• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.121-139
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• 2000

This study is to test the possibility of applying the low-molecular weighted waste cellulase, which is produced in the process of cellulase production, to paper making. After experimenting on high-crystallized non-wood fibers with beating catalyst. I got the result that the condition for the optimal effect is temperature 40~6$0^{\circ}C$, the time 90min to 120min, pH 5.0 to 6.0, the enzyme contents 0.3% and that the effect of beating such as slight reduction of fiver viscosity, increase of water retention value(WRV) and shortening of fiber length was increased with waste cellulase. Through this process, the density, folding endurance, tensile strength and burst strength of paper was remarkably increased, which is inferred to result from the increased flexibility of fiber by individual characteristics of non-wood fiber, which was high-crystallized by penetrated low-molecular weight cellulases in the fiber.

• Journal of Korean Institute of Industrial Engineers
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• v.7 no.2
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• pp.3-17
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• 1981

Isometric muscle strength has become important as it is realized that a large variation in the human exists and is affected by many personal and environmental factors. Experiments have been performed for estimating the individual capabilities of the quadriceps femoris muscle in man. The surface EMG has been recorded on the belly of the rectus femoris muscle during voluntary isometric continuous exertion at 25%, 50%, 75%, and 100% MVC. As a muscle force (% MVC) increases, the rectified mean EMG amplitude increases in a non-linear form. The rectified mean EMG amplitude also increases in a non-linear with respect to fatigue progression. As the muscle force (% MVC) increases, an endurance time of isometric exertion decreases linearly. Analysis shows that rectified mean EMG amplitude is a consistent and sensitive measure of motor unit recruitments and can be useful in estimating an individual capability of a local muscle. Further, the result satisfies the sufficient condition that type S motor units are recruited first, while large motor units are recruited progressively as the fatigue develops.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.1
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• pp.78-84
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• 1996

The presence of ammonia, usually in the form of ammonium ion ($NH_4{^+}$), can enhance bacterial growth m the distribution system and make the production of drinking water more costly if ammonium must be removed to ensure good disinfection. Removal of ammonia by biological oxidation could be economical which prevents excess chlorine dosage In this research, effects of hydraulic retention time (HRT) and media type on the ammonia removal efficiencies of submerged biofilm reactor were investigated. The biofilm reactors combined the characteristics of high biological solids capture efficiency and good hydraulic control. The results indicate that biofilms can remove over 77 percent of the ammonia with HRT of longer than 2 hr even at low temperature ranging from 14.6 to $16.6^{\circ}C$. The HRT has a significant effect on nitrification. The overall nitrification and efficiency of ammonia removal increase with increasing HRT. It has also been observed that when the fibrous media was used, the ammonia removal, nitrification rate and endurance to shock improved.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.86-89
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• 1991

In recent years, Vacuum Circuit Breaker(VCB) has been widely used to enhance the confidence and at the same time to ease maintenance of waterworks requipment as the power supply breaker of high voltage motor. When making and breaking the sources as VCB the powerful surge voltage, repetitive reignition phenomenon resulted from exceeding inter-pole endurance voltage of CB, has occured. It has transmitted to the winding of motor stator through the cable, and this surge voltage is repeated over and over again before finishing making and breaking action of CB according to cumulation of repetitive reignition surge, motor has become burned in the end. This paper describes surge voltage occuring in making and breaking of VCB as circuit parameters by transient phenonenon and examines closely the variance of peak values, wavefront-length, wavetail-length, when changing inductance and capacitance of a cable. Finally we will expect to protect motor winding breakdown from surge voltage through parallel connection of suitable-size in the motor.

• Korean Journal of Health Education and Promotion
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• v.18 no.3
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• pp.177-186
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• 2001

The purpose of this study was to investigate the of regular worksite health exercise program participation on related fitness. Subject for study were 34 middle-aged women in Kwangju-city. To achieve this, body composition, cardiopulmonary function, physical fitness of every subjects were measured before and post regular health exercise program participation during 12 week. The results of this study were as follows: 1. Regular health exercise program participation result from improving the body composition, but there is not significant different statistically(p〈.05). 2. Significant differences were observed in the cardiopulmonary function(vital capacity, VO$_2$ max) after regular exercise program during 12 week(p〈.05). 3. Significant differences were observed in the flexibility(sitting trunk flexion), abdominal endurance(sit-ups), power (standing high jump), agility(trunk reaction time) after regular exercise program during 12 week(p〈.05).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.575-580
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• 2010

This paper is to design an optimum power conversion device for the system required for development of a low cost 3-phase power inverter. For this purpose, in order to meet with endurance required by the industry, failure mode is standardized to guarantee lifetime of a power semiconductor by monitoring real time power loss and to facilitate failure mode analysis. As normality of heat loss of a power semiconductor is identified remaining in a certain range by comparing heat rise slope between that is calculated by using average current or average loss and that is measured at a heat sink, its feasibility is confirmed by experiment.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.103-111
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• 1993

There are four flexor muscles at elbow-biceps brachii, brachialis, brachioradialis, pronator teres. Muscle exertion force depends on the following conditions : elbow angle, external workload, and endurance time. The objectives of this study are to investigate the variations of the recruitment patterns of four muscles, and to analyze the changes of the role assigned to each muscle during elbow flexion. For three elbow angles, the transition point of type F motor unit of each muscle is inferred and the changes of the role assigned due to exertion level are identified by electromyographic analysis. The results showed that the recruitment pattern of biceps brachii is constant but those of other muscles are varied depending on elbow angle and exertion level. An EMG multiplexor is developed and simultaneous measurement of electromyographic signals of four elbow flexors is possible.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.781-787
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• 2011

Mine countermeasure missions(MCMs) may induce the loss of human and ship because of the covert of mine. In recent years, unmanned underwater vehicles(UUVs) have emerged as viable technical solution for conductimg underwater search, surveillance, and clearance operations in support of mine countermeasure missions because of her autonomy and long time endurance capability. This paper introduces a technical approach to mine countermeasure mission effectiveness analysis and presents some simulation-based analysis results for engineering of the UUV system definition which could be support analysis of alternatives for system definition and design.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.40-45
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• 2008

We developed small molecular organic nonvolatile $4F^2$ memory cells using metal layer evaporation followed by $O_2$ plasma oxidation. Our memory cells sandwich an upper ${\alpha}$-NPD layer, Al nanocrystals surrounded by $Al_2O_3$, and a bottom ${\alpha}$-NPD layer between top and bottom electrodes. Their nonvolatile memory characteristics are excellent: the $V_{th},\;V_p$ (program), $V_e$ (erase), memory margin ($I_{on}/I_{off}$), data retention time, and erase and program endurance were 2.6 V, 5.3 V, 8.5 V, ${\approx}1.5{\times}10^2,\;1{\times}10^5s$, and $1{\times}10^3$ cycles, respectively. They also demonstrated symmetrical current versus voltage characteristics and a reversible erase and program process, indicating potential for terabit-level nonvolatile memory.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.546-553
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• 2015

Recently, flash cache is widely adopted as the performance accelerator of legacy storage systems. Unlike other cache media, flash cache should be carefully managed as it has peculiar characteristics such as long write latency and limited P/E cycles. In particular, we make two prominent observations that can be utilized in managing flash cache. First, a serious worn-out problem happens when the working-set of a system is beyond the capacity of flash cache due to excessively frequent cache replacement. Second, more than 50% of data has no hit in flash cache as it is a second level cache. Based on these observations, we propose a cache admission control policy that does not cache data when it is first accessed, and inserts it into the cache only after its second access occurs within a certain time window. This allows the filtering of data disruptive to flash cache in terms of endurance and performance. With this policy, we prolong the lifetime of flash cache 2.3 times without any performance degradations.