• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.217-224
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• 2007

The present work addresses an experimental study on sound attenuation characteristics of silencer by live firing test. When a gun fires, there exists excessive noise which propagates as a form of blast wave. As muzzle energy of the weapon systems increases, the level of impulsive noise also increases. It is well known that the impulsive noise from a gun gives a serious damage to human bodies and structures. The adverse effects of impulsive sound also cause both social and military problems. So it is very important to study the characteristics of the impulsive sound attenuation. The live firing test is performed to evaluate the effect of four different silencers. The test result is compared with the case of bare muzzle which is not installed the silencer. The frequency characteristics are also analyzed to investigate the diminution of sound pressure level. The results of this study will be helpful to the designing silencer for large caliber weapon systems.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.755-760
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• 2008

The aim of this study was to produce resistant starch preparations from acid-modified com starches prepared at various hydrolysis levels (0.5-4.0 hr). Effect of autoclaving cycles on resistant starch (RS) formation was investigated. Molecular weight distribution, pasting and functional properties of acid-modified com starches were determined. For RS formation native and acid-modified starch samples were gelatinized and autoclaved (1 or 2 cycles). While native and acid-modified starches did not contain any RS, the levels increased to 9.0-13.5% as a result of storage at $95^{\circ}C$ after first autoclaving cycle. Second autoclaving cycle together with storage at $95^{\circ}C$ brought final RS contents of the samples incubated at 4 and $95^{\circ}C$ after the first cycle to comparable level. As acid modification level increased, the amount of high molecular weight fractions decreased, resulting in significant decreases in viscosities (p<0.05). The samples produced in this study had low emulsion stability and capacity values.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.10
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• pp.115-127
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• 2022

The study's goal was to investigate the levels of employee loyalty (EL) in two Thai railway rolling stock maintenance (RRSM) companies. Simple random sampling was used to obtain a final sample of 118 individuals from October 2021 through December 2021. The research instrument was a questionnaire with an expert IOC value between 0.67 to 1.00 and a questionnaire reliability Alpha (𝛼) average value of 0.82. Descriptive statistics included the mean and standard deviation (SD). SPSS for Windows Version 21 and Multiple Regression Analysis (MRA) was used for the analysis. Results showed that the 118 employee's overall perceptions of their RRSM employers' motivating factors, human resource management, satisfaction, and loyalty were high. HRM's performance evaluation had the most significant overall influence on EL. Moreover, from the analysis of the five EL questionnaire items, the most influential item was the employee's income as a contributing factor to their EL. This was followed by the suitability of their work. Also, it seems the employees had a high level of loyalty to their firms even if a better offer of more money was made. They also indicated a high level of pride in their respective firms.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.23-26
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• 2002

The generation of wastewood is currently about 40% level of the amount of domestic wood use. When the rate of wood self-supply is considered, the recycling of wastewood in wood panel products industry should be encouraged. This study was evaluated the performance of particleboard (PB) made from wastewood. PBs were manufactured with the synthesized urea-formaldehyde resin at 5 minutes hot-press time, and at 162℃ press temperature with 6 percent resin solids level on an ovendry wastewood particle weight basis. The PBs were tested by the procedure of ASTM D 1037. Test results exceeded the minimum strength requirement according to KS F 3104 Particleboard type 8.0. The PB's performance showed that wastewood is suitable raw material for PB.

• Educational Technology International
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• v.7 no.1
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• pp.59-79
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• 2006

The purpose of this study is to measure the impact of motivation on academic achievement and satisfaction of adult learners in an e-Learning environment, and to come up with strategies to improve the effectiveness of e-Learning for adult learners. In order to find answer, devices were developed, tested for validity and reliability, and use for testing variables for 289 adult learners. To measure the impact of achievement motivation on learning in job training, a multiple regression analysis was performed. The analysis results show that achievement motivation has an impact on academic achievement with significance level .001, but does not have an impact on a learner's satisfaction. Further analyses on the subcategories of achievement motivation show that individual-oriented motivation affects achievement with significance level of .001, while social-oriented motivation does not. From this finding, some strategies to boost individual-oriented motivation are suggested to enhance effectiveness of job training in e-Learning environment. Further strategies to boost individual-oriented motivation should be developed by studying various aspects of e-Learning such as learning environments, learning culture, learning modes and methods, and evaluation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.301-306
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• 2023

Attention is a fundamental aspect in the cognitive process of human. Cognitive system of human body requires to focus on selected information among a vast amount of information from sensory organs. It has widely studied that various environmental factors affected the level of attention; however, few researches have aimed to the effect of direct cryotherapy. In this research, level of attention was studied comparing sub-indexes of FAIR test between groups with different duration of direct cryotheapy to the back of neck. FAIR test is a evaluation tool for visual attention consisting of three sub-indexes. Selective attention, accuracy of attention, and persistence of attention can be independently analyzed by FAIR test. In the analysis of selective attention, cryotherapy for 5 to 20 minutes showed higher result than cryotherapy for 40 minutes. In the analysis of persistence of attention, cryotherapy for 5 to 15 minutes showed higher result than cryotherapy for 40 minutes. Overall, selective attention and persistence of attention turns out to be maximized between 5 to 20 minutes of cryotherapy and tends to decrease afterwards. However, accuracy of attention does not seem to be affected by the duration of cryotherapy. Correlation between selective attention and the skin temperature by cryotherapy tends to be negative supporting the findings by ANOVA and post-hoc test. Correlation between persistence of attention and the skin temperature showed similar results.

• YAKHAK HOEJI
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• v.57 no.4
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• pp.258-264
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• 2013

Herbal medicine has been traditionally used in Asian countries for a long time. Many pharmacological effects are identified in the herbs and these herbs are believed to be safe for human. However, the safety or adverse effect of some traditional herbal medicines has not been established. We have chosen Cyperi rhizoma based on the Korea Herbal Pharmacopoeia and which have been widely used for an anti-inflammatory effect in Korea. The object of the study was to evaluate safety of Cyperi rhizoma in rats. The aqueous extract of Cyperi rhizoma was prepared according to the standard hot water extraction method of the Korea Pharmacopoeia. In the sub-chronic study, the aqueous extract of Cyperi rhizoma was orally administered once daily as 0, 125, 250, 500, 1000 and 2000 mg/kg/day to male and female F344 rats for 13 weeks. There were no treatment related abnormalities in mortality, clinical signs, food consumption, ophthalmologic examination, hematology, serum chemistry, urinalysis, gross observation, organ weight and histopathologic examination. In conclusion, The NOAEL (No Observed Adverse Effect Level) for Cyperi rhizoma aqueous extract was determined as more than 2000 mg/kg/day in the present experimental condition.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.3
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• pp.8-17
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• 2023

The current weapon system is operated as a complex weapon system with various standards and protocols applied, so there is a risk of failure in smooth information exchange during combined and joint operations on the battlefield. The interoperability of weapon systems to carry out precise strikes on key targets through rapid situational judgment between weapon systems is a key element in the conduct of war. Since the Korean military went into service, there has been a need to change the configuration and improve performance of a large number of software and hardware, but there is no verification system for the impact on interoperability, and there are no related test tools and facilities. In addition, during combined and joint training, errors frequently occur during use after arbitrarily changing the detailed operation method and software of the weapon/power support system. Therefore, periodic verification of interoperability between weapon systems is necessary. To solve this problem, rather than having people schedule an evaluation period and conduct the evaluation once, AI should continuously evaluate the interoperability between weapons and power support systems 24 hours a day to advance warfighting capabilities. To solve these problems, To this end, preliminary research was conducted to improve defense interoperability capabilities by applying natural language processing techniques (①Word2Vec model, ②FastText model, ③Swivel model) (using published algorithms and source code). Based on the results of this experiment, we would like to present a methodology (automated evaluation of interoperability requirements evaluation / level measurement through natural language processing model) to implement an automated defense interoperability evaluation tool without relying on humans.

• Economic and Environmental Geology
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• v.48 no.4
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• pp.361-369
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• 2015

Interest of unconventional Oil and Gas, which is produced in a different way, has been increasing due to exhaustion of traditional oil and gas. However production of unconventional Oil and Gas is closely related to its technology level. Accordingly in this research, we can analyze technology level of unconventional Oil and Gas with country/sector/year patent analysis. Through the result of this research, U.S is highest patent application national, patent application in oil sand is increasing. In addition, oil sands-realated patents and shale oil-realated patents applying actively in early 1970's and since the mid-1980's showed a decreasing trend. And patent application in unconventional oil and gas has been increasing due to the rise in the oil price 2000's.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1182-1193
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• 2021

The aims of this study were to develop a milk protein-based probiotic delivery system using a modified rennet-induced gelation method and to determine how the skim milk powder concentration level and pH, which can affect the rennet-induced intra- and inter-molecular association of milk proteins, affect the physicochemical properties of the probiotic delivery systems, such as the particle size, size distribution, encapsulation efficiency, and viability of probiotics in simulated gastrointestinal tract. To prepare a milk protein-based delivery system, skim milk powder was used as a source of milk proteins with various concentration levels from 3 to 10% (w/w) and rennet was added to skim milk solutions followed by adjustment of pH from 5.4 or 6.2. Lactobacillus rhamnosus GG was used as a probiotic culture. In confocal laser scanning microscopic images, globular particles with a size ranging from 10 ㎛ to 20 ㎛ were observed, indicating that milk protein-based probiotic delivery systems were successfully created. When the skim milk powder concentration was increased from 3 to 10% (w/w), the size of the delivery system was significantly (p < 0.05) increased from 27.5 to 44.4 ㎛, while a significant (p < 0.05) increase in size from 26.3 to 34.5 ㎛ was observed as the pH was increased from 5.4 to 6.4. An increase in skim milk powder concentration level and a decrease in pH led to a significant (p < 0.05) increase in the encapsulation efficiency of probiotics. The viability of probiotics in a simulated stomach condition was increased when probiotics were encapsulated in milk protein-based delivery systems. An increase in the skim milk powder concentration and a decrease in pH resulted in an increase in the viability of probiotics in simulated stomach conditions. It was concluded that the protein content by modulating skim milk powder concentration level and pH were the key manufacturing variables affecting the physicochemical properties of milk protein-based probiotic delivery systems.