• Journal of the Korean Society for Marine Environment & Energy
• /
• v.17 no.2
• /
• pp.146-152
• /
• 2014

Design procedure of WEC (wave energy converter) using the heaving motion of a floating cylinder-type buoy coupled with LEG (linear electric generator) system is introduced. It is seen that the maximum power can actually be obtained at the optimal conditions ($c_{PTO}=b_T$, ${\omega}={\omega}_N$). Then, based on the developed theory, several design strategies are proposed to further enhance the maximum PTO (power take off), which includes the intentional mismatching with the heave natural frequency, which is 15% higher value than the peak frequency of input velocity spectrum. By using the intentional mismatching strategy, the generated power is actually increased and the corresponding draft as well as the required PTO damping value is significantly reduced, which is a big advantage in manufacturing the WEC with practical LEG (linear electric generator) system.

• The Journal of Korean Physical Therapy
• /
• v.34 no.1
• /
• pp.45-50
• /
• 2022

Purpose: The purpose of this study was to compare the spatiotemporal and kinematic gait parameters and muscle activity of the lower extremities between forward walking on sand (FWS) and backward walking on sand (BWS) in normal adults. Methods: This study was conducted on 13 healthy adults. Subjects performed FWS and BWS and the spatiotemporal and kinematic gait parameters of stride time, stride length, velocity, cadence, step length, stance, swing, double support, and hip range of motion (ROM), knee ROM were measured by a wearable inertial measurement unit system. In addition, the muscle activity of the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GA) was measured. Results: The stride length, stride velocity, cadence, and step length in the BWS were significantly lower than FWS (p<0.05), and stride time was significantly greater (p<0.05). However, there was no significant difference in the ratio of stance, swing, and double support between the two (p>0.05). The kinematic gait parameters, including hip and knee joint range of motion in BWS, were significantly lower than FWS (p<0.05). The muscle activity of the RF in BWS was significantly higher than FWS (p<0.05), but the muscle activity of the BF, TA, GA did not show any significant differences between the two movements (p>0.05). Conclusion: A strategy to increase stability by changing the gait parameters is used in BWS, and this study confirmed that BWS was a safe and effective movement to increase RF muscle activity without straining the joints. Therefore, BWS can be recommended for effective activation of the RF.

• Journal of Fashion Business
• /
• v.27 no.1
• /
• pp.110-125
• /
• 2023

Virtual idol groups are a product of changes in cultural content and development of digital technology. The purpose of this study is to derive the characteristics of technical expression and fashion of virtual idol groups of Korean entertainment companies, and the significance of this study is to provide basic data for creating a new content business model for virtual idol groups. The research method of this study consisted of literature research and case analysis. Korean virtual idol groups 'K/DA', 'Aespa', and 'Eternity', which show the evolved business model of the entertainment industry through rapid advances in digital technology, were selected as the subject of case analysis for this study, and newspaper articles were searched by keywords and analyzed. As a result of the study, the technical expressions shown in Korean virtual idol groups were 'implementation of realistic content through interaction technology', 'delicate motion expression through motion capture technology', and 'convergence of information between the real world and virtual world through AR technology', 'provision of experience similar to reality by VR technology' and 'formation of cultural contents by Deep Real technology' were deriven. In addition, the characteristics of the Korean virtual guide idol group's fashion are 'marketing strategy through collaboration with fashion items', 'giving recognition as a digital fashion icon of real existence', 'creating a sensuous image as a fashion brand ambassador' and 'fashion style expression of the Z generation's sensibility'.

• Korean Security Journal
• /
• no.5
• /
• pp.19-40
• /
• 2002

For front, aspect of terror may have to prepare indeed even chemical terror or rocket and small size missile and radioactivity terror because is predicted to become various. Furthermore, when see motion of every countries about nuclear engineerses' bringing round and illicit sale of plutonium, our country may have to prepare in terrorism which is expected thus. So that can finish international event successfully because the United States of America supports great manpower and budget since New York's World Trade Center terror and when see that is considering terror prevention countermeasure, we operate temporarily bursting tube state complete charge team such as terror by each field specialist such as a concern interested including special CBR complete charge moving team among 2002 World Cups soccer game period ahead of international event, must consider safety countermeasure. Specially, biology weapon of chemical weapon and cholera etc. 13 kinds of 5000ton that North Korea plans CBR terror society confusion that North Korea that to terror support nation as well as nuclear weapons development suspicion is defending South Korea communization strategy as real condition that is amplified as well as is saving production brand gets imprinted uses CBR terror at normal times, when see that is planing powerlessness communization unity using CBR weapon at time of war, must operate until bias 2002 World Cups international event finishes cooperation safety countermeasure utensil safely under closer talk between the South Korea ${\cdot}$ Japan ${\cdot}$ North Korea. As for us which must serve 2002 World Cup successfully to accomplish perfectly preparedness of CBR terror firstly, all inhabitants knows well CBR protection trick, and secondly, CBR existing formation that solidify realignment CBR complete charge moving team which of course is consisted of CBR specialist compose and keeping immediate going out attitude operating, by third, that expand CBR individual protection equipment and CBR evacuation equipment and establish individual and group protection attitude naturally, supplement as there is main room that actualize CBR pollution patient's slogan countermeasure by fourth, and develop standard model for CBR terror provision by fifthBecause constructing infra of CBR safety establishing CBR preparedness that utilize it, must minimize damage and contribute inhabitants' life and property protection.

• Smart Structures and Systems
• /
• v.21 no.3
• /
• pp.359-371
• /
• 2018

Strong seismic events commonly cause large drift and deformation, and functionality failures in the superstructures. One way to prevent functionality failures is to design structures which are ductile and flexible through yielding when subjected to strong ground excitations. By developing forces that assist motion as "negative stiffness forces", yielding can be achieved. In this paper, we adopt the weakening and damping method to achieve a new approach to reduce all of the structural responses by further adjusting damping phase. A semi-active control system is adopted to perform the experiments. In this adaptation, negative stiffness forces through certain devices are used in weakening phase to reduce structural strength. Magneto-rheological (MR) dampers are then added to preserve stability of the structure. To adjust the voltage in MR dampers, an inverse model is employed in the control system to command MR dampers and generate the desired control forces, where a velocity control algorithm produces initial required control force. An extensive numerical study is conducted to evaluate proposed methodology by using the smart base-isolated benchmark building. Totally, nine control systems are examined to study proposed strategy. Based on the numerical results of seven earthquakes, the use of proposed strategy not only reduces base displacements, base accelerations and base shear but also leads to reduction of accelerations and inter story drifts of the superstructure. Numerical results shows that the usage of inverse model produces the desired regulated damping, thus improving the stability of the structure.

• International Journal of Computer Science & Network Security
• /
• v.22 no.2
• /
• pp.341-347
• /
• 2022

This research is designed to help and offer hold up to complete the requirements of aged and disable in a home. The control approach and the tone approach are used to manage the house appliances. The major organize system implementation in technology of wireless to offer distant contact from a phone Internet Protocol connectivity for access and calculating strategy and appliance remotely. The planned system no need a committed server PC with value of parallel systems and offers a new communication-protocol to observe and control a house environment with more than just the switch functionality. To express the possibility and efficiency of this system, devices like as lights switches, power plugs, and motion-sensors have been included with the planned home control system and supply more security manage on the control with low electrical energy activate method. The rank of switches is corresponding in all this control system whereby all user interfaces indicate the real time existing status. This system planned to manage electrical-appliances and devices in house with reasonably low cost of design, user friendly interface, easily install and provide high security. Research community generally specified that the network "Reconnaissance Attacks" in IPv6 are usually impossible due to they will take huge challenge to carry out address scanning of 264 hosts in an IPv6 subnet."It being deployed of IPv6 shows that it definitely enhances security and undermines the probability". This research of the IPv6 addressing-strategies at present utilizes and planned a new strategy and move toward to "mitigate reconnaissance attacks".

• Journal of the Korean Chemical Society
• /
• v.67 no.4
• /
• pp.241-252
• /
• 2023

This study aims to increase students' understanding of equilibrium, one of the many concepts in chemistry that students find difficult. Dynamic equilibrium must be dealt with at the sub-microscopic level where the real and the representation overlap in order to microscopically understand the constant motion and interaction of particles and to understand the macroscopic characteristics expressed through this. However, as a result of analyzing 9 Chemistry I textbooks, the expression approach for equilibrium had some limitations. As a strategy to understand equilibrium at a sub-microscopic approach, the classes using scratch were consisted of a total of 4 hours, and it was implemented with 56 students. The classes were composed of 6 steps, and it was designed to understand equilibrium step by step. As a result of comparing the pretest and post- test, the number of students who got both the microscopic and macroscopic explanations of chemical equilibrium correct increased largely. Through this, it was possible to get a glimpse of the applicability of classes using scratch as the approach strategy of the sub-microscopic representation.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.4
• /
• pp.77-87
• /
• 2008

This study is to formulate strategy for subject who are selected as national team in horizontal bars event in apparatus gymnastics. For this, skill training program was applied to players for 8 weeks. Then it was analyzed by using 3D motion Analysis system to seek the difference between before and after using the program. There were decisive demerit element K's first try for Tkatchev stretched movement from low elevation and crooked body while elevating. Not only, the location of his center of mass is far and low and there was some concern in his landing due to bended his hip-joint, but also, it exposed weak point in retro-action followed technique. Thus, to overcome that weak point, the subject repeated practices on following; when preparing for Tkatchev stretched movement at downward for big spin, make sure extend shoulder angle faster, make sure Tap movement is short and concise using hip-joint angular while delaying Tap timing for folding the body, and moreover, while backlashing the body, used shoulder joint angle wide to pull up the body. As a result, the speed of vertical upward did rut increase when separation from the bar. However, height of elevation increased that the leg would rut hit the horizontal bar even straight up the hip-joint. Therefore, the movement itself provided magnificent motion and even helped decrease the demerits.

• Journal of Astronomy and Space Sciences
• /
• v.30 no.4
• /
• pp.269-277
• /
• 2013

In this study, we present results of precise orbital geodetic parameter estimation using satellite laser ranging (SLR) observations for the International Laser Ranging Service (ILRS) associate analysis center (AAC). Using normal point observations of LAGEOS-1, LAGEOS-2, ETALON-1, and ETALON-2 in SLR consolidated laser ranging data format, the NASA/GSFC GEODYN II and SOLVE software programs were utilized for precise orbit determination (POD) and finding solutions of a terrestrial reference frame (TRF) and Earth orientation parameters (EOPs). For POD, a weekly-based orbit determination strategy was employed to process SLR observations taken from 20 weeks in 2013. For solutions of TRF and EOPs, loosely constrained scheme was used to integrate POD results of four geodetic SLR satellites. The coordinates of 11 ILRS core sites were determined and daily polar motion and polar motion rates were estimated. The root mean square (RMS) value of post-fit residuals was used for orbit quality assessment, and both the stability of TRF and the precision of EOPs by external comparison were analyzed for verification of our solutions. Results of post-fit residuals show that the RMS of the orbits of LAGEOS-1 and LAGEOS-2 are 1.20 and 1.12 cm, and those of ETALON-1 and ETALON-2 are 1.02 and 1.11 cm, respectively. The stability analysis of TRF shows that the mean value of 3D stability of the coordinates of 11 ILRS core sites is 7.0 mm. An external comparison, with respect to International Earth rotation and Reference systems Service (IERS) 08 C04 results, shows that standard deviations of polar motion $X_P$ and $Y_P$ are 0.754 milliarcseconds (mas) and 0.576 mas, respectively. Our results of precise orbital and geodetic parameter estimation are reasonable and help advance research at ILRS AAC.

• Journal of Broadcast Engineering
• /
• v.23 no.1
• /
• pp.45-52
• /
• 2018

The virtual reality (VR) cartoon is a format of VR contents that leverage the characteristics of webtoons that provides the simple story line and graphical storytelling tools to strategically surmount limitations of VR contents design. The VR cartoon enables people to experience the imaginary three-dimensional space in the webtoon as a real space by the transformation of webtoon contents through VR prototyping. The VR cartoon successfully presents focused environment where people can readily pay attention to the contents without notable motion sickness. People have been familiar with the storytelling strategy in the context of published cartoons and webtoons, likely we've understood the narrative of a movie through the continuous scenes projected in the screen. Indeed, it has been recognized as a popular toolset of communication, where visual images are sequentially delivered by replacing multiple planar spaces to tell a story narrative. While there are discrete panels with the time and space resolution in the graphical cartoons, people can distill a commit closure based on their past experiences. This is a typical "grammar" of the cartoon, which can be extrapolated to the VR cartoon that provides a seminal storytelling strategy. In this article, we review how the storytelling strategy in webtoons has been transformed into that in VR cartoons, and analyze the key components of VR cartoons. We envision that our research can potentially create keystones to produce variety of new VR contents by reflecting various narrative media including cartoon as a 'sequential art'.