• Journal of KIISE:Software and Applications
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• v.32 no.9
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• pp.868-877
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• 2005

Arcs are usually treated as significant features in the field of pattern recognition. This paper presents a method to detect arcs from digital planar curves and estimate their arc centers and radii by using geometric analysis. The deviation of distance between the original curve and the detected arc by the proposed method does not exceed a tolerant error. The experimental results show that the proposed method is available for the detection of arcs iron not only smooth but also heavily noisy curves.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.277-285
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• 2003

연안의 방조제 건설은 하천수와 바다물의 교환을 인위적으로 차단하고, 방조제 내부에는 호수를 형성하게 된다. 이렇게 형성된 인공호수의 수질은 호수로 유입되는 하천의 수질에 크게 영향을 받을 수 있으며, 인공호수의 수질이 악화되면 인근 해양생태계에 영향을 미칠 수 있다. 본 연구는 인공호수의 물이 바다로 방류될 때 해양생태계에 어떠한 영향을 미칠 것인지를 예측하고자 수행되었다. 방조제 건설로 이미 형성되어 있는 시화호, 아산호, 부사호와, 현재 건설중인 새만금 방조제로 인하여 형성될 호수의 유입 하천인 만경강에서 표층수를 채수하여 둥근성게(Strongylocentrotus nudus)의 정자와 수정란을 이용한 생물 검정을 실시하였다. 담수호의 수질을 해양생물을 이용하여 평가할 수 있도록 하기 위하여 시료의 염분을 조절하면서 실험을 실시하였다. 정자를 이용한 수정 실험 결과, 시화호에서는 수정률에 영향을 미치지 않았고, 아산호와 부사호에서는 약간의 영향이 있었으나 그 정도는 미약하였다. 반면, 만경강의 경우 수정률의 저해가 상당히 크게 나타났다. 수정란을 이용한 발생 실험 결과, 시화호, 아산호, 부사호에서는 약간의 영향이 나타난 반면, 만경강의 경우는 매우 큰 영향이 나타났다. 이들 실험 결과를 종합하면, 시화호, 아산호, 부사호의 수질은 대체로 양호하나, 만경강의 수질은 크게 우려되는 수준이었다. 따라서, 앞으로 건설될 새만금 호수와 인근 해양생태계를 보전하기 위해서는 만경강의 수질 개선을 위한 대책이 마련되어야 할 것이다.

• Journal of Internet Computing and Services
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• v.2 no.4
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• pp.1-10
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• 2001

In this paper, we define requirements for call distribution of service control logic in Intelligent Network, Also, we propose call distribution mechanism for every subscriber with different call distribution rates, The call distribution mechanism had been developed as a function of Premium-rate Service in Intelligent Network. Our call distribution mechanism applies to percentage distribution instead of circular or hierarchical distribution. The call distribution mechanism consists of call input. output. call distribution processing logic part, random number generator, and customers database. We propose the practical implementation of a call distribution mechanism and call distribution decision indicating number computation method. We show three methods, the rand() function in C language, microsecond by system clock, and proposed algorithm, to get call distribution decision indicating number. In order to optimal call distribution mechanism, we estimated the results of three methods on occurrence values and the number of occurrences.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.201-209
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• 1987

Solutions of food colorants were tested with insoluble drugs (kaolin, active carbon, talc, natural aluminum silicate) for their adsorption phenomena in purified water, gastric and intestinal fluid test solutions, respectively. The adsorption isotherms of kaolin with Red 2 in purified water, and active carbon with Red 2, 3, 40 in the three media, with Yellow 4 in purified water, gastric fluid, with Yellow 5 in intestinal fluid and natural aluminum silicate with Red 3 in purified water, intestinal fluid, with Yellow 4, 5 in purified water followed the Freundlich equation, and those of talc with Red 2, 3, Yellow 5 in the three media, with Red 40 in purified water, gastric fluid, with Yellow 4 in intestinal fluid fitted the Langmuir equation. With decrease of the alcohol content of aqueous solutions, the adsorption of coloring food additives is increased, but it decreased in high temperature. Also the activation energy of adsorption of coloring food additives by active carbon was determined.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.45-53
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• 2000

In wireless environment, due to the limited capacity of radio channels it is not easy to guarantee QoS provisioning to mobile users. Therefore, one of the key problems to support broadband multimedia multi-services in wireless ATM networks is to study an effective call admission control(CAC). The purpose of this paper is to propose a distributed CAC scheme that guarantees multi QoS and multi-class service. Control parameters of the proposed scheme are QoS threshold and channel overload probability. With these parameter control, we show that the scheme can guarantee the requested QoS to both new and handover calls. In the scheme, channels are allocated dynamically, and QoS measurements are made in a distributed manner. We show that by providing variable data rate to calls it can effectively prohibit the QoS degradation even if there are severe fluctuations of network traffic. We compare the proposed CAC scheme to the well-known schemes such as guard band call admission control scheme. Through numerical examples and simulations, the proposed scheme is shown to improve the performance by lowering the probability of handover call dropping

• The Science & Technology
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• no.1 s.404
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• pp.88-90
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• 2003

이리 호에 대해 과학자들은 1960년대만 해도 확신에 차 있었다. 이리 호 오염의 원인이 단순했기 때문이다. 그러나 지금은 세 배, 혹은 그 이상으로 복잡하고 다층적이다. 외래 침입종에다 지구 온난화 문제, 거기에 인을 비롯한 독성 화학물질까지 가세해 이리 호 문제 해결을 더욱 어렵게 만들고 있다. 과학자들은 과연 죽어 가는 이리 호를 되살릴 수 있을까?

• 전자공학회논문지 IE
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• v.46 no.3
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• pp.42-47
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• 2009

In CDMA system, the call admission control method using the variable effective bandwidth concept is employed in this paper. The bandwidth for a new call and a handoff call is allocated by considering the number of mobile station being served and dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. There is reserved resource for handoff call. In the case radio resource is insufficient, a new call and a handoff call stand by in buffer for constant time. When radio resource come about, the waiting call is allocated the resource. I analyze the performance of system according to existence and nonexistence of buffer by a simulation study.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.50-55
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• 2008

In CDMA system, the number of mobile stations which can be served simultaneously in a base station is limited by the amount of total interference received. Considering the facts, the call admission control method using the effective bandwidth concept is employed in this paper. The bandwidth for a new call and a handoff call is allocated by considering the number of mobile station being served and dynamically assigned by taking account of the blocking rate of new calls and the dropping rate of handoff calls. Also, there is reserved resource for handoff call. We analyze the performance of system according to reserved resource by a simulation study. The more a resource reserved, the less it is the dropping rate of handoff.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1282-1289
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• 2000

In this paper we propose a Fractional Channel Reservation (FCS) scheme to satisfy a desired handoof dropping probability and to reduce the blocking probability of new calls using mobility characteristics and incoming handoff rate in mobile communication networks. When the ratio of the handoff call arrival rate is less then the ratio of the new call arrival rete, the proposed scheme is capable of determining the number of the guard channels which can guarantee the Quality of Service(QoS) in terms of the request handoff dropping probability and allocating dynamically the wireless channels the new calls according to the rest of the guard channels to reduce the new call blocking probability. Also we perform mathematical analysis and simulation to evaluate the performance of proposed scheme and compare to conventional guard channel scheme in terms of dropping probability blocking probability and the utilization efficiency of wireless channels.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.927-934
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• 2002

In order to provide various multimedia services in a wireless network, the call admission control for wireless channels should be resolved at the time of call setup and handoff by moving mobile terminal. In this paper. we propose a reliable DCAC( Distributed Call Admission Control)scheme using virtual cluster concept. The proposed DCAC scheme considers the state of $1^{st}$ and $2^{nd}$ adjacent cells to provide a reliable call handling. The proposed scheme is analyzed by simulations and mathematical methods.