• International conference on construction engineering and project management
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• 2013.01a
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• pp.576-582
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• 2013

Typical highway infrastructure systems include roadway pavement, drainage systems, tunneling, and other hardware components such as guardrails, traffic signs, and lighting. Tunnels in a highway system have provided significant advantages to overcoming various natural challenges including crossing underneath bodies of water or through mountainous areas. While only a few tunnel failure cases have been reported, the failure rate is likely to increase as these assets age and because agencies have not emphasized tunneling asset management. A tunnel system undergoes a deterioration life cycle pattern that is similar to other infrastructure systems. There are very few agencies in the United States implementing comprehensive tunnel asset management programs. While current tunnel asset management programs focus on inspection, maintenance, and operation safety, there is an increasing need for the development of a comprehensive life cycle tunnel asset management program. This paper describes a conceptual framework for a comprehensive tunnel asset management program. The framework consists of three basic phases including a strategic plan, a tactical plan, and an operational plan to provide better information to the decision makers. The strategic plan is a basic long term approach of tunnel asset management. The tactical plan determines specific objectives and the operational plan actually applies asset management objectives in practice. The information includes operational condition, structural condition, efficiency of the system, emergency response, and life cycle cost analysis for tunnel capital improvement project planning.

• Steel and Composite Structures
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• v.52 no.1
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• pp.1-14
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• 2024

This paper introduces a system allows for seismic isolation of the pallet from the rack in the down-aisle direction, occupies minimal vertical space (5 cm) and ±7.5 cm of deformation range. A conceptual model of the isolation system is presented, leading to a constitutive equation governing its behavior. A first experimental campaign studying the response of the isolation system's components was conducted to calibrate the parameters of its constitutive equation. A second experimental campaign evaluated the response of the isolation system with mass placed on it, subjected to cyclic loading. The results of this second campaign were compared with the numerical predictions using the pre-calibrated constitutive equation, allowing a double-blind validation of the constitutive equation of the isolation system. Finally, a numerical evaluation of the isolation system subjected to a synthetic earthquake of one component. This evaluation allowed verifying attributes of the proposed isolation system, such as its self-centering capacity and its effectiveness in reducing the absolute acceleration of the isolated mass and the shear load transmitted to the supporting beams of the rack.

• 대한공업교육학회지
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• v.40 no.1
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• pp.64-86
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• 2015

The objective of this study is to develop NCS-based vocational curriculum procedures developing models recognized by experts in the National Skill Standards and to verify them. As for a research method for efficiently achieving this study, Delphi research has been conducted three times based on the result of preliminary Delphi investigation, contents of in-depth interview (review and advice), and consideration of previous studies and literature research related to NCS in Korea and abroad. Major results of study in regard of validation of NCS-based vocational curriculum procedures developing models recognized by experts of National Skill Standards are as follows. First, validity of conceptual model(plan) of NCS-based vocational curriculum developing procedures was verified. According to the result of implementing it on 10 members of verification for Delphi preliminary investigation tools, the average was higher than 4.70, and validity of contents was turned out to be outstanding in 1.00. Secondly, validity of conceptual model(plan) of NCS-based vocational curriculum developing procedures was verified by using Delphi preliminary investigation tools. According to the result of verifying it in order on 10 members of verification for Delphi preliminary investigation tools, validity of contents on questions in each area from the development procedures model(plan) was all 1.00, and appropriateness of contents on the components was turned out to be outstanding in 1.00. In addition, validity of contents on interrelation and comprehensiveness of components in the development procedures model(plan) was all turned out to be very satisfying in 1.00. Third, Delphi investigation was implemented in three rounds on 26 Delphi panel members for the verification. As a result consistency rate of interrelation and comprehensiveness among questions in each area of development procedures model(plan), components on the contents, and elements was turned out to be outstanding in .75 from all of three rounds. Here, consistency rate from all three rounds was turned out to be 1.00, and convergence rate was shown to be .00 that very well satisfied the conditions(except for 1 question out of 29). Therefore, it was confirmed that opinion from Delphi panel members was completely consistent in the third round of Delphi investigation research. Such a result in the study was from how Delphi selection criteria were strictly reinforced, and, at the same time, implies how will of participation of Delphi panel members was important.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.9-17
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• 2017

Ensuring the safety of automobiles and trains during system operation is regarded as indispensable due to the progress in unmanned operation. The automotive functional safety standard, ISO 26262, has been proposed to ensure the safe design of vehicles. This standard describes in detail the required risk analysis and evaluation procedure and safety measures, while appropriately reflecting the system design information. Therefore, much research has been done on the risk analysis procedure, wherein the design information is mostly extracted from physical components of similar systems already in operation, the information traced back to obtain constituent functions, and then methods of identifying risk sources are studied. This method allows the sources of risk to be identified quickly and easily, however if the design requirements are changed or systems are newly developed, others may be introduced which are not accounted for, thereby yielding mismatched design information. To resolve this problem, we propose a top-down analysis in order to utilize the system design information appropriately. Specifically, a conceptual system is designed to obtain the functions, which are then analyzed. Then, a function-based fault tree analysis is conducted, followed by a risk source analysis. In this paper, a case study of automotive safety is presented, revealing that the proposed method can analyze the risk sources with reduced possibility of omission by systematically reflecting the system design information.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.4 s.117
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• pp.69-83
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• 2006

Nature rehabilitation has become a major theme in river management in South Korea. An analysis and evaluation of the landscape is a crucial step to select the suitable tracts for developing or conserving land use in the process of landscape planning. The purpose of this paper is to establish a hierarchical procedure for the setting of the landscape units on the various scales at which field biologists performed their observations and to select the preserves through by a suitability model for synthesizing the ecological empirical, and biophysical data. An evaluation process needs to be performed according to the landscape scales: site, local, and regional scales, at which the environmental data were collected, analyzed, and synthesized. Introducing of three level scales was crucially necessary for evaluating the various multi level ecological data for zoning of preserves in river corridors. The evaluation level at different scales are hierarchically established into three phases. The first evaluation phase can be performed by the long length units defined by the ranges of stream widths at regional scale. Secondly, each of these long units can be divided into two or more segments according to its landscape homogeneity at local level. Finally the segments at the last phase can be designated according to the location of the reservoir weirs and bridges at site level. The conceptual model components are adopted for collecting, evaluating, and interpreting the biological and abiotic data at site level. Three preserves are selected, having high potentials for being intensely managed as the Ecological Education Areas in the river. Despite a lot of assumption the results are expected to facilitate discussion and decision making about which frameworks of evaluation are desirable and adaptable for integrating the ecological data into the rehabilitation design process in South Korea.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.681-692
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• 2021

Vegetation processes have a significant impact on rainfall runoff processes through evapotranspiration control, but are rarely considered in the conceptual lumped hydrological model. This study evaluated the model performance of the Hapcheon Dam watershed by integrating the ecological module expressing the leaf area index data sensed remotely from the satellite into the hydrological partition module. The proposed eco-hydrological model has three main features to better represent the eco-hydrological process in humid regions. 1) The growth rate of vegetation is constrained by water shortage stress in the watershed. 2) The maximum growth of vegetation is limited by the energy of the watershed climate. 3) The interaction of vegetation and aquifers is reflected. The proposed model simultaneously simulates hydrologic components and vegetation dynamics of watershed scale. The following findings were found from the validation results using the model parameters estimated by the SCEM algorithm. 1) Estimating the parameters of the eco-hydrological model using the leaf area index and streamflow data can predict the streamflow with similar accuracy and robustness to the hydrological model without the ecological module. 2) Using the remotely sensed leaf area index without filtering as input data is not helpful in estimating streamflow. 3) The integrated eco-hydrological model can provide an excellent estimate of the seasonal variability of the leaf area index.

• Journal of the Korean earth science society
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• v.43 no.3
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• pp.446-463
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• 2022

This study suggests the need for polar literacy education as an effective conceptual system to explain climate change in terms of science education in line with the common effort of humankind to respond to global environmental changes. To this end, we investigated the status of polar literacy in high school students through quantitative tests and qualitative interviews and discussed the resulting implications. A total of 329 high school sophomore students from two high schools participated in a test consisting of 25 true and false questions developed by referring to the Polar Literacy Principles, while 13 students agreed to be interviewed. The results showed that a somewhat insufficient understanding and conceptual gaps appeared regarding several areas of the Polar Literacy Principles. Knowledge of the geographic features of the polar regions was weak, and little was known about the components and key characteristics of the cryosphere. The lack of understanding of these concepts results in the inability of students to link the operational mechanisms of polar and global climate change sufficiently. While accepting unsatisfactory concepts in the school curriculum without criticism from outside media, students perceived the mechanism of climate change as somewhat monotonous or distorted. Moreover, linguistic information, analogies, and visual observation were used as cognitive strategies to compensate for the ambiguous understanding of polar and climate change. Based on the abovementioned results, we argue that polar literacy education should be introduced as a new knowledge system that can be used to aid a systematic and comprehensive understanding of climate change within the school science curriculum. Additionally, we suggest the following implications: review the consistency of knowledge related to polar literacy in other subjects, provide critical standards for out-of-school media information related to climate change, examine students' misconceptions, and identify improved thinking strategies.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.305-308
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• 2005

This paper presents a fabrication of a full-stale combustion chamber of a liquid rocket engine for a ground hot firing test. Engine drawings for manufacturing were prepared after conceptual and detail designs. The combustor is composed of a head and a chamber. SUS316L is used for materials of the head because of the good quality in low temperature. Inner materials of the ablative cooling chamber is silica/phenolic and outer case materials is the SUS316L. Materials of the regenerative cooling chamber are C18200 and SUS316L. After lathe, general milling and MCT machinings, components were finished by electrolytic polishing. A brazing method was applied for bonding the injectors and the injector plate, the regenerative cooling chamber because of structure configurations.

• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.13-25
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• 2003

The advent of LBS is caused by mobility advantage of wireless internet. The mobility has the information such as location which is based on LBS(Location based Services). It comes out as a killer application for wireless internet when market of wireless internet is diffused. In this paper, we build up the technical model and survey the requirement of technologies related LBS expanded as wireless internet services rapidly. First, we construct the conceptual model for LBS based on functions of LBS and characteristics of foreign models. This model is consisted of generalized components of LBS and can be used as a basic model to survey the requirement of each technologies. Second, we survey the demand of each technology for LBS. Then we analyze the importance of technologies for LBS to prepare developing various LBS. From this research, we can introduce proper plans and policy for LBS to develop technology stepwise, to promote industry activities and how to make up the foundation for LBS by government.

• Research in Community and Public Health Nursing
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• v.11 no.1
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• pp.3-20
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• 2000

The purpose of this study was to compare the concept of community and community health, community health assessment tool, and community health nursing diagnosis based on the concept of 'Community as Client'. The method for this purpose was to search the articles and textbooks related to community assessment and review the contents by the researchers who were 5 community health nursing faculties and 1 doctoral candidate. The sources of articles were limited in Public Health Nursing and the Journal of Community Health Nursing. As the result, three types of conceptual model were classified: epideiological model. fuctional model. system model. System model by Newman and Helvie included more comprehensive concept of community health than others. Helvie model suggested the most specific indicators among them. The components of nursing diagnosis in the system model had the subjectives. problems and the related factors. It makes the nursing care plan related to the nursing diagnosis. But there was no nursing diagnosis system among the three model. It is needed to compare the nursing intervention based on the concept of 'Community as Client'. It will be helpful to the community health nursing practice to develop the nursing diagnosis system based on the system model. For the community health nursing education, it is suggested to try the case study by the using three types of model. Finally, it is needed to validate the community assessment tool in Korean setting.