• Title/Summary/Keyword: Optimal control period

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Gamma Knife Radiosurgery for Trigeminal Neuralgia : Review and Update

  • Lee, Seunghoon;Lee, Jung-Il
    • Journal of Korean Neurosurgical Society
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    • v.65 no.5
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    • pp.633-639
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    • 2022
  • Accurate diagnosis of trigeminal neuralgia (TN) is the starting point for optimal treatment. Gamma knife radiosurgery (GKRS) is currently regarded as one of the first-line treatment options for medically refractory TN. GKRS is a less invasive treatment with a low risk of complications than other surgical procedures that provides a favorable pain control Barrow Neurological Institute (BNI) I-IIIb rate of >75% at short-term follow-up. Drawbacks of GKRS include the latency period before pain relief and higher recurrence rate compared with microvascular decompression. Therefore, repeat treatment is necessary if the initial GKRS was effective but followed by recurrence. The concept of dose rate and the biologically effective dose of radiation has been actively studied in radiation oncology and is also applied in GKRS for TN to achieve high safety and efficacy by prescribing the optimal dose. Recent progress in functional imaging, such as diffusion tensor imaging, enables us to understand the pathophysiology of TN and predict the clinical outcome after GKRS. Here, we review TN, GKRS, and recent updates, especially in the concepts of radiation dose, diffusion tensor imaging studies, and repeat treatment in GKRS for TN.

An Enhanced Adaptive Power Control Mechanism for Small Ethernet Switch (소규모 이더넷 스위치에서 개선된 적응적 전력 제어 메커니즘)

  • Kim, Young-Hyeon;Lee, Sung-Keun;Koh, Jin-Gwang
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.3
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    • pp.389-395
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    • 2013
  • Ethernet is the most widely deployed access network protocol around the world. IEEE 802.3az WG released the EEE standard based on LPI mode to improve the energy efficiency of Ethernet. This paper proposes improved adaptive power control mechanism that can enhance energy-efficiency based on EEE from small Ethernet switch. The feature of this mechanism is that it predicts the traffic characteristic of next cycle by measuring the amount of traffic flowing in during certain period and adjusts the optimal threshold value to relevant traffic load. Performance evaluation results indicate that the proposed mechanism improves overall performance compared to traditional mechanism, since it significantly reduces energy consumption rate, even though average packet delay increases a little bit.

Effect of Recombinant Bovine Somatotropin on Growth of Olive Flounder, Paralichthys of olivaceus

  • Rho, Sum-Rho;Kim, Pil-Youn;Lee, Young-Don;Choi, Kwang-Sik;Song, Choon-Bok
    • Journal of Aquaculture
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    • v.12 no.2
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    • pp.79-89
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    • 1999
  • The recombinant bovine somatotropin (rBST) was administered to the oliver flounder, Paralichthys olivaceus, to know the effects and optimal administration frequency and dosage of the hormone. The experiment was conducted with three different treatment groups (A, B and C) designated based on the duration and administration frequency of rBST and one control (D) from April 14, 1996 to March 16, 1997. The fish of hormone treated groups grew 7.86 to 10.07% (47.45 to 60.75 g in weight) better than the control at the end of the experiment (P<0.05). No significant differences in their growth were detected among treatment groups. The distinct growth improvement was recognized four weeks after completion of the first four hormone administration. When considering water temperatures measured from the experimental tanks, the effect of rBST on the flounder was greater during the period showing relatively lower temperature. The survival rates were higher in treatment groups than in the control, revealing 98.3% (A), 98.4% (B), 97.7% (C) and 93.1% (D) during the first stage of culture; 92.7% (A), 91.3% (B), 86.7% (C) and 80.0% (D) during the second stage of culture.

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The LQG/LTR Dynamic Digital Control System Design for the Nuclear Steam Generator Water Level (증기발생기 디지탈 수위조절 시스템의 LQG / LTR 동적 제어설계)

  • Lee, Yoon-Joon
    • Nuclear Engineering and Technology
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    • v.27 no.5
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    • pp.730-742
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    • 1995
  • The steam generator feedwater and level control system is designed by two steps of the feedwater control design and the feedback loop controller design. The feedwater sen system is designed by the optimal LQR/LQG approach and then is modified by the LTR method to recover the robustness. The plant characteristics are subject to change with the power variation and these dynamic properties are considered in the design of the feedback controller. All the designs are made in the continuous domain and are digitalized by applying the proper sampling period. The system is simulated for the two cases of power increase and decrease. From the results of simulation, it is found that the controller constants would rather be invariable during the power increase, while for the case of power decrease they should be changed with the power variation to keep the system stability.

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An Intelligent Wireless Sensor and Actuator Network System for Greenhouse Microenvironment Control and Assessment

  • Pahuja, Roop;Verma, Harish Kumar;Uddin, Moin
    • Journal of Biosystems Engineering
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    • v.42 no.1
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    • pp.23-43
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    • 2017
  • Purpose: As application-specific wireless sensor networks are gaining popularity, this paper discusses the development and field performance of the GHAN, a greenhouse area network system to monitor, control, and access greenhouse microenvironments. GHAN, which is an upgraded system, has many new functions. It is an intelligent wireless sensor and actuator network (WSAN) system for next-generation greenhouses, which enhances the state of the art of greenhouse automation systems and helps growers by providing them valuable information not available otherwise. Apart from providing online spatial and temporal monitoring of the greenhouse microclimate, GHAN has a modified vapor pressure deficit (VPD) fuzzy controller with an adaptive-selective mechanism that provides better control of the greenhouse crop VPD with energy optimization. Using the latest soil-matrix potential sensors, the GHAN system also ascertains when, where, and how much to irrigate and spatially manages the irrigation schedule within the greenhouse grids. Further, given the need to understand the microclimate control dynamics of a greenhouse during the crop season or a specific time, a statistical assessment tool to estimate the degree of optimality and spatial variability is proposed and implemented. Methods: Apart from the development work, the system was field-tested in a commercial greenhouse situated in the region of Punjab, India, under different outside weather conditions for a long period of time. Conclusions: Day results of the greenhouse microclimate control dynamics were recorded and analyzed, and they proved the successful operation of the system in keeping the greenhouse climate optimal and uniform most of the time, with high control performance.

A Study on Demand Selection in Supply Chain Distribution Planning under Service Level Constraints (서비스 수준 제약하의 공급망 분배계획을 위한 수요선택 방안에 관한 연구)

  • Park, Gi-Tae;Kim, Sung-Shick;Kwon, Ick-Hyun
    • Journal of the Korea Society for Simulation
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    • v.15 no.3
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    • pp.39-47
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    • 2006
  • In most of supply chain planning practices, the estimated demands, which are forecasted for each individual period in a forecasting window, are regarded as deterministic. But, in reality, the forecasted demands for the periods of a given horizon are stochastically distributed. Instead of using a safety stock, this study considers a direct control of service level by choosing the demand used in planning from the distributed forecasted demand values for the corresponding period. Using the demand quantile and echelon stock concept, we propose a simple but efficient heuristic algorithm for multi-echelon serial systems under service level constraints. Through a comprehensive simulation study, the proposed algorithm was shown to be very accurate compared with the optimal solutions.

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Market Prediction Methodology for a Medical 3D Printing Business : Focusing on Dentistry (의료분야 3D프린팅 비즈니스 시장규모 예측 연구 : 치과 분야를 중심으로)

  • Kim, Min Kwan;Lee, Jungwoo;Kim, Young Myung;Lee, Kikwang;Han, Chang Hee
    • Journal of Information Technology Applications and Management
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    • v.23 no.2
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    • pp.263-277
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    • 2016
  • Recently, 3D printing technology has been considered as a core applicable technology because it brings many improvements such as the development of medical technology, medical customization, and reducing production cost and shortening treatment period. This research suggests a market prediction framework for medical 3D printing business. As an immature market situation, it is important to control some uncertainty for market prediction such as a customers' conversion rate. So we adopt decision making tree (DMT) model which used to choose an optimal decision making among diverse pathway. Among medical industries this paper just focuses on dentistry business. For predicting a 5 year period trend expected market size, we identified some replaceable denture procedure by 3D printing, collected related data, controlled uncertain variables. The result shows that medical 3D printing business could be a market of 28.2 billion won at 1st year and in the end of fifth year it could become on a scale of 61.1 billion won market.

A Study on Entrepreneurial Orientation and Financial Performance using Taguchi Method (다구찌 기법을 적용한 기업가지향성과 재무성과에 관한 실증적 연구)

  • Kim, Yong-Jun;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.4
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    • pp.245-250
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    • 2014
  • The purpose of this study is to introduce a empirical study of using Taguchi Method for the Entrepreneurial Orientation and Financial Performance. In this study, three factors of Entrepreneurial Orientation, innovation, pro-activity and risk taking, are used of the control factors and an element, period of establishment, is chosen as a noise factor. In order to carry out this research, we obtained 200 survey sheets and performed the reliability and validity analysis of the questionnaires and then the experiment was conducted by Taguchi's experimental design. To improve Financial Performance under the noise factor of period of establishment, optimal condition are as follows; the two factors of Entrepreneurial Orientation, innovation, pro-activity should be maintained to a high level. Also, other factor, risk taking should be performed as the level that the company has maintained. Through this paper, we find out that Taguchi method is applicable for analysis of questionnaire.

Water temperature and salinity tolerance of embryos and spat of the mussel, Musculista senhousia

  • Liang, Zhuo Liang;Kim, Young-Hun;Zhang, Zhi Fang;Lim, Sang-Min;Kang, Kyoung-Ho
    • The Korean Journal of Malacology
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    • v.25 no.3
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    • pp.179-187
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    • 2009
  • The effects of water temperature and salinity on embryonic development and spat survival of mussel Musculista senhousia were investigated. Embryos were incubated in water ranging from 0 to $35^{\circ}C$ and with salinity from 5‰ to 40‰. Mussel spat were tested in water from 0 to $40^{\circ}C$ and with salinity from 0‰ to 100‰. The optimal conditions for mussel embryos were $20-25^{\circ}C$ and salinity from 25‰ to 35‰, based on Within this temperature range, higher temperatures correponded to a shorter duration of the embryonic period. Optimisation of mussel spat survival was at $25-35^{\circ}C$ and salinity from 30‰ to 40‰; both values are higher than those for embryo, which hinted M. senhousia embryos are more vulnerable than spat. Temperatures below $15^{\circ}C$ were lethal for embryos, making temperature a feasible method with which to control the large population of M. senhousia in ark-shell farm during its spawning period.

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How Consignment Should be Implemented to be an Effective Supply Chain Collaboration Program?

  • Chungsuk RYU
    • The Journal of Industrial Distribution & Business
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    • v.14 no.6
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    • pp.17-25
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    • 2023
  • Purpose: This study observes how the consignment performs over time and proposes the proper way to operate the consignment to bring its best benefit to the supply chain system. Research design, data, and methodology: The supply chain system is represented as the mathematical model where a manufacturer and a retailer trade one type of products to maximize their own profits. In the numerical examples of the proposed models, the consignment is compared with the fully coordinated system as well as the traditional system, and both advantages and limitations of the consignment are detected. Results: The consignment makes greater profit than the traditional system after a certain time period. The consignment is still outperformed by the fully coordinated system. The numerical examples also show that the performance of the consignment is sensitive to the consignment ratio. Conclusions: This study finds out that a certain time period must be spent until the consignment brings the benefit to the supply chain system. The numerical outcomes also imply that the consignment requires additional features to be a completely effective supply chain collaboration program. To obtain the best result from the consignment, the supply chain members are recommended to decide the appropriate consignment ratio by consent.