• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.63-82
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• 1997

In experimental situations where n two or three level fac-tors are involoved and n observations are taken then the D-optimal first order saturated design is an $n{\times}n$ matrix with elements $\pm$1 or 0, $\pm$1, with the maximum determinant. Cononical forms are useful for the specification of the non-isomorphic D-optimal designs. In this paper we study canonical forms such as the Smith normal form the first sec-ond and the jordan canonical form of D-optimal designs. Numerical algorithms for the computation of these forms are described and some numerical examples are also given.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1549-1557
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• 2018

Optimizing the design of large-scale electric machines based on nonlinear finite element analysis (FEA) requires longer computation time than other applications of FEA, mainly due to the huge size of the machines. This paper addresses a new region decision method (RDM) with mesh adaptive direct search (MADS) for the optimal design of wind generators in order to reduce the computation time. The validity of the proposed algorithm is evaluated using Rastrigin and Goldstein-Price benchmark function. Moreover, the algorithm is employed for the optimal design of a 5.6MW interior permanent magnet synchronous generator to minimize the torque ripple. Additionally, mechanical stress analysis as well as electromagnetic field analysis have been implemented to prevent breakdown caused by large centrifugal forces of the modified design.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.99.2-99.2
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• 2008

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.3-5
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• 2006

In this paper, annual energy production(AEP) of the wind generator system is analogized considering the regions of a variable wind speed and it is applied to optimal design of the PM wind generator for capturing maximum energy in the operating regions. In addition, internet parallel computing is used to loose excessive calculation times through optimization of the finite element analysis(FEA).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.123-130
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• 2010

In general, a design method based on the equivalent magnetic circuit has been used for basic design of Interior Permanent Magnet Synchronous Motor(IPMSM). However, the equivalent magnetic circuit method has difficulty in considering the arrangement of PM. IPMSM has high degree of freedom for PM rotor design. In this paper, we proposed the multiobjective optimal design method considering the arrangement of PM for the double-layer PM rotor structure that minimizes the torque ripple as well as maximizes the torque of IPMSM. The design variables of double-layer PM rotor structure are obtained from the Response Surface Method. Torque and torque ripple were calculated by Finite Element Method.

• Journal of Animal Environmental Science
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• v.22 no.1
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• pp.35-44
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• 2016

This study was conducted to establish a database of high solid manure(HSM) in domestic. Theoretical methane potential and HSM characteristics was evaluated using breef and dairy manure (n=156). Total solids and Volatile solids of HSM increased depending on time flow, the results showed $20.4{\pm}3.2$ and $17.4{\pm}2.8%$. respectively. C/N ratio of breef HSM was higher than dairy HSM C/N ratio. In theoretical methane potential, the result of breef and dairy HSM was showed $505.2{\pm}25.3$ and $493.5{\pm}20.2$, respectively. Nitrogen content of total HSM increased depending on time flow, the result of breef and dairy nitrogen content was showed $1.9{\pm}0.3$ and $2.8{\pm}0.2$, respectively. Carbon content of total HSM showed approximately 10% reduction. The optimal time of bed replacement was indicated between 29 amd 31 days based on the optimal C/N ratio. Therefore, this study was considered that it has high utilization for livestock manure recycling and basis of relevant research.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.83-87
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• 2001

This study was carried out to investigate the optimal medium and optimal dextrose concentration of 12 entomopathogenic fungi. The colonies of Cordyceps gracilioides, C. sp.(J23), Paecilomyces farinosus(J5), P tenuipes, Paecilomyces sp.(J4), Beauveria bassiana and B. brongniartii on SLA(silkworm larva agar) medium are similar to those on PDA(Potato dextrose agar) medium. On the contrary, the colonies of 5 fungi are very various according to its medium. The optimal medium for 1 1 fungi was SLA-A medium, which was better than PDA medium with regard to the mycelial growth. The optimal concentration on mycelial growth was superior to 6% for 6 fungi. When silkworm larvae was injected with P. tenuipes on SLA medium for fruiting body production. Infection rate, fruiting body formation rate, synnemata number and synnemata length were 91.3 $\pm$ 1.5%, 88.6 $\pm$ 2.3%, 56.6 $\pm$ 3.2 and 33.4 $\pm$ 2.88 ㎜ respectively. In economical analysis, the prototype medium can reduce 61.9% of production cost per 1 liter compared with PDA medium.

• Korean Journal of Medicinal Crop Science
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• v.6 no.3
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• pp.227-231
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• 1998

Flowering characteristics and optimal harvest time for seed of wasabi variety. Daruma, were investigated from Dec. 1995 to June 1996 in film house of Suwon. The number of peduncle was $10.2{\pm}2.29$ and most of the peduncle emerged between Jan. 20 and Feb. 10. Average peduncle length was $124{\pm}29.60cm$ and the peduncle grew most rapidly in the middle of march. Flowering started on Jan. 27 and lasted until June 4 with a peak at march 21 and flowering period was $99{\pm}21.32$ days. Flowers which bloomed later than the middle of March set seed but those bloomed earlier became sterile because days with minimum temperature below freezing occurred until the middle of March. Maturing period was $37.5{\pm}2.60$ days and total seed set was $43.2{\pm}8.77%$ in the natural culture condition. Optimal harvest time for seed was the last ten days of May and seed yield per $m^2$ was $79.0{\pm}19.94g%$(11,177 seeds).

• Journal of Digital Convergence
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• v.11 no.1
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• pp.361-368
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• 2013

The purpose of this study is to know the clinical usefulness of optimal b-values by quantitative, qualitative evaluation of DW-MRI for lesions of benignity and malignity of female pelvis. The b-values used in DWI were 600, 800, 1000, 1200, 1400($s/mm^2$). Mean SNR and CNR of myoma in b-value 800 were the highest result as $84.6{\pm}4.57$(p=0.024) and $50.13{\pm}5.47$(p=0.028), Mean SNR and CNR of cervical cancer were the highest result as $12.0{\pm}2.04$(p=0.047) and $10.6{\pm}1.24$(p=0.001), Mean ADC value in myoma and cervical cancer in b-value 800 were $1.19{\times}10^{-3}mm^2/s$(p=0.008), $0.96{\times}10^{-3}mm^2/s$(p=0.027). As a qualitative analysis, the delineation and conspicuity were the highest result as $4.02{\pm}0.18$(p=0.028), $4.39{\pm}0.25$(p=0.015) on b-value 800. DW-MRI is an important method, and the optimal b values is 800 $s/mm^2$ for differentiation between benign and malignant lesions of female pelvis.

• International journal of thyroidology
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• v.11 no.2
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• pp.137-142
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• 2018

Background and Objectives: Radioactive iodine therapy (RAI) is an important treatment modality of Graves' disease (GD), but there is still not a consensus on the optimal dosage regimen. We studied the treatment success rate of different RAI doses, and examined which clinical markers were useful for determining the optimal RAI dosage for successful therapy in Korean patients. Materials and Methods: We retrospectively studied 123 patients with GD treated with RAI between 2004 and 2014 at Chonnam National University Hwasun Hospital. The responder group was defined as patients who developed hypothyroidism requiring levothyroxine replacement following RAI, regardless of the RAI dosage. Results: A total of 54 patients (43.9%) became hypothyroid after the first dose, and 31 needed two to four additional doses to achieve hypothyroidism. In the responder group as a whole (85 patients), the mean total dose of RAI was $15.5{\pm}7.0mCi$ and the mean thyroid volume (TV) was $35.4{\pm}23.4mL$. When divided into low dose (<15 mCi, n=46) and high dose (${\geq}15mCi$, n=39) responder groups, TV was significantly lower in the low-dose responder group ($25.7{\pm}11.4$ vs. $48.4{\pm}31.3$, p<0.001). The optimal cut-off TV for the low-dose responder group was <32.37 mL (sensitivity 80.9%, specificity 76.7%). Conclusion: TV had significant effects on the outcome of RAI in GD patients. The optimal fixed RAI dose for Korean GD patients with a large goiter (${\geq}33mL$) should be at least 15 mCi to achieve the best outcome.