• 터널과지하공간
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• 제22권6호
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• pp.412-428
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• 2012

본 연구에서는 재개광을 계획하고 있는 (구)양양철광의 수갱광체를 연구대상으로 설정하고 이를 재개광하기 위한 운반시스템의 구축을 목적으로 광체 및 광체 주변의 지질구조와 구갱도 현황 및 신갱도 개설 계획을 3차원으로 모델링 하였다. 연구에 사용된 software는 GEMCOM사(社)의 GEMS로써 3차원의 매장량평가, 개발타당성 평가, 운영 관리용 프로그램이다. 2차원 지형도와 지표 지질도를 자료로 하여 지표 지형 및 지질을 3차원으로 모델링 하였으며 (구)양양철광 개발 당시 작성된 지질 단면도와 시추자료를 토대로 연구대상지역의 지질 구조 및 광체를 3차원적으로 생성하였다. 수갱광체는 충전된 채굴적, 공동, 잔광으로 구분하여 모델링하고 잔광부의 품위에 대한 시추 정보로부터 지구통계학적 기법을 적용하여 품위별 매장량 평가 결과를 얻을 수 있었다. 또한 기존 2차원 구갱도 개설 현황 자료를 이용하여 구갱도에 대한 3차원 모델링을 수행하였고, 무궤도 운반 시스템의 적용을 고려하여 신갱도의 크기와 배치를 3차원으로 설계하였다. 완성된 광체 및 운반 시스템의 3차원 모델을 이용하여 지하선광장의 위치를 선정하였다. 마지막으로 채취한 시료의 암석 물성값들을 기초로 광체 주위에 부존하는 물성을 암종별로 입력하고 지구통계학적 기법을 통해 미조사 부분에 대한 암석물성을 추정할 수 있는 3차원 공학적 모델링을 수행하였다. 이러한 과정을 통하여 얻어진 재개광 광산의 3차원 모델은 매장량 평가 및 개발계획 수립, 추가 탐사 지역의 선정이나 개발 계획의 변경 등의 문제들을 해결하고 체계적이고도 지속적인 광산 개발 기술 확립에 기여할 수 있을 것이다.

• 융합보안논문지
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• 제10권4호
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• pp.39-48
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• 2010

복잡한 환경에서 안전한 IT환경은 하나이상으로 분리된 데이터의 그룹으로 나뉘어 같은 시스템에 상주하지 않게 함으로서 그 목적을 얻을 수 있다. 이러한 시스템의 사용자는 특정 데이터에 접근하는 방법과 등급을 다르게 하여야 한다. 정보구조, 물리적 구조, 사용자 권한 및 응용프로그램 보안 정책을 위한 유지 보수 등은 이러한 환경 관리를 더욱 복잡하게 하고 보안 관리자의 수의 증가를 가져온다. 본 논문은 이러한 환경관리를 위한 CM 툴을 시스템 공학의 CASE 툴을 모델로 하여 제안하고자 한다. 시스템 공학의 모델링 기법은 다중 정보 보안을 처리하는 데 사용할 수 있다. SE의 CASE 툴 모델은 동일 시스템에 대한 논리와 물리적인 관리를 쉽게 할 수 있는 중요한 구성 요소를 가지게 된다. CASE 툴의 확장된 영역은 물리적인 CM 툴을 사용자 친화적이고 안전한 IT시스템의 관리 환경의 문제점을 해결하는 기본을 제공하게 될 것이다.

• 새물리
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• 제68권12호
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• pp.1364-1373
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• 2018

사람의 생각을 사람들이 인지할 수 있게 표현한 인문학적 기호를 물리학적 기호로 체계적으로 변환한다. 기호를 체계적으로 사용하는 언어의 개념 구조를 수학적 형식으로 정리하고, 합리적인 개인의 선택을 함수로 표현하는 효용을 도입하였다. 일관성을 도입하여 효용을 보편화하고, 언어의 개념구조와 호환되게 함수를 구성하였고, 확률 형태로 변형하였다. 확률에 대한 랜덤변수를 도입하고, 물리적 위치 변수와 랜덤변수를 연결하여 물리학적 기호를 도입하였다. 기호변화의 패턴을 유도하고 물리적 기호의 변화모델을 구성하였다. 모델은 점프형, 표류형과 확산형 변화 패턴을 예측하고, 주가흐름의 패턴에서 약 2분, 약 3.5분과 약 6분 정도에 나타나는 것을 보였다. 또한 인문학적인 도상기호, 상징기호와 지표기호가 모델에서 예측되는 것을 보였다.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.374-388
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• 2022

Cloud computing has been one of the most critical technology in the last few decades. It has been invented for several purposes as an example meeting the user requirements and is to satisfy the needs of the user in simple ways. Since cloud computing has been invented, it had followed the traditional approaches in elasticity, which is the key characteristic of cloud computing. Elasticity is that feature in cloud computing which is seeking to meet the needs of the user's with no interruption at run time. There are traditional approaches to do elasticity which have been conducted for several years and have been done with different modelling of mathematical. Even though mathematical modellings have done a forward step in meeting the user's needs, there is still a lack in the optimisation of elasticity. To optimise the elasticity in the cloud, it could be better to benefit of Machine Learning algorithms to predict upcoming workloads and assign them to the scheduling algorithm which would achieve an excellent provision of the cloud services and would improve the Quality of Service (QoS) and save power consumption. Therefore, this paper aims to investigate the use of machine learning techniques in order to predict the workload of Physical Hosts (PH) on the cloud and their energy consumption. The environment of the cloud will be the school of computing cloud testbed (SoC) which will host the experiments. The experiments will take on real applications with different behaviours, by changing workloads over time. The results of the experiments demonstrate that our machine learning techniques used in scheduling algorithm is able to predict the workload of physical hosts (CPU utilisation) and that would contribute to reducing power consumption by scheduling the upcoming virtual machines to the lowest CPU utilisation in the environment of physical hosts. Additionally, there are a number of tools, which are used and explored in this paper, such as the WEKA tool to train the real data to explore Machine learning algorithms and the Zabbix tool to monitor the power consumption before and after scheduling the virtual machines to physical hosts. Moreover, the methodology of the paper is the agile approach that helps us in achieving our solution and managing our paper effectively.

• 시스템엔지니어링학술지
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• 제12권2호
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• pp.101-114
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• 2016

A model-based systems engineering (MBSE) approach to implementing hardware-based network cybersecurity controls for APR1400 non-safety data network is presented in this work. The proposed design was developed by implementing packet filtering and deep packet inspection functions to control the unauthorized traffic and malicious contents. Denial-of-Service (DoS) attack was considered as a potential cybersecurity issue that may threaten the data availability and integrity of DCS gateway servers. Logical design architecture was developed to simulate the behavior of functions flow. HDL-based physical architecture was modelled and simulated using Xilinx ISE software to verify the design functionality. For effective modelling process, enhanced function flow block diagrams (EFFBDs) and schematic design based on FPGA technology were together developed and simulated to verify the performance and functional requirements of network security controls. Both logical and physical design architectures verified that hardware-based cybersecurity controls are capable to maintain the data availability and integrity. Further works focus on implementing the schematic design to an FPGA platform to accomplish the design verification and validation processes.

• Wind and Structures
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• 제19권6호
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• pp.623-647
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• 2014

In this paper, a probability distribution which is consistent with the observed phenomenon at the roof corner and, also on other portions of the roof, of a low-rise building is proposed. The model is consistent with the choice of probability density function suggested by the statistical thermodynamics of open systems and turbulence modelling in fluid mechanics. After presenting the justification based on physical phenomenon and based on statistical arguments, the fit of alpha-stable distribution for prediction of extreme negative wind pressure coefficients is explored. The predictions are compared with those actually observed during wind tunnel experiments (using wind tunnel experimental data obtained from the aerodynamic database of Tokyo Polytechnic University), and those predicted by using Gumbel minimum and Hermite polynomial model. The predictions are also compared with those estimated using a recently proposed non-parametric model in regions where stability criterion (in skewness-kurtosis space) is satisfied. From the comparisons, it is noted that the proposed model can be used to estimate the extreme peak negative wind pressure coefficients. The model has an advantage that it is consistent with the physical processes proposed in the literature for explaining large fluctuations at the roof corners.

• Wind and Structures
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• 제30권1호
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• pp.69-83
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• 2020

Modelling incompressible, neutrally stratified, barotropic, horizontally homogeneous and steady-state atmospheric boundary layer (ABL) is an important aspect in computational wind engineering (CWE) applications. The ABL flow can be viewed as a balance of the horizontal pressure gradient force, the Coriolis force and the turbulent stress divergence. While much research has focused on the increase of the wind velocity with height, the Ekman layer effects, entailing veering - the change of the wind velocity direction with height, are far less concerned in wind engineering. In this paper, a modified k-ε model is introduced for the ABL simulation considering wind veering. The self-sustainable method is discussed in detail including the precursor simulation, main simulation and near-ground physical quantities adjustment. Comparisons are presented among the simulation results, field measurement values and the wind profiles used in the conventional wind tunnel test. The studies show that the modified k-ε model simulation results are consistent with field measurement values. The self-sustainable method is effective to maintain the ABL physical quantities in an empty domain. The wind profiles used in the conventional wind tunnel test have deficiencies in the prediction of upper-level winds. The studies in this paper support future practical super high-rise buildings design in CWE.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.970-979
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• 2006

Construction of underground structure requires higher standard of planning and design specifications than in surface construction. However, high construction cost and difficult working environment limit design level and construction quality. One of the most sensitive factors to be considered are infiltration and external pore-water pressures. Development of pore-water pressure may accelerate leakage and cause deterioration of the lining. In this paper, the development of pore-water pressure and its potential effect on the linings are investigated using physical model tests. A simple physical equipment model with well-defined hydraulic boundary conditions was devised. The deterioration procedure was simulated by controlling both the permeability of filters and flowrate. Development of pore-water pressure was monitored on the lining using pore pressure measurement cells. Test results identified the mechanim of pore-water pressure development on the tunnel lining which is the effect of deterioration of drainage system. The laboratory tests were simulated using coupled numerical method, and shown that the deterioration mechanism can be reproduced using coupled numerical modelling method.

• Coupled systems mechanics
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• 제3권3호
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• pp.267-289
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• 2014

A proper physical modeling of infilled building frame-foundation beam-soil mass interaction system is needed to predict more realistic and accurate structural behavior under static vertical loading. This is achieved via finite element method considering the superstructure, foundation and soil mass as a single integral compatible structural unit. The physical modelling is achieved via use of finite element method, which requires the use of variety of isoparametric elements with different degrees of freedom. The unbounded domain of the soil mass has been discretized with coupled finite-infinite elements to achieve computational economy. The nonlinearity of soil mass plays an important role in the redistribution of forces in the superstructure. The nonlinear behaviour of the soil mass is modeled using hyperbolic model. The incremental-iterative nonlinear solution algorithm has been adopted for carrying out the nonlinear elastic interaction analysis of a two-bay two-storey infilled building frame. The frame and the infill have been considered to behave in linear elastic manner, whereas the subsoil in nonlinear elastic manner. In this paper, the computational methodology adopted for nonlinear soil-structure interaction analysis of infilled frame-foundation-soil system has been presented.

• Geomechanics and Engineering
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• 제12권6호
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• pp.983-1001
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• 2017

The extent by which economy and safety concerns can be addressed in earth retaining structure design depends on the accuracy of the assumed failure surface. Accordingly, this study attempts to investigate and quantify mechanical backfill properties that control failure surface geometry of cohesionless backfills at the active state for translational mode of wall movements. For this purpose, a small scale 1 g physical model study was conducted. The experimental setup simulated the conditions of a backfill behind a laterally translating vertical retaining wall in plane strain conditions. To monitor the influence of dilative behavior on failure surface geometry, model tests were conducted on backfills with different densities corresponding to different dilation angles. Failure surface geometries were identified using particle image velocimetry (PIV) method. Friction and dilation angles of the backfill are calculated as functions of failure stress state and relative density of the backfill using a well-known empirical equation, making it possible to quantify the influence of dilation angle on failure surface geometry. As a result, an empirical equation is proposed to predict active failure surface geometry for cohesionless backfills based on peak dilatancy angle. It is shown that the failure surface geometries calculated using the proposed equation are in good agreement with the identified failure surfaces.