• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.87-90
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• 2002

Daylight responsive dimming system, which is always able to automatically maintain the target illuminance, is a energy strategic system. It is importance note that the photosensor depends how to be precisely indicated workplane illuminance at any location of indoor. Therefore, the purpose of this paper is to find out the optimum location and spatial characteristics of photosensor by considering the correlation for the correct calibration of workplane illuminance and photosensor signal.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.8-14
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• 2003

The daylight responsive dimming system, which uses daylight and automatically controls the light output of electric lighting according to the amount of 3.vailable daylight, is an energy saving system Successful performance relies on how photosensor signal can precisely represent workplace illuminance. However, it is not accurately identified due to the dynamic nature of the sun and the sky changed with respect to different seasons or time. The purpose of this research is to identify the correlation between workplace illuminance and photosensor signals, and propose an optimal location and spatial characteristics of the photosensor through experiments, which minimizes the above impacts and improve system performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.1-8
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• 2005

Daylight responsive dimming systems have been used to save the energy in office buildings. It is needed to consider a configuration of photosensor shape for efficient management of daylight responsive dimming systems. The configuration of optimal photosensor shape must be able to measure the exact luminous flux without changing of setting positions corresponding to the changes of room situations. On this occasion optimal photosensor shape must be designed with configuration of a proper photosensor spatial distribution and location for the daylight responsive dimming systems.

• Journal of Photoscience
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• v.9 no.2
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• pp.302-304
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• 2002

pharaonis phoborhodopsin (ppR), a photophobic sensor of haloalkaliphilic bacteria, Natronobacterium phar-aonis, has retinal as a chromophore covalently bound to Lys in G-helix via a protonated Schiff base (PSB), as is the same as bacteriorhodopsin (bR). For ppR, the corresponding counter-ion is Asp residue (Asp75) located in C-helix. Here we investigated the influence of the protonated state of this counter-ion and its location on the chromophore configuration. Under alkaline condition, the chromophore configuration of D75E mutant was analyzed by HPLC. D75E had a much larger content of 13-cis isomer: the ratio of 13-cis to all-trans was 6:4 while the wild-type had this ratio of 1 :9. On the other hand, under acidic condition where Glu was associated, D75E had no 13-cis retinal isomer. Mutants whose Asp75 was replaced by neutral amino acids (D75N and D75Q) did not contain 13-cis retinal. Furthermore, retinal isomer compositions and the change in the visible ab- sorption spectra (indicating the dissociation state of Glu75) were measured under varying pH, and these were almost the same dependencies. These results indicate that an important factor determining the 13-cis isomer content is the presence of negative charge of the counter-ion against PSB, but not the size of this residue. Com- parison between the wild-type and D75E in alkaline solutions indicates the influence of the location of the counter-ion.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.6-11
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• 2010

Amount of power generated from solar photovoltaic can vary according to solar flux of sunlight due to nature of solar cell panel, and an angle that the sun and the surface of cell makes brings difference in amount of power generation. Solar flux is decided by location of surface of the Earth that is classified into longitude and latitude, but on the other hand, an angle that the sung and the surface of cell makes can be changed by changing the angle of a solar power generation device at the fixed location. A method of changing the angle of a solar power generation device as a measure for improving practical power generation efficiency. and studies about a solar tracking device for this are in active. This study conducted a research on a solar tracking system for improvement of solar power generation efficiency. A solar tracking system of this study is composed of a sensor part to confirm a location of the sun with a semiconductor photosensor using the photo conductive effect, and it analyzed output signal of a sensor by using microprocessor and it produced a control signal of driving part for tracking the sun. A solar power generator (25W) was produced to analyze performance of a solar tracking system and usefulness of a solar tracking device that was designed and produced in this study was confirmed through experiments.

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.263-270
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• 2003

Monte Carlo simulation has been peformed to induce optimized parameters of the detector head of gamma camera for the diagnosis of breast cancer and to evaluate it under the diagnosis condition of the breast cancer. For the simulation, we used Tungsten collimator, having a lattice structured array with holes of $3mm{\times}3mm$ and septal thickness of 0.25 mm, which are corresponding to the pixellated photosensor. For driving optimum parameters we used Trade-Offs procedure between the geometric efficiency and the spatial resolution, varying the detector head components. In order to pre-evaluate the performance of the optimized detector head, we assumed diagnosis condition that the breast tumor is located in the middle of phantom with various sizes and its location is 25 mm from the collimator surface, considering background count caused by radiation sources from other organs. It was shown that the performance of the optimized detector head can be degraded according to the breast cancer size and the background count under real diagnosis conditions of breast cancer. Therefore, it is concluded that the spatial resolution, which is used as an indicator to distinguish the various sizes of breast cancer and is dependent on the characteristic of the detector head, appears to be meaningless in early diagnosis of the breast cancer.