• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.1
• /
• pp.1-7
• /
• 2024

This study was investigated the effect of heat treatment on the microstructure and hardness of internally hardened ductile cast iron roll. The following conclusions were obtained. Some of the graphite was decreased and a bainite was produced by heat treatment. It decreased due to the decomposition of some of the cementite precipitated in the as-cast by heat treatment, but there was no significant change when it reached a certain depth. Hardness increased due to formation of bainite by heat treatment. On the surface, the hardness decreased due to the decrease in the amount of transformation of cementite into bainite, but there was no change beyond a certain depth.

• Korea Journal of Hospital Management
• /
• v.29 no.2
• /
• pp.48-56
• /
• 2024

Purpose: Despite growing interest in health information sharing, researchers remain uncertain whether hospitals' sharing of information increases patient satisfaction, one of the key measures of the quality of care. This study evaluates the effect of health information sharing on patient satisfaction and whether the effect varies with context. Methodology: Regression analysis was conducted using a sample consisting of 6,641 year-hospital observations, based on data from the annual and IT surveys of the American Hospital Association (AHA) and Census. Findings: Our results suggest that information sharing using health IT increases patient satisfaction, while the extent (breadth) of information sharing increases patient satisfaction, the level of detail (depth) of information sharing does not. Our results also show that the effects of the breadth and depth of information sharing vary with different contexts, e.g., the percentage of people over 65 and Hirschman-Herfindahl index (HHI). Practical Implications: Policymakers should pay greater attention to realizing the full benefits of hospitals' information sharing based on market characteristics.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.321-322
• /
• 2002

This paper presents study of effects of cutting parameters such as cutting speed, feed rate and depth of cut on the surface roughness in hard turning. Taguchi Method and linear regression model of design parameters were utilized to identify the controlling process parameters that can monitor the surface roughness in the hard turning operation. In the process optimization, experimental planning was performed using the orthogonal array and concept of the signal-to-noise ratio. Cutting parameters such as speed, feed rate, and depth of cut were selected as process parameters and the ANOVA analysis showed that feed rate and cutting speed had more effect on the roughness variation that depth of cut.

• Geomechanics and Engineering
• /
• v.6 no.5
• /
• pp.487-502
• /
• 2014

A three dimensional finite element model was used to simulate rapid impact compaction (RIC) in loose granular soils using ABAQUS software for one impact point. The behavior of soil under impact loading was expressed using a cap-plasticity model. Numerical modeling was done for a site in Assalouyeh petrochemical complex in southern Iran to verify the results. In-situ settlements per blow were compared to those in the numerical model. Measurements of improvement by depth were obtained from the in-situ standard penetration, plate loading, and large density tests and were compared with the numerical model results. Contours of the equal relative density clearly showed the efficiency of RIC laterally and at depth. Plastic volumetric strains below the anvil and the effect of RIC set indicated that a set of 10 mm can be considered to be a threshold value for soil improvement using this method. The results showed that RIC strongly improved the soil up to 2 m in depth and commonly influenced the soil up to depths of 4 m.

• Computers and Concrete
• /
• v.20 no.2
• /
• pp.129-143
• /
• 2017

Seismic design of reinforced concrete (RC) structures requires a certain minimum level of flexural ductility. For example, Eurocode EN1998-1 directly specifies a minimum flexural ductility for RC beams, while Chinese code GB50011 limits the equivalent rectangular stress block depth ratio at peak resisting moment to achieve a certain nominal minimum flexural ductility indirectly. Although confinement is effective in improving the ductility of RC beams, most design codes do not provide any guidelines due to the lack of a suitable theory. In this study, the confinement for desirable flexural ductility performance of both normal- and high-strength concrete beams is evaluated based on a rigorous full-range moment-curvature analysis. An effective strategy is proposed for flexural ductility design of RC beams taking into account confinement. The key parameters considered include the maximum difference of tension and compression reinforcement ratios, and maximum neutral axis depth ratio at peak resisting moment. Empirical formulae and tables are then developed to provide guidelines accordingly.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.2
• /
• pp.105-110
• /
• 2017

We propose a effectiveness of the assistant pad during cardiopulmonary resuscitation and provide basic data for high quality cardiopulmonary resuscitation. The subjects of the study were 28 students in the emergency department who completed the BLS Health Care-Provider under the experimental study by the randomized crossover design. Data were analyzed by using SPSS 20.0 Version. The results of this study showed that chest compressions using assistant pads decreased pain and fatigue than normal chest compressions, and the depth of chest compressions was deeper than normal depth. The results of this study shows that the use of assistant pads between the one hand and the other hand during cardiopulmonary resuscitation may increase accuracy and depth were improved. Therefore intensive indicator also improved. However, with regard to the use of assistant pads, further studies will be needed to identify the potential for clinical use.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.3 no.3
• /
• pp.98-103
• /
• 1979

The fatigue limit of an ion-nitrided steel was investigated experimentally and analytically. It is found that fatigue limit can singificantly be increased by ion-nitriding, and that the case depth is the most important parameter which determines the fatigue limit. The data indicate that fatigue limit increases with the case depth as well as the surface hardness of the nitrided steel. The fracrographs of the fracture surfaces taken by a scanning electron microscope show that the fisch-eye is located at the subsurface of failed specimens. Assuming that crack propagates from the subsurface inclusions, an analytical model is proposed to predict the fatigue limit. Taking into account the stress distrbution of a nitrided specimen, fatigue limit is predicted as a function of the case depth. The proposed semiemprical formula agrees satisfactorily with the experimental data obtained from rotating beam fatigue testing.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.959-961
• /
• 2003

Cirrus clouds observation was conducted using a lidar system in order to measure their height, thickness and optical depth at Kwangju (35$^{\circ}$10'N, 126$^{\circ}$53'), Korea in winter, December 2002, and spring March and April 2003. Cirrus clouds at high altitude can be distinguished from atmospheric aerosols location by high depolarization ratio and high altitude. Cirrus clouds were observed at 5${\sim}$12km altitudes with a high depolarization ratio from 0.2 to 0.5. Optical depth of cirrus clouds had varied from 0.28 to 1.81. Radiative effect of observed cirrus cloud on climate system was estimated to be negative net flux from ?0.24 to ?31.04 W/m$^{2}$.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.6
• /
• pp.29-35
• /
• 2010

Recently the industry high-speed machining has been applied to the automotive, aircraft, electronics parts machining because the effect of cost savings, machining time reduction and productivity improvement. In this study recently the aircraft structural aluminum alloy 7075 used in cutting the ball end-mill on the surface roughness terms most affect the parameters of the spindle speed and feed rate on the surface roughness of the work-piece according to the cutting depth is to investigate. Cutting depth at 0.3 mm has the lowest surface roughness.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.1
• /
• pp.143-151
• /
• 2005

This paper study the effect of open cracks on the dynamic behavior of simply supported Timoshenko beam with a moving mass. The influences of the depth and the position of the crack in the beam have been studied on the dynamic behavior of the simply supported beam system by numerical method. Using Lagrange's equation derives the equation of motion. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modeled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces on the crack section and is derived by the applying fundamental fracture mechanics theory. As the depth of the crack is increased the mid-span deflection of the Timoshenko beam with the moving mass is increased. And the effects of depth and position of crack on dynamic behavior of simply supported beam with moving mass are discussed.