• Steel and Composite Structures
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• v.50 no.2
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• pp.149-158
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• 2024

Considering that different boundary conditions can have an important impact on structural vibration characteristics. In this paper, the nonlinear forced vibration behavior of functionally graded material (FGM) doubly curved shells with initial geometric imperfections under different boundary conditions is studied. Considering initial geometric imperfections and von Karman geometric nonlinearity, the nonlinear governing equations of FGM doubly curved shells are derived using Reissner's first order shear deformation (FOSD) theory. Three different boundary conditions of four edges simply supported (SSSS), four edges clamped (CCCC), clamped-clamped-simply-simply (CCSS) were studied, and a system of nonlinear ordinary differential equations was obtained with the help of Galerkin principle. The nonlinear forced vibration response of the FGM doubly curved shell is obtained by using the modified Lindstedt Poincare (MLP) method. The accuracy of this method was verified by comparing it with published literature. Finally, the effects of curvature ratio, power law index, void coefficient, prestress, and initial geometric imperfections on the resonance of FGM doubly curved shells under different boundary conditions are fully discussed. The relevant research results can provide certain guidance for the design and application of doubly curved shell.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.23-34
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• 2002

Borehole image analysis has been carried out to obtain the detailed geological data by approach of direct observation. Direct application of borehole image analysis inevitably gives rise to a few of restriction of data acquisition due to the limited information within narrow borehole space. Considering the apparent dip of discontinuity surface depending upon the direction, the visualized program of two-dimensional subsurface discontinuities is coded. Borehole image analysis can compensate the distribution of subsurface discontinuity extending into the expected area of investigation. In order to draw subsurface profile in the proposed area of subsurface construction, visualized program is coded as a window GUI (Graphic User Interface) using Fortran and Visual Basic Programming languages. It is to open publicly for the usage of whoever is in want. Discontinuity distribution map is visualized along the Proposed line of tunnel in the Janggye-ri area, Jangsu-gun. Using the visualized program, the limited information from borehole spatially applies into analysis of overall subsurface structures, and the distributional characteristics of discontinuity anticipate at the proposed area. In addition, spacing and extension of joint and depth of discontinuity effecting tunnel safety can be visualized along the direction of the proposed tunnel. These lines of visualization apply design and construction of fundanmental structures.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.9
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• pp.416-424
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• 2007

The Bio-Inspired system is a computing model that emulates the objects in ecosystem which are evolving themselves and cooperate each other to perform some tasks. Since it could be used to solved the complex problems that have been very difficult to resolve with previous algorithms, there have been a lot of researches to develop an application based on the Bio-Inspired system. However, since this computing model requires the process of evolving and cooperating with a lot of objects and this process takes a lot of times, it has been very hard to develop an application based on this computing model. This paper presents a parallel simulator for a Bio-Inspired system that is designed and implemented with OMNeT++ on PC clusters, and proves its usefulness by showing its simulation performance for a couple of applications. In the proposed parallel simulator, the functions required in the ERS platform for evolving and cooperating between objects (called Ecogent) are mapped onto the functions of OMNeT++, and they are simulated on PC clusters simultaneously to reduce the total simulation time. The simulation results could be monitored with a GUI In realtime, and they are also recorded into DBMS for systematic analyses afterward. This paper shows the usefulness of the proposed system by analyzing its performances for simulating various applications based on Bio-Inspired system on PC clusters with 4 PCs.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.403-412
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• 2019

The characteristics of the manoeuvring motion of a ship are dependent on the ship type, as well as draft or speed in the same ship. In recent years, the number of extra-large vessels has increased significantly, which can cause enormous material and environmental damage in the event of a marine accident. Thus, the importance of ship maneuvering is increasing. The IMO has forced the officers to be trained in simulators through the STCW 95 amendment. However, FMSS is costly and difficult to access and the PC-based simulator has the disadvantage that only one person can engage in simulation. The purpose of this study was to solve the shortcomings of the FMSS and PC-based simulators by enabling multiple people to use their PCs to simulate based on a network. The simulator is implemented through the analysis and numerical calculation of the Nomoto model, Radar function mounting, data transfer protocol design, and GUI building. To verify the simulator, the simulation results were compared and analyzed with the test results of T.S. HANBADA according to the criteria of the Korean Register of Shipping(KR) and IMO standards for ship maneuverability. As a result, It showed a relative error of 0%~ 32.1% with an average of 13.7%, and it satisfied the IMO criteria for ship maneuverability.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.194-201
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• 2014

This paper is able to be solved by improving degradation in multi-path environment by adjust beam pattern angle through modifying pulse phase of each antennas by using TRM (Transmitter Receiver Module). Beam Scanning Array Antenna, which is transmitter/receiver that improves degradation in multi-path environment without any signal distortion, is designed and manufactured. Beam Scanning Array Antenna should be able to send/receive signal at the antenna's longitudinal part without distortion and should not influences other systems. Also, it should include target detecting ability by beam steering.Dispersion characteristic of Beam Scanning Antenna, which is designed, is analysed by using fidelity, and steering and radar resolution performance is verified by using $1cm{\times}1cm$ sized target. To manufacture Beam Scanning Array Antenna, control board and GUI, which is able to control Vivaldi Antenna for IR-UWB, Tri-Band Wilkinson power divider, and TRM (Transmitter Receiver Module), is designed. Throughout this research, developed Beam Scanning UWB Array Antenna system is adoptable for radar application field. and time domain analysis techniques by using network analyser made the antenna characteristics analysis for setting up antenna more accurate. In addition, it makes beam width checking without difficulties.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.291-298
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• 2002

Recently, construction of reinforced concrete tall buildings is widely increased according to the improvement of material quality and design technology. Therefore, differential shortenings of columns due to elastic, creep, and shrinkage have been an important issue. But it has been neglected to predict the Inelastic behavior of RC structures even though those deformations make a serious problem on the partition wall, external cladding, duct, etc. In this paper, analysis system for prediction and compensation of the differential column shortenings considering time-dependent deformations and construction sequence is developed using the objected-oriented technique. Developed analysis system considers the construction sequence, especially time-dependent deformation in early days, and is composed of input module, database module, database store module, analysis module, and analysis result generation module. Graphic user interface(GUI) is supported for user's convenience. After performing the analysis, the output results like deflections and member forces according to the time can be observed in the generation module using the graphic diagram, table, and chart supported by the integrated environment.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.8
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• pp.571-578
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• 2013

The IHO S-100 is a standard on the universal hydorgraphic data model for supporting information services that integrate various data in maritime and provide proper information for safety of vessels. The S-100 is used to develop S-10x product specifications which are standards on guideline for creation and delivery of specific data set in maritime. The product specification for feature-based data such as ENC(Electronic Navigational Chart) data includes a feature catalogue that describes characteristics of features in that feature-based data. The feature catalogue is developed by domain experts with knowledge on data of the target domain. However, it is not feasible to develop a feature catalogue according to the XML schema by manual. In the IHO TSMAD committee meeting, needs of developing technology on building feature catalogue has been discussed. Therefore, we present a feature catalogue builder that is a GUI(Graphic User Interface) system supporting domain experts to build feature catalogues in XML. The feature catalogue builder is developed to connect with the FCD(Feature Concept Dictionary) register in the IHO(International Hydrographic Organization) GI(Geographic Information) registry. Also, it supports domain experts to select proper feature items based on the relationships between register items.

• Spatial Information Research
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• v.9 no.2
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• pp.207-225
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• 2001

This study develops a GIS-based system which examines the adequacy of the Groundwater development project before the actual designing of the project. A system environment is constructed in order to efficiently and scientifically manage and analyze data related to Groundwater through a Server/Client environment. For this programs such as GIS S/W ArcVies3.2, RDBMS ORACLE, ArcSDE (Spatial Database Engine) are used. WHPA and AQTESOLV are employed as a underground water simulation program and Scripts, a language for ArcView, is used to develop graphic user interface (GUI). Using the system developed here, we can transfer simulation results obtained by WHPA regarding Groundwater levels in new development projects into GIS. We can also judge whether a Groundwater development project should be permitted through examining overlaps of th effects of the development and comparing with o pollutants. At the same time, the system has a feature of supporting Groundwater development and based designing through judging the proper amount of Groundwater in a new project. It is also possible to easily and quickly prepare charts and reports using the outputs of the system. Since a two-tiered system which shares DB using inter-and intranets is developed, all the departments in the ministry of agriculture and forest and the agriculture base corporation can share accurate, reliable and latest information related to Groundwater.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1021-1030
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• 2010

In the sensor network, many tiny nodes construct Ad-Hoc network using wireless interface. As this type of system consists of thousands of nodes, managing each sensor node in real world after deploying them is very difficult. In order to install the sensor network successfully, it is necessary to verify its software using a simulator beforehand. In fact Sensor network simulators require high fidelity and timing accuracy to be used as a design, implementation, and evaluation tool of wireless sensor networks. Cycle-accurate, instruction-level simulation is the known solution for those purposes. In this paper, we developed an instruction-level sensor network simulator for Telos sensor node as named TeloSlM. It consists of MSP430 and CC2420. Recently, Telos is the most popular mote because MSP430 can consume the minimum energy in recent motes and CC2420 can support Zigbee. So that TeloSlM can provide the easy way for the developers to verify software. It is cycle-accurate in instruction-level simulator that is indispensable for OS and the specific functions and can simulate scalable sensor network at the same time. In addition, TeloSlM provides the GUI Tool to show result easily.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.63-70
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• 1994

This study presents the nonlinear dynamic analysis method of the multi-span continuous bridge considering the friction of the expansion bearings. Also the numerical analysis is performed for estimating the effect of the friction on the seismic response of the multi-span continuous bridge under the longitudinal ground motion compatible to Korean bridge design response spectra. It is found that even small friction coefficient of the expansion bearings has significant effect on reducing the superstructure displacement due to energy dissipation and distributing the inertia force of the superstructure to the substructures due to frictional force. It is observed that such favorable friction effects increase as the friction coefficient increases and the magnitude of the ground motion decreases. Therefore, the friction of the expansion bearings can be effectively used for the safe and economic design of the continuous span bridge with many spans and large superstructure weight under the small to medium scale longitudinal ground motions.