• Earthquakes and Structures
• /
• 제1권4호
• /
• pp.391-410
• /
• 2010

There are several important considerations that need to be made in the capacity design of RC frame-wall structures. Capacity design forces will be affected by material overstrength, higher mode effects and secondary loadpaths associated with the 3-dimensional structural response. In this paper, the main issues are identified and different means of predicting capacity design forces are reviewed. In order to ensure that RC frame-wall structures perform well it is explained that the prediction of the peak shears and moments that develop in the walls is particularly important and unfortunately very challenging. Through examination of a number of case study structures it is shown that there are a number of serious limitations with capacity design procedures included in current codes. The basis and potential of alternative capacity design procedures available in the literature is reviewed, and a new simplified capacity design possibility is proposed. Comparison with the results of 200 NLTH analyses of frame-wall structures ranging from 4 to 20 storeys suggest that the new method is able to predict wall base shears and mid-height wall moments reliably. However, efforts are also made to highlight the uncertainty with capacity design procedures and emphasise the need for future research on the subject.

• Safety and Health at Work
• /
• 제11권1호
• /
• pp.1-9
• /
• 2020

Background: As the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea. Methods: The data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis. Results: Our findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea. Conclusion: Although previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

• 자원ㆍ환경경제연구
• /
• 제25권1호
• /
• pp.113-140
• /
• 2016

한 가지의 용량가격만으로는 발전용량 설비투자에 대한 안정적 보상과 시장 기능 유지라는 두 가지 목표를 동시에 달성하기 힘들다. 본 논문은 이런 한계를 극복할 수 있도록 복수의 용량가격을 도입하여 용량가격의 비중을 높이면서 동시에 시장 기능을 유지할 수 있는 이원적 용량가격 제도를 제안한다. 즉, 현재 가스터빈 발전기를 기준으로 하면서 행정적으로 결정되는 용량가격을 그대로 유지하면서, 동시에 LNG복합발전기를 대상으로 한 제2의 용량가격을 도입한다. 이 용량요금은 더 낮은 에너지 가격 상한의 적용을 받으며, 상이한 전원들 사이의 대체관계를 고려한 수요와 용량공급 상황을 반영하도록 설계함으로써 시장 기능을 유지하게 한다.

• Journal of Communications and Networks
• /
• 제11권3호
• /
• pp.287-296
• /
• 2009

Although asymptotic bounds of wireless network capacity have been heavily pursued, the answers to the following questions are still critical for network planning, protocol and architecture design: Given a three-dimensional (3D) network space with the number of active users randomly located in the space and using the wireless communication technology, what are the expected per-flow throughput, network capacity, and network transport capacity? In addition, how can the protocol parameters be tuned to enhance network performance? In this paper, we focus on the ultra wideband (UWB) based wireless personal area networks (WPANs) and provide answers to these questions, considering the salient features of UWB communications, i.e., low transmission/interference power level, accurate ranging capability, etc. Specifically, we demonstrate how to explore the spatial multiplexing gain of UWB networks by allowing appropriate concurrent transmissions. Given 3D space and the number of active users, we derive the expected number of concurrent transmissions, network capacity and transport capacity of the UWB network. The results reveal the main factors affecting network (transport) capacity, and how to determine the best protocol parameters, e.g., exclusive region size, in order to maximize the capacity. Extensive simulation results are given to validate the analytical results.

• 열처리공학회지
• /
• 제31권2호
• /
• pp.56-62
• /
• 2018

Many researchers have studied on the precipitation control after solution treatment to improve the damping capacity without decreasing the strength. However, studies on the damping capacity and microstructure changes after deformation in the solid solution strengthening alloys were inadequate, such as the Al-Zn series magnesium alloys. Therefore, in order to investigate the effect of annealing condition on microstructure change and damping a capacity of AZ61 magnesium alloy. In this study, it was confirmed that the microstructure changes affect the damping capacity and hardness when annealed AZ61 alloy. AZ61 magnesium alloy was rolled at $400^{\circ}C$ with rolling reduction of 30%. These specimens were annealed at $350^{\circ}C$ to $450^{\circ}C$ for 30-180 minutes. After annealing, microstructure was observed by using optical microscopy, and damping capacity was measured by using internal friction measurement machine. Hardness was measured by Vickers hardness tester under a condition of 0.3 N. In this study, static recrystallization was observed regardless of the annealing conditions. In addition, uniform equiaxed grain structure was developed by annealing treatment. Hardness is decreased with increasing grain size. This is associated with Hall-Petch equation and static recrystallization. In case of damping capacity, bigger grain size show the larger damping capacity.

• 융합경영연구
• /
• 제7권3호
• /
• pp.1-12
• /
• 2019

Purpose - This study aims to investigate the major capabilities of airline cabin crew to improve the performance of the organization by identifying how they are affected by turnover and customer orientation. Research, design, data, and methodology -The survey participants were limited to all airline cabin crew members in Korea to look at the component measurement items. To verify the validity of the questionnaire, the final questionnaire for this survey was prepared by modifying and supplementing the questionnaire by analyzing factors and validating the questionnaire through reliability verification Results - The analysis on the impact of personal capacity of the airline cabin crew on turnover revealed that some factors had an effect of the positive and the personal capacity of the airline cabin crew has a statistically positive effect on the customer orientation relationship, which is a sub-factor of the cabin crew Conclusions -The capacity of the cabin crew of the airline was defined and the components were established as technical capacity, knowledge capacity and expertise capacity. It was found that the intangible performance of the individual capabilities and customer orientation were very closely related. Airline cabin crew have verified the importance of good talent selection and capacity development training, which are essential requirements for securing the airline's competitiveness.

• Structural Monitoring and Maintenance
• /
• 제9권1호
• /
• pp.81-105
• /
• 2022

The use of concrete filled steel tube (CFST) column is widely accepted due to its property of high axial load carrying capacity, more ductility and more resistant to earthquake specially using in bridges and high-rise buildings. The initial imperfection (δ) that produces during casting or fixing causes the reduction in load carrying capacity, this is the reason, experimental capacity is always less then theoretical one. In this research, the effect of δ on load carrying capacity and behavior of concrete filled steel tube (CFST) column have been investigated by numerically simulation of large number of models with different δ and other geometric parameters that include length (L), width (B), steel tube thickness (t), f'_c and f_y. Finite element analysis software ANSYS v18 is used to develop model of SCFST column to evaluate strength capacity, buckling and failure pattern of member which is applied during experimental study under cyclic axial loading. After validation of results, 42 models with different parameters are evaluated to develop empirical equation predicting axial load carrying capacity for different value of δ. Results indicate that empirical equation shows the 0 to 9% error for finite element analysis Forty-two models in comparison with ANSYS results, respectively. Empirical equation can be used for predicting the axial capacity of early estimating the axial capacity of SCFT column including 𝛿.

• Geomechanics and Engineering
• /
• 제35권1호
• /
• pp.41-54
• /
• 2023

The use of a skirt, a vertical projection attached to the footing, is a recently developed method to increase the bearing capacity of soils and reduce foundation settlements. Most of the studies were focused on vertical skirted circular footings resting on clay while neglecting the rigidity and inclination of skirts. This study employs finite element limit analysis to investigate the bearing capacity enhancement of flexible and rigid inclined skirts in cohesionless soils. The results indicate that the bearing capacity initially improves with an increase in the skirt inclination but subsequently decreases for both flexible and rigid skirts. However, the rigid skirt exhibits more apparent optimum skirt inclination and bearing capacity enhancement than the flexible one, owing to differences in their failure mechanisms. Furthermore, the bearing capacity of the inclined skirted foundation increases with the skirt length, footing depth, and internal friction angle of the soil. In the case of rigid skirts, the bearing capacity increases linearly with skirt length, while for flexible skirts, it reaches a stable value at a certain skirt length. The efficiency of the flexible footing reduces as the footing depth and soil internal friction angle increase. Conversely, the efficiency of the rigid skirt decreases only with an increase in the depth of the footing. The paper also presents a detailed analysis of various failure patterns, highlighting the behaviour of inclined skirted footings. Additionally, nonlinear regression equations are provided to quantify and predict the bearing capacity enhancement with the inclined skirts.

• Journal of Information Technology Applications and Management
• /
• 제31권2호
• /
• pp.15-34
• /
• 2024

This study aims to analyze the effect of absorptive capacity on technology collaboration performance and the moderating effect of innovation intermediaries. We set absorptive capacity (potential, realized) as independent variables and technology collaboration performance (relative technology level, development period, cost savings, new product development, collaboration satisfaction) as dependent variables, with innovation intermediaries as a moderating variable. We conducted a survey of 145 ICT companies that experienced technology collaboration and analyzed the data using 101 valid responses. The results show that potential absorptive capacity has a significant effect on new product development and collaboration satisfaction, while realized absorptive capacity has a significant effect on relative technology level, cost savings, and new product development. Furthermore, innovation intermediaries have a moderating effect between realized absorptive capacity and new product development. The contribution of this study to academia and industry is that it highlights absorptive capacity as a key factor influencing technology collaboration performance. The limitations of this study include the lack of accurate measurement of absorptive capacity and innovation intermediaries, as well as a lack of control over external factors. These limitations should be addressed through more in-depth research by systematically defining and measuring them in future follow-up studies.

• 디지털융복합연구
• /
• 제17권11호
• /
• pp.171-181
• /
• 2019

본 연구는 기업이 추구하는 방향성을 통해 혁신을 실현할 수 있는지 확인하기 위하여 전략적 지향성과 혁신역량의 관계를 실증적으로 분석하였다. 구체적으로 선행연구를 기초로 전략적 지향성을 고객지향성과 기술지향성으로 구분하고 혁신역량을 전략기획역량, 연구개발역량, 기술사업화역량으로 구분하였다. 그리고 고객지향성과 기술지향성이 각각의 혁신역량에 미치는 영향을 분석하였다. 데이터 수집은 경북지역 제조업 종업원을 대상으로 368부의 설문지를 배포, 회수하였으며, 가설은 구조방정식을 사용하여 검증하였다. 연구결과, 기술지향성은 세 혁신역량에 모두 유의한 영향을 미치는 것을 확인하고, 고객지향성은 전략기획역량과 기술사업화역량에 유의한 영향을 미치는 것으로 나타났다. 하지만 고객지향성이 연구개발역량에 유의한 영향을 미치지 않는 것으로 확인되었다. 이러한 결과는 조직의 전략적 지향성과 혁신역량과의 인과관계를 설명함으로써 조직이 추구하는 전략 방향과 조직문화 측면에서 혁신을 끌어내는 방법에 대해 시사점을 제공할 수 있을 것이다.