• Journal of Industrial Convergence
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• v.17 no.4
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• pp.9-14
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• 2019

This paper presents several problems that can occur in the development of the ultra-compact LED package of less than 1.0mm and introduces the solution to them. In the existing mold structure, since the upper and lower core parts are integrated, various errors have occurred due to the roughness of EDM in the small model, which is a limiting factor in further reducing the mold size. As a countermeasure, the prefabricated model was presented in an earlier study to overcome the obstacles to the development of a ultra-compact LED package. In this paper, several problems have been found during the fabrication of prototypes as a starting work to produce the results for the presented model. The types are suggested and the solutions are discussed. And by changing the existing 2-row structure to 3-row structure in the same size lead frame, the aspect of efficient production is considered. The experimental procedure verifies the proposed solution and conducts a test to produce a prototype to confirm that a good product can be produced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.1005-1009
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• 2017

In this study, the shock resistance of a gas turbine package subjected to a shock load caused by non-contact underwater explosion was investigated using numerical analysis. To perform shock analysis, the time-history shock load was calculated according to BV-043 (German Navy Regulation). The direct transient response analysis in the time domain for the simplified Whole Engine Model (WEM) was performed using the calculated shock load. In addition, the structural integrity of a detailed model was evaluated by considering the shock load transferred to each component. As a result, it was confirmed that the safety factor was at least 1.0 as compared with the reference stress. Finally, the structural and functional integrity of the Engine Management System (EMS) of the gas turbine package was verified through an actual shock test.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.1
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• pp.49-57
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• 2002

Including RF Package inductance, substrate coupling through conductive silicon(Si)-substrate is modeled and quantitatively characterized. 2-port substrate coupling model is extended for the characterization of multi-port substrate coupling between digital circuit block and analog/RF circuit block. Furthermore, scalable parameter extraction model is developed. Multi-port substrate coupling can be investigated by linearly superposing a frequency-dependent 2-port substrate coupling model using scalable parameters. In addition, Substrate coupling including RF package inductance effect is quantitatively investigated. It is shown that package effect increases substrate coupling and shifts a characteristic frequencies(i.e., poles) to the higher frequency range. The proposed methodology can be efficiently used to the mixed-signal circuit performance verification.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.3
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• pp.241-253
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• 2003

SCA (Software Communication Architecture), which has been adopted as a SDR(Software Defined Radio) Forum standard, provides a framework that successfully exploits common design patterns of embedded systems software. However, the SCA is inadequate as a component framework since it does not explicitly specify (1) a component model that defines how to express a component interface and how to implement it, (2) a package model that defines what and how to package in deployment units, and (3) a deployment model that defines the deployment environment and deployment process. In this paper, we propose a SCA-based component framework for SDR. Specifically, we present (1) a component model that defines a component as a specialized CORBA object that implements object management functionality, (2) a package model exploiting the existing XML descriptors of the SCA, and (3) a deployment model that defines a SCA-based deployment environment, a boot-up process that restores the deployment state, and a deployment process that supports lazy application instantiation and dynamic component replacement.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2444-2448
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• 2007

The multi channel of DDI which is the core part of the LCD-TV has been propelled. When multi channel in DDI is introduced, it brings a thermal problem because of the increased power. To solve the thermal problem of the DDI it needs to be investigated each at the package level and module level. It is important to extract the junction temperature(Tj) of DDI clearly from the system level. The objective of this research is to construct a compact model. The compact model is to reduce LCD module including DDI. When the compact model is used, it will be able to easily handle the boundary condition and accurately predict the temperature. Consequently, the temperature of DDI can be calculated easily at the system level. Through this research,we also proposed the cooling plan of DDI for a protection of overheating. The cooling plan was utilized in DDI design.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.883-888
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• 2014

Simulation is now using in various area as an effective decision analysis tool in complex environment of today. But, There is a focus to the simulation model development and execution better than result analysis. This article will emphasis to the importance of result analysis apart from model development in simulation, and will use R package for profit optimization simulation. R has a various function in statistic analysis and data manipulation, graphic display. So this research can show the value of R as a tool for simulation.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.6
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• pp.386-394
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• 2016

In this research, in order to optimize the multi-objective function effectively, we suggested the optimization model to maximize the total destruction of ground targets and minimize the total damage of aircrafts and cost of air munitions by using goal programming. To satisfy the various variables and constraints of this mathematical model, the concept of air strike package is applied. As a consequence, effective attack can be possible by identifying the prior ground targets more quickly. This study can contribute to maximize the ROK air force's combat power and preservation of high value air asset in the war.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.380-387
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• 2009

The reliability concerns of solder interconnections in flip chip PBGA packages are produced mainly by the mismatch of coefficient of thermal expansion(CTE) between the module and PCB. Finite element analysis has been employed extensively to simulate thermal loading for solder joint reliability and deformation of packages in electronic packages. The objective of this paper is to study the thermo-mechanical behavior of FC-PBGA package assemblies subjected to temperature change, with an emphasis on the effect of the finite element model, material models and temperature conditions. Numerical results are compared with the experimental results by using $moir{\acute{e}}$ interferometry. Result shows that the bending displacements of the chip calculated by the finite element analysis with viscoplastic material model is in good agreement with those by $moir{\acute{e}}$ inteferometry.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.21-27
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• 1999

In order to increase our understanding of the injury mechanism in the child occupant, three year old child model was developed using commercial dynamic package DADS. Total 14 segments and 12 joints were used to compose a model in three points belted condition with booster seat. HYGE sled test case was simulated to validate the developed model. Based on the comparison of the model and published test results, the developed model appears to be a resonable representation of the three year old dummy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1717-1722
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• 2016

Availability, one of the important metrics used to assess the performance of network system, is defined as the probability that a system is operational at a given point in time under a given set of environmental conditions. To improve the availability of the network service, the redundancy models and the rejuvenation schemes are the effective schemes to be typically used. In this paper, we analyse the effect of 2N redundancy model and/or rejuvenation scheme on the availability of network service. The 2N redundancy model consists of one active and one standby component and the performance of time-based rejuvenation scheme mainly depends on its rejuvenation period. We design stochastic reward net model for the 2N redundancy model with time-based rejuvenation scheme and analyse the service availability of the model using stochastic Petri net package. We provide some numerical examples of the service availability, which shows that the system with rejuvenation has higher availability than the system without rejuvenation.