Database Research: Achievements and Challenges

Database system is the infrastructure of the modern information system. The R＆D in the database system and its technologies is one of the important research topics in the field. The database R＆D in China took off later but it moves along by giant steps. This report presents the achievements Renmin University of China （RUC） has made in the past 25 years and at the same time addresses some of the research projects we, RUC, are currently working on. The National Natural Science Foundation of China supports and initiates most of our research projects and these successfully conducted projects have produced fruitful results.     

Bifurcation Control,Manufacturing Planning and Formation Control

The paper consists of three topics on control theory and engineering applications, namely bifurcation control, manufacturing planning, and formation control. For each topic, we summarize the control problem to be addressed and some key ideas used in our recent research. Interested readers are referred to related publications for more details. Each of the three topics in this paper is technically independent from the other ones. However, all three parts together reflect the recent research activities of the first author, jointly with other researchers in different fields.     

Fault-tolerant Control Systems—An Introductory Overview

This paper presents an introductory overview on the development of fault-tolerant control systems. For this reason, the paper is written in a tutorial fashion to summarize some of the important results in this subject area deliberately without going into details in any of them. However, key references are provided from which interested readers can obtain more detailed information on a particular subject. It is necessary to mention that, throughout this paper, no efforts were made to provide an exhaustive coverage on the subject matter. In fact, it is far from it. The paper merely represents the view and experience of its author. It can very well be that some important issues or topics were left out unintentionally. If that is the case, the author sincerely apologizes in advance.After a brief account of fault-tolerant control systems, particularly on the original motivations, and the concept of redundancies, the paper reviews the development of fault-tolerant control systems with highlights to several important issues from a historical perspective. The general approaches to fault-tolerant control has been divided into passive, active, and hybrid approaches. The analysis techniques for active fault-tolerant control systems are also discussed. Practical applications of fault- tolerant control are highlighted from a practical and industrial perspective. Finally, some critical issues in this area are discussed as open problems for future research/development in this emerging field.     

Gesture Recognition Summarization

Gesture recognition is an important research in the field of human-computer interaction. Hand Gestures are strong variable and flexible, so the gesture recognition has always been an important challenge for the researchers. In this paper, we first outlined the development of gestures recognition, and different classification of gestures based on different purposes. Then we respectively introduced common methods used in the process of gesture segmentation, feature extraction and recognition. Finally, the gesture recognition was summarized and the studying prospects were given.     

图像拼接技术

Image mosaics have been an active area of research in the fields of computer vision,image processing and computer graphics in recent years.The automatic fast construction of unlimited field of view,high-resolution image mosaics is a main research task of this area.According to the procedure of image mosaics,the paper introduces and discusses image acquisition,geometric corrections,image register and image blending in detail.In the last part of the paper,we make a discussion on some problems of research and point out the future research directiions.     

Study on Parallel Computing

In this paper, we present a general survey on parallel computing. The main contents include parallel computer system which is the hardware platform of parallel computing, parallel algorithm which is the theoretical base of parallel computing, parallel programming which is the software support of parallel computing. After that, we also introduce some parallel applications and enabling technologies. We argue that parallel computing research should form an integrated methodology of ＂architecture algorithm programming application＂. Only in this way, parallel computing research becomes continuous development and more realistic.     

Preface

The International Conference on Knowledge Science, Engineering and Management (KSEM), which was held in Belfast, Northern Ireland in 2010, was the fourth success in the series of such conferences. The conference focuses on the three themes of knowledge science, engineering and management, covering a wider range of research topics in the KSEM-related areas. This event offered an invaluable opportunity to bring together researchers, engineers and practitioners to present original work, the latest advances on knowledge representation, pioneered knowledge engineering, knowledge related systems, as well as discuss and debate practical challenges in deploying knowledge-based systems and research opportunities in the research community. To highlight research activities drawn by this event and provide an insight into the latest developments in the related areas, we present this special issue which is dedicated to all the delegates and researchers in the community who made the conference a success. We selected more than 10 papers that were presented in the conference and asked the authors to extend these papers. After careful review, we finally select 6 papers to be included in this special issue. This collection of extended versions of papers consists of the KSEM2010''s finest papers and covers the prominent topics of knowledge representation and reasoning, ontology engineering and applications, data mining and knowledge discovery. They represent state of the art of research in KSEM-related research areas.     

Preface

Recent advances in database related applications propose many new challenges and have inspired database researchers and practitioners to further make their efforts on new database technologies. Currently, there are many related ongoing research fields, such as XML databases, data mining, data warehouses, data streams, database integration, moving object management, bioinformatics, peer-to-peer data systems and so on. In order to promptly reflect the advances and trends in the emerging fields, the Journal of Computer Science and Technology （JCST） decided to publish a special issue on new database technologies.     

无线传感器网络及其应用

As a result of combination of microsensor technology, low power computing and wireless networking,wireless sensor networks are becoming an active branch of computer science. In this paper, we introduce the up-to-date research work of wireless sensor networks. First, we simply introduce the background of producing wireless sensor networks. Then, we describe their characteristics and application scopes. Finally we suggest the research direction in wireless sensor networks in the future.     

A New Approach to Database Auto-Design by Logic

The database auto-design is an important problem in database research.In this paper we propose some new ideas and an approach called “logic approach” to implement the database auto-design.Given a relational scheme and a set of the functional dependencies for the relation we can obtain all of the functional dependencies and key for the relation and determine the normal form the relation satisfies.     

Applications of structure from motion: a survey

Structure from motion (SfM) has been an active research area in computer vision for decades and numerous practical applications are benefiting from this research. While no previous work has tried to summarize the applications appearing in the literature, this paper deals with a comprehensive overview of recent applications of SfM by classifying them into 10 categories, namely augmented reality, autonomous navigation/guidance, motion capture, hand-eye calibration, image/video processing, image-based 3D modeling, remote sensing, image organization/browsing, segmentation and recognition, and military applications. The goal is to provide insights for researchers to position their work more appropriately in the context of existing techniques, and to perceive both new applications and relevant research problems.     

The Global Crisis and Academic Communication： The Challenge of Social Networks in Research

The global economic crisis is seriously affecting academic research. The situation is provoking some big changes and an urgent need to seek alternatives to traditional models. It is as if the academic community was reinventing itself; and this reinvention is happening online. Faced with a lack of funding, researchers have determined to help each other develop their projects and they are doing so on social knowledge networks that they have created for this mission. The purpose of this paper is to analyze different social networks designed for academic online research. To this end, we have made a selection of these networks and established the parameters for their study in order to determine what they consist of, what tools they make use of, what advantages they offer and the degree to which they are bringing about a revolution in how research is carried out. This analysis is conducted from both a qualitative and a quantitative perspective, allowing us to identify the percentage of these networks that approach what would be the ideal social knowledge network. As we will be able to confirm, the closer they are to this ideal, the more effective they will be and the better future they will have, which will also depend on the commitment of users to participation and the quality of their contributions.     

Phrase-Level Sentiment Polarity Classification Using Rule-Based Typed Dependencies and Additional Complex Phrases Consideration

The advent of Web 2.0 has led to an increase in user-generated content on the Web.This has provided an extensive collection of free-style texts with opinion expressions that could influence the decisions and actions of their readers.Providers of such content exert a certain level of influence on the receivers and this is evident from blog sites having effect on their readers’ purchase decisions,political view points,financial planning,and others.By detecting the opinion expressed,we can identify the sentiments on the topics discussed and the influence exerted on the readers.In this paper,we introduce an automatic approach in deriving polarity pattern rules to detect sentiment polarity at the phrase level,and in addition consider the effects of the more complex relationships found between words in sentiment polarity classification.Recent sentiment analysis research has focused on the functional relations of words using typed dependency parsing,providing a refined analysis on the grammar and semantics of textual data.Heuristics are typically used to determine the typed dependency polarity patterns,which may not comprehensively identify all possible rules.We study the use of class sequential rules(CSRs) to automatically learn the typed dependency patterns,and benchmark the performance of CSR against a heuristic method.Preliminary results show CSR leads to further improvements in classification performance achieving over 80% F1 scores in the test cases.In addition,we observe more complex relationships between words that could influence phrase sentiment polarity,and further discuss on possible approaches to handle the effects of these complex relationships.     

Three-dimensional deformation in curl vector field

Deformation is an important research topic in graphics.There are two key issues in mesh deformation:(1) selfintersection and(2) volume preserving.In this paper,we present a new method to construct a vector field for volume-preserving mesh deformation of free-form objects.Volume-preserving is an inherent feature of a curl vector field.Since the field lines of the curl vector field will never intersect with each other,a mesh deformed under a curl vector field can avoid self-intersection between field lines.Designing the vector field based on curl is useful in preserving graphic features and preventing self-intersection.Our proposed algorithm introduces distance field into vector field construction;as a result,the shape of the curl vector field is closely related to the object shape.We define the construction of the curl vector field for translation and rotation and provide some special effects such as twisting and bending.Taking into account the information of the object,this approach can provide easy and intuitive construction for free-form objects.Experimental results show that the approach works effectively in real-time animation.     

Dynamic evolution of collective emotions in social networks: a case study of Sina weibo

Emotion is a fundamental object of human existence and determined by a complex set of factors. With the rapid development of online social networks (OSNs), more and more people would like to express their emotion in OSNs, which provides wonderful opportunities to gain insight into how and why individual emotion is evolved in social network. In this paper, we focus on emotion dynamics in OSNs, and try to recognize the evolving process of collective emotions. As a basis of this research, we first construct a corpus and build an emotion classifier based on Bayes theory, and some effective strategies (entropy and salience) are introduced to improve the performance of our classifier, with which we can classify any Chinese tweet into a particular emotion with an accuracy as high as 82%. By analyzing the collective emotions in our sample networks in detail, we get some interesting findings, including a phenomenon of emotion synchronization between friends in OSNs, which offers good evidence for that human emotion can be spread from one person to another. Furthermore, we find that the number of friends has strong correlation with individual emotion. Based on those useful findings, we present a dynamic evolution model of collective emotions, in which both self-evolving process and mutual-evolving process are considered. To this end, extensive simulations on both real and artificial networks have been done to estimate the parameters of our emotion dynamic model, and we find that mutual-evolution plays a more important role than self-evolution in the distribution of collective emotions. As an application of our emotion dynamic model, we design an efficient strategy to control the collective emotions of the whole network by selecting seed users according to k-core rather than degree.     

基于笔画段分割和组合的汉字笔画提取模型

The offline recognition of Chinese Characters is a very important research field in OCR. In this paper, the authors propose an effective stroke extraction model for Chinese Character based on Stroke Segmentation and Combination. Comparing with the existed models, the experiments prove that it could improve the precision for the stroke extraction and reduce the computation complexity considerably.     

Information retrieval:a view from the Chinese IR community

During a two day strategic workshop in February 2018,22 information retrieval researchers met to discuss the future challenges and opportunities within the field.The outcome is a list of potential research directions,project ideas,and challenges.This report describes the major conclusions we have obtained during the workshop.A key result is that we need to open our mind to embrace a broader IR field by rethink the definition of information,retrieval,user,system,and evaluation of IR.By providing detailed discussions on these topics,this report is expected to inspire our IR researchers in both academia and industry,and help the future growth of the IR research community.     

分布式视频点播系统的接入控制研究

Video on Demand(VoD)systems are considered as one of the most valuable services for the next generation broad-bandwidth Internet. To provide high-quality service, the VoD system must employ an admission control module to guarantee QoS, but there are still less research works having been made in this field, especially for distributed VoD systems. In this paper, we mainly focus on distributed admission control for VBR video streams in distributed VoD systems. We firstly discuss different approaches and then two admission control strategies are proposed with experimental comparisons. Our research is also further extended to resource assignment in distributed VoD systems. At the end of this article, we address issues in implementing distributed admission control.     

A survey for image resizing

Image resizing is a key technique for displaying images on different devices, and has attracted much attention in the past few years. This paper reviews the image resizing methods proposed in recent years, gives a detailed comparison on their performance, and reveals the main challenges raised in several important issues such as preserving an important region, minimizing distortions, and improving efficiency. Furthermore, this paper discusses the research trends and points out the possible hotspots in this field. We believe this survey can give some guidance for researchers from relevant research areas, offering them an overall and novel view.     

Progress and Prospect of Some Fundamental Research on Information Security in China

With the development of network and information technologies, information security is more and more widely researched in China. To know where the work is and where it goes, we focus on comprehensively surveying the twenty years of important fundamental research by Chinese scholars, and giving, from our point of view, the significance as well as the outlook of future work. Some of the reviewed work, including the researches on fundamental theory of cryptography, cryptographic algorithm, security protocol, security infrastructure and information hiding, greatly advances the related sub-fields, and is highly recognized in and outside of China. Nevertheless, the overall work, we think, is still facing the problems of unbalanced development of sub-areas, limited scope of research, lack of systematic work and application, etc., leaving much room for improvement in the near future.