• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.1
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• pp.14-19
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• 2008

Semiconductor testing area challenges many testing issues due to the minimization and ultra high performance of current semiconductors. Among these issues, signal integrity test on interconnections must be solved for highly integrated circuits like SoC. In this paper, we propose an effective pattern application method for signal integrity test on interconnects. Proposed method can be applied by using boundary scan architecture and very efficient test can be preceded with pretty short test time.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.3
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• pp.384-391
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• 1998

When a device is mounted on the PCB, it is impossible to have zero defects due to many unpredictable problems. Among these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). It is obvious that given the complexity of the inspection task, the efficiency of a human inspection is questionable. Thus, new technologies for inspection of SMD(Surface Mounting Device) should be explored. An example of such technologies is the Automated Visual Inspection(AVI), wherein the vision system plays a key role to correct this problem. In implementing vision system, high-speed and high-precision are indispensable for practical purposes. In this paper, a new algorithm based on the Radon transform which uses a projection technique to inspect the FIC(Flat Integrated Circuit) device is proposed. The proposed algorithm is compared with other algorithms by measuring the position error(center and angle) and the processing time for the device image, characterized by line scan camera.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.85-92
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• 2004

A design of a preceding instruction decoding module(PIDM) is proposed aiming at performance enhancement of JTAG-based test complying to the IEEE 1149.1 standard. The PIDM minimizes the number of clocks by performing test access port(TAP) instruction decoding process prior to the execution of TAP-controlled test activities. The scheme allows the generation of signals such as test mode select(TMS) inside of a target system. The design employing PIDM demonstrates 15% performance enhancement with simulation of a CORDIC processor and 48% reduction of the TAP-controller's circuit size with respect to the conventional design of a non-PIDM version.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1619-1622
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• 2002

최근에 생산되는 디지털 VLSI칩들은 그 집적도가 계속 높아지고 있으며, 이러한 칩들을 장착한 보드의 경우도 그 복잡성이 점차 높아지고 있다. 이에 따라 칩 및 보드에 대한 철저한 테스트 과정이 요구된다. 지금까지 보드 테스트 방법으로 널리 쓰였던 ICT(In-Circuit Test)는 칩의 고집적화에 따른 핀 간격의 조밀화와 SMT(Surface Mount Technology), BGA(Ball Grid Array), MCM(Multi Chip Module) 등의 새로운 패키징 방식의 등장에 따라 테스트 방법으로의 한계성을 드러내고 있다. 이에 대한 대안으로 등장한 IEEE Std 1149.1 은 ICT의 한계성을 극복할 수 있는 기술일 뿐 아니라 여러 가지 장점을 가지고 있으며 그 활용 분야도 다양하다. 본 논문에서는 IEEE Std 1149.1에 따라 설계된 보드 상에서 발생 가능한 고장들에 대한 고장 모델을 제시한다. 또한 각 고장 모델들의 양상과 진단 기법을 제시한다. 이를 통해 IEEE Std 1149.1에 따라 설계된 보드 상에서 발생한 고장들을 검출할 수 있으며, 고장의 종류 및 성격, 그리고 고장의 발생 위치 등의 정보를 얻을 수 있다. IEEE Std 1149.1에 따른 보드 설계가 보드의 신뢰성 보장에 긴요함을 인식하는 계기가 되기를 기대하며 제시된 고장 모델 및 진단 기법이 기술적으로 중요한 참고자료가 되기를 기대한다.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.385-389
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• 1997

We report on the development of a new method to control the coverage of a metal film prepared with immersion method. An Sb species in solution adsorbed irreversibly at an open circuit potential (∼0.2 V) as an oxygenous Sb(Ⅲ) on a clean Au electrode, and the adsorbates showed voltammetric features in the potential range from 0.1 V to - 0.4 V. The full coverage of the Sb adsorbates was ∼0.45. On the contrary, the Sb species in solution did not adsorb at all on iodine-covered Au electrode surfaces, when the iodine coverages were more than 0.25. As the iodine coverage decreased below 0.25, however, the irreversible adsorption of Sb took place and the coverage of Sb increased accordingly. This electrochemical behavior has been interpreted as the penetration of the adsorbing Sb species in solution through open spaces among the iodine adlattices of coverages less than 0.25. With the manipulation of the iodine coverage, the controllable range of Sb coverage was from 0 to 0.45, i.e. the full coverage of Sb. In addition, the reversible deposition of Sb on an iodine-saturated Au electrode with voltammetric scan has been observed, which is contrasted with the adsorptive behavior of Sb on the clean Au electrode.

• Current Photovoltaic Research
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• v.6 no.4
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• pp.119-123
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• 2018

The High Performance Module With The Shingled String Has Several Advantages Such As The Larger Active Area, Higher Open-Circuit Voltage And Smaller Cell To Module (Ctm) Loss. To Obtain Increase Of Power In Pv Shingled Module, The Detailed Condition Of Various Parameters Related To Cutting And Bonding Process Were Investigated In This Study. We Searched The Optimized Cutting Conditions Of Laser Scan Speed, The Number Of Laser-Scribing And Also Bonding Conditions Of Electrically Conductive Adhesives (Eca) By Varying Amount Of Eca, Curing Time And Curing Temperature. The Shingled Pv Module Showed 25.4W of Maxmimum Power At 60 Rpm Of Dipensing Motor Speed, 30 Seconds Of Curing Time And $140^{\circ}C$ Of Curing Temperature, Respectively.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.1
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• pp.31-38
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• 2019

In this paper, we develop a beamforming front end platform with pipeline circuit configuration method that can apply various clinical diagnostic applications of ultrasound image technology. Hardware design targets compression applications as well as scalable applications where power, integration levels and replication possibilities are important. Firmware design was implemented to achieve optimal FPGA parallel processing level by constructing new IP and system-oriented design environment to accelerate design productivity with maximum productivity improvement using Vivado HLS tool, which is a next generation high level synthesis tool. Former supports the high-speed management function of scan data that can create an image area arbitrarily and can be appropriately corrected and supplemented when reconfiguring or changing system specifications in the future.

• Current Optics and Photonics
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• v.7 no.3
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• pp.283-296
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• 2023

An intraoral spectral domain optical coherence tomography (SD-OCT) system has been developed, using a custom-built hand-held scanner and spectrometer. The hand-held OCT probe, based on a microelectromechanical systems scanner and a self-built miniaturized drive circuit, had a field of view sufficient for dental diagnosis. The spectrometer using a fabricated f-theta lens provided the image depth required for dental diagnosis. The axial and transverse resolutions of the OCT system in air were 7.5 ㎛ and 12 ㎛ respectively. The hand-held probe could scan an area of 10 × 10 mm², and the spectrometer could image along a depth of 2.5 mm. To verify the utility of the developed OCT system, OCT images of tooth hard and soft tissues were acquired, and a user-interface program for diagnosis was developed. Early caries and microcracks that were difficult to diagnose with existing methods could be found, and the state of restoration could be observed. Measuring the depth of the gingival sulcus, distinguishing subgingival calculus, and detecting an implant under the gingiva suggested the possibility of the SD-OCT system as a diagnostic for dental soft tissues. Through the presented OCT images, the capability of the developed SD-OCT system for dental diagnosis was demonstrated.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.15-21
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• 2009

Purpose : A method to estimate a real k-space trajectory based on a circuit model of the gradient system is proposed for spiral imaging. The estimated k-space trajectory instead of the ideal trajectory is used in the reconstruction to improve the image quality in the spiral imaging. Materials and Methods : Since the gradient system has self resistance, capacitance, and inductance, as well as the mutual inductance between the magnet and the gradient coils, the generated gradient fields have delays and transient responses compared to the input waveform to the gradient system. The real gradient fields and their trajectory in k-space play an important role in the reconstruction. In this paper, the gradient system is modeled with R-L-C circuits, and real gradient fields are estimated from the input to the model. An experimental method to determine the model parameters (R, L, C values) is also suggested from the quality of the reconstructed image. Results : The gradient fields are estimated from the circuit model of the gradient system at 1.5 Tesla MRI system. The spiral trajectory obtained by the integration of the estimated gradient fields is used for the reconstruction. From experiments, the reconstructed images using the estimated trajectory show improved uniformity, reduced overshoots near the edges, and enhanced resolutions compared to those using the ideal trajectory without model. Conclusion : The gradient system was successfully modeled by the R-L-C circuits. Much improved reconstruction was achieved in the spiral imaging using the trajectory estimated by the proposed model.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.438-444
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• 2005

Purpose: Anhedonia has been proposed to be the result of a basic neurophysiologic dysfunction and a vulnerability marker that precede and contribute to the liability of developing schizophrenia. We hypothesized that anhedonia, as a construct reflecting the decreased capacity to experience pleasure, should be associated with decreased positive hedonic affect trait. This study examined the relationship between anhedonia and positive hedonic affect trait and searched for the brain legions which correlate with anhedonia in normal subjects. Materials and Methods: Using $^{18}F$-FDG PET scan, we investigated the brain activity of twenty one subjects during resting state. Questionnaires were administrated after the scan in order to assess the self-rated individual differences in physical/social anhedonia and positive/negative affect traits. Results: Negative correlation between physical anhedonia score and positive affect trait score was significant (Pearson coefficient =-0.440, p<0.05). The subjects physical and social anhedonia scores showed positive correlation with metabolic rates in the cerebellum and negative correlation with metabolic rates in the inferior temporal gyrus and middie frontal gyrus. In addition, the positive affect trait score positively correlated with various areas, most prominent with the inferior temporal gyrus. Conclusion: These results suggest that neural substrates, such as the inferior temporal gyrus and prefrontal-cerebellar circuit, which dysfunction has been proposed to be involved with the cognitive deficits of schizophrenia, may also play a significant role in the liability of affective deficits like anhedonia.