• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.93-94
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.143-144
• /
• 2011

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.5 no.3
• /
• pp.178-197
• /
• 1976

Based on the measurement data on Radiation on a Horizontal Surface at 84 different areas in South Korea which were collected and recorded by the Central Meteorological Office, the average values in the period of 5 years from 1971 thru 1975 at 12 particular areas of Gangreung, Gyeongju, Gwangju, Gimhae, Mogpo, Seoul, Iri, Jeju, Jinju, Cheongju and Chungju are indicated in this report. For above 12 areas the following data have been obtained and are indicated in each tables. Annual totalization of Radiation on a Horizontal Surface and its yearly averaged daily totalization$cdots$Table 1. Monthly totalization of Radiation on a Horizontal Surface and its monthly averaged daily totalization$cdots$Table 2 Maximum and minimum values of daily totalization of Radiation on a Horizontal Surface$cdots$Table 3 Daily variation of monthly averaged Radiation on a Horizontal Surface$cdots$Table 4 thru 15 Decade averaged Radiation on a Horizontal Surface$cdots$Table 16 thru 27

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.292-298
• /
• 2009

This paper investigates the control performance of the proposed hybrid mount system for vibration isolation table. The hybrid mount system consists of an air spring as a passive device and a PZT stack actuator as an active device in series. The feasibility of the PZT stack actuator as an active actuator was examined through the simple experiments. After that, a series of numerical simulations were carried out to evaluate the control performance of the proposed hybrid mount system. The equations of motion of the table with a set of hybrid mount systems consisting of four devices are derived. The air spring is considered as a 1 spring and 1 dashpot elements, and PID control algorithm is adopted to estimate the control force. The results of the numerical simulations presents that the proposed hybrid mount system could be the promising control system for vibration isolation table.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.3
• /
• pp.408-412
• /
• 2007

It is almost impossible to secure the reproductibility and stability of a commercial Thick-Film Metal Oxide Semiconductor Gas Sensor since it is very difficult to keep the consistency of the manufacturing environment. Thus it is widely known that the general Semiconductor-Oxide Gas Sensors are not appropriate for precise measurement systems. In this paper, the output characteristic analyzer of the various Thick-Film Metal Oxide Semiconductor Gas Sensors that are used to recognize the air quality within an automobile are proposed and examined. The analyzed output characters in a normal air chamber are grouped by sensor ranks and used to fill out the characteristic table of the Thick-Film Metal Oxide Semiconductor Gas Sensors. The characteristic table is used to determine the rank of the sensor that is equipped in the current air cleaner system of an automobile. The proposed air control system can also adapt the on-demand operation that recognizes the history of the passenger's manual-control.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.1
• /
• pp.7-12
• /
• 2007

In this paper, we introduce an approach to design multi-fuzzy controllers for the superheat and the low pressure that have an influence on energy efficiency and stabilization of aft conditioning system. Air conditioning system is composed of compressor, condenser several evaporators and several expansion valves. It is quite difficult to control the air conditioning system because the change of the refrigerant condition give an impact on the overall air conditioning system. In order to solve the drawback, we design multi-fuzzy controllers which control simultaneously both three expansion valve and one compressor for the superheat and the low pressure of air conditioning system. The proposed multi fuzzy controllers are given as two kinds of controller types such as a continuous simplified fuzzy inference type and a discrete fuzzy lookup_table type. Here the scaling factors of each fuzzy controller ate efficiently adjusted by veal coding type Genetic Algorithms. The values of performance index of the conventional type are compared with the simulation results of discrete lookup_table type and continuous simplified inference type.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.14 no.3
• /
• pp.30-39
• /
• 2006

The purpose of this study is to analyze how much Air Transportation Industry contribute to national economy by measuring economic spreading effects of Air Transportation Industry on national economy. To achieve the purpose of the study, the study uses an Air Transportation Input-Output Table of year 2000 of korea. The results shows that Air Transportation Industry induce 274,530.8 billion won of national production, import inducement 13,7073.7 billion won, value-added 110,994.9 billion won, especially Air Transportation Industry shows that production inducement coefficient is 1.36803, import inducement coefficient is 0.60581, value-added coefficient is 0.45189, income inducement coefficient is 0.18599 and employment inducement coefficient is 0.00841.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.734-737
• /
• 2001

A study was conducted in order to remove PVC from the waste plastic film mixture. The fittings of Air Table was modified to increase the separation efficiency of PVC. By using the improved air table, the PE and PVC was successfully separated from PVC-PE film mixture with the yield of PE 90% or more and with the content of PVC in PE 1% or less. The detail of the separation condition and result will be discussed in this paper.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.4
• /
• pp.635-642
• /
• 2013

We have prepared a DEMO conveyor device for conveying a large 8G class glass sheet using ahorizontal air-cushion system. This device consists of the body frame and the driving frame that are combined to realize a frame for conveying glass without any contact.The driving frame comprises an air flotation table (bed), drive roller supported at both ends, and ASU. Part of the ASU serves to control the airflow as the chamber consists of a porous pad and fan. Fiber filters replace the porous pad and axial fans serve as an air compressor. In addition, to determine the appropriate glass levitation from the air table, this study examined the design specifications of the applied filter (discharge speed of HEPA and ULPA filters, and flow rate) as well as the height of the and the proper supporting roller height (14mm). Then, after adjusting the position of the ASU and the number of ASUs required to configure the UNIT air floating C/V, we analyzed the height and flatness of the glass and derived the appropriate layout (1140-mm distance between ASUs).

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.4
• /
• pp.721-729
• /
• 1988

Recently, the precision required by precision manufacturing and machinery related to electronics is within the domain of submicron that it is difficult to evaluate them by traditional measuring equipments and methods. Accordingly, precision of sub 0.1.mu.m super precise position-decision-apparatus and straight-guide air bearing have been researched and they are almost ready to be used. In utilizing straight-guide-table for super-precision-measurement which used externally pressurized porous air bearing as a way of externally pressurized air bearing, the high-precision-straight movement is the most crucial. In this study, the researcher conducted the experimental study with trial manufacture to see how the surrounding temperature and support condition influenced the selection and allocation of the machine composing element which is important to the high-precision-straight movement. The researcher finding showed that when the property of the rail part and support part of the semi-closed slider form is different, the heat generation of the working motor and surrounding temperature influence the high-precision-straight movement significantly and the researcher showed the influence of the condition of central load and eccentric load to the straight movement precision when the support stand of the straight-table was supported by numerical values.