• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.133-139
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• 2013

This paper proposes a vision-based indoor localization method for autonomous vehicles. A single upward-facing digital camera was mounted on an autonomous vehicle and used as a vision sensor to identify artificial landmarks and any natural corner features. An interest point detector was used to find the natural features. Using an optical flow detection algorithm, information related to the direction and vehicle translation was defined. This information was used to track the vehicle movements. Random noise related to uneven light disrupted the calculation of the vehicle translation. Thus, to estimate the vehicle translation, a Kalman filter was used to calculate the vehicle position. These algorithms were tested on a vehicle in a real environment. The image processing method could recognize the landmarks precisely, while the Kalman filter algorithm could estimate the vehicle's position accurately. The experimental results confirmed that the proposed approaches can be implemented in practical situations.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1174-1179
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• 2003

Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. This study shows that ferrite content can be predicted by use of the artificial neural network. The neural network has trained learning data of chemical components and ferrite contents using backpropagation learning process. The predicted results of the ferrite content using trained neural network are in good agreement with experimental ones.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.11
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• pp.812-819
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• 2010

Recently residential buildings are characterized with high-rise and high density. Under this circumstance, achieving comfortable and healthy indoor environment with minimized energy consumption becomes a very challenging engineering and societal issue. Along this the increased size and transparency of window as well as light surface caused by high stories lowers the heat shield efficiency of building. Since glass that constitutes building surface has low heat efficiency, it aggravates heat loss of all building considerably, thereby resulting in extreme heating load and cooling load in the country where temperature varies much in summer and winter. The research will check whether experiment can be effectively done by overcoming the limit of existing artificial solar laboratory constructed in the country and properly adjusting controlled variables with simplified function through construction of this experimental set.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.460-466
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• 2004

Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. This study shows that ferrite content can be predicted by use of the artificial neural network. The neural network has trained teaming data of chemical components and ferrite contents using backpropagation learning process. The predicted results of the ferrite content using trained neural network are in good agreement with experimental ones.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.87-93
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• 1999

This study was conducted to investigate the morphological characteristics and cultural conditions for artificial fruiting body(synnemata) production of Paecilomyces japonica. In the morphological characteristics of P. japonica, the size of it's conidia was ranged from $5.0{\sim}1.5\;to\;7.9{\sim}2.4\;{\mu}m$. The artificial fruiting body showed yellow in color, shape was confirmed ellipsoidal or obovoid type, and the length was $50.6{\sim}104.5\;mm$. The mycelial growth on the PDA medium treated with pH7, at $25^{\circ}C$ was superior to that of other treatments. The formation period of an artificial fruiting body of P. japonica treated with polypropylene and glass bottle culture was 30 days and 50 days, respectively. The length and number of fruiting body was longer and higher in the polypropylene bottle culture than those of the glass bottle culture. As the results, the artificial fruiting body production in the polypropylene bottle increased 1.2g per bottle compared to that of the glass bottle. It also increased in $100{\sim}400\;lx$ illumination, whereas the elongation of synnemata, pinheading and fruiting body growth were inhibited by continuous use of 900 lx illumination. The results of these experiment indicated that fruiting body formation seemed to be lower as the light intensity increased. The fruiting body formation was also dependent on the light color. There was a higher incidence in red color light and fluorescent light treatment than that of incandescent and blue color light. The fruiting body of the naked barley medium had so much better growth compared to other media that it would be able to use for it's production. The growth of fruiting body was affected by $CO_2$ concentration. It increased after putting the lid on the bottle.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.56-60
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• 1986

The purpose of this study is to find the light intensity which induced maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using rock trout, He.'~agrammos otakii (Jordan et starks). An experimental tank (360L x SOW x 55H cm) was set up in a dark room. An illumination system was attached to the end of one side of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5 W, 150 W) and seven filters. During the experiment water depth was maintained 50 em level in the tank. The tank was marked into six longitudinal sections each being 60 em long to observe the distribution of fish. The fish were acclimatized in dark condition for 50 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds. and the gathering rate was obtained from the average number of fish in each section. The light intensity inducing maximum gathering rate was O. 7 lux (0. 5~1. 1 lux) in the daytime and 5. 2/ux (3.2-7.7 lux) at night. The variation of the gathering rate of fish in illumination time was sma II and showed the decreasing trend.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1595-1600
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• 2011

We analyzed the noise effect from artificial light and sunlight on the signal performance in visible light communication systems based on Intensity Modulation/Direct Detection(IM/DD). System performance was experimentally demonstrated by transmitting 50ksysmbol/s QPSK signals at 2MHz sub-carrier. And received signals were analyzed using EVM and RF spectrum. Finally, the system performance was improved by utilizing a visor and we confirm that the outdoor visible light communication was possible using IM/DD method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.7-16
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• 2015

This study is intending to look into the status of the hitherto established local governments light pollution control ordinance, and to use the ordinance status as basic data of ordinance enactment related to light pollution in time of its establishment and revision in accordance with regional characteristics of each local government for the time to come. This study conducted this research in a total of 3-phase research methods. 1) This study inquired into the direction of the research plan through the theoretical consideration and analysis of the preceding researches after setting up research objectives according to research background and purpose. 2) Targeting 11 local governments which are enforcing the hitherto established ordinance, this study surveyed the status of the light pollution control ordinance. 3) This study carried out the contents analysis of the ordinance in the method of doing a comparative analysis of each provision of the ordinance according to local governments. It's hoped that on the basis of this research, local governments across the nation, which have not yet established the same ordinance, could minimize the damage to natural eco-system due to artificial lighting by promoting the urgent ordinance establishment suited for each region, and create human-oriented light environment by modifying various disorderly lighting environment.

• Journal of Technologic Dentistry
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• v.43 no.2
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• pp.48-55
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• 2021

Purpose: This study aimed to analyze deformation according to post-curing of complete arch artificial teeth for temporary dentures printed with a digital light processing (DLP) printer. Methods: An edentulous model was prepared and an occlusal rim was produced. The edentulous model and occlusal rim were scanned using a model scanner. A complete denture was designed using a dental computer-aided design, and the denture base and artificial tooth were separated. Ten complete arch artificial teeth were printed using a 3D printer (DLP). Complete arch artificial teeth was classified into the following three groups: a group no post-curing (NC), a group with 10 minutes post-curing (10M), and a group with 20 minutes post-curing (20M). Specimens were scanned using a model scanner. The scanned data were overlapped with the reference data. Statistical analysis was performed using one-way ANOVA analysis of variance, Kruskal-Wallis test, and Mann-Whitney U test (α=0.05). Results: Regarding the overall deviation of complete arch artificial teeth, the NC group showed the lowest mean deviation of 111.13 ㎛ and the 20M group showed the highest mean deviation of 131.03 ㎛. There were statistically significant differences among the three groups (p<0.05). Conclusion: The complete arch artificial tooth showed deformation due to post-curing. In addition, the largest shrinkage deformation was observed at 10 minutes of post-curing, whereas the least deformation was observed at 20 minutes.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.13-24
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• 2018

Recently, light pollution has become a serious environment issue caused by excessive uses of artificial light. Central and local governments have made efforts to manage light pollution and mitigate light pollution damages. Developing methods to diagnose light pollution is critical to effectively monitor light pollution conditions in Seoul. This study develops a methodology to create a map that presents the status of light pollution in Seoul, using International Space Station(ISS) night-time images. Through the map, we evaluated the areas that show high levels of light intensity and found out local characteristics of light intensity; Commercial area, office building concentrated area, and large sports facilities. The result of study provides basic understanding to present a new way for monitoring light pollution in urban sites.