• Journal of Korean Society for Quality Management
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• v.32 no.1
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• pp.113-129
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• 2004

The reliability of the product can be improved by making the product less sensitive to noises. Especially, it Is important to make products robust against various noise factors encountered in production and field environments. In this paper, the phenomenon of degradation assumes a simple random coefficient degradation model to present analysis procedures of degradation data for robust experimental design. To alleviate weak points of previous studies, such as Taguchi's, Wasserman's, and pseudo failure time methods, novel techniques for analysis of degradation data using the cross array that regards amount of degradation as a dynamic characteristic for time are proposed. Analysis approach for degradation data using robust experimental design are classified by assumptions on parametric or nonparametric degradation rate(or slope). Also, a simulation study demonstrates the superiority of proposed methods over some previous works.

• Structural Engineering and Mechanics
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• v.53 no.2
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• pp.373-392
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• 2015

In the present work, structural joints have been modeled as a pair of translational and rotational springs and frequency equation of the overall system has been developed using sub-structure synthesis. It is shown that using first few natural frequencies of the system, one can obtain a set of over-determined system of equations involving the unknown stiffness parameters. Method of multi-linear regression is then applied to obtain the best estimate of the unknown stiffness parameters. The estimation procedure has been developed first for a two parameter joint model and then for a three parameter model, in which cross coupling terms are also included. Two cases of structural connections have been considered, first with a cantilever beam with support flexibility and then a pair of beams connected through lap joint. The validity of the proposed method is demonstrated through numerical simulation and by experimentation.

• Computers and Concrete
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• v.15 no.3
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• pp.373-389
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• 2015

The development of a finite element model for the geometric and material nonlinear analysis of bonded prestressed concrete continuous beams is presented. The nonlinear geometric effect is introduced by the coupling of axial and flexural fields. A layered approach is applied so as to consider different material properties across the depth of a cross section. The proposed method of analysis is formulated based on the Euler-Bernoulli beam theory. According to the total Lagrangian description, the constructed stiffness matrix consists of three components, namely, the material stiffness matrix reflecting the nonlinear material effect, the geometric stiffness matrix reflecting the nonlinear geometric effect and the large displacement stiffness matrix reflecting the large displacement effect. The analysis is capable of predicting the nonlinear behaviour of bonded prestressed concrete continuous beams over the entire loading stage up to failure. Some numerical examples are presented to demonstrate the validity and applicability of the proposed model.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.404-410
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• 2016

Compared to wheel locomotion, walking has many advantages : Better to cross over obstacles, the contact with ground is in a determined point, the ground is damaged less. Because Theo Jansen mechanism can make walking motion that is very soft, there are many researches about that mechanism. In this paper, We designed walking robot based on Theo Jansen mechanism. Most important design factor is velocity and stability. First of all, we considered kinematics knowledge and then, we made a new model by using simulation. Finally we developed the model by solving few design problems.

• Journal of Korean Society for Quality Management
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• v.21 no.1
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• pp.181-189
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• 1993

Over the past two decades, forecasting has gained widespread acceptance as an integral part of business planning and decision making. Accurate forecasting is a prerequisite to successful planning. Accordingly, recent advances in forecasting techniques are of exceptional value to corporate planners. But most of forecasting mothods are reveal its limit and problem for precision and reliability duing to each relationship for raw data and possibility of explanation for each variable. Therefore, to construct the Integrated Forecasting Model(IFM) for Information Factor Analysis, it shoud be considered that whether law data has time lag and variables are explained. For this. following several method can be used : Least Square Method, Markov Process, Fibonacci series, Auto-Correlation, Cross-Correlation, Serial Correlation and Random Walk Theory. Thus, the unified property of these several functions scales the safety and growth of the system which may be varied time-to-time.

• Journal of Home Health Care Nursing
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• v.25 no.3
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• pp.240-248
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• 2018

Purpose: The purpose of this study was to evaluate the validity of an educational program developed for geriatric visiting nurses in Seoul by assessing their satisfaction level and level of learning goal achievement. Methods: This descriptive research study was conducted to develop, implement, and evaluate the educational program in accordance with the ADDIE Instructional System Model. Participants were 170 nurses hired for the 2016 Seoul Metropolitan Government visiting service for older people. Based on Kirkpatrick's Training Evaluation Model, reaction and learning evaluations were conducted during and after the educational program. Data were analyzed using descriptive statistics. Results: The developed educational program consisted of basic and professional courses. The evaluations showed that participants were highly satisfied with the lectures and field placement. Over 90% of the participants achieved the learning achievement goals. Conclusion: The program developed for geriatric visiting nurses in Seoul is considered a valid educational program because of the participants' high levels of satisfaction and academic achievement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.7
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• pp.2407-2424
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• 2022

Recently, Transformer has made great progress in video retrieval tasks due to its high representation capability. For the structure of a Transformer, the cascaded self-attention modules are capable of capturing long-distance feature dependencies. However, the local feature details are likely to have deteriorated. In addition, increasing the depth of the structure is likely to produce learning bias in the learned features. In this paper, an improved Transformer structure named TransDCS (Transformer with Dynamic Convolution and Shortcut) is proposed. A Multi-head Conv-Self-Attention module is introduced to model the local dependencies and improve the efficiency of local features extraction. Meanwhile, the augmented shortcuts module based on a dual identity matrix is applied to enhance the conduction of input features, and mitigate the learning bias. The proposed model is tested on MSRVTT, LSMDC and Activity-Net benchmarks, and it surpasses all previous solutions for the video-text retrieval task. For example, on the LSMDC benchmark, a gain of about 2.3% MdR and 6.1% MnR is obtained over recently proposed multimodal-based methods.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.8
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• pp.2670-2680
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• 1996

Effeccs of porous wind fence on surface-pressure around 2-dimensional prism model of triangular cross-section were investigated experimentally. The pressure data were obtained at a Reynolds number based on the model height of Re=2.1*10$^{5}$ . Flow visualization also carried out to investigate the flow structure qualitatively. The mean velocity and turbulent intensity profiles measured at fence location were well fitted to the neutral atmospheric surface boundary layer over the open terrain. Various fences with different porosity and height were tested to investigate their effects on the surface pressure acting on a prism model at different locations. As the results, porous fence with porosity 40 ~ 50% is most effective for abating wind erosion. With decreasing porosity of the fence, pressure fluctuations on the model surface are increased. The mean pressure coefficients are decreased only when the fence height is greater than the model height. The effect of distance between wind fence and triangular prism was not significant, compared to that of the fence porosity and height.

• Journal of Korean Academy of Nursing
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• v.46 no.5
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• pp.630-641
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• 2016

Purpose: This study was designed to construct a model which explains drug misuse behaviors in community-dwelling older adults. Methods: The design of this research is a cross-sectional study using structure equation modeling. The hypothetical model consisted of two types of variables: the exogenous variables of health status, cognitive ability, and negative emotion, and the endogenous variables of number of drugs, and drug misuse behaviors. The data collection was conducted from September 2 to September 21, 2013 through self-report questionnaires. Participants were 320 community-dwelling adults over the age of 65 living in J city. Data were analyzed with SPSS 21.0 program and Amos 18.0 program. Results: The results of the model fitness analysis were satisfied. The predictor variables for the hypothetical model explained 62.3% of variance regarding drug misuse behaviors. Drug misuse behaviors were directly affected by health status, cognitive ability, negative emotion and number of drugs and indirectly affected by health status, and negative emotion through number of drugs. Conclusion: These findings indicate factors that should be used in developing effective nursing interventions for safe and proper drug use and the prevention of drug misuse behaviors in community-dwelling older adults.

• Coupled systems mechanics
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• v.5 no.4
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• pp.355-369
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• 2016

Changes in chemical structure have profound effects on the physical properties of epoxy-based materials, and eventually affect the durability of the entire system. Microscopic structural voids generally existing in the epoxy cross-linked networks have a detrimental influence on the epoxy mechanical properties, but the relation remains elusive, which is hindered by the complex structure of epoxy-based materials. In this paper, we investigate the effect of structural voids on the epoxy-based materials by using our developed mesoscale model equipped with the concept of multiscale modeling, and SU-8 photoresist is used as a representative of epoxy-based materials. Developed from the results of full atomistic simulations, the mesoscopic model is validated against experimental measurements, which is suitable to describe the elastic deformation of epoxy-based materials over several orders of magnitude in time- and length scales. After that, a certain quantity of the structure voids is incorporated in the mesoscale model. It is found that the existence of structural voids reduces the tensile stiffness of the mesoscale epoxy network, when compared with the case without any voids in the model. In addition, it is noticed that a certain number of the structural voids have an insignificant effect on the epoxy elastic properties, and the mesoscale model containing structural voids is close to those found in real systems.