Diamond interchange design has been commonly utilized in United States to facilitate traffic exchange between freeway and frontage roads. Another less common interchange design is X-ramp interchange, which is the reversed version of diamond. The major benefit of X-ramp interchange is that it can keep travelers on the freeway until the downstream exit ramp to avoid going through the intersection. It also has drawbacks such as travelers with cross street destinations will experience more delay. This study focuses on when the ramp reversal is desirable. To compare the diamond and X-ramp design, an experimental design is conducted using Latin Hypercube Design method. Four varying factors include interchange design type, traffic volume on the frontage road, through movement percentage and saturation rate of the intersection. 40 scenarios are generated for simulation study using Synchro and VISSIM. Based on the simulation study, optimal signal timing strategies are recommended for each type of interchange design under various traffic conditions. Also, ramp reversal is found closely related to the following factors such as interchange frequency, upstream interchange design, traffic volume on frontage road, through movement percentage and intersection saturation rate. Conclusions are made on when X-ramp is better than diamond interchange design. At last, future research directions are recommended.

Thesis (Ph. D. in Engineering)--University of California, Berkeley, 2005. / "May 2005." Includes bibliographical references (p. 64-66). Also available online via the ITS Berkeley web site (www.its.berkeley.edu).

Made available in DSpace on 2014-06-11T19:22:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-01Bitstream added on 2014-06-13T19:28:12Z : No. of bitstreams: 1 fioramonte_isk_me_prud.pdf: 478645 bytes, checksum: 419ea45576dee0fb0d8d49b20ebe7459 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A velocidade de contração é um importante fator de interferência na relação entre força e eletromiografia. O presente trabalho visa promover uma melhor compreensão da relação EMG x força no quesito velocidade de contração. Foi coletado o sinal eletromiográfico de superfície do músculo bíceps braquial de dez voluntários. Os sujeitos realizaram três CIVM, onde a média das três foi considerada a capacidade máxima de força gerada pelo indivíduo sendo utilizada para a normalização dos valores de RMS. Em seguida os sujeitos foram orientados a realizar 10 contrações isométricas em rampa e 10 contrações isométricas em degrau de maneira aleatória com sobrecarga de 40% da CVM. Nos exercícios em rampa a força era incrementada de maneira gradativa de 0 a 40% da CVM, e nos exercícios em degrau o indivíduo era orientado a incrementar a força em sua máxima velocidade de contração, em ambas as velocidades de contração o voluntário realizava os exercícios com encorajamento verbal e “feedback” visual na tela do computador. Resultados: o tempo de subida em degrau variou significantemente, o aumento dos valores de RMS em rampa e em degrau foi gradativo, porém em rampa foi maior do que em degrau. O resultado neste trabalho nos permite concluir que há diferenças quando se aplica diferentes velocidades de contração. Sendo que essas diferenças podem indicar um maior recrutamento de fibras do tipo II e ativação muscular nos exercícios em rampa e que esse recrutamento pode ser gradativo. / Filho, Presidente Prudente, 2011. The speed of contraction is an important factor that influences the relationship between strength and electromyography. The present work aims to promote a better understanding of the relation x EMG power in the issue of contraction speed. We collected surface electromyographic signal of the biceps brachii ten volunteers. The subjects performed three MVC, where the average of the three was considered the maximum force generated by person being used for the normalization of the RMS values. Then the subjects were instructed to perform 10 isometric ramps and step isometric 10 randomly loaded with 40% of MVC. In the exercise on ramp the force was increased will gradually from 0 to 40% of MVC, and exercises on step the individual was instructed to increase the force at its maximum speed of contraction in both the voluntary contraction speeds perform the exercises with verbal encouragement and visual feedback on the computer screen. Results: the ascent time in step varied significantly, the increase of RMS values in step and ramp were gradual, but a ramp was higher than in step. The result of this work allows us to conclude that there are differences when applying different speeds of contraction. Since these differences may indicate a higher recruitment of type II fibers and muscle activation exercises ramp and that recruitment may be gradual.

No description available.

A numerical investigation of the performance of two candidate designs for injection into supersonic flow, including a comparison of two renormalized group theory (RNG) based k-epsilon turbulence models with a more conventional k-epsilon model. The chosen designs were an unswept ramp injector with four injection ports and a novel nine-hole injector array. The objectives of the investigation were to provide reliable computational solutions to the flowfields in question using both RNG and standard k-epsilon turbulence models and to compare the solutions to experiment, thereby to judge the relative performance of the turbulence models. A second objective of the investigation was to use the computed data to provide design insights for the nine-hole injector array. This investigation made use of GASP(tm) version 2.2, a commercial computational fluid dynamics code that was augmented by the addition of one RNG-based k-epsilon turbulence model derived by Zhou, et. al. and one variant of Zhou's model, which was derived by the author. Mesh sequencing studies were performed to measure solution quality, with the fine mesh for the injector array containing roughly one million grid nodes and the fine mesh for the ramp injector containing more than six million grid nodes. Results of these studies indicated that the injector-array solution was significantly under-resolved in the farfield, though the quality was better in the vicinity of the injector itself. The ramp-injector solution, while not perfectly grid-resolved, showed much better grid convergence in both the nearfield and farfield. Accordingly, comparison with experiment was better for the ramp injector than for the injector array. For both injectors, the differences between solutions generated with RNG-based k-epsilon and standard k-epsilon turbulence models were negligibly small." Despite inadequate grid resolution in the farfield, the computational investigation of the nine-hole injector array did yield several important design insights. Particularly, the significance to mixing and losses of the placement of the outer injectors of the second and third rows was determined. / Ph. D.

Myxococcus xanthus, a model organism for studying development and Type IV pili (T4P), harbors three Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) on its chromosome. CRISPR systems, which function as an adaptive immune system in prokaryotes, are classified into three types based on CRISPR-associated genes. Evidence suggests that these three types mediate immunity slightly differently. M. xanthus CRISPR1 and CRISPR2 are Type I systems while CRISPR3 is a Type III-B system. In a genetic screen, a mariner transposon insertion in the 13th spacer of CRISPR3 (3SP13) was found to restore exopolysaccharide (EPS) production to a pilA mutant. Since the deletion of CRISPR3 failed to suppress a pilA mutation and expression of CRISPR3 from a heterologous promoter led to pilA suppression, it was concluded that the 3SP13 transposon insertion is a gain-of-function mutation. Deletion of the adjacent Repeat Associated Mysterious Proteins (RAMP) genes indicated that they are essential for the 3SP13 transposon insertion to suppress pilA, providing evidence that Type III-B systems may be involved in the regulation of chromosomal genes. We suggest that one of the spacers, once expressed and processed, may inhibit the expression of a negative regulator of EPS production in M. xanthus. / Master of Science

Throughout the past century, many changes in the conceptualization of the school counselor have occurred. Although most states endorse a national model developed through the American School Counseling Association (ASCA), not all school and district personnel have changed their views of the school counselor role to the most current conceptualization. The focus of this study was to gather current information on principal perceptions of appropriate and inappropriate school counselor activities based on the ASCA model. Differences were examined in principal perceptions at the elementary and secondary levels, and between appropriate and inappropriate activities to see if principals ranked appropriate activities more highly. Differences were also examined in schools with Recognized ASCA Model Program (RAMP) designation and schools without RAMP designation. Results showed differences in perception between elementary and secondary principals, with secondary principals rating all counseling activities significantly higher than elementary school principals, although there were similarities in ratings between groups. Appropriate activities were rated significantly higher than inappropriate activities by principals overall as well as the elementary principal group and secondary principal group. There were no significant differences overall in RAMP versus non-RAMP school principal perceptions. Discussion includes reviewing specific activities where perceptions differed; how these results fit with previous research; and implications for policy and practice, future research, and higher education. / Doctor of Philosophy / Throughout the past century, many changes in the conceptualization of the role of the school counselor have occurred. Although most states endorse a national model developed through the American School Counseling Association (ASCA), not all school and district personnel have changed their views of the school counselor role to the most current conceptualization. The focus of this study was to gather current information on principal perceptions of appropriate and inappropriate school counselor activities based on the ASCA model. Differences were examined in principal perceptions at the elementary and secondary levels, and between appropriate and inappropriate activities to see if principals ranked appropriate activities more highly. Differences were also examined in schools with Recognized ASCA Model Program (RAMP) designation and schools without RAMP designation. Results showed differences in perception between elementary and secondary principals, with secondary principals rating all counseling activities significantly higher than elementary school principals, although there were similarities in ratings between groups. Appropriate activities were rated significantly higher than inappropriate activities by principals overall as well as the elementary principal group and secondary principal group. There were no significant differences overall in RAMP versus non-RAMP school principal perceptions. Discussion includes reviewing specific activities where perceptions differed; how these results fit with previous research; and implications for policy and practice, future research, and higher education.

The primary objective of the study is to evaluate safety performances of different exit ramps used in Florida and nationally. More specific, the research objectives include the following two parts: (1) to evaluate the impacts of different exit ramp types on safety performance for freeway diverge areas; and (2) to identify the different factors contributing to the crashes happening on the exit ramp sections. To achieve the research objectives, the research team investigated crash history at 424 sites throughout Florida. The study area includes two parts, the freeway diverge area and the exit ramp sections. For the freeway diverge areas, exit ramp types were defined based on the number of lanes used by vehicular traffic to exit freeways. Four exit ramp types were considered here including single-lane exit ramps (Type 1), sing-lane exit ramps without a taper (Type 2), two-lane exit ramps with an optional lane (Type 3), and two-lane exit ramps without an optional lane (Type 4). For the exit ramp sections, four ramp configurations, including diamond, out connection, free-flow loop and parclo loop, were considered. Cross-sectional comparisons were conducted to compare crash frequency, crash rate, crash severity and crash types between different exit ramp groups. Crash predictive models were also built to quantify the impacts of various contributing factors. On the freeway diverge areas, it shows that Type 1 exit ramp has the best safety performance in terms of the lowest crash frequency and crash rate. The crash prediction model shows that for one-lane exit ramp, replacing a Type 1 with a Type 2 will increase crash counts at freeway diverge areas by 15.57% while replacing a Type 3 with a Type 4 will increase crash counts by 10.80% for two-lane ramps. On the exit ramp sections, the out connection ramps appear to have the lowest average crash rate than the other three. The crash predictive model shows that replacing an out connection exit ramp with a diamond, free-flow, and parclo loop will increase crashes counts by 26.90%, 68.47% and 48.72% respectively. The results of this study will help transportation decision makers develop tailored technical guidelines governing the selection of the optimum design combinations on freeway diverge areas and exit ramp sections.

Le travail de cette thèse vise la réalisation d’un nouveau capteur d’images pour mobile en technologie CMOS (Complementary Metal Oxide Semiconductor). Ce capteur a été développé en vue de répondre à une forte demande du marché. Les prochaines générations de produits, nécessitent des capteurs d’image avec des performances agressives. Par exemple, le niveau de qualité d’image peut être fortement amélioré avec des architectures faible bruit, ou l’utilisation de nouvelles technologies, pour augmenter le niveau du signal ou diminuer la consommation. L’augmentation de la qualité d’image entraîne un agrandissement de la taille des matrices de pixels, et de la résolution des données. La vitesse de conversion devient donc critique. Le sujet de cette thèse porte sur l’amélioration de ce dernier point. Une étude comparative a été réalisée pour étudier différentes architectures. Le convertisseur à rampe est le mieux adapté pour les petits pixels. Toutefois, son principal inconvénient est son temps de conversion qui nécessite 2N cycles d’horloge. Afin d’obtenir un frame rate plus élevé, une méthode tirant profit du bruit photonique a été proposée. Ce circuit de lecture est fondé sur un convertisseur à rampe par morceaux, et un algorithme qui permet la linéarisation des données. Afin de réduire le bruit, cette nouvelle architecture doit prendre en compte le double échantillonnage corrélé digital. Durant la période de conception, des modes de test ont été mis en place pour permettre la caractérisation du circuit. L’innovation se trouve dans le développement d’une rampe par morceaux qui réduit le temps de lecture d’une ligne de 1us. Cependant, ce développement a besoin d’une calibration adaptée. Un prototype de capteur d’image CMOS de 13Mpixel a été fabriqué en 65 nm, 5 niveaux de métaux, et 1 seul niveau de poly en technologie CMOS standard. Les mesures ont montré que l’INL et DNL du convertisseur étaient aussi performantes qu’avec une rampe linéaire classique. Une attention particulière a été apportée sur la mesure du bruit. Malheureusement, le bruit s’est montré plus élevé qu’avec un capteur « classique ». Cependant, la consommation reste identique en ayant une vitesse de conversion plus rapide. Les solutions proposées sont simples à intégrer structurellement, et faciles à mettre en œuvre. Elles ont l’avantage de ne pas impacter la surface du pixel et préservent donc les performances de ce dernier. Les résultats issus des mesures sur silicium sont très encourageants, car on obtient un gain de presque 20% sur le temps de lecture. / The aim of this thesis is the implementation of new image sensors for mobile in CMOS (Complementary Metal Oxide Semiconductor) technology to meet strong market demand. Next generations of products require image sensors with high performances.These improvements would change the image quality with low noise architecture in one hand, and the use of new technologies to increase the signal level, or reduce the power consumption in the other hand. The gain in image quality leads to increase the size of the pixel’s array, and the resolution of the data -the conversion speed becoming critical-. The subject of this thesis focuses on improving this latter point. A comparative study has been made between several architectures to find the best solution that would fit our needs.The ramp converter is the most suitable for small pixels, but his main drawback is the conversion time that requires 2N clock cycles. To obtain a higher frame rate, a method taking advantage of the photon noise has been presented. This readout circuit is based on a piecewise linear ramp converter and an algorithm that allows the linearization of the data. Furthermore, for noise reduction, the new architecture must take into account the digital correlated double sampling. During the period of design, test modes have also been designed and implemented to allow characterization of the circuit.The innovative part is the use of a piecewise linear ramp, which in simulation, reduces the readout time of 1us per row. However, this element needs calibration. A CMOS image sensor prototype of 13Mpixel has been made in 65 nm, 5 levels of metals, and 1 level of poly standard CMOS technology. Measurements showed that the INL and DNL of the converter were as good as with a conventional linear ramp. A careful consideration has been given to the measurement of noise, which unfortunately is higher than a "conventional" sensor. However, the consumption remains the same while having a faster conversion speed. The solutions are simple to integrate structurally and easy to implement. They have the advantage of not affecting the surface of the pixel, thus preserve the performance of the latter. The results found from the silicon-on measures are very encouraging, we gain almost 20% of the conversion time.

Research recently conducted at the University of Central Florida involving crashes on Interstate-4 in Orlando, Florida has led to the creation of new statistical and neural networks models that are capable of determining the crash risk on the freeway (Abdel-Aty et al., 2004; 2005, Pande and Abdel-Aty, 2006). These models are able to calculate rear-end and lane-change crash risks along the freeway in real-time through the use of static information at various locations along the freeway as well as real-time traffic data obtained by loop detectors. Since these models use real-time traffic data, they are capable of calculating rear-end and lane-change crash risk values as the traffic flow conditions are changing on the freeway. The objective of this study is to examine the potential benefits of combining two ITS strategies (Ramp Metering and Variable Speed Limits strategies) for reducing the crash risk (both rear-end and lane-change crash risks) along the I-4 freeway. Following this aspect, a 36.25-mile section of I-4 running though Orlando, FL was simulated using the PARAMICS micro-simulation program. Gayah (2006) used the same network to examine the potential benefits of two ITS strategies separately (Route Diversion and Ramp Metering) for reducing the crash risk along the freeway by changing traffic flow parameters. Cunningham (2007) also used the same network to examine the potential benefits of implementing Variable Speed Limits strategy for reducing the crash risk along the freeway. Since the same network is used, the calibration and validation procedures used in this study are the same as these previous two studies. This study simulates three volume loading scenarios on the I-4 freeway. These are 60, 80 and 90 percent loading scenarios. From the final experimental design for the 60 % loading, it was concluded that implementing VSL strategy only was more beneficial to the network than either implementing Ramp Metering everywhere (through the whole network) in conjunction with VSL everywhere or implementing Ramp Metering downtown (in downtown areas only) in conjunction with VSL everywhere. This was concluded from the comparison of the results of this study with the results from Cunningham (2007). However, either implementing Ramp Metering everywhere or downtown in conjunction with VSL everywhere showed safety benefits across the simulated network as well as a reduction in the total travel time. The best case for implementing Ramp Metering everywhere in conjunction with VSL everywhere was using a homogeneous speed zone threshold of 2.5 mph, a speed change distance of half speed zone and a speed change time of 5 minutes in conjunction with a 60 seconds cycle length for the Zone algorithm, a critical occupancy of 0.17 and a 30 seconds cycle length for the ALINEA algorithm. And the best case for implementing Ramp Metering downtown in conjunction with VSL everywhere was using a homogeneous speed zone threshold of 2.5 mph, a speed change distance of half speed zone and a speed change time of 10 minutes in conjunction with a 60 seconds cycle length for the Zone algorithm, a critical occupancy of 0.17 and a 30 seconds cycle length for the ALINEA algorithm. For the 80 % loading, it was concluded that either implementing Ramp Metering everywhere in conjunction with VSL everywhere or implementing Ramp Metering downtown in conjunction with VSL everywhere was more beneficial to the network than implementing VSL strategy only. This was also concluded from the comparison of the results of this study with the results from Cunningham (2007). Moreover, it was concluded that implementing Ramp Metering everywhere in conjunction with VSL everywhere showed higher safety benefits across the simulated network than implementing Ramp Metering downtown in conjunction with VSL everywhere. Also, both of them increased the total travel time a bit, but this was deemed acceptable. Additionally, both of them had successive fluctuations and variations in the average lane-change crash risk vs. time step. The best case for implementing Ramp Metering everywhere in conjunction with VSL everywhere was using a homogeneous speed zone threshold of 5 mph, a speed change distance of half speed zone and a speed change time of 30 minutes in conjunction with a 60 seconds cycle length for the Zone algorithm, a critical occupancy of 0.17 and a 30 seconds cycle length for the ALINEA algorithm. And the best case for implementing Ramp Metering downtown in conjunction with VSL everywhere was using a homogeneous speed zone threshold of 5 mph, a speed change distance of half speed zone and a speed change time of 30 minutes in conjunction with a 60 seconds cycle length for the Zone algorithm, a critical occupancy of 0.17 and a 30 seconds cycle length for the ALINEA algorithm. Searching for the best way to implement both Ramp Metering and VSL strategies in conjunction with each other, an indepth investigation was conducted in order to remove the fluctuations and variations in the crash risk with time step (through the entire simulation period). The entire simulation period is 3 hours, and each time step is 5 minutes, so there are 36 time steps representing the entire simulation period. This indepth investigation led to the idea of not implementing VSL at consecutive zones (using either a gap of one zone or more). Then this idea was applied for the best case of implementing Ramp Metering and VSL everywhere at the 80 % loading, and the successive fluctuations and variations in the crash risk with time step were removed. Moreover, much better safety benefits were found. So, this confirms that this idea was very beneficial to the network. For the 90 % loading, it was concluded that implementing Ramp Metering strategy only (Zone algorithm in downtown areas, and ALINEA algorithm in non downtown areas) was more beneficial to the network than implementing Ramp Metering everywhere in conjunction with VSL everywhere. This was concluded from the comparison of the results of this study with the results from Gayah (2006). However, implementing Ramp Metering everywhere in conjunction with VSL everywhere showed safety benefits across the simulated network as well as a reduction in the total travel time. The best case was using a homogeneous speed zone threshold of 2.5 mph, a speed change distance of the entire speed zone and a speed change time of 20 minutes in conjunction with a 60 seconds cycle length for the Zone algorithm, a critical occupancy of 0.17 and a 30 seconds cycle length for the ALINEA algorithm. In summary, Ramp Metering was more beneficial at congested situations, while Variable Speed Limits were more beneficial at free-flow conditions. At conditions approaching congestion, the combination of Ramp Metering and Variable Speed Limits produced the best benefits. These results illustrate the significant potential of ITS strategies to improve the safety and efficiency of urban freeways.