• Journal of Mechanical Science and Technology
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• v.18 no.2
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• pp.230-239
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• 2004

A compact model approach of a network of spring elements for elastic loading is presented for the thermal deformation analysis of BGA package assembly. High-sensitivity moire interferometry is applied to evaluate and calibrated the model quantitatively. Two ball grid array (BGA) package assemblies are employed for moire experiments. For a package assembly with a small global bending, the spring model can predict the boundary conditions of the critical solder ball excellently well. For a package assembly with a large global bending, however, the relative displacements determined by spring model agree well with that by experiment after accounting for the rigid-body rotation. The shear strain results of the FEM with the input from the calibrated compact spring model agree reasonably well with the experimental data. The results imply that the combined approach of the compact spring model and the local FE analysis is an effective way to predict strains and stresses and to determine solder damage of the critical solder ball.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.100-112
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• 1991

Software system is a hierarchical structure with collection of program units. Software system can import external packages globally or locally depending on the usage within a system. If the imported package is used globally, the soft-ware system can be influenced globally by any change of package and programmer's debugging time for the program maintenance will be greater. To solve these problems, it is desirable to use the imported package locally right on the usage point within the system. The model presented in this paper analyzed entity usage of package in structure of program, identified the usage level to obtain localization and provided information for restructure of the program to localize package usage. To obtain localization, it identified declared entities inside the imported package and analyzed the specification and body part of program unit to identify entities referenced from the imported package. The proposed model can be used to improve the maintainability of software system and contributed to reduction of programmer's debugging time in program maintenance.

• The Korean Journal of Emergency Medical Services
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• v.9 no.2
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• pp.207-221
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• 2005

Purpose: The purpose of this study was to develop and apply a simulation-problem based learning(S-PBL) package in basic life support(BLS). Methods: This study was used to developed BLS' S-PBL package throughout 12 steps of PBL package development model. Then, BLS' S-PBL methodology was implemented in second year student in the undergraduate emergency medical technology, and survey was done. Results: 1. S-PBL package model was presented based on conceptual model II of PBL ; PEL for professional action. 2. Quantitative analysis of survey was to the effectiveness of learning, 3.59 points ; 4.15 of BLS and 3.84 of integration and practical use of knowledge. 3. As to the satisfaction of student, S-PBL package management, tutor and self-satisfaction' score was 3.59, 3.82, 3.39 respectively. Conclusion: This study was suggested that S-PBL education would be necessary with improved tutor skill and achieved advantage of simulation and PBL.

• The Korean Journal of Emergency Medical Services
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• v.14 no.2
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• pp.25-40
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• 2010

Purpose : The purpose of this study was to develop and apply a Core Skill-TLP(Core Skill-Tutorial, Laboratory, Practicum) package in Patient Management and to effect of core skill-TLP education. Methods : This study was used to developed Patient Management' Core Skill-TLP package throughout 14 steps of Core Skill-TLP package development model. Then, Core Skill-TLP Learning methodology was implemented in first year student in the undergraduate emergency medical technology, and survey was done. Results : 1. Core Skill-TLP package model was presented based on conceptual model of PBL(S-PBL). 2, The student in OSCE did significantly better in clinical patient management core skills performance. 3. As to the satisfaction of Core Skill-TLP package management, student, tutor and self-satisfaction score was 3.21, 3.42, 3.38 respectively. Conclusion : This study was suggested that Core Skill-TLP education would be necessary with well-structured package and achieved advantage of simulation and PBL.

• Journal of the Korean Society of Food Culture
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• v.21 no.4
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• pp.414-419
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• 2006

The purpose of this study was to measure the factor influencing tourist preferences for leaf mustard iimchi. Among 250 questionnaires, 230 questionnaires were utilized for the analysis. Frequencies, conjoint model, max. utility model, BTL model, Logit model, K-means cluster analysis, and one-way ANOVA analysis were used for this study. The findings from this study were as follows. First, the Pearson's R and Kendall's tau statistics showed that the model fitted the data well. Second, it was found that total respondents and three clusters regarded taste and price as the very important factor. Third, it was found that the first cluster most preferred product with light red color, plain package, and mild taste sold at a cheap price in factory. The second cluster most preferred product with light red color, plain package, and moderately pungent taste sold at a expensive price in factory. The third cluster most preferred product with dark red color, shaped package, and highly pungent taste sold at a cheap price in factory. Fourth, it was found that the first cluster most preferred simulation product with light red color, shaped package, and mild taste sold at a cheap price in factory. The second cluster most preferred simulation product with light red color, shaped package, and moderately pungent taste sold at a cheap price in factory. The third clutter most preferred simulation product with dark red color, shaped package, and highly pungent taste sold at a cheap price in factory.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.12
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• pp.21-26
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• 2004

In this paper, a direct method is developed to extact RF equivalent circuit of a packaged BJT without optimization. First, parasitic components of plastic package are removed from measured S-parameters using open and short package patterns. Using package do-embedded S-parameters, a direct and simple method is proposed to extract bonding wire inductance and chip pad capacitance between package lead and chip pad. The small-signal model parameters of internal BJT are next determined by Z and Y-parameter formula derived from RF equivalent circuit. The modeled S-parameters of packaged BJT agree well with measured ones, verifying the accuracy of this new extraction method.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1141-1144
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• 1998

A new design methodology for the shortchannel CMOS IC-package is presented. It is developed by representing the package inductance with an effective lumpedinductance. The worst case maximum-simultaneous-switching noise (SSN) and gate propagation delay due to the package are modeled in terms of driver geometry, the maximum number of simultaneous switching drivers, and the effective inductance. The SSN variations according to load capacitances are investigated with this model. The package design techniques based on the proposed guidelines are verified by performing HSPICE simulations with the $0.35\mu\textrm{m}$ CMOS model parameters.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.11
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• pp.18-28
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• 1999

A new equivalent circuit model of package (SOP, Small Outline Package) is presented for designing radio frequency integrated circuits (RFIC). In the RF region, the paddle of a package does not work as an ideal ground. Further parasitics due to both coupling and loss have a substantial effect on MMIC. The equivalent circuit model and parameter extraction methodology for the electrical characteristics of the package are described by illustrating the SOP type packages. The accuracy of the model is evaluated by comparing the s-parameters of the commercial full-wave solver and those of HSPICE simulation with the circuit model. The proposed model shows an excellent agreement with full-wave analysis up to about 8GHz.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.729-737
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• 1994

A three-dimensional finite element model of a 20-pin plastic dual-in-line package(PDIP) plugged into a PCE has been developed by using the finite element code ANSYS. The model has been used for thermal characterization of the package during its normal operation under natural convection cooling. Temperature distributions in the package and PCB are obtained from numerical analysis and compared with experimentally measured data. Various cases are assumed and analyzed to study the effects of package and PCB materials on thermal characteristics of PDIP with and without aluminum heatspreader. Thermal dissipation capability of PDIP is greatly increased due to copper die pad/lead frame and heatspreader. However, thermally induced stresses in the package and fatigue life of chip are improved for PDIP with Alloy 42 die pad/lead frame and no heatspreader. It is also found that the role of PCB on thermal characteristics of PDIP is very imporatant.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.43-50
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• 1998

The purpose of the paper is to protect the damage of plastic IC package with searching the cause of the fracture due to the delamination and crack when the encapsulant of plastic IC package is on viscoelastic behavior with the effect of creep on high temperature, The model for analysis is the plastic SOJ package with dimpled diepad in the IR soldering process of surface mounting technology. The risk of delamination with calculating the distribution of viscoelastic thermal stress in the package without the crack in the surface mounting process is checked. The package model with the perfect delamination between chip and diepad is chosen to estimate the resistance against fracture in thermal loading with calculating C (t)-integrals according to the change of the design. The optimum design to depress the delamination and crack is presented.