近年来,不但日本国内各个方面,就连一些国际组织如世界银行、国际货 币基金组织以及有关国家政府(如美国等),都对日本金融机构的不良资产问 题迟迟得不到解决表示关切,呼吁日本加快处置不良资产的速度,加大处置不 良资产的力度,尽快使经济恢复正常, 日本银行业的不良资产问题已久拖10年,至今不但未能得到有效解决,而 且严重的通货紧缩局面(截至2002年11月,消费者物价指数已连续37个月 下降)加剧了银行业的不良资产。据日本有关方面的报道,从上个世纪90年代 以来,日本金融机构一共处置了约90万亿日元的不良资产(占同期贷款总额的 约1/8)

Automatic repeat request (ARQ) Break large files into packets FILE PKT PKT PKT Check received packets for errors Use a feedback channel to request retransmissions Retransmit packets containing errors acket Receive ACK

The TCP/P Protocol Suite Transmission Control Protocol Internet protocol Developed by darPa to connect Universities and Research Labs Four Layer model Applications Telnet, FTP, email, etc Transport TCP, UDP Network IP ICMP, IGMP Link

1、美国等发达国家一般根据金融中介机构的负债与资产将其 分为三类。第一类为存款型金融机构,包括商业银行、储蓄银 行、信用社等;第二类为契约型储蓄机构,主要包括保险公司 (人寿保险公司和财产、意外灾害保险公司)以及养老基金 ;第三类为投资型金融机构,主要包括金融公司、(资本市场 )共同基金和货币市场共同基金

1、20世纪70年代以前,投资银行经历了漫长的产生和早期发 展过程。1929年以前是投资银行产生及持续发展的阶段; 19291933是投资银行膨胀及动荡的阶段。大量的商业银行 和投资银行倒闭;1933年《格拉斯—斯蒂格尔法》颁布以 后,美国的商业银行和投资银行开始实行分业经营,投资银行 进入新的发展阶段

Packet Multiple Access SHARED UPLIN TERMINAL APPL TERMINALL TRANS NET LLC DLC MAC

Routing Must choose routes for various origin destination pairs o/d pairs) or for various sessions Datagram routing: route chosen on a packet by packet basis Using datagram routing is an easy way to split paths Virtual circuit routing: route chosen a session by session basis Static routing: route chosen in a prearranged way based on O/D pairs Eytan Modiano

Used for analyzing network performance In packet networks, events are random Random packet arrivals Random packet lengths While at the physical layer we were concerned with bit-error-rate, at the network layer we care about delays How long does a packet spend waiting in buffers?

Modulation Representing digital signals as analog waveforms Baseband signals Signals whose frequency components are concentrated around zero Passband signals Signals whose frequency components are centered at some frequency fc away from zero Baseband signals can be converted to passband signals through modulation Multiplication by a sinusoid with frequency fc Eytan Modiano

Channel Coding When transmitting over a noisy channel, some of the bits are received with errors Example: Binary Symmetric Channel (BSc) Pe= probability oferror Q: How can these errors be removed? A: Coding: the addition of redundant bits that help us determine what was sent with greater accuracy