• Journal of information and communication convergence engineering
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• v.18 no.2
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• pp.88-93
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• 2020

The IEEE 802.11p-based wireless access in vehicular environments (WAVE) [1] communication is a method used exclusively for wireless communication on the road. This technique enables information sharing not only among moving vehicles but also between vehicles and infrastructure [2]. As part of WAVE communication, data is transmitted to and from vehicles in motion; in this case, it is difficult to determine the channel accurately in an outdoor environment owing to the Doppler shift [3]. This paper proposes a new channel estimation scheme for enhancing the reception performance of the IEEE 802.11p-based WAVE system. The proposed technique obtains the initial channel value by estimating the least square in the time domain by inserting a pilot signal for channel estimation into the IEEE 802.11p virtual subcarrier. Subsequently, a least mean square algorithm is applied to the initial channel value to update the estimated channel value. The simulation results obtained using the proposed channel estimation technique confirm its remarkable efficiency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1520-1542
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• 2020

Traditional software testing typically uses many physical resources to manually build various test environments, resulting in high resource costs and long test time due to limited resources, especially for small enterprises. Cloud computing can provide sufficient low-cost virtual resources to alleviate these problems through the virtualization of physical resources. However, the provision of various test environments and services for implementing software testing rapidly and conveniently based on cloud computing is challenging. This paper proposes a multilayer cloud testing model based on cloud computing and implements a hybrid cloud testing system based on virtual machines (VMs) and networks. This system realizes the automatic and rapid creation of test environments and the remote use of test tools and test services. We conduct experiments on this system and evaluate its applicability in terms of the VM provision time, VM performance and virtual network performance. The experimental results demonstrate that the performance of the VMs and virtual networks is satisfactory and that this system can improve the test efficiency and reduce test costs through rapid virtual resource provision and convenient test services.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.29-33
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• 2008

The focus of this study is to develop a virtual reality program for safe training and virtual reality of hydrogen station. This programme consists of 4 modules such as hydrogen and safety module, hydrogen station module, hypothetical experience module, and accident scenarios module for hydrogen experts. User can experience with principles and operation condition and collect the information of hydrogen station by this programme and can simultaneously study the probable scenarios, emergency response plan/standard operating procedure about hydrogen stations. It makes it possible to educate and safety publicity for the trainee. This virtual reality program will be expected to be helpful for hydrogen station's construction propagation and technology development which is essential for hydrogen energy induction.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.6
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• pp.605-613
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• 2020

In July and October of this year, the government announced the 'Green new deal plan within the Korean new deal policy' and 'Strategies for proliferation of future vehicles and market preoccupation'. And, in response to changes in the global climate agreement, it has decided to expand green mobility such as electric vehicles and hydrogen electric vehicles with the aim of a "net-zero" society. Accordingly, the goal is to build 310 hydrogen refueling stations along with the supply of 60,000 hydrogen vehicles in 2022, and the hydrogen infrastructure is being expanded. however, it is difficult to secure hydrogen infrastructure due to expensive construction costs and difficulty the selection of a site. In Korea, it is possible to build a mobile hydrogen station according to the safety standards covering special case of the Ministry of Industry. Since the mobile hydrogen station can be charged while moving between authorized place, it has the advantage of being able to meet a large number of demands with only one hydrogen refueling station, so it is proposed as a model suitable for the early market of hydrogen infrastructure. This study demonstrates the establishment of a hydrogen refueling station by deriving a virtual accident scenario for leakage and catastrupture for each facility for the risk factors in a mobile hydrogen station, and performing a quantitative risk assessment through the derived scenario. Through the virtual accident scenario, direction of demonstration and implications for the construction of a mobile hydrogen refueling station were derived.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.770-771
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• 2011

발전사업자는 한국전력거래소(KPX)의 급전지령을 원활히 수행하기 위해 EMS(Energy Management System) RTU를 설치하고 있다. 한국수자원공사는 수력발전소에 전기판넬 형식의 EMS RTU 대신 컴퓨터 기반의 가상(Virtual) EMS RTU를 설치하여 기존의 RTU방식에 비하여 설비 면적을 대폭 줄였으며, 설비 변동에 따른 감시제어 데이터의 수정시 하드웨어적인 작업을 소프트웨어적으로 간단하게 처리할 수 있다. 그래서 가상 EMS RTU는 발전통합운영시스템(GIOS)을 실시간으로 운영, 감시하여 장애를 신속히 복구함으로써 중앙급전소 발전기 원격운전 응답 특성을 향상시켜 전력계통의 안정적인 운영에 크게 기여하고 있다.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.137-141
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• 2022

To inspect the power facility faults using artificial intelligence, it need that improve the accuracy of the diagnostic model are required. Data augmentation skill using generative adversarial network (GAN) is one of the best ways to improve deep learning performance. GAN model can create realistic-looking fake images using two competitive learning networks such as discriminator and generator. In this study, we intend to verify the effectiveness of virtual data generation technology by including the fake image of power facility generated through GAN in the deep learning training set. The GAN-based fake image was created for damage of LP insulator, and ResNet based normal and defect classification model was developed to verify the effect. Through this, we analyzed the model accuracy according to the ratio of normal and defective training data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.1-11
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• 2017

Expressway network which plays an important role on land transportation system, have been developing quantitatively and qualitatively with $7{\times}9$ structure. To cope with complex geometric condition, guidance lane marking has been installed to induce safer lane-changing maneuver. However, there is no standard on guidance lane marking and its effectiveness is also verified with limited scope. The major purpose of this research is to clarify its effectiveness in terms of driving safety aspect using virtual driving simulator and to suggest standard on the proper length. To carry this out, preference data from subjects was collected and lane-changing pattern within virtual driving environment was investigated. In addition, in order to quantify the level of comfort, Electroencephalogram data was collected and validated using statistical test. Finally, it is expected that this research can be used to establish standard on guidance lane marking.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.133-140
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• 2017

The performance prediction software developed in this paper is a process analysis tool that enables one to foretell the behavior of processes when certain conditions of operation are altered. The immediate objective of this research is to predict the process characteristics of combined heat and power plant under varying operating conditions. A cogeneration virtual power plant that mimics the mechanical performance of the actual plant was constructed and the performance of the power plant was predicted in the following varying atmospheric conditions: temperature, pressure and humidity. This resulted in a positive outcome where the performance of the power plant under changing conditions were correctly predicted as well as the calorific value of low calorific gas fuel such as shale gas and PNG. The performance prediction tool can detect the operation characteristics of the power plant through the performance index analysis and thus propose the operation method taking into consideration the changes in environmental conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1770-1774
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• 2007

In this paper we deal with a design of the evaluation system to assess the vehicle operational control algorithm for Personal Rapid Transit(PRT) system. PRT system is different from the conventional rail traffic system in such that the station is off-line so as to guarantee a very short headway. In this study we propose an evaluation system to assess the performance of the proposed vehicle control algorithm. The evaluation system is composed of virtual vehicles, central control system, virtual wayside facilities, monitoring equipments. The virtual vehicles are made up by the laptop computers and the central control system employs Power PC process of Motorola Inc. The wayside facilities are implemented by employing the PXI module of the National Instruments Corporation. In order to test the proposed evaluation system a test algorithm is used, which has been simulated in the combined simulation system between Labview Simulation Interface Toolkit and Matlab/Simulink.

• Smart Structures and Systems
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• v.5 no.4
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• pp.397-413
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• 2009

Composite bridges offer many advantages compared to current steel and aluminum bridges. This paper presents the results of a comprehensive on-going research program to develop innovative Diagnostic Prognostic System (DPS) and a structural evaluation of Composite Army Bridge (CAB) system. The DPS is founded on three technologies: optical fiber sensing, remote data transmission, and virtual testing. In developing this system, both laboratory and virtual test were used in different damage scenarios. Health monitoring with DPS entailed comparing live strain data to archived strained data in various bridge locations. For field repairs, a family of composite chords was subjected to simple ramp loads in search of ultimate strength. As such, composite bridge specimens showcased their strengths, heralded the viability of virtual testing, highlighted the efficacy of field repair, and confirmed the merits of health monitoring.