• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.521-523
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• 2005

A Jumper wire is currently used to connect each fixed power line on both sides of dead end tower for overhead transmission line, but in case of a jumper wire swing under circumstances of typhoon, etc. and the air clearance is deficient then a flashover fault may Happen. Now the angle tower has the jumper support string to prevent a swing of jumper wire and to secure the air clearance between jumper wire and tower main body, but the flashover fault by swing of jumper wire was happened yl times across all over the country, because of the typhoon 'Rusa' in year 2002 and 'Maemi' in year 2003. This paper presents the design and development of 'Counter Weight' which enables to keep the swing angle of jumper wire under 40 degree in design condition to prevent a flashover fault by swing of jumper wire by a high wind pressure load in case of typhoon and have completed a mechanical and electrical characteristic test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.944-951
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• 2009

In this paper, we use image processing algorithms to detect the defects existed on a welding area automatically. It is difficult to detect the welding defects because it is sensitive to lights and has irregular patterns. For this reason, images are captured with 2 kinds of illumination condition, and are processed by 2 different algorithms for each image. The first algorithm separates some ROI's from the captured image and compares the similarity of intensity between each divided region. The second algorithm extracts boundary information from the processed image by the first algorithm, and calculates the length of boundary, curvature and base line area based on boundary information. The proposed method showed high performance in detection and classification of defects.

• Journal of Korean Clinical Nursing Research
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• v.21 no.2
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• pp.243-251
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• 2015

Purpose: The aim of this study was to develop an educational program for the children's guardian with cochlear implants in order to provide knowledge and information about cochlear implants. Methods: The educational program was developed based on a literature review, potentially relevant website analysis, and validation by an expert group. Two out of twenty-two educational items under four domains that had item-level content validity index (CVI) greater than 0.8 by the ten experts were finally selected and used. After the children's guardian participated in this educational activity through a specially designed booklet and DVD, the effectiveness of the program was evaluated. Results: A total of 8 children's guardian participated in the program. Their knowledge levels significantly increased after participating the program (mean $15.0{\pm}3.02$ vs. $19.0{\pm}0.93$, Z= 2.371, p=.018). Satisfaction levels with the program was high, $4.1{\pm}0.87$ out of 5. Conclusion: This newly developed educational program for the children's guardian with cochlear implants is proved to be effective and can be used in nursing practice. In addition, the participants seemed to be satisfied with the program. Furthermore, this program may also improve the effects of adult with cochlear implants.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1864-1869
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• 2003

A novel piezoelectric micropump using active check valves in place of conventional passive check valves in inlet and outlet has been proposed and investigated. It actively controls open/close motion of check valves using piezoelectric actuator for expansion/contraction of pump chamber. In this paper, bi-directional flow characteristics and load characteristics are experimentally investigated using an adequate timing control for valve closing motion with a prototype micropump fabricated with the effective size of $17{\times}8{\times}11mm^{3}$. From the experimental results, it is ascertained that optimal values of phase shift against voltage to drive pump chamber for realization of a miniaturized but powerful micropump, are $15^{\circ}$ in inlet check valve and $195^{\circ}$ in outlet. Based on the obtained results, a sheet-type active shuttle valve that has a unified valve-body for inlet and outlet check valves is proposed. A micropump with the effective size of $10{\times}10{\times}10mm^{3}$ is fabricated and basic characteristics are experimentally investigated.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.125-144
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• 2009

Korean logistics industry have been focused on transportation business. However, with the expansion of the electronic commerce and on-line shopping, delivery service is now dramatically growing. Despite the expansion of logistics market, the domestic logistics industry have significant structural problems such as low productivity comparing with the advanced countries, relatively high cost and shortage of human resources and lack of professionalism of people in the industry. Logistics companies reallocate employees, use subcontractors, expand consignment and training the employees to overcome the labor shortages but it has some limits. In recognition of the importance of labor in the logistics industry, financial support and investment have increased. Logistics companies tend to hire consultants, set up logistics department or R&D center in order to establish highly productive logistics process and system so it is viewed that there will be considerable demands of human resources in the logistics industry. This study indicates implications and development direction of human resources in the logistics industry by looking into prospect and characteristic of the industry, employment status, training programs and qualification requirements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.757-758
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• 2015

The digital watermark is one of important techniques to solve copyright authentication problems of digital media. Researches on the digital watermark are rapidly increasing in various media. The watermark system can resist some attacks such as signal attack, geometric attack and protocol attach. However, so far the robustness of the watermark needs to be improved. This paper suggests a watermarking technique with which a watermark is embedded on a coefficient of wavelet-based frequency band and extracted from it for protection of property rights and authentication of Blackfin processor-based digital sound. By carrying out hardware implementation of the suggested sound watermarking, the commercialization of protection of property rights and robustness of watermarks resulted from development of high-level programs can be confirmed.

• Child Health Nursing Research
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• v.13 no.4
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• pp.478-485
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• 2007

Purpose: The study was done to investigate factors in mothers related to their intention to get additional vaccination for their children aged $4{\sim}6$ years. Methods: A descriptive correlational study was conducted. The participants were 858 mothers conveniently selected from a public health center in Seoul. Data were collected using self-administered questionnaires. Descriptive statistics, t-test, ANOVA, correlation and stepwise multiple regression were used for data analysis. Results: The mothers got a high of 2.08 marks on intention to get additional vaccination. The intention was positively correlated to attitude, perceived benefits, self-efficacy and negatively to perceived barriers, parenting stress. The most significant variables was attitude, perceived benefits, self-efficacy and those three variables explained 42.7% of mother's intention for additional vaccination. Conclusion: The above mentioned findings were identified as significant factors affecting mother's intention for additional vaccination. The findings are expected to make a positive contribution to creating an ideal intervention and to promoting an increased vaccination rate.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.4
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• pp.191-197
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• 2012

In this paper, method using electric braking from stop area to high-speed area was presented in order to improve air-brake. And electric braking method can be improved environmental problems, efficiency, economy, etc.. Method for electrical complete braking are two ways that method of inserting series resistance between the motor and the inverter, and method of inverter output voltage increase. In this paper, use series resistance insert method because economical and easy to apply. In addition, Series resistor is used short circuit method for reduce the power loss. In improved efficiency and the laboratory environment for secure braking, resistance insert method and inverter output voltage increase method showed same characteristics in all areas.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.3
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• pp.127-137
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• 2012

In this paper, method using electric braking from stop area to high-speed area was presented in order to improve air-brake. And electric braking method can be improved environmental problems, efficiency, economy, etc. Method for electrical complete braking are two ways that method of inserting series resistance between the motor and the inverter, and method of inverter output voltage increase. In this paper, use series resistance insert method because economical and easy to apply. In addition, Series resistor is used short circuit method for reduce the power loss. In improved efficiency and the laboratory environment for secure braking, resistance insert method and inverter output voltage increase method showed same characteristics in all areas.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.292-296
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• 2023

Until recently, ships, automobiles, and drones using hydrogen energy are being actively researched. In addition, stations and facilities for hydrogen supply are being developed widely. Among them, a hydrogen pump is necessary for compressing it and transfer to other stations. The liquid hydrogen pump is operated at very high pressure up to 90 MPa. In our research, a reciprocating plunger pump is studied. Especially, a leakage in a liquid hydrogen pump is predicted using a finite element method. As a result, it was found that leak mass flow rates changed from 0.09 to 2.20 kg/h, when the gaps were given from 2 to 6 ㎛. Thus pump efficiencies were calculated from 99.9 to 97.9%, when the gaps changed from 2 to 6 ㎛. These results are useful for the design of the liquid hydrogen pump.