Fast and Accurate Random Walk with Restart on Dynamic Graphs with Guarantees

Given a time-evolving graph, how can we track similarity between nodes in a fast and accurate way, with theoretical guarantees on the convergence and the error? Random Walk with Restart (RWR) is a popular measure to estimate the similarity between nodes and has been exploited in numerous applications. Many real-world graphs are dynamic with frequent insertion/deletion of edges; thus, tracking RWR scores on dynamic graphs in an efficient way has aroused much interest among data mining researchers. Recently, dynamic RWR models based on the propagation of scores across a given graph have been proposed, and have succeeded in outperforming previous other approaches to compute RWR dynamically. However, those models fail to guarantee exactness and convergence time for updating RWR in a generalized form. In this paper, we propose OSP, a fast and accurate algorithm for computing dynamic RWR with insertion/deletion of nodes/edges in a directed/undirected graph. When the graph is updated, OSP first calculates offset scores around the modified edges, propagates the offset scores across the updated graph, and then merges them with the current RWR scores to get updated RWR scores. We prove the exactness of OSP and introduce OSP-T, a version of OSP which regulates a trade-off between accuracy and computation time by using error tolerance {\epsilon}. Given restart probability c, OSP-T guarantees to return RWR scores with O ({\epsilon} /c ) error in O (log ({\epsilon}/2)/log(1-c)) iterations. Through extensive experiments, we show that OSP tracks RWR exactly up to 4605x faster than existing static RWR method on dynamic graphs, and OSP-T requires up to 15x less time with 730x lower L1 norm error and 3.3x lower rank error than other state-of-the-art dynamic RWR methods.Comment: 10 pages, 8 figure

Addressing Distribution Shift in RTB Markets via Exponential Tilting

Distribution shift in machine learning models can be a primary cause of performance degradation. This paper delves into the characteristics of these shifts, primarily motivated by Real-Time Bidding (RTB) market models. We emphasize the challenges posed by class imbalance and sample selection bias, both potent instigators of distribution shifts. This paper introduces the Exponential Tilt Reweighting Alignment (ExTRA) algorithm, as proposed by Marty et al. (2023), to address distribution shifts in data. The ExTRA method is designed to determine the importance weights on the source data, aiming to minimize the KL divergence between the weighted source and target datasets. A notable advantage of this method is its ability to operate using labeled source data and unlabeled target data. Through simulated real-world data, we investigate the nature of distribution shift and evaluate the applicacy of the proposed model

The role of prototypical brand image on shaping country image and product quality evaluation: A cross-cultural examination

This study paid attention to the role of a corporate brand that most represents the country, referred to as prototypical brand, in shaping country image. Since the role of the prototypical brand (e.g., Samsung) in creating positive image will be critical in newly industrialized countries (NIEs), this study examines the context of Korea. Built on prototype, schema, and cue theories, this study proposes a research model that examines the impact of prototypical brand image on shaping the overall country image (i.e., macro country image) and product-specific country image (i.e., micro country image), which influences consumers\u27 evaluation of product quality of Korean cosmetics and empirically tests the model with the U.S. and Chinese consumers. This study tests the model in two cultures to see if the proposed model is robust across two cultures: high collectivism and individualism cultures

The Effects of Discrimination Experience on Life Satisfaction of North Korean Refugees:Mediating Effect of Stress

Objective This study investigated the mediation effect of stress between the experience of discrimination and life satisfaction among North Korean refugees who resettled in South Korea. The findings of the current study provide empirical evidence for the need of social interventions to mitigate adverse effects of stress on North Korean refugees who are subject to social discrimination on a daily basis. Methods In this study, we included 500 subjects among 2,138 North Korean refugees who took refuge in South Korea in 2007. The interview started from April 6th 2009 and finished on May 25th 2009. We conducted moderator effect analysis with Path analysis was conducted because we confirm the experience of discrimination was affected by life satisfaction and stress can affected life satisfaction as a moderator. Results The experience of discrimination significantly affects stress and stress significantly affects life satisfaction. However, the experience of discrimination was not directly related to life satisfaction. The more stress the study respondents experienced, the lower the life satisfaction they reported. Conclusion The present finding suggests that the effects of discriminating experiences on the life satisfaction of North Korean refugees in South Korea were mediated by their own perceived stress

Overexpression of the miR-141/200c cluster promotes the migratory and invasive ability of triple-negative breast cancer cells through the activation of the FAK and PI3K/AKT signaling pathways by secreting VEGF-A

Migration in miR-141/200c-transduced HCC-38 and Hs578T cells treated with an anti-VEGF-A-neutralizing antibody. (A, D) Migration in miR-141/200c-transduced HCC-38 and Hs578T cells. Images of the crystal violet-stained cells that migrated horizontally in the trans-well migration assay (upper). The absorbance values of extracted crystal violet in migrated cells (lower). The migratory abilities of the miR-200c cells (~1.6-fold and ~1.7-fold, HCC-38 and Hs578T, respectively) were significantly increased compared with those of the control cells. (B, E) Measurement of the secreted levels of cytokines and growth factors (IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, GM-CSF, IFN-γ, TNF-α, and VEGF-A). Transduction of miR-141/200c into HCC-38 and Hs578T cells promoted significantly higher VEGF-A secretion than that of control cells. (C, F) Trans-well migration of anti-VEGF-A-neutralizing antibody-treated cells. The enhanced migration of the miR-141/200c-transduced HCC-38 cells were significantly suppressed by treatment with anti-VEGF-A-neutralizing antibodies, but miR-141/200c-transduced Hs578T cells still showed increased migratory ability compared with control cells. *p < 0.05, **p < 0.001. (JPG 188 kb

Gender Differences and Socioeconomic Factors Related to Osteoporosis:A Cross-Sectional Analysis of Nationally Representative Data

Background: Osteoporosis has been considered a disease that primarily affects women, but recently male osteoporosis is also attracting attention. This study aims to comparatively analyze socioeconomic and other factors that are related to the prevalence of osteoporosis in both men and women. Materials and Methods: This study used data from the Korean Community Health Survey conducted in 2013. To determine factors related to osteoporosis prevalence, researchers applied a binary logistic regression model, first for all research participants, then separately for male and female participants. Results: Women were more likely than men to have osteoporosis (odds ratio 12.33, 95% confidence interval 11.55-13.17). Factors related to osteoporosis prevalence included age, education level, region, economic activity, alcohol consumption, salt intake, depression, and body mass index in both genders. Low education and income levels were more highly associated with osteoporosis prevalence in women than in men. Conclusions: Most of the factors were not gender specific, but some socioeconomic determinants varied by gender. Future studies that will focus on the effects of socioeconomic factors on osteoporosis, as well as gender-related differences in prevention and control of osteoporosis, are needed