Gaussian processes for POMDP-based dialogue manager optimization

A partially observable Markov decision process (POMDP) has been proposed as a dialog model that enables automatic optimization of the dialog policy and provides robustness to speech understanding errors. Various approximations allow such a model to be used for building real-world dialog systems. However, they require a large number of dialogs to train the dialog policy and hence they typically rely on the availability of a user simulator. They also require significant designer effort to hand-craft the policy representation. We investigate the use of Gaussian processes (GPs) in policy modeling to overcome these problems. We show that GP policy optimization can be implemented for a real world POMDP dialog manager, and in particular: 1) we examine different formulations of a GP policy to minimize variability in the learning process; 2) we find that the use of GP increases the learning rate by an order of magnitude thereby allowing learning by direct interaction with human users; and 3) we demonstrate that designer effort can be substantially reduced by basing the policy directly on the full belief space thereby avoiding ad hoc feature space modeling. Overall, the GP approach represents an important step forward towards fully automatic dialog policy optimization in real world systems.This is the accepted manuscript version of an article first published in IEEE/ACM Transactions on Audio, Speech, and Language Processing. The final published version is available online from IEEE at http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6601004. © 2013 IEEE

Stochastic Language Generation in Dialogue using Recurrent Neural Networks with Convolutional Sentence Reranking

The natural language generation (NLG) component of a spoken dialogue system (SDS) usually needs a substantial amount of handcrafting or a well-labeled dataset to be trained on. These limitations add significantly to development costs and make cross-domain, multi-lingual dialogue systems intractable. Moreover, human languages are context-aware. The most natural response should be directly learned from data rather than depending on predefined syntaxes or rules. This paper presents a statistical language generator based on a joint recurrent and convolutional neural network structure which can be trained on dialogue act-utterance pairs without any semantic alignments or predefined grammar trees. Objective metrics suggest that this new model outperforms previous methods under the same experimental conditions. Results of an evaluation by human judges indicate that it produces not only high quality but linguistically varied utterances which are preferred compared to n-gram and rule-based systems.Comment: To be appear in SigDial 201

Turizam u funkciji razvoja ruralnih područja južne i istočne Srbije

Contemporary tourism trends are characterized by the increasing tourist movements towards rural destinations. Tourism in rural areas has become reality, the need and desire of tourists, but also an important activity for the development of rural areas. Southern and Eastern Serbia region has great potential for the development of rural tourism, but despite this, it is still at an early stage of development. The reason for this situation lies in a number of limiting factors and inadequate valorisation of available resources. For that reason, it is necessary to identify the key factors of development and establish the proposed measures, based on the available resources as well as on the experience of other countries, all in order to define strategic solutions which would enable faster development of rural tourism

Phytochemicals as markers of botanical and geographical origin of honey.

Predmet istraživanja ove doktorske disertacije bio je određivanje polifenolnog i šećernog profila meda i njihove veze sa botaničkim i geografskim poreklom. Postoji veliki broj eksperimentalnih metoda kombinovanih sa hemometrijskim tehnikama, već opisanih u literaturi, koje se bave utvrđivanjem autentičnosti meda, odnosno njegovog botaničkog i geografskog porekla analizom specifičnih fitohemikalija. Pronalaženje hemijskih biomarkera, odnosno fitohemikalija karakterističnih za pojedine vrste meda je predmet interesovanja značajnog broja istraživača. U literaturi su kao potencijalni biomarkeri botaničkog i geografskog porekla meda opisani niži šećeri i njihovi karakteristični odnosi, aminokiseline, isparlјive supstance, minerali, polifenoli i druge supstance. Do sada, kvantitativni sadržaj polifenola i šećera u kombinaciji sa analizom glavnih komponenata nije korišćen za procenu botaničkog i geografskog porekla meda. U cilјu identifikacije polifenolnih jedinjenja u medu korišćena je ultra-visoko efikasna tečna hromatografija sa hibridnim masenim detektorom visoke rezolucije koji kombinuje linarni trap-kvadrupol i orbitrap maseni analizator (UHPLC-LTQ OrbiTrap XL), dok je za kvantifikaciju polifenola korišćen UHPLC sa ultravioletnim detektorom sa više dioda (DAD) i masenim detektorom sa tri analizatora - trostruki kvadrupol (QQQ, triple quadrupol, UHPLC-DAD MS/MS). Profil šećera određen je visokoefikasnom anjonskom hromatografijom sa elektrohemijskom detekcijom (HPAECPAD). Tečno-masena hromatografija se pokazala kao brza i efikasna metoda za određivanje velikog broja polifenola u medu, dok je jonska hromatografija bila veoma pogodna metoda za određivanje šećernog profila meda. Odabrane su dve botaničke vrste meda: lipov med sa dva lokaliteta (Fruška Gora i Istočna Srbija) i med od žalfije (kadulјe) sa područja Hrvatske (Primorsko-goranska regija). Kvantitativni podaci (sadržaj polifenola i šećera) dobijeni analizom ovih medova upotreblјeni su za utvrđivanje veze između određenih hemijskih karakteristika meda i njegovog botaničkog, odnosno geografskog porekla...The research topic of this doctoral thesis was determination of polyphenolic and sugar profiles of honey and their relations with its botanical and geographical origin. There are a large number of experimental methods combined with multivariate analysis techniques, already described in the literature, engaged in determining the authenticity of honey, its botanical and geographic origin by analyzing specific phytochemical constituents. Finding phytochemicals characteristic for particular species of honey is the subject of interest of a significant number of researchers. Potential biomarkers of botanical and geographical origin of honey can be sugars, amino acids, volatiles, minerals, antioxidants and others, as well as their characteristic relations. Until now, the quantitative content of polyphenols and sugars combined with principal component analysis was not used to estimate the botanical and geographical origin of honey. Identification of the polyphenolic compounds from honey was achived using ultra-high performance liquid chromatography coupled with a hybrid mass spectrometer which consists of a linear ion trap and an Orbitrap mass analyzer (UHPLC-LTQ Orbitrap XL), while the quantification of the them was done by UHPLC with DAD (doide array detection) and triple quadrupole mass spectrometry (UHPLC-DAD MS/MS) detection. Sugar profile was determined by high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Liquid chromatography-mass spectrometry technique are proved to be a quick and efficient method for the determination of a large number of polyphenols in honey, while anion exchange chromatography was very suitable method for the determination of the sugars in honey. In order to isolate polyphenols from honey samples solid phase exraction (SPE) was used. Analysis of individual sugar was performed from aqueous solution of honey sample. For this invastigation, two botanical varieties of honey were selected: linden honey from two locations (Fruška Gora and Eastern Serbia) and sage honey from Croatia (Primorsko-goranska region). Quantitative data (polyphenols and sugars) obtained by the analysis of these honeys were used to establish the relationship between certain chemical properties of honey and its botanical or geographical origin..

Identification of Agrobacterium vitis as a causal agent of grapevine crown gall in Serbia

In 2010, a serious outbreak of crown gall disease was observed on grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) in several commercial vineyards located in the Vojvodina province, Serbia. Bacteria were isolated from the young tumor tissue on nonselective YMA medium and five representative strains were selected for further identification. Tumorigenic (Ti) plasmid was detected in all strains by PCR using primers designed to amplify the virC pathogenicity gene, producing a 414-bp PCR product. The strains were identified as Agrobacterium vitis using differential physiological and biochemical tests, and a multiplex PCR assay targeting 23S rRNA gene sequences. In the pathogenicity assay, all strains induced characteristic symptoms on inoculated tomato and grapevine plants. They were less virulent on tomato plants in comparison to the reference strains of A. tumefaciens and A. vitis. [Ministarstva nauke Republike Srbije, br. III46008: Development of integrated management of harmful organisms in plant production in order to overcome resistance and to improve food quality and safety

Policy committee for adaptation in multi-domain spoken dialogue systems

Moving from limited-domain dialogue systems to open domain dialogue systems raises a number of challenges. One of them is the ability of the system to utilise small amounts of data from disparate domains to build a dialogue manager policy. Previous work has focused on using data from different domains to adapt a generic policy to a specific domain. Inspired by Bayesian committee machines, this paper proposes the use of a committee of dialogue policies. The results show that such a model is particularly beneficial for adaptation in multi-domain dialogue systems. The use of this model significantly improves performance compared to a single policy baseline, as confirmed by the performed real-user trial. This is the first time a dialogue policy has been trained on multiple domains on-line in interaction with real users.The research leading to this work was funded by the EPSRC grant EP/M018946/1 ”Open Domain Statistical Spoken Dialogue Systems”.This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/ASRU.2015.740487

Efekti aspirina na apoptozu neutrofilnih granulocita

Neutrophils are a part of the immune system, and they are involved in host defence against microorganisms. Neutrophil granulocytes have the shortest lifespan among leukocytes, which can be modulated by cytokines and pharmacological agents. The effect of aspirin on apoptosis of inflammatory granulocytes has not been studied in detail yet, and therefore was the chosen subject of this study. Inflammatory granulocytes have been isolated from polyvinyl sponges implanted under the skin of Albino Oxford (AO) rats. Inflammatory cells that were isolated 20 hours later were more than 95% neutrophil granulocytes. The cells were cultivated 24 h with different concentrations of aspirin ranging from 1 µM to 10 mM. After the cultivation period, apoptosis of neutrophils was assessed by morphological criteria, as well as by flow cytometry (after staining the cells with propidium iodide). We found that at concentrations from 0,1 mM to 2,5 mM aspirin inhibited apoptosis of granulocytes, but at 10 mM aspirin induced apoptosis of these cells.Neutrofilni granulociti su deo imunog sistema, uključenog u odbranu od mikroorganizama. Oni imaju najkraći životni vek među leukocitima, koji se može modulisati citokinima i farmakološkim agensima, a do sada nije ispitivan efekat aspirina na apoptozu inflamatornih granulocita. Zbog toga je u ovoj studiji ispitivan efekat aspirina na apoptozu inflamatornih neutrofilnih granulocita pacova. Inflamatorni granulociti su izolovani iz polivinilskih sunđera, potkožno implantiranih, pacovima Albino Oxford (AO) soja. Inflamatorne ćelije, izolovane 20 sati kasnije, najvećim delom (više od 95 %) predstavljaju neutrofilne granulocite. Ove ćelije su kultivisane 24 sata sa aspirinom u koncentracijama od 1 µM do 10 mM. Posle ovog perioda supernatanti su sakupljani i korišćeni za merenje koncentracije NO. Ćelije su bojene propidijum jodidom i apoptoza je analizirana na protočnom citofluorimetru, kao i pomoću morfoloških kriterijuma. Ustanovljeno je da u koncentracijama od 0,1 do 2,5 mM aspirin inhibira, a samo u visokim koncentracijama (10 mM) indukuje apoptozu ovih ćelija. Aspirinom indukovana apoptoza je bila u pozitivnoj korelaciji sa smanjenom produkcijom NO

Supplementary material for the article: Koprivica, M. R.; Trifković, J. Đ.; Dramićanin, A. M.; Gašić, U. M.; Akšić, M. M. F.; Milojković-Opsenica, D. M. Determination of the Phenolic Profile of Peach (Prunus Persica L.) Kernels Using UHPLC–LTQ OrbiTrap MS/MS Technique. European Food Research and Technology 2018, 244 (11), 2051–2064. https://doi.org/10.1007/s00217-018-3116-2

Supplementary material for: [https://doi.org/10.1007/s00217-018-3116-2]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2226