• Proceedings of the KSR Conference
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• 2009.05a
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• pp.593-598
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• 2009

This paper presents a preliminary study to monitor the lateral behavior of pile foundation using multiplexed fiber Bragg grating (FBG) sensors. In the preliminary study, an 1.7 meter long cantilever beam with the shape of square hollow box was fabricated and tested under the static loading. Four FBG sensors were multiplexed in a single optical fiber and installed into the top and bottom of the cantilever beam. The strains are directly measured from FBG sensors followed by curvature calculations based on the plane section assumption. Vertical deflections are then estimated using the regression analyses based on the geometric relationships. It has been found that excellent correlation with conventional sensing system was observed. The success of the test encourages the use of the FBG sensing system as a monitoring system for pile foundations. However, further consideration should be given in the case of the sensor malfunction for the practical purpose.

• Journal of Auto-vehicle Safety Association
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• v.5 no.2
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• pp.5-10
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• 2013

The pole side crash caused fatal injury by comparison with other crash impact mode such as frontal and rear crash. EuroNCAP proposed the pole side crash test using WorldSID(World Side Impact Dummy). The objective of this study is to develop the pole side impact sled test using dummy rib deflection between crash and sled test. In the pursuit of this purpose, we fabricated new pole side sled buck and test preliminary pole sled using ES-2re. Through this, we found the sled acceleration pulse scale. Hardness and thickness of the EPP affects the rib deflection. We conducted the pole sled test using WorldSID based on the preliminary results. As a result, rib deflection was shown to correlate well between crash test and pole side sled test.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.445-450
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• 2007

CWR(Continuous Welded Rail) and bridge interaction produce rail force, bridge displacement and rail/bridge relative displacement. Each of these has limitation by many codes. In this paper, analysis of interaction has been carried out by using foreign codes(UIC 774-3 R code of Europe etc.) because there is no code about interaction between rail and bridge in Korea. Recently, railway bridges with CWR has been constructed for structural and economical reasons. When designer plans railway bridges, design a bridge model first and then investigate railway forces and displacement by interaction analysis. If these results go out bounds from limitation, designer plans railway bridges again and again. In this paper, using the parametric study on CWR and railway bridge interaction, railway bridge parameters such as length of bridge span, area of bridge, moment of inertia, stiffness of pier, etc. are presented. It helps preliminary design of railway bridges.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.63-65
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• 1993

We have done a preliminary study on the detection of ventricular late potentials using high-resolution electrocardiography. We designed a battery powered low-noise ECG amplifier. We used the XYZ lead system and the amplifier provides 3 channels of X, Y, and Z signals with a conventional gain and another 3 channels of the amplitude-limited X, Y, and Z signals with high-gain. 12-bit data acquisition system interfaces the amplifiers to a personal computer for further signal analysis. Beat alignment algorithm was implemented on the low-gain signals to synchronize the signal averaging of the high-gain amplitude-limited signals. We suggest the use of the weighted vector sum of X', Y', and Z' signals based on the SNR of each channel. We speculate that this new method will increase the accuracy of the LP detector at the expense of more complicated hardware.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.591-598
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• 2006

Port development has been remarkably increasing due to the progress of industrialization in ASEAN area. Especially, Vietnam has increased the international physical distribution in this area rapidly. The main issues facing decision makers at container terminals in Vietnam are how to expand the existing container terminals and construct new container terminals. In this paper, we performed the basic design based on simulation analysis in order to support the expansion of Quy Nhon port in Vietnam as a case study. The preliminary capacity analysis was conducted on the one berth at the port to analyze the scale of C/C(Container Crane)and yard area. Alternative scenarios were created based on the preliminary capacity analysis and the detailed simulation analysis was conducted for supporting the scenarios.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.119-120
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• 2015

Appropriate management of the finish works in construction project is one of most important activities that must be conducted considering the total duration of the project. Masonry work is a fundamental process that is performed in the preliminary steps of finish works. However, it has been investigated that the analysis of delay factors affecting masonry work has been neglected in the domestic construction site. Therefore, this study deducts delay factors affecting masonry work by literature review and survey on site engineers and labors. This study has been conducted as a preliminary step of developing a construction project interference management system which is expected to suggest objective information for the decision making in construction sites.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.105-111
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• 2010

The purpose of this study was to detect early children with hyperactivity which is one of the symptoms of Attention Deficit-Hyperactivity Disorder (ADHD). This study used two methods: K-CBCL and observation of children's behavior. K-CBCL was done online by parents at home. For observation of children's behavior, the school asked children to wear a 3-axis accelerometer on their wrists. The data from K-CBCL and 3-axis accelerometer were analyzed and clustered to separate hypersensitive children from ordinary children. This experiment confirmed that 3-axis accelerometer which is one of Ubiquitous techniques and the K-CBCL questionnaire were helpful for detection of hypersensitive children.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.2
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• pp.1-7
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• 1984

This paper is concerned with an optimum design study of containerships in preliminary stage by applying economic criteria. The Net Present Value Index (NPVI) and the Required Freight Rate(RFR) are used as measures of merit. Hooke & Jeeves direct search method and External Penalty Function method of Sequential Unconstrained Minimization Techniques(SUMT) are used for solving constrained nonlinear optimization problem. Sensitivity analysis is carried out to investigate the effect on the optimum solution due to change of values in some parameters such as crane capacity, load factor, oil price, ship speed and the ratio between loaded FEU and TEU.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.300-305
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• 2004

A preliminary study on. field emitter array cathodes was conducted aiming at applying for electrodymanic tether (EDT) propulsion systems. The EDT propulsion systems are assumed to use for active removal systems of post-mission spacecraft, which would otherwise become space debris. A survey on field emit-ter array cathode technology was conducted, and it showed that carbon nanotube (CNT) emitters are suit-able to EDT application. Trial fabrications and evaluation tests of CNT emitters were conducted, which demonstrated a target emission current density of 10 ㎃/$\textrm{cm}^2$. It was found out that the most important technical issue for developing CNT emitters is to improve the performance against voltage breakdown between the emitter and the opposite electrode.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.157-164
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• 1998

preliminary study on the chemical compositions of forty seven precipitations from March 1994 to May 1995 In Yeoncheon-gun, which Is adjacent to the southern boundary of demilitarized zone (DMZ) in the northernmost tip of Kyunggi Province has been Performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion chromatography, respectively. pH/lon meter and direct nesslerization method were used for the concentration measurements of $H^+$ ion and $NH_46+$ ions, respectively Based on the data, the quantitative orders of the cation and anion average concentrations were $Ca^{2+}>NH_4^+>Na^+>K^+>Mg^{2+}>H^+ and SO_4^{2+}>Cl^-> NO_3^-$, respectively..The ratio of average total anion concentration to average total cation concentration was 0.97. The average pH value of the precipitations was 5.60. These results, correlation coefficients between the ion concentrations, and monthly variations of pH value and precipitation amount are used for chemical analysis on the environmental Pollution and Pollutant sources In Yeoncheon-gun of Kyunggi province near DMZ.