• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.306-312
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• 2001

In this research, we are trying to develop a framework to evaluate the prevention program for Tsunami disaster based on the Multi-agent simulation model. Tsunami has arisen by the earthquake. It happened after flew minutes or few hours when it occurred. It is clear that Tsunami will come after earthquake and from seashore. If we prevent the damage by Tsunami, we should make people who is in the seashore and lived near the seaside escape from there. Moreover we must forecast the escape activity from Tsunami. Former research of this field, some researches try to forecast the escape activity as macro level. However, people who escape from Tsunami is differ from their physical ability and ability of information processing. It needs a more accuracy model to forecast the escape activity of them. Furthermore they make a decision step by step using the various information. Therefore escape activity from Tsunami will describe using an agent based model which can only treat the information processing of human being. In this paper, we develop the evacuation model from Tsunami disaster using the Multi agent based model. The purpose of this study is to analyze the human action pattern when Tsunami occurred, and to make an accurately assessment for damages by Tsunami. The Fujisawa city government is planning and operating the various prevention program far Tsunami. However nobody assess it, because they do not have any simulation models for Tsunami disaster. If they want to set an effective prevention program for Tsunami, they should have any kinds of simulation model. The results of this study are 1) To develop the Multi agent based evacuees escape activity model. 2) Assess the damage of Tsunami in Fujisawa-City.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1339-1345
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• 2017

In the framework of the EU funded project NURESAFE, the subchannel code CTF and the neutronics code DYN3D were integrated and coupled on the NURESIM platform. The developments achieved during this 3-year project include assembly-level and pin-by-pin multiphysics thermal hydraulics/neutron kinetics coupling. In order to test this coupling, a PWR rod ejection transient was simulated on a MOX/UOX minicore. The transient is simulated using two different models of the minicore. In the first simulation, both codes model the core with an assembly-wise resolution. In the second simulation, a pin-by-pin fuel-centered model is used in CTF for the central assembly, and a pin power reconstruction method is applied in DYN3D. The analysis shows the influence of the different models on global parameters, such as the power and the average fuel temperature, but also on local parameters such as the maximum fuel temperature.

• Journal of Information Technology Applications and Management
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• v.19 no.1
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• pp.37-46
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• 2012

The scheduling problem of large products like ships, airplanes, space shuttles, assembled constructions, and automobiles is very complex in nature. To reduce inherent computational complexity, we often design scheduling systems that the original problem is decomposed into small sub-problems, which are scheduled independently and integrated into the original one. Moreover, the steep growth of communication technology and logistics makes it possible to produce a lot of multi-nation corporation by which products are produced across more than one plant. Therefore vertical and lateral coordination among decomposed scheduling systems is necessary. In this research, we suggest an agent-based coordinating mechanism for multi-level scheduling systems in supply chain. For design of a general coordination mechanism, at first, we propose a grammar to define individual scheduling agents which are responsible to their own plants, and a meta-level coordination agent which is engaged to supervise individual scheduling agents. Second, we suggest scheduling agent communication protocols for each scheduling agent topology which is classified according to the system architecture, existence of coordinator, and direction of coordination. We also suggest a scheduling agent communication language which consists of three layers : Agent Communication Layer, Scheduling Coordination Layer, Industry-specific Layer. Finally, in order to improve the efficiency of communication among scheduling agents we suggest a rough capacity coordination model which supports to monitor participating agents and analyze the status of them. With this coordination mechanism, we can easily model coordination processes of multiple scheduling systems. In the future, we will apply this mechanism to shipbuilding domain and develop a prototype system which consists of a dock-scheduling agent, four assembly-plant-scheduling agents, and a meta-level coordination agent. A series of experiment using the real-world data will be performed to examine this mechanism.

• International Journal of Contents
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• v.14 no.4
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• pp.57-64
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• 2018

Among many UNESCO world heritage sites in Korea, "Historic Village: Hahoe" is adjacent to Nakdong River and it is imperative to monitor the water level near the village in a bid to forecast floods and prevent disasters resulting from floods.. In this paper, we propose a recurrent neural network with multiple hidden layers to predict the water level near the village. For training purposes on the proposed model, we adopt the sixth-order error function to improve learning for rare events as well as to prevent overspecialization to abundant events. Multiple hidden layers with recurrent and crosstalk links are helpful in acquiring the time dynamics of the relationship between rainfalls and water levels. In addition, we chose hidden nodes with linear rectifier activation functions for training on multiple hidden layers. Through simulations, we verified that the proposed model precisely predicts the water level with high peaks during the rainy season and attains better performance than the conventional multi-layer perceptron.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.313-326
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• 2021

This study was to introduce ecological momentary assessment and show how to apply it to real-world research. As preliminary study for sustainable development, the result explained growth model using senior's longitudinal data and suitability of multi-level model in EMA data with regression analysis. The total variance of dependent variable was determined through a base model with only intercept and approximately 47% of total variance was caused by individual differences and 53% by time point differences. Second model was used to verified that each individual has a different effect on the senior vitality and effect on time was not significant. This is because it is the result of a preliminary stage where treatment is not involved and there is no significant change in process of collecting EMA data without external intervention. Third model that add gender as an independent variable showed significant change in both time and gender. Finally compared the PRD for each model and found models that without gender variables fit the data more effectively. This suggests that studies dealing with longitudinal data such as EMA data should adopt multi-level model that can measure individual characteristics, taking into account respondents' time and context.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.359-366
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• 2013

Although many research efforts have been conducted to address the effect of crew members' work skills (e.g., technical and planning skills) on work performance (e.g., work duration and quality) in construction projects, the relationship between skill and performance has generated a great deal of controversy in the field of management (Inkpen and Crossan 1995). This controversy can lead to under- or over-estimations of the overall project schedule, and can make it difficult for project managers to implement appropriate managerial policies for enhancing project performance. To address this issue, the following aspects need to be considered: (a) work performances are determined not only by individual-level work skill but also by the group-level work skill affected by work team members, each member's role, and any working behavior pattern; (b) work planning has significant effects on to what extent work skill enhances performance; and (c) different types of activities in construction require different types of work, skill, and team composition. This research, therefore, develops a system dynamics (SD) model to analyze the effects of both individual-and group-level (i.e., multi-level) skill on performances by utilizing the advantages of SD in capturing a feedback process and state changes, especially in human factors (e.g., attitude, ability, and behavior). The model incorporates: (a) a multi-level skill evolution and relevant behavior development mechanism within a work group; (b) the interaction among work planning, a crew's skill-learning, skill manifestation, and performances; and (c) the different work characteristics of each activity. This model can be utilized to implement appropriate work planning (e.g., work scope and work schedule) and crew management policies (e.g., work team composition and decision of each worker's role) with an awareness of crew's skill and work performance. Understanding the different characteristics of each activity can also support project managers in applying strategic work planning and crew management for a corresponding activity, which may enhance each activity's performance, as well as the overall project performance.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.391-398
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• 2001

To design and develop secure operating systems, the BLP (Bell-La Padula) model that represents the MLP (Multi-Level Policy) has been widely adopted. However, user\`s security level in the most developed systems based on the BLP model is inherited to a process that is actual subject on behalf of the user, regardless whatever the process behavior is. So, there could be information disclosure threat or modification threat by malicious or unreliable processes even though the user is authorized in the system. These problems can be solved by defining the subject as (user, process) ordered pair and by defining the process reliability. Moreover, when the leveled programs which exist as objects in a disk are executed by a process and have different level from the process level, the security level decision problem occurs. This paper presents an extended BLP (E-BLP) model in which process reliability is considered and solves the security level decision problem. And this model is implemented into the Linux kernel 2.4.7.

• Journal of IKEEE
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• v.18 no.4
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• pp.593-602
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• 2014

One of the purposes of an artificial neural netowrk(ANNet) is to implement the largest number of functions as possible with the smallest number of nodes and layers. This paper presents a CoreNet which has a multi-leveled input value and a multi-leveled output value with a 2-layered ANNet, which is the basic structure of an ANNet. I have suggested an equation for calculating the capacity of the CoreNet, which has a p-leveled input and a q-leveled output, as $a_{p,q}={\frac{1}{2}}p(p-1)q^2-{\frac{1}{2}}(p-2)(3p-1)q+(p-1)(p-2)$. I've applied this CoreNet into the simulation model 1(5)-1(6), which has 5 levels of an input and 6 levels of an output with no hidden layers. The simulation result of this model gives, the maximum 219 convergences for the number of implementable functions using the cot(${\sqrt{x}}$) input leveling method. I have also shown that, the 27 functions are implementable by the calculation of weight values(w, ${\theta}$) with the multi-threshold lines in the weight space, which are diverged in the simulation results. Therefore the 246 functions are implementable in the 1(5)-1(6) model, and this coincides with the value from the above eqution $a_{5,6}(=246)$. I also show the implementable function numbering method in the weight space.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.583-592
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• 2005

The turbulent free surface flow around a self-propelled KRISO 138K LNG Carrier is numerically simulated using the finite volume based multi-block RANS code, WAVIS developed at HRISO. The realizable k-$\varepsilon$ turbulence model with a wail function is employed for the turbulence closure. The free surface is captured with the Level-Set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. In order to obtain an accurate free surface solution and stable convergence, the computations are executed with a proper fine grid refinement around the free surface and with an adoption of implicit discretization scheme for the Level-Set formulation. The computed velocity vectors at the several stations and wave patterns show a good agreement with the experimental results measured at the KRISO towing tank.

• Journal of Korean Society of Rural Planning
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• v.16 no.1
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• pp.49-62
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• 2010

As people get aged, we need to pay more attention to the elderly living condition with respect to welfare policy. The present study focuses on housing condition of elderly people living in rural area, and analyzes its determinants, periodical difference, and regional disparities, incorporating an index of minimum housing standard. This study applies multi-level logit model that has a strong statistical advantage that can take random aspects of household and regional context into account. We found that married couple household, presence of economically-active family members, higher education, specialized profession, migration and higher level of land price tend to lower the probability of residing in substandard housings. We also found that housing conditions for elderly people prove to be different by regions and it is particularly noticeable in mountainous rural areas in Gyeongsangnam-do and Gyeongsangbuk-do with the poorest elderly housing conditions. Results also implies that housing welfare policies should be implemented differently considering the target groups based on regional differences. We conclude with some additional policy implications for the elderly living in rural areas.