• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.152-160
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• 2021

Converter steel slag(BOF slag) is a vast amount of solid waste generated in the steelmaking process which has very low utilization rate in Korea. Due to the presence of free CaO which can derive bad volume stability in BOF slag, it usually land filled. For recycling BOF and identify its applicability as fine aggregate, this study investigates the fundamental characteristics of mortar with cement replaced ferronickel slag(FNS), which has the potential to be used as a binder. The results suggest that the mineral phases of BOF slag mainly include larnite(CaSiO₄), mayenite(Ca₁₂Al₁₄O₃₃) and wuestite(FeO) while olivine crystallines are shown in FNS. The results of flow and setting time reveals that the flowability and process of hardening increased when the amount of FNS and BOF slag incorporated was increased. The length change shows that the amount of change in the length of the mortar was almost constant regardless of mix proportion while compressive strength was reduced. Micro structure test results revealed that FNS or/and BOF slag mix took a long time to react in the cement matrix to form a complete hydration products. To achieve the efficient utilization of B OF slag as construction materials, proper replacement rate is necessary.

• International Area Studies Review
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• v.13 no.2
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• pp.393-416
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• 2009

This paper explores the technology resource-based determinants influencing internationalization performance of Korean software-related new ventures. On the ground of the study by Zahra et al.(2003), this paper aims to test empirically in Korea how interaction effects of tangible and intangible technological resources, as firm capability, are related to software new ventures' internationalization performance. The test results shows that intangible technological resource represented by R&D intensity is not significantly related to internationalization performance, but reveals that intangible technological resource represented by strength of technological cooperation network and technological reputation is positively and significantly associated with internationalization performance. Internationalization performance is more significantly and positively associated with the interactions of tangible technological resource and intangible technological resource than those resources respectively. The implication for the findings in the paper is that cutting edge technological capability of software new ventures can be more closely associated with internationalization performance if those resources are fully utilized or leveraged by intangible resources acquired by cooperation with local networks and created through technological reputation of new ventures.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1501-1510
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• 2019

Objective: An experiment was conducted to evaluate genetic diversity of 26 Chinese indigenous goats by 30 microsatellite markers, and then to define conservation priorities to set up the protection programs according to the weight given to within- and between-breed genetic diversity. Methods: Twenty-six representative populations of Chinese indigenous goats, 1,351 total, were sampled from different geographic regions of China. Within-breed genetic diversity and marker polymorphism were estimated calculating the mean number of alleles, observed heterozygosities, expected heterozygosities, fixation index, effective number of alleles and allelic richness. Conservation priorities were analyzed by statistical methods. Results: A relatively high level of genetic diversity was found in twenty-four population; the exceptions were in the Daiyun and Fuqing goat populations. Within-breed kinship coefficient matrices identified seven highly inbred breeds which should be of concern. Of these, six breeds receive a negative contribution to heterozygosity when the method was based on proportional contribution to heterozygosity. Based on Weitzman or Piyasatian and Kinghorn methods, the breeds distant from others i.e. Inner Mongolia Cashmere goat, Chengdu Brown goat and Leizhou goat obtain a high ranking. Evidence from Caballero and Toro and Fabuel et al method prioritized Jining Gray goat, Liaoning Cashmere goat, and Inner Mongolia Cashmere goat, which agree with results from Kinship-based methods. Conclusion: Conservation priorities were determined according to multiple methods. Our results suggest Inner Mongolia Cashmere goat (most methods), Jining Gray goat and Liaoning Cashmere goat (high contribution to heterozygosity and total diversity) should be prioritized based on most methods. Furthermore, Daiyun goat and Shannan White goat also should be prioritized based on consideration of effective population size. However, if one breed can continually survive under changing conditions, the straightforward approach would be to increase its utilization and attraction for production via mining breed germplasm characteristics.

• The Journal of Korean society of community based occupational therapy
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• v.8 no.2
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• pp.29-37
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• 2018

Objective : Sleep disorder caused by stress or disease to elderly currently. We tried to make clear constant exercise according to exercise intensity would have effect on sleep disorder in elderly using EEG and melatonin. Methods : Thirty subjects were over 65 years old who lived a senior facility in some parts. They were able to communicate and understand the purpose of the study. They also expressed their intension to participate actively in experiment. They should have alert consciousness and orientation about time, place, and people. Sleep disorder was assessed via below 6 hr total sleep time and Pittsburge Sleep Quality Index, which was satisfied with both of criterion at the same time. Exercises composed of low intensity walking, moderate aerobic exercise, and high intensity resistance strength. We used QEEG 8-System (LAXTHA Inc. KOREA) to check wave type and Polysomnograpy (Compumedics, Australia) to test quality of sleep. and Histologic features were observed by TTC (triphenyltetrazolium chloride) staining and H & E (Hematoxylin & Eosin) staining. Results : There was a significant sleep index and change of melatonin after aerobic exercise. There was a significant SOL, S1, S2, and SWS in aerobic exercise, but there was a significant SWS in walking and resistance strength. There was a significant change of delta wave especially in frontal and temporal region between exercises. Conclusion : They had different effects according to type of exercise, when elderly who have chemical, behavioral change of circadian rhythms did exercise consistently. Aerobic exercise had more effect on sleep disorder than other exercise. Therefore, we may supply proper exercise to elderly and high quality of life.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.437-442
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• 2019

Green $BaSi_2O_2N_2:0.02Eu^{2+}$ phosphor is synthesized through a two-step solid state reaction method. The first firing is for crystallization, and the second firing is for reduction of $Eu^{3+}$ into $Eu^{2+}$ and growth of crystal grains. By thermal analysis, the three-time endothermic reaction is confirmed: pyrolysis reaction of $BaCO_3$ at $900^{\circ}C$ and phase transitions at $1,300^{\circ}C$ and $1,400^{\circ}C$. By structural analysis, it is confirmed that single phase [$BaSi_2O_2N_2$] is obtained with Cmcm space group of orthorhombic structure. After the first firing the morphology is rod-like type and, after the second firing, the morphology becomes round. Our phosphor shows a green emission with a peak position of 495 nm and a peak width of 32 nm due to the $4f^65d^1{\rightarrow}4f^7$ transition of $Eu^{2+}$ ion. An LED package (chip size $5.6{\times}3.0mm$) is fabricated with a mixture of our green $BaSi_2O_2N_2$, and yellow $Y_3Al_5O_{12}$ and red $Sr_2Si_5N_8$ phosphors. The color rendering index (90) is higher than that of the mixture without our green phosphor (82), which indicates that this is an excellent green candidate for white LEDs with a deluxe color rendering index.

• Education of Primary School Mathematics
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• v.22 no.1
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• pp.49-64
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• 2019

The purpose of the study was to examine the current status of prospective elementary school teachers' mathematical beliefs. 339 future elementary school teachers majoring in mathematics education from 4 universities participated in the study. The questionnaire used in the TEDS-M(Tatto et al., 2008) was translated into Korean for the purpose of the study. The researchers analyzed the pre-service elementary teachers' beliefs about the nature of mathematics and about mathematics learning. Also, the results of the survey was analyzed by various aspects. To determine differences between the groups, one-way analysis of variance was used. To check the relationship between beliefs about the nature of mathematics and about the mathematics learning, correlation analysis was used. The results of the study revealed that the pre-service elementary teachers tends to believe that the nature of mathematics as 'process of inquiry' rather than 'rules and procedures' which is a view that mathematics as ready-made knowledge. In addition, the pre-service elementary teachers tend to consider 'active learning' as desirable aspects in mathematics teaching-learning practice, while 'teacher's direction' was not. We found that there were statistically significant correlation between 'process of inquiry' and 'active learning' and between 'rules and procedures' and 'teacher direction'. On the basis of these results, more extensive and multifaced research on mathematical beliefs should be needed to design curriculum and plan lessons for future teachers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.137-148
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• 2019

This study was conducted to investigate the factors influencing burnout of nurses in long-term care hospitals based on the expanded JD-R model (Xanthopoulou et al, 2007). Participants were 167 nurses who worked in long-term care hospitals. The instruments used in this study were the Maslach Burnout Inventory, Copenhagen Psycho-social Questionnaire version II, Connor-Davidson Resilience Scale and the instrument developed by Thomas and Ganster (1995). Data were collected from August 25 to September 6, 2018 and analyzed based on frequency, t-tests, ANOVA, Pearson's correlation, and hierarchical regression using the SPSS WIN 23.0 program. The results were as follows: Nurses' burnout in long-term care hospitals was positively correlated with job demands (r=.24, p=.002) and negatively correlated with resilience (r=-.43, p<.001) and social support (r=-.41, p<.001). Factors influencing the level of burnout were resilience (${\beta}=-.28$, p<.001), social support (${\beta}=-.20$, p=.016), and job demands (${\beta}=.17$, p=.016) ), which together explained 32.0% of the total variance in burnout. Therefore, we strongly recommend interventions that reduce job demands and enhance resilience and social support to prevent and reduce the burnout of nurses in long-term care hospitals.

• 한국노년학
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• v.37 no.1
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• pp.125-149
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• 2017

The purpose of this study is to analyse the mediating effects of spirituality on the relationship between functional capacity and depression among the elderly. The conceptual framework was based on the integrated theory by Brief et al.(1993) to life satisfaction. The sample was collected through convenience sampling of 413 elderly persons who were 65 years of age or older drawn from senior welfare centers, community senior centers, and religious institutions in Seoul, Incheon, and Gyeonggi Province. Data analysis was performed using Structural Equation Modeling(SEM). The main findings of the present study are as following: First, spirituality had the mediated effects on which depression and IADL influenced life satisfaction. Particularly, existential spirituality on life satisfaction had larger effect size than religious spirituality. Second, the results showed that religious spirituality had positive effects on existential spirituality. These findings demonstrate that the development and implementation of programs geared for fostering religious spirituality and existential spirituality of senior citizens are needed to improve life satisfaction in the field of social welfare. To this end, the foundation of spiritual practice in the field of social work with older people should be constructed through a spirituality-related system and professional training.

• Journal of vocational education research
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• v.30 no.4
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• pp.281-300
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• 2011

This study tried to look into what are happening in the 'class for the talented in invention' using COS-R developed by VanTassel-Baska. Teaching and learning activities within the classroom were observed and analyzed in terms of teacher's observation and teacher's observation, respectively. Based on results of this study, conclusions are as follows. First, it was founded that there are some commonalities between teacher observations and student observations. Based on teacher observations, differentiated teaching activities considering individual characteristics are rarely observed, and for students, it was true. Therefore, supplying a special training program for teachers are needed in order to make teachers and students engage in changing their teaching and learning behaviors. Second, on the side of teachers, they usually emphasize the importance of curriculum planning and implementation, problem solving, creative thinking et al. However, they barely stress the characteristics of research methods, critical thinking, and considering individual characteristics and the level of intellectual ability. Third, on the side of students, they frequently respond to solving problems and critical thinking at the same degree. On the other hand, systemic efforts of considering individual differences and adapting to them have been less regarded in both teaching and learning. In sum, for the successful 'Invention gifted classroom', establishing an educational environment to consider individually guided instruction and taking a balance among various factors embedded in teaching and learning situation should be required.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.659-662
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• 2018

We report the properties of infrared photodetectors based on two kinds of quantum dots(QDs): i) 2.0 ML InAs QDs by the Stranski-Krastanov growth mode(SK QDs) and ii) sub-monolayer QDs by $4{\times}[0.3ML/1nm\;In_{0.15}Ga_{0.85}As]$ deposition(SML QDs). The QD infrared photodetector(QDIP) structure of $n^+-n^-(QDs)-n^+$ is epitaxially grown on GaAs (100) wafers using molecular-beam epitaxy. Both the bottom and top contact GaAs layers are Si doped at $2{\times}10^{18}/cm^3$. The QD layers are grown with Si doping of $2{\times}10^{17}/cm^3$ and capped by an $In_{0.15}Ga_{0.85}As$ layer at $495^{\circ}C$. The photoluminescence peak(1.24 eV) of the SML QDIP is blue-shifted with respect to that (1.04 eV) of SK QDIPs, suggesting that the electron ground state of SML QDIP is higher than that of the SK QDIP. As a result, the photoresponse regime(${\sim}9-14{\mu}m$) of the SML QDIP is longer than that (${\sim}6-12{\mu}m$) of the SK QDIP. The dark current of the SML QDIP is two orders of magnitude smaller value than that of the SK QDIP because of the inserted $Al_{0.08}Ga_{0.92}As$ layer.