• Journal of Drive and Control
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• v.9 no.2
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• pp.28-38
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• 2012

Monitoring of system cleanliness levels and counting of particulate contaminant are fundamental to achieving hydraulic system reliability as any departure from the specified cleanliness level is often a precursor to future failures. On-line monitoring of cleanliness levels has the advantage of giving data both very quickly and accurately as environmental influences are eliminated. In this way, corrective actions can be promptly implemented. Most on-line instruments are sensitive to system conditions to a greater or lesser extent, but Automatic Particle Counters (APCs) working on light extinction principles are especially sensitive to the presence of optical interfaces caused by such conditions as fluid mixtures, emulsions, free water and air bubbles. These conditions give erroneous data and can result in drawing incorrect conclusions, wasting maintenance time and ultimately, reduced user confidence in cleanliness monitoring. This paper describes such conditions and shows how the correct selection of the analysis technique can result in reliable cleanliness level data.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.331-332
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• 2007

This Paper deals with the high sensitive camera circuit design, which is more sensitive than those on the market now in a way that it got rid of chronic smearing problem in CCD sensor and other kinds of noises in video signal effectively. This paper focused on the principle of CCD and video signal process and analyzed the specialized technique of industry and fundamental high sensitivity of CCTV camera. 1 also looked into the SONY super-HAD CCD camera which is very popular in the field now and compared this with the SONY EXview CCD camera to analyze the picture improvement using video test equipment. For the result, it had 190mv on camera sensitivity, 14dB on smearing, and 2dB on signal to noise ratio.

• Journal of Navigation and Port Research
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• v.28 no.7
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• pp.647-651
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• 2004

FPSOs are commonly proposed and used for offshore oil production. Due to the fundamental requirement of FPSOs to remain moored at their location, they are unable to avoid severe weather. FPSOs normally operate head to the weather, and sensitive equipment located near the bow will be susceptible to green water damage. Damage may occur to both equipment and superstructure, with resulting risk to personnel. To initially access green water is allowed by the physical understanding of green water events. In this paper the main focus is put on the physical phenomena of green water accounted for with the tested data in regular waves.

• Journal of Welding and Joining
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• v.34 no.5
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• pp.6-12
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• 2016

This study was performed bead welding of pure titanium by using fiber laser. Since titanium is very sensitive to oxidation and nitriding during welding, it is important to compose the shielding equipment compared with different material. Thus side and coaxial shield nozzle, rail and chamber type shielding equipment are widely used to protect effectively the weld during welding. Experiments were performed by changing nozzle angle and distance using side and coaxial shield nozzle. The bead colors of gold, brown, blue, purple and yellowish white were obtained by changing variables of shield nozzle, and then its weldability was investigated. As experiment result, sound and not brominated beads were formed when side nozzle angle and distance were respectively $45^{\circ}$ and 10 mm.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1103-1106
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• 2008

For the current display process, the innovative micro pattern fabrication process using semiconductor process should be developed, which requires the expensive equipment, the limited process environment and the expensive optic-sensitive material. The effort of process innovation during past several years ends up the limit of cost reduction. The existing ink jet technologies such as a thermal bubble ink jet printing and a piezo ink jet printing are required to shorten the nozzle diameter in order to apply to the micro pattern fabrication. In this paper, as one way to cope these problems the micro pattern equipment based on the electrostatic ink jet has been developed and carried out some experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.839-843
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• 2005

In this paper, wish to improve reception performance of general receiver manufacturing maritime broadband reception amplifier that can thread easily in VHF transmit-receive equipment into downsize, light weight, low-coat. Manufactured reception amplifier expressed Characteristic that improve reception sensitive 3dBm in $140MHz\~170MHz$ frequency band. Therefore, may use communications equipment that utilize VHF wide-band more efficiently. Also, practical use degree is considered to be very high because telecommunication of good quality is available.

• Journal of KSNVE
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• v.9 no.6
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• pp.1227-1233
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• 1999

Modern technology depends on the reliability of extremely high technology equipments. In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a nanometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. This paper deals with the structural dynamic design in high class semiconductor factory in order to be satisfied more strict vibration criteria for high sensitive equipment.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1106-1110
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• 1998

Voltage Sags, different from electric outages, are important to industrial reliability because modern process controls are often sensitive to voltage sag, the designer and operator should recognize sag characteristics of the electric system not only to protect malfunction of equipment but also to make best choices between reliability and equipment cost. The voltage sags and compensation countermeasures of large md industrial distribution systems have been simulated using EMTDC. The causes of voltage sags occurred in the system are discussed in detail and several countermeasures including the transfer of large induction motor from normal power source to backup source are recommended in order to enhance the ride-through characteristics of equipments.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1099-1101
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• 2007

In this paper, a study has been performed for development of dynamic voltage restorer(DVR) system using EDLC (Electric Double Layer Capacitor) to solve voltage sags which are considered the dominant disturbances affecting power quality. With the prolific use of semiconductor devices in electrical equipment, modern-day loads are becoming increasingly sensitive to the sags and the disturbances prove to be costly to industries. As a technology-driven custom power installation, the Dynamic Voltage Restorer (DVR) is recognized to be most effective equipment that can be used to counter the voltage sag problem. Hence, this paper proposes the high-performance optimal design of On-Line type DVR system which can efficiently compensate the instantaneous voltage sag and instantaneous interruption of the utility voltage source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.165-169
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• 2000

High level vibrationional environments induced while launching of spacecraft can damage sensitive equipment or payloads, unless the equipment is properly designed. This is a critical issue for KOMPSAT-2 which will carry a high resolution electro-optic camera and a sophisticated attitude and orbit control system. Thus careful consideration on the launch environment is required in the design stage of spacecraft. This requires generation of vibration specification for each component. This paper describes the generation process of vibrational specification for KOMPAT-2, which is designed and tested by Korean engineers.