• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.1268-1271
• /
• 2002

The major threat of geometric manipulations is that they change the positions of watermarks, therefore the detection process fails to extract watermark properly. Since they cause the same effects on the host image as watermarks simultaneously, evaluating the distorted host image can be helpful to measure the nature of distortions. In this paper, we propose a geometrical distortion-resilient watermarking algorithm based on this property. Firstly we evaluate the orientation of a host image by filtering it with directional Gabor kernels, then we insert embedding pattern aligned to the estimated orientation. In its detection step, we evaluate the orientation again by Gabor filtering, then simply project and average the projected value to obtain a 1-D projection average pattern. Finally, auto-correlation function of the 1-D projection average pattern identifies periodic peaks. Analysed are experimental results against geometrical attacks including aspect ratio changes.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.4 s.181
• /
• pp.162-167
• /
• 2006

Hot embossing lithography(HEL) has the production advantage of comparatively few process step, simple operation, a relatively low cost for embossing tools(Si), and high replication accuracy for small features. In this paper, we considered the nano-molding characteristic according to molding parameters(temperature, pressure, times, etc) and induced a optimal molding condition using HEL. High precision nano-patter master with various shapes were designed and manufactured using the DRIE(Deep Reactive ion Etching), LPCVD(Low Pressure Chemical Vapor Deposition) and thermal oxidation process, and we investigated the molding characteristic of DVD and Blu-ray nickel stamp. We induced flow behaviors of polymer, rheology by shapes and sizes of the pattern through various molding experiments. Finally, with achieving nano-structure molding with high aspect ratio, we will secure a basic technology about the molding of large-area nano-pattern media.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.3
• /
• pp.751-758
• /
• 2016

The modifiable walking pattern generation (MWPG) algorithm can handle dynamic walking commands by changing the walking period, step length, and direction independently. When an infeasible command is given, the algorithm changes the command to a feasible one. After the feasibility of the navigational command is checked, it is translated into the desired center of mass (CM) state. To achieve the desired CM state, a reference CM trajectory is generated using predefined zero moment point (ZMP) functions. Based on the proposed algorithm, various complex walking patterns were generated, including backward and sideways walking. The effectiveness of the patterns was verified in dynamic simulations using the Webots simulator.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.5
• /
• pp.575-584
• /
• 1998

The purpose of this study was to develop the better fitting and more comfortable sleeve pattern for women's jacket, as the first step. Five types of existent sleeve pattern were collected, made and worn compared with the sensory evaluations method. The main results of this study were as follows 1. Sensory evaluation for appearance; According to the result of Duncan's multiple range test among the five sleeve patterns, TOJAIUN method sleeve was most satisfactory, and the next was the JUNGMYUNGJA method sleeve followed by NASAN, MOONWHA, ESMOD method sleeve. 2. Sensory evaluation for comfort; The result of Duncan's multiple range test showed that the ESMOD method sleeve was comfortable, and the next was the Japanese MOONWHA method sleeve followd by JUNGMYUNGJA, TOJAIVN, NASAN method sleeve. The result of 3-way ANOVA, main effect for 3 independent variables and interaction for pattern x part, posturers part showed significant difference.

• Fashion & Textile Research Journal
• /
• v.2 no.3
• /
• pp.239-245
• /
• 2000

The purpose of this study was for analysis of ease about basic bodice pattern, as the first step of the research process for the drawing method of basic bodice for women in their twenties. The five selected basic bodice were made and they were worn by FRP body The garment space of each bodice was measured by analysis of the garment space of each section in figure of polymerization of cross section by a 3-D measuring instrument. The research suggests that this compared analysis is an objective reference. This analysis not only of the area of cross section of garment space and ease but also of the girth of the body shape and wearing shape, using the PAD system and 3-D measuring instrument, can be helpful in making garment patterns.

• Journal of IKEEE
• /
• v.20 no.3
• /
• pp.291-294
• /
• 2016

A new optical one-time pattern password(OTPT) mutual authentication method is proposed, which presents a two-factor authentication by 2-step phase-shifting digital holography and performs a two-way authentication by a challenge-response handshake of the optical OTPT in both directions. Because a client and a server use OTPT once as a random number and encrypt it for mutual authentication, it protects against a replay or a man-in-the middle attack and results in higher security level.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.6
• /
• pp.1073-1080
• /
• 2011

In this study, a target detection algorithm was proposed for using hyperspectral imagery. The proposed algorithm is designed to have minimal processing time, low false alarm rate, and flexible threshold selection. The target detection procedure can be divided into two steps. Initially, candidates of target pixel are extracted using matching ratio of spectral pattern that can be calculated by spectral derivation. Secondly, spectral distance is computed only for those candidates using Euclidean distance. The proposed two-step method showed lower false alarm rate than the Euclidean distance detector applied over the whole image. It also showed much lower processing time as compared to the Mahalanobis distance detector.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.226-230
• /
• 2001

Electronic Speckle Pattern Interferometry (ESPI) has been recently developed and widely used because it has advantage to be able to measure surface deformations of engineering components and materials in industrial areas with non-contact. The spekle patterns to be formed with interference phenomena of scattering phenomena measure the out-of-plane deformations, together with the use of digital image equipment to process the informations included in the speckle patterns and the display consequent interferogram on a computer monitor. In this study, the experimental results of a canti-levered plate using ESPI were compared with those obtained from the simple beam theory. The ESPI results of the canti-levered plate analyzed by 4-step phase shifting method are close to the theoretical expectation. Also, out-0of-plane displacements of a spot welded canti-levered plate were measured by ESPI with 4-step phase shifting technique. The phase map of the spot welded canti-levered plate is quite different from that of the canti-levered plate without spot welding.

• Journal of computational fluids engineering
• /
• v.10 no.2
• /
• pp.30-37
• /
• 2005

To evaluate LBM we performed the simulation of the unsteady two dimensional flow over a square cylinder in a channel in moderate Reynolds number range, $100\~500$ by using LBM and Fractional-Step method. Frist of all we compared LBM solution of Poiseuille flow applied Farout and periodic boundary conditions with the analytical solution to verify the applicability of the boundary conditions. For LBM simulation the calculation domain was formed by structured 500x100 grids. Prescribed maximum velocity and density inlet and Farout boundary conditions were imposed on the in-out boundaries. Bounceback boundary condition was applied to the channel and the cylinder waifs. The flow patterns and vortex shedding strouhal numbers were compared with previous research results. The flow patterns by LBM were in agreement with the flow pattern by fractional step method. Furthermore the strouhal number computed by LBM simulation result was more accurate than that of fractional step method through the comparison of the previous research results.

• Korean Management Science Review
• /
• v.18 no.2
• /
• pp.125-134
• /
• 2001

This paper is concerned with the development of a GIS-based distribution system with service consideration. The proposed model could be used for a wide range of logistics applications in planning, engineering and operational purpose for logistics system. This research addresses the formulation of those complex prob1ems of two-echelon logistics system to plan the incorporating supply center locations and distribution problems based on GIS. We propose an integrated logistics model for determining the optimal patterns of supply centers and inventory allocations (customers) with a three-step sequential approach. 1) First step, Developing GIS-distance model and stochastic set-covering program to determine Optimel pattern of supply center location. 2) Second step, Optimal sector-clustering to support customers. 3) Third step, Optimal vehicle rouse scheduling based on GIS, GIS-VRP In this research we developed GUI-tree program, the GIS-VRP provide the vehicle to users and freight information in real time. We applied a set of sample examples to this model and demonstrated samp1e results. It has been found that the proposed model is potentially efficient and useful in solving multi-depot problem through examples. However the proposed model can provide logistics decision makers to get the best supply schedule.