• Smart Structures and Systems
• /
• v.13 no.5
• /
• pp.849-868
• /
• 2014

An indirect approach is explored for structural health bridge monitoring allowing for wide, yet cost-effective, bridge stock coverage. The detection capability of the approach is tested in a laboratory setting for three different reversible proxy types of damage scenarios: changes in the support conditions (rotational restraint), additional damping, and an added mass at the midspan. A set of frequency features is used in conjunction with a support vector machine classifier on data measured from a passing vehicle at the wheel and suspension levels, and directly from the bridge structure for comparison. For each type of damage, four levels of severity were explored. The results show that for each damage type, the classification accuracy based on data measured from the passing vehicle is, on average, as good as or better than the classification accuracy based on data measured from the bridge. Classification accuracy showed a steady trend for low (1-1.75 m/s) and high vehicle speeds (2-2.75 m/s), with a decrease of about 7% for the latter. These results show promise towards a highly mobile structural health bridge monitoring system for wide and cost-effective bridge stock coverage.

• Journal of Power System Engineering
• /
• v.17 no.4
• /
• pp.45-50
• /
• 2013

This paper presents the comparison of heat transfer and pressure drop of various secondary refrigerants (single-phase and two-phase) in the indirect refrigeration system. The main results were summarized as follows: In case of heat transfer, it is useful to use secondary refrigerants in low evaporating temperature region and the heat transfer coefficient of single-phase is larger than two-phase secondary refrigerants. In case of pressure drop, it is useful to use secondary refrigerants in high evaporating temperature region and the pressure drop of two-phase is smaller than single-phase secondary refrigerant. Also, $CO_2$ is the best useful because pressure drop of $CO_2$ among the secondary refrigerants is the smallest.

• Tunnel and Underground Space
• /
• v.15 no.3 s.56
• /
• pp.228-235
• /
• 2005

Friction angle and cohesion of rock masses can be estimated from Hoek and Brown failure criterion and then plastic corrections can be applied using Mohr-Coulomb yield function. This study finds that this estimation procedure would not be appropriate for weak rock masses and for cases where low confining stress is expected to develop. A procedure is outlined in this paper for estimating plastic corrections directly from Hoek and Brown material model. Comparative study shows that direct procedure would simulate non-linear failure surface better than indirect procedure especially in the low confining stress regime.

• Asia-Pacific Journal of Business
• /
• v.14 no.4
• /
• pp.151-161
• /
• 2023

Purpose - In this study, we examine the factors related to the asset allocation decisions of individual investors who 1) directly invest in stocks or bonds, 2) indirectly invest in various fund products (excluding CMA and MMF), and 3) invest in both products. Design/methodology/approach - We collect a sample of 3,000 individual investors and investigate the factors influencing investment behavior, especially the diversification tendency in asset allocation, with the "Investor Behavior Survey" that is conducted jointly by the Korea Financial Investment Association and the Korea Gallup Research Institute in 2011 and 2012. Findings - Our regression analyses estimate the marginal effects of various factors such as the amount of total financial assets, monthly income, occupation, age, and gender. The results reveal that male investors with manual labor occupations were less inclined to diversify their investments compared to female investors in office jobs. Additionally, higher monthly income is associated with a greater inclination toward diversification. Therefore, if a positive relationship exists between income and educational level, we may suggest that higher educational levels lead to a greater tendency for diversification. Research implications or Originality - Interestingly, investors who engage in direct investments tend to exhibit a weaker diversification tendency as the amount of their direct investment increases. On the other hand, investors who engage in both direct and indirect investments show a weaker diversification tendency as the amount of total financial assets increases. This suggests that the investment style of investors is closely related to their diversification behavior.

• Journal of Korean Academy of Nursing
• /
• v.33 no.2
• /
• pp.246-255
• /
• 2003

Purpose: This study was designed to compare direct cost and indirect cost between home care and hospital care according to subject's characteristics. Method: The subjects of this study were patients with cerebrovascular disease. They were 50 patients in six university hospitals and 49 in four home care centers. Data were collected by using two type of questionnaires and reviewing medical records, home care service records and medical-fee claims from April 4th to September 13th, 2001. Result: The results were as follows; First, there was a statistically significant difference of direct cost between home care and hospital care, however, there was not a statistically significant difference of indirect cost. Second, according to subject's characteristics, six variables had statistically significant differences; sex, age, marital status, economy, job and diagnosis. Conclusion: It was found that cost-saving effect of home care was affected by subject's characteristic factors. More study needs to be done to develop a more detailed selection criteria for home care subjects.

• Journal of the Ergonomics Society of Korea
• /
• v.20 no.1
• /
• pp.73-86
• /
• 2001

An analysis of anthropometric data of feet of Korean adults was made in this study. Anthropometric data were measured with the direct measurement method and indirect measurement method. Martin scales and a tapeline were used for direct measurement. Digital images taken with a digital camera as an indirect measurement method were analyzed using AutoCAD program. Total 114 adults aged from 20's to 40's participated in this study. Especially right and left feet were measured. Right and left side were compared and differences according to age were compared too. Feet shape, arch height, and deformation of toe were analyzed. The comparison between right and left foot showed that many subjects had different anthropometric data in their feet. Feet deformation including arch height and claw toe shape showed very serious status. Close and continuous attention to feet deformation is strongly needed.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.88-94
• /
• 2010

In this paper, the effect of the ultrasonic energy on the diesel engine's smoke reduction has been investigated for indirect injection diesel engine. The smoke concentration of the ultrasonically reformed diesel fuel was reduced remarkably in comparison with conventional diesel fuel. And in-cylinder pressure, heat release rate and mass fraction burned was improved but combustion duration was decreased. However, The combustion durations and the smoke concentrations of both diesel fuels were proportional to the increases of engine loads. Also, When the combustion duration has been increasing, the smoke emission has been augmenting in the shape of the exponential functions.

• Structural Engineering and Mechanics
• /
• v.64 no.1
• /
• pp.93-107
• /
• 2017

The article presents the vibration and acoustic responses of un-baffled doubly curved laminated composite panel structure under the excitation of a harmonic point load. The structural responses are obtained using a simulation model via ANSYS including the effect various geometries (cylindrical, elliptical, spherical and hyperboloid). Initially, the model has been established by solving adequate number of available examples to show the convergence and comparison behaviour of the natural frequencies. Further, the acoustic responses are obtained using an indirect boundary element approach for the coupled fluid-structure analysis in LMS Virtual.lab by importing the natural frequency values. Subsequently, the values for the sound power level are computed using the present numerical model and compared with that of the available published results and in-house experimentally obtained data. Further, the acoustic responses (mean-square velocity, radiation efficiency and sound power level) of the doubly curved layered structures are evaluated using the current simulation model via several numerical experimentations for different structural parameters and corresponding discussions are provided in detail.

• Journal of Biomedical Engineering Research
• /
• v.38 no.3
• /
• pp.137-141
• /
• 2017

The indirect-contact bio-electric measurements using capacitive electrodes show large motion artifacts in comparison with conventional direct-contact measurements. It is necessary to measure the motion artifacts quantitatively, for the researches of reducing the motion artifacts. In this study, a device for quantitative measurement of motion artifacts was built. Using the device, an electrode was rubbed against some cloth(cotton) and the voltage variation of the electrode was measured as motion artifact in several environmental conditions(temperature and relative humidity). The measured waveforms agreed with that expected by the triboelectricity and the prior observations of the motion artifacts. Therefore, the results demonstrated the usability of the measurement system built in this study. The measurement system will be a great contribution to future research for reducing motion artifact.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.05a
• /
• pp.9-19
• /
• 1999

A clad material is a different type of the typical composites which is composed of two or more materials joined at their interface surface. The advantage of clad material is that the combination of different materials can satisfy both the need of good mechanical properties and the other demand of user such as electrical properties instantaneouly. This paper is concerned with the direct and indirect extrusion process of copper-clad aluminum rod. Extrusion of copper-clad aluminum rod was simulated using a commercially available finite element package of DEFORM. The simulations were performed for copper-clad aluminum rod to predict the distributions of temperature, effective stress, effective strain rate and moan stress for some sheath thicknesses, die exit diameters and die temperatures.