• Journal of Applied and Pure Mathematics
• /
• v.4 no.5_6
• /
• pp.287-297
• /
• 2022

In this paper, we consider a risk-minimization hedging problem for a special European contingent claims. The existence and uniqueness of strategy are given constructively. Firstly, a non-standard European contingent is demonstrated as stochastic payment streams. Then the existence of the risk minimization strategy and also the uniqueness are proved under two kinds market information by using Galtchouk-Kunita-Watanabe decomposition and constructing a 0-achieving strategy risk-minimizing strategies in full information. And further, we have proven risk-minimizing strategies exists and is unique under restrict information by constructing a weakly mean-selffinancing strategy.

• Journal of Gifted/Talented Education
• /
• v.25 no.6
• /
• pp.905-926
• /
• 2015

This study examined differences among high, medium, and low achievers' motivation, self-regulation strategy, and learning style in an online gifted program. The sample included 788 middle and high school students who participated in the 3-months online gifted program. Participants volunteerly completed 60 questions on their motivation, self-regulation strategy use, and learning style. Multivariate analysis of variance(MANOVA) was conducted for data analysis using SPSS 19.0. The results of this study showed that (1) as levels of students' achievement increased, levels of intrinsic motivation increased as well; (2) statistically significant differences also existed on the levels of elaboration strategy, effort management, and time management strategy use among three levels of achievement and (3) no significant differences in students' learning style preference were found between competitive or cooperative learning style. To sum up, high achieving students' levels of intrinsic motivation, elaboration strategy, effort management strategy, and time management strategy use were the highest compared to medium and low achieving students.

• Journal of Korean Neurosurgical Society
• /
• v.59 no.4
• /
• pp.405-409
• /
• 2016

Meningiomas are typically diagnosed by their characteristic appearance on conventional magnetic resonance imaging (MRI). However, detailed image findings regarding peri- and intra-tumoral anatomical structures, tumor consistency and vascularity are very important in pre-surgical planning and surgical outcomes. At the 7.0 T MRI achieving ultra-high resolution, it could be possible to obtain more useful information in surgical strategy. Four patients who were radiologically diagnosed with intracranial meningioma in 1.5 T MRI underwent a 7.0 T MRI. Three of them underwent surgery afterwards, and one received gamma knife radiosurgery. In our study, the advantages of 7.0 T MRI over 1.5 T MRI were a more detailed depiction of the peri- and intra-tumoral vasculature and a clear delineation of tumor-brain interface. In the safety issues, all patients received 7.0 T MRI without any adverse event. One disadvantage of 7.0 T MRI was the reduced image quality of skull base lesions. 7.0 T MRI in patients with meningiomas could provide useful information in surgical strategy, such as the peri-tumoral vasculature and the tumor-brain interface.

• Proceedings of the KIPE Conference
• /
• 2014.11a
• /
• pp.1-2
• /
• 2014

In this paper the partial switching PFC converter which is based on predictive control is proposed. In terms of satisfying the harmonic standard, the predictive control shows a similar performance to the conventional average current mode control PFC in the normal input condition. Moreover, the current harmonic characteristic is insensitive to the distorted input voltage. With predictive control method, novel on-line partial switching strategy is suggested in this paper. Depending on the operating condition, the partial switching PFC converter can boost its output voltage. Also when its efficiency needs to be improved, according to load condition, the partial switching can be achieved. The proposed strategy is proved by the results of FFT and the loss analysis using PSIM 9.0.

• Nuclear Engineering and Technology
• /
• v.56 no.7
• /
• pp.2534-2544
• /
• 2024

This paper proposes a flooding safety system (FSS) and its operation strategy that can provide long-term safety and effective maintenance for modules of small modular reactor (SMR) and metal containment maintained at dried environment during normal operation. During hypothesized accidents, the FSS re-collects the evaporated steam into the common pool by the condenser installed above the common water pool and provides an emergency coolant for the cavities and auxiliary pools. This study suggested that the condensate re-collection strategy using the FSS can effectively delay the depletion of available water in response to the accidents. Without recollection, the achievable grace periods ranged from 44 to 1507 days for six-module and one-module accidents, respectively. However, with a full re-collection (ratio = 1.0), the time to total depletion of emergency coolant was estimated indefinite. Even with a partial re-collection ratio of 0.3, a grace period of 83.5 days could be ensured for a six-module transient. This study reported the effectiveness of condensate re-collection and the FSS as an innovative safety management strategy and system. Employing a condensate re-collection strategy with a high re-collection ratio can enhance the long-term safety and effective convenience of SMR operations and maintenance.

• Management & Information Systems Review
• /
• v.15
• /
• pp.19-35
• /
• 2004

Top management's will was considered most positive by all of the surveyed local businesses, followed by organizational culture, information technology, evaluation and reward, and organizational structure in order. When influences of educational background on factors of success in knowledge management were analyzed, it was found that such background was affecting organizational structure at the significance level of 0.01 and information technology and top management's will at that of 0.05. Those who were more educated responded that success in knowledge management were dependent more on top management's will. but less on organizational structure. Concerning effects of organizational position on factors of success in knowledge management, it was found that such position was influencing top management's will at the significance level of 0.01 and organizational structure at that of 0.05. Those who were higher in organizational position responded that success in knowledge management were dependent less on top management's will, but more on organizational culture, and evaluation and reward. It as generally agreed among the surveyed businesses that knowledge management is a key strategy for business survival in the 21st century. To utilize knowledge management as their strategy, Korea's businesses should change their recognition of such management, reform their organizational culture, have CEOs of strong conviction and will and firmly establish their own information technology. It is necessary to make recognized the importance of knowledge management and culture knowledge management culture. If a person has a strong conviction or will of achieving goals by using intellectual efforts, creative imagination and necessary information, such information can be regarded as a proper knowledge. In conclusion, knowledge enterprises should strengthen their ability of knowledge use by associating their competition strategies with knowledge management. They also need to positively invest in the capture and new development of knowledge and build up infrastructures for knowledge management.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.12
• /
• pp.2491-2502
• /
• 2015

Main issue for embodiment of smart factory in small-medium manufacturing business(SMMB) is to whether might be successful or not in achieving a goal, exact materializing for smart factory related technology, and in seeking possible solutions for limited capacity to invest and develop technology. It is required for effective driving of manufacturing innovation 3.0 paradigm that ensures expertise to push forward technology policy based on value chain level of SMMB, and ensures detailed action plans by investment priority and development of core technology against global trend. This paper focuses to suggest countermeasure strategy and task through analysis of advanced technology and patent trend about industrial IoT(IIoT) and cyber physical system(CPS), and support embodiment of smart factory in underlying manufacturing innovation 3.0 scheme.

• Korean Journal of Materials Research
• /
• v.34 no.9
• /
• pp.448-455
• /
• 2024

We conducted a study on excessive doping of the Cr and In elements in Bi-Sb-Te materials satisfying the Hume-Rothery rule, and investigated the resulting electrical and thermal properties. From X-ray diffraction (XRD) results, we confirmed the formation of a single phase even with excessive doping. Through analysis of electrical properties, we observed the highest enhancement in electrical characteristics at y = 0.2, suggesting that the appropriate ratio of Bi-Sb significantly influences this enhancement. Using the Callaway-von Baeyer (CvB) model to assess scattering due to point defects, we calculated the experimental point defect scattering factor (Γ_CvB.exp), which was notably high due to the substantial differences in volume and atomic weight between the substituted (Cr, In) and original (Bi, Sb) elements. Additionally, we conducted a single parabolic band (SPB) modeling analysis of materials with compositions y = 0.1 and 0.2, where, despite a decrease in density-of-states effective mass (m_d^*) during the enhancement process from y = 0.1 to 0.2, a sharp increase in non-degenerate mobility (μ₀) led to an 88 % increase in weighted mobility (μ_w). Furthermore, analyzing zT with respect to n_H revealed a 51 % increase in zT at a composition of y = 0.2. This study confirmed a significant reduction in lattice thermal conductivity with the co-doping strategy, and with further compositional studies to improve electrical properties, we anticipate achieving high zT.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.7
• /
• pp.939-946
• /
• 2012

Antibiotic production with Streptomyces sindenensis MTCC 8122 was optimized under submerged fermentation conditions by artificial neural network (ANN) coupled with genetic algorithm (GA) and Nelder-Mead downhill simplex (NMDS). Feed forward back-propagation ANN was trained to establish the mathematical relationship among the medium components and length of incubation period for achieving maximum antibiotic yield. The optimization strategy involved growing the culture with varying concentrations of various medium components for different incubation periods. Under non-optimized condition, antibiotic production was found to be $95{\mu}g/ml$, which nearly doubled ($176{\mu}g/ml$) with the ANN-GA optimization. ANN-NMDS optimization was found to be more efficacious, and maximum antibiotic production ($197{\mu}g/ml$) was obtained by cultivating the cells with (g/l) fructose 2.7602, $MgSO_4$ 1.2369, $(NH_4)_2PO_4$ 0.2742, DL-threonine 3.069%, and soyabean meal 1.952%, for 9.8531 days of incubation, which was roughly 12% higher than the yield obtained by ANN coupled with GA under the same conditions.

• Korean Journal of Cognitive Science
• /
• v.28 no.3
• /
• pp.149-171
• /
• 2017

In this research, based on the fact that spatial ability is important for the achievement in the STEM fields, and technological innovation, Purdue Spatial Visualization Test-Rotation has been used to investigate engineering freshmen's spatial ability and gender differences. Students who have taken advanced mathematics courses in high school(those who have taken type B math test in Korean SAT test) and students with general math courses(those who have taken type A in Korean SAT-Math test) are included in this study to find out the relationship between mathematics achievement and spatial ability. Finding out the strategies taken by students was another aim of this study. This strategic differences between high achievers and lower achievers, male and female students were analyzed from students' self report. Spatial ability test score was highest in the SAT-Math type B male students, decreased in the order of type A male students, type B female students, and lastly type A female students. There was no substantial difference between second and third groups. In each group, male students' average score was 8~10% higher than female students, which affirms 2015's results. The correlation between spatial ability and mathematics achievement was negligible in each group, but male students' math score and spatial ability score were higher than that of female students. This can be interpreted that there is some correlation between these two. Strategic choices can vary in the continuous spectrum with analytic method and holistic method at both ends. From students' self report, using Mann-Witney test, it turned out that there exists strategic differences between male and female students. Male students have a tendency to use holistic strategy more often than female students. I also found that the strategy choice did not vary greatly among all score groups. For the perfect score groups, both female and male students used holistic strategy most frequently. For low achieving groups, there is an evidence that these students overuse one method compared to average or high achieving groups, which turned out to be less effective. Based on these, I suggest that low achieving students need to have more chances to adopt efficient strategies and to practice challenging problems to improve their spatial abilities.