• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.411-424
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• 2018

Purpose: The purpose of this study is to improve submarine TACM launcher system safety device performance. Methods: In this study, EPLD(Electrically Programmable Logic Device) control and time sharing method to the safety device actuator motor and discrete signal processor in launch control panel were used to resolve unusual performance of safety system. Results: The result of this study are as follows; First, sporadic stopping of safety device actuator motor due to insufficient In-Rush current was resolved. Second, repeat of safety device condition as lock & release due to chattering for motor activating was resolved. Third, simultaneous release function for safety device actuator was available. Conclusion: The unusual performance of function for submarine TACM launcher system was overcame by applying EPLD control and time sharing method. The suggestions were proved by performance test in the pressure chamber. The results of this study enhanced survivability of ${\bigcirc}{\bigcirc}{\bigcirc}$ class submarine from enemy torpedo.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.159-164
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• 2021

The examination using diagnostic x-ray equipment is one of the most useful diagnostic equipment for identifying information in the human body in diagnostic radiology. For this reason, the number of examinations has recently increased a lot. Increasing the number of examinations will accelerate the aging of the device. In addition, this makes them aware of the importance of quality control for the diagnostic x-ray device. Particularly, in a diagnostic x-ray device, quality control refers to an act of always maintaining a certain level of image quality by identifying and correcting all problems that may lead to reduction of the diagnosis area in advance. Therefore, this study summarizes and reports general information about quality control in examinations using diagnostic x-ray equipment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.784-799
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• 2013

This paper presents an adaptive rate control scheme for streaming-based content sharing service. This scheme delivers multimedia contents from a user device to another device or seamlessly redirects streaming service across heterogeneous user devices. In the proposed scheme, a streaming server adjusts video quality level according to the network and client status. Our scheme is different from other rate control schemes, because the video quality at the server is decided not only based on the available bandwidth, but also based on the device characteristics and bandwidth requirement at the access network. We also propose a bandwidth estimation method to achieve more equitable bandwidth allocations among streaming flows competing for the same narrow link with different Round Trip Times (RTTs). Through the simulation, we prove that our scheme improves the network stability and the quality of streaming service by appropriately adjusting the quality of the video stream. The simulation results also demonstrate the ability of the proposed scheme in ensuring RTT-fairness while remaining throughput efficient.

• Journal of Integrative Natural Science
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• v.12 no.1
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• pp.9-13
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• 2019

Recently, as the sleep disorder problem of modern people deepens, the interest towards quality of sleep is increasing. To increase the quality of modern people's sleep. This paper has suggested an LED lighting control system according to the sleep stage using PPG sensors of wearable devices. The pulse of the wrist radial artery was measured using a wearable device mounted with PPG sensor, which enables heart rate-measuring, and by using the point that heart rate lowers during stable sleep than non-sleeping, the LED lighting of indoors was controlled, which is the disturbing element when sleeping. For the performance evaluation, a 10-Fold cross analysis was conducted for performance evaluation, and a result of an average accuracy 87.02% was obtained as a result. Therefore, the LED lighting control system according to the sleep stage using a wearable device of this paper is expected to contribute to raise the quality of the user's life.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.59-66
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• 2006

In laser welding, automatic seam tracking is important to adjust the laser head position in real time as it moves along the seam. Also if the joint gap is occurred, filling the missing material into the joint gap is necessary to prevent welding defects and bad welding quality. In general, the joint gap width is not constant along the seam due to a variety of reason. So it is essential to control the filler wire speed into the joint gap to acquire good welding quality. This paper describes an intelligent filler wire feeding device which can control 3-dimensional seam tracking and the filler wire speed by measuring the gap position and the joint gap width in laser welding. We call this device as Smart Micro Control system(SMC). To achieve this objective, we assessed weld quality in 2mm sheets of A16061 which had various gap width by using the developed device. From the experimental results, It was found the possibility that the developed device could be used in welding various 3-dimensional structures.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.605-616
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• 2020

The construction quality control of hull blocks is of great significance for shipbuilding. The total station device is predominantly employed in traditional applications, but suffers from long measurement time, high labor intensity and scarcity of data points. In this paper, the Terrestrial Laser Scanning (TLS) device is utilized to obtain an efficient and accurate comprehensive construction information of hull blocks. To address the registration problem which is the most important issue in comparing the measurement point cloud and the design model, an automatic registration approach is presented. Furthermore, to compare the data acquired by TLS device and sparse point sets obtained by total station device, a method for key point extraction is introduced. Experimental results indicate that the proposed approach is fast and accurate, and that applying TLS to control the construction quality of hull blocks is reliable and feasible.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.139-143
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• 2006

Recently, standard of living improved and Information-Communication industry developed rapidly. Thereby, interest about electric power quality is rising worldwide. So, research and Development to enhance electric power quality in various viewpoint until most suitable supply system from each kind device to improve electric power quality. And specially, interest about voltage quality is rising by diffusion increase of information communication appliance and minuteness control appliance etc. Also Power consumption is increasing, but expansion of large size generator by environmental and site security problem is difficult. So, introduction of distribution generation is investigated actively by electric-power industry reorganization. Voltage management of power system had been controlled by ULTC (Under Load Tap Changer) in substation and pole transformer on the high voltage distribution line. But, voltage control device on substation and distribution line is applied each other separatively. Therefore, efficiency of line voltage control equipment is dropping. Also, research about introduction upper limit of distribution generation is consisting continuously. This paper presents cooperation use way between voltage control device and introduction upper limit of distribution generation for most suitable voltage control in distribution power system.

• Journal of radiological science and technology
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• v.41 no.4
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• pp.329-337
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• 2018

This study was investigated quantitative ultrasound (QUS) usage in Korea for the QUS quality control guidelines. A total of 344 questionnaires collected from July 24th to August 25th 2017 were analyzed. Questionnaires were created through user interviews, expert group advice, literature review and field observation. As a result of the general characteristics of quantitative ultrasound holding amounted to 81.98% of clinic and 6.69% of hospitals. The main user was radio-logical technologists as 31.39%. The contact methods of the gel pad (balloon) were the most used at 56.68% and the scan region was 91.9% of calcaneus. The quantitative ultrasound quality control cycle was 67.37% when the abnormality was found in the equipment, and 63.66% when the accuracy control was implemented according to the manual. The phantoms of QUS were 34.30% of the manufacturer's own phantoms. User of QUS had never received education for quality control of quantitative ultrasound as 62.20%. This study was expected to be useful when creating detailed quality control guidelines in the future, as well as guidelines for the quality control of Korea's standard quantitative ultrasound.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.118.3-118
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• 2001

CLED (Contact Light Emitting Device) has three layers consisting of a transparent electrode, a light emitting layer and a substrate. When the substrate of the CLED comes in contact with a fingerprint under AC input voltage, it makes an electric field between the fingerprint and the device. Due to the electric field, the light is emitted along the ridgeline of the fingerprint. The intensity along the ridge on the surface of the CLED increase in proportion to the electric field. To achieve uniform performance of fingerprint verification devices, inspection system of CLED for quality control were required. In this research, we proposed the factors for quality controls such as dimensions of the CLED, uniformity ...

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.1
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• pp.65-75
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• 2005

An accurate characterization of the display device is essential for better color matching. The calibration and characterization process in display device is needed to transform the device dependent color to the device independent color. The process of characterization performs a linearization and transforms the linearized values into the CIE XYZ tristimulus values. The purposes of this paper is to propose optimal color transformation method for accurate reproduction of original copy in display device and to explain the propriety of transformation method using specific variable for the power of gradation expression.