• Tunnel and Underground Space
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• v.18 no.5
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• pp.343-354
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• 2008

A new method is suggested herein to measure the virgin earth stresses by means of a borehole. This novel concept is basically a combination of borehole stress relieving and borehole fracturing techniques. The destressing of the borehole is achieved by means of inducing thermal tensile stresses at the borehole periphery by using a cryogenic fluid such as Liquid Nitrogen($LN_2$). The borehole wall eventually develops fractures when the induced thermal stresses exceed the existing compressive stresses at the borehole periphery in addition to the tensile strength of the rock. The above concept is theoretically analyzed for its potential applicability to interpret in situ stress levels from the tensile fracture stresses and the corresponding borehole wall temperatures. Coupled thermo-mechanical numerical simulations are also conducted using FLAC3D, with thermal option, to check the validity of the proposed techniques. From the preliminary theoretical and numerical analysis, the method suggested for the measurement of in situ stresses appears to be capable of accurate estimation of the virgin stresses by monitoring tensile crack formation at a borehole wall and recording the wall temperatures at the time of crack initiation.

• Informatization Policy
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• v.19 no.2
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• pp.21-38
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• 2012

The proliferation of the Internet and the advent of e-commerce have amplified public concerns about privacy. Accordingly, much research effort has been made on the issue. While existing research on online information privacy has usually focused on the examination of antecedents of personal information disclosure, the literature has not paid attention to the potential changes of the antecedents' effects depending on the user's experience of the service. The current study aims to investigate the moderating role of site usage experience in Internet users' decision on personal information disclosure. Specifically, this study considers two types of antecedents of personal information disclosure on a site - the attributes of personal information requested (sensitivity and relevance of information) and the value of the service provided by the site; and examines how the effects of the antecedents on the disclosure intention are affected by the users'experience of the site. Our analysis of the data gathered through a web-based experiment reveals that site usage experience moderates the relationship between the attributes of personal information and disclosure intention. While usage experience attenuates the negative effect of information sensitivity on disclosure intention, it intensifies the positive impact that relevance of information has on disclosure intention. Based on the analysis results, we provide implications for the mitigation of the Internet users' privacy concerns as well as theoretical implications.

• Journal of Astronomy and Space Sciences
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• v.14 no.1
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• pp.44-58
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• 1997

The BVR CCD photometric observations of W UMa-type eclipsing binary SS Ari were made on ten nights from November 1996 to December 1996. Eight new times of minimum lights were derived. The analysis of times of minima of SS Ari confirms the suggestions of other previous investigators that the orbital period of SS Ari have been suffering from a sinusoidal varition. The amplitude and period for the cyclic period changes were calculated as about $58^{y}$ and $0.^{d}053$, respectively. The period variation has been discussed in terms of two potential mechanisms: 1) the light-time effect due to a hypothetical third body and 2) deformations in the convective envelope of a magnetically active component. In the earlier case, the third body has a mass of $1.3M_{\odot}$, if exist, in the form of a white dwarf or a binary system. It seems that the system velocities from the spectroscopic observations supports this interpretation. Meanwhile in the latter case, the primary component is mainly responsible for the magnetic activity of this system with a theoretical amplitude of $\pm0.^{m}08$. However, we cannot make a conclusion which is reasonable explanation at this point, due to lack of observational data. Moreover, the period variation of SS Ari shows duplication about $14^y$, cyclic period with an amplitude of about $0.^d001$ to the above periodic change. We also cannot make an acceptable conclusion for it at this time.

• Journal of Korea Game Society
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• v.14 no.5
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• pp.161-182
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• 2014

As environmental problems such as global warming, and ecocide have a great influence on society, the attention to environmental pollution is being expanded. To solve the environmental problems, the awareness and practice of members of society in question is required. However, it has been found that few people are participating in practising environmental protection in real life. Our main goals are to show that Gamification has great potential in delivering messages for public interest and to suggest guidelines for researchers and public contents developers who engage in designing in relation to Gamification. Based on the domestic and foreign theoretical investigations, we found that Gamification mechanism made based on psychological mechanism of users aims at public interests' value by maximizing motivations of users and spreading social relationships among people. As shown in the case study, if contents are developed by reflecting the elements which stimulate challenging of users, the elements which can express their opinions, and the elements of altruism which form the sympathy in the development of public interest contents in the future, practical participation of people to solve social problems can be expected.

• Structural Engineering and Mechanics
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• v.31 no.2
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• pp.181-210
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• 2009

This paper presents the theoretical developments of an exact finite strip for the buckling and initial post-buckling analyses of isotropic flat plates. The so-called exact finite strip is assumed to be simply supported out-of-plane at the loaded ends. The strip is developed based on the concept that it is effectively a plate. The present method, which is designated by the name Full-analytical Finite Strip Method in this paper, provides an efficient and extremely accurate buckling solution. In the development process, the Von-Karman's equilibrium equation is solved exactly to obtain the buckling loads and the corresponding form of out-of-plane buckling deflection modes. The investigation of thin flat plate buckling behavior is then extended to an initial post-buckling study with the assumption that the deflected form immediately after the buckling is the same as that obtained for the buckling. It is noted that in the present method, only one of the calculated out-of-plane buckling deflection modes, corresponding to the lowest buckling load, i.e., the first mode is used for the initial post-buckling study. Thus, the postbuckling study is effectively a single-term analysis, which is attempted by utilizing the so-called semi-energy method. In this method, the Von-Karman's compatibility equation governing the behavior of isotropic flat plates is used together with a consideration of the total strain energy of the plate. Through the solution of the compatibility equation, the in-plane displacement functions which are themselves related to the Airy stress function are developed in terms of the unknown coefficient in the assumed out-of-plane deflection function. These in-plane and out-of-plane deflected functions are then substituted in the total strain energy expressions and the theorem of minimum total potential energy is applied to solve for the unknown coefficient. The developed method is subsequently applied to analyze the initial postbuckling behavior of some representative thin flat plates for which the results are also obtained through the application of a semi-analytical finite strip method. Through the comparison of the results and the appropriate discussion, the knowledge of the level of capability of the developed method is significantly promoted.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.270-276
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• 2018

Background: Notoginsenoside Ft1 is a promising potential candidate for cardiovascular and cancer disease therapy owing to its positive pharmacological activities. However, the yield of Ft1 is ultralow utilizing reported methods. Herein, an acid hydrolyzing strategy was implemented in the acquirement of rare notoginsenoside Ft1. Methods: Chemical profiles were identified by ultraperformance liquid chromatography coupled with quadruple-time-of-flight and electrospray ionization mass spectrometry (UPLC-Q/TOF-ESI-MS). The acid hydrolyzing dynamic changes of chemical compositions and the possible transformation pathways of saponins were monitored by ultrahigh-performance LC coupled with tandem MS (UHPLC-MS/ MS). Results and conclusion: Notoginsenoside Ft1 was epimerized from notoginsenoside ST4, which was generated through cleaving the carbohydrate side chains at C-20 of notoginsenosides Fa and Fc, and vinaginsenoside R7, and further converted to other compounds via hydroxylation at C-25 or hydrolysis of the carbohydrate side chains at C-3 under the acid conditions. High temperature contributed to the hydroxylation reaction at C-25 and 25% acetic acid concentration was conducive to the preparation of notoginsenoside Ft1. C-20 epimers of notoginsenoside Ft1 and ST4 were successfully separated utilizing solvent method of acetic acid solution. The theoretical preparation yield rate of notoginsenoside Ft1 was about 1.8%, which would be beneficial to further study on its bioactivities and clinical application.

• Journal of The Korean Association of Information Education
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• v.8 no.3
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• pp.321-332
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• 2004

Recently, learning how to learn is a matter of concern among many pedagogists and become the important subject matter of school education. That's why there are many learners who fail to get good results compared with their potential abilities and efforts, as well as the necessity to educate independent and self-determined learner by teaching learning strategies that can help leaners to get new information and skills by themselves in an information-oriented society was emphasized. Therefore, this study is to utilize the learning strategy in order to improve the learners study skills, and grope for the method of self-directed learning about the social studies centered on the learners. And, it is to utilize the reciprocal teaching with the learning strategy for improving the learners study skills. Also, it is to make the learners induced to participate in the teaching for social studies actively, grafting the characteristics of web on the reciprocal teaching. According to this intent, this study was developed as three steps. As for the first step, it investigated the reciprocal teaching, a teaching-learning theory to apply to the program, and the theoretical background about web utility in the social studies. On the second step, it embodied the reciprocal teaching-learning system about the we-based social studies that will be available in the self-directed learning centered on the learners. Lastly, it analysed the change of recognition about the learners social study skills and the learning the social studies after applying the materialized website to the actual lesson.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.761-766
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• 2020

Phenylamine derivatives are substances that have a biochemical action and are widely applied as psychotropic drugs. In particular, with regard to the quantitative analysis of substances such as ephedrine, amphetamine, pentermine, and dopamine, many previous studies such as electrochemical, vacuum ultraviolet method, and gas chromatography have been conducted. However, there have not been many studies on the structural characteristics of molecular units. Therefore, In this study, we used (HyperChem8.0's, HC) semi-empirical PM3 method to calculate the total energy, band gap, electrostatic potential, and net charge of ephedrine, amphetamine, pentamine and dopamine to investigate the chemical properties of each derivative according to the molecular structure change. The results showed that for total energy -43,171.8, -32,9538.3, -36,407.3 and -43,061.2 Kcal/mol, respectively, while for band gaps, 10.16379377, 9.9531666, 9.7878002 and 9.0589282 eV. Also, for electrostatic potentials, 1.301~-0.045, 1.694~0.299, 0.694~-0.158 and 1.587~-0.048 respectively. Finally, looking at the distribution of net charges, the oxygen atoms, nitrogen atoms and carbon atoms were -0.312~-0.242, -0.161~-0.051 and +0.13~-0.12 respectively. These results are expected to lead to chemical action centered on phenyl radicals and oxygen and nitrogen atoms common to phenethylamine derivatives.

• Management & Information Systems Review
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• v.32 no.1
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• pp.19-41
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• 2013

The primary purpose of this study is to identify the influencing factors on the acceptance behavior of user in smartwork. For this purpose, a research model and hypotheses are developed based on relevant literature reviews. The data have been collected from 320 potential users and respondents were employee of Daejeon and Chungnam region. The results of hypotheses testing through covariance structural model analysis are summarized as follows. First, individual innovativeness has positive influence upon perceived ease of use and acceptance intention of smartwork, and self efficacy has positive influence upon perceived ease of use. Second, subjective norm of social influence has positive influence upon perceived ease of use and image has positive influence upon perceived ease of use and perceived usefulness. Third, number of exception of task characteristics has positive influence upon perceived ease of use and autonomy has positive influence upon perceived usefulness. Lastly, perceived ease of use has positive effect on the perceived usefulness and acceptance intention, and perceived usefulness positively related to acceptance intention in smartwork. Based on the findings, this study ends with theoretical and practical implications, as well as limitations and future research directions.

• Journal of the Economic Geographical Society of Korea
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• v.4 no.1
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• pp.61-76
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• 2001

The purposes of this research are to examine the theoretical background and industrial policy issues with regard to building a Innovation System for encouraging industrial competitiveness and fostering regional industry in Korea. Knowledge has become the driving force of economic growth and the primary source of competitiveness in the world market. So since 1990s, Innovation Systems have been put emphasis on as new industrial development strategy in a knowledge-based economy. It can be understood that Innovation System is composed of National Innovation System(NIS) and Regional Innovation System(RIS) and interrelated the concept of clusters and networks, which are contribute to industry development throughout boosting innovation. As for the Korean industrial policy, when the former centralized policy decision making process became decentralized through the implementation of local autonomy, the role of local or state government in relation to regional industrial promotion intensified. But with the impotance of for fostering strategic industry in the region. new industrial policy issues in Korea are needed as follows; $\circled1$ Building a market-oriented support system for industrial cluster through providing the resource of innovation. $\circled2$ Establishing agency for regional industrial development. $\circled3$ Making a evolutionary vision for broader region including 2 or 3 province, $\circled4$ Fostering strategic industry which is selected in term of specialization and potential of the region. The RIS model for industry development is outlined in this paper but policy initiatives for building a RIS have to be extracted from further case studies.