• Advances in Computational Design
• /
• v.1 no.4
• /
• pp.297-313
• /
• 2016

The flexural strength of circular concrete-filled tubes (CCFT) can be estimated by several codes such as ACI, AISC, and Eurocode 4. In AISC and Eurocode, two methods are recommended, which are the strain compatibility method (SCM) and the plastic stress distribution method (PSDM). The SCM of AISC is almost the same as the SCM of the ACI method, while the SCM of Eurocode is similar to the ACI method. Only the assumption of the compressive stress of concrete is different. The PSDM of Eurocode approach is also similar to the PSDM of AISC, but they have different definitions of material strength. The PSDM of AISC is relatively easier to use, because AISC provides closed-form equations for calculating the flexural strength. However, due to the complexity of calculation of circular shapes, it is quite difficult to determine the flexural strength of CCFT following other methods. Furthermore, all these methods give different estimations. In this study, an effort is made to review and compare the codes to identify their differences. The study also develops a computing program for the flexural strength of circular concrete filled tubes under pure bending that is in accordance with the codes. Finally, the developed computing algorithm, which is programmed in MATLAB, is used to generate design aid graphs for various steel grades and a variety of strengths of steel and concrete. These design aid graphs for CCFT beams can be used as a preliminary design tool.

• International Journal of High-Rise Buildings
• /
• v.12 no.3
• /
• pp.203-208
• /
• 2023

The implementation of artificial intelligence (AI) design for tall building structures is an essential solution for addressing critical challenges in the current structural design industry. Generative AI technology is a crucial technical aid because it can acquire knowledge of design principles from multiple sources, such as architectural and structural design data, empirical knowledge, and mechanical principles. This paper presents a set of AI design techniques for building structures based on two types of generative AI: generative adversarial networks and graph neural networks. Specifically, these techniques effectively master the design of vertical and horizontal component layouts as well as the cross-sectional size of components in reinforced concrete shear walls and frame structures of tall buildings. Consequently, these approaches enable the development of high-quality and high-efficiency AI designs for building structures.

• Tribology and Lubricants
• /
• v.19 no.1
• /
• pp.15-20
• /
• 2003

The purpose of the paper is to investigate the effects of design parameters on the noise of a rotor- bearing system supported in oil lubricated journal bearings. Effects of radial clearance and width of the bearing, lubricant viscosity and mass eccentricity of the rotor are also examined. Numerical results of the parametric studies are summarized through graph for the A-weighted sound pressure level of the bearing with respect to the rotational speed of the rotor. Results show that the sound pressure level of the bearing is markedly influenced by the mass eccentricity of the rotor and the radial clearance and the width of the bearing. The high viscosity of the lubricant slightly decreases the noise of the bearing, but its effect is relatively very low at high speed. The results of the paper could be an aid in the low noise design of rotor-bearing system supported in oil lubricated journal bearings.

• The Journal of Information Systems
• /
• v.27 no.1
• /
• pp.153-169
• /
• 2018

Purpose Since human brains catch images faster than texts or numbers, infographics has been widely used in business in the form of "information dashboard" to enhance the efficiency of decision-making. Groupware, however, has neglected the adoption and use of infographics, in particular, in the idea generation process. Given that an overall performance of groupware-based idea generation is no better than that of the (paper-and-pencil-based) Nominal Group Technique, Jung et al. (2010) adopted the notion of infographics in the form of performance feedback to solve the productivity paradox. With the consistent results, which demonstrate beneficial effects of infographics on performance enhancement, an interesting observation that groups with the bar chart treatment performed better than groups with the dot chart treatment was made. The main purpose of this study was to find if there were a performance consistency between the outcomes from the previous study and the outcomes from the current study. Design/methodology/approach In experiment 1, we employed the same system used in the previous study (i.e., Jung et al., 2010). As individuals' contributions accumulated, the mechanism visually displayed individuals' performances two-dimensionally in the form of a bar chart or a dot chart. Then, we compared the performance outcomes from this study to the outcomes from previous study (i.e., Jung et al., 2010). In experiment 2, we modified the performance graph to test the effect of "playfulness" on performance by converting dots to car images. Then, we compared the performance outcome from experiment 2 to the outcomes from experiment 1. Findings Just like our interesting (and unexpected) finding in Jung et al.'s study (2010), the outcome confirmed a consistent superior performance of a bar chart. This implies that a bar chart is a better choice when stimulating performance with a visual aid in the context of groupware-based idea generation. Although a bar chart was criticized in a way that errors of length-area judgments are 40 ~ 250% greater than those of positional judgments along a common scale, such illusion turned out to be facilitating upward performance comparison better. Regarding Experiment 2, the outcome showed that the revised-dot graph is as good as the bar graph in terms of quantity and quality score of ideas. We attribute the performance enhancement of the resized-dot to the interaction between the motivational characteristic and the situational characteristic of playfulness because individuals in the revised-dot graph treatment performed better than individuals in the dot graph treatment. Given the order of performance (Bar >= Revised Dot > Dot) that the revised-dot treatment performed the same as (or lower than) the bar treatment, an additional research is warranted to reach to a consistent outcome.

• Korean Institute of Interior Design Journal
• /
• v.21 no.3
• /
• pp.182-193
• /
• 2012

The percentage of senior citizens is increasing in Korea and it is expected to become an "aging society". Problems with the elderly are becoming a big concern, such as physical and mental illness, losing their jobs and having difficulties at home. But, the silver generation, as they are being known, has changed a lot these days. With the aid of medical developments, the elderly's lifespan has become longer, making them more independent and active. Senior Welfare Center's are places where the elderly can spend their golden years in comfort, meaningfully. Senior Welfare Center's these days provide many different programs, which naturally lead to an increase in elderly users. With the rise in welfare centers and users, research on the subject also grew. As this topic has only recently become an issue, there were not many spatial structure studies considering elderly movement. Therefore, there should be spatial structure research that considers older users space awareness and how it can be managed effectively. The goal of this study is to present basic resources for providing a comfortable senior welfare center for elders. This will be based on quantitative analysis derived from spatial structure research along with special construction characteristics based on the institution's general plan. As a research method, Senior Welfare Center's will be categorized into corridor type, hall type, and hybrid types which then be reproduced into a j-graph. Based on this, special structure characteristics and connection links will be comprehended. Then the connection link will be analyzed based on the space syntax result calculated from each type's integration, connectivity, control value, and intelligibility. The analysis result shows that Senior Welfare Center j-graph's average arrangement is hybrid>corridor>hall types. Those elders lacking awareness need easily perceivable spatial structure's and hall type's would be the best choice to increase their awareness as it has high articulation. However, hall type's would be difficult to construct with the size increase, so hybrid type would be the next logical solution. Space with relatively high articulation will need to be planned in hybrid type's where rest areas can be created within the halls in the Welfare Center in connection to its corridors.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.4
• /
• pp.366-372
• /
• 2016

This paper advances the software, hardware and mechanical design that the visually impaired can recognize the position and distance of the obstacle while walking. The first software implementation is proposed a method to implement the algorithm graph for the ratio of the distance measuring ultrasonic sensors for voltage. And it was extracted by the precise distance measuring parameter values from simulation to measure the precise distance. Second hardware implementation was designed to be able to detect obstacles in a relatively simple sensor-based walking aid for the visually impaired. In addition, using the switching regulator IC of high performance it was designed to be used to boost the Li-ion battery 3.7V to 5V. The third mechanism was developed by analyzing the sensor angle and the cane angle.