• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.105-111
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• 2006

Cryptographic application and coding theory require operations in finite field $GF(2^m)$. In such a field, the area and time complexity of implementation estimate by memory and time delay. Therefore, the effort for constructing an efficient multiplier in finite field have been proceeded. Massey-Omura proposed a multiplier that uses normal bases to represent elements $CH(2^m)$ [11] and Agnew at al. suggested a sequential multiplier that is a modification of Massey-Omura's structure for reducing the path delay. Recently, Rayhani-Masoleh and Hasan and S.Kwon at al. suggested a area efficient multipliers for modifying Agnew's structure respectively[2,3]. In [2] Rayhani-Masoleh and Hasan proposed a modified multiplier that has slightly increased a critical path delay from Agnew at al's structure. But, In [3] S.Kwon at al. proposed a modified multiplier that has no loss of a time efficiency from Agnew's structure. In this paper we will propose a multiplier by modifying Rayhani-Masoleh and Hassan's structure and the area-time complexity of the proposed multiplier is exactly same as that of S.Kwon at al's structure for type-II optimal normal basis.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.2
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• pp.20-30
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• 1999

We have made the single side hand filter for the dual channel receiver which is a heterodyne receiver to observe the cosmic radio waves with 100GHz band ranged from 85GHz to 115GHz and 150GHz band ranged from 125GHz to 175GHz simultaneously. We have introduced the filter theory using the principle of the Martion-Puplett interferometer, which has the characteristics of rotated polarization. To reduce the loss of the transmission and beam coupling which are caused from the path difference associated with the intermediate frequency the design and the implementation have been intensely considered. The receiver needs two filters with different characteristics each other. Because each of them has the optimum positions as a function frequency at which the signal frequency is fed to mixer and the image frequency is rejected to the image termination load. The intermediate frequency and its band width have been also evaluated. We have measured the property of two filters using the vector network analyser and the beam measurement system which is made by us. The responses of the filter as a function of the position and the frequency are compared with the theory. It is shown that not only the measured values are very close to the theoretical values, but also the image rejection ratios are better than 22dB for both filters. Through successful observation using a dual channel receiver with two manufactured filters, the performance of the filters has finally verified.

• Journal of the Korean earth science society
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• v.21 no.5
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• pp.635-646
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• 2000

Geological achievements of the 20th century revolutionized our views about geological understanding and concept. A good example is the concept of continental drift suggested early in the 20th century and later explained in terms of seafloor spreading and plate tectonics. Our understanding of the compositions of materials forming earth has also improved during the20th century. Radio and stable isotopes together with biostratigraphy and sequence stratigraphy allow us to interpret the evolution of sedimentary basins in terms of plate movement and sedimentation processes. The Deep Sea Drilling Project initiated in 1960s and continued as the Ocean Drilling Project in 1980s is one of the most successful international research observations, and new developments in computational techniques have provided a wholly new view about the interior of the earth. Most of the geological features and phenomena observed in deep sea and around continental margins are now explained in terms of global tectonic processes such as superplumes flowing up from the interior of our planet and interacting with such as Rodinia Pannotia and Nena back in the Precambrian time. The space explorations which began in the late 1950s opened up a new path to astrogeology, astrobiology, and astropaleontology. The impact theory rooted in the discovery of iridium and associated phenomena in 1980s revived Cuvier's catastrophism as a possible explanation for the extinctions of biotas found in the geological record of this planet. Due to the geological achievements made in the 20th century, we now have a better understanding of geologic times and processes that were too long to be grasped by human records.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.135-150
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• 2016

This study aims to investigate how perceived interactivity between the mobile messenger application and its user gives rise to user's enjoyment and continuous usage intention. Perceived interactivity was assumed to be formed by the combination of control, share, and responsiveness in light of the previous studies. The relations between perceived interactivity, enjoyment, and usage intention are hypothesized on the basis of the pleasure-arousal-dominance emotional state model, the theory of reasoned action, and the theory of planned behavior. Survey data were collected from 481 mobile messenger users in Korea and China. In order to test hypotheses, structural equation modeling analyses were conducted. As a result, perceived interactivity concerning connectedness and responsiveness not only positively affected enjoyment, but also had a significant effect on usage intention. However, while control positively influenced usage intention, it was not significantly related to enjoyment. In addition, there was a positive relation between enjoyment and usage intention. Incidentally, multi-group analysis was conducted to explore the differences between Korean and Chinese users. The findings would provide managerial implications for mobile messenger corporations on causal effects of perceived interactivity and the differences of the path coefficients between in Korea and China.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.441-453
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• 2020

This study conducted a questionnaire survey on SNS users who are conducting K-POP record collection activities using SNS and verified factors affecting the intention to continue K-POP record collection activities. The main methods of analysis were exploratory factor analysis, confirmatory factor analysis, correlation analysis, and path analysis using SPSS 21.0 program and AMOS 21.0 program. The results are summarized as follows. First, compatibility for K-POP record collection activities through SNS has a positive effect on perceived usefulness, and observability also has a positive effect on perceived usefulness and perceived ease of use. Second, perceived ease of use for K-POP records collection using SNS has a positive effect on perceived usefulness. Third, perceived usefulness and perceived ease of use for K-POP records collection using SNS have a positive effect on continuous intention of K-POP records collection activity through SNS. As a result of this study, it suggests that the intention to continue the collection activities of K-POP records using SNS can be explained through the integration of innovation diffusion theory and technology acceptance model.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.1-7
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• 2004

Oriental Medicine has long been centered around Qi[vital force], hence adopting Qigong and the art of regimen for training the body and relaxing the mind so as to prevent and heal illness. It has not been such a long time since Qigong method had been performed and spot-lighted out of numerous methods in Oriental Medicine. In China and Korea alone, diverse cases and papers are published, only revealing so many steps toward the establishment of diachronic description, theoretical foundation, and clinical practice. Historical approach is an essential part of recognizing a subject. When you step along its path and comprehend what it were, you can also grasp what it is and what it will be. Establishment of Qigong history is also vital to research Qigong in theory and practice. Generally, Qigong was transmitted from China to Korea, whereas the opposite explanation, that it originated from Korean Taoism, is supported by the minority based on certain texts concerning ancient history. In this paper, I support the theory of Korean originality based on the following grounds: First, the location of Qi and Van, the motherland of Chinese Taoism provides a strong evidence that Korean tradition had been absorbed by them and formed the tradition of mystic hermits(shenxian). Second, Guangchengzi, the originator of mystic hermits, is from Dongyi tribe according to Cheonghakjib. Third, the myth of Dangun has pure form of unique Korean folklore possessing the distinctive feature of mystic hermits tradition, uninfluenced by Chinese Taoism. Fourth, in ideographical aspect, the character 'xian(仙)', was invented as the Korean concept of mystic hermits[xian] was flowed in to China. Moreover, There is high probability that it was based on the concept of mystic hermits shown in the myth of Dangun in Its original formation. Fifth, considering the relation between wild ginseng and the tradition of mystic hermits, that tradition can be formed very naturally in Korean area. Sixth, the analogical similarity between archetype of Korean tradition and Taoistic trilogy, the foundational idea of the tradition, gives genealogical basis to its origin. Seventh, the tradition of mystic hermits and Shamanism, which constitues the prototype of Korean mind as an original religious tradition, are undiscernible in their root In Conclusion, We can reach the idea that the origin of Qigong derives from Korean tradition, not that of China. The tradition of mystic hermits was transformed to ego-centric seclusionism when it faced the anarchy of Warring states period in China, whereas it was developed into humane proriety and worship of Heaven base on the programme of 'universal fraternity in pursuit of interst for man'. In prospect, it is highly required to develop and interpret traditional discipline methods in Korea so as to utilize them for clinical Qigong in practice.

• Korean Journal of Social Welfare
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• v.35
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• pp.85-105
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• 1998

This article examined the trend of 125 empirical researches which were published in Jr. of Korean Social Welfare from the first issue to no. 33. in terms of theoretical and methodological orientations. The content analysis was employed for the purpose of the study. Since 1979, the number of empirical researches was in the trend of increasing. The findings from this research were as follows. 1) Among 166 authors, 96.4% were majored in social welfare. Also 6.0% were practitioners and the rest of them were in the position of professors or researchers. The outcome of lack of interdisciplinary co-work and researcher-practitioner co-work led the article to conclude that the nature of applied social science of social welfare was not so actively pursued in Korea. 2) It was almost impossible to find researches which studied same theme or employed same analytical framework. This meant that the work of re-verifying and proving the contray could not be done although it was essential for theory-building. In other words, the disciplinary of social welfare was far behind in the process of theory-building. 3) The methodology upon which most of researches were relied was quantitative methodology(92.8%). The article concluded 'paradigm shift' was not begun in the disciplinary of social welfare yet. 4) The study concluded that the particularity of empirical researches of social welfare in Korea was descriptive-configurative study. Whereas 65.5% of 125 empirical studies were descriptive-configurative, 25% were hypothesis - model test and only 6% causal analysis. 5) The most applied statistic models through the period from 1979 to 1997 were descriptive statistics such as frequency, chi square test, Pearson's r. More advanced statistics such as logit regression, probit regression, path analysis, covariance structure analysis were shown since 1990.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.32-33
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• 2003

Mechanism of a periodic oscillation of shock-induced combustion over a two- dimensional wedges and axi-symmetric cones were investigated through a series of numerical simulations at off-attaching condition of oblique detonation waves(ODW). A same computational domain over 40 degree half-angle was considered for two-dimensional and axi-symmetric shock-induced combustion phenomena. For two-dimensional shock-induced combustion, a 2H2+02+17N2 mixture was considered at Mach number was 5.85with initial temperature 292 K and initial pressureof 12 KPa. The Rankine-Hugoniot relation has solution of attached waves at this condition. For axi-symmetric shock-induced combustion, a H2+2O2+2Ar mixture was considered at Mach number was 5.0 with initial temperature 288 K and initial pressure of 200 mmHg. The flow conditions were based on the conditions of similar experiments and numerical studies.[1, 3]Numerical simulation was carried out with a compressible fluid dynamics code with a detailed hydrogen-oxygen combustion mechanism.[4, 5] A series of calculations were carried out by changing the fluid dynamic time scale. The length wedge is varied as a simplest way of changing the fluid dynamic time scale. Result reveals that there is a chemical kinetic limit of the detached overdriven detonation wave, in addition to the theoretical limit predicted by Rankine-Hugoniot theory with equilibrium chemistry. At the off-attaching condition of ODW the shock and reaction waves still attach at a wedge as a periodically oscillating oblique shock-induced combustion, if the Rankine-Hugoniot limit of detachment isbut the chemical kinetic limit is not.Mechanism of the periodic oscillation is considered as interactions between shock and reaction waves coupled with chemical kinetic effects. There were various regimes of the periodicmotion depending on the fluid dynamic time scales. The difference between the two-dimensional and axi-symmetric simulations were distinct because the flow path is parallel and uniform behind the oblique shock waves, but is not behind the conical shock waves. The shock-induced combustion behind the conical shockwaves showed much more violent and irregular characteristics.From the investigation of characteristic chemical time, condition of the periodic instability is identified as follows; at the detaching condition of Rankine-Hugoniot theory, (1) flow residence time is smaller than the chemical characteristic time, behind the detached shock wave with heat addition, (2) flow residence time should be greater than the chemical characteristic time, behind an oblique shock wave without heat addition.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1115-1123
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• 2008

When constructing projects such as road embankments, bridge approaches, dikes or buildings on soft, compressible soils, significant settlements may occur due to the consolidation of these soils under the superimposed loads. The compressibility of the soil skeleton of a soft clay is influenced by such factors as structure and fabric, stress path, temperature and loading rate. Although it is possible to determine appropriate relations and the corresponding material parameters in the laboratory, it is well known that sample disturbance due to stress release, temperature change and moisture content change can have a profound effect on the compressibility of a clay. The early research of Tezaghi and Casagrande has had a lasting influence on our interpretation of consolidation data. The 24 hour, incremental load, oedometer test has become, more or less, the standard procedure for determining the one-dimensional, stress-strain behavior of clays. An important notion relates to the interpretation of the data is the ore-consolidation pressure ${\sigma}_p$, which is located approximately at the break in the slope on the curve. From a practical point of view, this pressure is usually viewed as corresponding to the maximum past effective stress supported by the soil. Researchers have shown, however, that the value of ${\sigma}_p$ depends on the test procedure. furthermore, owing to sampling disturbance, the results of the laboratory consolidation test must be corrected to better capture the in-situ compressibility characteristics. The corrections apply, strictly speaking, to soils where the relation between strain and effective stress is time independent. An important assumption in Terzaghi's one-dimensional theory of consolidation is that the soil skeleton behaves elastically. On the other hand, Buisman recognized that creep deformations in settlement analysis can be important. this has led to extensions to Terzaghi's theory by various investigators, including the applicant and coworkers. The main object of this study is to suggestion the modified compression index value to predict settlements by back calculating the $C_c$ from different numerical models, which are giving best prediction settlements for multi layers including very thick soft clay.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.406-420
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• 2021

This study used Glaser's grounded theory method for the recognition of college students' majors in counseling psychology. Among the 3rd and 4th grade students majoring in counseling psychology, 19 students participated in the study, focusing on them for 5 months and collecting data through individual interviews. As a result of analyzing the data, 103 concepts, 26 subcategories, 9 upper categories, and 1 core category were derived. As a result of the study, first, the participants wanted to relieve the burden of people's hearts and had the hope of becoming a healer. Second, among the participants, in terms of their personality and aptitude for their major field, they perceived it as joy and satisfaction, such as 'It fits well with the major,' 'I made a good choice,' and 'It became a turning point in life.' However, they also recognized the incompatibility of the major, such as disharmony of aptitude, burden of the role of counselor, and rejection of major. Third, although participants showed usefulness in their major learning, their perception of the career path in their major was acting as anxiety and conflict, but their concerns and conflicts resulted in financial difficulties, poor job conditions, and emotional exhaustion caused by long-term study. The burden of job, fear of counseling job, limit of undergraduate graduation, uncertainty of career, etc. acted as an obstacle in choosing a major career. Fourth, as a result of analyzing the interview data of the participants, a core category called' understanding and growth and the will of the counselor to realize the dream' was derived. In conclusion, the participant's perception of their major is the change and growth of themselves, the formation of a healthy relationship with others, and satisfaction with the suitability of their major and their aptitudes. It turned out to have a lasting will to do.