• Wind and Structures
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• v.17 no.4
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• pp.419-433
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• 2013

This paper investigates the vertical profiles of horizontal mean wind speed and direction based on the synchronized measurements from a Doppler radar profiler and an anemometer during 16 tropical cyclones at a coastal site in Hong Kong. The speed profiles with both open sea and hilly exposures were found to follow the log-law below a height of 500 m. Above this height, there was an additional wind speed shear in the profile for hilly upwind terrain. The fitting parameters with both the power-law and the log-law varied with wind strength. The direction profiles were also sensitive to local terrain setups and surrounding topographic features. For a uniform open sea terrain, wind direction veered logarithmically with height from the surface level up to the free atmospheric altitude of about 1200 m. The accumulated veering angle within the whole boundary layer was observed to be $30^{\circ}$. Mean wind direction under other terrain conditions also increased logarithmically with height above 500 m with a trend of rougher exposures corresponding to lager veering angles. A number of empirical parameters for engineering applications were presented, including the speed adjustment factors, power exponents of speed profiles, and veering angle, etc. The objective of this study aims to provide useful information on boundary layer wind characteristics for wind-resistant design of high-rise structures in coastal areas.

• Journal of Information Technology Services
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• v.20 no.1
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• pp.41-54
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• 2021

The SW-centered battlefield management information system R&D project takes a long period of 5-10 years or more by applying a complex and rigid batch acquisition strategy. In order to solve this problem, it is necessary to institutionalize a rapid and flexible battlefield management information system R&D project management procedure applying agile development methodology, and a government project management organization and contract management method to support it In this study, we analyzed the case of applying the Agile development method centered on Scrum to the US SW-centered weapon system R&D project and the characteristics and problems of the battlefield management information system R&D project in Korea, and suggested improvement measures as follows. First, the battlefield management information system R&D model applies the hybrid development method, and the system requirements analysis and system structure design use the existing waterfall development procedure, and the agile method is applied from the SW requirements analysis to the system integration stage. Second, flexible adjustment of performance, schedule, and cost by organizing an Agile IPT in which military (requirements) - DAPA (project management) - developer - functional specialized organizations (test and evaluation, quality, government research institutes, etc.) participate. Third, improving the Basic Order Agreement so that it can be applied to agile R&D.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.183-183
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• 2021

Deep learning methods and their application have become an essential part of prediction and modeling in water-related research areas, including hydrological processes, climate change, etc. It is known that application of deep learning leads to high availability of data sources in hydrology, which shows its usefulness in analysis of precipitation, runoff, groundwater level, evapotranspiration, and so on. However, there is still a limitation on microclimate analysis and prediction with deep learning methods because of deficiency of gauge-based data and shortcomings of existing technologies. In this study, a real-time rainfall prediction model was developed from a sky image data set with convolutional neural networks (CNNs). These daily image data were collected at Chung-Ang University and Korea University. For high accuracy of the proposed model, it considers data classification, image processing, ratio adjustment of no-rain data. Rainfall prediction data were compared with minutely rainfall data at rain gauge stations close to image sensors. It indicates that the proposed model could offer an interpolation of current rainfall observation system and have large potential to fill an observation gap. Information from small-scaled areas leads to advance in accurate weather forecasting and hydrological modeling at a micro scale.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.596-601
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• 2013

In the current pavement construction practice, the state agencies traditionally determine the quality of the as-constructed pavement mix based on individual mixture material parameters (e.g., air voids, cement or asphalt content, aggregate gradation, etc.) and consider these parameters as key variables to influence payment schedule to the contractors and the present and future quality of the as-constructed mixture. A set of empirically pre-determined pay adjustment schedule for each parameter that was differently developed and being used by the individual agencies is then applied to a given project, in order to judge whether each parameter conforms to the designated specifications and consequently the contractor may either be rewarded or penalized in accordance with the payment schedule. With an improved quality assurance system, the Performance Related Specification, the individual parameters are not utilized as a direct judgment factor; rather, they become independent variables within a performance prediction function which is directly used to predict the performance. The quantified performance based on the prediction model is then applied to evaluate the pavement quality. This paper presents the brief history of the quality assurance in asphalt pavement construction including the Performance Related Specifications, statistical performance models in terms of fatigue and rutting distresses, as an example of the performance prediction models, and envisions the possibilities as to how this Performance Related Specification could be utilized in other infrastructures construction quality assurance.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.132-146
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• 2017

Appropriate speed limits at a reasonable level in urban roads are highly important factors for efficient and safe movement. Thus, it is greatly necessary to develop the objective models or methodology based on engineering study considering factors such as traffic accident rates, roadside development levels, and roadway geometry characteristics etc. The purpose of this study is to develop the estimate model of appropriate speed limits at each road sections in urban roads using traffic information big data and field specific data and to review the effects of accident decrease. In this study, the estimate method of appropriate speed limits in directional two or more lanes of urban roads is reflecting features of actual variables in a form of adjustment factor on the basis of the maximum statutory speed limits. As a result of investigating and testing influential variables, the main variables to affect the operating speed are the function of road, the existence of median, the width of lane, the number of traffic entrance/exit path and the number of traffic signal or nonsignal at intersection and crosswalk. As a result of testing this model, when the differences are bigger between the real operating speed and the recommended speed limits using model developed in this study, the accident rate generally turns out to be higher. In case of using the model proposed in this study, it means accident rate can be lower. When the result of this study is applied, the speed limits of directional two or more lane roads in Seoul appears about 11km/h lower than the current speed limits. The decrease of average operating speed caused by the decrease of speed limits is 2.8km/h, and the decrease effect of whole accidents according to the decrease of speed is 18% at research road. In case that accident severity is considered, the accident decrease effects are expected to 17~24% in fatalities, 11~17% in seriously injured road user, 6~9% in slightly injured road user, 5~6% in property damage only accidents.

• 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 Biosystems Engineering
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• v.20 no.2
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• pp.162-172
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• 1995

The ventilation in greenhouse have been important for such as adjustment of temperature, supplying of the oxygen, prevention of the overhumidity, density adjustment of $CO_2$, discharge of harmfulness gas, etc. However, the general ventilation which had been used the quantitative control method in discharge of a property of air mechanism in greenhouse, and caused mainly in waste of the heating energy and growth obstacle of the vegetable. Therefore, this study was peformed to obtain more scientific ventilation method using by analysis and measurement of the isothermal lines according to opening of window ventilation in greenhouse, and the results are summarized as follows. 1. The ventilating amount was more influenced by rather opening amount of window than the ventilating time. 2. In window ventilation, the temperature in greenhouse was mostly changed within 5 minutes after ventilating not regard to the spot of opening, after about 10 minutes temperature became to equilibrium state under the respective ventilating conditions. 3. In opening of the skylight only, isothermal lines were complicated, therefore, a tall vegetable may be possible to damage by a cold-weather from the lower central port in greenhouse. 4. Isothermal lines were a tendency to simply in opening of a side window that may be more effective ventilation in kinds of the short vegetable. 5. In conditions of internal temperature>setting temperature>external temperature, a skylight can be suitable to open 10~20cm in order to the optimum ventilation in greenhouse. 6. In conditions of internal temperature>external temperature>setting temperature, opening of all the windows or both the side windows that can be suitable in order to obtain the optimum ventilation in greenhouse. 7. An effect of ventilation was the most excellent to open of all the windows or both the side windows, and it were also found orderly excellent to open of the side window and the skylight or the skylight only, to open of the side window only. 8. Temperature was varied as the equation of T=Tc+ (To-Tc)e-at, and the ranges of (a) values were limited within 0.34~0.68. 9. A variations of humidity were similar to that of temperature, s.

• International Commerce and Information Review
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• v.16 no.4
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• pp.247-261
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• 2014

In this study, it investigates the highly controversial issue "low carbon car subsidy". Through the policy's intent, purpose, and necessity, it aims to present alternatives for automotive industry development. Introducing the low carbon car subsidy will bring a huge change to the vehicle purchase practices by changing vehicle purchase cost. It expects that this change will reduce greenhouse gas emission from vehicles. For successful settlement of the system, it shall set up the target sections for subsidy and levy appropriately in order to get the nation's consensus. Additionally, it has to conduct sufficient reviews the measures such as adjustment to the existing auto tax, divided payments of burden charge, etc before enforcing the system. In terms of the automobile industry, it must do their level best in technical development in order to meet the carbon dioxide emission level of imported cars until the enforcement. Also, the government has to strengthen its support to the industry.

• Korean Institute of Interior Design Journal
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• v.27 no.2
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• pp.118-127
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• 2018

To complete the appropriate pattern language as a planning tool for suburban houses in Korea, this study reviews the characteristics in applying the pattern language to suburban houses in Korea by creating the pattern application examination chart regarding 110 patterns in architecture and evaluating and analyzing 24 examples in terms of the applicability of the patterns, the results of which are as set forth below. Firstly, when grouping the upper 31 patterns by similar characteristics, it was distinguished by the characteristics relating to (i) securing of lighting and viewing; (ii) placing of buildings and space and adjustment of inside and outside privacy through such placing; (iii) placing of proper motion line and functions of adjacent space according to such motion line; and (iv) determining of important space such as personal room, area for couple or children, staircase, entrance, hallway, etc. Secondly, when analyzing the reasons that the lower 41 patterns have not been applied, it was characterized by (i) the work space not suitable for suburban houses or the patterns suitable for commercial space; (ii) the patterns not suitable in Korea due to cultural differences; and (iii) the patterns whose applicability cannot be confirmed due to the limitation of examples and materials used in this study. Thirdly, the analysis of each pattern group (A through M) revealed that the pattern groups D and G are rarely related to suburban houses and J and M are patterns whose applicability cannot be determined in this study. Another characteristics is that the pattern groups B, E, F, I and L which obtain high scores in applicability are importantly reflected in planning for suburban houses in Korea. Fourthly, this study renders the average score of applicability, and the applicability rate, of the examples and confirms the number of the patterns applied in confirmity, patterns partially or potentially applied and patterns not applied at all.

• Korean Institute of Interior Design Journal
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• v.26 no.3
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• pp.71-80
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• 2017

Korea is facing various social problems including single elderly household, increase in the number of disabled people and poverty rate and a difference in the proportion of males to females between urban areas and rural areas along with the advent of rapid aging society. Especially, the ratio of poor households in rural areas residing in housing which falls below the minimum housing level and most of them are in the dead zone of housing welfare. In addition, if it is impossible for them to move (relocate) to new housing, the house remodeling is the only measure for improving their housing welfare. However, we don't have enough prior relevant academic and practical experience, and house remodeling requires a series of process including prior planning construction and post-occupancy evaluation, but almost no fundamental research that provides relevant insight has been carried out. Therefore, the purpose of this study is to describe all field situations that occur in the whole customized house remodeling process for disabled female senior citizens living alone in a rural area. The remodeling process was classified into initial planning stage, field verification and adjustment stage and construction stage as the method to participate in the field directly, and any change in the remodeling plan and its causes at each stage were analyzed. As a result, some remodeling items were changed from the main viewpoint of participating parties before the beginning of construction and for reasons such as the deterioration level of housing site, limitation in building equipment and rearrangement of housing, etc., and the remodeling method and its details were developed. It was identified that constant change that occurred in the remodeling process resulted from 1) unique poor characteristics of existing housing and 2) physical condition of residents and their unique lifestyle characteristics that were two aspects required to be emphasized by customized remodeling.