• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.5
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• pp.51-59
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• 2007

The end-burning combustion field using impinging oxidizer injectors are analyzed with tangential type injectors in order to examine their mixing and combustion characteristics. The impinging type showed further improved mixing effect as well as the combustion efficiency compared to the previously studied tangential injector. A novel injector capable of delivering impinging and swirl effect is introduced in this study where it demonstrated that the grain coning effect can be avoided. It was found that the combined impinging and swirling flow would promote the radial mixing rate increasing the residence time and the turbulent intensity. However, the use of the step combustor which may augment the turbulent intensity did not show any notable difference compared to the basic combustor.

• Journal of Korean Physical Therapy Science
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• v.27 no.3
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• pp.75-83
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• 2020

Background: The effect of the Valsalva maneuver applied in resistance exercise has shown contradictory results. This study aims to investigate the effect of the Valsalva maneuver on resistance exercise by examining the changes that occur by applying the Valsalva maneuver during trunk flexion and extension resistance exercise in healthy adults. Design: Randomized controlled trial. Methods: 34 healthy adults were conveniently recruited. According to the with or without Valsalva maneuver, the flexion and extension of the trunk were measured and evaluated. Results: Paired t test showed that there was a statistically significant difference in maximum torque of trunk flexion in the resistance exercise with Valsalva maneuver. However, there was no statistically significant difference in trunk extension (p<.05), in the total and average work of trunk flexion and extension (p<.05). Conclusion: The results of this study in which the difference in the amount of exercise according to the application of the Valsalva maneuver was not significant, show that the practice of the Valsalva maneuver, which has a risk of injury, should be avoided in rehabilitation exercises.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.91-107
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• 2022

Purpose - This study quantitatively examines the level of financial inclusion of a microfinance institution in each region and how this is changing recently, and examines the level of financial inclusion by region and various financial characteristic factors related to it. It was empirically verified what kind of significant impact actually has on the institution's major management performance indicators (stability, profitability, efficiency, and public interest). Design/methodology/approach - It was confirmed that the institution's financial inclusion index declined rapidly after 2015 as a whole, although there were some differences by region depending on regional characteristics. However, considering the fact that the number of branches per 100,000 adult population is steadily increasing nationwide, it was found that, contrary to what is known, the simple decrease in the number of branches of the institution was not the main cause. Findings - The analysis results of this study show that the institution's efforts for financial inclusion have a positive impact on profitability, stability, efficiency, and public interest, and that the institution pursues profitability, efficiency, stability, and public interest. showed that some trade-offs exist. In other words, overall, it was analyzed that profitability of the institution has a positive effect on efficiency, and efficiency has a positive effect on stability and public interest. Research implications or Originality - Since the institution's efforts to improve its profitability do not have a negative impact on its stability and public interest, it is judged that it is important to take a strategic stance, so excessive loan supply that exceeds the scope of the institution's own control needs to be avoided as much as possible. More detailed financial supply strategies and business management capabilities that enhance the asset soundness and management efficiency of safes need to be demonstrated.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3
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• pp.113-120
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• 2006

This paper is concerned with a equalization technique for Orthogonal Frequency Division Multiplexing (OFDM) systems based on a block type pilot arrangement over slow fading channels. The bit rates obtained in underwater channels are relatively modest compared to some other communication channels such as cellular phones or indoor wireless systems. Consequently. the Doppler effect is the important parameter in tracking a channel. In case of a coherent demodulation scheme, the residual mean phase errors due to Doppler frequency may be fatal for the performance of the system. The equalizer could not solely handle mean Doppler shift. To account for the common Doppler effect a phase error tracking loop is used with the frequency equalizer. so that the rotation errors are avoided. Furthermore. simulations show that we can reduce the computational load of the tracking loop with negligible effect on performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.952-959
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• 2002

The natural frequencies of a flexible spinning disk misaligned with the axis of rotation are studied in an analytic manner. The effects of misalignment on the natural frequency need to be investigated, because the misalignment between the axis of symmetry and the axis of relation cannot be avoided in the removable disks such as CD-R, CD-RW or DVD disks. Assuming that the in -plane displacements are in steady state and the out-of-plane displacement is in dynamic state, the equations of motion are derived for the misaligned spinning disk. After the exact solutions are obtained fur the steady -state in-plane displacements, they are plugged into the equation for the dynamic-state out-of-plane motion. The resultant equation is a linear equation for the out -of-plane displacement, which is discretized by the Galerkin method. Based on the discretized dquations, the effects of the misalignment are analyzed on the vibration characteristics of the spinning disk, i.e., the natural frequencies and the critical speed.

• Journal of the Korean Society of Costume
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• v.39
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• pp.99-111
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• 1998

Cubism has played a great role to change traditional concept of art and visual of people as developed into one of new art stlyes. It has avoided three dimensional perspectives and reformed the concept of time and space. It expresses objects with geometric shape by simplifying and reconstructing the objects after taking them apart. This has the effect of simultaneous vision and transparency and brings in collage by combining geometric image and visual elements. The results of the study as follows: First, the geometric shape expresses straight lines, curves, faces, and cubics by simplifying the objects. In fashion, it expresses circles, triangles, squares with a cloth. This shows visual changes as three dimensional space moves. Second, simultaneity disassembles and recontructs the objects. It tries to understand the internal shape with method of disassembling and makes visions coexist. In so doing, cubists adopt simultaneity for expressing shapes. In fashion, it expresses new items through disassembling or combining with other items. Third, transparency simplifies cubics by duplicating with transparent flats and crosses contour lines for reconstructing the simplified objects. This implies broader spatial order. It allows people to perceive penetration of layed clothes. Fourth, collage expresses geometric shape by adding visual elements(concrete image and color). It uses concrete image with paper, letters, cloth, etcs, which is not related to painting, and introduces various colors. In fashion, it uses dolls, postcards, feathers, metals, plastics, for patchwork.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.308-314
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• 2015

This paper has proposed a new boost rectifier. Adequate input current was obtained by keeping the duty ratio constant without complicated conventional control methods and the improvement of the waveform was increased. With a decrease of distortion up to 12.9[%], the scope of restriction on harmonics was set to 13.0[%]($3^{td}$ harmonics), 1.1[%]($5^{td}$ harmonics) and 0.6[%]($7^{td}$ harmonics), respectively. Because complicated methods of control are avoided, the circuit configuration is simple and practical. In particular, the said effect turned out to be highly efficient in the low boosting ratio range(boosting ratio$({\alpha})=1.25$). The feasibility of these facts has been proven both theoretically and experimentally.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.3
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• pp.132-138
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• 1998

The dynamic analysis of stability in industrial power system is an important subject. In this paper, the effect of voltage dips for short duration (short-circuit) in the utility system on generators, synchronous motors of the industrial plant and the measures to be adopted to reduce the undesired effects of voltage dips re investigated. In the case of utility three-phase short-circuits of longer duration, both the generators and synchronous motors in the plant may become unstable. In order to avoid instability through fault clearing in the second zone time a decoupling device is necessary. The instability of voltage can be avoided with a well suited setting time of disconnecting device and load trip.

• Journal of Pharmaceutical Investigation
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• v.27 no.1
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• pp.15-22
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• 1997

The mucosal route of administration(nasal, buccal, conjunctival and vaginal) has recently been considered as an alternative to parenteral delivery for many peptide drugs because enzymatic degradation of these agents may be partly avoided. The objective of these study was to establish the optimal mucosal administration dosage form of $LHRH/[D-Ala^6]LHRH$, based on presystemic metabolism. We reported previously the peptidase inhibition effect of medium chain fatty acid salts(sodium caprylate, soadium caprate and sodium laurate), EDTA and STDHF on the proteolysis of $LHRH/[D-Ala^6]LHRH$ in rabbit mucosal homgenates. We also reported that EDTA, STDHF and sodium laurate markedly increased the potency of $LHRH/[D-Ala^6]LHRH$ solution applied vaginally. In the present study, by administration of polycarbophil hydrogel containing LHRH the ovulation inducing activity was 3.3 times greater than solution. These results indicate not only peptidase inhibitor but also polycarbophil hydrogel significantly improved the absorption of this drug. The results of this study would provide the feasibility as a rational dosage form for improving bioavailability and self administration of this hydrogel by the vaginal application.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.431-439
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• 2006

Due to the limitation of size of the test section, blockage effects could not be avoided in the model test of yacht sails for common wind tunnels. In this paper, a numerical analysis is performed to investigate the blockage effects on the lift and drag forces measured from wind tunnel experiments for a 30 feet sloop yacht sail. Complex airflows around the jib and main sails including three-dimensional flow separations are calculated for various close-hauled conditions. It is found that the blockage of a wind tunnel changes the flow separation and consequently the lift and drag forces of the sails, especially the main sail, reduce and increase, respectively, due to the blockage effects.