156 research outputs found
A 10Gb/s Full On-chip Bang-Bang Clock and Data Recovery System Using an Adaptive Loop Bandwidth Strategy
As demand for higher bandwidth I/O grows, the front end design of serial link
becomes significant to overcome stringent timing requirements on noisy and bandwidthlimited
channels. As a clock reconstructing module in a receiver, the recovered clock
quality of Clock and Data Recovery is the main issue of the receiver performance.
However, from unknown incoming jitter, it is difficult to optimize loop dynamics to
minimize steady-state and dynamic jitter.
In this thesis a 10 Gb/s adaptive loop bandwidth clock and data recovery circuit
with on-chip loop filter is presented. The proposed system optimizes the loop bandwidth
adaptively to minimize jitter so that it leads to an improved jitter tolerance performance.
This architecture tunes the loop bandwidth by a factor of eight based on the phase
information of incoming data. The resulting architecture performs as good as a
maximum fixed loop bandwidth CDR while tracking high speed input jitter and as good
as a minimum fixed bandwidth CDR while suppressing wide bandwidth steady-state jitter. By employing a mixed mode predictor, high updating rate loop bandwidth
adaptation is achieved with low power consumption. Another relevant feature is that it
integrates a typically large off-chip filter using a capacitance multiplication technique
that employs dual charge pumps.
The functionality of the proposed architecture has been verified through
schematic and behavioral model simulations. In the simulation, the performance of jitter
tolerance is confirmed that the proposed solution provides improved results and
robustness to the variation of jitter profile. Its applicability to industrial standards is also
verified by the jitter tolerance passing SONET OC-192 successfully
Fluorescent and photo-oxidizing TimeSTAMP tags track protein fates in light and electron microscopy.
Protein synthesis is highly regulated throughout nervous system development, plasticity and regeneration. However, tracking the distributions of specific new protein species has not been possible in living neurons or at the ultrastructural level. Previously we created TimeSTAMP epitope tags, drug-controlled tags for immunohistochemical detection of specific new proteins synthesized at defined times. Here we extend TimeSTAMP to label new protein copies by fluorescence or photo-oxidation. Live microscopy of a fluorescent TimeSTAMP tag reveals that copies of the synaptic protein PSD95 are synthesized in response to local activation of growth factor and neurotransmitter receptors, and preferentially localize to stimulated synapses in rat neurons. Electron microscopy of a photo-oxidizing TimeSTAMP tag reveals new PSD95 at developing dendritic structures of immature neurons and at synapses in differentiated neurons. These results demonstrate the versatility of the TimeSTAMP approach for visualizing newly synthesized proteins in neurons
Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature
Transparent electronic materials are increasingly in demand for a variety of
optoelectronic applications. BaSnO3 is a semiconducting oxide with a large band
gap of more than 3.1 eV. Recently, we discovered that La doped BaSnO3 exhibits
unusually high electrical mobility of 320 cm^2(Vs)^-1 at room temperature and
superior thermal stability at high temperatures [H. J. Kim et al. Appl. Phys.
Express. 5, 061102 (2012)]. Following that work, we report various physical
properties of (Ba,La)SnO3 single crystals and films including
temperature-dependent transport and phonon properties, optical properties and
first-principles calculations. We find that almost doping-independent mobility
of 200-300 cm^2(Vs)^-1 is realized in the single crystals in a broad doping
range from 1.0x10^19 to 4.0x10^20 cm^-3. Moreover, the conductivity of ~10^4
ohm^-1cm^-1 reached at the latter carrier density is comparable to the highest
value. We attribute the high mobility to several physical properties of
(Ba,La)SnO3: a small effective mass coming from the ideal Sn-O-Sn bonding,
small disorder effects due to the doping away from the SnO2 conduction channel,
and reduced carrier scattering due to the high dielectric constant. The
observation of a reduced mobility of ~70 cm^2(Vs)^-1 in the film is mainly
attributed to additional carrier-scatterings which are presumably created by
the lattice mismatch between the substrate SrTiO3 and (Ba,La)SnO3. The main
optical gap of (Ba,La)SnO3 single crystals remained at about 3.33 eV and the
in-gap states only slightly increased, thus maintaining optical transparency in
the visible region. Based on these, we suggest that the doped BaSnO3 system
holds great potential for realizing all perovskite-based, transparent
high-frequency high-power functional devices as well as highly mobile
two-dimensional electron gas via interface control of heterostructured films.Comment: 31 pages, 7 figure
Electric field control of nonvolatile four-state magnetization at room temperature
We find the realization of large converse magnetoelectric (ME) effects at
room temperature in a multiferroic hexaferrite
BaSrCoFeO single crystal, in which rapid
change of electric polarization in low magnetic fields (about 5 mT) is coined
to a large ME susceptibility of 3200 ps/m. The modulation of magnetization then
reaches up to 0.62 /f.u. in an electric field of 1.14 MV/m. We find
further that four ME states induced by different ME poling exhibit unique,
nonvolatile magnetization versus electric field curves, which can be
approximately described by an effective free energy with a distinct set of ME
coefficients
Deterministic bead-in-droplet ejection utilizing an integrated plug-in bead dispenser for single bead-based applications
This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads into a dispensing volume and the on-demand ejection of bead-encapsulated droplets. Single bead-encapsulated droplets were ejected every 3 s without any failure. Multiple-bead dispensing with deterministic control of the number of beads was demonstrated to emphasize the originality and quality of the proposed dispensing technique. The dispenser was mounted using a plug-socket type connection, and the dispensing process was completely automated using a programmed sequence without any microscopic observation. To demonstrate a potential application of the technique, bead-based streptavidin-biotin binding assay in an evaporating droplet was conducted using ultralow numbers of beads. The results evidenced the number of beads in the droplet crucially influences the reliability of the assay. Therefore, the proposed deterministic bead-in-droplet technology can be utilized to deliver desired beads onto a reaction site, particularly to reliably and efficiently enrich and detect target biomolecules.112Ysciescopu
Reliability and Validity of the Korean Version of Obsessive-Compulsive Inventory - Revised in a Non-clinical Sample
PURPOSE: The reliability and validity of a Korean version of the Obsessive-Compulsive-Inventory-Revised (OCI-R) was examined in non-clinical student samples.
MATERIALS AND METHODS: The Korean version of OCI-R was administered to a total of 228 Korean college students. The Maudsley Obsessive Compulsive Inventory (MOCI), Beck's Depression Inventory (BDI), and Beck's Anxiety Inventory (BAI) were administered to 228 students.
RESULTS: The total and each of subscale of the Korean OCI-R demonstrated excellent internal consistency, good test-retest reliability, moderate convergent validity and good divergent validity.
CONCLUSION: It was concluded that the Korean version of the OCI-R has strong psychometric properties as the original version.ope
High Mobility in a Stable Transparent Perovskite Oxide
We discovered that La-doped BaSnO3 with the perovskite structure has an
unprecedentedly high mobility at room temperature while retaining its optical
transparency. In single crystals, the mobility reached 320 cm^2(Vs)^-1 at a
doping level of 8x10^19 cm^-3, constituting the highest value among
wide-band-gap semiconductors. In epitaxial films, the maximum mobility was 70
cm^2(Vs)^-1 at a doping level of 4.4x10^20 cm^-3. We also show that resistance
of (Ba,La)SnO3 changes little even after a thermal cycle to 530 Deg. C in air,
pointing to an unusual stability of oxygen atoms and great potential for
realizing transparent high-frequency, high-power functional devices.Comment: 15 pages, 3 figure
A Feasible Technique for Transient Vascular Occlusion by Using a Vessel Loop and Hem-o-Lok Clips in Laparoscopic Partial Nephrectomy
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