• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.302-303
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• 2006

The response surface modeling of the pretilt angle control using ion-beam (IB) alignment on nitrogen doped diamond-like carbon (NDLC) thin film layer is investigated. The response surface model is used to analyze the variation of the pretilt angle under various process conditions IB exposure angle and IB exposure time are considered as Input factors. The analysis of variance technique is used to analyze the statistical significance, and effect plots are also investigated to examine the relationships betweenthe process parameters and the response. The model can allow us to reliably predict the pretilt angle with respect to the varying process conditions.

• Journal of KIISE
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• v.41 no.11
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• pp.900-910
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• 2014

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. The computational complexity of multi view video coding increases in proportion to the number of cameras. To reduce computational complexity and maintain the image quality, improved prediction structure and motion estimation method is proposed in this paper. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. And the proposed motion estimation method uses a hierarchical search strategy. This strategy method consists of modified diamond search pattern, progressive diamond search pattern and modified raster search pattern. Experiment results show that the complexity reduction of the proposed prediction structure and motion estimation method over JMVC (Joint Multiview Video Coding) reference model using hierarchical B pictures of Fraunhofer-HHI and TZ search method can be up to 40~70% while maintaining similar video quality and bit rates.

• Earthquakes and Structures
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• v.11 no.4
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• pp.583-607
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• 2016

One of the main applications of seismic risk assessment is that an specific design could be selected for a bridge from different alternatives by considering damage losses alongside primary construction costs. Therefore, in this paper, the focus is on selecting the shape of pylon, which is a changeable component in the design of a cable-stayed bridge, as a double criterion decision-making problem. Different shapes of pylons include H, A, Y, and diamond shape, and the two criterion are construction costs and probable earthquake losses. In this research, decision-making is performed by using developed seismic risk assessment process as a powerful method. Considering the existing uncertainties in seismic risk assessment process, the combined incremental dynamic analysis (IDA) and uniform design (UD) based fragility assessment method is proposed, in which the UD method is utilized to provide the logical capacity models of the structure, and the IDA method is employed to give the probabilistic seismic demand model of structure. Using the aforementioned models and by defining damage states, the fragility curves of the bridge system are obtained for the different pylon shapes usage. Finally, by combining the fragility curves with damage losses and implementing the proposed cost-loss-benefit (CLB) method, the seismic risk assessment process is developed with financial-comparative approach. Thus, the optimal shape of the pylon can be determined using double criterion decision-making. The final results of decision-making study indicate that the optimal pylon shapes for the studied span of cable-stayed bridge are, respectively, H shape, diamond shape, Y shape, and A shape.

• Journal of Environmental Health Sciences
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• v.36 no.4
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• pp.313-322
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• 2010

The aim of this research was to apply experimental design methodology to optimization of conditions of electrochemical oxidation of Rhodamine B (RhB) and N, N-Dimethyl-4-nitrosoaniline (RNO, indicative of the OH radical). The reactions of electrochemical oxidation of RhB degradation were mathematically described as a function of the parameters of current ($X_1$), NaCl dosage ($X_2$) and pH ($X_3$) and modeled by the use of the central composite design. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the removal efficiency of RhB and RNO and test variables in a coded unit: RhB removal efficiency (%) = $94.21+7.02X_1+10.94X_2-16.06X_3+3.70X_1X_3+9.05X_2X_3-{3.46X_1}^2-{4.67X_2}^2-{7.09X_3}^2$; RNO removal efficiency (%) = $54.78+13.33X_1+14.93X_2- 16.90X_3$. The model predictions agreed well with the experimentally observed result. Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the RhB degradation using canonical analysis was 100.0%(current, 0.80 A; NaCl dosage, 2.97% and pH 6.37).

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.159-168
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• 1994

The purpose of this study was to evaluate the shear bond strength of the porcelain laminate specimens according to the surface roughness of the cut enamel of human anterior teeth. Flat enamel surfaces were prepared in 30 extracted human anterior teeth with diamond disc which were divided into two groups. Group 1 Coarse enamel surface group prepared with LVS-3 bur. Group 2 Fine enamel surface group prepared with superfine diamond bur. 30 teeth specimens of two group were stored in normal saline during 24 hours. 30 disk - type porcelain laminate specimens with diameter 4mm and thickness 1mm were made and sand - blasted on internal surface which were to cemented on enamel surface. Porcelain laminate specimens were cemented on enamel surface with Choice Veneer System (Bisco Dental, U.S.A) according to manufacture's instructions. All teeth specimens of two groups were manipulated with same method and stored In normal saline before testing. An Universal Testing machine (Model No.UTM-4206,Instron, U.S.A) was used to apply shear loads in the vertical directed, and the force required for separation was recorded with a cross head speed of 3mm/min and 500kg in full scale. The results were as follow ; 1. The mean shear bond strength of coarse surface group was 36.30kg and that of fine surface group was 44.39 kg, but there was no significant difference in breaking strength of two groups(p>0.05).

• The Journal of shipping and logistics
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• v.34 no.4
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• pp.695-710
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• 2018

Following the collapse of Hanjin Shipping, building a strong maritime cluster is one of the policy measures for the re-construction of the Korean shipping and shipbuilding industries. Thus, the purpose of this study is to develop a policy alternative for building a maritime cluster. Using Porter's diamond models, we analyzed the Imabari maritime cluster of Japan, which is characterized by cooperation between key industries, such as shipping, shipbuilding, shipbuilding equipment, and finance. The Imabari Maritime Cluster is equipped with complete domestic demand conditions and related supporting industry conditions. Although the strengths of the production conditions include excellent family-based management and strong support from regional administration and banks which develops independency among cluster members, the weak points include the absense of robust port services and difficulty in recruiting young talent in small and medium-sized cities. We can confirm that the company's strategy is focused on stable management, rather than a short-term view.

• Journal of Venture Innovation
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• v.1 no.1
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• pp.1-14
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• 2018

The 4th Industrial Revolution is making a big change for our company like the tsunami. The CPS system, which is represented by the digital age, is based on the data accumulated in the physical domain and is making business that was not imagined in the past through digital technology. As a result, the business model of the 4th Industrial Revolution era is different from the previous one. In this study, we analyze the trends and the issues of business innovation theory research. Then, the business innovation model of the digital age was compared with the previous period. Based on this, we have searched for a business model suitable for the 4th Industrial Revolution era. The existing business models have many difficulties to explain the model of the digital era. Even though more empirical research should be supported, Michael Porter's diamond model is most suitable for four cases of business models by applying them. Type A sharing outcome with customer is a model that pay differently according to the basis of customer performance. Type B Value Chain Digitalization model provides products and services to customers with faster and lower cost by digitalizing products, services and SCM. Type C Digital Platform is the model that brings the biggest ripple effect. It is a model that can secure profitability by creating new market by creating the sharing economy based on digital platform. Finally, Type D Sharing Resources is a model for building a competitive advantage model by collaborating with partners in related industries. This is the most effective way to complement each other's core competencies and their core competencies. Even though numerous Unicorn companies have differentiated digital competitiveness with many digital technologies in their respective industries in the 4th Industrial Revolution era, there is a limit to the number of pieces to be listed. In future research, it is necessary to identify the business model of the digital age through more specific empirical analysis. In addition, since digital business models may be different in each industry, it is also necessary to conduct comparative analysis between industries

• The Journal of Fisheries Business Administration
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• v.46 no.2
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• pp.1-11
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• 2015

Due to the environmental changes such as decreasing and aging fishing population and increasing imported marine products, improvement of fishing business competitiveness has become one of important issues. This study aimed to analyze the coastal fishing business units in Busan region and compare their business performances in order to find out success factors. The logistic regression analysis between 4 determination factors of competitiveness and business performances showed that the ship tonnage in the factor conditions, catch of species of fishing types'kg per price in the demand conditions, cooperative sales ratio in the related & supporting industries, and net per cost in the firm strategy, and structure & rivalry had the positive(+) impacts on business performances.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.2
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• pp.10-15
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• 2005

For the development of compensation machining program, ultra precision grinding used in ultra precision machine and corrective machining was studied. We explored a new rough grinding technique on optical material such as zerodur. The facility used is a polishing machine with a custom grinding module and a range of diamond resin bond wheel. Surface roughness and form accuracy are measured by surface measurement equipment(Form Talysurf series2). Our compensation machining program has complied with a target of producing surface roughness better than $0.05{\mu}m$ Ra and form accuracy of around $0.05{\mu}m$ Rt and has been unveiled as a work-hour model.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1270-1279
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• 2002

Residual stress is a dominant obstacle to efficient production and safe usage of device by deteriorating the mechanical strength and failure properties. Therefore, we proposed a new thin film stress-analyzing technique using a nanoindentation method. For this aim, the shape change in the indentation load-depth curve during the stress-relief in film was theoretically modeled. The change in indentation depth by load-controlled stress relaxation process was related to the increase or decrease in the applied load using the elastic flat punch theory. Finally, the residual stress in thin film was calculated from the changed applied load based on the equivalent stress interaction model. The evaluated stresses for diamond-like carbon films from this nanoindentation analysis were consistent with the results from the conventional curvature method.