bluuebunny/crossref_metadata_2025 huggingface dataset:
Voices From the Future: What students, interns, and residents want from osteopathic graduate medical training
Authors: Kushner David , Cooney Joan
Published: February 2019

The need to attract students to-and keep them in-osteopathic internship and residency programs is great. Recognizing this fact, the osteopathic hospitals, through the American Osteopathic Hospital Association, have placed a renewed focus on liaisons with osteopathic medical education. Voices From the Future represents one such effort. This report reveals how osteopathic medical students, interns, and residents perceive the current state of osteopathic graduate medical education programs as well as the changes that they would like to see incorporated.
Suggestions for diagnosing avascular necrosis of the hip in the 1990s
Authors: Grimm Eric Scott , BLend, Michael J. , Anderson Thomas M.
Published: February 2019

Avascular necrosis of the hip is a serious clinical problem encountered by primary care physicians. It requires early detection for proper management and treatment. The clinician should be aware of the imaging modalities available for evaluation of patients with suspected avascular necrosis. Traditional studies include plain-film radiography, computed tomography, and planar bone scintigraphy. Magnetic resonance imaging and singlephoton emission computed tomography bone scanning have been developed to such an extent that they are now the most sensitive indicators of early avascular necrosis. The authors review currently available imaging modalities and provide a practical approach to the assessment of patients with suspected avascular necrosis of the hip.
Adult respiratory distress syndrome: A review for the clinician
Authors: Hammond Thomas Hooker, Michael P. D. , Salem Allen
Published: February 2019

Adult respiratory distress syndrome is a common respiratory problem with a wide array of precipitating causes and an overall mortality rate of more than 50%. Signs on physical examination tend to be nonspecific as do laboratory findings associated with the syndrome. Because of its diverse etiology, there is no one specific treatment for adult respiratory distress syndrome. Therapy is primarily supportive and centers around the use of mechanical ventilator support. The authors discuss the pathogenesis and management of this syndrome together with some of the newer approaches to mechanical ventilation.
Retained fetal scalp monitoring lead discovered in the wall of the jejunum
Authors: Kimm Kevin A. , Anderson Donald , Schossow Darwin
Published: February 2019

The retention of a foreign body following surgery is a longstanding and dreaded problem. We report the retention of a fetal scalp monitoring lead that was embedded in the wall of the patient's jejunum and discovered 2 years after cesarean section. In reviewing the American medical literature, we believe this case is, perhaps, unique. The treatment of this entity is discussed as well as ways to help to prevent it.
The lupus anticoagulant and antiphospholipid antibodies
Authors: Pertusi Raymond M.
Published: February 2019

Antiphospholipid antibody syndromes are primarily manifested as unexplained thrombotic events. Several antiphospholipid antibodies have been identified, the lupus anticoagulant being the most recognized. Considerable confusion surrounds this "anticoagulant," which is highly correlated with an increased risk of thrombosis. Several assays have been designed for the detection of antiphospholipid antibodies. There are limitations on their efficacy and interpretation requires judgment. Treatment strategies for the clinical manifestations of the antiphospholipid antibody syndrome are being developed. The explosive rise in the volume of literature dedicated to this topic will assure new and improved modalities for evaluation and treatment.
Hepatitis testing update
Authors: Burdash Nick , Fernandes John J.
Published: February 2019

During a 25-year period, four types of hepatitis-causing virus have been identified and can now be evaluated serologically. This final article in this clinical laboratory medicine series reviews routes of virus transmission and persistence and the availability of tests.
Roentgenographic documentation of atlanto-occipital sidebending
Authors: Goodbridge John P. , Donalson Brinton C.
Published: February 2019

It is assumed that the atlas (Cl) glides superiorly and laterally along the occipital (CO) condyle during translatory motion of the head in the opposite direction. To provide roentgenographic documentation, a translatory test of atlantooccipital (CO-Cl) motion was performed to the left and to the right on a healthy, asymptomatic volunteer subject. Roentgenographic examination was made at the extreme in each direction. The films indicate the change in atlantal position relative to the occiput and support the assumption. A translation of the head in the coronal plane to test for atlanto-occipital joint mobility is described.
Empty sella syndrome associated with partial hypopituitarism (visualized on MRI scan)
Authors: C.Serpico Peter , Freeman Jeffrey S. , Marks Burton
Published: February 2019

The empty sella syndrome has become a rather frequent finding in magnetic resonance imaging (MRI) scanning. The usual presentation of empty sella syndrome involves an incidental finding on a computed tomography scan or an MRI scan. It is unusual to find empty sella syndrome associated with hypopituitarism. The authors describe such an unusual finding in a 54-year-old nulliparous woman.
kuenm: an R package for detailed development of ecological niche models using Maxent
Authors: Cobos Marlon E. , Peterson A. Townsend , Barve Narayani , Osorio-Olvera Luis
Published: February 2019

Background

Ecological niche modeling is a set of analytical tools with applications in diverse disciplines, yet creating these models rigorously is now a challenging task. The calibration phase of these models is critical, but despite recent attempts at providing tools for performing this step, adequate detail is still missing. Here, we present the kuenm R package, a new set of tools for performing detailed development of ecological niche models using the platform Maxent in a reproducible way.

Results

This package takes advantage of the versatility of R and Maxent to enable detailed model calibration and selection, final model creation and evaluation, and extrapolation risk analysis. Best parameters for modeling are selected considering (1) statistical significance, (2) predictive power, and (3) model complexity. For final models, we enable multiple parameter sets and model transfers, making processing simpler. Users can also evaluate extrapolation risk in model transfers via mobility-oriented parity (MOP) metric.

Discussion

Use of this package allows robust processes of model calibration, facilitating creation of final models based on model significance, performance, and simplicity. Model transfers to multiple scenarios, also facilitated in this package, significantly reduce time invested in performing these tasks. Finally, efficient assessments of strict-extrapolation risks in model transfers via the MOP and MESS metrics help to prevent overinterpretation in model outcomes.
Species turnover reveals hidden effects of decreasing nitrogen deposition in mountain hay meadows
Authors: Roth Tobias , Kohli Lukas , Bühler Christoph , Rihm Beat , Meuli Reto Giulio , Meier Reto , Amrhein Valentin
Published: February 2019

Nitrogen (N) deposition is a major threat to biodiversity in many habitats. The recent introduction of cleaner technologies in Switzerland has led to a reduction in the emissions of nitrogen oxides, with a consequent decrease in N deposition. We examined different drivers of plant community change, that is, N deposition, climate warming, and land-use change, in Swiss mountain hay meadows, using data from the Swiss biodiversity monitoring program. We compared indicator values of species that disappeared from or colonized a site (species turnover) with the indicator values of randomly chosen species from the same site. While oligotrophic plant species were more likely to colonize, compared to random expectation, we found only weak shifts in plant community composition. In particular, the average nutrient value of plant communities remained stable over time (2003–2017). We found the largest deviations from random expectation in the nutrient values of colonizing species, suggesting that N deposition or other factors that change the nutrient content of soils were important drivers of the species composition change over the last 15 years in Swiss mountain hay meadows. In addition, we observed an overall replacement of species with lower indicator values for temperature with species with higher values. Apparently, the community effects of the replacement of eutrophic species with oligotrophic species was outweighed by climate warming. Our results add to the increasing evidence that plant communities in changing environments may be relatively stable regarding average species richness or average indicator values, but that this apparent stability is often accompanied by a marked turnover of species.
A STUDY ON WAVE TRANSFORMATION INSIDE SURF ZONE
Authors: Horikawa Kiyoshi , Kuo Chin-Tong
Published: February 2019

The wave transformation inside surf zone is treated analytically m this paper under the several appropriate assumptions. The theoretical curves computed numerically have a consistant agreement with the experimental data in the case of wave transformation on a horizontal bottom. On the other hand, m the case of wave transformation on a uniformly sloping beach, the analytical treatment seems to be inadequate to clarify the actual phenomena. Besides them the numerous data on wave height attenuation and others are presented m the graphical forms.
WAVE DAMPING EFFECT OF SUBMERGED DIKE
Authors: Nakamura Makoto , Shiraishi Hidehiko , Sasaki Yasuo
Published: February 2019

Up to present, submerged dikes were mainly used as detatched breakwaters for artificial nourishment of beach or a front dikes to protect a rear main dike. However, the application of submerged dike to artificial creation of a fishing-ground has been recently taken into consideration with great interest. The following four points are considered as the characteristics of a submerged dike. (1) Wave pressure and wave force acting on a submerged dike is smaller than those on other type breakwater because its crown is below the still water level. (2) Submerged dikes damp comparatively great waves, while comparatively small waves freely pass over submerged dikes. This is the most suitable condition for the fishing-ground. Namely, slightly wavy surface of water in the fishing-groud is rather desirable from a view-point of fish ecology. (3) Submerged dikes are usually constructed at comparativel low cost because their heights are lower and wave pressure operating on them is smaller in comparison with other type breakwater. (4) Since the water depth on the crown of submerged dikes is the most important facter that determines the effect of submerged dikes against wave action, the wave damping effect of submerged dike varies according to chang of tidal level. As for study on submerged dikes, many researchers have already published the results of their investigations, such as the theoretical studies by Lamb, Jeffreys, Dean, Johnson and Fuchs, the investigation of trapezoidal and triangular underwater barriers by the B.E.B. (U.S.A.), that of rectangular barriers by Morison, that of horizontal barrier by Hein and that of submerged cylinder by Ursell. Moreover, Johnson has recently reexamined a submerged dike, and in Japan the report by Hosoi and Tominaga was already published. The causes of wave damping due to a submerged dike can be considered that it absorbs some of the incident wave energy by causing the waves to break. Some of the remaining energy is dissipated by reflection and friction on the crown of the submerged dike and some transmitted shoreward. In the published reports as previously mentioned, the transmission coefficient has been obtained mainly by the investigations of wave reflection due to the submerged dike. The theoretical analysis of breaking phenomena is very difficult because of its complication. However, the wave damping effect due to submerged dike is made remarkable by causing the wave to break on the submerged dike. From this point of view, this report mainly deals with the wave damping effect due to breaking on tbe submerged dike and offers the experimental data for the practical use.
FIELD OBSERVATIONS OF WAVE PRESSURE, WAVE RUN-UP, AND OSCILLATION OF BREAKWATER
Authors: Muraki Yoshio
Published: February 2019

When a strong progressive wave collide against a shore structure, run-up and reflection of the wave take place on the front surface of the structure. At the same time, the structure is subjected to wave pressure resulting its oscillation or sometimes its sliding when the wave pressure is very large. Studies concerning such wave phenomena related to structures have been conducted by numerous scientists and engineers in many laboratories. While only a few investigations in the field have been made on these phenomena. At the same time it is noted that very few investigations have been carried out on the oscillation of breakwater caused by wave forces. The author performed some field observations on the wave pressure, wave run-up, and oscillation of breakwater at Haboro Harbor m Hokkaido, Japan, from 1957 to i960 (Refs. 1,2 and 3). In this paper the main results obtained from these observations such as the frequency of occurrence of shock pressure, the relationships among the run-up height, wave pressure and incident wave height, and the rocking phenomenon of the breakwater caused by wave pressure are summarized.
A STUDY ON MASS TRANSPORT IN BOUNDARY LAYERS IN STANDING WAVES
Authors: Noda Hideaki
Published: February 2019

This paper deals with the mass transport in the boundary layers developed on smooth and horizontal bottoms by standing waves in shallow water. In a theoretical approach, the basic equations of laminar boundary layers are applied to solving the oscillatory motion in the boundary layers caused by the standing waves. The mass transport velocities are derived on the basis of solutions of the second approximation which describe the flow velocity near the bottom, and the effects of convective terms involved in the basic equations are investigated. Experimental measurements in standing waves of mass transport velocity in the bottom boundary layer were carried out using dye-streak and solid-particle methods. The experimental data are compared with the theoretical prediction.
SYSTEMATIC COLLECTION OF BEACH DATA
Authors: Berg Dennis W.
Published: February 2019

Theoretical considerations of "beach "behavior are often hampered "by a lack of systematically obtained data sets which reflect the beach environment. For specific studies, lack of time and money often prevent the collection of such data sets. Thus, any opportunity for the collection of such data, on a routine basis, should be fully exploited l In 19679 the U S Army Corps of Engineers and the State of California initiated a cooperative program to collect empirical data at selected locations along the California coast. The objective was to establish a reservoir of repetitive, systematic observations, by qualified personnel, with the hope of securing a better understanding of the physical characteristics of the California shore and the littoral processes occurring there. Once a sufficient volume of data has been collected, analysis of the data will begin with the aim of determining meaningful correlations between the various recorded parameters. The number of distinct observations and sites dictated standardized observational procedures and recording methods amenable to automatic processing Observational methods and a recording form were designed to provide a base of comparison and an efficient means of processing the expected large volume of data Investigation of various methods of recording data led to the design of a suitable optical scanning form. This form, completed m the field by individual observers, can automatically be converted to punched cards for further processing Experience m collecting similar data in connection with other studies of the Coastal Engineering Research Center influenced the selection of comparatively inexpensive instruments for data collection. Approximately 50 observation sites, extending from the Oregon-California boundary to the United States-Mexican border are presently contributing data. These sites represent a wide variety of shore types, beach sediments, geographic orientations, and morphology It is anticipated that future expansion of this program will include sites other than those directly controlled by State agencies and will allow a more detailed description of the California shore Although not presently programmed, the extension of this study to other coastal areas of the United States where little or no information is presently available would be desirable, and could provide the necessary background for more comprehensive description of the overall behavior of the littoral zone.
THE THRESHOLD OP MOVEMENT OP COARSE MATERIAL IN OSCILLATORY PLOW
Authors: Rance P.J. , Warren N.F.
Published: February 2019

Experimental results are presented from which it is now possible to predict the threshold of movement of shingle. The experiments were conducted in an Oscillating Water Tunnel, (Ref. 1), on the threshold of movement of shingle size material. The Tunnel simulates the oscillatory water motion at the sea bed due to wave action with a semi-orbit range of 0-4.5 metres and a period range of 5-15 seconds. Additionally, a unidirectional current of up to 0.6 m/sec can also be superposed upon the oscillatory motion. Although limestone chips of between 0.32 cm and 2.5 cm diameters were the basic material tested, other materials such as coal and sand were examined in order to observe the effects of the various parameters over a wider range.
CLOSELY SPACED PILE BREAKWATER AS A PROTECTION STRUCTURE AGAINST BEACH EROSION
Authors: Hayashi Taizo , Hattori Masataro , Shirai Masujiro
Published: February 2019

The theory for the transmission and reflection of the waves at the closely spaced pile breakwater has been developed by the use of shallow water wave theory of small amplitude. Experiment on the hydraulic characteristics of the breakwater has been performed in a two dimensional wave flume. The agreement between the theory and the experiment is pretty good with respect to the coefficients of transmission and reflection of waves, and also to the shoreward velocity of the jet discharged from a space between any two adjacent piles. Experiment was also made on the local scouring at the foot of the clocely spaced pile breakwater. The maximrai scouring depth at the foot of the breakwater relates closely to the ratio of the velocity of the jet to the mean fall velocity of bed material. The relation between the maximum scouring depth and the power of the jet is discussed.
FLOATING BREAKWATERS
Authors: Brebner A. , Ofuya A.O.
Published: February 2019

The general objective of this investigation is to determine the wave damping characteristics of model floating breakwaters designed to reduce incident wave heights by processes of wave reflection, wave interference, forced instability of incident waves and turbulence action. Of most interest is the attempt to determine the method and the extent to which the requirement of large mass may be usefully replaced by large moment of inertia of mass in the development of floating breakwaters. Experiments are conducted in a two-dimensional wave channel. Reflection coefficients, transmission coefficients, breakwater motions and mooring forces are determined by experiments. It is found that the range of effectiveness in wave attenuation of floating breakwaters depends on several factors including breakwater design, incident wave properties, depth of water and the motion characteristics of the structures, it is remarkable that the 'A' Frame Breakwater exemplifies that the range of effectiveness of a floating breakwater can be increased by a large increase of its radius of gyration involving only a slight increase of its mass. The mooring forces are of reasonable magnitude. Experimental measurements and observations indicate that the 'A' Frame Breakwater is stable throughout the range of model tests.
SOLID AND PERMEABLE SUBMERGED BREAKWATERS
Authors: Dick T. Milne , Brebner A.
Published: February 2019

The behaviour of thin and rectangular solid submerged breakwaters is re-examined. Dean's theory is found to be correct for a thin barrier in infinitely deep water. An empirical and theoretical relationship for the reflection coefficient of a thin breakwater across the wave number spectrum is proposed. Rectangular solid breakwaters have a maximum reflection when the incident wave has the same period as a standing wave on top of the breakwater and with a wave length equal to the crest width. A submerged permeable breakwater for depths of submergence greater than 5% of the total depth transmits less wave energy than the solid over a certain frequency range. The minimum is transmitted when the criterion above for solid breakwaters is also met. Both permeable and solid rectangular breakwaters cause a substantial loss in wave energy and at least 501 of the incident energy is lost to turbulence. A substantial proportion, 30 to 601 of the energy transmitted is transferred to higher frequencies than the incident wave.
VARIATION OP LONGSHORE CURRENT ACROSS THE SURF ZONE
Authors: Thornton Edward B.
Published: February 2019

The wave-induced longshore current variation across the surf zone is described for a simplified model The basic assumptions are that the conditions are steady, the bottom contours are straight and parallel but allow for an arbitrary bottom profile, the waves are adequately described by linear theory, and that spilling breakers exist across the surf zone Conservation equations of mass, momentum, and energy, separated into the steady and unsteady components, are used to describe second order-wave-induced phenomena of shoaling waves approaching at an angle to the beach An expression for the longshore current is developed, based on the alongshore component of excess momentum flux due to the presence of unsteady wave motion Wave set-down and set-up have been included in the formulation Emphasis in the analysis is placed on formulating usable predictive equations for engineering practice Comparison with experimental results from the laboratory and field show that if the assumed conditions are approximately fulfilled, the predicted results compare quite favorably.
INFLUENCE OF GRAIN SIZE ON LITTORAL DRIFT
Authors: Castanho Jose
Published: February 2019

Influence of grain size in sediment transport depends on flow conditions For bed load transport a maximum probably exists for load discharge as a function of gram size The important parameter seems to be the ratio To/T between the threshold shear stress and the flow shear stress.
RELATIONSHIPS BETWEEN FLUID MOTION AND PRESSURE VARIATION BY DAM-BREAK FLOWS COLLIDING WITH VERTICAL WALL
Authors: Mizutani Natsuki , Umeda Jinji
Published: February 2019

The 2011 Tohoku Earthquake Tsunami ran up the height of over 40 m and covered over 560 km2 of the coastal land area in Tohoku, Japan. The tsunami destroyed many structures and killed over 15,000 people. Appropriate measures should be taken against the next giant tsunami to avoid such tragedy. The generation mechanism of wave force is uncertain when a tsunami wave running on land collides with a structure. Especially, the fluid motion of a tip of tsunami wave immediately after the collision with a structure is very complicated. The information of the pressure distribution acting on the structure is necessary to construct buildings in the coastal hazard area. The purpose of this study is to clarify the relationships between the fluid motion and pressure variation by a dam-break flow as a tsunami flow on a dry bed colliding with structures.
PROBABILISTIC TSUNAMI HAZARD ASSESSMENTS WITH CONSIDERATION OF UNCERTAIN EARTHQUAKE CHARACTERISTICS
Authors: Sepulveda Ignacio , Liu Philip L-F , Grigoriu Mircea , Pritchard Matthew
Published: February 2019

This study proposes a methodology to conduct probabilistic tsunami hazard assessments (PTHA) with consideration of uncertain earthquake characteristics. The methodology adopts a stochastic framework to model the earthquake slip and location as a random field and a random vector, respectively. The stochastic framework consists of three stages: (1) the definition of consistent probability properties for uncertain earthquake characteristics, (2) the generation of samples and (3) the uncertainty propagation. To complete each stage we follow the method recently proposed in SepÃºlveda et al. (2017). We illustrate our PTHA methodology by assessing the tsunami hazard in Kao Hsiung and Hong Kong, with consideration of earthquakes in the Manila Trench.
HARBOR AGITATION DUE TO OFFSHORE SHIP WAVES USING SWASH: A CASE STUDY OF KUMKAPI YACHT PARK, ISTANBUL
Authors: Baykal CÃ¼neyt , TarakcÄ±oÄŸlu GÃ¼lizar Ã–zyurt , IÅŸÄ±k Emrecan
Published: February 2019

This study presents the results of a numerical modeling study on the harbor agitation in case of offshore ship waves using SWASH (acronym for Simulating WAves till SHore), a numerical model developed for the simulating unsteady, non-hydrostatic, free-surface, rotational flow and transport phenomena in coastal waters as driven by waves, tides, buoyancy and wind forces (Zijlema et al. 2011). The study area is the Kumkapi Yacht Park, at the Marmara coast of Istanbul, 2.5 km west of the southern entrance of Bosphorus strait. The yacht park is currently used as a fishery harbor, which is severely affected by the ship waves of ferries and sea buses passing nearby almost parallel to the main breakwater of the harbor (aligned from west to east). The park is planned to berth a total of 140 yachts varying from 5 m to 40 m in length (Figure 1). For this purpose, the present harbor layout together with several alternative plans have been studied numerically to investigate agitation due to ship waves of ferries and sea buses considering the design safety requirements of ASCE (2012) for the safe mooring and berthing of yachts.
BEACHFACE EVOLUTION UNDER TWO SWASH EVENTS BY TWO SOLITARY WAVES
Authors: Zhu Fangfang , Dodd Nicholas
Published: February 2019

Swash zone morphodynamics is of great signi cance for nearshore morphological change, and it is important to provide reliable numerical prediction for beachface evolution in the swash zone. Most of the numerical work on swash zone morphodynamics carried out so far has focused primarily on beach evolution under one single swash event. In reality, multiple swash events interact, and these swash interactions have been recognised as important in the beachface evolution. Swash-swash interactions leads to energy dissipation, enhanced bed shear stresses and sediment transport (Puleo and Torres- Freyermuth, 2016). In this paper, we investigate the beachface evolution under two swash events using numerical simulations, in which shock-shock interactions are described by dam-break problems.
PHYSICAL AND NUMERICAL MODELLING OF THE FLOW STRUCTURE BEHIND STRUCTURE IN TSUNAMI-LIKE FLOW
Authors: Ishii Hidenori , Shibayama Tomoya , Stolles Jacob
Published: February 2019

Coastal structures are expected to play a role as evacuation buildings. Numerous studies have been examined tsunami-induced wave force acting on an inland building (Shigihara et al., 2009; Arimitsu et al., 2014). In addition, coastal structures have the potential to obstruct inundating tsunami waves, protecting structure further from the coastline. Hydraulic experiments and numerical calculations on shielding effect are being carried out. Alternatively, the vortices from these structures can result in significant scour downstream, influencing downstream structure stability. In the 2011 Tohoku Region Pacific Offshore Earthquake, many cases were reported that the structure was scrubbed and the structure fallen down. Skakiyama et al. (2007) and Sakakiyma et al. (2008) pointed out that the standing vortex generated around the structure winds sand and causes scouring. Therefore, understanding the vortices generated around the structure is also important in predicting the scouring phenomenon. As such, the flow properties around coastal structures must be considered and acknowledged within the design process. However, there are a few studies focusing on the flow fields behind structure.Arnason et al. (2009) measured velocity fields of dam-break flow around/in the wake of a vertical column. Wei et al. (2015) reproduced the experiment performed using SPH. However, in the experiment, vortexes are not considered and the influence of the existence of structures on the surroundings has not been sufficiently considered. Therefore, in this study, the flow fields of a tsunami-like wave around structures were examined through hydraulic experiments. This experiment was performed to clarify the local vortex structure behind structures by measuring the plane flow velocity field. Also, the effect of obstructing protecting the land side structure is assessed by measuring the wave force behind structures. Furthermore, a three-dimensional model (OpenFOAM) was used to further analyze the flow, focusing on water-level and wave forces behind the structure.
LABORATORY MODEL TEST OF TRANSIENT RIP CURRENTS DUE TO PSEUDO HONEYCOMB PATTERN WAVES
Authors: Choi Junwoo , Roh Min , Hwang Hyung-sik
Published: February 2019

The Haeundae coast of South Korea is famous for its beautiful beach, but the rip current, from which the beach-guards rescue more than 100 people every summer at the beach, is now a notorious phenomenon. The large-scale Haeundae rip current is known to be a transient rip current caused by multi-directional wave trains rather than the topography-induced rip current, for example, due to a gap of sandbar. In other words, the rip current seems develop along the cross-shore nodal line area in the honeycomb wave-crest pattern (Dalrymple et al., 2011) which are generated in a shallow water when two wave trains propagate with slightly different wave directions (i.e., interference pattern). The wave pattern is formed by the refraction of incident swells over submerged shoals and ridges of the Haeundae coast. The Haeundae rip current is an example explained by the vortex generation due to the ends of wave crests in Peregrine(1998), which is known of the basic generation mechanism of rip currents(Johnson and Pattiaratchi, 2006; Clark et al., 2012; Feddersen, 2014). To understand the generation mechanism and verify the numerical model results of the Haeundae rip current, the laboratory experiment was planned. This study showed the preliminary laboratory observations which include the pseudo honeycomb pattern of incident waves and its resultant rip current.
PERFORMANCES OF THE RIP CURRENT WARNING SYSTEM AT THE HAEUNDAE COAST OF SOUTH KOREA
Authors: Choi Junwoo , Yoon Sung-Bum , Ko Jimin , Kang Tae-Soon
Published: February 2019

Haeundae is one of the most beautiful beaches in Korea, and is also notorious for frequent and strong rip currents. Every recent year in this beach, hundreds of swimmers rescued from rip currents have been reported. The large-scale Haeundae rip current is known to be a kind of transient rip currents which is hardly predicted. The successive ends of wave-crest pattern (i.e., honeycomb wave-crest pattern(Dalrymple et al., 2011)), which generate rip current, are mainly formed by two-directional wave trains due to the refraction of incident swells over submerged shoals and ridges of the Haeundae coast. Many people are caught by the rip current in the relatively calm sea and weather conditions. The incident waves generating rip currents are nearly monochromatic with the wave period of 7-13 seconds. These swells are supposed to be generated by distant typhoons formed in the Philippine Sea. Some of them might propagate with dispersion and dissipation during the travel toward the south coast of the Korean Peninsula, especially to the Haeundae coast. In order to protect the swimmers from the rip current accidents, Choi et al. (2014) proposed a method for a rip current warning system, and Korea Hydrographic and Oceanographic Administration (KHOA) has established and operated the rip current warning system to the Haeundae beach. The rip current warning system estimates the rip current risk level based on the real-time incident wave conditions measured near the beach and the database pre-calculated by a numerical model according to various wave and tide conditions and the topography of the Haeundae coast. The Boussinesq wave model, FUNWAVE (Wei et al., 1999; Choi et al., 2015) was utilized for resolving the ends of the wave crests. This study showed the performance of the forecast and warning system of the rip current at the Haeundae coast of South Korea.
FIELD MEASUREMENTS AND SWASH PARAMETERIZATION ON BEACHES
Authors: Da Silva Paula Gomes , Medina RaÃºl , GonzÃ¡lez Mauricio , Garnier Roland
Published: February 2019

The wave runup, defined as the vertical oscillation of the water edge at the coast, is commonly used as criterion for coastal design projects and flooding/erosion risk analysis. Due to the complexity of nearshore wave processes, most runup studies are based on empirical approaches which directly relate these oscillations to the beach and offshore wave characteristics. However, there is still considerable debate about just how runup is related to these environmental parameters, as well as about the range of application of empirical models due to site specific conditions. Recent works emphasized the importance of including site specific conditions to reduce the scatter in available parameterizations. Parameters related to beach characteristics like the sediment size, the amount of reflection, wave spectral shape and morphodynamic beach state may improve runup predictions (Poate et al., 2016, Guza and Feddersen, 2012).
RUN-UP, BOUNDARY LAYERS AND SHEAR STRESSES BENEATH SHOALING TSUNAMIS
Authors: Larsen Bjarke Eltard , Fuhrman David R.
Published: February 2019

While the tsunami propagation, run-up and inundation has received considerable attention in literature, the associated boundary layer dynamics and induced sediment transport have received relatively little attention. Recently, Williams and Fuhrman (2016) simulated a series of tsunami scale boundary layers, emphasizing that they are simultaneously both current- and wave-like due to their long duration yet unsteady nature. They viewed the tsunami as a time varying current, something that has also been done by Larsen et al. (2017) and Larsen et al. (2018) in studies of tsunami-induced scour around monopile foundations. This approach is valid sufficiently far off-shore, but nearshore, the effects of the free-surface will inevitably become important. While difficult due to the large scales involved, the run-up and inundation can likewise be studied experimentally (Sriram et al. 2016). In this work the run-up process of full-scale tsunamis will be simulated in detail using CFD, which can naturally resolve shorter dispersive waves, wave breaking and boundary layer dynamics.
NUMERICAL MODELING OF A TURBULENT BOTTOM BOUNDARY LAYER UNDER SOLITARY WAVES ON A SMOOTH SURFACE
Authors: Sana Ahmad , Tanaka Hitoshi
Published: February 2019

A number of studies on bottom boundary layers under sinusoidal and cnoidal waves were carried out in the past owing to the role of bottom shear stress on coastal sediment movement. In recent years, the bottom boundary layers under long waves have attracted considerable attention due to the occurrence of huge tsunamis and corresponding sediment movement. In the present study two-equation turbulent models proposed by Menter(1994) have been applied to a bottom boundary layer under solitary waves. A comparison has been made for cross-stream velocity profile and other turbulence properties in x-direction.
FIELD STUDY ON INFLUENCE OF TIDAL CURRENTS ON INTRA-WAVE SEDIMENT TRANSPORT
Authors: De Wit Floris , Tissier Marion , Reniers Ad
Published: February 2019

Sediment transport by currents and waves determines the evolution of shoals and channels on the ebb-tidal delta. The channels are an important conduit for shipping and are often dredged to maintain access at considerable cost. A better understanding of the sediment transport processes within the channels is the basis for a more cost-effective maintenance strategy. In the vicinity of ebb-tidal inlets, waves from offshore encounter tidal currents. Depending on the tidal phase, incoming waves face strong positive or negative current gradients. Besides changes in wave height, period and direction, the current gradients also affect the nonlinear wave shape and corresponding velocity profile.
SEDIMENT TRANSPORT DUE TO CURRENT-SUPPORTED TURBIDITY CURRENTS OVER AN ERODIBLE BED
Authors: Ozdemir Celalettin Emre , Haddadian Sahar
Published: February 2019

Wave- and current-supported turbidity currents (WCSTCs), are one of the chief participants in shaping the marine geomorphology. What makes WCSTCs different from other turbidity currents is that boundary layer turbulence is required to suspend the sediments rather than the self-motion of the turbidity currents. In the presence of a mild slope, the gravitational acceleration drives the suspended sediments offshore (Sternberg et al., 1996; Wright et al., 2001). Depending on what dominates the boundary layer turbulence (BLT), we further define two major subclasses of WCSTCs: (i) wave-supported (WSTCs), and (ii) current-supported turbidity currents (CSTCs). Although significant advances have been made on the details of WSTCs (Ozdemir et al., 2011; Yu et al., 2014; Cheng et al., 2015), less is known about CSTCs. The objective of present study is to investigate the role of alongshore currents on CSTC dynamics over an erodible bottom boundary. The focus here is to identify the possible role of erosion on CSTC dynamics, and assess the coupling between current-induced BLT and suspended sediments for various bed erodibility parameters, i.e. critical shear stress, erosion coefficient, and settling velocity.
ESTIMATION OF GROUNDWATER DISCHARGE IN A SANDY BEACH; AN EXAMPLE OF FUKIAGEHAMA, KAGOSHIMA PREFECTURE, JAPAN
Authors: Kamo Takashi , Nishi Ryuichiro
Published: February 2019

It is recognized that links among forests, rivers and sea are important, because biological and fisheries production in the coastal zone is influenced by land-sea interaction. There are several nutrient supply systems in the coastal zone. River runoff, the most dominant nutrient supply system, has been evaluated by many previous studies. In addition, submarine groundwater discharge (SGD) has recently been considered as an important source of dissolved material to the coastal zone. For example, Johannes (1980) shows that SGD supplies several times as much nitrate volume as river runoff. However, the nutrient supply mechanisms in sandy beach ecosystem are not yet fully understood. Thus, it is necessary to quantitatively evaluate freshwater discharge and nutrient supply in a sandy beach ecosystem. This study reveals the estimated flow rate and volume of groundwater discharge in Fukiagehama, Kagoshima Prefecture, Japan.
HIGHLY-RESOLVED NUMERICAL AND LABORATORY ANALYSIS FOR NONBREAKING SOLITARY WAVE SWASH OVER A STEEP SLOPE
Authors: Higuera Pablo , Liu Philip L.-F. , Lin Cheng , Wong Wei-Ying , Kao Ming-Jer
Published: February 2019

In this paper we study the swash processes generated by a nonbreaking solitary wave running up and down a steep slope (1:3). We use experimental data to study flow features and velocities inside the boundary layer, and numerical modelling to investigate variables not measured during the laboratory experiments, such as pressures and bottom shear stress. We focus on the mechanisms that produce flow separation and vortex formation. Particularly, we study a system of vortices generated under a hydraulic jump during the rundown phase, which was first observed by Matsunaga & Honji (1980).
ESTIMATION OF BOUND AND RELEASED INFRAGRAVITY WAVES BASED ON WAVE OBSERVATION AND NUMERICAL SIMULATION IN SHALLOW WATER
Authors: Hirayama Katsuya , Kashima Hiroaki , Uno Yoshiyuki
Published: February 2019

It is mentioned that observed infragravity waves consist of bound waves propagating with short-wave groups, released waves due to reduction of short crest waves and free waves existing in a field. Though it is difficult to distinguish among them, a standard spectrum for infragravity waves is defined by using a relation to a wind wave spectrum. In this study, a comprehensive definition of standard spectrum is newly proposed to estimate infragravity wave heights with the relation between the ratio of wave height and the ursell number of observed wave property, represented by selected data of wave observation in shallow water. Moreover, the release process of bound waves at a harbor entrance is reproduced in numerical simulation using a Boussinesq model for short-wave transformation. These results are verified by comparison to infragravity waves observed at outside/inside of a harbor for a month.
TIME-VARYING EMULATOR FOR SHORT- AND LONG-TERM ANALYSIS OF COASTAL FLOODING (TESLA-FLOOD)
Authors: Anderson Dylan , Ruggiero Peter , Mendez Fernando J. , Rueda Ana , Antolinez Jose A. , Cagigal Laura , Storlazzi Curt , Barnard Patrick , Marra John
Published: February 2019

The ability to predict coastal flooding events and associated impacts has emerged as a primary societal need within the context of projected sea level rise (SLR) and climate change. The duration and extent of flooding is the result of nonlinear interactions between multiple environmental forcings (oceanographic, meteorological, hydrological) acting at varying spatial (local to global) and temporal scales (hours to centuries). Individual components contributing to total water levels (TWLs) include astronomical tides, monthly sea level anomalies, storm surges, and wave setup. Common practices often use the observational record of extreme water levels to estimate return levels of future extremes. However, such projections often do not account for the individual contribution of processes resulting in compound TWL events, nor do they account for time-dependent probabilities due to seasonal, interannual, and long-term oscillations within the climate system. More robust estimates of coastal flooding risk require the computation of joint probabilities and the simulation of hypothetical TWLs to better constrain the projection of extremes (Serafin [2014]).
WAVES AND STRONGLY SHEARED CURRENTS: EXTENSIONS TO COASTAL OCEAN MODELS
Authors: Banihashemi Saeideh , Kirby James T. , Shi Fengyan , Dong Zhifei
Published: February 2019

Significant progress has been made in the numerical modeling of wave-current interaction during the past decade. Typical coastal circulation and wave models, however, still only employ theoretical formulations which take depth-uniform mean flows into account, with realistic, non-uniform flows treated as being depth uniform through some chosen averaging procedure. Depending on the choice of average over depth, significant errors may arise in the estimation of properties such as group velocity and action density in realistic conditions. These errors, in turn, are fed back into the circulation model through incorrect representation of the vertical structure of wave forcing. A new framework for wave-current interaction theory for strongly sheared mean flows has been developed using vortex force formalism by Dong (2016). The resulting formulation leads to a conservation law for wave action identical to that of Voronovich (1976), and to expressions for wave-averaged forces in the Craik-Leibovich vortex force formalism. In this study, we are completing the development of a coupled NHWAVE/SWAN which implements the wave forcing formulation of Dong (2016) in a wave-averaged version of the non-hydrostatic model NHWAVE (Ma et al., 2012). The SWAN model is also being extended to incorporate a better representation of frequency and direction-dependent group velocity and intrinsic frequency in the neighborhood of the spectral peak, thus improving on the present practice of using quantities evaluated only at the spectral peak. The resulting model is being tested against field data collected in several recent experiments involving strong, vertically sheared currents in river mouths or straits.
IMPROVING THE ACCURACY OF SURGE MODELS USING SUBGRID CORRECTIONS
Authors: Kennedy Andrew , Wirasaet Damrongsak , Bolster Diogo , Dietrich J. Casey
Published: February 2019

Modern storm surge models to predict hurricane water levels have gone in two opposite directions: (1) Low resolution, fast, models that may be run thousands of times as a storm approaches land; and (2) High resolution, more accurate, models that are largely used for planning and hindcasts, and are too slow for real-time ensemble forecasts. Differences in predictions between the two types of models are particularly large over flooded ground, which is most important for human activities.
SUBMARINE MASS FAILURE: WAVE GENERATION BY GRANULAR SLIDES
Authors: Evers Frederic M. , Fuchs Helge , Vetsch David , Boes Robert M.
Published: February 2019

Submarine mass failures (SMF) are a potential source of hazardous tsunamis. While the link between seismic events and the magnitude of tsunami waves has been extensively studied and corresponding approaches are included in numerical tsunami warning models, the basic implementation of SMF generated waves is subject to ongoing research. In this context, laboratory experiments are essential for the validation of numerical schemes. Most experimental studies apply rigid slide models whereas only few include granular slides (e.g. Watts 1997, Ataie-Ashtiani & Najafi-Jilani 2008, Grilli et al. 2017). The objective of this study is to gain a better insight into the hydraulic processes related to wave generation by submarine granular slides based on experiments as well as establishing a comprehensive data set for the validation of numerical models.
TURBULENT FLOW INDUCED BY OSCILLATING CIRCULAR CYLINDER ARRAYS
Authors: Shigematsu Takaaki , Matsumoto Hiroshi
Published: February 2019

Vegetation association plays important role in the shallower coastal zone for sediment control and the nutrient and carbon absorption. It is necessary to understand the fluid motion including turbulence in the vegetation so that we may evaluate precisely shallow water region including vegetation and wet land. As the first step of research on fluid motion in the vegetation, circular cylinders are sometimes used. Many researches on the fluid force acting on the circular cylinder and fluid motion around the cylinder have been achieved so far. However, the properties of turbulent flow induced around circular cylinders in a wave, especially turbulence transition mechanism and spatial-temporal distribution of turbulence, are not almost investigated. The purpose of this study is to understand the fluid flow including turbulent induced by wave transmitting vegetation association. In this study fluid motion was measured by oscillating circular cylinder arrays in a tank by using the PTV technique.
A MULTI-MODEL APPROACH TO SIMULATE THE STORM SURGE AT PUERTO RICO DUE TO HURRICANES IRMA AND MARIA
Authors: Kelly David F. , Luczko Ewelina , Fullarton Michael , Kala Yahia
Published: February 2019

In this paper we present the results of a multimodel approach to simulating the recent storm surges due to hurricanes Irma and Maria. The study focuses on Puerto Rico which, as a consequence of hurricane Maria, experienced storm surge around the entire perimeter of the island. In this study the storm tide is modeled using a variety of state-of-the-art 2DH numerical models. All models are based on the long wave assumption and employ the Non-Linear Shallow Water (NLSW) equations. The models vary according to the form of the governing NLSW equations that they employ. Differences include linearization and primitive variable or conserved variable (divergence) form. The numerical solution techniques used to solve the governing equations, as well as the options available for the wind, pressure, tidal forcing terms and wetting/drying techniques also vary between (and within) the models.