• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.127-132
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• 1992

To relize the future intelligent robot the development of a special-purpose processor for a coordinate transformation is evidently challenging task. In this case the complexity of a hardware architecture strongly depends on the adopted algorithm. In this paper we have used an inverse kinemetics algorithm based on incremental unit computation method. This method considers the 3-axis articulated robot as the combination of two types of a 2-axis robot: polar robot and 2-axis planar articulated one. For each robot incremental units in the joint and Cartesian spaces are defined. With this approach the calculation of the inverse Jacobian matrix can be realized through a simple combinational logic gate. Futhermore, the incremental computation of the DDA integrator can be used to solve the direct kinematics. We have also designed a hardware architecture to implement the proposed algorithm. The architecture consists of serveral simple unitsl. The operative unit comprises several basic operators and simple data path with a small bit-length. The hardware architecture is realized byusing the EPLD. For the straight-line motion of the KAIST arm we have obtained maximum end effector's speed of 12.6 m/sec by adopting system clock of 8 MHz.

• Structural Engineering and Mechanics
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• v.19 no.2
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• pp.153-172
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• 2005

A new load/displacement parameter method is proposed for the simultaneous control of applied loads and structural displacements at one or more points. The procedure is based on a generalized Riks' method, which utilizes load/displacement parameters as scaling factors to analyze post-buckling phenomena including snap-through or snap-back. The convergence characteristics are improved by employing new relaxation factors through an incremental displacement parameter, particularly in a region that exhibits severe numerical instability. The improved performance is illustrated by means of a numerical example.

• Geotechnical Engineering
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• v.13 no.1
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• pp.123-136
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• 1997

By applying the finite element theory which is capable of handling the geometrically altered structure in a successive manner, the linear relationship between incremental displacements and the magnitude of the initial stress field was derived. Based on this relationship, back analysis code having the capability of dealing multi-step excavation problem was built and verified With this back analysis code, the measurements of the incremental displacements in a particular excavation step make it possible to back-calculate the initial stress state. illustrative examples showed the applicability of this code to a practical problem.

• Journal of the Korean Geophysical Society
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• v.7 no.2
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• pp.151-155
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• 2004

To solve the urban flood problems, it must get the enough channel conveyances and pumping capacities. It needs set up the detention system to control the flow over the channel capacity. Inspite of this detention system, the peak flow may increased by rainfall distribution and the delay of flow. This shows a design model of detention system which can consider the time problems from mutual connections of the detention storages and pumping flow using IDP(Incremental Dynamic Programming) method.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.322-325
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• 2005

In order to make a doubly-cowed sheet metal effectively, the sheet metal forming process has been developed by adopting the flexibility of the incremental forming process and the principle of bending deformation which causes slight deformation in thickness. The developed process is an unconstrained forming process without holder. The experimental equipment has been set up with the roll set which consists of two pairs of support rolls and one center roll. In order to analyze process parameters in the incremental roll forming process for the application to doubly curved ship hull plate, the orthogonal array is adopted. From the FEM results, among the process parameters, the distance between supporting rolls in pairs along the direction of one principal radius of curvature as well as the forming depth is shown to influence the generation of curvature in the same direction significantly. That is, the other distance between supporting rolls in pairs which are not located in the same direction of one principal radius of curvature, does not have an significant effect on the generation of the curvature in that direction. Also, the forming load and torque from the FEM simulation are acceptable to the system development of the incremental roll forming process for the forming of ship hull plate.

• Earthquakes and Structures
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• v.6 no.6
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• pp.611-625
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• 2014

This paper presents a simple methodology that integrates an improved storey shear modelling, Incremental Dynamic Analysis and Monte Carlo Simulation in order to carryout vulnerability analysis towards development of fragility curves for Unreinforced Brick Masonry buildings. The methodology is demonstrated by developing fragility curves of a single storey Unreinforced Brick Masonry building for which results of experiment under lateral load is available in the literature. In the study presented, both uncertainties in mechanical properties of masonry and uncertainties in the characteristics of earthquake ground motion are included. The research significance of the methodology proposed is that, it accommodates a new method of damage grade classification which is based on 'structural performance characteristics' instead of 'fixed limiting values'. The usefulness of such definition is discussed as against the existing practice.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.763-772
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• 2003

Design patterns are known widely by the techniques to improve software qualify. The design patterns are efficient solutions for problems occurring frequently in software development. Recently there are wide researches for design patterns to find them and to verify usability for them. But there are very few researches to define systematic development approaches about constructing application using design patterns. In this paper, we propose an approach for the pattern-oriented software development process using incremental composition for design patterns. For this proposal, first we define a development process using design patterns, propose technique for incremental composition for design patterns and view ports for software in the process. Also we deal with the problem of efficient traceability and maintenance to design patterns in the software system. And we use a feedback framework system as an illustrative example to show how the process can be used to develop the pattern-oriented software. In the development of software, the systematic development approach and usage increase efficiency to develop the system by using design experience and technique early in the development lifecycle. Therefore the system will assure the high stability and reusability and offer the low cost and time for development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.421-433
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• 2015

Recently, there have been fast-growing social network services based on the Internet environment and web technology development, the prevalence of smartphones, etc. Social networks also allow the users to convey the information and news so that they have a great influence on the public opinion formed by social interaction among users as well as the spread of information. On the other hand, these social networks also serve as perfect environments for rampant malware. Malware is rapidly being spread because relationships are formed on trust among the users. In this paper, an effective patch strategy is proposed to deal with malicious worms based on social networks. A graph is formed to analyze the structure of a social network, and subgroups are formed in the graph for the distributed patch strategy. The weighted directions and activities between the nodes are taken into account to select reliable key nodes from the generated subgroups, and the Incremental PageRanking algorithm reflecting dynamic social network features (addition/deletion of users and links) is used for deriving the high influential key nodes. With the patch based on the derived key nodes, the proposed method can prevent worms from spreading over social networks.

• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.168-178
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• 2005

The Delaunay triangular net is primarily characterized by a balance of the whole by improving divided triangular patches into a regular triangle, which closely resembles an equiangular triangle. A triangular net occurring in certain, point-clustered, data is unique and can always create the same triangular net. Due to such unique characteristics, Delaunay triangulation is used in various fields., such as shape reconstruction, solid modeling and volume rendering. There are many algorithms available for Delaunay triangulation but, efficient sequential algorithms are rare. When these grids involve a set of points whose distribution are not well proportioned, the execution speed becomes slower than in a well-proportioned grid. In order to make up for this weakness, the ids are divided into sub-grids when the sets are integrated inside the grid. A method for finding a mate in an incremental construction algorithm is to first search the area with a higher possibility of forming a regular triangular net, while the existing method is to find a set of points inside the grid that includes the circumscribed sphere, increasing the radius of the circumscribed sphere to a certain extent. Therefore, due to its more efficient searching performance, it takes a shorer time to form a triangular net than general incremental algorithms.