• International conference on construction engineering and project management
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• 2024.07a
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• pp.909-916
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• 2024

The emergence of Building Information Modelling (BIM), reality data, Virtual Reality (VR), and Augmented Reality (AR) has significantly enhanced the collaboration between stakeholders in construction management. The utilization of VR/AR devices holds considerable potential for monitoring safety in complex and constrained working environments on the construction site. On the other hand, near-miss incidents remain an important early sign of struck-by accidents. However, research on early warning and prevention methods for this risk is still limited. This paper, therefore, presents a framework for on-site and off-site collaborative safety monitoring framework using augmented and virtual reality for near-miss incidents. In the proposed framework, three phases to develop a VR/AR-based safety monitoring system include (1) construction safety simulation environment, (2) localization-based interaction system, and (3) safety monitoring system. The system can undertake the processing of data and enables communication among disparate VR/AR devices. VR clients are observational tools and offer guidance, while the AR client stays onsite for construction tasks. All clients connect to a processing computer, which also works as a host. The system embedded in the AR device can trigger an alarm or receive signals from the VR client when a near-miss issue happens. Additionally, all device clients possess the capability to share data acquired from onsite monitoring cameras, thereby fostering effective discussions and decision-making. The efficacy of this cross-platform system has been validated through the implementation of an outdoor coordination case study.

• Journal of Hydrogen and New Energy
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• v.20 no.1
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• pp.22-30
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• 2009

Energy environment has been changing rapidly such as the fluctuation of oil prices and the effect on UNFCCC. Oil price change affects Korea's economy heavily due to her poor natural resources and large dependence of consumed energy resources. Korea takes the 4th place of importing the crude oil and 9th place in $CO_2$ emissions with the 1st place of $CO_2$ emissions increasing rate. Considering the current statue of Korea including oil price change and UNFCCC, Korea will be expected to be the Annex I nation due to Korean energy environments and the quantity of $CO_2$ emission. Energy technology development is a crucial key to cope with Korea's national energy security and environments. In this study, we establish the framework, which allocates the relative weights of assessment criteria and sub-criteria, for assessing and selecting R&D programs of energy technologies strategically. We integrated fuzzy theory and analytic hierarchy process (AHP) approach since the fuzzy AHP approach reflects the vagueness of human thoughts and perception effectively as making pairwise comparisons of criteria and alternatives. The fundamental data of this research results will support R&D planning phase for policy-makers and the production of well focused R&D outcomes.

• Journal of Korea Multimedia Society
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• v.23 no.7
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• pp.830-839
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• 2020

As a popular mathematical framework for modeling decision making, Markov decision process (MDP) has been widely used to solve problem in many engineering fields. MDP consists of a set of discrete states, a finite set of actions, and rewards received after reaching a new state by taking action from the previous state. The objective of MDP is to find an optimal policy, that is, to find the best action to be taken in each state to maximize the expected discounted reward of policy (EDR). In practice, MDP is typically unknown, so simulation-based policy improvement (SBPI), which improves a given base policy sequentially by selecting the best action in each state depending on rewards observed via simulation, can be a practical way to find the optimal policy. However, the efficiency of SBPI is still a concern since many simulation samples are required to precisely estimate EDR for each action in each state. In this paper, we propose a method to select the best action accurately in each state using a small number of simulation samples, thereby improving the efficiency of SBPI. The proposed method accumulates the simulation samples observed in the previous states, so it is possible to precisely estimate EDR even with a small number of samples in the current state. The results of comparative experiments on the existing method demonstrate that the proposed method can improve the efficiency of SBPI.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.91-100
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• 2014

While IT security investment of organizations has been increased, the amount of the monetary loss of organizations caused by IT security breaches did not decrease as much as their expectation. Also, from surveys, it was discovered that the poor usage of their security budget thwarted the improvement of the organization's security level. In this paper, to resolve the poor usage of security budget of organizations, we propose a comprehensive economic model for determining the optimal amount of investment in security solutions, including the proactive security solutions(PSSs) and the reactive security solutions(RSSs). Using the proposed analytical model under different parameters of security solutions, we show the optimal condition to maximize the expected net benefits from IT security investment of organizations. Also, we verify the common belief that the optimal level of investment in security solutions is an increasing function of vulnerability. Through simulations, we find the optimal level of IT security investment, given parameters of different characteristics of security solutions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.10-24
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• 2014

In-vehicle warning information systems(IWIS) is an effective countermeasure for preventing traffic crashes. It provides drivers with warnng messages about upcoming hazards to draw proper evasive maneuvering. This study developed a methodology for evaluating the effectiveness of IWIS based on an integrated index to identify driver's responsive behavior. The proposed index consists of characteristics of longitudinal and lateral behavior of vehicle maneuverings. Also, a method to assign mixed-weights in the context of multi-criteria decision making framework was adopted to develop the evaluation method. It is expected that the outcome of this study is useful in designing more effective in-vehicle warning information systems.

• Journal of Korean Society on Water Environment
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• v.29 no.2
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• pp.259-269
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• 2013

This study aims to show the feasibility of wastewater reuse through hydrological analysis and propose a framework for planning using multi-criteria decision making technique. Ten alternatives of wastewater reuse (BOD: 3.0 mg/L & 4.7 mg/L) and two references in the urban watershed were considered and analyzed by using Hydrological Simulation Program in Fortran (HSPF). Though wastewater reuse has a positive effect on water quantity, it may degrade the water quality due to the high discharge concentration. This study showed that wastewater reuse can be a great alternative for the rehabilitation of distorted water cycle, if the quality is improved up to the natural streamflow and the quantity is increased up to the instreamflow requirement. In addition, to determine the project priority, three criteria were compared: 1) impacts on water quantity and water quality, respectively, 2) consideration of present hydrologic vulnerabilities on water quantity and quality and not, and 3) social and economic considerations and not. From the performance values to all criteria, the specific ranking can be derived and the feasibility of each wastewater reuse project can be checked with the comparison of the existing facilities. As a result, DJ and DR were derived to become effective in any evaluation conditions while SS and WG were improper alternatives if various criteria were considered. The decision making for project prioritization must be careful with the consideration of various impacts of wastewater reuse because the evaluation of wastewater reuse alternative showed very different priorities for each criteria.

• Journal of Intelligence and Information Systems
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• v.9 no.1
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• pp.1-21
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• 2003

As electronic commerce(EC) has grown rapidly, agents that work on the behalf of humans on the Internet are being used actively. However, most of the EC agents have some problems. They fail to fully support buyers' decision making behaviors and sellers' information supply activities. Further, they are not suited for mobile computing environment. In this paper, we introduce a Multi-Mobile Agents System(MMAS) that has been developed according to a conceptual framework that corrects the aforementioned problems. Built by using Tokyo IBM ASDK(Aglets Software Development Kit) for the area of hotel reservation, the system consists of buyer- and seller-side agents that interact with each other; buyer-side agents help buyers to make purchasing decisions by collecting and analyzing information through applying a multi-criteria decision making method, while seller-side agents substitute fur sellers by managing databases and providing real-time information to the buyer-side agents. In this system, multiple agents perform their shared tasks at the same time in order to increase efficiency. Users do not have to keep the connection with the system because they are notified when tasks are done.

• Journal of KIISE
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• v.44 no.6
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• pp.613-620
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• 2017

Skyline queries are used extensively to solve various problems, such as in decision-making, because they find data that meet a variety of user criteria. Recent research has focused on skyline queries by using the MapReduce framework for large database processing, mainly in terms of applying existing index structures to MapReduce. In a skyline, data closer to the origin dominate more area. However, the existing index structure does not reflect such characteristics of the skyline. In this paper, we propose a grid-block structure that groups grid cells to match the characteristics of a skyline, and a two-level grid-block structure that can be used even when there are no data close to the origin. We also propose an efficient skyline-query algorithm that uses the two-level grid-block structure.

• PNF and Movement
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• v.14 no.3
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• pp.157-176
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• 2016

Purpose: The purpose of this study was to share an experience about processes and lessons learned to execute evidence-based practice (EBP) in neurological physical therapy. Methods: The most important thing in applying EBP to practice is to search, find, and appraise the existing evidence. Many evidence databases are available, such as CENTRAL, PEDro, PUBMED, and EMBASE. However, the knowledge represented in these databases is not always perfect. The practice model is a set of processes to resolve client problems. Therapists should make hypothesis-focused decisions through EBP. Integrating clinical reasoning and evidence is most important when it comes to the execution of EBP. Results: The process of EBP consisted of following: coming up with clinical questions, followed by searching for, appraising, evaluating, and integrating evidence. To integrate EBP into practice, it is necessary to consider clinical expertise, patient value and preferences, as well as research wth the best evidence. We provided an example of a clinical case with a stroke patient to show how this process and framework concerning clinical reasoning through evidences can be integrateds. During this process, we also utilized information technology to improve EBP ability. Conclusion: We should recognize what manner of information is needed to resolve eash patient's problem, and we should search for this information efficiently. Then, we should judge the value of the information obtained as it applies, to the clinical setting.

• Journal of Korean Society of Transportation
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• v.14 no.4
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• pp.91-106
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• 1996

This paper deals with on the efficiency questions of the left-turn prohibit at an isolated intersection and a corridor with 5-phase signal system. Its objectives are three-fold ; (1) to analyze the efficiency of the left-turn prohibit with the use of an imaginary network, (2) to evaluate various factors under consideration in decision making on the left-turn prohibit, (3) to provide a framework for estimating and evaluating overall impacts of the left-turn prohibit in traffic network. the major findings using an imaginary network and computer packages such as MINUTP, TRANSYT-7F and STATGRAPH are followings. First, left-turn prohibit reduces cycle length by 33 seconds and delay time per vehicle by 36 seconds at an isolated intersection, and cycle length by 31 seconds and delay time per veicle by 43 seconds along a corridor. Second, total vehicle mile of travel and total travel time at an isolated intersection seem up to increase 38.85 miles(57.36km), 14.4 hour on the average, Regarding to a corridor, total vehicle mile of travel is increased by 50.14 miles(80.22km), but total travel time is decreased by129.9 hours. Third, the efficiency of left-turn prohibit are affected the following eight factors including left-turn volume(veh/hr) and ratio(%), average delay time per vehicle(sec/veh) and others. Finally, several simple and multiple regression models to evaluate the impacts on the left-turn prohibit are formulated from the above eight factors. It can be expected that these models will take an important role in decision-making of left-turn prohibit.