• Title/Summary/Keyword: model studies

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Early Prediction of Fine Dust Concentration in Seoul using Weather and Fine Dust Information (기상 및 미세먼지 정보를 활용한 서울시의 미세먼지 농도 조기 예측)

  • HanJoo Lee;Minkyu Jee;Hakdong Kim;Taeheul Jun;Cheongwon Kim
    • Journal of Broadcast Engineering
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    • v.28 no.3
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    • pp.285-292
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    • 2023
  • Recently, the impact of fine dust on health has become a major topic. Fine dust is dangerous because it can penetrate the body and affect the respiratory system, without being filtered out by the mucous membrane in the nose. Since fine dust is directly related to the industry, it is practically impossible to completely remove it. Therefore, if the concentration of fine dust can be predicted in advance, pre-emptive measures can be taken to minimize its impact on the human body. Fine dust can travel over 600km in a day, so it not only affects neighboring areas, but also distant regions. In this paper, wind direction and speed data and a time series prediction model were used to predict the concentration of fine dust in Seoul, and the correlation between the concentration of fine dust in Seoul and the concentration in each region was confirmed. In addition, predictions were made using the concentration of fine dust in each region and in Seoul. The lowest MAE (mean absolute error) in the prediction results was 12.13, which was about 15.17% better than the MAE of 14.3 presented in previous studies.

The Implications of Amore-Pacific's New Office Landscaping Through the Ground Theory (근거이론을 통해 본 아모레퍼시픽 신사옥 조경의 함의)

  • Park, Seong-uk;Hong, Youn-Soon;Kim, Woo-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.6
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    • pp.84-95
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    • 2022
  • The landscaping of Amore-Pacific's new building has received various awards since its construction. This study attempted to identify the mechanisms of planning, design, and construction of this project through the ground theory. The results of the study are summarized as follows. The client's place attachment of the sites, which was the company's parent, was the driving force for an international design competiton in which architecture and landscaping were integrated. After that, in the detailed design stage for the actual implementation of the contest-winning plan, competent local designers and contractors were selected, and a consultative body was operated to engage in various opinions and promote rational decision-making. As for consultative body's operation method, simulation, physical model production, and detailed drawings were created after sharing opinions, and landscape design supervision played a major role. Establishing consistency in design and construction through integrated planning and landscape design supervision is required to cultivate craftsmanship and foster landscape coordinators in today's industrialized practice. The accumulation of related follow-up studies and supplementation of the system is anticipated.

The effect of transformational leadership recognized by members of the telemarketing organization on organizational performance-centered on the moderating effect of followership (텔레마케팅 조직구성원이 인식한 변혁적 리더십이 조직성과에 미치는 영향-팔로워십의 조절효과를 중심으로)

  • JiHyun Shim
    • Journal of Service Research and Studies
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    • v.12 no.3
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    • pp.45-59
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    • 2022
  • This study attempted to investigate how the transformational leadership perceived by flowers of telemarketing organizations. In particular, this study explored the moderating effect of followership in the relationship between transformational leadership and organizational performance. To verify the research model, 321 surveys collected from 10 domestic call centers were analyzed. Reliability, correlation, factor analysis, and hierarchical regression analysis were performed, and as a result of the analysis, it was found that the transformational leadership in the telemarketing organizations had a positive effect on organizational performance. In addition, it was confirmed that goal consistency, proactive participation, critical thinking, and team spirit, which are the four sub-variables of followership, all have a positive (+) effect on organizational performance, and both goal consistency and proactive participation moderate the relationship between transformational leadership and organizational performance. Considering the special working environment of telemarketing organizations, the results of this study suggest the need for a corporate educational role to increase transformational leadership and followership and the need to build environments by setting up an atmosphere for members to exercise follow-up, and opening up communication structures for members to follow.

A Case Study on the Online Fractional Investment Securitization Platform (온라인 분할 투자 증권화 플랫폼 사례 연구)

  • Tae Hyup ROH
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.747-754
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    • 2023
  • With the development of information and communication technology, online fractional investment platforms have emerged through the convergence of online platform technology and new investment techniques for asset-backed derivatives. In this study, the concept and previous studies of the online fractional investment platform business, commercialization models and service processes, market status, and pending discussions and alternatives were presented. Recently, the Securities and Futures Commission's decision on securitization of split ownership has become an important guide to the stable business sustainability of platform operators, but academic research is needed according to the current status and case analysis. To identify specific market issues, examples of representative online fractional investment securitization platform businesses such as "MusiCow" for music copyright, "Tessa" based on art, "Kasa" for real estate, "Piece" based on real assets, and "BangCow" for Korean beef shipments were analyzed. Through the case analysis of this study, the characteristics of the business model according to the basic assets of the online fractional investment platform were compared and presented. Since most business models are judged to be securitic, they must comply with the provisions of the Capital Markets Act or be recognized as the target of innovative financial services. From a practical point of view, it is meaningful in that it presented improvement directions that online fractional securitization platform operators should consider and organized institutional considerations for investor protection.

The Effect of Problem-Based Learning (PBL) on the Ability to Participate in Field-Education Classes and Improvement of Problem-Solving Skills (문제중심학습(PBL)이 현장실습수업 참여능력과 문제해결력 향상에 미치는 영향)

  • Jung Hyun Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.1-9
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    • 2023
  • This study aims to construct a basic PBL class research data model that can strengthen and improve technical college students' abilities to participate in field-education classes and problem-solving skills. A significant effect was found in PBL classes with regard to technical college students' problem-solving skills and abilities to participate in field-education classes, as posited by the hypothesis. The results of the PBL course, which is a hypothesis of research, have been confirmed to have a significant effect on the participation of college students in field practice and on the ability to solve problems. Seventy-one students from five departments (humanities, social studies, and arts) at D University in North GyeongSang Province were selected as final subjects. The study was conducted for seven weeks from October 10 to December 05, 2021, in three stages: pre-inspection, PBL operation, and post-inspection. In the college life experiences of students with disabilities who study late within the Department of Social Welfare, it was confirmed that the study participants independently changed toward their independent life satisfaction and positive perception of themselves as a process of change in which the self-determination rights and goals and hopes for their lives by seeking the role for the disabled who have not yet been encountered and in the process of positively recognizing themselves.

S-PRESENT Cryptanalysis through Know-Plaintext Attack Based on Deep Learning (딥러닝 기반의 알려진 평문 공격을 통한 S-PRESENT 분석)

  • Se-jin Lim;Hyun-Ji Kim;Kyung-Bae Jang;Yea-jun Kang;Won-Woong Kim;Yu-Jin Yang;Hwa-Jeong Seo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.193-200
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    • 2023
  • Cryptanalysis can be performed by various techniques such as known plaintext attack, differential attack, side-channel analysis, and the like. Recently, many studies have been conducted on cryptanalysis using deep learning. A known-plaintext attack is a technique that uses a known plaintext and ciphertext pair to find a key. In this paper, we use deep learning technology to perform a known-plaintext attack against S-PRESENT, a reduced version of the lightweight block cipher PRESENT. This paper is significant in that it is the first known-plaintext attack based on deep learning performed on a reduced lightweight block cipher. For cryptanalysis, MLP (Multi-Layer Perceptron) and 1D and 2D CNN(Convolutional Neural Network) models are used and optimized, and the performance of the three models is compared. It showed the highest performance in 2D convolutional neural networks, but it was possible to attack only up to some key spaces. From this, it can be seen that the known-plaintext attack through the MLP model and the convolutional neural network is limited in attackable key bits.

Determining Groundwater-surface Water Interaction at Coastal Lagoons using Hydrogeochemical Tracers (수리화학적 환경 추적자를 이용한 강원도 석호지역에서의 지하수-지표수 상호작용에 대한 연구)

  • Dong-Hun Kim;Jung-Yun Lee;Soo Young Cho;Hee Sun Moon;Youn-Young Jung;Yejin Park;Yong Hwa Oh
    • Journal of Soil and Groundwater Environment
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    • v.28 no.2
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    • pp.1-11
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    • 2023
  • Groundwater-surface water interaction was evaluated using water quality parameters (temperature and electrical conductivity), distributions of stable water isotopes (δ2H and δ 18O), and Rn-222 in lagoon water, groundwater, and seawater at three coastal lagoons (Songji (SJ), Youngrang (YR), and Sunpo (SP) Lagoon) in South Korea. From the results of composition and distributions of δ2H and δ18O, it was found that groundwater fraction of lagoon water in YR Lagoon (76%) was slightly higher than those of SJ (42%), and SP (63%) Lagoon. Based on Rn-222 mass balance model, groundwater discharge into SJ Lagoon in summer 2020 was estimated to be (3.2±1.1)×103 m3 day-1, which showed a similar or an order of magnitude higher than the results of previous studies conducted in coastal lagoons. This study can provide advanced techniques to evaluate groundwater-surface water interaction in coastal lagoons, wetlands, and lakes, and help to determine the effects of groundwater on coastal ecosystems.

The Effect of Failure of Online Food Delivery Service Recovery Strategies on Consumer Attitude and Behavioral Intention: Focusing on Justice Theory (온라인 음식 배달 서비스 회복 전략의 실패가 소비자 태도 및 행동 의도에 미치는 영향: 공정성 이론(Justice Theory)을 중심으로)

  • Jungkun Park;Sangwoo Lee;Hyowon Hyun;Jihwan Yum
    • Journal of Service Research and Studies
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    • v.13 no.2
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    • pp.161-180
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    • 2023
  • This study empirically analyzed the effect of perceived injustice on service recovery measures proposed by online food delivery service (OFDS) companies on consumer disappointment. This study adopted interaction justice, information justice, procedural justice, and distributive justice as sub-variables of justice perception based on the justice theory. In addition, the differences by generation (MZ generation and other generations) were examined in the relationship between negative word-of-mouth behavior and switching intentions due to service recovery failure. An online survey was conducted targeting 250 adult consumers in the U.S for the empirical analysis of this research model. The results of the data analysis demonstrated that negative perceptions about the procedural justice and distributive justice among the service recovery strategies had a positive effect upon the consumer's disappointment. Furthermore, it was confirmed that the consumer's disappointment due to the perceived injustice of the service recovery strategy had a positive effect on the consumer's negative word-of-mouth behavior and switching intentions. The verification results of the moderation effect in the relationship between negative word-of-mouth behavior and switching intention, it was found that the younger the age(MZ generation), the higher the possibility of causing dysfunctional behavior. This study expands the scope of related research by presenting a new perspective on the justice perception in the service recovery process by verifying dysfunctional behavior of consumers caused due to the failure of the service recovery strategy. It is believed that the results of this study will be used as basic data for the establishment of practical strategies for OFDS companies to prevent double defection of their customers.

Global Value Chain and Misallocation: Evidence from South Korea

  • Bongseok Choi;Seon Tae Kim
    • Journal of Korea Trade
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    • v.26 no.4
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    • pp.1-22
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    • 2022
  • Purpose - This paper empirically investigates the effect of a rise in the global value chain (GVC) on the industry-level efficiency of resource allocation (based on plant-level inefficiency measures) in Korea, with a focus on various channels through which a rise in the GVC can increase competition among firms and thus induce resources to be allocated more efficiently across firms. Design/methodology - We empirically investigate the relationship between the industry-specific importance of GVC and the industry-level allocative inefficiency that is measured as the dispersion of the plant-level marginal revenue of capital (MRK) as in Hsieh and Klenow's (2009) influential model. We compute MRK dispersion for industries sorted by various characteristics that are closely related to firm/industry sensitivity to the GVC. In other words, we compute the average industry-level MRK dispersion for industries sorted by industry-specific importance of GVC and compute the difference between the two groups of industries (higher vs. lower than the median GVC); we also calculate the difference between industries sorted by industry-specific export (import) intensity. This is our difference-in-difference estimate of the MRK dispersion associated with the GVC for the export (import)-intensive industry versus the non-export (non-import)-intensive industry. This difference-in-difference estimate of the MRK dispersion conditional vs. unconditional on firm-level productivity is then calculated further (triple-difference estimate). Findings - A rise in GVC is associated with a decrease in the MRK dispersion in the export-intensive industry compared to the non-export-intensive industry. The same is true for industries that rely heavily on imports versus those that do not (i.e., import intensive vs. non-intensive). Furthermore, the reduction in the MRK dispersion in the export-intensive industry associated with an increase in the GVC is disproportionately greater for high-productivity firms. In contrast, the negative relationship between GVC and MRK dispersion in the import-intensive industry is disproportionately smaller for high-productivity firms. Originality/value - Existing studies focus on the relationship between GVC and aggregate output, exports, and imports at the country level. We investigate detailed firm/industry-level mechanisms that determine the relationship between GVC, trade, and productivity. Using the plant-level data in South Korea, we investigate how GVC is related to the cross-firm MRK dispersion, an important measure of allocative inefficiency, based on Hsieh and Klenow's (2009) influential economic theory. This is the first study to provide plant-level evidence of how GVC affects MRK dispersion. Furthermore, we examine how the relationship between GVC and MRK-dispersion varies across export intensity, import intensity, and firm-level productivity, providing insight into how GVC can affect firms' exposure to competition in the global market differently depending on market conditions and thus generate trade-related productivity gains.

Comparison of CNN and GAN-based Deep Learning Models for Ground Roll Suppression (그라운드-롤 제거를 위한 CNN과 GAN 기반 딥러닝 모델 비교 분석)

  • Sangin Cho;Sukjoon Pyun
    • Geophysics and Geophysical Exploration
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    • v.26 no.2
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    • pp.37-51
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    • 2023
  • The ground roll is the most common coherent noise in land seismic data and has an amplitude much larger than the reflection event we usually want to obtain. Therefore, ground roll suppression is a crucial step in seismic data processing. Several techniques, such as f-k filtering and curvelet transform, have been developed to suppress the ground roll. However, the existing methods still require improvements in suppression performance and efficiency. Various studies on the suppression of ground roll in seismic data have recently been conducted using deep learning methods developed for image processing. In this paper, we introduce three models (DnCNN (De-noiseCNN), pix2pix, and CycleGAN), based on convolutional neural network (CNN) or conditional generative adversarial network (cGAN), for ground roll suppression and explain them in detail through numerical examples. Common shot gathers from the same field were divided into training and test datasets to compare the algorithms. We trained the models using the training data and evaluated their performances using the test data. When training these models with field data, ground roll removed data are required; therefore, the ground roll is suppressed by f-k filtering and used as the ground-truth data. To evaluate the performance of the deep learning models and compare the training results, we utilized quantitative indicators such as the correlation coefficient and structural similarity index measure (SSIM) based on the similarity to the ground-truth data. The DnCNN model exhibited the best performance, and we confirmed that other models could also be applied to suppress the ground roll.