• Title/Summary/Keyword: Katrina

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SPH Modeling of Hydraulics and Erosion of HPTRM Levee

  • Li, Lin;Rao, Xin;Amini, Farshad;Tang, Hongwu
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.1
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    • pp.1-13
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    • 2015
  • Post-Katrina investigations revealed that most earthen levee damage occurred on the levee crest and landward-side slope as a result of either wave overtopping, storm surge overflow, or a combination of both. In this paper, combined wave overtopping and storm surge overflow of a levee embankment strengthened with high performance turf reinforcement mat (HPTRM) system was studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. After the SPH model is calibrated with full-scale overtopping test results, the overtopping discharge, flow thickness, flow velocity, average overtopping velocity, shear stress, and soil erosion rate are calculated. New equations are developed for average overtopping discharge. The shear stresses on landward-side slope are calculated and the characteristics of soil loss are given. Equations are also provided to estimate soil loss rate. The range of the application of these equations is discussed.

VRS-GPS Measure of Typhoon Surge Flood Determinedin Busan Coastal Topography (부산 연안지형 VRS-GPS 계측을 통한 태풍해일 침수예측)

  • Kim, Ga-Ya;Jung, Kwang-Hyo;Kim, Jeong-Ho
    • Journal of Ocean Engineering and Technology
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    • v.26 no.1
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    • pp.47-53
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    • 2012
  • A coastal flood area was predicted using the empirical superposition of the typhoon surge level and typhoon wave height along the Busan coastal area. The historical typhoon damages were reviewed, and the coastal topography was measured using VRS-GPS. A FEMA formula was applied to estimate the coastal flood area in a typhoon case when the measured and predicted data of typhoon waves are not available. The results in the area of Haeundae beach and Gwangalli beach were verified using the flood area data from the case of Typhoon Maemi (2003). If a Hurricane Katrina class typhoon were to pass through the Maemi trajectory, the areathat would be flooded along theBusan coastal area was predicted and compared with the results of the Maemi case. Because of the lack of ocean environment data such as data for the sea level, waves, bathymetry, wind, pressure, etc., it is hard to improve the prediction accuracy for the coastal flood area in the typhoon case, which could be reflected in the policy to mitigate a typhoon's impact. This paper discusses the kinds of ocean environment information that is needed to predict a typhoon's impact with better accuracy.

The use of mobile computing devices in microsurgery

  • Pafitanis, Georgios;Hadjiandreou, Michalis;Miller, Robert;Mason, Katrina;Theodorakopoulou, Evgenia;Sadri, Amir;Taylor, Kirsten;Myers, Simon
    • Archives of Plastic Surgery
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    • v.46 no.2
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    • pp.102-107
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    • 2019
  • Mobile computing devices (MCDs), such as smartphones and tablets, are revolutionizing medical practice. These devices are almost universally available and offer a multitude of capabilities, including online features, streaming capabilities, high-quality cameras, and numerous applications. Within the surgical field, MCDs are increasingly being used for simulations. Microsurgery is an expanding field of surgery that presents unique challenges to both trainees and trainers. Simulation-based training and assessment in microsurgery currently play an integral role in the preparation of trainee surgeons in a safe and informative environment. MCDs address these challenges in a novel way by providing valuable adjuncts to microsurgical training, assessment, and clinical practice through low-cost, effective, and widely accessible solutions. Herein, we present a review of the capabilities, accessibility, and relevance of MCDs for technical skills acquisition, training, and clinical microsurgery practice, and consider the possibility of their wider use in the future of microsurgical training and education.

Cost-effective method for reducing local failure of floodwalls verified by centrifuge tests

  • Chung R. Song;Binyam Bekele;Brian D. Sawyer;Ahmed Al-Ostaz;Alexander Cheng;Vanadit-Ellis Wipawi
    • Geomechanics and Engineering
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    • v.33 no.2
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    • pp.155-165
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    • 2023
  • Hurricane Katrina swept New Orleans, Louisiana, USA, in 2005, causing more than 1,000 fatalities and severe damage to the flood protection system. Recovery activities are complete, however, clarifying failure mechanisms and devising resilient and cost-effective retrofitting techniques for the flood protection system are still of utmost importance to enhance the general structural integrity of water retaining structures. This study presents extensive centrifuge test results to find various failure mechanisms and effective retrofitting techniques for a levee system. The result confirmed the rotational failure and translational failure mechanisms for the London Ave. Canal levee and 17th St. Canal levee, respectively. In addition, it found that the floodwalls with fresh waterstop in their joints perform better than those with old/weathered waterstop by decreasing pore water pressure build-up in the levee. Structural caps placed on the top of the joints between I-walls could also prevent local failure by spreading the load to surrounding walls. At the same time, the self-sealing bentonite-sand mixture installed along the riverside of floodwalls could mitigate the failure of floodwalls by blocking the infiltration of seepage water into the gap formed between levee soils and floodwalls.

A Review on Urban Resilience Assessment Methods

  • Barjau, Jaime;Wong, Francis K.W.;Fang, Dongping
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.685-686
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    • 2015
  • The world is currently undergoing an intense urbanization process. The percentage of urban dwellers has never been so high. In 2010, and for the first time, urban population surpassed the rural one, accounting for 51% of global population, and this trend will continue in the forthcoming years. This increment in concentration of population and supporting assets in cities, make their performance a critical issue for world population. Recent events such as Fukushima tsunami and the hurricane Katrina have shown how fragile built environments are and the unpredictability of occurrence and magnitude of the hazards. Such an expansion of the world's urban population, together with an increase in severity and number of hazards and catastrophes, has put under the spotlight the necessity to build cities not only sustainable, but resilient. Decision makers should acknowledge failure as an option, and the importance of developing city resilience. This paper will provide an initial review on urban resilience, definitions and assessment approaches as a first step for decision makers to account for resilience in their decision making process.

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Measurement of Time-Series Surface Deformation at New Orleans Using Small Baseline Subset (SBAS) Method

  • Jo, Min-Jeong;Eom, Jin-Ah;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.49-52
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    • 2008
  • New Orleans located in the estuary of the Mississippi River was attacked by Hurricane Katrina and suffered big flood on August 2005. Since unconsolidated Holocene to middle Miocene strata is the main basement rocks, land subsidence has been occurred steadily due to soil compaction and normal faulting. It was reported that the maximum subsidence rate from 2002 to 2005 was -29 mm/yr. Many studies in the area have been carried out for understanding the subsiding and potential risks caused by ground subsidence are weighted by the fact that a large area of the city is located below the mean sea level. A small baseline subset (SBAS) method is applied for effectively measuring time-series LOS (Line-of sight) surface deformation from differential synthetic aperture radar interferograms in this study. The time-series surface deformation at New Orleans was measured from RADARSAT-1 SAR images. The used dataset consists of twenty-one RADARSAT-1 fine beam mode images on descending orbits from February 2005 to February 2007 and another twenty-one RADARSAT-1 standard beam mode images on ascending orbits from January 2005 to February 2007. From this dataset, 25 and 38 differential interferograms on descending and ascending orbits were constructed, respectively. The vertical and horizontal components of surface deformation were extracted from ascending and descending LOS surface deformations. The result from vertical component of surface deformation indicates that subsidence is not significant with a mean rate of -3.1${\pm}$3.2 mm/yr.

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Effective Leadership in Public Organizations: The Impact of Organizational Structure in Asian Countries

  • Valero, Jesus N.
    • Journal of Contemporary Eastern Asia
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    • v.14 no.2
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    • pp.69-79
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    • 2015
  • Among public organizations, does variation in organizational structure explain variation in public managers' leadership styles (e.g., transformational and transactional leadership)? The study of leadership in public organizations is increasingly an area of scholarly interest partly sparked by movements to reform public organizations, particularly in the context of emergency management. There is, for example, a need for effective leadership that can help organizations respond to disasters (Kapucu et al. 2010; Van Wart and Kapucu 2011; Stern 2013). There are numerous documented cases where the lack of leadership skills has been linked to major social and economic losses as a result of poor disaster response (e.g., Hurricane Katrina in the U.S.). Yet, leadership is a complex concept and numerous theoretical frameworks have been developed to help explain it (Van Wart 2005). Practically speaking, the existence of different theories of leadership suggests that public managers can decide to exercise various styles of leadership. The style of leadership that a public manager exhibits matters because some styles are perceived to be more effective than others (Trottier et al. 2008). While the effects of leadership have been extensively studied, antecedents or predictors of leadership style have received little scholarly attention (Wright and Pandey 2009; Nielsen and Cleal 2011). The purpose of this research note then is to explore the potential causal relationship between the structure of an organization and the ability of a public manager to exercise transformational leadership in the context of emergency management in two Asian countries: South Korea and Japan. This research note consists of three main sections. The following section explores the relationship between leadership and organizational structure. The second section examines how certain concepts of leadership and organizational structure were applied in two case studies of disaster response. The final section presents some directions for future research.

Advancing Cardio-Oncology in Asia

  • Choon Ta Ng;Li Ling Tan;Il Suk Sohn;Hilda Gonzalez Bonilla;Toru Oka;Teerapat Yinchoncharoen;Wei-Ting Chang;Jun Hua Chong;Maria Katrina Cruz Tan;Rochelle Regina Cruz;Astri Astuti;Vivek Agarwala;Van Chien;Jong-Chan Youn;Jieli Tong;Joerg Herrmann
    • Korean Circulation Journal
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    • v.53 no.2
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    • pp.69-91
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    • 2023
  • Cardio-oncology is an emerging multi-disciplinary field, which aims to reduce morbidity and mortality of cancer patients by preventing and managing cancer treatment-related cardiovascular toxicities. With the exponential growth in cancer and cardiovascular diseases in Asia, there is an emerging need for cardio-oncology awareness among physicians and country-specific cardio-oncology initiatives. In this state-of-the-art review, we sought to describe the burden of cancer and cardiovascular disease in Asia, a region with rich cultural and socio-economic diversity. From describing the uniqueness and challenges (such as socio-economic disparity, ethnical and racial diversity, and limited training opportunities) in establishing cardio-oncology in Asia, and outlining ways to overcome any barriers, this article aims to help advance the field of cardio-oncology in Asia.

Development for the function of Wind wave Damage Estimation at the Western Coastal Zone based on Disaster Statistics (재해통계기반 서해 연안지역의 풍랑피해예측함수 개발)

  • Choo, Tai Ho;Kwak, Kil Sin;Ahn, Si Hyung;Yang, Da Un;Son, Jong Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.14-22
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    • 2017
  • The frequency and scale of natural disasters due to the abnormal climate phenomena caused by global warming have being increasing all over the world. Various natural disasters, such as typhoons, earthquakes, floods, heavy rain, drought, sweltering heat, wind waves, tsunamis and so on, can cause damage to human life. Especially, the damage caused by natural disasters such as the Earthquake of Japan, hurricane Katrina in the United States, typhoon Maemi and so on, have been enormous. At this stage, it is difficult to estimate the scale of damage due to (future) natural disasters and cope with them. However, if we could predict the scale of damage at the disaster response level, the damage could be reduced by responding to them promptly. In the present study, therefore, among the many types of natural disaster, we developed a function to estimate the damage due to wind waves caused by sea winds and waves. We collected the damage records from the Disaster Report ('91~'14) published by the Ministry of Public Safety and Security about wind waves and typhoons in the western coastal zone and, in order to reflect the inflation rate, we converted the amount of damage each year into the equivalent amount in 2014. Finally, the meteorological data, such as the wave height, wind speed, tide level, wave direction, wave period and so on, were collected from the KMA (Korea Meteorological Administration) and KHOA (Korea Hydrographic and Oceanographic Agency)'s web sites, for the periods when wind wave and typhoon damage occurred. After that, the function used to estimate the wind wave damage was developed by reflecting the regional characteristics for the 9 areas of the western coastal zone.

A Study on the Prediction Function of Wind Damage in Coastal Areas in Korea (국내 해안지역의 풍랑피해 예측함수에 관한 연구)

  • Sim, Sang-bo;Kim, Yoon-ku;Choo, Yeon-moon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.69-75
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    • 2019
  • The frequency of natural disasters and the scale of damage are increasing due to the abnormal weather phenomenon that occurs worldwide. Especially, damage caused by natural disasters in coastal areas around the world such as Earthquake in Japan, Hurricane Katrina in the United States, and Typhoon Maemi in Korea are huge. If we can predict the damage scale in response to disasters, we can respond quickly and reduce damage. In this study, we developed damage prediction functions for Wind waves caused by sea breezes and waves during various natural disasters. The disaster report (1991 ~ 2017) has collected the history of storm and typhoon damage in coastal areas in Korea, and the amount of damage has been converted as of 2017 to reflect inflation. In addition, data on marine weather factors were collected in the event of storm and typhoon damage. Regression analysis was performed through collected data, Finally, predictive function of the sea turbulent damage by the sea area in 74 regions of the country were developed. It is deemed that preliminary damage prediction can be possible through the wind damage prediction function developed and is expected to be utilized to improve laws and systems related to disaster statistics.