• Structural Engineering and Mechanics
• /
• v.33 no.2
• /
• pp.137-158
• /
• 2009

This paper investigates the behavior of reinforced concrete (RC) circular columns under combined loading including torsion. The main variables considered in this study are the ratio of torsional moment to bending moment (T/M) and the level of detailing for moderate and high seismicity (low and high transverse reinforcement/spiral ratio). This paper presents the results of tests on seven columns subjected to cyclic bending and shear, cyclic torsion, and various levels of combined cyclic bending, shear, and torsion. Columns under combined loading were tested at T/M ratios of 0.2 and 0.4. These columns were reinforced with two spiral reinforcement ratios of 0.73% and 1.32%. Similarly, the columns subjected to pure torsion were tested with two spiral reinforcement ratios of 0.73% and 1.32%. This study examined the significance of proper detailing, and spiral reinforcement ratio and its effect on the torsional resistance under combined loading. The test results demonstrate that both the flexural and torsional capacities are decreased due to the effect of combined loading. Furthermore, they show a significant change in the failure mode and deformation characteristics depending on the spiral reinforcement ratio. The increase in spiral reinforcement ratio also led to significant improvement in strength and ductility.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.24 no.1
• /
• pp.39-50
• /
• 2017

Purpose: The purpose of this study was to identify the effects simulation-based education combined team-based learning (SBE combined TBL) compared to simulation-based education (SBE) on undergraduate nursing students. Methods: A non-equivalent control group design with pre-and posttest measures was used. The participants in the study were 181 students. The SBE combined TBL group consisted of 84 senior students in 2013, and the SBE group consisted of 97 seniors in 2014. Collected data were analyzed using chi-square, independent t-test and ANCOVA with the statistical package SPSS 22.0 for Windows. Results: There was a significant improvement in communication skills, nursing performance confidence, team efficacy, and team performance scores in the SBE combined TBL group compared to the SBE group (t=2.45, p=.015; F=4.30, p=.040; t=3.06, p=.003; t=8.77, p<.001). However, there was no statistically significant difference in self-directed learning between the groups. Conclusion: SBE combined TBL compared to SBE is an effective teaching and learning method to enhance various positive educational outcomes for nursing students. Therefore, we suggest that future studies investigate the development of an integrated course in which team-based learning is applied to theoretical sessions and simulation-based training.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.460-468
• /
• 2008

Recent activities on the scramjet and rocket-ramjet combined-cycle engine of Japan Aerospace Exploration Agency(JAXA) are herein presented. The scramjet engines and combined-cycle engines have been studied in the world and JAXA has also studied such the engines experimentally, numerically and conceptually. Based on the studies, 2 to 3 m long, hydrogen-fueled engine models were designed and tested at the Ramjet Engine Test Facility(RJTF) and the High Enthalpy Shock Tunnel(HIEST). A scramjet engine model was tested in Mach 10 to 14 flight condition at HIEST. A 3 m long scramjet engine model was designed to reduce a dissociation energy loss in a high temperature condition. Drag reduction by a tangential injection and two ways of a transverse fuel injection were examined. Combustor model tests at three operating modes of the combined-cycle engine were conducted, demonstrating the combustor operation and producing data for the engine design at each mode. Aerodynamic engine model tests were conducted in a transonic wind tunnel, demonstrating the engine operation in the ejector-jet mode. A 3 m long combined-cycle engine model has been tested in the ejector-jet mode and the ramjet mode since March 2007. Carbon composite material was examined for application to the engines. Production of the cooling channel on a nickel alloy plate succeeded by the electro-chemical etching.

• PNF and Movement
• /
• v.10 no.4
• /
• pp.49-55
• /
• 2012

Purpose : The purpose of this study was to assess the effects of bridging exercise and combined lifting pattern bridging exercise on the lower extremity muscle activity. Methods : Twenty-five healthy adults volunteered to participate in this study. Subjects were required to complete following bridging exercises. Muscle activity was measured by QEMG-4 system(LXM 3204, Laxtha Korea). A paired t test was used to determine the influence of muscle activity for each exercise and descriptive statistics was used to characteristics of the subjects. Results : The biceps femoris, tibialis anterior, gastrocnemius of combined lifting pattern bridging exercise showed significance excepted vastus medialis(p<.05). In the case of men, biceps femoris showed significance in the combined lifting pattern bridging exercise(p<.05). In the case of women, biceps femoris and tibialis anterior showed significance in the combined lifting pattern bridging exercise(p<.05). Conclusion : The combined lifting pattern bridging exercise was more increased than bridging in lower extremity muscle activation. This result will be used for knee joint stabilizing exercises and biceps femoris strength training.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.121-127
• /
• 1968

This research has been dealt with the nutritional component analysis of two kinds of non-edible marine algae, Sargassum herneri (Turner) C. Ag. and Zostera marina Linne which grow abundantly around the southern coast of Korea, These marine algae were mixed in several kinds of samples rates with the combined feed for poultry sold in the market. These were given to 35 chicken in seven test divisions respectively. We have experimented with 35 chicken grown up for two weeks after hatchout. The combined food for poultry obtained from the market was set up as control divisions. The experiments were as follows: 1) The average weight increase in each test division during feeding (Table 5, Fig.2). 2) Food conversion rate and food efficiency in each test division (Table 7). 3) The comparison of digestive rate of crude protein during feeding (Table 8), The results were as follows: 1) The weight increasing rate of the test animal stock fed the food containing $5\~10\%$ of Sargassum horneri (Turner) C. Ag. powder was higher than the rate of those fed only market food for poultry. 2) The stock given food containing $10\%$ Zostera marine powder showed lower growth than the control divison. 3) No apparent trouble owing to salt component involved in the marine algae was found. 4) The stock given food containing sodium glutaminate and Sargassum horneri (Turner) C. Ag. had better result than that without sodium glutaminate.

• Journal of Korea Multimedia Society
• /
• v.1 no.1
• /
• pp.109-119
• /
• 1998

This paper describes a research result on automatic generation of Abstract Test Suite from INAP protocol in formal specifications by applying many existing related algorithms such as Rural Chinese Postman Tour and UIO sequence concepts. We use the I/O FSM generated from SDL specifications and a characterizing sequence concepts. We use the I/O FSM generated from SDL specifications and a characterizing sequence, called UIO sequence, is defined for the I/O FSM. The UIO sequence is combined with the concept of Rural Chinese Postman tour to obtain an optimal test sequence. It also proposes an estimation methodology of the fault courage for the Test Suite obtained by our method and their translation into the standardized test notation TTCN.

• Proceedings of the Korean Reliability Society Conference
• /
• 2006.05a
• /
• pp.116-125
• /
• 2006

Piston assemblies, which are key components of hydraulic high pressure pumps & motors, are major failure products operating at high pressure and high speed, and the main failure mode is wearout of the shoe surface. To predict the actual life of piston assemblies. we require to find out the most sensitive parameters and establish related empirical formula. In this study, we analyzed the life of piston and shoe assemblies in accordance with variation of speed, pressure, and temperature to reduce the life test time, then analyzed the result of combined accelerated life test which is applied by high speed, speed pressure, and high temperature simultaneously, and finally developed combined accelerated life test model.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.1
• /
• pp.95-101
• /
• 2006

Minimum weight design of laminated composite panel under combined loading was studied using linear and nonlinear deformation theories and by closed-form analysis and finite difference energy methods. Various buckling load factors are obatined for laminated composite panels with rectangular type longitudinal stiffeners and various longitudinal length to radius ratios, which are made from Carbon/Epoxy USNl25 prepreg and are simply-supported on four edges under combined loading, and then for them, minimum weight design analyses are carried out by the nonlinear search optimizer, ADS. This minimum weight design analyses are constructed with various process such as the simple design process, test simulation process and sensitivity analysis. Subseguently, the buckling mode shapes are obtained by buckling and minimum weight analyses.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.110-113
• /
• 2004

Aluminum and CFRP tube is light-weight material representatively but collapse mechanism is different under axial loading. Aluminum tube absorbs energy by stable plastic deformation under axialloading. While CFRP(Carbon Fiber Reinforced Plastics)tube absorb synergy by unstable brittle failure but its specific strength and stiffness is higher than that of aluminum tube. In this study, for complement of detect and synergy effect by combination with the advantages of each member, the axialcollapsetests were performed for combined aluminum CFRP tubes which are composed of aluminum tubes wrapped with CFRP out side aluminum square tubes. Collapsecharacteristics were analyzed for combined square tubes which have different CFRP orientation angle and thickness. Test results were compared with that of aluminum tubes and CFRP tubes.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.407-410
• /
• 2005

This research investigates experimentally an effect on the properties of the combined high flowing concrete by mix design factors. The purpose of this study is to determine the optimum mix proportion of the combined high flowing concrete having good flowability, viscosity, no-segregation and design strength(40.0MPa). For this purpose, trial mixings used belite cement+lime stone powder(LSP) are tested by mix design factors including water-cement ratio($47.9\~54.0\%$), fine aggregate volume ratio($41\~45\%$) and coarse aggregate volume ratio($41\~45\%$). As test results of this study, the optimum mix proportion for the combined high flowing concrete is as followings. Water-cement ratio $51.0\%$, fine aggregate volume ratio $43{\pm}1\%$ and coarse aggregate volume ratio $0.30{\pm}0.05m^3/m^3$ and replacement ratio of LSP $42.7\%$.