• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.537-549
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• 2012

The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Hamyangsangrim designated as Natural Monument No. 154 and surround areas by analyzing the ecological characteristics such as landuse and actual vegetation, plant community structure, soil chemical property and also to identify the tendency of the ecosystem changes through comparison with past studies. According to analysis the results, the landuse and actual vegetation of survey site was classified as 8 types which were forest, artificial greenspace, plaza and open-space, bare ground and the pavement, water bodies, facilities, agricultural land and etc.. It was also categorized as 38 types according to detailed characteristic. 15 kinds of forest vegetation community types comprising silva were classified among them. The changes of actual vegetation showed little variation that the Quercus serrata-Carpinus tschonoskii forest was the most widely distributed in 2003(forest area ratio is 48.3%) and 2010(forest area ratio is 48.1%), whereas, the Quercus serrata forest declined a more dramatic from 11.6% to 23.2%. The Quercus serrata-Carpinus tschonoskii forest increased sharply(11.6% ${\rightarrow}$ 23.2%) and also the Quercus serrata-Zelkova serrata forest increased steadily(2.2% ${\rightarrow}$ 7.9%). The agricultural land around forest was transformed into artificial green zone. Moreover, water bodies, bare ground and the pavement of areas have increased. In addition, the urbanized area has decreased because the damaged areas inside forest have been restored to the woodlands. According to the result of typical 6 types vegetation communities change, the middle layer trees grew up to the canopy layer trees and was formed the canopy layer structure. The middle layer trees expanded their forces widely. Also new species appeared. And the shrub individuals also more dramatically increased due to the growth of shrubs. The force of Quercus serrata declined as well. However the force of Carpinus tschonoskii and Zelkova serrata expanded and increased in the forest. It must be the result of the ecological vegetation succession and environmentally soundly health recovery by influence of the projects of forest surrounding environment improvement and limitation of access to forest have managed and maintained since 2003. Those sorts of changes seems to be going to develop continuously. In the future Carpinus tschonoskii and Zelkova serrata will not be only codominant in the canopy layer but also Carpinus Tschonoskii, Zelkova serrata, Meliosma myriantha, Sapium japonicum. Styrax obassia and Acer pseudo-sieboldianum will be codominant in the middle layer. As a result, the forest's codominance species are going to be changed such like that.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.2 s.314
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• pp.37-46
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• 2007

In this paper, we propose technologies for enhancing the immersive realization of virtual objects in AR-based product design. Generally, multimodal senses such as visual/auditory/tactile feedback are well known as a method for enhancing the immersion in case of interaction with virtual objects. By adapting tangible objects we can provide touch sensation to users. A 3D model of the same scale overlays the whole area of the tangible object so the marker area is invisible. This contributes to enhancing immersion. Also, the hand occlusion problem when the virtual objects overlay the user's hands is partially solved, providing more immersive and natural images to users. Finally, multimodal feedback also creates better immersion. In our work, both vibrotactile feedback through page motors, pneumatic tactile feedback, and sound feedback are considered. In our scenario, a game-phone model is selected, by way of proposed augmented vibrotactile feedback, hands occlusion-reduced visual effects and sound feedback are provided to users. These proposed methodologies will contribute to a better immersive realization of the conventional AR system.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.1
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• pp.119-152
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• 2009

Korea now has a rapidly expanding and developing space programme with exploration aspirations. The government is giving priority to the aerospace industry and, to put it on a better footing, enacted an Aerospace Industry Development Promotion Act in I987, a Space Development Promotion Act in 2005 and a Space Compensation for Damage Act in 2007. I would like to describe briefly the legislative history, main contents and comment for these three space acts including especially launch licensing, registration of space objects, use of satellite information, astronaut rescue, liability for compensation, third party liability insurance and establishment of committee and plans to assist the Korean space effort. Furthermore author proposed to legislate a new draft for the establishment of a Korean Aerospace Development Agency (KADA: tentative title) to create a similar body to Japan Aerospace Exploration Agency (JAXA), British National Space Centre (BNSC) of UK, French Centre National d'Etudes Spatiales (CNES), German Aerospace Center (DLR), Swedish Space Corporation (SSC), China Aerospace Science and Industry Corporation (CASIC), Indian Space Research Organization (ISRO) as well as the Korean Space Agency (KSA: Tentative title) to create a similar body to Canadian Space Agency, European Space Agency, Russian Space Agency, Italian Space Agency, Israel Space Agency, Indian Department of Space, National Aeronautics and Space Administration (NASA) of USA, China National Space Administration in order to develope efficiently space industry. If the Korean government will be establish the Korean Space Agency as an governmental organization in future, it is necessary to revise the contents of the Government Organization Act. It is desirable and necessary for us to establish an Asian Space Agency (ASA), in order to develop our space industry and to promote research cooperation among Asian countries, based on oriental idea and creative powers.

• Applied Microscopy
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• v.37 no.2
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• pp.83-91
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• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.2
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• pp.81-90
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• 2013

During the past decade, many changes and attempts have been tried and are continued developing new technologies in the computing area. The brick wall in computing area, especially power wall, changes computing paradigm from computing hardwares including processor and system architecture to programming environment and application usage. The high performance computing (HPC) area, especially, has been experienced catastrophic changes, and it is now considered as a key to the national competitiveness. In the late 2000's, many leading countries rushed to develop Exascale supercomputing systems, and as a results tens of PetaFLOPS system are prevalent now. In Korea, ICT is well developed and Korea is considered as a one of leading countries in the world, but not for supercomputing area. In this paper, we describe architecture design of MAHA supercomputing system which is aimed to develop 300 TeraFLOPS system for bio-informatics applications like human genome analysis and protein-protein docking. MAHA supercomputing system is consists of four major parts - computing hardware, file system, system software and bio-applications. MAHA supercomputing system is designed to utilize heterogeneous computing accelerators (co-processors like GPGPUs and MICs) to get more performance/$, performance/area, and performance/power. To provide high speed data movement and large capacity, MAHA file system is designed to have asymmetric cluster architecture, and consists of metadata server, data server, and client file system on top of SSD and MAID storage servers. MAHA system softwares are designed to provide user-friendliness and easy-to-use based on integrated system management component - like Bio Workflow management, Integrated Cluster management and Heterogeneous Resource management. MAHA supercomputing system was first installed in Dec., 2011. The theoretical performance of MAHA system was 50 TeraFLOPS and measured performance of 30.3 TeraFLOPS with 32 computing nodes. MAHA system will be upgraded to have 100 TeraFLOPS performance at Jan., 2013.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.403-411
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• 2007

The purpose of the study was to evaluate fish community, based on conventional at Shannon-Weaver diversity index (H'), and ecological health, based on the Index of Biological Integrity (IBI) using fish assemblage in the eight sites of Nakdong River during June${\sim}$August 1999. Total number of species sampled was 19 species, and two sensitive species of Zacco temminckii (51%) and Rhynchocypris oxycephalus (28%) dominated the fish community. Also, trophic guild analyses showed that insectivore was 87% of the total and omnivore was rare, indicating that the ecological health is well maintained in the system. The pattern of spatial variation in the diversity index(H') was very similar to patterns of the species number and individual number, whereas the pattern of H' was not matched with the tolerance and trophic guild data. The diversity index (H') showed highest (1.56) in Site 6 where the proportion of sensitive species and tolerant species was minimum and maximum, respectively, and where the insectivore and omnivore were minimum and maximum. In other words, the diversity index was not matched at all with the trophic and tolerant guilds, indicating that the conventional index did not reflect the ecological characteristics of fish community in the system. In the mean time, the ecological health (IBI) averaged 33.5 (n=8), indicating "good${\sim}$fair condition" and the IBI values matched with trophic and tolerance guilds. Maximum IBI occurred in Site 2 where the sensitive and msectivore species were nearly maximum, and the tolerant and omnivore species were almost minima, indicating that IBI values were closely associated with the ecological functions and health conditions. Overall data suggest that the conventional diversity index may not effective for a evaluation of fish community, and that in contrast the IBI approach may be a useful tool for diagnosis of stream community.

• Journal of Science Education
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• v.45 no.3
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• pp.292-303
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• 2021

This study identifies the terms frequently used together with energy in online science news articles and topics of the news reports to find out how the term energy is used in everyday life and to draw implications for science curriculum and instruction about energy. A total of 2,171 online news articles in science category published by 11 major newspaper companies in Korea for one year from March 1, 2018 were selected by using energy as a search term. As a result of natural language processing, a total of 51,224 sentences consisting of 507,901 words were compiled for analysis. Using the R program, term frequency analysis, semantic network analysis, and structural topic modeling were performed. The results show that the terms with exceptionally high frequencies were technology, research, and development, which reflected the characteristics of news articles that report new findings. On the other hand, terms used more than once per two articles were industry-related terms (industry, product, system, production, market) and terms that were sufficiently expected as energy-related terms such as 'electricity' and 'environment.' Meanwhile, 'sun', 'heat', 'temperature', and 'power generation', which are frequently used in energy-related science classes, also appeared as terms belonging to the highest frequency. From a network analysis, two clusters were found including terms related to industry and technology and terms related to basic science and research. From the analysis of terms paired with energy, it was also found that terms related to the use of energy such as 'energy efficiency,' 'energy saving,' and 'energy consumption' were the most frequently used. Out of 16 topics found, four contexts of energy were drawn including 'high-tech industry,' 'industry,' 'basic science,' and 'environment and health.' The results suggest that the introduction of the concept of energy degradation as a starting point for energy classes can be effective. It also shows the need to introduce high-tech industries or the context of environment and health into energy learning.

• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.47-60
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• 2021

Recently, as the occurrence frequency of sudden floods due to climate variability increased, the damage of aging chuteway slabs of spillway are on the rise. Accordingly, a wide array of field survey, hydraulic experiment and numerical simulation have been conducted to find the cause of damage on chuteway slabs. However, these studies generally reviewed the flow characteristics and distribution of pressure on chuteway slabs. Therefore the derivation of damage on chuteway slabs was relatively insufficient in the literature. In this study, the cavitation erosion and hydraulic jacking were assumed to be the causes of damage on chuteway slabs, and the phenomena were reproduced using 3D numerical models, FLOW-3D and COMSOL Multiphysics. In addition, the cavitation index was calculated and the von Mises stress by uplift pressure distribution was compared with tensile and bending strength of concrete to evaluate the possibility of cavitation erosion and hydraulic jacking. As a result of numerical simulation on cavitation erosion and hydraulic jacking under various flow conditions with complete opening gate, the cavitation index in the downstream of spillway was less than 0.3, and the von Mises stress on concrete was 4.6 to 5.0 MPa. When von Mises stress was compared with tensile and bending strength of concrete, the fatigue failure caused by continuous pressure fluctuation occurred on chuteway slabs. Therefore, the cavitation erosion and hydraulic jacking caused by high speed flow were one of the main causes of damage to the chuteway slabs in spillway. However, this study has limitations in that the various shape conditions of damage(cavity and crack) and flow conditions were not considered and Fluid-Structure Interaction (FSI) was not simulated. If these limitations are supplemented and reviewed, it is expected to derive more efficient utilization of the maintenance plan on spillway in the future.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.1
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• pp.67-76
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• 2024

In this paper, we present a DIP-MLS testing method that combines digital image processing with a rigid body-based MLS differencing approach to measure mechanical variables and analyze the impact of target location and image resolution. This method assesses the displacement of the target attached to the sample through digital image processing and allocates this displacement to the node displacement of the MLS differencing method, which solely employs nodes to calculate mechanical variables such as stress and strain of the studied object. We propose an effective method to measure the displacement of the target's center of gravity using digital image processing. The calculation of mechanical variables through the MLS differencing method, incorporating image-based target displacement, facilitates easy computation of mechanical variables at arbitrary positions without constraints from meshes or grids. This is achieved by acquiring the accurate displacement history of the test specimen and utilizing the displacement of tracking points with low rigidity. The developed testing method was validated by comparing the measurement results of the sensor with those of the DIP-MLS testing method in a three-point bending test of a rubber beam. Additionally, numerical analysis results simulated only by the MLS differencing method were compared, confirming that the developed method accurately reproduces the actual test and shows good agreement with numerical analysis results before significant deformation. Furthermore, we analyzed the effects of boundary points by applying 46 tracking points, including corner points, to the DIP-MLS testing method. This was compared with using only the internal points of the target, determining the optimal image resolution for this testing method. Through this, we demonstrated that the developed method efficiently addresses the limitations of direct experiments or existing mesh-based simulations. It also suggests that digitalization of the experimental-simulation process is achievable to a considerable extent.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.56-76
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• 2024

We for the first time made a successful longest continuous sectional observation in the East Sea by an underwater glider during 95 days from September 18 to December 21 2020 in the Korea along the 106 Line (129.1 °E ~ 131.5 °E at 37.9 °N) of the regular shipboard measurements by the National Institute of Fishery Science (NIFS) and obtained twelve hydrographic sections with high spatiotemporal resolution. The glider was deployed at 129.1 °E in September 18 and conducted 88-days flight from September 19 to December 15 2020, yielding twelve hydrographic sections, and then recovered at 129.2 °E in December 21 after the last 6 days virtual mooring operation. During the total traveled distance of 2550 km, the estimated deviation from the predetermined zonal path had an average RMS distance of 262 m. Based on these high-resolution long-term glider measurements, we conducted a comparative study with the bi-monthly NIFS measurements in terms of spatial and temporal resolutions, and found distinguished features. One is that spatial features of sub-mesoscale such as sub-mesoscale frontal structure and intensified thermocline were detected only in the glider measurements, mainly due to glider's high spatial resolution. The other is the detection of intramonthly variations from the weekly time series of temperature and salinity, which were extracted from glider's continuous sections. Lastly, there were deviations and bias in measurements from both platforms. We argued these deviations in terms of the time scale of variation, the spatial scale of fixed-point observation, and the calibration status of CTD devices of both platforms.