• The Journal of Korean Academy of Prosthodontics
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• v.30 no.3
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• pp.401-410
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• 1992

The purpose of this study was to investigate the dimensional changes and surface morphology of dentures processed by various polymerization conditions. The measurements were done by taking radiograph and using vernier calipers and each specimen was observed on scanning electron microscope. Results obtained were as follows. 1. The difference of dimensional stability was not recognized between various polymerization conditions(heat-cured resin, pour-type resin, microwave-cured resin, and injection molding resin). 2. There were expansion and shrinkage in the occlusal dimension, shrinkage in the frontal dimension, and expansion in the lateral dimension. 3. Scanning electron microscope pictures of heat-cured resin showed dense and regular surface morphology. 4. Microwave-cured resin surface appeared more regular and smooth than pour-type resin but less dense and more irregular than heat-cured resin. 5. Scanning electron microscope pictures of pour-type resin with the lowest dimensional change showed the most irregular surface morphology.

• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.162-171
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• 2020

The incidences of cardiovascular diseases are rapidly increasing worldwide. The electrocardiogram (ECG) is a test to detect and monitor heart issues via electric signals in the heart. Presently, detecting heart disease in real time is not only possible but also easy using the myDAQ data acquisition device and LabVIEW. Hence, this paper proposes a system that can acquire ECG signals in real time, as well as detect heart abnormalities, and through light-emitting diodes (LEDs) it can simultaneously reveal whether a particular waveform is in range or otherwise. The main hardware components used in the system are the myDAQ device, Vernier adapter, and ECG sensor, which are connected to ECG monitoring electrodes for data acquisition from the human body, while further processing is accomplished using the LabVIEW software. In the Results section, the proposed system is compared with some other studies based on the features detected. This system is tested on 10 randomly selected people, and the results are presented in the Simulation Results section.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.226-231
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• 2015

The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.43-51
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• 2015

Wood shrinkage, an important study subject with regard to the use of wood, has long been studied by researchers. However, when the size of a wood specimen is measured, distortion must be taken into account, which can be accomplished by applying external force on the wood specimen. However, when measuring a large number of specimens, this technique can be a lengthy process. If the size is measured and the shrinkage is calculated from images acquired with a flatbed scanner, it is possible to reduce the error in the measurement and to shorten the measurement time because the images of many specimens can be acquired with one scan. To clearly establish the boundary between a wood specimen and the background in a scan, an image threshold method was applied here. The size of a wood specimen measured by means of a scanner image was found to be longer than the value determined with a vernier caliper. The maximum pixel size of a scan image for highly accurate shrinkage calculations compared with the use of a vernier caliper was 0.053 mm/pixel.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.247-254
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• 2003

This paper describes a Delay Locked Loop (DLL) with low supply voltage and wide lock range for Synchronous DRAM which employs Double Data Rate (DDR) technique for faster data transmission. To obtain high resolution and fast lock-on time, a new type of phase detector is designed. The new counter and lock indicator structure are suggested based on the Dual-clock dual-data Flip Flop (DCDD FF). The DCDD FF reduces the size of counter and lock indicator by about 70%. The delay line is composed of coarse and fine units. By the use of fast phase detector, the coarse delay line can detect minute phase difference of 0.2 nsec and below. Aided further by the new type of 3-step vernier fine delay line, this DLL circuit achieves unprecedented timing resolution of 25psec. This DLL spans wide locking range from 500MHz to 500MHz and generates high-speed clocks with fast lock-on time of less than 5 clocks. When designed using 0.25 um CMOS technology with 1.8V supply voltage, the circuit consumes 32mA at 500MHz locked condition. This circuit can be also used for other applications as well, such as synchronization of high frequency communication systems.

• Journal of Technologic Dentistry
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• v.35 no.1
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• pp.29-35
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• 2013

Purpose: The purpose of this study was to evaluate the validity of digital models fabricated by dental scannable stone. Methods: Twenty same cases of stone models(maxillary full arch) were manufactured. Intercanine distance, intermolar distance, two dental arch lengths(right, left), two diagonal of dental arch lengths(right, left) were measured for comparison. Each of ten stone models were measured by digital vernier calipers and scanned by dental scanner. Ten digital models were measured by CAD program. The mean(SDs) values were compared by a Mann-Whitney U test(${\alpha}$=0.05). Results: No statistically significant differences between the two groups were found at intermolar distance, dental arch length(right)(p>0.05). However, intercanine distance, dental arch length(left) and two diagonal of dental arch lengths(right, left) were statistically significant(p<0.05). Conclusion: Stone models fabricated by dental scannable stone showed larger than digital models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.1-7
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• 2016

In the dentistry field, an ultrasonic surgery unit is widely used in bone cutting and scaling to reduce operation time and minimize hemorrhage. The purpose of this study was to evaluate bone cutting and the effect of a specimen's temperature on the two-type ultrasonic surgery unit using a handpiece moving system(HMS). A HMS, which can cut the bone, was developed to perform the experimental procedure with precision of motion control. Bone specimens were prepared from a combination of epoxy-hardener and cortical bone of bovine leg. Through the bone-cutting experiment, the cutting depth was evaluated by not only scanning electron microscopy, but also Vernier calipers. Also, the temperature distribution was measured by a thermo-graphic camera. This study may be applied methodically in various experimental evaluations on a performance test by a HMS.

• Physical Therapy Korea
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• v.20 no.3
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• pp.54-61
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• 2013

This study was to determine the reliability and validity of manual measurements of patellar height to standard radiographic measurements in 30 knees of 15 subjects. Patellar height was measured using manual and radiographic methods. The manual measurements were performed by two examiners using digital vernier calipers with the subject sitting and the knees in $30^{\circ}$ of flexion. The radiographic measurements were performed in the same position. The reliability of the manual measurements was assessed by means of intraclass correlation coefficients [ICC(3,1)], and the validity was investigated using the Pearson's product-moment correlation coefficient and an independent t-test. The intra- and inter-rater reliabilities of the manual measurement of patellar height were excellent (ICC=.86 and .88 respectively). The validity of patellar height measured manually compared to the radiographic method was good (Pearson's r=.69). In conclusion, the manual method is an objective, qualitative measurement of patella height.

• The Journal of the Acoustical Society of Korea
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• v.24 no.3E
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• pp.90-98
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• 2005

Enhanced approach using computational and experimental method is proposed and performed to describe very well the behavior of loudspeaker than conventional method. Proposed procedure is composed of four parts. First, Thiele-Small parameters for test loudspeaker are identified by an electrical impedance method like as a delta mass method. Second part includes the processes to measure physical properties. Physical data like masses and thicknesses of loudspeaker's components are measured by an electrical precision scale and a digital vernier caliper. Third, the identified Thiele-Small parameters are proposed to be used as load boundary conditions for vibration analysis instead of electromagnetic circuit analysis to get a driving force upon bobbin part. Also, these parameters and physical data are used to modify physical properties required for computation to accommodate simulated sound pressure level with measured one for loudspeaker enclosure system. These data like as Young's modulus and thickness for a diaphragm are required for vibration analysis of loudspeaker but not measured accurately. Finally, it was investigated that simulated sound pressure level with full acoustic modeling including an acoustic port for test loudspeaker agreed with experimental result very well in the midrange frequency band(from 100 Hz to 2,000 Hz). In addition, several design parametric study is performed to grasp acoustical behaviors of loudspeaker system due to variations of diaphragm thicknesses and shapes of dust cap.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.190-199
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• 1991

The purpose of this study was to evaluate the antimicrobial effect of root canal cements such as AH-26, Sealapex, Canals and Apatite root sealers(Type I, II, III) and to determine the efficacy of their activities. S.mutans(AHT), S.sanguis(NCTC 9811) and B.gingivalis(381) were streaked on blood agar and the PVC tybes filled with root canal cements were applied on. Then the microorganisms were cultured for 48 hours, anaerobically. B.cereus(KCTC 1012) was streaked on nutrient agar, PVC tubes were applied on and were cultured for 48 hours, aerobically. The inhibition zones of root canal cements were measured with vernier caliper. The data statistically analyzed, and the results were as followed. 1. Apatite root sealers(Type I, II, III) showed no inhibition zones. 2. AH-26, Sealapex and Canals had inhibition zones with varying degrees. The inhibition zone of AH-26 was greatest and followed by Canals and Sealapex(P<0.01). 3. As time goes by after mixing the root canal cements, AH-26, Canals and Sealapex showed significantly reducing inhibition zones(P<0.01). 4. There were the least inhibition zones of all the root canal cements on S.mutans and followed in such order as; B.gingivalis, S.sanguis and B.cereus(P<0.01).