• The KIPS Transactions:PartC
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• v.8C no.5
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• pp.667-676
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• 2001

We have solved a problem occurring in case that RSVP is applied to existing wired network in order to guarantee a QoS of multimedia traffic in mobile computing environment in this paper. If MN moves to another area when Mobile IP is applied to RSVP, HA makes new tunnel to FA because SESSION ID of MN is changed. However, we suggest MIP-DUDN method, which applied RSVP. Although MN moves to another area in this method, it does not make new tunnel because it eliminates the problem of existing Triangle Routing Problem. We design the new protocol of RMIP-DUDN and compare with the method of existing Mobile IP applied to RSVP.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.239-246
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• 2004

Image snapping for an image moves the cursor location to nearby features in the image, such as edges. In this paper, we propose geometric snapping for 3D triangular meshes, which is extended from image snapping. Similar to image snapping, geometric snapping also moves the cursor location naturally to a location which represents main geometric features in the 3D triangular meshes. Movement of cursor is based on the approximate curvatures which appear geometric features on the 3D triangular meshes. The proposed geometric snapping can be applied to extract main geometric features on 3D triangular meshes. Moreover, it can be applied to extract the geometric features of a tooth which are necessary for generating the occlusal surfaces in dental prostheses.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.114-123
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• 2017

This paper introduces a novel obstacle-climbing robot that moves on the facade of buildings and its climbing mechanism. A winch system set on the top of the building makes the vertical motion of the robot while it climbs obstacles that protrude from the wall surface. The obstacle-climbing robot suggested in this research is composed of a main platform and three modular climbing units. Various sensors installed on each climbing unit detect the obstacles, and the robot controller coordinates the three units and the winch to climb the obstacles using the obstacle-climbing mechanism. To evaluate the performance of the developed robot prototype, a test bed, which consists of an artificial wall and an obstacle, was manufactured. The obstacle size and the time required to climb the obstacle were selected as the performance indices, and extensive experiments were carried out. As a result, it was confirmed that the obstacle-climbing robot can climb various-sized obstacles with a reasonable speed while it moves on the wall surface.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.4
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• pp.215-224
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• 2009

Analysis for various driven nozzle position changes. The analysis was done for different Reynolds number in entrance region of jet-pump and for several diameter ratios of driven nozzle. (1) The largest absorption energy was found at the point s=1 in condition of diameter ratio 1:3.21 and point s=0.5 in condition of diameter ratio 1:2.25. (2) The absorption energy was not related to the change of entrance velocity and the driven nozzle position having the largest absorption energy was function for cross section ratio. (3) As the position of driven nozzle moves to the downstream, the absorption energy gets weaker. Because the energy from swirl was lost at the cross section gets smaller. (4) As the position of driven nozzle moves to the downstream, the injection energy leans to the upper direction wall and as the Reynolds number increase, the lean phenomenon is more distinct. (5) The flow quantity of driven nozzle, the diameter ratio 1:3.21, was 32% higher than that of 1 : 2.25 and as the inlet velocity gets faster the efficiency decreased. And as the cross section of the driven nozzle increases.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.37-58
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• 1997

An AI approach with tabu search is designed to solve multi-level knapsack problems. The approach performs intelligent actions with memories of historic data and learning effect. These action are developed ont only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The approach intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this approach uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. "Pseudo moves", similar to "aspirations", support these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied. To avoid redundant moves, short-term (tabu-lists), intemediate-term (cycle-detection), and long-term (recording frequency and significant solutions for diversfication) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1536-1543
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• 2011

Video stabilization is a very important step for vision based applications in the vehicular technology because the accuracy of these applications such as obstacle distance estimation, lane detection and tracking can be affected by bumpy roads and oscillation of vehicle. Conventional methods suffer from either the zooming effect which caused by a camera movement or some motion of surrounding vehicles. In order to overcome this problem, we propose a novel video stabilization method using FOE(Focus of Expansion). When a vehicle moves, optical flow diffuses from the FOE and the FOE is equal to an epipole. If a vehicle moves with vibration, the position of the epipole in the two consecutive frames is changed by oscillation of the vehicle. Therefore, we carry out video stabilization using motion vector estimated from the amount of change of the epipoles. Experiment results show that the proposed method is more efficient than conventional methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.225-232
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• 2001

In this paper, we describe a mechanism that supports the mobility service for VPN(Virtual Private Network) users on MPLS(Multiprotocol Label Switching) network. The MPLS VPN considered in this study is controlled by CE(Customer Edge) routers. In such a VPN, CE routers have additional functions to support mobile VPN users, i.e., Home Agent function, foreign Agent function, Correspondent Agent function. This mechanism is applied when a VPN node moves to other site of the saute VPN, or when it moves to other site of a different VPN, or to a non-VPN site. We perform a simulation study to compare the performance of CE based MPLS VPN with that of PE(Provider Edge) based MPLS VPN with mobility support.

• Speech Sciences
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• v.6
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• pp.33-44
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• 1999

This paper aims to analyze whether the phenomenon of /u/$\rightarrow$/i/ is a hypercorrection or not in the North Korean dialects. Most North Koreans pronounce /i/(gold) as /kum/ because the vowel /i/ merges into the peripheral vowel space of /u/ in their dialects. The merger of back vowel is one of most distinctive characters in North Korean dialects. But some speakers pronounce /chubann/(exile) as /chiban/. This time /u/ in peripheral space moves to /i/ in central vowel space. It seems that the vowels /i/ and /u/ exchange places with each other when they uttered in North Korean. Though it was observed that the vowel movement of /i/$\rightarrow$/u/ was caused by the merger of back vowels, the reason why vowel /u/ moves in the opposite direction, that is, the central space of vowel /i/ has not been analyzed yet. This experiment starts with hypothesis that the movement of /u/$\rightarrow$/i/ might be caused by hypercorrection. The first step of this research is to analyze /u/$\rightarrow$/i/ pronunciation of North Koreans. The second step is to compare the results of North Korean pronunciation with those of South Korean pronunciation and observe whether tendency of /u/$\rightarrow$/i/pronunciation can also be found in the standard Seoul dialect and other South Korean dialects.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.514-517
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• 1996

In solving multi-level knapsack problems, conventional heuristic approaches often assume a short-sighted plan within a static decision enviornment to find a near optimal solution. These conventional approaches are inflexible, and lack the ability to adapt to different problem structures. This research approaches the problem from a totally different viewpoint, and a new method is designed and implemented. This method performs intelligent actions based on memories of historic data and learning. These actions are developed not only by observing the attributes of the optimal solution, the solution space, and its corresponding path to the optimal solution, but also by applying human intelligence, experience, and intuition with respect to the search strategies. The method intensifies, or diversifies the search process appropriately in time and space. In order to create a good neighborhood structure, this method uses two powerful choice rules that emphasize the impact of candidate variables on the current solution with respect to their profit contribution. A side effect of so-called "pseudo moves", similar to "aspirations", supports these choice rules during the evaluation process. For the purpose of visiting as many relevant points as possible, strategic oscillation between feasible and infeasible solutions around the boundary is applied for intensification. To avoid redundant moves, short-term (tabu-lists), intermediate-term (cycle detection), and long-term (recording frequency and significant solutions for diversification) memories are used. Test results show that among the 45 generated problems (these problems pose significant or insurmountable challenges to exact methods) the approach produces the optimal solutions in 39 cases.lutions in 39 cases.

• 한국가시화정보학회:학술대회논문집
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• 2007.11a
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• pp.71-76
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• 2007

Flow visualization of a droplet passing through a straight channel and a diverging channel has been carried out using micro-PIV. Diverging channel is frequently used in lab-on-a-chip and microfluidic devices, where flow pattern inside the droplet passing is quite different from that through a straight channel. In the present study, we visualized the droplet flow in three different regions. The first region is where the droplet has a wide contact area with the channel wall, the second region is characterized with a narrow contact area and the third region is where droplet is detached from the channel wall. Visualization results show that the internal flow inside the droplet passing through the straight channel moves in the opposite direction to the droplet velocity in the near wall exhibiting complex flow patterns. But in the diverging channel the internal flow inside the droplet moves in the same direction as the droplet velocity due to the shear induced by oil phase flow exhibiting rather simple flow pattern.