• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.508-512
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• 2015

Carbon emission calculation guidelines provided by the Korean Ministry of Land, Infrastructure and Transportation (MOLIT) and existing environmental load assessment studies have suggested a method for estimating based on the volume determined after the design development. Therefore they are not being helpful in the decision making of the environmental economics of road facilities in the planning stage in which specific information on construction output volume is lacking. Based on literature analysis of existing studies and consultation from a group of construction environmental professionals, 12 types of property information considered to be related to environmental load were selected from an inventory of information that will be available in the road planning stage. In addition, multiple regression analysis was performed based on the environmental load computed through the life cycle assessment (LCA) of 40 national highway project cases of Korea to deduce five impact factors of environmental load in the road facilities planning stage.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.124-128
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• 1999

Since the traditional designing approach of forming processes is based on trial and error it consumes much time and needs cost to design successful processes. Today for higher marketability of products a manufacturing system is required that can reduce production time and enhance product properties greatly. In order to implement the system a computerized design-supporting tool is indispensable for the design and supply of optimized production process for high product quality in short time In this study a design supporting system is developed and implemented to ballstud die. Using the developed system the designer can rapidly produce layouts of dies for each process sequences with consistency.

• KIEAE Journal
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• 제15권4호
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• pp.85-90
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• 2015

Purpose: In design and planning Building Integrated Photovoltaic(BIPV) system can reduce cost by replacing building facade as construction material such as roofs, outer walls and windows as well as generating electricity. BIPV system should be applied at the early stage of architectural design. However, it is hard to decide whether using BIPV system or not for architects and builders who are not professional at BIPV system because performance of system is considerably influenced by types of module, installation position, installation methods and so on. It is also hard for experts because commercialized analytical program of photovoltaic systems is too complicated to use and domestic meteorological data is limited to partial areas. Therefore, we need evaluation program of BIPV system which can easily but accurately interpret generating performance and evaluate validity of BIPV system at the early stage of architectural design even for inexpert. Method: In this study, we collected meteorological data of domestic major region and analyzed generation characteristic of BIPV system by using PVsyst(commercialized software) in accordance with regions, types of solar module, place and methods of installation and so on. Based on this data, we developed performance evaluation program of BIPV system named BIPV-Pro, through multiple regression analysis and evaluated its validity. Result: When comparing predictive value of annual average PR and annual electricity production of BIPV-Pro an that of PVsyst, each of root mean square error was 0.01897 and 123.9.

• 한국항공우주학회지
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• 제38권10호
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• pp.1012-1019
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• 2010

본 논문에서는 다중표적 비행시험을 위한 비행 자료처리 시스템이 설계되었다. 비행자료 처리를 위해 표적그룹 처리, 자료융합 처리 및 자료연동 처리가 수행 되었으며, 자료융합 필터로서 집중형 칼만필터와 연합형 칼만필터를 설계하였다. 특히 집중형 필터에 레이더의 SNR과 추정기법을 적용하여 비행체의 저고도 계측을 개선하였다. 개발된 시스템을 다중표적 비행시험에 적용한 결과, 저고도 및 초기구간에서 개선된 비행궤적을 확인할 수 있었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.438-445
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• 2006

Due to the complicated character of the hemming process for automobile panels, it is very difficult to set up a consistent and reliable die design guide rule that does not require subtle decision of experienced experts during design stage and multiple trials during hemming die making. In this paper an automatic die design system of hemming units is pursued by presenting some algorithms, in which geometric data and constraints of the hemming units were converted to formula. two kinds of hemming units, 2-link type and 4-link type, were selected as examples and the geometries and kinematics of all parts were analyzed to build the design algorithm.

• International Journal of Human Ecology
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• 제13권1호
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• pp.129-145
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• 2012

The purpose of this study was to investigate housing cost burden of U.S. households according to current and previous tenure types and explore influences on their housing affordability. The public-use microdata of the 2009 American Housing Survey was analyzed in the following two stages: In the first stage, households were classified into eight groups by combining their current and previous tenure types, year moved into current housing units and mortgage status of current owners and their characteristics were compared. In the second stage, the factors that influenced the housing cost burden by each combined tenure group were explored using multiple regression analyses. The findings are as follows: (1) The mortgage status was more influential than the previous housing experiences of owner households to distinguish one owner household from another. (2) Renter households who had been owners of previous housing units showed significantly different characteristics compared to continuing and new renter households in terms of income, educational attainment, and householder's marital status as well as housing costs and housing cost burdens. (3) To see the multiple regression analysis results, households with different current and previous tenure types were found to have different factors that influenced the housing cost burdens. In addition, household characteristics were found to have significant influences on housing cost burdens as strong as cost-related variables such as annual mortgage payments and rent per square footage.

• 대한전자공학회논문지
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• 제25권8호
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• pp.1010-1018
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• 1988

This paper proposes a MOS circuit extractor which extracts a netlist from the hierarchical mask information, for the verification tools. To utilize the regularity and the simple representation of the hierarchical circuit, and to reduce the debug cycle of design, verification, and modification, we propose a hierarvhical and incremental circuit extraction algorithm. In flat circuit extraction stage, the multiple storage quad tree is used as an internal data structure. Incremental circuit extraction using the hierarchical structure is made possible, to reduce the re-extraction time of the modified circuit.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.975-978
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• 2002

A new conception of public-key cryptography MEPKC, Petri net based Multi-stage-Encryption Public-Key Cryptography, has been proposed in onder to guarantee stronger network communication security. Different from an ordinary public-key cryptography that opens only a single public key to the public, MEPKC opens a key-generator that can generate multiple encryption keys and uses these keys to encrypt a plain text to a cipher text stage by stage. In this paper, we propose the methods how to carry out the encryption operations. First, we describe how to design a hash function H that is used to conceal the encryption keys from attack. Then, given with a key-generator (a Petri net supposed to possess a large number of elementary T-invariants), we discuss how to randomly generate a series of encryption keys, the elementary T-invariants. Finally, we show how to use these encryption keys to encrypt a plain text to a cipher text by applying a private key cryptography, say DES.

• 유통과학연구
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• 제22권1호
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• pp.95-103
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• 2024

Purpose: Focusing on the complex supply chain operations beyond the simple dyadic relationship, this study evaluates the performance of the revenue sharing contract in three stage supply chain system. Research design, data, and methodology: The optimization model is developed to describe the supply chain system where one manufacturer, one wholesaler, and one retailer exist and pursue the maximum level of their own profits. In the numerical examples of the proposed supply chain model, two types of the revenue sharing contract, pairwise and spanning methods, are tested and their performances are compared with the traditional system. Results: The numerical analysis reveals that both types of the revenue sharing contract outperform the traditional system. All supply chain members can achieve the improved profits only when they determine the proper combination of revenue share ratios and price discount rates. Conclusions: This study finds out that both pairwise and spanning revenue sharing contracts can make the positive outcome that is acceptable to all members in three stage supply chain system. When the proper contract content is agreed among the supply chain members, the revenue sharing contract has the potential to be the practically feasible collaboration program for the multiple stage supply chain system.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 추계학술대회 논문집
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• pp.141-148
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• 1994

In order to improve the productivity of cold forging at low production cost, an integrated system's approach is necessary in handling the material preparation and the optimum process design, considering the forming machines, tooling, and operation including quality control. As the first step toward this approach, an expert system for multi-stage cold forging process design for fasteners with various head geometries is developed using Prolog language on IBM 486 PC. For effective representation of the complex part geometries, the system uses the multiple element input, and the forward inference scheme in determination of the initial billet size and intermediate forging steps. In order to determine intermediate steps, the basic empirical rules for extrusion, heading, and trimming were applied. The required forming loads and global strain distributions at each forging step were calculated and displayed on the PC monitor. The designed process sequence drawing can be obtained by AutoCAD. The developed system will be useful in reducing trial and error of design engineers in determining the diameter and height of the initial cylindrical billet from the final product geometry and the intermediate necessary sequences.