• Communications for Statistical Applications and Methods
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• v.31 no.2
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• pp.179-189
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• 2024

In multivariate regression with a high-dimensional response Y ∈ ℝ^r and a relatively low-dimensional predictor X ∈ ℝ^p (where r ≥ 2), the statistical analysis of such data presents significant challenges due to the exponential increase in the number of parameters as the dimension of the response grows. Most existing dimension reduction techniques primarily focus on reducing the dimension of the predictors (X), not the dimension of the response variable (Y). Yoo and Cook (2008) introduced a response dimension reduction method that preserves information about the conditional mean E(Y | X). Building upon this foundational work, Yoo (2018) proposed two semi-parametric methods, principal response reduction (PRR) and principal fitted response reduction (PFRR), then expanded these methods to unstructured principal fitted response reduction (UPFRR) (Yoo, 2019). This paper reviews these four response dimension reduction methodologies mentioned above. In addition, it introduces the implementation of the mbrdr package in R. The mbrdr is a unique tool in the R community, as it is specifically designed for response dimension reduction, setting it apart from existing dimension reduction packages that focus solely on predictors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.751-755
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• 1995

It become more difficult to anticipate the performance of fluid power systems as the number of components increases because of nonlinearrities inherent in hydraulic components. In this situation, the computer simulation technique can be an effective tool in the analysis and design of fluid power systems. In this paper, simulation results are presented for dynamic characteriatics of a knuckle crane. Simple models for hydraulic components and relatively detailed motion equations for attachments are used. the simulation reaults are very close to those of experiments. The simulation is performed using a simulation package developed with object-oriented method. This package provides the encironment that user can construct desirct desired circuits form the component library, checks the continuity and compatibility conditions automatically and executes simulation

• Journal of Welding and Joining
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• v.24 no.2
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• pp.57-63
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• 2006

In this study, the curing kinetics and thermal degradation of underfill were investigated using differential scanning calorimetry (DSC) and thermo gravimetry analysis (TGA). The mechanical and thermal properties of underfill were characterized using dynamic mechanical analysis (DMA) and thermo-mechanical analysis (TMA). Also, we presented on underfill dispensing process using Prostar tool. The non-isothermal DSC scans at various heating rates, the exothermic reaction peak became narrower with increasing the heating rate. The thermal degradation of underfill was composed of two processes, which involved chemical reactions between the degrading polymer and oxygen from the air atmosphere. The results of fluidity phenomena were simulated using Star CD program, the fluidity of the underfills with lower viscosity was faster.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.99-106
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• 1998

In this paper, we have constructed an expert system for semiconductor chip encapsulation which combines a knowledge-based system with CAE software. The knowledge-base module includes heuristic and pre analysis knowledge for evaluation and redesign. Evaluation of the initial design and generation of redesign recommendations can be developed from the rules as applied to a given chip package. The CAE programs can be used for simulating the filling and packing stage of encapsulation process. The expert system is a new tool which enables package design or process conditions with high yields and high productivity.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.423-428
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• 1995

Simulation models have been developed to predict the overall behavior of the CANDU plant systems during normal operational transients. For real time simulation purpose, simplified thermal hydraulic models are applied with appropriate system control logics, which include primary heat transport system solver with its component models and secondary side system models. The secondary side models are mainly used to provide boundary conditions for primary system calculation and to accomodate plant power control logics. Also, for the effective use of simulation package, hardware oriented basic simulation network has been established with appropriate graphic display system. Through validation with typical plant power maneuvering cases using proven plant performance analysis computer code, the present simulation package shows reasonable capability in the prediction of the dynamic behavior of plant variables during operational transients of CANDU plant, which means that this simulation tool can be utilized as a basic framework for full scope simulation network through further improvements.

• Proceedings of the KWS Conference
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• 2006.05a
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• pp.206-208
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• 2006

The reliability of BGA (ball grid array) package with OSP (organic surface preservative) surface finish under thermal cycle was investigated by using SEM (scanning electron microscopy), EDS(energy dispersive spectroscopy), image tool and ball shear test. The IMCs (intermetallic compounds) were increased with increasing number of thermal cycles. However, the shear strengths of solder ball were decreased with increasing number of thermal cycles. The order of solders which had the highest shear strength as follow: Sn-3.5wt%Ag-0.7wt%Cu, Sn-0.7wt%Cu, Sn-37wt%Pb.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.28-32
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• 2002

Recently, the miniature of electric products such as notebook, cellular-phone etc. is apparently appeared, due to the smaller size of the semiconductor chips. As the size of chip gets smaller, the circuit could be easily damaged by the slightest influence, therefore it is important to investigate the machining quality of $\mu$ BGA. This paper deals with machining characteristics of the $\mu$ BGA singulation. The relationships between the singulation face and machining quality of the $\mu$ BGA singulation are investigated. It is confirmed that machining quality improves as the singulation force decreases.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.82-87
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• 2006

Availability of defect test algorithm that recognizes exact and standardized defect information in order to fundamentally resolve generated defects in industrial sites by giving artificial intelligence to SAT(Scanning Acoustic Tomograph), which previously depended on operator's decision, to find various defect information in a semiconductor package, to decide defect pattern, to reduce personal errors and then to standardize the test process was verified. In order to apply the algorithm to the lately emerging Neural Network theory, various weights were used to derive results for performance advancement plans of the defect test algorithm that promises excellent field applicability.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.03a
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• pp.34-39
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• 1995

To reduce the shock in shifting the clutches and the brakes in automatic transmission have to be connected smoothly and disconnected rapidly. It is PCSV(Pressure Control Solenoid Valve) that play this role of automatic transmission. In this paper there were two steps in the analysis of the PCSV. The first step was modeling the elctromagnet by the permeance method. The second step was modeling the hydraulic circuit by the pressure differential equation. In addition to this modeling a experiment was performed and the commercial package program was used in order to justify modeling. The result of modeling coincide with the result of experiment and commercial package program. As a result this modeling is usable in analysis of dynamic characteractic of the PCSV.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.909-911
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• 2000

This paper introduce of program package for the numerical analysis of Electromagnetic field analysis using Finite Element Method, called Electro Magnetic Field(EMF). This software tool is developed by Changwon Nat'l Univ. cooperative with Hanyang Univ. and produced on a commercial scale. EMF has a simple, easy to use graphical interface which steps user through th problem setup, high accurate solution, and fast computation.