• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.36-45
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• 2000

Automated production system is composed of many complicated techniques and it become a very difficult task to control, monitor and diagnose this compound system. Moreover, it is required to develop an effective diagnosing technique and reduce the diagnosing time while operating the system in parallel under many faults occurring concurrently. This study develops a Modular Artificial Neural Network(MANN) which can perform a diagnosing function of multiple faults with the following steps: 1) Modularizing a complicated system into subsystems. 2) Formulating a hierarchical structure by dividing the subsystem into many detailed elements. 3) Planting an artificial neural network into hierarchical module. The system developed is implemented on workstation platform with $X-Windows^{(r)}$ which provides multi-process, multi-tasking and IPC facilities for visualization of transaction, by applying the software written in $ANSI-C^{(r)}$ together with $MOTIF^{(r)}$ on the fault diagnosis of PI feedback controller reactor. It can be used as a simple stepping stone towards a perfect multiple diagnosing system covering with various industrial applications, and further provides an economical approach to prevent a disastrous failure of huge complicated systems.

• Korean Journal of Artificial Intelligence
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• v.11 no.2
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• pp.1-6
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• 2023

This paper presents a comprehensive scheme for assessing the importance of multiple microgrids (MGs) network that includes distributed energy resources (DERs), renewable energy systems (RESs), and energy storage system (ESS) facilities. Due to the uncertainty of severe weather, large-scale cascading failures are inevitable in energy networks. making the assessment of the structural vulnerability of the energy network an attractive research theme. This attention has led to the identification of the importance of measuring energy nodes. In multiple MG networks, the energy nodes are regarded as one MG. This paper presents a modified PageRank algorithm to assess the importance of MGs that include multiple DERs and ESS. With the importance rank order list of the multiple MG networks, the core MG (or node) of power production and consumption can be identified. Identifying such an MG is useful in preventing cascading failures by distributing the concentration on the core node, while increasing the effective link connection of the energy flow and energy trade. This scheme can be applied to identify the most profitable MG in the energy trade market so that the deployment operation of the MG connection can be decided to increase the effectiveness of energy usages. By identifying the important MG nodes in the network, it can help improve the resilience and robustness of the power grid system against large-scale cascading failures and other unexpected events. The proposed algorithm can point out which MG node is important in the MGs power grid network and thus, it could prevent the cascading failure by distributing the important MG node's role to other MG nodes.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.131-145
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• 2010

The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.291-299
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• 2016

Recently, the knowledge industry center has played a role as a facility that creates economic added value because of the high-tech companies related to the knowledge industry, information, and communication. On the other hand, support facilities that are provided in the knowledge industry center are meant to support the company in the center and improve the working conditions of laborers. On the other hand, the support policy established by the government applies to some companies, and none of the support policy is carried out in supporting facilities in the knowledge industry center. In this study, multiple analysis was performed, focusing on the support facilities in the knowledge industry center that aims to improve the working environment of laborers. This study suggests the introduction of guidelines to secure adequate area, depending on the type of supporting facilities in the Knowledge Industrial Center. The sharing of facilities, such as cultural and commercial use for Knowledge Industrial Center, corresponding to poor provision, is recommended. Because the analysis of IPA indicates that the area of commercial support facilities are higher than others and cultural facilities are more important and preferred, it is necessary to compose support facilities that consider the user's individual characteristics. Facilities impacting the working environment need to be planned carefully through a district unit plan at the initial stages of development, thus assisting the production activity of workers.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1378-1389
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• 2021

TRIUMF, Canada's particle accelerator centre, is constructing a new high-power ISOL (Isotope Separation On-Line) facility called ARIEL (Advanced Rare IsotopE Laboratory). Thick porous targets will be bombarded with up to 48 kW of 480 MeV protons from TRIUMF's cyclotron, or up to 100 kW of 30 MeV electrons from a new e-linac, to produce short-lived radioisotopes for a variety of applications, including nuclear astrophysics, fundamental nuclear structure and nuclear medicine. For efficient release of radioisotopes, the targets are heated to temperatures approaching 2000 ℃, and are exposed to GSv/h level radiation fields resulting from intended fissions and spallations. Due to these conditions, the operational life for each target is only about five weeks, calling for frequent remote target exchanges to limit downtime. A few days after irradiation, the targets have a residual radiation field producing a dose rate on the order of 10 Sv/h at 1 m, requiring several years of decay prior to shipment to a national disposal facility. TRIUMF is installing new remote handling infrastructure dedicated to ARIEL, including hot cells and a remote handling crane. The system design applies learnings from multiple existing facilities, including CERN-ISOLDE, GANIL-SPIRAL II as well as TRIUMF's ISAC (Isotope Separator and ACcelerator).

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.411-423
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• 2020

To remove phosphorus from the effluent of public wastewater treatment facilities, hundreds of enhanced phosphorus treatment processes have been introduced nationwide. However, these processes have a few problems including excessive maintenance cost and sludge production caused by inappropriate coagulant injection. Therefore, the optimal decision of coagulant dosage and automatic control of coagulant injection are essential. To overcome the drawbacks of conventional phosphorus removal processes, the integrated sedimentation and dissolved air flotation(SeDAF) process has been developed and a demonstration plant(capacity: 100 ㎥/d) has also been installed. In this study, various jar-tests(sedimentation and / or sedimentation·flotation) and multiple regression analyses have been performed. Particularly, we have highlighted the decision-making algorithms of optimal coagulant dosage to improve the applicability of the SeDAF process. As a result, the sedimentation jar-test could be a simple and reliable method for the decision of appropriate coagulant dosage in field condition of the SeDAF process. And, we have found that the SeDAF process can save 30 - 40% of coagulant dosage compared with conventional sedimentation processes to achieve total phosphorus (T-P) concentration below 0.2 mg/L of treated water, and it can also reduce same portion of sludge production.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.123-136
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• 2003

In multiple apartment construction project, BCWS is a critical management factor and has a great influence on the success of the project. Due to the many apartment buildings & facilities which produce numerous activities, there are several problems in making out a time schedule of work as well as production and management of precise BCWS from the allocation of resources. In this study, actual condition survey was executed in terms of the calculation and the management of BCWS. This study propose better solutions for efficient calculation of BCWS through the analysis of the problems and standard schedule & progress curves.

• Smart Structures and Systems
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• v.24 no.3
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• pp.403-414
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• 2019

Offshore drilling has become a key process for obtaining oil. Offshore platforms have many applications, including oil exploration and production, navigation, ship loading and unloading, and bridge and causeway support. However, vibration problems caused by severe environmental loads, such as ice, wave, wind, and seismic loads, threaten the functionality of platform facilities and the comfort of workers. These concerns may result in piping failures, unsatisfactory equipment reliability, and safety concerns. Therefore, the vibration control of offshore platforms is essential for assuring structural safety, equipment functionality, and human comfort. In this study, an optimal multiple tuned mass damper (MTMD) system was proposed to mitigate the excessive vibration of a three-dimensional offshore platform under ice and earthquake loadings. The MTMD system was designed to control the first few dominant coupled modes. The optimal placement and system parameters of the MTMD are determined based on controlled modal properties. Numerical simulation results show that the proposed MTMD system can effectively reduce the displacement and acceleration responses of the offshore platform, thus improving safety and serviceability. Moreover, this study proposes an optimal design procedure for the MTMD system to determine the optimal location, moving direction, and system parameters of each unit of the tuned mass damper.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.762-774
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• 2022

The COVID 19 pandemic resulted in a considerable influence on the world economy. Being a big sector of the economy, the food supply chain struggled. The meat supply chain was most notably affected as every part of the supply chain from farm to shelf was closely inter-related. With the closure of businesses and restaurants the demand for at home food from grocery stores increased. Meat production facilities were impacted when the virus spread to the workers causing facilities to close or line speeds to slow. The combination of these two issues, in turn, led to there being less meat on the shelves. With less meat animals being harvested, there was less demand for livestock leading to farmers having an excess in slaughter ready animals. The decreased demand for livestock led to economic issues as money was lost in multiple sections of the supply chain. Aside from the economy and supply chain issues, other issues include concerns over the safety of meat products due to decreased safety protocols to increase line speed. Additionally, concerns of animal welfare with the excess of animals being culled were raised due to decreased capacity in processing facilities. While this review paper mainly focuses on characterizing the impact of COVID 19 on the meat supply chain in the USA, the compiled information should be able to provide practical insights to the meat/food industry across the globe to develop potential mitigating strategies against the COVID 19 and/or any similar pandemic incidences in the future.

• Journal of Forest and Environmental Science
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• v.39 no.3
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• pp.128-139
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• 2023

Urban forests serve multiple purposes by providing green resting spaces and environmental benefits for city residents. In the old city center, where parks are scarce, the campus of Kangwon National University, Chuncheon, Gangwon-do, South Korea, serves as an urban forest for students, faculty, and citizens. This study aims to quantitatively analyze the environmental functions of green spaces on campus, raising awareness about their importance among campus members. The total carbon storage of campus trees was estimated at 1,653,218 kg, including 1,512,586 kg in forest areas, 131,061 kg in planting spaces around buildings, and 9,571 kg in street spaces. The annual carbon uptake of campus trees was estimated to be 39,391 kg/year, with 30,144 kg/year in forest areas, 8,017 kg/year in planting spaces around buildings, and 1,230 kg/year in horizontal spaces. In addition, annual oxygen production was estimated to be 105,044 kg/year, with 80,385 kg/year in forest areas, 21,378 kg/year in planting spaces around buildings, and 3,281 kg/year in street spaces. Furthermore, we estimated carbon emissions from the use of on-campus facilities to be 4,856,182 kg/year, while oxygen consumption by members was estimated at 53,975 kg/year. However, the campus trees supplied a sufficient amount of oxygen, which was twice the amount required by school members. The carbon uptake amount was approximately 1% of the amount of carbon emissions, resulting in a modest contribution to improving the environmental conditions of the site.