• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.4
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• pp.343-350
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• 2015

The natural convection heatsink is the most commonly used cooling device, especially for high-power LED lights, because of its reliability and low long-term cost. High power LED lights are generally used in an inclined configuration for street lamps and security lamps. However, it was difficult to estimate the thermal performance of an inclined heatsink, because the results from previous studies are not applicable to the inclined configuration. In this study, we measured the thermal performance of an inclined cylindrical heatsink with plate fins. Various fin numbers, fin heights, base temperatures, and inclination angles ($30^{\circ}$ and $60^{\circ}$) were examined. Based on the experimental results, the Nusselt number correlation is presented. This correlation is applicable when the Rayleigh number, ratio of the fin height to cylinder diameter, and fin number are in the ranges 100,000-600,000, 1/6-1/2, and 9-72, respectively.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.322-331
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• 2021

This article has attempted to explore the topic of everyday life and memory based on theoretical and methodological discussions on daily life, everydayness, sociology of everyday life, memory, social construction of memory, and social memory. In order to do this, Koreeda Hirokazu's debut feature film (Hirokazu Koreeda, 1995) which inquires about the encounters and separations, life and death in everyday life was selected as a research subject. According to the results, structured with 61 scenes talked that Yumiko's daily life was shattered in an instant due to Ikuo's death and her memory was also fragmented. But after that, her social memory can reconstruct a new daily life through the 'light' of will or hope for life. Hirokazu Koreeda tried to confirm that human encounters and partings, life and death are daily life itself or a part of it through 'light' such as sunlight and moonlight, street lamps and electric lamps in this film.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.83-88
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• 2010

In this paper, to propose a valid method solving a problem relevant to grounding from actual field data, the experimental results relevant to touch and step voltages and surface potential profiles measured around the real-sized and small-sized grounding electrode models were described. The ground surface potential profiles and dangerous voltages around the concrete pedestals employed in street facilities such as street lamps, traffic signal lamp and controllers as a case study were measured and discussed. The hemispherical cell with a diameter of 1,160[mm] was employed to simulate uniform soil. As a result, the results measured with the small-sized model were in reasonably agreement with the data obtained from the real-sized installation. It was found that the small-sized model test could be employed as a useful means evaluating the dangerous voltages around grounding electrodes installed at the inaccessible areas such as mountains, underground, underwater, and so on.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1038-1046
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• 2017

In this paper, we propose the design of LED Streetlight Platform with capabilities of weather monitoring and color temperature control. Several previous works are focused on the energy efficiency or data management of streetlight system, but no work has been done on the lighting performance, especially when natural phenomenon such as fog or haze appears on the street and obstructs the visibility of drivers and pedestrians. To solve such issue, we propose the use of two LED lamps with different correlated color temperature, which will be activated interchangeably according to the condition on the street. We also present the design of communication scheme between each devices in the system. Moreover, our experimental results show the LED Streetlight Platform can perform well and the data can be displayed properly at the website.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.730-733
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• 2010

The Green Lamp Fixture (GLF) of LED prepared with thin panel structure was investigated for illumination of street lamps and other lighting system uses, which was also very useful to aquaculture and aquafarm lighting uses, or fish luring lights and marine aquanautics of aquamarinautics (aquamarine+aquanautics) uses, etc. In the case of fish luring lights, it was verified that the fish luring of Green Lamp Fixture of LED was very effective for phototaxis movement and ecological community promotion to the micro-living things of organisms and the small fries and fishes, like as 'crowding together'. For the aquaculture lightings, it was also very excellent in waterproof and heat-sink properties, photosynthetic growing of algae and micro-organisms, water-weeds and seaweeds living underwater.

• Journal of the Semiconductor & Display Technology
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• v.14 no.3
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• pp.13-22
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• 2015

LED (Light Emitting Diode) lighting is gaining more and more market penetration as one of the global warming countermeasures. LED is the next generation of fusion source composed of epi/chip/packaging of semiconductor process technology and optical/information/communication technology. LED has been applied to the existing industry areas, for example, automobiles, TVs, smartphones, laptops, refrigerators and street lamps. Therefore, LED makers have been striving to achieve the leading position in the global competition through development of core source technologies even before the promotion and adoption of LED technology as the next generation growth engine with eco-friendly characteristics. However, there has been a point of view on the cost compared to conventional lighting as a large obstacle to market penetration of LED. Therefore, companies are developing a Chip-Scale Packaging (CSP) LED technology to improve performance and reduce manufacturing costs. In this study, we perform patent analysis associated with Flip-Chip CSP LED and flow chart for promising technology forecasting. Based on our analysis, we select key patents and key patent players to derive the business strategy for the business success of Flip-Chip CSP PKG LED products.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.19-24
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• 2021

In this paper, an index of women's safety facilities was created and visualized using public data related to Seoul. CPTED, the women's safety facilities index was created by collecting and analyzing eight data related to the local women's safety index and five major crime victims of women. As a result of the correlation analysis between the factors of the female safety facility index and the number of female crime victims, three data were selected as the main factors, "CCTV," "street lamps," and "female security guardians", which were found to be meaningful at the 95% level of reliability. The distinction women's safety facility index was calculated by weighting the correlation coefficient between the main factors for calculating the women's safety facility index, and visualized using Python's Follium library.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.124-137
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• 2018

The main purpose of this study is to find the hotspots of crimes that occur frequently in the space and to derive the appropriate CCTV installation location. One of the characteristics of crime is clustered around past occurrence area, and these crimes are strongly correlated. It is also possible to find the cause of the clusters and the variables that affect the crime through the history of the crime. In addition to the traditional OLS model, spatial differential model including spatial autocorrelation and spatial error model were used to select the variables influencing the five major crime rate, the theft rate and the foreign resident rate. The variables affecting the Five major crimes were positive (+) sign for the welfare and the rate of the bar cluster rate, and negative (-) for the street density. The CCTV area occupies 46% of the hotspots based on the overlapping of the areas where the elderly people are crowded, the bar cluster, many multicultural families, and the areas with low density of street lamps. It turned out. Taking into account the current CCTV operation, the total number of new cases to cover the risk point was 89.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.2 s.121
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• pp.13-24
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• 2007

This study aims to investigate the characteristics of Lee Kyo-Won's landscape architecture and add to the literature in this field. Also, the current status of and issues in landscape design will be dealt with through the lens of the individual landscape architect's worts. By adopting a critical analysis, this study will look closely into the background of his career and ideas regarding landscape design. The inherent nature of his coherent style in landscape design will be listed as follows: total design, design-build systems, experimentation with new kinds of plants and materials, and the pursuit of minimalism. His design domain covers various elements such as paving, street lamps, and clock towers, among others. He was often involved in managing outdoor sculpture and he also provided the total packaging of the design-build systems for most of his landscape projects. These are the main reasons why his landscape works can maintain their high end quality; through his craftsmanship, a fine quality of detail was achieved in his landscape design. This tell us the possible options that can be adopted such as landscape architectural design management or landscape architectural turn-key systems, which differ from the prevailing dual system between design and construction. However, his own particular system can not be replicated in ordinary situations because contemporary practices require us to coordinate the various stakeholders concerned in the decision-making process of the design. In general, it is fair to say that we can give him the credit for enhancing the status of landscape design as an independent, specialized field.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.11
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• pp.696-701
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• 2016

In this study, to increase output of road piezoelectric energy harvester, it was made into rack type in which many piezoelectric materials can be installed and load transfer device of the leverage type to transfer vehicle load was made. By paving it in the road, the output characteristics depending on vehicle load and speed were evaluated. Changing vehicle load, harvester output characteristics depending on speed changes were evaluated at the interval of 10 km/h from 10 km/h to 100 km/h. Also, by making a wireless switch and sending wireless signal with output of rack type harvester, whether to receive it was evaluated by distance. It was checked that all switches work up to front-to-back 100 m from harvester.