• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1265-1270
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• 1990

A prototype integrated system and its theories for distributed SISO control structure synthesis of complete chemical plants is developed. The scope of this work includes control structure synthesis not only of simple units with unspecified control loops but also of the complex process at preliminary and basic design stage. Hierarchical approach and dual-decomposition strategy (that is multi-layer decomposition and multi-echelon decomposition) is applied to this system. Because automatic control structure synthesis of complex plants is a problem defined as a series of knowledge-intensive tasks within multiple spaces, the established methodology is complemented by not only techniques from knowledge-based expert systems but also shortcut and rigorous control theories. This system is used for education of control designers, process engineers, operators and students as well as for operability studying, in-line and on-line process control structure synthesis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.258-261
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• 2002

In this study, micro tools(WC) to produce micro-structure and parts, were fabricated ell a cylindrical grinding machine using ELID(Electrolytic In-process Dressing) technique. The shape of the micro-carbide tool was square, corn. The size of the micro-carbide tool was measured less than 10$\mu\textrm{m}$ respectively by SEM(Scanning Electron Microscope). Furthermore, we fabricated micro structure by different processing methods on the desk top cylindrical grinding machine. The manufactured shape was like a tower and the measurement showed that the endpoint of micro structure was $50{\times}50$$\mu{\textrm}{m}$.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.74-79
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• 2004

The effects of change in injection pressure on spray structure have been investigated in high temperature and pressure field. To analyze the structure of evaporative diesel spray is important in speculation of mixture formation process. Also emissions of diesel engines can be controlled by the analyzed results. Therefore, this study examines the evaporating spray structure by using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 72 MPa to 112 MPa with a high pressure injection system(ECD-U2). The PIV(Particle Image Velocimetry) technique was used to capture flow variation of the evaporative diesel spray. A study on the mixture formation process of diesel spray was executed by the results of flow analysis in this study. Consequentially the large-scale vortex flow could be found in downstream spray and the formed vortex governs the mixture formation process in diesel spray.

• Journal of Ocean Engineering and Technology
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• v.15 no.2
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• pp.141-147
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• 2001

The launching process is one of the most critical operations for large structure in offshore installation. Since as the size increases it limits the availability of offshore crane facilities, the large jacket structures are often installed by launching. As the structure approaches to tilt beam, it reaches critical load, and there are parameters to affect on launching procedure. The major influential parameters are trim, draft of barge, center of gravity, center of buoyancy and reserved buoyancy of jacket. As increasing of trim and draft, structural loads tend to decrease. The trim is found to be more contributing than draft on structural loads. Therefore the trim should be increased so as to decrease structural loads and to avoid stalling of structure and submergence of stern. During the launching process, the distance between jacket and seabed should be investigated which differs from the amount of reserved buoyancy and launching condition of barge. In this paper the effects of parameters on launching process are numerically investigated.

• Korean Journal of Computational Design and Engineering
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• v.14 no.4
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• pp.217-224
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• 2009

Most divide-and-conquer implementations for Delaunay triangulation utilize quad-edge or winged-edge data structure since triangles are frequently deleted and created during the merge process. How-ever, the proposed divide-and-conquer algorithm utilizes the array based data structure that is much simpler than the quad-edge data structure and requires less memory allocation. The proposed algorithm has two important features. Firstly, the information of space partitioning is represented as a permutation vector sequence in a vertices array, thus no additional data is required for the space partitioning. The permutation vector represents adaptively divided regions in two dimensions. The two-dimensional partitioning of the space is more efficient than one-dimensional partitioning in the merge process. Secondly, there is no deletion of edge in merge process and thus no bookkeeping of complex intermediate state for topology change is necessary. The algorithm is described in a compact manner with the proposed data structures and operators so that it can be easily implemented with computational efficiency.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.31-38
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• 2010

Bus manufacturers have tested and studied the dynamic collapse behavior of a bus body structure in rollover since UN ECE established ECE Regulation 66 to provide the requirement for the strength of bus structure. In spite of the costly cycles of practical tests, however, it is still a hard task to meet the rollover regulation by means of local reinforcements in the bus structure. Therefore it is necessary to develop a well designed strategy for the rollover strength implemented in the early stage of vehicle development. In this study, the suitable development method for each design stage from a component to complete body structure was considered to make a well-established development process of a bus body structure for rollover safety. For the efficient approach of the concept design stage, a numerical model based on the plastic hinge theory was used instead of detailed shell models. After setting up the concept design for the component size and geometry, the shell model was used to confirm and optimize the whole structure composition. The process developed in this study was practically used as an effective method to predict the rollover behavior of a new bus body structure.

• Korean Journal of Computational Design and Engineering
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• v.12 no.3
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• pp.191-199
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• 2007

In order to construct a data warehouse of process plant equipment, a classification structure should be defined first, identifying not only the equipment categories but also attributes of an each equipment to represent the specifications of equipment. ISO 15926 Process Plants is an international standard dealing with the life-cycle data of process plant facilities. From the viewpoints of defining classification structure, Part 2 data model and Reference Data Library (RDL) of ISO 15926 are seen to respectively provide standard syntactic structure and semantic vocabulary, facilitating the exchange and sharing of plant equipment's life-cycle data. Therefore, the equipment data warehouse with an ISO 15926-based classification structure has the advantage of easy integration among different engineering systems. This paper introduces ISO 15926 and then discusses how to define a classification structure with ISO 15926 Part 2 data model and RDL. Finally, we describe the development result of an ISO 15926-based classification structure for a variety of equipment consisting in the reactor coolant system (RCS) of APR 1400 nuclear plant.

• Journal of the Korean Statistical Society
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• v.30 no.3
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• pp.407-418
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• 2001

Buhlmann(1944) established the validity of the block bootstrap proposed by Kunsch when it is applied to p-dimensional $\alpha$-mixing dependent sequence. But his result requires a rather restrictive condition on p in the sense that p is entangled with dependence structure. We address that such restriction on p(or complication of dependence structure with p) could be removed completely when the underlying dependence structure is replace by more weakly dependent structure such as ø-mixing.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1125-1128
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• 2007

The laminating technique for developing flexible liquid crystal display was demonstrated by using a thin UV curable polymer film and a plastic substrate with patterned polymer wall structure. We adopted the rigid wall structure to provide a solid mechanical support for the stable molecular alignment of liquid crystals (LCs) in the device. The cover film was prepared to have an ability of aligning LC molecules by patterning a micro-groove structure using the soft-lithographic process. These two substrates can be assembled tightly by the laminating and one-step UV irradiation process because of the adhesive nature of the used UV curable polymers. Proposed method can be used to fabricate the flexible LC display with simplicity and also be applicable for a cost-effective roll-to-roll process.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.189-192
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• 2002

The autoclave process is frequently utilized in the manufacturing of aircraft parts because of the low void content and high fiber volume fraction. However, due to the slow curing process (5∼8 hours per part) and it's limited producibility for complicated shape, this process is very expensive and applied to the relatively simple geometry structures. RTM is considered as an alternative process to overcome the limitation of autoclave process. In this study, the idea of RTM application on the secondary Fairing structure of aircraft has been proved to be technically feasible and very cost effective by changing the multiple part of subassembly into one integral composite structure.