• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.292-297
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• 2022

Direct injection of CRISPR/Cas9 into zygotes enables the production of genetically modified nonhuman primates (NHPs) essential for modeling specific human diseases, such as Usher syndrome, and for developing novel therapeutic strategies. Usher syndrome is a rare genetic disease that causes loss of hearing, retinal degeneration, and problems with balance, and is attributed to a mutation in MYO7A, a gene that encodes an uncommon myosin motor protein expressed in the inner ear and retinal photoreceptors. To produce an Usher syndrome type 1B (USH1B) rhesus macaque model, we disrupted the MYO7A gene in developing zygotes. Identification of appropriately edited MYO7A embryos for knockout embryo transfer requires sequence analysis of material recovered from a trophectoderm (TE) cell biopsy. However, the TE biopsy procedure is labor intensive and could adversely impact embryo development. Recent studies have reported using cell-free DNA (cfDNA) from embryo culture media to detect aneuploid embryos in human in vitro fertilization (IVF) clinics. The cfDNA is released from the embryo during cell division or cell death, suggesting that cfDNA may be a viable resource for sequence analysis. Moreover, cfDNA collection is not invasive to the embryo and does not require special tools or expertise. We hypothesized that selection of appropriate edited embryos could be performed by analyzing cfDNA for MYO7A editing in embryo culture medium, and that this method would be advantageous for the subsequent generation of genetically modified NHPs. The purpose of this experiment is to determine whether cfDNA can be used to identify the target gene mutation of CRISPR/Cas9 injected embryos. In this study, we were able to obtain and utilize cfDNA to confirm the mutagenesis of MYO7A, but the method will require further optimization to obtain better accuracy before it can replace the TE biopsy approach.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.1
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• pp.9-23
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• 1997

A numerical study of a two-layer, stratified flow is investigated, using the implicit finite difference method in one dimension. The results of computational method have been tested and, in case of lock exchange flow, compared with the results of experimental data. The results of model experiments with various interfacial, bottom friction coefficients along with various time weighting factor of numerical scheme and dissipative interface are shown and discussed. Two-layer model experiment has been also carried out to investigate the generation and propagation characteristics of internal tidal wave over the steep bottom topography under stratified condition. The internal wave seems to well radiate through the downstream boundary under the experiments adopting radiation conditions both at two layers and only at upper layer, confirming the applicability of radiational boundary condition in stratified flows. It is also shown that the internal wave through the downstream boundary propagates more actively with increasing thickness of lower layer in the downstream. This implies that the potential tidal energy in the interface will depend upon the thickness of lower layer for the constant thickness of upper layer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2349-2356
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• 2008

In this paper, we present the method to effectively extract and classify the EEG caused by only brain activity when a normal subject is in a state of mental activity. We measure the synchronous EEG on the auditory event when a subject who is in a normal state thinks of a specific task, and then shift the baseline and reduce the effect of biological artifacts on the measured EEG. Finally we extract only the mental task signal by averaging method, and then perform the recognition of the extracted mental task signal by computing the AR coefficients. In the experiment, the auditory stimulus is used as an event and the EEG was recorded from the three channel $C_3-A_1$, $C_4-A_2$ and $P_Z-A_1$. After averaging 16 times for each channel output, we extracted the features of specific mental tasks by modeling the output as 12th order AR coefficients. We used total 36th order coefficient as an input parameter of the neural network and measured the training data 50 times per each task. With data not used for training, the rate of task recognition is 34-92 percent on the two tasks, and 38-54 percent on the four tasks.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1869-1879
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• 2000

A series of experiments were conducted for modeling the fate and effect of the coupled oxidation reduction reaction of ethanol and propionate recognized as important intermediates in anaerobic degradation metabolism. Anaerobic kinetics for conversion of propionate and the interaction with ethanol were investigated using the model of specific substrate priority utilization effect. Seed cultures for the experiment were obtained from an anaerobically enriched steady-state propionate master culture reactor (HPr-MCR), ethanol-propionate master culture reactor (EtPr-MCR) and glucose master culture reactor (Glu-MCR). Experiments were consisted of four phases. Phase I, II and III were conducted by fixing the propionate organic loading as 1.0 g COD/L with increasing ethanol loading of 0, 100, 200, 400 and 1,000 mg/L, to find metabolic interaction of ethanol and propionate degradation by each enriched anaerobic culture. In phase IV, different mixing ratios of Glu-MCR and HPr-MCR cultures with fixed propionate organic loading, 1.0 g COD/L, were applied to observe the propionate degradation metabolic behavior. In the results of this study, different pathways of propionate and ethanol conversion were found using a modified competitive inhibition kinetic model. Increase of $K_{s2}$ value reflected the formation of acetate followed by ethanol degradation. In addition. $K_3$ value was increased slightly as the reactions of acetate formation and degradation were occurred in acetoclastic methanogenesis.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.117-125
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• 2008

The Object tracking by real-time image analysis is one of the major concerns in computer vision and its application fields. The Object detection process of real-time images must be preceded before the object tracking process. To achieve the stable object detection performance in the exterior environment, adaptive background model generation methods are needed. The adaptive background model can accept the nature's phenomena changes and adapt the system to the changes such as light or shadow movements that are caused by changes of meridian altitudes of the sun. In this paper, we propose a robust background model generation method effective in an illegal parking auto-detection application area. We also provide a evaluation method that judges whether a moving vehicle stops or not. As the first step, an initial background model is generated. Then the differences between the initial model and the input image frame is used to trace the movement of object. The moving vehicle can be easily recognized from the object tracking process. After that, the model is updated by the background information except the moving object. These steps are repeated. The experiment results show that our background model is effective and adaptable in the variable exterior environment. The results also show our model can detect objects moving slowly. This paper includes the performance evaluation results of the proposed method on the real roads.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.124-134
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• 2018

We analyzed research topics, temporal distribution of field sites, and researcher network of 1,508 limnology publications in the Korean Journal of Limnology (1968~2012) and the Korean Journal of Ecology and Environment (2013~2017). We found that water quality and sediment, phytoplankton, invertebrates, and fish were major subjects during the study periods. Survey of flora and fauna and physiological experiment of freshwater species were the largest subjects during 1970~80s, while other subjects including production, behavior, modeling, and ecological assessment have been rapidly increased since the 1990s. Most of the biological taxa equally studied lotic and lentic system, however, invertebrates and fish related studies more focused on the lotic system. Spatially, the field site of Korean limnology studies was found to be concentrated in main river channels runs through urban areas and artificial lakes than preserved natural areas. Freshwater system, located at the elevation range of 301~400 m (upstream of main channels), had the lowest number of field sites. Collaboration among researchers and different institution types have been steadily increased and expanded as the number of publications increased.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.4
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• pp.375-387
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• 2004

A new finite element model will be presented to analyze the nonlinear behavior of RC beams and slabs strengthened by a patch repair. The numerical approach is based on the p-version degenerate shell element including theory of anisotropic laminated composites, theory of materially and geometrically nonlinear plates. In the nonlinear formulation of this model, the total Lagrangian formulation is adopted with large deflections and moderate rotations being accounted for in the sense of von Karman hypothesis. The material model is based on hardening rule, crushing condition, plate-end debonding strength model and so on. The Gauss-Lobatto numerical quadrature is applied to calculate the stresses at the nodal points instead of Gauss points. The validity of the proposed p-version nonlinear finite element model is demonstrated through the load-deflection curves, the ultimate loads, and the failure modes of RC beams or slabs bonded with steel plates or FRP plates compared with available result of experiment and other numerical methods.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.1-12
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• 2006

As national economies globalize, demand for intercontinental container shipping services is growing rapidly, providing a potential economic boon for the countries and communities that provide port services. On the promise of profits, many governments are investing heavily in port infrastructure, leading to a possible glut in port capacity, driving down prices for port services and eliminating profits as ports compete for business. Further, existing ports are making strategic investments to protect their market share, increasing the chance new ports will be overcapitalized and unprofitable. Governments and port researchers need a tool for understanding how local competition in their region will affect demand for port services at their location, and thus better assess the profitability of a prospective port. We propose to develop such a tool by extending our existing simulation model of global container traffic to incorporate demand-side shipper preferences and supply-side strategic responses by incumbent ports to changes in the global port network, including building new ports, scaling up existing ports, and unexpected port closures. We will estimate shipper preferences over routes, port attributes and port services based on US and international shipping data, and redesign the simulation model to maximize the shipper's revealed preference functions rather than simply minimize costs. As demand shifts, competing ports will adjust their pricing (short term) and infrastructure (long term) to remain competitive or defend market share, a reaction we will capture with a game theoretic model of local monopoly that will predict changes in port characteristics. The model's hypotheses will be tested in a controlled laboratory experiment tailored to local port competition in Asia, which will also serve to demonstrate the subtle game theoretic concepts of imperfect competition to a policy and industry audience. We will apply the simulation model to analyze changes in global container traffic in three scenarios: addition of a new large port in the US, extended closure of an existing large port in the US, and cooperative and competitive port infrastructure development among Korean partner countries in Asia.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.3
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• pp.183-196
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• 2010

Increasing human activity due to rapid economic growth and land use change alters the patterns of the Asian monsoon, which is key to crop yields in Asia. In this study, we tested the performance of regional climate model (RegCM3) by simulating important components of Indian summer monsoon, including land-ocean contrast, low level jet (LLJ), Tibetan high and upper level Easterly Jet. Three contrasting rain years (1994: excess year, 2001: normal year, 2002: deficient year) were selected and RegCM3 was integrated at 60 km horizontal resolution from April 1 to October 1 each year. The simulated fields of circulations and precipitation were validated against the observation from the NCEP/NCAR reanalysis products and Global Precipitation Climatology Centre (GPCC), respectively. The important results of RegCM3 simulations are (a) LLJ was slightly stronger and split into two branches during excess rain year over the Arabian Sea while there was no splitting during normal and deficient rain years, (b) huge anticyclone with single cell was noted during excess rain year while weak and broken into two cells in deficient rain year, (c) the simulated spatial distribution of precipitation was comparable to the corresponding observed precipitation of GPCC over large parts of India, and (d) the sensitivity experiment using NIMBUS-7 SMMR snow data indicated that precipitation was reduced mainly over the northeast and south Peninsular India with the introduction of 0.1 m of snow over the Tibetan region in April.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.118-126
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• 2011

The objective of this paper is to study the structural behavior of Composite Basement Wall (CBW) according to shear span-to-depth ratio through an experiment and predict the nonlinear behavior of CBW by using ADINA program widely has been being used for FE analysis. Especially, this study focuses on the part of CBW in which the Reinforced Concrete (RC) is under compression stress; At the region of CBW around each floor, RC part stresses by compressive force when lateral press by soil acts on the wall. The contact condition between RC wall and steel (H-Pile) including stud connector is main factor in the analysis since it governs overall structural behavior. In order to understand the structural behavior of CBW whose RC part is under compressive stress, an experimental work and finite element analysis were performed. Main parameter in the test is shear span-to-depth ratio. For simplicity in analysis, reinforcements were not modeled as a seperated element but idealized as smeared to concrete. All elements were modeled to have bi-linear relation of material properties. Three type of contact conditions such as All Generate Option (AGO), Same Element Group Option with Tie(SEGO-T) and Same Element Group Option with Not tie(SEGO-NT) were considered in the analysis. For each analysis, the stress flow and concentration were reviewed and analysis result was compared to test one. From the test result, CBW represented ductile behavior by contribution of steel member even if it had short shear span-to-depth ration which is close to "1". The global composite behavior of CBW whose concrete wall was under compressive stress could be predicted by using contact element in ADINA program. Especially, the modeling by using AGO and SEGO-T showed more close relation on comparing with test result.