• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.1 s.118
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• pp.24-32
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• 2007

This paper presents a finite element method to analyze the free vibration of a flexible HDD composed of the spinning disk-spindle system with fluid dynamic bearings(FDBs), the head-suspension-actuator with pivot bearings, and the base plate with complicated geometry. Experimental modal testing shows that the proposed method well predicts the vibration characteristics of a HDD. This research also shows that even the vibration motion of the spinning disk corresponding to half-speed whirl and the pure disk mode are transferred to a head-suspension-actuator and base plate through the air bearing and the pivot bearing consecutively. The proposed method can be effectively extended to investigate the forced vibration of a HDD and to design a robust HDD against shock.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.115-118
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• 2011

코호트 연구를 위한 식사조사 프로그램에 대한 수요는 나날이 증가하고 있는 반면 프로그램의 공급은 원활하지 않은 실정이다. 이 때문에 식사조사 프로그램을 SaaS 플랫폼을 기반으로 하는 연구가 활발해 지고 있다. 대부분의 SaaS 플랫폼 기반 소프트웨어는 멀티테넌시 기술을 지원한다. 하지만 멀티테넌시 기술을 지원하기 위해서는 데이터베이스에서 여러 테넌트를 지원해야 하기 때문에 구조의 변화가 불가피 하다. 멀티테넌시를 구현하기 위해서는 논리적인 스키마로부터 물리적인 스키마로의 매핑기술이 필요하다. 데이터베이스 스키마 매핑 기술에는 Pivot table, Chunk table 등이 있는데 이 기술을 이용하여 기존의 DB구조를 변경하여 여러 테넌트가 DB를 공유할 수 있고 결합될 수 있어야 한다. 이에 본 논문에서는 SaaS 기반 식사조사를 위한 pivot table과 chunk table을 보이고 실험을 통하여 chunk table구조가 좀 더 효율적이라는 사실을 보인다.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.575-580
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• 2016

This paper sought to find a way to improve the fuel consumption rate of a vehicle for the Shell Eco-marathon Asia 2014, with a special focus on the correlation between vehicle dynamics, aerodynamics and chassis weight reduction. In 'KUTY-Eco 1' designed for SEM Asia 2014, a chassis made with an aluminum alloy tube, semi-monocoque structure and a pivot steering system were adopted to reduce weight and to secure better performance. The goals were achieved using computer-aided engineering(CAE) and parameter study. Finally, 'KUTY-Eco 1' was created, the lightest car in the competition's prototype petrol(gasoline) type category. 'KUTY-Eco 1' secured the official record of 142.7 km/liter during the competition.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1063-1070
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• 1988

The influence of the inlet pressure on bearing performance of tilting pad bearings in laminar regime is examined. A simple flow model is presented to calculate the inlet pressure in inlet flow that occurs at a short distance ahead of the bearing inlet. The bearing performances are obtained, load capacity, friction torque and lubricated flow-rate, etc, numerically for the inlet pressure boundary conditions with and without pressure jump. The computed results of both cases show that bearing performance and the optimum pivot position changes remarkably according to the bearing operating conditions. The influence of the inlet pressure on bearing performance must be considered to analyze the bearing performance precisely.

• Journal of Contemporary Eastern Asia
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• v.18 no.1
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• pp.1-6
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• 2019

During the Obama administration, America made a shift in its foreign policies to re-focus on Asia. The strategy, known as 'Pivot to Asia', was used to contain a rising China. In this editorial note, I appropriate the geopolitical term to call for a scholarly refocus on Asia (and the broader Asia Pacific region). JCEA started as an area journal. While it has become more technology-focused and less geographically-bounded in its coverage of topics, the journal recognizes the centrality of the region's political economy and technological forces in setting (and upsetting) global norms and rules. The Asia Pacific contains the world's freest economies as well as the most oppressive regimes. It breeds both technology giants and laggards. As new geopolitical tensions loom, it is where the digital iron curtain is drawn, and where the vice and virtue of innovations debated. Social scientists in the English world, who lend extensively on European and American cases, can benefit from studying the Asia Pacific by testing whether and how local experience conforms to or confronts with universal theories. Very likely, western-centric norms and models become morphed and entangled in the grounded local particularity, reflecting many shades of this diverse place. In my arguments below, I highlight the Asia Pacific as a site of contradiction, as well as a site of contention and negotiation. My emphasis is that regional particularity holds the key to answer concurrent debates in the West concerning governance and accountability in the digital age.

• Structural Engineering and Mechanics
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• v.89 no.1
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• pp.77-91
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• 2024

During strong seismic events, inelastic shear deformation occurs in beam-column joints. To capture inelastic shear deformation, an analytical model for beam-column joint in reinforced concrete (RC) frame structures has been proposed in this study. The proposed model has been developed using a rotational spring and rigid links. The stiffness properties of the rotational spring element have been assigned in terms of a moment rotation curve developed from the shear stress-strain backbone curve. The inelastic rotation behavior of joint has been categorized in three stages viz. cracking, yielding and ultimate. The joint shear stress and strain values at these stages have been estimated using analytical models and experimental database respectively. The stiffness properties of joint rotational spring have been modified by incorporating a geometry factor based on dimensions of adjoining beam and column members. The hysteretic response of the joint rotational spring has been defined by a pivot hysteresis model. The response of the proposed analytical model has been verified initially at the component level and later at the structural level with the two actually tested RC frame structures. The proposed joint model effectively emulates the inelastic behavior precisely with the experimental results at component as well as at structural levels.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.12-17
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• 2008

Purpose: This study presents clinical results of anterior cruciate ligament(ACL) augmentation using autogenous two-strand semitendinosus tendon in the treatment of partial ACL tears with preservation of residual portion. Materials and Methods: From January 2004 to June 2006, twenty two patients who had an ACL injury underwent ACL augmentation using autogenous two-strand semitendinosus tendon were enrolled in this study. We evaluated the clinical results with regard to clinical findings(range of motion, Lachman test, pivot shift test), standard knee scales(Lysholm, Modified Feagin Scoring System), and KT-1000 arthrometer testing. Results: At minimum one year postoperatively, there was no limitation of range of motion. Lachman and pivot shift tests were negative in all knees. On instrumented anterior laxity test by KT-1000 arthrometer, mean side to side difference was improved from 4.6mm preoperatively to 1.7mm postoperatively. Average Lysholm score was improved from 70 to 92. Ninety one percent of cases were rated as good or excellent in Modified Feagin Scoring System. Conclusion: Augmentation using autogenous two-strand semitendinosus tendon with preservation of residual portion of the ACL seems to be an acceptable method for restoring knee stability and proprioceptive function.

• Journal of the Korean Arthroscopy Society
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• v.11 no.2
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• pp.85-91
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• 2007

Purpose: To analyze the clinical results and second look arthroscopic findings of anterior cruciate ligament(ACL) reconstruction with a tibialis anterior tendon allograft and a hamstring tendon autograft. Materials and Methods: We reviewed the cases of athroscopic ACL reconstructions using allogenous tibialis anterior(TA) tendon and autogenous hamstring tendon done from March, 2002 to August, 2005 and followed-up more than 1 year. The 250 cases were included in this study and allogenous TA tendon was used in 150 cases and autogenous hamstring tendon in 100 cases. The mean follow-up period was 15 months and 14 months, respectively. The clinical evaluation was done by Lachman test, Pivot shift test, KT-1000 arthrometer and International Knee Documentation Committee(IKDC) knee score. Graft tension, synovial coverage were observed in cases of second look arthroscopy. Results: At final follow-up, there was no significance between the two groups in clinical examination. On second look arthroscopy, synovial coverage was better in autogenous hamstring tendon group than allogenous TA tendon group(p=0.005). But no difference was found in graft tension(p>0.05). Conclusion: There were no significant differences between the two groups in the clinical results. But autogenous hamstring tendon group had better synovial coverage than allogenous TA tendon group in second look arthroscopy.

• Journal of the Korea Society for Simulation
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• v.27 no.4
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• pp.19-26
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• 2018

The aerial launching UAV(Unmanned Aerial Vehicle) mainly uses a set of folding tandem wings to maximize flight performance and minimize the space required for mounting in a mothership. This folding tandem wing has a unique aerodynamic problem that is different from the general type of fixed wing aircraft, such as the rear wing interference problem caused by the wing of the front wing wake and vortex, and the imbalance of the pivot moment applied to the front and rear wings when the wing is deployed. In this paper, we have modeled and simulated various cases through computational fluid dynamics based on the finite volume method and analyzed various aerodynamic phenomena of the tandem wing type aircraft. We find that the front wing shall be installed higher than the rear for minimizing the wake influence and the rear wing can be deployed faster than the front because of the pivot moment due to aerodynamic forces. Also, considering the pivot moment due to aerodynamic force, the rear wing can be deployed much faster than the front wing. Therefore, it is necessary to consider it when developing the wing deploy mechanism.

• Journal of the Daesoon Academy of Sciences
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• v.34
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• pp.1-26
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• 2020

In Taiwanese Daoism, the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe (九天應元雷聲普化天尊) is the highest deity in the Thunder Ministry. In the the Korean new religion, Daesoon Jinrihoe (大巡真理會), he is the Supreme God. However, since the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe has the same name in these two traditions, it naturally leads people to wonder whether or not they can be considered the same deity. Or failing that, it could still be asked, to what extent are these two deities related? Or it could further be asked what meaning does the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe have in these two religions? Anyhow, all such questions depend on first establishing a greater degree of basic clarity. Religious scripture can serve as a cornerstone in gaining such basic clarity. Scripture almost invariably contains information regarding the divine nature, divine authority, and sacrosanctity of deities reflective of what is understood by the devotees of those religions. Clues on the precise nature of these key attributes of deity-depiction can be drawn out of scriptural accounts, and as such, the research presented in this paper will begin by comparing two relevant scriptures. The representative scriptures highlighted in this paper will be The Canonical Scripture (典經) of Daesoon Jinrihoe and The Scripture of the Jade Pivot (玉樞寶經) of Zhengyi (Orthodox Unity, 正一) Daoism. These scriptures will serve as the basis for exploration and analysis of the divine attributes of the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe in terms of his divine nature, divine authority, and sacrosanctity. By comparing these two scriptural accounts of his divine attributes, the similarities and differences that arise can be properly explored. This paper endeavors to clarify the ultimate purpose of 'the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe.' In this paper, the first step will be an exploration of scriptural analysis. The contents of this paper is roughly divided into four sections. The first section is an exploration of the general contents of the two scriptures, including their origin, contents, and value. The second section focuses on the three main divine attributes of the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe: his divine nature, divine authority, and sacrosanctity. The third section will compare the depictions of the deity in the two scriptural accounts in terms of those three attributes. Lastly, the deity's evolutionary history in both religions is shown and compared and final remarks are made on the contemporary value of the Celestial Worthy of the Ninth Heaven, Responder, Thunderbolt-bearer, and Transformer of the Universe.