• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.392-395
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• 1999

The state assignment for a finite state machine greatly affects the delay, area, and testabilities of the sequential circuits. In order to minimize the dependencies among state variables, therefore possibly to reduce the length and number of feedback cycles, a new state assignment technique based on m-block partition is introduced in this paper. After the completion of state assignment and logic synthesis, partial scan design is performed to choose minimal number of scan flip-flops. Experiment shows drastic improvement in testabilities while preserving low area and delay overhead.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.341-342
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• 2007

3T MRI system에서 고해상도 영상을 얻기 위해서는 magnetic field를 균일하게 만들어야 한다. 특히 초고속 영상 기법인 Spiral scan 방식과 EPI scan 방식에서는 이미지 영역에서의 magnetic field의 inhomogeneity에 의해 영상의 왜곡이 심해진다. 본 논문에서는 magnetic field의 inhomogeneity를 단시간 내에 측정하기 위해 fast spin echo방식의 pulse sequence 제안하고, magnetic field를 분석하기 위한 field map의 구성과, field pattern의 효과적인 분석을 통하여, magnetic field를 균일하게 만드는 방법을 제안한다.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.134-139
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• 2001

Laser scanners are widely used for reverse engineering and inspection of freeform parts in industry such as motors, electronic products, dies and molds. Due to the lack of measuring software and positioning device, the laser scanning processes have been erroneous and inconsistent. In order to automate measuring processes, an automated scan plan generation software and a proprietary hardware are developed. In this paper, an automated laser scanning system using a 3-axis motorized stage is proposed. In the scan planning step, scan directions, paths, and the number of scans are generated considering optical and mechanical parameters. In the scanning step, the generated scan plan is downloaded into the laser scanner and the motorized stage and the points on the surface are captured automatically. Finally, the point data set is analyzed to evaluate the performance of the system.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.728-731
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• 2009

A negative waveform having inverted polarity of conventional waveform during reset and sustain periods was proposed to improve the driving characteristics. In order to control the negative wall-charge distribution, a positive bias on the scan electrode was applied during reset period. Compared to 0 V scan-bias condition, at 8 V scan-bias the formative time lag was improved about 23.95 % and the average time lag was improved about 14.91 %. All experiments were performed with the 42-inch PDP module in XGA resolution.

• Journal of Electrochemical Science and Technology
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• v.13 no.3
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• pp.347-353
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• 2022

Agarose hydrogel, a solid electrolyte, was investigated voltammetrically in terms of transport properties and natural convection effects using a ferrocenyl compound as a redox probe. To confirm the diffusion properties of solute on the agarose interface, the diffusion coefficients (D) of ferrocenemethanol in agarose hydrogel were determined by cyclic voltammetry (CV) according to the concentration of agarose hydrogel. While the value of D on the agarose interface is smaller than that in the bulk solution, the square root of the scan rate-dependent peak current reveals that the mass transport behavior of the solute on the agarose surface shows negligible convection or migration effects. In order to confirm the reduced natural convection on the gel interface, scan rate-dependent CV was performed in the solution phase and on the agarose surface, respectively. Slow scan voltammetry at the gel interface can determine a conventional and reproducible diffusion-controlled current down to a scan rate of 0.3 mV/s without any complicated equipment.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.5
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• pp.1-8
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• 2009

Since scan based testing is very efficient and widely used for testing large sequential circuits. However, since test patterns are serially injected through long scan chains, scan based testing requires very long test application time. Also, compared to the normal operations, scan shifting operations drastically increase power consumption. In order to solve these problems, this paper presents a new scan architecture for both test application time and test power reduction. The proposed scan architecture partitions scan chains into several segments and bypasses some segments which do not include any specified bit. Since bypassed segments are excluded from the scan shifting operation, the test application time and test power can be significantly reduced.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.440-444
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• 2006

Purpose: The nasal bone fracture is the most common type of facial bone fracture. In making a diagnosis, physical findings are much more important than the simple radiologic findings. Facial bone CAT scan can provide the accurate diagnosis and the correct location of nasal bone fractures, so it can be lessoned with proper intervention. The aim of this study was to evaluate the usefulness of facial bone CAT scan in the diagnosis of nasal bone fractures. Methods: The medical records and facial bone CAT scan of 45 patients clinically suspected nasal bone fracture but was not diagnosed on simple radiologic findings were analyzed. Results: All of the 45 patients were confirmed as nasal bone fractures in the facial bone CAT scan. The most common cause of fracture was assault. The mean age was 23.2 years. Physical findings were tenderness (100%), swelling(93.3%), epistaxis(66.6%), deviation (42.2 %), external wound(17.7%) and crepitus(4.4%) in order. Conclusions: It was concluded that the simple radiologic findings can not be conclusive, where the physical findings indicate a suspected nasal bone fracture. The facial bone CAT scan was more reliable for the correct diagnosis and follow-on treatment.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.40-46
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• 2018

In order to successfully detect and identify underwater targets located on the seabed, unmanned surface vehicles (USVs) typically acquire acoustic signals with a side-scan sonar device and reconstruct information about the target from the processed images. As the quality of the side-scan sonar images acquired by USVs depends on the environment and operating parameters, using modeling and simulation techniques to design side-scan sonar devices can help optimize the reconstruction of the sonar images. In this work, we study a side-scan sonar design for use in USVs, that takes the movement of the platform into account. First, we constructed a simulated seabed environment with underwater targets, and specified the maneuvering conditions and sonar systems. We then generated the acoustic signals from the simulated environment using the sonar equation. Finally, we successfully imaged the simulated seabed environment using simple signal processing. Our results can be used to derive USV side-scan sonar design parameters, predict the resulting sonar images in various conditions, and as a basis for determining the optimal sonar parameters of the system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.595-598
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• 2014

In order to provide the Mobile Stations operating in IEEE 802.11 Wireless LAN network with seamless handover, a comprehensive study on the functions of handover considering various networking environments and characteristics of Mobile Stations is required. Note that the channel scan process finding a new AP takes the major portion of handover time, and this is the most significant issue with seamless handover for real-time multimedia service in WLAN environment. In this paper the functions required to provide seamless handover in IEEE 802.11 WLAN network are identified, and a new scanning technique is proposed with which the Mobile Stations can selectively scan the channels to reduce the channel scan time in various network environments. Here each Mobile Station awares of the channels the neighbor APs are using by scanning them in advance according to the proposed technique. Afterwards, when handover is actually required, the optimal AP is decided quickly by scanning only the predetemined group of channels and order of scan without unnecessary scan of all the channels. In addition, proposes to enter the Scan Trigger Value and Handover Threshold Value in mobile phones in order to prevent the phenomenon can not handover.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.219-220
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• 2008