• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.48-53
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• 2013

Polynomial response surface model has been widely used as approximation model which replace physical or numerical experiments in various engineering fields. Generally, low-order model is used to reduce experimental points required to construct the response surfaces, but this approach has limit to represent the highly non-linear phenomena. In this paper, we developed the method to expand modeling capabilities of polynomial response surfaces by increasing order of polynomial and selecting optimum polynomial basis functions. Genetic algorithm is used to choose optimal polynomial basis functions. Developed method was applied to analytic functions with 1 or 2 variables and wind tunnel test data modeling. The results show that this method is applicable to building response surface models for highly non-linear phenomena.

• Journal of Internet Computing and Services
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• v.16 no.4
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• pp.51-59
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• 2015

JavaScript is a popular technique for activating static HTML. JavaScript has drawn more attention following the introduction of HTML5 Standard. In proportion to JavaScript's growing importance, attacks (ex. DDos, Information leak using its function) become more dangerous. Since these attacks do not create a trail, whether the JavaScript code is malicious or not must be decided. The real attack action is completed while the browser runs the JavaScript code. For these reasons, there is a need for a real-time classification and determination technique for malicious JavaScript. This paper proposes the Analysis Engine for detecting malicious JavaScript by adopting the requirements above. The analysis engine performs static analysis using signature-based detection and dynamic analysis using behavior-based detection. Static analysis can detect malicious JavaScript code, whereas dynamic analysis can detect the action of the JavaScript code.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.196-206
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• 2012

AESA radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability, compared with mechanically scanned array radar. AESA radar brings a new challenges, radar resource management(RRM), which is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. Especially radar beam scheduling is the most critical component for the success of RRM. In this paper, we proposed stochastic radar beam scheduling algorithm using simulated annealing(SA), and evaluated the performance on the multi-function radar scenario. As a result, we showed that our proposed algorithm is superior to previous dispatching rule based scheduling algorithm from the viewpoint of beam processing latency and the number of scheduled beams, with real time capability.

• Korean Journal of Materials Research
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• v.28 no.8
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• pp.459-465
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• 2018

This paper presents a study of the microstructure and mechanical properties of commercial high-hardness armor (HHA) steels tempered at different temperatures. Although the as-received specimens of all the steels exhibit a tempered martensite structure with lath type morphology, the A steel, which has the smallest carbon content, had the lowest hardness due to reduced solid solution hardening and larger lath thickness, irrespective of tempering conditions. As the tempering temperature increases, the hardness of the steels steadily decreases because dislocation density decreases and the lath thickness of martensite increases due to recovery and over-aging effects. When the variations in hardness plotted as a function of tempering temperature are compared with the hardness of the as-received specimens, it seems that the B steel, which has the highest yield and tensile strengths, is fabricated by quenching, while the other steels are fabricated by quenching and tempering. On the other hand, the impact properties of the steels are affected by specimen orientation and test temperature as well as microstructure. Based on these results, the effect of tempering on the microstructure and mechanical properties of commercial high-hardness armor steels is discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.6
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• pp.481-489
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• 2017

Situation awareness means recognizing everything necessary to understand progress in a flight or aircraft maintenance work. Situation awareness is based on more than simply recognizing important about the environment, and it is important to provide the meaning of information in an integrated form. The KHP provides the pilot with integrated situation display for an integrated form of situation awareness and warning that synchronizes the priority based audible signal with the visual signal. Provide integrated display and warning to reduce operator error and enable operators to focus on mission critical tasks and events. This paper introduces the integrated situation display and warning design implemented in the KHP.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.6
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• pp.29-37
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• 2016

This paper proposes a shape optimization of the metal boss for a composite motor case using finite element analysis. For the structural safety and the weight reduction of the composite motor case, under the internal pressure, the fiber stress in the dome area and the tightening bolt stress are constrained and the boss weight is set to objective function, respectively. The response surface models are constructed for the performance characteristics by using response surface method. The significance of the design variables about the performance characteristics is evaluated through the ANOVA(analysis of variance) and the goodness of fit test for the constructed model is performed through the regression analysis. The SQP(sequential quadratic programming) algorithm is used for the optimization and the proposed method is verified by performing structural analysis for the optimum shape.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.460-465
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• 2019

In this study, we aim to derive a solution from the structural analysis for electrical failure of single board computers for computing navigation information. By analyzing the characteristic factor, we identify that crack occur on the central processing unit board due to a certain structural problem, and that the physical effect by the crack make communication function be impossible to perform, which it causes booting error. In order to find the location of excessive stress causing the crack, structural analysis for the single board computer is done. From the structural analysis, the areas where stress concentration occurs are identified, and improvement methods changing the structures are developed. As a result, we shows that stresses are reduced entirely on the stress distribution for the improved structure. In addition, heat analysis shows that changing the structure to reduce stresses is not affect to the heat radiation, and the thermal resistance of the actual equipment is verified by measuring the temperature of the heat sink applied with the improved structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.26-35
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• 2019

By operating servers, storage, and networking devices, Data centers consume a lot of power such as cooling facilities, air conditioning facilities, and emergency power facilities. In the United States, The power consumed by data centers accounted for 1.8% of total power consumption in 2004. The data center industry has evolved to a large scale, and the number of large hyper scale data centers is expected to grow in the future. However, as a result of examining the server share of the data center, There is a problem where the server is not used effectively such that the average occupancy rate is only about 15% to 20%. To solve this problem, we propose a Virtual Machine Reallocation research using virtual machine migration function. In this paper, we use meta-heuristic for effective virtual machine reallocation. The virtual machine reallocation problem with the goal of maximizing the idle server was designed and solved through experiments. This study aims to reducing the idle rate of data center servers and reducing power consumption simultaneously by solving problems.

• International Journal of Advanced Culture Technology
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• v.10 no.2
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• pp.194-200
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• 2022

Traditionally, postal services that produce and deliver paper-based notices have been the mainstream. The reason is that it has the function of distribution and proof of delivery in the postal delivery system as well as the advantage of information delivery through postal delivery. After all, for the purpose of distribution and proof of delivery, many organizations use paper-based postal notices. However, in recent years, it has been in the spotlight to produce a paper-based postal notice as an electronic notice and deliver information to a mobile device through the Internet. In this paper, we propose a safe interworking method for user identification information required for private institutions to transmit mobile electronic notices. In order for a private institution to accurately deliver an electronic notice to a mobile service subscriber, a means to confirm whether the private institution and the mobile device subscriber are the same person is required. In the mobile electronic notification service, the connecting information provided by the personal identity proofing agency is used as a means of user identification. Connecting information is called a resident registration number on the Internet and is one-way hash information that can only be created by the personal identity proofing agency designated by the government. In order to transmit a mobile electronic notice, it is necessary to share connecting information for the same user identification between the institution that requests the sending of the electronic notice and the institution that processes the sending of the electronic notice. Connecting information is personal information that can uniquely identify a user, and if it is disclosed, damage such as personal information infringement may occur. As such, it is necessary to prevent problems that may arise from misuse and abuse of connecting information as well as increase in the benefits of sending the mobile electronic notice. In this paper, a safe and effective mobile electronic notification service can be performed by suggesting a method for safe interworking of information related to the mobile electronic notification service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.405-414
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• 2017

In this study, a survey for a satisfaction evaluation of the Test Report Information Service (TRIS) was conducted. A survey questionnaire on modified Information System Success Model(ISSM) of Delone and Mclean was carried out by 183 users in three groups, such as munition quality assurance agency, munition corporation, and test institute. As a survey result, training on the TRIS was in strong demand in all three groups. An understanding and proficiency of the overall system were different from the work process of each user group. In addition, the munition quality assurance agency needs to enhance the system function with its characteristics. Test institute has necessity of the linkage method with the TRIS depending on the authentication system. User groups are different in the operational method of TRIS between the contractor and cooperation. Accordingly, cooperation needs to be educated continually. This study can help in the construction of a Military Quality Integration Information System to secure the reliability of munitions.