• Title/Summary/Keyword: Time Base

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Software Development for Auto-Generation of Interlocking Knowledgebase Using Artificial Intelligence Approach (인공지능기법에 근거한 철도 전자연동장치의 연동 지식베이스 자동구축 S/W 개발)

  • Ko, Yun-Seok;Kim, Jong-Sun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.6
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    • pp.800-806
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    • 1999
  • This paper proposes IIKBAG(Intelligent Interlocking Knowledge Base Generator) which can build automatically the interlocking knowledge base utilized as the real-time interlocking strategy of the electronic interlocking system in order to enhance it's reliability and expansion. The IIKBAG consists of the inference engine and the knowledge base. The former has an auto-learning function which searches all the train routes for the given station model based on heuristic search technique while dynamically searching the model, and then generates automatically the interlocking patterns obtained from the interlocking relations of signal facilities on the routes. The latter is designed as the structure which the real-time expert system embedded on IS(Interlocking System) can use directly in order to enhances the reliability and accuracy. The IIKBAG is implemented in C computer language for the purpose of the build and interface of the station structure database. And, a typical station model is simulated to prove the validity of the proposed IIKBAG.

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Delay Analysis for Packet Forward Scheme in Wireless Packet Networks

  • Koh, Seung-Kwang;Park, Cheon-Won
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.121-124
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    • 1999
  • In a packet-switched wireless cellular network, a packet destined to a mobile station is queued at a base station and then broadcast over the base station's cell. When an active mobile station leaves a cell, there re-main packets which are destined to the mobile and not yet delivered to it at the cell's base station. For application which are sensitive to packet losses, such back- logged packets must be forwarded to the new base station. Otherwise, an end-to-end retransmission may be required. However, an increase in packet delay is incurred by employing the packet forward scheme, since a packet may be forwarded many times before it is delivered to the destined mobile station. For an enhanced quality-of-service level, it is preferred to reduce tile packet delay time. In this paper, we develop an analytical approximation method for deriving mean packet delay times. Using the approximation and simulation methods, we investigate the effect of network parameters on the packet delay time.

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Dissolution Characteristics of ph-Dependent Antacid Granules Agglomerated in High Speed Agitation Type Speed Agitation Type Granulator

  • Choi, Woo-Sik;Lee, Jung-Sun
    • Archives of Pharmacal Research
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    • v.18 no.5
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    • pp.314-319
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    • 1995
  • Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

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Application of Fuzzy Algorithm with Learning Function to Nuclear Power Plant Steam Generator Level Control

  • Park, Gee-Yong-;Seong, Poong-Hyun;Lee, Jae-Young-
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1054-1057
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    • 1993
  • A direct method of fuzzy inference and a fuzzy algorithm with learning function are applied to the steam generator level control of nuclear power plant. The fuzzy controller by use of direct inference can control the steam generator in the entire range of power level. There is a little long response time of fuzzy direct inference controller at low power level. The rule base of fuzzy controller with learning function is divided into two parts. One part of the rule base is provided to level control of steam generator at low power level (0%∼30% of full power). Response time of steam generator level control at low power level with this rule base is shown generator level control at low power level with this rule base is shown to be shorter than that of fuzzy controller with direct inference.

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Adaptation accuracy and mechanical properties of various denture base resins: a review (다양한 레진 의치상의 적합도와 기계적 특성)

  • Lee, Jung-Hwan;Lee, Chung-Jae;Lee, Hae-Hyoung
    • The Journal of the Korean dental association
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    • v.57 no.12
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    • pp.747-756
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    • 2019
  • This paper reviews the adaptation accuracy and mechanical properties of currently used denture processing systems with base resin materials and introduces the latest research on the development of antimicrobial denture base resins. Poly(methyl methacrylate) has been successfully used as a dental denture base resin material by the compress-molding method and heat polymerization for a long time, but recently, new processing techniques, injection molding-methods or fluid-resin technique are also used for fabricating denture base. However, studies indicated that there was no difference between the injectionmolding and the conventional compression-molding method in terms of adaption accuracy of denture base. The fluid-resin fabrication and one injection-molding systems exhibited better adaptation accuracy than the other processing methods. Resin denture bases in the oral cavity may undergo midline fractures due to flexural fatigue from repeated masticatory loading. For those patients, impact resistant denture base resins are recommended to prevent denture fracture during service. Thermoplastic denture base resins can be helpful for patients suffering from allergic reaction to resin monomers with a soft-fit, however, thermoplastic resins with low stiffness can irritate gum tissues and accelerate abnormal alveolar ridge resorption. Moreover, due to low chemical durability in oral cavity, those should be used for a limited period of time.

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Microstructure of the Brazed Joint for LRE Injector (액체로켓엔진용 인젝터 접합부의 미세조직)

  • 남대근;홍석호;이병호
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.87-89
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    • 2004
  • Brazing is an indispensable manufacturing technology for liquid rocket engine. In this study, for LRE injector, stainless steel 316L was used of base metal and Ni based MBF-20 of insert metal. The brazing and diffusion was carried out under various conditions. There are solid phase and. residual liquid phase in the brazed joint. With increment of holding time, the amount of solid phase increased and the elements of base metal and insert metal compositionally graded. Boron diffused from insert metal came into base metal and made boride with Cr and Mo at the brazed joint of base metal and insert metal.

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A Time Tree Scheduling Scheme for Energy Efficiency and Collision Avoidance in Sensor Networks (센서 네트워크에서 에너지 효율과 충돌 회피를 위한 타임 트리 스케줄링)

  • Lee, Kil-Hung
    • Journal of Korea Multimedia Society
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    • v.12 no.7
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    • pp.962-970
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    • 2009
  • This paper presents a data gathering and scheduling scheme for wireless sensor networks. We use a data gathering tree for sending the data from the sensor node to the base station. For an energy efficient operation of the sensor networks in a distributed manner, a time tree is built in order to reduce the collision probability and to minimize the total energy required to send data to the base station. A time tree is a data gathering tree where the base station is the root and each sensor node is either a relaying or a leaf node of the tree. Each tree operates in a different time schedule with possible different activation rate. Through the simulation, we found that the proposed scheme that uses time trees shows better characteristics in energy and data arrival rate when compared with other schemes such as SMAC and DMAC.

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A Study on the Properties in Friction Weldability of Ni-Cr-Mo and SM45C (Ni-Cr-Mo과 SM45C의 마찰용접특성(摩擦熔接特性)에 관한 연구(硏究))

  • Lim, Hyung-Taek;Min, Taeg-Ki
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.6
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    • pp.29-36
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    • 2007
  • The present study examined the mechanical properties of the friction welding of Ni-Cr-Mo to SM45C. Friction welding was conducted at welding conditions of 2,000 rpm, friction pressure of 100MPa, friction time of 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0 seconds, upset pressure of 150MPa, and upset time of 3.0 seconds. When the friction time was 1.6 seconds, the maximum tensile strength of the friction weld happened to be 1,020MPa, which is 120% of the base material's tensile strength(850MPa). At the same condition, the maximum shear strength was 438MPa, which is equivalent to 103% of the base material's shear strength(425MPa). At the same condition, the maximum vickers hardness was Hv490 at Ni-Cr-Mo nearby weld interface, which is higher Hv40 than condition of the friction time 0.8 seconds, and the maximum vickers hardness was Hv305 from weld interface of SM45C, which is higher Hv12 than condition of the friction time 0.8 seconds. The results of microstructure analysis show that the structures of two base materials have fined and rearranged along a column due to heating and axial force during friction, which has affected in raising hardness and tensile strength.

Fast Logic Minimization Algorithm for Programmable-Logic-Array Design (PLA 설계용 고속 논리최소화 알고리즘)

  • 최상호;임인칠
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.2
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    • pp.25-30
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    • 1985
  • This paper proposes an algorithm to simplify Boolean functions into near minimal sum-of-products for Programmable Logic Arrays. In contrast to the conventional procedures, where the execution time depends on the number of variables, the execution time by this procedure depends on the degree of consensus of base minterms. Thus as the number of variables is increased, the difference of CPU time becomes larger using this new Procedure than using other procedures and consequently the executable range of input function increasing. The algorithm has been implemented on CYEER 170-740 and it's results were compared with those using Arvalo's algorithm.

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Monte carlo analysis of InAlGaAs/InGaAs HBT (InAlGaAs/InGaAs HBT의 Monte carlo 해석)

  • 황성범;김용규;송정근
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.405-408
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    • 1998
  • Due to the large conduction band discontinuity between emitter base, OmGaAs HBT has an advantge to enable the hot electrons to inject into the base. In this paper, InAlGaAs/InGaAs HBT with the various emitter junction gradings and the modified collectors are simulated and analyzed by HMC(hybrid monte carlo) simulator in order to find a optimal structure for the shortest transit time. A minium base transit time (.tau.$_{b}$ ) of 0.21 ps was obtained for HBT with the grading layer, which is parabolically graded from x=1.0 to x=0.5. The minimum collector transit time (.tau.$_{c}$ ) of 0.31ps was found when the collector was modified by inserting p$^{[-10]}$ and p$^{+}$ layers. Thus HBT in combination with the emitter grading and the modified collector layer showed the cut-off frequency (f$_{T}$) of 183GHz.z.z.

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