22,288 research outputs found
An Investigation of Firm-Level R&D Capabilities in East Asia
This paper uses a survey of 1,826 firms distributed over ten East Asian metropolitan areas – Jakarta, Kuala Lumpur, Manila, Seoul, and five Chinese cities – to investigate the sources of firm-level R&D capabilities. The analysis identifies the impact of 23 survey variables, classified by openness, human capital, R&D network, and institutional quality, on the efficiency of firm R&D operations and on overall firm performance. These firmlevel results are used to construct composite measures R&D capabilities for each of the 10 metropolitan economies. Using the firm samples, returns to R&D are also estimated for each of the metropolitan areas. Where cross economy comparisons are possible, as they are for Seoul and the five Chinese cities, we find a strong association between overall R&D productivity in these city economies and the composite measures of citywide R&D capabilities. In particular, high composite measures in Seoul and Shanghai are associated with high returns to R&D in those cities. The large productivitywage gaps in the Chinese cities appear to be attracting large and visible investment in R&D operations. Whether R&D wages rise to narrow this gap or investment and technology flows continue to sustain the gap will substantially affect the pattern of R&D operations within the Asian region.http://deepblue.lib.umich.edu/bitstream/2027.42/39969/3/wp583.pd
An Investigation of Firm-Level R&D Capabilities in East Asia
This paper uses a survey of 1,826 firms distributed over ten East Asian metropolitan areas – Jakarta, Kuala Lumpur, Manila, Seoul, and five Chinese cities – to investigate the sources of firm-level R&D capabilities. The analysis identifies the impact of 23 survey variables, classified by openness, human capital, R&D network, and institutional quality, on the efficiency of firm R&D operations and on overall firm performance. These firmlevel results are used to construct composite measures R&D capabilities for each of the 10 metropolitan economies. Using the firm samples, returns to R&D are also estimated for each of the metropolitan areas. Where cross economy comparisons are possible, as they are for Seoul and the five Chinese cities, we find a strong association between overall R&D productivity in these city economies and the composite measures of citywide R&D capabilities. In particular, high composite measures in Seoul and Shanghai are associated with high returns to R&D in those cities. The large productivitywage gaps in the Chinese cities appear to be attracting large and visible investment in R&D operations. Whether R&D wages rise to narrow this gap or investment and technology flows continue to sustain the gap will substantially affect the pattern of R&D operations within the Asian region.Research and development, Technology transfer, East Asia
Depression and suicide risk prediction models using blood-derived multi-omics data
More than 300 million people worldwide experience depression; annually, ~800,000 people die by suicide. Unfortunately, conventional interview-based diagnosis is insufficient to accurately predict a psychiatric status. We developed machine learning models to predict depression and suicide risk using blood methylome and transcriptome data from 56 suicide attempters (SAs), 39 patients with major depressive disorder (MDD), and 87 healthy controls. Our random forest classifiers showed accuracies of 92.6% in distinguishing SAs from MDD patients, 87.3% in distinguishing MDD patients from controls, and 86.7% in distinguishing SAs from controls. We also developed regression models for predicting psychiatric scales with R2 values of 0.961 and 0.943 for Hamilton Rating Scale for Depression???17 and Scale for Suicide Ideation, respectively. Multi-omics data were used to construct psychiatric status prediction models for improved mental health treatment
Methane as an effective hydrogen source for single-layer graphene synthesis on Cu foil by plasma enhanced chemical vapor deposition
A single-layer graphene is synthesized on Cu foil in the absence of H2 flow
by plasma enhanced chemical vapor deposition (PECVD). In lieu of an explicit H2
flow, hydrogen species are produced during methane decomposition process into
their active species (CHx<4), assisted by the plasma. Notably, the early stage
of growth depends strongly on the plasma power. The resulting grain size (the
nucleation density) has a maximum (minimum) at 50 W and saturates when the
plasma power is higher than 120 W because hydrogen partial pressures are
effectively tuned by a simple control of the plasma power. Raman spectroscopy
and transport measurements show that decomposed methane alone can provide
sufficient amount of hydrogen species for high-quality graphene synthesis by
PECVD.Comment: 22 pages, 6 figure
A Passivity-based Nonlinear Admittance Control with Application to Powered Upper-limb Control under Unknown Environmental Interactions
This paper presents an admittance controller based on the passivity theory
for a powered upper-limb exoskeleton robot which is governed by the nonlinear
equation of motion. Passivity allows us to include a human operator and
environmental interaction in the control loop. The robot interacts with the
human operator via F/T sensor and interacts with the environment mainly via
end-effectors. Although the environmental interaction cannot be detected by any
sensors (hence unknown), passivity allows us to have natural interaction. An
analysis shows that the behavior of the actual system mimics that of a nominal
model as the control gain goes to infinity, which implies that the proposed
approach is an admittance controller. However, because the control gain cannot
grow infinitely in practice, the performance limitation according to the
achievable control gain is also analyzed. The result of this analysis indicates
that the performance in the sense of infinite norm increases linearly with the
control gain. In the experiments, the proposed properties were verified using 1
degree-of-freedom testbench, and an actual powered upper-limb exoskeleton was
used to lift and maneuver the unknown payload.Comment: Accepted in IEEE/ASME Transactions on Mechatronics (T-MECH
Geography and development
The most striking fact about the economic geography of the world is the uneven spatial distribution of economic activity, including the coexistence of economic development and underdevelopment. High-income regions are almost entirely concentrated in a few temperate zones, half of the world's GDP is produced by 15 percent of the world's population, and 54 percent of the world's GDP is produced by countries occupying just 10 percent of the world's land area. The poorest half of the world's population produces only 14 percent of the world's GDP, and 17 of the poorest 20 nations are in tropical Africa. The unevenness is also manifest within countries and within metropolitan concentrations of activity. Why are these spatial differences in land rents and wages not bid away by firms and individuals in search of low-cost or high-income locations? Why does economic activity cluster in centers of activity? And what are the consequences of remoteness from existing centers? The authors argue that understanding these issues is central for understanding many aspects of economic development and underdevelopment at the international, national, and subcontinental levels. They review the theoretical and empirical work that illuminates how the spatial relationship between economic units changes and conclude that geography matters for development, but that economic growth is not governed by a geographic determinism. New economic centers can develop, and the costs of remoteness can be reduced. Many explicit policy instruments have been used to influence location decisions. But none has been systematically successful, and many have been very costly-in part because they were based on inappropriate expectations. Moreover, many ostensibly nonspatial policies that benefit specific sectors and households have spatial consequences since the targeted sectors and households are not distributed uniformly across space. These nonspatial policies can sometimes dominate explicitly spatial policies. Further work is needed to better understand these dynamics in developing countries.Economic Theory&Research,Decentralization,Labor Policies,Environmental Economics&Policies,Banks&Banking Reform,Banks&Banking Reform,Municipal Financial Management,Health Economics&Finance,Economic Theory&Research,Environmental Economics&Policies
Yet Another Tutorial of Disturbance Observer: Robust Stabilization and Recovery of Nominal Performance
This paper presents a tutorial-style review on the recent results about the
disturbance observer (DOB) in view of robust stabilization and recovery of the
nominal performance. The analysis is based on the case when the bandwidth of
Q-filter is large, and it is explained in a pedagogical manner that, even in
the presence of plant uncertainties and disturbances, the behavior of real
uncertain plant can be made almost similar to that of disturbance-free nominal
system both in the transient and in the steady-state. The conventional DOB is
interpreted in a new perspective, and its restrictions and extensions are
discussed
A Survey of RFID Authentication Protocols Based on Hash-Chain Method
Security and privacy are the inherent problems in RFID communications. There
are several protocols have been proposed to overcome those problems. Hash chain
is commonly employed by the protocols to improve security and privacy for RFID
authentication. Although the protocols able to provide specific solution for
RFID security and privacy problems, they fail to provide integrated solution.
This article is a survey to closely observe those protocols in terms of its
focus and limitations.Comment: Third ICCIT 2008 International Conference on Convergence and Hybrid
Information Technolog
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