• Journal of the Korea Institute of Building Construction
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• v.19 no.3
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• pp.239-246
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• 2019

According to the survey on the status of aged buildings in Korea, A number of concrete buildings deterioration such as houses and apartment buildings has been increased rapidly. To solve this problem, the research related to the facility management, that is one of the importance factor, for monitoring buildings has been increased. The research is divided into Survey-based and Technique-based. However, the problem is that Survey-based research is required a lot of time, money and manpower for management. Also, safety cannot be guaranteed in the case of high-rise buildings. Technique-based research has limitations to applying to the current facility maintenance system, as detailed information of deteriorated facilities is difficult to grasp and errors in accuracy are feared. Therefore, this paper contribute to improve the environment of facility management by 4D maps using UAV, camera and Pix4D mapper program to make 3D model. In addition, it is expected to suggest that residents will be offered easy verification to their buildings deterioration.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.934-943
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• 2018

In these days, demand for agile spacecraft is gradually increasing, due to the fact that agile spacecraft can improve mission capability. In this paper, an attitude control logic based on reaction wheels that can enhance agility of spacecraft is proposed. Three methods are suggested, and all three or part of them can be integrated to the existing attitude control system. First, a feedforward/feedback controller is introduced, and its pros and cons are provided, compared to the conventional feedback controller. Second, an attitude command generation method that fully utilizes torque/momentum capacities of reaction wheels is proposed. Third, a torque (current) control mode for internal wheel control is introduced. Numerical results verify that the settling time can be significantly reduced by employing the feedforward/feedback control method, especially for large angle maneuver.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.123-128
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• 2020

In this paper, we presents a new cone beam computerized tomography (CBCT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time. And we showed the Rotation-based method was good rather than existing reconstruction technique for 3D images, also found weakness and a solution for it.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.657-659
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• 2022

Hydroponics and aquaponics are attracting attention as they enable automated farm management and stable production thanks to the spread of smart farms. There are issues that need to be addressed in applying smart farm, but one of them is to be able to respond flexibly to demand by automatically deciding when to ship, which requires a method for automatically determining the growth level of crops. In this paper, we focused on the simple fact that the area and volume occupied by crops increase with the growth of them, and showed that it is possible to monitor the growth process of crops with 2D and 3D cameras, and to determine the degree of growth of crops by calculating the area and volume. It is necessary to verify the method by applying it to various environments and crops, but in the case of common crops in hydroponics and aquaponics, it is possible to determine the growth level through the analysis of the acquired image through 2D and 3D camera.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.601-609
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• 2022

In August 2007, coastal upwelling occurred off the east coast of Korea, and vertical water temperature and salinity data were obtained from a real-time surface ocean buoy. Based on the time series observation data, a vertical sound velocity structure was calculated before, during, and after the occurrence of the coastal upwelling, and how the coastal upwelling affects the sound propagation and detection environment through acoustic modeling considering the horizontal scale and actual seabed topography. As a result of comparing and analyzing the low-frequency (500 Hz) sound transmission loss and the target detection range by depth using the parabolic equation model, it was analyzed that if coastal upwelling occurs, a detection gain of up to about 10 dB can be expected. In addition, through this study, it was confirmed that the characteristics of sound propagation can be greatly changed even in a short period of about 2 to 3 days before and after coastal upwelling.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.213-219
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• 2009

This study was carried out to establish breeding system for interspecific hybridization of Lilium using spontaneous meiotic polyploidization of $F_1$ OA hybrid and its progenies. Pollen viability and germination of $F_1$ OA interspecific hybrid showed variation by collection time, indicating that pollen grain in June, which was natural blooming season, had better viability and germination ability than in October. 2n-gametes from spontaneous meiotic polyploidization of OA hybrid were crossed with either diploid Asiatic or Oriental hybrid, and subsequent progenies crossed with Asiatic hybrid as female and OA hybrid as male showed the highest efficiency, where 2x-2x A$\times$OA produced 0.64 plants per cross combination, while 2x-2x, O$\times$OA and 2x-2x, OA$\times$A crosses produced 0.42 and 0.4 plant per ovary, and especially no progeny was obtained in 2x-2x, OA$\times$O cross combination. For the subsequent progeny production, a cross between diploid Asiatic hybrid as female and diploid OA hybrid as male was the best ploidy combination. Ploidy level of subsequent progeny derived from backcross with 2n-gametes of OA hybrid revealed that triploids from 2x-2x OA$\times$A, tetraploids from both 4x-2x, AA$\times$OA and OO$\times$OA, diploid from 2x-2x, O$\times$OA, and diploids or triploids from 2x-2x, A$\times$OA crosses were produced respectively.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.419-442
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• 2018

Space Treaty Article 2 stipuates non-appropriation by sovereignty, and in any other means. Interpretative controversies has continued as regards the meaning of any other means. It is not clear whether appropriation by private entity is also prohibited or not. Furthermore, the controverse around the binding force of Article 1 has made worse the controversy regarding such appropriation. U.S. Congress has enacted the law regarding the space resouce mining in 2015. Its main purpose is to alleviate legal unstability which U.S, private companies have faced, and it provides some provisions regarding private rights about space resources. Original bill, H.R. 1508 included the property right. Amendment to the bill is to ensure that an "asteroid resource utilization activity" is inter-preted as on a single asteroid and not on any asteroid. The use of the word "in situ" in defining space resources simply means resources in place in outer space; but any such resource within or on an asteroid would need to be "obtained" in order to confer a property right. The use of the word "in situ" in merely defining a space resource in the bill is not equivalent to claiming sovereignty or control over celestial bodies or portions of space. Further, there is clear Congressional direction in the bill that the President is only to encourage space resources exploration and utilization, including lowering barriers to such activity, "consistent with" and "in accordance with" US international obligations. Federal courts are granted original jurisdiction over entities defined in ${\S}$ 51301(4) and in-situ asteroid resources that have been removed from an asteroid by such entities. Federal courts are not granted jurisdiction over outer space, the Moon, other celestial bodies, or the asteroid from which the in-situ natural resource was removed. It is said that the Space Resource Utilization Exploration Act of 2015, talked about the rights of private players to own-kind of a "finders keepers" law.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.30-40
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• 2020

Monitoring the urban environmental changes caused by the urban regeneration project is necessary for evaluating the effect of the various types of urban regeneration projects that have been carried out in Seoul, South Korea. However, there is few available data and professional expert for evaluating the effect of these urban regeneration projects. This research evaluated the effect of the construction of rainwater village in Jangwi-dong area, constructed through the Seoul urban regeneration project, by utilizing the land surface temperatures derived from the multi-temporal Landsat-8 satellite images through the following steps. In the first step, the land surface temperature images were generated using the multispectral bands of the Landsat-8 satellite images. In the final step, the effect of constructing the rainwater villages was assessed by calculating the seasonal LST statistics for Jangwi-dong area, its neighbor area and entire Seoul area. The experimental results led the following conclusion: the construction of rainwater villages did not have the significant effect on the land surface temperature changes in Jangwi-dong area.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.623-631
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• 2004

Background: Using the neovascularizing properties of the omentum, we studied the viability and vascularity of the cryopreserved rat tracheal allografts with omental implantation. Material and Method: The cryopreserved tracheal allografts of eight-week old male Sprague Dawley rats were implanted into the omentum. The rats were divided into the four groups according to the duration of cryopreservation and of omental implantation. We examined the tracheal allografts histologically for viability of cartilages, inflammation and fibrosis of smooth muscle and connective tissue, and degree of vascularity. Result: The degree of inflammation in the smooth muscle and the connective tissue of the tracheal allografts was not statistically related to neither the duration of cryopreservation or of omental implantation. The tracheal cartilages of the tracheal allografts were found to be severely calcified in all cases. Significant difference in vascularity was found between the groups I and II (p < 0.05). And a sufficient vascularity in the intercartilaginous space was observed in the mid portion of the tracheal allografts as well as both ends. Conclusion: In conclusion, the omental implantation for 2 weeks could establish a sufficient vascularity in the intercartilaginous spaces for maintaining the viability of the tracheal allografts. This study might provide a possibility of the sequential tracheal allotransplantation after omental implantation.

• Electronics and Telecommunications Trends
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• v.27 no.3
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• pp.83-91
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• 2012

디지털 영상은 캡처 디바이스를 통해 획득된 후, 처리, 압축, 저장, 전송, 재생산 등의 과정을 거치면서 반드시 왜곡이 수반된다. 이렇게 왜곡된 영상은 인간 지각이 허용할 수 있는 범위 내에서 정확히 재생되어야 한다. 따라서, 영상이 재생되기 전 영상의 화질을 평가할 필요가 있다. 실제 응용에 있어서, 인간의 견해로 영상 화질의 점수를 정하는 주관적 화질평가는 일반적으로 불편하고 시간도 많이 소요되며, 비용이 많이 든다. 예를 들어, 사진, 동영상 등의 영상 콘텐츠를 대규모로 저장하고 있는 클라우드 서비스의 경우, 영상 콘텐츠가 상용으로 서비스되기 전 모든 영상의 화질을 인간이 직접 평가하는 것은 불가능하다. 영상 화질평가(visual quality assessment)에 대한 연구목적은 지각된 영상의 화질을 자동으로 예측하는 측도를 개발하는 것이다. 본고에서는 기존에 제안된 영상 화질평가 기술들을 설명하고, 앞으로의 연구에서 해결해야 할 이슈들을 살펴본다.