• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.2
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• pp.86-90
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• 2014

It is important to select an optimal capacity for equipment, because the initial cost of new and renewable energy system is more expensive than that of exiting system. An optimal equipment and enhanced rate of operation can be selected, to analyze the cooling and heating load of buildings. In this study, seawater heat pump system in the Jeju area will be applied, by the heat source equipment of district heating. The loads of buildings are analyzed from existing researches, to select optimal capacity of equipment. Also, an optimal rate of building use will be set up, from a combination of buildings.

• Journal of Korean Society for Quality Management
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• v.16 no.1
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• pp.8-14
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• 1988

Because of demand pattern variability and Product Liability pursuance for products, it is necessary to convert from Product Liability Defence to Product Liability Prevention. For aggravation of company environment, automation, mechanization and FMS are required, to reduce quality cost in this situation, we present the following two alternatives. (1) We solidify the PL policy by process improvement. (2) We set up sensor equipment for defective detection in its early stage.

• Journal of Information Management
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• v.2 no.3
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• pp.2-4
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• 1964

Scientific documentation is one of the three preconditions for scientific research and its technical application in the industrialization process. To solve the documentation problems on an international level, UNESCO promotes abstracting, standardization of terminology and of scientifc publications, automatic information processing and translating. Moreover, UNESCO has helped to establish since 1950, on the request of interested national governments, 12 documentation centers within the framework of United Nations Technical Assistance Programme by providing experts, fellowships and equipment. Some data on these documentation centers and a comparison of their features should be of interest for all those who wish to set up new documentation centers or to improve already existing ones.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1726-1735
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• 2008

Seoulmetro has operated the air cooling equipment for 57 stations to improve services focused on our customers who use Seoulmetro during the summer season and has established every year. However, a new set of problems has arisen with the cooling tower to support a heat exchange of cooling water. The most important matter is loss of efficiency in the cooling tower. The leading cause of this problem is that we use an indoor type. As the cooling tower room is located in the underground of the city because of the residents near the station. Therefore It is difficult to establish the cooling tower on the ground. But it is unsuitable for the location requirements of the underground type because it has a limited space to set up the air cooling equipment, for example, the cooling tower and a ventilating opening. As a result of such an unfavorable condition, the cooling tower doesn't work efficiently and the warmth of cooling water because of insufficiency of a heat exchange and a refrigerator's technical obstacle such as a high-temperature and a high-pressure has arisen. To prevent this situation, the operator tend to reduce refrigerant. Accordingly, the efficiency of the air conditioning is getting lower and lower. Study wishes to analyze the matter to improve indoor cooling tower efficiency and recommend a best practice for a person who manage the establishment.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.7-15
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• 2020

Purpose: In modern radiotherapy technology, several methods of image guided radiation therapy (IGRT) are used to deliver accurate doses to tumor target locations and normal organs, including CBCT (Cone Beam Computed Tomography) and other devices, ExacTrac System, other than CBCT equipped with linear accelerators. In previous studies comparing the two systems, positional errors were analysed rearwards using Offline-view or evaluated only with a Yaw rotation with the X, Y, and Z axes. In this study, when using CBCT and ExacTrac to perform 6 Degree of the Freedom(DoF) Online IGRT in a treatment center with two equipment, the difference between the set-up calibration values seen in each system, the time taken for patient set-up, and the radiation usefulness of the imaging device is evaluated. Materials and Methods: In order to evaluate the difference between mobile calibrations and exposure radiation dose, the glass dosimetry and Rando Phantom were used for 11 cancer patients with head circumference from March to October 2017 in order to assess the difference between mobile calibrations and the time taken from Set-up to shortly before IGRT. CBCT and ExacTrac System were used for IGRT of all patients. An average of 10 CBCT and ExacTrac images were obtained per patient during the total treatment period, and the difference in 6D Online Automation values between the two systems was calculated within the ROI setting. In this case, the area of interest designation in the image obtained from CBCT was fixed to the same anatomical structure as the image obtained through ExacTrac. The difference in positional values for the six axes (SI, AP, LR; Rotation group: Pitch, Roll, Rtn) between the two systems, the total time taken from patient set-up to just before IGRT, and exposure dose were measured and compared respectively with the RandoPhantom. Results: the set-up error in the phantom and patient was less than 1mm in the translation group and less than 1.5° in the rotation group, and the RMS values of all axes except the Rtn value were less than 1mm and 1°. The time taken to correct the set-up error in each system was an average of 256±47.6sec for IGRT using CBCT and 84±3.5sec for ExacTrac, respectively. Radiation exposure dose by IGRT per treatment was measured at 37 times higher than ExacTrac in CBCT and ExacTrac at 2.468mGy and 0.066mGy at Oral Mucosa among the 7 measurement locations in the head and neck area. Conclusion: Through 6D online automatic positioning between the CBCT and ExacTrac systems, the set-up error was found to be less than 1mm, 1.02°, including the patient's movement (random error), as well as the systematic error of the two systems. This error range is considered to be reasonable when considering that the PTV Margin is 3mm during the head and neck IMRT treatment in the present study. However, considering the changes in target and risk organs due to changes in patient weight during the treatment period, it is considered to be appropriately used in combination with CBCT.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.61-67
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• 2013

The turnout point system is installed to separate the main rail track from other tracks in rail load stations. It is also important to set up the switch point system to change the direction of the turnout point, to lead and change the direction of tracks. The switch point system can be negatively affected by heavy snow during winter seasons which can cause critical safety problems. Furthermore, the maintenance and repair of the conventional system is prohibitively expensive due to its complexity and high probability of failure. In this paper, an efficient switch point system is proposed which simplifies the equipment structure and lowers the cost for maintenance and repair, while improving safety and performance of the rail road system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.30-35
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• 2007

Various acoustic tests were carried out to investigate the acoustic performance of diesel engine exhaust silencers. In order to consider flow effects, test equipment composed of fan, duct and silencer was set up. Using the test equipment, insertion loss tests were carried out to improve the performance in the low-frequency ranges. Through a series of tests, the fact that array resonators may be effective in the low-frequency noise has been verified. Consequently, the hybrid-type silencer which is the combination of reflective silencer with array resonators and conventional absorptive silencer were proposed and its high acoustic performance in the low-frequency range has also been verified.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.357-369
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• 2011

Eco-robot for collecting recycling products is the machine which collects non-industrial wastes such as cans, PET bottles and etc. to reuse them as recycling resources. This eco-robot is operated in the condition that it should compress and hold various products without knowing their geometric shapes and material properties. For this reason reliability problems like malfunction or failure. comes to emerge, but the reliability test conditions to assess its performance and durability have not been founded yet. Therefore in this research failure mechanism of the eco-robot was analyzed and life test equipment which can reproduce actual usage conditions was developed. The compression levels in the life test were determined by measuring the crushing force acting on test products and Furthermore the test specimens which have equivalent shape and material properties with those of cans and PET bottles were proposed by simulating the deformation characteristics so that the actual compression conditions were set up in the test.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.939-945
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• 2002

The rise throughput and the stability in the device fabrication can be obtained by applying chemical mechanical polishing (CMP) process in 0.18 $\mu\textrm{m}$ semiconductor device. However, it still has various problems due to the CMP equipment. Especially, among the CMP components, process variables are very important parameters in determining the removal rate and non-uniformity. In this paper, we studied the DOE (design of experiment) method in order to get the optimized CMP equipment variables. Various process parameters, such as table and head speed, slurry flow rate and down force, have investigated in the viewpoint of removal rate and non-uniformity. Through the above DOE results, we could set-up the optimal CMP process parameters.

• Korean Journal of Computational Design and Engineering
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• v.14 no.6
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• pp.374-381
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• 2009

To meet the soaring demand recently, South Korea big shipbuilders are examining two things. One is new investment in plant and equipment. The other is replacement of production resources. Considering plant & equipment investment and replacement of production resources, even if actual production ability would be enough, the real output could be affected by limitation of logistics with lack of analysis. As we set up big shipyard in virtual space, we could perform actual production by using confirm production plan in virtual space. We've analyzed the load of block stock, load of road and load of transporter for logistics effects are followed by production increase. This research is to determine the possible problems of those analyzed results and to present the resolution using the current layout. And then modified yard layout, we reanalyzed previous three logistics effects. This simulation model could help administrator to make rational decision for changing yard layout.