• Membrane Journal
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• v.29 no.1
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• pp.61-65
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• 2019

Anisotropic particles have been issued in various fields due to their unique physical properties. Herein, a novel dynamic phase separation method (DPS) is introduced to fabricate anisotropic acorn-like nanoparticles. DPS consists of two dynamic conditions; solvent evaporation and nonsolvent induced precipitation. The bottom layer is controlled by feeding the water as a non-solvent diluent, and the phase separation of the upper layer relies on the diffusion and evaporation of a volatile good solvent. At this condition, the acorn-like particles were fabricated. Under a closed box filled with water (spontaneous phase separation), monodisperse polystyrene (PS) particles were synthesized. At the coexistence between DPS and spontaneous phase separation, the sizes of cap and particle were changed. Also, the volume of PS solutions influences on the particle shape. Since the unique structures could be utilized into various applications, if advanced techniques such as membrane-based controlled water feeding is developed, monodisperse acorn-like particles could be tuned.

• Earthquakes and Structures
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• v.15 no.6
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• pp.655-665
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• 2018

Shield tunnels are widely used throughout the world. However, their seismic performance has not been well studied. This paper focuses on the seismic response of a large scale model tunnel in compacted sand. A 9.3 m long, 3.7 m wide and 2.5 m high rigid box was filled with sand so as to simulate the sandy soil surrounding the tunnel. The setup was excited on a large-scale shake table. The model tunnel used was a 1:8 scaled model with a cross-sectional diameter of 900 mm. The effective shock absorbing layer (SAL) on the seismic response of the model tunnel was also investigated. The thickness of the tunnel lining is 60 mm. The earthquake motion recorded from the Kobe earthquake waves was used. The ground motions were scaled to have the same peak accelerations. A total of three peak accelerations were considered (i.e., 0.1 g, 0.2 g and 0.4 g). During the tests, the strain, acceleration and soil pressure on the surface of the tunnel were measured. In order to investigate the effect of shock absorbing layer on the dynamic response of the sand- tunnel system, two tunnel models were set up, one with and one without the shock absorbing layer of foam board were used. The results shows the longitudinal direction acceleration of the model tunnel with a shock absorbing layer were lower than those of model tunnel without the shock absorbing layer, Which indicates that the shock absorbing layer has a beneficial effect on the acceleration reduction. In addition, the shock absorbing layer has influence on the hoop strain and earth pressure of the model tunnel, this the effect of shock absorbing layer to the model tunnel will be discussed in the paper.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.93-99
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• 2018

The purpose of this study was to prove the effect of passive stretching after delayed muscular pain induction in university students and to propose a rehabilitation exercise program for effective pain relief and prevention in case of injury. Subjects were divided into passive stretching group and control group. Passive stretching group was performed passive stretching after delayed muscular pain induction and control group did not perform any treatment after delayed muscular pain induction. The delayed muscular pain induction method was induced by bench step motion. The height of the step box was 50cm. The data were analyzed by two-way RGRM ANOVA for comparison of passive stretching group and control group. In conclusion, passive stretching after delayed myalgia has a positive effect on blood fatigue (CRP, LDH) and subjective pain scale(VAS).

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.6
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• pp.1463-1474
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• 2018

Fuzzing is one of the software testing techniques that find security flaws by inputting invalid values or arbitrary values into the program and various methods have been suggested to increase the efficiency of such fuzzing. In this paper, focusing on the existence of field with high relevance to coverage and software crash, we propose a new method for intensively fuzzing corresponding field part while performing field based fuzzing. In this case, we use a deep learning model called Variational Autoencoder(VAE) to learn the statistical characteristic of input values measured in high coverage and it showed that the coverage of the regenerated files are uniformly higher than that of simple variation. It also showed that new crash could be found by learning the statistical characteristic of the files in which the crash occurred and applying the dropout during the regeneration. Experimental results showed that the coverage is about 10% higher than the files in the queue of the AFL fuzzing tool and in the Hwpviewer binary, we found two new crashes using two crashes that found at the initial fuzzing phase.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.304-313
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• 2019

Centered on top ten brands of jasmine tea in China "Zhang Yiyuan(張一元), Wu Yutai(吳裕泰), EFUTON (藝福堂), Shumingrun(蜀茗潤), Chunlun(春倫),Jinghua(京華),Bitan Piaoxue(碧潭飄雪), Tenfuku meicha(天福茗茶), Xiao Guan Tea(小罐茶),China Tea(中茶)", this paper has summarized four elements of packaging design (logo, color, layout, shape), developed a questionnaire of consumer preference degree on this basis, and conducted reliability and validity analysis. According to the questionnaire survey, the most popular logo is the "Xiao Guan Tea", and the most popular color among all six colors is the gray group. Among the eight lay outs of the jasmine tea package, the most popular lay out is the type 2 and the most popular package shape is shape 2 (rectangle).In conclusion, this paper has analyzed consumer preferences for packaging design of jasmine tea gift box based on the questionnaire survey results.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.476-481
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• 2019

Early detection of fire is an important measure for minimizing the loss of life and property damage. However, fire and smoke need to be simultaneously detected. In this context, numerous studies have been conducted on image-based fire detection. Conventional fire detection methods are compute-intensive and comprise several algorithms for extracting the flame and smoke characteristics. Hence, deep learning algorithms and convolution neural networks can be alternatively employed for fire detection. In this study, recorded image data of fire in a ship engine room were analyzed. The flame and smoke characteristics were extracted from the outer box, and the YOLO (You Only Look Once) convolutional neural network algorithm was subsequently employed for learning and testing. Experimental results were evaluated with respect to three attributes, namely detection rate, error rate, and accuracy. The respective values of detection rate, error rate, and accuracy are found to be 0.994, 0.011, and 0.998 for the flame, 0.978, 0.021, and 0.978 for the smoke, and the calculation time is found to be 0.009 s.

• Journal of the Korean Geotechnical Society
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• v.35 no.6
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• pp.27-38
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• 2019

Bearing capacity of a pile in homogeneous soil is the sum of end bearing and skin resistance, and the skin resistance is more prominent in sandy soil. Bearing capacity of a pile in pile groups especially in sandy ground should be designed under the consideration of the influence by the adjacent piles. In this study, the end bearing capacity of a pile in pile groups was experimentally investigated. For this purpose, piles were installed in sandy ground in a circular test box, and end bearing - settlement behavior of the pile was measured while the pile was loaded. As the results, end bearing - settlement relation curves of the piles showed a distinct limit value. Limit value of the end bearing was little affected by skin friction and pile diameter, and it became a constant value as pile penetrates deeper. End bearing was not affected by the adjacent piles in a group of piles, when their clearance was larger than the pile diameter.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.3
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• pp.58-67
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• 2019

The low-voltage connection box used as a low-voltage transmission line of KEPCO is intended to branch or connect to an underground line. In comparison with the utility considering the aesthetics of the distance, and safety measures are needed. In this paper, temperature and humidity, $CO_2$, water level, acceleration, and vibration sensor are installed inside the underground low voltage handhole, and the sensor data is transmitted to the ground using the Zigbee module. Antenna (Bolted Antenna) for communication with the ground was proposed and the data reception through it was confirmed. In the LF mode and the HEX mode, the transmitted data was confirmed to be a perfect reception success rate. In the case of the bolted antenna, the difference between the ground state and the underwater state was observed as a result of the experiment in the environmental environment. However, It was judged that reception sensitivity was sufficient for communication. The received data could be confirmed through PC based GUI.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.104-113
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• 2019

The road management institute needs lots of cost to repair road surface damage. These damages are inevitable due to natural factors and aging, but maintenance technologies for efficient repair of the broken road are needed. Various technologies have been developed and applied to cope with such a demand. Recently, maintenance technology for road surface damage repair is being developed using image information collected in the form of a black box installed in a vehicle. There are various methods to extract the damaged region, however, we will discuss the image recognition technology of the deep neural network structure that is actively studied recently. In this paper, we introduce a new neural network which can estimate the road damage and its location in the image by region-based convolution neural network algorithm. In order to develop the algorithm, about 600 images were collected through actual driving. Then, learning was carried out and compared with the existing model, we developed a neural network with 10.67% accuracy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1705-1713
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• 2018

It is currently undergoing the fourth industrial revolution, which is the convergence of ICT and manufacturing, connecting both industrial equipment and production processes to one network and communicating with each other. The fact that they are connected to one network has the advantage of management, but there is a risk of security. In particular, Wi-Fi can be easily accessed by outsiders through a software change of the MAC address or password exposures. In this paper, by applying the method of Beacon using a Bluetooth Low Energy Add in Bluetooth 4.0, we propose a system of black-box approach to secure connections to wireless Internet, users do not have to know the password. We also implemented the proposed system using the raspberry pi and verified the effectiveness of a real-time system by testing the communication.