• Journal of Industrial Convergence
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• v.22 no.5
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• pp.57-67
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• 2024

This study conducted to confirm the effect of college students' individual tendencies and psychological variables on the depth of chest pressure during CPR. For this, the depth of chest compression during CPR was measured after investigating individual tendencies, fatigue, performance confidence, and performance anxiety in 127 college students. Multiple linear regression analysis was performed using individual propensity and psychological variables as independent variables and chest compression depth as dependent variables to identify factors affecting chest compression depth. Pearson correlation analysis was performed to confirm the correlation between variables. As a result of the analysis, the higher the performance confidence, the deeper the chest compression depth, and the higher the performance anxiety, the lower the chest compression depth(p<0.05). The depth of chest pressure showed a positive correlation with individual tendencies, performance confidence, while it showed a negative correlation with fatigue and performance anxiety(p<0.01, p<0.05). Based on these results, it is necessary to increase performance confidence and lower performance anxiety in order to perform the correct chest compression depth. For this, various efforts such as program development, education and research are required.

• Journal of Family Resource Management and Policy Review
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• v.27 no.4
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• pp.19-33
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• 2023

The purpose of this study was to examine the mediating effect of ego resilience on the relationship between family strengths of Chinese international students and Social Networking Services(SNS) addiction tendency. The data were collected through a survey of 349 Chinese international students studying in Korea and analyzed using the SPSS Statistics version 28 program and SPSS Process Macro 4.3. The main results are as follows. First, Chinese international students exhibited higher-than-average levels of SNS addiction tendency, family strengths, and ego resilience. Second, the SNS addiction tendency of Chinese international students had a significant positive correlation with the average time spend on SNS per day. while demonstrating a negative correlation with family strengths and ego resilience. Third, the hierarchical regression analysis revelated that gender, frequency of contact with family, average time spend on SNS per day, qualitative bond as a sub variable of family strengths, and control as a sub variables of ego resilience were significant factors influencing SNS addiction tendency of Chinese international students. Fourth, the study confirmed the complete mediation of ego resilience in the effect of family strengths on SNS addiction tendency. Based on the research results, this study suggested specific directions for counseling interventions aimed at mitigating SNS addiction tendencies among Chinese international students.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.6
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• pp.541-554
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• 2023

The utilization of underground spaces in relation to tunnels and energy/waste storage is on the rise. To ensure the stability of underground spaces, it is crucial to reinforce rock fractures and discontinuities. Discontinuities, such as joints, can weaken the strength of the rock and lead to groundwater inflow into underground spaces. In order to enhance the strength and stability of the area around these discontinuities, rock grouting techniques are employed. However, during rock grouting, it is impossible to visually confirm whether the grouting material is being smoothly injected as intended. Without proper injection, the expected increases in strength, durability, and degree of consolidation may not be achieved. Therefore, it is necessary to predict in advance whether the grouting material is being injected as designed. In this study, we aimed to assess the injection performance based on injection variables such as the water/cement mixture ratio, injection pressure, and injection flow using UDEC (Universal Distinct Element Code) numerical program. Additionally, numerical results were validated by the lab experiment. The results of this study are expected to help optimize variables such as injection material properties, injection time, and pump pressure in the grouting design in the field.

• Industry Promotion Research
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• v.9 no.2
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• pp.37-44
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• 2024

This study selected the worst-case scenario for fireball and vapor cloud explosion (VCE) of a styrene monomer storage tank installed in a petrochemical production plant and performed damage prediction and accident impact analysis. The range of influence of radiant heat and overpressure due to fireball and vapor VCE during the abnormal polymerization reaction of styrene monomer, the main component of the mixed residue oil storage tank, was quantitatively analyzed by applying the e-CA accident damage prediction program. The damage impact areas of radiant heat and explosion overpressure are analyzed to have a maximum radius of 1,150m and 626m, respectively. People within 1,150m of radiant heat of 4kW/m2 may have their skin swell when exposed to it for 20 seconds. In buildings within 626m, where an explosion overpressure of 21kPa is applied, steel structures may be damaged and separated from the foundation, and people may suffer physical injuries. In the event of a fire, explosion or leak, determine the risk standards such as the degree of risk and acceptability to workers in the work place, nearby residents, or surrounding facilities due to radiant heat or overpressure, identify the hazards and risks of the materials handled, and establish an emergency response system. It is expected that it will be helpful in establishing measures to minimize damage to workplaces through improvement and investment activities.

• Research in Plant Disease
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• v.30 no.2
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• pp.194-198
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• 2024

Pathogens of fire blight can survive for a long time on pruning tools, etc., and fire blight can be spread through agricultural implements. In particular, in Korea, pruning is frequently performed to remove flowers, immature fruits, and succulent shoots, and this farm work is known to be a major factor of the spread of fire blight. Therefore, in this study, in order to completely sterilize pathogens on pruning shears, we verified the disinfection effect of disinfectants distributed domestically and used them to identify an effective disinfection method. When disinfecting by immersion after inoculating Erwinia amylovora TS3128 on the scissor blade, 70% ethanol and 1% and 0.2% sodium hypochlorite sterilized immediately 10 sec after immersion, while 30% chlorine dioxide showed little disinfection effect. When disinfecting by spraying, 70% ethanol sterilized bacteria 1 sec after spraying, but 1% and 0.2% sodium hypochlorite disinfected bacteria after 10 and 60 sec, respectively. After cutting the naturally disease occurring branches five and 100 times, the bacteria were not hardly sterilized in immersion treatment in 70% ethanol for 30 sec but perfectly disinfected over 60 sec. Considering these results, pruning shears should be disinfected by frequently immersing them in 70% ethanol for at least 60 sec during pruning work in the field.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.2
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• pp.37-48
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• 2024

Wastewater treatment plants (WWTPs) are obligated to reduce carbon emissions as a part of public sector greenhouse gas (GHG) emission reduction targets. However, Sewage Statistics(2022) shows that CO₂ emissions per wastewater treatment volumes have decreased by only 3.03 % compared to 2020, which is far from enough to meet the Nationally Determined Contribution (NDC) targets. This study aimed to find operational conditions of biological reactors that minimize total carbon footprint (CFP). Total CFP considers both direct emissions from biological processes and indirect emissions from energy consumption. A study was conducted using a computer simulation program which is called as EQPS for a 4-stage BNR WWTP. The results showed that total CFP was reduced by 10.97% compared to the design condition when the mixed liquor recirculation (MLR) was set to 100 % of the influent flow. The N₂O emission factor (EF) of the target WWTP was calculated to be 0.138-0.199 %, which is significantly lower than the IPCC default value of 1.6 %. This study proposes a method to minimize total CFP in WWTPs by optimizing biological reactor operation and emphasizes the need for further research on N₂O emission reduction.

• Journal of Industrial Convergence
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• v.22 no.6
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• pp.81-88
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• 2024

The purpose of this study is to provide academic basic data by identifying the effects of active seniors' online video physical activity on physical self-perception and successful aging. In order to achieve the purpose of this study, 10 active seniors in D city were selected, and after receiving consent to participate in online video physical activity, it was divided into pre and post, and from March 14 to April 22, 2022, Kakao Talk group chat was opened to watch online physical activity videos during the 12th session, download 2 videos a week, and exercise from Monday to Friday. To solve the research problem, frequency analysis and paired t-test were conducted using the SPSS Ver20.0 statistical program. As a result, first, as a result of analyzing the pre- and post-tests of physical self-perception through physical activity of active seniors, all of face satisfaction, body satisfaction, change in physical strength, and change in disease increased on average. Second, as a result of pre- and post-analysis of active seniors' successful aging through physical activity, acceptance of others, orientation toward self-fulfillment, self-acceptance, and satisfaction with children increased, but autonomous life and active participation in life decreased. Through these results, in the COVID-19 period, when activities were restricted due to social distancing, active seniors' online video physical activity has a positive effect on physical self-perception and successful aging, and various programs that can be active on their own should be developed in the future.

• Food Science and Preservation
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• v.30 no.4
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• pp.630-641
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• 2023

The quality characteristics of muffins with different types of rice flour, such as soft flour (CON), soft rice flour (SRF), floury rice flour (FRF), and rice flour (RF) were assessed by using Image J program, which includes their particle size analysis, moisture content, pH, color, specific volume, baking loss rate, texture. (D[4, 3]) is weighted mean diameter, which is directly obtained in particle size measurements showed large values in the order of rice flour, floury rice flour, soft rice flour, and soft flour. The moisture content was high in the CON and SRF groups with small particle sizes. There was no significant difference in pH, L and b value. The a value was significantly low only in the RF group with large particle size. The smaller the particle size, the higher the specific volume and baking loss rate. Image J showed that the number of pores decreased when fewer smaller particles were the powder, but the pores were larger. Among the rice flours, the SRF group, excluding the CON group, scored high in all the acceptability elements. The results from this study can be used as basic data that can contribute to research on various rice-processed foods.

• Journal of Korean Society of Disaster and Security
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• v.17 no.1
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• pp.1-8
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• 2024

In Korea, mountainous areas cover 60% of the land, leading to increased factors such as concentrated heavy rainfall and typhoons, which can result in debris flow and landslide. Despite the high risk of disasters like landslides and debris flow, there has been a tendency in most regions to focus more on post-damage recovery rather than preventing damage. Therefore, in this study, precise topographic data was constructed by conducting on-site surveys and drone measurements in areas where debris flow actually occurred, to analyze the risk zones for such events. The numerical analysis program RAMMS model was utilized to perform debris flow analysis on the areas prone to debris flow, and the actual distribution of debris flow was compared and analyzed to evaluate the applicability of the model. As a result, the debris flow generation area calculated by the RAMMS model was found to be 18% larger than the actual area, and the travel distance was estimated to be 10% smaller. However, the simulated shape of debris flow generation and the path of movement calculated by the model closely resembled the actual data. In the future, we aim to conduct additional research, including model verification suitable for domestic conditions and the selection of areas for damage prediction through debris flow analysis in unmeasured watersheds.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.91-103
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• 2024

This study conducted surveys and in-depth interviews to explore the perception of sports psychology counseling among athletes. The participants included a total of 8 individuals: 307 athletes surveyed, 4 athletes who had received counseling, and 4 who had not. The survey investigated athletes' perceptions and management of psychological training, the perceived necessity of seeking advice for everyday concerns, willingness to use and perceived need for sports psychology counseling, prior experiences, and pre-engagement considerations. According to the survey results, 69.1% of athletes recognized the importance of mental training, but only 33.2% actually underwent psychological training. Furthermore, while 67.8% expressed a desire to receive education on psychological training from professionals, only 19.9% reported having searched for related information. When asked about their willingness to pay for sports psychology counseling services, 55.7% expressed willingness. Reasons for wanting to receive counseling, reasons for not wanting to receive counseling, and preferences or considerations for counseling sessions were listed as well. In the in-depth interviews, participants were classified into those who had received counseling and those who had not, delving deeply into motivations for seeking counseling or reasons for not doing so, perceptions during counseling sessions, considerations, preferred types of counselors, and program preferences. Based on this research, discussions and recommendations were provided with the perspective of utilizing sports psychology counseling as foundational data for providing high-quality services to users.