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71.
An Efficient Hybrid Music Recommender System Using an Incrementally Trainable Probabilistic Generative Model 总被引:3,自引:0,他引:3
Yoshii K. Goto M. Komatani K. Ogata T. Okuno H.G. 《IEEE transactions on audio, speech, and language processing》2008,16(2):435-447
This paper presents a hybrid music recommender system that ranks musical pieces while efficiently maintaining collaborative and content-based data, i.e., rating scores given by users and acoustic features of audio signals. This hybrid approach overcomes the conventional tradeoff between recommendation accuracy and variety of recommended artists. Collaborative filtering, which is used on e-commerce sites, cannot recommend nonbrated pieces and provides a narrow variety of artists. Content-based filtering does not have satisfactory accuracy because it is based on the heuristics that the user's favorite pieces will have similar musical content despite there being exceptions. To attain a higher recommendation accuracy along with a wider variety of artists, we use a probabilistic generative model that unifies the collaborative and content-based data in a principled way. This model can explain the generative mechanism of the observed data in the probability theory. The probability distribution over users, pieces, and features is decomposed into three conditionally independent ones by introducing latent variables. This decomposition enables us to efficiently and incrementally adapt the model for increasing numbers of users and rating scores. We evaluated our system by using audio signals of commercial CDs and their corresponding rating scores obtained from an e-commerce site. The results revealed that our system accurately recommended pieces including nonrated ones from a wide variety of artists and maintained a high degree of accuracy even when new users and rating scores were added. 相似文献
72.
Ogata M. Nakamura T. Matsumoto K. Ohta R. Hyuga R. 《Electron Devices, IEEE Transactions on》1991,38(5):1005-1010
A charge modulation device (CMD) imager with pixel dimensions of 7.3 μm(H)×7.6 μm(V) was designed, fabricated, and examined. These pixel dimensions are suitable for an HDTV imager with a 1-in image format. The optical aperture ratio is 34%. The effective number of pixels in the imager is 660 horizontal and 492 vertical. The saturation signal current is 17 μA/pixel at an exposure of 1 lx-s with good linearity of photoconversion characteristics. The peak of its spectral response occurs at a wavelength of 575 nm. The blooming suppression ratio of the CMD was measured to be -122 dB. The sensor produces a high-quality image with no degradation in spatial resolution and no image lag. These features show that the CMD imager is eminently suitable for a further high-resolution imager sensor 相似文献
73.
A supervising instrument designed to measure the operating states of a high-power, medium-wave AM radio transmitter and its peripheral devices is described. The instrument can be used to measure the load impedance, output power, and efficiency of the final stage amplifier of the medium wave AM radio transmitter and can be used as a data logging and data analyzing instrument when the GP-1 B digital and analog interfaces are attached to the devices 相似文献
74.
75.
K Kataoka T Mizushima Y Ogata T Miki K Sekimizu 《Canadian Metallurgical Quarterly》1996,271(40):24806-24810
Genetic studies revealed that DNA gyrase seems to catalyze immediate and transient DNA relaxation after Escherichia coli cells are exposed to heat shock (Ogata, Y., Mizushima, T., Kataoka, K., Miki, T., and Sekimizu, K. (1994) Mol. Gen. Genet. 244, 451-455). We have now obtained biochemical evidence to support this hypothesis. DNA gyrase catalyzed an increase in the linking number of DNA and relaxation of negatively supercoiled DNA, under physiological concentrations of ATP. Analyses by gel filtration chromatography of each subunit revealed that DNA relaxation activity co-migrated with each subunit. The linking number of DNA increased as the temperature increased. Further, the reaction was inhibited by nalidixic acid or by oxolinic acid. Based on these results, we propose that DNA gyrase participates in a concerted reaction with DNA topoisomerases in the immediate relaxation of DNA in cells exposed to heat shock. 相似文献
76.
G Teoh L Chen M Urashima YT Tai LA Celi D Chen D Chauhan A Ogata RW Finberg IJ Webb DW Kufe KC Anderson 《Canadian Metallurgical Quarterly》1998,92(12):4591-4601
Adenoviruses are efficient gene delivery agents for a variety of neoplasms. In the present study, we have investigated the use of adenoviruses for the delivery of the thymidine kinase (tk) gene into multiple myeloma (MM) cells. We first demonstrated that MM cell lines and MM patient cells express both adenovirus receptors as well as the DF3/MUC1 protein, thus providing a rationale for using adenoviruses to selectively deliver genes under the control of the DF3 promoter. By using an adenoviral construct containing beta-galactosidase (beta-gal) gene driven by the DF3 promoter (Ad. DF3-betagal), we demonstrate greater than 80% transduction efficiency in OCI-My5 and RPMI 8226 MM cell lines at a multiplicity of infection of 1 to 100. Importantly, transduction with the tk gene driven by the DF3 promoter (Ad.DF3-tk) followed by treatment with 50 micromol/L ganciclovir (GCV) purged >/=6 log of contaminating OCI-My5 and RPMI 8226 MM cells within bone marrow mononuclear cells. In contrast, normal human hematopoietic progenitor cell number was unaffected under these conditions. Selectivity of DF3/MUC1 promoter was further confirmed, because Ad.DF3-betagal or Ad.DF3-tk did not transduce MUC1-negative HeLa cervical carcinoma cells. In addition, GCV treatment of Ad.DF3-tk-transduced RPMI 8226 MM cells did not induce a significant bystander effect. These findings demonstrate that transduction with Ad vectors using a tumor-selective promoter provides a highly efficient and selective approach for the ex vivo purging of MM cells. 相似文献
77.
Reactive ion etching of InP, GaInAs and GaAs using a mixture of ethane and hydrogen, C2H6/H2, is demonstrated for the first time. It has been found that by choosing optimum etching parameters one can obtain excellent vertical sidewalls as well as very smooth surfaces, keeping the etching rate at a convenient value of 20-60 nm/min 相似文献
78.
This paper describes a study carried out to obtain the heat transfer characteristics of liquid helium l in a vertical tube under forced convection conditions. The test section was a straight stainless-steel tube with a length of 8.5 cm and an id of 0.109 cm. Helium pressures ranged from 1.1 to 1.9 atm (0.11 to 0.19 MN m?2) and qualities (vapour mass fractions) ranged from zero to 1.Results were correlated using conventional equations and compared with the data already obtained. The hysteresis observed in the nucleate boiling region is qualitatively discussed. The quality dependence of two-phase flow heat transfer was clearly observed during an increase, but not during a decrease, of heat flux or quality. 相似文献
79.
Comparison of the clinical features, especially prognosis, in cerebral infarction was made between nine normotensive subjects and 16 hypertensive patients with an 80% stenosis or occlusion of the intracranial or extracranial arteries. Our own criteria for evaluating hypertension were employed on the basis of the following items: a past history of hypertension, blood pressure levels on admission and during hospitalization, degree of retinopathy, and ECG changes. In 17 of 25 cases, brain circulation was measured by the intravenous RISA technique. Abnormalities of the EEG and reduction of cranial blood flow were greater, and an early prognosis for neurological deficits in the first two months after the onset of stroke was poorer in the hypertensive group than inthe normotensive group. These results are contradictory to the observations of others. 相似文献
80.
Two kinds of aromatic–aliphatic polyamide oligomers were newly prepared by the reactant pairs of 3,4′-oxydianiline–adipic acid and 3,4′-oxydianiline–azelaic acid. These oligomers were then condensed separately with α, ω-polybutadienedicarboxylic acid giving two series of polybutadiene–polyamide multiblock copolymers. Properties of four series of polybutadiene–polyamide multiblock copolymers, whose polyamide blocks consisted of not only newly prepared polyamides but also previously synthesized aromatic polyamides derived from 4,4′-oxydianiline–isophthalic acid and 3,4′-oxydianiline–isophthalic acid, were investigated on the view point of structure-property relationship. A larger extent of the Tg depression of polybutadiene phase, and higher tensile strength and modulus were observed in the block copolymers having aromatic polyamides compared with those having aliphatic ones. 相似文献