Influence of Principle Parameters on the Average Stiffness of Optical Tweezer Using Pulsed Gaussian Beams

In this article expresions used to simulate the trap stiffness k of the optical trap are derived. The influence of principle parameters as total energy, beam waist and duration of pulsed laser beam, radius of dielectric particle, and viscosity of surrounding medium on the stiffness  is simulated and discussed

Indoor assistance for visually impaired people using a RGB-D camera

In this paper a navigational aid for visually impaired people is presented. The system uses a RGB-D camera to perceive the environment and implements self-localization, obstacle detection and obstacle classification. The novelty of this work is threefold. First, self-localization is performed by means of a novel camera tracking approach that uses both depth and color information. Second, to provide the user with semantic information, obstacles are classified as walls, doors, steps and a residual class that covers isolated objects and bumpy parts on the floor. Third, in order to guarantee real time performance, the system is accelerated by offloading parallel operations to the GPU. Experiments demonstrate that the whole system is running at 9 Hz

Measurement Profile of Surface Revolution by Laser Scan Micrometer Method

Measurement profile of surface revolution by laser scan micrometer method is a non-contact measurement method that allows de-tailed profile measurements with fast measuring speed by using laser scanning and accuracy is much higher than other non-contact scanning methods. This paper presents the mathematical model profile of surface revolution and the application of the laser scan micrometer method for measuring this detailed profile. Fabricating complete equipment model according to the author's proposed method. Compare the results of measuring the profile of surface revolution on a construction measuring device with a roundness meter Jenoptik F315 to prove the feasibility of the construction measurement method

Idiosyncratic volatility and firm-specific news: evidence from the Chinese stock market

This study investigates the effect of firm-specific news on the pricing of idiosyncratic volatility (IVOL) in China. Using a sample of non-financial A-share listed firms from January 2006 to June 2018, we find that the predictive ability of IVOL is much weaker around firm announcements compared to that without news, suggesting that the limited arbitrage cannot disentangle the IVOL puzzle completely in the emerging market. Additionally, we investigate the effect of news sentiment on the predictive ability of IVOL and find that it is much stronger following bad news compared to good news. Finally, when we include the macroeconomic variables known to predict returns to adjust the systematic risk, we obtain novel findings that the negative premium of IVOL becomes insignificant, suggesting that the negative premium is time-varying with macroeconomy

Ectopic Pregnancy Located at Pelvic Wall and Liver: Two Uncommon Case Reports From Vietnam and Mini-Review Literature

INTRODUCTION AND IMPORTANCE: Abdominal ectopic pregnancy (AEP) located at hepatic region and pelvic-wall ectopic pregnancy (EP) are rare entities, that provoking a potentially life-threatening condition. Due to insufficient data, a proper management of non-specific types remains a challenge for all gynecologists worldwide. CASE PRESENTATION: Two child-bearing age women were hospitalized due to delayed menstruation and a urine pregnancy test was positive without a determination of intrauterine pregnancy. The first EP case was located at the pelvic wall which identified incidentally during laparoscopy for a presumed tubal ectopic pregnancy on ultrasonography throughout. The second EP case was found at the hepatic region due to intermittent pain rising from the right upper quadrant region and serial ultrasonic findings. In our management, both cases were successfully assessed by laparoscopy and laparotomy without requiring further intervention, respectively. CLINICAL DISCUSSION: An accurate diagnosis of EP location at liver and pelvic wall is totally difficult since its uncommon location. An initial assessment should be based on clinical symptoms and the treatment remains controversial. The surgical management including laparotomy and laparoscopy depends on clinical evaluation, experience of surgeon, and interdisciplinary team. Thus, these abnormal sites of ectopic pregnancy ought to take into consideration for all gynecologists in an emergency condition with a major hemorrhage. CONCLUSIONS: In reproductive age women, primary EP at liver and pelvic wall should be considered with high index of suspicion if intrauterine pregnancy is totally excluded. Timely diagnosis, rational management by surgical excision, and a multidisciplinary team can reduce substantially adverse outcomes

Modeling of milling forces in facing process of aluminum alloy AL7075 using the square inserts

Cutting forces play very important in designing the tool machine, cutting tool, and in optimization of machining processes. Modeling and prediction of cutting forces by theoretical methods are quite difficult, so, this study was focused on modeling the cutting force in face milling process using combination of theoretical and experimental methods. This study was performed to model the milling forces (MFs) and determine the milling force coefficients (MFCs) in the face milling process of aluminum alloy Al7075 using square inserts. From theoretical and experimental methods, the relationship of average milling forces (AMFs) and feed per flute (ft) were determined as the linear regression. Using experimental data, the linear regressions of AMFs and feed per flute were determined with high values of determination coefficients (larger than 95 %). MFCs were determined including shear and edge MFCs (tangential shear MFC (Ktc) of 538.127 N/mm2, radial shear MFC (Krc) of 185.967 N/mm2, axial shear MFC (Kac) of -691.297 N/mm2, tangential edge MFC (Kte) of 11.253 N/mm, radial edge MFC (Kre) of 6.991 N/mm, and axial edge MFC (Kae) of –32.971 N/mm. The MF models were successfully verified by comparing the measured and predicted MFs in face milling process of Al7075. The tendency and shape of predicted MFs were quite close to the measured ones. The differences between the predicted and the measured MFs can be due to the several reasons such as the influence of vibrations, the influence of cutting heat, etc., and these are also the limitations of this study. The modeling and prediction methods of this study can be used to model and predict the cutting forces in face milling of other milling types and other pairs of cutting tool and workpiece material as wel

Theoretical basis for reasonable population distribution in Tho Chu archipelago

Tho Chu archipelago is one of administrative units of Kien Giang province, Hon Nhan- one of its islands - is selected to become A1 base point of baseline for Vietnam territorial waters. If Tho Chau district is established, it will contribute to identifying sovereignty of Vietnam Southwest sea area following the United Nations Convention on the Law of the Sea, creating favourable conditions for islands’ socio-economic development, developing culture, enhancing effects of administration work and life quality of population in this island, firmly protecting sea border, securing island and sea sovereignty… However, the establishment of Tho Chu district appears in the context of streamlining administrative apparatus and limitation of capital for infrastructure construction in district level. This article focuses on the analysis of some factors affecting a reasonable population distribution in order to meet the requirement of building the Tho Chu into a district-level administrative unit in Kien Giang province

Study of Melting Temperature of Metals: Pressure Dependence

The melting temperature of metals are studied using the statistical moment method, going the quasi-harmonic appromations. The melting temperature of metals are calculated as a function of the pressure. We discuss the pressure dependence of melting temperatures of Ce, Fe metals and compare the present results with those of the experimental results