• Magazine of the Korea Concrete Institute
• /
• v.10 no.4
• /
• pp.93-100
• /
• 1998

This paper presents a study on the flexural stiffness, plastic hinge length and plastic hinge rotation capacity of reinforced high performance concrete beams. 15 beams with different strength of concrete, reinforcement ratio and the pattern of loadings were tested. From the test results of reinforced normal strength concrete beams and reinforced high performance concrete beams with the concrete which has cylinder compressive strength of 700kg/${cm}^2$, slump value of 20~25cm and slump-flow value of 60~70cm. It is found that an extreme fiber concrete compressive strain of ${\varepsilon}_{cu}=0.0047$ may be used in ultimate curvature computations of reinforced high performance concrete beams. An empirical equation is proposed to estimate the effective moment of inertia. length and rotation capacity of plastic hinge of simply supported reinforced high performance concrete beams. The estimated deflections using this equation agree well with the experimental values.

• KIEAE Journal
• /
• v.7 no.5
• /
• pp.135-142
• /
• 2007

This is an experimental study on the structural characteristics of reinforced concrete beams using of the oyster shells as a substitute fine aggregate of concrete. In this study, the main factors consist of the grain sizes and the percentage of substitution of oyster shells to fine aggregate in the equal water cement ratio. The results of the study showed as followed. The initial load value of them represented similar constant within 10% of the maximum load value in each test beam. But the maximum load value and the ultimate load value decreased with increased grain size and the rate of substitution. As the grain size of oyster shells became smaller, the load values of them were somewhat higher. The deflection among deformation properties of reinforced concrete beams with oyster shells represented typical curves like that of normal reinforced concrete. In the deformation of steel and concrete, the deformation was proportionated to the load till yield point and from yield point until approaching the ultimate load point. One type was typical curve of the load and the deformation and the other type irregularly was changed to very small deformation for the load increase centering around load axis. After the analyzing structural behaviors and the properties of reinforced concrete test beams with oyster shells, the most excellent grain size of oyster shells represented 1.0mm and less or 5.0mm and less with taking uniformly, and the percentage of practicable substitution of them to fine aggregate was about 30%.

• Computers and Concrete
• /
• v.20 no.4
• /
• pp.491-502
• /
• 2017

In this research, the application of ultrasonic pulse velocity (UPV) test as a nondestructive method for estimating some of the mechanical and dynamic properties of reactive powder concrete (RPC) containing steel and polyvinyl alcohol (PVA) fibers, as well as their combination was explored. In doing so, ten different mix designs were prepared in 19 experimental groups of specimens containing three different volume contents of steel fibers (i.e., 1, 2, and 3 %) and PVA fibers (i.e., 0.25, 0.5, and 0.75 %), as well as hybrid fibers (i.e., 0.25-0.75, 0.5-0.5, and 0.75-0.25 %). The specimens in these groups were prepared under the two curing regimes of normal and heat treatment. Moreover, the UPV test results were employed to estimate the compressive strength, dynamic modulus, shear modulus, and Poisson's ratio of the RPC concrete and to investigate the quality level of the used concrete. At the end, the effect of the specimen shape and in fact the measuring distance length on the UPV results was explored. The results of this research suggest that the steel fiber-containing RPC specimens demonstrate the highest level of ultrasonic pulse velocity as well as the highest values of the mechanical and dynamic properties. Moreover, heat treatment has a positive effect on the density, UPV, dynamic modulus, Poisson's ratio, and compressive strength of the RPC specimens, whereas it leads to a negligible increase or decrease in the shear modulus and static modulus of elasticity. Furthermore, the specimen shape affects the UPV of fiber-lacking specimens while negligibly affecting that of fiber-reinforced specimens.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.34 no.5 s.118
• /
• pp.1-13
• /
• 2006

The Attention Restoration Theory (ART) developed by Kaplan and Kaplan proposes that effortful directed attention required in normal life can be fatigued. Restoration can occur in a setting that has restorative qualities. The restorative quality described by the ART involves four concepts: being away, fascination extent, and compatibility. The purpose of this study was to investigate how the restorative quality of landscape influenced the preferences and satisfaction of visitors to an heritage landscape. Four kinds of heritage landscapes of Kyongju were used as environmental surrogates and 150 americans participated in the study. Hartig et al.'s Revised Perceived Restorativeness Scale (RPRS) was used as the psychological measure for the restorative quality, along with other measurement constructs such as cultural uniqueness and novelty. The results showed that RPRS was a reliable measurement tool for assessing the restorative quality of artificial landscapes. Factor analysis identified three valid factors: escape-fascination compatibility, anti-extent. Among the three factors, only two, escape-fascination and compatibility, were found to have important effects on visiting preference and satisfaction. Specifically, higher levels of preference and satisfaction were associated with higher levels of escape-fascination and compatibility. The results indicate that the restorative quality has a high possibility to be used as a frame of reference for assessing various types of landscapes, from natural to artificial. It was also proposed that restorative quality could better explain the experience of the landscape strongly related to specific purpose or motivation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.12
• /
• pp.5588-5593
• /
• 2011

In this paper, measure of change the speech analysis parameter by stimulating ears blood points corresponding to cardiac. To do this, we collected voice of before and after a stimulation corresponding points to ears to select normal heart having 10 subjects. We analyzed changes before and after corresponding points to ear in cardiac to apply Jitter, the second zFormant Frequency Bandwidths related to heart of elements of voice analysis. As a result of us experiment, we were able to analyze correlation of voice with cardiac according to corresponding points to ears decreased values of Jitter, the Second Formant Frequency Bandwidths of 90% of subjects. Finally, the effectiveness of proposed method is demonstrated by several experiments.

• Genomics & Informatics
• /
• v.11 no.4
• /
• pp.263-271
• /
• 2013

We investigated the contribution of genetic variations of KLF5 to basal metabolic rate (BMR) and resting metabolic rate (RMR) and the inhibition of obesity in Korean children. A variation of KLF5 (rs3782933) was genotyped in 62 Korean children. Using multiple linear regression analysis, we developed a model to predict BMR in children. We divided them into several groups; normal versus overweight by body mass index (BMI) and low BMR versus high BMR by BMR. There were no differences in the distributions of alleles and genotypes between each group. The genetic variation of KLF5 gene showed a significant correlation with several clinical factors, such as BMR, muscle, low-density lipoprotein cholesterol, and insulin. Children with the TT had significantly higher BMR than those with CC (p=0.030). The highest muscle was observed in the children with TT compared with CC (p=0.032). The insulin and C-peptide values were higher in children with TT than those with CC (p=0.029 vs. p=0.004, respectively). In linear regression analysis, BMI and muscle mass were correlated with BMR, whereas insulin and C-peptide were not associated with BMR. In the high-BMR group, we observed that higher muscle, fat mass, and C-peptide affect the increase of BMR in children with TT (p < 0.001, p < 0.001, and p=0.018, respectively), while Rohrer's index could explain the usual decrease in BMR (adjust $r^2$=1.000, p < 0.001, respectively). We identified a novel association between TT of KLF5 rs3782933 and BMR in Korean children. We could make better use of the variation within KLF5 in a future clinical intervention study of obesity.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.11
• /
• pp.80-85
• /
• 1996

The various function of the cardiovascular system(CVS) and the dynamic characteristics on each part of human body can be acquired in the electric analog circuit model. According to the performed outcome by other researchers, viscos resistance, flow inertia, and vascular compliance in the CVS are analogous to resister, inductor, and capacitor in electric circuit, so the CVS models were represented by the electric circuit models. these approaches were to propose the suitable models interest part of body and to simulate the various characteristics on the CVS. In this paper, the electric circuit model considering the characteristics of morphologic structure is represented, the parameter values of model is sotted up, and the dynamic characteristics of the the CVS is simulated using VisSim, one of the simulation tools. The observed simulation results are similar to the cardiovascular functions of nomal adults who have no heart failure. Besides, the simulation is operated to observe the pathophysiological abnomal symptoms(for example, bleeding within a certain period). The controller by baroreceptor, which is one of controllers to control the CVS, is appended in the model. and the dynamic response characteristics and the procedure to return normal state is observed in simulation when the bleeding last within a certain period.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.05
• /
• pp.88-90
• /
• 1996

The right and left atrial pressures are important parameters in automatic control of a total artificial heart (TAH) within normal physiological ranges. Our TAH is composed of a moving actuator, right and left ventricles and the interventricular space enclosed by a semi-rigid housing. During operation of the TAH, the jnterventpicular space's volume is changed dynamically by the difference between the ejection volume of one ventricle and the inflow volume of the other. Therefore, the changes in pressure of the interventricular space is related to both atrial pressures. We measured the interventricular pressure (IVP) waveform using a pressure sensor and attempted to indirectly estimate the changes of atrial pressures. This method has an advantage that the sensor does not contact the blood directly. Furthermore, the IVP waveforms have its zero baseline in each pump cycle, thus the pressure measurements are free from the transducer drift problems by measuring the peak pressure from these baseline values. From the In vitro experiments, we found that the IVP waveform contained several useful parameters such as negative peak, dP/dT on the initial break, the area enclosed by the profile in each stroke, which are associated with atrial pressures and the filling conditions of the ventricles. The measured atrial pressures were linearly related to the negative peak of the interventricular pressure.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.9
• /
• pp.6254-6259
• /
• 2015

On the optical system and the system itself of the noise of the noise from the outside always present. This noise is to function as reducing performance of the optical system. Therefore, the probability of error, thereby changing the system. In this paper, the error probability of the optical system due to changes in various values by introducing the characteristic variable the value of the optical system was calculated using the ${\kappa}$-square method. Was confirmed also in accordance with the calculation result is an error probability of the optical system changes, it was confirmed that when the value of the holding case for holding the standard about 400 Lux on the probability of the optical system. This case was found to be an optical system using a light source with a low output, so that means the smaller output is no problem to maintain the error probability value of the optical system is large. This means that more effective and less expensive to implement because it means that the optical system does not require the use of pre-amplifier for amplifying the signal at the receiving end of an optical system using a light source with a low output when the normal case.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.2
• /
• pp.439-446
• /
• 2017

Portable low-cost Kinect sensor was used to analyze standing balance ability of the elderly. Eighty subjects who can walk alone and have a normal cognitive level participated in this experiment. Based on Berg Balance scale (BBS) test with 52 points, subjects were divided into Healthy older (HO: 46 persons, BBS: $53.80{\pm}1.19$) and Impaired older (IO: 34 persons, BBS: $49.06{\pm}2.03$) group. Each subject performed 30 seconds four different standing balance tests (EO: Eyes Open, EC: Eyes Close, EOf: Eyes Open on foam, ECf: Eyes Close on foam). Five variables (Mean distance, Range of distance, Root mean square, Mean velocity, 95% ellipse area) were calculated from the hip joint center movement of Kinect sensor. Results showed that there were significant differences between groups for four different standing tests. Calculated variables from kinect sensor showed significant correlation with BBS score. Especially, mediolateral mean distance, mediolateral root mean square, mediolateral range of distance and 95% ellipse area showed discriminative ability for all tests. Mean values of variables of IO were higher than those of HO, which means the decreased balance ability in IO compared with HO. Therefore, it was possible to estimate simple balance assessment of the elderly using portable low-cost Kinect sensor.