Encoderless Gimbal Calibration of Dynamic Multi-Camera Clusters

Dynamic Camera Clusters (DCCs) are multi-camera systems where one or more cameras are mounted on actuated mechanisms such as a gimbal. Existing methods for DCC calibration rely on joint angle measurements to resolve the time-varying transformation between the dynamic and static camera. This information is usually provided by motor encoders, however, joint angle measurements are not always readily available on off-the-shelf mechanisms. In this paper, we present an encoderless approach for DCC calibration which simultaneously estimates the kinematic parameters of the transformation chain as well as the unknown joint angles. We also demonstrate the integration of an encoderless gimbal mechanism with a state-of-the art VIO algorithm, and show the extensions required in order to perform simultaneous online estimation of the joint angles and vehicle localization state. The proposed calibration approach is validated both in simulation and on a physical DCC composed of a 2-DOF gimbal mounted on a UAV. Finally, we show the experimental results of the calibrated mechanism integrated into the OKVIS VIO package, and demonstrate successful online joint angle estimation while maintaining localization accuracy that is comparable to a standard static multi-camera configuration.Comment: ICRA 201

Integrated STEM: Impact of Engineering Design and Computer Science in STEM Labs

By integrating physics laboratories with engineering design and computer science, students apply physics principles to ill-structured and complex problems, engage in knowledge transfer, and gain interest in STEM. The introductory physics labs at Purdue have been updated to include engineering design and computer science principles that ground physics in authentic problems. Integrated labs have been evaluated using student perception post-surveys, student course performance, interviews, and case-study observations. Preliminary results indicate that integrated physics labs promote transfer, enhanced metacognitive skills, student interest, and motivation

Preliminary studies of the cytotoxicity and photoprotective properties of Benzophenone and Lactone derivatives.

A Radia??o solar ultravioleta(RUV) pode induzir efeitos ? pele devidos a sua a??o direta ou indireta, por meio da gera??o de radicais livres. Esses efeitos podem provocar diversas les?es na pele humana como o c?ncer de pele. Como medida de prote??o da pele contra os efeitos da radia??o solar pode-se citar o uso de protetores solares, produtos t?picos adicionados de filtros solares UV sint?ticos com propriedades de absor??o e reflex?o de raios solares.Um fotoprotetor org?nico ideal deve proteger a pele contra os raios UVB (290-320 nm) e UVA (320-400 nm), possuir um fator de prote??o solar (FPS) seguro, ser fotoest?vel e n?o ser fotot?xico. Este trabalho objetiva em estudos preliminares de fotoprote??o dos derivados das Benzofenonas e Lactonas. Os produtos obtidos foram sintetizados e caracterizados por t?cnicas espectrosc?picas usuais e foram submetidos a ensaios de viabilidade celular frente ao MTT e determina??o do valor de prote??o solar (FPS) in vitro pelo m?todo espectrofotom?trico UV/VIS. Os espectros de IV, RMN de 1 H e RMN de 13C mostraram bandas e sinais em conformidades com as estruturas propostas para os compostos estudados. Os compostos 1 e2 apresentaram um FPS proporcional ? concentra??o analisada, ou seja, quanto maior a concentra??o, maior ? o Fator de Prote??o, por?m o composto 3 apresentou fator prote??o menor em concentra??es mais elevadas. No estudo de viabilidade celular, os compostos 1 e 2 n?o foram citot?xicos nas concentra??es avaliadas neste trabalho.Ultraviolet solar radiation can generate free radicals that damage skin and cause skin lesions or skin cancer. Sunscreens are a protective measure against the effects of solar radiation that protects the skin by absorbing or reflecting solar rays. Ideally, the sunscreen should protect the skin against UVB (290-320 nm) and UVA (320-400 nm) rays, be photostable and non-toxic. This work describes a preliminary study on the SPF of a benzophenone and a lactone derivative. The synthesized compounds were characterized by spectroscopic techniques, submitted to cell viability assays against MTT and SPF determined in vitro by UV/VIS spectroscopy measurements. The spectroscopic data was in agreement with the proposed structures of the compounds studied. The SPF was proportional to concentration, and in one case, the sun protection factor was lower at higher concentrations. The benzophenone derivatives were evaluated for toxicity by a cell viability study, and found to be non-cytotoxic at the tested concentrations

Preparation and characterization of a quercetin-tetraethyl ether-based photoprotective nanoemulsion.

Although Quercetin absorbs in the UVA/UVB electromagnetic region, it is limited for applications as a UV filter due to its low lipophilicity and capacity to penetrate the epidermis. In order to overcome this limitation, we synthetized and evaluated the photo protective properties of a derivative obtained from Quercetin. The derivative was prepared by alkylation of Quercetin with iodoethane and characterized by IR and NMR spectroscopy. The in vitro Solar Protection Factor was determined by the Mansur method and the cytotoxicity was evaluated using hepatocellular cell (Hep G2) cells. Finally, Quercetin and the corresponding derivative were incorporated in nanoemulsions. Nanoemulsions with particles sizes between 53 and 73 nm were obtained, and polydispersity indexes were around 0.1, indicating good homogeneity of the nanoemulsion particles. The cell viability study for the Quercetin derivative indicated a very low cytotoxicity profile. The chemical modification of Quercetin resulted in a promising compound with improved properties desirable for skin penetration and incorporation into sunscreen formulations

Identification of Pik3ca mutation as a genetic driver of prostate cancer that cooperates with Pten loss to accelerate progression and castration-resistant growth

Genetic alterations that potentiate PI3K signalling are frequent in prostate cancer, yet how different genetic drivers of the PI3K cascade contribute to prostate cancer is unclear. Here, we report PIK3CA mutation/amplification correlates with poor prostate cancer patient survival. To interrogate the requirement of different PI3K genetic drivers in prostate cancer, we employed a genetic approach to mutate Pik3ca in mouse prostate epithelium. We show Pik3caH1047R mutation causes p110-dependent invasive prostate carcinoma in-vivo. Furthermore, we report PIK3CA mutation and PTEN loss co-exist in prostate cancer patients, and can cooperate in-vivo to accelerate disease progression via AKT-mTORC1/2 hyperactivation. Contrasting single mutants that slowly acquire castration-resistant prostate cancer (CRPC), concomitant Pik3ca mutation and Pten loss caused de-novo CRPC. Thus, Pik3ca mutation and Pten deletion are not functionally redundant. Our findings indicate that PIK3CA mutation is an attractive prognostic indicator for prostate cancer that may cooperate with PTEN loss to facilitate CRPC in patients

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe