• Journal of Korean Society of Steel Construction
• /
• v.21 no.1
• /
• pp.83-91
• /
• 2009

Buckling Restrained Braces (BRBs) show good seismic behavior. They do not dissipate energy, however, when they are subjected to minor earthquakes or wind. Hybrid Buckling Restrained Braces (H-BRBs), which can improve the wind performance of the BRB system, are a kind of hybrid damper system composed of a viscoelastic damper and BRBs. In this paper, two H-BRB specimens with different cores were experimentally investigated to ensure the structural behavior of the H-BRB system in an elastic range. The axial deformation of the primary resisting system was compared with that of the secondary resisting system, and the equivalent damping ratio of the H-BRBs was estimated. It was concluded that H-BRBs with double shear dampers show good structural behavior and are applicable to tall buildings, to improve the building performance at a comfortable level.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.21 no.4
• /
• pp.126-136
• /
• 2013

Aircraft accidents these days, following the mega sizing trend of the aircraft, result in enormous losses of human lives apart from those of property, which cannot be replaced by any means. As most recently, in April 20, 2012, a Boeing 737 passenger plane departed Karachi on an augural flight to Islamabad, Pakistan, crashed close to an express highway on final approach, all 121 passengers and 6 crew members were killed. As such a large number of fatalities have been recorded in aircraft accidents while accident investigation results show that more than 95% of aircraft accidents are now survivable. There are three basic stages in surviving the aircraft accident: surviving the crash impact, the evacuation process and the hostile post evacuation environmental elements. These stages require the cabin crew's expeditious and appropriate actions on the basis of systematic and thorough cabin safety training in order to increase occupants' survivability, along with the passengers' preparedness. In this aspect, this paper examines the issues acting as the impediments to the passenger survival in inflight emergency situations, that are the deficiencies with cabin crew safety training, related performances and the shortcomings in passengers' knowledge on inflight safety information, leading to their inappropriate responses to emergency situations. These issues are analyzed and the root causes are identified, suggesting the resolving countermeasures.

• Journal of Educational Research in Mathematics
• /
• v.25 no.1
• /
• pp.59-74
• /
• 2015

It is an increasing research area to explore mathematics learning from discursive perspectives. However, there have been little studies conducted on why and how discursive perspectives in mathematics learning were adopted and developed. Especially, not much discussion has been done on the later Wittgenstein's philosophical stance in terms of the relationship between language and thought as a background of discursive approach to learning mathematics. This study aims to explore the later Wittgenstein on language to get better understanding about discursive approaches to mathematics learning. For the attainment of this aim, first the later philosophy is compared with the former philosophy in depth. Then the later philosophy is discussed focusing on how his point of view on the world and the language have been changed. After providing an account of his later philosophy, it is clarified that what is discursive approaches to learning mathematics and how this philosophy brace the approaches. This research concludes with implications and limitations, as well as suggestions for future researches.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.18 no.3
• /
• pp.1-9
• /
• 2014

Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. In this study, a non-compression cross-bracing system using the Carbon Fiber Composite Cable (CFCC), which consists of CFCC bracing and bolt connection was proposed to replace the conventional steel bracing. This paper presented the seismic resistance of a reinforced concrete frame strengthened using CFCC X-bracing. Cyclic loading tests were carried out, and the maximum load carrying capacity and ductility were investigated, together with hysteresis of the lateral load-drift relations. Test results revealed that the CFCC X-bracing system installed RC frames enhanced markedly the strength capacity and no buckling failure of the bracing was observed.

• Physical Therapy Korea
• /
• v.24 no.1
• /
• pp.1-8
• /
• 2017

Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group ($n_2=15$). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

• Journal of the Korean Society of Costume
• /
• v.56 no.6 s.105
• /
• pp.58-71
• /
• 2006

This research is aimed to develop the functional clothing designs for disabled women in the manner of investigating design preferences among them by means of questionnaire and interview with 150 disabled women as respondents and interviewees. The findings of this research are summarized as follows: 1. Regarding satisfaction with ready-made clothes, the respondents answered 'very satisfied' (1.6%), 'usually satisfied' (14.1%), 'moderate' (20.3%) and 'unsatisfied' (53.1%), suggesting that they had been generally unsatisfied with ready-made clothes. 2. There were more disabled women preferring to ready-made clothes with one-grade bigger (loose.) size than the actual one (53.1%) instead of completely fitted size (43.8%) when they purchased such clothes. This result indicates that they prefer to ready-made clothes with bigger size than the actual one because most of such clothes are made up of non-elastic materials which may be unfavorable for wearer's activities. 3. It was found that primarily worn upper garment among them was T-shirt (59.4%). The reason may be that T-shirt is favorable for using prosthesis and orthotics such as wheelchair, walking stick and crutches thanks to its remarkably high activity as well as simple to maintain, compared with other kinds of upper garments. 4. Regarding preferences to functional clothing designs, the primarily worn lower garment among them was trousers (85.9%); the reason was easiness to move. The main reasons of avoiding to wear a skirt included 'difficult to move' (40.6%) and 'exposed disabled region' (30.3%). Accordingly, functional clothing for disabled women should be developed in consideration for their individual characteristics of disability associated with the disabled region such as wheelchair user, crutch user or brace user, In addition, the designs should be made so that they are not different from those for non-disabled people.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.1
• /
• pp.111-119
• /
• 2005

This study presents continuous and discrete optimum design algorithm and computer programs for unbraced and braced steel frame structures under earthquake loads. The program, which is avaliable to perform structural analysis and optimum design, continuous and discrete, simultaneously is developed. And the program adopts various braced types, Untraced, Z-braced(V), Z-braced(inverse-V), X-braced(A), X-braced(B), X-braced(C) and K-braced, in steel structures with static loads and seismic effects. The objectives in this optimization are to minimize the total weight of steel, and design variables, based on the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06, and various constraints. The purpose is to present proper braced type for seismic effects by comparing and analysing results of various cases.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.2
• /
• pp.29-37
• /
• 2003

In this study, a story-wise distribution of hysteretic energy in steel moment resisting framse(MRF), buckling restrained braced frames(BRBF), and hinge-connected framed structures with buckling restrained braces(HBRBF) subjected to various earthquake ground excitations was investigated. Sixty earthquake ground motions recorded in different soil conditions were used to compute the energy demand in model structure. According to analysis results, the hysteretic energy in MRF and BRBF turned out to be the maximum at the base and monotonically diminishes with increasing height. However the story-wise distribution of hysteretic energy in HBRBF was relatively uniform over the height of the structure. In this case damage is not concentrated in a single story, and therefore it is considered to be more desirable than other systems. The story-wise energy distribution pattern under three different soil types turned out to be approximately the same.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.241-244
• /
• 2008

In general, RC flat plate frames have been used as a gravity load resisting system(GLRS) in building. This system should be constructed with lateral force resisting system(LFRS) such as shear walls and brace frames. When lateral loads such as earthquakes occur, LFRS undergo displacement by which connected gravity systems experience lateral displacement. Thus, flat plate system designed as GLRS should be predict unbalanced moments and punching failure due to lateral deformation. This study developed an analytical mode for predicting nonlinear behavior of RC slab column connection for the seismic performance evaluation of RC flat plate frames. For verifying the analytical model, the test results of two flat plate specimens having two continous spans with the difference gravity shear ratio($V_g/{\phi}V_c$) were compared with the results of analysis. The developed model can predict the failure modes and punching failures.

• Journal of Korean Academic Society of Home Health Care Nursing
• /
• v.24 no.3
• /
• pp.255-263
• /
• 2017

Purpose: This study was conducted to assess the incidence and characteristics of pressure ulcer in relation to the type of equipment and supplies(EnS) in intensive care unit(ICU). Method: By using secondary data analysis and descriptive investigation, 29 patients of pressure ulcers caused by EnS were examined from January 2013 to December 2015, at the advanced general hospital located in Gyeongsangnam-do. The subjects were aged 19 years and above and had been in the ICU for more than 3 days. The data were analyzed using the SPSS WIN 23.0 with frequency, percentage, and mean and standard deviation. Result: The incidence of EnS-related pressure ulcers was 3.71%. The EnS-related causes for pressure ulcers were endotracheal tube(31.03%), restraint(20.69%), and neck brace(10.34%). The longest use of EnS was oxygen tube(29 days). EnS that were possibly causing pressure ulcer for one day were restraint(upper extremities), endotracheal tube(oral and face), and oxygen mask(ear and nose). Conclusion: This study has been limited to secondary data analysis that may result in missing records of pressure ulcers related to EnS in ICU. However, the analysis of this research is expected to contribute to the development of nursing interventions to clarify the guidelines for the prevention of pressure ulcers related to EnS in ICUs.