• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.34-39
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• 1996

In many industrial applicatiosns such as machine tools and automation equipments the control performance of the feed-drive systems as positioning devices of the tools and workpieces have great influences on the quality of related machines. For many electrically driven mechanical feed systems resilient couplings between motors and mechanical elements which mostly consist of elasttic shafts and gears often are unavoidable. Commonly these systems can be regarded as an elastic multi-mass systems can be regarded as an elastic multi-mass system which is dealt with this contribution. S high performance speed or position control can only be achieved with the considering of the mechanical elastic characteristics of the system. n this paper some practic characteristics of the system In this paper some practical information is given about experience in modeling design simulation and experiments for linear elastic multi-mass system,

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.97-103
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• 2008

In this paper, the Post Process for the manifold complex processing using CAD/CAM Software of two and a half Dimensions(2.5D) has been developed to maximize the application of the manifold manufacturing machine. Many companies are currently making use of high price systems to improve manufacturing process using the multi-axial complex manufacturing machine. In accordance with the requirements, the utilization of CAD/CAM Software for the manifold complex manufacturing machine is earnestly demanded. However, the experts who have experience in manifold manufacturing machine are insufficient. Consequently the outcomes of the Post Process for 2.5D CAD/CAM Systems have been dealt in order to be smoothly operated by those who have basic skills and be understood in process drawings. CNC program functions can be specially used as they are, when drawn up. The Post Process for the original point designation and transformation of coordinates has been developed and applied. The results gave proof of practical manufacturing outcomes.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1680-1684
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• 2010

CBTC(Communication-Based Train Control) system which is based on wireless communication can provide high density operation of the train using location tracking between ground and onboard train. It can also reduces maintenance expense because it does not require the ground equipment for tracking circuit and signal flag and so on. Recently, research and interest have been done on CBTC system. The high-speed trains up to 300km/h experience multi-path fading channel which bring about the performance degradation of wireless CBTC system. In this paper, we consider MIMO (Multi-Input Multi-Output) antenna-based CBTC system for trains with Alamoutip-type space-time diversity transmission for reliable communication. Also we model a channel considering practical environment and evaluate performance improvement of proposed CBTC system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.10a
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• pp.30-36
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• 1995

Conventionally design for multi-stage cold forging depends on the designer's experience and decision-making. Due to such non-deterministic nature of the process sequence design, a flexible inference engine is needed for process design expert system. In this study, A* searching algorithm was introduced to arrive at the vetter process sequence design considering the number of forming stages and levels of effective strain, effective stress, and forming load during the porcess. In order to optimize the process sequence in producing the final part, cost function was defined and minimized using the proposed A* searching algorithm. For verification of the designed forming sequences, forming experiments and finite element analyses were carried out in the present investigation. The developed expert system using A* searching algorithm can produce a flexible design system based on changes in the number of forming stages and weights.

• Advances in Computational Design
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• v.2 no.3
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• pp.241-256
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• 2017

This paper introduces the process for Multi-objective Optimization Framework (MOF) which mediates multiple conflicting design targets. Even though the extensive researches have shown the benefits of optimization in engineering and design disciplines, most optimizations have been limited to the performance-related targets or the single-objective optimization which seek optimum solution within one design parameter. In design practice, however, designers should consider the multiple parameters whose resultant purposes are conflicting. The MOF is a BIM-integrated and simulation-based parametric workflow capable of optimizing the configuration of building components by using performance and non-performance driven measure to satisfy requirements including build programs, climate-based daylighting, occupant's experience, construction cost and etc. The MOF will generate, evaluate all different possible configurations within the predefined each parameter, present the most optimized set of solution, and then feed BIM environment to minimize data loss across software platform. This paper illustrates how Multi-objective optimization methodology can be utilized in design practice by integrating advanced simulation, optimization algorithm and BIM.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.431-445
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• 2012

In this regard, urban agriculture is developing into a variety of shapes. Urban agriculture includes various types, such as industrial agriculture, experience agriculture, educational agriculture, exchange agriculture and cyclic agriculture. The result of evaluation on citizens' values about multi-functions provided by urban agriculture can be used for policy making to overcome crisis of urban agriculture due to urban development and industrialization and to vitalize urban agriculture. The willingness-to-pay for the maintenance fund was categorized into vegetable garden users, general consumers, and all respondents, for analysis. The estimation results for the valuation of multi-functionality were KRW 20,367 per household for general consumers; KRW 22,174 for urban agriculture users; and KRW 21,467 for all respondents.

• Journal of Trauma and Injury
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• v.31 no.2
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• pp.96-102
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• 2018

Ipsilateral fractures of proximal femur with shaft and condylar region are very rare. Current concept of management is based on fixation of each fracture as independent entity using separate fixation modalities for proximal and distal parts of femur. However, we considered that antegrade femoral nailing with cephalomedullary screw fixation is a good option for ipsilateral multi-level femoral fractures. Here, we present an experience of satisfactory treatment for ipsilateral femoral neck fracture, subtrochanteric fracture, comminuted shaft fracture with supracondylar fracture following road traffic accident.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.233-240
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• 2001

Artificial neural networks(ANN) have been exploited where the relationship among information is very complicated and nonlinear. It is appropriate to computerize the information and knowledge used in the preliminary design stage where it lacks of formality of representation of designers' experience and intuition. However, most designers start the preliminary design stage with very little information. Therefore, the ANN model for this stage must be designed to have input much less than output. This case usually causes big troubles such as in learning time, convergence and reliability of solutions. To address this problem, this paper proposes multi-level neural networks for progressive structural design considering that all the design information can not be obtained at a time but are growing gradually. The use of multi-level networks developed in this paper has been proved its validity by applying it to the preliminary design of cable-stayed bridges.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.155-158
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• 1999

Because the traditional filters have many demerits, multi-step electric oil filter have manufactured the efficiency of insulating oil to improve. Therefore, the function of oil filter to improve based on my experience and know-how about my job. Through this study have obtained many merits. The efficiency of insulating oil is improved. The waste oil reused in repair works of the damaged transformer. Multi-step filter is shortening the working time and safety. it is handy for use and movement. This study lengthen the expected life span of filter. The improvement of oil filter bring about elevation of productivity.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.100-112
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• 1996

This paper presents a design experience of a control language for coordination of a multi-robot system. To effectively program job commands, a Petrinet-type Graphical Robot Language(PGRL) is proposed, where some functions, such as concurrency and synchronization, for coordination among tasks can be easily programmed.In our system, the proposed task commands of PGRL are implemented by employing formal model languages, which are composed of three modules, sensory, data handling, and action module. It is expected that by using our proposed PGRL and formal languages, one can easily describe a job or task, and hence can effectively operate a complex real-time and concurrent system. The control system is being implemented by using VME-based 32-bit microprocessor boards for supervisory, each module controller(arm, hand, leg, sensor data processing module) and a real time multi-tasking operating system(VxWorks). (author). 17 refs., 16 figs., 2 tabs.