• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.11
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• pp.568-576
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• 2002

This paper presents a new algorithm for the enhancement of voltage stability by optimal routing (OR) technique. A new voltage stability index (VSI) for optimal routing is also proposed by using theories of critical transmission path based on voltage phasor approach and equivalent impedance method. Furthermore, the proposed algorithm automatically detect the critical transmission path to critical transmission path to critical load which are faced to voltage collapse due to additional real or reactive loading. We also adopt a improved branch exchange (IBE) algorithm based on a tie branch power (TBP) flow equation to apply the OR technique. The proposed IBE algorithm for the VSI maximizing can effectively search the optimal topological structures of distribution feeders by changing the open/closed states of the sectionalizing and tie switches. The proposed algorithm has been evaluated with the practical IEEE 32, 69 bus test systems and KEPCO 148 bus test system to show favorable performance.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.625-630
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• 2002

PSC box girder is widely used in a domestic bridge and overpass, etc., therefore, the design and construction technique for the PSC box girder is developing day by day. Even if it were so, however, the design for anchorage zone in PSC box girder has depended on common sense and empirical results. And it is the current situation that the designer has difficulty due to inadequacy of provisions in the domestic design code and lack of understanding for behavior of anchorage zone. Besides, the design based on Leonhardt's method is being done in general, but the design may be various even for the same structure because of the difference in a way of applying. In this paper, therefore, anchorage zone in PSC box girder bridge is analyzed and designed by using strut-tie model. Adequacy for the application of strut-tie model is verified by comparison with the way used in current design practice, and this study presents that strut-tie model can be a rational and an economical design than current design methods.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.259-262
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• 2013

After skin grafting, to prevent hematoma or seroma collection at the graft site, a tie-over dressing has been commonly used. However, although the conventional tie-over dressing by suture is a useful method for securing a graft site, refixation is difficult when repeated tie-over dressing is needed. Therefore, we recommend a redoable tie-over dressing technique with multiple loops threads and connecting silk threads. After the raw surface of each of our cases was covered with a skin graft, multiple loop silk thread attached with nylon at the skin graft margin. We applied the ointment gauze and wet cotton/fluffy gauze over the skin graft, then fixed the dressing by connecting cross-counter multiple loop thread with connecting silk threads. When we opened the tie-over dressing by cutting the connecting silk threads, we repeated the tie-over dressing with the same method. The skin graft was taken successfully without hematoma or seroma collection or any other complications. In conclusion, we report a novel tie-over dressing enabling simple fixation of the dressing to maintain proper tension for wounds that require repetitive fixation. Further, with this reliable method, the skin grafts were well taken.

• Archives of Plastic Surgery
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• v.45 no.3
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• pp.266-270
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• 2018

Background Skin grafting is a commonly performed operation in plastic and reconstructive surgery. The tie-over dressing is an effective technique to secure the grafted skin by delivering persistent downward pressure. However, if an additional dressing is required due to incomplete graft healing, the process of re-implementing the tie-over dressing may be frustrating for both patients and surgeons. Therefore, we introduce the double tie-over dressing, which readily allows for an additional tie-over dressing after the first dressing, and we present a comparison of its effectiveness with that of the simpler bolster dressing. Methods Of 128 patients with a skin defect, 69 received a double tie-over dressing and 59 patients received a simple bolster dressing. Using the independent t-test, the mean healing time, which was defined as the mean time it took for the wound to heal completely so that no additional dressing was required and it was washable with tap water, was compared between the 2 groups in both the head and neck region and in other areas. Results The mean healing time for the head and neck region in the double tie-over dressing group was $9.19{\pm}1.78days$, while it was $11.05{\pm}3.85days$ in the bolster dressing group. The comparison of the 2 groups by the independent t-test revealed a P-value of 0.003 for the mean healing time. Conclusions In the head and neck area, the double tie-over dressing required less time to heal than the simple bolster dressing.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.1
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• pp.10-15
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• 2003

Background and Objectives : Ankyloglossia, commonly known as tongue-tie, is the result of a short, fibrous lingual frenulum or highly attached geioglossus muscle. This condition may cause sucking and swallowing problems, articulation disorders, interference with the tongue's cleansing action, increased the potential for caries, and inability to lick the lips, play a wind instrument, and 'french kiss' Treatment is surgical procedure. In the most cases, horizontal sectioning and mucosal suture(the conventional procedure) is preferred, but in some cases, the Z-plastic procedure is effective. This study is aimed to compare the result of the two procedures. Materials and Methods : Twenty tongue-tie patients underwent operation. Ten patients were treated with the Z-plastic procedure and ten patients were treated with the conventional method randomly. We checked preoperative mobile tongue length, postoperative mobile tongue length, operation time and postoperative wound states. Results : Among the 20 cases of tongue-tie, 2 cases are excepted due to pre-operative state, thus we compared 18 cases of tongue-tie patients. There is no statistically significant difference between the two procedures except in operation time. The Z-plastic procedure apparently needs a little more operating time. Conclusion : Patients treated with the Z-plastic procedures appeared to have better outcomes, but the data shows no statistical significance except in operating time. Consequently, the Z-plastic procedure is indicated in a limited amount of cases.

• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.629-644
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• 2010

A real-time image georeferencing system requires all inputs to be determined in real-time. The intrinsic camera parameters can be identified in advance from a camera calibration process while other control information can be derived instantaneously from real-time GPS/INS data. The bottleneck process is tie point acquisition since manual operations will be definitely obstacles for real-time system while the existing extraction methods are not fast enough. In this paper, we present a fast-and-automated image matching technique based on the KLT tracker to obtain a set of tie-points in real-time. The proposed work accelerates the KLT tracker by supplying the initial guessed tie-points computed using the GPS/INS data. Originally, the KLT only works effectively when the displacement between tie-points is small. To drive an automated solution, this paper suggests an appropriate number of depth levels for multi-resolution tracking under large displacement using the knowledge of uncertainties the GPS/INS data measurements. The experimental results show that our suggested depth levels is promising and the proposed work can obtain tie-points faster than the ordinary KLT by 13% with no less accuracy. This promising result suggests that our proposed algorithm can be effectively integrated into the real-time image georeferencing for further developing a real-time surveillance application.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.161-166
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• 2016

Deformation, stress and fatigue life due to the configuration of tie rod end are investigated in this study. Tie rod ends with the total three kinds of configurations are modelled with three dimensions through CATIA program and the simulation analysis is carried out with the ANSYS finite element analysis program. There are the models of A, B and C by the configuration of the rod end. As this study result, maximum deformation, maximum equivalent stress and maximum fatigue life of A type model are shown to be 0.0614mm, 160.27MPa and 336,930cycles respectively. And maximum deformation, maximum equivalent stress and maximum fatigue life of B type model are shown to be 0.0648mm, 90.889MPa and 1,171,000cycles respectively. Maximum deformation, maximum equivalent stree and maximum fatigue life of C type model are also shown to be 0.0402mm, 84.794MPa and 20,000,000cycles respectively. The durability of the models of tie rod ends through the values of this result could be estimated and the data for the design and development of more improved tie rod end could be secured. And it is possible to be grafted onto the convergence technique at design and be shown as the esthetic sense.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.407-414
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• 2015

Interest points are generally located at the pixels where height changes occur. So, interest points can be the significant pixels for DSM generation, and these have the important role to generate accurate and reliable matching results. Manual operation is widely used to extract the interest points and to match stereo satellite images using these for generating height information, but it causes economic and time consuming problems. Thus, a tie point extraction method using Harris-affine technique and SIFT(Scale Invariant Feature Transform) descriptors was suggested to analyze height information of buildings in this study. Interest points on buildings were extracted by Harris-affine technique, and tie points were collected efficiently by SIFT descriptors, which is invariant for scale. Searching window for each interest points was used, and direction of tie points pairs were considered for more efficient tie point extraction method. Tie point pairs estimated by proposed method was used to analyze height information of buildings. The result had RMSE values less than 2m comparing to the height information estimated by manual method.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.302-310
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• 2002

This paper presents an application of a improved branch exchange (IBE) algorithm with a tie branch power (TBP) flow equation to solve the Optimal Routing problem for operation of a radial Power system including power distribution system. The main objective of the Optimal Routing problem usually is to minimize the network real power loss and to improve the voltage profile in the network. The new BE algorithm adopts newly designed methods which are composed by decision method of maximum loss reduction and new index of loss exchange in loop network Thus, the proposed algorithm in this paper can search the optimal topological structures of distribution feeders by changing the open/closed states of the sectionalizing and tie switches. The proposed algorithm has been evaluated with the practical IEEE 32, 69 bus test systems and KEPCO 148 bus test system to show favorable performance gained.

• ETRI Journal
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• v.25 no.2
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• pp.109-120
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• 2003

Though the airborne laser scanning (ALS) technique is becoming more popular in many applications, horizontal accuracy of points scanned by the ALS is not yet satisfactory when compared with the accuracy achieved for vertical positions. One of the major reasons is the drift that occurs in the inertial measurement unit (IMU) during the scanning. This paper presents an algorithm that adjusts for the error that is introduced mainly by the drift of the IMU that renders systematic differences between strips on the same area. For this, we set up an observation equation for strip-wise adjustments and completed it with tie point and control point coordinates derived from the scanned strips and information from aerial photos. To effectively capture the tie points, we developed a set of procedures that constructs a digital surface model (DSM) with breaklines and then performed feature-based matching on strips resulting in a set of reliable tie points. Solving the observation equations by the least squares method produced a set of affine transformation equations with 6 parameters that we used to transform the strips for adjusting the horizontal error. Experimental results after evaluation of the accuracy showed a root mean squared error (RMSE) of the adjusted strip points of 0.27 m, which is significant considering the RMSE before adjustment was 0.77 m.