• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.121-122
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• 2002

The main principle of radiation therapy is to deliver optimum dose to tumor to increase tumor cure probability while minimizing dose to critical normal structure to reduce complications. RTP system is required for proper dose plan in radiation therapy treatment. The main goal of this research is to develop dose model for photon, electron, and brachytherapy, and to display dose distribution on patient images with optimum process. The main items developed in this research includes: (l) user requirements and quality control; analysis of user requirement in RTP, networking between RTP and relevant equipment, quality control using phantom for clinical application (2) dose model in RTP; photon, electron, brachytherapy, modifying dose model (3) image processing and 3D visualization; 2D image processing, auto contouring, image reconstruction, 3D visualization (4) object modeling and graphic user interface; development of total software structure, step-by-step planning procedure, window design and user-interface. Our final product show strong capability for routine and advance RTP planning.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.101-110
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• 1999

QFD is a market driven design and development methodology for products and services to meet or exceed customer's needs and expectations, This method enables to specify clearly the customer's needs and then evaluate the product capability in terms of its impact on meeting those needs. Process of satisfying customers begins with effectively soliciting their different needs and wants which may be non-technical and imprecise in nature. Although the HoQ is a comprehensive tool for showing the relationships between attributes, it lacks the flexibility to deal with the inherent inexactness and vagueness in the voice of customer. In this paper, fuzzy theory is introduced to overcome this limitation. Qualitative customer requirements are interpreted quantitative data through fuzzy inference procedure, and then target value is determined.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.278-281
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• 2005

Today, manufacturing capability at the micro or nano scale production field is requested strongly in view of parts and product miniaturization. Miniaturized parts and products will introduce lots of benefits in terms of high precision functionality and low energy consumption. This paper presents the results of micro milling machine tool development for micro machining process. Finite element analysis has been performed to know the relationship between design dimensional variables and structural stiffness in terms of static, dynamic, thermal aspects. Performance evaluation through machining has been tested and discussed for achievable machining characteristics.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.681-689
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• 2009

Disk grinding was often applied to deburring process in order to enhance the final product quality. Inherent chamfering capability of the flexible disk grinding process in the early stage was analyzed with respect to various process parameters including workpiece length, wheel speed, depth of cut and feed. Initial chamfered edge defined as arc zone was characterized with local radius of curvature. Averaged radius and arc zone ratio was well evaluated using neural network system. Additional neural network analysis adding workpiece length showed enhance performance in predicting arc zone ratio and curvature radius with reduced error rate. A process condition design parameter was estimated using remaining input and output parameters with the prediction error rate lower than 2.0% depending on the relevant input parameter combination and neural network structure composition.

• Clean Technology
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• v.24 no.1
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• pp.15-20
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• 2018

Hexafluoropropyleneoxide ($C_3F_6O$, HFPO) is highly expensive and it may be used as a raw material for the synthesis of various fluorine based compounds. Currently, extractive distillation method has gained considerable attention to collect the HFPO from a mixture of HFPO / hexafluoropropylene ($C_3F_6$, HFP). Optimized operating conditions are studied using a theoretical method for the extraction process. Among available solvents for the purification process, the use of 1,1-dichloro-1-fluoroethane exhibits a high purity of HFPO as a top product and minimize the required heat duty. Since the boiling point of the solvent increases as the pressure in the column increases, the enhanced extractive capability of the solvent led to the high purity of HFPO at the high pressure.

• Transactions of Materials Processing
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• v.12 no.5
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• pp.421-432
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• 2003

The dies & molds are a very economical production tool and a high value-added product because of its mass production capability compared to other production methods. Due to the very stiff international competitiveness, the industries meet many obstacles. For the promotion of the industry, the status and the international trends of the industry are measured. The vision and strategy are driven. In Korea, large portion of dies and molds are still low value-added and make large number of tools. In order to advance this industry to the high-tech area and gain competitiveness in the global marketplaces, effective means of resource investment and strategy should be properly provided.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.1
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• pp.8-14
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• 2013

A low density parity check (LDPC) decoder provides a most powerful error control capability for mobile communication devices and storage systems, due to its performance being close to Shannon's limit. In this paper, we introduce an efficient overlapped LDPC decoding algorithm using a upper dual-diagonal parity check matrix structure. By means of this algorithm, the LDPC decoder can concurrently execute parts of the check node update and variable node update in the sum-product algorithm. In this way, we can reduce the number of clock cycles per iteration as well as reduce the total latency. The proposed decoding structure offers a very simple control and is very flexible in terms of the variable bit length and variable code rate. The experiment results show that the proposed decoder can complete the decoding of codewords within 70% of the number of clock cycles required for a conventional non-overlapped decoder. The proposed design also reduces the power consumption by 33% when compared to the non-overlapped design.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.3
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• pp.9-14
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• 2013

Continuous airworthiness system is comprised of regulations and procedures to assure the safety and reliability through the total stage of development, certification and operation of aircraft. The purpose of this system is not only to provide the guidelines that should be kept by manufacturers and operators, but also to evaluate the maintenance capability in every activity of safety related procedures. During the development process of the mid and large size aircraft, operational experience should be reflected systematically for a safer and more reliable product by using the meaningful data base from operation. The relationship of safety roles between manufacturer and operator is mutually complementary, and the roles of each function have an influence to the next step. Overall structure of the procedure contains the concept of continuous analysis and feedback to achieve highest degree of safety and reliability during the entire life of aircraft. Finally, this paper describes how the feedback is made and used for aircraft design from operational experience under the continuous analysis and surveillance system.

• The KIPS Transactions:PartD
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• v.19D no.1
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• pp.29-38
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• 2012

Software globalization is becoming more important worldwide but little is known about how globalization technologies are actually carried out in the Korean software industry. In this paper, we have designed Globalization Quality Management (GQM) framework and applied the framework to the industry domestically for the first time. GQM provides a structured and effective way for software organizations to adopt globalization practices and evaluate the results. GQM consists of three main components: 1) software quality management process, 2) globalization support model and 3) globalization assessment model. This framework also supports both plan-driven and iterative/incremental development methods. On the basis of the GQM, a survey study was conducted among software engineering professionals, gathering the data from 31 IT companies across 7 large-scale projects in Korea. The result indicate that the evaluation score for globalization capability is 2.47 and global readiness is 2.55 out of 5 points. Also It said that internationalized product design (32.9%) and global/local product requirements analysis (28%) are needed to be taken care of first.

• Journal of Information Technology and Architecture
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• v.9 no.3
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• pp.275-285
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• 2012

DIFs (Data Interchange Formats) are needed to enhance interoperability of physically distributed organizations in SBA (Simulation Based Acquisition) process. DIFs play a role as a template of DPDs (Distributed Product Descriptions) and provide capability to use information directly without data format interchange process by allowing access to DPDs, which include various information and M&S (Modeling & Simulation) resources. This characteristic is essential for interoperability in ICE (Integrated Collaborative Environment) based SBA. This paper proposes a framework for the DIF and outputs from each phase of acquisition process for configuration data related to design and manufacturing in SBA process - Conceptual Data Model, Logical Data Model, Physical Data Model and Physical DIF based on XML. Finally, we propose the DIF model architecture and demonstrate the implementation of DIF example based on it.