• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.40-45
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• 2019

This paper is a purpose to study the failure example for heavy-duty vehicle fire. The first example, the researcher found the engine over-heating phenomenon causing a coolant leakage by the sealing poor of head-gasket because of D-ring part deformation contacting with cylinder liner top-part and cylinder head. He certified a fire breakout by short transferred to surrounding wiring of air-cleaner. The second example, a brake lining by return fault of break operating S cam causing with much wear of a rear 4 wheel brake lining repeatably was worn by friction. In the long run, it became the cause of fire. The third example, the researcher knew the fire cause was came about the short of wire by overload of tilting motor when the driver tilted up the cap to inspect a engine. Therefore, a heavy-duty fire must minimize the fire occurrence by thorough controlling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.74-79
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• 2019

The military vehicle produces electric power through an engine-integrated serial hybrid generator that is connected to the engine and does not have a separate generator installation space. However, depending on the mechanical characteristics of the connection between the generator and the engine, iron oxide for internal rusting and lubrication grew scattered. The iron oxide is adhered to the starter to deteriorate the starting performance, and there is a problem that the noise of the leg due to wear of the gear is increased. To solve this problem, the connection spline material and the surface treatment of the engine were improved and the shape was changed to a grease sealing type to prevent the generation of iron oxide inside. As the shape of the generator connector composing the shafting system was changed, the integrity of the structure was confirmed through the torsional endurance test. In addition, through the actual vehicle load test, it was verified that no corrosion occurred during the target life span without internal corrosion. It was confirmed that the anti-scattering structure of the grease effectively suppresses the generation of iron oxide, thereby reducing the noise generated from the generator. In this paper, we propose a fundamental solution to the degradation of the starter and the noise generation by preventing the back corrosion caused by the serial hybrid generator installed between the engine and the transmission.

• Journal of Korea Technology Innovation Society
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• v.22 no.2
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• pp.159-185
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• 2019

Chemical industry, as one of the basis industries of the country, is characterized by converged high-end technology and large scale capital investment. In 2018, the government announced "The Strategy for Chemical Industry Development" with the vision of 'An Upgrade to the Advanced Chemical Industry'. In the meantime, the advanced chemical industry in Korea has been developed not by its own R&D, but by the upgrading of technologies and processes through the technology transfer from developed countries. The method of technology transfer was mainly achieved with international joint ventures (hereafter IJV) linked with technology transferors from developed countries. As it is necessary to grasp the determinants of the technology transfer and their importance to promote the transfers through IJVs, this relative importance analysis study was conducted by using the method of quantifying experts' opinions (AHP) on the determinants of the technology transfer of both parties. As a result of the analysis, in the Hierarchy1(PEST factors), the technology transferees focus on economic factors such as 'profitability of technology transfer' and 'cost efficiency', while technology transferors considered technical factors such as 'operational excellence (abilities to continuously improve technology process)'. In addition, transferors and transferees have different priorities for technology transfer determinants in all areas of Hierarchy 2 (sub-determinants). This suggests that Korean government or enterprise should shift the policy direction toward 'technology-oriented' when they promote advanced-technology transfer through IJVs.

• Journal of Music and Human Behavior
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• v.16 no.1
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• pp.89-117
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• 2019

The purpose of this study was to explore and better understand special education music teachers' perceptions of their music curriculum. For this purpose, we conducted a focus group interview with seven special education music teachers. During the interview, four major themes and 14 sub-themes were identified. The main themes were the following: (a) types of applied activities and the goals of music classes (e.g., activities to be applied in various ways depending on the characteristics of the disability and intended outcome), (b) difficulty in implementing the music curriculum (e.g., lack of fit between textbook and students' chronological ages, lack of time and focus, self-evaluation of performance as a music teacher, (c) therapeutic experiences during music classes (e.g., expectation for positive effects through music therapy, joy of witnessing changes in students, and sense of togetherness), and (d) obstacles to the therapeutic approach of music classes and need for support (e.g., lack of professional knowledge regarding therapeutic approaches and problems with administrators and school environment). Based on these results, problems in implementing the music therapy approach as part of the music curriculum in special education schools are discussed and practical solutions for educators are offered.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.345-353
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• 2021

This study examined the effects of social capital on psychological identity and practical wellbeing for the Korean baby boom generation. To achieve this, an empirical survey was carried out on baby boomers who use elderly welfare centers and cultural centers living in D City. The overall research results showed that trust (t=6.893, p<.05), participation (t=5.157, p<.05), network (t=8.093, p<.05), and norm and reciprocity (t=4.787, p<.05), as sub-factors of social capital for baby boomers, had a significant effect on their practical wellbeing. Psychological identity was moderated (t=2.023, p<.05) in the effect of trust on practical wellbeing, adopting the hypothesis. This means that the social ties and the strong trust relationship between family members and relatives, which built up amid rapid economic growth, work with positive expectations of social capital and have a major effect on practical wellbeing. Moreover, practical welling also rated high, along with the high trust relationship and psychological identity. Consequently, various exchange programs and group and volunteer activity programs for baby boomers should be established to decrease their psychological identity due to the loss of social roles. Moreover, the decline of activities at a time of retirement can slow practical wellbeing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.345-353
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• 2021

This study examined the level of resilience and forgiveness, which are important factors of the future competencies of university students. First, a liberal arts course based on mindfulness theory, "Future Society and understanding of the human mind," was developed with expert validity. This class was opened as a liberal arts class. A test of resilience test and forgiveness scale were conducted before and after the class to determine if there was any change in the level of resilience and forgiveness of university students. There were 18 students in the experimental group and 21 general students in the control group attending S University in Seoul. In both groups, a structured resilience test and forgiveness scale were conducted before and after the experiment. SPSS 20.0 program was used for data processing, and the effectiveness was analyzed using a t-test, paired t-test, and cohen d score for the effect size. The group that showed an effect was verified by confirming the effect size to determine if it was meaningful. The analysis revealed a significant difference in the total resilience score and the sub-factors in positivity and control ability.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.349-355
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• 2021

The effect of night temperature was investigated on mango (Mangifera indica cv. Irwin) for setting appropriate night temperature and managing mango cultivation in a greenhouse. Different night temperatures (10, 15, and 20℃) were treated from budding to fruit development in mango trees. As night temperature increased, the initiation of flowering, full blooming, fruiting, and fruit development tended to be accelerated. There were no significant differences in the growth of shoots flushed after the fruit harvest among trees treated with different night temperatures. The lengths of the flower stalk were the shortest at 10℃ of night temperature; however, there were no significant differences between 15℃ and 20℃ of the night temperature. The length, diameter, and weight of mango fruits were higher at 15℃ and 20℃ than 10℃. Soluble solid contents and acidities showed no difference; the firmness and skin color were better as the night temperature increased. Accordingly, setting the minimum night temperatures to 15℃ or 20℃ can increase the number of fruits and produce high-quality fruits when cultivating mango in the greenhouse. Even the minimum night temperature to 15℃ can reduce heating costs in the greenhouse.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.204-214
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• 2022

Objective : Osteoporosis result from age-related decline in the number of osteoblast progenitors in the bone marrow. Probiotics have beneficial effects on the host, when administered in appropriate amounts. This study investigated the effects of probiotics expressing specific genes, especially the effects of genetically modified bone morphogenetic protein (BMP)-2-expressing Lactobacillus plantarum CJNU 3003 (LP) on ovariectomized rats. Methods : Twenty-eight female Wistar rats (250-300 g, 12 weeks old) were divided into four groups : the sham (control), the ovariectomy (OVX)-induced osteoporosis group (OVX), the OVX and LP (OVX/LP), OVX and genetically modified BMP-2-expressing LP (OVX/LP with BMP) groups. The three groups underwent bilateral OVX and two of these groups were administered two different types of LP via oral gavage daily. At 16 weeks post-OVX, blood was collected from the heart and the bilateral tibiae were extracted and were scanned by ex-vivo micro-computed tomography and stained with hematoxylin-and-eosin (H&E) and Masson's trichrome stain for pathological assessment. The serum levels of osteocalcin (OC), rat C-telopeptide of type I collagen (CTX-I), BMP-2, and receptor activator of nuclear factor-ĸB ligand (RANKL) were measured. Results : The 3D-micro-computed tomography images showed that the trabecular structure in the OVX/LP with BMP group was maintained compared with OVX and OVX/LP groups. No significant differences were detected in trabecular thickness (Tb.Th) between control and OVX/LP with BMP groups (p>0.05). Furthermore, a tendency toward increased BMD, trabecular bone volume, Tb.Th, and trabecular number and decreased trabecular separation was found in rats in the OVX/LP with BMP groups when compared with the OVX and OVX/LP groups (p>0.05). The H&E and Masson's trichrome stained sections showed a thicker trabecular bone in the OVX/LP with BMP group compared with the OVX and OVX/LP groups. There was no difference in serum levels of OC, CTX and RANKL control and OVX/LP with BMP groups (p>0.05). In contrast, significant differences were found in OC and CTX-1 levels between the OVX and OVX/LP with BMP groups (p<0.05). Conclusion : Our results showed that the expression of genetically modified BMP-2 showed inhibition effect for bone loss in a rat model of osteoporosis.

• Korean Journal of Culture and Social Issue
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• v.28 no.4
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• pp.627-659
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• 2022

This study aimed to translate and validate the Positive and Negative Ex-Relationship Thoughts (PANERT), a scale measuring the positive and negative valence of thoughts about past relationships in early adulthood. For this purpose, PANERT was translated into Korean and the study surveyed on 337 single male and female adults in their 20. Then, the gender difference between major variables was analyzed. After going through item analysis, all twelve original items were used to construct the Korean version of PANERT. The confirmatory factor analysis(CFA) supported the two factors structure of the Korean version of PANERT: positive vs, negative thought content valence. Also, the reliability coefficients of each two factors were all satisfactory. As a result of a correlation analysis, the criterion-related validity of the two sub-factors was good with other related scales(Intrusive rumination scale of K-ERRI, K-DASS-21-D, and K-PANAS-Revised) except for changes of self-perception. Finally, the research model was built to examine the mediating effect of two affect responses(positive and negative) in the relationship between two thought content valences and depression. In this process, the convergence and discriminant validity of the Korean version of PANERT were confirmed and the indirect effect was also confirmed in the structural equation model. In conclusion, the Korean version of PANERT consists of two factors and twelve items in total. Also, it is a reliable and valid tool for measuring the thought content valences in the romantic relationship breakup experience of early adults.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.3
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• pp.119-126
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• 2023

Sarcopenia is not well known enough to be classified as a disease in 2021 in Korea, but it is recognized as a social problem in developed countries that have entered an aging society. The diagnosis of sarcopenia follows the international standard guidelines presented by the European Working Group for Sarcopenia in Older People (EWGSOP) and the d Asian Working Group for Sarcopenia (AWGS). Recently, it is recommended to evaluate muscle function by using physical performance evaluation, walking speed measurement, and standing test in addition to absolute muscle mass as a diagnostic method. As a representative method for measuring muscle mass, the body composition analysis method using DEXA has been formally implemented in clinical practice. In addition, various studies for measuring muscle mass using abdominal images of MRI or CT are being actively conducted. In this paper, we develop an AI image segmentation model based on abdominal images of CT with a relatively short imaging time for the diagnosis of sarcopenia and describe the multicenter validation. We developed an artificial intelligence model using U-Net that can automatically segment muscle, subcutaneous fat, and visceral fat by selecting the L3 region from the CT image. Also, to evaluate the performance of the model, internal verification was performed by calculating the intersection over union (IOU) of the partitioned area, and the results of external verification using data from other hospitals are shown. Based on the verification results, we tried to review and supplement the problems and solutions.