• 제목/요약/키워드: Hierarchical cell

검색결과 160건 처리시간 0.022초

Simulation of Dynamic Behavior of Glucose- and Tryptophan-Grown Escherichia coli Using Constraint-Based Metabolic Models with a Hierarchical Regulatory Network

  • Lee Sung-Gun;Kim Yu-Jin;Han Sang-Il;Oh You-Kwan;Park Sung-Hoon;Kim Young-Han;Hwang Kyu-Suk
    • Journal of Microbiology and Biotechnology
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    • 제16권6호
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    • pp.993-998
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    • 2006
  • We earlier suggested a hierarchical regulatory network using defined modeling symbols and weights in order to improve the flux balance analysis (FBA) with regulatory events that were represented by if-then rules and Boolean logic. In the present study, the simulation results of the models, which were developed and improved from the previou model by incorporating a hierarchical regulatory network into the FBA, were compared with the experimental outcome of an aerobic batch growth of E. coli on glucose and tryptophan. From the experimental result, a diauxic growth curve was observed, reflecting growth resumption, when tryptophan was used as an alternativee after the supply of glucose was exhausted. The model parameters, the initial concentration of substrates (0.92 mM glucose and 1 mM tryptophan), cell density (0.0086 g biomass/1), the maximal uptake rates of substrates (5.4 mmol glucose/g DCW h and 1.32 mmol tryptophan/g DCW h), and lag time (0.32 h) were derived from the experimental data for more accurate prediction. The simulation results agreed with the experimental outcome of the temporal profiles of cell density and glucose, and tryptophan concentrations.

State-Dependent Call Admission Control in Hierarchical Wireless Multiservice Networks

  • Chung Shun-Ping;Lee Jin-Chang
    • Journal of Communications and Networks
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    • 제8권1호
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    • pp.28-37
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    • 2006
  • State-dependent call admission control (SDCAC) is proposed to make efficient use of scarce wireless resource in a hierarchical wireless network with heterogeneous traffic. With SDCAC, new calls are accepted according to an acceptance probability taking account of not only cell dwell time but also call holding time and system state (i.e., occupied bandwidth). An analytical method is developed to calculate performance measures of interest, e.g., new call blocking probability, forced termination probability, over. all weighted blocking probability. Numerical results with not only stationary but nonstationary traffic loads are presented to show the robustness of SDCAC. It is shown that SDCAC performs much better than the other considered schemes under nonstationary traffic load.

소프트 핸드오프를 갖는 CDMA 계층구조 셀룰러 시스템의 Erlang 용량과 호 차단확률 (Erlang Capacity and Call Blocking Probability of CDMA Hierarchical Cellular Systems with Soft Handoff)

  • 성봉훈;오현석;한재충
    • 대한전기학회논문지:시스템및제어부문D
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    • 제49권8호
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    • pp.481-490
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    • 2000
  • This paper analyzes interference power, Erlang capacity, the number of handoff occurrences, and call blocking probability with respect to the cell radius, the soft handoff region, and the mobile's velocity in a CDMA hierarchical cellular system. The microcell cellular system has the higher Erlang capacity than the macrocell cellular system. However, the microcell cellular system, which has a high system capacity through frequency reuse has the call blocking probability higher than macrocell cellular system. Also the interference power and the call blocking probability are decreased with the operation of soft handoff. Therefore, this paper presents the optimization of soft handoff region so as to maximize system's Erlang capacity with the low the call blocking probability according to mobile's velocity in the CDMA hierarchial cellular system.

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배선 전용 영역을 이용한 계층적 배치 (Hierarchical placement with routing region assignment)

  • 김원종;신현철
    • 전자공학회논문지A
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    • 제32A권2호
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    • pp.130-139
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    • 1995
  • A hierarchical placement system based on routing region assignment has been developed to increase the probability of routing completion after placement. While most of the existing placement systems attempt to reduce the cell density at the portions where routing density is high, our method is distinguished in that specific routing regions are allocated to secure complete routing where the routing density is greater than the routing capacity. Hierarchy is vuilt by clustering and recursive paritioning, and the initial placement obtained by partitioning at each level is improved by using the region refinement algorithm. After placement at each hierarchical level, global routing is performed and fouting regions are assigned, if routing density is greater than routing capacity, to be considered at the next level of placement. the proposed algorithm has been implemented and applied to place several industrical gate-array circuits. A couple of circuits which cannot be routed by using conventional placement techniques can be completely routed by using our new placement technique with routing region assignment.

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Dwell Time에 따른 계층 셀룰라 시스템의 성능 분석 (The Performance Analysis of Hierarchical Cellular System According to Dwell Time)

  • 성홍석;원영진;윤기방
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2007년도 하계종합학술대회 논문집
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    • pp.471-472
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    • 2007
  • At this paper, we use non reversible hierarchical scheme and fixed channel assignment scheme at the hierarchical cellular system with macrocell and microcell for the call process strategy Using this strategy, we analyze the system performance in accordance with the various dwell time at each cell. In this simulation result, the more the dwell time is small at microcell, the more the blocking probability and the handover failure probability is low.

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Baicalin을 처리한 HL-60 백혈병 세포주에서 대규모 유전자 분석 발현 연구 (Studies on Gene Expression of baicalin treated in HL-60 cell line using High-throughput Gene Expression Analysis Techniques)

  • 김봉주;차민호;전병훈;윤용갑;윤유식
    • 동의생리병리학회지
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    • 제18권5호
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    • pp.1291-1300
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    • 2004
  • Baicalin, a biologically active flavonoid form the roots of Scutallaria baicalensis (Skullcap), have been reported to not only function as anti-oxidants but also cause anticancer effect. We investigated the mechanism of baicalin-induced cytotoxicity and the macro scale gene expression analysis in leukemia cell line, HL-60 cells. Baicalin (10 μM) were used to treat the cells for 6h, 12h, 24h, 48h and 72h. In a human cDNAchip study of 65,000 genes evaluated 6, 12, 24, 48. 72 hours after treated with Baicalin in HL-60 cells. Hierarchical cluster against the genes which showed expression changes by more than two fold. One hundred one genes were grouped into 6 clusters according to their profile of expression by a hierarchical clustering algorithm. For genes differentially expressed in response to baicalin treatment, we tested functional classes based on Gene Ontology (GO) terms. This study provides the most comprehensive available survey of gene expression changes in response to baicalin treatment in HL-60 cell line.

Joint User Association and Resource Allocation of Device-to-Device Communication in Small Cell Networks

  • Gong, Wenrong;Wang, Xiaoxiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권1호
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    • pp.1-19
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    • 2015
  • With the recent popularity of smart terminals, the demand for high-data-rate transmission is growing rapidly, which brings a new challenge for the traditional cellular networks. Both device-to-device (D2D) communication and small cells are effective to improve the transmission efficiency of local communication. In this paper, we apply D2D communication into a small cell network system (SNets) and study about the optimization problem of resource allocation for D2D communication. The optimization problem includes system scheduling and resource allocation, which is exponentially complex and the optimal solution is infeasible to achieve. Therefore, in this paper, the optimization problem is decomposed into several smaller problems and a hierarchical scheme is proposed to obtain the solution. The proposed hierarchical scheme consists of three steps: D2D communication groups formation, the estimation of sub-channels needed by each D2D communication group and specific resource allocation. From numerical simulation results, we find that the proposed resource allocation scheme is effective in improving the spectral efficiency and reducing the outage probability of D2D communication.

카오스 신경회로망에서의 정보의 인코딩 해석 (Analysis of information encoding in a chaotic neural network)

  • 여진경
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2002년도 춘계학술대회 논문집
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    • pp.367-371
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    • 2002
  • I construct a chaotically driven contraction system having some analogy with the information transfer mechanism in the brain system especially from CA1 cell to CA3 cell known from the empirical result. And I consider the properties of the response system on a state space according to the external input into the drive neuron by observing the fractal hierarchical structure. Then I induce the relation between the information about state transition of the chaotic time series and the spatial information on a fractal attractor to confirm the possibility of encoding of time series data to spatial information.

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