• Proceedings of the Korean Nuclear Society Conference
• /
• 1997.05a
• /
• pp.374-379
• /
• 1997

The thermal margin of CANDU-6 reactor is estimated by the CCP, which is dependent on fuel channel hydraulics and the CHF of fuel bundle. This paper intents to describe the characteristics of CCP behavior for the CANDU-6 channel in which CANFLEX-NU fuel bundles are assumed to be loaded. Also, it includes the thermal margin evaluation of the CANDU-6 channel loaded with a mixed CANFLEX-NU and 37-element fuel bundles as a simulation of the partial loading of CANFLEX-NU fuel bundle in the CANDU-6 reactor. For the mixed fuel channels, the effects of axial flux distribution(AFD) on CCP were investigated by using the AFD tilted in the downstream. The CCP of CANFLEX-NU fuel bundle was found to be improved by the CHF enhancement, despite of the slight flow decrease, in case of both full and partial loading, compared with those of a standard 37-element fuel bundle.

• Proceedings of the KIEE Conference
• /
• 2008.11a
• /
• pp.155-156
• /
• 2008

제4차 전력수급기본계획 수립을 위한 발전소 건설의향 조사 수행이 지식경제부 주관하에 시행되었다. 이와 관련하여 발전소 건설의향조사 결과에 대한 계통영향 평가를 의뢰받아 수행하였다. 계통측면에서의 송전요금제도를 적용하여 계통보강비용 배분의 형평성 및 송전요금의 시장신호 기능 반영으로 경제적인 전력수급계획 수립을 도모하기위해 노력하였다. 이에 본 논문에서는 한국전력에서 수행한 발전소 건설의향 계통영향평가 내용에 대하여 알아보고자 한다.

• Journal of the Korean Society of Safety
• /
• v.28 no.5
• /
• pp.83-89
• /
• 2013

Occupational Safety and Health Act provides that industrial safety helmets are personal protective equipment(PPE) to protect heads against falls from a height. Relevant domestic regulations are distinguished and different from other countries' cases. This study investigated industrial safety helmet's protective purposes and characteristics related to falls and the notion of fall prevention. A comparative analysis of regulations on safety helmets and fall prevention as well as standards on safety helmet's impact test requirements is followed by a literature review. It is also suggested that the term "fall" related to safety helmets should be changed to "impact on the upper part of head" in domestic regulations and standards.

• Journal of the Korean Society for Precision Engineering
• /
• v.13 no.9
• /
• pp.84-93
• /
• 1996

This paper describes the development of new feature positioning method which embedded into the top-down assembly modeling system supporting conceptual design. In this work, the user provides the geometric constraints representing the position and size of features, then the system calculates their proper solution. The use of geometric constraints which are easy to understand intuitively enables the user to represent his design intents about geometric shapes, and enables the system to propagate the changes automatically when some editing occurs. To find the proper solution of given constraints, the Selective Solving Method in which the redundant or conflict equations are detected and discarded is devised. The validity of feature shapes satisfying the constraints can be maintained by this technique, and under or over constrained user-defined constraints can also be estimated. The problems such as getting the initial guess, controlling the multiple solutions, and dealing with objects of rotational symmetry are also resolved. Through this work, the feature based modeling system can support more general and convenient modeling method, and keeps the model being valid during modifying models.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.12
• /
• pp.2061-2071
• /
• 2003

The macro-parametric approach, which is a method of CAD model exchange, has recently been proposed. CAD models can be exchanged in the form of a macro file, which is a sequence of modeling commands. As an event-driven commands set, the standard macro file can transfer design intents such as parameters, features and constraints. Moreover it is suitable for the network environment because the standard macro commands are open, explicit, and the data size is small. This paper introduces the concept of the macro-parametric method and proposes its representation using XML technology. Representing the macro-parametric data using XML allows managing vast amount of dynamic contents, Web-enabled distributed applications, and inherent characteristic of structure and validation.

• International Journal of CAD/CAM
• /
• v.3 no.1_2
• /
• pp.43-50
• /
• 2003

This paper presents a methodology in which the knowledge of design intents and change requests is communicated unambiguously cross collaboration partners through features. The domain of application is focused on the plastic part design for enabling effective collaboration between the product design and plastic mold making. The methodology takes the feature-based design approach and allows design features and knowledge to be reused in plastic injection mold design. It shortens the mold design lead-time, reduces mold design efforts, and enables unambiguous and fast design change management between product and mold designers. These contribute to the reduction of product development cycle time.

• Korean Journal of Computational Design and Engineering
• /
• v.9 no.1
• /
• pp.19-26
• /
• 2004

It is not possible to exchange parametric information of CAD models based on the current version of STEP (Standard for the Exchange of Product model data). The designer intents are lost during the transfer of CAD models. To resolve this problem, the macro-parametric approach had been proposed. To enable this approach, a set of standard modeling commands has been defined. Errors or missing elements of the standard modeling commands can be discovered by implementing macro-parametric translators. But there is a limit to discover problems only by using translators. This paper proposes a method to verify the standard modeling commands by implementing a geometric modeler. First, each argument of a modeling command is verified. Second, the set of the standard modeling commands is applied to geometric modeling of commercially available product parts. For the geometric modeling, nine test models have been selected.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.6
• /
• pp.58-68
• /
• 2003

Despite the availability of 3D CAD systems, the designers in shipyards still use 2D CAD systems because of the need to produce drawings rapidly and a shortage of labor. The design information of ship structure contained in 2D drawings is represented by symbols that are well known among designers in shipyard. The shapes of symbols are recognized by analysis of experienced and knowledgeable designers. We propose a method for automatic recognition of 2D symbols and extraction of design information from the midship drawings. The shape and rationale of 20 symbols used in ship design have been analyzed, and symbols have been classified according to the analysis. Based on the classified symbols, the developed system recognizes the symbols expressed in 2D drawings. The meaningless geometric shape is translated into the design information including designer's intents. The extracted design data can be applied to the downstream design process in shipyards, and the 3D ship model can be automatically created.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.2
• /
• pp.113-119
• /
• 1997

This research intents to gain the sight for the qualitative characteristics of precision cutting by using the CNC lathe with a mono-crystal diamond(MCD) tool having a straight cutting edge. As an absolute value of tool setting angle becomes smaller, the surface roughness has improved. We knew that according to each of the machine tools and cutting edge radius, there exist a proper mininum feed and depth of engagement for improving the surface roughness. This results suggest that the proper values of feed and depth of engagement are about 11-15 .mu. m/rev, 10 .mu. m, respectively.

• Journal of Information Technology Services
• /
• v.2 no.1
• /
• pp.111-121
• /
• 2003

This paper intents to suggest the re-engineering methodology to transform and integrate the legacy systems to new system in modern environment. While existing reverse engineering and re-engineering approaches have focused on analyzing and maintaining the source code of program. our methodology can provide the procedures and techniques for evolving into new system by recovering the reverse engineering informations and transforming them into component informations. Our methodology for componentization of legacy system is consisted of plan step, reverse engineering step, componentization step, and delivery step, and we describes activities and detail procedures about each step.