• Current Applied Physics
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• 제18권11호
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• pp.1368-1374
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• 2018

In this paper, forced vibration was used to regulate the droplet migration, fully recording the transient migration of droplets on a micro-textured substrate under the resonance frequency by a high-speed camera. The influence of resonance frequency and dynamic migration characteristics of droplets on the solid micro-texture surface under lateral vibration were researched. The experiment demonstrates that the driving force is caused by the difference between the left and right contact angles made the droplet oscillate and migrate, and as time t increases, the left and right contact points are periodically shifted and the amplitude of migration increases. Therefore, based on the droplet migration behavior and its force balance mechanism, a spring vibration model of migration behavior of the vibrating droplet micro unit was set up to predict the complete trajectory of its migration on a solid surface. The calculation results show that the theoretical displacement is less than the experimental displacement, and the longer the time, the larger the difference. Affected by the vibration, part of the droplet permeates through the micro-texture, resulting in the droplet losing height and the contact angle becoming smaller as well. While the other part of droplet overcomes the internal surface tension to migrate.

• 대한후두음성언어의학회지
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• 제28권1호
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• pp.32-37
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• 2017

Background and Objectives : This study evaluated the efficacy of combination therapy of proton pump inhibitor (PPI) and steroid inhaler (SI), with or without botulinum toxin injection (BTX) for contact granuloma. Subjects and Methods : Fourteen contact granuloma patients were enrolled in this study. Combination therapy of PPI and SI were used for the first line treatment. When combination therapy was not effective, BTX was performed as the second method. Treatment results were recorded as responsible or non-responsible. Farwell grade, size, history of voice abuse, gender, and reflux finding score (RFS) were compared between responsible group and non-responsible group. Results : Initial response rate was 28.6% after treatment of PPI and SI. BTX was performed on three un-responsible patients. After BTX injection, three patients had complete remission of granuloma. Final response rate was 50.0%. Un-responsible group had significantly higher RFS than responsible group. Conclusion : The efficacy of PPI and SI was limited for contact granuloma in this study. Botulium toxin injection was recommended in early phase when PPI and SI did not effective for contact granuloma. Prospective studies evaluating the effects of PPI and SI are warranted.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.642-647
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• 2018

Gas compressors are mostly driven by motors. It is important to measure the power of motors to evaluate their power efficiency, because the mechanical loads of gas compressors are always varied. In order to measure the power given to the driving motors, the torque should be measured. Manufacturers of compressors usually use the torque data to calculate the compressors qualities such as power consumption, efficiencies and failures. In general, measurements for the shaft torque of the compressors have been based upon contact types, strain gauges. In the cases of larger compressors, the contact type of strain gauges have several disadvantages such as large size and high cost. In this study, a relatively inexpensive and simple torque sensing technique that is not restricted to shaft diameter is introduced using visualization technique. Particle image velocimetry (PIV) has been adopted to complete non-contact torques measurements for rotating motors. In order to compare the performance of the newly constructed torque measurement technique, torque measurement by a transducer based on MEMS technology has been performed simultaneously during experiments.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2709-2712
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• 2003

In this paper, dynamic constraints are considered for the analysis of manipulability of robotics systems comprised of two cooperating arms. Given bounds on the torques of joint actuators for each robot, the purpose of this study is to derive the bounds of task acceleration of object carried by the system. Under the assumption of complete constraint contact, a set of examplar polytope describing acceleration bounds of two cooperating robots are included.

• 대한수학회지
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• 제32권3호
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• pp.471-482
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• 1995

A complex n-dimensional Kaehlerian manifold of constant holomorphic sectional curvature c is called a comples space form, which is denoted by $M_n(c)$. A complete and simply connected complex space form consists of a complex projective space $P_nC$, a complex Euclidean space $C^n$ or a complex hyperbolic space $H_nC$, according as c > 0, c = 0 or c < 0. The induced almost contact metric structure of a real hypersurface M of $M_n(c)$ is denoted by $(\phi, \zeta, \eta, g)$.

• Korean Journal of Mathematics
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• 제29권3호
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• pp.547-554
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• 2021

The object of the present paper is to characterize Sasakian 3-manifolds admitting a gradient Ricci-Yamabe soliton. It is shown that a Sasakian 3-manifold M with constant scalar curvature admitting a proper gradient Ricci-Yamabe soliton is Einstein and locally isometric to a unit sphere. Also, the potential vector field is an infinitesimal automorphism of the contact metric structure. In addition, if M is complete, then it is compact.

• 한국안광학회지
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• 제7권1호
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• pp.15-20
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• 2002

콘택트렌즈 착용에 따른 사용자의 실태조사는 안경원과 안과에 내원한 콘택트렌즈 사용자 237명(남자 56명, 여자 181명)을 대상으로 문진과 세극 등 검사, 각막곡률 검사, 굴절검사 등을 하였다. 연구 결과 연령에 따른 현재 착용하고 있는 콘택트렌즈 착용률은 10대 40.9%, 20대 52.3%, 30대 5.5%, 40대 1.3%로 조사되었으며, 콘택트렌즈의 종류는 소프트콘택트렌즈의 경우 10대의 착용률은 82.5%, 20대 83.1%, 30대 38.5%이었으며, 하드 콘택트렌즈 착용률은 10대 17.5%, 20대 16.9%, 30대 61.5%로 조사되었다. 콘택트렌즈 착용목적은 전체 조사자의 40.5%는 안경이 불편해서, 32.1%는 미용목적으로 9.7%는 스포츠를 목적으로 17.7%는 시력교정목적으로 착용한 것으로 조사되었으며, 렌즈관리 시스템의 경우 전체 조사자의 16.5%는 매일세척을 하였으며, 29.1%는 매일 세척과 단백질 제거를 한 것으로 조사되었고, 21.9%는 매일세척과 다목적용액을 사용하였으며, 32.5%는 매일세척과 단백질제거 그리고 다목적용액을 사용한 것으로 조사되었다. 렌즈 착용시간은 10시간 이내가 31.6%, 11~13시간 미만의 경우가 41.3%, 14시간이상은 27%로 조사되었다. 콘택트렌즈 보관방법에서 62%는 보존액, 38%는 식염수를 사용하였다. 콘택트렌즈 교체 이유는 렌즈분실 35%, 렌즈손상 37.6% 이물질 침착 21.9%, 5.5%는 렌즈수명의 이유로 렌즈를 교체하였다. 현재 사용 중인 콘택트렌즈의 주요 자각증상은 급성 충혈의 자각증상 21%, 이물감 20.8%, 통증 19.6%, 건조감 9.4%, 흐린 시야 5.5%, 시야감소 3.8%, 유루 3.7%, 삼출물 2.8%, 가려움 2.6%, 자각증상이 없는 착용자는 10.2%로 조사되었다. 콘택트렌즈 사용자의 렌즈관리 교육에 대한 만족도에서 51%는 만족하였으나 28.7%는 불만족을 나타냈다. 착용자의 정기검사에서 81.1%는 정기검사를 하지 않았으며, 18.1%는 정기검사를 하고 있는 것으로 조사되었다.

• 구강회복응용과학지
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• 제35권2호
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• pp.90-97
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• 2019

목적: 교합접촉면적에 관련된 이전의 연구들은 교합두께 수준이나 교합측정방법 상 부정확성이 한계로 지적되어 왔다. 본 연구의 목적은 머리 위치가 교합접촉면적에 미치는 영향을 광조사교합분석법을 이용하여 조사하는 것이다. 연구 재료 및 방법: 건전한 치열을 갖는 54명(남성 44명, 여성 10명, 23 - 33세)을 대상으로 시험을 진행하였다. 머리 위치와 교합접촉면적의 관계를 알아보기 위해 시험대상은 치과용 유닛체어에 세 가지 자세(누운 자세($0^{\circ}$), 기울인 자세($45^{\circ}$), 직립 자세($90^{\circ}$))로 하여 최대 교두간 접촉위를 이용하여 악간관계기록을 채득하였다. 광조사교합분석기($BiteEye^{(R)}$)를 이용하여 교합접촉면적을 분석하였다. SPSS 25.0을 이용하여 유의수준 95%에서 통계분석을 시행하였다. 결과:머리 위치는 교합접촉면적과 유의미한 영향이 없는 것으로 나타났다(P > 0.05). 결론: 머리 위치는 교합접촉면적에 유의미한 영향이 없으므로 교합관계가 안정적이라면 최대 교두간접촉위의 악간관계 기록 채득 시 환자의 자세는 변수가 되지 않으며 광조사교합분석기를 이용한 교합접촉면적의 측정은 재료적, 용이성 측면으로 유용하다고 할 수 있다.

• The Journal of Advanced Prosthodontics
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• 제4권2호
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• pp.61-71
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• 2012

PURPOSE. To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS. Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS. Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION. Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.

• 대한치과보철학회지
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• 제32권4호
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• pp.515-525
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• 1994

Impression taking is a very important procedure in complete denture fabrication for reproduction of the tissue surface from which obtain retention and support of denture base. Therefore, we can not construct retentive denture without precise impression taking. Retention in complete denture can be obtained by the closest contact between denture base and underlying tissue, maximum coverage and proper displacement of the border tissue for peripheral sealing. Therefore, it is very important to take impression of the border tissue displaced properly. Nowadays, impression of the border tissue is mainly taken by the border molding techniques by means of manual muscle trimming, but due to various muscle trimming methods as clinicians, it is difficult to select proper method. This technique is also bodersome to do and time-consuming procedure. Retention is also likely reduced, because of the recording excessive muscle movement than actural physiological border tissue movement. Therefore, the impression technique that records actual physiologic functional muscle movement is helpful to increase denture retention and easy to do. We named this technique a functional border molding technique. This technique is originally introduced by D. J. Neill and R. I. Nairn in 1968. We tried to fabricate complete denture by the impression by means of functional border molding technique for better retention and the convenience, and obtained good results.