• 제목/요약/키워드: Complex images

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Deep Learning-based Fracture Mode Determination in Composite Laminates (복합 적층판의 딥러닝 기반 파괴 모드 결정)

  • Muhammad Muzammil Azad;Atta Ur Rehman Shah;M.N. Prabhakar;Heung Soo Kim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.4
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    • pp.225-232
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    • 2024
  • This study focuses on the determination of the fracture mode in composite laminates using deep learning. With the increase in the use of laminated composites in numerous engineering applications, the insurance of their integrity and performance is of paramount importance. However, owing to the complex nature of these materials, the identification of fracture modes is often a tedious and time-consuming task that requires critical domain knowledge. Therefore, to alleviate these issues, this study aims to utilize modern artificial intelligence technology to automate the fractographic analysis of laminated composites. To accomplish this goal, scanning electron microscopy (SEM) images of fractured tensile test specimens are obtained from laminated composites to showcase various fracture modes. These SEM images are then categorized based on numerous fracture modes, including fiber breakage, fiber pull-out, mix-mode fracture, matrix brittle fracture, and matrix ductile fracture. Next, the collective data for all classes are divided into train, test, and validation datasets. Two state-of-the-art, deep learning-based pre-trained models, namely, DenseNet and GoogleNet, are trained to learn the discriminative features for each fracture mode. The DenseNet models shows training and testing accuracies of 94.01% and 75.49%, respectively, whereas those of the GoogleNet model are 84.55% and 54.48%, respectively. The trained deep learning models are then validated on unseen validation datasets. This validation demonstrates that the DenseNet model, owing to its deeper architecture, can extract high-quality features, resulting in 84.44% validation accuracy. This value is 36.84% higher than that of the GoogleNet model. Hence, these results affirm that the DenseNet model is effective in performing fractographic analyses of laminated composites by predicting fracture modes with high precision.

A Refined Method for Quantification of Myocardial Blood Flow using N-13 Ammonia and Dynamic PET (N-13 암모니아와 양전자방출단층촬영 동적영상을 이용하여 심근혈류량을 정량화하는 새로운 방법 개발에 관한 연구)

  • Kim, Joon-Young;Lee, Kyung-Han;Kim, Sang-Eun;Choe, Yearn-Seong;Ju, Hee-Kyung;Kim, Yong-Jin;Kim, Byung-Tae;Choi, Yong
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.73-82
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    • 1997
  • Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two-compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE $Advance^{TM}$ PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by the refined method incorporating myocardium geometric information into the two-compartment model using N-13 ammonia and PET.

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An Analysis of the Comparison between the Image of the Landmarks in Daejeon (대전시 상징물과 도시 이미지에 대한 비교 분석)

  • Byeon, Jae-Sang;Kim, Dae-Soo;Lee, Jung-Soo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.2
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    • pp.53-63
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    • 2010
  • It constitutes a very important preliminary step to analyze how city image is assessed in order to determine the direction towards a desirable city image in planning on an urban landscape for future city image. This study aims to quantify the recognition and evaluation of a city image on the part of citizens, using multidimensional scaling and correspondence analysis. Furthermore, this study hopes to contribute to the quantified policy-making for improving city image by understanding how professionals and civil servants in the related field tend to recognize such image. The results from the study are as follow: 1. The image of Daejon City tends to be assessed strongly in the light of its history, dynamics, and size. While the City is recognized as new and changing in general, the civil servants consider the city as modest, and the professionals as mediocre. Therefore, the City should strive to conceive its own unique identity, which would lessen the current image of modest and mediocre. 2. Gap river, Dunsan New Town, and the Daeduk Reseach Complex turn out to be the symbolic representative venues of Daejon City, inspiring the city’s image. In contrast, Yoosung Springs, the original town, and the Expo Park do not fit the image of the City. The need to renovate these places presents itself. 3. As for the questions using “like” and “not-like”, citizens and professionals show the tendency of not liking the city’s image, whereas civil servants like it. It follows that the City needs to highlight its “modern and high-technological” image, illuminated by Dunsan New Town and Daeduk Reseach Complex. 4. An image positioning drawn from a correspondence analysis shows that the City of Daejeon can be classified as an administrative and horizontal city. As opposed to the prior simplistic analyses of city image, this study attempts to diagnose it accurately, so as to help with the gearing towards city images in the future.

The Molecular Weight Dependance of Paramagnetic Gd-chelates on T1 and T2 Relaxation Times (상자성 복합체의 분자량에 따른 T1 및 T2 자기이완시간에 관한 연구)

  • Kim In-Sung;Lee Young-Ju;Kim Ju-Hyun;Sujit Dutta;Kim Suk-Kyung;Kim Tae-Jeong;Kang Duk-Sik;Chang Yong-Min
    • Progress in Medical Physics
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    • v.17 no.2
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    • pp.61-66
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    • 2006
  • To evaluate the T1, T2 magnetic relaxation properties of water molecule according to molecular weight of paramagnetic complex. 4-aminomethyicyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 ml) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with $Gd_2O_3$ (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1 mM and then the relaxation times were measured at 1.57 (64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG (Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. In case of inversion recovery sequence, total 35 images with different inversion time(T1)s ranging from 50 msec to 1,750 msec. To estimate the relaxation times, the signal intensity of each sample was measured using region of Interest (ROI) and then fitted by non-linear least square method to yield T1, T2 relaxation times and also R1 and R2. Compared to T1=($205.1{\pm}2.57$) msec and T2=($209.4{\pm}4.28$) msec of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, T1 and T2 values of new paramagnetic complexes were reduced along with their molecular weight. That is, T1 value was ranged from $(96.35{\pm}2.04)\;to\;(79.38{\pm}1.55)$ msec and T2 value was ranged from $(91.02{\pm}2.08)\;to\;(76.66{\pm}1.84)$ msec. Among new paramagnetic complexes, there is a tendency that the R1 and R2 increase as the molecular weight is increases. As molecular weight of paramagnetic complex increases, T1 and T2 relaxation times reduce and thus the increase of relaxivity (R1 and R2) Is proportional to molecular weight.

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Serial MR Imaging of Magnetically Labeled Humen Umbilical Vein Endothelial Cells in Acute Renal Failure Rat Model (급성 신부전 쥐 모델에서 자기 표지된 인간 제대정맥 내피세포의 연속 자기공명영상)

  • Lee, Sun Joo;Lee, Sang Yong;Kang, Kyung Pyo;Kim, Won;Park, Sung Kwang
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.3
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    • pp.181-191
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    • 2013
  • Purpose : To evaluate the usefulness of in vivo magnetic resonance (MR) imaging for tracking intravenously injected superparamagnetic iron oxide (SPIO)-labeled human umbilical vein endothelial cells (HUVECs) in an acute renal failure (ARF) rat model. Materials and Methods: HUVECs were labeled with SPIO and poly-L-lysine (PLL) complex. Relaxation rates at 1.5-T MR, cell viability, and labeling stability were assessed. HUVECs were injected into the tail vein of ARF rats (labeled cells in 10 rats, unlabeled cells in 2 rats). Follow-up serial $T2^*$-weighted gradient-echo MR imaging was performed at 1, 3, 5 and 7 days after injection, and the MR findings were compared with histologic findings. Results: There was an average of $98.4{\pm}2.4%$ Prussian blue stain-positive cells after labeling with SPIOPLL complex. Relaxation rates ($R2^*$) of all cultured HUVECs at day 3 and 5 were not markedly decreased compared with that at day 1. The stability of SPIO in HUVECs was maintained during the proliferation of HUVECs in culture media. In the presence of left unilateral renal artery ischemia, $T2^*$-weighted MR imaging performed 1 day after the intravenous injection of labeled HUVECs revealed a significant signal intensity (SI) loss exclusively in the left renal outer medulla regions, but not in the right kidney. The MR imaging findings at days 3, 5 and 7 after intravenous injection of HUVECs showed a SI loss in the outer medulla regions of the ischemically injured kidney, but the SI progressively recovered with time and the right kidney did not have a significant change in SI in the same period. Upon histologic analysis, the SI loss on MR images was correspondent to the presence of Prussian blue stained cells, primarily in the renal outer medulla. Conclusion: MR imaging appears to be useful for in vivo monitoring of intravenously injected SPIO-labeled HUVECs in an ischemically injured rat kidney.

Business Application of Convolutional Neural Networks for Apparel Classification Using Runway Image (합성곱 신경망의 비지니스 응용: 런웨이 이미지를 사용한 의류 분류를 중심으로)

  • Seo, Yian;Shin, Kyung-shik
    • Journal of Intelligence and Information Systems
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    • v.24 no.3
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    • pp.1-19
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    • 2018
  • Large amount of data is now available for research and business sectors to extract knowledge from it. This data can be in the form of unstructured data such as audio, text, and image data and can be analyzed by deep learning methodology. Deep learning is now widely used for various estimation, classification, and prediction problems. Especially, fashion business adopts deep learning techniques for apparel recognition, apparel search and retrieval engine, and automatic product recommendation. The core model of these applications is the image classification using Convolutional Neural Networks (CNN). CNN is made up of neurons which learn parameters such as weights while inputs come through and reach outputs. CNN has layer structure which is best suited for image classification as it is comprised of convolutional layer for generating feature maps, pooling layer for reducing the dimensionality of feature maps, and fully-connected layer for classifying the extracted features. However, most of the classification models have been trained using online product image, which is taken under controlled situation such as apparel image itself or professional model wearing apparel. This image may not be an effective way to train the classification model considering the situation when one might want to classify street fashion image or walking image, which is taken in uncontrolled situation and involves people's movement and unexpected pose. Therefore, we propose to train the model with runway apparel image dataset which captures mobility. This will allow the classification model to be trained with far more variable data and enhance the adaptation with diverse query image. To achieve both convergence and generalization of the model, we apply Transfer Learning on our training network. As Transfer Learning in CNN is composed of pre-training and fine-tuning stages, we divide the training step into two. First, we pre-train our architecture with large-scale dataset, ImageNet dataset, which consists of 1.2 million images with 1000 categories including animals, plants, activities, materials, instrumentations, scenes, and foods. We use GoogLeNet for our main architecture as it has achieved great accuracy with efficiency in ImageNet Large Scale Visual Recognition Challenge (ILSVRC). Second, we fine-tune the network with our own runway image dataset. For the runway image dataset, we could not find any previously and publicly made dataset, so we collect the dataset from Google Image Search attaining 2426 images of 32 major fashion brands including Anna Molinari, Balenciaga, Balmain, Brioni, Burberry, Celine, Chanel, Chloe, Christian Dior, Cividini, Dolce and Gabbana, Emilio Pucci, Ermenegildo, Fendi, Giuliana Teso, Gucci, Issey Miyake, Kenzo, Leonard, Louis Vuitton, Marc Jacobs, Marni, Max Mara, Missoni, Moschino, Ralph Lauren, Roberto Cavalli, Sonia Rykiel, Stella McCartney, Valentino, Versace, and Yve Saint Laurent. We perform 10-folded experiments to consider the random generation of training data, and our proposed model has achieved accuracy of 67.2% on final test. Our research suggests several advantages over previous related studies as to our best knowledge, there haven't been any previous studies which trained the network for apparel image classification based on runway image dataset. We suggest the idea of training model with image capturing all the possible postures, which is denoted as mobility, by using our own runway apparel image dataset. Moreover, by applying Transfer Learning and using checkpoint and parameters provided by Tensorflow Slim, we could save time spent on training the classification model as taking 6 minutes per experiment to train the classifier. This model can be used in many business applications where the query image can be runway image, product image, or street fashion image. To be specific, runway query image can be used for mobile application service during fashion week to facilitate brand search, street style query image can be classified during fashion editorial task to classify and label the brand or style, and website query image can be processed by e-commerce multi-complex service providing item information or recommending similar item.

Land-Cover Change Detection of Western DMZ and Vicinity using Spectral Mixture Analysis of Landsat Imagery (선형분광혼합화소분석을 이용한 서부지역 DMZ의 토지피복 변화 탐지)

  • Kim, Sang-Wook
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.1
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    • pp.158-167
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    • 2006
  • The object of this study is to detect of land-cover change in western DMZ and vicinity. This was performed as a basic study to construct a decision support system for the conservation or a sustainable development of the DMZ and Vicinity near future. DMZ is an is 4km wide and 250km long and it's one of the most highly fortified boundaries in the world and also a unique thin green line. Environmentalists want to declare the DMZ as a natural reserve and a biodiversity zone, but nowadays through the strengthening of the inter-Korean economic cooperation, some developers are trying to construct a new-town or an industrial complex inside of the DMZ. This study investigates the current environmental conditions, especially deforestation of the western DMZ adopting remote sensing and GIS techniques. The Land-covers were identified through the linear spectvral mixture analysis(LSMA) which was used to handle the spectral mixture problem of low spatial resolution imagery of Landsat TM and ETM+ imagery. To analyze quantitative and spatial change of vegetation-cover in western DMZ, GIS overlay method was used. In LSMA, to develop high-quality fraction images, three endmembers of green vegetation(GV), soil, water were driven from pure features in the imagery. Through 15 years, from 1987 to 2002, forest of western DMZ and vicinity was devastated and changed to urban, farmland or barren land. Northern part of western DMZ and vicinity was more deforested than that of southern part. ($52.37km^2$ of North Korean forest and $39.04km^2$ of South Korean were change to other land-covers.) In case of North Korean part, forest changed to barren land and farmland and in South Korean part, forest changed to farmland and urban area. Especially, In North Korean part of DMZ and vicinity, $56.15km^2$ of farmland changed to barren land through 15 years, which showed the failure of the 'Darakbat' (terrace filed) project which is one of food increase projects in North Korea.

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Multi-day Trip Planning System with Collaborative Recommendation (협업적 추천 기반의 여행 계획 시스템)

  • Aprilia, Priska;Oh, Kyeong-Jin;Hong, Myung-Duk;Ga, Myeong-Hyeon;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.22 no.1
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    • pp.159-185
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    • 2016
  • Planning a multi-day trip is a complex, yet time-consuming task. It usually starts with selecting a list of points of interest (POIs) worth visiting and then arranging them into an itinerary, taking into consideration various constraints and preferences. When choosing POIs to visit, one might ask friends to suggest them, search for information on the Web, or seek advice from travel agents; however, those options have their limitations. First, the knowledge of friends is limited to the places they have visited. Second, the tourism information on the internet may be vast, but at the same time, might cause one to invest a lot of time reading and filtering the information. Lastly, travel agents might be biased towards providers of certain travel products when suggesting itineraries. In recent years, many researchers have tried to deal with the huge amount of tourism information available on the internet. They explored the wisdom of the crowd through overwhelming images shared by people on social media sites. Furthermore, trip planning problems are usually formulated as 'Tourist Trip Design Problems', and are solved using various search algorithms with heuristics. Various recommendation systems with various techniques have been set up to cope with the overwhelming tourism information available on the internet. Prediction models of recommendation systems are typically built using a large dataset. However, sometimes such a dataset is not always available. For other models, especially those that require input from people, human computation has emerged as a powerful and inexpensive approach. This study proposes CYTRIP (Crowdsource Your TRIP), a multi-day trip itinerary planning system that draws on the collective intelligence of contributors in recommending POIs. In order to enable the crowd to collaboratively recommend POIs to users, CYTRIP provides a shared workspace. In the shared workspace, the crowd can recommend as many POIs to as many requesters as they can, and they can also vote on the POIs recommended by other people when they find them interesting. In CYTRIP, anyone can make a contribution by recommending POIs to requesters based on requesters' specified preferences. CYTRIP takes input on the recommended POIs to build a multi-day trip itinerary taking into account the user's preferences, the various time constraints, and the locations. The input then becomes a multi-day trip planning problem that is formulated in Planning Domain Definition Language 3 (PDDL3). A sequence of actions formulated in a domain file is used to achieve the goals in the planning problem, which are the recommended POIs to be visited. The multi-day trip planning problem is a highly constrained problem. Sometimes, it is not feasible to visit all the recommended POIs with the limited resources available, such as the time the user can spend. In order to cope with an unachievable goal that can result in no solution for the other goals, CYTRIP selects a set of feasible POIs prior to the planning process. The planning problem is created for the selected POIs and fed into the planner. The solution returned by the planner is then parsed into a multi-day trip itinerary and displayed to the user on a map. The proposed system is implemented as a web-based application built using PHP on a CodeIgniter Web Framework. In order to evaluate the proposed system, an online experiment was conducted. From the online experiment, results show that with the help of the contributors, CYTRIP can plan and generate a multi-day trip itinerary that is tailored to the users' preferences and bound by their constraints, such as location or time constraints. The contributors also find that CYTRIP is a useful tool for collecting POIs from the crowd and planning a multi-day trip.

Shear bond strength and debonding failure mode of ceramic brackets according to the surface treatment of porcelain (도재 표면 처리가 따른 세라믹 브라켓의 전단 접착 강도 및 탈락 양상)

  • Lee, Jeong-Nam;Lee, Cheol-Won
    • The korean journal of orthodontics
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    • v.28 no.5 s.70
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    • pp.803-812
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    • 1998
  • The purpose of this study was to evaluate the shear bond strength and failure mode of ceramic brackets according to the surface treatment of porcelain. Sixty Porcelain samples were randomly divided into six groups of ten samples. Then they were treated as follows: Group 1(silane only), Group 2(etching+silane), Group 3(stone+silane), Group 4(sandblasting+silane), Group 5(stone +etching+silane), Group 6(sandblasting+etching+silane) After surface treatment of porcelain, sixty Transcend 6000 brackets were bonded to the prepared porcelain surface and they were stored in $37^{\circ}C$ saline for 24 hours. An Instron universal testing machine was used to test the shear bond strength of ceramic brackets to porcelain. After debonding, bases of ceramic brackets and porcelain surfaces were examined under scanning electron microscope(SEM) to determine failure mode. Statistical analysis of the data was carried out with one-way ANOVA and Duncan's multiple range test. The results were as follows : 1. The shear bond strength of surface-treated groups 2 to 6 was higher than that of only silane-treated group 1, and there was statistical significance. (P<0.05) 2. There was no significant difference among the groups 3 to 6. (P>0.05) 3. The shear bond strength of etching-surface treated group 2 was significantly lower than those of sandblasting-surface treated group 4, complex surface treated group 5 and group 6. 4. According to the scanning electromicroscopic images, the surface roughness of sandblasting-surface treated group 4 was less than those of the group 5 and 6, but there was no significant difference in the shear bond strength. (P>0.05) As a conclusion we can have a clinically adequate bond strength when an application of silane is done after the treatment of porcelain surface with more than one way to bond ceramic bracket on the porcelain. Also, it is considered that the sandblasting and application of silane is effective for the simplication and convenience of the treatment.

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A Study on the Preference Factors of KakaoTalk Emoticon (카카오톡 이모티콘 선호도에 미치는 영향 요인에 관한 연구)

  • Lee, Jong-Yoon;Eune, Juhyun
    • Cartoon and Animation Studies
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    • s.51
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    • pp.361-390
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    • 2018
  • Users of KakaoTalk emoticons use Kakao Talk emoticons as means of communicating their emotions in virtual space. Emotional state is represented by design element (auxiliary, color, form, motion) and storytelling element contained in emoticons. The purpose of this study is to investigate the factors of the storytelling and design elements of kakaoTalk emoticons and how they prefer the kakaoTalk emoticons as emotional expression means. In terms of storytelling, crocodiles, peaches, dogs, ducks, lions, moles, and rabbits were made up of ordinary fruits and animals. Most of the emoticons are composed of stories with unique personality, and each story has a complex one by one, which makes it easy for users to approach and use them. In terms of design, I used various auxiliary elements (flame, sweat, tears, runny nose, angry eyes, etc.) to express angry, sincere, nervous, begging, joy, and sadness. The color elements consisted of most of the warm color series with the unique colors (green, red, yellow, pink, white, black, brown, etc.) of emoticon characters regardless of feelings of joy, anger, sadness, pleasure. The form factor is composed of a round shape when expressing factors such as joy and sadness. On the other hand, when FRODO and NEO express sadness and anger, they represent the shape of a rectangle. The motion elements are horizontal, vertical, and oblique expressions of APPEACH, NEO, TUBE, and JAY-G, expressing emotional expressions of sadness, anger, and pleasure. APEACH, TUBE, MUZI & / Shows the dynamic impression of the oblique and the radiation / back / forward / rotation. The anger of TUBE and FRODO shows horizontal / vertical / diagonal and radial motion. As a result of this study, storytelling is structured in accordance with each emoticon character. In terms of design, auxiliary elements such as flame, sweat, and tears are represented by images. The color elements used the unique colors of the character series regardless of the difference of emotion. The form factor represented various movements for each emotion expression. These findings will contribute to the development of communication, emotional design and industrial aspects. Despite the significance of the above paper, I would like to point out that the analysis framework of the storytelling and the semiotic analysis of the supplementary elements are not considered as limitations of the study.