0000000000132939

AUTHOR

Yi Chang

0000-0003-2697-8093

showing 13 related works from this author

Vectors of Pairwise Item Preferences

2019

Neural embedding has been widely applied as an effective category of vectorization methods in real-world recommender systems. However, its exploration of users’ explicit feedback on items, to create good quality user and item vectors is still limited. Existing neural embedding methods only consider the items that are accessed by the users, but neglect the scenario when a user gives high or low rating to a particular item. In this paper, we propose Pref2Vec, a method to generate vector representations of pairwise item preferences, users and items, which can be directly utilized for machine learning tasks. Specifically, Pref2Vec considers users’ pairwise item preferences as elementary units. …

Computer scienceneuraalilaskentaInitialization02 engineering and technology010501 environmental sciencesRecommender systemMachine learningcomputer.software_genre01 natural sciences0202 electrical engineering electronic engineering information engineeringvectorizationPreference (economics)Independence (probability theory)0105 earth and related environmental sciencesbusiness.industryComputer Science::Information RetrievalsuosittelujärjestelmätConditional probabilityneural embeddingVectorization (mathematics)Benchmark (computing)020201 artificial intelligence & image processingPairwise comparisonArtificial intelligencebusinesscomputer
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The first example of cofacial bis(dipyrrins)

2016

International audience; Two series of cofacial bis(dipyrrins) were prepared and their photophysical properties as well as their bimolecular fluorescence quenching with C-60 were investigated. DFT and TDDFT computations were also performed as a modeling tool to address the nature of the fluorescence state and the possible inter-chromophore interactions. Clearly, there is no evidence for such interactions and the bimolecular quenching of fluorescence, in comparison with mono-dipyrrins, indicates that C-60-bis(dipyrrin) contacts occur from the outside of the "mouth" of the cofacial structure.

010402 general chemistryPhotochemistry01 natural sciences[ CHIM ] Chemical SciencesCatalysisTransition metalexcitation-energiesmolecular-orbital methodsorganometallic compoundsMaterials Chemistry[CHIM]Chemical Sciencessinglet energy transfersdensity-functional theoryvalence basis-setsGroup 2 organometallic chemistryQuenching (fluorescence)010405 organic chemistryChemistryGeneral ChemistryTime-dependent density functional theorytransition-metalsFluorescence0104 chemical scienceslight-harvesting systems2nd-row elementsDensity functional theoryextended basis-sets
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Identifying Oscillatory Hyperconnectivity and Hypoconnectivity Networks in Major Depression Using Coupled Tensor Decomposition

2021

AbstractPrevious researches demonstrate that major depression disorder (MDD) is associated with widespread network dysconnectivity, and the dynamics of functional connectivity networks are important to delineate the neural mechanisms of MDD. Cortical electroencephalography (EEG) oscillations act as coordinators to connect different brain regions, and various assemblies of oscillations can form different networks to support different cognitive tasks. Studies have demonstrated that the dysconnectivity of EEG oscillatory networks is related with MDD. In this study, we investigated the oscillatory hyperconnectivity and hypoconnectivity networks in MDD under a naturalistic and continuous stimuli…

masennusElementary cognitive taskComputer scienceBiomedical EngineeringmusiikkiElectroencephalographyMusic listeningvärähtelytInternal MedicinemedicineHumansTensor decompositionEEGDepressive Disorder Majormedicine.diagnostic_testQuantitative Biology::Neurons and CognitionDepressionsignaalinkäsittelyGeneral NeuroscienceFunctional connectivityRehabilitationBrainComputer Science::Software Engineeringsignaalianalyysihermoverkot (biologia)ElectroencephalographyHyperconnectivitymajor depression disorder naturalistic music stimuli oscillatory networksMagnetic Resonance ImagingPotential biomarkersCorrelation analysiscoupled tensor decompositiondynamic functional connectivitykognitiivinen neurotiedeNeuroscienceMusicärsykkeet
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Functional connectivity of major depression disorder using ongoing EEG during music perception

2020

Abstract Objective The functional connectivity (FC) of major depression disorder (MDD) has not been well studied under naturalistic and continuous stimuli conditions. In this study, we investigated the frequency-specific FC of MDD patients exposed to conditions of music perception using ongoing electroencephalogram (EEG). Methods First, we applied the phase lag index (PLI) method to calculate the connectivity matrices and graph theory-based methods to measure the topology of brain networks across different frequency bands. Then, classification methods were adopted to identify the most discriminate frequency band for the diagnosis of MDD. Results During music perception, MDD patients exhibit…

Adultmasennusmedicine.medical_specialtymusic perceptionFrequency bandmusiikkiElectroencephalographyAudiologybehavioral disciplines and activitiesnaturalistic stimuli050105 experimental psychology03 medical and health sciencesBeta bandYoung Adult0302 clinical medicinePhysiology (medical)mental disordersmedicineHumans0501 psychology and cognitive sciencesEEGDepression (differential diagnoses)AgedDepressive Disorder Majormedicine.diagnostic_testFunctional connectivity05 social sciencesfunctional connectivitymajor depression disorderBrainElectroencephalographyMiddle AgedSensory SystemsPhase lagongoing EEGNeurologyMusic perceptionAuditory PerceptionClassification methodsNeurology (clinical)Psychology030217 neurology & neurosurgeryMusicärsykkeet
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Shared and Unshared Feature Extraction in Major Depression During Music Listening Using Constrained Tensor Factorization

2021

Ongoing electroencephalography (EEG) signals are recorded as a mixture of stimulus-elicited EEG, spontaneous EEG and noises, which poses a huge challenge to current data analyzing techniques, especially when different groups of participants are expected to have common or highly correlated brain activities and some individual dynamics. In this study, we proposed a data-driven shared and unshared feature extraction framework based on nonnegative and coupled tensor factorization, which aims to conduct group-level analysis for the EEG signals from major depression disorder (MDD) patients and healthy controls (HC) when freely listening to music. Constrained tensor factorization not only preserve…

masennusmajor depressive disordersignaalinkäsittelymusiikkinaturalistic music stimulisignaalianalyysiNeurosciences. Biological psychiatry. NeuropsychiatryHuman Neuroscienceconstrained tensor factorizationbehavioral disciplines and activitiesBehavioral NeurosciencePsychiatry and Mental healthNeuropsychology and Physiological PsychologyNeurologyCANDECOMP/PARAFACaivotutkimusEEGärsykkeetBiological PsychiatryRC321-571Original ResearchFrontiers in Human Neuroscience
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Inside Cover: Synthesis and Characterization of Carbazole-Linked Porphyrin Tweezers (Chem. Eur. J. 34/2015)

2015

ChemistryCarbazoleOrganic ChemistrySonogashira couplingGeneral ChemistryElectrochemistryPhotochemistryPorphyrinCatalysisCharacterization (materials science)chemistry.chemical_compoundTweezersCover (algebra)Glaser couplingChemistry - A European Journal
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Synthetic strategy for preparation of a folate corrole DOTA heterobimetallic Cu–Gd complex as a potential bimodal contrast agent in medical imaging

2015

Abstract An efficient sequential route to synthesize heterobimetallic complexes is reported herein. A folate, Cu corrole, Gd DOTA complex that addresses the requirements of a potential contrast agent (CA) for bimodal imaging (e.g., MRI/PET) is reported. The over-expression of the folate receptor in a variety of malignant tumors, along with its limited expression in healthy tissues, makes this an attractive tumor-specific molecular target. Synthesis of a bimetallic ligand potentially targeting the folate receptor, was easily achieved in only a few steps. Interestingly, preliminary studies showed that the relaxivity of the folic heterobimetallic derivative was higher in comparison to a clinic…

StereochemistryGadoliniumMRI contrast agentOrganic Chemistrychemistry.chemical_elementLigand (biochemistry)BiochemistryCombinatorial chemistryImaging agentchemistry.chemical_compoundchemistryIn vivoFolate receptorDrug DiscoveryDOTACorroleTetrahedron Letters
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Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysis.

2020

AbstractBackgroundNonnegative matrix factorization (NMF) has been successfully used for electroencephalography (EEG) spectral analysis. Since NMF was proposed in the 1990s, many adaptive algorithms have been developed. However, the performance of their use in EEG data analysis has not been fully compared. Here, we provide a comparison of four NMF algorithms in terms of accuracy of estimation, stability (repeatability of the results) and time complexity of algorithms with simulated data. In the practical application of NMF algorithms, stability plays an important role, which was an emphasis in the comparison. A Hierarchical clustering algorithm was implemented to evaluate the stability of NM…

lcsh:Medical technologyComputer scienceBiomedical EngineeringStability (learning theory)ElectroencephalographySignal-To-Noise RatioClusteringNon-negative matrix factorizationBiomaterialsNonnegative matrix factorization03 medical and health sciencesklusterit0302 clinical medicineEeg dataalgoritmitmedicineHumansRadiology Nuclear Medicine and imagingSpectral analysisstabiilius (muuttumattomuus)EEGCluster analysisTime complexity030304 developmental biology0303 health sciencesRadiological and Ultrasound Technologymedicine.diagnostic_testResearchnonnegative matrix factorizationElectroencephalographySignal Processing Computer-AssistedGeneral MedicinestabilityModels TheoreticalHierarchical clusteringlcsh:R855-855.5AlgorithmStability030217 neurology & neurosurgeryAlgorithmsclusteringspektrianalyysiBiomedical engineering online
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Tetracationic and Tetraanionic Manganese Porphyrins: Electrochemical and Spectroelectrochemical Characterization

2017

International audience; The electrochemistry and spectroelectrochemistry of four tetrapositively charged and two tetranegatively charged porphyrins were characterized in two nonaqueous solvents (dimethyl sulfoxide and N,N-dimethylformamide) containing 0.1 M tetra-n-butylammonium perchlorate. The tetrapositively charged compounds are represented by the tetrapyridylporphyrins [TRPyPM]4+(X-)4, where R is a methyl or [2-[2-(2-methoxy)ethoxy]ethoxy]ethyl group, M = MnIIII, MnIIICl, CuII, or PdII, and X = I- or Cl-. The tetranegatively charged porphyrins are represented by the tetrasulfonato derivatives [TPPSMn(OAc)]4-(NH4+)4 and [TArPSMn(OAc)]4-(NH4+)4, where Ar = 4-O-[2-[2-(2-methoxy)ethoxy]eth…

010405 organic chemistryDimethyl sulfoxidechemistry.chemical_element[ CHIM.INOR ] Chemical Sciences/Inorganic chemistryManganese[CHIM.INOR]Chemical Sciences/Inorganic chemistry010402 general chemistryElectrochemistryPhotochemistry01 natural sciencesMedicinal chemistry0104 chemical sciencesInorganic Chemistrychemistry.chemical_compoundPerchloratechemistry13. Climate actionAlkoxy groupPyridiniumEthyl groupPhysical and Theoretical Chemistry
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Protonation and Electrochemical Properties of Pyridyl- and Sulfonatophenyl-Substituted Porphyrins in Nonaqueous Media

2017

International audience; The protonation and electrochemical properties of positively charged and negatively charged porphyrins are reported in up to five different nonaqueous solvents. The positively charged porphyrins are represented by mono- and di-pyridyl derivatives having the formula Pyx(PhMe)4-xPM, where P=the dianion of the porphyrin macrocycle, PhMe is a meso-tolyl group, Py a meso-pyridyl group, x=1 or 2, and M=H2, NiII, CuII, ZnII, or CoII. The negatively charged porphyrins are comprised of meso-tetrasulfonato derivatives having the formula [(R)4(TPPS)H2]4−(X+)4, where [(TPPS)H2]4− represents the porphyrin with four SO3− groups on the meso-phenyl substituents of the macrocycle, R=…

010405 organic chemistryChemistryProtonation010402 general chemistryPhotochemistryElectrochemistry[ CHIM ] Chemical Sciences01 natural sciencesMedicinal chemistryPorphyrinRedoxCatalysis0104 chemical sciencesSolventchemistry.chemical_compoundPEG ratioElectrochemistryTrifluoroacetic acid[CHIM]Chemical SciencesTitrationChemElectroChem
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Synthesis and Characterization of Carbazole-Linked Porphyrin Tweezers

2015

Herein the synthesis, spectroscopic characterization, two-photon absorption and electrochemical properties of 3,6-disubstituted carbazole tweezers is reported. A dimer resulting from a Glaser homocoupling was isolated during a Sonogashira coupling reaction between a diethynyl-carbazole spacer and a 5-bromo-triarylporphyrin and the properties of this original compound were compared with the 3,6-disubstituted carbazole bisporphyrin tweezers. The dyads reported herein present a two-photon absorption maximum at 920 nm with two-photon absorption cross-section in the 1200 GM range. Despite a strong linear absorption in the Soret region and moderate fluorescence quantum yield, they both lead to a …

CarbazoleDimerOrganic ChemistrySonogashira couplingQuantum yieldGeneral ChemistryPhotochemistryPorphyrinCatalysischemistry.chemical_compoundchemistryTweezersGlaser couplingAbsorption (electromagnetic radiation)Chemistry - A European Journal
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Altered EEG Oscillatory Brain Networks During Music-Listening in Major Depression

2021

To examine the electrophysiological underpinnings of the functional networks involved in music listening, previous approaches based on spatial independent component analysis (ICA) have recently been used to ongoing electroencephalography (EEG) and magnetoencephalography (MEG). However, those studies focused on healthy subjects, and failed to examine the group-level comparisons during music listening. Here, we combined group-level spatial Fourier ICA with acoustic feature extraction, to enable group comparisons in frequency-specific brain networks of musical feature processing. It was then applied to healthy subjects and subjects with major depressive disorder (MDD). The music-induced oscil…

masennusmedicine.medical_specialtyComputer Networks and Communicationsneural oscillationsFeature extractionmusiikkiAlpha (ethology)musiikkipsykologiaMajor depressive disordernaturalistic music listeningAudiologyElectroencephalographyDIAGNOSISbehavioral disciplines and activities050105 experimental psychology03 medical and health sciences0302 clinical medicineSIGNALSmedicine0501 psychology and cognitive sciencesEEGRESTING-STATE NETWORKSmajor depressive disorderINDEPENDENT COMPONENT ANALYSISONGOING EEGmedicine.diagnostic_testsignaalinkäsittely05 social sciences3112 Neuroscienceshermoverkot (biologia)signaalianalyysiFUNCTIONAL CONNECTIVITYADULTSGeneral MedicineMagnetoencephalographymedicine.diseasebrain networksIndependent component analysisongoing EEGhumanitiesElectrophysiologyindependent component analysisFMRI DATAFeature (computer vision)SYNCHRONIZATIONMajor depressive disorderPsychology030217 neurology & neurosurgeryRESPONSESInternational Journal of Neural Systems
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Response to Discussion on Y. Zhu, X. Wang, K. Mathiak, P. Toiviainen, T. Ristaniemi, J. Xu, Y. Chang and F. Cong, Altered EEG Oscillatory Brain Netwo…

2021

Biopsychosocial modelmedicine.medical_specialtyDepressive Disorder MajorMusic therapymedicine.diagnostic_testComputer Networks and CommunicationsDepressionBrainElectroencephalographyGeneral MedicineAudiologyMusic listeningElectroencephalographymedicineHumansPsychologyDepression (differential diagnoses)MusicInternational journal of neural systems
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