• Title/Summary/Keyword: ablation performance

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LAM 공정을 위한 Underpass를 갖지 않는 나선형 박막 인덕터의 주파수 특성 (Frequency Characteristics of Spiral Planar Inductor without Underpass for LAM Process)

  • Kim, Jae-Wook
    • Journal of IKEEE
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    • v.12 no.3
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    • pp.138-143
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    • 2008
  • In this study, we propose that the structures of spiral inductors have the environment advantage utilizing direct-write and LAM(Laser Ablation of Microparticles) processes without process step of lithography and etching etc. of existing semiconductor process. The structures of inductors have Si thickness of 540${\mu}m$, $SiO_2$ thickness of 3${\mu}m$. The width of Cu coils and the space between segments have 30${\mu}m$, respectively, using for direct-write and LAM processes. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The inductors without underpass and via have inductance of 1.11nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 38 at 5 GHz, SRF of 18 GHz. Otherwise, inductors with underpass and via have inductance of 1.12nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 35 at 5 GHz, SRF of 16 GHz.

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Improvement of Tribological Characteristics of Multi-Scale Laser-Textured Surface in terms of Lubrication Regime (윤활영역에서 멀티크기 Laser Surface Texturing 효과)

  • Kim, Jong-Hyoung;Choi, Si Geun;Segu, Dawit Zenebe;Jung, Yong-Sub;Kim, Seock-Sam
    • Tribology and Lubricants
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    • v.30 no.1
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    • pp.59-63
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    • 2014
  • Laser Surface Texturing(LST) is a surface engineering process used to improve tribological characteristics of materials by creating patterned microstructures on the mechanical contact surface. In LST technology, a pulsated laser beam is used to create arranged dimples on a surface by a material ablation process, which can improve such as load capacity, wear resistances, lubrication lifetime, and reduce friction coefficients. In the present study, the effect of multi-scale LST on lubricant regime was investigated. A pulsed Nd:YAG laser was applied on the bearing steel(AISI 52100) to create arranged dimples. To optimize the surface texturing effect on friction, multi-scale texture dimples with some specific formula arrays were fabricated by combining circles, ellipses and the laser ablation process. The tribological testing of multi-scale textured surface was performed by a flat-on-flat unidirectional tribometer under lubrication and the results compared with that of the non-textured surface. Through an increase in sliding speed, the beneficial effect of multi-scale LST performance was achieved. The multi-scale textured surface had lower friction coefficient performances than the non-textured surface due to the hydrodynamic lubrication effect.

Manufacturing and Properties of Low Vacuum Plasma Sprayed W-Carbide Hybrid Coating Layer (진공 플라즈마 스프레이 공정을 이용한 W계 복합 코팅층의 제조 및 특성 연구)

  • Cho, Jin-Hyeon;Jin, Young-Min;Ahn, Jee-Hoon;Lee, Kee-Ahn
    • Journal of Powder Materials
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    • v.18 no.3
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    • pp.226-237
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    • 2011
  • W-ZrC and W-HfC composite powders were fabricated by the Plasma Alloying & Spheroidization (PAS) method and the powders were sprayed into hybrid coating layers by using Low Vacuum Plasma Spray (LVPS) process, respectively. Microstructure, mechanical properties, and ablation characteristics of the fabricated coating layers were investigated. The LVPS process led to successful production of W-Carbide hybrid coatings, approximately 400 ${\mu}M$ or above in thickness. As the substrate preheating temperature increased from $870^{\circ}C$ to $917^{\circ}C$, the hardness of the W-ZrC coating layer increased due to decreased porosity. Vickers hardness showed higher value (about 108.4 HV) in W-ZrC hybrid coating material compared to that of W-HfC while adhesive strength was found to be similar in both coating layers. The plasma torch test revealed good ablation resistance of the W-Carbide hybrid coating layers. The relatively high performance W-ZrC coating layer at the elevated temperature is thought to be attributed to both the strengthening effect of ZrC particle remained in the layer and the formation of ZrO2 phase with high temperature stability.

ZoomISEG: Interactive Multi-Scale Fusion for Histopathology Whole Slide Image Segmentation (ZoomISEG: 조직 병리학 전체 슬라이드 영상 분할을 위한 대화형 다중스케일 융합)

  • Seonghui Min;Won-Ki Jeong
    • Journal of the Korea Computer Graphics Society
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    • v.29 no.3
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    • pp.127-135
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    • 2023
  • Accurate segmentation of histopathology whole slide images (WSIs) is a crucial task for disease diagnosis and treatment planning. However, conventional automated segmentation algorithms may not always be applicable to WSI segmentation due to their large size and variations in tissue appearance, staining, and imaging conditions. Recent advances in interactive segmentation, which combines human expertise with algorithms, have shown promise to improve efficiency and accuracy in WSI segmentation but also presented us with challenging issues. In this paper, we propose a novel interactive segmentation method, ZoomISEG, that leverages multi-resolution WSIs. We demonstrate the efficacy and performance of the proposed method via comparison with conventional single-scale methods and an ablation study. The results confirm that the proposed method can reduce human interaction while achieving accuracy comparable to that of the brute-force approach using the highest-resolution data.

3D Packaging Technology Using Femto Laser (팸토초 레이저를 이용한 3차원 패키징 기술)

  • Kim, Ju-Seok;Sin, Yeong-Ui;Kim, Jong-Min;Han, Seong-Won
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.190-192
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    • 2006
  • The 3-dimensional(3D) chip stacking technology is one of the leading technologies to realize a high density and high performance system in package(SIP). It could be found that it is the advanced process of through-hole via formation with the minimum damaged on the Si-wafer. Laser ablation is very effective method to penetrate through hole on the Si-wafer because it has the advantage that formed under $100{\mu}m$ diameter through-hole via without using a mask. In this paper, we studied the optimum method for a formation of through-hole via using femto-second laser heat sources. Furthermore, the processing parameters of the specimens were several conditions such as power of output, pulse repetition rate as well as irradiation method and time. And also the through-hole via form could be investigated and analyzed by microscope and analyzer.

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Fabrication of Superconducting Dual Mode Resonator using Laser Ablation (레이저 어블레이션에 의한 초전도 이중모드 공진기 제작)

  • Park, Joo-Hyung;Yang, Seung-Ho;Lee, Sang-Yeol;Ahn, Dal;Sok, Jung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.41-44
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    • 1998
  • Dual mode resonators were fabricated using high temperature superconductor. The deposited material was $Y_1Ba_2Cu_3O_{7-x}$(YBCO) on MgO(100) substrate using pulsed laser deposition. Dual mode resonators were patterned by standard photolithography process and wet etching. At the back-side of the substrate, the ground plane with the metal layer of Ti and Ag was fabricated. The transition temperatures of YBCO films were 85-88 K, and network analyzer was used for testing the performance of the resonators. The input/output feedline angles of each resonator were $60^{\circ}$and $100^{\circ}$. The resonant frequency of resonators was 10 GHz. In this paper, dual mode resonator was fabricated for the application of satellite communication.

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Evaluation Method I of the Small Current Breaking Performance for SF(sub)6-Blown High-Voltage Gas Circuit Breakers (초고압 $SF_6$ 가스차단기의 소전류 차단성능 해석기술 I)

  • 송기동;이병운;박경엽;박정후
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.7
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    • pp.331-337
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    • 2001
  • With the increasing reliability of analysis schemes and the dramatically increased calculating speed, the computer simulation has become and indispensable process to predict the interruption capacity of circuit breakers. Generally, circuit breakers have to possess both the small current and large current interruption abilities and the circuit breaker designers need to evaluate its capacities to save the time and the expense. The analysis of small current and the large current interruption performances have been considered separately because the phenomena occurring in a interrupter are quite different. To analyze the dielectric recovery after large current interruption many physical phenomena such as heat transfer, convection and arc radiation, the nozzle ablation, the ionization of high temperature SF(sub)6 gas, the electric and themagnetic forces and so forth mush be considered. However, in the analysis of small current interruption performance only the cold gas flow analysis needs to be carried out because the capacitive current is to small that the influence from the current can be neglected. In this paper, an empirical equation which is obtained from a series of tests to estimate the dielectric recovery strength has been applied to a real circuit breaker. The results of analysis have been compared with the test results and the reliability has been investigated.

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Diagnostic value of Thyroglobulin Measurement with Fine-needle Aspiration Biopsy for Lymph Node Metastases in Patients with a History of Differentiated Thyroid Cancer

  • Zhang, Hai-Shan;Wang, Ren-Jie;Fu, Qing-Feng;Gao, Shi;Sun, Bu-Tong;Sun, Hui;Ma, Qing-Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10905-10909
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    • 2015
  • Purpose: The aim of this study was to evaluate the diagnostic value of FNA-Tg for detecting lymph node metastases in patients with a history of differentiated thyroid cancer (DTC). Materials and Methods: A total of 58 patients with DTC diagnosis and evidence of single or multiple suspicious cervical lymph nodes were assessed. All underwent total or near-total thyroidectomy with (35 cases) or without (23 cases) radioiodine (RAI) ablation, followed by thyroid stimulating hormone (TSH) suppression therapy. A total of 68 lymph nodes were examined by ultrasound-guided fine needle aspiration (US-FNA) for both cytological examination and FNA-Tg measurement. Serum Tg and anti-thyroglobulin antibody (TgAb) levels were also measured. Diagnostic performance including sensitivity, specificity, accuracy, positive (PPV) and negative predictive value (NPV) of FNAC and FNA-Tg were calculated and compared. The Spearman's rank correlation coefficient was used to estimate the relationship between FNA-Tg and serum TgAb. Results: The FNA-Tg levels were significantly higher with DTC metastatic lymph nodes (median 927.7 ng/mL, interquartile range 602.9 ng/mL) than non-metastatic lymph nodes (median 0.1 ng/mL, interquartile range 0.4 ng/mL) (p<0.01). Considering 1.0 ng/mL as a threshold value for FNA-Tg, the sensitivity, specificity, accuracy, PPV and NPV of FNA-Tg were 95.7%, 95.5%, 95.6%, 97.8% and 91.3%, respectively. The sensitivity and accuracy of the combination of FNAC and FNA-Tg were significantly higher than that of FNAC alone (p<0.05). The diagnostic performance of FNA-Tg was not significantly different between cases with or without RAI ablation, and the serum TgAb levels did not interfere with FNA-Tg measurements. Conclusions: Measurement of FNA-Tg is useful. The combination of FNAC and FNA-Tg is more sensitive and accurate for detecting lymph node metastases in patients with a history of DTC than FNAC alone. Serum TgAbs appear to be irrelevant for measurement of FNA-Tg.

Development of Membrane Filters with Nanostructured Porous Layer by Coating of Metal Nanoparticles Sintered onto a Micro-Filter (마이크로-필터 상에 소결 처리된 금속 나노입자 코팅에 의한 나노구조 기공층 멤브레인 필터 개발)

  • Lee, Dong-Geun;Park, Seok-Joo;Park, Young-Ok;Ryu, Jeong-In
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.8
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    • pp.617-623
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    • 2008
  • The membrane filter adhered with nanostructured porous layer was made by heat treatment after deposition of nanoparticle-agglomerates sintered in aerosol phase onto a conventional micron-fibrous metal filter as a substrate filter. The Sintered-Nanoparticle-Agglomerates-coated NanoStructured porous layer Membrane Filter (SNA-NSMF), whose the filtration performance was improved compared with the conventional metal membrane filters, was developed by adhesion of nanoparticle-agglomerates of dendrite structure sintered onto the micron-fibrous metal filter. The size of nanoparticle-agglomerates of dendrite structure decreased with increasing the sintering temperature because nanoparticle-agglomerates shrank. When shrinking nanoparticle-agglomerates were deposited and treated with heat onto the conventional micron-fibrous metal filter, pore size of nanostructured porous layer decreased. Therefore, pressure drops of SNA-NSMFs increased from 0.3 to 0.516 kPa and filtration efficiencies remarkably increased from 95.612 to 99.9993%.

The Study on Aerodynamic Characteristics for the Design of High Efficiency Jet Vane (고 효율 제트 베인 설계를 위한 공기역학적 특성 연구)

  • 길경섭;정용갑;박종호
    • Journal of the Korean Society of Propulsion Engineers
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    • v.7 no.4
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    • pp.39-45
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    • 2003
  • Of the various means for active trajectory correction, a thrust vector control system represents the only principle independent of missile external forces so that this method is operative. The purpose of this study is to analyze the characteristic of jet vane TVC(Thrust vector control) system among mechanical jet deflection. To ensure high performance leading edge shape, aspect ratio and ablated condition is optimized. Supersonic flow system, jet vanes and nozzle with Mach number 2.88 and under expansion ratio 2 were designed to study aerodynamic characteristics of leading edge shape, aspect ratio and ablated conditions.