• Spatial Information Research
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• v.19 no.2
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• pp.19-28
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• 2011

Three dimensional modeling for seafloor topography is essential to monitoring displacements in underwater structures as well as all sorts of disasters along the shore. MBES is a system that is capable of high-density water depth measurement for seafloor topography and is in broad uses for gathering 3D data and detecting displacements. MBES data, however, contain random errors that take place in the equipment offset and surveying process and require systematic researches on the correction of wrong depth measurements. Thus this study set out to propose a post-processing technique to eliminate an array of random errors taking place after equipment offset correction and basic noise correction in the MBES system and analyze its applicability to seafloor topography modeling by applying it to the subject area.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.275-282
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• 2013

Applications such as vibration isolation, gravity compensation, pick-and-place machines, etc., would benefit from (long-stroke) cylindrical/tubular permanent magnet (PM) actuators with integrated passive gravity compensation to minimize the power consumption. As an example, in component placing (pick-and-place) machines on printed circuit boards, passive devices allow the powerless counteraction of translator including nozzles or tooling bits. In these applications, an increasing demand is arising for high-speed actuation with high precision and bandwidth capability mainly due to the placement head being at the foundation of the motion chain, hence, a large mass of this device will result in high force/power requirements for the driving mechanism (i.e. an H-bridge with three linear permanent magnet motors placed in an H-configuration). This paper investigates a tubular actuator topology combined with passive gravity compensation. These two functionalities are separately introduced, where the combination is verified using comprehensive three dimensional (3D) finite element analyses.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2749-2753
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• 2009

Structural characteristics that influence on the insecticidal activity ($pI_{50}$) of 2-(n-octyl)isothiourea analogues (1-45) against the diamondback moth (Plutella xylostella, L.) based on three dimensional quantitative structure activity relationships (3D-QSARs) were discussed quantitatively using a comparative molecular field analysis (CoMFA) and a comparative molecular similarity indeces analysis (CoMSIA) methods. The statistical values of the CoMFA 2 model were better than those of the CoMSIA 1 model. The CoMFA 2 model was the optimized model with the correlativity (the training set: Ave. = 0.104 & PRESS = 0.613) and the predictability (the test set: Ave. = 0.086 & PRESS = 0.096). Insecticidal activities with the optimized CoMFA 2 model were dependent upon steric factors (79.4%) of $R_1-R_3$ substituents. From the analytical results of CoMFA contour maps, it is predicted that the R1 substituent of 1-45 which has a steric favor in a broad space, $R_2\;and\;R_3$ groups with a steric favor in a narrow space and a H-bond donor favor would have better the insecticidal activity.

• Earthquakes and Structures
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• v.8 no.3
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• pp.573-589
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• 2015

In order to investigate the seismic behavior of highway bridges under near-fault earthquakes, a parametric study was conducted for different regular and irregular bridges. To this end, an existing regular viaduct Highway Bridge was used as a reference model and five irregular samples were generated by varying span length and pier height. The seismic response of the six highway bridges was evaluated by three dimensional non-linear response history analysis using an ensemble of far-fault and scenario-based near-fault records. In this regard, drift ratio, input and dissipated energy as well as damage index of bridges were compared under far- and near-fault motions. The results indicate that the drift ratio under near-fault motions, on the average, is 100% and 30% more than far-fault motions at DBE and MCE levels, respectively. The energy and damage index results demonstrate a dissipation of lower energy in piers and a significant increase of collapse risk, especially for irregular highway bridges, under near-fault ground motions.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.273-280
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• 2001

In architecture, each project participant must maintain organic relationship with others. However, current practices are rather procedural and discrete than organic, which result in considerable inefficiencies. The cool-downs of Korean construction market also force the architects to be familiar with the new construction methods and systems. This research mainly focuses on the pre-development stage of such systems, analysing relationships between the information of architectural design and other parts of construction information like structure, construction, environment, and so forth. The result of analysis can be organized into attributes of members in a physical building, which can be modeled in a 3D system. The resulting model can be used for automated generation of drawing, Bill of Materials, finite element meshes for structural analysis and energy analysis, etc. by extracting meaningful information from it. Hence, the purpose of this research is to analysis the relationship among domain-specific information (e.g. structural engineering, construction detail, energy evaluation) that are represented in drawings, and to represent the attributes of the information relevantly so that they can be applied to each unit task that forms the whole project. Therefore, an object oriented methodology is introduced to compose design informations in three dimension, and expressing properties of building factors and materials, and to construct a database for computers to recognize architecture informations.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.214-220
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• 2010

Three-dimensional(3D) structure of specific DNA can be changed between two conformations under an external environmental transition such as pH and salt concentration variations. We have experimentally observed the conformational transitions of i-motif DNA using AFM cantilever bioassay. It is shown that pH change of a solvent induces the bending defleciton change of a cantilever functionalized by i-motif DNA. This indicates that cantilever bioassay enables the label-free detection of DNA structural changes upon pH change. It is implied that cantilever bioassay can be a de novo route to quantitatively understand the conformational transitions of biological molecules under environmental changes.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.11 no.2
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• pp.84-95
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• 2007

Background and Purpose: We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. According to chaos theory, irregularity of EEG signals can result from low dimensional deterministic chaos. A principal parameter to quantify the degree of Chaotic nonlinear dynamics is correlation dimension. The aim of this study was to analyze correlation between the correlation dimension of EEG and HRV(heart rate variability). We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. Methods: EEG raw data were measured by moving windows during 15 minutes. Then, the correlation dimension(D2) was calculated by each 40-seconds-segment in 15 minutes data, totally 36 segments. 8 channels EEG study on the Fp, F, T, P was carried out in 30 subjects. Results and Conclusion: Correlation analysis of HRV was calculated with deterministic non-linear data and stochastic non-linear data. 1. Ch1(Fp1), Ch4(F3), Ch4(F4) is positive correlated with In LF. 2. Ch1(Fp1), Ch3(F3) is positive correlated with In TF.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.388-390
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• 1994

We are familiar with the holography in these days. For making holography the coherent sources like LASER are used in many fields. But coherent holography has many problems. Coherent holography needs many instrument for practical use like 3-D TV case. In solving the problem we use the non-coherent source. Nowadays many methods like conoscopic holo graphy using anisotropic crystal, shadow casting and interferometric systems are suggested. In this paper we make the hologram using the triangular interferometric systems. [1],[2],[3],[4]. We explain the afocal and double-afocal system which consists of the triangular interferometric system. The holography made in one point and two point cases is imaged on CCD camera and we handle the image data digitally for the reconstruction efficiently. In reconstructing the hologram the Fraunhofer diffraction theory is used. We adopt the rectangular aperture for the convenience of calculation. In the future we must reconstruct the perfect 3-Dimensional object by optical method. For this, we have many problems like resolution problem. We must solve these problem for perfect reconstruction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1584-1590
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• 2008

The combined query which consists of the region and trajectory query finds trajectories of moving objects which locate in a certain region. The trajectory query is very informant factor to determine query performance because it processes a point query continuously to find predecessors. This results in bad performance due to revisiting nodes in an index. This paper suggests an efficient method for the combined query based on the 3-dimensional R-tree which has good performance of the region query. The basic idea is that we define the least common search line which enables to search single path and a filtering method based on prediction without revisiting nodes.

• Korean Journal of Remote Sensing
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• v.19 no.3
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• pp.181-190
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• 2003

Since the operation of the first satellite-based navigation service, satellite positioning has played an increasing role in both surveying and geodesy, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with CPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the CPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-dimensional digital map. Through this developed simulation system, it is possible to calculate the number of simultaneously visible satellites and available area for positioning without the need of actual observation. Furthermore, this system can calculate the Dilution Of Precision (DOP) and the error distribution.