4,275 research outputs found
Weiqi games as a tree: Zipf's law of openings and beyond
Weiqi is one of the most complex board games played by two persons. The
placement strategies adopted by Weiqi players are often used to analog the
philosophy of human wars. Contrary to the western chess, Weiqi games are less
studied by academics partially because Weiqi is popular only in East Asia,
especially in China, Japan and Korea. Here, we propose to construct a directed
tree using a database of extensive Weiqi games and perform a quantitative
analysis of the Weiqi tree. We find that the popularity distribution of Weiqi
openings with a same number of moves is distributed according to a power law
and the tail exponent increases with the number of moves. Intriguingly, the
superposition of the popularity distributions of Weiqi openings with the number
of moves no more than a given number also has a power-law tail in which the
tail exponent increases with the number of moves, and the superposed
distribution approaches to the Zipf law. These findings are the same as for
chess and support the conjecture that the popularity distribution of board game
openings follows the Zipf law with a universal exponent. We also find that the
distribution of out-degrees has a power-law form, the distribution of branching
ratios has a very complicated pattern, and the distribution of uniqueness
scores defined by the path lengths from the root vertex to the leaf vertices
exhibits a unimodal shape. Our work provides a promising direction for the
study of the decision making process of Weiqi playing from the angle of
directed branching tree.Comment: 6 Latex pages including 6 figure
Network analysis of the worldwide footballer transfer market
The transfer of football players is an important part in football games. Most
studies on the transfer of football players focus on the transfer system and
transfer fees but not on the transfer behavior itself. Based on the 470,792
transfer records from 1990 to 2016 among 23,605 football clubs in 206 countries
and regions, we construct a directed footballer transfer network (FTN), where
the nodes are the football clubs and the links correspond to the footballer
transfers. A systemic analysis is conduced on the topological properties of the
FTN. We find that the in-degrees, out-degrees, in-strengths and out-strengths
of nodes follow bimodal distributions (a power law with exponential decay),
while the distribution of link weights has a power-law tail. We further figure
out the correlations between node degrees, node strengths and link weights. We
also investigate the general characteristics of different measures of network
centrality. Our network analysis of the global footballer transfer market sheds
new lights into the investigation of the characteristics of transfer
activities.Comment: 7 pages, 6 figure
Inheritance involved in the pathogenesis of idiopathic scoliosis
Idiopathic scoliosis is a common cause of spinal deformity in children and adolescents. Although
the incidence of the scoliosis is up to 2 %-3 % of the world’s population, the pathogenesis
is still obscure. Recent evidences show that the disease has a hereditary basis. Clinical
manifestations as well as family studies reveal the familial tendency of idiopathic scoliosis,
and support that the heredity is an important cause of this disease. Many related genes, such
as SNTGI and CHD7, are believed to play a role in the development of idiopathic scoliosis
but the underlying mechanism is still not clear. This review focus on the mode of inheritance
of idiopathic scoliosis and some related molecules
Controlling the Intrinsic Josephson Junction Number in a Mesa
In fabricating intrinsic Josephson
junctions in 4-terminal mesa structures, we modify the conventional fabrication
process by markedly reducing the etching rates of argon ion milling. As a
result, the junction number in a stack can be controlled quite satisfactorily
as long as we carefully adjust those factors such as the etching time and the
thickness of the evaporated layers. The error in the junction number is within
. By additional ion etching if necessary, we can controllably decrease
the junction number to a rather small value, and even a single intrinsic
Josephson junction can be produced.Comment: to bu published in Jpn. J. Appl. Phys., 43(7A) 200
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