Abstract Due to advances of technologies and growth of Internet usage, demand for larger and larger network capacity remains the major challenge for network operators. To meet the increasing demand, optical network has become the key technology in the current and next-generation Internet. In terms of network architecture, optical packet switching (OPS) is a promising up-star in achieving high efficiency just as the electronic counterpart. However, it is currently far reached because of the difficulty in making optical random access memory and ultra-high cost in making fast optical switches that can handle more than 10^9 packets per second. Optical burst switching (OBS), on the other hand, is a more achievable, economical alternative. In OBS networks, packets are aggregated into much larger sized bursts before entering the core network. It thus does not require fast optical switches. And by incorporating one-way delayed reservation scheme, OBS avoids using optical RAM. There have been many research activities toward OBS. However, for Internet with 90% of TCP traffic, the effect of packet aggregation introduced by OBS on TCP performance is still not well understood. Detti and Listanti derived a model for it and the model was verified in simulation [2]. Yet, we found many of the assumptions in their study are not realistic. The obtained result is therefore questionable. In this thesis, we relax their assumptions and design two new models accordingly in order to get deeper understanding on the effects of packet aggregation on TCP performance. From our simulation results, we conclude three affecting factors: burst assembly, assembly delay and assembler buffer size. Burst assembly shows positive effect, while the other two demonstrate negative effects, on TCP throughput.

Because of the development of the Internet, there are more and more users. Various kinds of services are provided by companies. They are usually web based for easy use. The performance of web servers is a key factor of the quality of services. In a user¡¦s view, the response time is a important metric for the performance of a web server, so we implement a passive performance evaluation tool for web servers in this paper. In this paper we discussed phenomenons when bottlenecks at a web server occur. We make experiments to show how bottlenecks in the CPU, network, and in the Disk can affect the response time. The result shows that response time is affected in different way according to the type of the request when the bottleneck is CPU, network or disk.

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Abstract The price of the initial public offerings should reflect the real value of the issuers. To quote the IPOs is very important in underwriting process. The mainly roles in IPOs are investors¡]buyer¡^, issuers¡]supplier¡^, and underwriters¡]broker¡^. The pricing-decisions on IPOs are opposite between investors and issuers. It is difficult for underwriters to equalize among risk adverse, specialistic goodwill, and maintenance of clients¡¦ relationship. This research tries to find out the effect factors to underwriters. This research observed 104 IPOs in Taiwan during the period of January 2001 to February 2003. The methods to analyze the data are mainly blocked analysis¡]including six blocks¡^, Pearson correlation analysis and multiple regression analysis. According to the results of empirical research, we can get conclusions as followings: 1.The effect factors of IPO¡¦s are ¡§the favorites with industry¡¨, and ¡§operating performance¡¨. They are statistically significant. 2. The factors of ¡§unit cost of the majority¡¨ and ¡§sales consideration¡¨ which underwriters and issuers always negotiated are not statistically significant. 3.the IPO¡¦s who booked on Emerging Stock are higher than the others.

This thesis develops the theoretical foundation of the strategic-culture paradigm. This model focuses attention upon culture and appeals to the profit requisite associated with commercial activities, and is an integrator of business / domestic cultural expectations. I describe culture as an organizational attribute integral to behavior and strategy which represents a potentially powerful resource facilitating operational effectiveness, sustained competitive advantage, and increased business social accountability. This explanation relies upon conceptualizing culture at both the national and company level, and then explicating the dependent interplay between these realms. Specifically, I submit that corporations who establish and continually adapt their culture with the aim of striving to maintain a fit with the domestic context are more inclined to realize opportunities, attract customers, and endure unanticipated business environmental pressures. Using information collected on Nucor Steel and Southwest Airlines, I provide a preliminary assessment of the virtues of the strategic-culture model as it relates to explaining these firms and their operations.

Birth (BW) (n = 1,107) and weaning weight (WW) (n = 1,024), pregnancy rate (PR) (n = 1,255), calf crop born (CCB) (n = 1,232), calf crop weaned (CCW) (n = 1,225), and cow??s weight at palpation (CW) (n = 1,403) were evaluated from 1994 to 2004 in 143 F1 females who were sired by Brahman (B), Boran (Bo), and Tuli (T) bulls and who were out of Angus and Hereford cows. In 2004, mouth scores (MS) (n = 71) were assigned to the remaining females. PR, CCB, CCW, CW, and BCS were evaluated using a model that consisted of sire of dam breed, dam of dam breed, and calf??s birth year/age of dam as fixed effects. Sire of dam within sire breed of dam and dam within sire of dam within sire breed of dam were used as random effects. BW and WW were analyzed using the same model including calf??s gender. Two-way interactions were tested for significance. Year/age was significant for all traits (P < 0.05). Adjusted means for BW for calves out of cows by B, Bo, and T sires were 35.66, 35.38, and 35.59 kg respectively, and were not different (P > 0.05). Adjusted means for WW for calves out of cows by B, Bo, and T sires were 233.4, 220.1, and 208.2 kg respectively, and were significantly different. For both BW and WW, male calves were heavier (P < 0.05) than females. Adjusted means for PR for females sired by B, Bo, and T bulls were 0.914, 0.945, and 0.920, and were not different (P > 0.05). Adjusted means for CCB for females sired by B, Bo, and T bulls were 0.890, 0.943, and 0.910 respectfully, and Bo was higher (P < 0.05) than B. CCW showed the same ranking as CCB with adjusted means of 0.834, 0.887, and 0.857 for cows by B, Bo, and T bulls, with Bo being higher (P < 0.05) than B. CW adjusted means, in the fall of 2002, were 594.29, 519.38, and 517.3 kg. B-sired females were heavier (P < 0.05) than Bo- or T- sired cows. More Bo- (P = 0.013) and B-sired (P = 0.003) cows had solid mouths in 2004 than T-sired cows.

Today, there are numerous versions of the continuous performance test (CPT) used in clinical and research settings. Although CPTs may constitute a similar group of tasks with a common paradigm, they are very different in the parameters they measure (Conners, 1995). To learn more about the effects of different CPT versions as well as the numerous scoring indices, two very different CPTs, the Conners’ Continuous Performance Test-Second Edition (CCPT-II) and the Gordon Diagnostic System (GDS), were compared with a population of children and adolescents exhibiting ADHD and normal controls. Major findings were as follows: (a) the CCPT-II and GDS measures were not able to separate children with ADHD from normal controls; (b) individual variables from neither the CCPT-II nor the GDS were able to adequately differentiate children with ADHD and normal controls; and (c) score profiles obtained from the overall group of children and adolescents did not successfully separate the ADHD group from normal controls using the CCPT-II and GDS.

Although research supports the use of measures of typical performance for assessing academic and cognitive skills, there are currently few such measures in existence. Other measures have been used for research purposes, but they are not normed on a large, nationally-representative sample. The Ratings of Everyday Academic and Cognitive Skills (REACS) was created to address the need for a measure of typical academic and cognitive skills. The goal of the REACS is to provide a timely, easy to administer, and comprehensive assessment of a child's typical functioning in various academic and cognitive domains. The purpose for this dissertation was to develop the initial scale and conduct analyses to provide evidence of its reliability and validity. In an attempt to provide preliminary evidence of the validity of scores from this measure, Parent (n = 142) and Teacher (n = 109) REACS forms were collected for data analysis. A subsample of parents and teachers completed forms to examine interrater and test-retest reliability. A group of children (n = 32) were assessed with measures of academic achievement, cognitive ability, and memory for comparison to the REACS. Results generally showed high internal consistency, yet less reliable test-retest and interrater reliability. While the confirmatory factor analysis (CFA) of the parent scale supported a factor structure that approximated the intended structure of the REACS, a better fit was found with a simpler model for the teacher scale. Finally, both the Parent and Teacher REACS forms were found to predict academic achievement better than cognitive ability. The predictive ability of the REACS was enhanced when used in conjunction with a measure of cognitive ability.

In the wake of global warming and fossil fuel depletion, renewed attention has been paid to shifting away from the use of petroleum based fuels. The world?s energy demand is commencing its dependency on alternative fuels. Such alternative fuels in use today consist of bio-alcohols (such as ethanol), hydrogen, biomass, and natural oil/fat derived fuels. However, in this study, the focus will be on the alternative fuel derived from natural oils and fats, namely biodiesel. The following study characterizes the performance of a medium-duty diesel engine fuelled with biodiesel and conventional diesel. The objective is accomplished by taking measurements of manifold pressure and temperature, fuel flow, air flow, and torque. The study first characterizes a John Deere 4.5 liter 4 cylinder direct injection engine with exhaust gas recirculation (EGR), common rail fuel injection, and variable turbo-charging with conventional petroleum diesel to set a reference for comparison. The study then proceeds to characterize the differences in engine performance as a result of using biodiesel relative to conventional diesel. The results show that torque decreases with the use of biodiesel by about 10%. The evaluation of engine performance parameters shows that torque is decreased because of the lower heating value of biodiesel compared to conventional diesel. The insignificant difference between the other performance parameters shows that the ECM demands the same performance of the engine regardless of the fuel being combusted by the engine.