• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.72-78
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• 2023

Objectives : This study aims to identify various psychiatric symptoms and psychosomatic symptoms caused by COVID-19 infection and investigate their long-term impact. Methods : A systematic literature review was conducted, selecting papers from domestic and international databases using keywords such as "COVID-19" and "psychosomatic." A total of 16 papers, including those using structured measurement tools for psychosomatic symptoms, were included in the final analysis. Results : Psychiatric symptoms such as anxiety, depression, and somatic symptoms have been reported in acute COVID-19 infection, while long-term post-COVID symptoms include chest pain and fatigue. The frequency of long-term psychosomatic symptoms has been estimated to be 10%-20%. Factors contributing to these symptoms include psychological and social stress related to infectious diseases, gender, elderly age, a history of psychiatric disorders, and comorbid mental illnesses. It is suggested that systemic inflammation, autoimmune responses, and dysregulation of the autonomic nervous system may be involved. Conclusions : Psychosomatic symptoms arising after COVID-19 infection have a negative impact on quality of life and psychosocial functioning. Understanding and addressing psychiatric aspects are crucial for symptom prevention and treatment.

• Composites Research
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• v.12 no.4
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• pp.42-54
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• 1999

FMLC(Fiber-Metal Laminate Composites) is a new structural material combining thin metal laminate with adhesive fiber prepreg, it nearly include all the advantage of metallic materials, for example: good plasticity, impact resistance, processibility, light weight and excellent fatigue properties. This research studied the optimum design of the FMLC subject to various loading conditions using genetic algorithm. The finite element method based on the shear deformation theory was used for the analysis of FMLC. Tasi-Hill failure criterion and Miser yield criterion were taken as fitness functions of the fiber prepreg and the metal laminate, respectively. The design variables were fiber orientation angles. In genetic algorithm, the tournament selection and the uniform crossover method were used. The elitist model was also used to be effective evolution strategy and the creeping random search method was adopted in order to approach a solution with high accuracy. Optimization results were given for various loading conditions and compared with CFRP(Carbon Fiber Reinforced Plastic). The results show that the FMLC is more excellent than the CFRP in point and uniform loading conditions and it is more stable to unexpected loading because the deviation of failure index is smaller than that of CFRP.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.409-415
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• 2013

PURPOSE. The midline fracture of maxillary complete dentures is a frequently encountered complication. The purpose of this study was to assess the effect of frenulum height on midline strains of maxillary complete dentures. MATERIALS AND METHODS. A removable maxillary complete denture was fabricated and duplicated seven times. Four different labial frenulum heights were tested for stresses occurring on the palatal cameo surface. The strains were measured with strain gauges placed on 5 different locations and the stresses were calculated. To mimic occlusal forces bilaterally 100 N of load was applied from the premolar and molar region. RESULTS. A statistically significant association between the height of the labial frenulum and the calculated stresses and strains was shown (P<.05) predominantly on the midline and especially on the incisive papilla. The results showed that stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. CONCLUSION. Within the limitations of this in vitro study, it can be concluded that the stress on the anterior midline of the maxillary complete denture increases with a higher labial frenulum. Surgical or mechanical precautions should be taken to prevent short-term failure of maxillary complete dentures due to stress concentration and low cycle fatigue tendency at the labial frenulum region.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.141-147
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• 2018

To investigate the relationship between dental hygiene students' stress and college life satisfaction, 299 dental students and students in Gyeongnam area studied stress, stress response scale, and university life satisfaction. The results of systematic analysis according to the scale of stress response showed high values in fatigue, frustration, depression and anger. In addition, satisfaction with stress experienced negatively. Stress can give you a negative impact that can lead to serious illness. A systematic analysis using the stress response scale is expected to help reduce stress and improve college life satisfaction when the stress of college life is expected to increase maladjustment and dissatisfaction. We suggest the development and analysis of a stress response tool suitable for dental hygienists.

• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.117-124
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• 1989

The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan`s method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements.

• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.76-82
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• 2002

The rapid-set cement concrete causes high hydration temperature and nay result in a high drying shrinkage and shrinkage-induced cracking. This problem may be fixed by incorporating polypropylene fibers in rapid-set cement concrete, because of increased toughness, resistance to impact, corrosion, fatigue, and durability. A series of concrete drving shrinkage tests was peformed in order to investigate the shrinkage properties of polypropylene fiber reinforced concrete with experimental variables such as concrete types, fiber reinforcement, W/C ratio, with and without restraint. Uni-axially restrained bar specimens were used for the restrained shrinkage tests. The results were as follows; The dry shrinkage of rapid-set cement concrete was much lessor than that oi OPC, probably because of smaller weight reduction rate by early hydration and strength development. The constraint and bridging effects caused by polypropylene fibers were great for the rapid-setting cement concrete when compared with that of plain concrete, and this resulted In increased resistance against tensile stress and cracking.

• The Journal of the Korean dental association
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• v.57 no.12
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• pp.747-756
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• 2019

This paper reviews the adaptation accuracy and mechanical properties of currently used denture processing systems with base resin materials and introduces the latest research on the development of antimicrobial denture base resins. Poly(methyl methacrylate) has been successfully used as a dental denture base resin material by the compress-molding method and heat polymerization for a long time, but recently, new processing techniques, injection molding-methods or fluid-resin technique are also used for fabricating denture base. However, studies indicated that there was no difference between the injectionmolding and the conventional compression-molding method in terms of adaption accuracy of denture base. The fluid-resin fabrication and one injection-molding systems exhibited better adaptation accuracy than the other processing methods. Resin denture bases in the oral cavity may undergo midline fractures due to flexural fatigue from repeated masticatory loading. For those patients, impact resistant denture base resins are recommended to prevent denture fracture during service. Thermoplastic denture base resins can be helpful for patients suffering from allergic reaction to resin monomers with a soft-fit, however, thermoplastic resins with low stiffness can irritate gum tissues and accelerate abnormal alveolar ridge resorption. Moreover, due to low chemical durability in oral cavity, those should be used for a limited period of time.

• Journal of Acupuncture Research
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• v.30 no.2
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• pp.43-53
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• 2013

Objectives : The purpose of this study is to review of Clinical trials related to the treatment of chemotherapy induced-toxicity by acupuncture therapy. Methods : We searched PubMed by using word of "chemotherapy induced, acupuncture" (Limits : Full text available, 10 years, Clinical trials, Humans, English). We analyzed 15 research paper and examined published journals, years, countries, topic, study design, their results, interventions, participants and instruments of assessment. Results : Eleven journals with fifteen papers were searched. These papers were published in USA, Germany, etc. On the topic of these clinical trials, seven of them were about nausea(vomiting), two about peripheral neuropathy, two about hot flash, two about arthralgia and one about neutropenia, one about fatigue. Six of these studies were single blinded, randomized controlled trial. Twelve studies reported significant effect. The median for number of final participants was 35.5 persons. Assessment for outcomes were versatile questionnaire, nerve conduction studies, WBC, ANC, G-CSF examination, etc. Conclusions : Their median for impact factor was 3.650 and average modified Jadad score of six RCTs was 4.33. In order to provide appropriate evidence regarding the effectiveness of acupuncture in treatment for chemotherapy-induced toxicity, more rigorous and well-designed studies are necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6932-6942
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• 2014

The expressway is a key area of road networks for national industry, economics and social development. In addition, the number of lines are increasing continuously. Recently, road management policy have shown a paradigm shift to safe road, low-carbon and green etc. Nevertheless, the road condition has deteriorated dramatically by fatigue cracking, thermal cracking and weather impact. On the other hand, the budgets for highway maintenance have shrunk dramatically. In this study, an effective pavement management and maintenance process was developed to extend the pavement serviceability and pavement life to overcome the rack of budgets.

• Composites Research
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• v.29 no.5
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• pp.249-255
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• 2016

The fiber metal laminates have been widely used at aerospace industry due to outstanding fatigue characteristic, corrosion resistance and impact resistance and so forth. The objective of this research is to establish the proper manufacturing variables for enhancing the interfacial energy release rate of fiber metal laminates using Taguchi method. The major variables of the manufacturing process are surface treatment, pre-specified temperature holding time and additional pressure. In order to determine the interfacial adhesive strength, the double cantilever beam and end-notched flexure tests were conducted. Afterward, Mode I and II energy release rates at various conditions were introduced signal-to-noise ratio with respect to each condition. Finally, the most efficient manufacturing variables are recognized using larger-the-better characteristic.