• Steel and Composite Structures
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• v.44 no.2
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• pp.271-281
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• 2022

This study discusses challenges of running expandable profile liners (EPLs) to isolate trouble zones in directional section of a deep well, and summary the expandable profile liner technology (EPLT) field trial experience. Technically, the trial result reveals that it is feasible to apply the EPLT solving lost-circulation control problem and wellbore instability in the deep directional section. Propose schemes for optimizing the EPLT operation procedure to break through the existing bottleneck of EPLT in the deep directional section. Better-performing transition joints are developed to improve EPL string reliability in high borehole curvature section. High-performing and reliable expanders reduce the number of trips, offer excellent mechanical shaping efficiency, simplify the EPLT operation procedure. Application of the expansion and repair integrated tool could minimize the risk of insufficient expansion and increase the operational length of the EPL string. The new welding process and integrated automatic welding equipment improve the welding quality and EPL string structural integrity. These optimization schemes and recent new advancements in EPLT can bring significant economic benefits and promote the application of EPLT to meet future challenges.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3544-3564
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• 2022

With the development of the NB-IoT (Narrow band Internet of Things) and smart cities, coupled with the emergence of smart smoke sensors, new requirements and issues have been introduced to study on the deployment of sensors in large spaces. Previous research mainly focuses on the optimization of wireless sensors in some monitoring environments, including three-dimensional terrain or underwater space. There are relatively few studies on the optimization deployment problem of smart smoke sensors, and leaving large spaces with obstacles such as libraries out of consideration. This paper mainly studies the deployment issue of smart smoke sensors in large spaces by considering the fire probability of fire areas and the obstacles in a monitoring area. To cope with the problems of coverage blind areas and coverage redundancy when sensors are deployed randomly in large spaces, we proposed an optimized deployment strategy of smart smoke sensors based on the PSO (Particle Swarm Optimization) algorithm. The deployment problem is transformed into a multi-objective optimization problem with many constraints of fire probability and barriers, while minimizing the deployment cost and maximizing the coverage accuracy. In this regard, we describe the structure model in large space and a coverage model firstly, then a mathematical model containing two objective functions is established. Finally, a deployment strategy based on PSO algorithm is designed, and the performance of the deployment strategy is verified by a number of simulation experiments. The obtained experimental and numerical results demonstrates that our proposed strategy can obtain better performance than uniform deployment strategies in terms of all the objectives concerned, further demonstrates the effectiveness of our strategy. Additionally, the strategy we proposed also provides theoretical guidance and a practical basis for fire emergency management and other departments to better deploy smart smoke sensors in a large space.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.381-389
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• 2021

The purpose of this study is to examine the mediating effect of perceived stress on the relationships between adult anxious attachment and smartphone addiction. To examine the relationships among variables, SPSS program and Amos program were utilized to analyze with 272 college students (male 132, female 139). The present study found a partial mediation effect of perceived stress in the relationship between anxious attachment and smatphone addiction. The result of this study implys that anxious attachment influences cognitive process and the perceived stress may precipitate smartphone addiction. This finding can contribute to the field by enlarging the depth of knowledge about risk factor affecting psychological health (i.e., smartphone addiction) of college students who are "in the beginning of adulthood period" in their lifespan. Current finding may help to providing the protection and treatment of smartphone addiction of college students and help to promote the psychological health of college students.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.39-48
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• 2022

Purpose : This study aimed to determine the experiences of the disaster response team 9 participants who participated in the disaster after the fire incident occurred in Jecheon Sports Center and their meaning and essence. Methods : Nine disaster response teams were the subjects of the study, and Individual in-depth interviews were conducted. Data were collected online between January 6 and April 30, 2021, from the software Zoom^TM. This study was conducted as a qualitative study by applying Giorgi's phenomenological experiential research method, which has an advantage in revealing the essential structure and meaning of experience. Results : Three major themes were derived from the study results: the stimulus through unfamiliar experiences, the grievances due to work environment and regional characteristics, and dullness resulting from hiding and enduring. The following 17 sub-themes were identified: learning through unfamiliar experiences, frustration due to unexpected circumstances, shock from unfamiliar experiences, doing my best in the present, confidence due to increased experience, disunified system, intervention of various interests, the atmosphere that puts responsibility on others, inactive help, unforgettable regional characteristics, working without time to settle, tolerating it in my own way, memories left in the unconsciousness, sudden suffering from memories that come to mind, movement in anxiety and tension, dullness, work with colleagues in the same situation. Conclusion : This study is meaningful in that it attempted to provide basic data in preparing a long-term strategy for effective policy direction and institutional protection based on the systematic mental health management of the disaster response team. Additionally, this study's results can be used as primary data for future research among Disaster Response Team.

• Journal of Advanced Technology Convergence
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• v.1 no.1
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• pp.1-6
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• 2022

Since 2015, the government has been making efforts to distribute Korean smart farms. However, the supply is limited to large-scale facility vegetable farms due to the limitations of technology and current cultivation research data. In addition, the efficiency and reliability compared to the introduction cost are low due to the simple application of IT technology that does not consider the crop growth and cultivation environment. Therefore, in this paper, data analysis services was performed based on public and external data. To this end, a data-based target smart farm system was designed that is suitable for the situation of farms growing in facilities. To this end, a farm risk information notification service was developed. In addition, light environment maps were provided for proper fertilization. Finally, a disease prediction model for each cultivation crop was designed using temperature and humidity information of facility farms. Through this, it was possible to implement a smart farm data service by linking and utilizing existing smart farm sensor data. In addition, economic efficiency and data reliability can be secured for data utilization.

• Archives of Craniofacial Surgery
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• v.23 no.2
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• pp.89-92
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• 2022

Post-traumatic pseudoaneurysms of internal maxillary artery are rare, but may be life-threatening. When arterial damage leads to pseudoaneurysm formation, delayed intractable epistaxis can occur. We report our experience with the diagnosis and management of a ruptured internal maxillary arterial pseudoaneurysm that was discovered preoperatively in a patient with a zygomaticomaxillary complex (ZMC) fracture. He presented to the emergency room with epistaxis, which ceased shortly, and sinus hemorrhage was observed with a fracture of the posterior maxillary wall. The patient was scheduled for open reduction and internal fixation (ORIF) of the ZMC fracture. However, immediately before surgery, uncontrolled epistaxis of unknown origin was observed. Angiography indicated a pseudoaneurysm of the posterior superior alveolar artery. Selective endovascular embolization was performed, and hemostasis was achieved. After radiologic intervention, ORIF was successfully implemented without complications. Our case shows that in patients with a posterior maxillary wall fracture, there is a risk of uncontrolled bleeding in the perioperative period that could be caused by pseudoaneurysms, which should be considered even in the absence of typical symptoms.

• Asia-Pacific Journal of Business
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• v.12 no.2
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• pp.187-203
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• 2021

Purpose - The purpose of this study is to analyze the effects of non-tariff barriers on the Free Trade Agreement. Currently, it has achieved significant export effects by signing free trade agreements with many countries in Korea. However, most countries have implemented non-tariff barriers to protect their industries. This study analyzes the effects of non-tariff barriers in counterpart countries that have signed a free trade agreement. Design/methodology/approach - For analysis, first, prior studies were summarized, and second, the current status of free trade agreements and non-tariff barriers were identified. And, based on the current situation, the relationship between non-tariff barriers and export volume was analyzed. The targets of analysis are the United States, China, and Vietnam, which are Korea's three largest exporters. As for non-tariff barriers, anti-dumping tariffs, countervailing tariffs, and emergency import restrictions were analyzed as import regulatory measures. Findings - In the case of the United States, it can be seen that the decline in textiles, steel and electronics sectors is even greater. In the case of China, it can be seen that exports declined after imposing non-tariff barriers in the steel sector. Finally, it can be seen that exports declined after Vietnam implemented a non-tariff barrier on the steel sector. It was found that non-tariff barriers offset the effects of the Free Trade Agreement. Research implications or Originality - Currently, Korea has free trade agreements with numerous countries. However, after the free trade agreement entered into force, the number of annual average import regulation investigations for Korean products is on the rise. In the end, the implementation of non-tariff barriers is offsetting the effects of free trade agreements. Therefore, when signing a free trade agreement, it is necessary to thoroughly prepare for import regulatory measures such as the insertion of provisions of non-tariff barriers.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.135-142
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• 2022

In this paper, we propose a graph-based user route control for rapidly conducting virus inspections in emergency situations (eg, COVID-19) and a framework that can simulate this on a city map. A^* and navigation mesh data structures, which are widely used pathfinding algorithms in virtual environments, are effective when applied to CS(Computer science) problems that control Agents in virtual environments because they guide only a fixed static movement path. However, it is not enough to solve the problem by applying it to the real COVID-19 environment. In particular, there are many situations to consider, such as the actual road traffic situation, the size of the hospital, the number of patients moved, and the patient processing time, rather than using only a short distance to receive a fast virus inspection.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.195-202
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• 2022

This study explored the effects of Tai Chi on cardiovascular disease(CVD) risk factors among the Korean elderly. 68 elderly were selected and divided into two groups: an experiment group(34 patients) and a control group(34 patients). The experimental group practiced Tai Chi for 60 minutes a day, five times per week for 6 weeks total. The control group continued their routine levels of activity. CVD risk factors evaluated in both groups including body mass index, fasting blood sugar, triglyceride, high density lipoprotein cholesterol(HDL-C), and low density lipoprotein cholesterol(LDL-C). Each factor was measured before and after the 6-week intervention. Results showed that the experimental group had a significant decrease in measurements of body mass index, fasting blood sugar, triglyceride, and LDL-C levels. The experimental group also had an increase HDL-C level. Based on such findings, we believe that Tai Chi exercise program would function as an effective intervention strategy for preventing CVD in the elderly. Therefore, it is recommended that health and medical service personnel should seek to apply Tai Chi intervention as a daily component of elderly care.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.205-212
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• 2023

In the modern society, the extreme weather caused by climate change has brought about exceptional damage in succession over the world due to the use of fossil fuels, and infectious diseases such as COVID-19 worsen the quality of human life. It is urgently necessary to reduce green-house gas and use new renewable energy. The global environmental pollution should be decreased by reducing the use of fossil fuels and using new renewable energy. This paper suggests a system which can function for the environment of four seasons, safety and communication, through the photovoltaic power-based intelligent CCTV, internet and WiFi, and cooling and heating systems, and can optimally manage power, through the real-time monitoring of the production and the consumption of the photovoltaic power. It suggests a hybrid generation system supporting diesel generation without discontinuation in the case of emergency such as system power outage caused by cold waves, typhoons and natural disasters in which the photovoltaic power generating system cannot be used.