• Journal of Korea Water Resources Association
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• v.50 no.9
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• pp.647-652
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• 2017

Many islands are scattered around the southern area of the Korean Peninsula and they may be very vulnerable to unexpected tsunami attacks. During the East Japan Tsunami Event occurred on March 11, 2011, many islands located at the southern area were affected by tsunamis. In this study, maximum run-up heights of solitary waves on a circular island with asymmetrical crest lengths investigated by using a numerical model based on the shallow-water theory. The obtained results could be used by local authorities to establish a defense plan against unexpected tsunami invasion.

• The Journal of Korea Robotics Society
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• v.9 no.1
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• pp.1-10
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• 2014

In recent years, the research of 3D mapping technique in urban environments obtained by mobile robots equipped with multiple sensors for recognizing the robot's surroundings is being studied actively. However, the map generated by simple integration of multiple sensors data only gives spatial information to robots. To get a semantic knowledge to help an autonomous mobile robot from the map, the robot has to convert low-level map representations to higher-level ones containing semantic knowledge of a scene. Given a 3D point cloud of an urban scene, this research proposes a method to recognize the objects effectively using 3D graph model for autonomous mobile robots. The proposed method is decomposed into three steps: sequential range data acquisition, normal vector estimation and incremental graph-based segmentation. This method guarantees the both real-time performance and accuracy of recognizing the objects in real urban environments. Also, it can provide plentiful data for classifying the objects. To evaluate a performance of proposed method, computation time and recognition rate of objects are analyzed. Experimental results show that the proposed method has efficiently in understanding the semantic knowledge of an urban environment.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.207-218
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• 2017

Clustered regulatory interspaced short palindromic repeats (CRISPR) in association with CRISPR-associated protein (Cas) is an adaptive immune system, playing a pivotal role in the defense of bacteria and archaea. Ease of handling and cost effectiveness make the CRISPR-Cas system an ideal programmable nuclease tool. Recent advances in understanding the CRISPR-Cas system have tremendously improved its efficiency. For instance, it is possible to recapitulate the chronicle CRISPR-Cas from its infancy and inaugurate a developed version by generating novel variants of Cas proteins, subduing off-target effects, and optimizing of innovative strategies. In summary, the CRISPR-Cas system could be employed in a number of applications, including providing model systems, rectification of detrimental mutations, and antiviral therapies.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.332-339
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• 2014

This paper presents on the development of wheel-terrain interaction device using low-priced sensors, which will be used to predict the drawbar pull and optimal slip of off-road vehicle in real time. The essential variables obtained in the device to predict the mobility of vehicles are determined based on semi-empirical model describing the wheel-terrain interaction. Using the developed device, the experiments about the wheel-terrain interaction were performed on the soil of the Jumunjin standard sand, which yielded dynamic weight, motor driving torque, drawbar pull, and sinkage with respect to wheel slip ratio. Finally, the repeatability of the measured data are verified through repeating the experiments three times on the same condition.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.124-132
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• 2018

This paper presents a shelf life assessment for K-1 military gas masks in the Republic of Korea using test data of Chemical Materiels Stockpile Reliability Program(CSRP). For the shelf life assessment, over 2,500 samples between 2006 and 2015 were collected from field tests and analyzed to estimate a probability of proper and improper functionality using Bayesian estimation. For this, three stages were considered; a pre-processing, a processing and an assessment. In the pre-processing, major components which directly influence the shelf life of the mask were statistically analyzed and selected by applying principal component analysis from all test components. In the processing, with the major components chosen in the previous stage, both proper and improper probability of gas masks were computed by applying Bayesian estimation. In the assessment, the probability model of the mask shelf life was analyzed with respect to storage periods between 0 and 29 years resulting in between 66.1 % and 100 % performances in accuracy, sensitivity, positive predictive value, and negative predictive value.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.145-154
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• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at this paper, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS. DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding against the Hacker's attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• KSCI Review
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• v.15 no.1
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• pp.65-75
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• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at these papers, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS, DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding an external denial of service attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack like DoS, DDoS, IP Spoofing, and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.17-25
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• 2017

Vertical reaction force between ground and tire is an important parameter determining the ground behavior characteristics of aircraft. This parameter can be used to calculate the lateral force and friction. However, it is hard to obtain this parameter in real-time when the aircraft is taxiing. Therefore, pre-analysis of ground behavior and vertical reaction force should be conducted using ground simulation results to prevent rollover or hazardous scenarios. In this paper, a Landing Gear and Full-Aircraft model was constructed using VI-Aircraft S/W. The roll behavior of aircraft was analyzed using steering simulation results compared with taxi-test data.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.1
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• pp.1-7
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• 2011

Cavitation is the formation of vapour bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapor pressure. Various types of cavitations are generated on the propeller blades. As cavity bubbles passing the blade are forced to oscillate in size or shape and come to collapse, they cause very strong local acoustic waves in the fluid and radiate noise. Comparing the Sound Pressure Level(SPL) before and after cavitation, SPL increases 2dB per 1 knot increase in ship speed above the cavitation inception speed(CIS). Consequently, the CIS is an important criteria to design silent propellers. In this work, experimental measurements of radiated noise according to various types of cavitations from the model propeller are carried out in a large cavitation tunnel and their acoustical characteristics are extensively investigated.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.5
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• pp.407-414
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• 2020

SVM (Support vector machine) analysis was performed after applying a deep learning technique based on an Inception-based model (GoogLeNet). The accuracy of automatic image classification was analyzed using an SVM with multiple virtual grid sizes. Six classes were selected from a standard land cover map. Cars were added as a separate item to increase the classification accuracy of roads. The virtual grid size was 2-5 m for natural areas, 5-10 m for traffic areas, and 10-15 m for building areas, based on the size of items and the resolution of input images. The results demonstrate that automatic classification accuracy can be increased by adopting an integrated approach that utilizes weighted virtual grid sizes for different classes.