• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.381-389
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• 1994

In the communication network, multimedia service such as high quality voice, high speed data, image etc. will be added to the existing service. This service generates new requirements for the communication networks. The priority control mechanism can be used to control multimedia traffics generated by many communication systems. The priority mechanism which assigns prioirities to generated cells according to service quality is one of the traffic control. The priority assignment can be divided by priority criterion for each traffic characteristics such as loss sensitivity and delay sensitivity. In this paper, we alnalyzed the partial buffur sharing (PBS) mechani느 as a traffic control reducing the cell loss, and proposed analysis method. We analyzed the PBS mechanism using classical approach as a Markov chain. In order to validata proposed analysis method, simulation is performed using simulation package SIMSCRIPT 11.5. From this results, we confirmed that proposed analysis method can be verified. Also, we presented cell loss probability of ATM network when this results are to be applied to ATM networks.

• Polymer(Korea)
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• v.31 no.6
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• pp.461-468
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• 2007

In order to understand the structure of the existing aggregate in the nanocomposite, which has been prepared with polyester and trisilanolisobutyl polyhedral oligomeric silsesquioxane(TBPOSS), laser light scattering(LLS) and SEM-EDS were applied to its 1,1,1,3,3,3-hexafluoro-2-propanol solution and original sample, respectively. Although aggregate particles appeared as spherical shape of the average diameter of 120 nm in SEM image, they were not microgels but almost linear copolymer chains ($M_w=2.3{\times}10^6\;g/mol$) alternating 320 molecules of TBPOSS with polyester subchains. It has been microphase-separated from the matrix polyester due to the difference of chemical composition. As the matrix, polyester chain of $M_w=4.0{\times}10^4\;g/mol$ had averagely 2.5 molecules of TBPOSS per chain. It is also found that about 93% of total TBPOSS molecules existed in matrix phase and the residual 7% in spherically aggregated phase.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.73-79
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• 2012

This study attempts to analyze changes in land use patterns in a compound urban and agricultural city Kimje-si, using LANDSAT TM imagery and to forecast future changes accordingly. As a new approach to supervised classification, HSB(Hue, Saturation, Brightness)-transformed images were used to select training zones, and in doing so classification accuracy increased by more than 5 percent. Land use changes were forecasted by using a cellular automaton algorithm developed by applying Markov Chain techniques, and by taking into account classification results and GIS data, such as population of the pertinent region by area, DEMs, road networks, water systems. Upon comparing the results of the forecast of the land use changes, it appears that geographical features had the greatest influence on the changes. Moreover, a forecast of post-2030 land use change patterns demonstrates that 21.67 percent of mountain lands in Kimje-si is likely to be farmland, and 13.11 percent is likely to become city areas. The major changes are likely to occur in small mountain lands located in the heart of the city. Based on the study result, it seems certain that forecasting future land use changes can help plan land use in a compound urban and agricultural city to procure food resources.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.477-480
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• 2010

Purpose: Ganglioneuromas are well-differentiated tumors derived from neuroectodermal neural crest cells. Although these tumors can occur anywhere along the sympathetic chain from the base of the skull to the pelvic cavity, they usually develop in the posterior mediastinum and retroperitoneum these tumors are rarely found in the cervical region. Method: We report the case of a 16-year-old male patient with neurofibromatosis type 1 who was admitted because of a palpable mass centrally located on the left side of the neck. A preoperative contrast-enhanced neck computed tomography image showed a low-density homogeneous mass on the parapharyngeal space along with marked displacement of the trachea and carotid vessels. Round and soft masses were also detected on both axillae. Results: The patient subsequently underwent complete excision of the neck mass via the transcervical approach. The mass was smooth and well encapsulated between the sternocleidomastoid muscle and the trachea. Further, the mass appeared to arise from the cervical sympathetic chain, which was preserved during surgery. Both the axillary masses were also excised. The histopathological findings were ganglioneuroma for the neck mass and neurofibroma for both the axillary masses. Conclusion: Cervical ganglioneuromas are rare tumors that present as enlarging parapharyngeal cervical masses in the oropharynx or neck. To our knowledge, a case of cervical ganglioneuroma associated with neurofibromatosis type 1 has never been reported. In patients with neurofibromatosis, multiple tumors may develop, and therefore periodic clinical and radiological follow-up is recommended. Further, repeated imaging analysis should be performed if the presence of another tumor is suspected.

• Journal of Information Technology Services
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• v.2 no.1
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• pp.51-73
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• 2003

The success of 2002 Korea Japan Worldcup became a good opportunity to give the message of revival to the people of Korea. With the effect of it, the national brand image has risen. Nevertheless, in order to maximize the chance of time, the most necessary thing that need to be done is to find the strategic counterproposal of the Post Worldcup. Especially, to find the more active plan in the respect of economy. In this research, we have studied the IT industry(especially SI industry) of the economy in order to look into the strategic counterproposal to get the development effect after the Worldcup. We mainly analyzed the SI industry in the respect of economy, because it is not only a high-value added industry of the integration of knowledge and technology but also a high-tech industry which has a spreading effect on the related industries. To implement the analysis of SI industry, derive and verify the strategy, and get the activating plan, we studied with 4 stages. Firstly, analyze the exterior environment and the interior strength with the Competitive Strategy Model(Specially, 7 Force Model & Value Chain Model). Secondly, get the strategy with SWOT analysis. Thirdly, verify the Strategy with interview and survey. Fourthly, classify the SI industry activation plan into 5 kinds after Worldcup through panel discussion and seminar with the data which we got through interview and survey.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.148-156
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• 2021

Single-chain antibodies against epidermal growth factor receptor variant III (EGFRvIII) are potentially promising agents for developing antibody-based cancer treatment strategies. We described in our previous study the successful expression of an anti-EGFRvIII scFv antibody in Escherichia coli. However, we could also observe the formation of insoluble aggregates in the periplasmic space, limiting the production yield of the active product. In the present study, we investigated the mechanisms by which growth conditions could affect the expression of the soluble anti-EGFRvIII scFv antibody in small-scale E. coli NiCo21(DE3) cultures, attempting to maximize production. The secreted scFv molecules were purified using Ni-NTA magnetic beads and protein characterization was performed using SDS-PAGE and western blot analyses. We used the ImageJ software for protein quantification and determined the antigen-binding activity of the scFv antibody against the EGFRvIII protein. Our results showed that the highest percentage of soluble scFv expression could be achieved under culture conditions that combined low IPTG concentration (0.1 mM), low growth temperature (18℃), and large culture dish surface area. We found moderate-yield soluble scFv production in the culture medium after lactose-mediated induction, which was also beneficial for downstream protein processing. These findings were confirmed by conducting western blot analysis, indicating that the soluble, approximately 30-kDa scFv molecule was localized in the periplasm and the extracellular space. Moreover, the antigen-binding assay confirmed the scFv affinity against the EGFRvIII antigen. In conclusion, our study reveals that low-speed protein expression is preferable to obtain more soluble anti-EGFRvIII scFv protein in an E. coli expression system.

• The KIPS Transactions:PartB
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• v.14B no.6
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• pp.453-460
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• 2007

In this paper, we present a method to extract the text lines in poorly structured documents. The text lines may have different orientations, considerably curved shapes, and there are possibly a few wide inter-word gaps in a text line. Those text lines can be found in posters, blocks of addresses, artistic documents. Our method based on the traditional perceptual grouping but we develop novel solutions to overcome the problems of insufficient seed points and vaned orientations un a single line. In this paper, we assume that text lines contained tone connected components, in which each connected components is a set of black pixels within a letter, or some touched letters. In our scheme, the connected components closer than an iteratively incremented threshold will make together a chain. Elongate chains are identified as the seed chains of lines. Then the seed chains are extended to the left and the right regarding the local orientations. The local orientations will be reevaluated at each side of the chains when it is extended. By this process, all text lines are finally constructed. The proposed method is good for extraction of the considerably curved text lines from logos and slogans in our experiment; 98% and 94% for the straight-line extraction and the curved-line extraction, respectively.

• Journal of Distribution Science
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• v.13 no.5
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• pp.103-111
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• 2015

Purpose - When it comes to first impressions of family restaurants, people basically think of the following factors: cozy, a refreshing space, indoor lighting, atmospheric music, the best-quality service through mutual interactions with employees, birthday events, follow-up customer management, brand image, and many others. Focusing on such family restaurants characteristics, with consumption experience and customer satisfaction determined as mediator variables, this study looks into the selection factors that affect customer loyalty when choosing a family restaurant. Subsequently, the study conducts an empirical analysis of these selection factors with the greatest influence. Research design, data, and methodology - This study analyzed 200 total surveys of family restaurant customers including college students, workers, housewives, and others. The survey was conducted over two weeks in May 2014. For statistical processing, SPSS 21 was used for factor analysis and reliability analysis as well as AMOS for structural equation analysis. In terms of a variable that would influence either consumption experience or customer satisfaction at the restaurants, the study introduced the concept of customer equity. The study designed a model based on a hypothesis developed using the following factors: customer encounter service value, customer convenience value, brand equity, relationship equity, and other factors defined as components of customer equity by Rust et al. (2000) determined as independent variables as well as with customer experience and customer satisfaction set as mediator variables. The hypothesis, after all, assumed that customer loyalty would be positively (+) influenced. Results - The analysis results from the study reported that brand value, customer encounter service value, and relationship value have positive (+) effects on consumption experience and customer satisfaction. However, as for customer convenience value, this turned out not to have a statistically significant influence on consumption experience and customer satisfaction. In regard to a relation between consumption experience and customer satisfaction, the results showed that the former affects the latter, and in terms of intervening variables, both of these appeared to have a positive (+) effect on customer loyalty. Conclusions - This study suggests that family restaurants should look for strategies that focus on how to promote customer relationships. For example, restaurants could try birthday events or discount events to achieve this goal. Since the study ended up realizing relatively low levels of suitability and statistical significance, the path of the study changed. After all, in order to increase suitability and statistical significance, the study had to eliminate factors such as service quality and others and for this reason the study was unable to conduct the analysis as initially planned. In addition, the data samples of the research were mainly gathered from students, which made it hard to say that the analysis was carried out on samples from every different group. Future research should analyze the characteristics of each group of customers for factors affecting customer satisfaction and customer loyalty in the family restaurant chain.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1213-1224
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• 2021

Objective: To develop a machine learning (ML) pipeline based on radiomics to predict Coronavirus Disease 2019 (COVID-19) severity and the future deterioration to critical illness using CT and clinical variables. Materials and Methods: Clinical data were collected from 981 patients from a multi-institutional international cohort with real-time polymerase chain reaction-confirmed COVID-19. Radiomics features were extracted from chest CT of the patients. The data of the cohort were randomly divided into training, validation, and test sets using a 7:1:2 ratio. A ML pipeline consisting of a model to predict severity and time-to-event model to predict progression to critical illness were trained on radiomics features and clinical variables. The receiver operating characteristic area under the curve (ROC-AUC), concordance index (C-index), and time-dependent ROC-AUC were calculated to determine model performance, which was compared with consensus CT severity scores obtained by visual interpretation by radiologists. Results: Among 981 patients with confirmed COVID-19, 274 patients developed critical illness. Radiomics features and clinical variables resulted in the best performance for the prediction of disease severity with a highest test ROC-AUC of 0.76 compared with 0.70 (0.76 vs. 0.70, p = 0.023) for visual CT severity score and clinical variables. The progression prediction model achieved a test C-index of 0.868 when it was based on the combination of CT radiomics and clinical variables compared with 0.767 when based on CT radiomics features alone (p < 0.001), 0.847 when based on clinical variables alone (p = 0.110), and 0.860 when based on the combination of visual CT severity scores and clinical variables (p = 0.549). Furthermore, the model based on the combination of CT radiomics and clinical variables achieved time-dependent ROC-AUCs of 0.897, 0.933, and 0.927 for the prediction of progression risks at 3, 5 and 7 days, respectively. Conclusion: CT radiomics features combined with clinical variables were predictive of COVID-19 severity and progression to critical illness with fairly high accuracy.

• Journal of Photoscience
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• v.9 no.2
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• pp.479-481
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• 2002

UV-induced DNA damage causes cell killing and mutations leading to carcinogenesis. In normal human cells, UV damage such as cyclobutane pyrimidine dimers (CPDs) and primidine-prymidone (6-4) photoproducts are mainly repaired by nucleotide excision repair mechanism. The molecular processes have been well characterized recently. To know the influence of mitochondrial genome on the nucleotide excision repair mechanism against CPDs, we comparatively examined the production of CPDs by UVC irradiation and their repair kinetics in human cells completely lacking mitochondrial DNA (mtDNA) and the parental HeLa S cells. Whole DNA extracted from the cells exposed to UVC was treated with T4-endonuclease V to break the phosphodiester bond adjacent to CPDs. The DNA was electrophoresed in a denaturing agarose gel, which was visualized by ethidium bromide staining. The relative amount of CPDs was determined by image analysis using NIH Image software. MtDNA- less (rho-O) cells were apparently more sensitive to UVC than HeLa S cells, while the level of induction of CPDs in rho-O and HeLa cells was comparable. The repair of CPDs was less efficient in rho-O cells compared with HeLa cells. The residual amount of CPDs after 24-h repair was larger in rho-O cells than in HeLa cells where more than 90 % of CPDs were repaired by then. The non-repaired CPDs would lead to apoptosis in rho-O cells. These results suggest that mitochondrial genome may contribute to some ATP-dependent steps in nucletide excision repair by supplying sufficient ATP which is generated through a respiratory chain in mitochondria.