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A highly integrated, high-voltage dual-mode boost converter is presented for solid-state drives applications in portable devices, where standby mode efficiency with 100-mA load. To enhance efficiency in light load conditions and to achieve a wide operation load range, loss minimization by balancing conduction and switching losses is adopted, and a dynamic power-gating scheme is applied for pulse frequency modulation mode operation. Moreover, robust dual-mode operation is implemented with a time-based control scheme, which enables operation with a lower peak current for optimal loss balancing. The proposed converter is fabricated in 130-nm complementary metal-oxide-semiconductor process with an area of 1.7 mm2. The measured efficiency for supplying 12-V output from 5.5-V input is 91% at its peak load of 40 mA and 85% with an extremely light load of 200 μA. It also achieves a wide dynamic load range from 200 μA to 600 mA for >85% efficiency and from 2 to 150 mA for >90% efficiency.

The Korea Atomic Energy Research Institute (KAERI) has developed the DeCART2D 2-dimensional (2D) method of characteristics (MOC) transport code and the MASTER nodal diffusion code and has established its own two-step procedure. For design code licensing, KAERI prepared a critical experiment on the verification and validation (V&amp, V) of the DeCART2D code. DeCART2D is able to perform the MOC calculation only for 2D nuclear fuel systems, such as the fuel assembly. Therefore, critical buckling in the vertical direction is essential for comparison between the results of experiments and DeCART2D. In this study, the B1 theory-augmented Monte Carlo (MC) method was adopted for the generation of critical buckling. To examine critical buckling using the B1 theory-augmented MC method, TCA critical experiment benchmark problems were considered. Based on the TCA benchmark results, it was confirmed that the DeCART2D code with the newly-generated critical buckling predicts the criticality very well. In addition, the critical buckling generated by the B1 theory-augmented MC method was bound to uncertainties. Therefore, utilizing basic equations (e.g., SNU S/U formulation) linking input uncertainties to output uncertainties, a new formulation to estimate the uncertainties of the newly generated critical buckling was derived. This was then used to compute the uncertainties of the critical buckling for a TCA critical experiment, under the assumption that nuclear cross-section data have uncertainties.

A multi-channel audio CODEC with interchannel interference suppression is proposed, in which channel switching noise-referred sampling error is significantly reduced. It also supports a coarse/fine mode operation for fast frequency tracking with good harmonic performance. The proposed multi-channel audio CODEC was designed in a 65 nm CMOS process. Measured results indicated that SNR and SNDR of ADC were 93 dB and 84dB, respectively, with SNDR improved by 43 dB. Those of DAC were 96 dB and 87 dB, respectively, with SNDR improved by 45 dB when all the channels are running independently.

McCARD is a Monte Carlo (MC) neutron-photon transport simulation code developed exclusively for the neutronics design and analysis of nuclear reactor cores. McCARD is equipped with the hierarchical modeling and scripting functions, the CAD-based geometry processing module, the adjoint-weighted kinetics parameter and source multiplication factor estimation modules as well as the burnup analysis capability for the neutronics design and analysis of both research and power reactor cores. This paper highlights applicability of McCARD for the research reactor core neutronics analysis, as demonstrated for Kyoto University Critical Assembly, HANARO, and YALINA.

A compact decision-error-tolerant 2b/cycle SAR ADC architecture is presented. Two DACs with different designated functions, SIG-DAC and REF-DAC, are implemented to make the structure compact and to eliminate the sampling skew issue. Use of a nonbinary decision scheme with decision redundancies not only increases the ADC speed with a relaxed DAC settling requirement but also makes the performance robust to reference fluctuations and comparator offset variations. The proposed dynamic register and direct DAC control scheme enhance the conversion speed by minimizing logic delay in the SAR decision loop. The proposed comparator-error detection with digital error correction scheme enhances high-speed ADC performance. A prototype 7b ADC fabricated in a 45 nm CMOS process operates at a sampling rate of 1 GS/s under a 1.25 V supply while achieving a peak SNDR of 41.6 dB and maintaining an ENOB higher than 6 up to 1.3 GHz signal frequency. The FoM under a 1.25 V supply is an 80 fJ/conversion-step with a power consumption of 7.2 mW.

We propose a DLNA proxy∗ for home-to-home content distribution that enables a source DLNA-compliant device to multicast a high-quality video to target ones in different UPnP-enabled home networks by applying a large-scale media distribution scheme to the DLNA architecture. The proposed EAFR scheme helps the DLNA proxy efficiently distribute overall network traffic load for a massive content delivered to the DLNA devices placed on different home networks by utilizing unused forwarding bandwidth on delivery paths, among them based on a multiple multicast trees approach.

Existing, home networking protocols such as UPnP are not ready to support media streaming services among home networks. Furthermore, a home router with NAT makes it difficult to provide such home-to-home network services. Considering the constraints of real home network environments such as these, we propose a solution that offers a personal control space so that users can freely control their own home devices and remote devices on their moving UPnP-enabled networks with zero-configuration. For this, we have implemented the personal mobile A/V control point (PMCP) and the UPnP relay.

A multiplying delay-locked loop (MDLL) is an attractive architecture for a low-jitter clock generator, as it does not suffer much from jitter accumulation [1–4]. By periodically replacing the output edge of the oscillator by a clean edge of the reference, an MDLL has a large effective loop bandwidth for oscillator phase noise, which cannot be obtained in a PLL. With this advantage in mind, several MDLLs have been implemented recently [2], [3]. Unfortunately, these works are limited in their practical use as the frequency multiplication factor is only 4 [2] or 8 [3]. While the prior works show good jitter performance, it is primarily due to their wide effective loop bandwidth of nearly one hundred MHz that arises from using reference frequencies of 375 to 575MHz. It is much more challenging to achieve same level of jitter performance if the multiplication factor is increased and reference frequency is decreased. In this work, a low-power digital MDLL (DMDLL) with a multiplication factor of 32 is presented. To achieve low-jitter despite the large multiplication factor, a background-calibrated double-injection scheme is proposed which exploits both the rising and falling edge of the reference.

A time-to-digital converter (TDC) is a key element for the digitization of timing information in modern mixed-signal circuits such as digital PLLs, DLLs, ADCs, and on-chip jitter-monitoring circuits. To build high-resolution TDCs, many researchers have focused on minimizing the unit delay of quantization. Vernier delay-line-based TDCs [1] are a good example. Their performance, however, is limited by delay variation and random mismatch among delay cells, unless additional error correction or external control are applied. A time-domain successive-approximation scheme [2] could be an option to achieve high resolution but it consumes too much power and area to generate precisely tuned delay cells. In another case, time-amplifier-based multi-step TDCs [3,4] that can alleviate the requirement on the minimum unit delay of the quantization by time-difference amplification, may be an attractive option. However these tend to be power-hungry or to require additional calibration circuitries due to the inaccuracy and PVT vulnerability of the time amplifier or time register. In this paper, we present a simple, low-power, and PVT-variation-tolerant TDC architecture without any calibration, using stochastic phase interpolation and 16x spatial redundancy.

A power-efficient and speed-enhancing technique for time-interleaved (TI) SAR ADCs that is assisted by a low-resolution flash ADC is presented. The 3 b MSBs achieved from a flash ADC at every clock save two decision cycles from every SAR ADC channel, resulting in a reduced number of time interleaving channels with a total 27% energy saving compared with the energy consumption of a conventional TI SAR ADC. A prototype 6 b 2 GS/s ADC in a 45 nm CMOS consumes 14.4 mW under a 1.2 V supply and achieves 5.2 ENOBNyq with a background offset calibration.

A switched-capacitor second-order audio ΔΣ analog-to-digital converter (ADC) is presented. The proposed ΔΣ ADC employs low-distortion input feed-forward architecture to relax the linearity requirement of the integrators. A 4-bit asynchronous successive approximation register (SAR) type internal quantizer is used for power efficient design by incorporating the analog adder with the quantizer. A tree-structured dynamic element matching (DEM) technique is employed to reduce the distortion resulted from the capacitor mismatch in the feedback digital-to-analog converter (DAC). The prototype ΔΣ ADC implemented in a 45nm CMOS process achieves 85.4 dB peak signal-to-noise ratio (SNR), 82.3 dB peak signal-to-noise and distortion ratio (SNDR) and 98.1 dB dynamic range (DR) for a signal bandwidth of 24 kHz while consuming 517.4 μW at 1.1 V supply voltage.

A 45nm CMOS 7b nonbinary 2b/cycle SAR ADC that operates up to 1GS/s with a 1.25V supply is presented. Use of a nonbinary decision scheme for decision error correction in a 2b/cycle structure not only increases the ADC speed with a relaxed DAC settling requirement but also makes the performance robust to reference fluctuation and signal-dependent comparator offset variation. Proposed dynamic registers and a register-to-DAC direct control scheme enhance the conversion speed by minimizing logic delay in the decision loop. At a sampling rate of 1 GS/s, the chip achieves a peak SNDR of 41.6dB and maintains ENOB higher than 6b up to 1.3GHz signal frequency. The FoM is 80fJ/ conversion-step at 1GS/s with a power consumption of 7.2mW.

Ubiquitous home refers not only to home but also to logical space, including a wide range of out-home personal devices such as mobile phones, PDAs, laptops, car navigators, and office PCs. There are certain connection barriers among the devices, such as the dynamic IP address, NAT. In a home network, various devices coexist in heterogeneous networks, such as IP, IEEE1394, PLC, Bluetooth, ZigBee, UWB, and IrDA, all of which lack interoperability due to their different physical transmission characteristics and protocols. In ubiquitous home where an unrestricted collaboration of the devices is essential to offer services that meet the users’ requirements, free interoperability among the devices must be guaranteed. This paper proposes a framework for interoperability of the heterogeneous devices in a ubiquitous home based on a virtual overlay network which hides the complicated physical network configurations and heterogeneity of the service protocols. Compared with conventional approaches, the framework offers improvements in terms of its capacity to support network and device types, its reliability.

In ubiquitous home environment, it is essential that every personal devices at home and out-home can collaborate with others to provide users with the home services and personal contents anywhere and anytime. To achieve this, it is recommended the virtual overlay network where every device can collaborate with others in peer-to-peer manner to share contents, send messages, and control services remotely just like in a local network. In this paper we propose the collaboration platform based on virtual overlay network for ubiquitous home devices.

In this paper, we design a location-aware UPnP AV session manager1. This system automatically detects a user's movement using RFID technology, and then captures or restores his UPnP A/V session information by invoking service actions defined in the UPnP AV architecture. The designed system is based on RFID-based multi-user access control algorithm to reduce both service transition time from a person in service to another person, and unnecessary processing time, by filtering invalid tags.

We designed and developed a virtual home platform based on peer-to-peer (P2P) based networking service. Also, we designed a P2P based social networking service method and apparatus capable of appropriately providing a social networking service under P2P environments. This paper proposed a method for easily providing a social networking service, which will be used as an Application Programming Interface (API) on the basis of a universal P2P platform irrelevant to application characteristics.

The stereo audio DAC with novel single-ended class-D amplifier achieving a 103-dB SNR is fully integrated in a 65 nm CMOS technology. Novel asymmetric pulse-width modulation (PWM) is applied to minimize switching noise and nonlinearity in the class-D amplifier. The adjustable delta-sigma modulator is also used to suppress supply-voltage modulation. All the functions needed for portable audio playback are implemented in a 0.53-mm2 area dissipating only 1.3-mW per channel from a 2.5-V supply.

The general peer-to-peer based service system formed as an overlay network on top of the underlying physical computer network and the overlay network can be distinguished with the hybrid peer-to-peer network or the pure peer-to-peer network in terms of their centralization and structure. Because of no central server, the pure peer-to-peer network can release the server management cost, the single point of failure problem, the traffic overload or the scalability problem. Regardless of this kind of advantages, the pure peer-to-peer network has the critical problem in the case of that if the peers known to have the requested shared resource is temporary offline, there is no way to connect or to send a request to that peer because there is no central server. In this paper, we proposed the asynchronous peer-to-peer service extension method using email server in pure peer-to-peer networking environment. According to this method, it is possible to provide the peer-to-peer services not only when the two edge peers are online but also when one of the edge peers is temporary offline. Therefore, the proposed method can be used to increase the service availability of the small-sized peer-to-peer network in which the shared resources are not guaranteed to be always available. Also, the proposed method can be effective for the mobile network in which mobile device is not always online.

To ensure continuity of a UPnP A/V session following a user's movement trajectory in the home, we designed a RFID-based UPnP A/V session manager. It automatically detects a user's movement with an RFID reader, and captures or restores the states of playing A/V contents using the UPnP AVTransport service which defines a common model for A/V transport control. We present the functions and control flow operation of the designed session manager, and describe how its state is changed by the event messages generated by an RFID reader or its internal timer, and explain an algorithm for controlling access of multi-users at the same time.

In this paper, we suggest a strong peer authentication algorithm that authorizes the peer which requests a service usage of the other peer in super peer based P2P network environment. The proposed peer authentication method, at which public key certificate (PKC) and Kerberos authentication mechanism is applied, enables each peer to perform strong mutual authentication in P2P network environment. The peer mutual authentication is performed by getting authentication ticket and verification it by other peer. Also, the lifetime of a ticket can be controlled by the peer providing services according to each service.

We developed a peer-to-peer (P2P) based networking service and designed a P2P based social networking service method and apparatus capable of appropriately providing a social networking service under P2P environments. This paper proposed a method for easily providing a social networking service, which will be used as a principal service on the basis of a universal P2P platform irrelevant to application characteristics. Also, this paper provides a universal P2P platform which can easily construct a community for a social networking service by using a peer group management function.

Recently various services using the P2P technology such as e-donkey and Napster are appearing. The purpose of these P2P services is to allow many users to share, download and upload multimedia contents such as music and video files. However, even though the basic protocols for P2P networks are similar, different P2P services are not compatible with one another. The reason is because each P2P service has been developed on the proprietary P2P platform designed by the respective service provider, and does not support other P2P services although they are similar. To enable compatibility among these P2P services that have been designed differently, a common P2P platform and common service support structure for P2P service programs developed on this platform are required. This paper defines the essential components of a P2P application as U-Share services, and designs peer and peer group management structure among them.

To automatically move a mobile user's desktop environment following his/her movement trajectory, we implement the RFID-based desktop migration system. This system automatically detects a user's movement with a RFID reader, and then captures or restores application states by dynamically binding to an interface exported by application-specific libraries. We present the functional architecture of the implemented system, and define the protocols for advertising an application-specific library or delivering migration data. We describe how its state is changed by the events generated by a RFID reader or internal timer.

This paper shows a design and implementation case of the contents sharing service application which is executed on the peer-to-peer based virtual home platform middleware. The virtual home platform provides an upper layer application with the peer-to-peer network configuration mechanism such as peer discovery, peer grouping, pipe binding and etc. An application based on virtual home platform implemented using U-Share application architecture. In this architecture, an U-Share application is implemented by two layers. U-Share management and primitive service layer provide U-Share application layer with P2P functions which can be generally reused to implement various P2P applications. And the U-Share applications which are implemented on top layer include GUI and service dependent functions. In this work, we are following the U-Share application architecture to implement contents sharing application. We use U-Share management services to discover other peers and groups and to manage buddy list. We also use U-Share file transfer and message transfer primitive services to exchange messages and files between peers. U-Share contents sharing application search not only files but also service enabled peers which share contents. And application provides GUI by which the user can explore peers, groups and contents files on each peers. We also present an application level message routing method using hypercube graph to reduce the P2P message traffic.

This paper discusses the method for making the legacy apparatus not to load the P2P middleware participation in the P2P infra. The proxy peer is comprised of the P2P middleware core, the proxy core service and the driver controlling apparatus. It is the contents which is in the apparatus searched on the P2P infra with share. It provides the number method moreover remote-controlling the legacy apparatus.

The peer-to-peer (P2P) networking is the service spreading between the user terminal (peer) without the separate server system through the direct exchange and the technology together sharing a resource. According to the development of the communications environment and high performance conversion of the personal terminal, the demand for the service interworking and contents share anytime and anywhere increases between the apparatus. Therefore, the virtual space providing the connection which does between the individual terminal equipment with seamless is comprised and the technology which searches a service and contents and which it shares between the instrument of the P2P mode is requested. We present a application platform based P2P virtual home middleware.

This study is about an e-commerce model for advertisement of products on Internet shopping malls by using consumer's personal blog or personal homepage that contain review information of the products. A user can post review or experiences of using a product with pictures or movie clips of it on the user's personal blog. After registration of the contents to the e-commerce system with the peer-to-peer (P2P) application, the manager of a Internet shopping mall can search and apply contents on the mall. Consumer will check the contents when he/she want to buy the product on the mall. The owner of the shopping mall could pay some money or cash back points for the using the contents of the blog users. A blog user can also apply the price information of shopping malls to the product review page after searching them through the P2P communication.

For continuous provision and upgrade of home services, a service delivery & management platform with openness and scalability will cat as the key element. Service delivery & management platforms give us how to manage home gateways and the life cycle of sewices downloaded to home gateways. When service providers register developed service applications to the service platform, the applications will go through the operation of service delivery and be downloaded to the framework of home gateways. Upon the installation, the corresponding service application will be activated to provide service users with services. This paper proposes the structure and functional models of a service delivery and management platform to work out the closeness found in the service provision and management system of home network when individual companies offer services, while presenting functional implementations and the results of system performance evaluation.

Service delivery & management platforms give us how to manage home gateways and the life cycle of services downloaded to home gateways. When service providers register developed service applications to the service platform, the applications will go through the operation of service delivery and be downloaded to thefi.amework of home gateways. Upon the installation, the corresponding service application will be activated to provide service users with services. This paper proposes the structure andfunctional models of a service delivery and management platform to work out the closeness found in the service provision and management system of home network when individual companies ofer services, while presenting functional implementations and the results of system performance estimation.

The Internet has affected to diversification of information and growing of users. Such users are widely distributed in terms of the Internet service providers, so the increasing users can cause traffic overhead between the users and service providers like a bottle-neck problem. Especially, users in home networks cannot avoid such a problem because they exploit many devices which are connected with many servers in the Internet. For the reason, this paper proposes an OPES-applied mechanism for real-time translation services based on digital-home delivery & management system in digital-home networks. Thus, OPES processors are included into the home gateway and digital-home delivery & management servers. The OPES processors in the proposed mechanism for real-time translation services connect both phone-users, who speak in different languages from each other, to a translator by using third party call of SIP. To support such a service, a definition of profile for SIP protocol of the OPES callout protocol is necessary as well.

For the purpose of realization of the automated desktop migration environment based on dynamic linking of application specific library, we suggest a desktop migration system which supports application registration, global ID generation, application state management, and library management function. This system can save cost and time in generating a task description and developing application specific communication protocol, and also enables legacy applications to move their application states by supporting open delivery platform of application specific library.

When using the Mobile IP, which is the representative technology to secure the mobility in general IP networks, the packet loss during the handover is inescapable. To remedy the packet loss problem, the smooth handover was introduced. However, this solution is also flawed. In particular, the smooth handover causes the packet sequence to be disrupted during the packet forwarding procedure. In turn, it may result in the degradation of the network performance. The same problem also occurs in the HPi (High-speed Portable Internet) system; the next generation portable IP service system. The HPi system, which provides the high speed data service just like xDSL and leased line in wired internet, aims to guarantee the portability, mobility, and the differentiated service based on IEEE 802.16. In this paper, we will propose a handover mechanism and a packet sequence control algorithm that prevent the packet loss and the out-of-sequence packet problem for differentiated service in the HPi system.

This paper introduces the Electronic Commerce Payment System-Telephone Number (ECPS-TN) with a deferred payment method that bills the price of merchandise in electronic commerce shopping mall based on business to customer (B2C) together with a telephone bill, and presents its configurations, functions, and performances. The ECPS-TN consists of a server and gateway system that presents the service of ECPS-TN which can be linked by the present electronic commerce shopping mall of the Web/Merchant server, customer management and billing system, and the TCP/IP. By introducing a different payment method from the present payment such as credit card, electronic money wallet, and on-line depositing, it can not only serve a variation of payment but also secure a member of service for almost of users by using the system that bills the price of merchandise in electronic commerce shopping mall together with the number of public switched telephone network/integrated service digital network (PSTN/ISDN) which belongs to an average Internet user.

A scenario socket architecture model (SSAM) for ATM switch software is proposed. Its goal is to provide a distributed processing environment that enhances software extensibility and maintainability. Especially, it gives a good reusability of software and provides a way that cultivates system engineers naturally. The SSAM and its target application are based on a distributed concurrent processing model with its state transition diagram. We adapt a scenario socket model for inter- and intra-scenario processing. We design the SSAM structure and defined the scenario, protocol based software model with B-ISDN UNI protocol, and the implementation with the structure for the ATM switch. The structure can be adapted to implement the B-ISDN NNI (B-ISUP) protocol. For high adaptability, the SSAM supports a table driven mechanism for state transition and uses a register reference model. We implement the SSAM as call/connection software of a small scale ATM switch.

A clock synchronization scheme based on a newly proposed dual-loop delay locked loop (DLL) is presented. The proposed scheme incorporates analog and digital DLLs to align phases of two different frequency clocks. Simulation results represent that the internal clock is synchronized to the reference clock by tracking the dual feedback loop. The whole circuit design was performed using 0.35 /spl mu/m CMOS technology. Power dissipation is about 42 mW at 320 MHz with a single 3.3 V supply.

To meet the rigorous demands of today's fast-moving telecommunication environment, every carriers want to deploy new services smoothly with minimal impact on the underlying infrastructure. Also it is necessary to create an open environment that enables the deployment of multivendor switching systems with optimum functionality and performance. The MSF(Multiservice Switching Forum) is an industrial forum to develop the network infrastructure that meets the above requirements. The MSF has been focusing on reaching and promoting consensus on the implementation of MSS(Multiservice Switching System) that realizes the vision of multiservice switching and defines a set of open intra-switching system interfaces. In this paper, we review the system architecture and characteristics of the MSS based on MSF architecture. We propose the open software architecture for the implementation of the MSS, the control scenarios for ATM SVC(Switched virtual Connection) service and management functions in the software architecture. The environment for software development is also considered.