• Tunnel and Underground Space
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• v.26 no.2
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• pp.120-130
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• 2016

Considering the applicability of Kuz-Ram model, which has been used extensively for predicting rock fragmentation size distribution by blasting, to domestic open-pit limestone mine, a total of 21 blasting tests have been executed at an open-pit limestone mine in eastern Gangwon of South Korea. A comparative analysis of field measured value and Kuz-Ram predicted value showed that there are a considerable amount of error in the predicted values regardless of application of various correction parameters for rock factor and uniformity factor; up to 56.45% in mean fragmentation size and 37.52% in uniformity index. Also the problem of applying different correction parameters has been derived even though a similar blasting pattern has been adopted for a same blasting bench. The authors therefore suggest that Kuz-Ram model needs to be modified for a proper application to domestic open-pit limestone mine.

• 지반과기술
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• v.3 no.3
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• pp.15-22
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• 2006

The optimum blasting pattern to excavate a quarry efficiently and economically can be determined based on the minimum production cost, which is generally estimated according to rock fragmentation. Therefore, it is a critical problem to predict fragment size distribution of blasted rocks over an entire quarry. By comparing various prediction models, it can be ascertained that the result obtained from Kuz-Ram model relatively coincides with that of field measurements. Kuz-Ram model uses the concept of rock factor to signify conditions of rock mass such as block size, rock jointing, strength and others. For the evaluation of total production cost, it is imperative to estimate 3-D spatial distribution of rock factor for the entire quarry. In this study, a sequential indicator simulation technique is adopted for estimation of spatial distribution of rock factor due to its higher reproducibility of spatial variability and distribution models than Kriging methods. Further, this can reduce the uncertainty of predictor using distribution information of sample data. The entire quarry is classified into three types of rock mass and optimum blasting pattern is proposed for each type based on 3-D spatial distribution of rock factor. In addition, plane maps of rock factor distribution for each ground level are provided to estimate production costs for each process and to make a plan for an optimum blasting pattern.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.347-356
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• 2010

Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.123-130
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• 2009

Fragmentation due to land developments causes disturbances and changes of composition in forest vegetation. The purpose of the study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest vegetation to determine degree of impact from land developments. The results of field survey, there was a difference in structure and composition of forest vegetation such as tree canopy, herbaceous cover, and number of vine and alien species the distances from edge to interior area such as 0m, 10m, 20m, 40m, and over 60m. To assess the disturbance of forest vegetation, the factors selected were the rate of vine's cover and appearance of alien species. The impact assessment model about vine species explained by a distance, forest patch size, type of forest fragmentation, and type of vegetation ($R^2$=0.44, p<0.001). The other model about alien species explained by a distance, type of forest fragmentation, type of vegetation, and width of road (85.9%, p<0.005). The models applied to Samsong housing development in Goyang-si, Gyunggi-do. The vines and alien species in the study area have had a substantial impact on forest vegetation from edge to 20 or 40m. The impact assessment models were high reliability for estimating impacts to land developments. The impact of forest vegetation by development activities could be minimized thorough the adoption of the models introduced at the stage of EIA.

• Animal cells and systems
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• v.16 no.2
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• pp.104-113
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• 2012

The nucleolus is a distinct nuclear territory involved in the compartmentalization of nuclear functions. There is some evidence of a relationship between nuclear fragmentation during spermatogenesis and chromatoid body (CB) formation. The CB is a typical cytoplasmic organelle of haploid germ cells, and is involved in RNA and protein accumulation for later germ-cell differentiation. The goal of this study was to qualitatively and quantitatively describe the nucleolar cycle during the spermatogenesis of $Phrynops$ $geoffroanus$ (Reptilia Testudines), and compare this nucleolar fragmentation with CB formation in this species through the use of cytochemical and ultrastructural analysis. Qualitative analysis showed a fragmentation of the nuclear material after pachytene of the first meiotic division in the primary spermatocytes. Quantitative analysis of the nucleolar cycle revealed a significant difference in the number of nucleoli and in the size of the nucleolus between spermatogonia and early spermatids. Using ultrastructural analysis, we recorded the beginning of the CB formation process in the cytoplasm of primary spermatocytes at the same time as when nuclear fragmentation occurs. In the cytoplasm of primary spermatocytes, the CB was observed in association with mitochondrial aggregates and the Golgi complex. In the cytoplasm of early spermatids, the CB was observed in association with lipid droplets. In conclusion, our data show that the nucleolus plays a role in the CB formation process. During spermatogenesis of $P.$ $geoffroanus$, the CB is involved in some important biological processes, including acrosome formation and mitochondrial migration to the spermatozoon tail and middle piece region.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2943-2948
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• 2010

Silica monolith powders were prepared by a new procedure where ground powders of proper size distribution were obtained without sieving. An initiator was attached to this ground monolith and polystyrene was bound by reversible addition-fragmentation chain transfer polymerization to give a new stationary phase. The separation efficiency of this phase was found better than that of the polystyrene bound phase based on conventional silica particles and that of the C18 bound silica monolith powders.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.672-674
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• 1998

Java virtual machine has the garbage collector that automate memory management. Mark-compact algorithm is one of the garbage collection algorithm that operating in 2 phases, marking and sweeping. One is Marking is marking live objects reachable from root object set. Sweeping is sweeping unmarked object from memory(return to free memory pool). This algorithm is easy to implement but cause a memory fragmentation. So compacting memory, before memory defragmentation become serious. When compacting memory, all other processes are suspended. It is critical for embedded system that must guarantee real-time processing. This paper introduce enhanced mark-compact garbage collection algorithm. Grouping the objects by their size that minimize memory fragmentation. Then apply smart algorithm to the grouped objects when allocating objects and compacting memory.

• Journal of Electrical Engineering and information Science
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• v.1 no.1
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• pp.129-139
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• 1996

The processor allocation problem in mesh multicamputers is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best-fit submesh allocation strategy for mesh multicomputers. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to preserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out t compare the proposed strategy with the previous strategies and experimental results indicate that the proposed strategy exhibits the best performance along with about 10% to 30% average improvement over the best previous strategy.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.240-250
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• 1998

This study is to have attempted to analyze the characteristics of the change in forest landscape pattern of Seoul for 18 years by grasping it through satellite image data on the forest area in Seoul where a rapid change according urbanization and industrialization is going on. On the basis of Landsat MSS data- satellite image data, this writer analyzed the change in the number and size of patch and the mean edge length of each forest land, and the index of patch shape by each year from a landscape -ecological point of view. The results are as follows; First, in the pattern change of the forest patch of Seoul, the highest patch fragmentation area is the forest of the Yangchon-gu district where is decreasing it forest area by 654ha, 511ha, 495ha, 402ha each year from its total size of 742ha in 1979. Second, the change tendency shows that the average forest size decreased at 552.58ha in 1983, 435.03ha in 1988, 396.23ha in 1992, and 379.96ha in 1996. And analysis showed that even in the number of patches, the forest fragmentation phenomenon was presenting by the increase of development disturbance. Third, the mean edge by year was longest at 23,385m in 1979, but it is decreasing continuously. This shows the regular and artificial uniformity of forest landscape by disturbance-effect increase of the built-up development and shows low portion against edge effect by the time-series change like 1979>1983>198>1992>1996. Finally, in the analysis of a shape index indicated by ratio of size and edge, total averages were 2.56, 2.33, 2.17, 2.14, 2.14 each year, so that it is considered that the disturbance and ecological health status against forest landscape can be grasped according to being examined as 1979>1983>1988>1992, 1996 by the time-series change of the landscape.

• Journal of the Korean Geographical Society
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• v.47 no.1
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• pp.79-97
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• 2012

This study examines on the impact of biodiversity in circular greenspace of Cheongju city since 2002 greenbelt release. Research has carried out to investigate the biotope pattern change with landscape fragmentation. Major landscape fragmentation has occurred with development of residential sector and build-up of major highways. Settlement has been expanded to the entire area connected to urban district excluding the eastern forest. North-south district shows high road density, where inter-regional roads meet in the cross-section. It is found that landscape fragmentation impact on species richness as well as population size of the species varies depending on the animal species. The birds show high species richness in N2, N3, N4, S2(north-south zone) even with high fragmentation rate. This can be explained that birds can access to aquatic environment where they can find abundant food resources. The amphibians and the reptiles show almost no zonal variation in species richness than the birds. The more a zone fragmented in small patches, the species richness of the amphibians and the reptiles also tends to be declined. Information accumulation on biodiversity for integrating landscape planning in urban planning, various level of community participation in decision making process, and cross border cooperation with neighbouring Cheongwon-gun will be required for sustainable greenspace management of Cheongju City.