Browsing by Author "Wang, Qi"

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    5th International Symposium on Focused Ultrasound
    Abounader, Roger; Abraham, Christopher; Adema, Gosse; Agrawal, Punit; Airan, Raag; Aleman, Dionne; Alexander, Phillip; Alkins, Ryan; Alnazeer, Moez; Altman, Michael; Aly, Amirah; Amaral, Joao G.; Amrahli, Maral; Amraoui, Sana; Andarawewa, Kumari; Andriyakhina, Yulia; Angstadt, Mary; Ankou, Bénédicte; Arias, Ana C.; Arvanitis, Costas; Asadnia, Kiana; Aubert, Isabelle; Aubry, Jean-Francois; Aubry, Jean-Francois; Aurup, Christian; Bader, Kenneth; Badr, Lena; Baek, Hongchae; Barbato, Gaetano; Beccaria, Kevin; Bellorofonte, Carlo; Benson, Lee; Bernus, Olivier; Berriet, Rémi; Bertolina, Jim; Beskin, Viktoriya; Bessière, Francis; Bethune, Allison; Bezzi, Mario; Bond, Aaron; Bonomo, Guido; Borowsky, Alexander; Borys, Nicolas; Böttcher, Joachim; Bouley, Donna; Bour, Pierre; Bourekas, Eric; Brenin, David; Brokman, Omer; Brosh, Inbar; Buckner, Andrew; Bullock, Timothy; Cafarelli, Andrea; Cahill, Jessica; Camarena, Francisco; Camelo-Piragua, Sandra; Campbell, Benjamin; Campbell, Fiona; Cannata, Jon; Canney, Michael; Carlson, Roy; Carneiro, Antonio; Carpentier, Alexandre; Catheline, Stefan; Cavin, Ian; Cesana, Claudio; Chabok, Hamid R.; Chamanara, Marzieh; Chang, Jin H.; Chang, Won S.; Changizi, Barbara; Chapelon, Jean Y.; Chaplin, Vandiver; Chapman, Martin; Chaudhary, Neeraj; Chaussy, Christian; Chen, Cherry; Chen, Johnny; Chen, Wohsing; Chen, Xiaoming; Chevalier, Philippe; Chiou, George; Chisholm, Alexander; Christofferson, Ivy; Chung, Hyun H.; Ciuti, Gastone; Clement, Gregory; Cooper, Mark; Corea, Joseph; Corso, Cristiano; Cosman, Josh; Coughlin, Dezba; Crake, Calum; Cunitz, Bryan; Curiel, Laura; Curley, Colleen T.; Czarnota, Gregory; Dababou, Susan; Dallapiazza, Robert; de Bever, Joshua; de Jager, Bram; de Ruiter, Joost; de Senneville, Baudouin D.; Deckers, Roel; Delattre, Jean-Yves; den Brok, Martijn; Dhanaliwala, Ali; Diodato, Alessandro; Dixon, Adam; Donner, Elizabeth; Downs, Matthew; Du, Zhongmin; Dubois, Rémi; Dupre, Aurelien; Eikelenboom, Dylan; Elias, W. J.; Ellens, Nicholas; Endre, Ruby; Eran, Ayelet; Erasmus, Hans-Peter; Everstine, Ashli; Farahani, Keyvan; Farrer, Alexis; Farry, Justin; Federau, Christian; Feng, Xue; Ferrer, Cyril; Ferrera, Vincent; Fishman, Paul; Foley, Jessica; Frenkel, Victor; Fütterer, Jurgen; Gach, H. M.; Gandhi, Dheeraj; Gertner, Michael; Goldsher, Dorit; Gorgone, Alessandro; Greillier, Paul; Griesenauer, Rebekah; Grissom, William; Grondin, Julien; Guha, Chandan; Gulati, Amitabh; Gullapalli, Rao; Guo, Sijia; Gupta, Samit; Gurm, Hitinder; Gwinn, Ryder; Hadley, Rock; Haïssaguerre, Michel; Hammoud, Dima; Hananel, Arik; Hargrove, Amelia; Hatch, Robert; Haworth, Kevin; Hazan, Eilon; He, Ye; Heemels, Maurice; Heerschap, Arend; Hilas, Elaine; Hoang-Xuan, Khe; Hocini, Mélèze; Hodaie, Mojgan; Hofmann, Denis; Holland, Christy; Hoogenboom, Martijn; Hopyan, Sevan; Hossack, John; Houdouin, Alexandre; Hsu, Po-Hung; Hu, Jim; Hurwitz, Mark; Huss, Diane; Hwang, Chang-il; Hwang, Joo H.; Idbaih, Ahmed; Ikeuchi, Masahiko; Ingham, Elizabeth; Ives, Kimberly; Izumi, Masashi; Jackson-Lewis, Vernice; Janát-Amsbury, Margit; Jang, Kee W.; Jedruszczuk, Kathleen; Jiménez-Gambín, Sergio; Jiménez, Noé; Johnson, Sara; Jonathan, Sumeeth; Joy, Joyce; Jung, Hyun H.; Jung, Na Y.; Kahn, Itamar; Kamimura, Hermes; Kamrava, Seyed K.; Kang, Jeeun; Kang, Kook J.; Kang, Soo Y.; Kao, Yi-tzu; Katti, Prateek; Kawasaki, Motohiro; Kaye, Elena; Keupp, Jochen; Kim, AeRang; Kim, Harry; Kim, Hyun-Chul; Kim, Hyuncheol; Kim, Hyungmin; Kim, Min S.; Kim, Namho; Kiyasu, Katsuhito; Kneepkens, Esther; Knopp, Michael; Kobus, Thiele; Koral, Korgun; Kreider, Wayne; Krishna, Vibhor; Krug, Roland; Krupa, Steve; Kuo, Chia-Chun; Kwiecinski, Wojciech; Lacoste, Romain; Lam, Heather; Lamberti-Pasculli, Maria; Lang, Brian; Larner, James; Larrabee, Zachary; Leach, J. K.; LeBlang, Suzanne; Leclercq, Delphine; Lee, Hak J.; Lee, Jong-Hwan; Lehericy, Stéphane; Leighton, Wan; Leung, Steven; Lewis, Bobbi; Lewis, Matthew; Li, Dawei; Linn, Sabine; Lipsman, Nir; Liu, Hao-Li; Liu, Jingfei; Lopes, M. B.; Lotz, Jeff; Lu, Xin; Lundt, Jonathan; Luo, Xi; Lustgarten, Lior; Lustig, Micheal; Macoskey, Jonathan; Madore, Bruno; Maev, Roman; Magat, Julie; Maimbourg, Guillaume; Maimon, Noam; Mainprize, Todd; Malayer, Jerry; Maples, Danny; Marquet, Fabrice; Marrocchio, Cristina; Marx, Mike; Mastorakos, Panagiotis; Mauri, Giovanni; McLean, Hailey; McMichael, John; Mead, Brian P.; Melodelima, David; Melot-Dusseau, Sandrine; Menciassi, Arianna; Merrill, Robb; Meyer, Joshua; Midiri, Massimo; Miga, Michael; Migliore, Ilaria G.; Miller, Eric; Minalga, Emilee; Moon, Hyungwon; Moore, David; Mourad, Pierre; Mouratidis, Petros; Mueller, Michael; Mugler, John; Muller, Sébastien; Namba, Hirofumi; Naor, Omer; Nassar, Maria; Nazai, Navid; Negron, Karina; Negussie, Ayele; Nguyen, Thai-Son; Nicolay, Klaas; Nikolaeva, Anastasia V.; Oetgen, Matthew; Olive, Kenneth; Olumolade, Oluyemi; Orsi, Franco; Owens, Gabe; Ozilgen, Arda; Padegimas, Linas; Palermo, Carmine; Pan, Chia-Hsin; Pandey, Aditya; Papadakis, Georgios; Park, Chang K.; Park, Sang M.; Parker, Jonathon; Parvizi, Mohammad H.; Pascal-Tenorio, Aurea; Patel, Janish; Patz, Sam; Payen, Thomas; Perich, Eloi; Pernot, Mathieu; Perol, David; Perry, James; Pillarisetty, Venu; Pioche, Mathieu; Pizzuto, Matthew; Plaksin, Michael; Plata, Juan; Price, Karl; Prince, Jessica; Przedborski, Serge; Quinones-Hinojosa, Alfredo; Ramachandran, Akhilesh; Ranjan, Ashish; Ravikumar, Vinod; Reichenbach, Juergen; Repasky, Elizabeth; Rezai, Ali; Ritter, Philippe; Rivoire, Michel; Rochman, Carrie; Rosenberg, Jarrett; Rosnitskiy, Pavel B.; Ruiz, Antonio; Sahgal, Arjun; Samiotaki, Gesthimani; Sanghvi, Narendra; Santin, Mathieu D.; Santos, Domiciano; Sasaki, Noboru; Sastra, Steve; Schade, George; Schall, Jeffrey; Schlesinger, Ilana; Schmitt, Paul; Schwaab, Julia; Scionti, Stephen; Scipione, Roberto; Scoarughi, Gian L.; Scott, Serena; Sebeke, Lukas; Seifabadi, Reza; Seo, Jai; Sesenoglu-Laird, Ozge; Shah, Binit; Shahriari, Kian; Shaikh, Sumbul; Shea, Jill; Shi, Jiaqi; Shim, Jenny; Shinkov, Alexander; Shuman, Jillian; Silvestrini, Matthew; Sim, Changbeom; Sin, Vivian; Sinai, Alon; Singh, Manoj; Sinilshchikov, Ilya; Skalina, Karin; Slingluff, Craig; So, Po-Wah; Solomon, Stephen; Son, Keon H.; Sperling, Scott; Stein, Ruben; Stein, Sherman; Stevens, Aaron; Stimec, Jennifer; Storm, Gert; Straube, William; Suelmann, Britt; Sutton, Jonathan; Svedin, Bryant; Takemasa, Ryuichi; Takiguchi, Mitsuyoshi; Tam, Emily; Tan, Jeremy; Tang, Xinyan; Tanter, Mickael; Tebebi, Pamela; Tehrani, Seruz; Temple, Michael; Teofilovic, Dejan; ter Haar, Gail; Terzi, Marina E.; Thueroff, Stefan; Timbie, Kelsie; Tognarelli, Selene; Tretbar, Steffen; Trudeau, Maureen; Tsai, Yi-Chieh; Tsysar, Sergey A.; Tucci, Samantha; Tuveson, David; Ushida, Takahiro; Vaessen, Paul; Vaillant, Fanny; Van Arsdell, Glen; van Breugel, Johanna; Van der Jeugd, Anneke; Van der Jeugd, Anneke; Van der Wall, Elsken; van Diest, Paul; van Stralen, Marijn; Varano, Gianluca; Velat, Manuela; Vidal-Jove, Joan; Vigna, Paolo D.; Vignot, Alexandre; Vincenot, Jeremy; Vykhodtseva, Natalia; Wang, Bin; Wang, Han; Wang, Kevin; Wang, Qi; Wang, Qingguo; Wang, Shengping; Wang, Yak-Nam; Wang, Zhaorui; Wardlow, Rachel; Warren, Amy; Waszczak, Barbara; Watson, Katherine; Webb, Taylor; Wei-Bin, Shen; Wei, Kuo-Chen; Weiss, Steffen; Weissler, Yoni; Werner, Beat; Wesseling, Pieter; Williams, Noelle; Wilson, Emmanuel; Wintermark, Max; Witkamp, Arjen; Wong, Carlos; Wu, Jing-Fu; Wydra, Adrian; Xu, Alexis; Xu, Doudou; Xu, Su; Yang, Georgiana; Yang, Nai-Yi; Yao, Chen; Yarowsky, Paul; Ye, Patrick P.; Yuldashev, Petr; Zaaroor, Menashe; Zachiu, Cornel; Zahos, Peter; Zangos, Stephan; Zhang, Dandan; Zhang, Hua; Zhang, Jimin; Zhang, Junhai; Zhang, Xi; Zhao, Li; Zhong, Pei; Zhuo, Jiachen; Zidowitz, Stephan; Zinke, Wolf; Zorgani, Ali (2016-11-21)
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    Aggregated responses of human mobility to severe winter storms: An empirical study
    Wang, Yan; Wang, Qi; Taylor, John E. (PLOS, 2017-12-07)
    Increasing frequency of extreme winter storms has resulted in costly damages and a disruptive impact on the northeastern United States. It is important to understand human mobility patterns during such storms for disaster preparation and relief operations. We investigated the effects of severe winter storms on human mobility during a 2015 blizzard using 2.69 million Twitter geolocations. We found that displacements of different trip distances and radii of gyration of individuals' mobility were perturbed significantly. We further explored the characteristics of perturbed mobility during the storm, and demonstrated that individuals' recurrent mobility does not have a higher degree of similarity with their perturbed mobility, when comparing with its similarity to non-perturbed mobility. These empirical findings on human mobility impacted by severe winter storms have potential long-term implications on emergency response planning and the development of strategies to improve resilience in severe winter storms.
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    Atomic-Level Structural Dynamics of Polyoxoniobates during DMMP Decomposition
    Wang, Qi; Chapleski, Robert C. Jr.; Plonka, Anna M.; Gordon, Wesley O.; Guo, Weiwei; Thuy-Duong Nguyen-Phan; Sharp, Conor H.; Marinkovic, Nebojsa S.; Senanayake, Sanjaya D.; Morris, John R.; Hill, Craig L.; Troya, Diego; Frenkel, Anatoly I. (Springer Nature, 2017-04-10)
    Ambient pressure in situ synchrotron-based spectroscopic techniques have been correlated to illuminate atomic-level details of bond breaking and formation during the hydrolysis of a chemical warfare nerve agent simulant over a polyoxometalate catalyst. Specifically, a Cs-8[Nb6O19] polyoxoniobate catalyst has been shown to react readily with dimethyl methylphosphonate (DMMP). The atomic-level transformations of all reactant moieties, the [Nb6O19](8)-polyanion, its Cs+ counterions, and the DMMP substrate, were tracked under ambient conditions by a combination of X-ray absorption fine structure spectroscopy, Raman spectroscopy, and X-ray diffraction. Results reveal that the reaction mechanism follows general base (in contrast to specific base) hydrolysis. Together with computational results, the work demonstrates that the ultimate fate of DMMP hydrolysis at the Cs-8[Nb6O19] catalyst is strong binding of the (methyl) methylphosphonic acid ((M) MPA) product to the polyanions, which ultimately inhibits catalytic turnover.
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    Diffusion Dynamics of Energy Saving Practices in Large Heterogeneous Online Networks
    Mohammadi, Neda; Wang, Qi; Taylor, John E. (PLOS, 2016-10-13)
    Online social networks are today's fastest growing communications channel and a popular source of information for many, so understanding their contribution to building awareness and shaping public perceptions of climate change is of utmost importance. Today's online social networks are composed of complex combinations of entities and communication channels and it is not clear which communicators are the most influential, what the patterns of communication flow are, or even whether the widely accepted two-step flow of communication model applies in this new arena. This study examines the diffusion of energy saving practices in a large online social network across organizations, opinion leaders, and the public by tracking 108,771 communications on energy saving practices among 1,084 communicators, then analyzing the flow of information and influence over a 28 day period. Our findings suggest that diffusion networks of messages advocating energy saving practices are predominantly led by the activities of dedicated organizations but their attempts do not result in substantial public awareness, as most of these communications are effectively trapped in organizational loops in which messages are simply shared between organizations. Despite their comparably significant influential values, opinion leaders played a weak role in diffusing energy saving practices to a wider audience. Thus, the two-step flow of communication model does not appear to describe the sharing of energy conservation practices in large online heterogeneous networks. These results shed new light on the underlying mechanisms driving the diffusion of important societal issues such as energy efficiency, particularly in the context of large online social media outlets.
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    Human Mobility Perturbation and Resilience in Natural Disasters
    Wang, Qi (Virginia Tech, 2015-04-30)
    Natural disasters exert a profound impact on the world population. In 2012, natural disasters affected 106 million people, forcing over 31.7 million people to leave their homes. Climate change has intensified natural disasters, resulting in more catastrophic events and making extreme weather more difficult to predict. Understanding and predicting human movements plays a critical role in disaster evacuation, response and relief. Researchers have developed different methodologies and applied several models to study human mobility patterns, including random walks, Lévy flight, and Brownian walks. However, the extent to which these models may apply to perturbed human mobility patterns during disasters and the associated implications for improving disaster evacuation, response and relief efforts is lacking. My PhD research aims to address the limitation in human mobility research and gain a ground truth understanding of human mobility patterns under the influence of natural disasters. The research contains three interdependent projects. In the first project, I developed a novel data collecting system. The system can be used to collect large scale data of human mobility from large online social networking platforms. By analyzing both the general characteristics of the collected data and conducting a case study in NYC, I confirmed that the data collecting system is a viable venue to collect empirical data for human mobility research. My second project examined human mobility patterns in NYC under the influence of Hurricane Sandy. Using the data collecting system developed in the first project, I collected 12 days of human mobility data from NYC. The data set contains movements during and several days after the strike of Hurricane Sandy. The results showed that human mobility was strongly perturbed by Hurricane Sandy, but meanwhile inherent resilience was observed in human movements. In the third project, I extended my research to fifteen additional natural disasters from five categories. Using over 3.5 million data entries of human movement, I found that while human mobility still followed the Lévy flight model during these disaster events, extremely powerful natural disasters could break the correlation between human mobility in steady states and perturbation states and thus destroy the inherent resilience in human mobility. The overall findings have significant implications in improving understanding and predicting human mobility under the influence of natural disasters and extreme events.
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    International Workshop on Digital Twins for Smart Health
    Deng, Jun; Ding, Ying; Achenie, Luke; Liu, Jinwei; Pan, Shimei; Purushotham, Sanjay; Wu, Huanmei; Wang, Qi (ACM, 2023-05)
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    Patterns and Limitations of Urban Human Mobility Resilience under the Influence of Multiple Types of Natural Disaster
    Wang, Qi; Taylor, John E. (Public Library of Science, 2016-01-28)
    Natural disasters pose serious threats to large urban areas, therefore understanding and predicting human movements is critical for evaluating a population’s vulnerability and resilience and developing plans for disaster evacuation, response and relief. However, only limited research has been conducted into the effect of natural disasters on human mobility. This study examines how natural disasters influence human mobility patterns in urban populations using individuals’ movement data collected from Twitter. We selected fifteen destructive cases across five types of natural disaster and analyzed the human movement data before, during, and after each event, comparing the perturbed and steady state movement data. The results suggest that the power-law can describe human mobility in most cases and that human mobility patterns observed in steady states are often correlated with those in perturbed states, highlighting their inherent resilience. However, the quantitative analysis shows that this resilience has its limits and can fail in more powerful natural disasters. The findings from this study will deepen our understanding of the interaction between urban dwellers and civil infrastructure, improve our ability to predict human movement patterns during natural disasters, and facilitate contingency planning by policymakers.
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    Quantifying Human Mobility Perturbation and Resilience in Hurricane Sandy
    Wang, Qi; Taylor, John E. (Public Library of Science, 2014-11-19)
    Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.
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    Tracking Disaster Dynamics for Urban Resilience: Human-Mobility and Semantic Perspectives
    Wang, Yan (Virginia Tech, 2018-06-11)
    Fostering urban resilience and creating agility to disaster response is an urgent task faced by cities worldwide in the context of climate change and increasing frequencies of natural disasters. Understanding and tracking the dynamic process of resilience to disasters is the first step to operationalize the concept of urban resilience. In this dissertation, I present four related but evolutionary perspectives to investigate the impact of natural disasters on interactive human-environment systems as well as the dynamic process of resilience, including human mobility, spatial networks, and coupled mobility and sentiment perspectives. In the first, human-mobility perspective, I examine the nuanced impact of a severe winter storm on human mobility patterns and the relationship between perturbed mobility during the storm and recurrent mobility under normal circumstances. In the second, where I adopt a spatial network perspective, I investigate the dynamic process of resilience over time by analyzing networked human-spatial systems using an ecology-inspired approach. The third perspective involves sentiment as an additional factor to human mobility to understand urban dynamics during an earthquake. In this perspective, I explore the relation between disaster magnitude and a population's collective sentiment, as well as temporal correlations between sentiment and mobility. Each of the three empirical studies employs a quantitative, empirical research methodology and uses voluntarily reported geo-referenced data collected through a Twitter Streaming API. After multiple investigations on diverse types of natural disaster (e.g. severe winter storm, flooding, hurricane, and earthquake), I develop a Detecting Urban Emergencies Technique (DUET), as the fourth part of my dissertation, for identifying and tracking general types of emergencies in a short period without prior definitions of emergent topics. Research findings from the three empirical studies and the proposed DUET detection technique introduce a new lens and approach for understanding population dynamics and achieving urban resilience. This dissertation contributes to a more complete understanding of urban resilience to disasters with crowdsourced data, and enables more effective urban informatics in the face of extreme events.