91 research outputs found
Improving surface current resolution using direction finding algorithms for multiantenna high-frequency radars
No full textAuthor Posting. © American Meteorological Society, 2019. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 36(10), (2019): 1997-2014, doi: 10.1175/JTECH-D-19-0029.1.While land-based high-frequency (HF) radars are the only instruments capable of resolving both the temporal and spatial variability of surface currents in the coastal ocean, recent high-resolution views suggest that the coastal ocean is more complex than presently deployed radar systems are able to reveal. This work uses a hybrid system, having elements of both phased arrays and direction finding radars, to improve the azimuthal resolution of HF radars. Data from two radars deployed along the U.S. East Coast and configured as 8-antenna grid arrays were used to evaluate potential direction finding and signal, or emitter, detection methods. Direction finding methods such as maximum likelihood estimation generally performed better than the well-known multiple signal classification (MUSIC) method given identical emitter detection methods. However, accurately estimating the number of emitters present in HF radar observations is a challenge. As MUSIC’s direction-of-arrival (DOA) function permits simple empirical tests that dramatically aid the detection process, MUSIC was found to be the superior method in this study. The 8-antenna arrays were able to provide more accurate estimates of MUSIC’s noise subspace than typical 3-antenna systems, eliminating the need for a series of empirical parameters to control MUSIC’s performance. Code developed for this research has been made available in an online repository.This analysis was supported by NSF Grants OCE-1657896 and OCE-1736930 to Kirincich, OCE-1658475 to Emery and Washburn and OCE-1736709 to Flament. Flament is also supported by NOAA’s Integrated Ocean Observing System through Award NA11NOS0120039. The authors thank Lindsey Benjamin, Alma Castillo, Ken Constantine, Benedicte Dousset, Ian Fernandez, Mael Flament, Dave Harris, Garrett Hebert, Ben Hodges, Victoria Futch, Matt Guanci, and Philip Moravcik for assistance in building, deploying, and operating the radars.2020-04-1
Bridging clinic to home: domestic devices in dermatological diagnostics and treatments
No full textThe integration of diagnostic and therapeutic tools into home-used devices has significantly transformed dermatology, making advanced skincare technologies more accessible to the public. Home-based diagnostic devices empower individuals to monitor, assess, and track skin conditions in real time, promoting earlier interventions and personalized skincare. Therapeutic devices, on the other hand, enable users to actively treat cosmetic and dermatological concerns, offering greater autonomy in managing skin health outside the clinical setting. These technologies, often inspired by clinical-grade equipment, promise enhanced patient engagement but also raise critical questions regarding safety, efficacy, and regulatory oversight. Importantly, the regulatory status of these devices, particularly for diagnostic tools, varies significantly across regions, affecting standards for quality, permitted energy outputs, and intended uses. This commentary separately explores the opportunities and challenges posed by home-used diagnostic and therapeutic devices, evaluates their roles in cosmetic dermatology, and highlights key insights from the literature to contextualize their growing influence on personalized skincare
Solar exposure(s) and facial clinical signs of aging in Chinese women: impacts upon age perception
No full textFrederic Flament,1 Roland Bazin,2 Huixia Qiu,3 Chengda Ye,3 Sabine Laquieze,4 Virginie Rubert,1 Aurelie Decroux,1 Elisa Simonpietri,5 Bertrand Piot1 1L'Oreal Research and Innovation, Paris, France; 2RB Consult, Bievres, France; 3L'Oreal Research and Innovation, Shanghai, People's Republic of China; 4Private Dermatology Consultancy, Montpellier, France; 5Biotherm International, Levallois-Perret, France Abstract: A new reference clinical atlas of facial signs dedicated to photoaging was applied to 301 Chinese women of various ages through standardized photographs. Such approach aimed at better describing the facial changes induced by both real/chronological age and sun exposure and their respective impact on two subcohorts of different behavior with regard to sun exposure. A total of 28 various facial signs were individually graded according to their severity by a panel of experts, and a perceived apparent age of each subject was assessed. Results showed that the severity of major signs significantly increased rather linearly with age, with a higher rate in sun-exposed subjects as compared with subjects who regularly avoid sun exposure. The severity of facial signs, all impacted by sun exposure, better correlated with perceived apparent age than real/chronological age. The protocol used in the present work, similar to that previously applied to two cohorts of French women, assigned a greater impact of sun exposure in the facial aging signs of Asian women – all clinical signs are influenced by extrinsic factors – as compared with Caucasian women of comparable ages, likely related to much more intense ultraviolet (UV) radiation. Keywords: photoaging, clinical evaluation, UV, perceived apparent age, solar exposur
Seasonal skin darkening in Chinese women: the Shanghaiese experience of daily sun protection
No full textHuixia Qiu,1 Frederic Flament,2 Xiaohui Long,1 Jun Wu,1 Mengzhi Xu,1 Didier Saint Leger,2 Helene Meaudre,2 Jerome Senee,1 Bertrand Piot,2 Roland Bazin2 1L’Oréal Research and Innovation, Shanghai, People’s Republic of China; 2L’Oréal Research and Innovation, Chevilly, France Abstract: The facial skin tone of two groups of Chinese women from Shanghai was compared using standard colorimetric space techniques during a 6-month interval between January and July 2011. During the study period, one group of women (n = 40) applied a potent sun-protective cosmetic product daily, while the other group (n = 40) did not use any sun protection. The results, based on images taken using a standardized digital camera coupled to a spectroradiometer, showed that sun protection largely mitigated changes in the components of skin tone, ie, lightness, melanization, and individual typology angle parameters. The skin darkening process appeared to be reduced or prevented in the sun-protected group when compared with the control group. The sun-protected women had participated in an earlier study in 2008, which confirmed that seasonal skin darkening occurs from winter through summer in Shanghaiese women. Comparing the data obtained in the winters of 2008 and 2011, we were able to identify better the impact of 3 years of aging on the components of skin tone. Comparing data between seasons on the same women with (2011 study) and without (2008 study) sun protection highlights the role of the test product in preventing skin darkening. Keywords: skin tone, skin seasonal darkening, sun protection, agin
Classement stylistique et essai de périodisation des monnaies au loup d'Argos
No full textThis article proposes a stylistical analysis of the Argive "Wolfs" with symbols and letters on the reverse. On the basis of this examination, the author defines three major periods within this coinage, which do not strictly correspond to the evolution of the design of the reverse. The author also discuss the signification of the secondary devices on the reverse : for the most ancient series, it seems that those marks do not refer to mint magistrates but are actually mint combinations.Cet article propose un classement stylistique des monnaies argiennes pourvues de lettres et de symboles au revers. Un examen approfondi permet de définir trois grandes périodes au sein de ce monnayage, qui ne correspondent pas exactement au classement que l'on serait tenté d'établir sur base de l'évolution du revers. On y discute également de la signification des différents monétaires au revers : l'auteur pense que pour les plus anciennes séries il ne s'agit pas de noms de magistrats abrégés, mais de marques de contrôle.Flament Christophe. Classement stylistique et essai de périodisation des monnaies au loup d'Argos. In: Revue numismatique, 6e série - Tome 165, année 2009 pp. 81-105
Gender‐related differences in the facial aging of Chinese subjects and their relations with perceived ages
No full textCristallisation du trihydrate d'alumine: Concentration d'équilibre et constante cinétique de croissance
No full textEvaluating the respective weights of some facial signs on perceived ages in differently aged women of five ethnic origins
No full textOn the viscosity influence on a helical vortex flament evolution
No full textHelical vortices whose parameters have a strong influence on the efficiency of the apparatus is often occur in technical devices using swirling flow (cyclones, separators, etc.). To date the internal structure of such vortices is poorly understood. In [1] a model of helical vortex with uniform vorticity distribution in the core is proposed. Vortices arising in real flow always have a smooth vorticity distribution due to the viscosity action. The problem on steady moving helical vortices with the vortex core of small size in an inviscid fluid was solved in [2]. The non-orthogonal ‘helical’ coordinate system was introduced that allowed author to reduce the problem to two dimensional one. However, the velocity of the vortex motion was written only in the form of a quadratures computation of which is difficult. This paper presents first attempt for research on the diffusion and dynamics of a viscous helical vortex
Facial skin pores: a multiethnic study
No full textFrederic Flament,1 Ghislain Francois,1 Huixia Qiu,2 Chengda Ye,2 Tomoo Hanaya,3 Dominique Batisse,3 Suzy Cointereau-Chardon,1 Mirela Donato Gianeti Seixas,4 Susi Elaine Dal Belo,4 Roland Bazin5 1Department of Applied Research and Development, L’Oreal Research and Innovation, Paris, France; 2Department of Applied Research and Development, L’Oreal Research and Innovation, Shanghai, People’s Republic of China; 3Department of Applied Research and Development, L’Oreal Research and Innovation, Tokyo, Japan; 4Department of Applied Research and Development, L’Oreal Research and Innovation, Rio de Janeiro, Brazil; 5RB Consult, Bievres, France Abstract: Skin pores (SP), as they are called by laymen, are common and benign features mostly located on the face (nose, cheeks, etc) that generate many aesthetic concerns or complaints. Despite the prevalence of skin pores, related literature is scarce. With the aim of describing the prevalence of skin pores and anatomic features among ethnic groups, a dermatoscopic instrument, using polarized lighting, coupled to a digital camera recorded the major features of skin pores (size, density, coverage) on the cheeks of 2,585 women in different countries and continents. A detection threshold of 250 µm, correlated to clinical scorings by experts, was input into a specific software to further allow for automatic counting of the SP density (N/cm2) and determination of their respective sizes in mm2. Integrating both criteria also led to establishing the relative part of the skin surface (as a percentage) that is actually covered by SP on cheeks. The results showed that the values of respective sizes, densities, and skin coverage: 1) were recorded in all studied subjects; 2) varied greatly with ethnicity; 3) plateaued with age in most cases; and 4) globally reflected self-assessment by subjects, in particular those who self-declare having “enlarged pores” like Brazilian women. Inversely, Chinese women were clearly distinct from other ethnicities in having very low density and sizes. Analyzing the present results suggests that facial skin pore’s morphology as perceived by human eye less result from functional criteria of associated appendages such as sebaceous glands. To what extent skin pores may be viewed as additional criteria of a photo-altered skin is an issue to be further addressed. Keywords: aging, clinical evaluation, ethnicity, imperfections, oily ski
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