• Title/Summary/Keyword: 경영수학

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A Study on the Perception of Professionalism of the Open Competitive Exam Subjects for Civil Service Librarian (사서공무원 공개채용 시험과목의 직무전문성에 대한 인식 분석 연구)

  • Park, So-Yeon;Noh, Younghee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.25 no.2
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    • pp.229-260
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    • 2014
  • The purpose of this study was to investigate the appropriateness of the open competitive examination subjects to selecting the personnel with work profession targeted the public official librarian engaging the libraries directly operated by education office and city hall of Seoul. Also, this study suggested the ways for selecting excellent personnel within work profession. First, the public official librarian recognized that there was no practicality regarding the subjects of the open recruitment that recruit for the personnel with work profession. Second, 78.5% of the public official librarian responded the new subjects including science of public administration, social studies, science, and mathematics needed to be revised to a written examination. Third, the public official librarian thought the subjects such as library management theory, organization of information, and collection management was more appropriate for the improvement of the profession.

The Measurement of Graphical Modeling Ability in Systems Analysis and Design (시스템분석 설계를 위한 그래픽 모델링 능력 측정)

  • Getalado, Nancy;Kang, Shin-Cheol;Lee, Jae-Gwang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.1
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    • pp.221-229
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    • 2015
  • This paper looks into the measurement of modeling ability in different fields like science, mathematics, operations research and management science and emulates the ideas to system analysis and design where modeling is a very useful skill. An assessment tool was designed to measure the graphical modeling ability in systems analysis and design. It was administered to 92 students and submitted to 10 MIS experts and tested statistically for its reliability and validity.

Comparative Study of Causality based quantitative Economic Impact Analysis Models for Utilizing Spectrum Resource (전파자원 활용을 위한 인과 관계 기반 정량적 경제 파급 효과 분석모형 비교 연구)

  • Kim, Taehan;Kim, Tae-Suk
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.430-446
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    • 2018
  • In this paper, we conducted a comparative study on the methodology for impact analysis as the economic grounds for formulating policy and investment plan concerned with utilizing spectrum resource. In order to provide numerical results for objective comparison and selection among policy and investment planning, methods to be analyzed are focused on quantitative methodology based on mathematical models, consequently the utility and limits of econometric model, input-output analysis, computable general equilibrium and system dynamics are compared from various viewpoints including analysis cost. Besides, we compared the methodologies in the standpoint of utilizing spectrum and discussed the recent findings of mixed models combining multiple methodologies to exploit the advantages of each methodology and to offset the limit. Results of the research can be used as reference indicators to select the method that conforms to the purpose and priority of analysis verifying the efficiency of execution of policies and investment plans.

A Study on Building a Cyber Attack Database using Open Source Intelligence (OSINT) (공개출처정보를 활용한 사이버공격 데이터베이스 구축방안 연구)

  • Shin, Kyuyong;Yoo, Jincheol;Han, Changhee;Kim, Kyoung Min;Kang, Sungrok;Moon, Minam;Lee, Jongkwan
    • Convergence Security Journal
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    • v.19 no.2
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    • pp.113-121
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    • 2019
  • With the development of the Internet and Information Communication Technology, there has been an increase in the amount of Open Source Intelligence(OSINT). OSINT can be highly effective, if well refined and utilized. Recently, it has been assumed that almost 95% of all information comes from public sources and the utilization of open sources has sharply increased. The ISVG and START programs, for example, collect information about open sources related to terrorism or crime, effectively used to detect terrorists and prevent crime. The open source information related to the cyber attacks is, however, quite different from that in terrorism (or crime) in that it is difficult to clearly identify the attacker, the purpose of attack, and the range of damage. In addition, the data itself of cyber attacks is relatively unstructured. So, a totally new approach is required to establish and utilize an OSINT database for cyber attacks, which is proposed in this paper.

Sample Average Approximation Method for Task Assignment with Uncertainty (불확실성을 갖는 작업 할당 문제를 위한 표본 평균 근사법)

  • Gwang, Kim
    • Journal of Korea Society of Industrial Information Systems
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    • v.28 no.1
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    • pp.27-34
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    • 2023
  • The optimal assignment problem between agents and tasks is known as one of the representative problems of combinatorial optimization and an NP-hard problem. This paper covers multi agent-multi task assignment problems with uncertain completion probability. The completion probabilities are generally uncertain due to endogenous (agent or task) or exogenous factors in the system. Assignment decisions without considering uncertainty can be ineffective in a real situation that has volatility. To consider uncertain completion probability mathematically, a mathematical formulation with stochastic programming is illustrated. We also present an algorithm by using the sample average approximation method to solve the problem efficiently. The algorithm can obtain an assignment decision and the upper and lower bounds of the assignment problem. Through numerical experiments, we present the optimality gap and the variance of the gap to confirm the performances of the results. This shows the excellence and robustness of the assignment decisions obtained by the algorithm in the problem with uncertainty.

DGA-based Botnet Detection Technology using N-gram (N-gram을 활용한 DGA 기반의 봇넷 탐지 방안)

  • Jung Il Ok;Shin Deok Ha;Kim Su Chul;Lee Rock Seok
    • Convergence Security Journal
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    • v.22 no.5
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    • pp.145-154
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    • 2022
  • Recently, the widespread proliferation and high sophistication of botnets are having serious consequences not only for enterprises and users, but also for cyber warfare between countries. Therefore, research to detect botnets is steadily progressing. However, the DGA-based botnet has a high detection rate with the existing signature and statistics-based technology, but also has a high limit in the false positive rate. Therefore, in this paper, we propose a detection model using text-based n-gram to detect DGA-based botnets. Through the proposed model, the detection rate, which is the limit of the existing detection technology, can be increased and the false positive rate can also be minimized. Through experiments on large-scale domain datasets and normal domains used in various DGA botnets, it was confirmed that the performance was superior to that of the existing model. It was confirmed that the false positive rate of the proposed model is less than 2 to 4%, and the overall detection accuracy and F1 score are both 97.5%. As such, it is expected that the detection and response capabilities of DGA-based botnets will be improved through the model proposed in this paper.

The Enhancement of intrusion detection reliability using Explainable Artificial Intelligence(XAI) (설명 가능한 인공지능(XAI)을 활용한 침입탐지 신뢰성 강화 방안)

  • Jung Il Ok;Choi Woo Bin;Kim Su Chul
    • Convergence Security Journal
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    • v.22 no.3
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    • pp.101-110
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    • 2022
  • As the cases of using artificial intelligence in various fields increase, attempts to solve various issues through artificial intelligence in the intrusion detection field are also increasing. However, the black box basis, which cannot explain or trace the reasons for the predicted results through machine learning, presents difficulties for security professionals who must use it. To solve this problem, research on explainable AI(XAI), which helps interpret and understand decisions in machine learning, is increasing in various fields. Therefore, in this paper, we propose an explanatory AI to enhance the reliability of machine learning-based intrusion detection prediction results. First, the intrusion detection model is implemented through XGBoost, and the description of the model is implemented using SHAP. And it provides reliability for security experts to make decisions by comparing and analyzing the existing feature importance and the results using SHAP. For this experiment, PKDD2007 dataset was used, and the association between existing feature importance and SHAP Value was analyzed, and it was verified that SHAP-based explainable AI was valid to give security experts the reliability of the prediction results of intrusion detection models.

A Scalability based Energy Model for Sustainability of Blockchain Networks (블록체인 네트워크의 지속 가능성을 위한 확장성 기반 에너지 모델)

  • Seung Hyun Jeon;Bokrae Jung
    • Journal of Industrial Convergence
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    • v.21 no.8
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    • pp.51-58
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    • 2023
  • Blockchains have recently struggled to design for the ideal distributed trust networks by solving scalability trilemma. However, local conflicts between some countries lead to imbalance on energy distribution. Besides, blockchain networks (e.g., Bitcoin) currently consume enormous energy for transaction and mining. The existing data volume based trust model evaluated an increasing blockchain size better than Lubin's trust model in scalability trilemma. In this paper, we propose a scalability based energy model to evaluate sustainability for blockchain networks, considering energy consumption for transaction, time duration, and the blockchain size of growing blockchain networks. Through the rigorous numerical analysis, we compare the proposed scalability based energy model with the existing model for the satisfaction and optimal blockchain size. Thus, the scalability based energy model will provide an assessment tool to choose the proper blockchain networks to solve scalability trilemma problem and prove sustainability.

A Two-Stage Learning Method of CNN and K-means RGB Cluster for Sentiment Classification of Images (이미지 감성분류를 위한 CNN과 K-means RGB Cluster 이-단계 학습 방안)

  • Kim, Jeongtae;Park, Eunbi;Han, Kiwoong;Lee, Junghyun;Lee, Hong Joo
    • Journal of Intelligence and Information Systems
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    • v.27 no.3
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    • pp.139-156
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    • 2021
  • The biggest reason for using a deep learning model in image classification is that it is possible to consider the relationship between each region by extracting each region's features from the overall information of the image. However, the CNN model may not be suitable for emotional image data without the image's regional features. To solve the difficulty of classifying emotion images, many researchers each year propose a CNN-based architecture suitable for emotion images. Studies on the relationship between color and human emotion were also conducted, and results were derived that different emotions are induced according to color. In studies using deep learning, there have been studies that apply color information to image subtraction classification. The case where the image's color information is additionally used than the case where the classification model is trained with only the image improves the accuracy of classifying image emotions. This study proposes two ways to increase the accuracy by incorporating the result value after the model classifies an image's emotion. Both methods improve accuracy by modifying the result value based on statistics using the color of the picture. When performing the test by finding the two-color combinations most distributed for all training data, the two-color combinations most distributed for each test data image were found. The result values were corrected according to the color combination distribution. This method weights the result value obtained after the model classifies an image's emotion by creating an expression based on the log function and the exponential function. Emotion6, classified into six emotions, and Artphoto classified into eight categories were used for the image data. Densenet169, Mnasnet, Resnet101, Resnet152, and Vgg19 architectures were used for the CNN model, and the performance evaluation was compared before and after applying the two-stage learning to the CNN model. Inspired by color psychology, which deals with the relationship between colors and emotions, when creating a model that classifies an image's sentiment, we studied how to improve accuracy by modifying the result values based on color. Sixteen colors were used: red, orange, yellow, green, blue, indigo, purple, turquoise, pink, magenta, brown, gray, silver, gold, white, and black. It has meaning. Using Scikit-learn's Clustering, the seven colors that are primarily distributed in the image are checked. Then, the RGB coordinate values of the colors from the image are compared with the RGB coordinate values of the 16 colors presented in the above data. That is, it was converted to the closest color. Suppose three or more color combinations are selected. In that case, too many color combinations occur, resulting in a problem in which the distribution is scattered, so a situation fewer influences the result value. Therefore, to solve this problem, two-color combinations were found and weighted to the model. Before training, the most distributed color combinations were found for all training data images. The distribution of color combinations for each class was stored in a Python dictionary format to be used during testing. During the test, the two-color combinations that are most distributed for each test data image are found. After that, we checked how the color combinations were distributed in the training data and corrected the result. We devised several equations to weight the result value from the model based on the extracted color as described above. The data set was randomly divided by 80:20, and the model was verified using 20% of the data as a test set. After splitting the remaining 80% of the data into five divisions to perform 5-fold cross-validation, the model was trained five times using different verification datasets. Finally, the performance was checked using the test dataset that was previously separated. Adam was used as the activation function, and the learning rate was set to 0.01. The training was performed as much as 20 epochs, and if the validation loss value did not decrease during five epochs of learning, the experiment was stopped. Early tapping was set to load the model with the best validation loss value. The classification accuracy was better when the extracted information using color properties was used together than the case using only the CNN architecture.

An Option Pricing Model for the Natural Resource Development Projects (해외자원개발사업 평가를 위한 옵션가격 결정모형 연구)

  • Lee, In-Suk;Heo, Eunnyeong
    • Environmental and Resource Economics Review
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    • v.13 no.4
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    • pp.735-761
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    • 2004
  • As a possible alternative to Traditional Discounted Cash Flow Method, "Option Pricing Model" has drawn academic attentions for the last a few decades. However, it has failed to replace traditional DCF method practically due to its mathematical complexity. This paper introduces an option pricing valuation model specifically adjusted for the natural resource development projects. We add market information and industry-specific features into the model so that the model remains objective as well as realistic after the adjustment. The following two features of natural resource development projects take central parts in model construction; product price is a unique source of cash flow's uncertainty, and the projects have cost structure from capital-intense industry, in which initial capital cost takes most part of total cost during the projects. To improve the adaptability of Option Pricing Model specifically to the natural resource development projects, we use Two-Factor Model and Long-term Asset Model for the analysis. Although the model introduced in this paper is still simple and reflects limited reality, we expect an improvement in applicability of option pricing method for the evaluation of natural resource development projects can be made through the process taken in this paper.

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