6,818 research outputs found
Integration and Growth in East Asia
This paper empirically analyzes the experience of East Asiafs economic growth with data both at aggregate-economy and micro-firm levels, focusing on the role of international integration through trade and direct investment. The analysis within a framework of cross-country panel regression shows that trade openness and foreign direct investment (FDI) inflows have a positive effect on gross domestic product (GDP) growth? particularly in the 1970 and 1980s?while FDI outflows appear to have a negative effect on GDP growth. Micro-level evidence based on manufacturing data in the Republic of Korea (Korea) confirms the positive effect of trade and investment integration on plant-level productivity growth. It also suggests the relationship between FDI outflows and productivity growth depends on the characteristics of a recipient economy. We find that FDI to the Peoplefs Republic of China tends to reduce productivity growth of firms in Korea while FDI to the United States or Japan works in favor of productivity growth.integration, growth, trade, foreign direct investment, East Asia
Evidence for ion irradiation induced dissociation and reconstruction of Si-H bonds in hydrogen-implanted silicon
We observe that H-related chemical bonds formed in H-implanted Si will evolve under subsequent ion irradiation. During ion irradiation hydrogen is inclined to dissociate from simple H-related defect complexes (i.e., VHx and IHx), diffuse, and attach to vacancy-type defects resulting in new platelet formation, which facilitate surface blistering after annealing, a process completely inhibited in the absence of ion irradiation. The understanding of our results provides insight into the structure and stability of hydrogen-related defects in silicon. © 2008 American Institute of Physics
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Retrospective model-based inference guides model-free credit assignment
An extensive reinforcement learning literature shows that organisms assign credit efficiently, even under conditions of state uncertainty. However, little is known about credit-assignment when state uncertainty is subsequently resolved. Here, we address this problem within the framework of an interaction between model-free (MF) and model-based (MB) control systems. We present and support experimentally a theory of MB retrospective-inference. Within this framework, a MB system resolves uncertainty that prevailed when actions were taken thus guiding an MF credit-assignment. Using a task in which there was initial uncertainty about the lotteries that were chosen, we found that when participantsâ momentary uncertainty about which lottery had generated an outcome was resolved by provision of subsequent information, participants preferentially assigned credit within a MF system to the lottery they retrospectively inferred was responsible for this outcome. These findings extend our knowledge about the range of MB functions and the scope of system interactions
3D Geometric Analysis of Tubular Objects based on Surface Normal Accumulation
This paper proposes a simple and efficient method for the reconstruction and
extraction of geometric parameters from 3D tubular objects. Our method
constructs an image that accumulates surface normal information, then peaks
within this image are located by tracking. Finally, the positions of these are
optimized to lie precisely on the tubular shape centerline. This method is very
versatile, and is able to process various input data types like full or partial
mesh acquired from 3D laser scans, 3D height map or discrete volumetric images.
The proposed algorithm is simple to implement, contains few parameters and can
be computed in linear time with respect to the number of surface faces. Since
the extracted tube centerline is accurate, we are able to decompose the tube
into rectilinear parts and torus-like parts. This is done with a new linear
time 3D torus detection algorithm, which follows the same principle of a
previous work on 2D arc circle recognition. Detailed experiments show the
versatility, accuracy and robustness of our new method.Comment: in 18th International Conference on Image Analysis and Processing,
Sep 2015, Genova, Italy. 201
In situ 4D tomography image analysis framework to follow sintering within 3D-printed glass scaffolds
We propose a novel image analysis framework to automate analysis of X-ray
microtomography images of sintering ceramics and glasses, using open-source
toolkits and machine learning. Additive manufacturing (AM) of glasses and
ceramics usually requires sintering of green bodies. Sintering causes shrinkage,
which presents a challenge for controlling the metrology of the final architecture.
Therefore, being able to monitor sintering in 3D over time (termed 4D) is important when developing new porous ceramics or glasses. Synchrotron X-ray tomographic imaging allows in situ, real-time capture of the sintering process at both
micro and macro scales using a furnace rig, facilitating 4D quantitative analysis
of the process. The proposed image analysis framework is capable of tracking and
quantifying the densification of glass or ceramic particles within multiple volumes of interest (VOIs) along with structural changes over time using 4D image
data. The framework is demonstrated by 4D quantitative analysis of bioactive
glass ICIE16 within a 3D-printed scaffold. Here, densification of glass particles
within 3 VOIs were tracked and quantified along with diameter change of struts
and interstrut pore size over the 3D image series, delivering new insights on the
sintering mechanism of ICIE16 bioactive glass particles in both micro and macro
scale
Microwave enhanced ion-cut silicon layer transfer
Microwave heating has been used to decrease the time required for exfoliation of thin single-crystalline silicon layers onto insulator substrates using ion-cut processing. Samples exfoliated in a 2.45 GHz, 1300 W cavity applicator microwave system saw a decrease in incubation times as compared to conventional anneal processes. Rutherford backscattering spectrometry, cross sectional scanning electron microscopy, cross sectional transmission electron microscopy, and selective aperture electron diffraction were used to determine the transferred layer thickness and crystalline quality. The surface quality was determined by atomic force microscopy. Hall measurements were used to determine electrical properties as a function of radiation repair anneal times. Results of physical and electrical characterizations demonstrate that the end products of microwave enhanced ion-cut processing do not appreciably differ from those using more traditional means of exfoliation. © 2007 American Institute of Physics
Effect of substrate growth temperatures on H diffusion in hydrogenated Si/Si homoepitaxial structures grown by molecular beam epitaxy
We have investigated hydrogen diffusion in hydrogenated ă100ă Si/Si homoepitaxial structures, which were grown by molecular beam epitaxy at various temperatures. The substrate growth temperature can significantly affect the H diffusion behavior, with higher growth temperatures resulting in deeper H diffusion. For the Si/Si structure grown at the highest temperature of 800°C, H trapping occurs at the epitaxial Si/Si substrate interface, which results in the formation of (100) oriented microcracks at the interface. The mechanism of H trapping and the potential application of these findings for the development of a method of transferring ultrathin Si layers are discussed. © 2006 American Institute of Physics
Detection and tracking volumes of interest in 3D printed tissue engineering scaffolds using 4D imaging modalities.
Additive manufacturing (AM) platforms allow the production of patient tissue engineering scaffolds with desirable architectures. Although AM platforms offer exceptional control on architecture, post-processing methods such as sintering and freeze-drying often deform the printed scaffold structure. In-situ 4D imaging can be used to analyze changes that occur during post-processing. Visualization and analysis of changes in selected volumes of interests (VOIs) over time are essential to understand the underlining mechanisms of scaffold deformations. Yet, automated detection and tracking of VOIs in the 3D printed scaffold over time using 4D image data is currently an unsolved image processing task. This paper proposes a new image processing technique to segment, detect and track volumes of interest in 3D printed tissue engineering scaffolds. The method is validated using a 4D synchrotron sourced microCT image data captured during the sintering of bioactive glass scaffolds in-situ. The proposed method will contribute to the development of scaffolds with controllable designs and optimum properties for the development of patient-specific scaffolds
Properties of 125 GeV Higgs boson in non-decoupling MSSM scenarios
Tantalizing hints of the Higgs boson of mass around 125 GeV have been
reported at the LHC. We explore the MSSM parameter space in which the 125 GeV
state is identified as the heavier of the CP even Higgs bosons, and study two
scenarios where the two photon production rate can be significantly larger than
the standard model (SM). In one scenario, is
enhanced by a light stau contribution, while the () rate
stays around the SM rate. In the other scenario, is
suppressed and not only the but also the
() rates should be enhanced. The rate can be
significantly larger or smaller than the SM rate in both scenarios. Other
common features of the scenarios include top quark decays into charged Higgs
boson, single and pair production of all Higgs bosons in collisions at
GeV.Comment: 20 pages, 5 figures, accepted version for publication in JHE
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