bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined Standard Medication and Acupuncture for Copd: A Case Series
Authors: Suzuki Masao , Namura Kenji , Ohno Yasushi , Egawa Masato , Sugimoto Takako , Ishizaki Naoto , Fujiwara Hisayoshi
Published: April 2012

Background

Traditional acupuncture has been used in patients with chronic obstructive pulmonary disease (COPD). However, only a few studies have been performed to determine the efficacy of this treatment.

Objective

To observe changes in the symptoms of COPD during acupuncture treatment in patients with COPD stratified according to the severity of the disease.

Methods

A prospective case series of 26 patients with dyspnoea on exertion due to COPD was followed from October 2004 to October 2008 in the Departments of Respiratory Internal Medicine, Gifu University of Medicine and Meiji University of Integrative Medicine, Japan. All participants received acupuncture treatments once a week for 10 weeks in addition to standard medication therapy. The main outcome measure was the modified Borg dyspnoea scale after the 6 min walk test (6MWT) and the secondary outcome measure was the BODE index.

Results

All 26 patients showed significant improvement in the Borg dyspnoea scale after 10 weeks of acupuncture treatment (from 4.02 (2.85) to 1.96 (1.97), mean difference −2.06, 95% CI −3.03 to −1.09, p=0.0002, paired t test). Improvements in the BODE index, 6MWT and oxygen saturation during exercise, which indicates better reduced dyspnoea on exertion and prognosis, were also found.

Conclusion

The results of this study suggest that acupuncture treatment has clinically useful effects, at least in the short term, in reducing dyspnoea on exercise in patients with COPD, particularly in those more severely affected.
Early lactation failure and formula adoption after elective caesarean delivery: cohort study
Authors: Zanardo Vincenzo , Pigozzo Anna , Wainer Gary , Marchesoni Diego , Gasparoni Antonella , Di Fabio Sandra , Cavallin Francesco , Giustardi Arturo , Trevisanuto Daniele
Published: April 2012

Objective

To investigate the effects of elective primary and elective repeat caesarean deliveries on lactation at hospital discharge.

Design

Cohort study.

Setting

Four Italian teaching hospitals – Padua, Brescia, L'Aquila and Udine.

Interventions

Deliveries were classified as vaginal, elective caesarean (primary and repeat) or emergency caesarean. A total of 2296 (24.7%) infants born by caesarean section (CS), 816 of which (35.5%) classified as primary elective CS and 796 (34.7%) as repeat elective CS, were studied. Moreover, 30.2% of the elective CS deliveries took place before 39 weeks.

Main outcome measures

Feeding modalities at discharge: formula, complementary and breastfeeding.

Results

At discharge, 6.9% of the vaginal delivery mothers, 8.3% of the emergency CS mothers, 18.6% of the elective CS mothers, 23.3% of the primary CS mothers and 13.9% of the repeat CS mothers were using infant formula exclusively. Multivariate analysis (OR; 95% CI) identified primary elective delivery (3.74; 3.0 to 4.60), lower gestational age (1.16; 1.10 to 1.23), and place L'Aquila versus Udine (1.42; 1.01 to 2.09) and of Brescia versus Udine hospitals (6.16; 4.53 to 8.37) as independent predictors of formula feeding at discharge.

Conclusions

These findings provide new information about the risks of breastfeeding failure connected to elective CS delivery, particularly if primary and scheduled before 39 weeks of gestation.
Definitive therapy for a rare cause of recurrent ascites
Authors: Naghibi Mani , Ward Robert , Shutt James
Published: April 2012

Extrahepatic arterioportal fistulas are a rare cause of portal hypertension in infants and adults. Most cases of arterioportal fistulas in adults are due to trauma, liver biopsy, surgery or tumours. The authors present a case of arterioportal fistula diagnosed in adult life without any of the above aetiologies. The patient became acutely symptomatic with diarrhoea and ascites at the age of 66 years and was successfully treated with a single endovascular embolisation procedure after failed medical therapy.
SYMPLECTIC QUANTIZATION OF MASSIVE BOSONIC STRING IN BACKGROUND B-FIELD
Authors: SHIRZAD A. , BAKHSHI A. , KOOHSARIAN Y.
Published: April 2012

We give the details of symplectic quantization for a system containing second class constraints. This method is appropriate for imposing infinite series of constraints due to the boundary conditions. We use this method for massive bosonic strings in a background B-field and find the correct expansions of the fields in terms of the physical modes. We have found a canonical basis for this model.
LEPTON MIXING AND THE NEUTRINO MIXING ANGLE θ13
Authors: FRITZSCH HARALD
Published: April 2012

We discuss the neutrino oscillations, using texture zero mass matrices for the leptons, including radiative correction. The neutrino mixing angle θ13 is calculated and agrees with the result of the new Daya Bay experiment.
SUPERSYMMETRIC AXION-NEUTRINO MODEL WITH A HIGGS HYBRID
Authors: MA ERNEST
Published: April 2012

In 2001, a supersymmetric model was proposed to relate the axion scale to that of neutrino mass seesaw. Whereas this scenario is realistic, the particles associated with this mechanism are either too heavy or too weakly coupled for them to be observed (other than the axion itself or perhaps the axino). A variation of that model is here proposed which allows significant mixing of the Higgs boson with a new singlet related to the saxion (the scalar partner of the pseudoscalar axion), rendering it possible to be observed at the large hadron collider (LHC). With the addition of exotic color superfields, this also becomes a specific realization of how the production of such a Higgs hybrid may be suppressed or enhanced at the LHC, which is very relevant to ongoing experimental efforts to find the Higgs boson.
THERMODYNAMIC POTENTIAL WITH CORRECT ASYMPTOTICS FOR PNJL MODEL
Authors: MOREIRA J. , HILLER B. , OSIPOV A. A. , BLIN A. H.
Published: April 2012

An attempt is made to resolve certain incongruities within the Nambu–Jona-Lasinio (NJL) and Polyakov loop extended NJL models (PNJL) which currently are used to extract the thermodynamic characteristics of the quark–gluon system. It is argued that the most attractive resolution of these incongruities is the possibility to obtain the thermodynamic potential directly from the corresponding extremum conditions (gap equations) by integrating them, an integration constant being fixed in accordance with the Stefan–Boltzmann law. The advantage of the approach is that the regulator is kept finite both in divergent and finite valued integrals at finite temperature and chemical potential. The Pauli–Villars regularization is used, although a standard 3D sharp cutoff can be applied as well.
ENTROPIC INFLATION
Authors: EASSON DAMIEN A. , FRAMPTON PAUL H. , SMOOT GEORGE F.
Published: April 2012

One of the major pillars of modern cosmology theory is a period of accelerating expansion in the early universe. This accelerating expansion, or inflation, must be sustained for at least 30 e-foldings. One mechanism used to drive the acceleration is the addition of a new energy field, called the inflaton; often this is a scalar field. We propose an alternative mechanism which, like our approach to explain the late-time accelerating universe, uses the entropy and temperature intrinsic to information holographically stored on a surface enclosing the observed space. The acceleration is due in both cases to an emergent entropic force, naturally arising from the information storage on the horizon.
DISFLUENCY DETECTION ON SPONTANEOUS SPEECH USING LEARNING CELLULAR AUTOMATA
Authors: KHEYRANDISH MOHAMMAD , SETAYESHI SAEED , RAHMANI AMIR MASOUD
Published: April 2012

Speech recognition is an efficient tool for interacting between human and machines; but the speech includes some undesirable components (disfluencies), sometimes, and is called spontaneous speech in these cases. This paper focuses on detecting some simple disfluencies in this speech type, using a Learning Cellular Automata. This is a set of cells that each is a learning automata (LA), and selects an action with a determined probability. Each LA is assigned to a word of the speech transcription sentence, and the action set for each LA includes four simple disfluencies types and "Fluent". The environment considered for interacting with cells, evaluates the action selected by each cell in every step, and sends back a response to the LA. That response will be considered for rewarding or penalizing the selected type. Because of parallel operation by the cells, and by selecting appropriate values for rewarding and penalizing coefficients, the proposed model can reach a desirable performance for tagging the disfluencies, regarding the time consumption and precision.
OPEN-EYED ONE-LEG STANDING BALANCE TIME ON INTACT LEG OF HOSPITALIZED ELDERLY LEG FRACTURE PATIENTS: ASSOCIATION WITH AND PREDICTOR OF LOCOMOTIVE ABILITY AND LIVING PLACE AFTER HOSPITAL DISCHARGE
Authors: Konagi Tanaka , Takashi Ohe , Kosuke Uehara
Published: April 2012

Open-eyed one-leg balance (OLB) time on the intact leg of patients aged 65+, hospitalized with leg fracture was measured once a week from start of rehabilitation until discharge to estimate association between OLB time and changes of locomotive ability and post-discharge living place. Patients were in three groups: Group A, OLB time of at least 1 s at all measurements, Group B, OLB under 1 s at first, but 1 s or more by time of discharge, and Group C, OLB under 1 s throughout hospitalization. Patients in Groups A and B showed no significant differences in gait performance or rate of returning home after discharge, but both Groups A and B had better gait ability, and significantly higher rates of home return than Group C. Better OLB time, even only for intact leg, associated significantly with better gait performance and higher home return rate. OLB training is known to increase muscle power, bone mineral density, and balance, and is recommended in the concept of "locomotive syndrome". We considered that increasing OLB time might improve gait ability and probability of returning home after hospital discharge. This could be an effective counterplan against increasing cost for nursing care of elderly people.
A PERSISTENT MEDIAN ARTERY AND BIFID MEDIAN NERVE IN THE SETTING OF CARPAL TUNNEL SYNDROME
Authors: Lee Spangler M. , Almusa Emad , Britton Cynthia
Published: April 2012

We present a case of bifid median nerve and a persistent median artery presenting in the setting of carpal tunnel syndrome. The importance of these anatomic variants and their imaging features and workup are discussed.
THE STABILITY SPECTRUM FOR CLASSES OF ATOMIC MODELS
Authors: BALDWIN JOHN T. , SHELAH SAHARON
Published: April 2012

We prove two results on the stability spectrum for Lω1,ω. Here [Formula: see text] denotes an appropriate notion (at or mod) of Stone space of m-types over M. (1) Theorem for unstable case: Suppose that for some positive integer m and for every α < δ(T), there is an M ∈ K with [Formula: see text]. Then for every λ ≥ |T|, there is an M with [Formula: see text]. (2) Theorem for strictly stable case: Suppose that for every α < δ (T), there is Mα ∈ K such that λα = |Mα| ≥ ℶα and [Formula: see text]. Then for any μ with μℵ0 > μ, K is not i-stable in μ. These results provide a new kind of sufficient condition for the unstable case and shed some light on the spectrum of strictly stable theories in this context. The methods avoid the use of compactness in the theory under study. In this paper, we expound the construction of tree indiscernibles for sentences of Lω1,ω. Further we provide some context for a number of variants on the Ehrenfeucht–Mostowski construction.
A DECADE AFTER THE FIRST FULL HUMAN GENOME SEQUENCING: WHEN WILL WE UNDERSTAND OUR OWN GENOME?
Authors: EISENHABER FRANK
Published: April 2012

The contrast between the pomp of celebrating the first full human genome sequencing in 2000 and the cautious tone of recollections a decade thereafter could hardly be greater. The promises with regard to medical cures and biotechnology applications have been realized not even nearly to the expectations. Understanding the human genomes means knowing the genes' and proteins' functions and their interconnectedness via biomolecular mechanisms. This articles estimates how long will it take to achieve this goal if we extrapolate from the previous decade (indeed, a century!) and the possible disruptive trends in science, technology and society that may accelerate the pace of progress dramatically.
China's Politics: Preparing for Leadership Reshuffling and Maintaining Status Quo
Authors: ZHENG Yongnian , CHEN Gang , LYE Liang Fook
Published: April 2012

In 2011, the Chinese government overcame a string of challenges ranging from inflation and corruption to social unrest. However, the government's soaring fiscal revenue in the aftermath of a global financial crisis has sparked a domestic backlash of guofu minqiong (the state is rich, the people are poor). The Chinese Communist Party on the other hand has been busy reshuffling Party and administrative officials at various levels to prepare for leadership succession at the 18th Party Congress in 2012.
China's Coming Central Military Commission: Leadership Change and Political Implications
Authors: BO Zhiyue
Published: April 2012

China's Central Military Commission (CMC) will witness another round of generational change at the forthcoming Eighteenth National Congress of the Chinese Communist Party in 2012. Hu Jintao and Xi Jinping would remain top leaders of the CMC and seven members are likely to be replaced. Although the new military leadership is unlikely to alter civil-military relationship, the emergence of princeling generals would tip the balance in favour of the gun.
PERFORMANCE EVALUATION OF CASCADE REFRIGERATION SYSTEMS USING DIFFERENT REFRIGERANTS
Authors: MESSINEO ANTONIO , PANNO DOMENICO
Published: April 2012

Due to the negative effects of synthetic refrigerants on the environment, natural refrigerants have obtained again interest as alternative refrigerants for different applications because of their zero ODP and negligible GWP. This paper presents a thermodynamic analysis of different two-stage cascade refrigeration systems using as refrigerant carbon dioxide (R744) in low-temperature circuit, and, respectively, ammonia (R717), propane (R290), butane (R600), R404A, R410A and R134a in high-temperature circuit. The operating parameters considered in this study include condensing and evaporating temperatures in high-temperature circuit, temperature difference in the cascade heat exchanger, and evaporating and condensing temperatures in the low-temperature circuit. The results obtained show that a cascade refrigeration system using natural refrigerants is an interesting alternative to systems using synthetic refrigerants for energetic, security and environmental reasons.
Experimental and Analytical Characterization of Dual-Gated Germanium Junctionless p-Channel Metal–Oxide–Semiconductor Field-Effect Transistors
Authors: Zhao Dan Dan , Lee Choong Hyun , Nishimura Tomonori , Nagashio Kosuke , Cheng Guo An , Toriumi Akira
Published: April 2012

The operation of germanium (Ge) dual-gated junctionless p-channel field-effect transistors (DG JL pFETs) is demonstrated. The top-gated hole mobility is approximately 120 cm2·V-1·s-1, which is close to the bulk mobility of p-type Ge with a doping concentration of 1019 cm-3. The mobility has a weak hole density dependence and increases by applying a negative bottom gate voltage. In addition, simple analytical expressions for both the current–voltage characteristics and the threshold voltage in the linear region of the DG JL pFET are described. The result shows that normally-off Ge DG JL pFETs are achievable. Furthermore, the threshold voltage variation due to the random dopant number fluctuations in the channel is also discussed, which indicates that it can be reduced by decreasing the Ge and oxide thicknesses.
Channel Strain Measurement in 32-nm-Node Complementary Metal–Oxide–Semiconductor Field-Effect Transistor by Raman Spectroscopy
Authors: Takei Munehisa , Hashiguchi Hiroki , Yamaguchi Takuya , Kosemura Daisuke , Nagata Kohki , Ogura Atsushi
Published: April 2012

We performed a strain analysis of a 32-nm-node microprocessing unit by Raman spectroscopy in conjunction with transmission electron microscopy. The channel surface was exposed by chemical etching and mechanical polishing for Raman spectroscopy. Some defects and Ge concentration variation were observed in embedded SiGe of a p-channel metal–oxide–semiconductor field-effect transistor (pMOSFET). Uniform defects lying at the same angle were observed in the source and drain regions of an n-channel MOSFET (nMOSFET). From the Raman measurement, the Raman peak from strained Si in the pMOSFET shifted toward a higher frequency at approximately 7.5 cm-1, which corresponds to -3.75 GPa (compressive) under the assumption of uniaxial stress along the channel direction. On the other hand, the Raman peak shift from strained Si in the nMOSFET was -1.7 cm-1corresponding to 0.85 GPa (tensile) under the assumption of uniaxial stress. From the nanobeam diffraction measurements, the compressive strain at the channel edge was larger than that at the channel center in the pMOSFET. On the other hand, the tensile strain in the nMOSFET was induced uniformly in the channel region. We think that understanding and control of channel strain introduction are indispensable in the state-of-the-art complementary MOSFET technology.
Estimation of Breakdown Electric-Field Strength While Reflecting Local Structures of SiO2 Gate Dielectrics Using First-Principles Molecular Orbital Calculation Technique
Authors: Seki Hiroshi , Shibuya Yasuhiro , Kobayashi Daisuke , Nohira Hiroshi , Yasuoka Kenji , Hirose Kazuyuki
Published: April 2012

To achieve metal–oxide–semiconductor field-effect transistors (MOSFETs) with high reliability, it is important to investigate the dielectric breakdown of gate oxide films of MOSFETs. It is known that dielectric breakdown is usually due to the presence of defects in films. Estimating the breakdown electric-field strength while reflecting local structures such as defects is important for investigation of the reliability of gate SiO2 films. In this study, we introduce the “recovery rate”, which is a parameter potentially capable of estimating the breakdown electric-field strength while reflecting the local structures of the film. The recovery rate has a strong correlation with the breakdown electric-field strength of bulk Si and Al compounds. Using this correlation, we estimate the breakdown electric-field strength of SiO2 with oxygen vacancies and strains.
Postannealing Effects on Strain/Crystal Quality of Lateral Source Relaxed/Strained Layer Heterostructures Fabricated by O+ Ion Implantation
Authors: Mizuno Tomohisa , Takehi Juria , Tanabe Shou
Published: April 2012

We have experimentally studied postannealing effects on the relaxation rate of strain and crystal quality of a lateral relaxed/strained heterostructure layer after the O+ ion implantation process. We have demonstrated the critical annealing temperature as well as the critical recoil energy E
R of implanted O+ ions for relaxing the strained layers, using UV-Raman spectroscopy. Moreover, we have shown that the crystal quality increases with increasing postannealing temperature, and high-resolution transmission electron microscopy (HRTEM) images of the cross sections and plane views of the O+-ion-implanted strained-Si layers also show the high crystal quality. Moreover, we have observed a threading dislocation of about 15 nm length between high-quality lateral abrupt-relaxed/strained layer heterostuctures, and the threading dislocation area is a stress buffer layer to form the abrupt lateral-strain distribution.
Design of Thin-Body Double-Gated Vertical-Channel Tunneling Field-Effect Transistors for Ultralow-Power Logic Circuits
Authors: Sun Min-Chul , Kim Sang Wan , Kim Hyun Woo , Kim Garam , Kim Hyungjin , Lee Jong-Ho , Shin Hyungcheol , Park Byung-Gook
Published: April 2012

A structure of a tunneling field-effect transistor (TFET) featuring an extremely thin body, a double-gated vertical channel, and a source design to maximize the drive current is proposed and optimized on the basis of technology computer-aided design (TCAD) simulation. The field-coupling effect at the double-gated thin-body channel and an engineered tunneling barrier are implemented to maximize the operation current of the device. Weak current drivability under a small drain bias and the directionality of current flow are the expected challenges in building logic circuits with TFETs. A co-integration scheme to build vertical-channel TFETs and metal–oxide–semiconductor field-effect transistors (MOSFETs) is proposed as the solution. A new low-power design using the co-integration scheme is suggested.
Nanowire-Width and Dopant-Species Dependences of Carrier Transport Characteristics of Schottky Barrier Source/Drain Nanowire Field-Effect Transistors
Authors: Ishikawa Takayuki , Saitoh Masumi , Ota Kensuke , Tanaka Chika , Numata Toshinori
Published: April 2012

Schottky barrier (SB) source/drain (S/D) nanowire field-effect transistors (FETs) were fabricated with lateral silicidation process, and their nanowire-width and dopant-species dependences were investigated systematically by means of electrical characterization and physical analyses. Carrier transport characteristics of these nanowire FETs showed a nanowire-width dependence and its dependence varied among dopant species. The degree of the lateral silicidation process also showed nanowire-width and dopant-species dependences. We found that the carrier transport mechanisms depending on S/D dopant species and nanowire width can be attributed to the difference of the lateral silicidation progress.
Advantages of Silicon Nanowire Metal–Oxide–Semiconductor Field-Effect Transistors over Planar Ones in Noise Properties
Authors: Feng Wei , Hettiarachchi Ranga , Sato Soshi , Kakushima Kuniyuki , Niwa Masaaki , Iwai Hiroshi , Yamada Keisaku , Ohmori Kenji
Published: April 2012

We have investigated the low-frequency noise behavior of silicon nanowire metal–oxide–semiconductor field-effect transistors (NWFETs) by comparison with that of a planar FET. We have found that the NWFET exhibits lower noise intensity than the planar FET. By analyzing the factors influential to noise intensity, one of the most possible origins of this advantage of the NWFET results from the electron distribution in the channel in NWFET. Owing to quantum confinement, the position of charge-centroids in the channel of NWFET is located further from the interface, resulting in the lower trapping probability between the electrons and oxide traps. These results clearly demonstrate the advantage of three-dimensional structures in static and noise properties.
Zero Additional Process, Local Charge Trap, Embedded Flash Memory with Drain-Side Assisted Erase Scheme Using Minimum Channel Length/Width Standard Complemental Metal–Oxide–Semiconductor Single Transistor Cell
Authors: Miyaji Kousuke , Shinozuka Yasuhiro , Takeuchi Ken
Published: April 2012

This paper proposes for the first time the completely complemental metal–oxide–semiconductor (CMOS) compatible embedded flash memory with the small cell size as well as the lowest process cost. The single transistor cell with the minimum channel length and width realizes the ideal smallest cell. The non-volatile memory operation is realized with locally injected electrons at the drain-edge by the hot electron injection. This paper also proposes the novel forward-bias assisted erase. The proposed memory is experimentally demonstrated with the 65 nm standard CMOS process without additional process or mask. The cell size is 10F2 with the 65 nm CMOS logic design rule. The excellent reliability such as 100-times program/erase endurance, 10-year data retention and high immunity to the read/program/erase disturb is also experimentally demonstrated. The proposed cell is the ideal candidate for the code-storage embedded non-volatile memories in system-on-chip and microcontroller unit.
Reset Current Reduction with Excellent Filament Controllability by Using Area Minimized and Field Enhanced Unipolar Resistive Random Access Memory Structure
Authors: Ryoo Kyung-Chang , Oh Jeong-Hoon , Jung Sunghun , Jeong Hongsik , Park Byung-Gook
Published: April 2012

We firstly propose a novel resistive random access memory (RRAM) cell structure, which makes it possible to minimize the switching area and to maximize the electrical field where resistive switching occurs, resulting in the improvement of resistive switching characteristics. With excellent structural advantages, resistive switching characteristics such as reset current and set voltage fluctuation are improved through the enhancement of conductive filament (CF) controllability. A simple fabrication process is delivered and the device performance from the viewpoints of the forming voltage, set voltage, and reset current is investigated. Conducting defect effects are also investigated in comparison with the conventional RRAM cell structure. Numerical simulation is performed using a random circuit breaker (RCB) model to confirm the proposed structure.
Complementary Metal Oxide Semiconductor Compatible Hf-Based Resistive Random Access Memory with Ultralow Switching Current/Power
Authors: Zhang Feifei , Li Xiang , Gao Bin , Chen Bing , Huang Peng , Fu Yihan , Chen Yuansha , Liu Lifeng , Kang Jinfeng , Singh Navab , Guo-Qiang Lo , Kwong Dim-Lee
Published: April 2012

Although Resistive random access memory (RRAM) is a promising alternative for next-generation nonvolatile memory, it still suffers from high switching current/power, resulting in large selectors that are normally in series with resistive devices. In this paper, a novel Dynamic random access memory (DRAM) like one-transistor–one-resistor (1T1R) structure is proposed, in which the source/drain of the transistor also serves as the bottom electrode of the RRAM device. Complementary metal oxide semiconductor (CMOS) compatible Hf-based Si/HfO2/TiN RRAM devices were fabricated and ultralow switching current/power was obtained. The set/reset current can be as low as 50 nA/1.25 nA. The programming power for set and reset is only 18 µW and 1.625 nW, respectively. The mechanism of both Schottky emission and electronic hopping via oxygen vacancy defects is proposed to explain the measured resistive switching characteristics.
Excellent Uniformity and Multilevel Operation in Formation-Free Low Power Resistive Switching Memory Using IrOx/AlOx/W Cross-Point
Authors: Banerjee Writam , Rahaman Sk. Ziaur , Maikap Siddheswar
Published: April 2012

Excellent uniformity and multilevel operation in formation-free low-power resistive switching memory fabricated using the IrO
x
/AlO
x
/W cross-point structure have been investigated. The thickness of the deposited films has been measured by high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy for each layer. The cross-point resistive switching memory devices have a tight distribution of SET/RESET voltages and low/high-resistance states as well as switching cycles. A high resistance ratio of >8×102 is obtained. This memory device shows excellent AC endurance of >5×103 cycles, read endurance of >1×105 cycles, and 10-year-data retention at 85 °C at a low power of 55 µW and low-current compliances of 50–200 µA. This study is not only important for cross-point memories but will also help in the design of high-density nanoscale nonvolatile memories in the future.
Record Resistance Ratio and Bipolar/Unipolar Resistive Switching Characteristics of Memory Device Using Germanium Oxide Solid Electrolyte
Authors: Rahaman Sheikh Ziaur , Maikap Siddheswar , Ray Samit Kumar , Lee Heng-Yuan , Chen Wei-Su , Chen Frederick T. , Kao Ming-Jer , Tsai Ming-Jinn
Published: April 2012

The bipolar and unipolar resistive switching characteristics of a memory device using a Cu filament in a new Cu/GeO
x
/W structure under low-voltage operation (<1.5 V) have been investigated. The germanium oxide (GeO
x
) solid electrolyte with a thickness of approximately 12 nm has been observed by both high-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy analyses. A small device size of 150×150 nm2 has been observed by HRTEM. The composition of Ge:O has been investigated by X-ray photoelectron spectroscopy analysis. The memory device shows bipolar switching under current compliances of 1 nA–50 µA with a large SET voltage of approximately 0.5 V and unipolar switching with a larger current compliance of >100 µA. This memory device has excellent uniformity in SET/RESET voltages, low resistance state/high resistance state (LRS/HRS), long read endurance of >1×105 cycles, and good data retention of >1×104 s with high resistance ratios of >105 in the bipolar mode and >109 in the unipolar mode.
Electrical Property of DNA Field-Effect Transistor: Charge Retention Property
Authors: Matsuo Naoto , Takagi Shyogo , Yamana Kazushige , Heya Akira , Takada Tadao , Yokoyama Shin
Published: April 2012

We discovered the charge retention property of the field-effect transistor (FET) in a Si gate/SiO2/DNA channel structure. The DNA FET with the Si source and drain showed hole conduction, and the drain current was controlled by the gate voltage application. In addition, the experimental results that currents similar to the space change limited currents (SCLCs) and hysteresis were observed in the drain current–drain voltage (I
d–V
d) characteristics indicate that the negative charges captured at the trap sites in the DNA enhance the hole currents. Also, the drain currents increased as the repetition number of the measurement increased. However, by inserting the refresh process of gate voltage application of -50 V between each measurement, the current increase was restrained. This phenomenon indicates that the trap and detrap process of electrons occurs in the DNA channel depending on the gate voltage application. The charge retention mechanism was also discussed.
Effect of Oxidation Amount on Gradual Switching Behavior in Reset Transition of Al/TiO2-Based Resistive Switching Memory and Its Mechanism for Multilevel Cell Operation
Authors: Oh Jeong-Hoon , Ryoo Kyung-Chang , Jung Sunghun , Park Yongjik , Park Byung-Gook
Published: April 2012

To analyze and explain the gradual reset switching property of the bipolar switching resistive random access memory (RRAM) for multilevel cell (MLC) operation, the effect of the amount of plasma oxidation on the gradual reset switching behavior of the Al/TiO2-based RRAM cell structure is investigated. The device that undergoes plasma oxidation in a shorter time has a better ON/OFF current (I
ON/I
OFF) ratio and shows increased ON current (I
ON). The device that undergoes long plasma oxidation occasionally shows the step reset switching behavior because of the thick conductive filament formation in the ON state. This is clearly explained by the different conduction mechanisms during the ON state.
Manipulation of Dispersed Magnetic Beads for On-Chip Immunoassay
Authors: Ishikawa Tomohiro , Lee Jaesung , Miyake Ryo
Published: April 2012

To provide a simple and low-cost mobile immunoassay platform, a test chip on which dispersed magnetic beads are manipulated was designed and fabricated by a 180 nm standard complementary metal–oxide–semiconductor (CMOS) process. In preliminary experiments, beads that have a diameter of 2.8 µm were successfully manipulated and their motion were captured and analyzed. Then, an immunoassay was conducted on the chip. First, the nonspecific binding of hydrophilic beads coated with an antibody was compared with that of hydrophobic beads that were used for the preliminary experiments. Next, comparison of an immunoassay of mouse IgG with a control assay and a test on the feasibility of the blocking process were conducted simultaneously. The beads coated with the antibody were successfully immobilized onto the chip surface in the presence of the target antigen, which was checked through bead manipulation. This indicates that an immunoassay on an inexpensive CMOS chip is feasible using an affordable amount of driving current.
Multicore Large-Scale Integration Lifetime Extension by Negative Bias Temperature Instability Recovery-Based Self-Healing
Authors: Matsumoto Takashi , Makino Hiroaki , Kobayashi Kazutoshi , Onodera Hidetoshi
Published: April 2012

We propose a multicore large-scale integration (LSI) lifetime extension method, which is based on negative bias temperature instability (NBTI) recovery-based self-healing and circuit parallelization. NBTI recovery is characterized by the recently proposed NBTI sensor with 400 ns measurement delay that measures the off-leak current of p-channel metal–oxide–semiconductor (PMOS) transistors. The circuit is fabricated in a commercial 65 nm complementary MOS (CMOS) technology. It is found that the recoverable component of the LSI performance characterized by the off-leak current remains almost constant after repeatedly adding NBTI stress. The NBTI stress corresponds to circuit operation for several years at room temperature and a nominal operating voltage. It is also found that the amount of NBTI recovery can be tuned by the relaxation time in a real application, and it follows log
t from 400 ns to 3000 s. It is shown that for multicore LSI, by recovering one of the n + 1 cores, the n-core LSI system does not stop and the lifetime can be extended by NBTI recovery. For the first time, transforming silicon area into LSI reliability is shown to be a promising and realistic concept for the ever-shrinking CMOS technology.
0.1 V 13 GHz Transformer-Based Quadrature Voltage-Controlled Oscillator with a Capacitor Coupling Technique in 90 nm Complementary Metal Oxide Semiconductor
Authors: Kamimura Tatsuya , Lee Sang-yeop , Tanoi Satoru , Ito Hiroyuki , Ishihara Noboru , Masu Kazuya
Published: April 2012

A low power-supply voltage and high-frequency quadrature voltage-controlled oscillator (QVCO) using a combination of capacitor coupling and transformer feedback techniques is presented. The capacitor coupling technique can boost the transconductance of the LC-VCO core and coupling transconductance of QVCO at high frequency. Also, this technique can improve the quality factor of the QVCO at high frequency with low power-supply voltage, compared with the conventional QVCO. In addition, the capacitor coupling QVCO with transformer feedback can improve the quality factor of QVCO. Using this topology, the QVCO is able to operate at over 10 GHz with lower power-supply voltage. Implemented in the 90 nm complementary metal oxide semiconductor (CMOS) process, the proposed QVCO measures 1-MHz-offset phase noise of -94 dBc/Hz at 13 GHz while consuming 0.68 mW from a 0.1 V power-supply.
Postfabrication Independent Inductance and Quality Factor Adjustments of On-Chip Inductors by Above-CMOS Processing for Rapid Prototyping of Radio Frequency System on Chips
Authors: Sasaki Yuki , Kotani Koji
Published: April 2012

The flexible adjustment of on-chip inductor characteristics after a regular complementary metal–oxide–semiconductor (CMOS) fabrication was realized by the “above-CMOS” processing technology for radio frequency (RF) system-on-a-chip (SoC) rapid prototyping. It is shown that the above-CMOS metal pattern formation in a chip-by-chip manner can both increase and decrease the inductance (L) values of on-chip inductors. It is realized by applying various planar patterns of a metal layer deposited on the passivation layer of the chip. To increase the modification range of the characteristics and to establish an independent L and quality factor (Q) adjustment scheme, we have newly developed a pre-design method and a Q-compensation method. By combining these methods, the effective L and Q values of the on-chip inductors can be independently and arbitrarily modified. The adjustment of the input impedance matching frequency of a low-noise amplifier (LNA) using this scheme has also been demonstrated.
Wireless Charge Based Capacitance Measurement Circuits with On-Chip Spiral Inductor for Radio Frequency Identification Biosensor
Authors: Kim Boram , Uno Shigeyasu , Nakazato Kazuo
Published: April 2012

A wireless measuring system of charge based capacitance measurement (CBCM) circuit has been designed and demonstrated for biomedical applications. The radio frequency identification (RFID) chip that includes on-chip spiral inductor tag antenna, and RFID circuit, and CBCM sensor chip are fabricated within standard complementary metal oxide semiconductor (CMOS) process. The capacitance change caused by DNA detection can be converted into the voltage output using capacitance-to-voltage conversion circuit. To confirm the transmission of the capacitance, the poly-capacitor of fixed capacitance and on-chip spiral inductor tag antenna were fabricated using 1.2 µm, 2-metal, 2-poly CMOS technology. As a result of measurement, three different capacitances (34, 141, 564 fF) were detected wirelessly.
An Integrated Amorphous Silicon Gate Driver Circuit Using Voltage-Controlled Capacitance Modeling for High Definition Television
Authors: Han Sang-Kug , Choi Hoon , Moon Kyo-Ho , Choi Young-Seok , Jeong Kyung-Deuk , Park Kwang-Mook , Choi Sie-Young
Published: April 2012

We have developed the integrated amorphous silicon gate driver circuit using the model extraction technique of the inverted staggered and nonsymmetric amorphous silicon (a-Si) thin film transistor. The relation between capacitance characteristics of hydrogenated a-Si (a-Si:H) integrated transistors and the output signal of the gate driver circuit is analyzed using UTMOST IV ver. 1.6.4.R and SMARTSPICE ver. 3.19.15.C. The accuracy of the simulated gate output signal using voltage-controlled capacitance modeling is verified with measured data. The a-Si gate driver circuit using the proposed (TFT) model increased the accuracy of rising (95.3%) and falling (92%) time, compared to the conventional model. The suggested model extraction technique can be used for bottom gate and asymmetric TFT structures.
Fully Parallel Self-Learning Analog Support Vector Machine Employing Compact Gaussian Generation Circuits
Authors: Zhang Renyuan , Shibata Tadashi
Published: April 2012

An analog support vector machine (SVM) processor employing a fully parallel self-learning circuitry was developed for the classification of highly dimensional patterns. To implement a highly dimensional Gaussian function, which is the most powerful kernel function in classification algorithms but computationally expensive, a compact analog Gaussian generation circuit was developed. By employing this proposed Gaussian generation circuit, a fully parallel self-learning processor based on an SVM algorithm was built for 64 dimension pattern classification. The chip real estate occupied by the processor is very small. The object images from two classes were converted into 64 dimension vectors using the algorithm developed in a previous work and fed into the processor. The learning process autonomously proceeded without any clock-based control and self-converged within a single clock cycle of the system (at 10 MHz). Some test object images were used to verify the learning performance. According to the circuit simulation results, it was shown that all the test images were classified into correct classes in real time. A proof-of-concept chip was designed in a 0.18 µm complementary metal–oxide–semiconductor (CMOS) technology, and the performance of the proposed SVM processor was confirmed from the measurement results of the fabricated chips.
Schottky Source/Drain InAlN/GaN Metal–Insulator–Semiconductor High-Electron-Mobility Transistor with High Breakdown Voltage and Low On-Resistance
Authors: Zhou Qi , Chen Hongwei , Zhou Chunhua , Feng Zhihong , Cai Shujun , Chen Kevin J.
Published: April 2012

In this work, we present a novel device technology of using Schottky source/drain (SSD) in InAlN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MISHEMTs) for off-state breakdown voltage V
BD improvement. The Schottky source/drain design can effectively prevent the source carrier injection compared to the conventional MISHEMTs, leading to enhanced V
BD in the SSD MISHEMTs. A V
BD of 460 V is obtained in an InAlN/GaN SSD MISHEMTs with low specific R
on of 2.27 mΩ·cm2, at a 170% V
BD improvement compared to conventional MISHEMTs. Despite the Schottky source/drain used, a SSD MISHEMT with a gate length of 1 µm exhibits respectable drain current density of 416 mA/mm and transconductance of 113 mS/mm.
Large Area of Ultraviolet GaN-Based Photonic Quasicrystal Laser
Authors: Chen Cheng-Chang , Chiu Ching-Hsueh , Tu Po-Min , Kuo Ming-Yen , Shih M. H. , Huang Ji-Kai , Kuo Hao-Chung , Zan Hsiao-Wen , Chang Chun-Yen
Published: April 2012

In this study, large-area GaN-based photonic quasicrystal (PQC) nanopillars were fabricated on an n-GaN substrate using the nanoimprint lithography (NIL) technique. Under optical pumping condition, a high lasing action from the GaN photonic quasicrystals was observed. The lasing wavelength is at 366 nm with a low threshold power density of 0.009 kW/cm2. To confirm the band-edge lasing mode, the finite-element method (FEM) was used to perform the simulation for the 12-fold symmetry photonic quasicrystal lattices.
Femtosecond Laser-Excited Two-Photon Fluorescence Microscopy of Surface Plasmon Polariton
Authors: Hattori Tatsumi , Kubo Atsushi , Oguri Katsuya , Nakano Hidetoshi , Miyazaki Hideki T.
Published: April 2012

We demonstrate microscopic imaging of surface plasmon polaritons (SPPs) on silver films excited by 11 fs near-infrared laser pulses. A fluorescence layer placed on the silver film converts surface electromagnetic fields to propagating lights in visible wavelengths via two-photon excitation process. The wavelength of SPP determined from fluorescence micrographs agrees well with the calculated value of SPP at the silver-fluorescent film interface.
Terahertz Radiation from a (113)B GaAs/AlAs Coupled Multilayer Cavity Generated by Ultrashort Laser Pulse Excitation
Authors: Katoh Sho , Takimoto Toshikazu , Nakagawa Yoshinori , Morita Ken , Kitada Takahiro , Isu Toshiro
Published: April 2012

Terahertz (THz) radiation was demonstrated using a GaAs/AlAs coupled multilayer cavity grown on a (113)B GaAs substrate. Two cavity modes realized in the high-reflection band were simultaneously excited using ultrashort laser pulses for the difference frequency generation (DFG). Oscillations with a period of 0.3 ps were clearly observed in the temporal waveforms of time-resolved THz measurements. The oscillation period well agreed with the difference frequency between the two cavity modes (3.3 THz). We also measured the THz waveforms depending on the polarization direction of the excitation laser pulses, and the anisotropic signal amplitudes also agreed with the calculated anisotropy of the second-order nonlinear polarization on the (113)B GaAs substrate.
Improving Optical Properties of Ge Layers Fabricated by Epitaxial Growth Combined with Ge Condensation
Authors: Oda Katsuya , Tani Kazuki , Saito Shin-ichi , Okumura Tadashi , Ido Tatemi
Published: April 2012

Single crystal Ge layers were successfully fabricated on the buried oxide layer of a silicon-on-insulator wafer using a combined technique of two-step selective epitaxial growth and Ge condensation. X-ray diffraction measurements revealed that the single crystal Ge layer formed on the buried oxide layer had a tensile strain of 0.07% on the <110> lattice plane in a large unpatterned area. Furthermore, a steep photoluminescence spectrum was obtained from Ge stripes fabricated on the buried oxide layer, and a red shift in the photoluminescence peak was observed due to tensile strain with a wavelength of 1620 nm. The peak intensity of a 10-mm-wide Ge stripe on the buried oxide layer was three times higher than that on a Ge stripe on an Si substrate, which was achieved by improving the crystallinity and carrier confinement within the Ge stripes. These results indicate that this combined technique efficiently improves the performance of Ge light-emitting devices.
Structural and Luminescence Properties of Highly Crystalline ZnO Nanoparticles Prepared by Sol–Gel Method
Authors: Bousslama Wiem , Elhouichet Habib , Gelloz Bernard , Sieber Brigitte , Addad Ahmed , Moreau Myriam , Férid Mokhtar , Koshida Nobuyoshi
Published: April 2012

ZnO nanoparticles were synthesized using sol–gel method. The structural and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), Raman spectroscopy, and photoluminescence (PL). XRD analysis demonstrates that the nanoparticles have the hexagonal wurtzite structure and the particle size is increased with annealing temperature. The average size of the nanoparticles was determined by SEM as well as XRD data and found to be ∼50 nm after annealing at 800 °C. A sharp, strong and dominant UV emission with a suppressed green emission has been observed at 300 and 10 K, indicating the good optical properties of ZnO nanoparticles. The 10 K UV band is dominated by a neutral-donor bound exciton, and the surface-related SX emission at 3.31 eV is evidenced.
In-Plane Grain Orientation Alignment of Polycrystalline Silicon Films by Normal and Oblique-Angle Ion Implantations
Authors: Nakajima Anri , Kuroki Shin-Ichiro , Fujii Shuntaro , Ito Takashi
Published: April 2012

Random crystallographic orientations of polycrystalline silicon (poly-Si) grains in the films grown on a SiO2 substrate by chemical vapor deposition were laterally aligned by maintaining the 110 restricted pillar texture through double Si+ self-ion implantations. The in-plane X-ray diffraction pattern and rocking curve clearly indicate the lateral alignment. The oblique-angle Si+ self-ion implantation was also found to be useful for increasing the amount of the 110 pillar texture. The electron backscatter diffraction (EBSD) pattern supports the increase in the amount of the 110 pillar texture and the lateral crystal orientation alignment. The transmission electron micrography and EBSD results also suggest that grain size is increased by double Si+ self-ion implantations. Although further systematic optimization may be required, the technique will be useful for improving the electrical characteristics of poly-Si devices for future electronic systems on insulators.
Room-Temperature Fabrication of HfON Gate Insulator for Low-Voltage-Operating Pentacene-Based Organic Field-Effect Transistors
Authors: Liao Min , Ishiwara Hiroshi , Ohmi Shun-ichiro
Published: April 2012

Low-voltage-operating pentacene-based organic field-effect transistors (OFETs) with different channel lengths have been fabricated by employing a room-temperature-processed HfON gate insulator. It was found that the on/off current ratio of the OFETs can be improved by decreasing the channel length. However, the hole mobility in the OFETs decreases with decreasing channel length owing to the effect of contact resistance. Interestingly, such OFETs with a short channel length (channel W/L = 500/50 µm) also show good electrical properties, such as a high hole mobility of 0.26 cm2 V-1 s-1, a low subthreshold swing of 0.13 V/decade, and a large on/off current ratio of 1×105 at an operating voltage of -2 V.