In goal-oriented dialog systems, belief trackers estimate the probability distribution of slotvalues at every dialog turn. Previous neural approaches have modeled domain-and slot-dependent belief trackers, and have difficulty in adding new slot-values, resulting in lack of flexibility of domain ontology configurations. In this paper, we propose a new approach to universal and scalable belief tracker, called slot-utterance matching belief tracker (SUMBT). The model learns the relations between domain-slot-types and slotvalues appearing in utterances through attention mechanisms based on contextual semantic vectors. Furthermore, the model predicts slot-value labels in a non-parametric way. From our experiments on two dialog corpora, WOZ 2.0 and MultiWOZ, the proposed model showed performance improvement in comparison with slot-dependent methods and achieved the state-of-the-art joint accuracy.

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A new multiplexed NIR in vivo imaging is showcased by using quantum dots and NaYF(4):Yb(3+),Tm(3+) nanoparticles. The 'temporal' multiplexing is demonstrated by alternating the excitation wavelengths and unmixing the emissions of different probes. Multiplexed cellular imaging and the cellular trafficking in animal models are shown.

Strongly luminescent and highly loaded CdSe quantum dot (QD)-silica composite films are prepared by a simple one-step method. QDs are grown in situ as the silica matrix forms from spin-on-glass organosiloxane polymers. The nucleation and growth of QDs in the silica matrix is directly observed using TEM. The QD composites are comprehensively characterized, which includes photoluminescence(PL) decay, PL efficiency, and QD volume fraction. The QD emission can span the entire visible range and can be tuned by the preparation condition. The PL of QDs is very strong, reaching the quantum efficiency up to 35%. Very high QD loading is achieved with the volume fraction as high as 13%, which makes our composite the highest loaded QD-silica composite material. We further showcase the versatile applicability of our method by a QD-silica composite capped down-conversion pseudo white LED.