Trajectory computation during a maneuver: Thrust estimation with the Goddard Trajectory Determination System (GTDS)

Existing thrust modeling capabilities of the Goddard Trajectory Determination System (GTDS) have been enhanced to allow calibration of the onboard propulsion system. These enhancements provide one or more thrust scale factors, based on estimation using the batch least-squares technique, for the case of along-track thrust and the case of attitude-dependent thrust. The enhancements are evaluated using simulated tracking measurements for a test spacecraft and using actual tracking measurements for the Earth Radiation Budget Satellite (ERBS). The effects of tracking measurement noise and distribution on the accuracy of the estimation are investigated and found to be significant. Results and conclusions of the analysis are presented

Automation of orbit determination functions for National Aeronautics and Space Administration (NASA)-supported satellite missions

The Flight Dynamics Facility (FDF) at Goddard Space Flight Center (GSFC) provides spacecraft trajectory determination for a wide variety of National Aeronautics and Space Administration (NASA)-supported satellite missions, using the Tracking Data Relay Satellite System (TDRSS) and Ground Spaceflight and Tracking Data Network (GSTDN). To take advantage of computerized decision making processes that can be used in spacecraft navigation, the Orbit Determination Automation System (ODAS) was designed, developed, and implemented as a prototype system to automate orbit determination (OD) and orbit quality assurance (QA) functions performed by orbit operations. Based on a machine-resident generic schedule and predetermined mission-dependent QA criteria, ODAS autonomously activates an interface with the existing trajectory determination system using a batch least-squares differential correction algorithm to perform the basic OD functions. The computational parameters determined during the OD are processed to make computerized decisions regarding QA, and a controlled recovery process isactivated when the criteria are not satisfied. The complete cycle is autonomous and continuous. ODAS was extensively tested for performance under conditions resembling actual operational conditions and found to be effective and reliable for extended autonomous OD. Details of the system structure and function are discussed, and test results are presented

Topological insight into the non-Arrhenius mode hopping of semiconductor ring lasers

We investigate both theoretically and experimentally the stochastic switching between two counter-propagating lasing modes of a semiconductor ring laser. Experimentally, the residence time distribution cannot be described by a simple one parameter Arrhenius exponential law and reveals the presence of two different mode-hop scenarios with distinct time scales. In order to elucidate the origin of these two time scales, we propose a topological approach based on a two-dimensional dynamical system.Comment: 4 pages, 3 figure

Exploring multi-stability in semiconductor ring lasers: theory and experiment

We report the first experimental observation of multi-stable states in a single-longitudinal mode semiconductor ring laser. We show how the operation of the device can be steered to either monostable, bistable or multi-stable dynamical regimes in a controlled way. We observe that the dynamical regimes are organized in well reproducible sequences that match the bifurcation diagrams of a two-dimensional model. By analyzing the phase space in this model, we predict how the stochastic transitions between multi-stable states take place and confirm it experimentally.Comment: 4 pages, 5 figure

Multi-channel Kondo impurity dynamics in a Majorana device

We study the multi-channel Kondo impurity dynamics realized in a mesoscopic superconducting island connected to metallic leads. The effective 'impurity spin' is non-locally realized by Majorana bound states and strongly coupled to lead electrons by non-Fermi liquid correlations. We explore the spin dynamics and its observable ramifications near the low-temperature fixed point. The topological protection of the system raises the perspective to observe multi-channel Kondo impurity dynamics in experimentally realistic environments.Comment: 4.6 pages; published versio

Analisis Bauran Pemasaran Jamur Tiram di Kota Pekanbaru

The research aims to figure out the characteristic of Oyster Mushroom in Pekanbaru, the level of belief, consumers' importance and consumers' attitude on marketing mix of Oyster Mushroom in Pekanbaru. The research was carried out on Limbungan street BPD Complex in Rumbai Pekanbaru. This research used primary data that was gained from interview and secondary data that was gained from Board of Statistic Center and other references, and then those data were analayzed by using validity and reliability test, importance and belief level, cartesian diagram, Multiattribute Fishbein. The result showed that the biggest number of consumers' chracteristicswere in productive age41-50 years old, female, mostly in S1 and High School as the educational level, and jobs were housewife and private employee, with 2-3 children, with income range between Rp. 3,000,000-Rp.5,000,000/month, and have been subscribing for 4-6 months. The attributes of Oyster Mushroom producer with above the average level of belief were the affordable price, discount, reachable location, packaging, texture, benefit, nutrients, and expiry. The attributes with below the average level of belief were the price that was cheaper than other types of mushroom, parking area, the street condition, hygiene and the place comfortability, promotion in newspaper and billboard. The attributes of Oyster Mushroom producer with above the average level of importance were affordable price, discount, reachable location, good street condition, hygiene, and the place comfortability, product availibility, texture, benefit, nutrients, and expiry. The consumers' attitude toward the Oyster Mushroom producer according to the scale score was 436.2273it was located in “a bit agree scale of measurement” (5), therefore the consumers' attitude in the research was chategorized as “a bit agree” in scale of measurement

Observation of nonlinear dynamics and transition to chaos in photonic integrated circuits

Photonic Integrated Circuit (PIC) technology has revolutionized the application and fabrication of optoelectronic devices. Most affected by this development is the field of telecommunications, where both active and passive photonic devices are key components in the optical networks. PIC based optical components are cheaper to fabricate than their stand-alone counter parts, multifunctional, low energy consumers and much smaller in size. These qualities make PICs very attractive from a mass-integration point of view and they are generally viewed as the successors of electronic ICs. In this work we demonstrate that the nonlinear dynamics exhibited by the PICs are stable, well-classifiable from a bifurcational theoretical point of view and reproducible from batch-to-batch

Acetylation of tamarind seed jellose

The hexa, duodeca and hexadeca acetyl derivatives of tamarind seed jellose have been prepared by treatment with acetic anhydride under different conditions. Boiling glacial acetic acid also effects partial acetylation. Some of the acetyl derivatives in appropriate solvents give fairly strong, flexible, glossy and transparent films, which adhere to glass, metallic and also wooden surfaces. They may also be useful as thermoplastic resins on account of their wide melting range

Analysis of sugars using paper chromatography (Horizontal Migration)

Employing filter-paper chromatography a convenient method (Horizontal Migration Method) has been developed for the identification of reducing sugars, when present either alone or in mixtures. Since only small amounts are required for the identification, the method may be useful both to the regular student and the research worker. Under the conditions of the experiment the components of mixtures separate in ½ to 1 ½ hours into circular zones, which can be easily detected by spraying with a suitable reagent like aniline hydrogen phthalate. Each sugar has its own characteristic circular RF value (the ratio between the distances through which the sugar moves on the one hand and the solvent front on the other) with a particular solvent, and its determination enables the identification of the sugar. Since some of the sugars have the same or very close RF values with a particular solvent, it is desirable to run the chromatogram with at least 2 different solvents to confirm the identification. In the case of mixtures it may be necessary to determine the RF values with 3 or more different solvents in order to definitely identify the individual components. Some of the advantages of the method are the speed and ease of manipulation, simplicity and compactness of the apparatus, and accuracy and reproducibility of the results