Deep Learning Approach for Automatic Discontinuity Mapping on 3D Model of Tunnel Face (터널 막장 3차원 지형모델 상에서의 불연속면 자동 매핑을 위한 딥러닝 기법 적용 방안)
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- Tunnel and Underground Space
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- v.33 no.6
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- pp.508-518
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- 2023
This paper presents a new approach for the automatic mapping of discontinuities in a tunnel face based on its 3D digital model reconstructed by LiDAR scan or photogrammetry techniques. The main idea revolves around the identification of discontinuity areas in the 3D digital model of a tunnel face by segmenting its 2D projected images using a deep-learning semantic segmentation model called U-Net. The proposed deep learning model integrates various features including the projected RGB image, depth map image, and local surface properties-based images i.e., normal vector and curvature images to effectively segment areas of discontinuity in the images. Subsequently, the segmentation results are projected back onto the 3D model using depth maps and projection matrices to obtain an accurate representation of the location and extent of discontinuities within the 3D space. The performance of the segmentation model is evaluated by comparing the segmented results with their corresponding ground truths, which demonstrates the high accuracy of segmentation results with the intersection-over-union metric of approximately 0.8. Despite still being limited in training data, this method exhibits promising potential to address the limitations of conventional approaches, which only rely on normal vectors and unsupervised machine learning algorithms for grouping points in the 3D model into distinct sets of discontinuities.
The propaganda paintings in oil colors or in forms of posters made from 1949 to 1966 have gone through some changes experiencing the influence of the Soviet Union Art and discussion of nationalization, while putting political messages of the time in the picture planes. The propaganda paintings which have been through this process became an effective means of encouraging the illiterate people in political ideologies, production, and learning. Alike other propaganda paintings in different mediums, the ones which were painted in oil colors and in the form of posters have been produced fundamentally based on Mao Zedong's intensification of the literary art on the talks on literature at Yenan. Yet, the oil paintings and posters were greatly influenced by the socialist realism and propaganda paintings of the Soviet Union, compared to other propaganda paintings in different mediums. Accordingly, they were preponderantly dealt in the discussions of nationalization of the late '50s. To devide in periods, the establishment of People's Republic of China in 1949 as a diverging point, the propaganda paintings made before and after 1949 have differences in subject matters and styles. In the former period, propaganda paintings focused on the political lines of the Communists and enlightenment of the people, but in the latter period, the period of Cultural Revolution, the most important theme was worshiping Mao Zedong. This was caused by reflection of the social atmosphere, and it is shown that the propaganda painters had reacted sensitively to the alteration of politics and the society. On the side of formalities, the oil paintings and posters made before the Cultural Revolution were under a state of unfolding several discussions including nationalization while accepting the Soviet Union styles and contents, and the paintings made afterwards show more of unique characteristics of China. In 1956, the discussion about nationalization which had effected the whole world of art, had strongly influenced the propaganda paintings in oil colors more than anything. There were two major changes in the process of making propaganda paintings in oil colors. One was to portray lives of the Chinese people truthfully, and the other was to absorb the Chinese traditional styles of expression. After this period, the oil painters usually kept these rules in creating their works, and as a result, the subject matters, characters, and backgrounds have been greatly Sinicized. For techniques came the flat colored surface of the new year prints and the traditional Chinese technique of outlining were used for expressing human figures. While the propaganda paintings in oil colors achieved high quality and depth, the posters had a very direct representation of subject matters and the techniques were unskilled compared to the oil paintings. However, after the establishment of People's Republic of China, the posters were used more than any other mediums for propagation of national policy and participation of the political movements, because it was highly effective in delivering the policies and political lines clearly to the Chinese people who were mostly illiterate. The poster painters borrowed techniques and styles from the Soviet Union through books and exhibitions on Soviet Union posters, and this relation of influences constantly appears in the posters made at the time. In this way, like the oil paintings, the posters which have been made with a direct influence of the Soviet Union had developed a new, sinicised process during the course of nationalization. The propaganda paintings in oil colors or in forms of posters, which had undergone the discussion of nationalization, had put roots deep down in the lives of the Chinese people, and this had become another foundation for the amplification of influences of political propaganda paintings in the following period of Cultural Revolution.
This paper explores in depth Gaston Bachelard's theory of imagination so as to establish the philosophical bases of creativity. While he had begun his studies on imagination to eliminate unreliable subjectivity hampering objectivity of philosophy of science, he was fascinated to become a philosopher of imagination by its unlimited power. Since his theory of imagination marked a prominent spot in the history of Western idea, this paper will seek its significant implications that will also shed light on the philosophical grounds of creativity. The best way to approach his theory is to differentiate whether imagination is the power of forming images or that of transforming them. If not misguided by surface simplicity of the aforementioned differentiation, it will be revealed that it has accrued strata in the history of Western idea. The power of forming images is related to theory of mimesis or of representation, and to ocularcentric and logo-centric structures. Bachelard strongly opposes to the theory of imagination as power of forming images, since, if it is so, its expansion and development are not possible. He thereby constructs the theory of imagination as power of transforming images. The force of movement lies at the core of his theory. Imagination as an ability to intuit movement is directly related to the problem of change in the history of Western idea. If an entity is incessantly changes itself, it becomes a crucial role of imagination to capture the force perse in the perpetual movement without distortedly and abruptly fixing it at a still point of time and space. Bachelard criticizes such a method that makes movement a controllable entity consisting of partitioned moments of space; instead, he constructs theory of imagination that reveals the true power of indispensable movement. Furthermore, it will be revealed that Bachelard's theory has more affinities with Kantian imagination and reflective judgement of aesthetics than the past researches on Bachelard showed. This paper, by means of the above investigation, will transcend the superficiality of defining what are Bachelard's formal, material, and dynamic imaginations; simultaneously, it will bear philosophical conditions of possibility that makes us experience imagination fully. These conditions also become the philosophical foundations of creativity. It will draw to a provisional close its imaginative journey of everlasting movement by making ontological and ethical dimensions of imagination and creativity.
American superhero comics are being produced in numerous different forms for multiple, and cross-platform media. In cinema, films based on superhero comics top the list of all time box office records. The same phenomenon of the 'Invasion of Superhero' is duplicated in Korean box office 2012, however, the korean fans are not familiar with the superheroes from the publication which provides the original source of characters and stories for other superhero related media products. Based on observing the multiple and vastness of world building characteristics of superhero comic, this paper attempts to associate the continuous creative nature and the infinite repetition of superheroes and comic texts with the identity of superhero on ontological level. First, chapter 2 examines how one superhero exists in multiple and different worlds individually by utilizing the concept of 'multi-universe' or 'multiverse' in comic texts. Initially, duplicating a superhero on multiple settings and series destroyed continuity and allowed contradiction and paradox confused narrative as a whole, but it also gave chances for comics to be more vibrant and experimental with their stories and characters. Chapter 3 analyzes the superhero comic texts in the light of repetition, concept developed by french philosopher Gilles Deleuze, and make the argument that the superheroes and texts are not repeated to generate surplus of source for economic utilitarian purposes, but it is, first and foremost, a repetition of creativeness and capability. Many concepts introduced by Deleuze in his early masterpiece,
Snow is an essential climate factor that affects the climate system and surface energy balance, and it also has a crucial role in water balance by providing solid water stored during the winter for spring runoff and groundwater recharge. In this study, statistical analysis of Local Data Assimilation and Prediction System (LDAPS), Modern.-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), and ERA5-Land snow depth data were used to evaluate the applicability in South Korea. The statistical analysis between the Automated Synoptic Observing System (ASOS) ground observation data provided by the Korea Meteorological Administration (KMA) and the reanalysis data showed that LDAPS and ERA5-Land were highly correlated with a correlation coefficient of more than 0.69, but LDAPS showed a large error with an RMSE of 0.79 m. In the case of MERRA-2, the correlation coefficient was lower at 0.17 because the constant value was estimated continuously for some periods, which did not adequately simulate the increase and decrease trend between data. The statistical analysis of LDAPS and ASOS showed high and low performance in the nearby Gangwon Province, where the average snowfall is relatively high, and in the southern region, where the average snowfall is low, respectively. Finally, the error variance between the four independent snow depth data used in this study was calculated through triple collocation (TC), and a merged snow depth data was produced through weighting factors. The reanalyzed data showed the highest error variance in the order of LDAPS, MERRA-2, and ERA5-Land, and LDAPS was given a lower weighting factor due to its higher error variance. In addition, the spatial distribution of ERA5-Land snow depth data showed less variability, so the TC-merged snow depth data showed a similar spatial distribution to MERRA-2, which has a low spatial resolution. Considering the correlation, error, and uncertainty of the data, the ERA5-Land data is suitable for snow-related analysis in South Korea. In addition, it is expected that LDAPS data, which is highly correlated with other data but tends to be overestimated, can be actively utilized for high-resolution representation of regional and climatic diversity if appropriate corrections are performed.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70