• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.4
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• pp.124-129
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• 2008

Design practice has been made on an oil-less scroll air compressor as an air supply device for a 2 kW fuel cell system where air pressure of 2 bar and flow rate of 120 liter/min are required. Basic structure of the scroll compressor includes double-sided scroll wrap for the orbiting scroll driven by two crankshafts connected to each other by a timing belt. These features can eliminate thrust surface which otherwise would produce frictional heat and jeopardize reliable operation of the orbiting scroll and the scroll element's deformation as well. This study focuses on optimum scroll wrap design; orbiting radius has been chosen as an independent design parameter. As the orbiting radius changes, scroll sizes such as scroll base plate and discharge port diameters change accordingly. Gas compression-related losses and mechanical loss also change with the orbiting radius. With a scroll base plate diameter of 120mm at most and discharge port of at least 10mm, the orbiting radius should be within the range of 2.5-4.0mm. With this range of the orbiting radius, it was estimated by performance analysis that the compressor efficiency reached to a maximum of ${\eta}_c$=96% at the orbiting radius of $r_s$=3.5mm for the scroll wrap height-to-thickness ratio of h/t=5.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.397-403
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• 2007

In this paper, conceptual design of scroll expander-compressor for Stirling engine utilizing solar energy as heat source has been carried out. Orbiting scroll member was designed to have a double-sided structure to reduce the overall scroll size and to cancel out the axial forces on the orbiting scroll base plate. Diameter of designed scroll base plate was about 251 mm for the expander, and it was about 218 mm for the compressor. With operating condition such as temperature range of $400^{\circ}C/20^{\circ}C$, pressure range of 6 MPa/2 MPa, and shaft speed of 2700 rpm, the shaft output of the designed scroll expander was calculated to be 49.8 kW, while input power for the scroll compressor was 38.6 kW, yielding 11.2 kW for the output power of the Stirling engine. Overall efficiencies of the scroll expander and compressor were 93.73% and 92.87%, respectively.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.3
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• pp.2107-2112
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• 2020

Background: With the increasing elderly population, the need for gait analysis of these elderly individuals is also increasing. Most devices are costly and not portable; however, smartphones using built-in sensors capable of measuring motion and are easily available. Objectives: To examine the reliability and validity of knee joint angles of the elderly using smartphone measurements during walking. Design: Quasi-experimental research. Methods: Sixteen elderly people, aged 65+ and living in Daejeon and Chungbuk, South Korea, participated in the study. Electrogoniometers and smartphones were attached to the thigh and the side and front of the shank of each subject, respectively, using double-sided tape, an arm band, and an elastic band. Each subject completed two sets of at least seven gait cycles (14 steps). Results: Both the smartphones and electrogoniometers exhibited high agreement in terms of their primary and secondary measurements (ICC>.75). The agreement between the smartphones and electrogoniometers was also high in terms of both the primary and secondary measurements (ICC<.60). Conclusion: These results indicate that smartphones can be costly equipment cannot, even though they cannot completely replace existing clinical-grade devices. Their utility is emphasized herein for measuring knee joint angles of the elderly during walking.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1313-1321
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• 2000

This paper presents a novel HTS microstrip pseudo-lumped element resonator for the compact and simple filter design. A 7-pole bandpass filter with quasi-elliptic response is designed and fabricated using non-adjacent couplings between resonators. A seven-pole quasi-elliptic filter is fabricated using double sided YBCO on a LaAlO$_3$ substrate with thickness of 0.5 mm and dielectric constant of 23.5. The filter has an insertion loss of 0.8 dB at 20K, a bandwidth of 8 MHz at the center frequency of 1774 MHz, and an attenuation of 33 dB for the cut-off-band of 1 MHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.705-707
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• 2011

Smart devices have the characteristics of duality of fire and the property of double-sided swords. They also both conveniency and the weakness at a time due to the structure of the devices. Although there have not been a big threat with the smart devices, but they have potential enough to destroy the network society. This is because of the fact that the devices mainly depend on the applications and the applications can abuse the devices' critical hardware sections such as camera, file system, etc.. In this contribution, we analyze the issues and the problems of the weakness of smart devices and discuss a method to solve the issues.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.54-62
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• 2014

This study deals with the design and characteristics analysis on a linear synchronous motor (LSM) with a long stator and phase concentrated winding (PCW) to apply for a propulsion system such as a roller coaster for leisure facilities. First of all, the required propulsion force of LSM is computed and its design with double sided permanent magnets (PMs) and a phase concentrated winding is processed. The phase concentrated winding is composed of a module with each A, B, and C phase unlike an conventional concentrated winding (CW). It has an advantage of the installation and manufacture, compared to the conventional concentrated winding in the propulsion system for leisure facilities that have a long acceleration area and stator configuration placed on rail continuously. Thus, the design for the propulsion system and characteristics comparison between the phase concentrated winding and concentrated winding are carried out in this paper. Also, the analysis on dynamic characteristics is conducted to confirm the performance at operation.

• Journal of Engineering Education Research
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• v.22 no.5
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• pp.49-55
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• 2019

Folded structure is widely applied in various engineering fields. Many of the Japanese folding fans in the Edo era (1603-1868) have been successfully blended with the processing technology of "natural materials" that is the origin of Japan's "Monodzukuri" (craftsmanship) and its application "artistic originality". The charm of a fan lies in the diversity of stereoscopic expression not born in plane representation. For example, the effects of folds, the expression of the front and back sides flowing from the front to the back by double-sided description, and the two-layer effect of raising the backside from the surface using the permeability of Japanese paper, the calculated depiction are also seen. Moreover, by handling the fan, it also produced an illusion effect which skillfully calculated the change due to movement of the viewpoint. Students experience the natural materials such as Japanese paper, bamboo and starch paste, which are the materials of paint and fan at the time, and processing method, and know the difference with the current one. This study is to verify the effectiveness of engineering education which gains experience by making concrete fans and to understand deeply this traditional technology with the artistry of a Japanese fan at the same time. And we can learn from the characteristics of the fan to Japan's history and culture.

• Steel and Composite Structures
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• v.32 no.3
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• pp.337-346
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• 2019

The present paper tries to contribute fill the gap of application of the component method to tubular connections. For this purpose, one typical joint configuration in which just one component can be considered as active has been studied. These joints were selected as symmetrically loaded welded connections in which the beam width was the same as the column width. This focused the study on the component 'side walls of rectangular hollow sections (RHS) in tension/compression'. It should be one of the main components to be considered in welded unstiffened joints between I beams and RHS columns. Many experimental tests on double-sided I-beam-to-RHS-column joint with a width ratio 1 have been carried out by the authors and a finite element (FE) model was validated with their results. Then, some different analytical approaches for the component stiffness and strength have been assessed. Finally, the stiffness proposals have been compared with some FE simulations on I-beam-to-RHS-column joints. This work finally proposes the most adequate equations that were found for the stiffness and strength characterization of the component 'side walls of RHS in tension/compression' to be applied in a further unified global proposal for the application of the component method to RHS.

• Journal of the Korea Fashion and Costume Design Association
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• v.20 no.4
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• pp.17-30
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• 2018

This study discusses the ambivalence and ambiguity in the relationship between the women's body and fashion drawings in respect to post-feminism perspectives. Deconstructivist post-feminists, perceiving the body as a passive subject, asserted that women internalize the male gaze by becoming the object of male desire, then manipulate the body to conform to that ideal. In this perspective, corsets assumed the role of the tool for forcing women's body to be obedient, restraining and suppressing the body. On the other hand, in the essentialist post-feminist perspective, which regards the women's body as an active object, insists that fashion, in its essence, is not necessarily about sex, nor is it devised to attract the male gaze. In such a viewpoint, the women's body functions as a vehicle for empowerment; by wearing corset women gain power and embraces the cultural norms of dominant beauty. As investigated in this study, the corset is both a tool for oppressing the women's body, as well as a vehicle for the voluntary expression of femininity. This ambivalence in the perception of the corset in the post-feminist theory represents the double-sided perspective in fashion as being both a subordinate construction and a powerful tool for self-expression.

• The Journal of Korean Medicine
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• v.40 no.3
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• pp.21-34
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• 2019

Objectives: The purpose of this article is to develop steering of program accreditation system in Korean Medicine Education through meta-evaluation. For this study, the subjects of our research were categorized as the accreditation criteria and system, results and effects, tasks for improvement on Korean Medicine Education. Methods: We conducted Focus Group Interview on 102 full-time professors with experience of participating on accreditation of Korean Medicine Education from 12 college of Korean Medicine Education and we analyzed it by thematic analysis. Results: The accreditation criteria and program evaluation system of Korean Medicine were listed as 'Confusion about the goals of program evaluation', 'High hurdles on accreditation', 'obsession to success cases', 'Small college complaints about applying the same criteria', 'Dilemma of quantitative and qualitative evaluation'. The results and effects of program evaluation in Korean Medicine Education were listed as 'Establishment of base infrastructure for basic medical education', 'Benchmarking and exchanging opinions through evaluation certification', 'Resistance to documents and document-based evaluation', and 'Double-sided of evaluation certification'. As for the tasks for further improvement, the following list is suggested. 'Actively promote evaluation certification', 'Simplification and standardization of forms', 'Requesting for activating about Evaluation committee', 'Need for consulting before regular evaluation'. Conclusion: It is necessary to upgrade the accreditation system and make efforts to improve the issues discovered for better Korean Medicine Education.