Study of drag reduction in microstructured channel with patterned cavities and wettability control

This work is done in part as a requirement towards the fulfillment of the master's degree. Four chapters are covered in this work. Chapter 1 gives an overview of the various works that have been done in the field, including some basic background and theory. Chapter 2 discusses the details of the numerical model. Grid independency study and validation of these models are accomplished by comparing with the analytical solution and quantitatively with the experiments. Chapter 3 explores the parametric study of different initial condition and geometries. Here, we are particularly interested in the effects of initial interface assumption. It is found that the effective slip length of preset interface assumption is in good agreement with the initially air-filled interface assumption, as well as the experimental results, at low gas fraction. However, the effective slip length of a preset interface has a dramatic deviation at high gas fraction with the initially air-filled channel. Large difference occurs when changing the surfaces from hydrophobic to hydrophilic. For a preset interface, air patterns are trapped in the structured cavities and compressed by the liquid flow. An air-water interface still exists even the surface of the cavity is hydrophilic, thus, drag reduction increases. However, for an initially air-filled microchannel, water expel the air out of the microchannel and completely wets the whole channel at the end. No air-water interface is found and drag reduction decreases. Studies also show that drag reduction increases when increasing the contact angle of the cavity surfaces. To extend our work further, parametric studies have been carried out to investigate the effect of geometry by changing the cavity width, fraction and numbers at low gas fraction. It is found that increasing the gas fraction and decreasing the cavity numbers can provide better performance on drag reduction, as the interfaces provide longer and continuous slip-boundary condition. Conclusions and future works are discussed in Chapter 4. More cases are carried out to build the relationship between friction reduction and different configurations in transient state to find a smaller range of depth-to-width ratio in which the air pockets can be successfully trapped in the cavity. Different shapes of posts can be studied to observe the position of the air-water interface because the mechanism for depinning is strongly dependent on the details of the post geometry and on the Young's contact angle, and depinning from both the top and the side edges of the posts is important in controlling the fluid behavior. The effect of air diffusion and how to overcome this effect will be taken into consideration

Deep Multimodal Speaker Naming

Automatic speaker naming is the problem of localizing as well as identifying each speaking character in a TV/movie/live show video. This is a challenging problem mainly attributes to its multimodal nature, namely face cue alone is insufficient to achieve good performance. Previous multimodal approaches to this problem usually process the data of different modalities individually and merge them using handcrafted heuristics. Such approaches work well for simple scenes, but fail to achieve high performance for speakers with large appearance variations. In this paper, we propose a novel convolutional neural networks (CNN) based learning framework to automatically learn the fusion function of both face and audio cues. We show that without using face tracking, facial landmark localization or subtitle/transcript, our system with robust multimodal feature extraction is able to achieve state-of-the-art speaker naming performance evaluated on two diverse TV series. The dataset and implementation of our algorithm are publicly available online

MOGU LI STRUKTURALNE PRILAGODBE VLADINOG UPRAVLJANJA POBOLJŠATI EKONOMSKE UČINKE? SLUČAJ WUHANSKOG VELEGRADSKOG PODRUČJA U KINI

The paper employs M-form and U-form organization theory to analyze the structural innovation of government governance, and tries to study the resources integration and economic performances among different cities in a metropolis circle by using the example of Wuhan metropolis circle in China. Specifically, we focus on analyzing the difference between economic performance before and after the formation of Wuhan metropolis circle. The research result shows that, on the one hand, the formation of Wuhan metropolis circle can make full use of the U-form organization; on the other hand, different cities also benefit from coordinated regional development and rational resources allocation thanks to the formation of metropolis circle. Furthermore, each city has individual characteristics and complementary to other cities. Consequently, the economic performance of theses cities greatly differs from each other.Rad koristi organizacijsku teoriju M-forme i U-forme za analizu strukturalnih inovacija vladinog upravljanja, te pokušava proučiti integraciju resursa i ekonomske učinke vladinog upravljanja među raznim gradovima velegradskog područja koristeći primjer wuhanskog velegradskog područja u Kini. Posebno je usredotočen na analizu razlike između ekonomskih učinaka prije i nakon stvaranja wuhanskog velegradskog područja. Rezultati istraživanja pokazuju da, s jedne strane, stvaranje wuhanskog velegradskog područja može u potpunosti iskoristiti U-formu organizacije, dok s druge strane, različiti gradovi također profitiraju radi koordiniranog područnog razvoja i racionalne raspodjele resursa zahvaljujući stvaranju velegradskog područja. Osim toga, svaki grad ima individualne karakteristike i one komplementarne drugim gradovima. Stoga se ekonomski učinci ovih gradova uvelike razlikuju jedni od drugih

The Duality of Autonomy on Continuous Usage of Intelligent Personal Assistants (IPAs): From Agency Perspective

Based on the contradictory phenomenon of rapid development of Intelligent Personal Assistants (IPAs) embedded in smart IoT devices, this study examines the dual role of IPAs Autonomy (in terms of decision-making autonomy, scheduling autonomy and methods autonomy) in influencing users’ IPAs usage through users’ experience of agency. Drawing on agency theories, we identify two different types of experience of agency — perceived competence and perceived uncertainty. We hypothesize that these two contradictory aspects of experiences of agency would well explain the complex relationship between IPAs autonomy and IPAs usage. Scale development and data collection would be conducted for the future work. It is expected that the findings of this study could contribute to theoretical and practical implications for the design of IPAs

Estimation of seatbelt and frontal-airbag effectiveness in trucks: U.S. and Chinese perspectives

The objectives of this study were (1) to estimate the effectiveness of seatbelts and driver airbags for mitigating medium- and heavy-truck driver injuries, and (2) to discuss the implication of these estimates with respect to truck-driving conditions in the U.S. and China. U.S. data showed that fatal or serious injuries of truck drivers are caused mainly by rollover, collision with a light vehicle or another truck, or collision with fixed objects. Rollover crashes account for most serious injuries, and pose the highest injury risk per crash. By controlling for the difference in crash-type distributions between trucks and light vehicles, seatbelts were estimated to be about 58% effective in reducing truck-driver injuries—comparable to the value for light vehicles. Airbags’ effectiveness was calculated to be about 6% for unbelted truck drivers and 4% for belted truck drivers—lower than that for light vehicles, primarily because of the higher proportion of rollover injuries sustained by truck drivers. The main relevant difference between truck-driving conditions in the U.S. and China is the seatbelt-use rate of truck drivers: greater than 70% in the U.S., but likely less than 10% in China. This difference would likely reduce the true effectiveness of seatbelts. Therefore, it is important to encourage Chinese truck drivers to wear seatbelts, because the effectiveness of seatbelts at high use rates is much greater than that for airbags. In addition, the lower truck traveling speeds in China would likely result in a lower percentage of truck rollover crashes than in the U.S. Consequently, the effectiveness of both seatbelts and airbags in reducing truck driver injuries may be slightly higher in China than in the U.S.Sustainable Worldwide Transportationhttp://deepblue.lib.umich.edu/bitstream/2027.42/95707/1/102923.pd

Generating Persona Consistent Dialogues by Exploiting Natural Language Inference

Consistency is one of the major challenges faced by dialogue agents. A human-like dialogue agent should not only respond naturally, but also maintain a consistent persona. In this paper, we exploit the advantages of natural language inference (NLI) technique to address the issue of generating persona consistent dialogues. Different from existing work that re-ranks the retrieved responses through an NLI model, we cast the task as a reinforcement learning problem and propose to exploit the NLI signals from response-persona pairs as rewards for the process of dialogue generation. Specifically, our generator employs an attention-based encoder-decoder to generate persona-based responses. Our evaluator consists of two components: an adversarially trained naturalness module and an NLI based consistency module. Moreover, we use another well-performed NLI model in the evaluation of persona-consistency. Experimental results on both human and automatic metrics, including the model-based consistency evaluation, demonstrate that the proposed approach outperforms strong generative baselines, especially in the persona-consistency of generated responses.Comment: AAAI20. Update code link

PO-164 Effect of exercise intervention on appetite regulating hormones in obese children

Objective Obesity in children usually develops from early age and is due to chronic energy imbalance, and long-term exercise has been shown to have the capacity to alter the sensitivity of the appetite regulatory system. Therefore, the current study was designed to examine the circulating levels of appetite regulating hormones after exercise intervention in obese children. Methods 24 obese children were subjected to exercise training program lasted for 6 weeks, and eating behavior of the children were evaluated using the Children Eating Behavior Questionnaire (CEBQ) before and after intervention. Plasma leptin and ghrelin were also determined using ELISA kits. Results Circulating levels of cholesterol, triglycerides, and low-density lipoprotein cholesterol were also decreased with significant difference (P<0.05), while high-density lipoprotein cholesterol was significantly increased (P<0.05). Fasting plasma glucose was also decrease but with no significant difference. The level of leptin was decreased after 6 weeks intervention with no statistical significance, while the circulating level of ghrelin was significantly enhanced (P<0.05). The scores of FR and EF were significantly decreased (P<0.05) after intervention. No significant change was found on SR and SE of CEBQ, even though they were observed increased compared with that of baseline. Conclusions The current study found that there were obvious effects of 6 weeks exercise intervention on appetite regulating hormones and subjective appetite changes in obese children