• East Asian mathematical journal
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• v.24 no.1
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• pp.45-55
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• 2008

We consider an M/G/1 queue with $P^M_{\lambda}$-service policy, which is a two-stage service policy. The server starts to serve with rate 1 if a job arrives to the sever in idle state. If the workload of the system upcrosses $\lambda$, then the service rate is changed to M and this rate continues until the system is empty. It costs to change the service rate to M and maintaining the rate. When the expectation of the stationary workload is supposed to be less than a given value, we derive the optimal value of M.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.10
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• pp.2171-2180
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• 1997

In this paper, we proposed a MAC protocol called P/S-DCA that using dynamci channel allocation scheme for supports the multimedia traffic in wireless ATM, and analysis theoretically the throughput and delay of up/down link according to varying the down traffic load. To evaluate and the dynamic channel allocation scheme, simulations are executed with varying down traffic load. The results are proved that system capacity is improved better than PRMA and C-PRAM. The system capacity, denoting by $M_{0.01}$, is defined as the maximum number of conversations which can be supported under constraint of packet dropping probability no more than 1%. It is shown that the values of $M_{0.01}$ for ${\lambda}_{d}=0.5,\;{\lambda}_{d}=0.2\;{\lambda}_{d}=0.1\;{\lambda}_{d}=0.001$ are about 43, 69, 77 and 83, respectively. This indicates that P/S-DCA protocol achieves a significant improvement in system capacity relative to PRMA and C-PRMA protocol.

• BMB Reports
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• v.38 no.1
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• pp.97-103
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• 2005

Under the condition of expression of $\lambda$ P protein at lethal level, the oriC DNA-binding activity is significantly affected in wild-type E. coli but not in the rpl mutant. In purified system, the $\lambda$ P protein inhibits the binding of both oriC DNA and ATP to the wild-type DnaA protein but not to the rpl DnaA protein. We conclude that the $\lambda$ P protein inhibits the binding of oriC DNA and ATP to the wild-type DnaA protein, which causes the inhibition of host DNA synthesis initiation that ultimately leads to bacterial death. A possible beneficial effect of this interaction of $\lambda$ P protein with E. coli DNA initiator protein DnaA for phage DNA replication has been proposed.

• Journal of the Korean Mathematical Society
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• v.44 no.4
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• pp.863-872
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• 2007

Let D be an integral domain with quotient field K, A a nonempty set of height-one maximal t-ideals of D, F$({\Lambda})={I{\subseteq}D|I$ is an ideal of D such that $I{\subseteq}P$ for all $P{\in}A}$, and $D_F({\Lambda})={x{\in}K|xA{\subseteq}D$ for some $A{\in}F({\Lambda})}$. In this paper, we prove that if each $P{\in}A$ is the radical of a finite type v-ideal (resp., a principal ideal), then $D_{F({\Lambda})}$ is a weakly Krull domain (resp., generalized weakly factorial domain) if and only if the intersection $D_{F({\Lambda})}={\cap}_{P{\in}A}D_P$ has finite character, if and only if $F({\Lambda})$ is a t-splitting set of ideals, if and only if $F({\Lambda})$ is v-finite.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.95-101
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• 2016

In this paper, miniaturized ${\lambda}/4$ folded microstrip antennas is presented for parking monitoring base station system. The proposed antenna reduced a width of the radiating element for miniaturizing a size and we changed an aperture such as folded shape for reducing a length of the antenna by the pertubation effect by reducing a width of the antenna. Finally, the ${\lambda}/2$ length of the folded microstrip antenna to ${\lambda}/4$ folded microstrip antenna was miniaturized by reducing the length. The proposed antenna was designed to receive 425 MHz of center frequency that can be used without permission. Dimensions are $134mm{\times}143.85mm{\times}20.1mm$($0.19{\lambda}{\times}0.2{\lambda}{\times}0.028{\lambda}$, ${\lambda}$ is wavelength at 425 MHz) that are compared with basic microstrip patch antenna miniaturized 97.2%. Also, Measured -10 dB bandwidth was 2.44 MHz(0.57%). On the other hand, measured radiation patterns was 1.82 dBi at E-plane $15^{\circ}$.

• Proceedings of the Korean Statistical Society Conference
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• 2003.10a
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• pp.189-194
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• 2003

We consider an M/G/1 queueing system under P$_{\lambda}^{M}$-service policy. As soon as the workload exceeds threshold ${\lambda}$ > 0, the service rate is increased from 1 to M ${\geq}$ 1 and is kept until the system becomes empty. After assigning several costs, we show that there exists a unique M minimizing the long-run average cost per unit time.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.44 no.3
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• pp.270-273
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• 1995

This paper proposes an optimal load shedding algorithm by which the system loss can be minimized when the load shedding is unavoidable in case of severe contingency such as the outage of key generators or lines. Shedding load .DELTA.S = .DELTA.P + J.DELTA.Q(MVA) is performed on the weakest bus (on the view of voltage stability), step by step, by the priority of the I.DELTA. = SQRT(.lambda.$\_$P/$\^$2/ + .lambda.$\_$Q/$\^$2/) index given for each load bus, where .lambda.$\_$P/ and .lambda.$\_$Q/ are the sensitivity indices representing the system loss variation versus active and reactive power change of the bus load bus. All loads are assumed to be constant power loads for convenience. A 5 bus sample system proves the effectiveness of the algorithm proposed.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1057-1067
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• 2010

Vibration and noise analysis as well as strength of gear teeth, gear profile design are considered in order to develop the multi-gear train devices of synchro system for the guns of a warship. A new approach to the critical speed calculation of practical industrial multi-mesh geared system is presented. A transfer matrix model based on Hibner's branch method is developed and the natural properties of the branched rotor system are calculated with using the ${\lambda}$-matrix formulation. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered, shows that, at theoperating speed, there are not the critical speed.

• 한국데이터정보과학회:학술대회논문집
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• 2005.04a
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• pp.25-29
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• 2005

We analyze an M/G/1 queueing system under $P_{\lambda,\tau}^M$ service policy. By using the level crossing theory and solving the corresponding integral equations, we obtain the stationary distribution of the workload in the system explicitly.

• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.531-537
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• 2001

In order for all participants at video conference to communicate mutually, the conference key should be necessary. In this paper, we present the communication protocol that generates a conference key efficiently based on $(\upsilon,\kappa,\lambda)$-configuration, one class of block designs, which minimizes message transmission overhead needed for this key. Especially, in the case of ${\lambda}=1$, the protocol requires only $O(\sqrt[v]{v})$ messages, where v is the number of participants.