• Maritime Security
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• v.7 no.1
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• pp.31-60
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• 2023

This study proposes a new convergence weapon system that combines the covert placement and detection abilities of a self-propelled mobile mine with the rapid tracking and attack abilities of supercavitating rocket torpedoes. This innovative system has been designed to counter North Korea's new underwater weapon, 'Haeil'. The concept behind this convergence weapon system is to maximize the strengths and minimize the weaknesses of each weapon type. Self-propelled mobile mines, typically placed discreetly on the seabed or in the water, are designed to explode when a vessel or submarine passes near them. They are generally used to defend or control specific areas, like traditional sea mines, and can effectively limit enemy movement and guide them in a desired direction. The advantage that self-propelled mines have over traditional sea mines is their ability to move independently, ensuring the survivability of the platform responsible for placing the sea mines. This allows the mines to be discreetly placed even deeper into enemy lines, significantly reducing the time and cost of mine placement while ensuring the safety of the deployed platforms. However, to cause substantial damage to a target, the mine needs to detonate when the target is very close - typically within a few yards. This makes the timing of the explosion crucial. On the other hand, supercavitating rocket torpedoes are capable of traveling at groundbreaking speeds, many times faster than conventional torpedoes. This rapid movement leaves little room for the target to evade, a significant advantage. However, this comes with notable drawbacks - short range, high noise levels, and guidance issues. The high noise levels and short range is a serious disadvantage that can expose the platform that launched the torpedo. This research proposes the use of a convergence weapon system that leverages the strengths of both weapons while compensating for their weaknesses. This strategy can overcome the limitations of traditional underwater kill-chains, offering swift and precise responses. By adapting the weapon acquisition criteria from the Defense force development Service Order, the effectiveness of the proposed system was independently analyzed and proven in terms of underwater defense sustainability, survivability, and cost-efficiency. Furthermore, the utility of this system was demonstrated through simulated scenarios, revealing its potential to play a critical role in future underwater kill-chain scenarios. However, realizing this system presents significant technical challenges and requires further research.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.105-115
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• 2006

The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.615-625
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• 2014

Ministry of National Defense, MND, established a "Master Plan of Military Facility" in 2010 based on the defense reform to prepare for future war. It was a plan for consolidating small military facilities into battalion units, reflecting on and preparing for the needs of various changes in defense environment as well as balanced growth of ROK Army, Navy, and Air Force. However, to move forward with "Military Facility Master Plan," current design criteria for military facilities need to be revised to be enacted due to numerous calculation errors in facility footprints because of the absence of a sound facility criteria. Because the future war environment will be changed from Platform basis to Network Centric Warfare basis, Command & Control capability of C4I systems is getting more important. Therefore, Successful mission accomplishment can be secured by convergence of facility and military Information Technology(IT). So, MND should quickly prepare for the operational guidance, design criteria and policy that are suitable for Network Centric Warfare accomplishment, and implement infrastructure of IT and installation of C2 facility in conjunction with consolidation movement of military facilities. In this paper, we propose the defense I3A framework in order to solve this problem.

• Physical Therapy Korea
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• v.11 no.2
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• pp.35-45
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• 2004

The purpose of this study was to investigate the correlation and characteristics between electromyographic (EMG) activities of lower leg muscles and the posturographic assessment of static balance control in normal adults. Twenty-four young, healthy adults(12 males, 12 females) participated in the study. Center of pressure (COP) parameters were obtained using force platform as total path distance, total sway area, X mean frequency and Y mean frequency for 20 seconds in the following conditions: (1) comfortable standing with eyes opened or closed, (2) uncomfortable standing (feet together) with eyes opened or closed, (3) virtual moving surround delivered using Head mount display (HMD) with four different moving patterns. The virtual moving patterns consisted of close-far, superior-inferior tilting (pitch), right-left tilting (roll), and horizontal rotation (yaw) movements. Surface electromyographic activites were recorded on the tibialis anterior, peroneus longus, medial and lateral heads of gastrocnemius muscles under each condition. Correlation between the posturographic measures and EMG activities were evaluated. Total path distance and total sway area of COP were significantly increased during uncomfortable standing. EMG activity of tibialis anterior was significantly more during uncomfortable standing and virtual moving surround stimulation than during comfortable standing. Total path distance and sway area of COP during comfortable standing with closed eyes showed significant positive correlation with the EMG activities of the lateral head of gastrocnemius muscle. Total path distances and total sway area of COP during muscle. Total path distances and total sway area of COP during presentation of virtual moving surround also had significant positive correlations with EMG activities of the lateral head of gastrocnemius muscle under close-far movement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.643-651
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• 2020

A capsule train runs inside a sub-vacuum tube and can reach very high speed due to the low air resistance. A capsule train uses a superconducting electrodynamic suspension (SC-EDS) method for levitation, which allows for a large levitation gap and does not require gap control. However, SC-EDS has inherent characteristics such as the large gap variation and a small damping effect in the levitation force, which can degrade the running stability and ride comfort. To overcome this, a stability improvement device should be designed and applied based on dynamic analysis. In this study, a 1/10 small-scale testbed was developed to replicate the dynamic characteristics of a capsule train and investigate the performance of stability improvement devices. The testbed is composed of a 6-degree-of-freedom Stewart platform for the realization of bogie motion, a secondary suspension with a running stabilization device, and a carbody. Based on the dynamic similarity law proposed by Jaschinski, the small-scale testbed was manufactured, and a bogie motion algorithm was applied with the consideration of guideway irregularity and levitation stiffness. The experimental results from the testbed were compared with simulation results to investigate the performance of the testbed.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.233-244
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• 2002

The purpose of this study is to assess the ability of balance control in moving surround using head mount device and force platform and to examine the clinical usefulness of COP parameters. Fifteen patients with stroke and healthy persons were participated. COP parameters were obtained as total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) in comfortable standing with opened or closed eyes, (2) in virtual moving surround delivered using HMD to four different moving pattern. In virtual moving surround setting, moving pattern was composed of close-far, superior-inferior tilting(pitch), right-left tilting(roll) and horizontal rotation(yaw) movement. In all parameters, the reliebility of COP analysis system was significantly high. Also, the construct validity compared between fifteen patients with stroke and normal persons was excellent in virtual moving surround condition(p

• Korean Chemical Engineering Research
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• v.46 no.6
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• pp.1100-1106
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• 2008

In this study, we presented rapid and simple fabrication method of functionalized surface on various substrates as a universal platform for the selective immobilization of cells. The functionalized surface was achieved by using deposition of polyelectrolyte such as poly(allyamine hydrochloride) (PAH), poly(diallyldimethyl ammonium chloride) (PDAC), poly(4-ammonium styrene sulfonic acid) (PSS), poly(acrylic acid) (PAA) and fabrication of poly(ethylene glycol) (PEG) microstructure through micro-molding in capillaries (MIMIC) technique on each glass, poly(methyl methacrylate) (PMMA), polystyrene (PS) and poly(dimethyl siloxane) (PDMS) substrate. The polyelectrolyte multilayer provides adhesion force via strong electrostatic attraction between cell and surface. On the other hand, PEG microstructures also lead to prevent non-specific binding of cells because of physical and biological barrier. The characteristic of each modified surface was examined by using static contact angle measurement. The modified surface onto several substrates provides appropriate environment for cellular adhesion, which is essential technology for cell patterning with high yield and viability in the micropatterning technology. The proposed method is reproducible, convenient and rapid. In addition, the fabrication process is environmentally friendly process due to the no use of harsh solvent. It can be applied to the fabrication of biological sensor, biomolecules patterning, microelectronics devices, screening system, and study of cell-surface interaction.

• Physical Therapy Korea
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• v.17 no.3
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• pp.20-30
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• 2010

This study examined whether any changes by mental task types on postural control in chronic stroke persons. Sixteen chronic stroke persons (mean age=53.75 yr) and sixteen age-and gender-matched healthy controls (mean age=54.44 yr) took part in this study. Participants randomly performed three different tasks on the stable and unstable surfaces. The no mental task was to stand while holding a 100 g weight in each hand, the arithmetic task (mental task) was to perform a silent 1-backwards counting while standing and holding a 100 g weight in each hand, and the simple task (mental task) was to stand and hold with both hands a tray (200 g) on which a glass filled with water has been placed. Sway path and sway velocity of the center of pressure (COP) were measured to assess standing postural control by task performance using the force platform. According to the results, in stroke group, total sway path and total sway velocity of COP was significantly decreased during arithmetic and simple task compared to no mental task on the stable surface (p<.05), and sway path (anteroposterior AP, mediolateral ML) of COP, total and sway velocity (AP, ML, total) of COP was significantly decreased during arithmetic and simple task compared to no mental task on the unstable surface (p<.05). Especially, sway path (AP, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased under the simple task when compared to the arithmetic task on the unstable surface (p<.05). In healthy control group, sway path (AP, ML, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased during arithmetic and simple task compared to no mental task on the stable and unstable surface (p<.05), and sway path (AP, total) of COP and sway velocity (AP, ML, total) of COP was significantly decreased under the simple task when compared to the arithmetic task on the unstable surface (p<.05). In conclusion, the findings of this study showed that arithmetic and simple task improved standing postural control for chronic stroke patients and the type of arithmetic and simple tasks were critical factor that reduced standing postural sway in dual-task conditions. Future research should determine whether dual-task conditions, including simple task, would be effective as a training program for standing postural control of stroke patients.

• Journal of Service Research and Studies
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• v.10 no.1
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• pp.17-31
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• 2020

Open banking, the global trend of the financial industry, is the driving force behind various innovations in the financial market in the future. The right policy direction and detailed tasks are important for triggering the differentiation and reunion of the financial industry. The purpose of this study is to investigate and analyze the background of open banking, domestic and international trends, and Korea's open banking policy. The policy directions and tasks for successful settlement and activation of open banking system are carefully suggested. Open banking is a policy to allow third party provider(TPP) access to bank accounts and open payment functions under the explicit consent of the customer. The opening of the open banking era is expected to begin competition and cooperation between banks and fintech companies in earnest, thus enhancing the competitiveness of the financial industry and contributing to the utility of financial consumers. To this end, policymakers should make every effort to advance open-ended financial settlement infrastructure, open banking legal grounds, and minimize side effects such as customer data leakage and poor financial system stability. Banks and fintech companies will need to focus on scattered customer financial information on a single platform and develop it into a convergence and discrimination of true financial services.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.153-168
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• 2005

The purposes of this study were to determine the influence of midsole hardness and sole thickness of sports shoes on ball flex angle and position with increment of running velocity. The subjects employed for this study were 10 college students who did not have lower extremity injuries for the last one year and whose running pattern was rearfoot striker of normal foot. The shoes used in this study had 3 different midsole hardness of shore A 40, shore A 50, shore A 60 and 3 different sole thickness of 17cm, 19cm, 21cm. The subjects were asked to run at 3 different speed of 2.0m/sec, 3.5m/sec, 5.0m/sec and their motions were videotaped with 4 S-VHS video cameras and 2 high speed video cameras and simultaneously measured with a force platform. The following results were obtained after analysing and comparing the variables. Minimum angle of each ball flex position were increased with the increment of running velocity and shoe sole thickness(P<0.05), but mid-sole hardness did not affect minimum ball flex angle. The position which minimum angle was shown as smallest was 'D'. Midsole hardness and sole thickness did not affect time to each ball flex minimum angle, total angular displacement of ball flex angle, and total angular displacement of torsion angle(P<0.05). The position which minimum angle was appeared to be earliest was similar at walking velocity, and E and F of midfoot region at running velocity. Total angular displacement of ball flex position tended to increase as shifted to heel. It was found that running velocity had effects on ball flex angle variables, but shoe sole thickness partially affected. It would be considered that running velocity made differences between analysis variables at walking and running when designing shoes. Also, it was regarded that shoes would be developed at separated region, because ball flex angle and position was shown to be different at toe and heel region. It is necessary that midsole hardness and thickness required to functional shoes be analyzed in the further study.