176 research outputs found
Web document classification using topic modeling based document ranking
In this paper, we propose a web document ranking method using topic modeling for effective information collection and classification. The proposed method is applied to the document ranking technique to avoid duplicated crawling when crawling at high speed. Through the proposed document ranking technique, it is feasible to remove redundant documents, classify the documents efficiently, and confirm that the crawler service is running. The proposed method enables rapid collection of many web documents; the user can search the web pages with constant data update efficiently. In addition, the efficiency of data retrieval can be improved because new information can be automatically classified and transmitted. By expanding the scope of the method to big data based web pages and improving it for application to various websites, it is expected that more effective information retrieval will be possible
Insights from Analysis of Video Streaming Data to Improve Resource Management
Today a large portion of Internet traffic is video. Over The Top (OTT)
service providers offer video streaming services by creating a large
distributed cloud network on top of a physical infrastructure owned by multiple
entities. Our study explores insights from video streaming activity by
analyzing data collected from Korea's largest OTT service provider. Our
analysis of nationwide data shows interesting characteristics of video
streaming such as correlation between user profile information (e.g., age, sex)
and viewing habits, viewing habits of users (when do the users watch? using
which devices?), viewing patterns (early leaving viewer vs. steady viewer),
etc. Video on Demand (VoD) streaming involves costly (and often limited)
compute, storage, and network resources. Findings from our study will be
beneficial for OTTs, Content Delivery Networks (CDNs), Internet Service
Providers (ISPs), and Carrier Network Operators, to improve their resource
allocation and management techniques.Comment: This is a preprint electronic version of the article accepted to IEEE
CloudNet 201
The full repertoire of Drosophila gustatory receptors for detecting an aversive compound.
The ability to detect toxic compounds in foods is essential for animal survival. However, the minimal subunit composition of gustatory receptors required for sensing aversive chemicals in Drosophila is unknown. Here we report that three gustatory receptors, GR8a, GR66a and GR98b function together in the detection of L-canavanine, a plant-derived insecticide. Ectopic co-expression of Gr8a and Gr98b in Gr66a-expressing, bitter-sensing gustatory receptor neurons (GRNs) confers responsiveness to L-canavanine. Furthermore, misexpression of all three Grs enables salt- or sweet-sensing GRNs to respond to L-canavanine. Introduction of these Grs in sweet-sensing GRNs switches L-canavanine from an aversive to an attractive compound. Co-expression of GR8a, GR66a and GR98b in Drosophila S2 cells induces an L-canavanine-activated nonselective cation conductance. We conclude that three GRs collaborate to produce a functional L-canavanine receptor. Thus, our results clarify the full set of GRs underlying the detection of a toxic tastant that drives avoidance behaviour in an insect
Object-based SLAM utilizing unambiguous pose parameters considering general symmetry types
Existence of symmetric objects, whose observation at different viewpoints can
be identical, can deteriorate the performance of simultaneous localization and
mapping(SLAM). This work proposes a system for robustly optimizing the pose of
cameras and objects even in the presence of symmetric objects. We classify
objects into three categories depending on their symmetry characteristics,
which is efficient and effective in that it allows to deal with general objects
and the objects in the same category can be associated with the same type of
ambiguity. Then we extract only the unambiguous parameters corresponding to
each category and use them in data association and joint optimization of the
camera and object pose. The proposed approach provides significant robustness
to the SLAM performance by removing the ambiguous parameters and utilizing as
much useful geometric information as possible. Comparison with baseline
algorithms confirms the superior performance of the proposed system in terms of
object tracking and pose estimation, even in challenging scenarios where the
baseline fails.Comment: This paper has been accepted to ICRA 202
Stability of SiNX/SiNX double stack antireflection coating for single crystalline silicon solar cells
Double stack antireflection coatings have significant advantages over single-layer antireflection coatings due to their broad-range coverage of the solar spectrum. A solar cell with 60-nm/20-nm SiNX:H double stack coatings has 17.8% efficiency, while that with a 80-nm SiNX:H single coating has 17.2% efficiency. The improvement of the efficiency is due to the effect of better passivation and better antireflection of the double stack antireflection coating. It is important that SiNX:H films have strong resistance against stress factors since they are used as antireflective coating for solar cells. However, the tolerance of SiNX:H films to external stresses has never been studied. In this paper, the stability of SiNX:H films prepared by a plasma-enhanced chemical vapor deposition system is studied. The stability tests are conducted using various forms of stress, such as prolonged thermal cycle, humidity, and UV exposure. The heat and damp test was conducted for 100 h, maintaining humidity at 85% and applying thermal cycles of rapidly changing temperatures from -20°C to 85°C over 5 h. UV exposure was conducted for 50 h using a 180-W UV lamp. This confirmed that the double stack antireflection coating is stable against external stress
Predict to Detect: Prediction-guided 3D Object Detection using Sequential Images
Recent camera-based 3D object detection methods have introduced sequential
frames to improve the detection performance hoping that multiple frames would
mitigate the large depth estimation error. Despite improved detection
performance, prior works rely on naive fusion methods (e.g., concatenation) or
are limited to static scenes (e.g., temporal stereo), neglecting the importance
of the motion cue of objects. These approaches do not fully exploit the
potential of sequential images and show limited performance improvements. To
address this limitation, we propose a novel 3D object detection model, P2D
(Predict to Detect), that integrates a prediction scheme into a detection
framework to explicitly extract and leverage motion features. P2D predicts
object information in the current frame using solely past frames to learn
temporal motion features. We then introduce a novel temporal feature
aggregation method that attentively exploits Bird's-Eye-View (BEV) features
based on predicted object information, resulting in accurate 3D object
detection. Experimental results demonstrate that P2D improves mAP and NDS by
3.0% and 3.7% compared to the sequential image-based baseline, illustrating
that incorporating a prediction scheme can significantly improve detection
accuracy.Comment: ICCV 202
Cyber Blackbox for collecting network evidence
In recent years, the hottest topics in the security field are related to the advanced and persistent attacks. As an approach to solve this problem, we propose a cyber blackbox which collects and preserves network traffic on a virtual volume based WORM device, called EvidenceLock to ensure data integrity for security and forensic analysis. As a strategy to retain traffic for long enough periods, we introduce a deduplication method. Also this paper includes a study on the network evidence which is collected and preserved for analyzing the cause of cyber incident. Then, a method is proposed to suggest a starting point for incident analysis to a forensic practitioner who has to investigate on the vast amount of network traffic collected using the cyber blackbox. Experimental results show this approach is effectively able to reduce the amount of data to search by dividing doubtful flows from normal traffic. Finally, we discuss the results with the forensically meaningful point of view and present further works
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