• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.137-141
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• 2004

Ship structures are basically an assembly of plate elements and the load-carrying capacity or the ultimate strength is one of the most important criteria for safety assessment and economic design. Also, Structural elements making up ship plated structures do not work separately, resulting in high degree of redundancy and complexity, in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy needed and the degree of complexity of the analysis to be used. On this study, to investigate effect of modeling range, the finite element method are used and their results are compared varying the analysis ranges. The model has been selected from bottom panels of large merchant ship structures. For FEA, three types of structural modeling are adopted in terms of the extent of the analysis. The purpose of the present study is to numerically calculate the characteristics of ultimate strength behavior according to the analysis ranges of stiffened panels subject to uniaxial compressive loads.

• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.1-12
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• 2008

The major components of an engine are the cylinder block, cylinder head, crankshaft, connecting rod, and camshaft, which are more popularly known as the 5 C's. Thus, the engine shop usually consists of six sub-lines, including five machining lines and one assembly line. The flow line is the typical concept of the layout when the engineer designs the engine shop. This paper introduces a simulation study regarding the new crankshaft machining line in a Korean automotive factory. The major factors for designing the machining line are considered, and their effects on the system performance are evaluated with a three-dimensional(3D) simulation model that is developed with $QUEST^{(R)}$. The initial layout is analyzed using the simulation model, and we suggest some ideas for improvement.

• Korean Journal of Computational Design and Engineering
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• v.15 no.5
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• pp.362-374
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• 2010

Product Lifecycle Management (PLM) is an integrated business approach to manage the creation and distribution of product information throughout the product development process. From the product perspective, PLM encompasses a holistic approach to product development and product information management. It supports the integrated product information in conjunction with the efficient product structures and BOM (Bill Of Material), user interfaces, proper functions, design processes and enterprise integration. Therefore, PLM should not only satisfy required functions as an enterprise software but also offer a systematic method for the efficient application from the initial stage of its development. Recently, many shipyards have been considering the PLM as a strategic solution to get the efficient management of product information such as 3-D models, BOM, drawings, documents, and the other product data. Though many studies on PLM are performed, most of them are performed in a function-based approach adequate for mass productive assembly industries. It could not help having limitations on applying the proper PLM system to the shipbuilding business since the requirements of shipbuilding PLM are too diverse and huge to design the architecture. This study presents the PLM framework which effectively reflects the diverse requirements of shipbuilding PLM. In order to get the macroscopic architecture of shipbuilding PLM, authors suggest the four-tier architecture model which considers the various requirements collected from shipyards. Entities of ship design data are modeled BOM in terms of product structure and hierarchical class diagram. Applicable functions of shipbuilding PLM are also investigated by analysis of issues of ship design. Finally, by reflecting the design process of shipbuilding, To-Be ship design procedure cooperated with the suggested PLM framework has been summarized.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.410-415
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• 2001

Earned Value Management System(EVMS) has been considered as a useful tool of managing construction projects lately and its instruction into a private industry is now under consideration by the Korean government. It is on the basis of C/SCSC that had been released by the U.S. Department of Defense(DOD) since 1967. Its research has been in the active progress in order to utilize the earned value concept as a project management tool for construction project ordered by both government and private sector. Material Requirement Planning(MRP) is also known as a tool of planning and scheduling resources for assembly product as a part of inventory control models in the manufacturing industry. The purpose of this study is the effective employment of Earned Value Management to manage the construction projects by utilizing Material Requirement Planning(MRP), based on project management software and Workpackaging model.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.11
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• pp.601-611
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• 2002

As resent trends in structural construction have been to build taller and larger structures than any time in the past, they have had high flexibility and low damping that can cause large vibration response under severe environmental loading such as earthquakes, winds, and mechanical excitations. The damper with mass and sqring is one aproach to safeguarding the structure against excessive vibrations. In this paper, a large capacity hybrid-type linear motor damper(LMD) was designed and fabricated for the application to the vibration control of a large building structure model. It has been designed to be able to move the damper mass, 1,500 kg up to ${\pm}250mm$ strokes at the first mode natural frequency of the building structure model, ${\pm}0.51Hz$. Linear motor is consisted of the fixed coil and the movable NdFeB permanent magnets field part. The PM field part composed magnet modules and iron yoke, is the damper mass itself, 1500kg. LMD therefore has a simplified structure and requires a few elements in the driving system, being compared with a rotary motor damper and a hydraulic damper. However, the manufacture of large PM linear actuator is difficult because of the limit of PM size and the attraction and repulsion at the assembly of PM. Therefore, large damper system is manufactured and tested for dynamic characteristics and frequency response.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.135-145
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• 2000

Manufacturing Message Specification (MMS) is designed as a communication standard protocol, ISO/IEC 9506, on factory automation for messaging between heterogeneous programmable unit controller, PLC, NC, Robot, of different vendors on the networks. MMS is also a standard protocol of OSI reference model application layer, In this paper, we show an implementation of MMS over TCP/IP using ANSI-C programming language on the unix environment, and make java classification using java native interface (NJI) with MMS library. The use of java classification provides a basic environment ot overcome a difficult programming with different MMS application programming interface (MMS-I) which requires a siklled programming technique of graphic user interface (GUI). In this paper, we implement a MMS application program of the automated assembly model for printed circuit board based on WWW which shows the operation, control and monitoring of real manufacturing device (RMD) with web browser providing users for consistent user interface.

• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.157-161
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• 2009

Minimum Letter Flips(MLF) and Weighted Minimum Letter Flips(WMLF) can perform the haplotype reconstruction more accurately from SNP fragments when they have many errors and gaps by introducing the related genotype information. And it is known that WMLF is more accurate in haplotype reconstruction than those based on the MLF. In the paper, we analyze two models under the conditions that the different rates of homozygous site in the genotype information and the different confidence levels according to the sequencing quality. We compare the performance of the two models using neural network and genetic algorithm. If the rate of homozygous site is high and sequencing quality is good, the results of experiments indicate that WMLF/GI has higher accuracy of haplotype reconstruction than that of the MCIH especially when the error rate and gap rate of SNP fragments are high.

• Journal of Arbitration Studies
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• v.23 no.4
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• pp.97-122
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• 2013

Vietnam has become an attractive destination for foreign investors, but confidence in the country's legal system to resolve commercial disputes remains low. Reasons include the lack of an independent judiciary, the lack of published court decisions, and a tendency to criminalize civil disputes, among others. As such, arbitration has become a preferred alternative to litigation. On June 17, 2010, the National Assembly of Vietnam passed a new act on commercial arbitration replacing the July 1, 2003 ordinance on commercial arbitration. The new act will take effect on January 1, 2011, and it is widely expected by the Vietnamese legal profession and lawmakers will create a favorable legal framework for the expansion of the arbitration service market in Vietnam. The new act is inspired by the UNCITRAL Model Arbitration Law of 1985 as are most new arbitration laws throughout the world. As opposed to the 2003 ordinance, the 2010 Act allows parties to request interim relief from the arbitrators. Also the new act eliminates the mandate that arbitrators be Vietnamese. The law has addressed the ordinance's shortcomings and reflects international standards. Commercial arbitration law is an important milestone in the improvement process of the laws on commercial arbitration in Vietnam. However, it is still too soon to affirm anything definitely because there remain many obstacles to the activation of arbitration. Rule of law and business cultural factors are important. The leading arbitral institution, VIAC, which is attached to the Vietnam Chamber of Commerce and Industry, is expected to play an important role for boosting the competitiveness of Vietnamese arbitration as an avenue to dispute settlement.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.84-91
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• 2017

The dynamic characteristics of a ducted fan in hovering condition were investigated. The section properties of the fan blade were calculated, and a simulation model was developed according to the rotor system components. Dynamic analyses were conducted relative to the rotational speed and the collective pitch. The proposed ducted fan system showed less aero-elastic instability within the designated operating ranges. To verify the analytical approach, a rotating test stand of the ducted fan was set up. A functional test of the assembly was carried out to determine the kinematics and interference between components. The non-rotating and rotating normal frequencies were measured by excitation of the collective pitch using hydraulic actuators. The results indicated a correlation between the test equipment and the simulation model.

• Journal of Korea Water Resources Association
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• v.43 no.4
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• pp.337-351
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• 2010

There is a growing dissatisfaction with use of conventional statistical methods for the prediction of extreme events. Conventional methodology for modeling extreme event consists of adopting an asymptotic model to describe stochastic variation. However asymptotically motivated models remain the centerpiece of our modeling strategy, since without such an asymptotic basis, models have no rational for extrapolation beyond the level of observed data. Also, this asymptotic models ignored or overestimate the uncertainty and finally decrease the reliability of uncertainty. Therefore this article provide the research example of the extreme rainfall event and the methodology to reduce the uncertainty. In this study, the Bayesian MCMC (Bayesian Markov Chain Monte Carlo) and the MLE (Maximum Likelihood Estimation) methods using a quadratic approximation are applied to perform the at-site rainfall frequency analysis. Especially, the GEV distribution and Gumbel distribution which frequently used distribution in the fields of rainfall frequency distribution are used and compared. Also, the results of two distribution are analyzed and compared in the aspect of uncertainty.