• Earthquakes and Structures
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• 제17권1호
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• pp.31-37
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• 2019

This work presents a free vibration analysis of functionally graded beams by employing an original high order shear deformation theory (HSDBT). This theory use only three unknowns, but it satisfies the stress free boundary conditions on the top and bottom surfaces of the beam without requiring any shear correction factors. The mechanical properties of the beam are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. In order to investigate the free vibration response, the equations of motion for the dynamic analysis are determined via the Hamilton's principle. The Navier solution technique is adopted to derive analytical solutions for simply supported beams. The accuracy and effectiveness of proposed model are verified by comparison with previous research.

• Archives of Plastic Surgery
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• 제41권2호
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• pp.148-152
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• 2014

Background Free flap surgery for head and neck defects has gained popularity as an advanced microvascular surgical technique. The aims of this study are first, to determine whether the known risk factors such as comorbidity, tobacco use, obesity, and radiation increase the complications of a free flap transfer, and second, to identify the incidence of complications in a radial forearm free flap and an anterolateral thigh perforator flap. Methods We reviewed the medical records of patients with head and neck cancer who underwent reconstruction with free flap between May 1994 and May 2012 at our department of plastic and reconstructive surgery. Results The patients included 36 men and 6 women, with a mean age of 59.38 years. The most common primary tumor site was the tongue (38%). The most commonly used free flap was the radial forearm free flap (57%), followed by the anterolateral thigh perforator free flap (22%). There was no occurrence of free flap failure. In this study, risk factors of the patients did not increase the occurrence of complications. In addition, no statistically significant differences in complications were observed between the radial forearm free flap and anterolateral thigh perforator free flap. Conclusions We could conclude that the risk factors of the patient did not increase the complications of a free flap transfer. Therefore, the risk factors of patients are no longer a negative factor for a free flap transfer.

• Archives of Plastic Surgery
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• 제50권3호
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• pp.315-324
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• 2023

Hemoglobinopathies such as sickle cell disease (SCD) are traditionally considered a relative contraindication to free tissue transfer, due to concerns that erythrocyte sickling will increase the risk of microvascular thrombosis and flap failure. This article describes a case report with the successful use of free tissue transfer in a patient with SCD and provides a systematic literature review on free tissue transfer in SCD. A retrospective chart review was performed of a patient with SCD who underwent free tissue transfer at the authors' institution. A systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed using the keywords "free tissue transfer," "free flap," or "microsurgery" and "sickle cell" on PubMed, Ovid/Medline, and Scopus. A 29-year-old male with delayed presentation of an electrical burn to the face and scalp underwent wound closure with a free anterolateral thigh flap. Key management principles included red blood cell transfusion to keep hemoglobin S under 30% and hemoglobin greater than 10 g/dL, maintenance of hydration, normothermia, adequate analgesia, and postoperative anticoagulation. Systematic literature review identified 7 articles describing 13 cases of free tissue transfer in 10 patients with SCD, with combined complete free flap success in 10 of the 13 flaps. Free tissue transfer can be successfully performed in patients with SCD. However, evidence on the optimal management of this unique patient population in the perioperative period after free tissue transfer is limited to case reports in the literature.

• 문화기술의 융합
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• 제10권1호
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• pp.143-152
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• 2024

코로나 19로 인해 국내 면세점산업은 큰 타격을 입었으며 언택트 시장이 확대되면서 모바일 면세점 쇼핑의 비중이 늘고 있다. 경쟁이 매우 치열한 면세점시장에서 차별화와 고객 지속사용 유도하기 위해 AR 기술을 투입하여 모바일 쇼핑뿐만 아니라 오프라인 점포 활성화에 기여할 수도 있다. 그러나 현재까지 모바일 면세점 AR 쇼핑은 활발하지 않으며, 관련 연구도 미미한 실증이다. 이에 우리는 AR 기술 투입된 모바일 면세점 쇼핑 앱의 활성화를 목적으로 외국인 사용자의 니즈를 연구하여 앱 개선방안을 제시하였다. 첫째, 모바일 면세점 앱에서 AR 쇼핑 인터페이스는 눈에 잘 띄는 위치에 있어야 열고 사용하기 편리하다. 둘째, 모든 사용자가 AR 쇼핑 인터페이스를 쉽게 인식할 수 있도록 위치와 기능에 대한 설명 또는 도움말이 있어야 한다. 셋째, AR 쇼핑 인터페이스에서 면세품을 착용하거나 관심상품 저장 및 장바구니에 추가 시 인터페이스는 간결하고 유연해야 해 사용 및 조작이 편리하다. 넷째, 오류 발생 방지를 위해 기술적 개선이 이루어져야 한다. 우리는 연구를 통해 AR 쇼핑 기술 및 국내 면세점 AR 쇼핑 기술 발전과 온·오프라인 면세점 활성화에 도움이 될 것으로 기대한다.

• Archives of Reconstructive Microsurgery
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• 제23권1호
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• pp.1-7
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• 2014

Purpose: Recent studies have reported on application of fibrin glue composed of fibrinogen and thrombin to nerve anastomosis, which can be another candidate for vessel anastomosis. However, no research regarding the risk and effectiveness of thrombin in microvascular free tissue transfer has been reported. Therefore, the aim of study is to determine the risk and effectiveness of thrombin on microvascular free tissue transfer through clinical cases. Materials and Methods: Twenty-five patients underwent free flap reconstruction for soft tissue defect or bone exposure in our institute from March 2011 to February 2014. In the group using thrombin, dissolved powder thrombin (5,000 IU/amp) was mixed with 10 mL normal saline. Saline mixed with thrombin was applied on the flap, recipient, and around vessel anastomosis. In the control group, free flap was performed using the same method, except using thrombin. We analyzed the results between the two groups. Results: All flaps survived. The group using thrombin included 14 patients and the control group included 11 patients. Hematoma was found in two cases, respectively, in each group. The group using thrombin showed lower incidence of hematoma than the control group. No difference in survival rate of the flap was observed between the thrombin group and the control group. Conclusion: Results of this study showed that use of saline mixed with thrombin in free tissue transfer may be safe and effective for prevention of hematoma formation in the recipient site.

• 동력기계공학회지
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• 제19권4호
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• pp.50-55
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• 2015

Recently, because of the deterioration of the nuclear generating station and increase of the cooler and heater, energy problem is increasing. To save the energy, the free cooling system is developed. The free cooling system is that cool the water to use cooled air in winter and is used in industrial process or data center. Yoon check the energy of free cooling system with dry cooler in korea. In this study, the value of the free cooling system with dry cooler is confirmed through using the NPV that is economic evaluation. when temperature degree of the cooled water is 10, in Chuncheon and Seoul the value is the most high. When temperature degree of the cooled water is 20, in Ulsan the value is the most high. As the result, because the using the temperature degree of the cooled water is high in the industrial process, the free cooling system is advantageous in korea.

• Archives of Plastic Surgery
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• 제42권1호
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• pp.73-77
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• 2015

The latissimus dorsi flap is popular due to the versatile nature of its applications. When used as a pedicled flap it provides a robust solution when soft tissue coverage is required following breast, thoracic and head and neck surgery. Its utilization as a free flap is extensive due to the muscle's size, constant anatomy, large caliber of the pedicle and the fact it can be used for functional muscle transfers. In facial palsy it provides the surgeon with a long neurovascular pedicle that is invaluable in situations where commonly used facial vessels are not available, in congenital cases or where previous free functional muscle transfers have been attempted, or patients where a one-stage procedure is indicated and a long nerve is required to reach the contra-lateral side. Although some facial palsy surgeons use the trans-axillary approach, an operative guide of raising the flap by this method has not been provided. A clear guide of raising the flap with the patient in the supine position is described in detail and offers the benefits of reducing the risk of potential brachial plexus injury and allows two surgical teams to work synchronously to reduce operative time.

• 센서학회지
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• 제21권2호
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• pp.156-166
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• 2012

Over the past 15 years productive BCI research programs have arisen. Current mainstream EEG electrode setups permit efficient recordings but most of electrodes has the disadventages of need for skin preparation and gel application to correctly record signals. The new gel-free probe was adapted for EEG recording and it can be fixed to the scalp with the micro needle without neuro-gel. It use standard EEG cap for wearing electrodes on scalp so it is compatible with standard EEG electrodes. A comparison between electrode characteristics is achieved by performing simultaneous recordings with the gel electrodes and gel-free probe placed in parallel scalp positions on the same anatomical regions. The quality of EEG recordings for all two types of experimental conditions is similar for gel-electrodes and gel-free probe. Subjects also reported not having special tactile sensations associated with wearing of gel-free probes. According to our results, it is expected that gel-free probe can be adapted to BCI, BMI(Brain Machine Interface), HMI(Human Machine Interface) because of its simple application and comfortable wearing process.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.539-543
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• 2012

Background: The results of the Global School Personnel Survey (GSPS) conducted in India in 2009 are compared with 2006 GSPS to assess any change in 2009 on tobacco use and knowledge and attitudes to tobacco use, training and availability of tobacco control teaching material in schools and the existence of school tobacco control policies. Methods: GSPS is a cross sectional survey conducted twice (2006 and 2009) in entire India. A total of 180 schools were surveyed each time. Results: Of the participating school personnel, 2660 in 2006 and 2575 in 2009, about 95% were teachers and the balance administrators. In 2009, compared to 2006 the prevalence of current smoking of cigarettes (19.6% in 2006 and 10.3% in 2009) and bidis (21.5% in 2006 and 13.9% in 2009) was found to be significantly lower; the percentage of teachers receiving training on preventing youth tobacco use has significantly reduced (16.7% in 2006 and 10.1% in 2009); access of teachers to educational materials on tobacco use and how to prevent its use among youth had not increased (34.6% in 2006 and 37.8% in 2009); there was no change in policy prohibiting tobacco use among students and school personnel; however, ever use of any tobacco on school premises was significantly lower (15.6% in 2006 and 9.6% in 2009). Conclusions: The prevalence of current smoking (cigarettes/bidis) among school personnel and use of any tobacco on school premises were significantly decreased in 2009 as compared to 2006. Necessary action should be planned to increase the number of teachers trained and the availability of teaching materials on preventing youth tobacco use in order to have effective prevention of tobacco use among students.

• 한국가축번식학회지
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• 제5권2호
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• pp.60-65
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• 1981