• Architectural research
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• v.1 no.1
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• pp.47-53
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• 1999

An interesting of desktop air-conditioning system is the Personal Environmental Module(PEM) System. The PEM system allows the occupant to choose the desired temperature, air volume and direction of the discharged air. In this study, the measurements on the age of air and the air change effectiveness, using the tracer gas method, are carried out to analyze the ventilation performance for provision of fresh air near the breathing zone by the PEM. The relations between the PEM for optimal control and other factors related to indoor air quality, and the ventilation for the PEM are examined. Also, three different supply diffuser types(desktop, floor and ceiling) are compared in view of their ability to distribute supply air to the workstation breathing zone. The desktop diffuser type could deliver air directly to the occupants breathing zone with a high degree of effectiveness. The minimum local age of air was measured in the breathing zone, which is directly supplied with air from the PEM diffusers, and the measured local air change effectiveness of the desktop diffuser in the breathing zone was about 1.13 to 1.23 times greater than that of the ceiling and floor diffusers. When the minimum outside air change rate as specified using ASHRAE Standard 62R is supplied with a desktop diffuser type, the volume of outside air can be reduced 13 to 23%, resulting in a commensurate in ventilation energy use.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.4
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• pp.252-261
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• 2001

Room air flow and temperature distribution was numerically investigated where a PAC(personal air conditioning) system was installed. The calculated results were compared with those from experiments. The effects of the important operation parameters such as the air flow rate, velocity, and temperature at the diffuser on the thermal performance of the system were studied. The possibility of energy saving using the PAC system was verified from the results, It was shown that the warm air from the diffuser could not spread over the whole task area if the inlet temperature was too high.

• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.1-8
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• 1998

A Hardware system of hybrid environmental control was developed for using it in the multi-greenhouse. Now, an on/off control system is most utilized in protected cultivation, but a hybrid environmental control system is not yet. This system consists of a hardware to be devided by physical elements and a software for the hardware a personal computer, a hybrid environmental control and a communication Program for modules. The hardware was made of several independent modules with independent CPU. Each module was made to slots. which are very convenient to mount and take off. Also, they are managed easily to repair, add, remove, and change of their function and expansion. The software for a personal computer was a menu driven program written in visual basic within a Windows environment for easy applications by a user. The hybrid environmental control software have operating factors operate continuously with temperature, humidity and others in greenhouse. Communication programs were used both 485 communication method for long distance communication between modules and CRC communication method for making easy to program, and less errors between personal computer and modules.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.76-94
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• 2001

Promoting positive values, attitudes, participation and personal actions on the basis of the acquisition of one's knowledge and skills is emphasized on teaching environmental education. To complete this purpose of environmental education, it is necessary not only to use various and practical educational resources, but also to develop information system, with multimedia and internet, which are effective for learning. This research attempts to assess the consistency of planning, organization and operation of integrated program for social environmental education which was developed for the necessities mentioned above. We surveyed about the accuracy of contents, usefulness, convenience and easiness of Integrated program for social environmental education. Also, we used a questionnaire to clarify the values and attitudes of respondents after they took environmental education. Then, technically, descriptive statistical method has been used to analyze the results of these surveys. Finally, we conduct an examination of the distribution of chi-square to verify the relationship between the learner's experience of using computer and one's concern about environmental issues. The results of this program, developed by research team, can be assessed by following five basic elements: usefulness, practicality, appropriation, efficiency and effectiveness. More than 90% of respondents said that this program is convenient and easy to loam. Also, more than 85% of whole respondents identified that after teaming this program they recognized more clearly what the main contents of environmental education are. In addition, we got positive response from 93% of respondents that they could understand environmental problems. On the other hand, values and attitudes of respondents have not improved a lot after the environmental education compared with the remarkable change in their recognition and understanding of environmental issues; only 34% of respondents responded that they changed their life style for making better environment after teaming this program. But it is clear that they understand much better about the environmental policy after they are educated. Developed by using information system, this integrated program for social environmental education may get different results according to a respondent's experience of using computer. Therefore, the more a respondent got a chance to use computer for a long period of time, the more he/she gave positive evaluation on the convenience and easiness of this program. However, there was no certain relationship between the frequence of using computer and one's understanding of environmental issues. Futhermore, a person who has constant concerns about environmental problems showed more positive attitudes against the understanding of environmental education. This integrated program for social environmental education, characterized by integrated, specialized and efficient educational system, can also be used as a curriculum or teaching materials for environmental education for adults; especially, it would be appropriate for teaching learners at all levels, who have different personal characteristics, to let them acquire virtual education by using information system.

• International Journal of Contents
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• v.10 no.4
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• pp.69-74
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• 2014

General location aware systems are only applied to indoor and outdoor environments using more than three transmitters to estimate a fixed object location. Those kinds of systems have environmental restrictions that require an already established infrastructure. To solve this problem, an Object Location Estimation (OLE) algorithm based on PTP (Point To Point) communication has been proposed. However, the problem with this method is that deduction of performance parameters is not enough and location estimation is very difficult because of unknown restriction conditions. From experimental tests in this research, we determined that the performance parameters for restriction conditions are a maximum transmission distance of CSS communication and an optimum moving distance interval between personal locations. In this paper, a system applied OLE algorithm based on PTP communication is implemented using a CSS (Chirp Spread Spectrum) communication module. A maximum transmission distance for CSS communication and an optimum moving distance interval between personal locations are then deducted and studied to estimate a fixed object location for generalization.