• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.13 no.2
• /
• pp.87-100
• /
• 2009

Hedging strategy for European option of jump-type semimartingale asset model, which is derived from stochastic differential equation whose driving process is a jump-type semimartingle, is discussed.

• Journal of dental hygiene science
• /
• v.2 no.2
• /
• pp.75-83
• /
• 2002

By extracting the variables related to the work stress generated from dental hygiene, identifying their relationships, this study aims to contribute to academic progress on work stress. The test results of this study are as follows for each hypothesis: 1. Among the work stress sensing factors, role ambiguity showed correlation to the active coping strategy and the passive coping strategy, whereas it did not have any correlation to the evasive reation. However, the physical resource environmental factor showed correlation to the active coping strategy, whereas it did not have any correlation to the other reation. 2. The passive coping strategy, among the work stress coping strategies, influences the role ambiguity, B type, work ambiguity, physical resource environmental factor by about 18.7%. 3. The active coping strategy, among the work stress coping strategies, influences the social support, role ambiguity, work place of health center factor by about 18.9%. 4. The evasive reaction, among the work stress coping strategies, was influenced by only the 36 years old over factor by approximately 4.2%. 5. It was found in all work stress sensing factors that the group with lower social support had a more degree of experiencing stress than the group with higher social support. In case of the behavior pattern, the type A experienced more stress than the type B only in role ambiguity. 6. It was found that the group with the higher social support tended to choose more active coping strategy than the lower social support. In case of behavior pattern, the type B coped more actively than type A in the passive coping strategy.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.2
• /
• pp.586-594
• /
• 2015

This paper proposes a maximum efficiency operation strategy for three-level T-type inverter in entire operation areas. The three-level T-type inverter has higher and lower efficiency areas compared with two-level inverter. The proposed strategy aims to operate in the maximum efficiency point for the low-voltage and low-power home appliances. The three-level T-type inverter is analyzed in detail, and the two operation mode selection strategy is developed. The proposed algorithm is verified by theoretical analysis and experimental results.

• 한국경영정보학회:학술대회논문집
• /
• 2008.06a
• /
• pp.270-275
• /
• 2008

The various research on Communities of practices (CoP) for propagation of softer type knowledge in new Knowledge Management (KM) strategy having been performed for past couple of years. CoP is one of effective process innovation tool for diffusion of knowledge. Based on CoP's voluntary and spontaneous characteristic, it performs a function of delivering softer type knowledge of workers to the other colleagues of organization. But one step further to CoP's function of propagation of internal knowledge, research on function of CoP's contribution in enterprise strategy are insufficient yet. This paper presents enterprise CoP should be managed and aligned to strategic objectives of enterprise, and also, suggests the methodology for CoPs to maintain a lifecycle as a tool to contribute in strategic goal attainment. Although CoPs are voluntary and spontaneous informal organization, it can display a contribution as tool for KM strategy when it is aligned to strategy properly and form efficient lifecycle.

• International Journal of Automotive Technology
• /
• v.8 no.6
• /
• pp.791-798
• /
• 2007

The hydraulic hybrid vehicle(HHV) is an application of hydrostatic transmission technology to improve vehicle fuel economy and emissions. A relatively lower energy density of hydraulic accumulator and complicated coordinating operations between two power sources require a special energy management strategy to maximize the fuel saving potential. This paper presents a new type of configuration for parallel HHV to minimize the disadvantages of the hydraulic accumulator, as well as a methodology for developing an energy management strategy tailored specially for PHHV. Based on an analysis of the optimal energy distribution between two power sources over a representative urban driving cycle with a Dynamic Programming(DP) algorithm, a fuzzy-based optimal torque management strategy is designed and developed to control the torque distribution. Simulation results demonstrates that the optimal torque management strategy maximizes the advantages of this hybrid type of configuration, and the high power density characteristics of hydraulic technology effectively improve the robustness of the energy management strategy and fuel economy of the PHHV.

• English Language & Literature Teaching
• /
• v.16 no.3
• /
• pp.101-117
• /
• 2010

This study examines whether English users at a U.S. university apply avoidance strategy in using English articles. All participants had learned English for at least 10 years and had used English for at least 15 years at the time of the data collection, so they made an ideal sample to examine the differences between native speakers of English and non-native speakers of English, in terms of avoidance strategy usage of English articles. To examine whether non-native speakers avoid using a certain feature when unsure of the correct usage, the mean differences of each article usage between NS and NNS groups were calculated and compared. On the basis of results showing that there are no statistically significant differences in terms of article usage between the groups, it is concluded that the highly advanced level participants did not use avoidance strategy in English articles, and that the type of English article and the task type did not affect learners' avoidance strategy usage. This research is expected to provide teachers and researchers with information about highly advanced level L2 language speakers' usage patterns with regards to avoidance strategy.

• Journal of the Korean School Mathematics Society
• /
• v.11 no.4
• /
• pp.609-627
• /
• 2008

The purpose of this research was to investigate the relationship between the students' strategy types and the recognition for proportional situations. The students' strategy types which were based on the results of ratio and proportion tests were divided into an additive type, a multiplicative type, and a formal type. This research analyzed the students' activities of categorization when were given the proportional problems and nonproportional problems to the students. And it also explored how to develop students' recognizing for the discrimination between the proportional situations and nonproportional situations. The results was the following. First, the students didn't discriminate the proportional situations and the nonproportional situations in the initial state but they came to discriminate little by little. Secondly, the students didn't discriminate the direct proportions and the inverse proportions until the last stage. Third, the multiplicative type was outperformed more than the formal type in solving the ratio and proportion problems but the formal type was outperformed more than the multiplicative type in discriminating between proportional situations and nonproportional situations. These results are interpreted as showing that solving ratio and proportion tasks and recognizing proportional situations are different aspects of proportional reasoning and it is necessary to understand multiplicative strategy with formal strategy in recognizing proportional situations.

• Journal of Digital Convergence
• /
• v.9 no.1
• /
• pp.13-24
• /
• 2011

IT is the core industry in Korea which has the most international competitiveness and counts for 35% of the total exports of Korea. Nevertheless, it tends to be concentrated in small range of items, a few countries and mostly large companies. Therefore, it is needed for small and medium-sized enterprises which can have prompt decision making processes and various changes to export wide range of items and to diverse countries. This study will introduce 'the fleet-type expansion strategy of overseas export' that is about large and small enterprises perform the appropriate role based on their own character, thus they produce the mutual benefit. This strategy will contribute to improve the export structure of Korea and perform the major role for Korea's IT industry to become the dynamic force for growth in the future.

• Tissue Engineering and Regenerative Medicine
• /
• v.15 no.6
• /
• pp.673-697
• /
• 2018

BACKGROUND: Cartilage tissue engineering (CTE) aims to obtain a structure mimicking native cartilage tissue through the combination of relevant cells, three-dimensional scaffolds, and extraneous signals. Implantation of 'matured' constructs is thus expected to provide solution for treating large injury of articular cartilage. Type I collagen is widely used as scaffolds for CTE products undergoing clinical trial, owing to its ubiquitous biocompatibility and vast clinical approval. However, the long-term performance of pure type I collagen scaffolds would suffer from its limited chondrogenic capacity and inferior mechanical properties. This paper aims to provide insights necessary for advancing type I collagen scaffolds in the CTE applications. METHODS: Initially, the interactions of type I/II collagen with CTE-relevant cells [i.e., articular chondrocytes (ACs) and mesenchymal stem cells (MSCs)] are discussed. Next, the physical features and chemical composition of the scaffolds crucial to support chondrogenic activities of AC and MSC are highlighted. Attempts to optimize the collagen scaffolds by blending with natural/synthetic polymers are described. Hybrid strategy in which collagen and structural polymers are combined in non-blending manner is detailed. RESULTS: Type I collagen is sufficient to support cellular activities of ACs and MSCs; however it shows limited chondrogenic performance than type II collagen. Nonetheless, type I collagen is the clinically feasible option since type II collagen shows arthritogenic potency. Physical features of scaffolds such as internal structure, pore size, stiffness, etc. are shown to be crucial in influencing the differentiation fate and secreting extracellular matrixes from ACs and MSCs. Collagen can be blended with native or synthetic polymer to improve the mechanical and bioactivities of final composites. However, the versatility of blending strategy is limited due to denaturation of type I collagen at harsh processing condition. Hybrid strategy is successful in maximizing bioactivity of collagen scaffolds and mechanical robustness of structural polymer. CONCLUSION: Considering the previous improvements of physical and compositional properties of collagen scaffolds and recent manufacturing developments of structural polymer, it is concluded that hybrid strategy is a promising approach to advance further collagen-based scaffolds in CTE.

• Journal of Digital Convergence
• /
• v.19 no.6
• /
• pp.163-174
• /
• 2021

This paper investigated the role of CEO leadership in the relationship between Korean small firm's competitive strategy and performance. This study conducted an empirical analysis by collecting data through a questionnaire survey targeting small firms in Korea. The main findings of this study are as follows. First, it was found that the competitive strategies of small firms all had a positive effect on the performance, and it was found that a strategic consistency rather than the type of strategy was positive for firm performance. Second, it was found that the type of leadership of the CEO should also be changed according to the type of strategy. Specifically, it was found that transformational leadership was more appropriate for differentiation strategies, and transactional leadership was more appropriate for cost advantage strategies. This study clarified that the pursuit of a strategic consistency is more important than the type of strategy in the competitive strategy, and that the CEO needs to pursue an appropriate leadership style according to the competitive strategy.