• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.722-728
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• 2012

Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

• Telecommunications review
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• v.24 no.5
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• pp.677-691
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• 2014

Connectivity is becoming more important keywords recently. For example, many devices are going to be connected to the internet. It is usually called as the IoT(internet of things). Many IoT devices can be evolved as a part of giant system of the world wide web. It is a great opportunity for us, because many new services can have emerged through this paradigm. In this paper, we propose a device virtualization framework for smart home service. The proposed framework connects the many home appliances devices and the internet using a dynamic protocol conversion. After our protocol conversion for device virtualization, our framework provides a RESTful API to access the resources of device through the internet. Therefore, the proposed framework can provide a variety of services, so it also can be developed into the ecosystem for smart home service. The current framework version only supports UPnP enabled devices of the home, but it can easily be extended to many other home middleware solutions. To verify the feasibility of the framework, we have implemented several service scenarios.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.18-25
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• 2019

In this study, in order to solve the problem of the program of calculating code input by experienced users in the power generation, the wide area energy network research group developed the local heating operation analysis program EntPLAN, which can be easily used by anyone, including scalability, with domestic technology. Therefore, the Commission intended to compare the heat sources, heat demand, and the results of operation of the combined heat plant (CHP) on the energy network through simulation with the EnetPLAN and the program A on the market. The results showed that the heat and power output on the energy network of the EnetPLAN and A programs were mostly similar in pattern in the simulation results of the heat supply and the operation method of the accumulator. This enabled the application of the simulation for the various operation modes of the cogeneration facilities existing on the energy network. It is expected that EntPLAN, which was developed with domestic technology, will be easily applied in the field in the future and will present efficient operation simulation results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.557-565
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• 2021

Path-following control is considered as one of the most fundamental skills to realize autonomous navigation of marine vessels in the ocean. This study addresses with the path-following control for a ship in which there are environmental disturbances in the directions of the surge, sway, and yaw motions. The guiding principle and back-stepping method was utilized to solve the ship's tracking problem on the reference path generated by a virtual ship. For path-following control, error dynamics is one of the most important skills, and it extends to the research fields of automatic collision avoidance and automatic berthing control. The algorithms for the guiding principles and error variables have been verified by numerical simulation. As a result, most error variables converged to zero values with the controller except for the yaw angle error. One of the most interesting results is that the tracking errors of path-following control between two ships are smaller than the existing safe passing distances considering interaction forces from near passing ships. Moreover, a trade-off between tracking performance and the ship's safety should be considered for determining the proper control parameters to prevent the destructive failure of actuators such as propellers, fins, and rudders during the path-following of marine vessels.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.889-898
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• 2021

Currently, due to the demographic cliff phenomenon in Republic of Korea, A serious defense vacuum could occur due to the lack of South Korean military's personal strength. As a result, The South Korean military has a possibility to implement the polices the prepare for military provocations and preemptive strikes by the North Korean military while resolving the South Korean defense vacuum caused by the shrinking population. It seems like that the only way for the South Korean military to solve the shortage of personal strength due to the population decline is to reduce the number of Mechanized Units(MU) other than, infantry and automate, and autonomous driving the weapons system of the Mechanized Units(MU). In this paper, we propose the use of the virtual autonomous driving of the self propelled artillery K-9's in self selection of the position and occupation of position and self positioning in the position. At the same time in this paper, the self propelled artillery K-9 model robot is used to simulate and the explain about the operation method, necessity and feasibility in the self propelled artillery K-9. In addition, this paper predicted the problems that would arise if the South Korean military deployed autonomous driving self propelled K-9, in real combat.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.202-202
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• 2018

본 논문에서는 분포형 강우-유출 모형인 GRM(Grid based Rainfall-runoff Model)(최윤석, 김경탁, 2017)을 이용해서 낙동강 유역을 대상으로 대유역 홍수해석시스템을 구축하고, 유출해석을 위한 실행시간을 평가하였다. 유출모형은 낙동강의 주요 지류와 본류를 소유역으로 구분하여 모형을 구축하고, 각 소유역의 유출해석 결과를 실시간으로 연계할 수 있도록 하여 낙동강 전체 유역의 유출모형을 구축하였다. 이와 같이 하나의 대유역을 다수의 소유역시스템으로 분할하여 모형을 구축할 경우, 유출해석시스템 구성이 복잡해지는 단점이 있으나, 소유역별로 각기 다른 자료를 이용하여 다양한 해상도로 유출해석을 할 수 있으므로, 소유역별 특성에 맞는 유출모형 구축이 가능한 장점이 있다. 또한 각 소유역시스템은 별도의 프로세스로 계산이 진행되므로, 대유역을 고해상도로 해석하는 경우에도 계산시간을 단축할 수 있다. 본 연구에서는 낙동강 유역을 20개(본류 구간 3개, 1차 지류 13개, 댐상류 4개)의 소유역으로 분할하여 계산 시간을 검토하였으며, 최종적으로 21개(본류 구간 3개, 1차 지류 13개, 댐상류 5개)의 소유역으로 분할하여 유출해석시스템을 구축하였다. 댐 상류 유역은 댐하류와 유량전달이 없이 독립적으로 모의되고, 댐과 연결된 하류 유역은 관측 방류량을 상류단 하천의 경계조건으로 적용한다. 지류 유역은 본류 구간과 연결되고, 지류의 계산 유량은 본류와의 연결지점에 유량조건으로 실시간으로 입력된다. 이때 본류와 지류의 유량 연계는 데이터베이스를 매개로 하였다. 유출해석시스템의 성능을 평가하기 위해서 Microsoft 클라우드 서비스인 Azure를 이용하였다. 낙동강 유역을 20개 소유역으로 구성한 경우에서의 유출해석시스템의 속도 평가 결과 Azure virtual machine instance DS15 v2(OS : Windows Server 2012 R2, CPU : 2.4 GHz Intel $Xeon^{(R)}$ E5-2673 v3 20 cores)에서 1.5분이 소요 되었다. 계산시간 평가시 GRM은 'IsParallel=false' 옵션을 적용하였으며, 모의 기간은 24시간을 기준으로 하였다. 연구결과 분포형 모형을 이용한 대유역 유출해석시스템 구축이 가능했으며, 계산시간도 충분히 단축할 수 있었다. 또한 추가적인 CPU와 병렬계산을 적용할 경우, 계산시간은 더 단축될 수 있으며, 이러한 기법들은 분포형 모형을 이용한 대유역 유출해석시스템 구축시 유용하게 활용될 수 있을 것으로 판단된다.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.269-282
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• 2021

As the distribution of 3D content such as augmented reality and virtual reality increases, the importance of real-time computer animation technology is increasing. However, the computer animation process consists mostly of manual or marker-attaching motion capture, which requires a very long time for experienced professionals to obtain realistic images. To solve these problems, animation production systems and algorithms based on deep learning model and sensors have recently emerged. Thus, in this paper, we study four methods of implementing natural human movement in deep learning model and kinect camera-based animation production systems. Each method is chosen considering its environmental characteristics and accuracy. The first method uses a Kinect camera. The second method uses a Kinect camera and a calibration algorithm. The third method uses deep learning model. The fourth method uses deep learning model and kinect. Experiments with the proposed method showed that the fourth method of deep learning model and using the Kinect simultaneously showed the best results compared to other methods.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.83-89
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• 2022

Recentely, the military needs to apply various technologies for the improvement of teamwork. The government should take the non-face-to-face system due to the social interest of young military members. In this study we investigated collective cohesion by helping soldiers who have difficulty expressing their feelings and delivering messages while living in groups, or who are unable to adapt to group life due to psychological disorders such as relationship anxiety. We proposed the Multi-perspective Relationship Experience program as a new VR application. We showed feeling a sense of reality equivalent to the actual situation, interpersonal tension and social distance were significantly reduced, and communication, which was difficult to actually do, was naturally achieved. In addition, positive effects were confirmed on the sense of belonging and leadership among all participants. We will be effectively used in manpower management policies that improve the collective cohesion of soldiers and support the adaptability of the military environment in line with the rapidly changing social interaction method.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.897-903
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• 2021

Purpose: Recently, ransomware damage that encrypts victim's data through hacking and demands money in exchange for releasing it is increasing domestically and internationally. Accordingly, research and development on various response technologies and solutions are in progress. Method: A secure storage area and a general storage area were created in the same virtual environment, and the sample data was saved by registering the access process. In order to check whether the stored sample data is infringed, the ransomware sample was executed and the hash function of the sample data was checked to see if it was infringed. The access control performance checked whether the sample data was accessed through the same name and storage location as the registered access process. Result: As a result of the experiment, the sample data in the secure storage area maintained data integrity from ransomware and unauthorized processes. Conclusion: Through this study, the creation of a secure storage area and the whitelist-based access control method are evaluated as suitable as a method to protect important data, and it is possible to provide a more secure computing environment through future technology scalability and convergence with existing solutions.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.3
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• pp.248-256
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• 2021

The purpose of this study is to investigate the perception of pre-service elementary teachers on the educational approach to metaverse. Questions about metaverse were asked to 71 pre-service elementary teachers who were taking the course 'Study of Textbooks in Elementary Science II'. The results of analyzing the contents of the questions are as follows. The results and conclusions were presented through numerical analysis and static analysis based on the responses to questions presented using the university's LMS system. First, the level of understanding of the metaverse of pre-service elementary teachers is very high. Pre-service elementary teachers, as the MZ generation, are already living in a very fast IT environment that can be the basis of the metaverse, so it would have been helpful to understand the metaverse. Second, the need for the metaverse of pre-service elementary teachers is very high. There was a tendency to think that the perception of pre-service elementary teachers is because the metaverse has many factors that can provide higher quality education beyond the current educational environment. Third, in the question of applicability exploration in the 'Earth and Space' domain of Pre-service elementary teachers, there have been few cases in which instructional design was planned based on instructional design principles. Based on these results, if the possibility of metaverse application is proposed in the 'Earth and Space' domain, educational contents using virtual space that can transcend time and space will be very necessary. Based on these results, suggestions are made as follows. First, educational content incorporating the metaverse technique based on instructional design should be developed and utilized. Second, financial support should be provided so that the metaverse can be implemented in the educational environment. Third, it is necessary to provide training opportunities for teachers (including Pre-service elementary teachers) to give lectures on metaverse.