Recognition of Man-made Objects from Range Data

The subject of this thesis is object recognition from range data. Being developed for applications of machine vision in engineering tasks, the discussion of this subject is restricted to the class of man-made objects where object surfaces can be modelled with quadric primitives. The study aims at developing optimal representation and recognition of the objects from range data

New compounds of natural resources in 2008

Natural products have been the most productive source of new compounds. Hundreds of new compounds are in development. Some of them have pharmaceutical activities, particularly as anticancer and anti-infective agents. Until October, there are 1913 new compounds separated from natural sources in 2008. The compounds have covered a wide range of species, including alkaloids, flavones, terpenoids and so on. It is hoped that more efficient and effective compounds of natural resources wil

Observation of Ultrahigh Mobility Surface States in a Topological Crystalline Insulator by Infrared Spectroscopy

Topological crystalline insulators (TCIs) possess metallic surface states protected by crystalline symmetry, which are a versatile platform for exploring topological phenomena and potential applications. However, progress in this field has been hindered by the challenge to probe optical and transport properties of the surface states owing to the presence of bulk carriers. Here we report infrared (IR) reflectance measurements of a TCI, (001) oriented $Pb_{1-x}Sn_{x}Se$ in zero and high magnetic fields. We demonstrate that the far-IR conductivity is unexpectedly dominated by the surface states as a result of their unique band structure and the consequent small IR penetration depth. Moreover, our experiments yield a surface mobility of 40000 $cm^{2}/(Vs)$, which is one of the highest reported values in topological materials, suggesting the viability of surface-dominated conduction in thin TCI crystals. These findings pave the way for exploring many exotic transport and optical phenomena and applications predicted for TCIs

NEW MOTHERS’ MANAGEMENT OF COMPLAINTS IN COMPUTER-MEDIATED COMMUNICATION CHANNELS

This study examines new mothers’ complaining behaviors in computer-mediated communication (CMC) channels and investigates mothers’ privacy management when self-disclose family issues online. This study includes data collected through face-to-face in-depth interviews and interview surveys with new mothers (i.e., who had at least one child younger than 3 years old at the time), which were analyzed through constant comparative methods and descriptive statistics. In total, 35 participants were recruited for this study, including 16 American mothers and 19 Chinese mothers who live in the US. The study examines new mothers’ complaining behaviors in CMC channels through two steps. First, I explore the facilitators and barriers that influence new mothers’ choices when selecting the appropriate CMC channel(s) to complain about motherhood-related challenges and problems. Then I categorize these facilitators and barriers into four areas of consideration (i.e., emotion management, impression management, information control, and problem-solving) that mothers may think of when balancing the benefits and risks of using any CMC channel to express their negative feelings. Based on the Communication Privacy Management theory, I also investigate mothers’ self-disclosure behaviors in different channels. From level 1 (vague) to level 5 (full of details), mothers disclosed sensitive and private family issues with varying levels when complaining in different channels. The four areas of consideration can be applied again to explain their choices. I further identify four underlying factors across these areas of consideration that affect new mothers’ online complaining behavior: mothers’ expected social support types, the nature of the complaining subject, online privacy literacy, and cultural differences. Finally, I propose an integrated model of negative self-disclosure via CMC which demonstrates all the factors that potentially impact people’s channel selection and message-framing processes

Coordinate transformation of an industrial robot and its application in deterministic optical polishing

An IRB6620 industrial robot from ABB Co. Ltd. (Zurich, Switzerland) is used as a processing platform for optical processing, and computer-controlled optical surfacing is applied as a key technology. The function of each coordinate system of the robot in processing is reviewed, as well as the relationship of each coordinate system and coordinate transformation. An algorithm governing coordinate transformations is provided. In order to assess the functionality of the robot as a polishing instrument, experiments have been designed so that the removal rate and surface form error correction of the robot facility have been compared with those from established computer numerical control polishing. The importance for the application of industrial robot in optical processing is also presented

Unsteady dynamics of cloud cavitating flows around a hydrofoil

The unsteady dynamics of cloud cavitating flow around a hydrofoil are investigated by joint experimental and numerical methods. Experiments are carried out in a rectangular test section of a cavitation tunnel. A high-speed video camera is used to visualize the unsteady flow structures. The visualized data are analyzed by using a home made soft ware. The drag and lift under the cavitation condition are measured. The spectral analysis for the measured date is conducted. The computations are conducted on the two-dimensional hydrofoil section, based on a single-fluid model of the cavitation: the liquid/vapor mixture is considered as a homogeneous fluid whose composition is regulated by mass transfer equation. The RNG k- ? turbulence model with modified eddy viscosity coefficient is used for the computations, and the modified coefficient is related to the vapor and liquid densities in cavitated regions for simulating the cavitating flow. A good agreement is obtained between experimental data and numerical simulations. The cloud cavitating area is divided in two parts: attached vapor sheet in the foreside of the cavity, and unsteady two-phase mixture in the rear region in the process of cavity breaking off. The local pressure increasing induced by the re-entrant jet is the main reason to lead the cloud cavity. The adverse pressure gradient in the rear area of the cavity is mainly responsible for the generation of the re-entrant jet.http://deepblue.lib.umich.edu/bitstream/2027.42/84269/1/CAV2009-final9.pd

Impacts of Drought on Maize and Soybean Production in Northeast China During the Past Five Decades.

Climate change has a distinct impact on agriculture in China, particularly in the northeast, a key agriculture area sensitive to extreme hydroclimate events. Using monthly climate and agriculture data, the influence of drought on maize and soybean yields-two of the main crops in the region-in northeast China since 1961 to 2017 were investigated. The results showed that the temperature in the growing season increased by 1.0 °C from the period 1998-2017 to the period 1961-1980, while the annual precipitation decreased slightly. However, precipitation trends varied throughout the growing season (May-September), increasing slightly in May and June, but decreasing in July, August and September, associated with the weakening of the East Asian summer monsoon. Consequently, the annual and growing season drought frequency increased by 15%, and 25%, respectively, in the period 1998-2017 relative to the period 1961-1980. The highest drought frequency (55%) was observed in September. At the same time, the drought intensity during the growing season increased by 7.8%. The increasing frequency and intensity of drought had negative influences on the two crops. During moderate drought years in the period 1961-2017, 3.2% and 10.4% of the provincial maize and soybean yields were lost, respectively. However, during more severe drought years, losses doubled for soybean (21.8%), but increased more than four-fold for maize (14.0%). Moreover, in comparison to the period 1961-1980, a higher proportion of the yields were lost in the period 1998-2017, particularly for maize, which increased by 15% (increase for soybean was 2.4%). This change largely depends on increasing droughts in August and September, when both crops are in their filling stages. The impact of drought on maize and soybean production was different during different growth stages, where a strong relationship was noted between drought and yield loss of soybean in its filling stage. Given the sensitivity of maize and soybean yields in northeast China to drought, and the observed production trends, climate change will likely have significant negative impacts on productivity in the future

Study of Word-Level Accent Classification and Gender Factors

Abstract In this work, we conduct word-level accent classification. Different features, words, and learning methods are explored for accent classification, and results show that HMM-MFCC models show promising performance. Besides, we also explore the effect of gender on accent classification. Results show that models trained on male data do not generalized well on female data; Models trained on both male and female data is not always better than models trained on female data only. At last, we propose to use stacked ensemble classifier to classify gender firstly and then classify accent to improve accuracy

LncRNA gas5 regulates granulosa cell apoptosis and viability following radiation by x-ray via sponging miR-205- 5p and Wnt/β-catenin signaling pathway in granulosa cell tumor of ovary

Purpose: To investigate the role of lncRNA gas5 in ovarian granulosa cells exposed to x-ray in granulosa cell tumor of ovary (GCTO). Methods: KGN cell line was exposed to X-ray to mimic the radiotherapy for GCSO patients in vitro, cell viability was checked by CCK8 assays. RNA expression of apoptosis-related genes was determined by quantitative reverse transcriptase-polymerase reaction (qRT-PCR) while Western Blot for biomarkers in wnt/β-catenin signaling. Differential expressions of lncRNA gas5 were examined after cells were exposed to a ray for 0,24,48hs. We over expressed gas5 and assessed resultant cell viability, apoptosis and signaling. The sponging between gas5 and miR-205-5p was verified by luciferase assay. CCK8, qRT-PCR and Western blot were applied to investigate the correlation between miR-205-5p, cell viability, and apoptosis after miR-205-5p augmentation. Similarly, interaction between gas5 and miR-205-5p was assessed after co-transfection of miR-205-5p mimics and oe-gas5. Finally, wnt inhibitor was used to study the role of signaling pathway in KGN cells. Results: Exposure of KGN to x-ray reduced cell viability and increased apoptosis. Gas5showed reduced expression in the cells, while miR-205-5p  expression increased. Gas5 upregulation protected the cells against apoptosis and contributed to cell viability and activation of wnt//β-catenin signaling. lncRNA gas5 targeted miR-205-5p and miR-205-5p mimics counteracted the functions of up-regulated lncRNA gas5, regulating Wnt/β-catenin signaling pathway. Inactivation of Wnt/β-catenin suppressed cell viability. Conclusions: lncRNA gas5 regulates cell apoptosis and viability following cellular radiation, thus presenting a potential therapeutic target for the application radiotherapy in GCTO patients. Keywords: Ovary, Proliferation, Apoptosis, lncRNA gas5, Radiotherapy, β-catenin signalin