• Korean Journal of Computational Design and Engineering
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• v.17 no.1
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• pp.54-61
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• 2012

In this paper, we performed numerical analysis to improve the heat exchange efficiency of wasted heat recovery ventilator which has a delivery and a exhaustion fan. One of the most important design factors that affect the efficiency of heat exchange is uniform counter-flow between inbound and outbound air flows. We had simulated several types of porous plates which were installed at air intake area. With plate having 45 degrees of installation angle and 15 mm diameter holes which are uniformly arranged, we can generate a uniform air flows at the area of porous media where inbound and outbound air flows are cross over. In addition, we installed a duct to reduce vortex flows at the outlet and to discharge exhaust airs rapidly. By using the proposed numerical assessment, we expect the improvement of the heat exchange efficiency of ventilator.

• Korean Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.44-52
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• 1997

A design process is difficult to describe comprehensively because a design problem has a multi-disciplinary nature and the design itself evolves as solutions are attempted by the designer. The process of design has been investigated in this paper with the purpose of characterizing the role that a system of this kind may have. In defining the system, an approach has been used that privileges the relationships with the existing CAD tools based on data exchange standards in course of definition today. Integrated design environment normally consists of a centralized data model a data management system and a set of CAD tools. In this study, all further investigations are directed towards the data management system, as one of the main components of the proposed environment. Moreover, product modeling, as a prerequisite for the data management core, is taken into special consideration.

• Korean Journal of Computational Design and Engineering
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• v.6 no.3
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• pp.147-156
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• 2001

In the construction industry, construction process includes a variety of design stages with cooperation and regulation by many related disciplines. In addition, the construction market is growing and becoming more complex. With this characteristic, design information has become more and more complicated and difficult to manage by the simple and traditional data management methodology. In the practical field, although CAD has been widely available for the last ten years, related disciplines have not shared digital information efficiently. This paper suggests a construction CAD data exchange model that has been developed through investigation and analysis of Korean construction CAD practices and foreign CAD standards. Moreover, this paper investigates a CAD data exchange model using STEP to improve information availability and overcome the limit of CAD systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8C
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• pp.821-826
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• 2003

In this paper, constrained Remez exchange algorithm is proposed to reduce the critical path of an IIR filter. The proposed algorithm is based on Remez exchange algorithm and least squares method. By IIR filter design examples, it is shown that the proposed method can maximally increase speed by 20%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.39-51
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• 2002

Online exchange is a cost-effective approach to trade goods and information among multiple sellers and buyers. Shipping industry includes lots of global entities such as shippers, liners, ship owners and shipping agents. Marine insurance companies and ship repairers and many other groups are also supporting the industry. However, international shipping exchanges are located on few cities in the world. Its our motivation that a shipping market can be online so that market participants do the dealing while sitting where they are with more efficient manner, preferable price and larger pool of candidates of trading partners. This paper presents Korean governmental project of building a cyber shipping exchange. The exchange covers ship sale and purchase, charter, insurance, freight futures, repairs, supplying of ships oil and database service. The workflows of each business were analyzed and designed to fit for online environment. The project includes design of trading mechanism, online documents, data flow, data storage and security. Online match making and trading mechanisms such as auction, reverse auction, bid are used. The whole trading process involves multiple organizations and business processes. So, this Paper focuses on how each organization would play their roles so that users can complete transactions with integrated and transparent view. The online exchange selves also as maritime portal site that links to other sites for cooperation vertically or horizontally, and serves database and information in global perspective. This paper also issues and discusses the justification of an online shipping exchange

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.24-34
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• 2015

As recent multilateral collaboration design system has been advanced, BIM based data exchange is a key factor for successful next generation building project. Even though many studies have been trying to set up a data compatibility system for collaboration, There are still a lot of problem in data exchange between design and engineering phase. Therefore, In this study, we analysis causes of problem for information exchange and suggest a IFC based Information exchange framework for improving BIM based design collaboration environment. In order to find out problems that hinder establishment of advanced open BIM information exchange, proper analysis about transition of process from current and to-be BIM based design collaboration process is important, at first. From analysis of main obstacles to information exchange, this research suggests solution plan using open API and IFC based BIM collaboration supporting system. The suggested open API solution named Integrity feedback system perform a role making up for weak point derived from IFC based data exchange. And main system suggestion about framework for IFC based information exchange reflect technological system support, requirement of function for collaboration including API/BCF plug-in.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1049-1061
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• 2013

In this paper, a relative heat exchange rate is numerically compared for cast-in-place concrete energy piles with different heat exchange pipe configurations, and a new design method for energy piles is proposed. An equivalent heat exchange rate was estimated for the W-type (one series loop), multiple U-type (four parallel loops), and coil-type heat exchanger installed in the same large-diameter drilled shaft. In order to simulate a cooling operation in summer by a CFD analysis, the LWT (leaving water temperature) into a energy pile was fixed at $35^{\circ}C$ and then the EWT (entering water temperature) into a heat pump was monitored. In case of continuously applying the artificial maximum cooling load for 100 hours, all of the three types of heat exchangers show the marginally similar heat exchange rate. However, in case of intermittently applying the cooling load with a cycle of 8 hours operation-16 hours off for 7 consecutive days, the coil type heat exchanger exhibits a heat exchange rate only 86 % of the multiple U-type due to measurable thermal interference between pipe loops in the energy pile. On the other hand, the W-type possesses the similar heat exchange rate to the multiple U-type. The equivalent heat exchange rates for each configuration of heat exchangers obtained from the CFD analysis were adopted for implementing the commercial design program (PILESIM2). Finally, a design method for cast-in-place concrete energy piles is proposed along with a design chart in consideration of typical design factors.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.95-102
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• 2006

A product is designed through the collaboration among engineers in several fields such as design, analysis, and manufacturing. These series of functions are performed repeatedly during the design process. An easy access and exchange of the model data is one of the important elements that help to shorten production development time. Especially, the importance of data exchange between CAD and CAE applications is increasing in the field of verification and estimation of the products. However, information and knowledge of model which is generated by a CAD software cannot be transferred by a function of CAE software, as an exchange of product data between CAD and CAE applications. It causes a delay in design analysis and eventually discourages a designer's effort in improving his design. Therefore, we need to integrate a commercial CAD and CAE applications effectively and to use the same interface on a product model obtained in a distributed environment. This paper shows how to implement a model exchange between CAD and CAE by a web-service and how to provide a communication environment among engineers.

• Korean Journal of Computational Design and Engineering
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• v.11 no.3
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• pp.164-171
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• 2006

As collaborative design and configuration design are of increasing importance in product development, it becomes essential to exchange the feature and parametric CAD models among participants. A history-based parametric method has been proposed and implemented. But each translator which exchanges the feature and parametric information tends to be heavy because to implement duplicated functions such as the identification of the selected geometries, mapping between features which have different attributes. Furthermore. because the history-based parametric translator uses the procedural model as the neutral format, which is the XML macro file, the history-based parametric translators need a geometric modeling kernel to generate an internal explicit geometric model. To ease the problem, we implemented a shared integration platform, the TransCAD. The TransCAD separates translators from the XML macro files. The translators for various CAD systems need to communicate with only the TransCAD. To support the communication with the TransCAD, we exposed the functions of the TransCAD by using the Automation APIs, which is developed by Microsoft. The Automation APIs of the TransCAD consist of the part modeling functions, the data extraction functions, and the utility functions. Each translator uses these functions to translate a parametric CAD model from the sending CAD system into the XML format, or from the in format into the model of the receiving CAD system This paper introduces what the TransCAD is and how it works for the exchange of the feature and parametric models.

• The Journal of Society for e-Business Studies
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• v.3 no.2
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• pp.113-124
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• 1998

The architectural design requires collaboration among various participants, such as architects, clients and engineers in the stages of the design process. Rapid development of information technology enables effective and prompt exchange and sharing of digital architectural information, otherwise should have been exchanged and managed by traditional ways. However, the core technology for supporting this demands has not been fully investigated so far. This paper aims to show the possibility of adopting network based architectural design information sharing system through surveying and analyzing the state-of-the-art network technology and its uses in architectural information exchange among various design actors. To realize these aims, this paper 1) investigates and analyzes the current status of network technology in the architectural and construction practice, 2) suggests systematic information exchange and sharing mechanism for architectural products and drawings data, and 3) demonstrates network based prototypical architectural information system.