• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.64-71
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• 2021

Recently, climate change has gradually accelerated the occurrence of landslides. Among the various effects caused by landslides,debris flow is recognized as particularly threatening because of its high speed and propagating distance. In this study, the impacts of various factors were analyzed using quantification theory(I) for the prediction of debris flow hazard soil volume in Seoraksan National Park, Korea. According to the range using the stepwise regression analysis, the order of impact factors was as follows: vertical slope (0.9676), cross slope (0.6876), altitude (0.2356), slope gradient (0.1590), and aspect (0.1364). The extent of the normalized score using the five-factor categories was 0 to 2.1864, with the median score being 1.0932. The prediction criteria for debris flow occurrence based on the normalized score were divided into four grades: class I, >1.6399; class II, 1.0932-1.6398; class III, 0.5466-1.0931; and class IV, <0.5465. Predictions of debris flow occurrence appeared to be relatively accurate (86.3%) for classes I and II. Therefore, the prediction criteria for debris flow will be useful for judging the dangerousness of slopes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.488-498
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• 2022

Collision prevention education, which takes up the longest time among officer training courses, is one of the most important training and practice courses for trainees. The purpose of this study is to investigate the trainees' perception of collision risk in order to develop a systematic and quantified collision prevention training course. For this, factors for judging collision risk were derived from previous studies, and each trainee's perspective on collision risk was derived for each scenario through a questionnaire survey for trainees. Using the PARK Model, the same was compared with the collision risk perceived by the officer. Resultingly, it was found that trainees and of icers consider the distance to other ships the most important among collision risk factors. Additionally, although the risk trends of two groups for each scenario were similar, the average risk of trainees (5.39) was higher than that of officers (5.20). However, the trainees perceived a lower level of risk than the officers in certain scenarios, and this is judged to be the result of the trainees' lack of navigational experience. This study is expected to be used as basic data for the development of collision prevention practice education by quantitatively suggesting the difference between the collision risk of trainees and officers respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.217-226
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• 2022

In the view of the application of high-precision spatial information production, UAV (Umanned Aerial Vehicle)-Photogrammetry has a problem in that it lacks specific procedures and detailed regulations for quantitative quality verification methods or certification of captured images. In addition, test tools for UAV image quality assessment use only the GSD (Ground Sample Distance), not MTF (Modulation Transfer Function), which reflects image resolution and contrast at the same time. This fact makes often the quality of UAV image inferior to that of manned aerial image. We performed MTF and GSD analysis simultaneously using a siemens star to confirm the necessity of MTF analysis in UAV image quality assessment. The analyzing results of UAV images taken with different payload and sensors show that there is a big difference in σ_MTF values, representing image resolution and the degree of contrast, but slightly different in GSD. It concluded that the MTF analysis is a more objective and reliable analysis method than just the GSD analysis method, and high-quality drone images can only be obtained when the operator make images after judging the proper selection the sensor performance, image overlaps, and payload type. However, the results of this study are derived from analyzing only images acquired by limited sensors and imaging conditions. It is therefore expected that more objective and reliable results will be obtained if continuous research is conducted by accumulating various experimental data in related fields in the future.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.139-148
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• 2020

Through this study, the policy proposals were intended to be presented to the head of the farming policy. Therefore, the meaning of this study is as follows. First, rather than judging the returning farmer on his own, he should provide sufficient information to consult with his family and increase access to agriculture. Second, by opening up SNS and YouTube to returning farmers, they should instill confidence in rural areas by providing them with information about the joy of rural life and the success of farming so that they can easily access information about rural life through villages, youth associations and women's associations. Efforts should be made to create vibrant rural areas by providing infrastructure around farmland, providing various amenities for settling young people and forming a family farmers' association. Third, the head of the return farming policy should come up with customized support policies for the return farming (e.g., one-year farm support, free farm support, institutional sales guarantee, tourism in advanced countries, modernization of farmland facilities). Public relations strategies should also be strengthened so that such policies can lead to agriculture. Finally, the government should provide subsidized economic activities (e.g. Airbnb, donation of expertise and work-related personnel before returning home, rural experience, etc.).

• Composites Research
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• v.35 no.5
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• pp.303-308
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• 2022

PIC (Piecewise Integrated Composite) is a new concept for designing a composite structure with mosaically assigning various types of stacking sequences in order to improve mechanical properties of laminated composites. Also, machine learning is a sub-category of artificial intelligence, that refers to the process by which computers develop the ability to continuously learn from and make predictions based on data, then make adjustments without further programming. In the present study, the tapered box beam type PIC robot arm for carrying and transferring wide and thin LCD display was designed based on the machine learning in order to increase structural stiffness. Essential training data were collected from the reference elements, which were intentionally designated elements among finite element models, during preliminary FE analysis. Additionally, triaxiality values for each finite element were obtained for judging the dominant external loading type, such as tensile, compressive or shear. Training and evaluating machine learning model were conducted using the training data and loading types of elements were predicted in case the level accuracy was fulfilled. Three types of stacking sequences, which were to be known as robust toward specific loading types, were mosaically assigned to the PIC robot arm. Henceforth, the bending type FE analysis was carried out and its result claimed that the PIC robot arm showed increased stiffness compared to conventional uni-stacking sequence type composite robot arm.

• Smart Media Journal
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• v.10 no.4
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• pp.91-101
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• 2021

Visual communication based on socio-cultural context, such as emoticons on social media, is increasing. Therefore, it is necessary to study the visual expression of metonymy as a means to correctly understand the communication method in the age of visual culture. The purpose of this study is to explore how metonymy is visualized within a cultural context. Specifically, , a typical underlying phenomenon of metonymy expression, and the expression principles of various reproduced through it are identified by pairing them with the cultural context. Based on context theory, which is a representative discourse in the social science field, emoticons from in high context and emoticons in in low context were selected and compared as case study subjects. The major findings are: First, a visual application model of metonymy was proposed regarding the process through which metonymy is reproduced as a visual result. Second, the types of metonymy and their salience attribute applied to the emoticon expression method was identified in detail. Third, based on the contextual theory, how the characteristics of high-context visual metonymy differ from that of low-context visual metonymy were presented. In the future, the results of this study can be used as a criterion for judging the local acceptability and local suitability of design results in the design development process that requires the use of localization strategies.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.385-391
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• 2022

Quality evaluation of beef carcasses is an important issue in the livestock industry. Recently, through the AI monitor system based on artificial intelligence, the quality manager can receive help in making accurate decisions based on the analysis of beef carcass images or result information. This artificial intelligence dataset is an important factor in judging performance. Existing datasets may have different surface orientation or resolution. In this paper, we proposed a two-stage classification model that can efficiently manage the grades of beef carcass image using deep learning. And to overcome the problem of the various conditions of the image, a new dataset of 1,300 images was constructed. The recognition rate of deep network for 5-grade classification using the new dataset was 72.5%. Two-stage evaluation is a method to increase reliability by taking advantage of the large difference between grades 1++, 1+, and grades 1 and 2 and 3. With two experiments using the proposed two stage model, the recognition rates of 73.7% and 77.2% were obtained. As this, The proposed method will be an efficient method if we have a dataset with 100% recognition rate in the first stage.

• Conservation Science in Museum
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• v.28
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• pp.17-34
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• 2022

This study seeks to identify the material characteristics of earthenware excavated from the Bangi-dong Ancient Tomb No. 3 and the articulated stone-mound tomb of the Seokchon-dong ancient tombs in the Songpa region, and analyze the homogeneity and the firing temperature of the materials used at each excavated site. The remains have been studied relatively recently, and the groups of tombs in which they were found demonstrate the transition of ancient Korean burial systems, and at the same time, provide important archaeological data about those in power at the time. The earthenware pottery excavated from the two sites examined in the study were buried at different times, and it is assumed that they were made by procuring weathered soil of similar gneiss, judging from the behavior of the compatible and incompatible elements and the weathering tendency found by examining the main components. In addition, the examination of the mineral composition and microstructure of clay indicates that the earthenware from Seokchon-dong was fired at 950 degrees Celsius or lower at a relatively early stage. On the other hand, the earthenware from Bangi-dong Tomb No. 3 was confirmed to have experienced temperatures below 850 degrees Celsius and above 1,000 degrees Celsius. However, it is difficult to interpret the difference as the result of the changes in firing temperature throughout the eras. It is expected that it will be possible to interpret the changes in earthenware manufacturing techniques by comparing more diverse earthenware potteries and ancient soils.

• Journal of Conservation Science
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• v.36 no.6
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• pp.511-518
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• 2020

There have been reports that the "jeongcho (定礎)" letters of the foundation stone at the historical site No. 280 of the "Main Building of the Bank of Korea in Seoul" were written by Prince Ito Hirobumi (伊藤博文), the first Resident-General of Japan in Korea. An on-site investigation by an advisory group consisting of three experts in calligraphy; revealed that the two characters of '定礎' inscribed on the foundation stone are the characteristics of Ito Hirobumi's handwriting, judging from the writing style and habits observed in the collections of the Central Library of Hamamatsu City, Japan. It was reported that his writing was confirmed by the experts, but no basis was provided. To provide more objective and quantitative supporting data, rather than qualitative judgment based on feeling, it is necessary to present the basis for judgment through quantitative image comparison results through image analysis. In this paper, using image analysis software, Ito Hirobumi's calligraphy writing and the inscribed characters of the foundation stone were compared and analyzed to confirm the contents of the press release. The character comparison process and character area measurement results are a good example showing that if objective judgment basis data are needed in a similar situation, an objective judgment basis can be prepared through quantification using image analysis.

• Journal of Korea Foundry Society
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• v.41 no.4
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• pp.349-356
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• 2021

Effects of cooling condition after solidification on the microstructure and the mechanical properties of 0.36Mn containing ductile cast iron have been studied based on the minimized addition of Cu and Sn for vehicle component applications with better quality and cost competitiveness. Cu and Sn were selected for additional elements judging from the well-known fact of strong tendency of pearlite promotion followed by the tensile property improvement. After pouring of the Mg treated cast iron melt with various chemical compositions into the block specimens, two ways of post solidification cooling conditions were applied for comparison; both cooling in the mold and cooling in the air after dismantle at 800℃. The pearlite fraction of the mold-cooled specimens was analyzed as 27-44%, with the tensile strength and elongation of 513-568N/mm² and 10.4-14.3%, respectively. Whilest, the air cooled specimens showed the pearlite fraction of 77~85%, with the tensile strength and elongation of 728~758N/mm² and 3.2~6.0%, respectively. It is worthwhile to note that the remarkable improvement of both tensile strength and elongation of the ductile iron was achieved by the present air cooling condition with the minimized combined addition of Cu and Sn to the 0.36Mn containing ductile iron.