• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.05a
• /
• pp.227-229
• /
• 2021

The modern society is advancing from the analog era to the digital imaging era, and in line with the trend of this era, various imaging devices such as exploration robots, medical equipment, and CCTV are helping our daily life a lot. However, noises caused by various causes in digital images not only cause image deterioration, but also deteriorate and deteriorate image quality. A typical noise is AWGN, and types of filters to remove it include an average filter, a median filter, and an alpha-trimmed average filter, but these filters have a disadvantage in that they show somewhat inadequate noise reduction performance in the high frequency region. Therefore, in this paper, a modified spatial division average filter based on standard deviation is proposed to effectively reduce AWGN existing in the high frequency region of the image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.118-120
• /
• 2021

In modern society, with the development of IoT technology, various digital equipment is being distributed in a wide range of fields such as CCTV and exploration robots. Accordingly, the importance of data processing is increasing, and various studies are being conducted to remove noise generated in the process of receiving data in the imaging field. Representative noise includes additive white Gaussian noise (AWGN), and existing filters for removing noise include an average filter (AF), an alpha trimmed average filter (A-TAF), and a median filter (MF). However, existing filters have a disadvantage in that they show somewhat insufficient performance in noise removal characteristics in high frequency areas. Therefore, in this paper, in order to effectively remove AWGN existing in the high frequency region, a weight filter according to a distance based on the standard deviation is proposed.

• Journal of the Society of Naval Architects of Korea
• /
• v.37 no.3
• /
• pp.21-26
• /
• 2000

For coastal service ships, the water depth is a very important parameter in the design stage of the hull form that has an influence on the restriction of the speed and draft of ships. In this study, the water depth is important for ship design. In this research, the change of total resistance, trim and sinkage due to the variation of water depth are measured by using on equipment for shallow water condition. For the basic research step about the shallow water effect, the effects on Series60($C_B=0.6$) hull form are experimented. To compare with existing experiment results, the test conditions are same with those. The water depth conditions are 10, 15, 20, 25% of LPP of the model ship, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.6
• /
• pp.498-504
• /
• 2011

The flapping characteristics and advance ratios at torque equilibrium state of autorotation were investigated when the airspeed, shaft angle, and pitch angle were varied. To simulate the airspeed increase, the aerodynamic data analyzed by using the compressible Navier-Stokes solver and Pitt/Peters inflow theory were used. Transient Simulation Method(TSM) was used to catch the torque equilibrium states. The maximum flapping angles at torque equilibrium state were correlated to the airspeed, shaft angle, and pitch angle. By comparing flapping behavior to the variation of advance ratio, the phenomenon that the extension of reverse flow area of retreating blade affects the characteristics of autorotation was qualitatively considered.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.17 no.3
• /
• pp.138-148
• /
• 2005

Dynamic response of floating structures such as floating body and floating bridges subject to wave load is to be calculated in frequency domain. Added mass coefficient, damping coefficient and wave exciting force are obtained numerically from frequency domain formulation of linear potential theory and boundary element method for a floating body which is partially submerged into water and subjected to wave force. Next, the equation of motion for the dynamic behavior of a floating structure which is supported by the floating bodies and modeled with finite elements is written in frequency domain. hker a hemisphere is analyzed and compared with the published references as examples of floating bodies, the hydrodynamic coefficients for a pontoon type floating body which supports a floating bridge are determined. The dynamic response of the floating bridge subject to design wave load can be solved using the coefficients obtained for the pontoons and the results are plotted in the frequency domain. It can be seen from the example analysis that although the peak frequency of the incoming wave spectrum is near the natural frequency of the bridge, the response of the bridge is not amplified due to the effect that the peak frequency of wave exciting force is away from the natural frequency of the bridge.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.232-233
• /
• 2017

In this research, tunnel stern was applied on the asymmetric high-speed catamaran to evaluate vessel's hydrodynamic performance by numerical method, and the tunnel stern types are distinguished by angle of inclination of tunnel exit region into 3cases ($0^{\circ}$, $3^{\circ}$ and $6^{\circ}$). Consequently, it is confirmed that the total resistances of tunnel stern which have $0^{\circ}$ of inclination are lower about 4.8-17.9% than the bare hull in the wide speed range, but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are higher than bare hull about 5-14% and 5-29%, respectively. On the other hand, trim angles of $0^{\circ}$ of inclination tunnel stern show similar trend with those of bare hull in whole ranges of FnV but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are stabilized and declined respectively after FnV=1.54. These phenomena indicated that increasing angle of inclination of tunnel exit region had negative influence on resistance performance, however, it could make vessel's operation performance better than bare hull.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.8
• /
• pp.807-815
• /
• 2008

In this paper, design, development and evaluation of DIP(Database Interface Program) are presented. The main purpose of this study is to improve the simulation quality to get more realistic response of target system. The designed and developed major function is composed of flexible memory structure, efficient arithmetic database language and high speed interpolation/extrapolation algorithm. To evaluate the operation speed and accuracy of returned data, trim simulation is performed based on in-house software and, DIP is applied to existing real-time simulator such as engineering HQS(Handling Quality Simulator) to evaluate reliability and performance. The result of evlaution reveals that calculation speed and data accuracy are satisfied, and flight performance is satisfied in the real-time simulator environments.

• Journal of the Korea Convergence Society
• /
• v.8 no.4
• /
• pp.59-65
• /
• 2017

The purpose of this study was conducted to identify differences of the self confidence for newborn baby care before and after clinical convergence baby massage training program. Study subjects were 50 juniors in B nursing college located in Chungnam Province, modified baby massage training programs had been provided 2 hours a day, total 4 times from March 1 to March 25, 2016. Confidence for newborn baby care was measured pre and post program, collected data were analyzed using SPSS 21.0 program, paired t-test. The results of the study showed that the score of self confidence for newborn baby care(t=-7.209, p<.001), feeding(t=-6.025, p<.001), belching(t=-3.870, p<.001), bathing(t=-7.432, p<.001), after bathing hygiene(t=-5.892, p<.001), navel care(t=-3.843, p<.001), assessment of baby condition and baby care(t=-6.113, p<.001) were statistically significant differences before and after baby massage training program. Finally, the findings of this study, clinical convergence baby massage training program based on the necessary knowledge and practice in clinical filed will positively help to develop a confidence for newborn baby care for nursing students in nursing practice and clinical nursing care.

• Clean Technology
• /
• v.20 no.3
• /
• pp.232-240
• /
• 2014

The significance of thermoplastic polyolefin polypropylene (PP) lies in its potential to replace polyvinyl chloride (PVC), the most widely used material for automobile interiors (door trim, dash board), which discharges harmful compounds in certain conditions. Another benefit of PP (0.855 amorphous - 0.946 crystalline $g/cm^3$) is its low density compared to that of PVC ($1.1-1.45g/cm^3$), which reduces vehicle weight. Market demand for eco-friendly water-based adhesive/coating material is rising significantly as a substitute for solvent-based adhesive/coating material which emits VOC and causes harmful working conditions. Under such context, in this study, a series of eco-friendly waterborne polyurethane-urea primer (a paint product that allows finishing paint to adhere much better than if it were used alone) for hydrophobic PP were prepared from different mix of DMPA content, NCO/OH molar ratio, various wt% of silicone diol and various soft segment content, among which DMPA of 21 mole %, NCO/OH molar ratio of 1.2, modified silicone diol of 5 wt% and soft segment content of 73 wt% led to good adhesion strength. Additionally, the incorporation of optimum content of additives (0.5 wt% dispersing agent, 0.5 wt% levelling agent, 1.5 wt% antifoaming agent, 3.0 wt% matting agent) into the optimum waterborne polyurethane-urea also enabled good stability, levelling, antifoaming and non-glossy.