Accuracy study of the Upper Atmosphere Research Satellite (UARS) definitive attitude determination

The Upper Atmosphere Research Satellite (UARS) has two definitive attitude determination requirements: the definitive attitude of the Modular Attitude Control Subsystem (MACS) and the definitive attitude of the gimbaled Solar-Stellar Pointing Platform (SSPP). The onboard computer (OBC) will compute the MACS attitude using a Kalman filter and will transform this attitude solution through the SSPP gimbals to calculate the SSPP attitude. The attitude ground support system (AGSS) will compute the MACS attitude using a batch least-squares differential corrector algorithm and will also transform this solution through the gimbals to obtain the SSPP attitude. This paper reports the results of a prelaunch study to predict the accuracy of the OBC attitude solutions and the accuracy of the AGSS attitude solutions. The OBC and AGSS solution accuracies are then compared to establish the relative quality. The effects of star observability, sensor noise, and sensor misalignment uncertainties on attitude determination accuracy are analyzed for each case

Regio- and stereo-specific propylene-carbon monoxide alternating copolymers :: synthesis, characterization, and application/

Compounds of palladium with many different chelated bisphosphine ligands were investigated for their catalysis of alternating copolymerization of propylene (P) with carbon monoxide (CO). The bisphosphine structure and chelate ring size influence strongly the activity, regio- and stereo-selectivity of the catalysts. Molecular mechanics calculations on $\pi$-olefin complex showed that the non-bonded interaction between propylene and the ligands on Pd is both regio- and stereo-selective. Electronic factor and presence of chiral center were crucial for the regio- and stereo-regularity control of the catalyst, respectively. Primary insertion is more probable than secondary insertion, and the enantioselective catalysts favor the meso enchainment of propylene. The crystalline copolymer has the hexagonal unit cell structure with a = b = 15.5 A, and c = 8.97 A. The single crystalline copolymer chain is a 3\sb1 fold helix. GC-MS of oligomers showed that most chains are initiated by Pd-H species; and $\beta$-hydrogen elimination is the dominant chain termination process. The anaerobic photodegradation behaviors of bulk alternating copolymers of P-CO and E-CO have been studied by irradiation with 2537 A light. Photolysis of the former resulted in weight loss, molecular weight depression, cross-linking, and the formation of hydroxyl and terminal vinyl groups. The room temperature quantum yields of chain scission and Norrish type II reactions were found to be 0.015 $\pm$ 0.002 and 0.011 $\pm$ 0.002. P-CO alternating copolymer was blended with poly(methyl methacrylate) (PMMA) by solution precipitation. Various aspects of blends behavior were studied by DSC, DMTA, DETA, FTIR, and CP-MAS solid state NMR. The blends exhibited single T\rm\sb{g}\u27s at all compositions, which is an indication of the miscible blends. $\beta$-relaxation of P-CO copolymer was detected by DETA at -65\sp\circC for the first time. The measurement of rotating frame NMR relaxation time, \rm T\sb{1\rho}\sp{H}, showed that the average distance between P-CO and PMMA is less than 30 A

Order-Preserving Abstractive Summarization for Spoken Content Based on Connectionist Temporal Classification

Connectionist temporal classification (CTC) is a powerful approach for sequence-to-sequence learning, and has been popularly used in speech recognition. The central ideas of CTC include adding a label "blank" during training. With this mechanism, CTC eliminates the need of segment alignment, and hence has been applied to various sequence-to-sequence learning problems. In this work, we applied CTC to abstractive summarization for spoken content. The "blank" in this case implies the corresponding input data are less important or noisy; thus it can be ignored. This approach was shown to outperform the existing methods in term of ROUGE scores over Chinese Gigaword and MATBN corpora. This approach also has the nice property that the ordering of words or characters in the input documents can be better preserved in the generated summaries.Comment: Accepted by Interspeech 201

Mobility in China

The evidence on rank and income mobility in China reveals an important change around the year 2000. Using panel data from the China Health and Nutrition Survey we show that rank mobility fell markedly from the decade immediately preceding the millennium to the decade immediately following: in this respect China is becoming noticeably more rigid. By contrast income mobility has carried on increasing; so has income inequality. The simultaneous increase in rigidity and inequality presents China with a challenging policy problem

Senior Recital

List of performers and performances