• Journal of Power Electronics
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• v.16 no.4
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• pp.1551-1564
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• 2016

The high penetration level of inverter-based distributed generation (DG) power plants is challenging the low-voltage ride-through requirements, especially under unbalanced voltage sags. Recently, a flexible injection of both positive- (PS) and negative-sequence (NS) reactive currents has been suggested for the next generation of grid codes. This can enhance the ancillary services for voltage support at the point of common coupling (PCC). In light of this, considering distant grid faults that occur in a mainly inductive grid, this paper proposes a complete voltage support control scheme for the interface inverters of medium or high-rated DG power plants. The first contribution is the development of a reactive current reference generator combining PS and NS, with a feature to increase the PS voltage and simultaneously decrease the NS voltage, to mitigate voltage imbalance. The second contribution is the design of a voltage support control loop with two flexible PCC voltage set points, which can ensure continuous operation within the limits required in grid codes. In addition, a current saturation strategy is also considered for deep voltage sags to avoid overcurrent protection. Finally, simulation and experimental results are presented to validate the effectiveness of the proposed control scheme.

• Journal of Korean Academy of Nursing
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• v.47 no.1
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• pp.39-48
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• 2017

Purpose: The purpose of this study was to verify the relationships among social support, resilience and post traumatic stress disorder (PTSD), and especially to identify factors influencing PTSD in police crime scene investigators. Methods: A cross-sectional design was used, with a convenience sample of 226 police crime scene investigators from 7 Metropolitan Police Agencies. Data were collected through self-report questionnaires during July and August, 2015. Data were analyzed using t-test, ${\chi}^2$-test, Fisher's exact test, and binary logistic regression analysis with SPSS/WIN 21.0 program. Results: The mean score for PTSD in police crime scene investigators was 13.69 .11 points. Of the crime scene investigators 181 (80.1%) were in the low-risk group and 45 (19.9%) in high-risk group. Social support (t=5.68, p<.001) and resilience (t=5.47, p<.001) were higher in the low-risk group compared to the high-risk group. Logistic regression analysis showed that resilience (OR=4.74, 95% CI: 1.57~14.35), and social support (OR=2.13, 95% CI: 1.23~3.69) are effect factors for PTSD low group. Conclusion: For effective improvement of PTSD in police crime scene investigators, intervention programs including social support and strategies to increase should be established.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.226-236
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• 2021

The purpose of this study was to investigate the effect of social support on suicidal ideation among the elderly at welfare centers through the mediating effect of avoidance coping style. This is a descriptive research survey of 392 elderly people at four elderly welfare centers located in G city. Data were collected from October 21 to November 8, 2019, and analyzed using the IBM SPSS/win 26.0 program by t-test, ANOVA, and the Pearson's correlation coefficient. The mediating effect was analyzed by multiple regression analysis according to Baron and Kenny's 3-step analysis procedure. Social support of the subjects was found to be high with an average score of 5.73±1.23, avoidance coping style with 12.53±3.47 points, and suicidal ideations with 6.21±2.06 points. In the correlation between the variables, suicidal ideations were negatively correlated with social support (r=-.146, p=.004) and avoidance coping style (r=.315, p<.001), and these correlations were statistically significant. There was a positive correlation. The avoidance coping style of the elderly using the welfare centers was found to partially mediate the relationship between social support and suicidal ideation (Z=-.270, p<.001). Therefore, to prevent negative emotions such as suicidal ideations in the elderly, various policies and support programs at the local and government level should be continuously implemented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.129-139
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• 2004

This paper studies the support region of an optimum (minimum mean-squre error) fixed-rate scalar quantizer for a Weibull source. The support region is defined to be the interval determined by the outermost thresholds of a quantizer and plays an important role in its performance, and hence it motivates this study. The paper reports the following specific results. First, approximation formulas are derived for the outermost thresholds of optimum scalar quantizers for a Weibull distributions. Second, in the case of Rayleigh and exponential distributions the derived approximation formulas are compared for the evaluation of their accuracy with the true values of optimum quantizers. Numerical results show that the formula for the leftmost threshold stays within 1% of the true value for 128 and 256 quantization points or more, for Rayleigh and exponential distribution, respectively, while that for the rightmost threshold does so for 512 and 32 quantization points or more. These formulas exhibit increased accuracy with the number of quantization points. In conclusion, the formulas have high accuracy. The contribution of the paper consists in the derivation of closed accurate formulas for the support of optimum.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.83-93
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• 2020

As the importance of the biohealth industry has recently increased, innovative government support is required. However due to the limitation in the support framework, a complementary support system for commercialization is needed. This study examines the concept of TRL which the existing support being following, and investigates domestic support system and overseas support cases. It points out that the current TRL-based government support policy has limitations for the commercialization of the biohealth industry, which requires a lot of time and investment. The new concept of the support system reflecting the characteristics of the bio-industry and solving the problems of late R&D stage was proposed and connected with the policy direction. It is meaningful that the role as a guideline for overcoming the gap between research and industry for the commercialization of the biohealth.

• Women's Health Nursing
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• v.28 no.2
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• pp.134-144
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• 2022

Purpose: A descriptive correlational survey was conducted to examine nurses' attitudes and stress related to perinatal bereavement care (PBC) and their relationships, with the ultimate goal of improving nurses' capabilities related to PBC. Methods: Korean nurses (N=136) who had experienced perinatal death at least once were recruited from seven hospitals. Data were analyzed using descriptive statistics. The Korean version of Nurses' Attitudes towards Perinatal Bereavement Support was assessed in terms of three subdomains (attitudes to PBC, importance of policies related to PBC, and importance of training related to PBC), and nurses' stress was measured. Results: The participants gave high scores for the attitude-related items of "giving sufficient time to bereaved parents to mourn for their dead baby" (4.54 points) and "nurses should treat bereaved parents with respect and dignity" (4.51 points), and they perceived a high level of importance for the policy-related items of "every staff member in the hospital should understand the policies relevant for PBC" and "when nurses feel emotional exhaustion, they should seek support" (4.58 points). Nurses' attitude toward PBC was associated with the perceived importance of policies (r=.40, p<.001), the perceived importance of PBC-related training (r=.61, p<.001), and stress related to PBC (r=.29, p<.001). Nurses' perceived importance of PBC-related training was associated with stress related to PBC (r=.38, p<.001). Conclusion: Establishing hospital policies related to PBC and providing PBC training for nurses could positively affect nurses' attitudes toward PBC. A stress management program for nurses could reduce the stress caused by PBC.

• Genomics & Informatics
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• v.17 no.4
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• pp.39.1-39.20
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• 2019

Analyzing patterns in data points embedded in linear and non-linear feature spaces is considered as one of the common research problems among different research areas, for example: data mining, machine learning, pattern recognition, and multivariate analysis. In this paper, data points are heterogeneous sets of biosequences (composite data points). A composite data point is a set of ordinary data points (e.g., set of feature vectors). We theoretically extend the derivation of the largest generalized eigenvalue-based distance metric D_ij(γ₁) in any linear and non-linear feature spaces. We prove that D_ij(γ₁) is a metric under any linear and non-linear feature transformation function. We show the sufficiency and efficiency of using the decision rule $\bar{{\delta}}_{{\Xi}i}$(i.e., mean of D_ij(γ₁)) in classification of heterogeneous sets of biosequences compared with the decision rules min_𝚵iand median_𝚵i. We analyze the impact of linear and non-linear transformation functions on classifying/clustering collections of heterogeneous sets of biosequences. The impact of the length of a sequence in a heterogeneous sequence-set generated by simulation on the classification and clustering results in linear and non-linear feature spaces is empirically shown in this paper. We propose a new concept: the limiting dispersion map of the existing clusters in heterogeneous sets of biosequences embedded in linear and nonlinear feature spaces, which is based on the limiting distribution of nucleotide compositions estimated from real data sets. Finally, the empirical conclusions and the scientific evidences are deduced from the experiments to support the theoretical side stated in this paper.

• Journal of the Korean Dietetic Association
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• v.17 no.3
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• pp.229-242
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• 2011

The purpose of this study was to investigate the status of the safety system and safety education in institutional foodservices in the Changwon and Masan areas. The survey was conducted from February 1 to March 31, 2009 via questionnaires that were sent to 300 dietitians, and 142 dietitians responded. It was determined that most of the safety managers were 'dietitians (87.1%)', whereas facilities/equipment managers consisted of 'dietitians (45.7%)', 'department of facilities management in the organization (36.4%)' and 'outsourced company of facilities management (17.9%)'. Out of the 11 safety practices, seven safety practices showed less than 50% of total implementation ratio, which meant that the safety systems were not functioning properly. Except for 'non-skid shoes (85.9%)', other safety equipment was seldom used. The survey respondents recognized that safety education was very necessary (4.47 points); however, they responded so-so (3.46 points) to the question of whether or not the actual frequency and time spent on safety education were enough. The average time spent on safety education was 28 minutes 11 seconds. Regarding the difficulties in performing safety education, 'not many safety education materials and media (3.44 points)', 'not many varieties in the subjects and contents for safety education (3.40 points)', and 'not much organizational support on safety education (3.33 points)' showed higher scores than 'lack of education time due to workload (3.20 points)'. The following were cited as education materials that should be developed as it is currently difficult to obtain relevant information and data: 'root causes of musculoskeletal injury and preventive measures (15.8%)', 'healthcare and disease preventive exercises for employees who do simple and repetitive works (14.9%)', and 'instruction on safe handling of chemicals (12.7%)'

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.1057-1062
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• 2014

This paper proposes a tip-over detection method for a mobile robot using a support inscribed circle defined as an inscribed circle of a support polygon. A support polygon defined by the contact points between the robot and the terrain is often used to analyze the tip-over. For a robot moving on uneven terrain, if the intersection between the extended line of gravity from the robot's COG and the terrain is inside the support polygon, tip-over will not occur. On the contrary, if the intersection is outside, tip-over will occur. The terrain is detected by using an RGB-D sensor. The terrain is locally modeled as a plane, and thus the normal vector can be obtained at each point on the terrain. The support polygon and the terrain's normal vector are used to detect tip-over. However, tip-over cannot be detected in advance since the support polygon is determined depending on the orientation of the robot. Thus, the support polygon is approximated as its inscribed circle to detect the tip-over regardless of the robot's orientation. To verify the effectiveness of the proposed method, the experiments are carried out using a 4-wheeled robot, ERP-42, with the Xtion RGB-D sensor.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.229-236
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• 2018

In the past, technology commercialization was implemented in a narrow sense, such as technology transfer or start-up support. It has been pointed out that lack of entrepreneurial experience, failure in technology development, and insecure markets lead to failure of technology commercialization. The project supporting direct commercialization of technologies owned by academic and research institutes conjoins public funds and operating power of large enterprises to introduce a new technology commercialization model that combines commercialization technology with capital, market, and government policies. And pain points for direct commercializing technology was derived. Through research and analysis, a gap was found between the demand factors and the capability of the actors performing the technology commercialization, and it showed a significant correlation with the paint points. In consequence, measures were drawn to improve support policies to enhance the efficiency of commercialization of technologies held by universities and research institutes.