• Korean Chemical Engineering Research
• /
• v.52 no.4
• /
• pp.475-480
• /
• 2014

In the fields of researches associated with plant layout optimization, the main goal is to minimize the costs of pipelines for connecting equipment. However, what is the lacking of considerations in previous researches is to handle the multi floor processes considering the safety distances for domino impacts on a complex plant. The mathematical programming formulation can be transformed into MILP (Mixed Integer Linear Programming) problems as considering safety distances, maintenance spaces, and economic benefits for solving the multi-floor plant layout problem. The objective function of this problem is to minimize piping costs connecting facilities in the process. However, it is really hard to solve this problem due to complex unequality or equality constraints such as sufficient spaces for the maintenance and passages, meaning that there are many conditional statements in the objective function. Thus, it is impossible to solve this problem with conventional optimization solvers using the derivatives of objective function. In this study, the PSO (Particle Swarm Optimization) technique, which is one of the representative sampling approaches, is employed to find the optimal solution considering various constraints. The EO (Ethylene Oxide) plant is illustrated to verify the efficacy of the proposed method.

• Journal of the Korea Safety Management & Science
• /
• v.17 no.1
• /
• pp.75-84
• /
• 2015

Successful development of weapon systems requires a stringent verification and validation (V&V) process due to the nature of the weapons in which continual increase of operational capability makes the system requirements more complicated to meet. Thus, test and evaluation (T&E) of weapon systems is becoming more difficult. In such a situation, live fire tests appear to be effective and useful methods in not only carrying out V&V of the weapon systems under development, but also increasing the maturity of the end users operability of the system. However, during the process for live fire tests, a variety of accidents or mishaps can happen due to explosion, pyro, separation, and so on. As such, appropriate means to mitigate mishap possibilities should be provided and applied during the live fire tests. To study a way of how to accomplish it is the objective of this paper. To do so, top-level sources of hazard are first identified. A framework for T&E is also described. Then, to enhance the test range safety, it is discussed how test scenarios can be generated. The proposed method is based on the use of the anticipatory failure determination (AFD) and multiple event tree analysis (ETA) in analyzing range safety. It is intended to identify unexpected hazard components even in the environment with constraints. It is therefore expected to reduce accident possibilities as an alternative to the traditional root-cause analysis.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.6
• /
• pp.3052-3060
• /
• 2013

When planning to construct adjacent structure by the side tunnel, the criteria of safety zone of tunnel have been proposed. There are no specific theoretical basis regarding load conditions and the distance of structure and the geological strata and the conditions of adjacent structure's location, and the conditions applied load. Two and three dimensional numerical analysis preformed to prove the deformation of the ground and structures caused by the tunnel excavation and evaluated the correlation and the suitability of the tunnel's safety zone regarding the location of adjacent structures and the changes in the modulus of deformation. This paper proposed the safety zone's range is getting bigger as the modulus of deformation is higher. Also, it seems that the possible range of construction under constraints in the diagram of revalued safety zone significantly expands as shear failure line appears on the invert extension line below the spring line.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.3
• /
• pp.58-70
• /
• 2023

Based on the current state of safety management for small-scaled old buildings, this study identified problems and proposed improvement plans. The study investigated the current status of safety management based on relevant laws and government and financial portal data, as well as budget documents related to the targets of safety management, the organization responsible for safety management, and the budget required for organizational operation. As a result, the study revealed the problem of safety management blind spots for buildings that are not included in the legal safety inspection targets. It also identified difficulties in securing specialized personnel for the operation of local building safety centers and financial constraints for the operation of building safety special accounting. To address these issues, the study proposed measures such as expanding the scope of safety inspection targets for small-scaled old buildings to reduce safety management blind spots, improving compensation regulations for specialized personnel, setting a minimum ratio for enforcement fines to secure financial resources, and gradually adjusting building permit fees. The study aimed to contribute to improving the efficiency of safety management for small-scaled old buildings based on these proposed measures.

• Nuclear Engineering and Technology
• /
• v.55 no.9
• /
• pp.3150-3163
• /
• 2023

To improve the performance of blanket: maximizing the tritium breeding rate (TBR) for tritium self-sufficiency, and minimizing the Dose of backplate for radiation protection, most previous studies are based on manual corrections to adjust the blanket structure to achieve optimization design, but it is difficult to find an optimal structure and tends to be trapped by local optimizations as it involves multiphysics field design, which is also inefficient and time-consuming process. The artificial intelligence (AI) maybe is a potential method for the optimization design of the blanket. So, this paper aims to develop an intelligent optimization method based on an improved multi-objective NSGA-III algorithm and an adaptive BP neural network to solve these problems mentioned above. This method has been applied on optimizing the radial arrangement of a conceptual design of CFETR HCSB blanket. Finally, a series of optimal radial arrangements are obtained under the constraints that the temperature of each component of the blanket does not exceed the limit and the radial length remains unchanged, the efficiency of the blanket optimization design is significantly improved. This study will provide a clue and inspiration for the application of artificial intelligence technology in the optimization design of blanket.

• Nuclear Engineering and Technology
• /
• v.56 no.6
• /
• pp.2352-2366
• /
• 2024

Reinforced concrete (RC) shear walls with precast steel-concrete composite modular (PSCCM) are strongly recommended in the structural design of nuclear power plants due to the need for a large number of process pipeline crossings and industrial construction. However, the effect of the PSCCM on the mechanical behavior of the whole RC shear wall is still unknown and has received little attention. In this study, three 1:3 scaled specimens, one traditional shear wall specimen (TW) and two shear wall specimens with the PSCCM (PW1, PW2), were designed and investigated under cyclic loadings. The failure mode, hysteretic curve, energy dissipation, stiffness and strength degradations were then comparatively investigated to reveal the effect of the PSCCM. Furthermore, numerical models of the RC shear wall with different PSCCM distributions were analyzed. The results show that the shear wall with the PSCCM has comparable mechanical properties with the traditional shear wall, which can be further improved by adding reinforced concrete constraints on both sides of the shear wall. The accumulated energy dissipation of the PW2 is higher than that of the TW and PW1 by 98.7 % and 60.0 %. The failure of the shear wall with the PSCCM is mainly concentrated in the reinforced concrete wall below the PSCCM, while the PSCCM maintains an elastic working state as a whole. Shear walls with the PSCCM arranged in the high stress zone will have a higher load-bearing capacity and lateral stiffness, but will suffer a higher risk of failure. The PSCCM in the low stress zone is always in an elastic working state.

• Convergence Security Journal
• /
• v.14 no.1
• /
• pp.3-10
• /
• 2014

Private security organizations are complementary to the national safety of life and property of individuals as a social role to play in maintaining peace and order. Pursuit of profit is to the public practice according to the logic of capitalist markets and customers seeking to protect the lives and property. However, the legal and institutional constraints of private security is being requirements inhibited by the development. Crime prevention as a private security role that the private companies, which will pursue the public interest. After all, the expansion of the private security crime is results in an increase in unit. The current level of private security in the 1970s remain, and the constraints is being under goodwill and expertise outside of the training system on the market. Variety of crimes, including cyber crime increases and considering the reality of the constraints on private security requirements are able to improve or supplement shall be realistic. In particular, the legal, regulatory and institutional factors must be improved, with goodwill, and for the creation of new industrial policy as a complement to the public interest should be also provided. The private security law interests through integration of private security guards should be guaranteed, and the term of the theorem, sales activities, ensuring the training of professional staff with professional qualifications system is to be settled. As a private security guard industry growth and development can be based on this composition.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3A
• /
• pp.193-200
• /
• 2010

Structural design requires simultaneously to ensure safety by considering quantitatively uncertainties in the applied loadings, material properties and fabrication error and to maximize economical efficiency. As a solution, system reliability-based design optimization (SRBDO), which takes into consideration both uncertainties and economical efficiency, has been extensively researched and numerous attempts have been done to apply it to structural design. Contrary to conventional deterministic optimization, SRBDO involves the evaluation of component and system probabilistic constraints. However, because of the complicated algorithm for calculating component reliability indices and system reliability, excessive computational time is required when the large-scale finite element analysis is involved in evaluating the probabilistic constraints. Accordingly, an algorithm for SRBDO exhibiting improved stability and efficiency needs to be developed for the large-scale problems. In this study, a more stable and efficient SRBDO based on the performance measure approach (PMA) is developed. PMA shows good performance when it is applied to reliability-based design optimization (RBDO) which has only component probabilistic constraints. However, PMA could not be applied to SRBDO because PMA only calculates the probabilistic performance measure for limit state functions and does not evaluate the reliability indices. In order to overcome these difficulties, the decoupled algorithm is proposed where RBDO based on PMA is sequentially performed with updated target component reliability indices until the calculated system reliability index approaches the target system reliability index. Through a mathematical problem and ten-bar truss problem, the proposed method shows better convergence and efficiency than other approaches.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.1
• /
• pp.101-114
• /
• 2013

This paper presents the findings relative to the influence factors on the safety of construction worker's actions. It identifies the factors which are involved in the safety behavior exercised by construction worker. They are compiled from existing studies that investigates the factors relative to the safety behavior. This study finds some factors which have powerful direct effects on safety behavior of construction workers. In addition, a model which defines the relationship between the factors and the behaviors of workers is established to analyze the effects. This study contributes to designe a theoretical model that shows workers' behaviors and analyzes the effects attributed to these factors: i.e., organizational commitment, stress reaction, safety motivation, safety knowledge, and safety climate. Survey questionaries are administered to the workers on the construction job sites located in Daegu metropolitan city. using SPSS18.0 and AMOS18.0, Exploratory Factor Analysis, Cronbach's alpha, Confirmatory Factor Analysis, Structural Equations Model analysis were performed. The research findings are as follows; The communication and educational training have the direct effect on the safety behavior. The factors of the safety climate constraints and/or contributes to the safety motivation, safety knowledge, and organizational commitment.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.1
• /
• pp.29-36
• /
• 2014

To meet changing education needs due to globalization, interdisciplinary convergence, and ICT development, it is necessary for engineering disciplines to provide student-centered education. Not only do teaching methods using ICT reproduce teaching contents in a digital format, but they are also expected to be effective media for constructive student-centered learning whereby learners build knowledge themselves. The aim of this study was to develop a tool for safety education using virtual reality technology. To achieve the objectives, the author defined the requirements and constraints of the tool, and implemented a 3D educational tool in a virtual reality environment. A pilot test with 10 students showed positive results.