• Nuclear Engineering and Technology
• /
• 제19권4호
• /
• pp.266-278
• /
• 1987

이 논문은 원자력발전소의 안전성 규제를 위한 성능 기준을 설정하는데 야기되는 몇가지 문제점을 다룬다. 저층 성능 기준을 설정하는 것이 고충 성능 기준을 설정하는 것보다 훨씬 더 어려운 과제이기 때문에, 저층 성능 기준은 보다 쉽게 결정될 수 있는 고충 성능기준으로부터 그와 부합되게 유도되어야 한다. 본 논문은 또한, 평균치-평균치 mapping에 의거한 신뢰도 할당 방법론을 상태변수가 불확실한 stochastic 다목적 최적화 문제로 적용 확장함으로써 성능 기준의 불확실성을 규명하는 몇 가지 방법을 제안한다.

• 한국전자통신학회논문지
• /
• 제15권2호
• /
• pp.237-244
• /
• 2020

본 논문은 2차원 공간에서 SLAM(: Simultaneous Localization and Mapping)의 구현을 설명한다. 본 논문에서 사용한 방법은 불변량이라고 하는 변수가 일정하게 유지 될 때 변환된 변수가 선형 공간을 구성하도록 상태 변수와 측정 변수를 변환하는 IEKF(: Invariant extended Kalman filter)를 사용한다. 따라서, IEKF는 불변량이 일정하게 유지되는 경우 수렴을 보장한다. 제안된 IEKF 접근법 중 변환을 하는 과정에서는 리군(Lie group) 행렬을 사용한다. 이 방법은 시뮬레이션을 통해 테스트 되었으며 결과는 선형 칼만 필터의 경우와 마찬가지로 칼만 이득이 일정하다는 것을 보여준다. 즉, 시뮬레이션 결과 이동체의 추정된 위치와 검출된 물체들 사이의 일관성을 보였다.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권7호
• /
• pp.279-291
• /
• 2020

This study aims to develop the concept of innovation models with the marketing channel construct approach, marketing innovation, product segmentation, and customer insight; as well as improvements to the theory of resource-based combined with the method of service-dominant logic. This study approach is based on quantitative descriptive conducted with three stages of testing scenarios. The first test is the mapping of the innovation model construct through testing the validity and reliability with the moderation of customer orientation variables. The second scenario examines the relationship of influence between the independent variables on the dependent variable of 29 hypothetical analysis equation modeling. The unit of analysis was conducted on 497 SMEs involved in the food and beverage sectors, with the criteria being SMEs must have a rating of 4-5 points on the Go-Food applications software. The results shown that: 1) the construct used to develop an innovative model both directly and via moderation is positive and significant; 2) Through a complicated relationship that involves all components of the variable, it outlines a positive and significant effect except for the path of analysis (μ5). The theoretical and managerial implications state that the service-dominant logic approach and resource-based view theory have extreme reliability and interrelations.

• 한국정밀공학회지
• /
• 제13권10호
• /
• pp.78-87
• /
• 1996

In this paper, a remeshing criterion has been suggested in order to order to automate the remeshing decision during finite element analysis of metal forming. In order to use for the remeshing decision, two of remeshing criteria have been investigated. One is the use of error estimates based on errors in stresses and strain rate of the finite element solution and the other is the use of geometric characterisreics of distorted elements. As a result, the strain rate error estimate in power norm based on the former is found to give more valuable information about remeshing decision than the ones based on the latter. Examples are given to demon- strate the usefulness of the suggested eroor estimate as a remeshing criterion.

• 한국분말재료학회지
• /
• 제30권1호
• /
• pp.29-34
• /
• 2023

A fixed-point iteration is proposed to integrate the stress and state variables in the incremental analysis of plastic deformation. The Conventional Newton-Raphson method requires a second-order derivative of the yield function to generate a complicated code, and the convergence cannot be guaranteed beforehand. The proposed fixed-point iteration does not require a second-order derivative of the yield function, and convergence is ensured for a given strain increment. The fixed-point iteration is easier to implement, and the computational time is shortened compared with the Newton-Raphson method. The plane-stress condition is considered for the biaxial loading conditions to confirm the convergence of the fixed-point iteration. 3-dimensional tensile specimen is considered to compare the computational times in the ABAQUS/explicit finite element analysis.

• Water Engineering Research
• /
• 제6권2호
• /
• pp.39-48
• /
• 2005

The Brazos River is one of the longest rivers contained entirely in the state of Texas, flowing over 700 miles from northwest Texas to the Gulf of Mexico. Today, the Brazos River Authority and Texas Commission on Environmental Quality interest in drought protection plan, waterpower project, and allowing the appropriation of water system-wide and water right within the Brazos River Basin to meet water needs of customers like farmers and local civilians in the future. Especially, this purpose of this paper primarily intended to provide the data for the engineering guidelines and make easily geological mapping tool. In the Brazos River basin, many stream-flow gage station sites are not working, and they can not provide stream-flow data sets enough for development of the Probable Maximum Flood (PMF) for use in the evaluation of proposed and existing dams and other impounding structures. Integrated GIS-Spatial Interpolation (GIS-SI) tool are composed of two parts; (1) extended GIS technique (new making interface for hydrological regionalization parameters plus classical GIS mapping skills), (2) Spatial Interpolation technique using weighting factors from kriging method. They are obtained from the relationship among location and elevation of geological watershed and existing stream-flow datasets. GIS-SI technique is easily used to compute parameters which get drainage areas, mean daily/monthly/annual precipitation, and weighted values. Also, they are independent variables of multiple linear regressions for simulation at un gaged stream-flow sites. In this study, GIS-SI technique is applied to the Brazos river basin in Texas. By assuming the ungaged flow at the sites of Palo Pinto, Bryan and Needville, the simulated daily/monthly/annual time series are compared with observed time series. The simulated daily/monthly/annual time series are highly correlated with and well fitted to the observed times series.

• Wind and Structures
• /
• 제16권5호
• /
• pp.433-455
• /
• 2013

A phase delay spectrum model towards the representation of spatial coherence of stochastic wind fields is proposed. Different from the classical coherence functions used in the spectral representation methods, the model is derived from the comprehensive description of coherence of fluctuating wind speeds and from the thorough analysis of physical accounts of random factors affecting phase delay, building up a consistent mapping between the simulated fluctuating wind speeds and the basic random variables. It thus includes complete probabilistic information of spatial stochastic wind fields. This treatment prompts a ready and succinct scheme for the simulation of fluctuating wind speeds, and provides a new perspective to the accurate assessment of dynamic reliability of wind-induced structures. Numerical investigations and comparative studies indicate that the developed model is of rationality and of applicability which matches well with the measured data at spatial points of wind fields, whereby the phase spectra at defined datum mark and objective point are feasibly obtained using the numerical scheme associated with the starting-time of phase evolution. In conjunction with the stochastic Fourier amplitude spectrum that we developed previously, the time history of fluctuating wind speeds at any spatial points of wind fields can be readily simulated.

• Asian Journal of Atmospheric Environment
• /
• 제12권3호
• /
• pp.232-243
• /
• 2018

The construction, development and maintenance of an economically, environmentally and socially sustainable campus involves the integration of measuring tools and technical information that invites and encourages the community to know the actual state to generate positive actions for reducing the negative impacts over the local environment. At the Universidad Nacional de Colombia - Campus $Bogot{\acute{a}}$, a public area with daily traffic of more than 25000 people, the Environmental Management Bureau has committed with the monitoring of the noise pollution and air quality, as support to the campaigns aiming to reduce the pollutant emissions associated to the student's activities and campus operation. The target of this study is based in the implementation of mobile air quality and sonometry monitoring equipment, the mapping of the actual air quality and noise pollution inside the university campus as a novel methodology for a sub-area inside a megacity. This results and mapping are proposed as planning tool for the institution administrative sections. A mobile Kunak$^{(R)}$ Air & OPC air monitoring station with the capability to measure particulate matter $PM_{10}$, $PM_{2.5}$, Ozone ($O_3$), Sulfur Oxide ($SO_2$), Carbon Monoxide (CO) and Nitrogen Oxide ($NO_2$) as well as Temperature, Relative Humidity and Latitude and Longitude coordinates for the data georeferenciation; and a sonometer Cirrus$^{(R)}$ 162B Class 2 were used to perform the measurements. The measurements took place in conditions of academic activity and without it, with the aim of identify the impacts generated by the campus operation. Using the free code geographical information software QGIS$^{(R)}$ 2.18, the maps of each variable measured were developed, and the impacts generated by the operation of the campus were identified qualitative and quantitively. For the measured variables, an increase of around 21% for the $L_{Aeq}$ noise level and around 80% to 90% for air pollution were detected during the operation period.

• 해양환경안전학회지
• /
• 제22권5호
• /
• pp.423-429
• /
• 2016

본 연구에서는 시스템 다이내믹스 기법을 적용하여 기름유출사고의 동태적 현상을 분석하고, 기름유출 사고초기 사고해역의 위험성을 판단할 수 있도록 기름유출사고의 사고이력에 기초하여 해역별 위험도를 산출하고 위험도 프로그램을 개발하였다. 이를 통해 다음의 결과를 얻었다. 첫째, 기름유출사고 고유데이터를 기초하여 전혀 다른 변수를 단일점수로 산출했으며, 해역별 기름유출 위험도를 정량적인 수치로 산출했다. 둘째, 산출된 사고별 위험도로 해역별 위험도를 도출했으며 이용의 극대화를 위해 스마트기기에서 실행기 가능한 프로그램을 구현했다. 셋째, 우리나라 해역별 기름오염 위험도를 직접적으로 비교평가가 가능해졌으며, 긴급시 신속한 의사결정을 유도할 수 있다. 기름유출사고 위험도를 특별한 제약없이 편리하고 신속하게 판단할 수 있게 됨에 따라 기름유출사고의 선제적인 대비(전략)에 도움을 줄 수 있을 것이라 판단된다.

• 한국HCI학회:학술대회논문집
• /
• 한국HCI학회 2009년도 학술대회
• /
• pp.961-970
• /
• 2009

지난 10여 년 동안 모바일폰과 같은 인터랙티브 기기들은 새로운 버전이 나올 때마다 새로운 기능들이 덧붙여지면서 점점 더 사용하기 복잡해졌다. 다기능 복합기기의 사용 복잡도를 줄이기 위한 한 가지 방법은 그것을 일관성 있게 설계하는 것이다. 일관성을 정의하기가 쉽지 않고 때로는 일관성 있게 디자인한 것이 오히려 사용성을 낮추는 경우도 존재하지만, 일반적으로 일관성 있게 설계된 시스템은 그 사용법을 더 배우기 쉽고, 기억하기 쉬우며, 에러가 덜 발생한다. 그러나 실제적으로 다기능 복합기기의 사용자 인터랙션 또는 인터페이스를 일관성 있게 설계하는 일은 쉽지 않다. 다기능 기기의 인터랙션 설계는 매우 많은 수의 설계 변수들과 그것들 간의 관계를 고려해야 하므로 많은 시간이 소요되고 디자인 에러가 발생하기 쉽다. 따라서, 이런 복잡한 설계 과정을 지원할 수 있는 방법론의 개발이 필요하다. 본 연구에서는 CUID (Consistent Design of User Interaction)라고 명명한 효과적이고 효율적인 인터랙션 설계 방법론을 개발하였다. CUID는 일관성 있는 인터랙션 설계를 위한 디자인 프로세스와 그것을 지원하는 소프트웨어 툴을 포함한다. 이 방법론은 물리적 또는 시각적인 일관성보다는 논리적 일관성에 초점을 맞추고 있으며, 태스크 절차의 설계, 각 시스템 상태에서 가능해야 하는 조작(기능)에 대한 결정, 그리고 가능한 조작(기능)들을 어떤 인터페이스 컨트롤(control)을 통해 수행하도록 할 것인지에 대한 결정을 주요한 설계 문제로 다룬다. 또한, 본 논문에서는 사례 연구를 통해 CUID의 효용성을 검증하였다.