• 대한치과보철학회지
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• 제36권5호
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• pp.669-682
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• 1998

The purpose of this study was to compare the retentive force of cast half round circumferential clasps, cast round circumferential clasps and wrought wire clasps on three different depths of undercut(10G,20G.30G), and to determine the proper amount of undercut for cast round circumferential clasp. Three different lower second premolar crowns were cast and each of clasp was made. Each of clasp affixed to the different types of clasp. Their retentive forces were measured with universal testing machine. The results were as follows : 1. When the depth of undercut was same, the greatest retentive force was exerted by cast half round circumferential clasp, followed by cast round - 33 - circumferential clasp and wrought wire clasp. 2. The degree of variation amount of retentive force according to depth of undercut was greatest for cast round circumferential clasp. 3. Not only elastic deformation but also permanent deformation of the retentive arm was observed after insertion and removal of the clasp. The results of this study show that the retentive force of cast round circumferential clasp falls between those of cast half round circumferential clasp and wrought wire clasp, and suggest that a 20G undercut is suitable for ensuring an appropriate degree of the retentive force.

• 토지주택연구
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• 제8권3호
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• pp.211-221
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• 2017

This study proposed hybrid coupled shear wall in the steel plate insertion method, which is capable of reinforcing the shear strength of the entire wall without increasing wall thickness in the wall-slab apartment buildings. The proposed hybrid coupled shear wall was tested for its effectiveness, shear strength and seismic behavior in experiment. As a test result, the shear strength improvement by the proposed hybrid coupled shear was found effective. Integral-type of steel plate insertion was found more effective than separate-type steel plate insertion. In this case, if the stud enforcement method proposed in this study was used, the shear strength of hybrid coupled shear wall was recommended to calculate using the KBC2016 0709.4.1(3) method. The steel plate inserted in the proposed method was found to have no significant impact on the final fracture behavior and bending strength of hybrid coupled shear wall. The shear strength at the final destruction of the wall was merely about 1/50 of the entire design shear strength. Thus, it is deemed that the wall was over excessively designed regarding the shear force in the existing design method. This finding indicates further study on wall designing to ensure effective and economic designing based on appropriate strength estimation under the destruction mechanism.

• 구강회복응용과학지
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• 제26권2호
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• pp.205-220
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• 2010

본 연구에서는 임플란트 디자인이 주입회전력과 주변 응력에 미치는 영향을 알아보고자 삼차원 유한 요소 분석을 이용하여 유효 응력과 모멘트 그리고 축력을 측정, 비교 조사하였다. 나사형 임플란트 매식체의 디자인을 4종의 평행형과 7종의 근첨형으로 구분하였고 하악골 소구치 부위에 식립한 것으로 가정하여 유한 요소 모델을 제작하였다. 각각의 임플란트가 식립될 때 주변부에 발생하는 응력을 분석하였으며 그 결과 근첨형 임플란트가 평행형 임플란트에 비해 높은 식립 회전력을 보여 초기 고정력이 우수할 것으로 예상되었으나 응력 분산 측면에 있어서는 효율성이 낮은 양상을 나타내었다. 근첨형 임플란트에 비해 평행형 임플란트가 나사산의 높이에 따른 영향을 크게 받는 것으로 나타났으며 근첨형 임플란트는 임플란트 몸체의 경사도가 증가함에 따라 높은 응력이 발생되는 것이 관찰되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.468-472
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• 2005

This paper is to investigate the influence of the endface quality on the loss characteristics of a plastic optical fiber connector for in-car network service. Using the parameters of the surface roughness and applied load, insertion loss of connector is measured. Due to scattering and change of refractive index, an optimal condition for low-loss coupling exists. We present the optimal condition as surface roughness $R_{rms}$ = 8 nm and contact load up to 50 N.

• 센서학회지
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• 제16권3호
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• pp.240-245
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• 2007

AlN thin film for SAW filter application was deposited on (100) silicon, sapphire, $Si_{3}N_{4}$/Si, and $Al_{2}O_{3}$/Si substrates by reactive magnetron sputtering method, respectively. The structural characteristics were dependent on the structure of substrates. Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Atomic Force Microscope (AFM) have been used to analyze structural properties and preferred orientation of AlN thin films. Preferred orientation and SAW characteristic of AlN were improved by insertion of $Al_{2}O_{3}$ buffer layer. Insertion loss of SAW devices using AlN/Si and AlN/$Al_{2}O_{3}$/Si were about 33.27 dB and 30.20 dB, respectively.

• Transactions on Electrical and Electronic Materials
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• 제3권1호
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• pp.42-45
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• 2002

Properties of lead zirconate titanate ferroelectric thin films prepared by rapid thermal annealing/direct insertion thermal annealing were investigated. The remnant polarization (Pr), saturation polarization (Ps), and coercive force (Ec) of typical samples annealed by rapid thermal annealing (RTA) are about 13.7 $\mu$ C/cm$^2$, 27.1 $\mu$C/cm$^2$, and 55.6 kV/cm, respectively. The dielectric constant of the sample is about 786, the dielectric loss tangent is about 2.4% at 1 kHz. Furthermore, ferroelectric, conduction, and piezoelectric properties of the thin films annealed by RTA process and the direct insertion thermal annealing (DITA) process were compared. The influence of temperature in the dry process on the above properties was also investigated.

• Neurospine
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• 제15권4호
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• pp.362-367
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• 2018

Objective: To assess the efficacy of cervical open-door laminoplasty by hydroxyapatite implant insertion between the lamina and the lateral mass without suturing. Methods: All patients who underwent cervical open-door laminoplasty with C2/C7 undermining and insertion of hydroxyapatite implants from C3 to C6 were retrospectively evaluated for surgical time and neurological outcomes according to the Japanese Orthopaedic Association (JOA) score. To assess the alignment of the cervical spine and postoperative cervical pain, the C2-7 angle and a visual analogue scale score were used, respectively. Results: The population consisted of 102 women and 222 men ranging in age from 32 to 90 years. The average surgical time was 86 minutes. Fourteen of 1,296 hydroxyapatite implants were kept in place with sutures due to a weak restoration force of the hinge during surgery. No hydroxyapatite implant dislocation was detected on cervical computed tomography at 1 year after surgery. The average JOA score was $10.2{\pm}2.5$ before surgery and $14.6{\pm}2.8$ at 1 year after surgery. The average recovery rate was 61.8%. The average C2-7 angle at the neutral position was $7.1^{\circ}{\pm}6.2^{\circ}$ before surgery and $6.5^{\circ}{\pm}6.3^{\circ}$ at 1 year after surgery. Conclusion: This method enabled us to achieve minimal exposure of the lateral mass, prevention of lateral mass injury and dural injury, and a shorter surgical time while maintaining acceptable surgical outcomes. The idea that firm suture fixation is needed to prevent spacer deviation during cervical open-door laminoplasty may need to be revisited.

• 한국소음진동공학회논문집
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• 제19권10호
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• pp.1062-1068
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• 2009

In this study, the impact force levels of bang machine and impact ball were measured, then the heavy-weight impact sounds generated by the bang machine and impact ball were investigated. It was found that the heavy-weight impact sources generated through modal excitation, and the impact force of the impact ball was similar to that of real impact source. The heavy-weight impact sounds were also measured in the real apartments with different slab thickness and floor structures. The results showed that the floor impact sound levels in terms of $L_{iFmax,AW}$, generated by impact ball sounds were reduced by using the resilient isolators. The frequency characteristics of heavy-weight impact sounds at 125 and 250 Hz were consistent with the characteristics of impact force spectrum. However, the difference between the impact sounds and the impact forces were found at 63 and 500 Hz due to the resonance of the floor structure and flanking noise, respectively.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2009년도 제17차 학술대회
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• pp.74-74
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• 2009

The purpose of this study was to estimate force of muscles that constituted the rotator cuff during elevation motion in scapula plane, using a skeletal muscle model and quantitatively evaluate rotator cuff function in vivo. A healthy volunteer was measured with an open MR and CT system at elevation positions in scapula plane (MR: $30^{\circ}$, $60^{\circ}$, $90^{\circ}$, $120^{\circ}$, $150^{\circ}$, CT: $0^{\circ}$). After reconstruction three-dimensional MRI-based and CT-based bone surface models, matched each models with registration technique. Then supraspinatus, infraspinatus, subscapularis, teres minor, deltoid (anterior, middle, posterior portions) represented as plural lines. These lines were proportional to physiologic cross-sectional area (PCSA) and defined straight line to bind origin and insertion. Force of supraspinatus became greatest at $59^{\circ}$ of elevation. Subsequently force of deltoid middle portion became greatest at $89^{\circ}$ of elevation. Infraspinatus and subscapularis were active at the meantime. In addition, supraspinatus was active during elevation. These results resembled clinical finding and were proved force couples that contribute to mobility and stability of shoulder complex.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.125-129
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• 2016

In this study, we have investigated a high-temperature AlN nucleation layer and AlGaN epilayers on c-plane sapphire substrate by low-pressure metal-organic chemical vapor deposition (LP-MOCVD). High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), scanning electron microscope (SEM) and Raman scattering measurements have been exploited to study the crystal quality, surface morphology, and residual strain of the HT-AlN nucleation layer. These analyses reveal that the insertion of an LT-AlN nucleation layer can improve the crystal quality, smooth the surface morphology of the HT-AlN nucleation layer and further reduce the threading dislocation density of AlGaN epifilms. The mechanism of inserting an LT-AlN nucleation layer to enhance the optical properties of HT-AlN nucleation layer and AlGaN epifilm are discussed from the viewpoint of driving force of reaction in this paper.