26,115 research outputs found
Capabilities' Substitutability and the "S" Curve of Export Diversity
Product diversity, which is highly important in economic systems, has been
highlighted by recent studies on international trade. We found an empirical
pattern, designated as the "S-shaped curve", that models the relationship
between economic size (logarithmic GDP) and export diversity (the number of
varieties of export products) on the detailed international trade data. As the
economic size of a country begins to increase, its export diversity initially
increases in an exponential manner, but overtime, this diversity growth slows
and eventually reaches an upper limit. The interdependence between size and
diversity takes the shape of an S-shaped curve that an be fitted by a logistic
equation. To explain this phenomenon, we introduce a new parameter called
"substitutability" into the list of capabilities or factors of products in the
tri-partite network model (i.e., the country-capability-product model) of
Hidalgo et al. As we observe, when the substitutability is zero, the model
returns to Hidalgo's original model but failed to reproduce the S-shaped curve.
However, in a plot of data, the data increasingly resembles an the S-shaped
curve as the substitutability expands. Therefore, the diversity ceiling effect
can be explained by the substitutability of different capabilities
Performance Characterization of Multi-threaded Graph Processing Applications on Intel Many-Integrated-Core Architecture
Intel Xeon Phi many-integrated-core (MIC) architectures usher in a new era of
terascale integration. Among emerging killer applications, parallel graph
processing has been a critical technique to analyze connected data. In this
paper, we empirically evaluate various computing platforms including an Intel
Xeon E5 CPU, a Nvidia Geforce GTX1070 GPU and an Xeon Phi 7210 processor
codenamed Knights Landing (KNL) in the domain of parallel graph processing. We
show that the KNL gains encouraging performance when processing graphs, so that
it can become a promising solution to accelerating multi-threaded graph
applications. We further characterize the impact of KNL architectural
enhancements on the performance of a state-of-the art graph framework.We have
four key observations: 1 Different graph applications require distinctive
numbers of threads to reach the peak performance. For the same application,
various datasets need even different numbers of threads to achieve the best
performance. 2 Only a few graph applications benefit from the high bandwidth
MCDRAM, while others favor the low latency DDR4 DRAM. 3 Vector processing units
executing AVX512 SIMD instructions on KNLs are underutilized when running the
state-of-the-art graph framework. 4 The sub-NUMA cache clustering mode offering
the lowest local memory access latency hurts the performance of graph
benchmarks that are lack of NUMA awareness. At last, We suggest future works
including system auto-tuning tools and graph framework optimizations to fully
exploit the potential of KNL for parallel graph processing.Comment: published as L. Jiang, L. Chen and J. Qiu, "Performance
Characterization of Multi-threaded Graph Processing Applications on
Many-Integrated-Core Architecture," 2018 IEEE International Symposium on
Performance Analysis of Systems and Software (ISPASS), Belfast, United
Kingdom, 2018, pp. 199-20
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