• Journal of the Earthquake Engineering Society of Korea
• /
• v.14 no.4
• /
• pp.37-48
• /
• 2010

The seismic control effect of reinforced concrete structures with low energy dissipating capacity due to stiffness degradation is investigated through nonlinear time history analysis. The primary structure is idealized as a SDOF system of modified Takeda hysteresis rule and an elasto-perfectly-plastic nonlinear spring is added to represent a hysteretic damping device. Based on statistics of the numerical analysis, equivalent linearization techniques are evaluated, and empirical equations for response prediction are proposed. As a result, estimation of the ductility demand with proposed empirical equations is more desirable than the equivalent linearization techniques. The optimal yield strengths based on empirical equations are significantly different from the optimal yield strength of elasto-perfectly-plastic systems. Also, the results indicate that the reduction effect of the ductility demand is more remarkable for smaller natural periods.

• Spatial Information Research
• /
• v.19 no.3
• /
• pp.43-52
• /
• 2011

Recently, interest in location-based service (LBS) which utilizes a DBMS in mobile system environment has been increasing, and it is expected to overcome the existing file-based system's limitation in advanced in-vehicle system by utilizing DBMS's advantages such as efficient storage, transaction management, modelling and spatial queries etc. In particular, the road network data corresponds to the most essential domain in a route planning system, which needs efficient management and maintenance. Accordingly, this study aims to develop an efficient graph-based geodata model for topological network data and to support dynamic path computation algorithm based on heuristic approach in mobile LBS system. To achieve this goal, we design a data model for supporting the hierarchy of network, and implement a path planning system to evaluate its performance in mobile LBS system. Last but not least, we find out that the designed path computation algorithm with hierarchical graph model reduced the number of nodes used for finding and improved the efficiency of memory.

• 한국벤처창업학회:학술대회논문집
• /
• 2016.04a
• /
• pp.67-69
• /
• 2016

이 연구는 경영학과 MBA교육과정이 세상의 모든 제품과 기업에 공통적으로 적용되듯이, 세상의 어떤 분야의 제품이든 그 시작인 한 개 착안에서부터 시장력 확보를 위해 시도 되는 도전행위의 매개인 모든 착안과 아이디어가 기업이 되는 과정인 제벤처행위에 공통적으로 적용되는 학문이 될, MVA(PH-MVA, master of venture arming, 벤처무장학)학의 개념적 모델링의 시작에 필요로하는 정의론과 개념론으로, MBA에 있어 경영학원론이 개론화되듯, MVA에 있어 그 개론서가 될 벤처학원론서 설계에 있어서의 시작인 1편 기초론을 구성하는 내용을 벤처창업이나 기업의 신제품개발 부서에의 취업을 희망하는 학생들과 제벤처 생태계의 모든 직간접 관련 직무자 들이 공통적으로 무장하면 벤처적 행위에 필요로하는 여러 가지 직무자들 같이 소통력은 물론 직무매칭력 등의 분업 협업력이 매우 높아 질 것이라는 주장을 바탕으로한다. 그리고 제시하는 정의와 개념을 제벤처 생태계 전체의 표준으로 참고 삼아, 누구의 어떤 모델이든, 창조경제의 일부로서 미생들의 벤처(창업, 기업만들기 도전)행위나 완생기업들의 신제품개발 모두에 두루 적용 될 수 있는, 누구나가 이해, 공감, 교감, 습득이 용이한 벤처학 개발이 왕성하게 활성화될 수 있도록 하는 것이 곧 창조경제 활성화를 위한 학자들의 사명이자 새로운 성장동력 모델의 발굴이기도하다는 측면에서의 동참이 될 수 있기를 바라는 마음이다. 아울러, 이러한 정의와 개념을 바탕으로 전개되어, 벤처생태계 전반에서 수행 될 교육이 개인들의 창업(기업만들기)을 목표로하는 공부가 되기도하고 연장에, 완생기업들이 필요로하는 신제품개발에 있어서의 기본적인 능력과 자질을 갖춘 인재선발적 취업준비공부도 될 수 있는 통합적 교육이되어야한다는 취지를 가지고있다. 또 연구를 통해 제벤처(기업의 신제품개발 도전협업행위 포함) 생태계에서의 직무자들의 직무매칭력 및 협업행위에 있어서의 다양한 용어와 정의와 개념들의 제각각으로 부터 발생되는 상치(相馳, 제각각, 불통, 협업마찰, 대립, 갈등, 등)력을 해소하는 것이 역설적으로 협업력을 최적으로 활성화 할 수 있다는 사실을 모두가 인지, 수용토록 하고자 함을 목적으로한다. 이러한 연구를 전벤처단계의 벤처기초학을 바탕으로하는 제벤처생태계 개념을 일원화 통합화하는 연장에 전개되는 공통무장교육 모델화를 목적으로한다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.8
• /
• pp.873-879
• /
• 2012

Metamodels have been developed with a variety of design optimization techniques in the field of structural engineering over the last decade because they are efficient, show excellent prediction performance, and provide easy interconnections into design frameworks. To construct a metamodel, a sequential procedure involving steps such as the design of experiments, metamodeling techniques, and validation techniques is performed. Because validation techniques can measure the accuracy of the metamodel, the number of presampled points for an accurate kriging metamodel is decided by the validation technique in the sequential kriging metamodel. Because the interpolation model such as the kriging metamodel based on computer experiments passes through responses at presampled points, additional analyses or reconstructions of the metamodels are required to measure the accuracy of the metamodel if existing validation techniques are applied. In this study, we suggest a sensitivity validation that does not require additional analyses or reconstructions of the metamodels. Fourteen two-dimensional mathematical problems and an engineering problem are illustrated to show the feasibility of the suggested method.

• The KIPS Transactions:PartD
• /
• v.12D no.1 s.97
• /
• pp.73-80
• /
• 2005

The purpose of using CBD in the object-oriented modeling is to improve the software capability by reducing iterative time and space complexity. Despites many achievements of CBD, it is needed to study about design patterns and it's standardization for the increment of CBD design reusability. However, it is rather possible that impetuous constructing meta-pattern languages and pattern repositories make adapting patterns to software development more complicate and difficult. By applying GoF design patterns to the design of the TMDL(Total Maximum Daily Load) environmental software discipline, this study suggests a method which specifies Pattern names at class names for retrieving, exploring the adapted patterns on the stage of software design without meta-pattern language which is a redundant abstraction, nor additional pattern repositories. Thus, this study can contribute on the reducing iterations and repetitions that are frequently occurred in the process of the environmental software developments.

• The KIPS Transactions:PartB
• /
• v.12B no.5 s.101
• /
• pp.595-606
• /
• 2005

The scale of game development are rapidly increasing as the blockbuster games which cost $7\~20$ billion won, often appear on the markets. The game mechanics which is concentrated on technological elements of the game, necessarily requires the management of quality. In this paper, we propose a computer simulator for the quality evaluation of game mechanics which can analyze the quality accurately and economically in the design phase. The proposed simulator provides Petri net[7,8] and Smalltalk[9] for convenient modeling. The simulator gives the realistic evaluation like play test because it uses the realistic data of gameplay environment such as player action-pattern, game world map, and item DB but the previous evaluation methods can not consider the realistic gameplay environment and can only cover a limited scope of evaluation. To prove good performance of the proposed simulator, we have 80 simulations for the quality evaluation of the game mechanics of Dungeon & Dragon[13,14] in a given world map. The simulation results show that the proposed simulator can evaluate the faultlessness, optimization, and play balance of the game mechanics and gives better good performance than other evaluation methods.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.9 no.6
• /
• pp.627-633
• /
• 1999

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a ？3-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. When the environmental condition (antigen) changes, a robot selects an appropriate behavior strategy (antibody). And its behavior strategy is stimulated and suppressed by other robot using communication (immune network). Finally much stimulated strateby is adopted as a swarm behavior strategy. This control scheme is based on clonal selection and immune network hypothesis, and it is used for decision making of optimal swarm strategy. Adaptation ability of robot is enhanced by adding T-cell model as a control parameter in dynamic environments.

• Journal of Astronomy and Space Sciences
• /
• v.14 no.2
• /
• pp.375-380
• /
• 1997

The accuracy of user position by GPS is heavily dependent upon the accuracy of satellite position which is usually transmitted to GPS users in radio signals. The real-time satellite position information directly obtained from broadcast ephimerides has the accuracy of 3~10 meters which is very unsatisfactory to measure 100km baseline to the accuracy of less than a few mili-meters. There are globally at present seven orbit analysis centers capable of generating precise GPS ephimerides and their orbit quality is of the order of about 10cm. Therefore, precise orbit model and phase processing technique were reviewed and consequently precise GPS ephimerides were produced after processing the phase observables of 28 global GPS stations for 1 day. Initial 6 orbit parameters and 2 solar radiation coefficients were estimated using batch least square algorithm and the final results were compared with the orbit of IGS, the International GPS Service for Goedynamics.

• International Journal of Highway Engineering
• /
• v.2 no.1
• /
• pp.147-156
• /
• 2000

Compaction is known to critically affect pavement performance. Due to its importance, a theoretical modelling of compacted density in the term of number of roller coverages is attempted by assuming compaction process essentially identical to pavement rutting. Excellent data fittings by the developed equation may prove the validation of assumptions made as well as justification of its use. According to the derived equation, a plot of density difference with respect to number of roller coverages in the logarithmic scale Produces a linear relationship. However, this linearity is turned out to be deviated by cooling effect, change of amplitude and frequency. Investigation of these three factors proposes a new generalized compaction density equation, which shows a promising future. By applying this general formula, the equations for the number of roller coverages required and the final compaction density obtained for a particular compaction project is derived first time in compaction research.

• Journal of Engineering Education Research
• /
• v.13 no.6
• /
• pp.49-56
• /
• 2010

In this study, we investigated the perception difference of industrial managers and engineering faculties in the engineering education, and searched for a rational solution to resolve this perception differences. Both engineering faculties and industrial managers place strong emphasis on practical training, but they showed a significant difference in addressing the issues on the graduates of engineering education have. This different perceptions are occurred since the industrial managers prefer "the instant(or ready-made) human resource type", the ones to put to work right away whereas professors prefer the ones with the strong basic knowledge, "the potential human resource type", who may in the long run contribute to the development of the industry. We believe Finland Helsinki Engineering School's co-op course and Pennsylvania State University's Capstone Design Education are the good examples of nurturing "practical" human resource although both programs are conducted in very different imaginative ways.