• Title/Summary/Keyword: M/M/1 model

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A Study on SE Process based Defense M&S System Development Procedures (SE 프로세스 기반 국방 M&S체계 개발 절차 연구)

  • Dong Joon Lee;Seong Hyun Koh;Sang Bok Lee;Kwan Ghyun Ro;Ju Il Yoon
    • Journal of the Korean Society of Systems Engineering
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    • v.19 no.1
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    • pp.44-55
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    • 2023
  • The defense M&S system, which has been classified as a weapon system between requirements determination and project implementation, is being developed by applying the weapon system development procedure of the Defense Acquisition Program Administration. The M&S system abstracts and models the real world to suit the intended use and proceeds with the process of developing it as a software-oriented system. Overseas, the conceptual model development stage is staged before entering the design stage after the requirements analysis. In addition, each step includes verification and validation processes. In Korea, while establishing and applying the weapon system development procedure based on the SE process, the M&S system is also applied in the same way as the general weapon system, limiting appropriate development outputs and verification and validation. In this study, the system development procedure of the M&S system is established and presented based on the relevant standards and SE process of developed countries.

A multi-phase model for predicting the effective chloride migration coefficient of ITZ in cement-based materials

  • Yang, C.C.;Weng, S.H.
    • Advances in concrete construction
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    • v.1 no.3
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    • pp.239-252
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    • 2013
  • Mortar microstructure is considered as a three-phase composite material, which is cement paste, fine aggregate and interfacial transition zone. Interfacial transition zone is the weakest link between the cement paste and fine aggregate, so it has a significant role to determine the properties of cementitious composites. In this study, specimens (w/c = 0.35, 0.45, 0.55) with various volume fractions of fine aggregate ($V_f$ = 0, 0.1, 0.2, 0.3 and 0.4) were cast and tested. To predict the equivalent migration coefficient ($M_e$) and migration coefficient of interfacial transition zone ($M_{itz}$), double-inclusion method and Mori-Tanaka theory were used to estimate. There are two stages to estimate and calculate the thickness of interfacial transition zone (h) and migration coefficient of interfacial transition zone ($M_{itz}$). The first stage, the data of experimental chloride ion migration coefficient ($M_s$) was used to calculate the equivalent migration coefficient of fine aggregate with interfacial transition zone ($M_e$) by Mori-Tanaka theory. The second stage, the thickness of interfacial transition zone (h) and migration coefficient of interfacial transition zone ($M_{itz}$) was calculated by Hori and Nemat-Nasser's double inclusion model. Between the theoretical and experimental data a comparison was conducted to investigate the behavior of interfacial transition zone in mortar and the effect of interfacial transition zone on the chloride migration coefficient, the results indicated that the numerical simulations is derived to the $M_{itz}/M_m$ ratio is 2.11~8.28. Additionally, thickness of interfacial transition zone is predicted from $10{\mu}m$, 60 to $80{\mu}m$, 70 to $100{\mu}m$ and 90 to $130{\mu}m$ for SM30, M35, M45 and M55, respectively.

Optimization of Growth Environment in the Enclosed Plant Production System Using Photosynthesis Efficiency Model (광합성효율 모델을 이용한 밀폐형 식물 생산시스템의 재배환경 최적화)

  • Kim Keesung;Kim Moon Ki;Nam Sang Woon
    • Journal of Bio-Environment Control
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    • v.13 no.4
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    • pp.209-216
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    • 2004
  • This study was aimed to assess the effects of microclimate factors on lettuce chlorophyll fluorescent responses and to develop an environment control system for plant growth by adopting a simple genetic algorithm. The photosynthetic responses measurements were repeated by changing one factor among six climatic factors at a time. The maximum Fv'/Fm' resulted when the ambient temperature was $21^{\circ}C,\;CO_2$ concentration range of 1,200 to 1,400 ppm, relative humidity of $68\%$, air current speed of $1.4m{\cdot}s^{-1}$, and the temperature of nutrient solution of $20^{\circ}C$. In PPF greater than $140{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, Fv'/Fm' values were decreased. To estimate the effects of combined microclimate factors on plant growth, a photosynthesis efficiency model was developed using principle component analysis for six microclimate factors. Predicted Fv'/Fm' values showed a good agreement to measured ones with an average error of $2.5\%$. In this study, a simple genetic algorithm was applied to the photosynthesis efficiency model for optimal environmental condition for lettuce growth. Air emperature of $22^{\circ}C$, root zone temperature of $19^{\circ}C,\;CO_2$ concentration of 1,400 ppm, air current speed of $1.0m{\cdot}s^{-1}$, PPF of $430{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and relative humidity of $65\%$ were obtained. It is feasible to control plant environment optimally in response to microclimate changes by using photosynthesis efficiency model combined with genetic algorithm.

Extraction of Individual Trees and Tree Heights for Pinus rigida Forests Using UAV Images (드론 영상을 이용한 리기다소나무림의 개체목 및 수고 추출)

  • Song, Chan;Kim, Sung Yong;Lee, Sun Joo;Jang, Yong Hwan;Lee, Young Jin
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1731-1738
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    • 2021
  • The objective of this study was to extract individual trees and tree heights using UAV drone images. The study site was Gongju national university experiment forest, located in Yesan-gun, Chungcheongnam-do. The thinning intensity study sites consisted of 40% thinning, 20% thinning, 10% thinning and control. The image was filmed by using the "Mavic Pro 2" model of DJI company, and the altitude of the photo shoot was set at 80% of the overlay between 180m pictures. In order to prevent image distortion, a ground reference point was installed and the end lap and side lap were set to 80%. Tree heights were extracted using Digital Surface Model (DSM) and Digital Terrain Model (DTM), and individual trees were split and extracted using object-based analysis. As a result of individual tree extraction, thinning 40% stands showed the highest extraction rate of 109.1%, while thinning 20% showed 87.1%, thinning 10% showed 63.5%, and control sites showed 56.0% of accuracy. As a result of tree height extraction, thinning 40% showed 1.43m error compared with field survey data, while thinning 20% showed 1.73 m, thinning 10% showed 1.88 m, and control sites showed the largest error of 2.22 m.

A Study on the Data Driven Neural Network Model for the Prediction of Time Series Data: Application of Water Surface Elevation Forecasting in Hangang River Bridge (시계열 자료의 예측을 위한 자료 기반 신경망 모델에 관한 연구: 한강대교 수위예측 적용)

  • Yoo, Hyungju;Lee, Seung Oh;Choi, Seohye;Park, Moonhyung
    • Journal of Korean Society of Disaster and Security
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    • v.12 no.2
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    • pp.73-82
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    • 2019
  • Recently, as the occurrence frequency of sudden floods due to climate change increased, the flood damage on riverside social infrastructures was extended so that there has been a threat of overflow. Therefore, a rapid prediction of potential flooding in riverside social infrastructure is necessary for administrators. However, most current flood forecasting models including hydraulic model have limitations which are the high accuracy of numerical results but longer simulation time. To alleviate such limitation, data driven models using artificial neural network have been widely used. However, there is a limitation that the existing models can not consider the time-series parameters. In this study the water surface elevation of the Hangang River bridge was predicted using the NARX model considering the time-series parameter. And the results of the ANN and RNN models are compared with the NARX model to determine the suitability of NARX model. Using the 10-year hydrological data from 2009 to 2018, 70% of the hydrological data were used for learning and 15% was used for testing and evaluation respectively. As a result of predicting the water surface elevation after 3 hours from the Hangang River bridge in 2018, the ANN, RNN and NARX models for RMSE were 0.20 m, 0.11 m, and 0.09 m, respectively, and 0.12 m, 0.06 m, and 0.05 m for MAE, and 1.56 m, 0.55 m and 0.10 m for peak errors respectively. By analyzing the error of the prediction results considering the time-series parameters, the NARX model is most suitable for predicting water surface elevation. This is because the NARX model can learn the trend of the time series data and also can derive the accurate prediction value even in the high water surface elevation prediction by using the hyperbolic tangent and Rectified Linear Unit function as an activation function. However, the NARX model has a limit to generate a vanishing gradient as the sequence length becomes longer. In the future, the accuracy of the water surface elevation prediction will be examined by using the LSTM model.

Quality Assessment of Digital Surface Model Vertical Position Accuracies by Ground Control Point Location (지상기준점 선점 위치에 따른 DSM 높이 정확도 분석)

  • Lee, Jong Phil
    • Journal of Cadastre & Land InformatiX
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    • v.51 no.1
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    • pp.125-136
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    • 2021
  • Recently, Unmanned Aerial Vehicle utilization and image processing technology for remote sensing have diversified remarkably with Orthophoto and Digital Surface Model. In particular, It uses more application fields such as spatial information analysis and hazardous areas as well as land surveying. This study analyses the accuracy of the coordinate on Orthophoto and DSM height on slope area with high and low differences by using UAV images. As the result of this study, in the case of GCP on 2D orthophoto, the location error was not produced significantly. The vertical position of the DSM showed the highest accuracy when the height difference between GCPs is under 30m(RMSEZ=0.07m). The location of the GCPs was divided into approximately 10m, 20m, 30m, and 40m with analysis for each of the eight points of GCP and inspection points in general. This study expects that producing both horizontal accuracy of Orthophoto and vertical accuracy of DSM using UAV on the sloped area which similar to this research area will help in spatial information fields.

Optimal Dimension of PE Film Bag According to Fruit Size in MAP Storage of 'Fuyu' Persimmon Fruit ('부유' 단감 MAP 저장에서 과실 크기에 따른 PE 필름 봉지의 적정 규격)

  • Lee, Yong-Jae
    • Korean Journal of Food Science and Technology
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    • v.36 no.5
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    • pp.733-739
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    • 2004
  • Model for optimally dimensioned PE film bag was developed according to fruit size to maintain best quality of 'Fuyu' persimmon in modified atmosphere packaging (MAP) storage based on relationship between quality and oxygen and carbon dioxide in PE film bag. Harvested persimmons were graded into five sizes, and average weights were LL:261, L:217, M:188, S:168, and SS:154 g. Five fruit units of each grade were optimized in five PE film bag sizes of $150{\times}376,\;140{\times}357,\;130{\times}344,\;130{\times}333,\;and\;120{\times}3l8\;mm$. To minimize quality deterioration such as softening and discoloration, optimal oxygen and carbon dioxide concentrations in PE film bag were 0.5-1.0 and 6.0-8.0%, respectively, and optimal thickness of PE film bag according to fruit size were LL:45, L:50, M:55, S:60, and $SS:65\;{\mu}m$. For all fruit sizes, model for PE film bag area $(mm^2)$ was good quadratic simple equation by fruit weight (g): $Y=-4055.707+627.993X_1-0.701{X_1}^2$. Model far optimal oxygen and carbon dioxide (Y) concentration in PE film bag was suited to linear multiple equation by fruit weight $(X_1,\;g)$ and PE film thickness $(X_2,\;{\mu}m)$. Equations for oxygen and carbon dioxide concentrations (%) were $Y=5.798-0.0109X_l-0.0491X_2\;and\;Y=-2.427+0.01927X_l +0.09646X_2$, respectively.

A Study on the Theory of Simulation Rule for Scale Model Experiment in Architectural Acoustics (건축음향모형실험의 상사법칙의 이론에 관한 연구)

  • Kim, Cheon-Su;Sin, Yeong-Mu;Park, Byeong-Jeon
    • The Journal of the Acoustical Society of Korea
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    • v.13 no.1
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    • pp.93-98
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    • 1994
  • This study aims to find the theoretical consideration of the basic simularity rule between scale model experiment and real building as a results ; 1. In the case of room acoustics, $f_m=n\cdot{f_r}\;T_m=T_r/n\; \alpha_m(f_m)=\alpha_r(f_r)$ 2. That of sound Insulation : $TL_m(f_m)=TL_r(f_r)$

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5W1H based resource management model for the expansion of oneM2M standard Data Filter rules

  • Min, Seong-Hyeon;Kwak, Ho-Young;Lee, Sang-Joon
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.9
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    • pp.85-90
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    • 2016
  • In this paper, we study the domain-independent sensor data structuring method and the derivations about ' Filter Criteria' expansion factors of heterogeneous domain systems. For this purpose, we propose a 5W1H based information search and retrieval method without knowledges about the target domains. And we also suggest a resource management model that can support expanding search of information. By the suggested method, the oneM2M standard able to implement the use-cases like 'data exchanging between the heterogeneous domains'.

A Study on Conflict Management Model for IS Integration: Focusing on Banking Industry under M&A (조직간 정보시스템 통합을 위한 갈등관리모형: 은행업종의 인수.합병을 중심으로)

  • Kim, Sang-Hoon;Choi, Jeom-Ki
    • Journal of Information Technology Services
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    • v.5 no.1
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    • pp.83-95
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    • 2006
  • The main objectives of this study are (1) to identify the conflict types in IS integration process with respect to M&A, (2) to propose the ways to manage the origin of conflict to be expected, and (3) to develop the conflict management model which establishes the relationship among the M&A strategy, the IS integration strategy and change management process that influence the source of conflict. In order to achieve these research objectives, this study focuses on banking industry under M&A with the viewpoint of change management instead of existing technology-oriented IS integration strategy. The findings of this study are thought not only to be useful as a practical guideline in carrying out IS integration project under M&A but also to provide significant basis for constructing the theoretical framework of effective IS integration strategy.