i>H</i>)-thione.

In the title compound, C13H11N3S2, the phenyl ring is twisted from the 1,2,4-triazole plane by 63.35 (9)° and by 47.35 (9)° from the thio-phene plane. In the crystal, chains of mol-ecules running along the c-axis direction are formed by N-H⋯S inter-actions [graph-set motif C(4)]. The 1,2,4-triazole and phenyl rings are involved in π-π stacking inter-actions [centroid-centroid distance = 3.4553 (10) Å]. The thio-phene ring is involved in C-H⋯S and C-H⋯π inter-actions. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are H⋯H (35.8%), followed by S⋯H/H⋯S (26.7%) and C⋯H/H⋯C (18.2%)