• Journal of Digital Convergence
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• v.20 no.5
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• pp.393-400
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• 2022

In a situation where the company handles accounting conservatively, the management's earnings forecasting information will be more conservative, and the conservativeness of this earnings forecasting information will have a differential effect in evaluating the performance of managers and paying compensation. This study aims to examine how the level of corporate accounting conservatism affects the forecast information of managers and how this affects the compensation of managers. This study establishes a hypothesis on the effect of the level of accounting conservatism on the earnings forecasting information and compensation of managers, and examines the relationship between managerial profit forecasting information & manager compensation according of conservatism in corporate accounting that can vary depending on the manager's disposition. As a result of the analysis, conservative managers are also conservative in earnings forecasting disclosure, and when corporate managers are highly conservative, they show their ability by making earnings forecasts disclosures more frequently and more accurately than corporate managers with low conservatism. It will help reduce the forecasting errors of stakeholders. Therefore, it is expected that this will play an important role in judging the manager's ability and determining compensation. Therefore, when a company handles accounting conservatively, management's earnings forecasts are also measured conservatively, which is expected to provide useful information on the basis and form of management's compensation to stakeholders.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.45-59
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• 2006

The successful performance of any numerical geotechnical simulation depends on the accuracy and efficiency of the numerical implementation of constitutive model used to simulate the stress-strain (constitutive) response of the soil. The corner stone of the numerical implementation of constitutive models is the numerical integration of the incremental form of soil-plasticity constitutive equations over a discrete sequence of time steps. In this paper a well known two-surface soil plasticity model is implemented using a generalized implicit return mapping algorithm to arbitrary convex yield surfaces referred to as the Closest-Point-Projection method (CPPM). The two-surface model describes the nonlinear behavior of coarse-grained materials by incorporating a bounding surface concept together with isotropic and kinematic hardening as well as fabric formulation to account for the effect of fabric formation on the unloading response. In the course of investigating the performance of the CPPM integration method, it is proven that the algorithm is an accurate, robust, and efficient integration technique useful in finite element contexts. It is also shown that the algorithm produces a consistent tangent operator $\frac{d\sigma}{d\varepsilon}$ during the iterative process with quadratic convergence rate of the global iteration process.

• Journal of the Korea Society of Computer and Information
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• v.28 no.11
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• pp.29-42
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• 2023

In this paper, we propose a method to enhance the prediction accuracy of solar irradiance for three major South Korean cities: Seoul, Busan, and Incheon. Our method entails the development of five generative models-vanilla GAN, CTGAN, Copula GAN, WGANGP, and TVAE-to generate independent variables that mimic the patterns of existing training data. To mitigate the bias in model training, we derive values for the dependent variables using random forests and deep neural networks, enriching the training datasets. These datasets are integrated with existing data to form comprehensive solar irradiance prediction models. The experimentation revealed that the augmented datasets led to significantly improved model performance compared to those trained solely on the original data. Specifically, CTGAN showed outstanding results due to its sophisticated mechanism for handling the intricacies of multivariate data relationships, ensuring that the generated data are diverse and closely aligned with the real-world variability of solar irradiance. The proposed method is expected to address the issue of data scarcity by augmenting the training data with high-quality synthetic data, thereby contributing to the operation of solar power systems for sustainable development.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.801-813
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• 2023

Recently, as studies about Artificial Neural Network (ANN) are actively progressing, studies for predicting water quality of rivers using ANN are being conducted. However, it is difficult to analyze the operation process inside ANN, because ANN is form of Black-box. Although eXplainable Artificial Intelligence (XAI) is used to analyze the computational process of ANN, research using XAI technology in the field of water resources is insufficient. This study analyzed Multi Layer Perceptron (MLP) to predict Water Temperature (WT), Dissolved Oxygen (DO), hydrogen ion concentration (pH) and Chlorophyll-a (Chl-a) at the Dasan water quality observatory in the Nakdong river using Layer-wise Relevance Propagation (LRP) among XAI technologies. The MLP that learned water quality was analyzed using LRP to select the optimal input data to predict water quality, and the prediction results of the MLP learned using the optimal input data were analyzed. As a result of selecting the optimal input data using LRP, the prediction accuracy of MLP, which learned the input data except daily precipitation in the surrounding area, was the highest. Looking at the analysis of MLP's DO prediction results, it was analyzed that the pH and DO a had large influence at the highest point, and the effect of WT was large at the lowest point.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.160-165
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• 2023

In this study, we propose an SNS sentence writing assistance system that utilizes YOLO and GPT to assist users in writing texts with images, such as SNS. We utilize the YOLO model to extract objects from images inserted during writing, and also extract meta-information such as GPS information and creation time information, and use them as prompt values for GPT. To use the YOLO model, we trained it on form image data, and the mAP score of the model is about 0.25 on average. GPT was trained on 1,000 blog text data with the topic of 'restaurant reviews', and the model trained in this study was used to generate sentences with two types of keywords extracted from the images. A survey was conducted to evaluate the practicality of the generated sentences, and a closed-ended survey was conducted to clearly analyze the survey results. There were three evaluation items for the questionnaire by providing the inserted image and keyword sentences. The results showed that the keywords in the images generated meaningful sentences. Through this study, we found that the accuracy of image-based sentence generation depends on the relationship between image keywords and GPT learning contents.

• Advances in nano research
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• v.16 no.6
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• pp.565-577
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• 2024

Vibration investigation of fluid-filled functionally graded cylindrical shells with ring supports is studied here. Shell motion equations are framed first order shell theory due to Sander. These equations are partial differential equations which are usually solved by approximate technique. Robust and efficient techniques are favored to get precise results. Employment of the Rayleigh-Ritz procedure gives birth to the shell frequency equation. Use of acoustic wave equation is done to incorporate the sound pressure produced in a fluid. Hankel's functions of second kind designate the fluid influence. Mathematically the integral form of the Langrange energy functional is converted into a set of three partial differential equations. A cylindrical shell is immersed in a fluid which is a non-viscous one. These shells are stiffened by rings in the tangential direction. For isotropic materials, the physical properties are same everywhere where the laminated and functionally graded materials, they vary from point to point. Here the shell material has been taken as functionally graded material. After these, ring supports are located at various positions along the axial direction round the shell circumferential direction. The influence of the ring supports is investigated at various positions. Effect of ring supports with empty and fluid-filled shell is presented using the Rayleigh - Ritz method with simply supported condition. The frequency behavior is investigated with empty and fluid-filled cylindrical shell with ring supports versus circumferential wave number and axial wave number. Also the variations have been plotted against the locations of ring supports for length-to-radius and height-to-radius ratio. Moreover, frequency pattern is found for the various position of ring supports for empty and fluid-filled cylindrical shell. The frequency first increases and gain maximum value in the midway of the shell length and then lowers down. It is found that due to inducting the fluid term frequency result down than that of empty cylinder. It is also exhibited that the effect of frequencies is investigated by varying the surfaces with stainless steel and nickel as a constituent material. To generate the fundamental natural frequencies and for better accuracy and effectiveness, the computer software MATLAB is used.

• Smart Media Journal
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• v.13 no.6
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• pp.9-15
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• 2024

In recent trends, there has been an increase in 'Qshing' attacks, a hybrid form of phishing that exploits fake QR (Quick Response) codes impersonating government agencies to steal personal and financial information. Particularly, this attack method is characterized by its stealthiness, as victims can be redirected to phishing pages or led to download malicious software simply by scanning a QR code, making it difficult for them to realize they have been targeted. In this paper, we have developed a classification technique utilizing machine learning algorithms to identify the maliciousness of URLs embedded in QR codes, and we have explored ways to integrate this with existing QR code readers. To this end, we constructed a dataset from 128,587 malicious URLs and 428,102 benign URLs, extracting 35 different features such as protocol and parameters, and used AutoML to identify the optimal algorithm and hyperparameters, achieving an accuracy of approximately 87.37%. Following this, we designed the integration of the trained classification model with existing QR code readers to implement a service capable of countering Qshing attacks. In conclusion, our findings confirm that deriving an optimized algorithm for classifying malicious URLs in QR codes and integrating it with existing QR code readers presents a viable solution to combat Qshing attacks.

• Korean Journal of Cognitive Science
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• v.29 no.2
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• pp.121-135
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• 2018

Dancers' motions are perceived by observers through visual processes with visual information forming the basis for the observers' appreciation and evaluation of the dancers' motions. There have been many discussions as to whether or not observers' personal athletic capabilities form an essential basis for accurate assessment of the motions of others but, so far, no valid conclusions have been reached. The purpose of this study is to investigate how the ability to predict motions of others varies depending on the athletic expertise of the observers. Participants of this research were ballet dancers of varying athletic expertise. Twenty seven participants were divided into three groups with nine in each: beginners, intermediate experts and experts. The participants watched the same dance video and then evaluated whether the motion would be successful or not. The movement related visual information required to evaluate the success of the motion was systematically adjusted by controlling the length of the video. Using the temporal occlusion method, this study measured the response accuracy of the participants by category of expertise. Under the circumstance with insufficient visual information to utilize, the experts showed higher rates of correct response than the intermediate experts and the beginners. The beginners showed higher rates of wrong response than the experts and the intermediate experts. These results showed that the ability to predict success or failure of a dance motion varied depending on motion expertise of the observers, although they had similar level of expertise in perception. Participants considered to have high athletic expertise showed high prediction ability on the result of the motion. In addition, high expertise in perception reduced the likelihood that participants would make hasty responses under the circumstance with insufficient information and helped to reduce wrong response rate. In conclusion, this study showed that motor expertise and perceptual expertise contribute to prediction accuracy of observed motions.

• Korean Journal of Oriental Medicine
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• v.3 no.1
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• pp.1-15
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• 1997

${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$(1445) is a book compiled the medical achievements of China and Choseon in those times and it's our source of pride to have it In this country. It also deserves careful investigation since this book can provide some clues of features of missing books in China and Korea. The extent of accuracy of xylographica of old books determines the possiblity of in depth further study. So authors attempted to investigate the xylographica of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ one of the 3 main books in Korea. Previous investigation done by Miki Sakae and Kim Doo Jong are noticeable. On the basis of their respective works, we analyzed 'Annals of the Choseon Dynasty' to find records related with ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ and estimated the situation of its publication. We tried figure the situation of those times of China, Japan and Korea(including North Korea) and tried to estimate the book's original xylographica as much as we could. By King Sejong's command, the first draft of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ consisted of 365 books was made by collaboration of civil officials and medical officers during the period from 1443 to 1445. And then from 1451(first year of Moonjong's reign) to 1464(l0th year of Sejo's reign) lots of manpowers were employed and through the process of countless erasure, proofreading, arrangement and rearrangement revised version of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ which is called by Sejo text was completed. After 3 years of wood engraving work, the first printed form of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ (alternately called Seongjong text) in folding case consisted of 266 chapters, 264 volumes came into the world in 1477.(8th year of Seongjong's reign). This was 32 years after the initial completion of the edition. So ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ exists in three forms as Sejong text, Sejo text and Seongjong text respectively. Since those texts were plundered during the Japanese invasion of Korea in 1592, none of the original copy remains within korea. The texts were constantly moved to kadeungcheongieong, to Kongdeungpyeongio, Jesookoan of Edo, to East University of department of classic books, to Cheoncho archives, to the Imperial Museum and finally is kept in the royal palace at present. (Doseoryo text Eulhae printing type) Reduced-size republication books of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ in wooden type were imported at the time of 'Byeongja Korea-Japan Treaty in 1876' and of those 2 books, one copy was treasured in the Royal Household of the Yi Dynasty and than was lost during the Korean War circa 1950. The other remaining copy has been kept succesively by Kojong's imperial grant, Royal doctor Hong Cheol Bo, Hong Taek Joo, Hong Ik Pyo the book agent, and now is kept In Yonsei University Library and this is the only existing copy in Korea at present. In 1965, Dongyang Medical college published the transcription version of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ consisting of 11 books and then in 1981 after edition and arrangement by Choonghoa(中華) publishing company, photoprint copy of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ was published in Keumgang(金剛) publishing company In 1991, October Yeokang(驛江) publishing company producd photocopies of ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ which were previously translated into Korean by North Korea Institute of Oriental Medicine and then issued by medical publishing company. In China, two institutes, Zhejiang Institute of Traditional Chinese Medicine and Huzhou Traditional Chinese Medical Hospital cooperated to publish a revised and marked text consiting of 11 books by adding marking points to japanse Edohakhoondang text which were used as a reference. Both the korean and chinese texts issued were grounded by the ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ kept in the royal palace. Any further study concerning ${\ulcorner}$Classified Collection of Medical Prescriptions${\lrcorner}$ can acquire its accuracy and objectivity when the japanese text kept in the royal palace is taken as an original copy.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.548-559
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• 1996

A series of performance measurements of positron emission tomography (PET) were performed following the recommendations of the Computer and Instrumentation Council of the Society of Nuclear Medicine and the National Electrical Manufacturers Association. We investigated the performance of the General Electric $Advance^{TM}$ PET. The measurements include the basic intrinsic tests of spatial resolution, scatter fraction, sensitivity, and count rate losses and randoms. They also include the tests of the accuracy of corrections: count rate linearity correction, uniformity correction, scatter correction and attenuation correction. GE $Advance^{TM}$ PET has bismuth germanate oxide crystals (4.0mm transaxial ${\times}$ 8.1mm axial ${\times}$ 30.0mm radial) in 18 rings, which form 35 imaging planes spaced by 4.25mm. The system has retractable tungsten septa 1mm thick and 12cm long. Transaxial resolution was 4.92mm FWHM in 2D and 5.14mm FWHM in 3D at the center. Average axial resolution in 2D decreased from 3.91mm FWHM at the center to 6.49mm FWHM at R=20cm. Average scatter fraction of direct and cross slices was 9.57%. Dead-time losses of 50% corresponded to a radioactivity concentration of $4.86{\mu}Ci/cc$ and a true count rate of 519 kcps in 2D. The accuracy of count rate linearity correction was 1.84% at the activity of $4.50{\mu}Ci/cc$. Non-uniformity was 2.06% in 2D and 2.93% in 3D. Remnant errors after scatter correction were 0.55% in 2D and 4.12% in 3D. The errors of attenuation correction were 6.21% (air), 0.20% (water), -6.32% (teflon) in 2D and 5.00% (air), 6.94% (water), 3.01% (teflon) in 3D. The results indicate the performance of GE $Advance^{TM}$ PET scanner to be well suited for clinical and research applications.