• Steel and Composite Structures
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• v.25 no.1
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• pp.79-92
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• 2017

Initial damage to a stud due to corrosion, fatigue, unexpected overloading, a weld defect or other factors could degrade the shear capacity of the stud. Based on typical push-out tests, a FEM model and theoretical formulations were proposed in this study. Six specimens with the same geometric dimensions were tested to investigate the effect of the damage degree and location on the static behavior and shear capacity of stud shear connectors. The test results indicated that a reduction of up to 36.6% and 62.9% of the section area of the shank could result in a dropping rate of 7.9% and 57.2%, respectively, compared to the standard specimen shear capacity. Numerical analysis was performed to simulate the push-out test and validated against test results. A parametrical study was performed to further investigate the damage degree and location on the shear capacity of studs based on the proposed numerical model. It was demonstrated that the shear capacity was not sensitive to the damage degree when the damage section was located at 0.5d, where d is the shank diameter, from the stud root, even if the stud had a significant reduction in area. Finally, a theoretical formula with a reduction factor K was proposed to consider the reduction of the shear capacity due to the presence of initial damage. Calculating K was accomplished in two ways: a linear relationship and a square relationship with the damage degree corresponding to the shear capacity dominated by the section area and the nominal diameter of the damaged stud. This coefficient was applied using Eurocode 4, AASHTO LRFD (2014) and GB50017-2003 (2003) and compared with the test results found in the literature. It was found that the proposed method produced good predictions of the shear capacity of stud shear connectors with initial damage.

• Journal of Korean Elementary Science Education
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• v.23 no.1
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• pp.44-49
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• 2004

This study was based upon the survey on the name of 13 basic experimental instruments used in elementary science class: Schale, evaporating dish, mortar & pestle, beaker, erlenmeyer flask, spuit(medicine dropper), graduated cylinder, balance, spatula, dropping bottle, gas collecting bottle, funnel, alcohol burner, and their uses. To implement this study, an open-ended, written questionnaire was administered to the subjects of in-service elementary school teachers, future elementary teachers who have attended at the Gyeongin national university of education, and elementary students in Korea. The findings of this study were as follows: The rates of in-service and pre-service elementary school teachers that knew correct name of experimental instruments were not high, the elementary school student's rates were especially very low. In this study, we found several reasons which they wrote inaccurately: the name to be represented at the textbook that they had studied, the confusion of the name about a fortis pronunciation, the recognition as the vocabulary like flask and cylinder to be meaningless, the habit to say in an everyday life, wrong expression in the internet and general book. All respondents had a wide range of perceptions of uses for the experimental instruments. Their understanding of uses for evaporating dish, erlenmeyer flask, balance, gas collecting bottle were very poor. And then most of them understood that graduated cylinder, beaker, and erlenmeyer flask were tools to measure the volume of solution or liquid, so they did not exactly distinguish the difference of their uses.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.73-81
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• 2003

The controlled load service defined within the IETF's Integrated Services architecture for quality-of-service (QoS) in the Internet requires source nodes to regulate their traffic while the network, in combination with an admission control strategy, provides a guarantee of performance equivalent to that achieved in a lightly loaded network. Packets sent in violation of the traffic contract are marked so that the network may assign them a lower priority in the use of bandwidth and buffer resources. In this paper, we define the requirements of a scheduler serving packets belonging to the controlled load service and present a novel scheduler that exactly achieves these requirements. In this set of requirements, besides efficiency and throughput, we include an additional important requirement to bound the additional delay of unmarked packets caused due to the transmission of marked packets while dropping as few marked packets as possible. Without such a bound, unmarked packets that are in compliance with the traffic contract are not likely to experience delays consistent with that in al lightly loaded network. For any given desired bound ${\alpha}$ on this additional delay, we present the CL(${\alpha}$) scheduler which achieves the bound while also achieving a per-packet work complexity of O(1) with respect to the number of flows. We provide an analytical proof of these properties of the CL(${\alpha}$) scheduler, and we also verify this with simulation using real traces of video traffic. The scheduler presented here may be readily adapted for use in scheduling flows with multi-level priorities such as in some real-time video streams, as well as in other emerging service models of the Internet that mark packets to identify drop precedences.

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.97-103
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• 2004

In case of a fire in road or railway tunnel it is always necessary to keep the escape condition as good as possible. Most of the victims of major fires in tunnels are because they couldn't leave the tunnel in time and were trapped by smoke, or rescue teams couldn't reach the place of the accident due to low visibility and high temperature. In spring 2003 a comprehensive field experiment was undertaken in a large scaled tunnel in Youngin City to test the effectiveness of a new water spray curtain system, designed to the air qualify inside of a tunnel in case of fire during passenger's escape to safe routes, In order to control the smoke propagation, fixed water sprayed nozzles were used to make water curtain system, which can be installed or hanging water piping line below ceiling. The experiment was accompanied by an extensive measurement campaign in order to measure temperature dropping effect and flow conditions as well as CO concentration for various water sprayed curtains produced by sprinkler heads or water spray nozzle. Eventually comparison analysis were undertaken to investigate the performance of water curtains under fixed water pressure. Therefore most effective water curtain system was presented on the basis of water droplet size in long tunnel.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.67-71
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• 2007

Objectives : This experimental study was performed to investigate the continuous anti-bacterial potency of Tangpo-san on cultivation of Staphylococcus species(S. aureus, S. epidermidis)that induce eye disease. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to 50 ${\mu}$l diluted Tangpo-san(100%, 10%, 1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. Anti-bacterial potency was measured by the size of inhibition zone with change of volume(20 ${\mu}$l,30 ${\mu}$l,40 ${\mu}$l,50 ${\mu}$l). Results : 1. Anti-bacterial potency of Tanpo-san on S. aureus was not appeared all samples. Anti-bacterial potency with change of volume was increased in propotion to increase volume, and the Anti-bacterial potency of 2 days was equal to 6 days. Anti-bacterial potency of Tangpo-san on S. aureus was appeared continuous. 2. Anti-bacterial potency of Tangpo-san on S. epidermidis was appeared in 100%, 10% on 2 and 6 days, and the Anti-bacterial potency of 6 days was decreased. In 2 days, Anti-bacterial potency was appeared 40 and 50u1, in 6 days, Anti-bacterial potency was appeared all samples. Anti-bacterial potency with change of volume was increased in propotion to increase volume and increased on 6 days, but bacteria was increased. Anti-bacterial potency of Tangpo-san on S. epidermidis wasn't appeared continuous. Conclusions : Anti-bacterial potency of Tangpo-san on cultivation of S. aureus showed continuous, but on cultivation of S. epidermidis was not showed continuous.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.19-23
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• 2007

Objectives : This experimental study was performed to investigate the continuous anti-bacterial potency of Sean-tang on cultivation of Staphylococcus species(S. aureus, S. epidermidis) that induce eye disease. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to 50${\mu}$l diluted Sean-tang(100%, 10%,1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. 1. Anti-bacterial potency was measured by the size of inhibition zone with change of volume(20${\mu}$l, 30${\mu}$l, 40${\mu}$l, 50${\mu}$l). Results : 1. Anti-bacterial potency of Sean-tang on S. aureus was appeared in 100% and increased on 6 days. Anti-bacterial potency with change of volume was increased in propotion to increase volume. Anti-bacterial potency of Sean-tang on S. aureus was appeared continuous. 2. Anti-bacterial potency of S. epidermidis was appeared in 100%, 10%, 1% on 2 days and in100%, 10% on 6 days. In 100% Sean-tang, Anti-bacterial potency of 6 days was increased, in 10%, 1%, Anti-bacterial potency of 2 days was increased. Anti-bacterial potency with change of volume was increased inpropotion to increase volume and increased on 6 days, but bacteria was increased. Anti-bacterial potency Sean-tang on S. epidermidis wasn't appeared continuous. Conclusions : Anti-bacterial potency of Sean-tang on cultivation of S. aureus was showed continuous, but on cultivation of S. epidermidis was not showed continuous.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.87-91
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• 2007

Objectives : This experimental study was performed to investigate the continuous anti-bacterial potency of Jinpi-san on cultivation of Staphylococcus species(S. aureus, S. epidermidis) that induce eye disease. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to 50${\mu}$l diluted Jinpi-san(100%, 10%, 1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. Anti-bacterial potency was measured by the size of inhibition zone with change of volume(20${\mu}$l, 30${\mu}$l, 40${\mu}$l, 50${\mu}$l). Results : 1. Anti-bacterial potency of Jinpi-san on S. aureus was appeared in 100% and increased on 6 days. Anti-bacterial potency with change of volume was increased in propotion to increase volume. Anti-bacterial potency of Jinpi-san on S. aureus was appeared continuous. 2. Anti-bacterial potency of Jinpi-san on S. epidermidis was appeared in 100%, 10%, 1% on 2 days and in 100%, 10% on 6 days. In 100% Jinpi-san, Anti-bacterial potency of 6 days was increased, in 10%, Anti-bacterial potency of 2 days was increased, in 1%, Anti-bacterial potency of 6 days was disappear. Anti-bacterial potency with change of volume was increased in propotion to increase volume except for 20${\mu}$l of 6days and increased on 6 days, but bacteria was increased. Anti-bacterial potency of Jinpi-san on S. epidermidis wasn't appeared continuous. Conclusions : Anti-bacterial potency of Jinpi-san on cultivation of S. aureus was showed continuous, but on cultivation of S. epidermidis was not showed continuous.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.25-38
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• 2010

This study focused on the analysis of satisfaction and preference of residents' for water space as a environmental friendly facility in residential complex. The purpose of this study is to serve design data of water space in residential complex, in order to make water space that residents' satisfaction are high. In this study, residents' satisfaction and preferences of water space in 5 residential complex were analyze through a questionnaire survey of residents. The major findings of the study are as follows. First, in terns of the need of the water space, 60.4% of the respondents answered that water space are need to improve the amenity. Secondly, in terms of satisfaction, 57.3% of the respondents have been satisfied with location of water space in the residential complex, and the maintenance satisfaction degree is above average level. Overall satisfaction degree is above average level too, but it is are not high as compared construction cost. Thirdly, in terms of preference, 26.5% of respondents have been prefer to the combined type of water space, and 25.9% of respondents prefer to dropping water type, and 25.9% of respondents prefer to flowing stream type. It appeared that the preference levels of 3 type is high similarly, so we can assume that residents prefer to moving water type because of having a feeling refreshed through the sound of water. The results of this study can be used as the design data of water space in residentialcomplex and expected to contributed in making the water space that residents' satisfaction are high.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.3
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• pp.85-90
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• 2014

In this paper, we propose a virtual violin implementation using the detection of bowing and finger dropping position from the estimated finger tip and finger board information with the 3D image data from a Kinect. Violin finger board pattern and depth information are extracted from the color image and depth image to detect the touch event on the violin finger board and to identify the touched position. Final decision of activated musical alphabet is carried out with the finger drop position and bowing information. Our virtual violin uses PC MIDI to output synthesized violin sound. The experimental results showed that the proposed method can detect finger drop position and bowing detection with high accuracy. Virtual violin can be utilized for the easy and convenient interface for a beginner to learn playing violin with the PC-based learning software.

• Restorative Dentistry and Endodontics
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• v.28 no.6
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• pp.457-466
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• 2003

The aim of study was to investigate the effect of flow, specimen geometry and adhesion on the measurement of linear polymerization shrinkage of light cured composite resins using linear shrinkage measuring device. Four commercially available composites - an anterior posterior hybrid composite Z100, a posterior packable composite P60 and two flowable composites, Filtek flow and Tetric flow-were studied. The linear polymerization shrinkage of composites was determined using 'bonded disc method' and 'non-bond-ed' free shrinkage method at varying C-factor in the range of 1∼8 by changing specimen geometry. These measured linear shrinkage values were compared with free volumetric shrinkage values. The viscosity and flow of composites were determined and compared by measuring the dropping speed of metal rod under constant load. In non-bonded method, the linear shrinkage approximated one third of true volumetric shrink-age by isotropic contraction. However, in bonded disc method, as the bonded surface increased the linear shrinkage increased up to volumetric shrinkage value by anisotropic contraction. The linear shrinkage value increased with increasing C-factor and approximated true volumetric shrinkage and reached plateau at about C-factor 5∼6. The more flow the composite was, reduced linear shrinkage was measured by compensation radial flow.