• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.695-698
• /
• 2010

본 논문은 High-speed signal에 대한 기본적인 설계 방법론, Differential signaling, Impedence matching, Decoupling Method 등에 대하여 논한 후 High-speed signal 의 전송 품질을 개선하기 위한 GND via 의 효과에 대하여 논하고자 한다. S-parameter simulation 및 실제 제품 적용 후 파형의 변화를 관찰하여 GND via 의 효용성을 살펴보아 High-speed signal Design 할 때 Design limitation 상황에 대해 적절한 방법론을 말하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.542-545
• /
• 2010

재료의 마이크로 스케일 해석에서 결정의 geometrically necessary dislocation (GND) 효과에 의한 소성구배(plastic gradient)를 고려하는 것은 재료의 소성 거동을 분석하는데 영향을 미친다. 본 연구에서는 먼거리(long range)에서 전위(dislocation)의 영향을 고려하는 GND의 효과를 적용하여 소성 구배의 영향을 받는 다결정(polycrystal) 고체의 거동을 유한요소해석을 이용하여 살펴보았다. 재료의 거동을 분석하기 위해 탄성(elastic)과 소성(plastic) 변형에 먼 거리 변형률(long range strain)을 고려한 항(term)이 포함된 변형 구배(deformation gradient)의 multiplicative decomposition 모델을 사용하였다. 먼 거리 변형률에 의한 영향을 고려하기 위해 구배 경화 계수(gradient hardness coefficient)와 먼 거리 변형률 길이에 대한 재료변수(parameter)가 사용되었다. 각각의 계수들이 다결정 고체의 거동에 미치는 영향을 확인하기 위해 두 변수의 적용에 따른 다결정 고체의 거동을 분석하였다. 다결정 재료의 GND 효과에 의한 소성 구배 효과를 고려해서, 고려하지 않은 경우와 비교하여 발생하는 경화(hardening)의 차이를 분석함으로서 GND에 의한 다결정 고체 거동의 영향을 확인하였다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.2
• /
• pp.185-191
• /
• 2011

Plastic gradient from geometrically necessary dislocation(GND) can affect material behavior significantly. In this research, mechanical behavior of polycrystalline solid is investigated using the finite element method incorporating plastic gradient from long range dislocation or GND effect. Plastic gradient effect is implemented in the analysis model by considering a long range strain term as well as elastic and plastic terms in the multiplicative decomposition. In the model, gradient hardness coefficient and length parameter are used to evaluate the effect of the long range strains and sensitive study is conducted for the parameters. It is confirmed that the GND amplifies hardening response of polycrystals compared with the single crystal.

• Journal of IKEEE
• /
• v.24 no.1
• /
• pp.132-139
• /
• 2020

The ionizer module used in this air cleaner supplies high voltages of 3.5KV / -4KV to the discharge electrode HV+ / HV- using a winding transformer to generate positive and negative ions by electric field radiation of carbon fiber brush. The ionizer module circuit using the existing MCU has the disadvantage of large PCB size and expensive price, and the gate driver chip using the existing ring oscillator has oscillation period sensitive to PVT (Process-Voltage-Temperature) fluctuation and there is risk of fire or electric shock because there is no fault detection function by short circuit of HV+ and GND as well as HV- and GND. Therefore, in this paper, even though PVT fluctuates, by using 7-bit binary up counter, HV+ voltage reaches the target voltage by adjusting oscillation period. And an HV+ short fault detection circuit for detecting a short circuit between HV+ and GND, an HV- short fault detection circuit for detecting a short circuit between HV- and GND, and an OVP (Over-Voltage Protection) for detecting that HV+ rises above an overvoltage are newly proposed.

• Clinics in Shoulder and Elbow
• /
• v.24 no.2
• /
• pp.55-65
• /
• 2021

Background: Although ultrasound-guided needle decompression (US-GND) can treat calcific tendinitis of the shoulder effectively, repeat procedures might be required for unresolved symptoms. We evaluated the overall clinical outcomes of US-GND with subacromial steroid injection and the final results and factors predisposing toward repeat procedures. Methods: Ninety-eight patients who underwent US-GND for calcific tendinitis of the supraspinatus/infraspinatus were analyzed between March 2017 and December 2018. The clinical outcomes (pain visual analog scale, functional visual analog scale [FVAS], and American Shoulder and Elbow Surgeons [ASES] score) and final subjective satisfaction were compared between groups A (single US-GND) and B (repeat US-GND). The factors predisposing toward repeated US-GNDs were analyzed. Results: We found that 59.3% (58/98) of patient ASES scores were ≥80, and 73.5% of patients (72/98) were satisfied with the outcome. Group B (n=14) demonstrated a significantly higher rate of dominant-arm involvement compared to group A (78.6% vs. 48.8%, p=0.046). However, initial calcification size, shape, number, density, subscapularis involvement, lavage, and procedure time did not differ significantly between the groups. Group B showed poorer final FVAS (7 [interquartile range, 6-8] vs. 8 [interquartile range, 7-9], p=0.036) and subjective satisfaction compared to group A (satisfied: 5 [35.7%] vs. 67 [79.8%], p<0.001]. Conclusions: US-GND with subacromial steroid injection is a viable treatment option for calcific tendinitis of the shoulder. Dominant-arm involvement was the only independent factor for repeated US-GND. Final outcome of repeated US-GND for unimproved patients was promising; however, these outcomes were poor compared to those of the patients who improved after the first procedure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.404-407
• /
• 2018

- A car is a means of transporting passengers or cargo on the ground by transmitting power from the engine to the wheels. In the past, automobiles started from internal combustion engines have recently been introduced with hybrid electric vehicles and pure electric vehicles. As a result, the deployment of high-tech electrical and electronic products is inevitably increased due to the development of technology and stability of various parts, resulting in a more complicated and diversified electromagnetic environment. CISPR 25 is conducting research on the test method for electromagnetic noise. In order to analyze the noise pattern according to the GND condition required in the radiation emission test, various conditions are applied for comparison. 2 Page - General characteristics of EMI chambers, techniques for testing and measuring equipmen 3 Page - RE test : Analysis of Noise due to Ground Strap Change when Sample is in Center, Analysis of Noise due to Ground Strap Changes when the Sample is not in the Center.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.2
• /
• pp.39-44
• /
• 2011

Plastic gradient from geometrically necessary dislocation(GND) can strongly affect micro-scale plastic behavior of polycrystalline solids. In this research, mechanical behavior of polycrystalline solid is investigated using the finite element method incorporating plastic gradient from GND effect. Gradient hardness coefficient and material length parameter are used to evaluate the effect of the plastic gradient on the behavior of materials. Sensitivity of the modeling parameters on the plastic gradient from GND is presented and effects of plastic gradient and material parameters on the behavior of single crystal inside a polycrystalline aggregate are investigated. It is confirmed that the plastic gradient from GND amplifies hardening response of polycrystals and affects single crystal behavior embedded in polycrystalline solids.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.9
• /
• pp.450-453
• /
• 2005

A high speed address recovery technique for AC plasma display panel(PDP) is proposed. Replacing GND switch by clamping diode. the recovery speed can be increased by saving GND hold-time and switching loss due to GND switch also becomes also be reduced. The proposed method is able to perform load-adaptive operation by controlling the voltage level of energy recovery capacitor, which prevents increasing inefficient power consumption caused by circuit loss during recovery operation. Test results with 50' HD single-scan PDP(resolution = 1366$\times$768) show that less than 3sons of recovery time is successfully accomplished and about$54\%$ of the maximum power consumption can be reduced, tracing minimum power consumption curves.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.5
• /
• pp.25-31
• /
• 2009

A low power SRAM using supply voltage charge recycling (SVCR-SRAM) scheme is proposed. It divides into two SRAM cell blocks and supplies two different powers. A supplied power is $V_{DD}$ and $V_{DD}/2$. The other is $V_{DD}/2$ and GND. When N-bit cells are accessed, the charge used in N/2-bit cells with VDD and $V_{DD}/2$ is recycled in the other N/2-bit cells with $V_{DD}/2$ and GND. The SVCR scheme is used in the power consuming parts which bit line, data bus, word line, and SRAM cells to reduce dynamic power. The other parts of SRAM use $V_{DD}$ and GND to achieve high speed. Also, the SVCR-SRAM results in reducing leakage power of SRAM cells due to the body-effect. A 64K-bit SRAM ($8K{\times}8$bits) is implemented in a $0.18{\mu}m$ CMOS process. It saves 57.4% write power and 27.6% read power at $V_{DD}=1.8V$ and f=50MHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.5
• /
• pp.163-168
• /
• 2019

In this paper, We investigated the effects of the transparency variations from 0% to 90.7% on meshed SF-MPAA(Series Fed Microstrip Patch Array Antenna). For this, we designed SF-MPAA in 3 cases that is meshed radiation patches, meshed GND, and meshed radiation patches plus GND. And we investigated the characteristics of SF-MPAA depend on the variations of transparency in each case. In the case of meshed radiation patches, the gain decreased by 18.8% and the operating frequency is lower by 5.5%. In the case of meshed GND, the gain decreased by 15.4% and the operating frequency is lower by 5.56%. In the case of meshed radiation patches plus GND, the gain decreased by 31.94% and the operating frequency is lower by 7.6%. However, the bandwidth and the SLL(Side Lobe Level) did not show apparent tendency on the the variations of transparency.