• Environmental Engineering Research
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• 제19권2호
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• pp.157-163
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• 2014

The adsorption of Cr(VI) from aqueous solutions to activated carbon fiber (ACF) was investigated using both batch and flow-through column experiments. The batch experiments (adsorbent dose, 10 g/L; initial Cr(VI) concentration, 5-500 mg/L) showed that the maximum adsorption capacity of Cr(VI) to ACF was determined to 20.54 mg/g. The adsorption of Cr(VI) to ACF was sensitive to solution pH, decreasing from 9.09 to 0.66 mg/g with increasing pH from 2.6 to 9.9; the adsorption capacity was the highest at the highly acidic solution pHs. Kinetic model analysis showed that the Elovich model was the most suitable for describing the kinetic data among three (pseudo-first-order, pseudo-second-order, and Elovich) models. From the nonlinear regression analysis, the Elovich model parameter values were determined to be ${\alpha}$ = 162.65 mg/g/h and ${\beta}$ = 2.10 g/mg. Equilibrium isotherm model analysis demonstrated that among three (Langmuir, Freundlich, Redlich-Peterson) models, both Freundlich and Redlich-Peterson models were suitable for describing the equilibrium data. In the model analysis, the Redlich-Peterson model fit was superimposed on the Freundlich fit. The Freundlich model parameter values were determined to be $K_F$ = 0.52 L/g and 1/n = 0.56. The flow-through column experiments showed that the adsorption capacities of ACF in the given experimental conditions (column length, 10 cm; inner diameter, 1.5 cm; flow rate, 0.5 and 1.0 mL/min; influent Cr(VI) concentration, 10 mg/L) were in the range of 2.35-4.20 mg/g. This study demonstrated that activated carbon fiber was effective for the removal of Cr(VI) from aqueous solutions.

• 지질동맥경화학회지
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• 제7권2호
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• pp.88-97
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• 2018

The prevalence of atherothrombotic disease continues to rise, presenting an increasing number of challenges to modern society and creating interest in functional foods. Platelet activation, adhesion, and aggregation at vascular endothelial disruption sites are key events in atherothrombotic disease. Physiological challenges such as hyperlipidemia, obesity, and cigarette smoking are associated with vascular changes underlying platelet aggregation and inflammatory processes. However, it is difficult to determine the beneficial response of functional foods in healthy subjects. To address this problem, challenge models and high-risk models related to smokers, obesity, and dyslipidemia are proposed as sensitive measures to evaluate the effects of functional foods in healthy subjects. In this review, we construct a model to evaluate the effects of functional food such as natural products on blood flow based on a human intervention study.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권4호
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• pp.284-288
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• 2009

단백질 상호작용의 예측 및 실험 결과가 대용량으로 배포되면서 바이오 정보 기술 연구자들은 생명체 내의 단백질 상호작용 네트워크를 구성하기 위해 노력하여 왔다. 일반적으로 대용량의 상호작용 데이터들은 많은 오류를 포함한다고 알려져 있으나, 최근 단백질의 물리 화학적 특성 및 구조를 기반으로 한 방법들이 실제 실험과 병행되어 고화질(High resolution)의 결과를 제공하게 되면서, 특정 종에 대한 단백질 상호작용 네트워크가 점차 완성되고 있다. 그러나, 단순 물리적 링크 수준의 단백질 상호작용 네트워크만으로는 특정 병원체의 발병 메커니즘 규명 등과 같은 응용분야의 활용에 한계가 있다. 본 논문에서는 실험을 통하여 보고된 신호 전달 경로(signaling transduction pathway)를 이용하여 단백질 기능 간의 관계를 방향성이 있는 그래프로 표현한 단백질 기능 흐름 모델을 제시한다. 제안하는 모델은 Gene Ontology에서 정의된 molecular function을 정점(vertex)으로 가지고 이들 사이의 관계를 간선(edge)으로 표현함으로써 특정 기능의 전이를 살펴볼 수 있다. 이러한 기능 흐름 모델은 수 만개의 정점(vertex)으로 구성된 단백질 상호작용 네트워크에서 의미 있는 경로를 추출하는 데에 제약 혹은 참조 조건으로 사용될 수 있어 향후 활용도가 클 것으로 기대한다. 평가는 KEGG에서 제공되는 11개의 인간 신호 전달 경로 각각에 대하여 대상 경로를 제외한 나머지로부터 생성된 모델과의 크론바하 알파 계수(Cronbach's alpha)를 측정하였고(${\alpha}=0.67$), 총 1023개의 흐름 중 ${\alpha}=0.6$ 이상의 신뢰도에 대하여 총 765개의 흐름을 가지는 기능 흐름 모델을 최종 구성하였다.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2576-2583
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• 2024

In this paper, the similarity criterion and dimensionless conversion method combined with the elasticity condition and Hooke's law are used to derive the functional relationship of the maximum effective value of the vibration velocity between the prototype pump and the model pump. The seawater circulation pump of a nuclear power plant is used as the prototype pump, and the model pump is obtained by performance conversion and choosing the appropriate scale, and the vibration state of the model pump under different flow rates is measured and analyzed. The vibration data of the model pump through the function relationship to find out the vibration parameters of the prototype model pump, and compare with the vibration data of the seawater circulation pump in reality. It can be seen that with the increase of flow rate, the maximum effective value of the vibration velocity of both model and prototype decreases and then increases, and the relative error is small, the maximum value is 7.7757%. Therefore, it can be considered that the functional relationship of model pump converted to prototype pump derived in this paper can be used to analyze the vibration of the actual seawater circulation pump of coastal nuclear power plant.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.174-179
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• 2000

Proposed in the paper is a V-FMS (Virtual Flexible Manufacturing System) model to be used as a prototyping tool for FMS design. The proposed V-FMS framework follows an object-oriented modeling (OOM) paradigm and is based on a set of user requirements for FMS prototyping. The V-FMS model consists of four types of object: virtual device, transfer handler, state manager and flow controller. A virtual device model, which corresponds to a static model in OOM, consists of two parts, shell and core, for reusability. A transfer handler corresponds to a functional model of OOM and it stores low level device commands required to perform job flow operations between giving and taking devices. The state manager and the flow controller constitute a dynamic model of OOM. The proposed V-FMS model has been implemented for a couple of linear type FMS-lines

• Nuclear Engineering and Technology
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• 제46권6호
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• pp.753-772
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• 2014

The paper presents functional modelling and its application for diagnosis in nuclear power plants. Functional modelling is defined and its relevance for coping with the complexity of diagnosis in large scale systems like nuclear plants is explained. The diagnosis task is analyzed and it is demonstrated that the levels of abstraction in models for diagnosis must reflect plant knowledge about goals and functions which is represented in functional modelling. Multilevel flow modelling (MFM), which is a method for functional modelling, is introduced briefly and illustrated with a cooling system example. The use of MFM for reasoning about causes and consequences is explained in detail and demonstrated using the reasoning tool, the MFMSuite. MFM applications in nuclear power systems are described by two examples: a PWR; and an FBR reactor. The PWR example show how MFM can be used to model and reason about operating modes. The FBR example illustrates how the modelling development effort can be managed by proper strategies including decomposition and reuse.

• Management Science and Financial Engineering
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• 제3권1호
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• pp.15-38
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• 1997

In a flexible manufacturing system, a cell controller is able to identify and evaluate a number of alternative decisions to meet the objectives set by the factory level controller. In this paper, a Petri net-based cell controller is presented to accomplish this task. A static model is developed by using the Integrated Computer Aided Definition(IDEF0) method to represent clear functional relationships among the objects of the system. Based on the static model, two Petri net models are developed for the physical part flow and for the information flow. Multiple decision alternatives are generated from the physical part flow model and are synchronized with the information flow model for execution of the selected alternative.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1591-1598
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• 2011

The objective of this paper is to study how to apply the functional models in the design reviews and the validation of the subsequent design specifications and standards in the urban rail transit standardization program. The functional models can be obtained based on the requirements. Specifically, the requirements are first represented by the use case and sequence diagrams and then the results are transformed into the functional models using the Systems Modeling Language (SysML) diagrams and the FFBD (Functional Flow Block Diagram) and others. Based on the results of the study, it can be checked whether the original requirements have been reflected properly in the designs. Also, it can be seen that how the possible changes in the requirements affect the functions and thus how the designs should be changed accordingly.

• 한국수자원학회논문집
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• 제37권12호
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• pp.1055-1063
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• 2004

공간적 위치 및 유량 값에 따라 각 계산점마다 조도계수의 값이 달리 주어질 수 있도록 하는 가변 조도변수 부정류 계산모형을 수립하였다. 유량과 조도계수의 관계식으로는 계단함수 또는 멱함수를 적용할 수 있도록 하였다. 수립된 모형을 충주댐부터 팔당댐까지의 남한강 구간에 적용하여 최적화에 의한 매개변수의 추정을 수행하였다. 가변 매개변수 모형의 보정 결과, 계단함수 도형 및 멱함수 모형 모두 유량이 커질수록 조도계수가 감소하는 경향이 일관되게 나타났다. 이러한 경향은 여주 지점 상류구간의 경우에 더욱 현저한 것으로 나타났다. 가변 조도계수 모형의 매개변수 추정에 따른 오차가 고정 조도계수 모형의 경우보다 작아짐을 알 수 있었다.

• 한국전자거래학회지
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• 제1권2호
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• pp.49-76
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• 1996

An industrial process is a sequence of steps intended to perform a useful task in an industrial organization, and can be described using a model or a representation framework such as function model, information model, process flow model, etc. Many researchers, however, claim that, all those models from different perspectives are required to describe complex systems such as CIMS. Thus these perspectives should be put together to build an optimal system. And the need for interconnection or transformation among different view points has arisen for effective communications between system developers and easy propogation of local changes in a model. But it seems to be difficult to integrate such models into a unified framework as they describe different aspects of the system on different purposes. This study is an attempt to interconnect these different perspectives, and thereby to support conceptual design of systems in a more effective manner. A methodology to transform the IDEFO functional model into a process flow model is proposed. The validity of the proposed approach is tested by developing a prototye of a computer-assisted design system on the operation processes of FMS installed at Seoul National University - Automation and Systems Research Institute.