• International conference on construction engineering and project management
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• 2024.07a
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• pp.988-995
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• 2024

With the modern workplace's increasing dependence on computer-based tasks, traditional lighting standards have been identified as insufficient for optimal occupant comfort and productivity. Therefore, this paper presents a comprehensive system framework designed to manage visual fatigue and cognitive performance within office environments. Classification and regression models using gradient boosting machine and random forest to predict visual fatigue and cognitive performance were developed based on data collected from 16 subjects in experiments. To this end, the proposed system consists of two modules: the first module predicts visual fatigue and cognitive performance levels using classification models, offering immediate feedback to occupants. The second module, targeted at facility managers, uses regression models and a genetic algorithm to identify optimal lighting settings, aiming to minimize visual fatigue and enhance cognitive performance. This system can help to manage visual fatigue and cognitive performance simultaneously, contributing to improvement of eye health and productivity.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.367-374
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• 2024

The detection and tracking of construction workers in building sites generate valuable data on unsafe behavior, work productivity, and construction progress. Many computer vision-based tracking approaches have been investigated and their capabilities for tracking construction workers have been tested. However, the dynamic nature of real-world construction environments, where workers wear similar outfits and move around in often cluttered and occluded regions, has severely limited the accuracy of these methods. Herein, to enhance the performance of vision-based tracking, a new framework is proposed which seamlessly integrates three computer vision components: detection, tracking, and re-identification (DTR). In DTR, a tracking algorithm continuously tracks identified workers using a detector and tracker in combination. Then, a re-identification model extracts visual features and utilizes them as appearance descriptors in subsequent frames during tracking. Empirical results demonstrate that the proposed method has excellent multi-object-tracking accuracy with better accuracy than an existing approach. The DTR framework can efficiently and accurately monitor workers, ensuring safer and more productive dynamic work environments.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.123-128
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• 2012

An overview of the North Ecliptic Pole (NEP) deep multi-wavelength survey covering from X-ray to radio wavelengths is presented. The main science objective of this multi-wavelength project is to unveil the star-formation and AGN activities obscured by dust in the violent epoch of the Universe (z=0.5-2), when the star formation and black-hole evolution activities were much stronger than the present. The NEP deep survey with AKARI/IRC consists of two survey projects: shallow wide (8.2 sq. deg, NEP-Wide) and the deep one (0.6 sq. deg, NEP-Deep). The NEP-Deep provides us with a $15{\mu}m$ or $18{\mu}m$ selected sample of several thousands of galaxies, the largest sample ever made at these wavelengths. A continuous filter coverage at mid-IR wavelengths (7, 9, 11, 15, 18, and $24{\mu}m$) is unique and vital to diagnose the contribution from starbursts and AGNs in the galaxies at the violent epoch. The recent updates of the ancillary data are also provided: optical/near-IR magnitudes (Subaru, CFHT), X-ray (Chandra), FUV/NUV (GALEX), radio (WSRT, GMRT), optical spectra (Keck/DEIMOS etc.), Subaru/FMOS, Herschel/SPIRE, and JCMT/SCUBA-2.

• Journal of Intelligence and Information Systems
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• v.15 no.1
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• pp.51-64
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• 2009

A location tracking sensor such as GPS, INS, Radar, and optical equipments is used in tracking Maneuvering Targets with a multi-sensor, and such systems are used to track, detect, and control UAV, guided missile, and spaceship. Until now, Most of the studies related to tracking Maneuvering Targets are on fusing multiple Radars, or adding a supplementary sensor to INS and GPS. However, A study is required to change the degree of application in fusions since the system property and error property are different from sensors. In this paper, we perform the error analysis of the sensor properties by adding a ground radar to GPS and INS for improving the tracking performance by multi-sensor fusion, and suggest the tracking algorithm that improves the precision and stability by changing the sensor probability of each sensor according to the error. For evaluation, we extract the altitude values in a simulation for the trajectory of UAV and apply the suggested algorithm to carry out the performance analysis. In this study, we change the weight of the evaluated values according to the degree of error between the navigation information of each sensor to improve the precision of navigation information, and made it possible to have a strong tracking which is not affected by external purposed environmental change and disturbance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.2
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• pp.98-108
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• 2006

The vessels, already built and is operating in Korea, have the hull form of catamaran, with LOA(Length Over All) 15 m, LBP(Length Between Perpendiculars) 12 m, GT(Gross Tonnage) 9.77ton, Light Load Displacement 15.1ton. Korean Society of Ship Inspection & Technology, Chungnam National University, Inha University, Seoul National University and Advance Marine Tech co. ltd developed by cooperation it for fishing vessels. And it used FRP(Fiber Reinforced Plastics) for hull material and main engine of diesel $360ps{\times}2800rpm{\times}2sets$ with a water jet system. Based on these results, this paper describe small leisure fishing vessels with multi-hull, in relation to the project of CTYS(Regional Reserch Center for Transportation System of Yellow Sea Inha University) that aimed to development of trimaran hull form(LOA=17m, LBP=14m(Side Hull=6m), GT=9.77ton, Light Weight=11.2 ton).

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.307-311
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• 2018

It is necessary to establish wide integrated surveillance system of marine territory to reduce damage caused by maritime security threats, marine pollution and accidents for safe and clean marine use and efficient development of marine resources. For marine surveillance, the information characteristics of space-time specific, accuracy and operability are required, and real-time information about the wide area should be provided at all times. This special issue has been published to identify the characteristics of each platform, evaluate its usability for the establishment of a wide integrated surveillance system, and present the direction for future convergence studies between platforms. Since 2015, KIOST and cooperative research team have been performing the project, "Base research for building wide integrated surveillance system of marine territory using multi-platform" that detect vessels and red tide etc. near real time by using satellite, UAV and HF Ocean Radar. The objective of this special issue is to introduce the significance for an integrated system for maritime surveillance and to create a forum for discussion on recent advances in remote sensing technology and applications for marine disasters, pollution, and accident surveillance.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.195-204
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• 2008

Multi-Criteria Analysis is one method for optimizing decisions that include numerous characteristics and objective functions. The Analytic Hierarchy Process (AHP) is used as a general Multi-Criteria Analysis considering many critical issues. However, since validation procedures for the decision reliability of AHP valuers had been left off existing methodologies, a new methodology including such validation procedures is required to make more reliable decisions. In this research, idea decision results are derived using Monte Carlo Simulation in cases where AHP valuers do not have expertise in the specific project, and these results are compared with the results derived from experts to develop a new analysis model to make more reliable decisions. Finally, this new analysis is applied to various field case studies of road and rail carried out by the Korea Development Institute (KDI) between 2003 and 2006 to validate the new analysis model. The study found that approximately 20% of decisions resulting from the existing methodology are considered prudent. In future studies, the authors suggest analyzing the correlation between initial weights and final results since final results are enormously influenced by the initial weight.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.1-9
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• 2023

In order to carry out construction work, it is urgent to introduce a proper wage system so that the cost burden of projects that have been won due to bleeding competition among original government buildings based on low-priced bids can be transferred to subcontractors. Purpose: Construction with illegal multi-level industrial structure needs to improve the wage reduction environment leading to order (100%) → original contractor (80%) → subcontractor (65%) → load contractor (65%) and aims to ensure wages for end workers. Method: Investigate the current status of labor cost appropriate payment plan in the construction industry, and investigate the case of the appropriate wage system (P.W) in the United States. In addition, the effect and direction of the appropriate wage system are presented. Result: Individual minimum wage security was also mentioned in the Constitution, and many researchers suggested that only the introduction of an appropriate wage system could solve the problem of reducing worker labor and ensure quality and safety. Conclusion: The proper wage system in the construction industry will block illegal multi-level and illegal foreign work, improve the labor environment in the construction market, create an influx of young workers, and have a significant impact on the construction industry's competitive structure, safety, and quality.

• Land and Housing Review
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• v.15 no.3
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• pp.129-140
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• 2024

This research explores the potential of purchased rental housing as a versatile solution for residential development. By focusing on smaller-scale construction compared to large residential complexes, purchased rental housing projects offer benefits such as shorter project durations and enhanced flexibility to accommodate residents' needs. This public-private collaboration extends to community planning, enabling tailored models beyond traditional rental housing frameworks. Currently, purchased rental housing, which is predominantly comprised of multi-unit house, multi-household house, and rowhouses, is in high demand and in short supply in metropolitan areas. Utilizing volumetric modular housing, considerations for module size and transportability are paramount, while advancements in construction methods, particularly prefabrication, offer efficiency and quality benefits. This study proposed three construction techniques to plan modular housing models and enhance construction and demolition efficiency: planning without columns in the middle of the unit, core production using volumetric modular construction methods, and industrialization of construction components alongside dry construction methods. Utilizing these methods, a new construction model for purchase lease housing was presented to address the need for new housing in the context of ageing housing renovation and demand fluctuations. The model comprises 16 units, with sizes ranging from 36 m² to 54 m², and can be applied on sites larger than 600 m² with access to roads wider than 6 m. This promotes cluster-style development, which in turn increases construction efficiency in nearby plots.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.11
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• pp.471-480
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• 2023

The Korean construction order volume in South Korea grew significantly from 91.3 trillion won in public orders in 2013 to a total of 212 trillion won in 2021, particularly in the private sector. As the size of the domestic and overseas markets grew, the scale and complexity of EPC (Engineering, Procurement, Construction) projects increased, and risk management of project management and ITB (Invitation to Bid) documents became a critical issue. The time granted to actual construction companies in the bidding process following the EPC project award is not only limited, but also extremely challenging to review all the risk terms in the ITB document due to manpower and cost issues. Previous research attempted to categorize the risk terms in EPC contract documents and detect them based on AI, but there were limitations to practical use due to problems related to data, such as the limit of labeled data utilization and class imbalance. Therefore, this study aims to develop an AI model that can categorize the contract terms based on the FIDIC Yellow 2017(Federation Internationale Des Ingenieurs-Conseils Contract terms) standard in detail, rather than defining and classifying risk terms like previous research. A multi-text classification function is necessary because the contract terms that need to be reviewed in detail may vary depending on the scale and type of the project. To enhance the performance of the multi-text classification model, we developed the ELECTRA PLM (Pre-trained Language Model) capable of efficiently learning the context of text data from the pre-training stage, and conducted a four-step experiment to validate the performance of the model. As a result, the ensemble version of the self-developed ITB-ELECTRA model and Legal-BERT achieved the best performance with a weighted average F1-Score of 76% in the classification of 57 contract terms.