Gender Differences in Spatial Navigation
This study aims to investigate the gender differences in
spatial navigation using the tasks of 2-D matrix navigation and
recognition of real driving scene. The results can be summarized as
followings. First, female subjects responded faster in 2-D matrix
navigation task than male subjects when landmark instructions were
provided. Second, in recognition task, male subjects recognized the
key elements involved in the past driving scene more accurately than
female subjects. In particular, female subjects tended to miss
peripheral information. These results suggest the possibility of gender
differences in spatial navigation.
Gender differences, Spatial navigation, 2-D matrixnavigation, Recognition of driving scene.
An Energy-Efficient Distributed Unequal Clustering Protocol for Wireless Sensor Networks
The wireless sensor networks have been extensively
deployed and researched. One of the major issues in wireless sensor
networks is a developing energy-efficient clustering protocol.
Clustering algorithm provides an effective way to prolong the lifetime
of a wireless sensor networks. In the paper, we compare several
clustering protocols which significantly affect a balancing of energy
consumption. And we propose an Energy-Efficient Distributed
Unequal Clustering (EEDUC) algorithm which provides a new way of
creating distributed clusters. In EEDUC, each sensor node sets the
waiting time. This waiting time is considered as a function of residual
energy, number of neighborhood nodes. EEDUC uses waiting time to
distribute cluster heads. We also propose an unequal clustering
mechanism to solve the hot-spot problem. Simulation results show that
EEDUC distributes the cluster heads, balances the energy
consumption well among the cluster heads and increases the network
Wireless Sensor Network, Distributed UnequalClustering, Multi-hop, Lifetime.
Analysis of Long-Term File System Activities on Cluster Systems
I/O workload is a critical and important factor to
analyze I/O pattern and to maximize file system performance.
However to measure I/O workload on running distributed parallel file
system is non-trivial due to collection overhead and large volume of
data. In this paper, we measured and analyzed file system activities on
two large-scale cluster systems which had TFlops level high
performance computation resources. By comparing file system
activities of 2009 with those of 2006, we analyzed the change of I/O
workloads by the development of system performance and high-speed
I/O workload, Lustre, GPFS, Cluster File System
Agent-based Framework for Energy Efficiency in Wireless Sensor Networks
Wireless sensor networks are consisted of hundreds or
thousands of small sensors that have limited resources.
Energy-efficient techniques are the main issue of wireless sensor
networks. This paper proposes an energy efficient agent-based
framework in wireless sensor networks. We adopt biologically
inspired approaches for wireless sensor networks. Agent operates
automatically with their behavior policies as a gene. Agent aggregates
other agents to reduce communication and gives high priority to nodes
that have enough energy to communicate. Agent behavior policies are
optimized by genetic operation at the base station. Simulation results
show that our proposed framework increases the lifetime of each node.
Each agent selects a next-hop node with neighbor information and
behavior policies. Our proposed framework provides self-healing,
self-configuration, self-optimization properties to sensor nodes.
Agent, Energy Efficiency, Genetic algorithm,Wireless Sensor Networks.