• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.2
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• pp.9-17
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• 2019

In order to deal with high uncertainty and variability in emergency medical centers, many researchers have developed various models for their operational planning and scheduling. However, most of the models just provide static plans without any risk measures as their results, and thus the users often lose the opportunity to analyze how much risk the patients have, whether the plan is still implementable or how the plan should be changed when an unexpected event happens. In this study, we construct a simulation model combined with a risk-based planning and scheduling module designed by Simio LLC. In addition to static schedules, it provides possibility of treatment delay for each patient as a risk measure, and updates the schedule to avoid the risk when it is needed. By using the simulation model, the users can experiment various scenarios in operations quickly, and also can make a decision not based on their past experience or intuition but based on scientific estimation of risks even in urgent situations. An example of such an operational decision making process is demonstrated for a real mid-size emergency medical center located in Seoul, Republic of Korea. The model is designed for temporal short-term planning especially, but it can be expanded for long-term planning also with some appropriate adjustments.

• Korean Circulation Journal
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• v.52 no.6
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• pp.414-428
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• 2022

Although tricuspid regurgitation (TR) is a general medical issue with growing prevalence and socioeconomic burden, most clinicians have not paid much attention to TR in the past. Several problems of TR have been pointed out in clinical practice, which include: ambiguous clinical manifestations and the difficulty in initial detection, limitations in generally used diagnostic tools, the absence of objective criterion for therapeutic intervention, high operative morbidity and mortality, and lack of long-term clinical data after the intervention for TR. Therefore, patients with TR usually visit clinicians at a much-advanced state, and this delay gives a major dilemma in clinical decision-making in a routine clinical practice. To improve the clinical outcome of TR, we need more knowledge about TR for solving the current problems and making strategies for better clinical practice. With this background, we have discussed in the present article about the pathophysiology of TR and the problems frequently experienced by clinical physicians in the diagnosis and treatment of TR. Furthermore, we have discussed the future strategy to improve the treatment of TR.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.233-234
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• 2022

In order to minimize casualties in case of a fire in a building, it is necessary to anticipate the time required for evacuation of occupants and the delay in evacuation in advance, and prepare countermeasures for possible occurrences. In fact, various factors that cannot be predicted exist and cannot be considered by excluding them, so the risk is predicted and evaluated through quantitative evacuation modeling. In order to understand this, we analyzed domestic and international evacuation modeling research trends. For about 40 years, starting with the characteristics of human movement, an evacuation modeling technique based on scientific methods has been developed through actual fire accident cases and various real-world experiments with humans. Then, in order to analyze the natural reaction of humans, which has a decisive influence in the recognition and decision-making phase, evacuation modelling studies have been conducted in depth using psychological and physical experimental methods.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.1-10
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• 2006

It is widely accepted that the coverage with high user densities can only be achieved with small cell such as micro- and pico-cell. The smaller cell size causes frequent handovers between cells and a decrease in the permissible handover Processing delay. This may result in the handover failure. in addition to the loss of some Packets during the handover. In these cases. re-transmission is needed in order to compensate errors, which triggers a rapid degradation of throughput. In this paper, we propose a new handover scheme in the next generation mobile communication systems, in which the handover setup process is done in advance before a handover request by predicting the handover cell based on mobile terminal's current position and moving direction. Simulation is focused on the handover failure rate and Packet loss rate. The simulation results show that our proposed method provides a better performance than the conventional method.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.91-99
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• 2013

PURPOSES : This study aims at proposing the methodology for benefit evaluations in pavement maintenance methods and timings using KoPMS(Korean Pavement Management System) software which was developed for efficient pavement management. METHODS : This study classified pavement sections into 4 clusters considering AADT(Annual Average Daily Traffic) and ESAL(Equivalent Single-Axle Load) using cluster analysis and used the deterioration models in each cluster. Increased user costs due to pavement deterioration as time goes by and agent costs for maintenance were estimated. Based on deterioration model and KoPMS software, Methodology for benefit evaluation was proposed in pavement maintenance methods and with/without implementation using real pavement section data. RESULTS : This study verified that considering agent costs only would be constrained to decide pavement maintenance methods and timings, and ascertained that decision making with agent and user costs would be effective. In addition, this study revealed that pavement maintenance methods and timings can be affected by AADT and ESAL and frequent pavement maintenances can be more efficient for benefits in pavement sections with more AADT and ESAL. Also this study found that user costs would be more affected to decision making than agent costs. Moreover, Delay of conducting pavement maintenance caused increased vehicle operating costs and environmental costs because of poor conditions of pavements. CONCLUSIONS : This study proposed LCCA and benefit estimation methodology of pavement with considering agent and user costs. The results of this study can be used for baseline data of efficient pavement asset management.

• International Journal of High-Rise Buildings
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• v.12 no.3
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• pp.225-234
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• 2023

Even at this point in the era of digital transformation, we are still facing many problems in the safety sector that cannot prevent the occurrence or spread of human casualties. When you are in an unexpected emergency, it is often difficult to respond only with human physical ability. Human casualties continue to occur at construction sites, manufacturing plants, and multi-use facilities used by many people in everyday life. If you encounter a situation where normal judgment is impossible in the event of an emergency at a life site where there are still many safety blind spots, it is difficult to cope with the existing manual guidance method. New variable guidance technology, which combines artificial intelligence and digital twin, can make it possible to prevent casualties by processing large amounts of data needed to derive appropriate countermeasures in real time beyond identifying what safety accidents occurred in unexpected crisis situations. When a simple control method that divides and monitors several CCTVs is digitally converted and combined with artificial intelligence and 3D digital twin control technology, intelligence augmentation (IA) effect can be achieved that strengthens the safety decision-making ability required in real time. With the enforcement of the Serious Disaster Enterprise Punishment Act, the importance of distributing a smart location guidance system that urgently solves the decision-making delay that occurs in safety accidents at various industrial sites and strengthens the real-time decision-making ability of field workers and managers is highlighted. The smart location guidance system that combines artificial intelligence and digital twin consists of AIoT HW equipment, wireless communication NW equipment, and intelligent SW platform. The intelligent SW platform consists of Builder that supports digital twin modeling, Watch that meets real-time control based on synchronization between real objects and digital twin models, and Simulator that supports the development and verification of various safety management scenarios using intelligent agents. The smart location guidance system provides on-site monitoring using IoT equipment, CCTV-linked intelligent image analysis, intelligent operating procedures that support workflow modeling to immediately reflect the needs of the site, situational location guidance, and digital twin virtual fencing access control technology. This paper examines the limitations of traditional fixed passive guidance methods, analyzes global technology development trends to overcome them, identifies the digital transformation properties required to switch to intelligent variable smart location guidance methods, explains the characteristics and components of AI-based public facility smart fire safety integrated system (ISFS).

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.122-128
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• 2017

Korean government announced long-term railway safety investment plan for the safety improvement by 2020. But no research have been done about differential analysis on railroad safety investment and safety improvement. In this study, recent 10 year data on safety investments and accident data are analysed for the differential analysis. Three main safety investments are analysed on regard to accident rate and accident fatalities. Three safety measures include level crossing accident, platform fatalities, and track trespass fatalities. About 90% of railway accident fatalities are caused by these three kind of accidents. Differential analysis shows about 4 to 6 years delay after railroad safety investment and safety improvement. This result can be utilized for the decision making on safety measures and safety target. Which required long term approach.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.7
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• pp.800-808
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• 2004

Wind tunnel test of an airplane model with forward swept wing was done in KARI LSWT to evaluate and measure the aerodynamic characteristics of initially designed configuration. Since the given wing planform did not fully satisfy the design requirements, local flow control devices such as vortilon, vortex generator and flow fence were used to delay separation and to enhance aerodynamic characteristics. Also decision making processes of design parameters such as vertical tail boom length, the location, size and the incidence angle of horizontal tail were discussed. The general aerodynamic characteristics of forward swept wing for various control surface deflection conditions of flap, aileron and elevator were also given.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.295-306
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• 2008

The Intersection is inner traffic facilities and the space where the roads are intersected and connected. And also, the Intersection is the decision-making section for drivers to select the route according to the geometric structure and operation method. However decision-making section cause to raise car accidents rate because it imposes a heavy burden on drivers. In that reason, many countries such as Europe use the Roundabouts to reduce the numbers of decision making and collision. In Korea, the kinds of method are just introduced and it is using now but there are no exact standards. Hence, this study suggests the process to evaluate and determine the types of Intersection which are based on the traffic flow (congestion) and traffic safety (accidents). Firstly, this study presents the number of accident at each Intersection which is depended on the traffic volume. Secondly, this study calculates and analysis the accident at signalized Intersection, non-signalized Intersection and Roundabout by TSIS-NETSIM program. Thirdly, this study concludes the best suitable Intersection type through the materials which are mentioned before.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.1-16
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• 2011

The real-time ubiquitous environment is required to be able to process a series of sensor data within limited time. The whole sensor data processing consists of several phases : getting data out of sensor, acquiring context and responding to users. The ubiquitous computing middleware is aware of the context using the input sensor data and a series of data from database or knowledge-base, makes a decision suitable for the context and shows a response according to the decision. When the real-time ubiquitous environment gets a set of sensor data as its input, it needs to be able to estimate the delay-time of the sensor data considering the available resource and the priority of it for scheduling a series of sensor data. Also the sensor data of higher priority can stop the processing of proceeding sensor data. The research field for such a decision making is not yet vibrant. In this paper, we propose a queuing time computation algorithm for sensor data processing in real-time ubiquitous environment.