I have some problem with open world.

[xingtong]

2013-03-15 01:22:13 [信息] [STDOUT] Loaded codechicken.nei.plugins.redpower.NEIRedPowerConfig
2013-03-15 01:22:13 [信息] [STDOUT] Loaded thermalexpansion.plugins.nei.NEIThermalExpansionConfig
2013-03-15 01:22:13 [信息] [STDOUT] IC2 NEI Submodule initialized
2013-03-15 01:22:26 [信息] [STDERR] java.lang.OutOfMemoryError: PermGen space
2013-03-15 01:22:26 [信息] [STDERR] at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:673)
2013-03-15 01:22:26 [信息] [STDERR] at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:599)
2013-03-15 01:22:26 [信息] [STDERR] at bdz.q(IntegratedServer.java:123)
2013-03-15 01:22:26 [信息] [STDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:497)
2013-03-15 01:22:26 [信息] [STDERR] at fy.run(SourceFile:849)
2013-03-15 01:22:26 [严重] [Minecraft] Encountered an unexpected exception OutOfMemoryError
java.lang.OutOfMemoryError: PermGen space
at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:673)
at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:599)
at bdz.q(IntegratedServer.java:123)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:497)
at fy.run(SourceFile:849)
2013-03-15 01:22:29 [信息] [STDERR] java.lang.OutOfMemoryError: PermGen space[DOUBLEPOST=1363328520][/DOUBLEPOST]please help me with this.