• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.33-42
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• 2002

Ground reaction curve is a very important information for evaluating the side wall displacements and installation time of the tunnle support. The ground reaction curve can be estimated by analytical closed form solutions derived on the supposition of circular section and isotropic stress condition. The conditions of stress field and tunnel configurations, however, are quite different in practice. Therefore, it is necessary to investigate the effects of stress anisotropy and tunnel configurations in order to use simply in practical design. This paper describes a study of influence factors in the ground reaction curve. In order to evaluate the applicability of analytical closed form solution in practical design, two sets of parametric studies were carried out by numerical analysis in elastic tunnel behaviour: one set of studies investigated the influence of the K and the other set investigated the influence of the tunnel configurations such as circular and horse-shoe shape. In the studies, K value varies between 0.5 and 3.0, initial ground vertical stress varies between 5～30MPa far each K values. The results indicated that the self-supportability of ground is larger in the ground having lower K value. However, it is suggested that the applicability of closed form solution may not be adequate to determine directly the installation time of the support and self-supportability of ground. It is necessary to consider stress anisotropy and tunnel configurations.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.1 no.1
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• pp.179-199
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• 2006

The objective of the study which it analyzes the result which goes made to the equity investor venture company IPOs stock of Korean venture capitalists. The sample company is the venture business 101 which IPO time venture capitalists invest in period KOSDAQ market from 1997 July 1st to 2006 June 30th for 9 years. The result of the study was as follows. First, it is found that syndication investing venture capitalists than the sale investing venture capitalists has desirable investment act which relax non-symmetry information between the publicly held company and the investor. The study support to Bygrave(1987), Lerner(1994) and so on. Second, The venture capitalists under postscript investing the venture business compared to under investing shows IPO excess benefit rate initially more highly from the venture business and the investor whom already invests early stage prove to use the manned it exaggerates the value of the venture business which venture capitalists oneself invests from postscript phase through the high position characteristic At last, it is discovered that the investment equity ratio of venture capitalists effect of sound (-) postscript investor IPO result which analyzed. It is showed that venture capitalists will remain more lowly excess benefit rate as the equity ratio which the venture capitalists invests at the venture business will be high.

• The Journal of the Acoustical Society of Korea
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• v.24 no.1
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• pp.11-20
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• 2005

In this paper, we deal with the research about a S/PDIF (Sony Philips Digital Interface) receiver which can operate without PLL (Phase Locked Loop) circuits. Although a S/PDIF receiver is used in most audio devices and audio processors in these days. yet there are only few domestic researches about S/PDIF. Currently used commercial DACs (Digital-to-Analog Converters) which can decode S/PDIF signals, have a PLL circuit inside them. The PLL makes it possible to extract clock information from S/PDIF digital signal and to synchronize a clock signal with input signals. But the PLL circuit makes many diffculties in designing the SOC (System On Chips) of VLSIs (Vew Large Scale Integrated Ciruits) because it is an "analog circuit". We proposed a S/PDIF receiver which doesn't have PLL circuits and only has Pure digital circuits. The key idea of the proposed S/PDIF receiver. is to use the ratio between a 16 MHz basic input clock and S/PDIF signals. After having decoded hundreds thousands S/PDIF inputs, it went to prove that a S/PDIF receiver can be designed with pure digital circuits and without any analog circuits such as PLL circuits. We have confidence that the proposed S/PDIF receiver can be used as an IP (Intellectual Property) for the SOC design of the digital circuits.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1305-1310
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• 2010

In a practical design process, the method of extracting the design space information of the complex system for verifying, improving, and optimizing the design process by taking into account the design variables and their shape tolerance is very important. Finite element analysis has been successfully implemented and integrated with design of experiment such as D-Optimal array; thus, a response surface model and optimization tools have been obtained, and design variables can be optimized by using the model and these tools. Then, to guarantee the robustness of the design variables, a robust design should be additionally performed by taking into account the statistical variation of the shape tolerance of the optimized design variables. In this study, a new approach based on the use of the response surface model is proposed; in this approach, the standard normal distribution of the shape tolerance is considered. By adopting this approach, it is possible to simultaneously optimize variables and perform a robust design. This approach can serve as a means of efficiently modeling the trade-off among many conflicting goals in the applications of finite element analysis. A case study on the robust optimal design of disc brakes under thermal loadings was carried out to solve multiple objective functions and determine the constraints of the design variables, such as a thermal deformation and weight.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.19-37
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• 2017

Visible Infrared Imaging Radiometer Suite Day-Night Band (VIIRS-DNB) data provides a much higher capability for observing and quantifying nighttime light (NTL) brightness in comparison with Defense Meteorological Satellite-Operational Linescan System (DMSP-OLS) data. In South Korea, there is little research on the detection of NTL brightness change using VIIRS-DNB data. This study analyzed the spatial distribution and change of NTL brightness between 2013 and 2016 using VIIRS-DNB data, and detected its spatial relation with possible influencing factors using regression models. The intra-year seasonality of NTL brightness in 2016 was also studied by analyzing the deviation and change clusters, as well as the influencing factors. Results are as follows: 1) The higher value of NTL brightness in 2013 and 2016 is concentrated in Seoul and its surrounding cities, which positively correlated with population density and residential areas, economic land use, and other factors; 2) There is a decreasing trend of NTL brightness from 2013 to 2016, which is obvious in Seoul, with the change of population density and area of industrial buildings as the main influencing factors; 3) Areas in Seoul, and some surrounding areas have high deviation of the intra-year NTL brightness, and 71% of the total areas have their highest NTL brightness in January, February, October, November and December; and 4) Change of NTL brightness between summer and winter demonstrated a significantly positive relation with snow cover area change, and a slightly and significantly negative relation with albedo change.

• The KIPS Transactions:PartD
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• v.14D no.4 s.114
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• pp.381-388
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• 2007

Consumers changed to the subject to produce a digital contents as data transmission technique is advanced and a digital machine is diffused variously. Users are interested greatly in a user creative movie (UCM) production among various online contents. The UCM production method which uses the music and picture is the method that users make the UCM more easily. However, the UCM production service has the problem that any association does not exist in the music and picture and that the picture changes according to fixed time interval without the relation at a music rhythm. To solve this problem, we propose the UCM production method which uses a music analysis and picture analysis in the paper. A music analysis finds a picture change time according to the rhythm and a picture analysis finds the association of the picture. A music analysis finds strong parts of the sound which uses Root-Mean-Square (RMS). And a picture analysis classifies the picture as a scenery picture and people picture which uses structure simplicity of the picture(SSP) and face region detection. A picture analysis got correct result of 86.4% in the experiment and we can finds the association at each picture and arranges the sequence which the picture appears. Therefore, if we use a music and picture analysis at the UCM production, users may make natural and efficient movie.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.333-340
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• 2018

Recently, free-form buildings have been designed with complex shapes due to digitization of the construction industry. Exterior and interior components of free-form buildings have free cross sections and curved shapes. Therefore, structural members with curvature are frequently seen. In the modeling and stability evaluation of these structures, commercial programs using classical finite element analysis are not able to perform rapid shape modeling, resulting in a decrease in productivity. Therefore, in this study, pre- and post-processing modules were developed using a prior study to rapidly model the surface of a free-form building and to automatically generate frame structures that make up the cladding. The developed modules use a subdivision algorithm with spline curves. This algorithm is used to automatically generate analytical elements from the configuration information of NURBS curves. In addition, the deformation after analysis can be viewed more realistically. The modules can quickly construct complex curved surfaces. An analysis model of the frame structure was also automatically generated. Therefore, the modules could contribute to the productivity improvement of free-form building design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.25-31
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• 2020

In this study, for the safe use of a portable ultrasonic skin-beauty device, an android app was developed to show the irradiation locations of focused ultrasound to a user through augmented reality (AR) and enable stable self-surgery. The utility of the app was assessed through testing. While the user is making a facial treatment with the beauty device, the user's face and the ultrasonic irradiation location on the face are detected in real-time with a smart-phone camera. The irradiation location is then indicated on the face image and shown to the user so that excessive ultrasound is not irradiated to the same area during treatment. To this end, ML-Kit is used to detect the user's face landmarks in real-time, and they are compared with a reference face model to estimate the pose of the face, such as rotation and movement. After mounting a LED on the ultrasonic irradiation part of the device and operating the LED during irradiation, the LED light was searched to find the position of the ultrasonic irradiation on the smart-phone screen, and the irradiation position was registered and displayed on the face image based on the estimated face pose. Each task performed in the app was implemented through the thread and the timer, and all tasks were executed within 75 ms. The test results showed that the time taken to register and display 120 ultrasound irradiation positions was less than 25ms, and the display accuracy was within 20mm when the face did not rotate significantly.

• Development and Reproduction
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• v.15 no.1
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• pp.71-76
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• 2011

Due to its role in maintaining the health of scientific societies, research ethics (or integrity) is notably receiving attention by academia, governments and even individuals who are not engaged in scientific researches. In this paper, I will introduce some valuable papers dealt with plagiarism as a representative research misconduct. In general, researcher's results that will soon be published must meet the crucial scientific criteria: originality, accuracy, reproducibility, precision and research ethics. The definition of plagiarism is "appropriation of another person's ideas, processes, results, or words without giving appropriate credit." Compared to fabrication and falcification, plagiarism is often considered as a minor misconduct. With intentionality, however, plagiarism can be corresponding to 'theft of intellectual product'. The context of plagiarism is not restricted to the stage of publication. It can be extended to prior stages of proposing (i.e. preparing the research proposal) and performing (executing the research), and reviewing (writing the review papers). Duplicate publication is regarded as a self-plagiarism in broad interpretation of plagiarism. To avoid dangers of plagiarism, earnest efforts from all members of scientific community are needed. First of all, researchers should keep 'transparency' and 'integrity' in their scientific works. Editorial board members and reviewers should keep fairness and well-deserved qualification. Government and research foundations must be willing to provide sufficient financial and policy support to the scientific societies; Up-graded editorial services, making good use of plagiarism detection tools, and thorough instruction on how to write a honest scientific paper will contribute to building up a healthy basis for scientific communities.

• Journal of Technology Innovation
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• v.20 no.1
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• pp.45-73
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• 2012

In this paper, we analyse empirically the effects of financial characteristics on the relationship between R&D investment and market value of firms listed on Korea Exchange. The main results of this study can be summarized as follows. Firm size increase the market valuation of R&D investment because it provides economies of scale, easier access to capital market, and R&D cost spreading. Market share also positively effects the relationship between R&D investment and firm value. Alternatively, free cash flow has a negative effect on the relationship between R&D investment and firm value because firms with high free cash flow could be tempted to use the free cash flow to undertake negative NPV projects. The dependence on external finance is a handicap negatively assessed by the market when firms undertake R&D projects due to the higher information asymmetry associated with this kind of project. Labor intensity has a negative effect on the relationship between R&D investment and firm value because the abnormal profits arising from R&D investment are diluted among employees. Capital intensity also has a negative effect on the relationship between R&D investment and firm value due to the greater financial constraints faced by capital intensive firms. In conclusion, several financial characteristics(firm size and market share) positively effect the relationship between R&D investment and firm value, while others(free cash flow, dependence on external finance, labor intensity, and capital intensity) exert a negative effect. Therefore, we conclude that the effectiveness of R&D investment depends on these financial characteristics.