• Title/Summary/Keyword: min-max control method

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Use of the Moving Average of the Current Weather Data for the Solar Power Generation Amount Prediction (현재 기상 정보의 이동 평균을 사용한 태양광 발전량 예측)

  • Lee, Hyunjin
    • Journal of Korea Multimedia Society
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    • v.19 no.8
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    • pp.1530-1537
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    • 2016
  • Recently, solar power generation shows the significant growth in the renewable energy field. Using the short-term prediction, it is possible to control the electric power demand and the power generation plan of the auxiliary device. However, a short-term prediction can be used when you know the weather forecast. If it is not possible to use the weather forecast information because of disconnection of network at the island and the mountains or for security reasons, the accuracy of prediction is not good. Therefore, in this paper, we proposed a system capable of short-term prediction of solar power generation amount by using only the weather information that has been collected by oneself. We used temperature, humidity and insolation as weather information. We have applied a moving average to each information because they had a characteristic of time series. It was composed of min, max and average of each information, differences of mutual information and gradient of it. An artificial neural network, SVM and RBF Network model was used for the prediction algorithm and they were combined by Ensemble method. The results of this suggest that using a moving average during pre-processing and ensemble prediction models will maximize prediction accuracy.

ATM Network Resource Mangement and Control via Virtual Path Reconfiguration (가상 경로 재구성을 통한 ATM망 자원 관리 및 제어)

  • 임재진;김종권
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.11
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    • pp.2199-2214
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    • 1994
  • In order to sufficiently utilize the potential effectiveness of ATM networks, systematic and effective network management and control systems must be employed. In addition to network design, planning, and call routing techniques used in traditional circuit-switched networks. ATM networks can provide logical VP(Virtual Path) reconfiguration capabilities which can adapt to changes in the network environment. With a proper application of the VP reconfiguration technique, ATM networks can reduce the overhead of frequent network redesign and the overhead of call routing processing. However, ATM VP reconfiguration is a very complex and difficult problem which consists of many facets of optimization subproblems such as VP routing. VP sizing, VP terminating point location and VC routing. Most previous research on the ATM logical network reconfiguration problem dealt with the subset of the problem. This paper mathematically formulates the ATM network reconfiguration problem completely considering all subproblems. Since it is very difficult to derive the optimal solution of the formulated problem, we develop a heuristic method based on a Max min bandwidth allocation principle. We show the feasibility of the proposed heuristic method with a simple example.

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Usefulness Assessment of Automatic Analysis Program for Flangeless Esser PET Phantom Images (Flangeless Esser PET Phantom 영상 자동 분석 프로그램의 유용성 평가)

  • NamGung, Chang-Kyeong;Nam, Ki-Pyo;Kim, Kyeong-Sik;Kim, Jeong-Seon;Lim, Ki-Cheon;Shin, Sang-Ki;Cho, Shee-Man;Dong, Kyung-Rae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.63-66
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    • 2009
  • Purpose: ACR (American College of Radiology) offers variable parameters to PET/CT quality control by using ACR Phantom. ACR Phantom was made to evaluate parameters which are uniformity, attenuation, scatter, contrast and resolution. Manual analysis method wasn't good for the use of QC because values of parameter were changed as it may user and it takes long time to analysis. Ki-Chun Lim, a nuclear scientist in AMC, developed program that automatically analysis values of parameter by using ACR Phantom to overcome above problems. In this study, we evaluated automatic analysis program's usability, through the comparing SUV of each method, reproducibility of SUV when repeated analysis and the time required. Materials and Methods: Using Flangeless Esser PET Phantom, the ideal ratio of 4 : 1 hot cylinder and BKG but it actually showed a ratio of 3.89 to 1 hot cylinder and BKG. SIEMENS Biograph True Point 40 was used in this study. We obtained images using ACR phantom at Fusion WB PET Scan condition (2 min/bed) and 120 kV, 100 mAs CT condition. Using True X method, 3 iterations, 14 subsets, Gaussian filter, FWHM 4 mm and Zoom Factor 1.0, $168{\times}168$ image size. We obtained Max. & Min. SUV and SUV Mean values at Cylinder (8, 12, 16, 25 mm, Air, Bone, Water, BKG) by automatic program and obtained SUV by manual method. After that, we compared manual and automatic method. we estimate the time required from opened the image data to final work sheet was completed. Results: Automatic program always showed same result and same the time required. At 8, 12, 16 and 25 m cylinder, manual method showed 6.69, 3.46, 2.59, 1.24 CV values. The larger cylinder size became, the smaller CV became. In manual method, bone, air, water's CV were over 9.9 except BKG (2.32). Obtained CV of Mean SUV showed BKG was low (0.85) and bone was high (7.52). The time required was 45 second, 882 second respectably. Conclusions: As a result of difference automatic method and manual method, automatic method showed always same result, manual method showed that the smaller hot cylinders became, the lager CV became. Hot cylinders mean region size, the smaller hot cylinder size becomes we had some trouble in doing ROI poison setting. And it means increase in variation of SUV. The Study showed the time required of automatic method was shorten then manual method.

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A Study on Dosimetry for Small Fields of Photon Beam (광자선 소조사면의 선량 측정에 관한 연구)

  • 강위생;하성환;박찬일
    • Progress in Medical Physics
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    • v.5 no.2
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    • pp.57-68
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    • 1994
  • Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.

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LUAV Software Certification Method using Checklists based on DO-178C (DO-178C 기반 체크리스트를 활용한 무인동력비행장치 소프트웨어 인증 방안)

  • Ji-Hun Kwon;Dong-Min Lee;Kyung-Min Park;Eun-Hee Lee;Sauk-Hoon Im;Yong-Hun Choi;Jong-Whoa Na
    • Journal of Aerospace System Engineering
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    • v.17 no.1
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    • pp.33-41
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    • 2023
  • As seen in the case of the Boeing 737 Max accident, the proportion of aircraft software is rapidly increasing. However, it is vulnerable to safety issues. In case of domestic aircraft software, to operate a Light Unmanned Aerial Vehicle (LUAV) less than an empty weight of 150 kg, safety certification is required for an Ultra-Light Vehicle (ULV). However, software certification procedure is not included. Since the use of LUAVs has increased recently, software verification is required. This paper proposed a checklist of LUAV software that could be applied to LUAV referring DO-178C, an aviation software certification standard. A case study of applying the proposed checklist to the Model-based Development-based Helicopter Flight Control Computer (FCC) project currently used by domestic and foreign advanced companies and institutions was conducted.

FUZZY LOGIC KNOWLEDGE SYSTEMS AND ARTIFICIAL NEURAL NETWORKS IN MEDICINE AND BIOLOGY

  • Sanchez, Elie
    • Journal of the Korean Institute of Intelligent Systems
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    • v.1 no.1
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    • pp.9-25
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    • 1991
  • This tutorial paper has been written for biologists, physicians or beginners in fuzzy sets theory and applications. This field is introduced in the framework of medical diagnosis problems. The paper describes and illustrates with practical examples, a general methodology of special interest in the processing of borderline cases, that allows a graded assignment of diagnoses to patients. A pattern of medical knowledge consists of a tableau with linguistic entries or of fuzzy propositions. Relationships between symptoms and diagnoses are interpreted as labels of fuzzy sets. It is shown how possibility measures (soft matching) can be used and combined to derive diagnoses after measurements on collected data. The concepts and methods are illustrated in a biomedical application on inflammatory protein variations. In the case of poor diagnostic classifications, it is introduced appropriate ponderations, acting on the characterizations of proteins, in order to decrease their relative influence. As a consequence, when pattern matching is achieved, the final ranking of inflammatory syndromes assigned to a given patient might change to better fit the actual classification. Defuzzification of results (i.e. diagnostic groups assigned to patients) is performed as a non fuzzy sets partition issued from a "separating power", and not as the center of gravity method commonly employed in fuzzy control. It is then introduced a model of fuzzy connectionist expert system, in which an artificial neural network is designed to build the knowledge base of an expert system, from training examples (this model can also be used for specifications of rules in fuzzy logic control). Two types of weights are associated with the connections: primary linguistic weights, interpreted as labels of fuzzy sets, and secondary numerical weights. Cell activation is computed through MIN-MAX fuzzy equations of the weights. Learning consists in finding the (numerical) weights and the network topology. This feed forward network is described and illustrated in the same biomedical domain as in the first part.

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A Study on Damping Improvement of a Synchronous Generator with Static VAR Compensator using a Fuzzy-PI Controller (퍼지-PI 제어기를 이용하여 정지형 무효전력 보상기를 포함한 동기 발전기의 안정도 개선에 관한 연구)

  • 주석민;허동렬;김상효;정동일;정형환
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.3
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    • pp.57-66
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    • 2001
  • This paper resents a control approach for designing a fuzzy-PI controller for a synchronous generator excitation and SVC system A combination of thyristor-controlled reactors and fixed capacitors (TCR-FC) type SVC is recognized as having the must fiexible control and high speed response, which has been widely utilized in power systems, is considered and designed to improve the response of a synchronous generator, as well as controlling the system voltage A Fuzzy-PI controller for SVC system was proposed in this paper. The PI gain parameters of the proposed Fuzzy-PI controller which is a special type of PI ones are self-tuned by fuzzy inference technique. It is natural that the fuzzy inference technique should be barred on humans intuitions and empirical knowledge. Nonetheless, the conventional ones were not so. Therefore, In this paper, the fuzzy inference technique of PI gains using MMGM(Min Max Gravity Method) which is very similar to humans inference procedures, was presented and allied to the SVC system. The system dynamic responses are examined after applying all small disturbance condition.

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Intelligent Range Decision Method for Figure of Merit of Sonar Equation (소나 방정식 성능지수의 지능형 거리 판단기법)

  • Son, Hyun Seung;Park, Jin Bae;Joo, Young Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.4
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    • pp.304-309
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    • 2013
  • This paper proposes a intelligent approach on range decision of figure of merit. Unknown range of the underwater target and the non-fixed signal excess make the uncertainty for the tracking process. Using the input data of signal excess related to the range, we establish the rule of the fuzzy set and the original data acquired by sonar can be transformed to the fuzzified data set. To reduce the error arisen from the unexpected data, we use the new data transformed in fuzzy set. The piecewise relations of the min value, max one, and the mean one are calculated. The three values are used for the expected range of the underwater target. By analysing the fluctuation of the data, we can expect the target's position and the characteristics of the maneuvering. The examples are presented to show the performance and the effectiveness of the proposed method.

Comparative Study on Anti-thrombotic Effects of Gamihyunbooleekyungtang with Decoction Method (탕전기의 추출방법(抽出方法)에 따른 가미현부이경탕(加味玄附理經湯)의 항혈전(抗血栓) 효능(效能) 비교(比較) 연구(硏究))

  • Jeong, Ji-Hye;Lee, Soon-Yee;Jang, Yun-Jeong;Choe, Chang-Min;Cho, Han-Baek;Kim, Song-Baeg
    • The Journal of Korean Obstetrics and Gynecology
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    • v.22 no.3
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    • pp.99-116
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    • 2009
  • Purpose: In this study, we investigated anti-thrombotic effects of Gamihyunbooleekyungtang currently used clinical treatment of dysmenorrhea and compared effects by decoction methods. Methods: Gamihyunbooleekyungtang was extracted by pressure extractor (GHYT) and nonpressure extractor(GHYT-1). Inhibitory effect of platelet cohesion, suppression effect of GPIIb/IIIa activity, inhibitory effect of $TXB_2$ and $PEG_2$ biosynthesis, and oxidative damage suppression effect were tested in vitro. Also suppression of pulmonary embolism was studied in vivo. Results: In this study, both GHYT and GHYT-1 extract showed a safety in cytotoxicity of hFCs. Both showed dose-dependent inhibitory effect on platelet coagulation. GHYT-1 extract is usually higher than GHYT, especially for $E_{max}$. GHYT and GHYT-1 extract showed dose-dependent inhibitory effect on GPIIb/IIIa activities. GHYT extract suppressed significantly $TXB_2$ biosynthesis at 1000, $500{\mu}g/m{\ell}$ and also suppressed significantly $PEG_2$ biosynthesis at $1000{\mu}g/m{\ell}$ as compared with the control group. GHYT-1 suppressed significantly $TXB_2$ biosynthesis at $1000{\mu}g/m{\ell}$ as compared with the control group. Also it suppressed pulmonary embolism triggered by collagen and epinephrine by respectively 50%, 75% as compared with the control group. Both GHYT and GHYT-1 extract showed dose-dependent decrease of oxidative damages caused by DPPH, whereas dose-dependent increase of superoxide dismutase like activity was observed. Conclusion: These results suggest that Gamihyunbooleekyungtang can be used for treating dysmenorrhea caused by thrombosis. Nonpressure decoction method is a little more effective, but more detailed studies would be needed.

Effect of Solubilizing and Microemulsifying Excipients in Polyethylene Glycol 6000 Solid Dispersion on Enhanced Dissolution and Bioavailability of Ketoconazole

  • Heo, Min-Young;Piao, Zong-Zhu;Kim, Tae-Wan;Cao, Qing-Ri;Kim, Ae-Ra;Lee, Beom-Jin
    • Archives of Pharmacal Research
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    • v.28 no.5
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    • pp.604-611
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    • 2005
  • Polyethylene glycol (PEG) 6000-based solid dispersions (SDs), by incorporating various pharmaceutical excipients or microemulsion systems, were prepared using a fusion method, t o compare the dissolution rates and bioavailabilities in rats. The amorphous structure of the drug in SDs was also characterized by powder X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The ketoconazole (KT), as an antifungal agent, was selected as a model drug. The dissolution rate of KT increased when solubilizing excipients were incorporated into the PEG-based SDs. When hydrophilic and lipophilic excipients were combined and incorporated into PEG-based SDs, a remarkable enhancement of the dissolution rate was observed. The PEG-based SDs, incorporating a self microemulsifying drug delivery system (SMEDDS) or microemulsion (ME), were also useful at improving the dissolution rate by forming a microemulsion or dispersible particles within the aqueous medium. However, due to the limited solubilization capacity, these PEG-based SDs showed dissolution rates, below 50% in this study, under sink conditions. The PEG-based SD, with no pharmaceutical excipients incorporated, increased the maximum plasma concentration (C$_{max}$) and area under the plasma concentration curve (AUC$_{0-6h}$) two-fold compared to the drug only. The bioavailability was more pronounced in the cases of solubilizing and microemulsifying PEG-based SDs. The thermograms of the PEG-based SDs showed the characteristic peak of the carrier matrix around 60$^{\circ}C$, without a drug peak, indicating that the drug had changed into an amorphous structure. The diffraction pattern of the pure drug showed the drug to be highly crystalline in nature, as indicated by numerous distinctive peaks. The lack of the numerous distinctive peaks of the drug in the PEG-based SDs demonstrated that a high concentration of the drug molecules was dissolved in the solid-state carrier matrix of the amorphous structure. The utilization of oils, fatty acid and surfactant, or their mixtures, in PEG-based SD could be a useful tool to enhance the dissolution and bioavailability of poorly water-soluble drugs by forming solubilizing and microemulsifying systems when exposed to gastrointestinal fluid.