• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.83-91
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• 1996

We present a model that rotating primordial blackholes(PBHs) produced at the end of inflation generate the random, non-oriented primordial magnetic field. PBHs are copiously produced as the Universe completes the cosmic phase transition via bubble nucleation and tunneling processes in the extended inflation hypothesis. The PBHs produced acquire angular momentum through the mutual tidal gravitational interaction. For PBHs of mass less than 1013g, one can show that the evaporation (photon) luminosity of PBHs exceeds the Eddington limit. Thus throughout the lifetime of the rotating PBH, radiation flow from the central blackhole along the Kerr-geodesic exerts torque to ambient plasma. In the process similar to the Bierman's battery mechanism electron current reaching up to the horizon scale is induced. For PBHs of Grand Unified Theories extended inflation with the symmetry breaking temperature of $T_{GUT}\;\~\;10^{10}$ GeV, which evaporate near decoupling, we find that they generate random, non-oriented magnetic fields of $\~10^{-11}G$ on the last-scattering surface on (the present comoving) scales of $\~O(10)Mpc$.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.4
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• pp.593-597
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• 2019

We proposed a current Interruption type DC superconducting circuit breaker(I-DC SCB), a protection device that combines the current limiting technology of a superconductor with the cut-off technology of circuit breaker. Unlike existing protective devices, the current I-DC SCB is a device that combines two protection functions, notably improving failure probability and operational reliability. It is also applicable to all DC systems, such as HV, MV, and LVDC, due to the ease in capacity increase. The 100 kV I-DC SCB was designed after taking into account the actual power system conditions, followed by an analysis of the transient characteristics and the breaking range of the limiter. The results of the analysis showed that the I-DC SCB had a fault current limit of about 75% at the rated voltage, and completed the cut-off operation within about 20 ms.

• Journal of Ocean Engineering and Technology
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• v.37 no.6
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• pp.256-265
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• 2023

Many numerical methods have been developed since 1961, but unresolved issues remain. This study developed a numerical method to address these issues and determine the coefficients and properties of rotational waves with a shear current in a finite water depth. The number of unknown constants was reduced significantly by introducing a wavelength-independent coordinate system. The reference depth was calculated independently using the shooting method. Therefore, there was no need for partial derivatives with respect to the wavelength and the reference depth, which simplified the numerical formulation. This method had less than half of the unknown constants of the other method because Newton's method only determines the coefficients. The breaking limit was calculated for verification, and the result agreed with the Miche formula. The water particle velocities were calculated, and the results were consistent with the experimental data. Dispersion relations were calculated, and the results are consistent with other numerical findings. The convergence of this method was examined. Although the required series order was reduced significantly, the total error was smaller, with a faster convergence speed.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1779-1784
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• 2016

Background: Western physicians tend to favour complete disclosure of a cancer diagnosis to the patient, while non-Western physicians tend to limit disclosure and include families in the process; the latter approach is prevalent in clinical oncology practice in India. Few studies, however, have examined patient preferences with respect to disclosure or the role of family members in the process. Materials and Methods: Structured interviews were conducted with patients (N=127) in the medical oncology clinic of a tertiary referral hospital in Bangalore, India. Results: Patients ranged in age from 18-88 (M=52) and were mostly male (59%). Most patients (72%) wanted disclosure of the diagnosis cancer, a preference significantly associated with higher education and English proficiency. A majority wanted their families to be involved in the process. Patients who had wanted and not wanted disclosure differed with respect to their preferences regarding the particulars of disclosure (timing, approach, individuals involved, role of family members). Almost all patients wanted more information concerning their condition, about immediate medical issues such as treatments or side effects, rather than long-term or non-medical issues. Conclusions: While most cancer patients wanted disclosure of their disease, a smaller group wished that their cancer diagnosis had not been disclosed to them. Regardless of this difference in desire for disclosure, both groups sought similar specific information regarding their cancer and largely favoured involvement of close family in decision making. Additional studies evaluating the influence of factors such as disease stage or family relationships could help guide physicians when breaking bad news.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.55-62
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• 2019

In this paper, we introduce a case of a fire accident during parking of a large truck that is repeatedly occurring. The shape and location of the combustion and electrical singularity commonly found in other vehicle fire accidents could limit the starter motor as the ignition section. In addition, it was possible to confirm the electrical melting singularity that could act as a cause of ignition between the start motor B terminal and the start motor enclosure. By combining the above investigations and investigations, it was possible to estimate the electric fire expressed from insulation breaking of the starter motor B terminal, and by using the renewable starter motor comparison product mounted on the fire vehicle, an experiment was performed to reproduce the ignition process from the starter motor under specific conditions. So. It is hoped that this will raise awareness about vehicle fires, which can lead to large fires or casualties, share the risks of using starter motors for regeneration, and help in the rapid and accurate investigation of similar vehicle fires in the future.

• Journal of Ocean Engineering and Technology
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• v.36 no.2
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• pp.101-107
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• 2022

Dean (1965) proposed the use of the root mean square error (RMSE) in the dynamic free surface boundary condition (DFSBC) and kinematic free-surface boundary condition (KFSBC) as an error evaluation criterion for wave theories. There are well known wave theories with RMSE more than 1%, such as Airy theory, Stokes theory, Dean's stream function theory, Fenton's theory, and trochodial theory for deep-water waves. However, none of them can be applied for deep-water breaking waves. The purpose of this study is to provide a closed-form solution for deep-water waves with RMSE less than 1% even for breaking waves. This study is based on a previous study (Shin, 2016), and all flow fields were simplified for deep-water waves. For a closed-form solution, all Fourier series coefficients and all related parameters are presented with Newton's polynomials, which were determined by curve fitting data (Shin, 2016). For verification, a wave in Miche's limit was calculated, and, the profiles, velocities, and the accelerations were compared with those of 5^th-order Stokes theory. The results give greater velocities and acceleration than 5^th-order Stokes theory, and the wavelength depends on the wave height. The results satisfy the Laplace equation, bottom boundary condition (BBC), and KFSBC, while Stokes theory satisfies only the Laplace equation and BBC. RMSE in DFSBC less than 7.25×10^-2% was obtained. The series order of the proposed method is three, but the series order of 5^th-order Stokes theory is five. Nevertheless, this study provides less RMSE than 5^th-order Stokes theory. As a result, the method is suitable for offshore structural design.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.718-724
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• 1999

This study was investigated the changes of the properties of matter such as the gel formation of the combined fish based on the mixed rate between the ocean jumbo squid and Alaska pollock surimi, and compared the relationships between the gel formation and water holding capacity. The changes of the gel formation based on 20 min fish grinding time and $2.5\%$ salt concentration according to the mixed rate was thought as the optimal addition limit. There was no significant function of gel product more than $20\%$ Jumbo squid meat. The more squid meat in the mixed meat could make the lower breaking stress but 7:3 rate of pollock : squid could retain breaking strain. The effect of the moisture content on mixed fish meat was studied and the drastic decrease of the gel formation and water holding capacity was indicated in $78\%$.

• Advanced Composite Materials
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• v.18 no.1
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• pp.77-93
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• 2009

This paper investigated the damage transition mechanism between the fiber-breaking mode and the fiber-avoiding crack mode when the fiber-length is reduced in the unidirectional discontinuous carbon fiber-reinforced-plastics (CFRP) composites. The critical fiber-length for the transition is a key parameter for the manufacturing of flexible and high-strength CFRP composites with thermoset resin, because below this limit, we cannot take full advantage of the superior strength properties of fibers. For this discussion, we presented a numerical model for the microscopic damage and fracture of unidirectional discontinuous fiber-reinforced plastics. The model addressed the microscopic damage generated in these composites; the matrix crack with continuum damage mechanics model and the fiber breakage with the Weibull model for fiber strengths. With this numerical model, the damage transition behavior was discussed when the fiber length was varied. The comparison revealed that the length of discontinuous fibers in composites influences the formation and growth of the cluster of fiber-end damage, which causes the damage mode transition. Since the composite strength is significantly reduced below the critical fiber-length for the transition to fiber-avoiding crack mode, we should understand the damage mode transition appropriately with the analysis on the cluster growth of fiber-end damage.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.69-79
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• 2011

The concept of architectural sustainability is gradually being highlighted in several ills and consciousness of crisis of modern architecture. However, many of us tend to realize its sustainability focusing on ecological sustainability in many ways. Such perspective is considerably technical and extensive. Therefore, I paid attention to Herman Hertzberger's architecture to find out how to consider spatial aspects, when interior architecture designers engage in design process. This study aims to analyze architectural progress for social communication of Herman Hertzberger's project, breaking from the existing research to only limit him to one of structuralism architects. In particular, it was found that in relation to social sustainability, universal/social design, cultural design and green/ecological design have been progressed in their forms through communicational perspectives of social architecture which he's insisted since the structuralism era. Recently, majority of issues about sustainability are restricted to economical aspects. Accordingly, further study is needed to consider his architecture from social aspects. As his architecture is concentrating on coexistence from a social perspective for communication, not on modern spatial discourse, his architectural works need to be analyzed consistently as realistic measurements.

• Fashion & Textile Research Journal
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• v.9 no.4
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• pp.363-372
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• 2007

T-shirt has changed into advanced and stylish outwear by new paradigm, taste of consumer, awareness of recycling, spread of subculture, DIY culture, refusal of standardization and pursuit of high quality goods, etc. The purpose of this study was to analyze aesthetic characteristics of t-shirt designs that changed into diverse designs in world fashion college since 2000. The method of this study was to analyze documentaries, fashion magazines and internet fashion site. Aesthetic characteristics of t-shirt designs were expressed in deconstruction, mixture, integration and imitation. And each of external expressions and internal meanings was as follows: First, deconstruction was expressed in partial cutwork and three dimensional texture by sewing and construction drape. It means breaking the conventional structure and break-ing the boundary of t-shirt and another item and possibility of multi-vocal analysis. Second, mixture was expressed in collage of diverse ornaments, diverse fabrics and diverse patterns. It means exceeding the limit of material, elaboratenes and high quality of handwork, reflection of self-identity, brand image, fashion trend, consumer's psychology and mind of experimentation and couture. Third, integration was expressed in extension of length, width, use and style. It means unification of functions, deconstruction of items and extension of meanings and images. Forth, imitation was expressed in stain of dye, irregular and ripped sign, cut out, rough warp, drawing and washing, etc. It means subculture, rarity value, monopolization, diversity, familiarity, yearning and uniqueness.