• The Journal of the Convergence on Culture Technology
• /
• v.5 no.1
• /
• pp.341-346
• /
• 2019

The study aims to provide a study on the mixing ratios and manufacturing methods of biodegradable PLA sheets for mid - term introduction, A 3-layer process was introduced to produce a multifunctional multi-layer structure sheet having improved heat resistance, impact resistance and transparency while having anti-fogging functionality as a biodegradable PLA sheet used for the purpose of anti-fogging function. Inner layer, core layer and outer layer were mixed and extruded. The inner layer and core layer were studied for a biodegradable PLA multi-layer sheet structure having inner hardness and high heat resistance and outer layer for imparting antifogging function. By applying the results of this study, plastic PLA properties and heat-resistant temperature can be improved to replace and expand plastics.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.2
• /
• pp.389-395
• /
• 2019

This study investigated the pharmaceutical extraction and the functional health food extraction, which have a beneficial effect on the human body and which can be used safely for a long period of time without adverse side effects and also have excellent effects of protecting liver and improving liver function. As the results, the cabbage extract does not show cytotoxicity, and thus can be used safely. In an experiment performed on an animal model with liver injury induced by a drug (APAP), it could be seen that the cabbage extract exhibited the effects of protecting liver and improving liver function by effectively reducing AST and ALT which are liver injury markers, indicating that the cabbage extract is effective as a pharmaceutical extraction for preventing or treating liver disease. In particular, the cabbage extract was effective in treating inflammation of the liver by reducing the expression of the inflammatory mediators iNOS and COX-2 and the proinflammatory cytokine $IL-1{\beta}$, which are involved in acute inflammatory reactions accompanying liver injury. In the results, an extract of cabbage heat-treated at a temperature of 100 to $150^{\circ}C$ had a better liver function-improving effect or anti-inflammatory effect than an extract of raw cabbage.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.14 no.5
• /
• pp.37-47
• /
• 2004

The security of personal informations has been an important issue since the field of smart card applications has been expanded explosively. The security of smart card is based on cryptographic algorithms, which are highly required to be implemented into hardware for higher speed and stronger security. In this paper, a SEED cryptographic processor is designed by employing one round key generation block which generates 16 round keys without key registers and one round function block which is used iteratively. Both the round key generation block and the F function are using only one G function block with one 5${\times}$l MUX sequentially instead of 5 G function blocks. The proposed SEED processor has been implemented such that each round operation is divided into seven sub-rounds and each sub-round is executed per clock. Functional simulation of the proposed cryptographic processor has been executed using the test vectors which are offered by Korea Information Security Agency. In addition, we have evaluated the proposed SEED processor by executing VHDL synthesis and FPGA board test. The die area of the proposed SEED processor decreases up to approximately 40% compared with the conventional processor.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.1
• /
• pp.513-522
• /
• 2022

The purpose of this study is to evaluate the accessibility of the Cakewalk TTS-1 for the screen reader users. An evaluation was performed by testing the accessibility of a editing virtual instrument that is a part of MIDI production based on the NCS(National Competency Standards) by using the TTS-1 and the Sense Reader. The results of this study are as follows. The TTS-1 itself can't provide enough accessibility for the screen users to do an above task. But the screen reader users can perform the above tasks if they use extended access functions like Sense Reader's Mouse Pointer function, Position Memory function and MIDI Control Signal function. Even if they use the extended access function, there are functions that is difficult to access. To solve this problem, several suggestions are proposed.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.691-696
• /
• 2022

This study explored the lexical sophistication features to distinguish the group membership of English proficiency, using the automatic analysis program of lexical sophistication. A total of 600 essays written by 300 Korean college students were extracted from the ICNALE (International Corpus Network of Asian Learners of English) corpus and a discriminant function analysis was performed using SPSS program. Results showed that the lexical features to distinguish three groups of English proficiency are SUBTLEXUS frequency content words, age of acquisition content words, lexical decision mean reaction time function words, and hypernymy verbs. High-level Korean students used frequent content words from SUBTLEXUS corpus to a lesser degree and produced more sophisticated words that can be learned at a later age and take longer reaction time in lexical decision task, and more concrete verbs.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.1
• /
• pp.551-556
• /
• 2023

This study was attempted to confirm whether the color therapy intervention study on the elderly with mild cognitive impairment was effective in cognitive function and depression as a method of meta-analysis. In this study, the size of the effect of cognitive function and depression on the final eight studies of the experimental study was calculated through a domestic database from 2000 to October 2022. As a result, the statistically significant average effect size of the entire study was confirmed. In the test of the difference in effect size between groups, both cognitive function and depression were found to have significant effect sizes. Through this study, it was confirmed that calerotherapy is an effective intervention that can improve cognitive function and alleviate depression in the elderly with mild cognitive impairment. Based on the results of this study, it is necessary to develop an intervention program for the elderly with mild cognitive impairment using calerotherapy.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.1
• /
• pp.149-157
• /
• 2009

The purpose of this project was to determine biomechanical differences between Type A(Korean brand) and Type B(world top brand) badminton shoes and to make recommendations to improve the fit and function of Type A badminton shoes. Measurements of shoe shape and dimensions, foot movement within the shoe, cushioning of ground reaction forces, in-shoe pressure and outsole traction were performed. In addition, subjective feedback of the fit and function of the shoes was quantified for 17 recreational badminton players. Type A shoe had a much higher heel and shallower heel cup, so the heel was not secured well in the shoe and the ankle joint was higher off the ground. Foot slippage was up to 40% greater in Type A shoe than Type B shoe. Impact forces and peak pressures under the foot were generally higher with Type A shoe compared to Type B shoe. The flexion axis of Type A shoe occurred in the midfoot, not at the ball of the foot like Type B shoe, where you would want the shoe flexion to occur. In summary, there are several characteristics where A Type shoe and B Type differ. Therefore, a few recommendations are provided to help improve the fit and function of A Type shoe.

• Journal of the Korean Society of Safety
• /
• v.31 no.3
• /
• pp.8-15
• /
• 2016

The purpose of this study is to design a model with the structural stability so as not to lose the operational function due to structural plastic or fail of a sliding blast door by blast pressure to this aim, a numerical simulation was performed using full-size experiments and M&S (Modeling & Simulation) of the sliding blast door. The sliding blast door ($W3,000{\times}H2,500mm$) under the blast load is in the form of a sliding type 2-way metal grill, which was applied by a design blast pressure (reflected pressure $P_r$) of 17 bar. According to the experimental results of a real sliding blast door under blast load, the blast pressure reached the sliding blast door approximately 4.3 ms after the explosion and lasted about 4.0 ms thereafter. The maximum blast pressure($P_r$) was 347.7 psi (2,397.3 kPa), it is similar to the UFC 3-340-02 of Parameter(91 %). In addition, operation inspection that was conducted for the sliding blast door after real test showed a problem of losing the door opening function, which was because of the fail of the Reversal Bolt that was installed to prevent the shock due to rebound of the blast door from the blast pressure. According to the reproduction of the experiment through M&S by applying the blast pressure measurement value of the full-size experiments, the sliding blast door showed a similar result to the full-size experiment in that the reversal bolt part failed to lose the function. In addition, as the pressure is concentrated on the failed reversal bolt, the Principal Tensile Failure Stress was exceeded in only 1.25 ms after the explosion, and the reversal bolt completely failed after 5.4 ms. Based on the result of the failed reversal bolt through the full-size experiment and M&S, the shape and size of the bolts were changed to re-design the M&S and re-analyze the sliding blast door. According to the M&S re-analysis result when the reversal bolt was designed in a square of 25 mm ($625mm^2$), the maximum pressure that the reversal bolt receives showed 81% of the principal tensile failure stress of the material, in plastic stage before fail.

• Safety and Health at Work
• /
• v.11 no.2
• /
• pp.178-186
• /
• 2020

Background: Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function. Methods: Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44-84 years) reported hours per week worked in all jobs in Exams 1 (2000-2002), 2 (2002-2004), 3 (2004-2005), and 5 (2010-2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work. Results: Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = -0.55, 95% CI = -0.99, -0.09) and (β = -0.80, -1.51, -0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = -0.80, -1.52, -0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function. Conclusion: Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.1
• /
• pp.108-118
• /
• 2017

In this paper, the path tracking controller for a surface vessel based on the sliding mode control (SMC) with the switching law is proposed. In order to have no restriction on movement and improved tracking performance, the proposed control system is developed as follows: First, the kinematic and dynamic models in Cartesian coordinates are considered to solve the singularity problem at the origin. Second, the new multiple sliding surfaces are designed with the SMC and approach angle concept to solve the under-actuated property. Third, the switching control system is designed to improve tracking performance. To prove the stability of the proposed switching system under the arbitrary switching, the Lyapunov stability analysis method with the common Lyapunov function is used. Finally, the computer simulations are performed to demonstrate the performance, effectiveness and stability of the proposed tracking controller of a surface vessel.