• Structural Engineering and Mechanics
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• v.12 no.6
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• pp.573-594
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• 2001

A two-level displacement-based design procedure is developed. To obtain the displacement demands, elastic spectra for occasional earthquakes and inelastic spectra for rare earthquakes are used. Minimum global stiffness and strength to be supplied to the structure are based on specified maximum permissible drift limits and on the condition that the structure responds within the elastic range for occasional earthquakes. The performance of the structure may be assessed by an inelastic push-over analysis to the required displacement and the evaluation of damage indices. The approach is applied to the design of a five-story reinforced concrete coupled wall structure located in the most hazardous seismic region of Argentina. The inelastic dynamic response of the structure subjected to real and artificially generated acceleration time histories is also analyzed. Finally, advantages and limitations of the proposed procedure from the conceptual point of view and practical application are discussed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.114-121
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• 2015

In conventional LEDs, a mesa-structure is usually used and it causes the current to be overcrowded in a specific region. We propose a novel structure of GaN-based LED to overcome this problem. In order to distribute the current in an active region, a spreading pad is inserted at the p-type region in the GaN based LED device. The inserted spreading pad helps the current flow because it is more conductive than the p-type GaN layer. By performing electrical and optical simulations, the effects of the spreading pad insertion are confirmed. The results of electrical simulation show that the current spreads more uniformly and more radiative recombination is produced as well. Moreover, from the optical simulation, it is revealed that the ITO is less absorptive material than p-GaN if the condition of specific wavelength sources is satisfied. Considering all of the results, we can conclude that the luminescent power is enhanced by the spreading pad.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.3
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• pp.10-17
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• 2012

In general, image-based 3D scenes can now be found in many popular vision systems, computer games and virtual reality tours. In this paper, we propose a method for creating 3D virtual scenes based on 2D image that is completely automatic and requires only a single scene as input data. The proposed method is similar to the creation of a pop-up illustration in a children's book. In particular, to estimate geometric structure information for 3D scene from a single outdoor image, we apply the tensor voting to an image segmentation. The tensor voting is used based on the fact that homogeneous region in an image is usually close together on a smooth region and therefore the tokens corresponding to centers of these regions have high saliency values. And then, our algorithm labels regions of the input image into coarse categories: "ground", "sky", and "vertical". These labels are then used to "cut and fold" the image into a pop-up model using a set of simple assumptions. The experimental results show that our method successfully segments coarse regions in many complex natural scene images and can create a 3D pop-up model to infer the structure information based on the segmented region information.

• Journal of the Korea Safety Management & Science
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• v.11 no.4
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• pp.139-145
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• 2009

The present study is to investigate the effect of wave-structure interaction such as wave oscillation. The theoretical method is based upon the linear diffraction theory obtained by the boundary element method. The water depth and incident wave period in fluid region are assumed to be constant. To investigate the wave interaction due to offshore structures, the numerical program has been developed and the simulation has been carried out by varying the conditions of distance and width of offshore structures. This study can effectively be utilized for safety assessment to various breakwater systems and layout of offshore breakwater in the ocean and coastal field. It can give information for the safety to construct offshore structure and revetment in coastal region.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.873-881
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• 2002

The fluid induced vibration (FIV) phenomena of an equivalent airfoil system of MAV have been investigated in low Reynolds number flow region. Unsteady flows with viscosity are computed using two-dimensional incompressible Navier-Stokes equations. The present fluid/structure interaction analysis is based on one of the most accurate computational approach with computational fluid dynamics (CFD) and computational structural dynamics (CSD) techniques. The highly nonlinear fluid/structure interaction phenomena due to severe flow separations have been analyzed for the low Reynolds region that has a dominancy of flow viscosity. The effects of Reynolds number and initial angle of attack on the fluid/structure coupled vibration instability are shown and the qualitative trend of FIV phenomenon is investigated.

• Spatial Information Research
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• v.20 no.4
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• pp.93-101
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• 2012

Due to complexity of indoor space, the demand of Location Based Services (LBS) in indoor space is increasing as well as outdoor. However, it includes privacy problems of exposing personal location. Location K-anonymity technology is a method to solve the privacy problems with cloaking their locations by Anonymized Spatial Region(ASR). It guarantees K users within a region containing the location of a given user. However previous researches have dealt the problems based on Euclidean distance in outdoor space, and cannot be applied in indoor space where there are constraints of movement such as walls. For this reason, we propose in this paper a K-anonymity for cloaking indoor location in consideration of structures and representation of indoor space. The basic concept of our approach is to introduce a hierarchical structure as ASR for including K-1 users for cloaking their locations. We also proposed a cost model by K and attributes of hierarchical structure to analyze the performance of the method.

• Journal of the Korean Geographical Society
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• v.38 no.2
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• pp.257-274
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• 2003

This study is to diagnose the tourism structure of the southern region in Kangwon province and to correct the problems regarding the subject. The methods of comparison and analysis on structural and geographical characteristics of tourists, tourism resources, and tourism industry by region have been employed. It was found that the southern region of Kangwon province has many advantages for tourism industry including excellent transportation networks such as Kangnws and Wonju and tourism demands are great for coal mines in the region including Chongson, Taebaek, and Samchok. Accordingly, tourism in the region has witnessed a distinctive increase in recent years. On the other hand, excessive dependence on nature-based tourism, concentration of tourism demands only during summer season, and insufficient tourism facilities are found to be problems. This study also found that for sustainable tourism developments in the southern region of Kangwon, categorization and diversification of tourism resources, development of combined programs connecting Kangwon province to other regions, improvement of tourism facilities, expansion of tourism market, and smaller division of tourism area are necessary.

• International Journal of Fluid Machinery and Systems
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• v.6 no.2
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• pp.87-93
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• 2013

In order to study the effect of the fluid-structure interaction (FSI) on the simulation results, the external characteristics and internal flow features of a diffuser pump were analyzed with a two-way flow solid coupling method. And the static and dynamic structure analysis of the blade was also caculated with the FEA method. The steady flow field is based on Reynolds Averaged N-S equations with standard $k-{\varepsilon}$ turbulent model, the unsteady flow field is based on the large eddy simulation, and the structure response is based on elastic transient structural dynamic equation. The results showed that the effect of FSI on the head prediction based on CFD really exists. At the same radius, the van mises stress on the nodes closed shroud and hub was larger than other nodes. A large deformation region existed near inlet side at the middle of blades. The strength of impeller satisfied the strength requirement with static stress analysis based on the fourth strength theory. The dynamic stress varied periodically with the impeller rotating. It was also found that the fundamental frequency of the dynamic stress is the rotating frequency and its harmonic frequency. The frequency of maximum stress amplitude at node 1626 was 7 times of the rotating frequency. The frequency of maximum stress amplitude at node 2328 was 14 times of the rotating frequency. No matter strength failure or fatigue failure, the root of blades near shroud is the key region to analyse.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2509-2515
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• 2014

In this paper, the conventional vertical structure for VLSI circuits CMOS intend to improve the stress effects of active region and built-in threshold voltage. For these improvement, the proposed structure is shallow trench isolation of moat shape. We want to analysis the electron concentration distribution, gate bias vs energy band, thermal stress and dielectric enhanced field of thermal damage between vertical structure and proposed moat shape. Physically based models are the ambient and stress bias conditions of TCAD tool. As an analysis results, shallow trench structure were intended to be electric functions of passive as device dimensions shrink, the electrical characteristics influence of proposed STI structures on the transistor applications become stronger the potential difference electric field and saturation threshold voltage, are decreased the stress effects of active region. The fabricated device of based on analysis results data were the almost same characteristics of simulation results data.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.611-622
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• 2012

This study proposed two multisensor fusion methods for segment-based image classification utilizing a region-growing segmentation. The proposed algorithms employ a Gaussian-PDF measure and an evidential measure respectively. In remote sensing application, segment-based approaches are used to extract more explicit information on spatial structure compared to pixel-based methods. Data from a single sensor may be insufficient to provide accurate description of a ground scene in image classification. Due to the redundant and complementary nature of multisensor data, a combination of information from multiple sensors can make reduce classification error rate. The Gaussian-PDF method defines a regional measure as the PDF average of pixels belonging to the region, and assigns a region into a class associated with the maximum of regional measure. The evidential fusion method uses two measures of plausibility and belief, which are derived from a mass function of the Beta distribution for the basic probability assignment of every hypothesis about region classes. The proposed methods were applied to the SPOT XS and ENVISAT data, which were acquired over Iksan area of of Korean peninsula. The experiment results showed that the segment-based method of evidential measure is greatly effective on improving the classification via multisensor fusion.