The link between R&D investment and market structure: evidence from Japan

This paper examines how market structure affects R&D investment at the firm level. Using a sample of 1338 Japanese firms, a sample selection model is employed to estimate R&D investment. The pooled sample results suggest that the likelihood of conducting R&D is negatively associated with market concentration. However, the relationship becomes insignificant when the model is estimated by industry group. Large market sales have a positive effect on the likelihood of conducting R&D for both pooled and industry group samples.

Lumpy capital adjustment and technical efficiency

This paper investigates the impact of lumpy capital adjustment on productivity at the firm level using data on Japanese manufacturing industries. We estimate stochastic production frontiers, taking firm heterogeneity into account. We find that investment spikes are negatively related to technical efficiency. Furtermore, we find a negative relationship between machinery capital age and measured efficiency.

Three-Dimensional Carbuncles and Euler Fluxes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83630/1/AIAA-2010-1273-957.pd

Optimizing the Performance of the Iptables Stateful NAT44 Solution

The stateful NAT44 performance of iptables is an important issue when it is used as a stateful NAT44 gateway of a CGN (Carrier-Grade NAT) system. The performance measurements of iptables published in research papers do not comply with the requirements of RFC 2544 and RFC 4814 and the usability of their results has serious limitations. Our Internet Draft has proposed a benchmarking methodology for stateful NATxy (x, y are in {4, 6}) gateways and made it possible to perform the classic RFC 2544 measurement procedures like throughput, latency, frame loss rate, etc. with stateful NATxy gateways using RFC 4814 pseudorandom port numbers. It has also defined new performance metrics specific to stateful testing to quantify the connection setup and connection tear down performance of stateful NATxy gateways. In our current paper, we examine how the performance of iptables depends on various settings, and also if certain tradeoffs exist. We measure the maximum connection establishment rate, throughput and tear down rate of iptables as well as its memory consumption as a function of hash table size always using 40 million connections. We disclose all measurement details and results. We recommend new settings that enable network operators to achieve significantly higher performance than using the traditional ones

Evaluation of Euler Fluxes for Hypersonic Heating Computations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83575/1/AIAA-41605-439.pd

Mobile IPv6 ベース プロトコルヨウ ケンキュウ カイハツ プラットホーム ノ セッケイ

博士(Doctor)工学(Engineering)奈良先端科学技術大学院大学博第820号甲第820号博士(工学)奈良先端科学技術大学院大