• KIEE International Transactions on Power Engineering
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• v.2A no.3
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• pp.83-88
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• 2002

An over current relay(OCR), one of the most frequently used protective devices, has time-current characteristics (TCC) to control its trip time according to the current level. It is because an appropriate operating time interval is necessary for coordination with other protective devices. A set of TCC curves of an OCR is, in general, given by the supplier from which a curve is selected by the operator. Therefore, in many cases, it is impossible to consider the operation condition of the given power system exactly. A novel concept of an OCR is suggested in this paper. The proposed OCR has an internal correction module so that it may produce the most adequate TCC curve according to the given protective information for coordination with other devices. With the generated TCC curve, a variety of operation and coordination conditions can be taken into consideration in an effective manner. The suggested OCR is applied to a simple test power system to show very promising results from a coordination point of view.

• Transactions on Electrical and Electronic Materials
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• v.14 no.2
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• pp.78-81
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• 2013

$0.95(Na_{0.5}K_{0.5})NbO_3-0.05BaTiO_3+0.2wt%\;Ag_2O$ (hereafter, No excess NKN) ceramics and $0.95(Na_{0.5}K_{0.5})NbO_3-0.05BaTiO_3+0.2wt%\;Ag_2O$ with excess $(Na_{0.5}K_{0.5})NbO_3$ (hereafter, Excess NKN) were fabricated by the conventional solid state sintering method, and their phase transition properties and dielectric properties were investigated. The crystalline structure of No excess NKN ceramics and Excess NKN ceramics were shown characteristics of polymorphic phase transition (hereafter, PPT), especially shift from the orthorhombic to tetragonal phase by increasing sintering temperature range from $1,100^{\circ}C$ to $1,200^{\circ}C$. Also, the temperature coefficient of capacitance (hereafter, TCC) of No excess NKN ceramics and Excess NKN ceramics from $-40^{\circ}C$ to $100^{\circ}C$ was measured to evaluate temperature stability for applications in cold regions. The TCC of No excess NKN and Excess NKN ceramics showed positive TCC characteristics at a temperature range from $-40^{\circ}C$ to $100^{\circ}C$. Especially, Excess NKN showed a smaller TCC gradient than those of Excess NKN ceramics in range from $-40^{\circ}C$ to $100^{\circ}C$. Therefore, NKN piezoelectric ceramics combined with temperature compensated capacitor having negative temperature characteristics is desired for usage in cold regions.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.4
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• pp.149-158
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• 2018

With the propagation and spread of the new regeneration energy and increase in electricity demand, power systems tend to be decentralized, and accordingly, the use of a power system stabilizer tends to expand for the stabilization of the distribution system. Thus, typical power system stabilizer, Static Var Compensator (SVC) is developed on a variety of topologies. In addition, the trend of technology leads from SVC to Static Synchronous Compensator(STATCOM) technology development. Recently, to overcome STATCOM's conversion losses and economic disadvantages, studies of a hybrid method using STATCOM and SVC in parallel have actively been conducted. This study proposes a new Soft-Step Switching method to limit inrush current problematic in Thyristor Controlled Capacitor (TCC) method in SVC function. In addition, to reduce Statcom's capacity, groups of reactive power compensation reactor and condenser for SVC were designed.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.192-197
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• 2001

Purpose: Urinary cytology and cystoscopic exam are effective methods for diagnosis of transitional cell carcinoma(TCC). But the former shows drawbacks such as the need for a well-trained examiner, and wide imprecision related to the variability of microscopic exam; the latter is an invasive method. $UBC^{TM}$ test detects the epitope on specific cytokeratin fragments released from epithelium of bladder cancer by immunoradiometric assay. We compared $UBC^{TM}$ test with urinary cytology for diagnosis of TCC to evaluate the utility of $UBC^{TM}$ test. Materials and Methods: Eighty-four patients with hematuria were included in our study. $UBC^{TM}$ tests (IDL Biotech, Sweden) were assayed in mid-stream urine according to the ordinary assay protocol. Nineteen patients were confirmed as TCC by cystoscopic examination and underwent transurethral resection (Group A). Other patients had various benign urinary tract conditions (Group B). Samples were considered positive as the $UBC^{TM}$ concentration was greater than $12{\mu}g/L$. Results: $UBC^{TM}$ levels were significantly different between group A ($95.9{\pm}166.4\;{\mu}g/L$) and group B ($19.2{\pm}85.6{\mu}g/L$) (P<0.001). Sensitivity for diagnosis of TCC was 89.5% (17/19) in UBC test and 47.4% (9/19) in cytology (p<0.05). Specificity for diagnosis of TCC was 81.5% (53/65) in $UBC^{TM}$ test and 100% (65/65) in cytology. $UBC^{TM}$ test was significantly more sensitive in stage Ta, $T_1$ tumors (84.6 vs 38.5%, p<0.05) and in grade I (83.3% vs 16.7%, p<0.05) than cytology. $UBC^{TM}$ test showed a tendency to be more sensitive as the grade was higher (83.3% in Grade I, 90% in Grade II and 100% in Grade III). Conclusion: $UBC^{TM}$ test could be a useful method in distinguishing TCC from other benign genitourinary diseases. Moreover, $UBC^{TM}$ test could be an especially valuable marker for diagnosis of TCC in patients with early TCC of low grade TCC compared to urinary cytology. Therefore, mbined use of $UBC^{TM}$ test in association with cytology is helpful to overcome the limited sensitivity of cytology.

• Journal of the Korean Ceramic Society
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• v.34 no.2
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• pp.123-130
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• 1997

In this study, (Sr.Pb.Ca)TiO3-Bi2O3.3TiO2(SPCT) systems were investigated to develop a new material which has a high dielectric constant, a low dielectric loss and a small TCC(Temperature Coefficient of Capa-citance), and are suitable for high voltage applications as a function of the additions of Bi2O3.3TiO2 from 5 mol.% to 9 mol.%. The result obtained from our investigation showed that up to 6 mol.% Bi2O3.3TiO ad-dition the dielectric constant increased and it deteriorated at higher concentrations with increasing amount of the acicular grains. As a result of some dopants (SiO2, Nb2O3, MnO2) addition to SPCT, the specimens with MnO2 showed good dielectric properties. The dielectric constant decreased, but the TCC was improved with the addition of MnO2 from 0.15 wt.% to 0.45 wt. %.

• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.163-176
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• 1995

Triphenyl Tetrazolium Chloride(TCC) reduction test is simple and sensitive to some residual antibiotics (especially to penicillin) in milk, but comparatively insensible to sulfo-namides. The volumn of sample is also large. Thus this study was undertaken to increase the detectable level of sulfonamides in raw milk. In this study, we used small transparent plastic hole and pulp disc instead of 10m1 test tube and made test medium in which was added 0.08%TTC, 0.3% agar, 10% skim milk, approximately $10^6$ CFU/ml streptococcus thermophilus and 5ppm Trimethoprim to enhance the sensitivity for sulfonamides The results of TCC reduction test by disc plate method were summarized as follows : 1. sensitivity to residual sulfonamides were much higher than official TCC reduction test. Detectable limites of sulfamethazine, sulfamerazine, sulfathiazole, sulfachloropy-ridazine, sulfadimethoxine, sulfamononethoxine, sulfadiazine and sulfaquinoxaline were 0.1-0.5ppm levels. 2. Detectable limites to some antibiotics were simillar or good than that of official method as 0.005-0.1ppm to three ${\beta}$ -lactams, 0.25-0.5ppm to one macrolide, 2-10ppm to three aminoglycosides, 0.2-0.5ppm to three tetracycline, 0.1-0.5ppm to chloramphenicol. 3. Only 0.1ml of milk was needed to test and the test medium could be stored appnoximatly 7days in the refrigerator. So test procedure was convenient than offcial method. 4. These results suggest that disc plate method is more useful to detect bacterial growth inhibition substances including sulfonamides in raw milk.

• Journal of Yeungnam Medical Science
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• v.37 no.3
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• pp.186-193
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• 2020

Background: Non-tunneled catheters (NTCs) are used for hemodialysis (HD) in many centers in which fluoroscopy is not easily accessed despite high complication rates and conditions requiring long-term HD. Therefore, here we aimed to evaluate the superiority of catheter-related outcomes after the application of tunneled cuffed catheter (TCC) without fluoroscopy versus unconditioned NTC insertion. Methods: We divided the participants into two phases: those receiving NTCs between March 2010 and February 2011 (phase I), and those receiving TCCs or NTCs between March 2011 and February 2012 (phase II). Catheter survival, nurse satisfaction, and reasons for catheter removal were analyzed. Results: Two hundred and sixty patients in phase I and 300 patients in phase II were enrolled in this study. The success rate of TCC insertion was 99.2%. The catheter survival rate in phase I was 65.5% at 1 month, while that in phase II was 74.9% at 1 month (p=0.023). We compared catheter survival between TCCs and NTCs for all periods regardless of phase. The TCC survival rate was higher than the NTC survival rate (p<0.001). Catheter-associated problems led to catheter removal in 97 patients (26.6%) in phase I and 68 patients (18.5%) in phase II (p=0.009). Among 14 HD nurses, all reported being satisfied with manipulation during pre-/post-HD, manupulation during HD, and overall. Eleven HD nurses (78.6%) reported being satisfied with the workload. Conclusion: Compared with unconditional NTC insertion for HD, TCC insertion without fluoroscopy improved the overall catheter survival and nurse satisfaction rates.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.445-451
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• 2022

Ultrasonic sensor is suitable as a next-generation autonomous driving assist device because its lower price compared to that of other sensors and its sensing stability in the external environment. Although Pb(Zr, Ti)O₃ (PZT)-relaxor ferroelectric system has excellent piezoelectric properties, the change in capacitance is large in the daily operating temperature range due to the low phase transition temperature. Recently, many studies have been conducted to improve the temperature stability of ferroelectric ceramics by controlling the grain size and crystal structure, so it is necessary to study the effect of the grain size on the piezoelectric properties and the temperature stability of PZT-relaxor ferroelectric system. In this study, the piezoelectric properties, phase transition temperature, and temperature coefficient of capacitance (TCC) of 0.9 Pb(Zr_1-xTi_x)O₃-0.1 Pb(Zn_1/3Nb_2/3)O₃ (PZT_x-PZN) ceramics with various grain sizes were investigated. PZT_x-PZN ceramics with larger grain size showed higher piezoelectric properties and temperature stability, and are expected to be suitable for ultrasonic devices in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.739-743
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• 2006

Postmortem proteolysis of breast (BM) and leg (LM) muscles from Taiwan colored chickens (TCC) and silkie bantams (SB) at $5^{\circ}C$ were compared. Myofibrils were prepared from BM and LM samples that were randomly taken from the carcasses of SB and TCC after 0, 1, 3, 7 and 14 days of storage at $5^{\circ}C$. pH of samples was determined, and degradation of myofibrillar proteins was analyzed by the SDS-PAGE and western blots. The results showed that pH was lower in BM than in LM samples from both avian strains. Appearance of 30 kDa components and disappearance of titin and nebulin were more rapidly as seen on SDS-PAGE in BM than in LM samples. Western blots labeled with a monoclonal antibody to desmin also demonstrated that desmin degraded more quickly in BM samples. Our data might suggest that postmortem proteolysis occurred more rapidly in BM than in LM from both TCC and SB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.30-32
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• 2005

The effects of mole ratio and Ti-ion on the dielectric properties and microstructure of modified $CaZrO_3$ composition such as $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructures were obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructures are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (temperature coefficient of capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.