• Journal of Korean Society for Quality Management
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• v.45 no.3
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• pp.521-532
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• 2017

Purpose: The purpose of this study is to structure affective factors related to the tactile sense in order to improve tactile sensibility satisfaction of interior material. In this paper, we propose the design direction of interior material by analyzing the association between material properties and affective factors for automotive interior material. Methods: The relationship between sensibility adjectives and feelings related to tactile sensation were derived through factor analysis after touching prepared samples that were made by changing the material properties of automotive interior material. The association between affective factors and interior material properties were analyzed through ANOVA. Results: Seven kinds of visual and tactile affective factors were derived from the correlation between feeling of material and sensibility adjectives measured by 215 subjects. It is found that there is a quadratic relationship rather than a linear relationship through association analysis between affective factors and the material properties such as roughness, friction coefficient, and hardness. Conclusion: This study suggests the direction of the interior material design which can improve the sensibility satisfaction of the automobile customers by identifying the tactile factors related to the material properties of automotive interior material.

• Structural Engineering and Mechanics
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• v.49 no.3
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• pp.285-296
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• 2014

Material damping affects the dynamic behaviors of engineering structures considerably, but up to till now little research is maintained on influence factors of material damping. Based on the damping-stress function of steel, the material damping of steel beams is obtained by calculating the stress distribution of the beams with an analytical method. Some key influence factors of the material damping, such as boundary condition, amplitude and frequency of excitation, load position as well as the cross-sectional dimension of a steel beam are analyzed respectively. The calculated results show that even in elastic scope, material damping does not remain constant but varies with these influence factors. Although boundary condition affects material damping to some extent, such influence can be neglected when the maximum stress amplitude of the beam is less than the fatigue limit of steel. Exciting frequency, load position and cross-section dimension have great effects on the material damping of the beam which maintain the similar changing trend under different boundary conditions respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.13-24
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• 2019

This paper brings up fallacy of material factors specified for the design of concrete members in the current Korean limit state design code for highway bridges, and proposes new material factors based on a robust optimization scheme to overcome the fallacy. It is shown that the current load factors in the code and the proposed material factors lead to a much higher reliability index than the target index. The load factors are adjusted to yield the target reliability index using the inverse reliability analysis. A reliability-based approach following the basic concept of Eurocode is formulated to determine material factors as well as load factors. The load-material factors obtained by the proposed reliability-based approach yield a lower reliability level than the target index. Drawbacks of the basic concept of Eurocode are discussed. It is pointed out that differences in the uncertainties between materials and members may cause the lower reliability index of concrete member than the target.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.110-117
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• 2011

The paper tries to understand the other side of characteristics on occupational injuries and diseases in forestry. Occupational injuries and diseases in forestry seems to be greatly influenced by the environmental characteristics of the mountain district and individual's ability of workers. A traditional method on the analysis of occupational injuries and diseases data may show that the main cause of occupational injuries and diseases is the material factors significantly. To identify the other side of occupational injuries and diseases in forestry, the occupational injuries and diseases data of 3,091 workers in forestry was analyzed. The data in forestry, 2009 shows certain characteristics among the recent occupational injuries and diseases data. The first step is to classify the data according to standard of classification of original cause materials. Material factors are 72.3% and human factors (included managerial factors) and environmental factors are 27.0%. The next step is to reclassify the first step data by using the concept of influence factors which caused and influenced occupational injuries and diseases. The result is that material factors are 2.4%, human factors(included managerial factors) and environmental factors are 97.0%. Also, an aging degree of workers in forestry is higher than other categories of business. It is true that an aging degree of injured or diseased workers in forestry is higher than that of other categories of business. However, relevance with increase of occupational injuries and diseases could not be explained. An injury and disease rate in forestry is remarkably increased recently than other categories of business. One of the reason why an injury and disease rate increased remarkably in 2009 could be considered as the increase of the number of workers and related budget. Therefore, this study proposes important measures or means to prevent occupational injuries and diseases in forestry.

• Tribology and Lubricants
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• v.32 no.2
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• pp.67-71
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• 2016

This study investigates the characteristics of the sapphire wafer chemical mechanical polishing (CMP) process. The material removal rate is one of the most important factors since it has a significant impact on the production efficiency of a sapphire wafer. Some of the factors affecting the material removal rate include the pressure, platen speed and slurry. Among the factors affecting the CMP process, we analyzed the trends in the material removal rate and surface roughness, which are mechanical factors corresponding to both the pressure and platen speed, were analyzed. We also analyzed the increase in the material removal rate, which is proportional to the pressure and platen speed, using the Preston equation. In the experiment, after polishing a 4-inch sapphire wafer with increasing pressure and platen speed, we confirmed the material removal rate via thickness measurements. Further, surface roughness measurements of the sapphire wafer were performed using atomic force microscopy (AFM) equipment. Using the measurement results, we analyzed the trends in the surface roughness with the increase in material removal rate. In addition, the experimental results, confirmed that the material removal rate increases in proportion to the pressure and platen speed. However, the results showed no association between the material removal rate and surface roughness. The surface roughness after the CMP process showed a largely consistent trend. This study demonstrates the possibility to improve the production efficiency of sapphire wafer while maintaining stable quality via mechanical factors associated with the CMP process.

• Korean Institute of Interior Design Journal
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• v.16 no.4
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• pp.89-98
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• 2007

This paper studied the spatial factors activating the personal interaction based on case studies of $M\'{e}diath\'{e}ques$ in France. The spatial factors are analyzed into material factors and dematerial factors. The material factors have physical features in space and directly or indirectly activate the personal interaction. They consist of 8 elements including pocket space, balcony, atrium, stairs, elevators, windows, conference rooms and furnitures. The dematerial factors consist of 6 elements including polycentrism, continuance, mixture, interpenetration, dematerialization, transparency. They are compounded of material factors and explain them conceptually. But dematerial factors are abstract concepts. To provide reliability I confirm the relationship with dematerial factors by using a connections, topology, a phased depth of the Depthmap as the framework of the visual recognition of the space syntax covering the characteristic of dematerial factors. The result of the quantitative analysis human-behavior in $V\'{e}nissieux$ $M\'{e}diath\'{e}que$ and the result of applying the spatial factors of $M\'{e}diath\'{e}ques$ as the community center to the $V\'{e}nissieux$ $M\'{e}diath\'{e}que$ proved that the spatial factors are significant factors of the $M\'{e}diath\'{e}ques$ as the community center.

• Journal of the Korea Concrete Institute
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• v.12 no.2
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• pp.21-30
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• 2000

In the Ultimate Strength Design, the design strength of a member is determined by multiplying the strength reduction factor to the nominal strength. This concept may be a reasonable approach, however it can not consider failure modes appropriately. Moreover, column design strength diagram show an abrupt change at a low level of axial load, which does not seem to be reasonable. This research compares the design strength determined by the strength resistance factors. As the material resistance factors for flexure and compression, 0.65 and 0.90 are proposed for concrete and steel, respectively. The design strength calculation process by applying material resistance factors addresses failure modes more effectively than by applying member strength reduction factor, and provides more resnable design strength for reinforced concrete flexural and compression members.

• Korean Institute of Interior Design Journal
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• v.13 no.2
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• pp.91-99
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• 2004

This study aims to embody material and non-material factors forming space and to explain our experience in space. Space is formed by material factors and their disposition. One space becomes a new space by such factors 'arrangement. Nevertheless, one space is never swayed by material factors and their disposition. Space is a reflection of social relations and historical process, and is also affected by its users. Space can not neutrally exist, for it compels its users to keep a specific life style. Space users have experience in space by practice. Practice enables its users to experience various relationships space makes, and as well it allows them to have creative experience in space by twisting them and inducing a new relationship.

• Structural Engineering and Mechanics
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• v.58 no.2
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• pp.217-230
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• 2016

Effects of temperature dependent material properties on mixed mode fracture parameters of functionally graded materials subjected to thermal loading are investigated. A domain form of the $J_k$-integral method including temperature-dependent material properties and its numerical implementation using finite element analysis is presented. Temperature and displacement fields are calculated using finite element analysis and are used to compute mixed mode stress intensity factors using the $J_k$-integral. Numerical results indicate that temperature-dependency of material properties has considerable effect on the mixed-mode stress intensity factors of cracked functionally graded structures.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.12
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• pp.1123-1131
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• 2005

The floor material is known as the most influential emission source of the residential building, because most floor material is made of wood compound and adhesive like a plywood flooring. Moreover, floor heating system keeps the inside temperature of the material high. As the emission of hazardous chemical compound from the construction material is influenced by many factors, it is necessary to analyze the emission characteristics of the floor material to improve IAQ. In this study, numerical analysis is performed to investigate the emission characteristics of the floor material affected by several factors such as temperature, air exchange rate, initial concentration, and internal diffusion coefficient. A simulation program is also written based on the mass transfer theory. The simulation results show that there is some level of difference on the TVOC concentration when each of the factors is variable.