• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.6
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• pp.376-382
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• 1988

A small-signal low-frequency disturbance of the input line affects the regulated-output voltage of the series resonant converter. To mitigate the detrimental effect, the output feedback PI-controller is employed. Small-signal linear models are represented to characterize the closed loop series resonant converter system. Design equations for the PI-controller which satisfy stability and percent ripple conditions are derived from the closed-loop linear model. Experimental results are presented which show excellent correlation with theory.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1065-1070
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• 2006

The avian uncoupling protein (avUCP) is a member of the mitochondrial transporter superfamily that uncouples proton entry in the mitochondrial matrix from ATP synthesis. The sequencing analysis method was used to identify nucleotide polymorphisms within the avUCP gene in Korean native chicken (KNC). This study identified ten single nucleotide polymorphisms (SNPs) in the avUCP gene. We analyzed the SNPs of the avUCP gene to investigate whether polymorphism in the gene might be responsible for quantitative variations in economic traits in KNC. Three significant polymorphic sites for economic traits were avUCP C+282T (mean body weight, p<0.05), avUCP C+433T (daily percent lay, p<0.05), and avUCP T+1316C (daily percent lay, p<0.05). The frequency of each SNP was 0.125 (C+282T in avUCP gene exon 1 region), 0.150 (C+433T in avUCP gene intron 1 region), and 0.15 (T+1316C in avUCP gene exon 3 region), respectively. Among the identified SNPs, one pair of SNPs (genotype CC, C+282T and TT, avUCP C+433T) showed the highest daily percent lay (p<0.05) and mean body weight (p<0.05) and the frequency was 0.067. This study of the avUCP gene could be useful for genetic studies of this gene and selection on economic traits for KNC.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3962-3969
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• 1975

1. When the frame of the experimental apparatus was directly fixed on the platform, result from the spectrum density analysis showed that the generated vibration frequecy of the system was nearly-same as the system's own characteristic vibration frequency, 80Hz, in the case of the forcing vibration frequency was 7.5 to 22.5Hz. The reduction ratio of acceleration by balanced type model compare to non-balanced type one was 26.66 percent. 2. When the frame of experimental apparatus was fixed on the platform with putting a shock absorbing rubber between the frame and the platform, the generated vibration frequency of the system was same as forcing vibration frequency. When either frequency or the amplitude of the forcing vibration was increased, the acceleration ratio was increased too. The average reduction ratio was resulted 44.77 per cent. It was concluded that this method of acceleration measurement(the method using a shock absorbing rubber) was a reaonable method, because actual machine will work under such condition. As the vibration frequency and aptitude were increased, the absolute magnitude of acceleration was increased. 3. unbalanced rotating parts, and unbalanced moment of inertia of links were supposed to be causing factors of residual vibration in spite of using the balanced type oscillating mole drainer. This fact suggested that the attachment of the counter weight on the rotating parts which satisfy the condition mw$.$rw=m0e, was necessary. And also, it was expected that the shock absorbing effect could be improved by putting the shock absorbing materials between the moving parts and their supports.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.551-565
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• 2017

Based on the strain gradient theory (SGT), vibration analysis of an embedded micro cylindrical shell reinforced with agglomerated carbon nanotubes (CNTs) is investigated. The elastic medium is simulated by the orthotropic Pasternak foundation. The structure is subjected to magnetic field in the axial direction. For obtaining the equivalent material properties of structure and considering agglomeration effects, the Mori-Tanaka model is applied. The motion equations are derived on the basis of Mindlin cylindrical shell theory, energy method and Hamilton's principal. Differential quadrature method (DQM) is proposed to evaluate the frequency of system for different boundary conditions. The effects of different parameters such as CNTs volume percent, agglomeration of CNTs, elastic medium, magnetic field, boundary conditions, length to radius ratio and small scale parameter are shown on the frequency of the structure. The results indicate that the effect of CNTs agglomeration plays an important role in the frequency of system so that considering agglomeration leads to lower frequency. Furthermore, the frequency of structure increases with enhancing the small scale parameter.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.3
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• pp.88-94
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• 2004

Hemifacial spasm is painless uncommon disorder characterized by involuntary paroxysmal movement of one side face. In the treatment of hemifacial spasm, the Western operation or non-operation therapy has many side effect such as hearing loss, exudative otitis media, facial paralysis etc. So we studied mainly the effect of cause, treatment frequency, diseased part of 29 cases with hemifacial spasm for effective clicical application of oriental medicine. The results of study are as follow; 1. It shows more female patients than male patients, and mostly patients in their forties. 2. The diseased part is shown more on left side than right side, and the left side hemifacial spasm is cured more effective. 3. The causes of hemifacial spasm are mainly stress, ignorance, overwork, and the stress, a cold are more effective causes than ignorance in. 4. The disease period is mainly within six months, and that period is the most effective time. 5. The palpebral site is the most frequent site, ineffective site. 6. The effect go with the treatment frequency is not available. 7. There is a 55 percent improvement of 29 cases.

• Korean Journal of Psychosomatic Medicine
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• v.3 no.2
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• pp.115-125
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• 1995

Reports about the prevalence of premenstrual symptoms state that occurs in 20 to 100% of most reproductive-age women. There is a close association between premenstrual syndrome and affective disorders as well as same some other psychiatric disorders. Late luteal phase dysphoric disorder (LLPDD) is a premenstrual condition defined in DSM-III-R by severe mood changes and other symptoms that repeatedly occur only in the luteal phase of the menstrual cycle. However, DSM-III-R does not specify how to compute the change from the follicular to the luteal phase or how to determine when the amount of change is great enough to warrant the diagnosis nor how to determine occupational or social functional impairment. This study was conducted to evaluate the nature, severity and magnitude of premenstrual syndrome in women with current psychiatric disorders by using prospective Daily Rating Form(DRF), and to measure symptom changes according to three scoring methods for diagnosing LLPDD. Our study obtains the data about premenstrual changes estimated by DRF from 22 women with psychiatric disorders who had met criteria for major depressive syndrome on the Premenstrual Assessment Form (PAF). The data was scored by each three methods and was determined to meet criteria A for LLPDD. The results are as follows: 1) the subjects, when scored according to the percent change method, effect size method and absolute severity method, met the DSM-III-R criteria A for LLPDD in 36.4% (8 subjects), 14% (3 subjects) and 4.5% (1 subject) of the cases respectively. 2) The items of irritability, anger and impatience were occurred most frequently on the DRF, when it was scored according to the three scoring methods. And the item of breast pain was next frequent according to the effect size method and the percent change method but according to the absolute severity method. 3) The PAF item of impaired social functioning was reported by 16 (73%) of the subjects. 4) 4 (18%) of the subjects met criteria A for LLPDD and reported impaired social functioning. The prevalency of LLPDD according to each method varied. The percent change method yielded the greatest (36.4%), and the absolute seventy method yielded the laest (4.5%), The effect size method yielded an intermediate frequency (14%). Therefore, for maximizing the diagnostic accuracy of LLPDD, a diagnostic procedure including a measure of change (e.q., effect size method, percent change method) as well as confirmed diagnosis by DRF, will be needed. Also, an accurate tool to evaluate impaired social functioning will be required.

• Geophysics and Geophysical Exploration
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• v.24 no.3
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• pp.73-77
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• 2021

Induced polarization (IP) is useful for mineral exploration and hydrogeological studies by visualizing the electrochemical reactions at the interface between polarized minerals and groundwater. Frequency-domain IP (FDIP) is not actively applied to field surveys because it takes longer to acquire data, despite its higher data quality than conventional time-domain IP. However, data quality is more important in current mineral exploration as the targets gradually shift to deep or low-grade ore bodies. In addition, the measurement time reduced by automated instrumentation increases the potential for FDIP field applications. Therefore, we demonstrate that FDIP can detect mineral exploration targets by performing geophysical logging in the boreholes of a skarn deposit, in South Korea. Alternating current (AC) resistivity, percent frequency effect (PFE) and metal factor (MF) were calculated from impedance values obtained at two different frequencies. Skarn zones containing magnetite or pyrite showed relatively low AC resistivity, high PFE, and high MF compared to other zones. Therefore, FDIP surveys are considered to be useful for mineral exploration.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.94-101
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• 2004

The purpose of this raper is to assess the benefits of frequency domain fatigue analysis and compare it with more conventional time domain techniques. The multi-body dynamic analysis, FE analysis and fatigue life prediction technique are applied for the frequency domain fatigue analysis. To obtain the dynamic load history used in the frequency domain fatigue analysis, the computer simulations running over typical road Profiles are carried out by utilizing vehicle dynamic model. The fatigue life estimation for the rear suspension system of small-sized passenger car is performed by using resonance durability analysis technique, and the estimation results are compared with the conventional quasi-static durability analysis results. For the pothole simulation, the percent changes, of the fatigue life between the two durability analysis techniques don't exceed 10%. But for the Belgian road simulation because of the resonance effect, the fatigue life using the resonance durability analysis technique are much smaller estimated than the quasi-static durability analysis results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.69-73
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• 1975

Jinheung rice seeds ranging from 5.6 to 14.7 percent of water content were X-irradiated from 1.5 to 25 kR in vacuum and then immediately hydrated in either oxygen- or nitrogen-bubbled water at around 19$^{\circ}C$ for 12 hours. Results, as reported in terms of reduction of $M_1$ seedling height and survival, sterility and $M_2$ mutation frequency, indicate that the post-irradiation oxygen effect in very dry seeds was conspicuous; the seedling height and the survival were drastically reduced, and the sterility and the mutation frequency were increased in super dry seeds.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.1
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• pp.59-64
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• 2002

A FEM model of the remote-field eddy current effect is presented for zirconium-2.5 percent niobium(Zr-2.5%Nb) nuclear reactor pressure tubes to demonstrate the important electromagnetic field phenomena. This model is applied to evaluate the optimal operating frequency and detector position. There are many ambiguous experimental results connected with this technique. Finite element calculations can be used in the interpretation of these experimental results even though the electromagnetic fields measured in the remote-field technique are very small.