• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.6
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• pp.488-494
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• 2013

The control law design and analysis environment of the FBW helicopter system have been developed using model base design method. The model based design is generally used in a aircraft, unmanned aerial system and automobile as well as rotorcraft development. The model based design provides many advantages such as development risk and schedule reduction using simulation and autocode generation. This paper describes a development of process for verification and validation of auto generated code for FBW helicopter flight control law. And this process is applied for Fly-By-Wire Helicopter Development Project. The results of functional test for auto generated code meet several specific requirements.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.148-154
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• 2018

When shooting small arms, the inner surface temperature is heated up to about $700{\sim}1,000^{\circ}C$ by the friction of the bullet and the inner wall of the barrel and the combustion of propellant. High-temperature propellant gas and high-speed movement of the bullet cause corrosion of the inner wall, which is noticeable immediately in front of the chamber. In this study, the mechanical properties of Cr-Mo-V steel, which is the base material, were tested using Taguchi experimental design to find the best nitriding treatment conditions. For the nitriding process, the working time, salt bath temperature, and salt concentration were combined as three conditions and placed in the $L_9(3^4)$, orthogonal array table. The thicknesses of the white layer and the nitrogen diffusion layer were measured after nitriding under each condition in a salt bath furnace. Durability was evaluated by measuring the degree of dispersion through actual shooting because it was difficult to evaluate the mechanical properties of the cylinder inner structure. As a result, it was confirmed that the durability was optimal at $565^{\circ}C$, 1 hour, 0.5%. These optimal conditions were selected by the statistical analysis of the Minitab program(ver.17).

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.413-420
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• 2020

The Tactical Information and Communication Network system provides real-time multimedia services such as voice and data by utilizing the Mobile Subscriber Access Point. At this time, an external transmission path is constructed through the Low Capacity Trunk Radio and the High Capacity Trunk Radio system. The communication devices of each wireless transmission system are mounted on a tactical vehicle and a secondary battery is used to prevent a power interruption when the supply power to the tactical vehicle is transferred to the integrated power control device. In this paper, the basic design of the Wireless Power Transfer device for charging the battery of the integrated power control system of the mobile base station system using the Loading Distribution Method and checking the number of primary windings and the core material selection by the air gap through the Finite Elements Method.

• The KIPS Transactions:PartD
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• v.17D no.5
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• pp.347-352
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• 2010

Automatic service identification and quality evaluation is one of key characteristics for a Service-Oriented Computing, being receiving a lot of attention from researchers in recent years. However, most researchers focus on identifying and evaluating application services and do not present methods for automatically identifying and evaluating business services from business processes. In general, the manual business service identification process by a human expert is a highly expensive and ambiguous task and may result in the service design with bad quality because of errors and misconception. We propose an automatic business service identification and quality evaluation method using Enterprise Architecture as a machine understandable knowledge-base. We verify the effectiveness of the proposed method through a case study on Department of Defense Enterprise Architecture.

• Journal of Korean Society for Quality Management
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• v.48 no.2
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• pp.297-307
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• 2020

Purpose: The purpose of this study is to analyze the factors that affect ammunition performance by applying data mining techniques to the Ammunition Stockpile Reliability Program (ASRP) data of the 155mm propelling charge. Methods: The ASRP data from 1999 to 2017 have been utilized. Logistic regression and decision tree analysis were used to investigate the factors that affect performance of ammunition. The performance evaluation of each model was conducted through comparison with an artificial neural networks(ANN) model. Results: The results of this study are as follows; logistic regression and the decision tree analysis showed that major defect rate of visual inspection is the most significant factor. Also, muzzle velocity by base charge and muzzle velocity by increment charge are also among the significant factors affecting the performance of 155mm propelling charge. To validate the logistic regression and decision tree models, their classification accuracies have been compared with the results of an ANN model. The results indicate that the logistic regression and decision tree models show sufficient performance which conforms the validity of the models. Conclusion: The main contribution of this paper is that, to our best knowledge, it is the first attempt at identifying the significant factors of ASPR data by using data mining techniques. The approaches suggested in the paper could also be extended to other types ammunition data.

• Journal of Applied Biological Chemistry
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• v.44 no.2
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• pp.59-64
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• 2001

Pepper plants (Nogkwang, 60-day old) were inoculated with Phytophthora capsici to induce sesquiterpene cyclase associated with the biosynthesis of phytoalexin (capsidiol), a substance related to the defense against pathogens in plants. One day after inoculation, mRNA was isolated from the root, cDNA synthesized, and a library constructed in a ZAP express XR vector. The efficiency was $2{\times}10^6pfu/{\mu}g$. Sesquiterpene cyclase cDNA from Hyoscyamus muticus was labeled with $^{32}P$ and used as a probe for screening the cDNA library. After the third screening, 25 positive clones were selected. Through restrictive digestion and DNA gel-blot analysis, six different cyclase gene expressions were identified. PSC1B sequences of the six clones were determined, which were 1966 base pairs encoded 556 amino acids with an expected molecular weight of 63.8 kDa. Response against the pathogen was different between the resistant and susceptible peppers. After the infection of the pathogen, the expression of PSC genes continued in the resistant peppers while the plants were alive. The expression in the susceptible peppers lasted for only 4 days.

• Journal of Internet Computing and Services
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• v.19 no.3
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• pp.15-23
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• 2018

A code reuse attack is an attack technique that can execute arbitrary code without injecting code directly into the stack by combining executable code fragments existing in program memory and executing them continuously. ROP(Return-Oriented Programming) attack is typical type of code reuse attack and serveral defense techniques have been proposed to deal with this. However, since existing methods use Rule-based method to detect attacks based on specific rules, there is a limitation that ROP attacks that do not correspond to previously defined rules can not be detected. In this paper, we introduce a method to detect ROP attack by learning command pattern used in ROP attack code using RNN(Recurrent Neural Network). We also show that the proposed method effectively detects ROP attacks by measuring False Positive Ratio, False Negative Ratio, and Accuracy for normal code and ROP attack code discrimination.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.88-93
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• 2015

To estimate RCS(Radar Cross Section) at arbitrary incident angles for large objects, an interpolation method is required based on the pre-calculated RCS database at finite discrete sampling points. It is numerically difficult to compute the RCS by a large object at all required sampling points, since the computation time may be very long for one sampling point and many sampling points are required to satisfy the exact sampling condition. Therefore, it may be required to accurately estimate the RCS at any incident angles based on a database whose size is as small as possible. In this paper, the accuracy of two interpolation methods base on the sinc-and VSH(Vector Spherical Harmonics) functions are numerically compared.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.205-211
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• 2019

Steganalysis is a technique that aims to detect and recover data hidden by steganography. Steganalytic methods detect hidden data by analyzing visual and statistical distortions caused during data embedding. However, for recovering the hidden data, they need to know which steganographic methods the hidden data has been embedded by. Therefore, we propose a hierarchical convolutional neural network (CNN) structure that identifies a steganographic method applied to an input image through multi-level classification. We trained four base CNNs (each is a binary classifier that determines whether or not a steganographic method has been applied to an input image or which of two different steganographic methods has been applied to an input image) and connected them hierarchically. Experimental results demonstrate that the proposed hierarchical CNN structure can identify four different steganographic methods (LSB, PVD, WOW, and UNIWARD) with an accuracy of 79%.

• International Journal of Contents
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• v.11 no.2
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• pp.31-36
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• 2015

Recent years have seen a significant increase in demand for multimedia data over wireless sensor networks for monitoring applications that utilize sensor nodes to collect multimedia data, including sound and video. However, the multimedia streams generate a very large amount of data. When data transmission schemes for traditional wireless sensor networks are applied in wireless multimedia sensor networks, the network lifetime significantly decreases due to the excessive energy consumption of specific nodes. In this paper, we propose a data compression scheme that implements the Chinese remainder theorem to a wireless multimedia sensor network. The proposed scheme uses the Chinese Remainder Theorem (CRT) to compress and split multimedia data, and it then transmits the bit-pattern packets of the remainder to the base station. As a result, the amount of multimedia data that is transmitted is reduced. The superiority of our proposed scheme is demonstrated by comparing its performance to that of an existing scheme. The results of our experiment indicate that our proposed scheme significantly increased the compression ratio and reduced the compression operation in comparison to those of existing compression schemes.