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Principal Component Analyses in Anthropological Genetics  [PDF]
Xingdong Chen, Chao Chen, Li Jin
Advances in Anthropology (AA) , 2011, DOI: 10.4236/aa.2011.12002
Abstract: Principal component analyses (PCA) is a statistical method for exploring and making sense of datasets with a large number of measurements (which can be thought of as dimensions) by reducing the dimensions to the few principal components (PCs) that explain the main patterns. Thus, the first PC is the mathematical combination of measurements that accounts for the largest amount of variability in the data. Here, we gave an interpretation about the principle of PCA and its original mathematical algorithm, singular variable decomposition (SVD). PCA can be used in study of gene expression; also PCA has a population genetics interpretation and can be used to identify differences in ancestry among populations and samples, through there are some limitations due to the dynamics of microevolution and historical processes, with advent of molecular techniques, PCA on Y chromosome, mtDNA, and nuclear DNA gave us more accurate interpretations than on classical markers. Furthermore, we list some new extensions and limits of PCA.
Design of a Child Localization System on RFID and Wireless Sensor Networks
Chao Chen
Journal of Sensors , 2010, DOI: 10.1155/2010/450392
Abstract: Radio Frequency Identification (RFID) and wireless sensor networks are wireless technologies that rapidly emerge and show great potential. Combining RFID and wireless sensor networks provides a cost-efficient way to expand the RFID system's range and to enable an RFID system in areas without a network infrastructure. These two technologies are employed to build a wireless localization system in a children's theme park. The main purpose of this child localization system is to track and locate children within a certain range near some landmarks in the park. The design experience in this project can be exported to other applications such as object tracking and surveillance. 1. Introduction In recent years, Radio Frequency Identification (RFID) technology has emerged to be a popular replacement for the Universal Product Code (UPC) barcode system in many industries. Specifically, RFID uses a short-range radio technology to communicate mainly digital information between a stationary location and a movable object or between movable objects. Since RFID does not require line-of-sight communication and offers a longer operating range, it outperforms barcode systems in many areas, such as electronic road tolling, supply chain management, and article tracking [1]. An RFID system generally consists of simple devices called tags (or transponders) and more complex devices called readers (or interrogators). RFID tags are small and inexpensive and can be deployed economically in very large numbers. Moreover, RFID tags usually carry a unique identity (UID) and can be attached to the objects to be managed. RFID readers employ tag-reading algorithms that are capable of identifying tags by the UIDs. Compared with the tags, the readers are more capable and are usually connected to a host computer or a network. A wireless sensor network consists of many spatially distributed devices called motes. These devices use sensors to monitor conditions such as temperature, sound, vibration, pressure, motion, or pollutants. Since motes are small and inexpensive, they can be produced and deployed in large numbers. Motes are equipped with wireless communication capability to other motes either directly or via multiple hops. The fast-growing research effort in academia and industry has resulted in many protocols and applications of wireless sensor networks [2]. Combining RFID devices with wireless sensor networks offers advantages in both sides. First, attaching the RFID readers enables the motes to monitor a wider range of objects than with traditional sensors. Second, the wireless
Energies, Fine Structures, and Hyperfine Structures of the States for the Beryllium Atom
Chao Chen
Journal of Atomic, Molecular, and Optical Physics , 2012, DOI: 10.1155/2012/569876
Abstract: Energies and wave functions of the states for the beryllium atom are calculated with the full-core plus correlation wave functions. Fine structures and hyperfine structures are calculated with the first-order perturbation theory. For the state, the calculated energies, fine structure, and hyperfine structure parameters are in good agreement with the latest theoretical and experimental data in the literature; it is shown that atomic parameters of the low-lying excited states for the beryllium atom can be calculated accurately using this theoretical method. For the () states, the present calculations may provide valuable reference data for future theoretical calculations and experimental measurements.
On Reading Test and Its Validity
Chao Chen
Asian Social Science , 2010, DOI: 10.5539/ass.v6n12p192
Abstract: Reading ability is undoubtedly a useful one when we use a foreign language. Therefore, reading comprehension has long been hold as an important way of testing testees’ language ability. Not matter what test it should have validity. Otherwise it cannot test what it intends to test. The present problem is that some reading tests lack validity and are not efficient tests. Test constructors should be well aware of this problem and pay attention to that and try to avoid composing such tests again.
Energies, Fine Structures, and Hyperfine Structures of the States for the Beryllium Atom
Chao Chen
Journal of Atomic and Molecular Physics , 2012, DOI: 10.1155/2012/569876
Abstract: Energies and wave functions of the states for the beryllium atom are calculated with the full-core plus correlation wave functions. Fine structures and hyperfine structures are calculated with the first-order perturbation theory. For the state, the calculated energies, fine structure, and hyperfine structure parameters are in good agreement with the latest theoretical and experimental data in the literature; it is shown that atomic parameters of the low-lying excited states for the beryllium atom can be calculated accurately using this theoretical method. For the ( ) states, the present calculations may provide valuable reference data for future theoretical calculations and experimental measurements. 1. Introduction In recent years, studies of energies, fine structures, and hyperfine structures of the low-lying excited states for the beryllium atom [1–10] have been of great interest to spectroscopists because there are many strong optical transitions suitable for spectral and hyperfine structure measurements. On the other hand, studies of the low-lying excited states for the beryllium atom play an important role in developing the excited state theory of multielectron atoms and better understanding the complicated correlation effects between electrons. The fine structure comes from the spin-orbit, spin-other-orbit, and spin-spin interactions. The hyperfine structure of atomic energy levels is caused by the interaction between the electrons and the electromagnetic multipole moments of the nucleus. The leading terms of this interaction are the magnetic dipole and electric-quadrupole moments. The fine and hyperfine structure is sensitive to the correlation effects among electrons. Experimentally, some properties of the atomic nucleus can be obtained by investigating the hyperfine structure of the atomic energy levels. The nuclear electric-quadrupole moment, which is difficult to measure directly with nuclear physics techniques, can be determined using the measured hyperfine structure and the accurate theoretical results. The state of the beryllium atom is of interest since it is the lowest excited state in which hyperfine effects can occur, and the ground state has no hyperfine splitting because it is . It is generally a very demanding task to calculate hyperfine structure accurately. Polarization of the closed shells in the ??core, due to the Coulomb interaction with open shells, can have a large effect on the hyperfine structure. Up till now, the most sophisticated theoretical calculations of the hyperfine structure parameters for the state of the Be atom
An ontology-based approach to the optimization of non-binary (2,v)-regular LDPC codes
Chao Chen
Mathematics , 2014,
Abstract: A non-binary (2,v)-regular LDPC code is defined by a parity-check matrix with column weight 2 and row weight v. In this report, we give an ontology-based approach to the optimization for this class of codes. All possible inter-connected cycle patterns that lead to low symbol-weight codewords are identified to put together the ontology. The optimization goal is to improve the distance property of equivalent binary images. Using the proposed method, the estimation and optimization of bit-distance spectrum becomes easily handleable. Three codes in the CCSDS recommendation are analyzed and several codes with good minimum bit-distance are designed.
图书馆如何迎接大数据时代?
chen,chao
图书馆杂志 , 2014,
Abstract: ?按照“从数字化到数据化”的逻辑,把握理解“大数据”本质并树立新的“数据观”,把图书馆放到出版产业链中考察“大数据”可能带来的机遇与挑战,梳理图书馆迎接大数据时代的策略。
Problems of Controlled Vocabulary versus Uncontrolled Vocabulary in Subject Indexing
Chao-chen Chen
Journal of Library Science , 1998,
Abstract: This article is mainly to survey the centennial controversy between controlled vocabulary v. uncontrolled vocabulary of subject indexing in the western library and information society. We also discuss the related problems in Chinese information retrieval systems and analyze the factors affecting their performance. [Article content in Chinese]
Organizational Models of Electronic Information
Chao-chen Chen
Journal of Library Science , 1997,
Abstract: Along with the popularity of Internet, electronic information is getting more and more important. To find efficient organization methods of electronic information is the main issue for information retrieval. Many solutions have been proposed.The aim of this article is to discuss the existing organizational models of electronic information. We explain their backgrounds of developments, their environments of applications and some related issues.[Article content in Chinese]
Political Connection, Management Promotion and Risk Taking Activities  [PDF]
Qiaoyi Zhao, Suowen Wang, Chao Chen
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.57071
Abstract:

This paper investigates how political connection and management promotion affect chances of risk-taking activities, in order to offer theoretical support for state-owned enterprises to select optimal managers, and to maintain and increase their company values. Using the data of chairman of state-owned listed enterprises in Shenzhen securities market, we find that in state-owned listed enterprises, the shorter the pyramid of listed enterprises to ultimate shareholders is, the closer the political connection is, the more likely the chairman is to take up risk-taking activities for promotion. While for the same pyramid, the longer the tenure of chairman, the more chances of risk-taking activities.

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