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A Study on the Deployment Plan of Fighter Aircraft Considering the Threat of Enemy Missiles (적 미사일 위협 고려한 전투기 전력 배치방안 연구)

  • Park, Inkyun;Ha, Yonghoon
    • Journal of the Korea Society for Simulation
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    • v.29 no.4
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    • pp.47-54
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    • 2020
  • North Korea has recently developed and deployed missiles with various ranges as asymmetrical forces. Among them, short-range ballistic missiles with improved accuracy are expected to aim at achieving tactical goals by hitting important military facilities in Korea with a small number of missiles. Damage to the air force airfields, one of North Korea's main targets of missiles attack, could limit the operation of air force fighters essential to gaining air superiority. Based on the attack by the short range ballistic missiles, the damage probability of military airfields was simulated. And as the one of the concepts of passive defense, the way to reduce the loss of combat power was studied through the changes of the air force squadrons deployment. As a result, the effective deployment plan could be obtained to reduce the amount of power loss compared to the current deployment.

Prediction of Material's Formation Energy Using Crystal Graph Convolutional Neural Network (결정그래프 합성곱 인공신경망을 통한 소재의 생성 에너지 예측)

  • Lee, Hyun-Gi;Seo, Dong-Hwa
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.2
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    • pp.134-142
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    • 2022
  • As industry and technology go through advancement, it is hard to search new materials which satisfy various standards through conventional trial-and-error based research methods. Crystal Graph Convolutional Neural Network(CGCNN) is a neural network which uses material's features as train data, and predicts the material properties(formation energy, bandgap, etc.) much faster than first-principles calculation. This report introduces how to train the CGCNN model which predicts the formation energy using open database. It is anticipated that with a simple programming skill, readers could construct a model using their data and purpose. Developing machine learning model for materials science is going to help researchers who should explore large chemical and structural space to discover materials efficiently.

Limitations and Future Work Suggetion on Safe Interaction Model between Rust and C/C++ (Rust와 C/C++간 안전한 상호작용에 관한 연구의 맹점과 개선 모델 연구)

  • Taehyun Noh;Hojoon Lee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.345-351
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    • 2023
  • As software development progresses and programs become increasingly complex, the cost of reducing and managing software vulnerabilities has also increased. To address this issue, the Rust programming language, which guarantees Memory Safety, has been suggested as an alternative for more error-prone languages such as traditional C/C++. However, Rust also supports the use of libraries written in C/C++ to enhance compatibility with older languages and avoid redundant development, compromising its original guarantees. For example, memory corruption happened in C/C++ can lead to exploits such as buffer overflow, Use-After-Free and null-pointer dereferecing. To tackle this problem, recent studies have been conducted to secure interactino between Rust and C/C++ by isolation. This paper uncovers areas that have not been fully explored in previous studies, following limitation analysis on each. Finally, this paper suggests the future direction of research on safe interaction between Rust and C/C++.

A Study on Automated Reinforcement Detailing for Reinforced Concrete Structures Using BIM (BIM 기반 철근콘크리트 구조물의 자동 배근 모델 생성)

  • Park, U-Yeol;Yun, Seok-Heon
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.4
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    • pp.507-515
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    • 2024
  • Recent advancements in Building Information Modeling(BIM) have significantly impacted the construction industry, driving competitiveness and innovation. However, rebar construction, a critical component influencing project quality and cost, has lagged behind in BIM adoption. Traditional methods relying heavily on 2D drawings for rebar detailing have hindered efficiency and introduced potential errors. This paper presents a novel system designed to automate the detailed modeling of rebar, thereby promoting BIM integration within rebar construction and optimizing construction management processes. The system leverages confirmed structural drawings from the post-structural design phase to automatically generate intricate rebar models for columns and beams. To ensure adherence to domestic structural design standards, the system is developed using C# programming language and the Revit API. By automating rebar modeling, this system aims to minimize human error, reduce labor-intensive tasks, and enhance overall rebar construction efficiency through the effective utilization of generated rebar model data.

Simulation of crop growth under an intercropping condition using an object oriented crop model (객체지향적 작물 모델을 활용한 간작조건에서의 작물 생육 모의)

  • Kim, Kwang Soo;Yoo, Byoung Hyun;Hyun, Shinwoo;Seo, Beom-Seok;Ban, Ho-Young;Park, Jinyu;Lee, Byun-Woo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.2
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    • pp.214-227
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    • 2018
  • An object oriented crop model was developed to perform crop growth simulation taking into account complex interaction between biotic and abiotic factors in an agricultural ecosystem. A set of classes including Atmosphere class, Plant class, Soil class, and Grower class were designed to represent weather, crop, soil, and crop management, respectively. Objects, which are instance of class, were linked to construct an integrated system for crop growth simulation. In a case study, yield of corn and soybean, which was obtained at an experiment farm in Rural Development Administration from 1984 to 1986, were compared with yield simulated using the integrated system. The integrated system had relatively low error rate of corn yield, e.g., <4%, under sole and intercropping conditions. In contrast, the system had a relatively large underestimation error for above ground biomass except for grain compared with those observed for corn and soybean. For example, estimates of biomass of corn leaf and stem was 31% lower than those of observed values. Although the integrated system consisted of simple models, the system was capable of simulating crop yield under an intercropping condition. This result suggested that an existing process-based model would be used to have more realistic simulation of crop growth once it is reengineered to be compatible to the integration system, which merits further studies for crop model improvement and implementation in object oriented paradigm.

Optimum Design of Two Hinged Steel Arches with I Sectional Type (SUMT법(法)에 의(依)한 2골절(滑節) I형(形) 강재(鋼材) 아치의 최적설계(最適設計))

  • Jung, Young Chae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.3
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    • pp.65-79
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    • 1992
  • This study is concerned with the optimal design of two hinged steel arches with I cross sectional type and aimed at the exact analysis of the arches and the safe and economic design of structure. The analyzing method of arches which introduces the finite difference method considering the displacements of structure in analyzing process is used to eliminate the error of analysis and to determine the sectional force of structure. The optimizing problems of arches formulate with the objective functions and the constraints which take the sectional dimensions(B, D, $t_f$, $t_w$) as the design variables. The object functions are formulated as the total weight of arch and the constraints are derived by using the criteria with respect to the working stress, the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge and including the economic depth constraint of the I sectional type, the upper limit dimension of the depth of web and the lower limit dimension of the breadth of flange. The SUMT method using the modified Newton Raphson direction method is introduced to solve the formulated nonlinear programming problems which developed in this study and tested out throught the numerical examples. The developed optimal design programming of arch is tested out and examined throught the numerical examples for the various arches. And their results are compared and analyzed to examine the possibility of optimization, the applicablity, the convergency of this algorithm and with the results of numerical examples using the reference(30). The correlative equations between the optimal sectional areas and inertia moments are introduced from the various numerical optimal design results in this study.

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A Comparison of the Effects of Optimization Learning Rates using a Modified Learning Process for Generalized Neural Network (일반화 신경망의 개선된 학습 과정을 위한 최적화 신경망 학습률들의 효율성 비교)

  • Yoon, Yeochang;Lee, Sungduck
    • The Korean Journal of Applied Statistics
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    • v.26 no.5
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    • pp.847-856
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    • 2013
  • We propose a modified learning process for generalized neural network using a learning algorithm by Liu et al. (2001). We consider the effect of initial weights, training results and learning errors using a modified learning process. We employ an incremental training procedure where training patterns are learned systematically. Our algorithm starts with a single training pattern and a single hidden layer neuron. During the course of neural network training, we try to escape from the local minimum by using a weight scaling technique. We allow the network to grow by adding a hidden layer neuron only after several consecutive failed attempts to escape from a local minimum. Our optimization procedure tends to make the network reach the error tolerance with no or little training after the addition of a hidden layer neuron. Simulation results with suitable initial weights indicate that the present constructive algorithm can obtain neural networks very close to minimal structures and that convergence to a solution in neural network training can be guaranteed. We tested these algorithms extensively with small training sets.

A Pattern Language for the Reactive Agent Framework (반응적 에이전트 프레임워크를 위한 패턴 언어)

  • 박성운;정재민;박수용
    • Journal of KIISE:Software and Applications
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    • v.31 no.3
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    • pp.317-331
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    • 2004
  • Recently software agent has been studied as a new abstraction unit of software engineering. The agent with autonomous, adaptability and cooperation attribute is accepted as a new abstraction unit especially in distributed systems, open systems, and complex systems. However, the progress of agent research has been slow and the realization of agent programming language seems to be far distant. Because the properties of agent are diverse, the opinions of researchers can not converge to one. In this situation, software agent framework is accepted more realistic alternative solution. However the knowledge for its development doesn't have been shared among developers. So they often have to make same errors. We will help sharing of knowledge and experience by using pattern language which has been used in object technology for long times. This paper proposes a reactive agent framework pattern language and validates it based on ATAM[l] The increase of such indirect experience can reduce the waste of resource by preventing the same try and error. So agent framework developers are able to concentrate on more essential issues. Finally quality of software agent framework will be increased.

Design and Control of Ultra-precision Dual Stage with Air bearings and Voice coil motor for nm scanning system (나노 정밀도 스캐닝 용 공기베어링과 보이스 코일 모터의 초정밀 이중 스테이지 설계 및 제어)

  • Kim K.H.;Choi Y.M.;Kim J.J.;Lee M.G.;Lee S.W.;Gweon D.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1883-1886
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    • 2005
  • In this paper, a decoupled dual servo (DDS) stage for ultra-precision scanning system with large working range is introduced. In general, dual servo systems consist of a fine stage for short range and a coarse stage for long range. The proposed DDS also consists of a $XY\theta$ fine stage for handling and carrying workpieces and one axis coarse stage. Its coarse stage consists of air bearing guide system and a coreless linear motor with force ripple. The fine has four voice coil motors(VCM) as its actuator. According to a VCM's nature, there are no mechanical connections between coils and magnetic circuits. Moreover, VCM doesn't have force ripples due to imperfections of commutation components of linear motor systems - currents and flux densities. However, due to the VCM's mechanical constraints the working range of the fine is about $25mm^2$. To break that hurdle, the coarse stage with linear motors is used to move the fine about 500mm. Because of the above reasons, the proposed DDS can achieve higher precision scanning than other stages with only one servo. With MATLAB's Sequential Quadratic Programming (SQP), the VCMs are optimally designed for the highest force under conditions and constraints such as thermal dissipations due to its coil, its size, and so on. And for their movements without any frictions, guide systems of the DDS are composed of air bearings. To get precisely their positions, a linear scale with 5nm resolution are used for the coarse stage's motion and three plane mirror laser interferometers with 5nm for the fine's $XY\theta$ motions. With them, on scanning the two stages have same trajectories. The control algorithm is named Parallel method. The embodied ultra-precision scanning system has sub 100nm following error and in-positioning stability.

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A Study on the Construction of Database, Online Management System, and Analysis Instrument for Biological Diversity Data (생물다양성 자료의 데이터베이스화와 온라인 관리시스템 및 분석도구 구축에 관한 연구)

  • Bec Kee-Yul;Jung Jong-Chul;Park Seon-Joo;Lee Jong-Wook
    • Journal of Environmental Science International
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    • v.14 no.12
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    • pp.1119-1127
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    • 2005
  • The management of data on biological diversity is presently complex and confusing. This study was initiated to construct a database so that such data could be stored in a data management, and analysis instrument to correct the problems inherent in the current incoherent storage methods. MySQL was used in DBMS(DataBase Management System), and the program was basically produced using Java technology Also, the program was developed so people could adapt to the requirements that are changing every minute. We hope this was accomplished by modifying easily and quickly the advanced programming technology and patterns. To this end, an effective and flexible database schema was devised to store and analyze diversity databases. Even users with no knowledge of databases should be able to access this management instrument and easily manage the database through the World Wide Web. On a basis of databases stored in this manner, it could become routinely used for various databases using this analysis instrument supplied on the World Wide Web. Supplying the derived results by using a simple table and making results visible using simple charts, researchers could easily adapt these methods to various data analyses. As the diversity data was stored in a database, not in a general file, this study makes the precise, error-free and high -quality storage in a consistent manner. The methods proposed here should also minimize the errors that might appear in each data search, data movement, or data conversion by supplying management instrumentation on the Web. Also, this study was to deduce the various results to the level we required and execute the comparative analysis without the lengthy time necessary to supply the analytical instrument with similar results as provided by various other methods of analysis. The results of this research may be summerized as follows: 1)This study suggests methods of storage by giving consistency to diversity data. 2)This study prepared a suggested foundation for comparative analysis of various data. 3)It may suggest further research, which could lead to more and better standardization of diversity data and to better methods for predicting changes in species diversity.