• Steel and Composite Structures
• /
• 제19권2호
• /
• pp.405-416
• /
• 2015

We proposed the concept of nominal rigidity of a long-span V-shaped rigid frame composite arch bridge, analyzed the effects of structural parameters on nominal rigidity, and derived a theoretical nominal rigidity equation. In addition, we discussed the selection of the arch-to-beam rigidity ratio and its effect on the distribution of internal forces, and analyzed the influence of the ratio on the internal forces. We determined the delimitation value between rigid arch-flexible beam and flexible arch-rigid beam. We summarized the nominal rigidity and arch to beam rigidity ratios of existing bridges. The results show that (1) rigid arch-flexible beam and flexible arch-rigid beam can be defined by the arch-to-beam rigidity ratio; (2) nominal rigidities have no obvious differences among the continuous rigid frame composite arch bridge, V-shaped rigid frame bridge, and arch bridge, which shows that nominal rigidity can reflect the global stiffness of a structure.

• Asia pacific journal of information systems
• /
• 제33권4호
• /
• pp.1043-1057
• /
• 2023

The objective of this study is to explore the perceptions of justice regarding the implementation of flexible work arrangements, as well as to analyze the effects of such arrangements on job satisfaction and organizational effectiveness. The present study posits three key aspects, namely distributive justice, procedural justice, and interactional justice, which are hypothesized to influence individuals' impression of justice in relation to flexible work systems. To investigate the influence of job types on an R&D organization, specifically comparing R&D employees and office management employees, a dataset of 190 R&D employees and 50 office management employees was collected. The findings of the investigation provide empirical evidence that distributive justice has a significant impact on the level of job satisfaction among employees in both research and development (R&D) and office administration roles. Moreover, the influence of work satisfaction on organizational performance is noteworthy, particularly with regard to factors such as job dedication, organizational citizenship behavior, and knowledge sharing. The aforementioned findings offer significant insights for research and development (R&D) firms that have incorporated flexible work arrangements. These insights underscore the significance of emphasizing specific justice perceptions in order to augment job satisfaction and overall performance within the organization.

• 구강회복응용과학지
• /
• 제33권1호
• /
• pp.19-24
• /
• 2017

탄성의치는 심미성, 유연성, 생체적합성 등의 장점이 있어서 최근 많이 사용되고 있다. 그러나 재료 자체의 유연성에 의한 의치의 운동 때문에 안정성에 대한 문제가 제기되고 있다. 저작 시 의치가 조직면으로 움직이면서 지지조직을 자극하게 되고, 이런 자극이 장기간 지속될 경우 외상과 잔존치조제의 급속한 흡수를 야기할 수 있기 때문이다. 본 증례에서는 안정, 유지 및 지지가 부족한 탄성의치를 장기간 사용하면서 지지점막의 지속적인 자극으로 인한 구개골 노출이 발생하였다. 안정성 및 유지력이 확보된 새로운 의치를 제작하여 환자의 불편감이 감소하였고 구개골 노출이 치유되었다. 탄성의치를 사용할 수 있는 증례를 신중하게 선택해야 하며 정기검진 및 적절한 처치를 시행하여 부작용을 예방할 수 있어야 한다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.380-383
• /
• 2006

The media transport system is used in a printer, a ATM(Automated Tellor Machine), and so on. The media transport system has many problems through miniaturization and rapid transportation of these machines. In the paper feeding mechanism, it is important to feed the sheet without jamming under any conditions. To avoid sheet jamming, first we need to predict the behavior of the sheet exactly. In this paper, the analysis of media behavior is based on J. Stolte's studies. In all of OA machines, a flexible beam or plate is pushed from the channel. The motion may be constrained by guides. This leads to a transient and geometrically nonlinear problem. The behavior of paper is simulated by dynamic elastica theory. The shape of guide is represented by parametric cubic curve. But J. Stolte's studies did not considered contact condition between sheet and guide. So Klarbring's Model. will be applied. And the analysis of flexible media has to include aerodynamic effect for more exact behavior analysis, because the flexible media can be deformed drastically by a little force. Therefore aerodynamic force must be applied to the governing equation. Lastly, the simulation of this model is performed, and the experiment is performed for verification of this model. The experimental results of low exit velocity are consistent with the simulation results, however experimental results of high exit velocity do not agree well with analytical results. The reason is that there may be other effects like nip Phenomena

• 한국전문물리치료학회지
• /
• 제20권4호
• /
• pp.55-64
• /
• 2013

The first purpose was to identify the plantar pressure distributions (peak pressure, pressure integral time, and contact area) during level walking, and stair ascent and descent in asymptomatic flexible flatfoot (AFF). The second purpose was to investigate whether peak pressure data during level walking could be used to predict peak pressure during stair walking by identifying correlations between the peak pressures of level walking and stair walking. Twenty young adult subjects (8 males and 12 females, age $21.0{\pm}1.7$ years) with AFF were recruited. A distance greater than 10 mm in a navicular drop test was defined as flexible flatfoot. Each subject performed at least 10 steps during level walking, and stair ascent and descent. The plantar pressure distribution was measured in nine foot regions using a pressure measurement system. A two-way repeated analysis of variance was conducted to examine the differences in the three dependent variables with two within-subject factors (activity type and foot region). Linear regression analysis was conducted to predict peak pressure during stair walking using the peak pressure in the metatarsal regions during level walking. Significant interaction effects were observed between activity type and foot region for peak pressure (F=9.508, p<.001), pressure time integral (F=5.912, p=.003), and contact area (F=15.510, p<.001). The regression equations predicting peak pressure during stair walking accounted for variance in the range of 25.7% and 65.8%. The findings indicate that plantar pressures in AFF were influenced by both activity type and foot region. Furthermore the findings suggest that peak pressure data during level walking could be used to predict the peak pressure data during stair walking. These data collected for AFF can be useful for evaluating gait patterns and for predicting pressure data of flexible flatfoot subjects who have difficulty performing activities such as stair walking. Further studies should investigate plantar pressure distribution during various functional activities in symptomatic flexible flatfoot, and consider other predictors for regression analysis.

• 대한조선학회논문집
• /
• 제47권3호
• /
• pp.421-429
• /
• 2010

In this paper, in order to analyze the dynamic response of a floating crane when it lifts a heavy cargo, the boom of the floating crane is considered as an elastic beam. The boom is divided into elements based on finite element formulation and the floating frame of reference formulation and nodal coordinates are employed to model the boom as a flexible body. As an extension of the previous study, in order to consider spatial motion in waves, the coupled equations of motions of the 6 degree of freedom (DOF) floating crane and 6 DOF cargo are developed based on the flexible multibody system dynamics. The 3 dimensional deformation of the elastic boom is considered with 18 DOF. The dynamic simulation of the floating crane and the cargo is performed under regular wave conditions with various cargo weights. Finally, the effects of the elastic boom on lifting cargo are discussed by comparing the simulation results between the elastic boom and a rigid boom.

• International Journal of Aeronautical and Space Sciences
• /
• 제17권1호
• /
• pp.132-138
• /
• 2016

Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53kg, the structure weight is 22kg, and features a flexible wing of 19.5m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, $V_{cr}=6m/sec$, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight because of the EAV-3 is the solar-electric driven UAV. Thus, static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing with the previously designed the EAV-2 and EAV-2H/2H+ to upgrade the flight performance of the EAV-3.

• Macromolecular Research
• /
• 제11권6호
• /
• pp.481-487
• /
• 2003

Polypyrrole (PPy) was coated sequentially by chemical and electrochemical methods on a woven fabric, giving rise to a fabric having high electrical conductivity. We investigated the effects of the preparation conditions on the various properties of the resulting fabric. The PPy-coated fabric with optimum properties was obtained when it was prepared sequentially by chemical polymerization at the elevated temperature of 100$^{\circ}C$ under a pressure of 0.9 kgf/$\textrm{cm}^2$ and then electrochemical polymerization with a 3.06 mA/$\textrm{cm}^2$ current density at 25 $^{\circ}C$ for 2 hrs with the separator plate. The surface resistivity of the resulting fabric was as low as 5 Ω/$\square$ .The PPy-coated fabric prepared under the optimum conditions showed practically applicable heat generating property. When electrical power was supplied to the fabric using a commercial battery for a mobile phone (3.6 V, LGLl-AHM), the temperature of the fabric increased very quickly from room temperature to ca. 55 $^{\circ}C$ within 2 min and was maintained for ca. 80 min at that temperature. The heat generating property of the fabric was extremely stable, exhibiting similar behavior over 10 repeated cycles. Therefore, we suggest that the PPy-coated fabric in this study may be practically useful for many applications, including flexible, portable surface-heating elements for medical or other applications.

• 척추신경추나의학회지
• /
• 제10권1호
• /
• pp.35-45
• /
• 2015

Objectives : To evaluate the clinical effectiveness of Flexible brace(SpineCor Brace). Methods : CNKI, PubMed databases and Korean Journal of Oriental Medicine in 1999-2014 were searched for studies on SpineCor. This study researched 4 randomized controlled trial studies. Results : The results suggested that the SpineCor brace reduced the probability of the progression of early idiopathic scoliosis comparing with its natural history or rigid brace. But some studies showed that there is no significant difference between SpineCor and rigid brace. Conclusions : These results indicate that SpineCor have obvious effects on treatment of scoliosis and no adverse reactions, therefore we need to study more researches on SpineCor.

• 디지털산업정보학회논문지
• /
• 제8권4호
• /
• pp.193-203
• /
• 2012

This study analyzed regular transportation costs between port warehouses and processing plants and between processing plants and central distribution centers and further transportation costs relations according to empty transfer rates in each circulation by examining the distribution routes of imported grain including wheat, barley, corn, and soybean, namely port warehouses, processing plants, and central distribution centers. Based on the results, the study compared and reviewed the logistics transportation costs. The analysis results of the alternative model show that logistics operational costs could be considerably cut down by introducing a flexible vehicle transportation operational method, which is to change the vehicle loading parts for proper substitute transportation after unloading and transport them to other locations such as central distribution centers instead of returning empty, as an alternative to high operational costs deriving from empty vehicle operation in each circulation after unloading items in case of transportation of imported grain and processed items. The results allow for a more realistic approach to general problems with large-scale distribution network operation and provide a theoretical foundation to serve as a guide to establish policies for corporate operation of imported grain logistics systems.