• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.1
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• pp.1-6
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• 2014

Properly designed plastic packages of fresh produce can preserve the quality by maintaining the optimal modified atmosphere (MA) at optimal low temperature conditions, but cannot do so at temperature abuse conditions in retail stage due to occurrence of injurious package atmosphere coming from imbalance between respiration and package gas permeation. Master packaging system consisting of a double-layered secondary package wrapping several individual (primary) packages has been proposed and applied recently to the commodities of sweet persimmon, king oyster mushroom, chestnut and strawberry. The master (secondary) pack is designed to be stored and distributed under chilled temperature, and then dismantled when moved to the retail display from the presale chilled storage. The master packaging system taking into consideration temperature dependence of produce respiration and package gas transfer was looked into with examination of its design variables to maintain the beneficial MA. Mathematical model was provided to help the design of master packaging system creating the desired MA. Its benefits of quality preservation and its limitations in practices of fresh produce marketing were discussed. Further research direction to extend the applicability of the produce master packaging system was presented.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.251-261
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• 1997

A package to transport the high level radioactive materials is required to withstand the hypothetical accident conditions as well as normal transport conditions according to IAEA standards and domestic regulations. The regulations require that the package should maintain the shielding, thermal and structural integrities to release no radioactive material. In general, safety evaluation of packages is performed by experimental methods using scale model and/or analytical methods using computer codes. This paper presents the safety evaluation of package to transport the radioisotopes produced in the HANARO to the radioisotope production facility. Radiation shielding, thermal and structural analyses were peformed using the computer codes. It has been verified that the package is safe under hypothetical accident conditions as well as normal transport conditions.

• Wind and Structures
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• v.10 no.1
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• pp.61-82
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• 2007

This paper presents a novel finite element (FE) model for analyzing coupled flutter of long-span bridges using the commercial FE package ANSYS. This model utilizes a specific user-defined element Matrix27 in ANSYS to model the aeroelastic forces acting on the bridge, wherein the stiffness and damping matrices are expressed in terms of the reduced wind velocity and flutter derivatives. Making use of this FE model, damped complex eigenvalue analysis is carried out to determine the complex eigenvalues, of which the real part is the logarithm decay rate and the imaginary part is the damped vibration frequency. The condition for onset of flutter instability becomes that, at a certain wind velocity, the structural system incorporating fictitious Matrix27 elements has a complex eigenvalue with zero or near-zero real part, with the imaginary part of this eigenvalue being the flutter frequency. Case studies are provided to validate the developed procedure as well as to demonstrate the flutter analysis of cable-supported bridges using ANSYS. The proposed method enables the bridge designers and engineering practitioners to analyze flutter instability by using the commercial FE package ANSYS.

• Atmosphere
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• v.27 no.1
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• pp.17-28
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• 2017

The sensitivity of the typhoon track and intensity simulation to physics schemes of the global model are examined for the typhoon Bolaven and Tembin cases by using the Global/Regional Integrated Model System-Global Model Program (GRIMs-GMP) with the physics package version 2.0 of the Korea Institute of Atmospheric Prediction Systems. Microphysics, Cloudiness, and Planetary boundary Layer (PBL) parameterizations are changed and the impact of each scheme change to typhoon simulation is compared with the control simulation and observation. It is found that change of microphysics scheme from WRF Single-Moment 5-class (WSM5) to 1-class (WSM1) affects to the typhoon simulation significantly, showing the intensified typhoon activity and increased precipitation amount, while the effect of the prognostic cloudiness and PBL enhanced mixing scheme is not noticeable. It appears that WSM1 simulates relatively unstable and drier atmospheric structure than WSM5, which is induced by the latent heat change and the associated radiative effect due to not considering ice cloud. And WSM1 results the enhanced typhoon intensity and heavy rainfall simulation. It suggests that the microphysics is important to improve the capability for typhoon simulation of a global model and to increase the predictability of medium range forecast.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.3
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• pp.50-57
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• 2024

Recently, applying a machine learning to surrogate modeling for rapid optimization of complex designs have been widely researched. Once trained, the machine learning surrogate model can predict similar outputs to Finite Element Analysis (FEA) simulations but require significantly less computing resources. In addition, combined with optimization methodologies, it can identify optimal design variable with less time requirement compared to iterative simulation. This study proposes a Deep Neural Network (DNN) model with Bayesian Optimization (BO) approach for efficiently searching the optimal design variables to minimize the warpage of electronic package. The DNN model was trained by using design variable-warpage dataset from FEA simulation, and the Bayesian optimization was applied to find the optimal design variables which minimizing the warpage. The suggested DNN + BO model shows over 99% consistency compared to actual simulation results, while only require 15 second to identify optimal design variable, which reducing the optimization time by more than 57% compared to FEA simulation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.3
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• pp.44-51
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• 2021

PIP is an abbreviation of 'Performance Improvement Package', which is a package that can improve performance by applying some design changes to existing aircraft. Boeing provides PIP applicable to B777-200, and Airbus provides PIP applicable to A350-900 as standard. PIP provided by Boeing and Airbus is a separate task, but it is expected to reduce fuel consumption by reducing drag through aerodynamic improvements. The PIP applied to the A350-900 includes work such as increasing Winglet Height and re-twisting Outboard Wing. This study is to verify the effect of PIP application of the A350-900 aircraft and use it as basic data for economic analysis. The aerodynamic improvement studies and expected effects of the PIP application were examined, and the actual flight data of the PIP-applied and the non-applied aircraft were compared to confirm the PIP application effect. This paper provides empirical results for the aviation industry on the PIP application efficiency as a method of improving fuel efficiency and reducing carbon emission.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.138-147
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• 2006

The objective of this research is to explore a more precise forecasting method by applying Case-based Reasoning (CBR). The newly suggested method in this study enables project managers to forecast monthly expenditures with less time and effort by retrieving and referring only projects of a similar nature, while filtering out irrelevant cases included in database. For the purpose of accurate forecasting, 1) the choice of the numbers of referring projects and 2) the better selection among three levels ? which include a 20-work package level, a 7-major work package level, and a total sum level analysis, were investigated in detail. It is concluded that selecting similar projects at $12{\sim}19%$ out of the whole database will produce a more precise forecasting. The new forecasting model, which suggests the predicted values based on previous projects, is more than just a forecasting methodology; it provides a bridge that enables current data collection techniques to be used within the context of the accumulated information. This will eventually help all the participants in the construction industry to build up the knowledge derived from invaluable experience.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.167-175
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• 1993

This article contains three objectives. First it is to revise unnecessary procedures of a transportation models and transform results of a model into an image. Second objectives is to develop an operational structures which automatically input all data needed from arc-node topology to link-node topology of transportation network. By solving the network discrepancy, time and money for constructing to transportation can be saved. In addition, the rate of errors that my caused during data input process can be reduced. Conclusively, it is found that the integration package may provide user friendliness and reduce the rate of errors. The package can extract informations such as distance between zones and nodes, lane numbers, and hierarchy from arc-node topology for executing SDI. Another advantage of integration is the ability of spatial analysis. The integrated package may provide adequate arrangements of traffic facilities and checking systems of the shortest path. Finally, the database function of GIS package provides various information about study area for transportation analysis.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.423-439
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• 1991

본 연구의 목적은 당제철소에서 생산하는 제품중 전기강판 방향성 제품의 제질(철손) 불량원인을 추적하여 조업 guidance를 제시하는 model개발이다. model개발은 현장조업 data에 대해 상관분석, 회귀분석, 분산분석등의 통계적분석을 통하여 재질에 영향을 미치는 주 관련인자들의 조업기준 재정립과 menu화면에 의한 자동 불량원인 추적 model을 개발하였으며, model개발을 위한 사용 tool은 SAS package를 활용하였다.

• Journal of the Korean Society of Industry Convergence
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• v.1 no.2
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• pp.13-19
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• 1998

A computer simulation program for the design of furnace witjin pakaged water-tube boilres is developed and the developed computer program is successfully applied to design the furnace for packaged water-tube boiler. The model by experiment and the model by Hottel are used to predict the exit gas temperature of furnace. The result by two models is discussed and is shown that in the case of constant cross section in furnace, the result is same but in changing the configuration of cross section, the difference by two models is not small.