A new on-chip interconnect crosstalk model and experimentalverification for CMOS VLSI circuit design

A new, simple closed-form crosstalk model is proposed. The model is based on a lumped configuration but effectively includes the distributed properties of interconnect capacitance and resistance. CMOS device nonlinearity is simply approximated as a linear device. That is, the CMOS gate is modeled as a resistance at the driving port and a capacitance at a driven port. Interconnects are modeled as effective resistances and capacitances to match the distributed transmission behavior. The new model shows excellent agreement with SPICE simulations. Further, while existing models do not support the multiple line crosstalk behaviors, our model can be generalized to multiple lines. That is, unlike previously published work, even if the geometrical structures are not identical, it can accurately predict crosstalk. The model is experimentally verified with 0.35-μm CMOS process-based interconnect test structures. The new model can be readily implemented in CAD analysis tools. This model can be used to predict the signal integrity for high-speed and high-density VLSI circuit design     

A Multi‐Strategic Concept‐Spotting Approach for Robust Understanding of Spoken Korean

We propose a multi‐strategic concept‐spotting approach for robust spoken language understanding of conversational Korean in a hostile recognition environment such as in‐car navigation and telebanking services. Our concept‐spotting method adopts a partial semantic understanding strategy within a given specific domain since the method tries to directly extract pre‐defined meaning representation slot values from spoken language inputs. In spite of partial understanding, we can efficiently acquire the necessary information to compose interesting applications because the meaning representation slots are properly designed for specific domain‐oriented understanding tasks. We also propose a multi‐strategic method based on this concept‐spotting approach such as a voting method. We present experiments conducted to verify the feasibility of these methods using a variety of spoken Korean data.     

Shorted Microstrip Patch Antenna Using Inductively Coupled Feed for UHF RFID Tag

A very small patch‐type RFID tag antenna (UHF band) using ceramic material mountable on metallic surfaces is presented. The size of the proposed tag is 25 mm×25 mm×3 mm. The impedance of the antenna can be easily matched to the tag chip impedance by adjusting the size of the shorting plate of the patch and the size of the feeding loop. The measured maximum reading distance of the tag at 910 MHz was 5 m when it was mounted on a 400 mm × 400 mm metallic surface. The proposed design is verified by simulation and measurements which show good agreement.     

Writing current reduction and total set resistance analysis in PRAM

We evaluated the limit of scaling bottom electrode contact (BEC) heater size and high resistivity heater to reduce writing current. It was found that the resistivity of heater should be increased for reducing writing current below the heater size of about 50 nm without any undesirable increase of resistance of the crystalline state (SET state, Rset). It was shown in the numerical simulations that the dissipated heat loss through BEC during melting GST was decreased in the increase of resistivity of heater. In addition, we analyzed the resistance components contributing to the total set resistance. It was observed that the undesired sharp increase of Rset as the BEC size decreases below 50 nm was attributed to the resistance component of GST–BEC interface. In the case of high resistivity heater, the contributions of both incomplete crystallization and heater itself were enhanced.     

Stress Mechanism about Field Lightning Surge of High Voltage BJT Based Line Driver for ADSL System

In this paper, we have verified stress root caused by lightning surge in High voltage BJT based line driver of ADSL telecommunication and created failure mechanism. To reproduce damages in Line driver, we have applied STD surge waveform in operating condition, which is specified in IEC-6000-4-5, to component and board level. Visual isolation for Damage root was conducted with Real-time Electrical Stress Analysis (RTESA) utilizing Photon Emission Microscopy (PEM). The surge made with input of Tx output created junction breakdown of amplifier, which is made of HVBJT cells, and also caused current crowding from Vcc (supply voltage). In case of Positive pulse, current crowding was observed from between Collector and Vcc (+)12V. For negative pulse, at between Emitter and Vee (−)12V, current crowding was found. For both cases, device damage level was the same. All of these could be considered as transient latchup phenomenon created in BJT cell. Applying temporary clamping diode to line driver Tx, we have conducted Board level surge injection test. As a result, with the correlation between surge level from component level reproduction test and the one from system level, we have decided field lightning surge damage level and set up line driver protection margin.     

A new method to suppress harmonics using /spl lambda//4 bias line combined by defected ground structure in power amplifiers

A new /spl lambda//4 bias line combined by a dumb-bell shaped defected ground structure (DGS) is proposed to suppress harmonics in power amplifiers. The proposed DGS bias line maintains the required high impedance even after DGS is inserted, while the width and length of the /spl lambda//4 bias line are broader and shorter than those of conventional bias lines. When the DGS bias line is used in power amplifiers, the third harmonic components as well as the second harmonic are reduced, because of the increased slow-wave effect over wide harmonic band. It is shown that the reduction of the third harmonic component, the improvement of 1 dB compression point, and power added efficiency are 26.5 dB, 0.45 dB, and 9.1%, respectively.     

Facile Fabrication and Superparamagnetism of Silica‐Shielded Magnetite Nanoparticles on Carbon Nitride Nanotubes

Using conventional methods to synthesize magnetic nanoparticles (NPs) with uniform size is a challenging task. Moreover, the degradation of magnetic NPs is an obstacle to practical applications. The fabrication of silica‐shielded magnetite NPs on carbon nitride nanotubes (CNNTs) provides a possible route to overcome these problems. While the nitrogen atoms of CNNTs provide selective nucleation sites for NPs of a particular size, the silica layer protects the NPs from oxidation. The morphology and crystal structure of NP–CNNT hybrid material is investigated by transmission electron microscopy (TEM) and X‐ray diffraction. In addition, the atomic nature of the N atoms in the NP–CNNT system is studied by near‐edge X‐ray absorption fine structure spectroscopy (nitrogen K‐edge) and calculations of the partial density of states based on first principles. The structure of the silica‐shielded NP–CNNT system is analyzed by TEM and energy dispersive X‐ray spectroscopy mapping, and their magnetism is measured by vibrating sample and superconducting quantum interference device magnetometers. The silica shielding helps maintain the superparamagnetism of the NPs; without the silica layer, the magnetic properties of NP–CNNT materials significantly degrade over time.     

Restorable Type Conversion of Carbon Nanotube Transistor Using Pyrolytically Controlled Antioxidizing Photosynthesis Coenzyme

Here, a pyrolytically controlled antioxidizing photosynthesis coenzyme, β‐Nicotinamide adenine dinucleotide, reduced dipotassium salt (NADH) for a stable n‐type dopant for carbon nanotube (CNT) transistors is proposed. A strong electron transfer from NADH, mainly nicotinamide, to CNTs takes place during pyrolysis so that not only the type conversion from p‐type to n‐type is realized with 100% of reproducibility but also the on/off ratio of the transistor is significantly improved by increasing on‐current and/or decreasing off‐current. The device was stable up to a few months with negligible current changes under ambient conditions. The n‐type characteristics were completely recovered to an initial doping level after reheat treatment of the device.     

Fabrication of a Superhydrophobic Surface from a Smectic Liquid‐Crystal Defect Array

A novel fabrication method is developed for the preparation of superhydrophobic surfaces. The procedure uses focal conic structures of semi‐fluorinated smectic liquid crystals (LCs) whose periodic toric focal conic domains (TFCDs) are prepared on a surface modified substrate. Reactive ion etching (RIE) on the periodic TFCD surface leads to a superhydrophobic surface with a water contact angle of ～160° and a sliding angle of ～2° for a 10 µL water droplet. The results show that this phenomenon is due to the development of a dual‐scale surface roughness arising from the nanoscale protuberance caused by applying the RIE process to the top of the microscale TFCD arrays. The unique surface behavior is further verified by demonstrating that RIE on a flat lamellar liquid crystal film, in which the director is aligned parallel with surface, results in a relatively low hydrophobicity as compared to when periodic TFCDs are subjected to REI. The observations made in this publication suggest that a new approach exists for selecting potential candidates of superhydrophic surface formation based on spontaneous self‐assembly in smectic liquid‐crystalline materials.     

Cue-based networking

In this paper we present a new approach called cue-based networking that uses hints or cues about the physical environment to optimize networked application behavior. We define the notion of cues and describe how cues can be obtained using wireless sensor networks as the underlying platform. We identify both the research and system challenges that need to be addressed to realize benefits of the approach under a target application of video delivery over IP networks. In the process, we identify key challenges of wireless sensor networks, namely timeliness and robustness. We design an adaptive algorithm that balances the tradeoff between them satisfying both timeliness and robustness requirements. Through an implementation of the video delivery application using the proposed algorithm in a real home environment, we highlight the practical benefits of the proposed approach.