• 방사성폐기물학회지
• /
• 제21권2호
• /
• pp.205-224
• /
• 2023

The emission of off-gas streams from used fuel recycling is a concern in nuclear energy usage as they contain radioactive compounds, such as, ³H, ¹⁴C, ⁸⁵Kr, ¹³¹I, and ¹²⁹I that can be harmful to human health and environment. Radioactive iodine, ¹²⁹I, is particularly troublesome as it has a half-life of more than 15 million years and is prone to accumulate in human thyroid glands. Organic iodides are hazardous even at very low concentrations, and hence the capture of ¹²⁹I is extremely important. Dynamic adsorption experiments were conducted to determine the efficiency of sodium mordenite, partially exchanged silver mordenite, and fully exchanged silver mordenite for the removal of methyl iodide present at parts per billion concentrations in a simulated off-gas stream. Kinetic analysis of the system was conducted incorporating the effects of diffusion and mass transfer. The possible reaction mechanism is postulated and the order of the reaction and the values of the rate constants were determined from the experimental data. Adsorbent characterization is performed to investigate the nature of the adsorbent before and after iodine loading. This paper will offer a comprehensive understanding of the methyl iodide behavior when in contact with the mordenites.

• 경영정보학연구
• /
• 제19권3호
• /
• pp.179-199
• /
• 2017

멀티채널 소비자들의 크로스오버 쇼핑행동이 두드러지는 시점에서 최근 사용자 행동 메커니즘에 대한 관심이 높아지고 있다. 단순한 멀티채널 사용자행동에 대한 이해 차원을 넘어 면밀한 관찰을 통해 기존 연구방식에서 발견할 수 없었던 크로스 오버 쇼핑행동에 대한 연구 축적이 필요한 시점이라 할 수 있다. 본 연구는 근거이론(grounded theory)를 활용하여 멀티채널 사용자들이 왜, 어떻게 크로스오버 쇼핑행동을 하는지를 살펴보는데 그 목적이 있다. 본 연구에서는 총 25명의 응답자를 대상으로 인터뷰를 진행하였으며, 근거자료의 분석을 통해 118개의 개념을 추출하였고, 유사 개념간의 통합과정을 통해 28개의 범주를 제시하였다. 본 연구는 근거이론을 적용하여 기존 설문연구에서는 파악하기 어려웠던 사용자들의 동적인 탐색과 구매행동의 메커니즘을 포착함으로써 멀티채널 환경에서 설명 가능한 행동연구 방안을 제안하고 있다는 점에서 의의가 있다.

• 한국게임학회 논문지
• /
• 제14권5호
• /
• pp.127-136
• /
• 2014

게임 NPC(Non Player Character)는 게임 플레이어와 대전 또는 협력함으로써 게임의 재미를 증가시키는 중요한 요소이다. 대부분 기존 게임에서 제공되는 NPC 인공지능은 FSM(Finite State Machine)으로 제작되어 행동 패턴이 정해져 있고 능력이 동일한 특징을 갖고 있다. 따라서 이러한 특징을 갖는 NPC들과 대전하는 플레이어는 창조적인 게임 플레이를 진행하는 것이 어려울 수 있다. 본 논문은 이 문제점을 개선하기 위하여 실제 생활에서 늑대들이 먹이를 사냥하는 행동 모델을 게임 NPC의 행동 모델로 제작하고 이를 평가하기 위한 것이다. 이를 위하여 첫째, 실세계에서 늑대들이 먹이를 포획하기 위한 행동 상태들을 조사 연구한다. 둘째, 이 행동 상태들을 Unity3D 엔진을 이용하여 구현한다. 셋째, 구현된 NPC들의 상태 전이 비율과 실세계의 NPC들의 상태 전이 비율, 일반적인 게임 NPC의 상태 전이 비율을 비교한다. 비교 결과, 구현된 NPC들의 상태 전이 비율은 실세계의 상태 전이 비율과 비슷함을 보인다. 이는 구현된 NPC들의 행동 패턴이 실세계의 늑대 사냥 행동 패턴과 유사함을 의미하는데, 이렇게 함으로써 플레이어에게 보다 증가된 사용자 경험을 제공할 수 있다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제35권7호
• /
• pp.899-906
• /
• 2011

Generally, load conditions of machine or structure in fatigue destruction is occurred not under single load conditions but under mixed load conditions. However, the experiment under mixing mode is insufficient because of no having test standard to the behavior of crack under mixing mode and variety of test methods, and many tests are required. In this paper measured crack direction path by created figure capture system when a experiment. Also, we studied by comparison the behavior of crack giving the change of stress ratio and inserting beach mark. Through the test under mixing mode, advancing path of crack is indicated that advancing inclined angle ${\Theta}$ (direction of specimen length) has increased depending on the increase of mixed mode impaction. It is indicated that according to the increase of mixed mode loading condition impaction under mixing mode, advancing speed of crack gets slow. Also, we found that inner crack(cross section of specimen) is progressed more rapidly than outer crack based on data through beach mark.

• Journal of Biosystems Engineering
• /
• 제24권5호
• /
• pp.431-438
• /
• 1999

The environmental control based on interactive thermoregulatory behavior for swine production has many advantages over the conventional temperature-based control methods. Therefore, this study was conducted to compare various feature selection methods using postural images of growing pigs under various environmental conditions. A color CCD camera was used to capture the behavioral images which were then modified to binary images. The binary images were processed by thresholding, edge detection, and thinning techniques to separate the pigs from their background. Following feature were used for the input patterns to the neural network ; \circled1 perimeter, \circled2 area, \circled3 Fourier coefficients (5$\times$5), \circled4 combination of (\circled1 ＋ \circled2), \circled5 combination of (\circled1 ＋ \circled3), \circled6 combination of (\circled2 ＋ \circled3), and \circled7 combination of (\circled1 ＋ \circled2 ＋ \circled3). Using the above each input pattern, the neural network could classify training images with the success rates of 96%, 96%, 96%, 100%, 100%, 96%, 100%, and testing images with those of 88%, 86%, 93%, 96%, 91%, 90%, 98%, respectively. Thus, the combination of perimeter, area and Fourier coefficients of the thinning images as neural network features gave the best performance (98%) in the behavioral classification.

• Computers and Concrete
• /
• 제11권1호
• /
• pp.1-20
• /
• 2013

There is an abundance of research on the strengthening of reinforced concrete (RC) structural elements such as beams, columns and slabs with fibre reinforced polymer (FRP) composites. Less research by comparison has been conducted on the strengthening of RC beam-column connections and the majority of such research has been predominantly experimental to date. Few existing experimental studies have reported extensive instrumentation of test specimens which in turn makes understanding the behavior of the connections and especially the contributions made by the FRP difficult to ascertain. In addition, there has been even more limited research on the analytical and numerical modelling of FRP-strengthened connections. In this paper, detailed descriptions of key strategies to model FRP-strengthened RC connections with finite elements are provided. An extensively instrumented and comprehensively documented set of experiments on FRP-strengthened connections is firstly presented and finite element models are then constructed using ANSYS. The study shows that the finite element approach is able to capture the overall behavior of the test specimens including the failure mode as well as the behavior of the FRP which will most importantly lead to a detailed understanding of the FRP and the future development of rational analytical models. The finite element models are, however, unable to model the stiffness of the connections with accuracy in the ultimate load range of response.

• Computers and Concrete
• /
• 제18권5호
• /
• pp.999-1018
• /
• 2016

Enhanced tensile properties of fiber reinforced concrete make it suitable for strengthening of reinforced concrete elements due to their superior corrosion resistance and high tensile strength properties. Recently, the use of fibers as strengthening material has increased motivating the development of numerical tools for the design of this type of intervention technique. This paper presents numerical analysis results carried out on a set of concrete beams reinforced with short fibers. To this purpose, a database of experimental results was collected from an available literature. A reliable and simple three-dimensional Finite Element (FE) model was defined. The linear and nonlinear behavior of all materials was adequately modeled by employing appropriate constitutive laws in the numerical simulations. To simulate the fiber reinforced concrete cracking tensile behavior an approach grounded on the solid basis of micromechanics was used. The results reveal that the developed models can accurately capture the performance and predict the load-carrying capacity of such reinforced concrete members. Furthermore, a parametric study is conducted using the validated models to investigate the effect of fiber material type, fiber volume fraction, and concrete compressive strength on the performance of concrete beams.

• Asia pacific journal of information systems
• /
• 제16권4호
• /
• pp.103-119
• /
• 2006

One of the most important reasons for using online game is intrinsic motivation which relates the drive to perform a behavior for perceptions of pleasure and satisfaction from the behavior itself. Therefore, most studies for using online game have been based on theories for intrinsic motivation such as flow. However, such theories have some limitations for explaining social aspects of online games such as Massively Multiplayer Online Role Game (MMORPG), which provides a society for game players by using a virtual space for playing games so called 'persistent world'. Adaptive structuration theory (AST) is one of trying to capture the change of using IT due to social interactions between users and system. In order to explain online game players' behavior considering social interaction, we suggest a research model based on AST. Our model aims to investigate the relationship between appropriation which is determined by faithfulness of appropriation (FOA) and consensus on appropriation (COA) and performance which is represented by the relationship among perceived winning, flow, and intention of reuse. An empirical test of our model for 125 MMORPG users which is analyzed by Partial Least Square method shows very satisfactory and interesting results. While hypotheses suggested in our model are supported, the influence of COA on game performance is shown to be stronger than that of FOA.

• Coupled systems mechanics
• /
• 제7권1호
• /
• pp.27-42
• /
• 2018

Behavior of soil is usually described with continuum type of failure models such as Mohr-Coulomb or Drucker-Prager model. The main advantage of these models is in a relatively simple and efficient way of predicting the main tendencies and overall behavior of soil in failure analysis of interest for engineering practice. However, the main shortcoming of these models is that they are not able to capture post-peak behavior of soil nor the corresponding failure modes under extreme loading. In this paper we will significantly improve on this state-of-the-art. In particular, we propose the use of a discrete beam lattice model to provide a sharp prediction of inelastic response and failure mechanisms in coupled soil-foundation systems. In the discrete beam lattice model used in this paper, soil is meshed with one-dimensional Timoshenko beam finite elements with embedded strong discontinuities in axial and transverse direction capable of representing crack propagation in mode I and mode II. Mode I relates to crack opening, and mode II relates to crack sliding. To take into account material heterogeneities, we determine fracture limits for each Timoshenko beam with Gaussian random distribution. We compare the results obtained using the discrete beam lattice model against those obtained using the modified three-surface elasto-plastic cap model.

• 한국시뮬레이션학회논문지
• /
• 제22권2호
• /
• pp.33-40
• /
• 2013

본 논문은 에이전트 기반 모델링 및 시뮬레이션을 바탕으로 한 한국군 GOP 경계시스템에 관한 연구이다. 에이전트 기반 모델링 및 시뮬레이션 기반 소프트웨어인 MANA를 이용하여 다양한 시나리오를 모델링하고 유전학적 알고리즘을 통해 침투 양상이 변화하는 적에 대해 분석하였다. 우리는 유전학적 알고리즘을 이용하여 침투하는 적의 최적화된 행동에 근사하는 값을 구하기 위해 최적화 모델을 구성하였다. 그 결과는 GOP 경계시스템에서 침투하는 적의 행동에 대한 최적화가 경계시스템의 효과성에 현저한 차이를 가져온다는 점과 침투하는 적의 아군 자산에 대한 회피 정도는 각각의 자산의 중요성을 반영한다는 점에서 두 가지 중요한 통찰력을 제공한다.