• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.5
• /
• pp.27-33
• /
• 2011

At FDTC'05 and CISC-W'10, the authors showed that if they decrease the number of rounds of AES and Triple-DES by using the fault injections, it is possible to recover the secret key of the target algorithms, respectively. In this paper, we propose a key recovery attack on HMAC by using the main idea of these attacks. This attack is applicable to HMAC based on MD-family hash functions and can recover the secret key with the negligible computational complexity. Particularly, the attack result on HMAC-SHA-2 is the first known key recovery attack result on this algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.101-104
• /
• 2016

In this study, we propose an algorithm to simulate the function of the coupling structure and having two neurons to find out exactly recover the temporary or permanent position errors that can occur during operation in a digital circuit was separated by function, a 3x3 array. If any particular part in the combined cells are differentiated cells have a problem that function to other cells caused an error and perform the same function are subjected to a step of apoptosis by the surrounding cells. Designed as a function block in the function and the internal structure having a cell structure of this digital circuit proposes an algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.11
• /
• pp.1329-1340
• /
• 2016

Recently, Zhang proposed a scheme to hide information in encrypted images using synchronous stream ciphers. After the receiver decrypts the encrypted image and extracts data by calculating the spatial correlation property value using the fluctuation function which is designed to calculate spacial correlation between adjacent pixels in a decrypted image. Then, Hong improved the Zhang's data hiding scheme by introducing the side match technique. In this paper, a novel fluctuation function is proposed to reduce the recovery errors which arise during extracting hidden data. Then, we also demonstrated that the proposed fluctuation function outperforms the previous functions through computer simulations for sample images.

• Physical Therapy Rehabilitation Science
• /
• v.11 no.4
• /
• pp.517-525
• /
• 2022

Objective: The rehabilitation protocols for functional recovery have been emphasized after total knee arthroplasty, and Pilates is in the spotlight as a safe and easily modified exercise method. The purpose of this study was to investigate the effects of mat Pilates exercise on lower extremity function, postural balance, and walking in the individuals with total knee arthroplasty. Design: One group pretest-posttest design. Methods: Eighteen older women with unilateral total knee arthroplasty was recruited in the study. The subjects were evaluated on lower extremity function, postural balance, and walking before and after mat Pilates exercise. All subject performed one hour mat Pilates exercise, 3 times a week for 8 weeks. Mat Pilates exercises were focused on core stability and lower extremity strengthening and, more dynamic movements were added to increase the difficulty of movements every two weeks. The lower extremity function was measured using the Western Ontario and McMaster Osteoarthritis Index (WOMAC), knee joint position sense, and five times sit-to-stand test. Postural balance was assessed by single leg stance test, functional reach test, and timed up and go test. Walking was measured by OptoGait system to temporospatial parameter. Results: The lower extremity function, postural balance, and walking were significantly improved after mat Pilates exercise, except for five times sit-to-stand test (p<0.05). Conclusions: This study demonstrated that the mat Pilates exercise was a useful method to improve lower extremity function, postural balance, and walking in the older women with unilateral total knee arthroplasty.

• Korea Journal of Cosmetic Science
• /
• v.1 no.1
• /
• pp.19-29
• /
• 2019

In this work, we fabricated liquid crystal (LC) emulsions with fatty alcohol in order to stabilize high content ceramide in cosmetic formulation. We investigated the role of fatty alcohol and surfactant in the formation of higher order structure. As a result, we found that they play a crucial role to form higher order structure. SAXS study shows that ceramide can be incorporated up to 3% in cosmetic formulation with higher order structure and its stability was maintained up to 12 weeks at room temperature. According to WAXS study, the higher order structure can suppress the re-crystallization of ceramide in cosmetic formulation. Finally, we performed in vivo skin barrier recovery test for the damaged skin. LC emulsions with ceramide and O/W emulsions show significant effect in skin barrier recovery at D 1, D 2 and D 6 compared to the untreated condition. While only LC emulsions show significant skin recovery effect at D 14. We expect that LC emulsions are the promising skin carrier to stabilize ceramide and LC emulsions with ceramide can improve the skin barrier function.

• Physical Therapy Korea
• /
• v.16 no.4
• /
• pp.44-52
• /
• 2009

It is known that individual factors as cognitive, perception, emotion, and motivation may greatly influence on recovery from neurologic region. This study was to investigate the effects of environmental reinforcement through motivation to perform the tasks voluntarily on motor and cognition function in rats with focal ischemic brain injury. Focal ischemic brain injury was induced in Sprague-Dawley rats (15 rats, $250{\pm}50$ g) through middle cerebral artery occlusion (MCAo). And then, experiment groups were randomly divided into three groups; The control group: MCAo induction ($n_1$=5), the environmental reinforcement (ER) group: the application for ER after MCAo induction ($n_2$=5), the environmental reinforcement through motivation (ERM) group: the application for ERM after MCAo induction ($n_3$=5). The climbing test (CT) and the modified limb placing tests (MLPTs) to measure the motor function and the Morris water maze acquisition test (MWMAT) and the Morris water maze retention test (MWMRT) to measure the cognitive function were performed. For the CT, the ERM group was significantly larger than the ER group. For the MLPTs, the ERM group was significantly decreased compared to other groups. For the MWMAT, the time to find the circular platform in the ERM group significantly decreased compared to other groups. For the MWMRT, the time to dwell on the quadrant circular platform in the ERM group was significantly increased compared to other groups. These results suggested that the ERM could improve the motor and cognitive functions in the rats with focal ischemic brain injury.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.6
• /
• pp.481-488
• /
• 2001

The sustaining driver for color AC Plasma Display Panel should provide alternating high voltage pulses and recover the energy discharged from the intrinsic capacitance between the scanning and sustaining electrodes inside the panel In this paper a novel efficient energy recovery circuit employing boost-up function is proposed to achieve a faster rise-time and in order to obtain a stable sustain voltage The principle of operation. features simulated results and experiment results are illustrated and verified on a 7.5-inch-panel with 200［kHz］switch frequency.

• Physical Therapy Korea
• /
• v.29 no.3
• /
• pp.200-207
• /
• 2022

Background: The oxygen uptake efficiency slope (OUES) is the most important index for accurately measuring cardiopulmonary function in patients with acute ischemic heart disease. However, the relationship between the OUES variables and important cardiopulmonary function parameters remain unelucidated for patients with acute ischemic heart disease, which accounts for the largest proportion of heart disease. Objects: The present cross sectional clinical study aimed to determine the multiple relationships among the cardiopulmonary function variables mentioned above in adults with acute ischemic heart disease. Methods: A convenience sample of 110 adult inpatients with ischemic heart disease (age: 57.4 ± 11.3 y; 95 males, 15 females) was enrolled at the hospital cardiac rehabilitation center. The correlation between the important cardiopulmonary function indicators including peak oxygen uptake (VO₂ peak), minute ventilation (VE)/carbon dioxide production (VCO₂) slope, heart rate recovery (HRR), and ejection fraction (EF) and OUES was confirmed. Results: This study showed that OUES was highly correlated with VO₂ peak, VE/VCO₂ slope, and HRR parameters. Conclusion: The OUES can be used as an accurate indicator for cardiopulmonary function. There are other factors that influence aerobic capacity besides EF, so there is no correlation with EF. Effective cardiopulmonary rehabilitation programs can be designed based on OUES during submaximal exercise in patients with acute ischemic heart disease.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.10
• /
• pp.21-30
• /
• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• Journal of Mechanical Science and Technology
• /
• v.15 no.9
• /
• pp.1281-1291
• /
• 2001

The hereditary integral form of a quasi-linear viscoelastic law has been employed. Four new concepts have been employed: 1. a reduced relaxation function with a non-linear exponential function of time, 2. an inverse method to determine the scale factor of the elastic response, 3. an instant elastic recovery strain during unloading, and 4. the results of a constitutive model for cyclic tests may be a function of the Heavyside class. These concepts have been supported by agreement between measured and predicted responses of soft connective tissue to three types of multiple cyclic tests which include rest periods of no extension and alternations between different strain levels. Such agreement has not been attained in the previous studies. Chun and Hubbard (2001) is our companion experimental analysis paper.