• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.203-215
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• 2019

As hyperspectral sensors that can be mounted on drones are developed, it is possible to acquire hyperspectral imagery with high spatial and spectral resolution. Although the importance of atmospheric correction has been reduced since imagery of drones were acquired at a low altitude,studies on the conversion process from raw data to spectral reflectance should be done for studies such as estimating the concentration of surface materials using hyperspectral imagery. In this study, a vicarious radiometric calibration and an atmospheric correction algorithm based on atmospheric radiation transfer model were applied to hyperspectral data of drone and the results were compared and analyzed. The vicarious calibration method was applied to an empirical line calibration using the spectral reflectance of a tarp made of uniform material. The atmospheric correction algorithm used ATCOR-4 based Modran-5 that was widely used for the atmospheric correction of aerial hyperspectral imagery. As a result of analyzing the RMSE of the difference between the reference reflectance and the correction, the vicarious calibration using the tarp in a single period of hyperspectral image was the most accurate, but the atmospheric correction was possible according to the application purpose of using hyperspectral imagery. If the correction process of normalized spectral reflectance is carried out through the additional vicarious calibration for imagery from multiple periods in the future, accurate analysis using hyperspectral drone imagery will be possible.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.2
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• pp.84-90
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• 2022

Machine tool state monitoring is a process that automatically detects the states of machine. In the manufacturing process, the efficiency of machining and the quality of the product are affected by the condition of the tool. Wear and broken tools can cause more serious problems in process performance and lower product quality. Therefore, it is necessary to develop a system to prevent tool wear and damage during the process so that the tool can be replaced in a timely manner. This paper proposes a method for diagnosing five tool states using a deep learning-based hierarchical convolutional neural network to change tools at the right time. The one-dimensional acoustic signal generated when the machine cuts the workpiece is converted into a frequency-based power spectral density two-dimensional image and use as an input for a convolutional neural network. The learning model diagnoses five tool states through three hierarchical steps. The proposed method showed high accuracy compared to the conventional method. In addition, it will be able to be utilized in a smart factory fault diagnosis system that can monitor various machine tools through real-time connecting.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.104-121
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• 2017

The present study attempted to produce the floor plan of the surroundings near Geumcheongyo Bridge in Changdeokgung Palace of the Late Joseon Period through the use of rubber sheeting transformation based on the drawing principles of "Donggwoldo(東闕圖)". First, the study compared the actual sizes of the major buildings that have existed since the production of "Donggwoldo(東闕圖)" with the sizes depicted in the picture to reveal that the front elevation of the buildings was produced by reducing it by approximately 1/200. However, the study could not confirm the same production proportions for the side elevation. Only the lengths of the side elevation were depicted at around half of the actual proportions, and as the diagonal line angles were found to be at an average of $39^{\circ}$, the study confirmed they were drawn in a manner similar to cabinet projection. Second, the study created an obliquely projected floor plan by inversely shadowing the drawing principles of "Donggwoldo(東闕圖)" and produced a floor plan of the surroundings near Geumcheongyo Bridge in Changdeokgung Palace through the use of rubber sheeting transformation. Projective transformation was confirmed as most suitable during the transformation, and with standard error of 2.1208m, the relatively high accuracy of the transformation shows that the production of a floor plan for "Donggwoldo(東闕圖)" is significant. Furthermore, it implies the possibility of producing floor plans for various documentary paintings produced using the paralleled oblique drawing method in addition to "Donggwoldo(東闕圖)". Third, the study evaluated the accuracy of the spatial information provided by the produced floor plan by comparing the three items of Geumcheongyo Bridge location, Geumcheongyo Bridge and Jinseonmun Gate arrangement, and Geumcheon stone embankment location. The results confirmed the possibility of utilizing the floor plan as a useful tool which helps understand the appearance of the surroundings at the time of "Donggwoldo(東闕圖)" production because it is parallel to the excavation results of the Geumcheongyo Bridge and its context. Therefore, the present study is significant in that it seeks the possibility of producing spatial information recorded in "Donggwoldo(東闕圖)" by applying rubber sheeting transformation and consequently in that it presents a new methodology for understanding the appearance of the East Palace of the Late Joseon Period.

• Journal of Elementary Mathematics Education in Korea
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• v.9 no.2
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• pp.161-180
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• 2005

The purpose of this study is to delve into how elementary mathematics textbooks deal with the areas of triangles and quadrilaterals from a viewpoint of the Didactic Transposition Theory. The following conclusion was derived about the teaching of the area concept: The area concept started to be taught perfectly in the 7th curricular textbook, and the focus of area teaching was placed on the area concept, since learners were gradually given opportunities to compare and measure areas. As to the area formulae of triangles and quadrilaterals, the following conclusions were made: First, the 1st curricular, the 2nd curricular and the 3rd curricular textbooks placed emphasis on transposition by textbooks, and the 4th curricular, the 5th curricular and the 6th curricular textbooks accentuated transposition by teachers. The 7th curricular textbooks put stress on knowledge construction by learners; Second, the focus of teaching shifted from a measurement of area to inducing learners to make area formula. Namely, the utilization of area formula itself was accentuated, while algorithm was emphasized in the past; Third, the way to encourage learners to produce area formula changed according to the curricula and in light of learners' level, but a wide range of teaching devices related to the area formulae were removed, which resulted in offering less learning chances to students; Fourth, what to teach about the areas of triangles and quadrilaterals was gradually polished up, and the 7th curricular textbooks removed one of the overlapped area formula of triangle.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.2 s.29
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• pp.61-66
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• 2004

By the advent of the high-resolution Satellite imagery, there are increasing needs in image mosaicking technology which can be applied to various application fields such as GIS(Geographic Information system). To mosaic images, various methods such as image matching and histogram modification are needed. In this study, automated image mosaicking is performed using image matching method based on the multi-resolution wavelet analysis(MWA). Specifically, both area based and feature based matching method are embedded in the multi-resolution wavelet analysis to construct seam line.; seam points are extracted then polygon clipping method are applied to define overlapped area of two adjoining images. Before mosaicking, radiometric correction is proceeded by using histogram matching method. As a result, mosaicking area is automatically extracted by using polygon clipping method. Also, seamless image is acquired using multi-resolution wavelet analysis.

• Convergence Security Journal
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• v.8 no.4
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• pp.73-80
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• 2008

In this paper, we developed a WMS (Warehouse Management System) Simulator. There is no Simulator that supports optimized design for Warehouse, consider goods which storage in warehouse and using RFID and USN based on cable wireless network. Also, there is no tool for monitoring which decides delivery time with information about temperature, humidity and illumination, after goods are stocked into warehouse. In this paper, WMS Simulator Implements function of drawing a blueprint. The Simulator that can analyze moving information of Palette with RFID tags and the change about temperature, humidity and illumination is developed in this paper. Inventory accuracy, space equipment practical use, and decreasing of picking time, faulty storage and product loss by product processing ability elevation are expected by designing the way of operating of warehouse for most suitable use of system in physical distribution through these treatise.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.547-557
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• 2014

This paper presents a method for designing circular template used in similarity measurement for image registration. Circular template has translation and rotation invariant property, which results in correct matching of control points for image registration under the condition of translation and rotation between reference and sensed images. Circular template consisting of the pixels located on the multiple circumferences of the circles whose radii vary from zero to a certain distance, is converted to two-dimensional Discrete Polar Coordinate Matrix (DPCM), whose elements are the pixels of the circular template. For sensed image, the same type of circular template and DPCM are created by rotating the circular template repeatedly by a certain degree in the range between 0 and 360 degrees and then similarity is calculated using mutual information of the two DPCMs. The best match is determined when the mutual information for each rotation angle at each pixel in search area is maximum. The proposed algorithm was tested using KOMPSAT-2 images acquired at two different times and the results indicate high accurate matching performance under image rotation.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.867-874
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• 2023

Recently, many problems are occurring in the bee ecosystem due to rapid climate change. The decline in the bee population and changes in the flowering period are having a huge impact on the harvest of bee-keepers. Since it is impossible to continuously observe the beehives in the hive with the naked eye, most people rely on knowledge based on experience about the state of the hive.Therefore, interest is focused on smart beekeeping incorporating IoT technology. In particular, with regard to swarming, which is one of the most important parts of beekeeping, we know empirically that the swarming time can be determined by the sound of the queen bee, but there is no way to systematically analyze this with data.You may think that it can be done by simply recording the sound of the queen bee and analyzing it, but it does not solve various problems such as various noise issues around the hive and the inability to continuously record.In this study, we developed a system that records queen bee sounds in a real-time cloud system and analyzes sound patterns.After receiving real-time analog sound from the hive through multiple channels and converting it to digital, a sound pattern that was continuously output in the queen bee sound frequency band was discovered. By accessing the cloud system, you can monitor sounds around the hive, temperature/humidity inside the hive, weight, and internal movement data.The system developed in this study made it possible to analyze the sound patterns of the queen bee and learn about the situation inside the hive. Through this, it will be possible to predict the swarming period of bees or provide information to control the swarming period.

• Development and Reproduction
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• v.12 no.1
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• pp.9-18
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• 2008

All the organisms on the earth are affected by the repeating signals from the ambient environment caused by the movements of the sun and the earth. Their physiological and behavioral activities such as reproduction, functional pathway of various molecules, and developmental stage, are reflected by the cyclicity whether it is daily(circadian) or annual rhythms. An essential function of circadian rhythms is to provide an internal estimate of the external local time, thereby allowing the organism to program its activities so that they occur at an appropriate time in the daily environment. Of many rhythmic patterns, the circadian rhythms are considered in this review, focusing on the limit cycle, which is a model to investigate the entrainment.

• 월간 기계설비
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• s.227
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• pp.40-49
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• 2009

해양에너지는 해양의 조수 파도 해류 온도차 등을 변환시켜 전기 또는 열을 생산하는 기술로서 전기를 생산하는 방식은 조력 파력 조류 온도차 발전 등이 있다. 해양에너지는 타 신재생에너지에 비해 부존량이 풍부하고 에너지 밀도가 높으며 대규모 개발이 가능하다는 장점을 가지고 있다. 특히 조력과 조류발전은 발전량의 정확한 장기예측이 가능해 전력계통망 운영에 유리하다는 큰 장점이 있다. 그러나 전 세계적으로 해양에너지의 보급은 미미한 실정이다. 화석에너지에 비해 경제성이 낮기 때문이다. 특히 조력발전은 막대한 초기건설비가 소요되고 입지가 제한적이다. 하지만 전문가들은 에너지자원 빈국인 우리나라의 경우 해양에너지 산업화가 시기적인 문제만 있을 뿐 향후 이에 따른 건설 및 서비스 시장도 확대될 것으로 전망하고 있다. 조력 조류발전의 경우 대규모 건설공사가 수반되며 이로 인한 산업적 파급효과는 막대할 것으로 예상되고 있다. 국내의 경우 시화호 조력발전소, 가로림 조력발전소, 울돌목 조류발전소의 경우 각각 약 3,600억원, 약 1조원, 약 2,500억원 총 건설비가 소요될 것으로 전망되고 있다. 이중 토목건설 부분이 약 50%, 기계 전기 부분이 약 50%를 차지한다. 이는 향후 5년간 약 1조 6,000억원 정도의 토목건설과 기계 전기 설비시장이 새롭게 형성될 수 있다는 것을 의미한다. 이번 호에는 해양에너지 중 가장 집중적으로 추진되고 있는 조력 조류발전에 대해 알아본다.