• Title/Summary/Keyword: Serial Properties

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New Battery Balancing Circuit using Magnetic Flux Sharing

  • Song, Sung-Geun;Park, Seong-Mi;Park, Sung-Jun
    • Journal of Power Electronics
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    • v.14 no.1
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    • pp.194-201
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    • 2014
  • To increase the capacity of secondary cells, an appropriate serial composition of the battery modules is essential. The unbalance that may occur due to the series connection in such a serial composition is the main cause for declines in the efficiency and performance of batteries. Various studies have been conducted on the use of a passive or active topology to eliminate the unbalance from the series circuit of battery modules. Most topologies consist of a complex structure in which the Battery Management System (BMS) detects the voltage of each module and establishes the voltage balancing in the independent electrical power converters installed on each module by comparing the module voltage. This study proposes a new magnetic flux sharing type DC/DC converter topology in order to remove voltage unbalances from batteries. The proposed topology is characterized by a design in which all of the DC/DC convertor outputs connected to the modules converge into a single transformer. In this structure, by taking a form in which all of the battery balancing type converters share magnetic flux through a single harmonic wave transformer, all of the converter voltages automatically converge to the same voltage. This paper attempts to analyze the dynamic properties of the proposed circuit by using a Programmable Synthesizer Interface Module (PSIM), which is useful for power electronics analysis, while also attempting to demonstrate the validity of the proposed circuit through experimental results.

Implementation of a New Parallel Spherical 3-Degree-of-Freedom Mechanism With Excellent Kinematic Characteristics (우수한 기구학 특성을 가지는 새로운 병렬형 구형 3자유도 메커니즘의 구현)

  • 이석희;김희국;오세민;이병주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.299-303
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    • 2004
  • In our pervious paper, a new parallel-type spherical 3-degree-of-freedom mechanism consisting of a two-degree-of-freedom parallel module and a serial RRR subchain was proposed[1]. In this paper, its improved version is suggested and implemented. Differently from the previous 3-dof spherical mechanism, gear chains are incorporated into the current version of the mechanism to drive the distal revolute joint of the serial subchain from the base of the mechanism and in fact, the modification significantly improves kinematic characteristics of the mechanism within its workspace. Firstly, after a brief description on its structure, the closed-form solutions of both the forward and the reverse position analysis are derived. Secondly, the first-order kinematic model of the mechanism for the inputs which are assumed to be located at the base is derived. Thirdly, through the simulations of the kinematic analysis via. kinematic isotropic index, it is confirmed that the mechanism has much more improved isotropic properties throughout the workspace of the mechanism than the previous mechanism in [1]. Lastly, the proposed mechanism is implemented to verify the results from this analysis.

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Comparative properties for serial-parallel connection of DSC with CNT and pt counter electrodes (CNT와 Pt 상대전극을 가지는 염료감응형 태양전지의 직렬 ${\cdot}$ 병렬 연결에 따른 특성비교)

  • Choi, Jin-Young;Hong, Ji-Tae;Kim, Mi-Jeong;Lee, Yong-Chul;Kim, Hee-Je
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.335-338
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    • 2007
  • Cost effectiveness is an important parameter for producing DSSCs as compared to the widely used conventional silicon based solar cells. A fluorine-doped tin oxide (FTO) substrate coated with a catalytic amount of platinum is used as counter electrode in dye-sensitized solar cell. Carbonaceous materials are quite attractive to replace platinum due to their high electronic conductivity, corrosion resistance towards $I_{2}$, good catalytic effect and low cost. In this paper, the unit DSSCs with Pt and CNT as a counter electrode were connected in series-parallel externally, then the current-voltage curves were investigated to find out the connection characteristics of the DSSC with CNT counter electrode. The connection characteristics of the DSSC with CNT counter electrode is superior to that of the DSSC with Pt counter electrode. And a parallel connection of the DSSC with CNT counter electrode has higher efficiency than a series connection of that.

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Development and Application of Porous Superelastic TiNi Materials for Medical Implants

  • Gjunter, V.E.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 1998.10b
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    • pp.7-7
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    • 1998
  • Research activities of Russian Medical Engineering Center and Institute of Medical Materials of Shape Memory Alloys and Implants are presented as follows: ${\bullet}$ The direction of elaboration of porous shape memory alloys for medicine. ${\bullet}$ Medical and technical requirements and physical and mechanical criteria of porous shape memory implants elaboration. ${\bullet}$ Basic laws of heat-, stress- and strain-induced changes of mechanical properties, shape memory effect and superelasticity in porous TiNi-based alloys. ${\bullet}$ Methods of regulation of shape memory effect parameters in porous alloys and methods for controlling the regulation-induced changes of physical and mechanical properties. ${\bullet}$ Original technologies of elaboration of porous alloys In various fields of medicine. ${\bullet}$ Arrangement of serial production of shape memory porous implants and examples of their medical use.

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Synthesis and in Vitro Antimicrobial Evaluation of Benzothiazole Incorporated Thiazolidin-4-ones Derivatives

  • Agarwal, Shikha;Agarwal, Dinesh Kumar;Gautam, Naveen;Agarwal, Kshamta;Gautam, Dinesh Chandra
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.33-38
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    • 2014
  • In the course of work on new pharmacologically active antimicrobial agents, we have reported the synthesis of a new class of structurally novel derivatives, incorporating two bioactive structures, a benzothiazole and thiazolidin-4-one, to yield a class of compounds having interesting antimicrobial properties. The antimicrobial properties of the synthesized compounds were investigated against bacteria (Staphylococcus aureus and Escherchia coli) and fungi (Candida albicans and Aspergillus niger) using serial plate dilution method. The structure of the synthesized compounds have been established by elemental analysis and spectroscopic data.

Plyometric Exercises (프라이오메트릭 운동)

  • Choi, Byung-Ok
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.3 no.1
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    • pp.29-42
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    • 1997
  • The theory of plyometric exercise was introduced by Soviet Jump Coach Yuri Verhoshanski in 1967. Plyo comes from the Greek word pleythein, which means to increase. Plyo is the Greek word for "more", while metric means "to measure". The practical definition of plyometrics is a quick powerful movement involving a prestretching or countermovement that activates the stretch-shortening cycle. The purpose of plyometric training is to heighten the excitability of the nervous system for improved reactive ability of the neuromuscular system. The success of plyometric exercise is based on the utilization of the serial elastic properties and stretch-reflex properties of the muscle.

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Micro-mechanical FE Analysis of Dual-phase Steels (미세조직이 고려된 이상 조직강의 유한 요소 해석)

  • Ha, J.;Lee, J.W.;Kim, J.H.;Barlat, F.;Lee, M.G.
    • Transactions of Materials Processing
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    • v.24 no.3
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    • pp.194-198
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    • 2015
  • Microstructure based FE simulations were conducted to investigate the micro-mechanical properties of ferrite-martensite dual-phase steels. The FE model was built based on real microstructure images which were characterized by optical microscopy through the thickness direction. Serial sectioned 2D images were converted into semi-2D representative volume elements (RVEs) model. Each RVE model was subjected to a non-proportional loading condition and the mechanical response was analyzed on both the macroscopic and microscopic levels. Macroscopically, stress-strain curves were described under tension-compression and tension-orthogonal tension conditions and the Bauschinger effect was well captured for both loading paths. In addition, micromechanical properties were investigated in the view of stress-strain partitioning and strain localization during monotonic tension.

3D Printing-Based Ultrafast Mixing and Injecting Systems for Time-Resolved Serial Femtosecond Crystallography (시간 분해 직렬 펨토초 결정학을 위한 3차원 프린팅 기반의 초고속 믹싱 및 인젝팅 시스템)

  • Ji, Inseo;Kang, Jeon-Woong;Kim, Taeyung;Kang, Min Seo;Kwon, Sun Beom;Hong, Jiwoo
    • Korean Chemical Engineering Research
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    • v.60 no.2
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    • pp.300-307
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    • 2022
  • Time-resolved serial femtosecond crystallography (TR-SFX) is a powerful technique for determining temporal variations in the structural properties of biomacromolecules on ultra-short time scales without causing structure damage by employing femtosecond X-ray laser pulses generated by an X-ray free electron laser (XFEL). The mixing rate of reactants and biomolecule samples, as well as the hit rate between crystal samples and x-ray pulses, are critical factors determining TR-SFX performance, such as accurate image acquisition and efficient sample consumption. We here develop two distinct sample delivery systems that enable ultra-fast mixing and on-demand droplet injecting via pneumatic application with a square pulse signal. The first strategy relies on inertial mixing, which is caused by the high-speed collision and subsequent coalescence of droplets ejected through a double nozzle, while the second relies on on-demand pneumatic jetting embedded with a 3D-printed micromixer. First, the colliding behaviors of the droplets ejected through the double nozzle, as well as the inertial mixing within the coalesced droplets, are investigated experimentally and numerically. The mixing performance of the pneumatic jetting system with an integrated micromixer is then evaluated by using similar approaches. The sample delivery system devised in this work is very valuable for three-dimensional biomolecular structure analysis, which is critical for elucidating the mechanisms by which certain proteins cause disease, as well as searching for antibody drugs and new drug candidates.

Smoke Control Performance of a Serial Structure Using "CONTAM" (CONTAM을 이용한 직렬형태 구조의 제연성능 구현에 관한 연구)

  • Kim, Mi-Seon;Seo, Dong-Gil;Gu, Seon-Hwan;Yoo, Young-Min;Song, Young-Joo
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.53-62
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    • 2019
  • A recent trend shows that more buildings are being constructed as mixed-use (residential and commercial) properties for efficient land use. This has led to an increased frequency in the occurrence of fires and the associated potential risks. In particular, in case of high-rise apartments, at least one of the elevators in each building is installed for evacuation purposes separately from the emergency elevator; therefore, for a combined ancillary room and emergency elevator platform situation, the structure is inevitably in series with the evacuation elevator platform. Thus, a proposal for a new type of ventilation zone based on existing national fire safety codes is required to achieve smoke control performance. To this end, the air egress velocity and differential pressure of each ventilation zone are checked using the "CONTAM" software; further, an alternative is proposed to secure smoke control performance for series structures.

The Stochastic Hydrological Analysis for the Discharge of River Rhine at Lobith (For River Rhine at Lobith in the Netherlands) (라인강 유량의 추계학적 수문분석에 관한 연구 (네덜란드의 Lobith지점을 중심으로))

  • 최예환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.23 no.4
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    • pp.46-52
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    • 1981
  • The aim at this study has the stochastic hydrological analysis for the annual mean discharge and monthly discharge which were observed at Lobith of River Rhine in the Netherlands from 1901 to 1972. After this study was analysed by computer IBM 370 and Hewlett Parkard 9800, the results were as follows; 1.When 72 data was divided into two groups of subsample data as 36 data, they do not have their properties to be non-homogeneous and inconsistent due to F-test and t-test. 2.The credit limits of the serial correlation coefficient was fluctuated $\pm$0. 231 which was shown in Fig. 3. at significant level 99% by Anderson's test. 3.The correlogram at short term was shown to be no short-term persistence as Fig. 3. 4.Since the correlogram at long term has displayed that Hurst's coefficient was 0.6144 between 0.6 and 0.7, it was to be no long-term persistence. 5.The stochastic model with annual discharge of this River Rhine was shown with $\chi$t=2195+483. 8 $\varepsilon$t as $\chi$t=$\mu$+oet and $\varepsilon$t=$_1$ø$\varepsilon$t-$_1$+ζt where t=1,2,3,..., ζt is an independent series with mean zero and variance (1-ø2), $\varepsilon$t is the dependent series, and 4' is the parameter of the model. 6.The serial correlation coefficient of monthly discharge was explained as $\chi$$_1$ = 0.34 . sin(6-$\pi$t+$\pi$) as Fig.4. and the River Rhine has no large fluctuation and smoothly changed during that time.

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