• 한국경영과학회지
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• 제22권4호
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• pp.173-182
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• 1997

In this paper, an efficient dynamic channel assignment scheme is suggested, which consists of two types of channel allocation strategies : ordinary channel allocation strategy and channel reallocation strategy. An analysis on the handoff probabilities of handoff and new calls is also performed, and using the analyzed handoff probability, the presented scheme is compared with other existing schemes in terms of three types of blocking probabilities- new call blocking probability, handoff call blocking probability, and network blocking probability (incomplete service probability). Simulation results show that the presented scheme significantly reduces those blocking probabilities over the existing schemes. Furthermore, the scheme has much smaller number of reallocation than other schemes.

• 한국위성정보통신학회논문지
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• 제11권4호
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• pp.21-26
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• 2016

PPS 소자가 삽입된 N형 실리콘 제어 정류기(NSCR_PPS) 소자에서 채널차단영역의 이온주입 변화가 정전기 보호 성능에 미치는 영향을 연구하였다. 종래의 NSCR 표준소자는 on 저항, 스냅백 홀딩 전압 및 열적 브레이크다운 전압이 너무 낮아 마이크로칩의 정전기보호소자로 적용이 어려웠다. 그러나 본 연구에서 제안하는 채널 차단 영역의 이온주입 조건을 변화시켜 각각 변형설계된 소자에서는 채널 차단 이온주입이 정전기 보호성능의 향상에 영향을 주는 중요한 파라미터였으며, CPS_PDr+HNF 구조의 변형소자는 정전기보호소자의 설계창을 만족시키는 향상된 정전기보호성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 한국경영과학회지
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• 제25권1호
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• pp.85-92
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• 2000

Channel management is critical in designing a cellular mobile system that offers high capacity and high quality. In this paper, an integrated channel management scheme is proposed, which consists of a dynamic channel allocation scheme and an admission control scheme. The dynamic channel allocation scheme allocates a call request the channel which minimizes the impact on its interfering cell, and consists of two types of channel allocation strategies : nominal channel allocation strategy and non-nominal channel allocation strategy. The admission control scheme named the variable cutoff priority scheme reserves some frequency channels for handoff cells in each cell the number of which varies according to the blocking probability of handoff class in that cell. Computationl tests are performed to evaluate the performance of the proposed scheme in terms of overall blocking probability, defined by the weighted value of the blocking probabilities of new calls and handoff calls. The results show that the proposed scheme yields better performance than other compared schemes.

• 한국정보처리학회논문지
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• 제6권3호
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• pp.692-698
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• 1999

이 논문에서는 CDMA(C여e Division Multiple Access) 셀롤러 시스템에서 전력할당개념 (Power Allocation Concept)을 이용한 채널할당기법(Channel Assignment Scheme)을 제안하였다. 또한, 제안한 기법의 성능을 분석한 후 고정 전력할당을 이용한 채널할당기법의 성능과 서로 비교하였다. 제안한 기법에서는 순방향링크(Forward Link)에서 인접 셀(Neighbor Cells) 의 트래픽 부하 및 트래픽 분포 패턴에 따라 적용적으로 전력을 할당한다 제안한 기법에 대한 분석결과, 전체 호 블럭킹 확률(Call Blocking Probability: Pr)은 물리적인 채널의 수($C_{th}$)가 30인 경우에 고갈 확률(Outage Probability: Po)보다 블럭킹 확률(Blocking Probability : $P_B$)에 더 의존적이라는 사실을 발견할 수 있었다. 그리고 Pr는 $C_{th}$가 32인 경우, $P_B$ 및 Po 에 동일 비율로 종속되고 이 경우에 $P_{TA}$(blc$\xi$king probability for the adaptive power 머location)는 $P_{TF}$(blocking probability f for the fixed power allocation) 보다 6%정도 높음을 알 수 있었다.

• 한국통신학회논문지
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• 제27권11C호
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• pp.1158-1163
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• 2002

In this paper it is focused on the relation between CLR (Cell Loss Ratio) and blocking probability, GoS(Grade of Services) parameters in the wireless ATM (Asynchronous Transfer Mode) access network which consists of access node and wireless channel. Traffic model of wireless ATM access network is based on the cell scale, burst scale and call connection level. The CLR equation due to buffer overflow for wireless access node is derived for CBR (Constant Bit Rate) traffic. The CLR equation due to random bit errors and burst errors for wireless channel is derived. Using the CLR equation for both access node and wireless channel, the CLR equation of wireless ATM access network is derived. The relation between access network CLR and blocking probability is analyzed for CBR traffic.

• Journal of Communications and Networks
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• 제6권3호
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• pp.245-257
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• 2004

Driven by the growing number of the mobile subscribers, efficient channel resource management plays a key role for provisioning multimedia service in the next generation personal communication systems. To reuse limited channel resources, diminishing the coverage areas of cells seems to be the ultimate solution. Thus, however, causes more handover events. To provide seamless connection environment for mobile terminals and applications, this article presents a novel handover scheme called the intelligent channel reservation (ICR) scheme, which exploits the location prediction technologies to accurately reserve channel resources for handover connections. Considering the fact that each mobile terminal has its individual mobility characteristic, the ICR scheme utilizes a channel reserving notification procedure (CRNP) to collect adequate parameters for predicting the future location of individual mobile terminals. These parameters will be utilized by the handover prediction function to estimate the expected handover blocking rate and the expected number of idle channels. Based on the handover prediction estimations, a cost function for calculating the damages from blocking the handover connections and idling channel resources, and a corresponding algorithm for minimizing the cost function are proposed. In addition, a guard channel decision maker (GCDM) determines the appropriate number of guard channels. The experimental results show that the ICR scheme does reduce the handover-blocking rate while keeping the number of idle channels small.

• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.23-38
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• 2004

We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

• Food Science and Biotechnology
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• 제17권1호
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• pp.156-160
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• 2008

This study was conducted to evaluate the hypotensive properties of the extract of Chinese balloon flower (Platycodon grandiflorum)'s root. In the studies for calcium channel-blocking using Xenopus oocytes, the ethanol-extract ($26.2{\pm}5.2%$) showed higher activity than water-extract. Twenty female rats were fed 25, 35, and 45 mg/kg BW/day of the ethanol-extract for 14 days to observe the changes in blood pressures and heart pulses. Ethanol-extract decreased the systolic, diastolic, and mean blood pressures of the rats. Especially, the rats fed with 45 mg/kg BW/day of the ethanol-extract showed significant decreases in the blood pressures. These results suggested that a decrease in blood pressures was due to the extension of a blood vessel with calcium channel-blocking by ethanol-extract of Chinese balloon flower. Forty %-ethanol showed the highest efficiency for ethanol-extraction of Chinese balloon flower.

• Journal of Information Processing Systems
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• 제11권4호
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• pp.583-600
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• 2015

Generally, the wireless network provides priority to handover calls instead of new calls to maintain its quality of service (QoS). Because of this QoS provisioning, a call admission control (CAC) scheme is essential for the suitable management of limited radio resources of wireless networks to uphold different factors, such as new call blocking probability, handover call dropping probability, channel utilization, etc. Designing an optimal CAC scheme is still a challenging task due to having a number of considerable factors, such as new call blocking probability, handover call dropping probability, channel utilization, traffic rate, etc. Among existing CAC schemes such as, fixed guard band (FGB), fractional guard channel (FGC), limited fractional channel (LFC), and Uniform Fractional Channel (UFC), the LFC scheme is optimal considering the new call blocking and handover call dropping probability. However, this scheme does not consider channel utilization. In this paper, a CAC scheme, which is termed by a uniform fractional band (UFB) to overcome the limitations of existing schemes, is proposed. This scheme is oriented by priority and non-priority guard channels with a set of fractional channels instead of fractionizing the total channels like FGC and UFC schemes. These fractional channels in the UFB scheme accept new calls with a predefined uniform acceptance factor and assist the network in utilizing more channels. The mathematical models, operational benefits, and the limitations of existing CAC schemes are also discussed. Subsequently, we prepared a comparative study between the existing and proposed scheme in terms of the aforementioned QoS related factors. The numerical results we have obtained so far show that the proposed UFB scheme is an optimal CAC scheme in terms of QoS and resource utilization as compared to the existing schemes.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.469-470
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• 2007

We used the non-reversible hierarchical scheme and the fixed channel assignment scheme for the strategy of call processing at hierarchical cellular system. We analyzed the performance of system according to the number of channel assigned at macrocell out of the usable channel at global system. Microcell is assigned the channel excepted the channel assigned at macrocell. The more the channel was aigned at macrocell, the more decreased the blocking probability became. The blocking probability of microcell had similar trend.