The demand for ceramic brackets, which have a high aesthetic purpose due to their high light transmission is increasing due to the application of poly-crystalline alumina material. Brackets using this material require stable properties that should not fracture during the treatment period. In this paper, the fracture strength of a ceramic bracket made of the same material used in clinical practice was checked by applying torque with a square stainless steel wire. The wire used in the test was prepared with cross-section sizes of 017 inch ✕ 025 inch, 018 inch ✕ 025 inch, and 019 inch ✕ 025 inch. There were a total of 150 bracket specimens and after ligating wires in the slots, torque was applied to each of 75 specimens in the gingival and occlusal directions. The torque test used digital torque meter equipment and the torque value at which the bracket slot fractured due to plastic deformation of the ligated wire was confirmed. Based on the resulting data we plan to use the data to recommend stable torque use and develop future bracket design.

Background: Smartphone addiction has emerged as a significant social problem. Numerous studies have indicated the association between smartphone use and discomfort in the musculoskeletal system of the upper extremities. Objects: This cross-sectional survey aimed to compare the characteristics of musculoskeletal pain in the neck, trunk, and upper limbs between individuals with smartphone addiction and those without addiction. Methods: We collected a total of 326 healthy individuals’ data from China and Korea who had owned and used smartphones for more than 5 years between 20–50s through an online questionnaire consisting of 84 questions in four major sections. The first part contained basic information on the participant's personal characteristics and smartphones. The second part contained questions about smartphone use and posture. The third part was the smartphone addiction. The fourth part was to investigate musculoskeletal pain in various upper body parts. Results: Smartphone addiction has a weak negative correlation with age (r = –0.20, p < 0.01) and a weak positive correlation with the hours of smartphone use (r = 0.376, p < 0.01). Frequent musculoskeletal pain symptoms related to smartphone use were observed in the neck, shoulder, lower back, and wrists. The hours of smartphone use was slightly positively associated with the prevalence of musculoskeletal pain in the shoulder (r = 0.162, p < 0.05) and lower back (r = 0.125, p < 0.05). The prevalence of musculoskeletal pain in the neck (χ2 = 3.993, p < 0.05), shoulder (χ2 = 6.465, p < 0.05), and wrist (χ2 = 4.645, p < 0.05) was significantly higher among females than males. Conclusion: The results suggest that smartphone addiction should be recognized as a dual concern encompassing both physical health and psychosocial aspects. Furthermore, healthcare professionals, including physicians and physical therapists, should consider clients' smartphone usage patterns when assessing and treating with musculoskeletal pain.

Background: In terms of physical performance, elastic tape (ET) is known to contribute to injury prevention and performance enhancement. Objects: This study aimed to compare and analyze the effect on lower extremity muscle activity of young adult women with and without ET during squats. Methods: In this study, six healthy, young women were recruited as participants in a university laboratory. Participants were allocated to two groups of three after measuring muscle activity in a pre-test, and the experiment was conducted for a total of two weeks (two sessions). First, 10 half squats were taped once in the first week, and 10 half squats were performed without taping in the second week. The other group did this in reverse and measured muscle activity after the squat was over. Results: As a result of this study, there was no significant difference in the quadriceps with or without ET (Z = –0.11, p > 0.05). Similarly, no significant difference was found in hamstring (Z = –0.31, p > 0.05). Conclusion: No beneficial effect was found on changes in muscle activity following ET application during squats. Further studies require randomized controlled trials that increase the number of participants and the intensity of the intervention, and measure pain, function, and performance rather than muscle properties depending on the biomechanical lifting mechanism.

In this study, we compare and analyze stress and vertical deflectional displacement according to cross sectional shape changes of the beam using finite element analysis. The 11,000mm long horizontal beam showed stress differences depending on the cross-sectional variation, with stress differences of up to 200MPa and at least 149MPa. The deflection at the end of the beam also differed by up to 586 mm and at least 208mm. The weight change applied according to the cross-sectional shape of the steel horizontal beam was up to 235kgf, at least 144kgf, and showed the best stress and deflection characteristics in the cross sectional shape with a weight of 185kgf. This allowed us to improve structural safety through sectional shape optimization despite the weight increase.

This study covered the Mulmae, architectural drawing recorded on Yeonggeon-uigwes and Sanleung-uigwes during the late Joseon Dynasty. In uigwes, the term ‘Mulmae’ was used as a mixture until the 17th century, but from the 18th century, the term ‘Mulmae(勿乙每, 勿每, 水每)’ was unified into ‘Mulmae(水每)’. The paper of the Mulmae was made to be used during the construction period by using a thick oil paper called Yudun. Four Yudun were connected, and its size was 197.4×141cm, which was rather large. The Yingzaofashi(營造法式) of Song Dynasty describes how to draw a longitudinal section on a scale of 1/10. The scale of 1/10 was the maximum when comparing the size of the Mulmae with the buildings in uigwes. A sectional drawing of Gongpo in Geunjeongjeon was drawn on a scale of 1/10. There is a testimony that a senior carpenter drew a cross-section on a scale of 1/10. Therefore, it was determined that the scale of the longitudinal section drawn on the Mulmae paper was 1/10. The term 'the Mulmae' was used equally by carpenter active in Japanese colonial era. The scope of the painting was clarified from pillar to rafter. Uigwes records that the Mulmae was made for wood processing. Through this, it can be understood that the Mulmae painted the entire structure as a longitudinal section.

Background: Due to aging, blood flow rate decreases, also posture and chewing habit may be changed. Objective: To identify that changes in blood velocity in the common carotid arteries (CCAs) in old persons with unilateral chewing habit (UCH) and forward head posture (FHP) in the elderly. Design: An observational cross-sectional study. Methods: Chewing habits, FHP, and CCAs velocities were assessed in 85 elderly subjects. Chewing habits were measured by visual observation. CCAs measured the peak systolic velocity (PSV), end-diastolic velocity (EDV), minimum diastolic velocity, and resistivity index. The subjects were divided into UCH and bilateral chewing habit groups depending on chewing habit. The subjects were also divided into >49 degrees and <49 degrees for comparison of blood flow between the left and right CCAs. Results: In the UCH, the chewing side had significantly higher EDV (P=.003), PSV (P=.023) than the non-chewing side. There was no significant difference in velocity between the CCAs in the FHP. Conclusion: This study shows that the blood flow velocity of the chewing side of UCH was higher, and unilateral chewing affects the CCAs velocity and thus highlight the importance of chewing habit in the elderly than head posture.

본 논문에서는 Co-Rotational plane beam transient analysis EDISON program(CR-보)를 이용한 에어포일 단면형상 변화 에 따른 진동특성 연구를 수행하였다. Co-Rotational 평면 보 해석은 대 회전과 작은 변형률을 갖는 보 해석에 적합하다. 항 공기의 날개를 외팔보로 가정하여, VABS를 통한 단면해석과 Fourier 변환을 통해 각 단면형상 변화에 따른 에어포일의 고 유진동수를 비교하였다. VABS를 사용하여 단면의 형상과 재료의 적층 정보를 고려한 단면에서의 유한요소 해석을 수행하 였다. 에어포일의 재질, spar 유무, 단일 등방성 재료·복합재료, 에어포일 최대두께의 변화에 따라 에어포일의 끝단 진폭과 고유진동수가 변화함을 확인할 수 있었다. 이를 바탕으로 에어포일 고유진동수 변화는 2차 관성모멘트/단면적, 밀도, 영률의 변화에 상당한 영향을 받음을 알 수 있었다.

Menopausal status and hormonal changes are important factors related to the prevalence of metabolic syndrome in women. Nutrient intake is also a risk factor for metabolic syndrome. Although, postmenopausal status and hormonal changes result in a 60% increased risk for metabolic syndrome, there has been no method to elucidate the effects of nutrient intake on metabolic syndrome following menopause. This study was conducted to evaluate the effects of nutrient intake by menopausal women on the prevalence of metabolic syndrome. All data were obtained from the Korean National Health and Nutrition Examination Survey 2007–2009. Menopausal women showed a 1.8-fold increase in the prevalence of metabolic syndrome. Metabolic syndrome group showed significantly lower values in calcium, iron, vitamin A, carotin, retinol and riboflavin intake than those of normal group in premenopausal women. In postmenopausal women, there are significant differences in crude fiber, calcium, iron, potassium, riboflavin and niacin. Indeed, different patterns of nutrient intake were observed by menopausal status and metabolic syndrome. As menopause cannot be controlled, a diet with adequate nutrient intake may be useful to control the rapid increase in the prevalence of metabolic syndrome due to menopause.

풍력발전 타워는 높은 세장비를 갖는 형상으로 인해 바람에 의해 발생하는 횡하중에 취약한 구조를 가지고 있기 때문에 바람은 풍력발전 타워를 설계하는데 있어서 중요한 설계요소 중 하나라고 할 수 있다. 본 논문에서는 타워 운송 편의성 향상을 위해 설계된 8각 및 6각 단면형상을 가지는 조립식 강관 타워 및 일반 원형 강관 타워의 일정 높이 이상에서부터 4개의 작은 기둥으로 분리되는 형상을 가지는 멀티기둥 강관 타워에 대한 2차원 단면모형 풍동실험과 3차원 모형 풍동실험을 수행하여 각 형상별 풍력계수를 산정하여 그 특성을 비교하였다. 또한 풍동실험 축소모형에 대한 CFD 해석을 수행하여 산정된 풍력계수값의 신뢰성을 확인하였으며, 마지막으로 실제스케일 풍력타워에 대한 CFD 해석을 수행하여 각 형상별 특성을 분석하였다.

The recent theory in L2 motivation has proposed viewing motivation as possible selves such as ideal L2 self, ought-to L2 self, and L2 learning experiences to complement the limitation of traditional socio-educational model. The purpose of the study was to test the traditional integrativeness and L2 motivational self system in Korean EFL college contexts and how those motivations have developed over time through a cross-sectional study. A total of five hundred fifty five college students taking English as elective in Korea completed the motivation questionnaires. The results showed that both traditional integrative motivations and L2 motivational self system have increased positively over time at college. The post-hoc test revealed that the senior students developed significantly higher motivations than the freshmen in integrative orientation, attitudes towards learning English, and criterion measures. L2 motivational self system such as ideal L2 self, ought-to L2 self, and L2 learning experiences better predicted motivated behaviors than integrative motivations even though both had significant correlations. Theoretic discussions were made for L2 motivations.

The objectives of this study were to investigate the relationship between fear-avoidance beliefs and functional status in individuals suffering from low back pain, and to identify factors that influence on fear-avoidance beliefs, functional status and pain. A cross-sectional study included 214 individuals with low back pain. Each of subjects completed a fear-avoidance beliefs questionnaire (FABQ) which divided into two subscales, FABQ for physical activity (FABQ-PA) and FABQ for work(FABQ-W), Oswestry disability index (ODI) and numeric pain rating scale (NPRS). Individuals with radiating pain were significantly higher in FABQ-PA, FABQ-total, and ODI scores than with no radiation pain (p<.05). Individuals who had received surgery were significantly higher in FABQ-PA, FABQ-total, ODI and NPRS scores when compared with individuals who had not received it (p<.05). And individuals with taking medication were significantly higher in all variables (FABQ-PA, FABQ-W, FABQ-total ODI and NPRS) than individuals not taking medication (p<.05). In correlation analysis. age appeared to be significantly correlated with FABQ-PA, FABQ-total and ODI scores (p<.05), and all variables was significantly correlated with each other (p<.01). These findings indicate that individuals suffering from low back pain have psychosocial problems such as fear-avoidance beliefs as well as functional status and pain. Fear-avoidance beliefs may contribute to aggravate physical symptoms, and therefore it should be carefully considered for the management of individuals with low back pain.

The main objective of this paper is a feasibility Study for measuring tensile forces in the steel wire which are widely used in various types of prestressed structures. A steel wire serves as a load-bearing element, and electromagnetic-acoustic transducers are used to excite and detect resonant vibrational modes. The results show a promising feasibility on measurement of tensile forces in the steel wire.

A study performs estimation of fatigue safety that is considering cross-sectional loss of cable by applying foreign regulatory review. Because of steel cable-stayed bridge cable`s corrosion which is occurred after construction completion more than 30 years. Analysis result, all cable members secure fatigue safety considering cross-sectional loss of cable.

In this study, trapezoidal corrugate plate were subjected to cyclic loading under displacement control. And then, results from the experiment, the behavioral characteristics and mechanism of energy dissipation were investigated. This result were different to the cumulative size of energy dissipation capacity in load-displacement curve. Based on these results, Influence of the shape is very large and it is determined the define an appropriate shape for the size.

In this study, the shear buckling strengths of the trapezoidal and sinusoidal corrugated plates with the same self-load were compared, and their characteristics and tendencies were analyzed. In the preceding comparative study of corrugation shapes, the corrugation wave depth and the corrugation wave angle were the same. As these target, A linear buckling analysis was conducted, and the differences in the shear buckling mode and the buckling stress were analyzed.