• Title/Summary/Keyword: Operations Research Models

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A Study on the Optimal Resource Configuration Considering Load Characteristics of Electric Vehicles in Micro Grid Environment (전기자동차 부하 특성을 고려한 마이크로그리드의 최적 전원 구성에 관한 연구)

  • Hwang, Sung-Wook;Chae, Woo-Kyu;Lee, Hak-Ju;Yun, Sang-Yun;Kim, Jung-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.2
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    • pp.228-231
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    • 2015
  • In power system research fields, one of current key issues is the construction and commercialization of micro grid site which is called green island, carbon zero island, energy independent island, building micro grid, etc. and various affiliated technologies have been being vigorously developed to realize. In addition, various researches about electric vehicles (EVs) are in progress and it is expected to penetrate rapidly with the next a few years. Some new load models should be developed integrating with electric vehicle loads because the EVs' deployment could cause the change of load composition rate on power system planning and operations. EVs are also resources for micro grid as well as distributed generation and demand response so that various supply and demand side resources should be considered for micro grid researches. In this paper, the load composition rate of residential sectors is prospected considering the deployment of EVs and the resource configuration of micro grid is optimized based on net present cost. In the optimization, the load patten of case studies includes EV's charging characteristics and various cases are simulated comparing micro grid environment and normal condition. HOMER is used to compare various cases and economic effects.

Application Strategies of Superintelligent AI in the Defense Sector: Emphasizing the Exploration of New Domains and Centralizing Combat Scenario Modeling (초거대 인공지능의 국방 분야 적용방안: 새로운 영역 발굴 및 전투시나리오 모델링을 중심으로)

  • PARK GUNWOO
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.3
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    • pp.19-24
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    • 2024
  • The future military combat environment is rapidly expanding the role and importance of artificial intelligence (AI) in defense, aligning with the current trends of declining military populations and evolving dynamics. Particularly, in the civilian sector, AI development has surged into new domains based on foundation models, such as OpenAI's Chat-GPT, categorized as Super-Giant AI or Hyperscale AI. The U.S. Department of Defense has organized Task Force Lima under the Chief Digital and AI Office (CDAO) to conduct research on the application of Large Language Models (LLM) and generative AI. Advanced military nations like China and Israel are also actively researching the integration of Super-Giant AI into their military capabilities. Consequently, there is a growing need for research within our military regarding the potential applications and fields of application for Super-Giant AI in weapon systems. In this paper, we compare the characteristics and pros and cons of specialized AI and Super-Giant AI (Foundation Models) and explore new application areas for Super-Giant AI in weapon systems. Anticipating future application areas and potential challenges, this research aims to provide insights into effectively integrating Super-Giant Artificial Intelligence into defense operations. It is expected to contribute to the development of military capabilities, policy formulation, and international security strategies in the era of advanced artificial intelligence.

A Study of Influencing Factors Upon Using C4I Systems: The Perspective of Mediating Variables in a Structured Model (C4I 시스템 사용의 영향 요인에 관한 연구: 구조모형의 매개변수의 관점에서)

  • Kim, Chong-Man;Kim, In-Jai
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.73-94
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    • 2009
  • The general aspects for the future warfare shows that the concept of firepower and maneuver centric warfare has been replacing with that of information and knowledge centric warfare. Thus, some developed countries are now trying to establish the information systems to perform intelligent warfare and innovate defense operations. The C4I(Command, Control, Communication, Computers and Intelligence for the Warrior) systems make it possible to do modern and systematic war operations. The basic idea of this study is to investigate how TAM(Technology Acceptance Model) can explain the acceptance behavior in military organizations. Because TAM is inadequate in explaining the acceptance processes forcomplex technologies and strict organizations, a revised research model based upon TAM was developed in order to assess the usage of the C4I system. The purpose of this study is to investigate factors affecting the usage of C4I in the Korean Army. The research model, based upon TAM, was extended through a belief construct such as self-efficacy as one of mediating variables. The self-efficacy has been used as a mediating variable for technology acceptance, and the variable was included in the research model. The external variables were selected on the basis of previous research. The external variables can be classified into following: 1) technological, 2) organizational, and 3) environmental factors on the basis of TOE(Technology-Organization-Environment) framework. The technological factor includes the information quality and the task-technology fitness. The organizational factor includes the influence of senior colleagues. The environmental factor includes the education/train data. The external variables are considered very important for explaining the behavior patterns of information technology or systems. A structured questionnaire was developed and administrated to those who were using the C4I system. Total 329 data were used for statistical data analyses. A confirmatory factor analysis and structured equation model were used as main statistical methods. Model fitness Indexes for measurement and structured models were verified before all 18 hypotheses were tested. This study shows that the perceived usefulness and the self-efficacy played their roles more than the perceived ease of use did in TAM. In military organizations, the perceived usefulness showed its mediating effects between external variables and dependent variable, but the perceived ease of use did not. These results imply that the perceived usefulness can explain the acceptance processes better than the perceived ease of use in the army. The self-efficacy was also used as one of the three mediating variables, and showed its mediating effects in explaining the acceptance processes. Such results also show that the self-efficacy can be selected as one possible belief construct in TAM. The perceived usefulness was influenced by such factors as senior colleagues, the information quality, and the task-technology fitness. The self-efficacy was affected by education/train and task-technology fitness. The actual usage of C4I was influenced not by the perceived ease of use but by the perceived usefulness and selfefficacy. This study suggests the followings: (1) An extended TAM can be applied to such strict organizations as the army; (2) Three mediation variables are included in the research model and tested at real situations; and (3) Several other implications are discussed.

Prediction of Sea Water Temperature by Using Deep Learning Technology Based on Ocean Buoy (해양관측부위 자료 기반 딥러닝 기술을 활용한 해양 혼합층 수온 예측)

  • Ko, Kwan-Seob;Byeon, Seong-Hyeon;Kim, Young-Won
    • Korean Journal of Remote Sensing
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    • v.38 no.3
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    • pp.299-309
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    • 2022
  • Recently, The sea water temperature around Korean Peninsula is steadily increasing. Water temperature changes not only affect the fishing ecosystem, but also are closely related to military operations in the sea. The purpose of this study is to suggest which model is more suitable for the field of water temperature prediction by attempting short-term water temperature prediction through various prediction models based on deep learning technology. The data used for prediction are water temperature data from the East Sea (Goseong, Yangyang, Gangneung, and Yeongdeok) from 2016 to 2020, which were observed through marine observation by the National Fisheries Research Institute. In addition, we use Long Short-Term Memory (LSTM), Bidirectional LSTM, and Gated Recurrent Unit (GRU) techniques that show excellent performance in predicting time series data as models for prediction. While the previous study used only LSTM, in this study, the prediction accuracy of each technique and the performance time were compared by applying various techniques in addition to LSTM. As a result of the study, it was confirmed that Bidirectional LSTM and GRU techniques had the least error between actual and predicted values at all observation points based on 1 hour prediction, and GRU was the fastest in learning time. Through this, it was confirmed that a method using Bidirectional LSTM was required for water temperature prediction to improve accuracy while reducing prediction errors. In areas that require real-time prediction in addition to accuracy, such as anti-submarine operations, it is judged that the method of using the GRU technique will be more appropriate.

Added Mass of Submerged Bodies Obtained by Forced Oscillation Tests and Numerical Calculations of Potential Flow (수중운동체의 강제동요시험 및 포텐셜 계산에 의한 부가질량 추정)

  • Kim, Dong Jin;Lee, Gyeong Joong;Kwon, Chang Seop;Kim, Yeon Gyu;Park, Jin-Yeong;Jun, Bong-Huan
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.4
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    • pp.214-224
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    • 2022
  • It is necessary to estimate manoeuvring characteristics of submerged bodies at the design stage in order to ensure the safe operations. In this study, added mass coefficients in the mathematical model of submerged bodies are estimated by captive model tests and numerical calculations. Two kinds of models, MARIN 'BB2'submarine model and AUV (Autonomous unmanned vehicle) model are utilized in the forced oscillation tests. Compared to BB2 submarine, AUV with cylindrical type hull form shows relatively small added masses in roll, pitch, and yaw directions. Next, numerical calculations based on potential theory are performed under the assumption that viscous effects on inertia forces are negligible. Added masses obtained by numerical calculations are in good agreements with forced oscillation test results. And if slow manoeuvres of submerged bodies are presumed, some of velocity coupled terms can be approximated by combinations of added mass coefficients.

Applications of Innovation Adoption and Diffusion Theory to Demand Estimation for Communications and Media Converging (DMB) Services (혁신채택 및 확산이론의 통신방송융합(위성DMB) 서비스 수요추정 응용)

  • Sawng Yeong-Wha;Han Hyun-Soo
    • Korean Management Science Review
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    • v.22 no.1
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    • pp.179-197
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    • 2005
  • This study examines market acceptance for DMB service, one of the touted new business models in Korea's next-generation mobile communications service market, using adoption end diffusion of innovation as the theoretical framework. Market acceptance for DMB service was assessed by predicting the demand for the service using the Bass model, and the demand variability over time was then analyzed by integrating the innovation adoption model proposed by Rogers (2003). In our estimation of the Bass model, we derived the coefficient of innovation and coefficient of imitation, using actual diffusion data from the mobile telephone service market. The maximum number of subscribers was estimated based on the result of a survey on satellite DMB service. Furthermore, to test the difference in diffusion pattern between mobile phone service and satellite DMB service, we reorganized the demand data along the diffusion timeline according to Rogers' innovation adoption model, using the responses by survey subjects concerning their respective projected time of adoption. The comparison of the two demand prediction models revealed that diffusion for both took place forming a classical S-curve. Concerning variability in demand for DMB service, our findings, much in agreement with Rogers' view, indicated that demand was highly variable over time and depending on the adopter group. In distinguishing adopters into different groups by time of adoption of innovation, we found that income and lifestyle (opinion leadership, novelty seeking tendency and independent decision-making) were variables with measurable impact. Among the managerial variables, price of reception device, contents type, subscription fees were the variables resulting in statistically significant differences. This study, as an attempt to measure the market acceptance for satellite DMB service, a leading next-generation mobile communications service product, stands out from related studies in that it estimates the nature and level of acceptance for specific customer categories, using theories of innovation adoption and diffusion and based on the result of a survey conducted through one-to-one interviews. The authors of this paper believe that the theoretical framework elaborated in this study and its findings can be fruitfully reused in future attempts to predict demand for new mobile communications service products.

Analysis of Variables and Errors of the Combinatorial Problem (순열 조합 문장제의 문제 변인과 오류 분석)

  • Lee, Ji-Hyun;Lee, Jung-Yun;Choi, Young-Gi
    • School Mathematics
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    • v.7 no.2
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    • pp.123-137
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    • 2005
  • Elementary combinatorial problem may be classified into three different combinatorial models(selection, distribution, partition). The main goal of this research is to determine the effect of type of combinatorial operation and implicit combinatorial model on problem difficulty. We also classified errors in the understanding combinatorial problem into error of order, repetition, permutation with repetition, confusing the type of object and cell, partition. The analysis of variance of answers from 339 students showed the influence of the implicit combinatorial model and types of combinatorial operations. As a result of clinical interviews, we particularly noticed that some students were not able to transfer the definition of combinatorial operation when changing the problem to a different combinatorial model. Moreover, we have analysed textbooks, and we have found that the exercises in these textbooks don't have various types of problems. Therefore when organizing the teaching , it is necessary to pose various types of problems and to emphasize the transition of combinatorial problem into the different models.

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Functional Neuroanatomy of Memory (기억의 기능적 신경 해부학)

  • Lee, Sung-Hoon
    • Sleep Medicine and Psychophysiology
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    • v.4 no.1
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    • pp.15-28
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    • 1997
  • Longterm memory is encoded in the neuronal connectivities of the brain. The most successful models of human memory in their operations are models of distributed and self-organized associative memory, which are founded in the principle of simulaneous convergence in network formation. Memory is not perceived as the qualities inherent in physical objects or events, but as a set of relations previously established in a neural net by simultaneousy occuring experiences. When it is easy to find correlations with existing neural networks through analysis of network structures, memory is automatically encoded in cerebral cortex. However, in the emergence of informations which are complicated to classify and correlated with existing networks, and conflictual with other networks, those informations are sent to the subcortex including hippocampus. Memory is stored in the form of templates distributed across several different cortical regions. The hippocampus provides detailed maps for the conjoint binding and calling up of widely distributed informations. Knowledge about the distribution of correlated networks can transform the existing networks into new one. Then, hippocampus consolidats new formed network. Amygdala may enable the emotions to influence the information processing and memory as well as providing the visceral informations to them. Cortico-striatal-pallido-thalamo-cortical loop also play an important role in memory function with analysis of language and concept. In case of difficulty in processing in spite of parallel process of informations, frontal lobe organizes theses complicated informations of network analysis through temporal processing. With understanding of brain mechanism of memory and information processing, the brain mechanism of mental phenomena including psychopathology can be better explained in terms of neurobiology and meuropsychology.

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Prediction of Vertical Sea Water Temperature Profile in the East Sea Based on Machine Learning and XBT Data

  • Kim, Young-Joo;Lee, Soo-Jin;Kim, Young-Won
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.11
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    • pp.47-55
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    • 2022
  • Recently, researches on the prediction of sea water temperature using artificial intelligence models has been actively conducted in Korea. However, most researches in the sea around the Korean peninsula mainly focus on predicting sea surface temperatures. Unlike previous researches, this research predicted the vertical sea water temperature profile of the East Sea, which is very important in submarine operations and anti-submarine warfare, using XBT(eXpendable Bathythermograph) data and machine learning models(RandomForest, XGBoost, LightGBM). The model was trained using XBT data measured from sea surface to depth of 200m in a specific area of the East Sea, and the prediction accuracy was evaluated through MAE(Mean Absolute Error) and vertical sea water temperature profile graphs.

A Simulation Study on the Performances of Revenue Management Models for an Air Cargo Network (시뮬레이션을 통한 항공화물 네트워크 수익관리 모형 성능 평가)

  • Lee, Kwang-Ryul;Yoon, Soo-Jeong;Lee, Chul-Ung
    • Journal of the Korea Society for Simulation
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    • v.18 no.1
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    • pp.41-51
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    • 2009
  • A discrete event simulation model is developed to evaluate the performances of three different revenue management methods for an air cargo network from Northeast China to North America and Europe. In the first method, a bid price model is applied only to the routes that pass through Incheon. In the second method, the bid price model is applied to all the routes. In third method, bid price and virtual nesting models are applied to the routes that pass through Incheon. The results show that the total revenue significantly increases with the employment of pricing and capacity control. The developed simulation model is a useful research tool to study marketing strategies for air cargo operations.