• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1211-1224
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• 2023

Clouds cause many difficult problems in observing land surface phenomena using optical satellites, such as national land observation, disaster response, and change detection. In addition, the presence of clouds affects not only the image processing stage but also the final data quality, so it is necessary to identify and remove them. Therefore, in this study, we developed a new cloud detection technique that automatically performs a series of processes to search and extract the pixels closest to the spectral pattern of clouds in satellite images, select the optimal threshold, and produce a cloud mask based on the threshold. The cloud detection technique largely consists of three steps. In the first step, the process of converting the Digital Number (DN) unit image into top-of-atmosphere reflectance units was performed. In the second step, preprocessing such as Hue-Value-Saturation (HSV) transformation, triangle thresholding, and maximum likelihood classification was applied using the top of the atmosphere reflectance image, and the threshold for generating the initial cloud mask was determined for each image. In the third post-processing step, the noise included in the initial cloud mask created was removed and the cloud boundaries and interior were improved. As experimental data for cloud detection, CAS500-1 L2G images acquired in the Korean Peninsula from April to November, which show the diversity of spatial and seasonal distribution of clouds, were used. To verify the performance of the proposed method, the results generated by a simple thresholding method were compared. As a result of the experiment, compared to the existing method, the proposed method was able to detect clouds more accurately by considering the radiometric characteristics of each image through the preprocessing process. In addition, the results showed that the influence of bright objects (panel roofs, concrete roads, sand, etc.) other than cloud objects was minimized. The proposed method showed more than 30% improved results(F1-score) compared to the existing method but showed limitations in certain images containing snow.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.2
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• pp.165-171
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• 2013

Due to the difficulty in considering dynamic load in the view point of a computer resource and computing time, it is common that external load is assumed as ideal static loads. However, structural analysis under static load cannot guarantee the safety of design of the structures under dynamic loadings. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. However, previously reported works to distribute equivalent static load were based on ad-hoc methods. Improper selection of equivalent static loading positions may results in unreliable prediction of structural design. The present study proposes the selection method of the proper locations of equivalent static loads to dynamically applied loads when we consider transient dynamic structural problems. Moreover, it is appropriate to take into account the stress constraint as well as displacement constraint condition for the safety design. But the previously reported studies of equivalent static load design methods considered only displacement constraint conditions but not stress constraint conditions. In the present study we consider not only displacement constraint but also stress constraint conditions. Through a few numerical examples, the efficiency and reliability of proposed scheme is verified by comparison of the equivalent stress between equivalent static loading and dynamic loading.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.151-161
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• 2001

Background: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost. In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. Method: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. Results: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. Conclusion: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.

• Industry Promotion Research
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• v.5 no.3
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• pp.61-71
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• 2020

The purpose of this paper is to reaffirm the logical framework of the saju analysis method by recreating the saju model of old-law to study and organize the theories of frame in old-law Myeongri, and then by organizing and comparing the logic structure of the saju analysis method of new-law and old-law. Some believe that Myeongri Theory first appeared in the world in the Warring States Period when they were active with Gwigokja and Naknokja as origin, while others believe that it was origin that "Okjokyeong" was written by Kwak-Bak of Eastern Jin after a while. Since then, Myeongri Theory, which had been organized by Won-Cheongang and Yi-Heojung, has undergone a major transformation since reaching the Song Dynasty Seo-Japyeong. Based on this point, the Myeongri Theory of the previous generation is called the Old-law, and the subsequent theory is called the New-law. The changes in the logic structure of the old-law and the new-law leave a big difference and disconnect between those. But comparative studies have confirmed that the philosophy and logic structure due to natural laws that have not changed much such as the symbolic system of nature called Yinyang & five elements and Cheongan-jiji, the idea of a heavenly response projected in the Three Wonders of heaven, earth and human, and the concept of generation and time in the position of year-month-day-time.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.540-545
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• 2006

T-DNA-mediated transformation is a common method for generating transgenic plants with insertional mutagenesis. In order to identify important genes involved in shoot development, a system of promoter trap insertional mutagenesis was employed in Arabidopsis thaliana. For this system, an efficient promoter trap vector, pFGL561 was developed. The pFGL561 includes a basta-resistant gene, an intron with multiple splicing donor and acceptor sites, and a promoter-less GFP reporter gene. Using floral-dipping method, we made total 300 $T_1$ promoter-trap lines which were screened for GFP expression. GFP signals in the $T_1$ plants were detected with high frequency, 26.7%, and the signals were reconfirmed in $T_2$ plants. To isolate the genes that are involved in shoot development, phenotypes were analyzed in $T_2$ plants of the 19 $T_1$ lines that had GFP signals in shoot apex, and 6 $T_1$ lines were selected that had abnormal shoot development. These lines will be very useful for the investigation of shoot development.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.4
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• pp.403-408
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• 2003

A general meaning of caricaturing is that a representation, especially pictorial or literary, in which the subject's distinctive features or peculiarities are deliberately exaggerated to produce a comic or grotesque effect. In other words, a caricature is defined as a rough sketch(dessin) which is made by detecting features from human face and exaggerating or warping those. There have been developed many methods which can make a caricature image from human face using computer. In this paper, we propose a new caricaturing system. The system uses a real-time image or supplied image as an input image and deals with it on four processing steps and then creates a caricatured image finally. The four Processing steps are like that. The first step is detecting a face from input image. The second step is extracting special coordinate values as facial geometric information. The third step is deforming the face image using local warping method and the coordinate values acquired in the second step. In fourth step, the system transforms the deformed image into the better improved edge image using a fuzzy Sobel method and then creates a caricatured image finally. In this paper , we can realize a caricaturing system which is simpler than any other exiting systems in ways that create a caricatured image and does not need complex algorithms using many image processing methods like image recognition, transformation and edge detection.

• Progress in Medical Physics
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• v.10 no.2
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• pp.103-114
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• 1999

In this study, as a preliminary study for developing a full 3D photon dose calculation algorithm, We developed 2.5D photon dose calculation algorithm by extending 2D calculation algorithm to allow non-coplanar configurations of photon beams. For this purpose, we defined the 3d patient coordinate system and the 3d beam coordinate system, which are appropriate to 3d treatment planning and dose calculation. and then, calculate a transformation matrix between them. For dose calculation, we extended 2d "Clarkson-Cunningham" model to 3d one, which can calculate wedge fields as well as regular and irregular fields on arbitrary plane. The simple Batho's power-law method was implemented as an inhomogeneity correction. We evaluated the accuracy of our dose model following procedures of AAPM TG#23; radiation treatment planning dosimetry verifications for 4MV of Varian Clinac-4. As results, PDDs (percent depth dose) of cubic fields, the accuracy of calculation are within 1% except buildup region, and $\pm$3% for irregular fields and wedge fields. And for 45$^{\circ}$ oblique incident beam, the deviations between measurements and calculations are within $\pm$4%. In the case of inhomogeneity correction, the calculation underestimate 7% at the lung/water boundary and overestimate 3% at the bone/water boundary. At the conclusions, we found out our model can predict dose with 5% accuracy at the general condition. we expect our model can be used as a tool for educational and research purpose.. purpose..

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.247-260
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• 2014

Purpose of this study is to analyze the roles and strategies of imagistic simulation observed in mental simulation about problematic situation of prediction, and thereby identify the process of generating prediction, explanation and sophistication. For this study, a framework for mental simulation process and strategy based on literary research was developed and content was validated from four experts of science education. This study was participated by 10 preliminary elementary school teachers, and a total of 20 cases were gathered for two thought experiment tasks based on the think-aloud method. The results were as follows: First, mental simulation process described based on the seven elements of 'perception,' 'interpretation,' 'statement of initial representation,' 'running imagistic simulation,' 'identifying result of simulation,' 'identifying alignment' and 'restatement structured representation.' The study confirmed that initial representation by interpreting related concepts and running imagistic simulation a number of times to develop explanation and prediction. Second, the study identified the use of strategies to enhance simulation such as 'zoom in,' 'partition,' 'dimensional enhancement,' 'dimensional reduction,' 'remove,' 'replace' and 'extreme case.' Running spatial transformation that uses strategy to enhance simulation contributed to discovering mechanism elements in problematic situations.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.4
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• pp.398-412
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• 2006

The purpose of this study is to investigate the relationship between the acceleration of vibration by the powered hand tools used in the shipbuilding industry, and to develop the prospective prevalence model for the hand-arm vibration syndrome among the shipbuilding workers.The acceleration levels and frequencies of six types of grinder were measured using the ISO5349 method along with the time of exposure to the vibration from the powered hand tools. Medical examination for 114 workers were performed using the cold provocation test. Comparisons were made between the estimated prevalence of hand-arm vibration syndrome from ISO5349 and the observed values from the medical examinations. By multiple regression, we developed the prospective prevalence model of hand-arm vibration syndrome produced by the hand tools used in the shipbuilding industry. 4 hour-energy-equivalent frequency-weighted accelerations were $6.23m/s^2$ in the grinding job done after welding, and $13.39m/s^2$ in the grinding job done before painting. The mean exposure time while holding powered hand tools was 4.64 hours. Prevalence rates of Raynaud's Phenomenon were 12.04% in the grinding after soldering, and 42.9% in the grinding before painting measured using the ISO5349 method. After exposure to vibration for 10.79 years, about a half of the workers in the grinding after welding could developed Raynaud's Phenomenon. For the workers in the grinding before painting, the latency was 5.02 years. The ISO equation for dose response relationship was not significantly correlated with observed recovery rates of finger skin temperatures, blood flows and amplitudes of nerve conduction velocities. A multiple regression model for dose-response relationship was proposed from the results. Recovery rate of the skin temperatures = -0.668+ 0.337 ${\times}$ 4 hour energy equivalent frequency-weighted accelerations + 0.767 ${\times}$ duration of vibration exposure(years) The validity was proved by multiple regression analysis after correlation transformation and regression results based on model-building data and validation data.

• Journal of Korea Water Resources Association
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• v.45 no.5
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• pp.505-516
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• 2012

The study applies a hydrologic simulation model, HEC-1 developed by Hydrologic Engineering Center to Daecheong dam watershed for modeling hourly inflows of Daecheong dam. Although the HEC-1 model provides an automatic optimization technique for some of the parameters, the built-in optimization model is not sufficient in estimating reliable parameters. In particular, the optimization model often fails to estimate the parameters when a large number of parameters exist. In this regard, a main objective of this study is to develop Bayesian Markov Chain Monte Carlo simulation based HEC-1 model (BHEC-1). The Clark IUH method for transformation of precipitation excess to runoff and the soil conservation service runoff curve method for abstractions were used in Bayesian Monte Carlo simulation. Simulations of runoff at the Daecheong station in the HEC-1 model under Bayesian optimization scheme allow the posterior probability distributions of the hydrograph thus providing uncertainties in rainfall-runoff process. The proposed model showed a powerful performance in terms of estimating model parameters and deriving full uncertainties so that the model can be applied to various hydrologic problems such as frequency curve derivation, dam risk analysis and climate change study.