• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.289-289
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• 2009

Light emitting diode(LED) has many advantages including lower energy consumption and longer lifetime and eco-friendly in comparison with traditional light sources. Spheric plastic lens generally used in LED lighting occurs aberration and ghost image which give displeasure and deteriorate vision quality in human eyes. Using the optical program (LightTools$^{TM}$, CodeV$^{TM}$), we were confirm the aberration and ghost image in optical simulation and employed aspheric lens form in the lens design to improve these problems. From the comparison of the simulation results between the aspheric lens and the spheric lens, we were ascertain to be improved both aberration and Ghost image.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.152-159
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• 2015

Contemporary architecture is philosophy and art, and science are different that holds the architecture of human thought and behavior based on a variety of physical space. In addition, the technology is used by the new media graphics, lasers, LED, which were possible only in imagination, using tools such as the time-space of the potential for explosion. In particular, it was found in the spacial color of atypical using the nature of light. Such these architecture is space people actively experiencing a sense towards the expansion of its place. Therefore, the study purpose is to explore the Steven Holl's spacial colors to utilize the space is important to the possibility of light. He prefers the connection to the invisible world is inferred from the visible world and other space. He thoughts an idea linked to the concept watercolors which is a tool that holds to the notion of the flexibility of light and shadow. Concept watercolor is the idea space, establish space, recombinant space, and the growthy space. These have shown the no fixed spacial color cause of the combination of the different tones according to the characteristics of the mixed-color development of a concept watercolors demonstrated the spacial color of the replacement. That is to establish a parody of the works light blending spacial color.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.2
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• pp.33-42
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• 2014

There have been growing demand of Light Rail Transit(LRT) which have a lot of advantages such as construction costs lower than the recent subway, reduction of operational costs, availability of line planning, operation of railway non-beneficiary region, flexible operations of trains, unmanned operation and also have eco-friendly advantages, it is now becoming urban railway systems when environmental issues have been highlighted all over the world. Therefore, RAMS(Reliability, Availability, Maintainability, Safety) Process and activities for effective implementation of light rail transit projects have become a very important element, and also the utilization of computerized tools to perform these more systematically and productively is sought after these days. In this paper, we have presented a plan that can support the RAMS activities by utilizing the function of the computerized SE(Systems Engineering) tool(CORE$^{(R)}$). Through support of the computerized SE tool, it would be possible more clear and efficient railway project execution.

• Journal of Environmental Science International
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• v.28 no.1
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• pp.125-135
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• 2019

For the purposes of enhancing usability of Numerical Weather Prediction (NWP), the quantitative precipitation prediction scheme by machine learning has been proposed. In this study, heavy rainfall was corrected for by utilizing rainfall predictors from LENS and Radar from 2017 to 2018, as well as machine learning tools LightGBM and XGBoost. The results were analyzed using Mean Absolute Error (MAE), Normalized Peak Error (NPE), and Peak Timing Error (PTE) for rainfall corrected through machine learning. Machine learning results (i.e. using LightGBM and XGBoost) showed improvements in the overall correction of rainfall and maximum rainfall compared to LENS. For example, the MAE of case 5 was found to be 24.252 using LENS, 11.564 using LightGBM, and 11.693 using XGBoost, showing excellent error improvement in machine learning results. This rainfall correction technique can provide hydrologically meaningful rainfall information such as predictions of flooding. Future research on the interpretation of various hydrologic processes using machine learning is necessary.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.222-224
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• 2019

Light Field (LF) camera captures not only the light intensity but also the light direction coming to camera. While the rich information captured by LF camera enables many interesting applications such as digital refocusing, viewpoint changing, and 3D reconstruction, but it also requires powerful coding tools to reduce its large volume of data. In this paper, we investigate using the intra prediction scheme of the versatile video coding (VVC), which is the most recent video coding technology currently under developing, to compress the LF image. The Intra Block Copy (IBC) technique in VVC is exploited considering special LF image structure. The experimental result shows that VVC intra predict ion outperforms the H.265/HEVC intra coding technique in encoding LF data irrespective of using the IBC mode or not.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.796-799
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• 2008

The hand carry digital media appliances is going to use widely, because the machines became to be small size and light weight for easy carry. Also the demand of various contents was increased for small personal media player:PMP. Now a day PMP was used as a private leisure instruments and will be used as active digital tools like a space culture guiding tools. In this research we will study on the development of user interface for space culture guide contents. Especially we proposed checking tools to be used in test and development phase of UI design for small display appliances.

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.698-707
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• 2023

Fish are an essential resource in human society, and while ecological research on them is challenging, it is absolutely necessary. Recent technologies enabled researchers to monitor underwater fish behavior. Acoustic signals, satellite-mediated location estimation, and light-based geolocation are powerful tools for tracking fish movements from freshwater to deep-sea habitats. These tools allow us to track various fish species and elucidate their ecology. Furthermore, based on these technologies, we can develop fisheries management plans and enhance aquaculture productivity. In this review, we also discuss challenges in improving current technologies and provide future recommendations for fish bio-logging studies.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.273-280
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• 2017

In this paper, a freeform reflector is designed for low road lighting. In the case of low road lighting, which requires light distribution over a wide lane compared to the height, it is difficult to match uniformity, compared to existing road lighting. To satisfy road lighting grade M3, the reflector was divided into nine parts, and the inclination of the reflecting surface was changed to have the desired light distribution. The fitted curves were drawn based on each point, following the formula that was derived. Through the Street Light Simulation of LightTools, we confirmed that it meets the M3 road lighting standard; we then made it directly and satisfied the lighting grade on an actual road, proving the validity of the design result.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.432-437
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• 2017

Yellow sticky traps have been commonly used for monitoring tobacco whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect tobacco whitefly capture. Therefore, the use of light-emitting traps can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out in tomato greenhouses to evaluate the light-emitting trap as potential attractants for Bemisia tabaci adults. The results showed that B. tabaci adults on average preferred (p>0.05) traps in yellow lights (590 nm) ($168{\pm}7.6adults/trap$) compared to traps in white lights ($106{\pm}4.6adults/trap$) and traps without lights ($60{\pm}4.8adults/trap$). The yellow light trap(590 nm) showed the most attractive to B. tabaci adults, followed by a little lower attraction to the white light trap(450-625 nm), whereas the control (no light trap) was little attractive to B. tabaci adults. These results suggested that yellow and white light traps could have a promising use in greenhouses for the identification, monitoring, and pest control tools of tobacco whiteflies.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.394-399
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• 2008

An integral imaging system enabling enhanced depth of field by incorporating a pair of liquid-crystal (LC) lens arrays was proposed and demonstrated. The lens arrays exhibit two different refractive indexes depending on the light polarization. The proposed LC lens array I and II were implemented by depositing a ZLI-4119 LC and an E-7 LC, respectively, on top of a lens-array substrate in glass. When the two LC lens arrays were aligned appropriately, a birefringence was obtained for a specific light polarization in such a way that the incoming light sees different refractive indexes for them. As a result, the focal length associated with the imaging system utilizing the LC lens arrays was adaptively varied, thereby enhancing the depth of field for the image reconstruction. We have theoretically analyzed the proposed integral imaging system with the $LightTools^{(R)}$ to confirm that the focal length could be adjusted with the help of the birefringent lens array. Finally the proposed imaging system successfully reconstructed the objects. The birefringent lens array employing the ZLI-4119 LC produced a real image with the focal length of 680 mm, while the other using the E-7 LC yielded a virtual image with the focal length of -29 mm.