• 한국BIM학회 논문집
• /
• 제6권4호
• /
• pp.27-34
• /
• 2016

A Building Information Model (BIM) is an attempt to simulate the process of building structures in a three-dimensional (3D) digital space. While the technology is usually applied to structured buildings, bridges, and underground facilities, it is rarely applied to an unstructured environment of earthwork operations. If a BIM is used for earthworks, the 3D simulation can be used for construction equipment guidance and earthwork management. This paper presents a real-time, 3D earthwork BIM that provides a 3D graphical simulation of excavators in conjunction with geographic modeling. Developing a real-time, 3D earthwork BIM requires handling a variety of factors, such as geographical information and vehicular movement. This paper mainly focuses on the management of these attributes and provides a database design for storing and retrieving data. In an example application, a prototype of the 3D earthwork BIM is presented to understand what it would provide when used during earthwork operations at a construction site.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2011년도 정기 학술발표대회
• /
• pp.12-19
• /
• 2011

Drawing on its extensive experience with natural disasters, Japan has been dispatching Japan Disaster Relief (JDR) team to disaster-stricken countries to provide specialist assistance in rescue and medical operations. The JDR team has assisted in the wake of disasters including the 2004 Indian Ocean Earthquake and the 2008 Sichuan Earthquake in China. Information about the affected area is essential for a rapid disaster response. However, it can be difficult to gather information on damages in the immediate post-disaster period. To help overcome this problem, we have built on an Earthquake Damage Estimation System. This system makes it possible to produce distributions of the earthquake's seismic intensity and structural damage based on pre-calculated data such as landform and site amplification factors for Peak Ground Velocity, which are estimated from a Digital Elevation Model, as well as population distribution. The estimation result can be shared with the JDR team and with other international organizations through communications satellite or the Internet, enabling more effective rapid relief operations.

• Journal of Electrical Engineering and Technology
• /
• 제3권1호
• /
• pp.36-42
• /
• 2008

In a gas insulated substation (GIS), Very Fast Transient Over-voltages (VFTOs) are generated due to switching operations and ground faults. These fast transients are associated with high frequency components of the order of a few hundreds of MHz. These transients may cause internal faults i.e., layer-to-layer faults or minor faults in a capacitively graded bushing, which is one of the important pieces of terminal equipment for GIS. In the present study, the PSPICE model has been developed to calculate the voltage distribution across the layers of 420kV graded bushing for high frequency pulses of rise time 1 to 50ns, which simulate the VFTO. For this simulation, an equivalent electrical network of bushing with different equivalent layers has been considered. The effect of different equivalent layers modeling circuits on the non-uniform voltage factor has been analysed. The influence of copper strip inductance on voltage distribution across layers has also been analysed for various rise times of high frequency transients. Finally, the leakage current of the bushing is calculated for evaluating the bushing condition under these transients.

• 한국항행학회논문지
• /
• 제15권6호
• /
• pp.977-985
• /
• 2011

항공기 분리보증은 자유비행 분리보증의 핵심요구사항이다. 본 논문에서는 자유비행 공역 효율성 측정을 위한 다양한 분리보증 및 효율성 측정 모델을 고찰하고, 자유비행 분리보증을 위한 포텐셜 필드 알고리즘과 기하학적 알고리즘, 두 가지의 충돌회피 기법을 모델링 하여 항공기 성능데이터와 두 가지 조건의 시나리오 상황에서 분리보증 해결과 운항 효율성을 측정하였다. 실험결과 자유비행 공역 하에서 기하학적 알고리즘 적용이 포텐셜 필드 알고리즘 보다 분리보증 해결, 운항 효율성 측면에서 우수하였으며, 동일한 알고리즘에서도 선회각, 속도 복합모델인 기하학적 결합 알고리즘이 더욱 효율적인 것으로 나타났다.

• 한국국방경영분석학회지
• /
• 제35권1호
• /
• pp.1-19
• /
• 2009

본 연구는 지상군용 지능형 포탄을 포함한 장갑차량 공격용 K-9 포탄의 전시 소요량을 산정하는 국방 시뮬레이션의 방법론을 개선하려는 것이다. K-2008에서 사용된 분석용 국방 시뮬레이션에 의한 방법에서는 입력자료의 부정확성과 모의논리의 왜곡으로 인하여 산정량이 과도하며, 산출된 각 무기체계별 기대점유비율이 장차전의 실상에서 일반적으로 기대하는 바와 상당한 차이를 보여주고 있다. 본 연구에서는 이러한 입력자료 및 모의논리의 왜곡현상의 원인을 분석하고 이를 바로잡기 위하여 훈련용 및 분석용 국방 시뮬레이션 모형을 상호 연계하여 사용 및 검증하는 하이브리드 국방 시뮬레이션 모형의 필요성을 제시하려는 것이다.

• 대한수학교육학회지:수학교육학연구
• /
• 제13권1호
• /
• pp.25-55
• /
• 2003

In the school mathematics, the negative numbers have been instructed by means of intuitive models(concrete situation models, number line model, colour counter model), inductive-extrapolation approach, and the formal approach using the inverse operation relations. These instructions on the negative numbers have caused students to have the difficulty in understanding especially why the rules of signs hold. It is due to the fact that those models are complicated, inconsistent, and incomplete. So, students usually should memorize the sign rules. In this study we studied on the didactical phenomenology of the negative numbers as a foundational study for the improvement of teaching negative numbers. First, we analysed the formal nature of the negative numbers and the cognitive obstructions which have showed up in the historic-genetic process of them. Second, we investigated what the middle school students know about the negative numbers and their operations, which they have learned according to the current national curriculum. The results showed that the degree they understand the reasons why the sign rules hold was low Third, we instructed the middle school students about the negative number and its operations using the formal approach as Freudenthal suggest ed. And we investigated whether students understand the formal approach or not. And we analysed the validity of the new teaching method of the negative numbers. The results showed that students didn't understand the formal approach well. And finally we discussed the directions for improving the instruction of the negative numbers on the ground of these didactical phenomenological analysis.

• 한국국방경영분석학회지
• /
• 제3권1호
• /
• pp.83-96
• /
• 1977

The combustion chamber and nozzle of an end burning, small spherical rocket is designed. A spherical external shape has a number of advantages such as fixed center-of-gravity and minimum aerodynamic precession torques during flight and a better mass distribution for gyro-stabilization as contrasted to a conventional ogive rocket shape. It is shown that the cross-sectional variation of the end burning solid propellant with length is an exponential geometry to provide a constant thrust-weight ratio of the rocket device during the propellant burning period, and that the factors which affect the attainment of the constant relationship of thrust to weight in the design are the initial propellant area, initial weight of the rocket and propellant density. The measurement of the transient thrust in the ground static test using black powder propellant supports the predicted results. A wind tunnel having a $30{\times}30{\times}75cm$ test section and Mach number 0.11 is constructed, and a simple balance-type device is designed for the measurement of the drag of a spinning sphere. The experimental results indicate that the. spinning has no effect on the magnitude of the drag up to the Reynolds number $3{\times}10^5$. Numerical computation of the flight trajectories for various launching angles is presented, and the gyro-stabilization of spinning sphere is discussed.

• 한국국방경영분석학회지
• /
• 제34권2호
• /
• pp.143-162
• /
• 2008

이 연구는 현재 개발이 진행 중인 장갑차량 상부 공격용 지능형 탄약을 포함한 155mm 포병 탄약의 전시소요량을 산정하는 방법론을 정립하려는 것이다. 종래의 워게임 시뮬레이션에 의한 방법에서는 장갑표적 공격용 무기체계별 기대점유비율이 지상군 및 공군간에 과도하게 차이가 발생하고 있다. 또한 상향식 소요산정방법은 최소소요량에 비하여 너무나 과도하게 산출하는 경향이 있으므로 이러한 점들을 보완하기 위하여 표적 수량에 따른 무기체계별 할당에 의한 하향식 모형을 구성한 것이다. 이모형이 워게임에 의한 상향식 소요산정보다는 더 믿을 만한 결과를 산출한다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
• /
• pp.49.1-49.1
• /
• 2009

Ground Complex, which is located at Naro Space Center, consists of Assembly Complex(AC) and Launch Complex(LC) which is necessary for successful launch of KSLV-I(NARO). AC consists of Assembly/Testing Building(ATB), Payload Processing Building(PPB), Kick Motor Building(KMB). The purpose of AC is accepting of KSLV-I components, testing, checkout, assembly(disassembly) of the launch vehicle(LV), readiness for transferring LV to LC, accepting of integrated Launch Vehicle(ILV) in case of launch cancellation and short/long time storage, and so on. Qualification tests(QT) for the total system at AC are carried out to check hardware used for operations with first stage unit mockup, upper stage unit Mockup and integrated mockup(GTV). The qualification tests is carried out according to program and procedures of QT. By course of this process, AC is certificated that all the systems and facilities of AC are guaranteed by the fulfillment of technological operations envisioned in the program of qualification tests during the work with the mock-up.

• 한국국방경영분석학회지
• /
• 제28권2호
• /
• pp.70-84
• /
• 2002

This paper deals with the attrition rate of major facility such as a particular building that is one of the most important target in the war time. In order to estimate the attrition rate, we use JAWS, WinJMEM which are programed by JTCG/ME of AMSAA and spreadsheet package which is able to assist the limitation of those programs and calculate all the procedure of this computation. This method uses the effectiveness index(El) which indicates the numerical measure of the effectiveness of a given weapon of a given target. The range error probable(REP) and the deflection error probable(DEP) in the ground plane also should be used. Those mean the measure of delivery accuracy of the weapon system. In this paper, it is improved that the El can be obtained from the regression analysis using the weight of the warhead explosive as the independent variable. It implies that we are able to obtain the El and the conditional probability of damage of the enemy weapon. After that, the single-sortie probability of damage can be computed using WinJMEM or another assistant program such as the spreadsheet package which shows the result immediately.