• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.104-109
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• 2005

The aircraft gas turbine engines with the Electronic Engine Controls(EEC) had been developed to save fuel and enhance their performance in the early days, and had employed the health monitoring function in the Full Authority Digital Engine Controls(FADEC) to improve their reliability. This has led to an increasing demand for the certification technology of these controls. The design and certification issues of power supply, aircraft supplied data, failure modes, software verification/validation, and lightning requirements need to be addressed. This paper presents the design considerations and the certification techniques applied to the electronic engine controls. And it is believed that this paper will be basis to establish a requirement in Korean Airworthiness Standard.

• Journal of the Korea Institute of Building Construction
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• v.19 no.3
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• pp.239-246
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• 2019

According to the survey on the status of aged buildings in Korea, A number of concrete buildings deterioration such as houses and apartment buildings has been increased rapidly. To solve this problem, the research related to the facility management, that is one of the importance factor, for monitoring buildings has been increased. The research is divided into Survey-based and Technique-based. However, the problem is that Survey-based research is required a lot of time, money and manpower for management. Also, safety cannot be guaranteed in the case of high-rise buildings. Technique-based research has limitations to applying to the current facility maintenance system, as detailed information of deteriorated facilities is difficult to grasp and errors in accuracy are feared. Therefore, this paper contribute to improve the environment of facility management by 4D maps using UAV, camera and Pix4D mapper program to make 3D model. In addition, it is expected to suggest that residents will be offered easy verification to their buildings deterioration.

• Convergence Security Journal
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• v.22 no.1
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• pp.93-98
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• 2022

Information service technology continues to develop, and information service continues to expand based on the IT convergence trend. The premeter-based security model chosen by many organizations can increase the effectiveness of security technologies. However, in the premeter-based security model, it is very difficult to deny security threats that occur from within. To solve this problem, a zero trust model has been proposed. The zero trust model requires authentication for user and terminal environments, device security environment verification, and real-time monitoring and control functions. The operating environment of the information service may vary. Information security management should be able to response effectively when security threats occur in various systems at the same time. In this study, we proposed a security policy distribution system in the object reference method that can effectively distribute security policies to many systems. It was confirmed that the object reference type security policy distribution system proposed in this study can support all of the operating environments of the system constituting the information service. Since the policy distribution performance was confirmed to be similar to that of other security systems, it was verified that it was sufficiently effective. However, since this study assumed that the security threat target was predefined, additional research is needed on the identification method of the breach target for each security threat.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.90-99
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• 2003

Java applets are downloaded from web server through internet and executed in Java Virtual Machine of clients' browser. Before execution of java applets, JVM checks bytecode program with bytecode verifier and performs runtime tests with interpreter. However, these tests will not protect against undesirable runtime behavior of java applets, such as denial of service attack, email forging attack, URL spoofing attack, and annoying sound attack. In order to protect malicious applets, a technique used in this paper is java bytecode modification. This technique is used to restrict applet behavior or insert code appropriate to profiling or other monitoring efforts. Java byte modification is divided into two general forms, class-level modification involving subclassing non-final classes and method-level modification used when control over objects from final classes or interface. This paper showed that malicious applets are controlled by java bytecode modification using proxy server. This implementation does not require any changes in the web sever, JVM or web browser.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1122-1127
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• 2014

WLAN is affordability, flexibility, and ease of installation, use the smart device due to the dissemination and the AP (Access Point) to the simplification of the Office building, store, at school. Wi-Fi radio waves because it uses the medium of air transport to reach areas where security threats are always exposed to illegal AP installation, policy violations AP, packet monitoring, AP illegal access, external and service access, wireless network sharing, MAC address, such as a new security threat to steal. In this paper, signature-based of wireless intrusion detection system for Snort to suggest how to develop. The public can use hacking tools and conduct a mock hacking, Snort detects an attack of hacking tools to verify from experimental verification of the suitability of the thesis throughout.

• Composites Research
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• v.18 no.1
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• pp.16-22
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• 2005

Application fields on structural health monitoring of fiber Bragg gratings (FBGs) are gradually expanded even to a primary structure as well as a secondary structure and a specimen. For the reason, verification for the reliability of FBGs such as signal characteristics and mechanical strength becomes much more important. In this study, mechanical strength characteristics of FBGs with their fabrication process and reflectivity are investigated with various grating lengths. From the results of tension tests, it is shown that the mechanical strength of optical fibers decreases about $50\%$ just by jacket stripping and the amount of decrease is dependent on stripping methods. About $55\%$ of mechanical strength of stripped optical fibers decreases if gratings are formed in the core and it is regardless of grating lengths and reflectivity. However, the width of strength distribution increases relative to increases in reflectivity.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.96-102
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• 1998

The use of computers as part of nuclear safety systems elicits additional requirements-software verification and validation (v/v), hardware qualification-not specifically addressed in general industry fields. The computer used in nuclear power plants is a system that includes computer hardware, software, firmware, and interfaces. To develop the computer systems graded with nuclear safety class, the developing environments have to be required in advance and the developed software have to be verified and validated in accordance with nuclear code and standards. With this requirements, the test facility for Inadequate Core Cooling Monitoring System (ICCMS) as one of safety systems in the nuclear power plants was developed. The test facility consists of three(3) parts such as Input/Output (I/O) simulator, Plant Data Acqusition System (PDAS) cabinets and supervisory computer. The performance of the system was validated by manual test procedure.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.113-120
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• 2009

Through the automatic sensing of the environment, USN technology can give the best services. In this work, we have developed an active RFID system and examined its performance. By implementing it into water quality sensors, we constructed a system that can detect diverse indoor/outdoor environment and provide information about the pollution level obtained from the temperature and PH sensors. Our RF system had an internal Print-on-PCB antenna for the miniaturization of the tag. We used a RF transceiver CC2510 chipset of TI company to realize the active RFID function. By using RSSI constants obtained, we performed the evaluation of real time location accuracy with a software written in Labview. Among 10 arbitrary locations, we obtained average measurement errors of 1.69 m in x axis and 1.66 m in y axis. This technology can be applied to logistics, environmental monitoring, prevention of missing children and various applications.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.50.1-50.1
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• 2014

The Multi-purpose InfraRed Imaging System (MIRIS) is the main payload of Science and Technology Satellite 3 (STSAT-3), which was launched onboard Dnepr rocket from Russian Yasny Launch Base in November 2013. The MIRIS is an infrared (IR) camera, and the telescope has to be cooled down to below 200K in order to reduce thermal background noise. For the effective cooling and low-power consumption, we applied passive cooling method to the thermal design of the MIRIS. We also conducted thermal analysis and tested for the passive cooling before the launch of STSAT-3. After the launch, we have received State-of-Health (SOH) data from the satellite on orbit, including temperature monitoring results. It is important that the temperature of the telescope was shown to be cooled down to below 200K. In this paper, we present both the temperature data of the MIRIS on orbit and the thermal analysis results in the laboratory. We also compare these results and discuss the verification of the passive cooling.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.3
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• pp.34-44
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• 2020

In order to suggest performance analysis directions of ecological components based on a vegetation-based LID system model, this study seeks to analyze the statistical significance between monitoring results by using SWMM computer simulation and rainfall and run-off simulation devices and provide basic data required for a preliminary system design. Also, the study aims to comprehensively review a vegetation-based LID system's soil, a vegetation model, and analysis plans, which were less addressed in previous studies, and suggest a performance quantification direction that could act as a substitute device-type LID system. After monitoring artificial rainfall for 40 minutes, the test group zone and the control group zone recorded maximum rainfall intensity of 142.91mm/hr. (n=3, sd=0.34) and 142.24mm/hr. (n=3, sd=0.90), respectively. Compared to a hyetograph, low rainfall intensity was re-produced in 10-minute and 50-minute sections, and high rainfall intensity was confirmed in 20-minute, 30-minute, and 40-minute sections. As for rainwater run-off delay effects, run-off intensity in the test group zone was reduced by 79.8% as it recorded 0.46mm/min at the 50-minute point when the run-off intensity was highest in the control group zone. In the case of computer simulation, run-off intensity in the test group zone was reduced by 99.1% as it recorded 0.05mm/min at the 50-minute point when the run-off intensity was highest. The maximum rainfall run-off intensity in the test group zone (Dv=30.35, NSE=0.36) recorded 0.77mm/min and 1.06mm/min in artificial rainfall monitoring and SWMM computer simulation, respectively, at the 70-minute point in both cases. Likewise, the control group zone (Dv=17.27, NSE=0.78) recorded 2.26mm/min and 2.38mm/min, respectively, at the 50-minutes point. Through statistical assessing the significance between the rainfall & run-off simulating systems and the SWMM computer simulations, this study was able to suggest a preliminary design direction for the rainwater run-off reduction performance of the LID system applied with single vegetation. Also, by comprehensively examining the LID system's soil and vegetation models, and analysis methods, this study was able to compile parameter quantification plans for vegetation and soil sectors that can be aligned with a preliminary design. However, physical variables were caused by the use of a single vegetation-based LID system, and follow-up studies are required on algorithms for calibrating the statistical significance between monitoring and computer simulation results.