• Title/Summary/Keyword: MBDA

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Synthesis and Properties of Novel Flame Retardant Poly(butylene terephthalate)

  • Park Jong Min;Park Yun Heum
    • Macromolecular Research
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    • v.13 no.2
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    • pp.128-134
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    • 2005
  • The phosphorus comonomer [(6-oxido-6H-dibenz<1,2>oxaphosphorin-6-yl)methyl]-methyl butane-dioate (DOP-MBDA) was synthesized through the addition reaction of dimethyl itaconate (DMI) with 9,10-dihydro­9-oxa-10-phosphaphenan threne-10-oxide (DOP). A series of novel flame retardant poly(butylene terephthalate)s (PBTs) containing different amounts of phosphorus were prepared using DOP-MBDA as a comonomer. These novel polymers were characterized by $^{1}H-NMR$, IR, and differential scanning calorimetry (DSC). The novel phosphorus­containing poly(butylene terephthalate)s, referred to as FR-PBTs, exhibited interesting thermal and mechanical behavior, as well as superior flame retardancy. These properties are attributed to the effect of incorporating the rigid structure of DOP-MBDA and the pendant phosphorus group into the poly(butylene terephthalate) (PBT) homopolymer. The UL 94-V2 rating could be achieved with this novel flame retardant PBT, which has a phosphorus content as low as $0.5 wt\%$, and the FR-PBTs emitted less fumes and toxic gases than the PBT homopolymer.

Consideration of Frequency Dependent Complex Stiffness of Rubber Busings in Transmission Force Analysis of a Vehicle Suspension System (고무 부싱의 주파수 의존 복소 강성을 고려한 차량 현가 장치에서의 전달력 분석)

  • 이준화;김광준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.34-39
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    • 1998
  • In order to compute the forces which are transmitted through rubber bushings with a commercial multibody dynamic analysis (MBDA) program, a rubber bushing model is needed. The rubber bushing model of MBDA programs such as DADS or ADAMS is the Voigt model which is simply a parallel spring-viscous damper system, meaning that the damping force of the Voigt model is proportional to the frequency. However, experiments do not necessarily support this proportionality. Alternatively, the viscoelastic characteristics of rubber bushings can be better represented by the complex stiffness. The purpose of this paper is to develop a viscoelastic rubber bushing model for the MBDA programs. Firstly, a methodology is proposed to calculate the complex stiffness of rubber bushings considering static and dynamic load conditions. Secondly, a viscoelastic rubber bushing model developed which uses standard elements provided by DADS. The proposed methods are applied to the rubber bushings of the lower control arms of a rear suspension of a 1994 Ford Taurus model. Then, the forces computed for the rubber bushing model are analyzed and compared with the Voigt model in time and frequency domains.

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Relay Assignment in Cooperative Communication Networks: Distributed Approaches Based on Matching Theory

  • Xu, Yitao;Liu, Dianxiong;Ding, Cheng;Xu, Yuhua;Zhang, Zongsheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.11
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    • pp.5455-5475
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    • 2016
  • In this article, we model the distributed relay assignment network as a many-to-one matching market with peer effects. We discuss two scenarios for throughput optimization of relay networks: the scenario of aggregate throughput optimization and the scenario of fairness performance optimization. For the first scenario, we propose a Mutual Benefit-based Deferred Acceptance (MBDA) algorithm to increase the aggregate network throughput. For the second scenario, instead of using the alternative matching scheme, a non-substitution matching algorithm (NSA) is designed to solve the fairness problem. The NSA improves the fairness performance. We prove that both two algorithms converge to a globally stable matching, and discuss the practical implementation. Simulation results show that the performance of MBDA algorithm outperforms existing schemes and is almost the same with the optimal solution in terms of aggregate throughput. Meanwhile, the proposed NSA improves fairness as the scale of the relay network expands.

Cloning of Reverse Transcriptase Gene of Avian Sarcoma Virus (역전사효소(逆轉寫酵素) 유전자(遺傳子)의 cloning 에 관(關)한 연구(硏究))

  • Kim, Yong-Woong;Kim, Kwang-Sik;Suh, Yong-Tack;Guntaka, R.V.
    • Applied Biological Chemistry
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    • v.31 no.3
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    • pp.219-225
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    • 1988
  • Reverse transcriptase gene of Avian sarcoma virus(ASV) was cloned with a thermoinducible expression vector, pPL-lambda. E. coli N4830 which carries temperature sensitive cI857 la mbda repressor, was transformed with this pPL-pol plasmid DNA. The RNA transcribed by those tranoformants was isolated and analyzed. It was shown that the inserted reverse transcriptase gene of ASV was transcribed at high-level when cells were grown at high temperature.

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Conditional sojourn time distributions in M/G/1 and G/M/1 queues under PMλ-service policy

  • Kim, Sunggon
    • Communications for Statistical Applications and Methods
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    • v.25 no.4
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    • pp.443-451
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    • 2018
  • $P^M_{\lambda}$-service policy is a workload dependent hysteretic policy. The policy has two service states comprised of the ordinary stage and the fast stage. An ordinary service stage is initiated by the arrival of a customer in an idle state. When the workload of the server surpasses threshold ${\lambda}$, the ordinary service stage changes to the fast service state, and it continues until the system is empty. These service stages alternate in this manner. When the cost of changing service stages is high, the hysteretic policy is more efficient than the threshold policy, where a service stage changes immediately into the other service stage at either case of the workload's surpassing or crossing down a threshold. $P^M_{\lambda}$-service policy is a modification of $P^M_{\lambda}$-policy proposed to control finite dams, and also an extension of the well-known D-policy. The distributions of the stationary workload of $P^M_{\lambda}$-service policy and its variants are studied well. However, there is no known result on the sojourn time distribution. We prove that there is a relation between the sojourn time of a customer and the first up-crossing time of the workload process over the threshold ${\lambda}$ after the arrival of the customer. Using the relation and the duality of M/G/1 and G/M/1 queues, we obtain conditional sojourn time distributions in M/G/1 and G/M/1 queues under the policy.