1,300 research outputs found
How to Deal With Speed Degradation in Computers of Today and What Causes It
Newly installed computer systems are always running fast, but as time increases, more and more computer system speed will gradually become slower. This is a big headache for most of the computer users. Therefore it is important to find out what causes the computer system speed degradation. In this study, we developed a cleaning product called “FlexClean” as a basic case study. We also reviewed related literatures, and used appropriate research methods to conduct qualitative interviews with 37 Windows OS users. The users consist of three different groups, which were students, company personnel, and home users. The interviewees were asked some questions around issues that cause computer system speed degradation. After that we summarized the data from the case study and the interviews. The research results have been divided into six key issues, which acted as a basis for discussions about computer system speed degradation. Then we gave out the final sum-up of this study
Jane’s Self-Development in The Diaries of Jane Somers: An Analysis of Doris Lessing’s Feminist Perspectives
Doris Lessing is one of the greatest women novelists in British literature. Though she refuses to be classified as a feminist writer and an advocator for the feminist movement, she is deeply concerned with the life of women and forms her own feminist perspectives in her novels.This paper aims to explore Doris Lessing’s feminist perspectives through the analysis of the protagonist Jane in The Diaries of Jane Somers who achieves her self-development after experiencing the lost of love and the search for love. Though it’s not Lessing’s most famous novel, it represents her deep thoughts on feminist existence and her continuous efforts to find a way out for women in the sexual relationship in a patriarchal society
Not only Online Review but also its Helpfulness is Manipulated: Evidence from Peer to Peer Lending Forum
Online reviews have become proposed as useful information for consumers to make decision. Meanwhile, review manipulation will weaken the credibility of online reviews. Except manipulating the review text and rating, we propose that review helpfulness, an important signal for consumer to filter the reviews, could also be manipulated. This study thus explores the existence of review helpfulness manipulation and the relationship between firm quality and review manipulation. Based on a dataset from a review forum in www.wdzj.com which is the leading and largest portal of peer to peer lending industry in China, we get the following interesting results. First, due to the manipulation of review helpfulness, a manipulated positive review is more likely to receive higher helpfulness, while a manipulated negative is more likely to get lower helpfulness. Second, a manipulated review tends to be lower quality in terms of readability and word count, which are found as positive predictors for review helpfulness. Third, high quality firms tend to manipulate more positive reviews, and at the same time high quality firms will receive more negative manipulated reviews. This study extends current understanding about online review manipulation, thereby providing theoretical and practice implications
Conservative State Value Estimation for Offline Reinforcement Learning
Offline reinforcement learning faces a significant challenge of value
over-estimation due to the distributional drift between the dataset and the
current learned policy, leading to learning failure in practice. The common
approach is to incorporate a penalty term to reward or value estimation in the
Bellman iterations. Meanwhile, to avoid extrapolation on out-of-distribution
(OOD) states and actions, existing methods focus on conservative Q-function
estimation. In this paper, we propose Conservative State Value Estimation
(CSVE), a new approach that learns conservative V-function via directly
imposing penalty on OOD states. Compared to prior work, CSVE allows more
effective in-data policy optimization with conservative value guarantees.
Further, we apply CSVE and develop a practical actor-critic algorithm in which
the critic does the conservative value estimation by additionally sampling and
penalizing the states \emph{around} the dataset, and the actor applies
advantage weighted updates extended with state exploration to improve the
policy. We evaluate in classic continual control tasks of D4RL, showing that
our method performs better than the conservative Q-function learning methods
and is strongly competitive among recent SOTA methods
Epigenetic silencing of glutaminase 2 in human liver and colon cancers
Abstract
Background
Glutaminase 2 (Gls2) is a p53 target gene and is known to play an important role in energy metabolism. Gls2 has been reported to be downregulated in human hepatocellular carcinomas (HCC). However, the underlying mechanism responsible for its downregulation is still unclear. Here, we investigated Gls2 expression and its promoter methylation status in human liver and colon cancers.
Methods
mRNA expression of Gls2 was determined in human liver and colon cancer cell lines and HCC tissues by real-time PCR and promoter methylation was analyzed by methylation-specific PCR (MSP) and validated by bisulfite genome sequencing (BGS). Cell growth was determined by colony formation assay and MTS assay. Statistical analysis was performed by Wilcoxon matched-pairs test or non-parametric t test.
Results
First, we observed reduced Gls2 mRNA level in a selected group of liver and colon cancer cell lines and in the cancerous tissues from 20 HCC and 5 human colon cancer patients in comparison to their non-cancerous counter parts. Importantly, the lower level of Gls2 in cancer cells was closely correlated to its promoter hypermethylation; and chemical demethylation treatment with 5-aza-2′-deoxycytidine (Aza) increased Gls2 mRNA level in both liver and colon cancer cells, indicating that direct epigenetic silencing suppressed Gls2 expression by methylation. Next, we further examined this correlation in human HCC tissues, and 60% of primary liver tumor tissues had higher DNA methylation levels when compared with adjacent non-tumor tissues. Detailed methylation analysis of 23 CpG sites at a 300-bp promoter region by bisulfite genomic sequencing confirmed its methylation. Finally, we examined the biological function of Gls2 and found that restoring Gls2 expression in cancer cells significantly inhibited cancer cell growth and colony formation ability through induction of cell cycle arrest.
Conclusions
We provide evidence showing that epigenetic silencing of Gls2 via promoter hypermethylation is common in human liver and colon cancers and Gls2 appears to be a functional tumor suppressor involved in the liver and colon tumorigenesis.
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Outracing Human Racers with Model-based Planning and Control for Time-trial Racing
Autonomous racing has become a popular sub-topic of autonomous driving in
recent years. The goal of autonomous racing research is to develop software to
control the vehicle at its limit of handling and achieve human-level racing
performance. In this work, we investigate how to approach human expert-level
racing performance with model-based planning and control methods using the
high-fidelity racing simulator Gran Turismo Sport (GTS). GTS enables a unique
opportunity for autonomous racing research, as many recordings of racing from
highly skilled human players can served as expert emonstrations. By comparing
the performance of the autonomous racing software with human experts, we better
understand the performance gap of existing software and explore new
methodologies in a principled manner. In particular, we focus on the commonly
adopted model-based racing framework, consisting of an offline trajectory
planner and an online Model Predictive Control-based (MPC) tracking controller.
We thoroughly investigate the design challenges from three perspective, namely
vehicle model, planning algorithm, and controller design, and propose novel
solutions to improve the baseline approach toward human expert-level
performance. We showed that the proposed control framework can achieve top
0.95% lap time among human-expert players in GTS. Furthermore, we conducted
comprehensive ablation studies to validate the necessity of proposed modules,
and pointed out potential future directions to reach human-best performance.Comment: 16 pages, 13 figures, 3 table
Early diagnosis and personalized comprehensive treatment of nasopharyngeal carcinoma based on Epstein-Barr virus-specific markers
Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in East Asia and Southeast Asia, particularly prevalent in southern China. Epstein-Barr virus (EBV)-related markers are crucial tumor markers for NPC and are also important reference indicators for early screening, diagnosis, prognosis, and the formulation of personalized treatment plans with the most mature and extensive clinical application. In recent years, significant progress has been made in the development and application of EBV-specific markers. This article reviews their current application value in NPC
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