• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.42-54
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• 2020

This study aimed to analyze the rate of increase and spread patterns of dead trees of the conifer (Abies koreana and others) in subalpine zones by using the high-resolution aerial images in Jirisan National Park around 10 years ago. Furthermore, factors affecting the death of conifer were identified by analyzing the altitude, topographical information, solar radiation, and moisture environment of the site where the dead trees are located. The number of dead trees per unit area increased by two to five times in the Banyabong peak, Yeongsinbong peak, and Cheonwangbong peak in Jirisan National Park over the past decade. The increase was about 2 times in the Banyabong peak, about 3.9 times in the Yeongsinbong peak, and about 5.2 times in the Cheonwangbong peak, indicating the most notable increase in the Cheonwangbong peak. It is estimated that dead trees commonly occurred in the environments where the soil moisture content was low due to the high slope, amount of evaporation was high due to strong solar radiation as the location faced south, and the soil was dry due to strong solar radiation and short rain retention time. In other words, dead conifer trees in subalpine zones were concentrated in dry location environments, and the tendency was the same more than ten years ago.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.431-437
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• 2013

Landslides are caused by earthquakes or heavy rains. Recently the incidence of landslides has been increased. However, it is impossible to predict the occurrence of landslide exactly. The purpose of this research is that subdivide the classes of elements in the landslide management system by using spatial analysis technique and AHP method. The existing landslide management system is only comprised of weighted value the slope elements without weighted value about the slop direction elements. For the accuracy improvement in landslide occurrence point, weighted value about the slope direction should be considered. This research is focused on segmentation in slope direction three categories. If the direction of landslide does not affect the structure, I do not think the subject is worth considerating. Based on these results will discuss the improvements in Landslides management systems. Analysis results, segmentation on the slope and the slope direction are needed. Segmented categories about topography elements will be increase the accuracy of landslides management system. Also, since topography of the elements is only considered, segmentation of different elements is needed.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.110-122
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• 2011

Purpose : The purpose of this study is to establish the method generating human brain anatomical connectivity from Korean children and evaluating the network topological properties using small-world network analysis. Materials and Methods : Using diffusion tensor images (DTI) and parcellation maps of structural MRIs acquired from twelve healthy Korean children, we generated a brain structural connectivity matrix for individual. We applied one sample t-test to the connectivity maps to derive a representative anatomical connectivity for the group. By spatially normalizing the white matter bundles of participants into a template standard space, we obtained the anatomical brain network model. Network properties including clustering coefficient, characteristic path length, and global/local efficiency were also calculated. Results : We found that the structural connectivity of Korean children group preserves the small-world properties. The anatomical connectivity map obtained in this study showed that children group had higher intra-hemispheric connectivity than inter-hemispheric connectivity. We also observed that the neural connectivity of the group is high between brain stem and motorsensory areas. Conclusion : We suggested a method to examine the anatomical brain network of Korean children group. The proposed method can be used to evaluate the efficiency of anatomical brain networks in people with disease.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.188-198
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• 2016

In order to supply the residential land for the promotion of public welfare, it must take a land of city suburb. That land have the difference in thinking is large for the determination of land prices to a variety of development pressure and land use regulations. In the process of executing a public project, the difference of these ideas has become a cause of conflict. Therefore, through objective study for the determination of land prices, to reduce the difference of ideas is going to be a clue of conflict resolution. This study selected the case area that is typical public district of many conflict, and then fix a compensation unit price like fair price as dependent variable. The selected variables through previous studies and expert consultation was an independent variable. To analyze the impact factors of land prices in the hedonic price model. The results were analyzed by distinguishing the group on the basis of the zoning and using, whether or not the site of the building in part that there is influence variable, the aspects of accessibility and regulation in part degree of influence variable came out different results for each group. It is analyzed that it reasonable results. Add selected site assimilation of the building that have not been presented in previous studies as a variable and which was applied at a rate to a variable of road have improved in more expliction of the influence of variables.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.91-97
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• 2012

The dispersion indices, spatial pattern and sampling plan for pink citrus rust mite (PCRM), Aculops pelekassi, monitoring was investigated. Dispersion indices of PCRM indicated the aggregated spatial pattern. Taylor's power law provided better description of variance-mean relationship than Iwao's patchiness regression. Fixed-precision levels (D) of a sequential sampling plan were developed using by Taylor's power law parameters generated from PCRM on fruit sample (cumulated number of PCRM in $cm^2$ of fruit). Based on Kono-Sugino's empirical binomial the mean density per $cm^2$ could be estimated from fruit ratio with more than 12 rust mites per $cm^2$: $ln(m)=4.61+1.23ln[-ln(1-p_{12})]$. To determine the optimal tally threshold, the variance (var(lnm)) for mean (lnm) in Kono-Sugino equation was estimated. The lower and narrow ranged change of variance for esimated mean showed at a tally threshold of 12. To estimate PCRM mean density per $cm^2$ at fixed precision level 0.25, the required sample number was 13 trees, 5 fruits per tree and 2 points per fruit (total 130 samples).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.2
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• pp.113-123
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• 2005

Samples were collected to investigate the effect of salinity change on biological interaction between primary producers and herbivores in water column of the Youngsan estuary (Mokpo Harbor) at 8 stations from October 2003 to September 2004. The highest river freshwater inputs were introduced into the estuary from the Youngsan dike during summer (June and July 2004). Ranges of salinity were between 6 and 28.9 psu when the gates of dike were open whereas the ranges were between 24.4 and 30.3 psu when the gates were closed. Algal bloom occurred in February and July when the gates were not open at the upper region of the Youngsan estuary and the bloom was dominated $(70\%)$ by large cells of phytoplankton $(micro-sized;>20{\mu}m).\;Nano-sized (2-20{\mu}m)$ and pico-sized phytoplankton $(<2{\mu}m)$ were dominant in October, November 2003, June, August and September 2004 when the gates were open suggesting that size structure was affected by river discharge from the dike. Micro-and meso-zooplankton (herbivores) displayed the similar pattern to that of phytoplankton. The biomass of zooplankton was higher when the gates were closed than when the gates open and also the biomass was higher at the upper region of the harbor system. This results suggest that freshwater inputs affect size structure and biomass of phytoplankton by changing salinity, nutrient inputs, turbidity or light level In water column resulting in the change of the interaction between primary producters and herbivores in the Youngsan estuary.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.90-100
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• 2011

We present a parallel bi-conjugate gradient (Bi-CG) matrix solver for large scale Bio-FET simulations based on recent graphics processing units (GPUs) which can realize a large-scale parallel processing with very low cost. The proposed method is focused on solving the Poisson equation in a parallel way, which requires massive computational resources in not only semiconductor simulation, but also other various fields including computational fluid dynamics and heat transfer simulations. As a result, our solver is around 30 times faster than those with traditional methods based on single core CPU systems in solving the Possion equation in a 3D FDM (Finite Difference Method) scheme. The proposed method is implemented and tested based on NVIDIA's CUDA (Compute Unified Device Architecture) environment which enables general purpose parallel processing in GPUs. Unlike other similar GPU-based approaches which apply usually 32-bit single-precision floating point arithmetics, we use 64-bit double-precision operations for better convergence. Applications on the CUDA platform are rather easy to implement but very hard to get optimized performances. In this regard, we also discuss the optimization strategy of the proposed method.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.508-528
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• 1996

The purpose of this study is to analyze the classification of the hierarchy in terms of centrality and the demarcation of shopping areas in the context of goods-purchasing activity in the Kyeong-ju si area (The old Kyeong-ju city and Wol-song Kyn). The basic data for this study include mail questionnaire materials and sources by the on-the-sport survey. The main results of this study are as follows. (1) When forty-two centers within the wide Kyeong-ju area are classified into hierarchies in terms of the functional index and the number of central functions, it is confirmed that there are five hierarchies or classes. Hierachy A is the City of Kyeong-ju. Hierarchy B is the Up of An-gang. Hierarchy Cis made up of three Up of Kam-p'o, Oe-dong and Kon-ch' on. Hierachy D consist of seven Myons and two Ris. Hierarchy E is composed of one Myon and twenty-seven Ris. (2) Hierarchy A has five proper functions of the center. Hierarchy B holds eleven of them. Hierarchy C takes forty-one. Hierarchy D cherish twenty-seven. And hierarchy E has three. Therefor Hierachies C and D have the most functions of all. The threshold populations of the lowest central function is fifty-eight of miscellaneous stores in the central place of Hierarchy E (3) The purchase distance of the central functions of a center becomes farther in the order of barbers' and beauty salons, dental clinics, TV and refrigerator shops, and furniture stores. (4) When the shopping areas are classified according to goods purchase activity, they can be divided into four: the Myon, small Up, big Up, and City areas. Each shopping area can be classified into two categories: the independent areas and compoung areas. The Kyeong-ju city area is the largest city shopping areas of Po-hang and Ull-san are very small.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.287-294
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• 2003

There are a lot of curved subway stations in Seoul metropolitan area. These must be straightly constructed as many as possible. But some of stations are roundly designed and built in order to avoid pre-existed underground obstacle such as basement of high rise building, underground gas or water pipe line and subway stations from another line. As shown fig 1, one of the biggest problem occurring curved subway station is considered large gap between platform and vehicle when vehicle completely stop at the station. The gap potentially is in existence to subway passenger as very dangerous factors in rush hours. If passenger accidentally drop their food or leg between this gap when they get on the train and train leaves station, the passenger will be seriously injured by vehicle. In this paper, various design and instruments are introduced and best solution for this matter will be presented. In order to eliminate any possibility of accident happened gap between platform and vehicle, KRRI(Korea Railroad Research Institute) have been developed new safety instrument. These technologies were applied for patent by KRRI. These mechanisms will provide confidence as well as safety to Korean subway passenger

• Journal of Korea Water Resources Association
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• v.51 no.1
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• pp.71-80
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• 2018

For the stream management, time of concentration is one of the important factors. In particular, as the requirement about various application of the stream increased, accuracy assessment of concentration time in the stream as waterfront area is extremely important for securing evacuation at the flood. the past studies for the assessment of concentration time, however, were only performed on the single hydrological event in the complex basin of natural streams. The development of a assessment methods for the concentration time on the complex hydrological event in a single watershed of urban streams is insufficient. Therefore, we estimated the concentration time using the rainfall- runoff data for the past 10 years (2006~2015) for the Oncheon stream, the representative stream of the Busan, where frequent flood were taken place by heavy rains, in addition, reviewed the reliability using artificial neural network method based on Matlab. We classified a total of 254 rainfalls events based on over unrained 12 hours. Based on the classification, we estimated 6 parameters (total precipitation, total runoff, peak precipitation/ total precipitation, lag time, time of concentration) to utilize for the training and validation of artificial neural network model. Consequently, correlation of the parameter, which was utilized for the training and the input parameter for the predict and verification were 0.807 and 0.728, respectively. Based on the results, we predict that it can be utilized to estimate concentration time and analyze reliability of urban stream.