• Tunnel and Underground Space
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• v.33 no.6
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• pp.519-533
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• 2023

In this study, the linear cutting tests of pick cutters were carried out on a granitic rock with the average compressive strength over 100 MPa. From the tests, the correlation between the cutter acting force and the temperature measured by infrared thermal imaging camera during rock cutting was analyzed. In every experimental condition, the maximum temperature was measured at the rock surface where the chipping occurred, and the temperature generated in the rock was closely correlated with the cutter acting force. On the other hand, the temperature of a pick cutter increased up to only 36℃ above the ambient temperature, and the correlation with the cutter force was not obvious. This can be attributed to the short cutting distance under laboratory conditions and the high thermal conductivity of the tungsten carbide inserts. However, the relatively high temperature of the tungsten carbide inserts was found to be maintained. Therefore, it is recommended that a reinforcement between the insert and the head of a pick cutter or the quality improvement of silvering brazing in the production of a cutter is necessary to maintain the high cutting performance of a pick cutter.

• Korean Journal of Culture and Social Issue
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• v.15 no.1
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• pp.169-186
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• 2009

This study aims to investigate the relationship between personality, especially temperament and subjective well-being. The participants were 681 college students (211 males and 470 females), whose ages ranged from 17 to 37 (M=20.91, SD=2.36). The instruments utilized in the present study were Korean Version of BAS/BIS Scale, The Big Five Locator, Satisfaction with Life Scale, Life Satisfaction Motivation Scale, Life Satisfaction Expectancy Scale, Emotion Frequency Test, and Subjective Happiness Scale. Result indicated that women expected more positive future than men did, while no gender differences were found in any other well-being variables. Correlational analyses revealed that emotional stability and extroversion were closely associated with life satisfaction, happiness, positive and negative emotion, whereas behavioral activation system (BAS) and behavioral inhibition system (BIS) were more closely associated with motivation to live and expectancy of satisfactory life. There was close relationship between conscientiousness and subjective well-being, because they were college students. As a internal factor, personality was better predictor for subjective well-being of female students. For instance, it accounted for around 35% variance of female's subjective happiness. The present findings reiterate the role of personality in quality of life, and it was discussed with characteristics of subjects, situational factors, and previous studies.

• Journal of Mushroom
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• v.21 no.4
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• pp.261-265
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• 2023

We aimed to develop outstanding domestic varieties suitable for both columnar and cylindrical-shape substrates, aiming to replace foreign varieties. and bred a high-quality new strain named 'Charmjon', using genetic resources collected from Japan and China. The optimal cultivation temperature for Charmjon's mycelial growth was found to be 25℃, and its mycelial growth at 15℃ and 25℃ was superior to the control variety. In terms of mycelial growth characteristics based on the substrate, Charmjon exhibited excellent mycelial strength on PDA medium compared to the control variety. Through columnar and cylindrical-shape substrates cultivation, we assessed the quantity and morphological characteristics of the fruiting bodies. The results confirmed that Charmjon can be produced stably using both cultivation methods, and it showed higher yields and individual weights than the control variety. In addition, the color of the pileus was notably darker, and the shape of the pileus varied depending on the cultivation method. The test of genetic diversity revealed that Charmjon has distinct genetic characteristics compared to the control varieties.

• Animal Bioscience
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• v.37 no.3
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• pp.500-508
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• 2024

Objective: Due to current selection practices for increased egg production and peak persistency, the production profile, age at maturity, and body weight criteria for commercial layers are constantly changing. Body weight and age at the time of photostimulation will thus always be the factors that need to be adequately addressed among various production systems. The current study was carried out to determine the effects of pullets' body weight (low, medium, and heavy) on their performance, welfare, physiological response, and hormonal profile. Methods: With regard to live weight, 150 16-week-old pullets were divided into three groups using a completely randomized design (CRD) and held until the 50th week. One-way analysis of variance was used to evaluate the data under the CRD, and the least significant difference test was used to distinguish between treatment means. Results: In comparison to the medium and light birds, the heavy birds had higher body weight at maturity, an earlier age at maturity, and higher egg weight, eggshell weight, eggshell thickness, egg yolk index, breaking strength, egg surface area, egg shape index, egg volume, and hormonal profile except corticosterone. However, the medium and light birds had lower feed consumption rates per dozen eggs and per kilogram of egg mass than the heavy birds. Light birds showed greater body weight gain, egg production, and egg specific gravity than the other categories. At 20 weeks of age, physiological response, welfare aspects, and catalase were non-significant; however, at 50 weeks of age, all these factors-aside from catalase-were extremely significant. Conclusion: The findings of this study indicate that layers can function at lower body weights during photostimulation; hence, dietary regimens that result in lighter pullets may be preferable. Additionally, the welfare of the birds was not compromised by the lighter weight group.

• The Transactions of the Korea Information Processing Society
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• v.13 no.6
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• pp.243-250
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• 2024

Biomimetic robots, which emulate characteristics of biological entities such as birds or insects, have the potential to offer a tactical advantage in surveillance and reconnaissance in future battlefields. To effectively utilize these robots, it is essential to develop technologies that emulate the wing flapping of birds or the movements of cockroaches. However, this effort is complicated by the challenges associated with securing the necessary hardware and the complexities involved in software development and validation processes. In this paper, we presents the design and implementation of a multi-HILS based biomimic robot software validation testbed using modeling and simulation (M&S). By employing this testbed, developers can overcome the absence of hardware, simulate future battlefield scenarios, and conduct software development and testing. However, the multi-HILS based testbed may experience inter-device communication delays as the number of test robots increases, significantly affecting the reliability of simulation results. To address this issue, we propose the data distribution service priority (DDSP), a priority-based middleware. DDSP demonstrates an average delay reduction of 1.95 ms compared to the existing DDS, ensuring the required data transmission quality for the testbed.

• Journal of the Korean Geosynthetics Society
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• v.23 no.2
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• pp.63-75
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• 2024

Drinking water is an essential element to ensure the basic human right to live, and the quality of clean water must always be ensured. However, domestic water facilities, which were installed intensively in the early 2000s, are deteriorating. The accidents such as discoloration of water such as chromaticity and turbidity as well as leakage of substances frequently occur. However, since it is virtually impossible to replace all water pipes, the detailed standards for maintenance of water pipe network facilities established in 2021 require water pipe cleaning. The swab pig method, one of the water pipe cleaning methods, is a method of physically removing substances in pipes and is evaluated as having the highest cleaning efficiency. However, Swab is highly likely to be damaged or deformed during the cleaning process, and may even be lost. Therefore, in this study, the material of the pig was changed to a material with high compressibility, and it was made as close as possible to the inner wall of the water pipe. And, to maximize cleaning efficiency, a rotation swab pig with a rotation blade was developed. In addition, high-strength wire and winding equipment were additionally developed to eliminate the possibility of loss and to determine the location of the pig. The inlet and outlet are connected with wires, and after verifying the performance of each detailed technology, the technology was applied on a test bed with a 30m section. As a result of the application, the performance of the technology was verified by measuring the process time and evaluating applicability.

• Journal of The Korean Association For Science Education
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• v.26 no.4
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• pp.527-536
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• 2006

This study investigated the components of science teacher professionalism, the meaning of PCK (Pedagogical Content Knowledge), examples of science PCK, and complementary measures that should be taken to improve teacher professionalism. Six science teachers recommended by their colleagues explained that the science teacher's professionalism (or professional knowledge) consists of science content knowledge, knowledge about teaching, knowledge about learners, and improvement efforts. Science teachers' definition of PCK, which is the professional knowledge that members of the wider society expect teachers to possess, is the teacher's materialized knowledge that aims at students' understanding and PCK is the accumulated know-how of teachers as they strive to make their teaching comprehensible by students. Science teachers also contended that teachers as professionals need to complement an accountability system, acknowledgement of continuous self-developmental efforts, collegiality, and securing validity in the teacher employment test. The teachers argued that the societal recognition of teaching professionalism is essential for a high quality teaching. Suggestions for how to improve science teaching professionalism are also discussed.

• Journal of The Korean Association For Science Education
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• v.29 no.6
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• pp.639-652
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• 2009

This projects was carried out under the assumption that an appealing leadership program would lead to students' increased leadership abilities. This leadership program is comprised of 16 materials based on seven factors of leadership for the gifted and talented. More than 46% of the gifted and talented have a positive response to leadership program, and some of these gifted and talented students (14.7%) reacted negatively. According to the result of the T-Test, a survey about leadership of gifted and talented, there are meaningful differences between before and after implementing this leadership program (p<.01). Especially, the leadership quality of the gifted and talented improved effectively in communication skills(p<.01), individualized considerations(p<.01), and interpersonal skills(p<.05). But there aren't statistical differences between the primary school students and the middle school students except leadership total score(p<.05) and communication skills(p<.01). Comprehensively, the primary school students scored slightly higher than did middle school students on the seven factors of leadership. So, we need an effective guide in planning a leadership program for middle school students.

• Therapeutic Science for Rehabilitation
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• v.13 no.1
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• pp.23-34
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• 2024

Objective : This study aims to compare the awareness of adolescent occupational therapy (AOT) among university students majoring in occupational therapy (OT) in Korea and the United States through an online survey. Methods : This online survey was conducted from January 9 to 13, 2023 to investigate the awareness about AOT among 55 students majoring in OT in Korea and the United States. An online survey was formulated in Korean and English. Data analysis was performed using descriptive statistics and an independent t-test. Results : In response to the question "Have you ever heard of AOT?", 65.5% of Korean students answered yes and 58.2% of the United States students answered no. In both countries, the average score for the question "Can AOT help improve the quality of life of teenagers?" was the highest, while the score for "Is AOT sufficiently advanced in your country?" was the lowest. For "Potential for future development of AOT," the scores for the two countries showed a significant difference (p < .05). Conclusion : Students in both countries acknowledged the necessity and importance of AOT, but there were differences noted in terms of prospects of the therapy.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.361-365
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• 2007

Aero-pulsation noise, generally caused by geometric asymmetry of a rotating device, is one of considerable sources of annoyance in passenger cars using the turbocharged diesel engine. Main source of this noise is the compressor wheel in the turbocharger system, and can be reduced by after-treatment devices such as silencers, but which may increase the manufacturing cost. More effective solution is to improve the geometric symmetry over all, or to control the quality of components by sorting out inferior ones. The latter is more simple and reasonable than the former in view of manufacturing. Thus, an appropriate discrimination method should be needed to evaluate aero-pulsation noise level at the production line. In this paper, we introduce the accurate method which can measure the noise level of aero-pulsation and also present its evaluation criteria. Besides verifying the reliability of a measurement system - a rig test system-, we analyze the correlation between the results from rig tests and those from vehicle tests. The gage R&R method is carried out to check the repeatability of measurements over 25 samples. From the result, we propose the standard specification which can discriminate inferior products from superior ones on the basis of aero-pulsation noise level.