• The Journal of Advanced Prosthodontics
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• v.1 no.1
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• pp.31-36
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• 2009

PURPOSE. To determine the change in stability of single-stage, three different design of implant systems in humans utilizing resonance frequency analysis for early healing period(24 weeks), without loading. MATERIAL AND METHODS. Twenty-five patients were included into this study. A total of 45 implants, three different design of implant systems(group A,C,R) were placed in the posterior maxilla or mandible. The specific transducer for each implant system was used. ISQ(implant stability quotient) reading were obtained for each implant at the time of surgery, 3, 6, 8, 10, 12, 24 weeks postoperatively. Data were analyzed for different implant type, bone type, healing time, anatomical locations. RESULTS. For each implant system, a two-factor mixed-model ANOVA demonstrated that a significant effect on ISQ values(group A=0.0022, C=0.017, R=0.0018). For each implant system, in a two-factor mixed model ANOVA, and two-sample t-test, the main effect of jaw position(P > .005) on ISQ values were not significant. CONCLUSIONS. All the implant groups A, C and R, the change patterns of ISQ over time differed by bone type. Implant stability increased greatly between week 0 and week six and showed slow increase between week six and six months(plateau effect).

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.119-122
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• 2005

In this paper, we investigated the recognition range according to modulation index for the ISO(International Standards Organization) 14443 13.56MHz contactless Type B RFID(Radio Frequency IDentification) system. We measured recognition range with changing modulation index step by step from 5% to 24% where we used 4 samples of Type B transponder with different resonance frequencies between 13.838MHz and 17.200MHz. While gradually increasing a distance in vertical direction from the center of the reader antenna, we measured the distance where the transponder's PUPI(Pseudo Unique PICC(Proximity IC Card) Identifier) is recognized continuously during 10 seconds and the distance where the transponder's PUPI is recognized at least two times during 5 seconds. From the measurement results, we found that the best recognition ranges were achieved when the reader had modulation index between 11% and 14%.

• Clinics in Shoulder and Elbow
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• v.19 no.4
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• pp.237-240
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• 2016

Retear patterns after arthroscopic rotator cuff repair are classified into two patterns according to retear location. Type 1 is when the retear pattern occurs directly on the tendon at the bone repair site using the suture anchor repair method. Type 2 is when the retear pattern occurs at the musculocutaneous junction with a healed footprint in patients who undergo the suture bridge method. Here, the authors report another retear pattern, which was identified as a type 2 retear on magnetic resonance imaging in patients who had undergone arthroscopic rotator cuff repair by the suture-bridge technique. This pattern was different from the type 2 retear and occurred at the portion of the cuff away from the healed rotator cuff under the view of the arthroscope.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.64-71
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• 2003

In order to analyze the effect of the chemical structure and the cetane number of reformed diesel fuels by ultrasonic energy irradiation, proton nuclear magnetic resonance spectrometer$(^1H-NMR)$ was used. From the study, following conclusive remarks can be made. 1) Branch Index(BI), aromatics percentages, and alpha methyl radical$(H_{\alpha})$ of the reformed diesel fuels by ultrasonic energy irradiation decreased more than the conventional ones. 2) All the cetane numbers which were calculated from carbon type structure and hydrogen type distribution of the reformed diesel fuels increased more than the conventional ones. 3) It is more reasonable to predict cetane number equation from carbon type structure than from hydrogen type distribution. 4) BI, aromatics percentages, and $H_{\alpha}$ on both for conventional fuel and reformed diesel fuels by ultrasonic energy irradiation are inversely proportional to cetane number fur these fuels.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.838-841
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• 2003

The aim of the study is to scrutinize the relationship between the area of resonance and insertion loss by analyzing the characteristics of 2-port resonator. This was done through designing an air-gap type Film Bulk Acoustic Resonator (FBAR) by using CAD model for the application of bandpass filter of high-frequency band with piezoelectric thin film. Moreover, through the design of ladder-type BPF, we were able to observe changes in bandwidth, resonation, out-of-band rejection depending on the number and area of resonator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.110-113
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• 2001

In this paper, vibration mode of Windmill type Ultrasonic Motors was analysed. We used the ANSYS program to analysis by FEM. Vibration Mode express 20 modes as each resonance frequency. We bind nearly same modes and compress 5 modes. Windmill type Ultrasonic Motor's rotation is generated the friction of rotor at top endcap. Thus, We will find the best driving frequency that generating large friction at top endcap.

• Journal of Aerospace System Engineering
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• v.4 no.2
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• pp.21-25
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• 2010

Fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. However, it is very difficult to apply conventional fatigue test loads in short period. Therefore, accelerating test speed and facilitating spectrum load realization are required. In this study, we have developed a fatigue testing method that uses a resonance of simply supported beam type blade specimen. This test consists in exciting the blade specimen with a frequency that corresponds to its natural frequency. In that case, the test specimen similar to a beam fixed between two pivot points starts vibrating and is significantly deformed. Resonant fatigue tests were performed by changing exciting vertical amplitude and frequency, and S-N curves of each composite materials were successfully obtained.

• Journal of the Korean Magnetic Resonance Society
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• v.1 no.2
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• pp.63-70
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• 1997

The conformation of the self-complementary decamer duplex, d(ACGTATACGT)2 (TATA-duplex) has been studied by proton NMR spectroscopy. The duplex is essentially B-type, with distortions apparent at the TATA steps. These conformational distortion which may be preferable to occur in the thymine residue on the 5'-side, has been investigated by unusual NOE crosspeaks.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.1-7
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• 2010

Fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. However, it is very difficult to apply conventional fatigue test loads in short period. Therefore, accelerating test speed and facilitating spectrum load realization are required. In this study, we have developed a fatigue testing method that uses a resonance of simply supported beam type blade specimen. This test consists in exciting the blade specimen with a frequency that corresponds to its natural frequency. In that case, the test specimen similar to a beam fixed between two pivot points starts vibrating and is significantly deformed. Resonant fatigue tests were performed by changing exciting vertical amplitude and frequency, and S-N curves of each composite materials were successfully obtained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.2002-2008
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• 2001

Nonlinear vibration characteristics of a piezoelectric-type micro actuator used for hard disk drives are experimentally studied. The nonlinear characterisitics include hysteresis, superharmonic resonance, jump phenomenon, and shifting of natural frequencies. The vibration modes and frequencies of the commercial actuator of the Hutchinson's Magnum series are measured using a laser vibrometer. From harmonic excitation to the PZT acturator, we observe interesting hysteresis patterns with 3 times input frequency. It is shown that the micro actuator has the typical 3 times superhamonic resonances coupled to the first torsional and sway modes of the suspension.