• 대한전기학회논문지
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• 제39권2호
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• pp.149-156
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• 1990

In DC electric railway systems, the feeding currrnt is not permitted to flow backward in almost all the substations and the pantograph voltages at the regenerating cars rise extremely by the voltage drop of the resistance of the feeder line. In order to prevent the overrise of the pantograph voltage in power regenerating cars, the squeezing circuits for the regenerative current are equipped and this leads to double losses, which are an extra worn-out of the brake-shoes and an ineffective use of regenerative power. In this study, the insertion of resistors in the feeder line system is proposed as a possible method for the effective utilization of the regenerative power in the electric railways. Also it is investigated how the output voltages of substations affect the effective use of regenertive capability. The investigation results show that the energy savings and the reduction of the worn-out of the brake-shoe can be achieved at the same time by the insertion of resistors in the feeder line system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.784-787
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• 2002

The NURBS surfaces are widely employed for exchanging geometric models between different CAD/CAE systems. However if the input NURBS surfaces are poorly parameterized, most surface meshing algorithms may fail or the constructed meshes can be ill-conditioned. In this paper presents a new method is presented that can generate well conditioned meshes even on poorly parameterized NURBS surfaces by regenerating NURBS surfaces. To begin with, adequate Points are sample on original poorly parameterized surfaces and new surfaces are created by interpolating these points. And then. mesh generation is performed on new surfaces. With this method, models with poorly parameterized NURBS surfaces can be meshed successfully.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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• pp.47-49
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• 2003

Development of drug delivery systems has been recognized as one of portfolios to gain a competitive edge in pharmaceutical industry over 30 years. The application of drug delivery technologies offers pharmaceutical companies and patients several therapeutic benefits, including improving efficacy and adverse effect profiles, enhancing patient compliance and potentially regenerating unsuccessful drugs. (omitted)

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.196-198
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• 2007

In the substations for traction systems and the large-scale discharging system of secondary batteries, the voltage of DC bus line goes up by the regenerated energy and the energy is usually wasted in resistor for system stability. This paper proposes the DC power regenerating system using a three phase PWM inverter. The proposed system can regenerate the excessive DC power from DC bus line to AC supply and control the power factor of AC supply to unity. To implement unity power factor, the magnitude of the inverter output voltage should be higher than that of AC supply and therefore SVPWM technique is adopted. Computer simulations are carried out to verify the validity of the proposed system.

• Animal cells and systems
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• 제5권3호
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• pp.263-266
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• 2001

Metallothionein (MT) is induced in the regenerating rat liver. We have investigated expression of MT gene by RT PCR as well as specific localization of MT by immunocytochemistry in regenerating rat liver after partial hepatectomy (PH). MT mRNA level started to increase from 1 h and reached the peak at 8 h after PH. The level decreased gradually by 24 h, and became similar to that of control group. In the immunocytochemical study, in all groups treated with primary antibody, immunogold particles indicating the presence of MT were evenly distributed throughout both cytoplasm and nucleus of the rat hepatocytes. Within the nucleus, the gold particles appeared to be intensely localized in the areas of euchromatin and nucleolus. Within the cytoplasm, gold particles did not seem to adhere to mitochondria or Iysosomes, but were freely distributed. However, rough endoplasmic reticulum was the obvious compartment on which the gold particles were localized. Time course of MT immunoreactivity revealed that distribution of gold particles in hepatocytes increased gradually by 24 h, and decreased at 48 h after PH. Briefly, PH resulted in the sharpest increase in the expression of MT mRNA at 8 h and in the immunoreactivity of MT at 24 h, respectively. It is suggested that the increase of MT mRNA expression, the intensity of immunoreactivity and the specific localization of MT may be associated with the compensatory cell proliferation followed by PH.

• Animal cells and systems
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• 제14권2호
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• pp.73-81
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• 2010

In this study, monoclonal antibodies against lysosomal acid phosphatase (LAP) of a salamander, Hynobius leechii, were used to determine the spatial and temporal expression of the LAP in the regenerating limbs. The Western blot and immunohistochemical analysis in the limb regeneration revealed that LAP was highly expressed at the dedifferentiation stage, especially in the wound epidermis and dedifferentiating limb tissues such as muscle and cartilage. With RA treatment, the LAP expression became upregulated in terms of both level and duration in the wound epidermis, blastemal cell and dedifferentiating limb tissues. In addition, in situ activity staining of LAP showed a similar result to that of immunohistochemistry. Thus, the activity profile of LAP activity coincides well with the expression profile of LAP during the dedifferentiation period. Furthermore, to examine the effects of lysosomal enzymes including LAP on salamander limb regeneration, lysosome extract was microinjected into limb regenerates. Interestingly, when the lysosome extract was microinjected into limb regenerates with a low dose of RA($50\;{\mu}g/g$ body wt.), skeletal pattern duplication occurred frequently in the proximodistal and transverse axes. Therefore, lysosomal enzymes might cause the regenerative environment and RA plays dual roles in the modification of positional value as well as evocation of extensive dedifferentiation for pattern duplication. In conclusion, these results support the hypothesis that dedifferentiation is a crucial event in the process of limb regeneration and RA-evoked pattern duplication, and lysosomal enzymes may play important role(s) in this process.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.351-354
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• 2000

This paper deals with the voltage amplitude control in inverter systems which can regenerate the excessive DC power from DC bus line to AC supply in substations for traction systems. To maintain the magnitude of output fundamental voltage constant in spite of the variation of input DC voltage inverters are operated in symmetrical $\alpha$-conduction mode with the range of $120^{\circ}$<$\alpha$<$180^{\circ}$ To match the output voltage of the inverter systems with AC supply voltage harmonic reduction techniques are also investigated. Computer simulations are carried out to verify the validity of the proposed systems.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.96-104
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• 2004

본 논문에서는 전철시스템의 변전소에서 직류모선에 발생하는 잉여분의 직류전력을 교류전원 측으로 회생시킬 수 있는 직류전력 회생시스템을 제안한다. 제안된 직류 전철용 회생인버터 시스템은 인버터와 능동전력필터로 사용할 수 있다. 회생인버터 모드에서는 전철의 감속에 의해 회생되는 에너지를 재사용 할 수 있으며, 능동전력필터 모드에서는 변전소의 정류기에 의해 발생되는 고조파 왜곡을 보상하기 위해 사용할 수 있다. 전력용량과 스위칭 손실을 고려하여 시스템은 3상 PWM 인버터를 기반으로 설계되며 병렬인버터, 출력변압기와LCL필터로 구성된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권4호
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• pp.1182-1199
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• 2023

Fractional repetition (FR) codes can achieve exact uncoded repair for multiple failed nodes, with lower computational complexity and bandwidth overhead, and effectively improve repair performance in distributed storage systems (DSS). The actual distributed storage system is dynamic, that is, the parameters such as node storage overhead and number of storage nodes will change randomly and dynamically. Considering that traditional FR codes cannot be flexibly applied to dynamic distributed storage systems, a new construction scheme of adaptive-and-resolvable FR codes based on hypergraph coloring is proposed in this paper. Specifically, the linear uniform regular hypergraph can be constructed based on the heuristic algorithm of hypergraph coloring proposed in this paper. Then edges and vertices in hypergraph correspond to nodes and coded packets of FR codes respectively, further, FR codes is constructed. According to hypergraph coloring, the FR codes can achieve rapid repair for multiple failed nodes. Further, FR codes based on hypergraph coloring can be generalized to heterogeneous distributed storage systems. Compared with Reed-Solomon (RS) codes, simple regenerating codes (SRC) and locally repairable codes (LRC), adaptive-and-resolvable FR codes have significant advantages over repair locality, repair bandwidth overhead, computational complexity and time overhead during repairing failed nodes.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권2호
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• pp.91-97
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• 2012

This paper presents a state space model of a two quadrant chopper and PWM inverter-fed Interior Permanent Magnet Synchronous Motor (IPMSM) drive system and its application to hybrid vehicles. The drive system has two different state equations for motoring and regenerating action. This paper presents a common state equation by using State Space Averaging method. Using this model of the IPMSM drive system, detailed simulation and controller design of the drive system, including PWM inverter switching, are given. The validity of this model and usefulness, according to a comparison among Maximum Torque/Ampere control, Maximum Torque/Flux control, and Maximum Efficiency optimization, are confirmed from simulation results.