• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.23-36
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• 2005

The main obstacle hindering the wide deployment of identity-based cryptosystem is that the entity responsible for creating the private key has too much power. As a result, private keys are no longer private. One obvious solution to this problem is to apply the threshold technique. However, this increases the authentication computation, and communication cost during the key issuing phase. In this paper, we propose a new effi ient model for issuing multiple private keys in identity-based encryption schemes based on the Weil pairing that also alleviates the key escrow problem. In our system, the private key of a user is divided into two components, KGK (Key Description Key) and KUD(Key Usage Desscriptor), which are issued separately by different parties. The KGK is issued in a threshold manner by KIC (Key Issuing Center), whereas the KW is issued by a single authority called KUM (Key Usage Manager). Changing KW results in a different private key. As a result, a user can efficiently obtain a new private key by interacting with KUM. We can also adapt Gentry's time-slot based private key revocation approach to our scheme more efficiently than others. We also show the security of the system and its efficiency by analyzing the existing systems.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.11-22
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• 2021

Sonobuoy is widely used as a very important sensor in combat management system using P-3 patrol aircraft due to its advantages of rapid searching into wide exploration range. It is necessary to verify the performance of developed sonobuoy system using various maritime test data in order to be successfully applied in combat management system. But it is difficult to acquire various real maritime data because it needs much time and effort. Therefore we have developed in this paper a synthetic signal generator and a simulator that they can verify the performance of sonobuoy system and evaluate its operational effectiveness without conducting maritime test. We have synthesized target signals based on the characteristics of underwater sound sources, and then developed the synthesized signal generator which consider to sound propagation etc. like as underwater environment. And in the simulator development we use a HMI technique to enhance the convenience of operator, and design to verify the performance of sonobuoy system. The developed signal generator and simulator can be used as useful tools to evaluate the operational effectiveness such as optimal deployment of sonobuoy in combat management system using P-3 patrol aircraft.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.299-323
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• 2021

This study investigated the impact of information and communication technology (ICT), trade openness, financial development, and economic growth on CO₂ emissions in Korea from 1990 to 2016. The cointegration relationship of the variables was confirmed by an autoregressive distributed lag (ARDL) bounds test. In the long-run, economic growth was statistically significant factor in the increase in CO₂ emissions, while other factors, as well as ICT, did not significant factors in the changes in CO₂ emissions. In the long-run, a link between economic growth and CO₂ emissions has been confirmed, but other factors, including ICT, have not been able to confirm the link between CO₂ emissions in the long-run. Meanwhile, in the short-run, economic growth and ICT increased CO₂ emissions, and financial development led to a decrease in CO₂ emissions. Trade openness did not have a significant effect on CO₂ emissions in the short-run as in the long-run. In particular, ICT did not contribute to the reduction of CO₂ emissions in the short-run as well as the long-run. In order to induce CO₂ mitigation through ICT, the development and deployment of technology that efficiently save energy by using ICT should be further promoted.

• Knowledge Management Research
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• v.22 no.1
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• pp.183-215
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• 2021

The purpose of this study is to present a framework for sales activities necessary for the successful sales development in the sales process of value-based selling and to explore individual sales activities for successful value-based selling. When we understand value-based selling as a procedural progression in the sales process, integrate it into the sales activity framework, and segment your sales activities to identify the key activity elements for successful execution, the intrinsic effect of value-based selling can be achieved. Sales activities related to the success of value-based selling are reflected in the sales activity framework based on the sales process through literature studies and application cases in actual sales field, and detailed elements of individual sales activities for successful deployment are identified through case studies. Through literature research and sales practice in actual field, 13 sales activities are presented in the five-stage sales process, and 42 detailed sales activities for successful value-based selling through case studies are identified in an improved sales activity framework. Through this study, the sales activity framework provides a role in evaluating whether the sales function of value-based selling is being performed as a correct activity in the sales process, and whether sales opportunities with specific customers can continue value-based selling activities. The sales activity framework serves as a guide for successful value-based selling.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.2
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• pp.127-135
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• 2022

Compared to the continuous increase of domestic nano-satellite development cases, the initial communication success rate is relatively low. In a situation where communication cases of LEO satellites using commercial satellite communication networks are increasing recently. In this situation, the SNIPE project developed by the KASI(Korea Astronomy and Space Science Institute), KARI(Korea Aerospace Research Institute), and Yonsei University apply an Iridium module for communication test to the SNIPE nano-satellites. Therefore, in this paper, the visibility analysis of the iridium module on the SNIPE satellite was analyzed under considering the orbital and communication environment of the iridium satellite constellation and the attitude control mode. In the case of LEO satellites, the communication possibility was limited due to the relatively small iridium communication coverage for high altitude and the high doppler shift considered in the iridium communication network. For this reason, in this paper, it could be simulated that there was a more performance difference according to the difference in relative RAAN(Right Ascension of Ascending Node) angle with the Iridium constellation. Finally, by checking the visibility of communication module under the tumbling situation that occurred during the initial deployment of the nano-satellite, the possibility of using the iridium communication technology was analyzed.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.11
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• pp.381-394
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• 2022

Recently, due to the personalization and customization of data, Internet-based services have increased requirements for real-time processing, such as real-time AI inference and data analysis, which must be handled immediately according to the user's situation or requirement. Real-time tasks have a set deadline from the start of each task to the return of the results, and the guarantee of the deadline is directly linked to the quality of the services. However, traditional container systems are limited in operating real-time tasks because they do not provide the ability to allocate and manage deadlines for tasks executed in containers. In addition, tasks such as AI inference and data analysis basically utilize graphical processing units (GPU), which typically have performance impacts on each other because performance isolation is not provided between containers. And the resource usage of the node alone cannot determine the deadline guarantee rate of each container or whether to deploy a new real-time container. In this paper, we propose a monitoring technique for tracking and managing the execution status of deadlines and real-time GPU tasks in containers to support real-time processing of GPU tasks running on containers, and a node list management technique for container placement on appropriate nodes to ensure deadlines. Furthermore, we demonstrate from experiments that the proposed technique has a very small impact on the system.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.547-557
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• 2022

The numbers of occurrences and the amount of spills of marine oil pollution have increased, and accordingly, it is necessary to secure additional control capabilities. Therefore, it was intended to present an empirical basis for improving the overall idle capacity through the relocation of control ships existing in each region. First, the marine pollution index was derived and the control capability compared to the marine pollution index of each region was compared to examine the appropriateness of the deployment of control ships. The marine oil pollution risk index was derived by multiplying the nine items that cause marine pollution by the weight derived by experts. We checked the control capacity (A) compared to the marine pollution risk index (F) for each sea area. Mokpo (F:13.4, A:1.9), Busan (F:14.3, A:6.4), and Yeosu (F:21.5, A:16.6) are the areas that lack control capabilities compared to the marine pollution risk index. On the other hand, the areas that have room for control compared to the marine pollution risk index for each sea area are Masan (F: 5.9, A:13.3), Gunsan (F:1.7, A:8.3), and Jeju (F:2.7, A:6.9). Therefore, for improving the standardized control capacity proportional to the risk of marine pollution nationwide, it is suggested that the control ships of Masan, Gunsan, and Jeju should be relocated to Mokpo, Busan, and Yeosu, which lack control capacity.

• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.49-62
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• 2020

Musicals are plays in which songs and dances are closely aligned with the plot development of the play, and songs and dances develop specific situations and a series of events. In particular, songs perform a fuction of causing the significant changes and emotional ventilation and amplification in the play by specifically capturing the goals and actions the characters are aiming for. This paper focuses on the song that takes on the function of the plot deployment, defines songs that embody actions and stories on stage' as 'action songs' and highlights their role and importance. Action Song is not a clearly defined or prescribed term in Musical. However, 'Action Song' is a song about how a character's desire or motivation for action, given as a 'character song' inserted at the beginning of an integrated musical play, provides a conflict that is a central event of action. In other words, 'action song' means a song that organically combines music and narrative by conveying the action on the stage as a song with lyrics. In addition, it is a song that moves the plot forward and contains a series of events or actions that are the material of the plot. This paper is intended to summarize the concept of'Action song which is not well known to us, and to lay the foundation of the stud, learned the concept, function and efficiency by the analyses of script and music of the musical . As a result, action songs accumulate and amplify tension caused by conflicts and induce the audience to immerse in their emotions. At the same time, the action song multiplies fun and interest of the play while the audience's expectation increased for the next scene after the action song and the progression of the play with single action makes the contents of the drama to be understood clearly.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.115-131
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• 2022

Carbon dioxide (CO₂) emissions from the transportation sector in South Korea accounts for 16.5% of all CO₂ emissions, and road transportation accounts for 96.5% of this sector's emissions in South Korea. Hence, constant research is being carried out on methods to reduce CO₂ emissions from this sector. With the emerging use of smart crossings, attempts to monitor individual vehicles are increasing. Moreover, the potential commercial deployment of autonomous vehicles increases the possibility of obtaining individual vehicle data. As such, CO₂ emission research was conducted at five signalized intersections in the Gangnam District, Seoul, using data such as vehicle type, speed, acceleration, etc., obtained from image detectors located at each intersection. The collected data were then applied to the MOtor Vehicle Emission Simulator (MOVES)-Matrix model-which was developed to obtain second-by-second vehicle activity data and analyze daily CO₂ emissions from the studied intersections. After analyzing two large and three small intersections, the results indicated that 3.1 metric tons of CO₂ were emitted per day at each intersection. This study reveals a new possibility of analyzing CO₂ emissions using actual individual vehicle data using an improved analysis model. This study also emphasizes the importance of more accurate CO₂ emission analyses.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.55-66
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• 2023

In recent years, naval vessels have been developed to fulfill a variety of missions by being equipped with various cutting-edge equipment and ICT technologies. One of the main missions of Korean naval vessels is anti-ballistic missile warfare to defend key units and areas against the growing threat of ballistic missiles. Because the process of detection and interception is too complex and the cost of failure is much high, a lot of preparation is required to effectively conduct anti-ballistic missile warfare. This paper describes the development of a simulation model of anti-ballistic missile warfare with combat systems and equipment to be installed on future naval vessels. In particular, the DEVS formalism providing a modular and hierarchical modeling manner was applied to the simulation model, which can be utilized to efficiently represent various anti-ballistic missile warfare situations. In the simulation results presented, experiments were conducted to analyze the effectiveness of the model for effective detection resource management in anti-ballistic missile warfare. This study is expected to be utilized as a variety of analysis tools necessary to determine the optimal deployment and configuration of combat resources and operational tactics required for effective anti-ballistic missile warfare of ships in the future.