• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1062-1070
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• 2018

Purpose: We evaluated the prognostic factors of open globe injuries in children and adolescents, and compared the ocular trauma score (OTS) and pediatric penetrating ocular trauma score (POTS). Methods: We performed a retrospective review of 77 children under 18 years of age who visited our clinic with open globe injuries between May 1993 and April 2014. We investigated the factors that may affect final visual acuity. We also compared the OTS and POTS using receiver operating characteristic curves as a method to predict final visual acuity. Results: By univariate analysis, an initial visual acuity less than 20/200, globe rupture, wound size greater than 7.0 mm, retinal detachment, lens dislocation, and total number of operations contributed to worse visual outcomes (<20/200). Conversely, central corneal involvement, traumatic cataract, wound size less than 7.0 mm, and initial visual acuity greater than 20/200 were better prognostic indicators (${\geq}20/32$). Both OTS and POTS had diagnostic value as a predictor of final visual acuity, although there were no statistically significant differences between the two scoring systems. Conclusions: Initial visual acuity and wound size are important prognostic factors for the final visual acuity in children and adolescent, following open globe injuries. Both OTS and POTS are reliable prognostic models for open globe injuries in children and adolescents.

• Food Science and Preservation
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• v.18 no.6
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• pp.986-992
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• 2011

The alcohol fermentation of apple juice was optimized as a preliminary study for the production of natural apple cider vinegar. To gain an optimal fermentation yield, a central composite design was used to investigate the effects of the independent variables [initial Brix (12/14/16/18/20, $X_1$), fermentation time(48/54/60/66/72h, $X_2$), and fermentation temperature(24/26/28/30/$32^{\circ}C$, $X_3$)] on the dependent variables (alcohol content, reducing sugar, Brix, acidity). The alcohol content was 3.4-6.4%, the reducing sugar was 1.93-6.24%, and the Brix was $6.1-13.8^{\circ}$. The alcohol content was mainly affected by the fermentation temperature and increased along with the fermentation time and temperature. The amount of the reducing sugar was significantly affected by the initial Brix and fermentation temperature. The optimal conditions for the alcohol content were found to be 15.22 initial Brix, 64.97 h fermentation time, and $31.56^{\circ}C$ temperature.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.85-99
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• 2019

Startups need proper external supports to survive and build strong foundations for growth in their early stage. Accelerators help such startups by providing tangible and intangible resources. Accordingly, accelerators are creating a social environment that can effectively support the startups in the early stage, distinct from other institutions that fund or help the startups. However, the actual impact of accelerators on startups has not been yet fully scrutinized thoroughly, especially with the lack of theoretical lenses to comprehend accelerators. This paper aims to build a theoretical foundation to understand the role of accelerator, focusing on the network-based perspective. We briefly overview the concept of accelerator and the current status of the accelerator industry. Subsequently, focusing on the network that accelerators and startups create, this paper examines how the characteristics of the network relationships affect the growth and survival of the early-stage startups. Thus, by offering systematic analysis of the underlying mechanisms of the effects of the accelerators under network-based approach, this paper suggests a direction for the future empirical research on the topic of startup accelerator.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.629-638
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• 2021

This study investigated the relationships between ADHD trait, emotional music use, relationship initiation, and expectation for future life in early adolescence, and to verify path model to predict the expectation for future life. The participants were 347 male and female middle school students, their average of ages was 13.35 (SD=.91). The ADHD trait was measured with self-report scale, emotional music use and relationship initiation were measured with sub-scales of Use of Music Inventory and Interpersonal Competence Questionnaire, and expectation for future life was measured with modified items of Satisfaction with Life Scale. Results revealed that ADHD trait was negatively correlated with relationship initiation and expectation for future life, whereas emotional music use was positively correlated with relationship initiation and expectation for future life. And, relationship initiation positively correlated with expectation for future life. The alternative model was adopted that included a direct path from ADHD trait to expectation for future life in the proposed model, rather than the proposed model in which ADHD trait and emotional music use affects expectation for future life through relationship initiation. The findings of this study should provide useful information for further studies and for professionals who try to promote the expectation for future life in early adolescence.

• 한국노년학
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• v.40 no.1
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• pp.147-161
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• 2020

The purpose of this research is to investigates 10-year trajectories of cognitive functions among older adults in their 70s to understand changes in cognitive functions as a continuum until very late life. This study also examines differences in trajectories of cognitive functions by gender and by changes in marital status, especially widowhood. Among participants of the Korean Longitudinal Study of Ageing(KLoSA), the sample of this study includes 800 older adults in their 70s during the first study wave (2006) and those who reported their cognitive functions for six consecutive study waves (2006, 2008, 2010, 2012, 2014, and 2016). The analyses were conducted in two steps. First, we conducted Latent Class Growth Analyses(LCGA) to investigated heterogeneous trajectories of cognitive functions in 10 years. Then, we performed multinomial logistic regression. Three heterogeneous trajectories of cognitive functions were identified. One group of 48.7% of older adults showed high cognitive function at baseline and maintained it over 10 years. Second group of 14.7% of older adults reported low cognitive function scores at baseline and showed continuous decline over time. Third group of 36.6% were showed mid-level cognitive functions and maintained their functions over time. We also found significant gender differences but not significant differences in marital status when we consider both in our model; however, the we found significant differences in changes in marital status when we did not consider gender in the model. The results suggest that the importance of considering dynamics of gender and changes in marital status to understand changes in cognitive functions in later life.

• Geophysics and Geophysical Exploration
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• v.26 no.3
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• pp.114-125
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• 2023

The physics-informed neural network (PINN) has been proposed to overcome the limitations of various numerical methods used to solve partial differential equations (PDEs) and the drawbacks of purely data-driven machine learning. The PINN directly applies PDEs to the construction of the loss function, introducing physical constraints to machine learning training. This technique can also be applied to wave equation modeling. However, to solve the wave equation using the PINN, second-order differentiations with respect to input data must be performed during neural network training, and the resulting wavefields contain complex dynamical phenomena, requiring careful strategies. This tutorial elucidates the fundamental concepts of the PINN and discusses considerations for wave equation modeling using the PINN approach. These considerations include spatial coordinate normalization, the selection of activation functions, and strategies for incorporating physics loss. Our experimental results demonstrated that normalizing the spatial coordinates of the training data leads to a more accurate reflection of initial conditions in neural network training for wave equation modeling. Furthermore, the characteristics of various functions were compared to select an appropriate activation function for wavefield prediction using neural networks. These comparisons focused on their differentiation with respect to input data and their convergence properties. Finally, the results of two scenarios for incorporating physics loss into the loss function during neural network training were compared. Through numerical experiments, a curriculum-based learning strategy, applying physics loss after the initial training steps, was more effective than utilizing physics loss from the early training steps. In addition, the effectiveness of the PINN technique was confirmed by comparing these results with those of training without any use of physics loss.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.1
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• pp.41-47
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• 2022

In this study, rainfall water outlet water quality monitoring was performed on the C industrial complex to evaluate the characteristics of non-point pollutant runoff from the industrial complex during rainfall and to use it as basic data for calculating the load and unit of non-point pollutant. As a result of calculating EMC according to the outflow amount by rainfall event, the 1st rainfall showed EMCs ranges of BOD, COD_Mn, SS, T-N, and T-P of 1.32~48.76, 3.32~43.75, 2.89~199.43, 2.76~8.93, 0.08~068, and the 2nd rainfall was 0.5~2.9, 2.71~7.13, 2.82~174.94, 1.33~4.03, 0.01~1.28 mg/L, respectively. As a result of calculating the ratio of cumulative outflow and cumulative pollution load, most of the pollution load was less than the rainfall outflow, but over time, the initial washing phenomenon occurred as the ratio of cumulative rainfall outflow and cumulative pollution load increased to more than 1.

• Journal of Venture Innovation
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• v.5 no.3
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• pp.1-17
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• 2022

Entrepreneurs recognize that their passion was an important factor in driving successful entrepreneurship. However, they were often unaware of the impact that third-party passions related to startups have on them. Therefore, in this study, it was verified whether the accelerator incubation program had an effective effect on portfolios. At this time, I tried to do an empirical analysis focusing on how the third-party accelerator entrepreneur passion affects the entrepreneurial performance of portfolios. To this end, a survey was conducted on representatives of portfolios across the country who completed the accelerator incubation program, and empirical testing was conducted based on 330 valid ones. As a result of empirical analysis, it was confirmed that mentoring and networking among accelerator incubation programs had a positive (+) effect on entrepreneurial performance of portfolios. On the other hand, education and seed investment in the accelerator program did not significantly affect the entrepreneurial performance of portfolios. On the other hand, it was tested that accelerator entrepreneur passion significantly moderated both the incubation program elements (education, mentoring, network, seed investment) and the entrepreneurial performance of portfolios. The results of this study are meaningful in that they reveal that the passion of accelerator entrepreneurs is an important lynchpin of incubation programs and the key to success in startups. In addition, this study suggests that it is important for startups to go one step further from seed investment and properly identify the accelerator entrepreneur and his passion, the key man of accelerators.

• International Commerce and Information Review
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• v.19 no.3
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• pp.3-23
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• 2017

With the globalization of the world economy, international trade networks are expanding beyond geographical proximity, and the expansion of such trade networks is playing a role in promoting globalization. Korea has established itself as a strong FTA for the past 13 years, starting with the Korea-Chile FTA. Successful establishment of a short-term FTA network has shown positive economic effects such as increased trade volume with partner countries and market share in overseas markets. Other countries are also turning to the paradigm of economic development through the formation of a regional economic integration and a bilateral trade agreement network, and it is time to investigate new opportunities through understanding the entire RTA and FTA network. In this study, we analyzed the status of RTA and FTA from the 1960s to 2010s, analyzed network structure and centrality through SNA(social network analysis). The results of the study show that the structure of the FTA network is gradually expanding, and the FTA network, which has been expanding to the center of the early European countries, is changing toward the Asian countries such as Korea, China and Japan. As a result of the analysis of the degree of centrality, Korea was ranked as the top in all the degree of centrality(Degree, Betweenness, Closeness and Eigenvector) indicators for a short period of time and it means that Korea's FTA strategy was evaluated as very successful. This study examines the FTA among the global RTAs, assesses the structure of the FTAs and evaluates Korea's FTA strategies and the FTA network from a network perspective.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1124-1129
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• 2009

This study aims to examine the effects of non-invasive constant microcurrent stimulation on expression of Bone Morphogenetic Protein(BMP) 4 after tibia fracture in rabbits. Twenty four rabbits with tibia fracture were randomly divided into control and experimental groups. Each group was divided into four subgroups, based on the duration of the experiment (3, 7, 14, 28 days). The experimental groups received a constant microcurrent stimulation of $20{\sim}25{\mu}A$ intensity with surface Ag-AgCl electrode (diameter 1cm, Biopac, U.S.A.) for 24 hours a day. Cathode of the microcurrent stimulator located on the tibia directly, anode of it did on the gastrocnemius muscle. Rabbits were sacrificed on each of the postoperative days 3, 7, 14, 28. To investigate how non- invasive constant microcurrent stimulation affects bone healing, immunohistochemical analysis of BMP-4 was performed at each point. After evaluation, the test results are as follows: Comparisons of immunohistochemical observation of BMP-4 in 7 days after tibial fracture show that there was shown to be a moderate positive reaction (++) on concentric circles of Harversian system andt he interstitial lamella in the control group, while there was a very strong positive reaction (++++) on concentric circles of Harversian system and interstitial lamellain the experimental group. These results suggest that applying non-invasive constant microcurrent stimulation on fractured bone is helpful to bone healing.