• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.115-131
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• 2013

The Mizunami Underground Laboratory (MIU) Project is a comprehensive research project investigating the deep underground environment within crystalline rock being conducted by Japan Atomic Energy Agency. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of 20 years. The overall project goals of the MIU Project from Phase I through to Phase III are: 1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and 2) to develop a range of engineering for deep underground application. For the overall project goals 1), the Phase I goals were set to construct models of the geological environment from all surface-based investigation results that describe the geological environment prior to excavation and predict excavation response. For the overall project goals 2), the Phase I goals were set to formulate detailed design concepts and a construction plan for the underground facilities. This paper introduces geosynthesis procedures for the investigation and assessment of the hydrochemistry of groundwater in crystalline rock.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.993-1001
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• 2024

The TANDEM project is a European initiative funded under the EURATOM program. The project started on September 2022 and has a duration of 36 months. TANDEM stands for Small Modular ReacTor for a European sAfe aNd Decarbonized Energy Mix. Small Modular Reactors (SMRs) can be hybridized with other energy sources, storage systems and energy conversion applications to provide electricity, heat and hydrogen. Hybrid energy systems have the potential to strongly contribute to the energy decarbonization targeting carbon-neutrality in Europe by 2050. However, the integration of nuclear reactors, particularly SMRs, in hybrid energy systems, is a new R&D topic to be investigated. In this context, the TANDEM project aims to develop assessments and tools to facilitate the safe and efficient integration of SMRs into low-carbon hybrid energy systems. An open-source "TANDEM" model library of hybrid system components will be developed in Modelica language which, by coupling, will extend the capabilities of existing tools implemented in the project. The project proposes to specifically address the safety issues of SMRs related to their integration into hybrid energy systems, involving specific interactions between SMRs and the rest of the hybrid systems; new initiating events may have to be considered in the safety approach. TANDEM will study two hybrid systems covering the main trends of the European energy policy and market evolution at 2035's horizon: a district heating network and power supply in a large urban area, and an energy hub serving energy conversion systems, including hydrogen production; the energy hub is inspired from a harbor-like infrastructure. TANDEM will provide assessments on SMR safety, hybrid system operationality and techno-economics. Societal considerations will also be encased by analyzing European citizen engagement in SMR technology safety.

• Journal of Korean Society for Quality Management
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• v.50 no.2
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• pp.265-286
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• 2022

Purpose: The time and cost of a project activity exists in a selected mode and there is a quality level for the selected mode, and the time and cost of the current activity is determined by the quality level of the preceding activity. When an activity is a predecessor activity of an activity, it is characterized as a trade-off problem in which the time and cost of the activity are determined according to the quality level of the activity. Methods: A neighbor search heuristic algorithm obtains a solution by (1) randomly determining the mode, quality level, and assignment order for each activity. (2) get a solution by improving the solution by changing the possible modes and quality levels; (3) to find a solution by improving the solution from the point where it is feasible to advance the start time. Here, Case[1] is a method to find the optimal solution value after repeating (1). Case [2] is a method for finding a solution including (1) and (2). Case [3] refers to a method for finding solutions including (1), (2), and (3). Results: It can be seen that the value of the objective function presented by the algorithm changes depending on how the model of the heuristic algorithm is designed and applied. In other words, it suggests the importance of algorithm design and proves the importance of the quality problem of activities in the project schedule. Conclusion: A study significance of the optimization algorithm and the heuristic algorithm was applied to the effect of the quality of the preceding activity on the duration and cost of itself and the succeeding activity, which was not addressed in the project schedule problem.

• 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.

• IE interfaces
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• v.12 no.3
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• pp.354-361
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• 1999

In this paper, resource leveling heuristics are developed for ship erection scheduling. The heuristics, which enable scheduling with limited resources, are composed of the gradual resource limit decrease anti the resource allocation. At first, earliest start(ES) schedule is derived by PERT to get initial resource limit. And then, the heuristics lower the resource limits by a given increment and derive a new schedule from day-by-day resource allocation procedure. The procedure is repeated until the project duration reaches at the given ship erection duration, called dock cycle. Through the application of the heuristics for real world ship erection projects, wc can observe significant improvement in resource leveling.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1424-1430
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• 2007

Corrugated structural plate is ductile structural member which has high sectional properties compared with same thickness of plate. Corrugated plate resists the external forces by the combined action of retained soils and structures. Since it is easy to transport and assemblage of in-situ, the duration and cost of construction can be reduced. Corrugated plate structures, therefore, are widely used in culverts, hydro passages and simple bridges. RC culvert with supported by unstable soil layersin railway construction project of pohang${\sim}$samchuk has been replaced by corrugated plate culvert due to the reduction of construction duration and cost, especially the performance of behavior of settlement of ground. The structural analysis, design processes, and the economic advantages of the corrugated plate culvert are studied in this paper.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.35-36
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• 2017

The finish works of construction projects comprises approximately 40% of the total construction duration. Thus, the management of finish works have as big as impacts on total project duration as the earthworks, foundation and structure works. Process interference management is considered one of the most important issues dealt during finish works. However, it was investigated that effective management systems have yet not been applied for practical use. Accordingly, this paper suggests a mobile technology based finish works management system that mainly focuses on preventing process interference occurred due to ineffective communication between general and sub-contractors.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1094-1099
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• 2005

Nowadays the Design-Build Delivery Method in public sector has been remarkably grown up in applying owing to its merits such as shortening construction duration. The Fast-Track is the wide-using method for accelerating schedule at Design-Build projects. But the public agency is in trouble to execute Fast-Track because of the lack of guideline for its process. As a result, in some cases applying Fast-Track methods, cost and construction duration are increased more than cases of non-Fast-Track projects. In this study, through the questionnaire surveys to professionals having actual implementation experiences as a construction manager, owner or general contractor, key success vehicles of Fast-Track are induced.

• Water for future
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• v.9 no.1
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• pp.101-105
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• 1976

This Study is developed in order to determine the probability of a raintall depth of short duration in Seoul as considering the profect life and the factor of safety of hydraulic structures. The raw annual maximum rainfall data are selected from 1915 to 1974 about short duration (10min-120min.) in Seoul. The selected data are treated by frequency analysis, and the hypothesis that the distribution fuction of the raw data is normal Distribution is performed by chi-square test that signifcance level has 5%. With the parameters (mean and standard deviation) of the accepted distribution function, the probabilitn of a rainfall depth can be easily determined on the graph which is made on this paper.

• Journal of Korean society of Dental Hygiene
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• v.19 no.4
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• pp.515-524
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• 2019

Objectives: This study aimed to investigate the effects of the amount and duration of smoking on gingival symptoms in adolescents. Methods: We used the web-based survey data of youth health behaviors from 2016 conducted by the Korean Centers for Disease Control and Prevention. The subjects of the study were 67,983 middle and high school students. Data analysis was performed using the SPSS Ver 20.0 program, and complex sample multivariate logistic regression analysis was performed to analyze gingival symptoms according to short- or long-term smoking habits. Results: In subjects with short-term smoking habits, there was no significant difference in gingival symptoms according to the smoking amount. However, after adjusting for socioeconomic characteristics and oral health behaviors in subjects with long-term smoking habits, a heavy smoking amount (${\geq}0.52PY$) had a 1.25 times higher effect than a light smoking amount (<0.52 PY) on gingival symptoms. Long-term heavy smoking (${\geq}0.52PY$) and low daily tooth-brushing frequency in high school students were factors affecting gingival symptoms. Conclusions: When conducting a project on the oral health of adolescents, it is argued that specific investigations and measures should be set up regarding health behavior factors, such as the amount and duration of smoking among adolescents.