Naver Corporation

About: Naver Corporation is a company organization based out in Seongnam-si, South Korea. It is known for research contribution in the topics: Terminal (electronics) & Computer science. The organization has 4038 authors who have published 4294 publications receiving 35045 citations. The organization is also known as: NAVER Corporation & NAVER.

Quality models for microblog retrieval

Abstract: Microblog services typically contain very short documents (e.g., tweets) containing comments about the latest news and events. Many of these documents are not informative or have very little content due to their personal and ephemeral nature. Providing effective retrieval in a microblog service will require addressing the challenge of distinguishing the high-quality, informative documents from the others. Recent work has focused on finding features that indicate the quality of microblog documents, but the impact these quality features on retrieval is not clear. In this paper, we suggest a low-cost quality model using surrogate judgments based on user behavior (i.e., retweets) that can be collected automatically. We analyze the relationship between document informativeness and relevance judgments for microblog retrieval. Then we demonstrate that our behavior-based quality metric has a high correlation with manual judgments. Also, we perform experiments to study the impact of the quality model on microblog retrieval. The results based on the TREC Microblog track show that the proposed quality model, combined with a variety of retrieval models, can improve retrieval performance and is competitive with a model trained using manual relevance judgments.

Representation Learning of Music Using Artist Labels

Abstract: In music domain, feature learning has been conducted mainly in two ways: unsupervised learning based on sparse representations or supervised learning by semantic labels such as music genre. However, finding discriminative features in an unsupervised way is challenging and supervised feature learning using semantic labels may involve noisy or expensive annotation. In this paper, we present a supervised feature learning approach using artist labels annotated in every single track as objective meta data. We propose two deep convolutional neural networks (DCNN) to learn the deep artist features. One is a plain DCNN trained with the whole artist labels simultaneously, and the other is a Siamese DCNN trained with a subset of the artist labels based on the artist identity. We apply the trained models to music classification and retrieval tasks in transfer learning settings. The results show that our approach is comparable to previous state-of-the-art methods, indicating that the proposed approach captures general music audio features as much as the models learned with semantic labels. Also, we discuss the advantages and disadvantages of the two models.

Antimicrobial effect of 7-O-butylnaringenin, a novel flavonoid, and various natural flavonoids against Helicobacter pylori strains.

Abstract: The antimicrobial effect of a novel flavonoid (7-O-butylnaringenin) on Helicobacter pylori 26695, 51, and SS1 strains and its inhibitory effect on the urease activity of the strains were evaluated and compared with those of several natural flavonoids. First, various flavonoids were screened for antimicrobial activities using the paper disc diffusion method. Hesperetin and naringenin showed the strongest antimicrobial effects among the natural flavonoids tested, and thus hesperetin and naringenin were selected for comparison with 7-O-butylnaringenin. The antimicrobial effect of 7-O-butylnaringenin was greater than that of the hesperetin and naringenin. H. pylori 51 was more sensitive to 7-O-butylnaringenin (2 log reduction of colony forming units, p < 0.05) than the other two strains at 200 μM. 7-O-Butylnaringenin also showed the highest inhibitory effect against urease activity of H. pylori. Morphological changes of H. pylori 26695 treated with these flavonoids indicated that both hesperetin and 7-O-butylnaringenin at 200 μM damaged the cell membranes.

System and method for providing avatar/game/entertainment functions on messenger platform

Abstract: Provided is a system and method for providing avatar, gaming and entertainment functions on a messenger platform. A method for providing a messenger service using a real graph displaying social information of users using a messenger may include: providing a messenger function among users between whom a relationship is established; providing a first user interface for providing a virtual world service through the messenger function; providing the virtual world service using a virtual graph displaying social information of users using the virtual world service; converting the real world service, to the virtual world service in response to a request from the first user interface, and providing a second interface for converting the virtual world service to the real world service. The virtual world service may include at least one of an avatar service and a game service.

Effect of Honokiol on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

Abstract: Honokiol is a bioactive component isolated from the medicinal herbs Magnolia officinalis and Magnolia grandiflora that has antioxidative, anti-inflammatory, antithrombotic, and antitumor activities. The inhibitory potentials of honokiol on eight major human cytochrome P450 (CYP) enzymes 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4, and four UDP-glucuronosyltransferases (UGTs) 1A1, 1A4, 1A9, and 2B7 in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. Honokiol strongly inhibited CYP1A2-mediated phenacetin O-deethylation, CYP2C8-mediated amodiaquine N-deethylation, CYP2C9-mediated diclofenac 4-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4-hydroxylation, and UGT1A9-mediated propofol glucuronidation with Ki values of 1.2, 4.9, 0.54, 0.57, and 0.3 μM, respectively. Honokiol also moderately inhibited CYP2B6-mediated bupropion hydroxylation and CYP2D6-mediated bufuralol 1'-hydroxylation with Ki values of 17.5 and 12.0 μM, respectively. These in vitro results indicate that honokiol has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP1A2, CYP2C8, CYP2C9, CYP2C19, and UGT1A9.