• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.61-70
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• 1999

In this paper, we analyze several exposure time schedules to obtain uniform multiple hologram and measure the diffraction efficiencies of holograms stored in $LiNbO_3$:Fe(0.015wt%) crystal through experiments. The minimum angular selectivity and the intensity ration of two incident beams are investigated precisely by the high resolution system(minimum angle : $0.0028^{\circ}$). Considering initial recording time, total exposure time and time constants, the efficiency distribution(0.014 ${\pm}$ 0.005%) of 100 holograms is measured and the 330 analog images are recorded in the same place. Also, total 500 holograms are retrieved by spatial multiplexing.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.920-927
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• 2009

Many schedule delays and cost overruns in interior construction are caused by a lack of understanding in detailed and complicated interior works. To minimize these potential impacts in interior construction, a systematic approach for project managers to detect discrepancies at early stages and take corrective action through use of visualized data is required. This systematic implementation is still challenging: monitoring is time-consuming due to the significant amount of as-built data that needs to be collected and evaluated; and current interior construction progress reports have visual limitations in providing spatial context and in representing the complexities of interior components. To overcome these issues, this research focuses on visualization and computer vision techniques representing interior construction progress with photographs. The as-planned 3D models and as-built photographs are visualized in a 3D walk-through model. Within such an environment, the as-built interior construction elements are detected through computer vision techniques to automatically extract the progress data linked with Building Information Modeling (BIM). This allows a comparison between the as-planned model and as-built elements to be used for the representation of interior construction progress by superimposing over a 3D environment. This paper presents the process of representing and detecting interior construction components and the results for an ongoing construction project. This paper discusses implementation and future potential enhancement of these techniques in construction.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.637-648
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• 2021

In order to support the establishment of a farming plan, it is important to preemptively evaluate crop changes and to provide precise information. Therefore, it is necessary to provide customized information suitable for decision-making by farming stage through scientific and continuous monitoring using drones. This study was carried out to support the establishment of the farming plan for ground vegetable. The cultivation management map of each information was obtained from preliminary study. Three cultivation management maps include 'field emergence map', 'stress map' and 'productivity map' reflected spatial variation in the plantation by providing information in units of plants based on 3-dimensions. Application fields of the cultivation management map can be summarized as follows: detect miss-planted, replanting decision, fertilization, weeding, pest control, irrigation schedule, market quality evaluation, harvest schedule, etc.

• Journal of Intelligence and Information Systems
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• v.6 no.2
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• pp.1-14
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• 2000

The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship, determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which cranes and berths should be assigned in such a way that all the spatial and temporal constraints are satisfied without any interference. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible, while the operation cost of the terminal should be minimized. In this paper, we present an effective and efficient approach to solving this type of problem, which combines constrain satisfaction search and heuristic repair. We first employ a constraint satisfaction search to find a feasib1e solution. Then, the feasible solution is modified to a more optimal one by iteratively applying our heuristic repair operations within the framework of constraint satisfaction search. Experimental results with a real data from Pusan East Container Terminal showed that our approach can derive a schedule of satisfactory quality in a very short time.

• The Journal of Information Systems
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• v.29 no.3
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• pp.179-195
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• 2020

Purpose & Design/methodology/approach Amidst the COVID-19 spread, interest in telework has been increasing as a way to respond to environmental changes and improve organizational performance. In this study, causal loop diagram, thinking process, and four principles of TRIZ were used to find various ways to achieve work-life balance for workers and firms in teleworking environment. Findings The result of the causal loop diagram shows that keeping work-life balance is needed to provide free extra time for workers and achieve the firm's performance through efficient coordination between departments in teleworking environment. Using thinking process of TOC, we proposed a evaporating cloud for work-life balance and reviewed assumptions and premises to maintain extra free time for workers and achieve firm's performance paradoxically, and suggested solutions through the breakdown of the assumptions and premises. Resolving the contradiction(RC) by spatial separation is to divide working spaces into home, smart center, and mobile work types, to find both ways to achieve the organizational performance, and to provide extra time for workers. RC by temporal separation is to divide working time into various unit time, and to find ways to achieve organizational performance through doing work at office or home periodically or shiftly according to a predetermined schedule and time setting. RC by situational separation is to give options of flexible methods of performing work according to the conditions of the company or the worker. RC by separation between part and a whole is to find ways to organize and do the work so that the entire work can be completed efficiently even if each work is performed separately in teleworking way. This study is meaningful in that it provides basic thinking framework for achieving work-life balance in teleworking environment and proposes ways to resolve conflict from various perspectives, but it is limited in that it has not been tested empirically.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1731-1737
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• 2007

This paper considers subway routing problem. Given a schedule of train to be routed by a railway stock, the routing problem determines a sequence of trains while satisfying turnaround time and maintenance restrictions. Generally, the solution of routing problem is generated from set partition formulation solved by column generation method, a typical integer programming approach for train-set. However, we find the characteristics of metropolitan subway which has a simple rail network, a few end stations and 13 departure-arrival patterns. We reflect a turn-around constraint due to spatial limitations has no existence in conventional railroad. Our objective is to minimize the number of daily train-sets. In this paper, we develop two basic techniques that solve the subway routing problem in a reasonable time. In first stage, we formulate the routing problem as a Min-cost-flow problem. Then, in the second stage, we attempt to normalize the distance covered to each routes and reduce the travel distance using our heuristic approach. Applied to the current daily timetable, we could find the subway routings, which is an approximately 14% improvement on the number of train-sets reducing 15% of maximum traveling distance and 8% of the standard deviation.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.67-75
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• 2012

For the last few years, LBS has attracted considerable attention from many industries and societies as a result of propagated smart devices. LBS has a high utilization of mobile users as it uses user positions as a significant factor. Current LBS has only taken user position into account and it makes some limits. So, it is necessarily suggested that support for personalized services which consider user's motion, traffic condition, weather condition, time, personal information and preferences that have a huge impact on the accuracy. The purpose of this study is to design the inference systems with user's motion, preferences and schedules and provide users with the personalized information. To achieve this, Movement Ontology, User Profile Ontology, Schedule Ontology and Work Ontology should be constructed and based on this, smart applications were developed. Developed applications induced appropriately recommended results according to user's preference, motion and directions.

• Spatial Information Research
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• v.23 no.1
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• pp.1-8
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• 2015

The purpose of this study is to develope BIM Template according to major building material for efficiently and quantitatively evaluating greenhouse gas emission at the design stage. Template users consider various environmental impacts without connecting simulation tools for analyzing environmental impact and Template users who have no prior knowledge can Life Cycle Assessment by using The green template. For this study, Database which was reflected in template was constructed considering environmental performance. and 6 kinds of environmental impact categories and PPS standard construction codes were analyzed by major building material derived from literature. Based on this analyzed data, The major Material Family according to the main building material was developed. When users conduct modeling by utilizing Family established, evaluating result can be confirmed in the Revit BIM Modeling program by using the schedule function of the Revit. Users through the modeling, the decision-making environment performance possible. In addition, we propose to create a guideline for the steps required to build an additional established family.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.119-126
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• 2011

During precise survey on the top of High rise buildings and civil structures, optical surveying equipments like a Total Station are not recommended to use because of some reasons that uneasier alignment with reflectors located at the top of building, increasing error depends on increasement of observation distance and unavailable dynamic positioning etc. Recently various GPS positioning methods have been applied to this job however almost of them are post-processing method which is required much longer time during for whole process includes stake-out, cross checking, fixing positions and final inspections. Therefore, in this study, we applied with RTK surveying system which allows stake-out and inspection in realtime to avoid delaying of construction schedule and also applied with Quasi Static RTK measurement and network adjustment to get a high accuracy within a few millimeters in structure positioning to achieve a successful management for process and quality control of the project. As a result, very high accurate surveying for structures within approx. 2mm in realtime has been achieved when surveyor conduct a network adjustment using least square method for 4 base lines created by Quasi Static RTK data and we expect this method will be applied to construction survey for high rise buildings and civil structures in the future.

• Journal of Korean Society of Transportation
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• v.32 no.5
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• pp.544-553
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• 2014

Activity-based models analyze individuals' various daily activities that are identified as a decision-making unit for transportation planning. In other words, it is the model that determines the types of activities according to the social, economic and situational characteristics of the groups with the same activity patterns and predicts individuals' activity time, distance, spatial movement and transportation mode. The activity-based model is a method of estimating more efficient and realistic demand in transportation forecasting because traffic is regarded as a complex decision-making process that an individual and other people participate in. In this paper, we grasp the factors affecting choice behavior of activity pattern and analyze choice behavior of activity pattern based on multi-dimensional characteristic of each person. First, we classify activity types of reviewing the trip chain and activity purpose. Next, we identified preferable activity types using complicated characteristics of main agent of activity. We concluded that choice behavior of activity pattern is dependent on complex characteristics of each agent, and further multi-dimensional characteristics of each person are affected over the whole decision process of activity schedule.