• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.200-205
• /
• 1989

The performance of conventional robot arms is inhibited by trade-off between speed and accuracy. Because these systems measure only joint angles, in spite of slow speed, they must rely on a stiff structure in order to attain positioning accuracy. Lightweight links would allow faster motion, but their flexibility would also produce positioning errors. This research is involved with the development and evaluation of an End-point Control System whose major goal is to compensate for link deflections and thus mitigate the speed versus accuracy conflict in conventional manipulator.

• The Journal of Information Systems
• /
• v.14 no.1
• /
• pp.19-40
• /
• 2005

The history of computer virus comes along with that of computer. Computer virus han surfaced as a serious problem in information age. The advent of open network and widespread use of Internet made the problem even more urgent. As a method of defense for computer virus most companies use anti-virus software. Selecting appropriate anti-virus software involves various criteria and thus it is a multiple-attribute decision making problem. The purpose of this study is to prioritize anti-virus software evaluation factors. To do that, first of all, important evaluation factors are selected based on previous research on anti-virus software as well as general software evaluation models. Then, a questionnaire survey was conducted on end-users, system administrators and anti-virus software developers. The survey result was analyzed with ExpertChoice 2000 which is based on Analytic hierarchy Process technique. This study found that there are clear differences among three survey groups regarding the relative importance of overall evaluation factors. End-user group ranked "cost" first, but it was the least important factor to developer group. Developers pointed out "operational support" ad the most important factor. There were also obvious differences in the relative importance of detail evaluation items. Both end-users and system administrators shared 7 common items among top 10 most important items. Moreover, neither of the two groups ranked any of the items in the "operational support" factor in top 10, whereas all 4 items in the factor were included in top 10 by developer group.

• Korean Journal of Bronchoesophagology
• /
• v.3 no.1
• /
• pp.94-100
• /
• 1997

Background and Objectives : In children with tracheal stenosis, operative management remains a challenging problem due to difficulties of operative techniques and postoperative care. The purpose of this study was to determine the effectiveness of tracheal resection with end to end anastomosis as operative management for tracheal stenosis in children. Materials and Methods : 6 children with severe tracheal stenosis underwent tracheal resection with end to end anastomosis. Causes of stenosis were trauma in 1 case and prolonged intubation or tracheotomy in 5 cases. The diagnoses were made by radiologic evaluation (plain X-ray, CT, 3-Dimensional CT) and confirmed by direct laryngoscopy and ventilating bronchoscopy under general anesthesia. Thyroplasty and unilateral arytenoidectomy were performed in 1 case. Suprahyoid release was done in 1 case with severe adhesion. Decanulation was achieved following postoperative endoscopic examination and pulmonary function test. Postoperative physical and radiologic examinations were given at regular intervals. Results : Stenosis were improved from grade III grade I in 4 cases and from grade II to grade I in 2 cases. Decanulation was achieved on average postoperative 6 months in 5 cases, and 10 years in 1 case due to exertional dyspnea. There were 1 each case of immediate postoperative subcutaneous emphysema, pneumothorax and wound infection. Postoperative granulomas at anastomosis site were treated with laser vaporization under suspension laryngoscope and bronchoscope in 3 cases. There was 1 each case of delayed postoperative vocal cord palsy, aspiration pneumonia and loss of cough reflex. Conclusion In tracheal stenosis of children, tracheal resection with end to end anastomosis has good result with preservation of normal airway. Preoperative evaluation of local factors such as swallowing, vocal cord movement and cough reflex and general condition was important for successful treatment. As the cases in adults, authors considered this operation to be a curable operative management for tracheal stenosis.

• Journal of Korea Multimedia Society
• /
• v.24 no.10
• /
• pp.1380-1390
• /
• 2021

The video face recognition (FR) is one of the most popular researches in the field of computer vision due to a variety of applications. In particular, research using the attention mechanism is being actively conducted. In video face recognition, attention represents where to focus on by using the input value of the whole or a specific region, or which frame to focus on when there are many frames. In this paper, we propose a novel attention based deep learning method. Main novelties of our method are (1) the use of combining two loss functions, namely weighted Softmax loss function and a Triplet loss function and (2) the feasibility of end-to-end learning which includes the feature embedding network and attention weight computation. The feature embedding network has a positive effect on the attention weight computation by using combined loss function and end-to-end learning. To demonstrate the effectiveness of our proposed method, extensive and comparative experiments have been carried out to evaluate our method on IJB-A dataset with their standard evaluation protocols. Our proposed method represented better or comparable recognition rate compared to other state-of-the-art video FR methods.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.36 no.4
• /
• pp.123-133
• /
• 2020

The purpose of this study is to analyze the method of retrofitting flexural strength and the flexural performance of retrofitted shear walls. There are various ways to reinforce the flexural strength of reinforced concrete shear wall structural systems that have already been built, in the case of that, the external force is increased, and the internal force is insufficient. However, there are various problems, such as excessive flexural stiffness after reinforcement and increasing the thickness and length of the wall. We have developed a retrofit method to solve these problems. The wall end is excavated to place the required vertical rebars, and concrete is poured after placing rebars. This is the same concept as creating wall end boundary elements later on. We also studied the anchorage method of reinforcement and the interaction method between the retrofitting end and the existing wall. The flexural test results for the reinforced concrete shear wall using the studied retrofit method can be predicted according to the sectional analysis and FEM analysis, and there are differences in the plastic hinge length, crack propagation, stiffness degradation and energy dissipation due to the bending depending on the vertical rebar ratio of wall end.

• ETRI Journal
• /
• v.45 no.1
• /
• pp.18-27
• /
• 2023

We present an English-Korean speech translation corpus, named EnKoST-C. End-to-end model training for speech translation tasks often suffers from a lack of parallel data, such as speech data in the source language and equivalent text data in the target language. Most available public speech translation corpora were developed for European languages, and there is currently no public corpus for English-Korean end-to-end speech translation. Thus, we created an EnKoST-C centered on TED Talks. In this process, we enhance the sentence alignment approach using the subtitle time information and bilingual sentence embedding information. As a result, we built a 559-h English-Korean speech translation corpus. The proposed sentence alignment approach showed excellent performance of 0.96 f-measure score. We also show the baseline performance of an English-Korean speech translation model trained with EnKoST-C. The EnKoST-C is freely available on a Korean government open data hub site.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.2
• /
• pp.192-201
• /
• 1993

According to technical advances of telecommunication, communication network has changed to digital transmission from analog transmission network. In the long run, current network will be altered into ISDN which makes end-to-end digital communication. This transition of communication network brings about an important questions for networking plan, administration, and speech quality in order to achieve the effective and advanced telecommunication. Speech quality criterions and degradation factors of digital communication system differ from those of existing analog system because of other characteristics like single echo. It is, therefore, necessary to design new criterions and specifications for digital communication network. This Paper describes the relation between speech communication and speech transmission quality and describes the implementation of model system for quality evaluation of digital speech communication network. In addition, some applications of model system implemented are proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.05b
• /
• pp.25-29
• /
• 2004

Corona on polymer materials causes deterioration by the combined action of the discharge striking the surface and the action of certain chemical compounds that are formed by the discharges. In the design and manufacture of polymer insulators must be sufficiently large to avoid corona discharges, otherwise a shielding or corona ring (grading ring) needs to be installed on the insulator. To conduct this purpose, many researchers have investigated end-fitting of polymer insulator by voltage distribution simulation and electrical test. Grading rings are used to improve the performance of the insulator in multiple ways. They can reduce corona and associated audible noise and radio influence and television interference. The factors determining the uses of a grading ring are line voltage, geometry and dimensions of end fittings, geometry and dimensions of line hardware, and environmental conditions. In this paper, electrical property of polymer insulator with end-fitting design have been investigated by electrical field analysis, various end-fitting design, tracking wheel test, corona inception voltage and extinction voltage. Electrical field analysis is conducted by FEM program and various end-fitting is designed through this result. Designed end-fittings are manufactured and their performance is conducted by electrical performance test.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.3
• /
• pp.247-253
• /
• 2013

This paper analyzes ship area network(SAN) with integrated gateway. For the analysis, this paper analyzes reference network architecture, end-to-end connection model, traffic model, and requirement of SAN. Also, the type of network element and minimum performance of integrated gateway is derived by ship area network simulator. The performance evaluation results show that a integrated gateway operating as network switch with performance over than 30,000 packets/sec can provides end-to-end connection with satisfaction of requirement of each end-to-end connection.

• Korean Journal of Metals and Materials
• /
• v.46 no.6
• /
• pp.390-401
• /
• 2008

The objective of this study is to evaluate various machining characteristics of AlN-hBN machinable ceramics in micro end-milling process for its further application. First, AlN based machinable ceramics with hBN contents in the range of 10 to 20vol% were prepared by hot-pressing. Material properties of the composites, such as relative density, Vickers hardness, flexural strength, Young's modulus and fracture toughness were measured and compared. Then, micro end-milling experiments were performed to fabricate micro channels using prepared system. During the process, cutting forces, vibrations and AE signals were measured and analyzed using applied sensor system. Machined micro channel shapes and surface roughness were measured using 3D non-contact type surface profiler. From the experimental results, it can be observed that the cutting forces, vibrations and AE signal amplitudes decreased with increasing hBN contents. Also, measured surface roughness and profiles were improved with increasing hBN contents. As a result of this study, optimum machining conditions can be determined to fabricate desired products with AlN-hBN machinable ceramics based on the experimental results of this research.