Image-Based Modeling of Urban Buildings Using Aerial Photographs and Digital Maps

A VR (virtual reality) simulator which is used for helicopter simulations requires a virtual environment of real world urban areas. However, real urban environments are continuously changing. It is necessary to develop a modeling method that makes direct use of GIS (geographical information system) data which is updated periodically. A flight simulation needs to visualize not only buildings in the near distance but also a large number of buildings in the far distance. We propose a method for modeling urban environments from aerial images and digital maps with relatively little manual work. An image‐based method is applied to the urban modeling that considers the characteristics of Korean cities. Buildings in the distance can be presented without creating a large number of polygons. The proposed method consists of a pre‐processing stage that prepares the model from the GIS data and a modeling stage that creates the virtual urban environment. The virtual urban environment utilizes the height map of buildings.     

Biomarker-based Seawater Temperatures of Winter Sinking Particles and Core-top Sediment in the Ulleung Basin of the East Sea

Ocean Science Journal - This study evaluates the application of biomarkerbased temperature proxy data (alkenone with its resultant $$U_{37}^{K'}$$ index and glycerol dialkyl glycerol tetraether...     

Re-evaluation of Morphological Diagnostic Characteristics of <Emphasis Type="Italic">Hexapleomera</Emphasis> Dudich, 1931 (Crustacea: Tanaidacea), with Description of a New Species

An undescribed species of Tanaidacea was collected from Yokji Harbor in the southern coast of Korea. Hexapleomera yokjidona n. sp. can be distinguished from other species of the genus by the distinguishing features of a uropod with five articles, a pleopod basal article lacking inner seta, a mandible setal row with two setae, maxilliped coxa with two proximal setae, pereonites 1–3 together longer than wide, and pereopods 2–3 propodus with three ventral setae. To prove that H. yokjidona is a new species, detailed morphological characteristics of both genders are described and a comprehensive comparison among the species of the genus is tabulated. Additionally, diagnostic characteristics previously used to identify the species of Hexapleomera are reassessed and upgraded.     

A probabilistic model for ghost delay time estimation based on recording geometry

In order to deconvolve the ghost response from marine seismic data, an estimate of the ghost operator is required. Typically, this estimate is made using a model of in‐plane propagation, i.e., the ray path at the receiver falls in the vertical plane defined by the source and receiver locations. Unfortunately, this model breaks down when the source is in a crossline position relative to the receiver spread. In this situation, in‐plane signals can only exist in a small region of the signal cone. In this paper, we use Bayes' theory to model the posterior probability distribution functions for the vertical component of the ray vector given the known source–receiver azimuth and the measured inline component of the ray vector. This provides a model for the ghost delay time based on the acquisition geometry and the dip of the wave in the plane of the streamer. The model is fairly robust with regard to the prior assumptions and controlled by a single parameter that is related to the likelihood of in‐plane propagation. The expected values of the resulting distributions are consistent with the deterministic in‐plane model when in‐plane likelihood is high but valid everywhere in the signal cone. Relaxing the in‐plane likelihood to a reasonable degree radically simplifies the shape of the expected‐value surface, lending itself for use in deghosting algorithms. The model can also be extended to other plane‐wave processing problems such as interpolation.     

Core-based reconstruction of paleoenvironmental conditions in the southern Drake Passage (West Antarctica) over the last 150 ka

A deep-sea sediment core (GC98-06) from the southernmost Drake Passage, West Antarctica, shows late Quaternary depositional environments distinctly different from sedimentary drifts commonly found along the southwestern Pacific margin of the Drake Passage. The chronology of the core has been inferred using geochemical tracers of paleoproductivity and diatom biostratigraphy, and represents the paleoceanographic conditions in a continental rise setting during the last 150,000 years. Three dominant sediment types associated with distinct sedimentary processes have been identified using textural/compositional analyses: (1) hemipelagic mud (interglacial sediments) deposited from pelagic settling of bioclasts, meltwater plumes, and ice-rafted detritus; (2) terrigenous mud (glacial sediments) delivered by turbid meltwater plumes; and (3) massive muds marking the boundaries from interglacial to glacial periods. The succession of the sedimentary facies in core GC98-06 is interpreted to reflect temporal changes in environmental conditions prevailing on the continental rise of the southern Drake Passage in the course of successive climatic stages over the last 150 ka: from the bottom upward, these are glacial, interglacial, glaciation, glacial, and interglacial episodes. Variability in sediment flux and diatom abundance seem to have been related to changes in glacial advance, sea-ice extent, and specific sedimentary environments, collectively influenced by mid- to late Quaternary climatic changes.     

Rainfall‐runoff analysis based on competing linear impulse responses: decomposition of rainfall‐runoff processes

Many recent studies have successfully used neural networks for non‐linear rainfall‐runoff modelling. Due to fundamental limitation of linear structures, approaches employing linear models have been generally considered inferior to the neural network approaches in this area. However, the authors believe that with an appropriate extension, the concept of linear impulse responses can be a viable tool since it enables one to understand underlying dynamics of rainfall‐runoff processes. In this paper, the use of competing impulse responses for rainfall‐runoff analysis is proposed. The proposed method is based on the switch over of competing linear impulse‐responses, each of which satisfies the constraints of non‐negativity and uni‐modality. The computational analyses performed for the rainfall‐runoff data in the Seolma‐Chun experimental basin, Korea showed that the proposed method can yield promising results. Considering the basin characteristics as well as the results from this study, it may be concluded that three impulse responses are enough for rainfall‐runoff analysis. Copyright © 2007 John Wiley & Sons, Ltd.     

Diffuse Emission of Hydrogen from Poás Volcano,Costa Rica,America Central

We report the results of four soil H₂ surveys carried out in 2000–2003 at Poás volcano, Costa Rica, to investigate the soil H₂ distribution and evaluate the diffuse H₂ emission as a potential surveillance tool for Poás volcano. Soil gas H₂ contents showed a wide range of concentration from 0.2 to 7,059 ppmV during the four surveys. Maps of soil gas H₂ based on Sequential Gaussian Simulation showed low H₂ concentration values in the soil atmosphere (<0.7 ppmV) for most of the study area, whereas high soil gas H₂ values were observed inside the active crater of Poás. A significant increase in soil gas H₂ concentration was observed inside the active crater during 2001 and 2002 with respect to year 2000, followed by a decrease in 2003. The observed spatial and temporal variations of soil H₂ concentration have been well correlated with seismicity, microgravimetry and fumarolic chemistry changes which occurred during this study. These observations evidence changes in the shallow magmatic-hydrothermal system of Poás, and it might be related to a potential magmatic intrusion during the period 1998–2004. Therefore, monitoring diffuse H₂ emission of Poás has become an important geochemical tool for the monitoring of its volcanic activity.