• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.5
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• pp.42-46
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• 2008

The papers in preserved books and archives experience aging which was affected by a variety of factors. Thus, the studies concerning impacts of those factors on paper aging are required. In this research, a simulation of a short-time accelerated paper aging was conducted in order to examine the effects of acid and metals (alum, copper (II) sulfate, copper (II) chloride, and iron (III) chloride) on the natural paper aging for a long time. As a result of experiments, it is found that both acid and metals have impacts on paper aging. Alum resulted in the significant decrease of pH, brightness, folding endurance, and viscosity of paper. Both copper (II) chloride and iron (III) chloride also resulted in the decrease of brightness, folding endurance, and viscosity of paper. In more detail, paper aging by iron (III) chloride showed much more significant than that by copper (II) chloride. The paper aging in case of copper (II) sulfate coexisting sulfate ion, where metal absorbed moisture was higher than in case of paper treated only by alum. This result indicated that metal catalyzes paper aging by acid. Based on these results, it was revealed that both alum and metal are the major factors in paper aging. In particular, paper aging was far more accelerated in case when acid and metals existed in paper at the same time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.338-346
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• 2023

During isometric elbow flexion, forearm length should be an important factor to determine not only joint torque but also maximum endurance time (MET), when the forearm is perpendicular to the direction of the force. The purpose of this paper is to examine the effect of forearm length as an additional factor on empirical models of MET such as an exponential model and a power model during isometric elbow flexion. Thirty volunteers participated in our experiment to measure factor variables such as circumferences and lengths of their upper and lower arms. Their METs were measured according to the percent of maximum voluntary contraction intensity (%MVC). For the multiple linear regression model of ln(MET) using these measurements, significant variables could be observed in %MVC and forearm lengths (P<0.05). The empirical models were assessed by these models using forearm length as the additional factor. Mean absolute deviations (MAD) between the measured METs amd the two empirical models were about 19.4 [s], but MAD using models applied forearm lengths were reduced to about 16.2 [s]. The correlation coefficients and intraclass correlation coefficients were about 0.87, but those applied forearm lengths were increased to about 0.91. These results demonstrated that forearm length was a significant additional factor to the empirical model.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.287-295
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• 2016

Involuntary physical activity induced by the avoidance of electrical shock leads to improved endurance exercise capacity in animals. However, it remains unknown whether voluntary stand-up physical activity (SPA) without forced simulating factors improves endurance exercise capacity in animals. We examined the effects of SPA on body weight, cardiac function, and endurance exercise capacity for 12 weeks. Twelve male Sprague-Dawley rats (aged 8 weeks, n=6 per group) were randomly assigned to a control group (CON) or a voluntary SPA group. The rats were induced to perform voluntary SPA (lifting a load equal to their body weight), while the food height (18.0 cm) in cages was increased progressively by 3.5 every 4 weeks until it reached 28.5 cm for 12 weeks. The SPA group showed a lower body weight compared to the CON group, but voluntary SPA did not affect the skeletal muscle and heart weights, food intake, and echocardiography results. Although the SPA group showed higher grip strength, running time, and distance compared to the CON group, the level of irisin, corticosterone, genetic expression of mitochondrial biogenesis, and nuclei numbers were not affected. These findings show that voluntary SPA without any forced stimuli in rats can effectively reduce body weight and enhance endurance exercise capacity, suggesting that it may be an important alternative strategy to enhance endurance exercise capacity.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.103-112
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• 2018

Purpose : The purpose of this study was to determined the effects of resistance and aerobic exercise on gait ability, physical fitness and body compositions in older women. Method : The subjects were 24 older women who were randomly divided into two groups (resistance exercise, n=12, and aerobic exercise, n=12). They 65~80 years old. The subjects done the Gym-ball, Togu, and senior dance exercise three times per week-for 70 minutes each time for 16 weeks. Body compositions, physical fitness, and gait ability were measured in this study. Result : There were significantly improved the walk performance after exercise training for 16 weeks. In particular, it was more effective on resistance exercise training in older women. There were significant differences in muscle endurance, flexibility, balance, body weight, percent of body fat, and body mass index (BMI) after the exercise program. Conclusion : It was more effective improved on muscle endurance, flexibility, and balance performance after resistance exercise program than an aerobic exercise program in older women.

• The Journal of Korean Physical Therapy
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• v.10 no.1
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• pp.67-74
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• 1998

To determine the effects of exercise program which is developed to advanced the physical fitness of the old aged, mountain climbing exercise for 12 weeks was performed to the agee 60's. Studied subjects consisted with 50 na: and 50 women, aged 60's, who resided in Taejon city and had not done regular exercise. Body fat, muscle strength, body flexibility and cardiovascular endurance of them were calculated and compared before and after mountain climbing exercise for 12 weeks from September 1, 1996. Following results were obtained therefrom; Body fat reduced $2.57\%$ in made, and $2.68\%$ in female, but muscle strength was improved 3.07kg in made and 2.43kg in female. Body flexibility, tested by bend forward, was improved 2.17cm in made, and 2.32cm in female. Cardiovascular endurance, tested by 1,200m running time, was reduced 18.2 seconds in made and 15.5seconds in female. For the conclusion, there showed advancement of physical fitness after the 12 weeks mountain climbing exercise.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1311-1314
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• 2005

Recently drum washing machines are required to improve not only functions, but also endurance security. The spider is one of the major parts in a drum washing machine as a power transmission device. It is needed estimating for fatigue life because it rotates at high velocity when the drum washing machine works. In this study, we tried to estimate fatigue life of the Spider with CAE and verified the accuracy by comparing the CAE results with the experimental results. The estimation method of fatigue life for the spider with CAE will be applied to raise the efficiency of time and money in the design process of a new drum washing machine.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.4
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• pp.77-84
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• 2015

Recently, as the needs for eco-friendly aero propulsion system increase gradually, many study works have been conducted to develop the hybrid propulsion system for High Altitude Long Endurance(HALE) UAV. In this study, we analyzed both suitable energy distribution and management methodology among the total energy collected from solar cell and the total required energy of aerial vehicle and required energy of the regenerative fuel cell(RFC) for driving in the night time and optimized the energy balance mechanism based on the ascribed mission profile.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1111-1116
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• 2005

ZnO varistor ceramics added a glass-frit 0.03 $wt\%$ were fabricated with variation of sintering temperature. The sintering temperature and time were $1125^{\circ}C\~1200^{\circ}C$ and 2 h. The average grain sizes increased and the varistor voltage decreased with increasing the sintering temperature. The values of the specimen sintered at $1200^{\circ}C$ were $23.7\;{\mu}m$ and 329 V, respectively. The leakage current of all specimens was less than $1\;{\mu}A$ at DC $82\%$ of varistor voltage. The clamping voltage ratio of the specimen sintered at $1175^{\circ}C$ was 1.37. The endurance of surge current and the deviation of varistor voltage of the specimen sintered at $1175^{\circ}C$ were 6400 $A/cm^2$ and ${\Delta}-2.81\%$, respectively. After the High Temperature Load Test(HTLT) at $85^{\circ}C$ for 1000 h, the specimen sintered at $1175^{\circ}C$ showed the lowest deviation of varistor voltage of ${\Delta}-1.92\%$.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.4
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• pp.201-208
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• 2016

Non-volatile counter is a counter that maintains the value without external power supply. It has been used for the applications related to warranty issues to count and record certain events such as power cycles, operating time, hard resets, and timeouts. It has been conventionally implemented with volatile memory-based counter and battery backup or non-volatile memory such as EEPROM. Both of them have a lifetime issue due to the limited lifetime of the battery and the endurance of the non-volatile memory cells, which incurs significant redundancy in design. In this paper, we introduce a hybrid architecture of volatile (SRAM) and non-volatile memory (EEPROM) cells to achieve required lifetime of the non-volatile counter with smaller cost. We conduct a design space exploration of the proposed hybrid architecture with the parameters of various kinds of non-volatile memories. The analysis result shows that the proposed hybrid non-volatile counter can extend the lifetime up to 6 times compared to the battery-backup volatile memory-based implementation.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.611-617
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• 2009

The primary purpose of this study was to analysis quantitatively the degree of injury and/or the progress of treatment for physical impairment. This study provided a more detailed study that evaluates all test parameters including maximum grip strength, duration of operation, average grip strength, acceleration work, dynamic endurance time and percent change in static endurance. Also, a complete database management system is developed and used to store related training, evaluation, and personal information. In addition, the system is developed a grip sensor using load.cell transducer (${\leq}60kg$). The system will be efficient to operate and convenient to use, furthermore, it can be helped for understanding and analysis the progress of a patient during a doctor's rehabilitation program.