Compatible taper and stem volume equations for <Emphasis Type="Italic">Larix kaempferi</Emphasis> (Japanese larch) species of South Korea     

Nova D. Doyog  Young Jin Lee  Sun Joo Lee  Jin Taek Kang  Sung Yong Kim 《山地科学学报》2017,14(7):1341-1349

In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups: 80% of the data were used in model fitting and the remaining 20% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.  相似文献   

Practical engineering approaches and infrastructure to address the problem of marine debris in Korea     

Rho-Taek Jung Author Vitae  Hong Gun Sung  Sang-In Keel 《Marine pollution bulletin》2010,60(9):1523-1532

As a solution to the problem of persistent solid marine debris, a nationwide project began in Korea in 1999 to develop and popularize fundamental changes to the infrastructure. The ten year project, called “A Practical Integrated System for Marine Debris,” consists of four linked types of technology: prevention, deep-water survey, removal and treatment (recycling). These reflect the characteristics of marine debris, which though widespread, vary by location and time of generation. Each technical component has each representative outcome that has been outreached the local governments and marine debris-related associations. The in situ infrastructures lead to enhance the retrieval of the marine debris and create direct and indirect benefits to industry. Both end-of-pipe technology improvement and the introduction of front-of-pipe technology should be considered as we strive to reduce the generation of marine debris in Korean coastal areas.  相似文献   

A time‐domain seismic SSI analysis method for inelastic bridge structures through the use of a frequency‐dependent lumped parameter model          下载免费PDF全文

Nikolaos Lesgidis  Oh‐Sung Kwon  Anastasios Sextos 《地震工程与结构动力学》2015,44(13):2137-2156

It is highlighted in the past that the soil–structure interaction phenomenon can produce a significant alteration on the response of a bridge structure. A variety of approaches has been developed in the past, which is capable of tackling the soil–structure interaction problem from different perspectives. The popular approach of a discretized truncated finite element model of the soil domain is not always a numerically viable solution, especially for computationally demanding simulations such as the probabilistic fragility analysis of a bridge structure or the real time hybrid simulation. This paper aims to develop a complete modeling procedure that is capable of coping with the soil–structure interaction problem of inelastic bridge structures through the use of a frequency dependent lumped parameter assembly. The proposed procedure encounters accuracy and global stability issues observed on past methods while maintaining the broad applicability of the method by any commercial FEM software. A case study of an overpass bridge structure under earthquake excitations is illustrated in order to verify the proposed method. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Assessment of soil loss in South Korea based on land-cover type     

Chunhwa Jang  Yongchul Shin  Donghyuk Kum  Rogyoung Kim  Jay E. Yang  Sung Chul Kim  Sang Il Hwang  Kyoung Jae Lim  Jeong-Ki Yoon  Youn Shik Park  Younghun Jung 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(8):2127-2141

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Interpretation of coastal wind transfer functions with momentum balances derived from idealized numerical model simulations     

Sung Yong Kim  Ganesh Gopalakrishnan  Aurelien Ponte 《Ocean Dynamics》2015,65(1):115-141

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Storm surge prediction using an artificial neural network model and cluster analysis   总被引：1，自引：1，他引：0  

Sung Hyup You  Jang-Won Seo 《Natural Hazards》2009,51(1):97-114

In this study, an artificial neural network model was developed to predict storm surges in all Korean coastal regions, with a particular focus on regional extension. The cluster neural network model (CL-NN) assessed each cluster using a cluster analysis methodology. Agglomerative clustering was used to determine the optimal clustering of 21 stations, based on a centroid-linkage method of hierarchical clustering. Finally, CL-NN was used to predict storm surges in cluster regions. In order to validate model results, sea levels predicted by the CL-NN model were compared with results using conventional harmonic analysis and the artificial neural network model in each region (NN). The values predicted by the NN and CL-NN models were closer to observed data than values predicted using harmonic analysis. Data such as root mean square error and correlation coefficient varied only slightly between CL-NN and NN model results. These findings demonstrate that cluster analysis and the CL-NN model can be used to predict regional storm surges and may be used to develop a forecast system.  相似文献   

Occurrence of gorgosterol in diatoms of the genus Delphineis     

Sebastiaan W. Rampen  John K. Volkman  Sung Bum Hur  Ben A. Abbas  Stefan Schouten  Ian D. Jameson  Daniel G. Holdsworth  Jean Hee Bae  Jaap S. Sinninghe Damsté 《Organic Geochemistry》2009,40(1):144-147

The presence of the C₃₀ sterol gorgosterol (22,23-methylene-23,24-dimethylcholest-5-en-3ß-ol) and its analogues in some marine and freshwater environments is generally associated with invertebrate animals or dinoflagellates since there have been no reports of them in other microalgal classes. Here we show that two unialgal cultures of different species of the marine diatom Delphineis contain gorgosterol in addition to sterols more commonly found in diatoms. Our findings suggest that some reports of gorgosterol in seawater and marine sediments may well have an origin, at least in part, from diatoms.  相似文献   

A frequency‐dependent and intensity‐dependent macroelement for reduced order seismic analysis of soil‐structure interacting systems          下载免费PDF全文

Nikolaos Lesgidis  Anastasios Sextos  Oh‐Sung Kwon 《地震工程与结构动力学》2018,47(11):2172-2194

The computational demand of the soil‐structure interaction analysis for the design and assessment of structures, as well as for the evaluation of their life‐cycle cost and risk exposure, has led the civil engineering community to the development of a variety of methods toward the model order reduction of the coupled soil‐structure dynamic system in earthquake regions. Different approaches have been proposed in the past as computationally efficient alternatives to the conventional finite element model simulation of the complete soil‐structure domain, such as the nonlinear lumped spring, the macroelement method, and the substructure partition method. Yet no approach was capable of capturing simultaneously the frequency‐dependent dynamic properties along with the nonlinear behavior of the condensed segment of the overall soil‐structure system under strong earthquake ground motion, thus generating an imbalance between the modeling refinement achieved for the soil and the structure. To this end, a dual frequency‐dependent and intensity‐dependent expansion of the lumped parameter modeling method is proposed in the current paper, materialized through a multiobjective algorithm, capable of closely approximating the behavior of the nonlinear dynamic system of the condensed segment. This is essentially the extension of an established methodology, also developed by the authors, in the inelastic domain. The efficiency of the proposed methodology is validated for the case of a bridge foundation system, wherein the seismic response is comparatively assessed for both the proposed method and the detailed finite element model. The above expansion is deemed a computationally efficient and reliable method for simultaneously considering the frequency and amplitude dependence of soil‐foundation systems in the framework of nonlinear seismic analysis of soil‐structure interaction systems.  相似文献   

The 9th International Workshop on Modeling the Ocean (IWMO 2017) in Seoul,Korea, July 3–6, 2017     

Oey  Lie-Yauw  Noh  Yign  Berntsen  Jarle  Kim  Sung Yong  Mitsudera  Humio  Ezer  Tal 《Ocean Dynamics》2020,70(1):163-164

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Estimating landslide susceptibility areas considering the uncertainty inherent in modeling methods     

Ho?Gul?Kim  Dong?Kun?LeeEmail author  Chan?Park  Yoonjung?Ahn  Sung-Ho?Kil  Sunyong?Sung  Gregory?S.?Biging 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(11):2987-3019

Landslides are one of the most dangerous types of natural disasters, and damage due to landslides has been increasing in certain regions of the world because of increased precipitation. Policy decision makers require reliable information that can be used to establish spatial adaptation plans to protect people from landslide hazards. Researchers presently identify areas susceptible to landslides using various spatial distribution models. However, such data are associated with a high amount of uncertainty. This study focuses on quantifying the uncertainty of several spatial distribution models and identifying the effectiveness of various ensemble methods that can be used to provide reliable information to support policy decisions. The area of study was Inje-gun, Republic of Korea. Ten models were selected to assess landslide susceptibility. Moreover, five ensemble methods were selected for the aggregated results of the 10 models. The uncertainty was quantified using the coefficient of variation and the uncertainty map we developed revealed areas with strongly differing values among single models. A matrix map was created using an ensemble map and a coefficient of variation map. Using matrix analysis, we identified the areas that are most susceptible to landslides according to the ensemble model with a low uncertainty. Thus, the ensemble model can be a useful tool for supporting decision makers. The framework of this study can also be employed to support the establishment of landslide adaptation plans in other areas of the Republic of Korea and in other countries.  相似文献