• International conference on construction engineering and project management
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• 2022.06a
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• pp.3-10
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• 2022

An estimated investment gap of $176 billion needs to be filled over the next ten years to improve America's inland waterway transportation systems. Many of these infrastructure systems are now beyond their original 50-year design life and are often behind in maintenance due to funding constraints. Therefore, long-term maintenance strategies (i.e., asset management (AM) strategies) are needed to optimize investments across these waterway systems to improve their condition. Two common AM strategies include policy-driven maintenance and performance-driven maintenance. Currently, limited research exists on selecting the optimal AM approach for managing inland waterway transportation assets. Therefore, the goal of this study is to provide a decision model that can be used to select the optimal alternative between the two AM approaches by considering key uncertainties such as asset condition, asset test results, and asset failure. We achieve this goal by addressing the decision problem as a single-criterion problem, which calculates each alternative's expected value and certain equivalence using allocated monetary values to determine the recommended alternative for optimally maintaining navigable waterways. The decision model considers estimated and predicted values based on the current state of the infrastructure. This research concludes that the performance-based approach is the optimal alternative based on the expected value obtained from the analysis. This research sets the stage for further studies on fiscal constraints that will effectively optimize these assets condition.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.133-140
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• 2018

In this study, a correlation between execution of quality management activities and their results was verified by applying the Malcolm Baldrige model (hereafter referred to as the MB model) as a quality management performance measurement indicator for small and medium enterprises (SMEs) in South Korea. To achieve this goal, we need to determine whether the categorical requirements in the MB model are recognized consistently in SMEs, as a prerequisite. To this end, factor analysis was conducted for measurement variables in each category, which revealed that the process indicator was made up of six factors and the outcome indicator was made up of five factors, like those configured in the MB model. This result can be interpreted to mean that the requirements in each category of the MB model were well produced and recognized consistently throughout SMEs in South Korea. In addition, the analysis of causality between the process indicator (quality management activities) and the outcome indicator (management results) showed high causality between them. Although the quality management levels of SMEs in South Korea are inferior to those of conglomerates or other national quality award-winning companies, this study is significant in that the causality between quality management activities and results was verified, since this study targeted SMEs in South Korea as the target of investigation. Thus, it is empirically proven that the MB model can contribute to improved management results for SMEs in Korea.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.225-236
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• 2005

The primary goal of the study is to provide a newly refined data model, an information exchange foundation of modeling operation for rapid prototyping, as one among non-milling STEP-NC modules. The previous data model has been first modified and refined by reflecting specific user requirements. Second, subsidiary information such as fabrication history as well as traditional process information has been introduced into the newly refined model in order to consolidate the model functionality. In short, the main contribution of the study is to provide a foundation where a newly refined data model is utilized easily and conveniently for practical rapid prototyping fabrication within the newly constructed STEP-NC environment.

• Archives of design research
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• v.6 no.1
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• pp.1-10
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• 1993

This paper described design as a purposeful human activity for solving its problems. This means, problem solving is finding a way to get from some initial situation to a desired goal.In order to do this, like a voyage, there should be a compass, and a route map to guide the designer through the design process. Evaluation gives information about the way a design is proceeding and suggests the direction in which change should be made in order that the complex of design concepts should be fulfilled in a satisfactory manner.I think Pugh's total design model discussing in this paper takes a layered approach through a series of sequential actions, part of which is to find the product status. Each layer has the $$\mu$ti-dimensional elements, Product Design Specification (PDS) around the design core. I made a comparative study of several evaluation tools wi th Pugh's model and examined the criteria for evaluation and the rating / weighing methods.It needs, however, more study in order that PDSs may have its values and be fixed from the dynamic design concepts.

• Steel and Composite Structures
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• v.10 no.6
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• pp.475-487
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• 2010

Most of steel structures in various industries are subjected to corrosion due to environmental exposure. Corrosion damage is a serious problem for these structures which may reduce their carrying capacity. These aging structures require maintenance and in many cases, replacement. The goal of this research is to consider the effects of corrosion by developing a model that estimates corrosion loss as a function of exposure time. The model is formulated based on average measured thickness data collected from three severely corroded I-beams (nearly 30 years old). Since corrosion is a time-dependent parameter. Analyses were performed to calculate the lateral buckling capacity of steel beam in terms of exposure time. Minimum curves have been developed for assessment of the remaining lateral buckling capacity of ordinary I-beams based on the loss of thicknesses in terms of exposure time. These minimum curves can be used by practicing engineers for better estimates on the service life of corrosion damaged steel beams.

• Smart Structures and Systems
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• v.13 no.3
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• pp.343-352
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• 2014

Given a body undergoing a stress-strain status as consequence of external excitations, sensors can be deployed on the accessible lateral surface of the body. The sensor readings are regarded as input of a numerical model of reduced order (i.e., the number of sensors is lower than the number of the state variables the full model would require). The goal is to locate the sensors in such a way to minimize the deviations from the response of the true (full) model. One adopts either accelerometers as sensors or devices reading relative displacements. Two applications are studied: a plane frame is first investigated; the focus is eventually on a 3D body.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.81-85
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• 2000

The purpose of this paper is to describe a new analytic method of capital budgeting projects that takes into account both customer wants and competitor's status and to give decision makers a tool for goal setting and planning for technology. This model, which is based on quality function deployment(QFD), has used the analytic hierarchy process(AHP) to determine the intensity of the relationship between the variables involved in each matrix of the model and the 0-1 integer programming to determine the allocation of funds to various technological projects. This paper also proposes how to calculate the new weight of columns to consider various strength levels of roof matrix, representing the correlation among the quality characteristics, using Lymsn's normalization procedure. To compare this model with Partovi's model, 1 adapt the same example which is suggested by Partovi and I show that the value of object function, has maximization problem, in this model is larger than that in Partovi's model.

• Journal of Nutrition and Health
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• v.46 no.1
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• pp.50-60
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• 2013

The aims of this study were to estimate daily intake of macrominerals from beverages, liquid teas, and liquid coffees and to evaluate their potential health risks for Korean children and adolescents (1-to 19 years old). Assessment of dietary intake was conducted using the actual level of sodium, calcium, phosphorus, potassium, and magnesium in non-alcoholic beverages and (207 beverages, 19 liquid teas, and 24 liquid coffees) the food consumption amount drawn from "The Fourth Korea National Health and Nutrition Examination Survey (2007-2009)". To estimate the dietary intake of non-alcoholic beverages, 6,082 children and adolescents (Scenario I) were compared with 1,704 non-alcoholic beverage consumption subjects among them (Scenario II). Calculation of the estimated daily intake of macrominerals was based on point estimates and probabilistic estimates. The values of probabilistic macromineral intake, which is a Monte-Carlo approach considering probabilistic density functions of variables, were presented using the probabilistic model. The level of safety for macrominerals was evaluated by comparison with population nutrient intake goal (Goal, 2.0 g/day) for sodium, tolerable upper intake level (UL) for calcium (2,500 mg/day) and phosphorus (3,000-3,500 mg/day) set by the Korean Nutrition Society (Dietary Reference Intakes for Koreans, KDRI). For total children and adolescents (Scenario I), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 7.93, 10.92, 6.73, 23.41, and 1.11, and 95th percentile daily intake of those was, respectively, 28.02, 44.86, 27.43, 98.14, and 3.87 mg/day. For consumers-only (Scenario II), mean daily intake of sodium, calcium, phosphorus, potassium, and magnesium estimated by probabilistic estimates using Monte Carlo simulation was, respectively, 19.10, 25.77, 15.83, 56.56, and 2.86 mg/day, and 95th percentile daily intake of those was, respectively, 62.67, 101.95, 62.09, 227.92, and 8.67 mg/day. For Scenarios I II, sodium, calcium, and phosphorus did not have a mean an 95th percentile intake that met or exceeded the 5% of Goal and UL.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.375-383
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• 2014

The purpose of this study was to assess the inter-segmental trunk motion during which multi-segmental movements of the spinal column was designed to interpret the effect of segmentation on the total measured spine motion. Also it analyzed the relative motion at three types of the spine models in drop landing. A secondary goal was to determine the intrinsic algorithmic errors of spine motion and the usefulness of such an approach as a tool to assess spinal motions. College students in the soccer team were selected the ten males with no history of spine symptoms or injuries. Each subject was given a fifteen minute adaptation period of drop landing on the 30cm height box. Inter-segmental spine motion were collected Vicon Motion Capture System (250 Hz) and synchronized with GRF data (1000 Hz). The result shows that Model III has a more increased range of motion (ROM) than Model I and Model II. And the Lagrange energy has significant difference of at E3 and E4 (p<.05). This study can be concluded that there are differences in the three models of algorithm during the phase of load absorption. Especially, Model III shows proper spine motion for the inter-segmental joint motion with the interaction effects using the seven segments. Model III shows more proper observed values about dynamic equilibrium than Model I & Model II. The findings have shown that the dynamic stability strategy of Model III toward multi-directional spinal motion supports for better function of the inter-segmental motor-control than the Model I and Model II.

• Journal of Biosystems Engineering
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• v.11 no.2
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• pp.77-87
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• 1986

This study was carried out to design the optimal systems of diversified farming by the mathematical model developed. In order to achieve this goal, a computer program named DFSDINGP was developed by the nonlinear goal programming(NGP), and for testing its effectiveness, the optimal systems of diversified farming were designed for three regions surveyed and compared them with those of the conventional. DFSDINGP was programmed with FORTRAN 77 and it could handle the NGP problem having 25 independent variables and 75 constraint functions. The study results showed that the developed models and DFSDINGP could design the optimal systems of diversified farming satisfying two goals which are maximum agricultural income and maximum power inputs of agricultural machinery. The agricultural incomes and power inputs of farm machinery of the optimal systems were more than those of the conventional as much as 29-62% and 9-134%, respectively.