• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.5
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• pp.259-266
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• 2022

In this study, we developed a deep learning and vision sensor-based assembly performance evaluation method isfor prefabricated steel structures. The assembly parts were segmented using a modified version of the receptive field block convolution module inspired by the eccentric function of the human visual system. The quality of the assembly was evaluated by detecting the bolt holes in the segmented assembly part and calculating the bolt hole positions. To validate the performance of the evaluation, models of standard and defective assembly parts were produced using a 3D printer. The assembly part segmentation network was trained based on the 3D model images captured from a vision sensor. The sbolt hole positions in the segmented assembly image were calculated using image processing techniques, and the assembly performance evaluation using the k-nearest neighbor algorithm was verified. The experimental results show that the assembly parts were segmented with high precision, and the assembly performance based on the positions of the bolt holes in the detected assembly part was evaluated with a classification error of less than 5%.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.113-123
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• 2022

Ray tracing-based rendering creates by far more realistic images than the traditional rasterization-based rendering. However, it is still burdensome when implemented for a Head-Mounted Display (HMD) system that demands a wide field of view and a high display refresh rate. Furthermore, for presenting high-quality images on the HMD screen, a sufficient number of ray sampling should be carried out per pixel to alleviate visually annoying spatial and temporal aliases. In this paper, we extend the recent selective foveated ray tracing technique by Kim et al. [1], and propose an improved real-time rendering technique that realizes the rendering effect of the classic Whitted-style ray tracing on the HMD system. In particular, by combining the ray tracing hardware-based acceleration technique and time-constrained rendering scheme, we show that fast HMD ray tracing is possible that is well suited to human visual systems.

• Journal of Science of Art and Design
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• v.5
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• pp.87-129
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• 2003

The purpose of this thesis is to propose a new concept of design of the 21st century, on the basis of the study on the general signification of the structures and the signs of industrial product design, by examining the difference between modern and post-modern design, which is expected to lead the users to different design practice and interpretation of it. The starting point of this study is the different styles and patterns of 'Gestalt' in the post-modern design of the late 20th century from modern design - the factor of determination in industrial product design. That is to say, unlike functional and rational styles of modern product design, the late 20th century is based upon the pluralism characterized by complexity, synthetic and decorativeness. So far, most of the previous studies on design seem to have excluded visual aspects and usability, focused only on effective communication of design phenomena. These partial studies on design, blinded by phenomenal aspects, have resulted in failure to discover a principle of fundamental system. However, design varies according to the times; and the transformation of design is reflected in Design Pragnanz to constitute a new text of design. Therefore, it can be argued that Design Pragnanz serves as an essential factor under influence of the significance of text. In this thesis, therefore, I delve into analysis of the 20th century product design, in the light of Gestalt theory and Design Pragnanz, which have been functioning as the principle of the past design. For this study, I attempted to discover the fundamental elements in modern and post-modern designs, and to examine the formal structure of product design, the users' aesthetic preference and its semantics, from the integrative viewpoint. Also, with reference to history and theory of design my emphasis is more on fundamental visual phenomena than on structural analysis or process of visualization in product design, in order to examine the formal properties of modern and post-modern designs. Firstly, In Chapter 1, 'Issues and Background of the Study', I investigated the Gestalt theory and Design Pragnanz, on the premise of formal distinction between modern and post-modern designs. These theories are founded upon the discussion on visual perception of Gestalt in Germany in 1910's, in pursuit of the principle of perception centered around visual perception of human beings. In Chapter 2, I dealt with functionalism of modern design, as an advance preparation for the further study on the product design of the late 20th century. First of all, in Chapter 2-1, I examined the tendency of modern design focused on functionalism, which can be exemplified by the famous statement 'Form follows function'. Excluding all unessential elements in design - for example, decoration, this tendency has attained the position of the international style based on the spirit of Bauhause - universality and regularity - in search of geometric order, standardization and rationalization. In Chapter 2-2, I investigated the anthropological viewpoint that modern design started representing culture in a symbolic way including overall aspects of the society - politics, economics and ethics, and its criticism on functionalist design that aesthetic value is missing in exchange of excessive simplicity in style. Moreover, I examined the pluralist phenomena in post-modern design such as kitsch, eclecticism, reactionism, hi-tech and digital design, breaking away from functionalist purism of modern design. In Chapter 3, I analyzed Gestalt Pragnanz in design in a practical way, against the background of design trends. To begin with, I selected mass product design among those for the 20th century products as a target of analysis, highlighting representative styles in each category of the products. For this analysis, I adopted the theory of J. M Lehnhardt, who gradated in percentage the aesthetic and semantic levels of Pragnantz in design expression, and that of J. K. Grutter, who expressed it in a formula of M = O : C. I also employed eight units of dichotomies, according to the G. D. Birkhoff's aesthetic criteria, for the purpose of scientific classification of the degree of order and complexity in design; and I analyzed phenomenal aspects of design form represented in each unit. For Chapter 4, I executed a questionnaire about semiological phenomena of Design Pragnanz with 28 units of antonymous adjectives, based upon the research in the previous chapter. Then, I analyzed the process of signification of Design Pragnanz, founded on this research. Furthermore, the interpretation of the analysis served as an explanation to preference, through systematic analysis of Gestalt and Design Pragnanz in product design of the late 20th century. In Chapter 5, I determined the position of Design Pragnanz by integrating the analyses of Gestalt and Pragnanz in modern and post-modern designs In this process, 1 revealed the difference of each Design Pragnanz in formal respect, in order to suggest a vision of the future as a result, which will provide systemic and structural stimulation to current design.

• Journal of Science of Art and Design
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• v.9
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• pp.49-87
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• 2006

Narrative has broad domains. So it is related to the everything man faces in his daily life and also performed in various modes. Narrative is revealed through all media including a character, which is also applied to plastic art. And narrative objects formed beyond the differences in media aid forms of expression are commonly based on a language. The study on such objects which created a new conceit of narratology can be said to be a spiritual trend by which to understand the world and man from the viewpoint of a 'story'. Plastic art took high interest in narrative in the same period as the rise of postmodernist art in the latter half of the 20th century, which was also applied to sculpture. The researcher, therefore, investigated through the history of sculpture in the 20th century the process in which narrative was denied under the value system of modernism and reappeared with the quickening of postmodernism. And as a result this period could be briefly characterized by 'return to figure' and 'reappearance of narrative'. The is, such flow means that late sculpture converted its center of interest from simple geometric abstract forms to irregular, figurative images. The researcher chose as the subject of his study the work of Louise Bourgeois, who was judged to have performed narrative positively and successfully among a great number of performed narrative positively and successfully among a great number of postmodernist sculptors who adopted it as their own strategy of expression. As the central artist of postmodrnist sculpture, She expressed human desire and condition as sexuality through the introspection of her own personal experience in contrast to the character of pop art sensitive to external world. The researcher borrowed narrative semiotics as a method of analyzing more elaborately the problem about the generation of narrative shown in her works. For it, he selected as the sample work for analysis Bourgeois's , which were judged to contain narrative most abundantly and as the metaphor of a gaze and recollection presented a new woman self that sublimed love, hatred, and loneliness. The narrative in her works are characterized by introspection questioning one's own trauma. It has independent domain and characteristics and clearly reveals narrative and content-centered characteristics, which are commonly discovered in postmodernist sculpture. The researcher could more concretely and definitely understand the characteristics of narrative through figurative images by analyzing the sample work. The researcher wanted to call your attention to the fact that the sculpture in the late 20th century contained narrative commonly and uniformly despite being characterized by various expressions and modes. And the focused on highlighting the fact that the narrative was more effectively revealed through figurative images of human body and simultaneously analyzing the formalizing process and structure for narrative. Besides he wanted to argue that the position of narrative defining the characteristics of sculpture should be valued more justly. Also, such acceptance of narrative, which is discovered in the sculpture, will have to be understood as the characteristics of the period reflecting the cultural aspect of the present time.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.115-125
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• 2007

Grould Reaction force(GRF) is important in human movements and GRF measurements are one of the most frequently used tool in biomechanical studies. In the studies of the golf swing motion, people refer to GRF as weight transfer. A successful golf swing motion requires many segments activation sequences which are controled by the nerve system. Due to the inter- and intra-individual variability of the human movement and the movement strategies, reliability of the measurements are important in human movement studies. Previous golf researches were based on group studies and certain events' values were analyzed. The purposes of this study were to determine the number of trials for the reliable golf swing GRF data collection, to reveal the variability level of the meaningful components of the golf swing GRF, and to classify the types of the golf swing GRF patterns. Twenty three male professional golfers($26.4{\pm}6.6$ years, $174.3{\pm}5.2\;cm$, $71.3{\pm}6.5\;kg$) signed an informed consent form prior to participation in this study. GRFs of driver swings were collected with Kistler 9285 force platform and 9865A amplifier, and calculated by the KwonGRF program(Visol, Korea). Sampling frequency was 1080 Hz. GRF data were trimmed from 1.5 s prior to the impact to 0.5 s after the impact. The number of trials for the reliable GRF collection was determined when the change in floating mean overs the 25 % of the standard deviation of that variable. Variabilities of the variables were determined by the coefficient of variation(CV) of 10 %. The types of GRF patterns were determined by visual inspection of the peak GRF shapes. The minimum number of trials for the reliable golf swing GRF data collection was five. Ten-trial seems more conservative. The value of the peak GRF was more reliable than the value of the impact GRF. The CV of the peak GRF and impact GRF were 7.4 %, 15.2 %, respectively. Because of the +/- sigh of the peak GRF appearance time, it was impossible to calculate CV of the peak GRF appearance time. Golf swing GRF patterns were classified as sing peak type, double peak type, and plateau peak type. This classification suggests the presence of the different golf swing weight transfer strategies.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.1-18
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• 2015

Collaborative filtering(CF) algorithm has been popularly used for recommender systems in both academic and practical applications. A general CF system compares users based on how similar they are, and creates recommendation results with the items favored by other people with similar tastes. Thus, it is very important for CF to measure the similarities between users because the recommendation quality depends on it. In most cases, users' explicit numeric ratings of items(i.e. quantitative information) have only been used to calculate the similarities between users in CF. However, several studies indicated that qualitative information such as user's reviews on the items may contribute to measure these similarities more accurately. Considering that a lot of people are likely to share their honest opinion on the items they purchased recently due to the advent of the Web 2.0, user's reviews can be regarded as the informative source for identifying user's preference with accuracy. Under this background, this study proposes a new hybrid recommender system that combines with users' review mining. Our proposed system is based on conventional memory-based CF, but it is designed to use both user's numeric ratings and his/her text reviews on the items when calculating similarities between users. In specific, our system creates not only user-item rating matrix, but also user-item review term matrix. Then, it calculates rating similarity and review similarity from each matrix, and calculates the final user-to-user similarity based on these two similarities(i.e. rating and review similarities). As the methods for calculating review similarity between users, we proposed two alternatives - one is to use the frequency of the commonly used terms, and the other one is to use the sum of the importance weights of the commonly used terms in users' review. In the case of the importance weights of terms, we proposed the use of average TF-IDF(Term Frequency - Inverse Document Frequency) weights. To validate the applicability of the proposed system, we applied it to the implementation of a recommender system for smartphone applications (hereafter, app). At present, over a million apps are offered in each app stores operated by Google and Apple. Due to this information overload, users have difficulty in selecting proper apps that they really want. Furthermore, app store operators like Google and Apple have cumulated huge amount of users' reviews on apps until now. Thus, we chose smartphone app stores as the application domain of our system. In order to collect the experimental data set, we built and operated a Web-based data collection system for about two weeks. As a result, we could obtain 1,246 valid responses(ratings and reviews) from 78 users. The experimental system was implemented using Microsoft Visual Basic for Applications(VBA) and SAS Text Miner. And, to avoid distortion due to human intervention, we did not adopt any refining works by human during the user's review mining process. To examine the effectiveness of the proposed system, we compared its performance to the performance of conventional CF system. The performances of recommender systems were evaluated by using average MAE(mean absolute error). The experimental results showed that our proposed system(MAE = 0.7867 ~ 0.7881) slightly outperformed a conventional CF system(MAE = 0.7939). Also, they showed that the calculation of review similarity between users based on the TF-IDF weights(MAE = 0.7867) leaded to better recommendation accuracy than the calculation based on the frequency of the commonly used terms in reviews(MAE = 0.7881). The results from paired samples t-test presented that our proposed system with review similarity calculation using the frequency of the commonly used terms outperformed conventional CF system with 10% statistical significance level. Our study sheds a light on the application of users' review information for facilitating electronic commerce by recommending proper items to users.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.8
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• pp.88-100
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• 1999

Detecting human face and facial landmarks automatically in an image is as essential step to a fully automatic face recognition system. In this paper, we present a new approach to detect automatically face and its eyes of input image with scale and rotation variations of faces by using an intensity based template matching with a single log-polar face template. In a template-based matching it is necessary to normalize the scale changes and rotations of an input image to a template ones. The log-polar mapping which simulates space-variant human visual system converts scale changes and rotations of input image into constant horizontal and cyclic vertical shifts in the output plane. Intelligent use of this property allows us to shift of the candidate log-polar faces mapped at various fixation points of an input image to be matched to a template over the log-polar plane. Thus, the proposed method eliminates the need of adapting multitemplate and multiresolution schemes, which inevitably give rise to intensive computation involved to cope with scale and rotation variations of faces. Through this scale and rotation involved to cope with scale and method can lead to detecting face and its eyes simultaneously. Experimental results on a database of 795 images show over 98% detection rate.

• The Journal of Art Theory & Practice
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• no.5
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• pp.109-133
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• 2007

What a concept of theatricality in modern art became more controversial is through a review "art and object-hood" on Michael Fried's minimal art, as having been already known broadly. As he had been concerned, the art following the minimalism is accepting as the very important elements such as the introduction of temporality, the stage in the exhibition space, and the audience's positive participation, enough to be no exaggeration to say that it was involved in almost all the theatricality. Particularly even in the installation art and the environment art, which have substantially positioned since the 1970s, the space is staged, and the audience's participation is greatly highlighted due to the temporal character and the site-specific in works. In such way, the theatricality in art work is today regarded as one of the most important elements. In this context, it is thought to have significance to examine theatricality, which is shown in the works of Arte Povera artists, who had been active energetically between 1967-1971. That is because the name of this group itself is what was borrowed from "Poor Theatre" in Jerzy Grotowski, who is a play director and theorist coming from Poland, and because of having many common points in the aspect of content and form. It reveals that the art called Arte Povera is sharing many critical minds in the face of commanding the field called a play and other media. Grotowski's theatre theory is very close to the theory and substance in Arte Povera in a sense that liberates a play, which was locked in literature, above all, renews the relationship between stage and seat and between actor and audience, and pursues a human being's change in consciousness through this. That is because Arte Povera also emphasizes the communication with the audience through appealing to a human being's perception and through the direct and living method, not the objective art concept of centering on the work. In addition, the poor play or poor art all has tendency that denies a system, which relies upon economic and cultural system, and seeks for what is anti-cultural, elemental, and fundamental. It is very similar even in a sense that focuses on the exploration process itself rather than the result, excludes the transcendental concept, and attaches importance to empiricism. However, Arte Povera accepts contradictoriness and complexity, and suggests eclecticism and tolerance, thereby being basically the nomadic art and the art difficult to be captured constitutively. On the other hand, there is difference in a sense that the poor play is characterized by purity, asceticism, seriousness, and solemnity. If so, which significance does this theatricality, which was introduced to art, ultimately have? As all the arts desire to be revealed with invisible things beyond the visual thing, theatricality comes to play a very important role at this time. If all the artists and audiences today came to acquire actual or virtual freedom much more, that can be said to be a point attributable to that art relied upon diverse conditions in a play.

• Journal of Pharmaceutical Investigation
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• v.29 no.3
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• pp.217-225
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• 1999

These studies were designed to determine the effect of hydroalcoholic gel system (lower alkanol concentration: 40-60%) compared to general hydrogel system (lower alkanol concentration: 10-35%) on transdermal delivery of piroxicam and its anti-inflammatory activity. Piroxicam was incorporated into a hydroalcoholic gel and a hydrogel containing polymers, solvents, and cosolvents. The pH of gel was about 6.3-7.3 and the solvent mixtures were composed of water and various concentrations of ethanol (35, 40, 50, and 60%). For the in vitro study, the skin permeation of piroxicam from the gel formulations was investigated using Franz modified diffusion cells fitted with hairless mouse skin. For the in vivo study, the anti-inflammatory activity of hydroalcoholic gel was compared to other commercial products (piroxicam hydrogel and ketoprofen hydrogel) in rat and human. The anti-inflammatory activity was determined using carrageenan induced foot edema model in rat. For the clinical study, it was evaluated from determining efficacy and acceptability with 98 patients suffering from musculoskeletal pain. A novel piroxicam hydroalcoholic gel was successfully formulated in the range of 40-50% of ethanol as solvent, more than 10% of propylene glycol, 5% of $Transcutol^{\circledR}$ and 1 % of benzyl alcohol. The skin permeation of piroxicam using hydroalcoholic gel system was greater than that of general hydrogel system $(flux\;:\;139.1-148.2\;{\mu}g/cm^2/hr\;vs.43.0-84.5 {\mu}g/cm^2/hr)$ in vitro. In carrageenan-induced edema model, the anti-inflammatory activity of hydroalcoholic gel was better than that of piroxicam hydrogel for edema inhibition (75.1 % vs. 62.9%, p

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.129-138
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• 2020

This study recognizes problems in the current system of providing navigation safety information (NSI), which is centered on merchant ships, to prevent maritime accidents of fishing boats and small vessels in coastal areas. The system proposed in this study is an effective method of providing NSI to support the safe navigation of small vessels such as fishing boats. First, the status and characteristics of recent maritime accidents were examined, and NSI service targets were identified. Second, the limitations of the current NSI system were determined, and measures were proposed to establish an NSI Integrated Platform (NSIP) that ensures the integration, accessibility, and usability of NSI for a substantial portion of the public. Third, to utilize the NSIP, various NSIs are applied as additional information for the electronic chart system used in the e-navigation ship terminals being developed in connection with the Korean e-navigation project. Functions that set the audiovisual alarm function to automatically operate when a ship enters a navigation risk zone is proposed. These functions are technically achieved by reviewing expert opinions of related organizations and professional producers. The results of this study suggest that NSI can be applied to small vessels such as fishing boats, through the Korean e-Navigation project, to prevent maritime accidents caused by the human error of navigators.