• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1963-1964
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• 2008

Scan design is a structured design-for-testability technique in which flip-flops are re-designed so that the flip-flops are chained in shift registers. We propose a new technique to re-design about clock operation. This technique propose about low power operation of scan clock and saved time of test operation.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.42-49
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• 2011

Ultrasonography is a powerful and useful method for the examination of the various shoulder diseases. The use of high-resolution transducer and technical evolution allowed the improvement of the accuracy of detection of various shoulder pathology including the rotator cuff disease. However, its limitation is that there is marked disparity in the interpretation according to the operators' experience. This article describes the appropriate scan technique of ultrasonography around shoulder.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.241-246
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• 2002

Usually vibration properties are obtained from frequency response functions or impulse response functions of a system. Since the contact type sensors can affect the characteristics of vibrating systems, the non-contact type sensors such as laser Doppler vibrometer (LDV) are being widely used. Currently researches are being carried out in terms of modal analysis using a scanning vibrometer. For the continuous scan; the Chebyshev demodulation (or polynomial) is apparently suggested to extract the mode shapes. With single frequency sinusoidal excitation, this approach is well fitted. In this research, the Chebyshev demodulation technique has been applied to the impact excitation case. The vibration of the tested structure is modeled using impulse response functions. The technique is also adopted to the random excitation case. In order to verify the technique, a simply supported beam was chosen as the test rig. The calculation modules are developed by using MATLAB$\^$(R)/ in WindowsNT$\^$(R)/ environment.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.89-94
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• 2020

This paper proposes a better shielding method to over sampling technique. The new method uses aluminum foil for RF shielding. As a result of the phantom test, when the over-sampling technique was applied, the aliasing artifact was reduced by about 94% compared to before the application, and the case where the aluminum shielding band was applied was also reduced by about 92% compared to before application. In addition, the scan time also increased by more than 3 times in the case of the over-sampling technique, while it was found that there was no change from before the application of the aluminum shielding band Therefore, it was confirmed that the shielding band using aluminum foil can effectively remove aliasing artifacts without increasing the scan time..

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.101-106
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• 2005

A ground penetrating image radar (GPR) using an ultra wideband (UWB)impulse waveform is developed for non destructive detection of metallic pipelines buried under the ground. Dielectric constant of test field is measured and then a GPR system is designed for better detection up to 1 meter deep. By considering total path loss, volume of complete system, and resolution, upper and lower frequencies are chosen. First, a UWB impulse for the frequency bandwidth of the impulse is chosen with rising time less than 1 ns, and then compact planar UWB dipole antenna suitable for frequency bandwidth of a UWB impulse is designed. Also, to receive reflected signals, a digital storage oscilloscope is used. For measurement, a monostatic technique and a migration technique are used. For visualizing underground targets, simple image processing techniques of A-scan removal and B-scan average removal are applied. The prototype of the system is tested on a test field in wet clay soil and it is shown that the developed system has a good ability in detecting underground metal objects, even small targets of several centimeters.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.1-7
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• 1996

PURPOSE : The purpose of this study is to know the ability of detecting malignant tumor tissue by Tl-201 scan, and to compare with that of Tc-99m-MIBI and Tc-99m-MDP scan. MATERIAL AND METHODS : Between February 1994 and December 1995,38 unselected patients with various bone pathologies were studied prospectively. Eighteen had malignant bone and soft tissue pathologies, while twenty had benign. All patients were studied with Tl-201, Tc-99mMIBI and Tc-99m-MDP scan prior to surgical biopsy. PICKER Prism 2000 gamma camera with high resolution parallel hole collimator was used for scanning. To avoid the interaction of isotope, the early(30min.) and delayed phase(3hrs.) of Tl-20l scan was performed first and Tc-99m-MIBI scan was performed after 30 minutes, and then Tc-99m-MDP scan 48 hours later. The scan images were visually evaluated by a blinded nuclear medicine physician. We could find true positive, true negative, false positive and false negative by the comparison of results with those of biopsy. We calculated positive and negative predictive value(%), sensitivity(%), specificity(%) and diagnostic accuracy(%) of each scan. RESULT : The results of each scan were 85.7, 100, 100, 85, 92.1% in Tl-201, 81, 94.1, 94.4, 80, 86.8% in Tc-99m-MIBI and 50, 66.7, 88.9, 20, 52.6% in Tc-99m-MDP scan. As a conclusion, Tl-201 scan was the most specific and accurate method for detecting malignant tumor tissue. Tc-99m-MIBI scan was also good for malignant tumor searching. CONCLUSION : With our results, we can use Tl-201 scan to differentiate benign from malignant tumor, and to evaluate the response of preoperative chemotherapy or radiotherapy, and to determine the residual tumor or local recurrence. For the better result, we need to have a more detail information about false positive cases and a more objective and quantitative reading technique.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.39-44
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• 2008

Scan architecture is very effective design-for-testability technique that is widely used for high testability, however, it requires so much test time due to test vector shifting time. In this paper, an efficient scan test method is presented that is based on the Illinois scan architecture. The proposed method maximizes the common input effect via a scan chain selection scheme. Experimental results show the proposed method requires very short test time and small data volume by increasing the efficiency of common input effect.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.5-12
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• 2008

We propose efficient scan testing method capable of reducing the test data and power dissipation for digital logic circuits. The proposed testing method is based on a hybrid run-length encoding which reduces test data storage on the tester. We also introduce modified Bus-invert coding method and scan cell design in scan cell reordering, thus providing increased power saving in scan in operation. Experimental results for ISCAS'89 benchmark circuits show that average power of 96.7% and peak power of 84% are reduced on the average without fault coverage degrading. We have obtained a high reduction of 78.2% on the test data compared the existing compression methods.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.199-208
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• 1994

This paper proposes a delay fault test technique for ICs and PCBs with the boundary-scan architectures supporting ANSI/IEEE Std 1149.1-1990. The hybrid delay fault model, which comprises both of gate delay faults and path delay faults, is selected. We developed a procedure for testing delay faults in the circuits with typical boundary scan cells supporting the standard. Analyzing it,we concluded that it is impractical because the test clock must be 2.5 times faster than the system clock with the cell architect-ures following up the state transition of the TAP controller and test instruction set. We modified the boundary-scan cell and developed test instructions and the test procedure. The modified cell and the procedure need test clock two times slower than the system clock and support the ANSI/IEEE standard perfectly. A 4-bit ALU is selected for the circuits under test. and delay tests are simulated by the SILOS simulator. The simulation results ascertain the accurate operation and effectiveeness of the modified mechanism.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.9
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• pp.559-566
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• 2005

An effective do-blurring algorithm is proposed to remove the blur of the even and the odd line images of the interlaced scan type camera. n the object or the camera moves fast while the interlaced scan type digital camera is acquiring images, blur is often created due to the misalignment between two images of even and odd lines. In this paper, the blurred original image is separated into the even and the odd line images of the half size. Two full sized images are generated using interpolation technique based on these two in ages. Again, these images are signed and combined through the processes of feature extraction, matching, sub-pixel matching, outlier removal, and mosaicking. De-blurring simulations about the images of different camera motions have been done.