• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.76-86
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• 2015

KSLV-II, a new launch vehicle of Korea, requires a new launch complex(LC) for its own and proper launch operations. The new launch complex will be constructed in NARO Space Center neighboring KSLV-I launch complex for maximizing operation efficiency and economic matters. The launch complex consists of three ground support equipments, i.e., mechanical, electrical, and fuel in general. The fuel ground support equipment could be defined as a combination of systems for storage and supply of propellants and gases which are required by a launch vehicle. The compositions, functions and capabilities of fuel ground support equipment are introduced in this paper. In addition, basic design results of flame deflector configurations are included.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.717-724
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• 2016

This paper presents design of a 40 GHz CMOS PLL frequency synthesizer for a 60 GHz sliding-IF RF transceiver. For stable locking over a wide bandwith for a injection-locked frequency divider, an inductive-peaking technique is employed so that it ensures the PLL can safely lock across the very wide tuning range of the VCO. Also, Injection-locked type LC-buffer with low-phase noise and low-power consumption is added in between the VCO and ILFD so that it can block any undesirable interaction and performance degradation between VCO and ILFD. The PLL is designed in 65 nm CMOS precess. It covers from 37.9 to 45.3 GHz of the output frequency. and its power consumption is 74 mA from 1.2 V power supply.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.600-603
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• 2008

In this paper, a new circuit design named memory-in-pixel for low power consumption of the liquid crystal display (LCD) is presented. Since each pixel has a memory, it is able to express 8 color grades using the data saved in the memory without the operation of the gate and source driver ICs so that it can reduce the power consumption of the LCD panel. A memory circuit consists of modified S-R flip-flop (NAND-type) implemented in the pixel, which can supply AC bias for operating the liquid crystal (LC) with the interlocking clocks (CLK_A and CLK_B). This circuit is more complex than the inverter-type memory circuit, but it has lower power consumption of approximately 50% than the circuit. We have investigated the power consumption both NAND and inverter-type memory circuit using a Smart SPICE for the resolution of $96{\times}128$. The estimated power consumption of the inverter-type memory was about 0.037mW. On the other hand, the NAND-type memory showed power consumption of about 0.007mW.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.6
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• pp.514-524
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• 2016

This work suggests a study on 5 kW plasma power supply design and reactor capacitance estimation algorithm for a wide range of linear output control to operate a plasma reactor. The suggested study is designed to use a two-stage circuit and control the full-bridge circuit of the two-stage circuit using the buck converter output voltage of the single-stage circuit. The switching frequency of the full-bridge circuit is designed to operate through high-frequency switching and obtain maximum output using LC parallel resonance. Soft switching technique(ZVS) is used to reduce the loss caused by high-frequency switching, and duty control of the buck converter is applied to control a wide range of linear output. The internal capacitance of the reactor cannot easily be extracted, and thus, the reactor cannot be operated in an optimized resonant state. To address this issue, this work designs the internal capacitance of the reactor such that estimations can be performed with the developed reactor capacitance estimation algorithm applied to the internal capacitance of the reactor. A 5 kW plasma power supply is designed for a wide range of linear output control, and the validity of the study on the reactor capacitance estimation algorithm is verified.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.288-295
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• 2012

Although some degree of mechanical properties of suede fabrics mainly related to non-woven suede fabric has some researched, the thin suede fabric has rarely been researched. In this study, polyester(DTY 50/72) was used for warp, and after producing latent yarn and sea-island yarn for weft, two yarns were compounded to produce sea-island DTY yarn. By using the two produced yarns for warp and weft, we produced thin suede fabric with stretch function. For weft 2ply, weft density 85, 90, 100(picks/in) were applied to weave fabric, and for weft 1ply, weft density 125, 135, 140(picks/in) were applied to produce weft face 5-end satin weave. The mechanical properties of the produced fabric were researched. The result are as followed. The weight loss ratio of the suede fabric produced for this experiment reached 15% on the conditions of temperature $90^{\circ}C$ and 20 minutes, so that island parts were completely separated. The strength of weft 1ply applied suede fabric was about 7.5kg and that of 2ply suede fabric and about 3.5kg. But the strain of two samples ranged from about 40 to 43%. Although Hari was high when weft was denser. The values of Koshi and Kisimi were low. And shear stiffness was high when sea-island DTY yarn was used. The WC value was higher in the case of 2ply than in that of 1ply sea-island DTY yarn for weft, so that we may conclude that Fukurami was more affected in the 2ply case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.344-348
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• 2007

In this paper, we propose the electrode of the Patterned Vertical Aligned (PVA) cell [1] for high transmittance. We use the 'TechWiz LCD' for calculation of the director configuration and optical characteristics to ensure the results of the proposed electrode structure. In general, the transmittance of the PVA cell depends on the shape of the electrode and cell gap. In this work the width of gate line and data line of the improved electrode design is set to be equal to that of the PVA conventional. Instead, we modified the shape of the top and bottom electrode on order to decrease the area of the defect. For verification, we compared the calculated optical transmittance of the PVA cell with the proposed electrode structure to the conventional PVA cell . As a result, we can confirm that the optical loss due to the variation of the retardation the LC cell around electrode can be definitely decreased by the proposed electrode.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.573-580
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• 2020

In this paper, the characteristics of the inductor and capacitor, which are the basic components of the circuit, are constructed in a form that can be used in the LTCC multilayer. The inductors and capacitors used for the analysis were designed with rectangular spiral structures and MIM structures inside dielectrics with a dielectric constant of 7, respectively. The measured results were extracted from each element of the equivalent circuit proposed by the curve fitting method and verified the validity of the proposed equivalent circuit based on the extracted results. The analyzed inductor and capacitor were implemented in the form of library and proved its usefulness by applying to Elliptical type 5th LPF design. The LPF was measured through practical production, and as a result, the insertion loss in the passband DC ~ 3.7 GHz was up to 1.0 dB, the return loss was 19.2 dB, and the attenuation in the rejection band was 23.9 dB, which was close to the design goal.

• Education of Primary School Mathematics
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• v.25 no.1
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• pp.19-41
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• 2022

Online classes have become one of the general teaching and learning method in elementary education, and elementary school teachers are essentially required to design and implement online math classes that reflect the characteristics of online environment and the specificity of the subject. The qualitative improvement of online mathematics lessons can start with examining what difficulties teachers actually have in enacting the online lessons, and this study focused on their educational needs by examining the degree to which elementary school teachers perceive and implement in terms of designing online interactions. The result showed that teacher education on Learner-Content Interaction (LC) and Learner-Learner Interaction (LL) was necessary for elementary school teachers designing online mathematics lessons, and the educational needs of detailed items of interactions were confirmed. Furthermore, it was found that there was a difference in educational needs for the types of online interactions according to the career life cycle of elementary school teachers. The instructional design strategies for online interactions in online mathematics lessons and implications for teacher education necessary for elementary school teachers were derived from the result.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.20 no.2
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• pp.31-44
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• 2009

The conspectus, based on a set number of subject descriptors derived essentially from LC subject classifications, provides a consistent framework within which libraries could report subject intensity. While library collection development has been benefitted by using this conspectus, its effectiveness in this digital era is under controversy. The purpose of this study is to survey the concepts and the various types of conspectus in library collection development and to test the applicability of a revised conspectus model to electronic resource management in libraries. For this, the focus was especially put on investigating the characteristics of electronic resources as considered the collection depth usually identified in collection development policies. Previous research has been also surveyed to consolidate their outcomes in order to design a matrix model of conspectus, which put the characteristics, persistence, and collection level in consideration in oder for the design of the conspectus model.

• Journal of Pharmaceutical Investigation
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• v.39 no.3
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• pp.207-216
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• 2009

Fluconazole is used as an orally administrated antifungal drug for the treatment of tinea corporis, candidiasis including skin mycotic pneumonia infections. The dosage of fluconazole varies with indication ranging from 50 mg/day to 400 mg/day. The fluconazole capsule 50 mg (3 capsules daily) is already available in Korean market. To improve the patient compliance, a fluconazole tablet 150 mg (once a day administration) was developed recently. The purpose of this study was to evaluate the bioequivalence of three doses of fluconazole capsule 50 mg (Diflucan 50 mg, Pfizer Korea Inc., as a reference drug) and a single dose of fluconazole tablet 150 mg (Plunazol 150 mg, Daewoong Pharm. Co., Korea) according to the guidelines of the Korea Food and Drug Administration (KFDA). The bioequivalence for three capsules of Diflucan 50 mg and a single tablet of Plunazol 150 mg was investigated in twenty-four healthy male volunteers under a randomized 2${\times}$2 crossover trial design. The average age of twenty-four volunteers was 24.78${\pm}$3.27 year-old, average height was 175.56${\pm}$5.45 cm and average weight was 67.24${\pm}$6.86 kg. After three capsules of Diflucan 50 mg or a single tablet of Plunazol 150 mg were orally administered, blood was taken at predetermined time intervals and the plasma concentrations of fluconazole in plasma were determined using LC-MS-MS. The 90% confidence intervals for the main parameters of statistical results after logarithmic transformation were AUCt 0.9272-1.0084 and Cmax 0.8423-0.9544 respectively, which are in the range of log 0.8 to log 1.25 and the statistical results of additional parameters (AUClast, t1/2 and MRT) were also in the 90% confidence interval that is in the range of log 0.8 to log 1.25. Therefore, the results of this study confirm the bioequivalence of three capsules of Diflucan 50 mg to one tablet of Plunazol 150 mg.