• Structural Engineering and Mechanics
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• v.38 no.1
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• pp.39-63
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• 2011

Referring to the formulation of physical stochastic optimal control of structures and the scheme of optimal polynomial control, a nonlinear stochastic optimal control strategy is developed for a class of structural systems with hysteretic behaviors in the present paper. This control strategy provides an amenable approach to the classical stochastic optimal control strategies, bypasses the dilemma involved in It$\hat{o}$-type stochastic differential equations and is applicable to the dynamical systems driven by practical non-stationary and non-white random excitations, such as earthquake ground motions, strong winds and sea waves. The newly developed generalized optimal control policy is integrated in the nonlinear stochastic optimal control scheme so as to logically distribute the controllers and design their parameters associated with control gains. For illustrative purposes, the stochastic optimal controls of two base-excited multi-degree-of-freedom structural systems with hysteretic behavior in Clough bilinear model and Bouc-Wen differential model, respectively, are investigated. Numerical results reveal that a linear control with the 1st-order controller suffices even for the hysteretic structural systems when a control criterion in exceedance probability performance function for designing the weighting matrices is employed. This is practically meaningful due to the nonlinear controllers which may be associated with dynamical instabilities being saved. It is also noted that using the generalized optimal control policy, the maximum control effectiveness with the few number of control devices can be achieved, allowing for a desirable structural performance. It is remarked, meanwhile, that the response process and energy-dissipation behavior of the hysteretic structures are controlled to a certain extent.

• Ocean and Polar Research
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• v.26 no.2
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• pp.113-120
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• 2004

The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to $3.79{\mu}g\;l^{-1}$ Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to $20.2{\mu}g\;C\;l^{-1}$ and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to $27.4{\mu}g\;C\;l^{-1}$, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.231-234
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• 2006

Semantic web ontologies can be viewed as logic-based domain-oriented contents which allow distributed and heterogeneous information to be semantically integrated, automatically circulated, and enable implicit knowledge to be reasoned. This paper describes the 'Science and Technology Research Area' ontology which is being developed by the Korea Institute of Science and Technology Information (KISTI). This ontology was defined to assist actual researchers and project planners to grasp the researchers community from a variety of viewpoints. We describe classes and properties as ontology components and exemplify the representation of real instances in the ontology. In order to represent the identities of real world instances within the ontology, the above ontology employs both class-dependent URI assignment schemes and the identity resolution methods.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.87-94
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• 2017

Many industrial accidents have occurred continuously in the manufacturing industries, construction industries, and service industries of Korea. Fatal accidents have occurred most frequently in the construction industries of Korea. Especially, the trend analysis of the accident rate and fatal accident rate is very important in order to prevent industrial accidents in the construction industries systematically. This paper considers forecasting of the accident rate and fatal accident rate with static and dynamic time series analysis methods in the construction industries. Therefore, this paper describes the optimal accident rate and fatal accident rate by minimization of the sum of square errors (SSE) among regression analysis method (RAM), exponential smoothing method (ESM), double exponential smoothing method (DESM), auto-regressive integrated moving average (ARIMA) model, proposed analytic function model (PAFM), and kalman filtering model (KFM) with existing accident data in construction industries. In this paper, microsoft foundation class (MFC) soft of Visual Studio 2008 was used to predict the accident rate and fatal accident rate. Zero Accident Program developed in this paper is defined as the predicted accident rate and fatal accident rate, the zero accident target time, and the zero accident time based on the achievement probability calculated rationally and practically. The minimum value for minimizing SSE in the construction industries was found in 0.1666 and 1.4579 in the accident rate and fatal accident rate, respectively. Accordingly, RAM and ARIMA model are ideally applied in the accident rate and fatal accident rate, respectively. Finally, the trend analysis of this paper provides decisive information in order to prevent industrial accidents in construction industries very systematically.

• Journal of the military operations research society of Korea
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• v.35 no.1
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• pp.83-93
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• 2009

The future warfare is known as an effective centric paralysis warfare where military high technologies such as pinpoint strikes are applied. In this future warfare, for supporting military operation leadership and power of concentration in the combat, a new concept of logistic support is required and the focused logistic is proposed as an alternative. To implement this focused logistic, asset visibility should be assumed for every combat units in real time. However, current logistic information systems provide only limited information. In this study, a prototype information system for class 2 and 4 supplies is proposed for overcome limitations of current information system. The developed prototype zooms in on combat units providing business process integrations and logistic function synchronization. Also, asset visibility, the essential element of focused logistics, is presented and utilized to show the speedy and effective logistic support.

• Journal of The Korean Association of Information Education
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• v.21 no.6
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• pp.607-618
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• 2017

Recently, there is a growing interest in learning to use games as a teaching method for digital native learners. In this study, we conducted a path analysis between bodily-kinesthetic intelligence, linguistic intelligence, flow, learning outcomes(academic achievement, persistence intention) in motion-capture game-based learning(the used game developed for elementary school history class). As a result, bodily-kinesthetic intelligence directly influenced flow and indirectly influenced learning outcomes. Linguistic intelligence did not have direct influence on flow and indirect effects on learning outcomes. Through this result, we expected that the motion-capture game-based learning facilitate learning motivation and performance of learners for higher bodily-kinesthetic intelligence.

• The Journal of Information Systems
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• v.13 no.1
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• pp.77-95
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• 2004

According to the increase of organizational complexity and the change of rapid information technology environment, many firms have shifted their information technology(IT) strategy from developing information systems in-house to purchasing application software such as Enterprise Resource Planning(ERP) Systems. Marketing and Sales functions within a Korean automotive part company include developing new assembly products, determining pricing, taking customer's orders, and shipping assembly products to customers. Marketing and Sales Information System(MSIS) in ERP system plays an important role in next Production Planning process. MSIS also makes management reporting and decision making faster and more uniform throughout an organization. MSIS promotes thinking about corporate goals, as opposed to thinking only about the goals of a single department or functional area. This paper intends to design and implement a MSIS in ERP systems for Korean automotive part company using object-oriented methodology In order to accomplish the implementation of MSIS in ERP system, we employed UML as its standard modeling language. In this study, four diagramming techniques such as use case diagram, sequence diagram, class diagram, component diagram among eight modeling techniques are used for analyzing hierarchical business process. In traditional marketing and sales function, a company with an unintegrated information system can have marketing and sales data that is data redundant or inaccurate. MSIS integrated in ERP system can solve the sales forecast problem, which minimizes the total costs of production, inventory, and transportation under constraints of production capacity. Also, the use of UML methodology makes S/W programmers shorten the phase of analysis and design in the implementation of MSIS system, and increase the reuse of software and the interoperability with corporate internal Information system.

• Journal of Family Resource Management and Policy Review
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• v.14 no.4
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• pp.213-237
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• 2010

This study aimed at figuring out the current state of 26 family-health support centers in Gyeonggi-do, in order to prepare an activation plan for the centers. These centers are the main mediators of the family health operation. This study also aimed to understand the center users' satisfaction and demands. The results were as follows. First, a total of 65,794 participants from 9,960 businesses were processed. The majority had attended various integrated family services, followed by family counseling and/or family-friendly culture-establishing businesses. Second, the main users' profiles were as follows: average age, 41; average number of persons in the family, 3.78; education above foundation-level degree; diverse jobs that included special occupations; average monthly incomes of 3,390,000 won; and a middle-class living standard (as self-described by participants). Third, the users' main concern for their families was "financial difficulties," and they had an interest in education and counseling. Although they thought education and counseling were suitable solutions, they hesitated because they did not think their problems were serious enough to merit them. Fourth, the satisfaction level of their participation in their center's program was generally high, at 3.9-4.2 points. The majority of them said they would attend again in the future.

• The Journal of Korean Association of Computer Education
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• v.7 no.1
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• pp.79-88
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• 2004

Since computer integrated technology was introduced to the field of education, it has offered an expanding range of interactive possibilities which are remarkably powerful and helpful for the learners, especially constructing the cyber learning environments. Interactivity, the critical element in cyber learning, is categorized into three dimensions: student-to-contents, student-to-student and student-to-instructors. Six surrogate variables are introduced, and two quantitative model are developed for evaluating the degree of interactivity. The first model, which is called Data Envelopment Analysis model, is a linear programming based technique for measuring the relative performance of organizational units where the presence of multiple inputs and outputs makes comparison difficult. DEA model allows each unit to adopt a set of weight that shows it in the most favorable light in comparison to the other unit. The Second model employes the weighted average of standardized input variables for evaluation. Actual data have been collected from the Cyber IT university and these two models are applied for comparison. The analysis shows that the results from these two models are very much similar to each other, and are highly correlated to the level of class satisfaction.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.35-45
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• 2011

Establishing housing supply strategies in Korean housing market is a crucial issue due to contradictory but concurrent two problems in market; one is the unstable working-class residential and the other is the high vacancy rate by the low-level of sales rate. Although government has been continuously implementing various supply policies in an attempt to evenly distribute houses as well as to keep supply and demand in balance, it is difficult to satisfy all of stakeholders, such as housing consumers, housing owners and housing suppliers. This paper, therefore, applies a system dynamics methodology and offers a dynamic and integrated model encompassing for-profit behaviors of each market participants. The proposed model simulates the future trends of house prices, the balances between supply and demand, construction companies earnings and vacancy rate when applying various housing supply scenarios. From the simulation result, recent governmental small-size rental housing supplies in bulks should utilize private construction companies to stabilize housing distribution rate and private supply system as well as the supply and demand are well balanced.