• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.187-192
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• 2010

본 논문에서는 휴대폰을 이용한 블루투스 기반의 LBS를 위하여 블루투스 AP의 용량에 대한 시뮬레이션 및 분석을 수행하였다. 블루투스의 연결과정 및 데이터 전송에 소요되는 시간을 분석하여 블루투스 AP를 위한 모델을 도출하고 모의 실험하였다. 콘텐츠 크기와 서비스 범주 내의 사용자 빈도를 추가적으로 고려하여 모델링하고 주어진 시간 내에 가능한 사용자 수를 도출함으로써 블루투스 기반의 LBS 서비스에 활용이 가능하도록 하였다.

• 한국BIM학회 논문집
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• 제5권3호
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• pp.41-50
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• 2015

Increasing size and complexity of indoor structures have led to much more complication in the spatial cognition and situational awareness. Contrary to outdoor environments, occupants have limited information regarding the indoor space syntax in terms of architectural and semantic information as well as how they interact with their surroundings. The availability of such information could give conveniences to both users and managers in various aspects. In order to visualize the exact location of rooms and utilities in 3D, many studies and projects have utilized BIM models because of its promising value of representing building components. In fact, the application of BIM provides definitive spatial indoor data and creates services for indoor space management and navigation. Therefore, this paper aims to provide an overview of practices on BIM-based indoor spatial information implementation and location-based services. It is expected that enabling of technologies, data-rich content and accessibility of information products will accelerate the growth of the spatially-related markets in various fields.

• 산업공학
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• 제22권3호
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• pp.234-242
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• 2009

It is most important for distribution center in retail business to delivery commodities in a timely manner. Accordingly, many companies try to make distribution center effective using the Warehouse Management System(WMS) integrated legacy system. Also, the Customer Relationship Management(CRM) is the most typical paradigm in management lately. Even though the WMS and CRM are independent system of each other, WMS, coupled with CRM makes customer satisfied more effectively. In this paper, we proposed the methodology for inventory location after analyzing and applying customer buying pattern data in the CRM through the MBA(Market Basket Analysis), which is part of data mining. We used an example modeling a real distribution center in retail through a 3D simulation tool and examined correlation between commodities using customer buying pattern. After that, we applied it to the inventory location system through the MBA in an example. Finally, we identified decrease in the time for picking, which is the majority of distribution center. Besides, we proposed a simulation methodology before applying new methodology. Consequently, it removes potential errors in advance and makes a optimized inventory location system.

• 한국BIM학회 논문집
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• 제7권1호
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• pp.45-53
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• 2017

Continuous research efforts have been made on acquiring location data on construction sites. As a result, GPS and RFID are increasingly employed on the site to track the location of equipment and materials. However, these systems are based on radio frequency technologies which require attaching tags on every target entity. Implementing the systems incurs time and costs for attaching/detaching/managing the tags or sensors. For this reason, efforts are currently being made to track construction entities using only cameras. Vision-based 3D tracking has been presented in a previous research work in which the location of construction manpower, vehicle, and materials were successfully tracked. However, the proposed system is still in its infancy and yet to be implemented on practical applications for two reasons. First, it does not involve entity matching across two views, and thus cannot be used for tracking multiple entities, simultaneously. Second, the use of a checker board in the camera calibration process entails a focus-related problem when the baseline is long and the target entities are located far from the cameras. This paper proposes a vision-based method to track multiple workers simultaneously. An entity matching procedure is added to acquire the matching pairs of the same entities across two views which is necessary for tracking multiple entities. Also, the proposed method simplified the calibration process by avoiding the use of a checkerboard, making it more adequate to the realistic deployment on construction sites.

• 한국정보시스템학회지:정보시스템연구
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• 제21권4호
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• pp.55-79
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• 2012

LBS(Location-Based Service) is one of the smartphone application services which has been receiving great attention recently. Various applications of smartphone use LBS to provide innovative services. However, use of LBS raises privacy concerns because the location information of users is constantly exposed. Privacy calculus perspective attempts to understand the characteristics of the user's privacy. It is based on the risk-benefit analysis in the economics' perspective. That is, when the benefit expected through personal information disclosure is higher than risk, we are willing to provide personal information. This research suggested a research model based on the privacy calculus perspective to clarify the effect of information disclosure intention of smartphone LBS application users. Based on the main factors of privacy calculus, perception of privacy risk and privacy benefit, the relationship of the perceived value and the information disclosure intention was empirically analyzed by utilizing structural equation modeling(SEM) methodology. According to the results of the empirical analysis, it was found that all relations have statistically significant explanatory power except the relation between privacy concern and information disclosure intention. This study showed a strong evidence of antecedent factors based on privacy calculus of personal information disclosure in smartphone LBS applications.

• 대한산업공학회지
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• 제39권6호
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• pp.587-598
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• 2013

In Korea military (KM), various military supplies are distributed to individual military units via three different multi-tier supply networks owned and operated by army, navy, and air force, respectively. Under the current supply networks, the chances for the occurrence of delayed supply, undersupply, and oversupply increase, and supply redundancy also can become a problem. Thus, KM is now trying to improve its current multi-tier supply networks by constructing logistics consolidation centers. Private companies operate logistics consolidation centers to effectively manage various types of inventories before delivering them to final customers. In this paper, we newly propose a mathematical model for building the optimized military supply network considering adopting the military logistics consolidation centers. Based on the real situation of KM, the proposed model was validated in terms of its feasibility, and it seems that the outcome (the location of the military logistics consolidation centers) of the proposed model can be one of the good alternatives for KM.

• 한국BIM학회 논문집
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• 제10권2호
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• pp.21-28
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• 2020

As the number of aging bridges increases, more studies are being conducted on developing effective and reliable methods for the assessment and maintenance of bridges. With the advancement in new sensing systems and data learning techniques through AI technology, there is growing interests in how to evaluate bridges using these advanced techniques. This paper presents a CNN(Convolution Neural Network) deep learning based technique for evaluating the damage existence and for estimating the damage location in PSC bridges using static strain data. Simulation studies were conducted to investigate the proposed method with error analysis. Damage was simulated as the reduction in the stiffness of a finite element. A data learning model was constructed by applying the CNN technique as a type of deep learning. The damage status and its location were estimated using data set built through simulation. It was assumed that the strain gauges were installed in a regular interval under the PSC bridge girders. In order to increase the accuracy in evaluating damage, the squared error between the intact and measured strains are computed and applied for training the data model. Considering the damage occurring near the supports, the results of error analysis were compared according to whether strain data near the supports were included.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.926-939
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• 2022

The area of this study will cover the location-wise seismic response variation of an electrical cabinet in nuclear power point (NPP) based on classical reliability analysis. The location-based seismic ground motion (GM) selection is carried out with the help of probabilistic seismic hazard analysis using PSHRisktool, where the variation of reliability analysis can be understood from the relation between the reliability index and intensity measure. Two different approaches such as the first-order second moment method (FOSM) and Monte Carlo Simulation (MCS) are helped to evaluate and compare the reliability assessment of the cabinet. The cabinet is modeled with material uncertainty utilizing Steel01 as the material model and the fiber section modeling approach is considered to characterize the section's nonlinear reaction behavior. To verify the modal frequency, this study compares the FEM result with recorded data using Least-Squares Complex Exponential (LSCE) method from the impact hammer test. In spite of a few investigations, the main novelty of this study is to introduce the reader to check and compare the seismic reliability assessment variation in different seismic locations and for different earthquake levels. Alongside, the betterment can be found by comparing the result between two considered reliability estimation methods.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1179-1186
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• 2022

Building Information Modeling (BIM) is widely used to efficiently share, utilize and manage information generated in every phase of a construction project. Recently, mixed reality (MR) technologies have been introduced to more effectively utilize BIM elements. This study deals with the haptic interactions between humans and BIM elements in MR to improve BIM usability. As the first step in interacting with virtual objects in mixed reality, we challenged moving a virtual object to the desired location using finger-pointing. This paper presents the procedure of developing a haptic interface system where users can interact with a BIM object to move it to the desired location in MR. The interface system consists of an MR-based head-mounted display (HMD) and a mobile application developed using Unity 3D. This study defined two segments to compute the scale factor and rotation angle of the virtual object to be moved. As a result of testing a cuboid, the user can successfully move it to the desired location. The developed MR-based haptic interface can be used for aligning BIM elements overlaid in the real world at the construction site.

• Structural Engineering and Mechanics
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• 제89권1호
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• pp.61-75
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• 2024

Strengthening of hollow structural sections using through-bolts is a cost-effective and straightforward approach. It's a versatile method that can be applied during both design and service phases, serving as a non-disruptive and budget-friendly retrofitting solution. Existing research on axially loaded hollow sections T-joints has demonstrated that this technique can amplify the joint strength by 50%, where single bolt could enhance the strength of the joint by 35%. However, there's a gap in understanding their use for K-joints. As the behavior of K-joints is more complex, and they are widely existent in structures, this study aims to bridge that gap by conducting comprehensive parametric study using finite element analysis. Numerical investigation was conducted to evaluate the effect of through bolts on K-joints focusing on using single through bolt to achieve most of the strengthening effect. A full-scale parametric model was developed to investigate the effect of various geometric parameters of the joint. This study concluded the existence of optimal bolt location to achieve the highest strength gain for the joint. Moreover, a rigorous statistical analysis was conducted on the data to propose design equations to predict optimal bolt location and the corresponding strength gain implementing the verified by finite element models.