• Journal of the Korea Society for Simulation
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• v.16 no.4
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• pp.23-31
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• 2007

Anti-Air Warfare(AAW) functionality of the naval combat system is the key functionality to ensure the ship's survivability. We have applied a novel method using model-based-simulation to analyze and design AAW functionality of the Patrol Killer Experimemnt Combat System. In this approach, an AAW functional model is described with the FSM(Finite State Machine) and directly executed for the AAW simulation. After prototyping using model based simulation, Hardware In Loop Simulation(HILS) is conducted as the AAW functionality is interfaced with the other ones of the combat system for completing the integration of the system components. This incremental and iterative development approach based on the model based simulation can minimize the development risks and costs caused by the system complexity for military system, bringing out the merit of the rapid prototyping.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.1-16
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• 2022

Although start-up is a key national strategy to increase national competitiveness and create employment, the survival rate of start-ups has not improved significantly. This is an important reason for the inability to provide timely and appropriate support to startups, which are in the early stages of start-up, due to the unique limitations of existing start-up support institutions and investors. The relatively recent accelerator is attracting attention as a subject of solving the above problems through professional incubation and investment. However, there are only a few empirical studies on investment determinants that affect the survival and success of accelerators, and there is a lack of theoretical evidence. Accordingly, in previous studies, 12 investment determinants were derived from a static, strategic, and dynamic perspective as accelerator investment determinants based on a business model innovation framework. This study subdivided the accelerator investment determinants derived through previous studies into 21 and analyzed the importance and priority of each factor using AHP (Analytic Hierarchy Process) analysis technique for domestic accelerator investment experts. As a result of the analysis, the top factors of importance of accelerator investment determinants were in the order of 'human resources', 'customer and market', 'intellectual resources', and 'entrepreneur's ability to realize opportunities'. It can be seen that the accelerator considers the core competencies of startups to implement solutions as the most important factor when making startup investment decisions. It was also confirmed that accelerators are strategic to create a clear value proposition and differentiated market position based on the core competitiveness of startups, and that the core value delivery method prefers a market-oriented business model and recognizes entrepreneurs's innovation capability is an important factor to realize a business model with limited resources in a rapidly changing market. This study is of academic significance in that it analyzes the importance and priority of accelerator investment determinants through demonstration as a follow-up study on accelerator investment determinants derived based on business model innovation theory that reflects the nature, goals, and major activities of accelerator investment. In addition, it is of practical value as it contributes to revitalizing the domestic startup investment ecosystem by providing accelerators with theoretical grounds for investment decisions and specific information on detailed investment determinants.

• Journal of Korean Library and Information Science Society
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• v.32 no.3
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• pp.353-395
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• 2001

Academic libraries presently are confronting the issues of organizational viability and relevance. Academic libraries are not the sole owners of the information gateway. The purpose of this study is modeling of university library's information service for effective implication of its role in order to ensure organizational viability and relevance in internet environment. New information service model of university library needs to be design according to four Principles. Firstly, building of web based library petals. Secondly, provision of web front-end with hybrid functions. Thirdly, provision of information literacy program Fourthly, extension resource sharing.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.304-312
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• 2018

Regulatory T cells (Treg), known as immune-suppressors, may help modulate the immune response. In this study, we investigated the effect of Treg-derived $TGF-{\beta}1$ on pancreatic islet cell function in vitro and in vivo. One hundred eighty IEQ (islet equivalents) of pancreatic islets, the marginal amount to regulate blood glucose level after syngeneic islet transplantation in mouse type 1 diabetes (T1D) model, were co-cultured with $4{\times}10^6$ Treg cells for 48 hours. The changes in $TGF-{\beta}1$, interleukin-6 (IL-6), and insulin secretion levels were measured and analyzed among the Treg-only group, the islet-only group, and the Treg/islet co-cultured group. In the Treg/islet co-cultured group, IL-6 and insulin secretion levels were increased (P<0.0005, P<0.005) and islet viability was improved (P<0.005) compared with the islet-only group. Furthermore, after transplantation, the co-cultured islets regulated blood glucose levels efficiently in the T1D mouse model. These data suggest that Treg could improve islet functions and viability via the $TGF-{\beta}1$ secretion pathway (P<0.05~0.005), thus the use of Treg in islet transplantation should be explored further.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.531-535
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• 1998

In 1964, Abbott and Colleagues published the world's first heterotopic heart transplantation technique in the rat. Their method established circulation by end-to-end anastomoses of the graft's aorta and pulmonary artery to the recipient's abdominal aorta and Inferior Vena Cava(IVC), respectively. In 1966, Tomita et al altered Abbott's technique by employing end-to-side rather than end-to-end anastomoses, thus eliminating the hind leg paralysis that sometimes resulted from Abbott's technique. In order to prevent postsuture hemorrhage (since 7-0 silk suture was the finest available at that time), Tomita's aortic anastomosis was done with double up-and-down continuous suture technique. A single layer continuous anstomosis effected the pulmonary artery-IVC anastomosis. The availability of Nylon monofilament suture made it possible for Ono and Lindsey to use a single layer suture technique for the aortic end-to-side anastomosis in their modified rat heart transplantation. We observed survival time between control group and Immunosuppression(Cyclosporine administration, 10mg/Kg${\times}$4 times postoperatively) group after heterotopic heart transplantation in the rat model. The cyclosporine adminstration group survived longer than the control group, thus we concluded that cyclosporine was based on Immunosuppressive drugs.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.6
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• pp.177-189
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• 2018

Business environment is always full of challenges. Despite various strategic efforts, there are so many failure cases of misfit. With the weaker resource base and institutional foundation, startup firms find it more difficult to find the right spot in the stiff competition. In the middle of evolutionary process, the startup firms need proper strategies meeting the differential challenges along the multiple stages of growth. Following the idea of product life cycle, this study applies the four stages of growth-startup, initial growth, accelerated growth, matured, and decliing. The next step for the startup manager is meeting each stage of growth with proper strategic efforts, including strategy, structure, decision-making pattern, and control method. When the knowledge factor is introduced, there is a potential for higher performance. Based on the 'Detailed Survey on Startup Ventures in 2017,' this study explores the impact of the government subsidy program on the firm competitiveness and performance-along the four stages of growth. In each stage, the strategy factors showed differential impact.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.61-71
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• 2023

As differences in the impact of each species on a spatial scale occur, analysis at the landscape scale is necessary to evaluate the impact of a development project. In previous studies, the Incidence Function Model (IFM) based on meta population theory was used to analyze the impact of species on the environment that changes according to urban development. However, since the model was required at least 10 occupied areas, it is difficult to use it for species that are difficult to monitor such as endangered species. Therefore, we proposed the Incidence Function Model (IFM) using species distribution model to fill the species data. In addition, we reviewed whether the developed model can be used in environmental impact assessment. As a result of the analysis, the minimum occupancy of Prionailurus bengalensis on urban development decreased to 56.5% and the possibility of survival to 28.7%. We confirmed that It rapidly decreased from the reference points of 230 and 70habitats through analysis of the meta-population capacity according to the decrease in the number of habitats. These results can be assessing the environment impact of each species on habitat loss. And it can support decision-making on the minimum number and area of habitat for species protection. This study is expected to be used as basic data for environment impact assessment on before and after development projects and mitigation measures plans, thereby increasing the effectiveness of reduction plans.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.574-583
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• 2021

Predicting shipping markets is an important issue. Such predictions form the basis for decisions on investment methods, fleet formation methods, freight rates, etc., which greatly affect the profits and survival of a company. To this end, in this study, we propose a shipping freight rate prediction model for container ships using gated recurrent units (GRUs) and long short-term memory structure. The target of our freight rate prediction is the China Container Freight Index (CCFI), and CCFI data from March 2003 to May 2020 were used for training. The CCFI after June 2020 was first predicted according to each model and then compared and analyzed with the actual CCFI. For the experimental model, a total of six models were designed according to the hyperparameter settings. Additionally, the ARIMA model was included in the experiment for performance comparison with the traditional analysis method. The optimal model was selected based on two evaluation methods. The first evaluation method selects the model with the smallest average value of the root mean square error (RMSE) obtained by repeating each model 10 times. The second method selects the model with the lowest RMSE in all experiments. The experimental results revealed not only the improved accuracy of the deep learning model compared to the traditional time series prediction model, ARIMA, but also the contribution in enhancing the risk management ability of freight fluctuations through deep learning models. On the contrary, in the event of sudden changes in freight owing to the effects of external factors such as the Covid-19 pandemic, the accuracy of the forecasting model reduced. The GRU1 model recorded the lowest RMSE (69.55, 49.35) in both evaluation methods, and it was selected as the optimal model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.1
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• pp.35-41
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• 2010

In developing modern aircraft, the reconfiguration control that can improve the safety and the survivability against the unexpected failure by partitioning control surfaces into several parts has been actively studied. This paper deals with the reconfiguration control using model predictive control method considering the saturation of control surfaces under the control surface failure. Linearized aircraft model at trim condition is used as the internal model of model predictive control. We propose the controller that performs optimization using LMI (linear matrix inequalities) based semi-definite programming in case that control surface saturation occurs, otherwise, uses analytic solution of the model predictive control. The performance of the proposed control method is evaluated by nonlinear simulation under the flight scenario of control surface failure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.279-282
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• 2022

Acute lymphoblastic leukemia is an acute leukemia caused by suppression of bone marrow function due to overgrowth of immature lymphocytes in the bone marrow. It accounts for 30% of acute leukemia in adults, and children show a cure rate of over 80% with chemotherapy, while adults show a low survival rate of 20% to 50%. However, research on a machine learning algorithm based on medical image data for the diagnosis of acute lymphoblastic leukemia is in the initial stage. In this paper, we compare and analyze CNN algorithm models for quick and accurate diagnosis. Using four models, an experimental environment for comparative analysis of acute lymphoblastic leukemia diagnostic models was established, and the algorithm with the best accuracy was selected for the given medical image data. According to the experimental results, among the four CNN models, the InceptionV3 model showed the best performance with an accuracy of 98.9%.