• Journal of Power Electronics
• /
• v.19 no.3
• /
• pp.625-636
• /
• 2019

This paper proposes an active leakage magnetic field (LMF) suppression scheme, which uses the dual-transmitter (DT) topology, for EV wireless charging systems (EVWCS). The two transmitter coils are coplanar, concentric and driven by separate inverters. The LMF components generated by the three coils cancel each other out to reduce the total field strength. This paper gives a detailed theoretical analysis on the operating principles of the proposed scheme. Finite element analysis is used to simulate the LMF distribution patterns. Experimental results show that when there is no coil misalignment, 97% of the LMF strength can be suppressed in a 1kW prototype. These results also show that the impact on efficiency is small. The trade-off between LMF suppression and efficiency is revealed, and a control strategy to balance these two objectives is presented.

• Asian Journal of Innovation and Policy
• /
• v.7 no.3
• /
• pp.489-510
• /
• 2018

Institution-based Technology Business Incubators are on the rise in India, as a means of promoting innovation-based tech start-up ecosystems, due to increased policy initiatives. Against this background, we have traced the origin and process of building a start-up ecosystem in IIT Madras, Chennai of India, based on semistructured interviews held with the stakeholders of the ecosystem. Subsequently, we have ascertained the key components of IIT Madras start-up ecosystem, and the process of incubation comprising pre-incubation, incubation and post-incubation phases. Finally, we have derived the key lessons from the ecosystem development experience and incubation process which enable generation of start-ups from both students and faculty, apart from alumni and ex-industry executives. Though this ecosystem model has emerged over a period of time through learning and experience, the ecosystem is able to generate more than 100 start-ups, majority of them being from students and faculty. Thus, the evolved start-up ecosystem of IIT Madras is able to generate faculty-supported and student-led entrepreneurship successfully.

• Structural Engineering and Mechanics
• /
• v.81 no.4
• /
• pp.513-522
• /
• 2022

Steel-concrete composite segments replacing the conventional reinforced concrete segments can provide the rectangular shield tunnel superiorities on bearing capacity, ductility and economy. A simplified model with high-efficiency on computation is proposed for investigating the nonlinear response of the rectangular tunnel lining composed of composite segments. The simulation model is developed by an assembly of nonlinear fiber beam elements and spring elements to express the transfer mechanism of forces through components of composite segments, and radial joints. The simulation is conducted with the considerations of material nonlinearity and geometric nonlinearity associated with the whole loading process. The validity of the model is evaluated through comparison of the proposed nonlinear simulation with results obtained from the full-scale test of the segmental tunnel lining. Furthermore, a parameter study is conducted by means of the simplified model. The results show that the stiffness of the radial joint at haunch of the ling and the thickness of inner steel plate of segments have remarkable influence on the behaviour of the lining.

• Bulletin of the Korean Mathematical Society
• /
• v.60 no.5
• /
• pp.1365-1374
• /
• 2023

Let F be a periodic singular fiber of genus g with dual fiber F^*, and let T (resp. T^*) be the set of the components of F (resp. F^*) by removing one component with multiplicity one. We give a formula to compute the determinant | det T | of the intersect form of T. As a consequence, we prove that | det T | = | det T^*|. As an application, we compute the Mordell-Weil group of a fibration f : S → ℙ¹ of genus 2 with two singular fibers.

• Progress in Superconductivity and Cryogenics
• /
• v.8 no.2
• /
• pp.1-10
• /
• 2006

This paper reviews the magnetic refrigeration technology that is a novel cooling method utilizing magnetic field to obtain low temperature. The key component of the refrigeration is a novel magnetic refrigerant which should possess sufficiently large magneto-caloric effect so that a pseudo-Carnot magnetic refrigeration cycle can cover reasonably large temperature span. Otherwise, a regenerative concept should be employed to expand the temperature span of the refrigeration cycle. There is a growing interest in magnetic refrigeration as a viable refrigeration technology not only for cryogenics as well as room temperature range. This paper covers historical developments, fundamental concepts, key components, application classification, and recent research trend of magnetic refrigerators.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.8
• /
• pp.1563-1579
• /
• 2024

More and more diterpenoids have attracted extensive attention due to the diverse chemical structures and excellent biological activities, and have been developed into clinical drugs or consumer products. The vast majority of diterpenoids are derived from plants. With the long-term development of plant medicinal materials, the natural resources of many plant diterpenoids are decreasing, and the biosynthetic mechanism of key active components has increasingly become a research hotspot. Using synthetic biology to engineer microorganisms into "cell factories" to produce the desired compounds is an essential means to solve these problems. In this review, we depict the plant-derived diterpenoids from chemical structure, biological activities, and biosynthetic pathways. We use representative plant diterpenes as examples to expound the research progress on their biosynthesis, and summarize the heterologous production of plant diterpenoids in microorganisms in recent years, hoping to lay the foundation for the development and application of plant diterpenoids in the future.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.04a
• /
• pp.97-104
• /
• 2000

Evaluating a Review-Level Ground Motion is a key to efficiently perform Seismic Margin Assessment of nuclear power plants whose purpose is to determine a ground motion level for which a plant has high-confidence-of-a-low-probability of seismic-induced core damage and to identify any weaker-link components. In this study a method to obtain RLGMs is reviewed which is recommended by Electric Power Research Institute and implemented to be applied to Limerick site in eastern and central U. S as a case study. This method provides reasonable and site-specific RLGMs as minimum required plant HCLPF for SMA that meet a target mean seismic core-damage frequency based on seismic hazard results and generic values of uncertainty and randomness parameters of the core-damage fragility curves. In addition high-frequency RLGM is justifiably modified to reflect the increased seismic capacity of high-frequency components and spatial variation and incoherence of input ground motion on a basemat of large structures by establishing a method to obtain high0-frequency reduction factors according to EPRI guidelines.

• Tribology and Lubricants
• /
• v.21 no.5
• /
• pp.227-235
• /
• 2005

This paper presents a tribological study on the failure cases of automatic transmission components in a passenger car. The automatic transmission system is composed of torque converter, clutch, brake, planetary gear, and valve body controlling oil pressure of an automatic transmission fluid. The most largest influence components in an automatic transmission are a torque converter and clutch plate in which are influenced by a wear and torque converting energy loss. The failure case study of an automatic transmission indicates that the tribological design and maintenance technologies should be considered as a key design concept. This means that the failure and power energy loss come from the friction, wear and a oil leakage of an automatic transmission, which is related to the oil seal and O-ring seal failures.

• Journal of Korean Institute of Industrial Engineers
• /
• v.38 no.3
• /
• pp.173-181
• /
• 2012

The size and layout of user interface components need to be optimally designed in terms of reachability, visibility, clearance, and compatibility in order for efficient and effective use of products. The present study develops an ergonomic design method which optimizes the size and layout of user interface components using adaptive genetic algorithm. The developed design method determines a near-optimal design which maximizes the aggregated score of 4 ergonomic design criteria (reachability, visibility, clearance, and compatibility). The adaptive genetic algorithm used in the present study finds a near-optimum by automatically adjusting the key parameter (probability of mutation) of traditional genetic algorithm according to the characteristic of current solutions. Since the adaptive mechanism partially helps to overcome the local optimality problem, the probability of finding the near-optimum has been substantially improved. To evaluate the effectiveness of the developed design method, the present study applied it to the user interface design for a portable wireless communication radio.

• BMB Reports
• /
• v.49 no.2
• /
• pp.81-92
• /
• 2016

Insulin/insulin-like growth factor (IGF)-1 signaling (IIS) pathway regulates aging in many organisms, ranging from simple invertebrates to mammals, including humans. Many seminal discoveries regarding the roles of IIS in aging and longevity have been made by using the roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster. In this review, we describe the mechanisms by which various IIS components regulate aging in C. elegans and D. melanogaster. We also cover systemic and tissue-specific effects of the IIS components on the regulation of lifespan. We further discuss IIS-mediated physiological processes other than aging and their effects on human disease models focusing on C. elegans studies. As both C. elegans and D. melanogaster have been essential for key findings regarding the effects of IIS on organismal aging in general, these invertebrate models will continue to serve as workhorses to help our understanding of mammalian aging.