• 한국경영과학회지
• /
• 제21권3호
• /
• pp.127-141
• /
• 1996

In this paper, we propose a 7-phase life cycle model which applies to Computer Integrated Manufacturing systems. The model emphasizes product design and manufacturing design activities of CIM to secure the critical success factors of CIM systems such as high quality, adaptability, productivity, and flexibility. It is argued that the product design aspect would be divided into three phases-conceptual design, embodiment design, and detialed design. The conceptual design phase is to build a conceptual model of the product based on requirements and specifications which reflect "the voice of the customer". THe embodiment design phase utilizes specific design tools such as DFM, CAE, and CAD, and results in a concrete model of the product and parts. The detailed design phase is to crete a working prototype of the product and design tools such as DFA. CAD and CAM are employed in this phase. The output of the product design activity is to be the input for the manufacturing design activity. Using the proposed model, one can effectively and efficiently manufacture a high-quality, low-cost product with short delivery time, and above all achieve customer'ssatisfaction.isfaction.

• 한국정밀공학회지
• /
• 제18권8호
• /
• pp.54-63
• /
• 2001

Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of a part due to layer-by-layer stacking, low build speed caused by point-by-point or line-by-line solidification to build one layer, and additional posts processing to improve surface roughness, so high cost is required to introduce and to maintain the RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing by using expandable polystyrene foam sheet as part material(VLM-S), and to design an apparatus for implementation of the process. So, the process parameters and design criterions of the apparatus were defined and the techniques were proposed to satisfy the design criterion. Based on the results, a knob-shape, pyramid shape. and a solid block were fabricated on the apparatus in which unit shape part(USP) was generated for building each layer.

• 한국항해항만학회지
• /
• 제37권6호
• /
• pp.647-653
• /
• 2013

Energy acquisition due to the increase of oil price is one of the most important issues and policy for most countries. Various tankers have been built in the world and sent to the trade market. It is necessary to build the port infrastructure and facilities to give them proper services such as mooring, packing, storing, and transshipment, etc. However, the domestic guidelines or standards for design and construction for the dolphin berth among these facilities are out of date and do not meet the recent trend of tanker types. Therefore, it requires amendment on the guidelines or standards. In this study, a detailed analysis of the tanker fleet, covering 8,000 ships under operation and order to build, is made to estimate the proper PBL(Parallel Body Length) of each tanker class. After discussion and comparison on the dolphin berth design and construction codes of various countries, those are the leading countries of tanker operation and management, suggestion was made to amend on the design code. The referred codes are of Korea, Japan, UK, USA, and Canada. The analysis of tanker fleet shows the PBL as 0.45L under the normal ballast condition. In order to verify the deduced amendment on the domestic design code for dolphin berth, it was selected one of the domestic dolphin berth, located at the Yeosu oil terminal, which is almost completed to construct. The design criteria and expected tankers to moor in that terminal were analyzed and the appropriateness and countermeasure for deficiency were summarized.

• 한국정밀공학회지
• /
• 제31권12호
• /
• pp.1085-1091
• /
• 2014

Recently, 3D printing has received increasing attention due to its boundless potentials. Because 3D printing starts from 3D geometry information, computer-aided design (CAD) is an essential technology to build 3D geometry data. These days, education of 3D CAD for engineering students has been changed from the theoretical lecture to practical design training using commercial CAD software. As a result, open-ended design projects have replaced the traditional theoretical examinations to evaluate students' outcomes. However, such design projects are not enough to evaluate students' outcomes because their results are expressed in two-dimensional ways. In this paper, applications of 3D printing in engineering design education are discussed by describing the procedure and outcomes of design projects. It was found that the use of 3D printing could improve students' outcomes by fabricating real physical models out of their designs.

• 한국CDE학회논문집
• /
• 제16권2호
• /
• pp.104-113
• /
• 2011

With the rising social interest in the sustainable life, demands are growing for Hanok, as a viable alternative to modernized architecture of Western origin. However, even Hanok is gaining popularity among the general public, its design and construction are still a minor practice. Aiming to build an information system of Hanok, this research proposes a new design process for traditional architecture, utilizing a parametric design methodology. This process, based on the understanding of tectonic joints and spatial composition of our traditional architecture, defines a parametric relationship among the structural elements that compose Hanok. The research uses Gehry Technologies' Digital Project and Autodesk Revit Architecture to apply a concurrent parametric design methodology, approaching the project in both bottom-up and top-down to present a new design process for Hanok elements.

• 산업경영시스템학회지
• /
• 제34권3호
• /
• pp.8-15
• /
• 2011

The computer-based simulation tools are currently used overwhelmingly to simulate the performance of automotive designs. Then, the search for an optimal solution that satisfies a number of performance requirements usually involves numerous iterations among several simulation tools. Therefore, meta-modeling techniques are becoming widely used to build approximations of computationally expensive computer analysis tools. The set-based approach proposed in the first report of a four-part paper has been a test bed for the innovation of vehicle structure design process in the Structural Design and Fabrication Committee of JSAE(Society of Automotive Engineers of Japan). In the second report, the proposed design approach is illustrated with a side-door impact beam design example using meta-modeling techniques.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.544-548
• /
• 2015

As urbanization increases in UAE, the demand for housing and infrastructures also grows. The challenge is to continue to build but in a different way considering more energy-efficient sustainable buildings. Producing a sustainable design is highly dependent upon effective participation among the diverse parties involved. In the construction industry in the UAE, these parties are fragmented due to the multistage nature of construction projects and multidisciplinary participants, particularly during the design stage. The decisions made during this stage have an extensive impact on subsequent stages of a project's life cycle. Having a sustainability expert during the design stage is important and the awareness of sustainability requirements by all design participants is of equal importance. In this research, recent advances in information technology are used to develop an information model that will improve the sustainability of building during the design stage. An information framework for storing design information and sustainability performance criteria is developed, allowing design participants to collaborate in an integrated environment. This research is expected to help designers produce sustainable designs for building projects.

• 한국정밀공학회지
• /
• 제20권2호
• /
• pp.76-84
• /
• 2003

Stereolithography is the technique using a laser beam to cure a liquid resin, a photopolymer, with three dimensional computer-aided design (CAD) data. The build parameters of stereolithography such as beam size, scan velocity. hatch spacing, layer thickness and etc. are determined by the accuracy of prototype, the build time and the cured properties of the resin. In particular, beam size is important processing parameter fur the other parameters. Therefore, this study observed the cured property to beam size. For this purpose, according to hatch spacing and beam size, the cure width and depth were measured on single cured line. Also, the cure width and depth were measured at single cured layer As a result of experiments. cure depth which varied from 0.23mm to 0.34mm was directly proportioned to beam radius. on the other hand, cure width which varied from 0.42mm to 1.07mm was inversely proportioned to beam radius. Surface roughness varied from 1.12 to 2.23 m for the ratio of hatch spacing to beam radius.

• Journal of Information Processing Systems
• /
• 제8권1호
• /
• pp.175-190
• /
• 2012

Shuffling is an effective method to build a publicly verifiable mix network to implement verifiable anonymous channels that can be used for important cryptographic applications like electronic voting and electronic cash. One shuffling scheme by Groth is claimed to be secure and efficient. However, its soundness has not been formally proven. An attack against the soundness of this shuffling scheme is presented in this paper. Such an attack compromises the soundness of the mix network based on it. Two new shuffling protocols are designed on the basis of Groth's shuffling and batch verification techniques. The first new protocol is not completely sound, but is formally analyzed in regards to soundness, so it can be applied to build a mix network with formally proven soundness. The second new protocol is completely sound, so is more convenient to apply. Formal analysis in this paper guarantees that both new shuffling protocols can be employed to build mix networks with formally provable soundness. Both protocols prevent the attack against soundness in Groth's scheme. Both new shuffling protocols are very efficient as batch-verification-based efficiency-improving mechanisms have been adopted. The second protocol is even simpler and more elegant than the first one as it is based on a novel batch cryptographic technique.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권8호
• /
• pp.2849-2864
• /
• 2021

The emerging of cloud data sharing can create great values, especially in multi-cloud environments. However, "data island" between different cloud service providers (CSPs) has drawn trust problem in data sharing, causing contradictions with the increasing sharing need of cloud data users. And how to ensure the data value for both data owner and data user before sharing, is another challenge limiting massive data sharing in the multi-cloud environments. To solve the problems above, we propose a Uniform Encoding and Parsing Framework (UEPF) with blockchain to support trustworthy and valuable data sharing. We design namespace-based unique identifier pair to support data description corresponding with data in multi-cloud, and build a blockchain-based data encoding protocol to manage the metadata with identifier pair in the blockchain ledger. To share data in multi-cloud, we build a data parsing protocol with smart contract to query and get the sharing cloud data efficiently. We also build identifier updating protocol to satisfy the dynamicity of data, and data check protocol to ensure the validity of data. Theoretical analysis and experiment results show that UEPF is pretty efficient.