Showing papers by "Samsung published in 2010"

Atomic structure of conducting nanofilaments in TiO2 resistive switching memory

Abstract: Resistance switching in metal oxides could form the basis for next-generation non-volatile memory. It has been argued that the current in the high-conductivity state of several technologically relevant oxide materials flows through localized filaments, but these filaments have been characterized only indirectly, limiting our understanding of the switching mechanism. Here, we use high-resolution transmission electron microscopy to probe directly the nanofilaments in a Pt/TiO2/Pt system during resistive switching. In situ current–voltage and low-temperature (∼130 K) conductivity measurements confirm that switching occurs by the formation and disruption of TinO2n−1 (or so-called Magneli phase) filaments. Knowledge of the composition, structure and dimensions of these filaments will provide a foundation for unravelling the full mechanism of resistance switching in oxide thin films, and help guide research into the stability and scalability of such films for applications. Nanoscale filaments with a Magneli structure are shown to be responsible for resistance switching in thin films of TiO2, and the properties of the filaments are directly observed during the switching process.

Li-alloy based anode materials for Li secondary batteries.

Abstract: Research to develop alternative electrode materials with high energy densities in Li-ion batteries has been actively pursued to satisfy the power demands for electronic devices and hybrid electric vehicles. This critical review focuses on anode materials composed of Group IV and V elements with their composites including Ag and Mg metals as well as transition metal oxides which have been intensively investigated. This critical review is devoted mainly to their electrochemical performances and reaction mechanisms (313 references).

White‐Light‐Emitting Diodes with Quantum Dot Color Converters for Display Backlights

Abstract: Quantum dots (QDs) have attracted great attention as good candidate for the next generation displays due to their narrow emission, and high luminescence efficiency, and tunable emission covering all visible range. However, QDs easily lost their initial optical properties during the process for a device fabrication and practical operation. We synthesized well passivated green and red light emitting QDs that show almost 100% of QE. When the highly luminescent green and red light emitting QDs were applied as color converters in InGaN blue LEDs, resulting cool white QD-LEDs showed 41lm/W and more than 100% of color reproducibility compared to NTSC standard in CIE1931 and maintained their optical properties for a long time operation. We also demonstrated a 46-inch LCD panel using the white QDLED backlight was successfully demonstrated (Figure).

Arrays of sealed silicon nanotubes as anodes for lithium ion batteries.

Abstract: Silicon is a promising candidate for electrodes in lithium ion batteries due to its large theoretical energy density. Poor capacity retention, caused by pulverization of Si during cycling, frustrates its practical application. We have developed a nanostructured form of silicon, consisting of arrays of sealed, tubular geometries that is capable of accommodating large volume changes associated with lithiation in battery applications. Such electrodes exhibit high initial Coulombic efficiencies (i.e., >85%) and stable capacity-retention (>80% after 50 cycles), due to an unusual, underlying mechanics that is dominated by free surfaces. This physics is manifested by a strongly anisotropic expansion in which 400% volumetric increases are accomplished with only relatively small (<35%) changes in the axial dimension. These experimental results and associated theoretical mechanics models demonstrate the extent to which nanoscale engineering of electrode geometry can be used to advantage in the design of rechargeable batteries with highly reversible capacity and long-term cycle stability.

Energy management system and method

Abstract: According to an aspect of the disclosure, a home energy management system and method includes a network device disposed at a residence and a wireless home energy network capable of establishing communication with the network device. A server is disposed remotely from the residence and capable of generating a control action report to control the network devices. A controller is located at the residence and in communication with the server and configured to establish the wireless home energy network; initiate a plurality of operating status requests of the network device; receive device data in response to at least one of the operating status requests; generate a site report including the device data; initiate a communication of the site report to the remote server; and detect an availability of the control action report at the remote server in conjunction with the communication of the site report.

Apex: extending Android permission model and enforcement with user-defined runtime constraints

Abstract: Android is the first mass-produced consumer-market open source mobile platform that allows developers to easily create applications and users to readily install them. However, giving users the ability to install third-party applications poses serious security concerns. While the existing security mechanism in Android allows a mobile phone user to see which resources an application requires, she has no choice but to allow access to all the requested permissions if she wishes to use the applications. There is no way of granting some permissions and denying others. Moreover, there is no way of restricting the usage of resources based on runtime constraints such as the location of the device or the number of times a resource has been previously used. In this paper, we present Apex -- a policy enforcement framework for Android that allows a user to selectively grant permissions to applications as well as impose constraints on the usage of resources. We also describe an extended package installer that allows the user to set these constraints through an easy-to-use interface. Our enforcement framework is implemented through a minimal change to the existing Android code base and is backward compatible with the current security mechanism.

Centrifugal microfluidics for biomedical applications

Abstract: The centrifugal microfluidic platform has been a focus of academic and industrial research efforts for almost 40 years. Primarily targeting biomedical applications, a range of assays have been adapted on the system; however, the platform has found limited commercial success as a research or clinical tool. Nonetheless, new developments in centrifugal microfluidic technologies have the potential to establish wide-spread utilization of the platform. This paper presents an in-depth review of the centrifugal microfluidic platform, while highlighting recent progress in the field and outlining the potential for future applications. An overview of centrifugal microfluidic technologies is presented, including descriptions of advantages of the platform as a microfluidic handling system and the principles behind centrifugal fluidic manipulation. The paper also discusses a history of significant centrifugal microfluidic platform developments with an explanation of the evolution of the platform as it pertains to academia and industry. Lastly, we review the few centrifugal microfluidic-based sample-to-answer analysis systems shown to date and examine the challenges to be tackled before the centrifugal platform can be more broadly accepted as a new diagnostic platform. In particular, fully integrated, easy to operate, inexpensive and accurate microfluidic tools in the area of in vitro nucleic acid diagnostics are discussed.

The impact of information technology and transactive memory systems on knowledge sharing, application, and team performance: a field study

Abstract: In contemporary knowledge-based organizations, teams often play an essential role in leveraging knowledge resources. Organizations make significant investments in information technology to support knowledge management practices in teams. At the same time, recent studies show that the transactive memory system (TMS)-the specialized division of cognitive labor among team members that relates to the encoding, storage, and retrieval of knowledge-is an important factor that affects a team's performance. Yet little is known of how IT support for knowledge management practices in organizations affects the development of TMS. Furthermore, the precise role of TMS on knowledge sharing and knowledge application, which in turn influences team performance, has not been fully explored. In order to close this gap in the literature, we conducted a field study that involved 139 on-going teams of 743 individuals from two major firms in South Korea. Our results show that IT support in organizations has a positive impact on the development of TMS in teams, and that both TMS and IT support have a positive impact on knowledge sharing and knowledge application. Furthermore, we found that knowledge sharing has a positive impact on knowledge application, which in turn has a direct impact on team performance. However, contrary to our expectation, knowledge sharing does not have a direct impact on team performance and its impact on team performance was fully mediated by knowledge application. Our research shows that organizations can improve team members' meta-knowledge of who knows what through the careful investment in information technology. Finally, our results show that sharing knowledge alone is not enough. Organizations must ensure that shared knowledge is in fact applied in order to improve team performance.

MIMO techniques in WiMAX and LTE: a feature overview

Abstract: IEEE 802.16m and 3GPP LTE-Advanced are the two evolving standards targeting 4G wireless systems. In both standards, multiple-input multiple-output antenna technologies play an essential role in meeting the 4G requirements. The application of MIMO technologies is one of the most crucial distinctions between 3G and 4G. It not only enhances the conventional point-to-point link, but also enables new types of links such as downlink multiuser MIMO. A large family of MIMO techniques has been developed for various links and with various amounts of available channel state information in both IEEE 802.16e/m and 3GPP LTE/LTE-Advanced. In this article we provide a survey of the MIMO techniques in the two standards. The MIMO features of the two are compared, and the engineering considerations are depicted.

Image processing apparatus and method

Abstract: An image processing apparatus and image processing method capable of providing a high-resolution image for a desired position by use of light field data are provided. The image processing apparatus may determine a position of a portion of light field data among light field data corresponding to a scene, according to a desired focusing position, generate a refocusing first image by use of the position determined portion of light field data, generate a high-resolution image having a predetermined setting ratio relative to the refocusing first image, determine a ratio for local synthesis between the high-resolution image and an enlarged image of the refocusing first image by use of a similarity with respect to the position determined portion of light field data, and generate a synthesized image by synthesizing the high-resolution image and the enlarged image of the refocusing first image according to the local synthesis ratio.

IEEE 802.11s: The WLAN Mesh Standard

Abstract: The wireless local area network standard IEEE 802.11 is the preferred solution for lowcost data services. Key to its success are the 2.4 and 5 GHz unlicensed bands. The transmit power limitations imposed due to regulatory requirements limit the range (coverage) that can be achieved by WLANs in these bands. However, the demand for "larger" wireless infrastructure is emerging, ranging from office/university campuses to city-wide deployments. To overcome the limitations of singlehop communication, data packets need to traverse over multiple wireless hops, and wireless mesh networks are called for. Since 2004 Task Group S has been developing an amendment to the 802.11 standard to exactly address the aforementioned need for multihop communication. Besides introducing wireless frame forwarding and routing capabilities at the MAC layer, the 802.11s amendment brings new interworking and security. In this article, we provide insights into the latest developments in 802.11s and explain how the overall mesh concept fits into the 802 set of networking standards.

Direct hydrazine fuel cells: A review

Abstract: Low-temperature fuel cells operating on hydrazine fuel in acid and alkaline media comprise a promising class of new, non-conventional sources of energy. High battery performance is expected of hydrazine-based cells. The electrooxidation of hydrazine on the surface of different catalysts has been extensively studied recently. Examples of Direct Hydrazine Fuel Cells (DHFC) with anion or cation-exchange membranes show notable power densities. These aspects of DHFC development with analysis of future improvements in their performance based on changes such as an increase in catalytic activity, membrane type selection and MEA fabrication, are summarized in the present review.

Mobile terminal having foldable display and operation method for the same

Abstract: A mobile terminal having a foldable display and an operation method for the same are disclosed. The foldable display unit includes a plurality of display zones, wherein the application of program depends on the degree of folding angle of the display unit, and the display unit displays on its screen according to the folding angle. Further, variations of closing and opening motion of the foldable display unit triggers different modes of operation and displays

Method and apparatus for encoding video, and method and apparatus for decoding video

Abstract: Disclosed are a method and a apparatus for encoding a video, and a method and apparatus for decoding a video, in which neighboring pixels used to perform intra prediction on a current block to be encoded are filtered and intra prediction is performed by using the filtered neighboring pixels.

Layer-by-layer doping of few-layer graphene film.

Abstract: We propose a new method of layer-by-layer (LbL) doping of thin graphene films. Large area monolayer graphene was synthesized on Cu foil by using the chemical vapor deposition method. Each layer was transferred on a polyethylene terephthalate substrate followed by a salt-solution casting, where the whole process was repeated several times to get LbL-doped thin layers. With this method, sheet resistance was significantly decreased up to ∼80% with little sacrifice in transmittance. Unlike samples fabricated by topmost layer doping, our sample shows better environmental stability due to the presence of dominant neutral Au atoms on the surface which was confirmed by angle-resolved X-ray photoelectron spectroscopy. The sheet resistance of the LbL-doped four-layer graphene (11 × 11 cm2) was 54 Ω/sq at 85% transmittance, which meets the technical target for industrial applications.

Sound‐Driven Piezoelectric Nanowire‐Based Nanogenerators

Abstract: Thus, sound power can be used for various novel applications including mobile phones that can be charged during conversations and sound-insulating walls near highways that generate electricity from the sound of passing vehicles. The latter development would have the additional benefi t of reducing noise levels near highways by absorbing the sound energy of vehicles. Here, we report the fi rst power-generating performance of sound-driven nanogenerators based on piezoelectric ZnO nanowires. Figure 1a and b show a schematic diagram of an integrated nanogenerator with piezoelectric ZnO nanowires and a crosssectional fi eld-emission scanning electron microscopy (FE-SEM) image of vertically well-aligned ZnO nanowire arrays (acting as a piezoelectric active layer), respectively. The nanowires were grown using a thermal chemical vapor deposition (CVD) system via a vapor-liquid-solid mechanism on an n-type GaN thin fi lm (acting as a bottom electrode)-deposited sapphire substrate. [ 14 ] It was found that there are no additional peaks other than (0002) and (0004) peaks of ZnO in X-ray diffraction measurements (not shown), indicating good alignment of the ZnO nanowires along the c -axis direction on GaN. A palladium gold (PdAu)coated polyethersulfone (PES) substrate were used as both a top electrode and a vibration plate and placed above the ZnO nanowire arrays. The integrated device was then sealed at the edges to prevent physical and chemical damage. The average length and diameter of the ZnO nanowires were ∼ 10 µ m and ∼ 150 nm, respectively. The integrated nanogenerator was then connected to a measurement system.

Method of dividing screen areas and mobile terminal employing the same

Abstract: A method of supporting divided screen areas and a mobile terminal employing the same are disclosed. The method includes: generating input signals for one of sequentially and simultaneously activating a plurality of user functions; activating the user functions according to generated input signals; dividing a screen into divided screen areas that correspond to activated user functions; and outputting functional view areas associated with the activated user functions to the corresponding divided screen areas.

Rechargeable lithium battery

Abstract: A rechargeable lithium cell comprising an anode, a separator, a cathode, and an electrolyte or an electrolyte solution, characterized in that said anode comprises (a) a metal capable of being alloyed with lithium and (b) a metal incapable of being alloyed with lithium, said anode contains lithium when charging is operated, and wherein an anode terminal is extended from a portion formed of said metal (b).

Compound for organic photoelectric device and organic photoelectric device including the same

Abstract: A compound for an organic photoelectric device, the compound being represented by the following Chemical Formula (“CF”) 1:

Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes

Abstract: [*] Prof. S.-W. Kim, H.-K. Park, J.-S. Seo School of Advanced Materials Science and Engineering SKKU Advanced Institute of Nanotechnology (SAINT) Center for Human Interface Nanotechnology (HINT) Sungkyunkwan University Suwon, 440-746 (Republic of Korea) E-mail: kimsw1@skku.edu Dr. J.-Y. Choi, Dr. D. Choi, Dr. W. M. Choi, H.-J. Shin, Dr. J. Park, S.-M. Yoon, Dr. S. Y. Lee, Dr. J. M. Kim Samsung Advanced Institute of Technology Yongin, Gyeonggi, 446-712 (Republic of Korea) E-mail: jaeyoung88.choi@samsung.com M.-Y. Choi School of Advanced Materials and System Engineering Kumoh National Institute of Technology Gumi, Gyeongbuk, 730-701 (Republic of Korea)

Chip coated light emitting diode package and manufacturing method thereof

Abstract: A chip coated LED package and a manufacturing method thereof. The chip coated LED package includes a light emitting chip composed of a chip die-attached on a submount and a resin layer uniformly covering an outer surface of the chip die. The chip coated LED package also includes an electrode part electrically connected by metal wires with at least one bump ball exposed through an upper surface of the resin layer. The chip coated LED package further includes a package body having the electrode part and the light emitting chip mounted thereon. The invention improves light efficiency by preventing difference in color temperature according to irradiation angles, increases a yield, miniaturizes the package, and accommodates mass production.

Three-dimensional semiconductor memory device and method of fabricating the same

Abstract: Methods of forming vertical nonvolatile memory devices may include forming an electrically insulating layer, which includes a composite of a sacrificial layer sandwiched between first and second mold layers. An opening extends through the electrically insulating layer and exposes inner sidewalls of the first and second mold layers and the sacrificial layer. A sidewall of the opening may be lined with an electrically insulating protective layer and a first semiconductor layer may be formed on an inner sidewall of the electrically insulating protective layer within the opening. At least a portion of the sacrificial layer may then be selectively etched from between the first and second mold layers to thereby define a lateral recess therein, which exposes an outer sidewall of the electrically insulating protective layer.

A Survey of Artificial Intelligence for Cognitive Radios

Abstract: Cognitive radio (CR) is an enabling technology for numerous new capabilities such as dynamic spectrum access, spectrum markets, and self-organizing networks. To realize this diverse set of applications, CR researchers leverage a variety of artificial intelligence (AI) techniques. To help researchers better understand the practical implications of AI to their CR designs, this paper reviews several CR implementations that used the following AI techniques: artificial neural networks (ANNs), metaheuristic algorithms, hidden Markov models (HMMs), rule-based systems, ontology-based systems (OBSs), and case-based systems (CBSs). Factors that influence the choice of AI techniques, such as responsiveness, complexity, security, robustness, and stability, are discussed. To provide readers with a more concrete understanding, these factors are illustrated in an extended discussion of two CR designs.

Semiconductor light emitting device, method of manufacturing the same, and semiconductor light emitting device package using the same

Abstract: There is provided a semiconductor light emitting device, a method of manufacturing the same, and a semiconductor light emitting device package using the same. A semiconductor light emitting device having a first conductivity type semiconductor layer, an active layer, a second conductivity type semiconductor layer, a second electrode layer, and insulating layer, a first electrode layer, and a conductive substrate sequentially laminated, wherein the second electrode layer has an exposed area at the interface between the second electrode layer and the second conductivity type semiconductor layer, and the first electrode layer comprises at least one contact hole electrically connected to the first conductivity type semiconductor layer, electrically insulated from the second conductivity type semiconductor layer and the active layer, and extending from one surface of the first electrode layer to at least part of the first conductivity type semiconductor layer.

Organic light emitting display and method of driving the same

Abstract: An organic light emitting display is capable of reducing power consumption. The organic light emitting display includes a scan driver for sequentially supplying scan signals to scan lines, a data driver for supplying data signals to data lines in synchronization with the scan signals, pixels located at crossing regions of the scan lines and the data lines, a timing controller for determining a normal driving mode for displaying a normal image and a standby driving mode displaying less information than the normal image, and a power source for supplying a first power and a second power to the pixels, wherein a voltage difference between the first power and the second power in the normal driving mode is a first voltage, and a voltage difference between the first power and the second power is a second voltage different from the first voltage.

Enhanced Performance in Polymer Solar Cells by Surface Energy Control

Abstract: Enhanced performance of an inverted-type polymer solar cell is reported by controlling the surface energy of a zinc oxide (ZnO) buffer layer, on which a photoactive layer composed of a polymer:fullerene-derivative bulk heterojunction is formed. With the approach based on a mixed self-assembled monolayer, the surface energy of the ZnO buffer layer can be controlled between 40 mN m − 1 and 70 mN m − 1 with negligible changes in its work function. For the given range of surface energy the power conversion effi ciency increases from 3.27% to 3.70% through enhanced photocurrents. The optimized morphology obtained by surface energy control results in the enhanced photocurrent and transmission electron microscopy analysis verifi es the correlation between the surface energy and the phase morphology of the bulk heterojunction. These results demonstrate that surface energy control is an effective method for further improving the performance of polymer solar cells, with potentially important implications for other organic devices containing an interface between a blended organic active layer and a buffer or an electrode layer.

Degrees of Freedom of the MIMO Y Channel: Signal Space Alignment for Network Coding

Abstract: In this paper, we study a network information flow problem for a multiple-input-multiple-output (MIMO) Gaussian wireless network with three users each equipped with M antennas and a single intermediate relay equipped with N antennas. In this network, each user intends to convey independent messages for two different users via the intermediate relay while receiving two independent messages from the other two users. This is a generalized version of the two-way relay channel for the three-user case. We will call it a "MIMO Y channel." For this MIMO Y channel, we show that the capacity is 3M log(SNR) + o(log(SNR)) if N ≥ ⌈3M/2⌉ by using two novel signaling techniques, which are signal space alignment for network coding, and network-coding-aware interference nulling beamforming.

Control of Electronic Structure of Graphene by Various Dopants and Their Effects on a Nanogenerator

Abstract: It is essential to control the electronic structure of graphene in order to apply graphene films for use in electrodes. We have introduced chemical dopants that modulate the electronic properties of few-layer graphene films synthesized by chemical vapor deposition. The work function, sheet carrier density, mobility, and sheet resistance of these films were systematically modulated by the reduction potential values of dopants. We further demonstrated that the power generation of a nanogenerator was strongly influenced by the choice of a graphene electrode with a modified work function. The off-current was well quenched in graphene films with high work functions (Au-doped) due to the formation of high Schottky barrier heights, whereas leakage current was observed in graphene films with low work functions (viologen-doped), due to nearly ohmic contact.