• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.333-336
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• 2003

For long time, the takeoff and landing control of airship was worked by human handling. With the development of the autonomous control system, the exact controls during the takeoff and landing were required and lots of methods and algorithms were suggested. This paper presents the result of airship take-off and landing by buoyancy control using air ballonet volume change and performance control of pitch angle for stable flight within the desired altitude. For the complexity of airship's dynamics, firstly, simple PID controller was applied. Due to the various atmospheric conditions, this controller didn’t give satisfactory results. Therefore, new control method was designed to reduce rapidly the error between designed trajectory and actual trajectory by learning algorithm using an artificial neural network. Generally, ANN has various weaknesses such as large training time, selection of neuron and hidden layer numbers required to deal with complex problem. To overcome these drawbacks, in this paper, the RBFN (radial basis function network) controller developed.

• Journal of KIBIM
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• v.8 no.2
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• pp.1-9
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• 2018

Nowadays Building Information Modeling (BIM) is a significant source of sharing project information in the construction industry. This method of sharing the information enhances the project understanding among stakeholders. Modeling of information using BIM is becoming an essential part of many construction projects around the globe. Despite rapid adoption of BIM in construction industry still, some sectors of the industry like earthwork have not yet reaped its full benefits. BIM has brought a paradigm shift through identification and integration of the roles and responsibilities of project participants on a single platform. BIM is a 3D model-based process which provides the insight into the efficient project planning and design. The 3D modeling can also be used significantly for the design of temporary structures in an earthwork project. This paper presents the quantity take-off methodology and parametric modeling technique for creating the temporary structures using 3D BIM process. A case study is conducted to implement the proposed temporary structure family design on a real site project. The study presented is beneficial for the earthwork project stakeholders to extract the relevant information using 3D BIM models in a project. It provides an opportunity to calculate the quantity of material required for a project accurately.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.109-116
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• 2010

This study aims to comparatively analyze kinetic variables that affect high jump records and thus to provide the basic data for enhancement of physical education teachers' teaching skills and expertise. 10 students who were majoring in physical education in a college of education - five males and five females - were chosen for the experiment in which the 3D image analyzer and ground reaction force measuring unit were adopted. The kinetic variables of the groups, the characteristics and differences were analyzed, and the correlation between each variable and record in each group was examined. The results are as follows: As to the height of center of gravity from one step before stamping to landing, the vertical velocity of the center of gravity at take off, the vertical velocity of the limbs at take off, the angles of the hip joint and ankle joint of the jumping leg, it turned out that male were better than female. As to the angles of the hip joint and ankle joint of the lead leg, female recorded higher values than male. As to the maximum vertical ground reaction force, the maximum horizontal ground reaction force, the vertical impulse, it turned out that male were better than female.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.580-585
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• 2005

A QRT(Quad-Rotor Type) hovering robot system is developed for quick detection and observation of the circumstances under calamity environment such as indoor fire spots. The UAV(Unmanned Aerial Vehicle) is equipped with four propellers driven by each electric motor, an embedded controller using a DSP, INS(Inertial Navigation System) using 3-axis rate gyros, a CCD camera with wireless communication transmitter for observation, and an ultrasonic range sensor for height control. The developed hovering robot shows stable flying performances under the adoption of RIC(Robust Internal-loop Compensator) based disturbance compensation and the vision based localization method. The UAV can also avoid obstacles using eight IR and four ultrasonic range sensors. The VTOL(Vertical Take-Off and Landing) flying object flies into indoor fire spots and sends the images captured by the CCD camera to the operator. This kind of small-sized UAV can be widely used in various calamity observation fields without danger of human beings under harmful environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.198-199
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• 2014

In construction management the estimation procedure of construction expanses follows a series of submission phases: production of drawings, the assessment report, and the expanse report. In South Korea, it is a widely known issue that the expanse report only includes the net expanses at each construction phase and part, which makes it difficult to trace detailed basis from the records. This issue with inefficient record management should pose a number of problems, which result from discontinuation of construction record, unproductiveness for reproduction of records at each construction and submission phases for construction management, and failure to perform fair management among the contracting parties. Thus, the amendment in which the assessment report and the quantity estimation report reflect common codes to share throughout types of construction, space, and parts should be applied into practices so as to model production of acceptable reports and record.

• Journal of KIBIM
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• v.7 no.2
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• pp.8-15
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• 2017

Building Information modeling is playing an important role in transforming the construction industry. It helped the industry with better visualization, minimum design errors, and excellent planning of the construction activities. Time and cost saving can be effectively achieved by using BIM for any construction project. It improves information exchange between all the project stakeholders. However, the development of earthwork 3D BIM is still underway and has not been fully implemented yet. This paper presents the study of a complete process for Earthwork BIM design using Autodesk Civil 3D. A real site road construction project is used as a case study to explain the process of earthwork modeling, starting from laser scanning to 3D model. Quantity take off calculation is very important part of any road construction project so during this study earthwork volume from two 3D earthwork model is calculated. The results obtained through this study will be the basis for future work which has been concluded in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.459-459
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• 2000

The purpose of this paper is the application of the techniques for the new estimation of robustness for the aircraft systems having structured uncertainties. The basic ideas to analyze the system which is the originally nonlinear is Lyapunov direct theorems. The nonlinear systems have various forms of terms inside the system equations and this investigation is confined in the form of bounded uncertainties. The number of uncertainties will be the degree of freedoms in the calculation of the robust stability regions called the robustness bounds. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. Using this relaxing stability conditions, in this paper, the quadratic form of Lyapunov function is utilized. In this paper, the practical system of vertical take-off and landing (VTOL) aircraft is analyzed with the proposed stability criteria based upon the Lyapunov direct method. The application of numerical procedures can prove the improvements in estimations of robustness with structured uncertainties. The applicable aircraft system is assumed to be linear with time-varying with nonlinear bounded perturbations.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.108-117
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• 2008

A transmission designed with P.T.O(Power Take-Off) axle for agricultural work vehicles including multi-purpose vehicles has been developed. It is focused on the 4-wheel drive transmission of synchronous contact type for practical use in fruit tree households which is required for a large-sized agricultural vehicle. Concerning to the specification performed, the load capacity is from 500kg to 1,000kg and the safety should be secured for passengers. In addition, the driving condition should also be secured under bad situations of the topographic slope, swampy land and the rest. In order to carry out above tests, a prototype vehicle through strength analysis of transmission design has been manufactured. Consequently, optimal design conditions on the power transmission with multi-purpose vehicle for various jobs are proposed such as an indication of optimal RPM and torque at a certain work situation. The performance test through the prototype of multi-purpose work vehicle is performed and the related data base is achieved. Finally, it is improved on troubles by the analysis of the results of R&D and provided the solutions on problems occurring to mass production in the future.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.56-66
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• 2013

Weight reduction of the VTHL / TSTO type of the reusable launch vehicles using RBCC engines are investigated. To predict weight and thrust of the vehicles, equations of motion are analyzed. Analysis results are compared with specifications of existing launch vehicles for validations. For the mission of inserting 2.5 ton payload to 200 km circular orbit, the case A, which uses the RBCC engine in the 1st stage shows smaller weight than the case B, which uses the RBCC engine in the 2nd stage. The weight of the case A shows only 25.8% of a existing rocket launch vehicle's weight.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.12
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• pp.663-672
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• 2017

Building information modeling (BIM) technology based on 3D modeling has been applied to the entire domestic construction industry since 2010. It can calculate quantity take-off considering construction productivity at design phase. Based on this, it is possible to improve the reliability of construction cost prediction of design phase in the process of cost estimation. However, Building Information Level (BIL) defined by Ministry of Land, Infrastructure and Transport and Public Procurement Service does not seem to offer doable environment due to the lack of detailed application items. By calculating construction cost that meets Construction Cost Estimate Accuracy by American Association of Cost Engineers (AACE) through quantity take-off and cost estimation based on 3D modeling of BIM technology, a BIL improvement proposal at design phase for Mechanical Contracts and Construction is provided here. Results showed that properties including outline and minimum specification of the main equipment, internal main piping, and internal main duct should be defined from the intermediate design phase to have reliable cost estimation.