• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.71-82
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• 2022

Most of the predictions using machine learning are neutral predictions considering the symmetrical situation where the predicted value is not smaller or larger than the actual value. However, in some situations, asymmetric prediction such as over-prediction or under-prediction may be better than neutral prediction, and it can induce better judgment by providing various predictions to decision makers. A method called Asymmetric Twin Support Vector Regression (ATSVR) using TSVR(Twin Support Vector Regression), which has a fast calculation time, was proposed by controlling the asymmetry of the upper and lower widths of the ε-tube and the asymmetry of the penalty with two parameters. In addition, by applying the existing GSVQR and the proposed ATSVR, prediction using the prediction propensities of over-prediction, under-prediction, and neutral prediction was performed. When two parameters were used for both GSVQR and ATSVR, it was possible to predict according to the prediction propensity, and ATSVR was found to be more than twice as fast in terms of calculation time. On the other hand, in terms of accuracy, there was no significant difference between ATSVR and GSVQR, but it was found that GSVQR reflected the prediction propensity better than ATSVR when checking the figures. The accuracy of under-prediction or over-prediction was lower than that of neutral prediction. It seems that using both parameters rather than using one of the two parameters (p_1,p_2) increases the change in the prediction tendency. However, depending on the situation, it may be better to use only one of the two parameters.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.2
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• pp.81-88
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• 2023

SHM (Structural Health Monitoring) technique for monitoring aircraft structural health and damage, EHM (Engine Health Monitoring) for monitoring aircraft engine performance, and APM (Application Performance Management) is used for each function. APMS (Airplane Performance Monitoring System) is a program that comprehensively applies these techniques to identify the difference between the performance manual provided by the manufacturer and the actual fuel mileage of the aircraft and reflect it in the flight plan. The main purpose of using APMS is to understand the performance of each aircraft, to plan and execute flights in an optimal way, and consequently to reduce fuel consumption. First, it is to check the fuel efficiency trend of each aircraft, check the correlation between the maintenance work performed and the fuel mileage, find the cause of the fuel mileage increase/decrease, and take appropriate measures in response. Second, it is to find the cause of fuel mileage degradation in detail by checking the trends by engine performance and fuselage drag effect. Third, the APMS is to be used in making maintenance work decisions. Through APMS, aircraft with below average fuel mileage are identified, the cause of fuel mileage degradation is identified, and appropriate corrective actions are determined. Fourth, APMS data is used to analyze the economic analysis of equipment installation investment. The cost can be easily calculated as the equipment installation cost, but the benefit is fuel efficiency improvement, and the only way to check this is the manufacturer's theory. Therefore, verifying the effect after installation and verifying the economic analysis is to secure the appropriateness of the investment. Through this, proper investment in fuel efficiency improvement equipment will be made, and fuel efficiency will be improved.

• Journal of Korea Entertainment Industry Association
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• v.5 no.4
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• pp.147-153
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• 2011

On 11 March 2011, earthquake occurred in Japan were left with the significant human and material damage. Among these, social media has emerged as a very useful communication channel by playing a important roles in the process of safety checking and disaster recovery. In fact, however, we have no specific response methods or systems to these occurrence of disaster in Korea. Therefore, we investigate the relevant literature in order to analyze the current status of foreign and domestic utilization of social media, and draw the ideal ways to use social media for responding to unpredictable disasters based on the relevant literature reviews. The results of this study are summarized as follows. First, Institutions such as Meteorological Administration or National Emergency Management Agency are able to utilize social media as the communication systems to public in emergency. Second, social media are able to used for building disaster information systems including location information such as emergency call for help or requests for dissemination materials. Lastly, online donation services via Facebook or Twitter are able to be provided. The findings have significant implications for official responsible for disaster response and academic researchers.

• The Journal of Internal Korean Medicine
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• v.45 no.1
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• pp.55-74
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• 2024

Objectives: This study reviewed the status of adverse event (AE) reporting in VigiAccess using anti-obesity agents as examples and explored the possibility of its use and future challenges. Methods: AE reports related to some representative drugs among herbal medicines (HMs), complex HM prescriptions, ingredients of supplements, and over-the-counter and prescription medicines were investigated using VigiAccess on February 1, 2024. Results: AE reports on prescription drugs were overwhelmingly higher than those on HMs or supplements. Although most reports were submitted from North America, reports on Ephedra sinica and green tea extract (GTE) were more from Asia and Europe, respectively. The female population reported more, and the difference in the sex ratio was the smallest for Ephedra spp. The age group was concentrated on young adults, but many older patients reported GLP-1 receptor agonist-related AEs. Symptoms related to the gastrointestinal and nervous systems were most commonly reported, but mental and cardiac disorders were common in Ephedra-type HMs. Hepatobiliary disorders are also commonly found in GTE-related reports. Conclusions: VigiAccess was useful for easily checking the global status of AE reporting for prescription drugs. However, several limitations were observed in using VigiAccess for HMs because of the few reports. Thus, it is necessary to increase the number of reports by education and to promote AE reporting among HM prescribers and users. The full range of HMs should be included in the pharmacovigilance system, and the coding and classification of HMs should be revised.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.3 no.1
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• pp.73-103
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• 2008

Over the past few years, "business models" has surged into the management vocabulary. But, while it has become quite fashionable to discuss business models, there has been still much confusion about what are business models and how they could make. In fact, business models can serve a positive and powerful role in corporate management. While other authors have recently offered definitions of "business model", none of them appears to be generally accepted. This paper presents the absence of the generally definition of the business models, elements of business model and classify business logic. To help start-up entrepreneurs better understand, found and check business models thus, this paper propose a method of business model, understanding, founding and checking. The dissertation will present an effective business model building method which is necessary for the start-up entrepreneurs to start business. This paper consists of three parts. first is showing the previous study of business model. The second is the re-definition business model and elements based on the first and to present a new method of business model plating and checking for start-up IT (information technology) company's entrepreneurs. The last is application of the methode. This study applied the methode to a company which is located in "DAEDEOK INNOPOLIS"; this company has specialized Information technology.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.140-152
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• 2020

This study analyzed the satisfaction and utilization of the institutional applications used by child-education institutions from a parent's perspective. The research target is a parent who enlisted their children in private kindergarten institution located in Gyeong-gi province and final research outcomes are 443 in total. The difference in satisfaction and utilization have been identified with demographic descriptive statistics, students t-test, and F-test statistics analysis method. First, the result of T-test on the difference in satisfaction and utilization based on parents' employment status shows that statistically significant difference was found in convenience from overall satisfaction, communication from overall utilization and child-parent relationship. Second, the F-test of differences in satisfaction and utilization showed a statistically significant difference in education utilization variables, with all variables in educational background and motivation. In terms of utilization, parents' educational background and overall utilization, and children's age were confirmed to have significant differences in communication, children's relationship, and motivation in basic life. Third, the result of multiple regression analysis shows that all predictors, including ease of use, communication, and satisfaction with educational activities, have a statistically significant impact on utilization standard variables, relative contributions showed the highest level of communication satisfaction. Therefore this paper implicates that institutional applications can maximize educational effectiveness by checking the applicability of active communication and educational activities with parents and actively communicating with parents in early childhood through various educational content applications.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.183-188
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• 2017

In recent years, the automatic remote control controller of the gamma ray irradiator malfunctions, and radiation workers are continuously exposed to radiation exposure accidents. In the non-destructive testing field, much time and resources are invested in establishing a radioactive source monitoring system in order to prevent potential incidents of radiation. In this study, the gamma-ray response properties of the lead monoxide-based radiation detector were estimated through monte carlo simulation as a previous study for the development of a radioactive source location monitoring system that can be applied universally to various non-destructive testing equipment. As a result of the study, the optimized thickness of the radiation detector varies according to the gamma-ray energy emitted from the radioactive source, and the optimized thickness gradually increases with increasing energy. In conclusion, the optimized thickness of the lead monoxide-based radiation detector was $200{\mu}m$ for the Ir-192, $150{\mu}m$ for the Se-75 and $300{\mu}m$ for the Co-60. Based on these results, the appropriate thickness of lead monoxide-based radiation detector considering secondary-electron equilibrium was evaluated to be $300{\mu}m$ for general application. These results can be used as a basic data for determining the appropriate thickness required in the radiation detector when developing a radiation source location monitoring system for universal application to various non-destructive testing equipment in the future.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.560-568
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• 2020

In recent years, as network technology develops, the usage of streaming services by users is increasing. However, the complexity of streaming services is also increasing due to various terminal environments. Even when streaming the same content, it is necessary to re-encode the content according to the type of service. In order to solve the complexity and latency of the streaming service, Moving Picture Experts Group (MPEG) has standardized the Common Media Application Format (CMAF). In addition, as content transmission using a communication network becomes possible, the Republic of Korea's Ultra High Definition (UHD) broadcasting standard has been enacted as a hybrid standard using a broadcasting network and a communication network. The hybrid service enables various services such as transmitting additional information of contents or providing user-customized contents through a communication network. The Republic of Korea's UHD transmission standard utilizes MPEG Media Transport (MMT), and Mobile MMT is an extension of MMT to provide mobile network-specific functions. This paper proposes a method of inserting CMAF contents suitable for various streaming services using signaling messages of MMT and Mobile MMT. In addition, this paper proposes a model for content insertion system in heterogeneous network environment using broadcasting and communication networks, and verifies the validity of the proposed technology by checking the result of content insertion.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.19-36
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• 2016

The purpose of this study was to analyze domestic and overseas cases of flipped learning instructional design model and actual classes in K-12 Education, and find out educational implications in order to design effective flipped learning. Papers, 14 articles in domestic and international journals, were collected. As results of the analysis, first, flipped learning instructional model was presented as flipped learning that applied to ADDIE model and 8C model etc. Second, 'Activities before classroom' consisted of watching lecture videos, lecture notes etc. 'Activities during classroom' was checking prior learning in early stage, individual activities and cooperative activities in middle stage, and solving quizzes, reviewing in later stage. After class, students performed tasks and questions&answers. Third, in case of creating lecture video, they used application such as Screencast-o-matic, Explain Everything; In contrast, some cases utilized online web-sites such as YouTube or Phet. Fourth, positive results were shown in learners' academic achievement, motivation and learning attitude etc. This research has a significance in terms of analyzing the flipped learning instructional model and flipped learning activities, and providing the preliminary data to facilitate the design for the effective flipped learning.

• Atmosphere
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• v.24 no.2
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• pp.173-188
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• 2014

The KMA has cooperated with the Oklahoma University in USA to develop a Polarimetric Radar Data (PRD) simulator to improve the microphysical processes in Korea Local Analysis and Prediction System (KLAPS), which is critical for the utilization of PRD into Numerical Weather Prediction (NWP) field. The simulator is like a tool to convert NWP data into PRD, so it enables us to compare NWP data with PRD directly. The simulator can simulate polarimetric radar variables such as reflectivity (Z), differential reflectivity ($Z_{DR}$), specific differential phase ($K_{DP}$), and cross-correlation coefficient (${\rho}_{hv}$) with input of the Drop Size Distribution (DSD) and scattering calculation of the hydrometeors. However, the simulator is being developed based on the foreign observation data, therefore the PRD simulator development reflecting rainfall characteristics of Korea is needed. This study analyzed a potential application of the 2-Dimension Video Disdrometer (2DVD) data by calculating the raindrop axis ratio according to the rain-types to reflect Korea's rainfall characteristics into scattering module in the simulator. The 2DVD instrument measures the precipitation DSD including the fall velocity and the shape of individual raindrops. We calculated raindrop axis ratio for stratiform, convective and mixed rainfall cases after checking the accuracy of 2DVD data, which usually represent the scattering characteristics of precipitation. The raindrop axis ratio obtained from 2DVD data are compared with those from foreign database in the simulator. The calculated the dual-polarimetric radar variables from the simulator using the obtained raindrop axis ratio are also compared with in situ dual-polarimetric observation data at Bislsan (BSL). 2DVD observation data show high accuracies in the range of 0.7~4.8% compared with in situ rain gauge data which represents 2DVD data are sufficient for the use to simulator. There are small differences of axis ratio in the diameter below 1~2 mm and above 4~5 mm, which are more obvious for bigger raindrops especially for a strong convective rainfall case. These differences of raindrop axis ratio between domestic and foreign rainfall data base suggest that the potential use of disdrometer observation can develop of a PRD simulated suitable to the Korea precipitation system.