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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. Ā© 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 podruÄja južne i istoÄne 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 odreÄivanje polifenolnog i
Å”eÄernog profila meda i njihove veze sa botaniÄkim i geografskim poreklom. Postoji
veliki broj eksperimentalnih metoda kombinovanih sa hemometrijskim tehnikama, veÄ
opisanih u literaturi, koje se bave utvrÄivanjem autentiÄnosti meda, odnosno njegovog
botaniÄkog i geografskog porekla analizom specifiÄnih fitohemikalija. Pronalaženje
hemijskih biomarkera, odnosno fitohemikalija karakteristiÄnih za pojedine vrste meda je
predmet interesovanja znaÄajnog broja istraživaÄa. U literaturi su kao potencijalni
biomarkeri botaniÄkog i geografskog porekla meda opisani niži Å”eÄeri i njihovi
karakteristiÄni odnosi, aminokiseline, isparlŃive supstance, minerali, polifenoli i druge
supstance. Do sada, kvantitativni sadržaj polifenola i Å”eÄera u kombinaciji sa analizom
glavnih komponenata nije koriÅ”Äen za procenu botaniÄkog i geografskog porekla meda.
U cilŃu identifikacije polifenolnih jedinjenja u medu koriÅ”Äena je ultra-visoko
efikasna teÄna 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 koriÅ”Äen UHPLC sa ultravioletnim detektorom
sa viŔe dioda (DAD) i masenim detektorom sa tri analizatora - trostruki kvadrupol
(QQQ, triple quadrupol, UHPLC-DAD MS/MS). Profil Å”eÄera odreÄen je visokoefikasnom
anjonskom hromatografijom sa elektrohemijskom detekcijom (HPAECPAD).
TeÄno-masena hromatografija se pokazala kao brza i efikasna metoda za
odreÄivanje velikog broja polifenola u medu, dok je jonska hromatografija bila veoma
pogodna metoda za odreÄivanje Å”eÄernog profila meda.
Odabrane su dve botaniÄke vrste meda: lipov med sa dva lokaliteta (FruÅ”ka Gora
i IstoÄna Srbija) i med od žalfije (kadulŃe) sa podruÄja Hrvatske (Primorsko-goranska
regija). Kvantitativni podaci (sadržaj polifenola i Å”eÄera) dobijeni analizom ovih
medova upotreblŃeni su za utvrÄivanje veze izmeÄu odreÄenih hemijskih karakteristika
meda i njegovog botaniÄkog, 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 (FruŔka 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 āOpen Domain Statistical Spoken Dialogue Systemsā.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 ĀµM 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, ukljuÄenog u odbranu od mikroorganizama. Oni imaju najkraÄi životni vek meÄu leukocitima, koji se može modulisati citokinima i farmakoloÅ”kim 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 sunÄera, potkožno implantiranih, pacovima Albino Oxford (AO) soja. Inflamatorne Äelije, izolovane 20 sati kasnije, najveÄim delom (viÅ”e od 95 %) predstavljaju neutrofilne granulocite. Ove Äelije su kultivisane 24 sata sa aspirinom u koncentracijama od 1 ĀµM do 10 mM. Posle ovog perioda supernatanti su sakupljani i koriÅ”Äeni za merenje koncentracije NO. Äelije su bojene propidijum jodidom i apoptoza je analizirana na protoÄnom citofluorimetru, kao i pomoÄu morfoloÅ”kih 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 Äelija. Aspirinom indukovana apoptoza je bila u pozitivnoj korelaciji sa smanjenom produkcijom NO
Supplementary material for the article: Koprivica, M. R.; TrifkoviÄ, J. Ä.; DramiÄanin, A. M.; GaÅ”iÄ, U. M.; AkÅ”iÄ, M. M. F.; MilojkoviÄ-Opsenica, D. M. Determination of the Phenolic Profile of Peach (Prunus Persica L.) Kernels Using UHPLCāLTQ OrbiTrap MS/MS Technique. European Food Research and Technology 2018, 244 (11), 2051ā2064. 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
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