1,721,132 research outputs found
Formation Flying of small Satellites Using Coulomb Force
No full textThe formation flying of satellites has been identified as an enabling technology for many future space missions. The application of conventional thrusters for formation flying usually results in high cost, limited life-time, and a large weight penalty. Various methods including the use of coulomb forces have been considered as an alternative to the conventional thrusters. In the present investigation, we investigate the feasibility of achieving the desired formation using Coulomb forces. This method has several advantages including low cost, light weight and no contamination. A simple controller based on the relative position and velocity errors between the leader and follower satellites is developed. The proposed controller is applied to circular formations considering the effects of disturbances in initial formation conditions as well as system nonlinearity. Results of the numerical simulation state that the proposed controller is successful in establishing circular formations of leader and follower satellites, for a formation size below 100 m.
Use of Dexpanthenol for Atopic Dermatitis—Benefits and Recommendations Based on Current Evidence
No full textBackground: Atopic dermatitis (AD) is an inflammatory skin disease of multiple phenotypes and endotypes, and is highly prevalent in children. Many people of all ages, including active adolescents, pregnant women, and the elderly, suffer from AD, experiencing chronicity, flares, and unexpected relapse. Dexpanthenol has multiple pharmacological effects and has been employed to treat various skin disorders such as AD. We aimed to summarize the up-to-date evidence relating to dexpanthenol and to provide a consensus on how to use dexpanthenol effectively for the treatment of AD. Methods: The evidence to date on the application and efficacy of dexpanthenol in AD was reviewed. The literature search focused on dexpanthenol use and the improvement of skin barrier function, the prevention of acute flares, and its topical corticosteroid (TCS) sparing effects. Evidence and recommendations for special groups such as pregnant women, and the effects of dexpanthenol and emollient plus in maintenance therapy, were also summarized. Results: Dexpanthenol is effective and well-tolerated for the treatment of AD. Dexpanthenol improves skin barrier function, reduces acute and frequent flares, has a significant TCS sparing effect, and enhances wound healing for skin lesions. Conclusion: This review article provides helpful advice for clinicians and patients on the proper maintenance treatment of AD. Dexpanthenol, as an active ingredient in ointments or emollients, is suitable for the treatment and maintenance of AD. This paper will guide dermatologists and clinicians to consider dexpanthenol as a treatment option for mild to moderate AD
UML-based Modeling and Simulation Method for Mission-Critical Real-Time Embedded System Development
Full text linkOptimal Perilune Altitude of Lunar Landing Trajectory
No full textIn general, the lunar landing stage can be divided into two distinct phases: de-orbit and descent, and the descent phase usually comprises two sub-phases: braking and approach. And many optimization problems of minimal energy are usually focused on descent phases. In these approaches, the energy of de-orbit burning is not considered. Therefore, a possible low perilune altitude can be chosen to save fuel for the descent phase. Perilune altitude is typically specified between 10 and 15km because of the mountainous lunar terrain and possible guidance errors. However, it requires more de-orbit burning energy for the lower perilune altitude. Therefore, in this paper, the perilune altitude of the intermediate orbit is also considered with optimal thrust programming for minimal energy. Furthermore, the perilune altitude and optimal thrust programming can be expressed by a function of the radius of a parking orbit by using continuation method and co-state estimator.This research was supported by NSL(National Space Lab) program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology.
Retrospective clinical trial of fusidic acid versus petrolatum in the postprocedure care of clean dermatologic procedures
Full text linkBackground: Clean dermatologic procedures create wounds with a low risk of infection (usually up to 5%). Whether the use of topical antibiotics is advocated, with regard to its efficacy and safety issues such as antibiotic resistance and sensitizing potential, is controversial. Fusidic acid, a topical antibiotic against gram-positive bacteria, is a rare sensitizer and commonly used in postprocedure care in Korea. Objective: This is a retrospective study aimed at comparing the efficacy and safety between fusidic acid and petrolatum for the postprocedure care of clean dermatologic procedures. Methods: Patients were treated with either fusidic acid or petrolatum ointment, applied on the wound created during clean dermatologic procedures such as biopsy of the punch, incisional, excisional, and shave types. The efficacy, adverse events, and subjective level of satisfaction were retrieved from medical records. Results: A total of 414 patients with a total of 429 wounds were enrolled. The overall rate of adverse events was 0.9%, and the rates of adverse events in the fusidic acid group and the petrolatum group were 1.4% and 0.5%, respectively (p = 0.370). There was no wound discharge, pain, tenderness, swelling, induration, or dehiscence in both groups. The patients' self-assessment of the wound was not significantly different between the two treatment groups. Conclusion: Our findings support the hypothesis that the routine prophylactic use of topical antibiotics is not indicated for clean dermatologic procedures. We recommend the use of petrolatum in the postoperative care of clean dermatologic procedures because of its equivalent efficacy and superior safety profiles.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/2008000790/1SEQ:1PERF_CD:SNU2015-01EVAL_ITEM_CD:102USER_ID:2008000790ADJUST_YN:NEMP_ID:A079501DEPT_CD:801CITE_RATE:.954FILENAME:bx and fusidic acid.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM:YY
Smartphone-based multispectral imaging and machine-learning based analysis for discrimination between seborrheic dermatitis and psoriasis on the scalp
Full text linkFor appropriate treatment, accurate discrimination between seborrheic dermatitis and psoriasis in a timely manner is crucial to avoid complications. However, when they occur on the scalp, differential diagnosis can be challenging using conventional dermascopes. Thus, we employed smartphone-based multispectral imaging and analysis to discriminate between them with high accuracy. A smartphone-based multispectral imaging system, suited for scalp disease diagnosis, was redesigned. We compared the outcomes obtained using machine learning-based and conventional spectral classification methods to achieve better discrimination. The results demonstrated that smartphone-based multispectral imaging and analysis has great potential for discriminating between these diseases. © 2019 Optical Society of America.1
The Effect of Bias Stress on the Performance of Amorphous InAlZnO-Based Thin Film Transistors
No full textIn amorphous InAlZnO (a-IAZO), the addition of the third cation of Al further slows the crystallization kinetics of In2O3 and enhances amorphous phase stability, compared to the binary cation system of InZnO. In addition, substantially high carrier mobilities of a-IAZO are obtained, in its unannealed state: Hall mobility of 30-50 cm(2)/Vs at a high carrier density regime (>similar to 10(18)/cm(3)) and thin film transistor (TFT) field effect mobility of similar to 8-15 cm(2)/Vs at a low carrier density regime (<similar to 10(16)/cm(3)). Gate bias stress stability of IAZO TFTs is investigated with positive and negative gate biases over time. Because of the channel depletion of n-type IAZO when negative gate bias is applied, no performance instabilities were identified. However, with positive gate bias stress (PBS) conditions (30 V), the threshold voltage (V-T) shifts towards higher voltages during the initial 100 s and then no significant changes in V-T are observed during the remaining time, over 10(5) s of the dependent measurements. The TFT field effect mobility shows a similar trend: increases from 7.64 cm(2)/Vs to 11.74 cm(2)/Vs within the first 100 s and then is saturated. It is identified that the PBS-induced device parameter variations are attributed to an increase and saturation of trap density at the channel/dielectric interface.
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