• Title/Summary/Keyword: bias current

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Acupuncture for Lumbar Spinal Stenosis in Korean Literature: a Systematic Review (요추 척추관 협착증에 대한 침구치료의 국내 임상근거: 체계적 문헌고찰)

  • Kim, Kun-Hyung;Noh, Seung-Hee;Lee, Byung-Ryul;Kim, Jae-Kyu;Yang, Gi-Young
    • Journal of Acupuncture Research
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    • v.28 no.6
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    • pp.93-105
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    • 2011
  • Objectives : This study aims to evaluate currently available clinical evidence for the use of acupuncture in patients with lumbar spinal stenosis in the context of Republic of Korea. Methods : Five Korean databases were searched for all clinical studies employing acupuncture for patients with lumbar spinal stenosis. The exceptions were case reports and series involving less than 10 patients from their inception to September 2011. Only studies reported in Korean databases were searched. Results : Five retrospective audits among 22 initially identified studies were eligible for analysis in this review. There was no randomized controlled trial for this topic. The number of patients varied between 15 and 119 in each audit, and all the patients analyzed were inpatients. In all the included studies, acupuncture was conducted in combination with other concomitant treatments, including moxibustion, cupping, herbal remedies, acupoint injection, Chuna, and various physical therapies. All the included audits reported symptomatic and/or functional improvements compared to baseline. None of the included audits indicated whether any adverse events were reported. Conclusions : Current evidence for the use of acupuncture in patients with lumbar spinal stenosis in the context of South Korea is based solely on five retrospective audits that are very likely prone to a high risk of bias. Thus, further prospective and methodologically sound clinical trials to overcome this huge gap between clinical practice and the available evidence for the use of acupuncture in patients with lumbar spinal stenosis are needed.

Analysis of Current-Voltage characteristics of AlGaN/GaN HEMTs with a Stair-Type Gate structure (계단형 게이트 구조를 이용한 AlGN/GaN HEMT의 전류-전압특성 분석)

  • Kim, Dong-Ho;Jung, Kang-Min;Kim, Tae-Geun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.6
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    • pp.1-6
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    • 2010
  • We present simulation results on DC characteristics of AlGaN/GaN HEMT having stair-type gate electrodes, in comparison with those of the conventional single gate AlGaN/GaN HEMTs and field-plate enhanced AlGaN/GaN HEMTs. In order to reduce the internal electric field near the gate electrode of conventional HEMT and thereby to increase their DC characteristics, we applied three-layered stacking electrode schemes to the standard AlGaN/GaN HEMT structure. As a result, we found that the internal electric field was decreased by 70% at the same drain bias condition and the transconductance (gm) was improved by 11.4% for the proposed stair-type gate AlGaN/GaN HEMT, compared with those of the conventional single gate and field-plate enhanced AlGaN/GaN HEMTs.

Evaluation of Coastal Sediment Budget on East Coast Maeongbang Beach by Wave Changes (파랑 변화에 따른 동해안 맹방 해수욕장 연안 표사수지 파악)

  • Kim, Gweon-Su;Ryu, Ha-Sang;Kim, Sang-Hoon
    • Journal of Ocean Engineering and Technology
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    • v.33 no.6
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    • pp.564-572
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    • 2019
  • Numerical simulation of the sediment by the Delft3d model was conducted to examine the changes in the sediment budget transport caused by long-term wave changes at the Maengbang beach. Representative waves were generated with input reduction tools using NOAA NCEP wave data for about 40 years, i.e., from January 1979 to May 2019. To determine the adequacy of the model, wave and depth changes were compared and verified using wave and depth data observed for about 23 months beginning in March 2017. As a result of the error analysis, the bias was 0.05 and the root mean square error was 0.23, which indicated that the numerical wave results were satisfactory. Also, the observed change in depth and numerical result were similar. In addition, to examine the effect due to long-term changes in the waves, the NOAA wave data classified into each of the representative wave grades, and then the annual trend of the representative wave was analyzed. After deciding the weight of each wave class considering the changed wave environment in 2100, the amounts of sedimentation, deposition, and the sediment transport budget were reviewed for the same period. The results indicated that the sedimentation pattern did not change significantly compared to the current state, and the amount of the local sediment budget shown in the present state was slightly less. And there has been a local increase in the number of sediment budget transport, but there is no significant difference in the net and amount of sediment movements.

Deep Neural Networks Learning based on Multiple Loss Functions for Both Person and Vehicles Re-Identification (사람과 자동차 재인식이 가능한 다중 손실함수 기반 심층 신경망 학습)

  • Kim, Kyeong Tae;Choi, Jae Young
    • Journal of Korea Multimedia Society
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    • v.23 no.8
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    • pp.891-902
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    • 2020
  • The Re-Identification(Re-ID) is one of the most popular researches in the field of computer vision due to a variety of applications. To achieve a high-level re-identification performance, recently other methods have developed the deep learning based networks that are specialized for only person or vehicle. However, most of the current methods are difficult to be used in real-world applications that require re-identification of both person and vehicle at the same time. To overcome this limitation, this paper proposes a deep neural network learning method that combines triplet and softmax loss to improve performance and re-identify people and vehicles simultaneously. It's possible to learn the detailed difference between the identities(IDs) by combining the softmax loss with the triplet loss. In addition, weights are devised to avoid bias in one-side loss when combining. We used Market-1501 and DukeMTMC-reID datasets, which are frequently used to evaluate person re-identification experiments. Moreover, the vehicle re-identification experiment was evaluated by using VeRi-776 and VehicleID datasets. Since the proposed method does not designed for a neural network specialized for a specific object, it can re-identify simultaneously both person and vehicle. To demonstrate this, an experiment was performed by using a person and vehicle re-identification dataset together.

The Behavior of the Mobility Degradation in Pocket Implanted MOSFETS (Halo 구조의 MOSFET에서 이동도 감소 현상)

  • Lee Byung-Heon;Lee Kie-Young
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.4 s.334
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    • pp.1-8
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    • 2005
  • The increased effective impurity due to the pocket ion implantation is well blown to give rise to a reduction of the effective mobility of halo MOSFETs. However, further decrease of the effective mobility can be observed in pocket implanted MOSFETs above the mobility reduction due to the Coulomb impurity scattering and the gate bias dependency of the effective mobility can also differ from the simple model describing the mobility behavior in terms of the effective impurity. Phonon scattering and surface scattering as well as impurity Coulomb scattering are also shown to be effective in the degradation of the carrier mobility of pocket implanted MOSFETs. Using the 1-D regional approximation the effect of the distribution of the inversion charge density along the channel on the drain current is investigated. The inhomogeneous channel charge distribution due to pocket implantation is also shown to contribute to the further reduction of the effective mobility in halo MOSFETs.

Characterization of Electrical Properties on Cu Diffusion in Low-k Dielectric Materials for ULSI Interconnect (반도체 배선용 저 유전 물질에서의 구리 확산에 대한 전기적 신뢰성 평가)

  • Lee Hee-Chan;Joo Young-Chang;Ro Hyun-Wook;Yoon Do-Young;Lee Jin-kyu;Char Kook-Heon
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.3 s.32
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    • pp.9-15
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    • 2004
  • We investigated the electrical properties of copolymer low-k materials that are compromised of the PMSSQ(Poly Methyl Silsesquioxane)-based matrix with the BTMSE (Bis Tri Methoxy Silyl Ethane) additives. We manufactured MIS-type test samples using the copolymer as the insulator and measured their leakage current and failure time by means of the BTS (bias-temperature-stress) test. The failure time was observed to decrease drastically when the porosity of the copolymer was increased over $30\%$. From the measurement of failure time with respect to temperature. the activation energy of Cu drift through the copolymer was calculated to be 1.51 eV.

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Analysis of Wavelength Conversion Characteristics in SSGDBR Laser Diode (SSGDBR 레이저 다이오드의 파장변환 특성 해석)

  • Kim, Su-Hyun;Chung, Young-Chul
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.2
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    • pp.81-89
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    • 1999
  • Among various wavelength conversion technologies, that using the cross-gain modulation in laser diode makes it possible to deal with the high speed signal quite simply and efficiently. In this paper, presented was the applicability of an improved time-domain large-signal dynamic model as a CAD tool to analyzed the characteristics of SSGDBR(Superstructure Grating Distributed Bragg Reflector) laser diodes used for wavelength converters. Using this model, it was shown that this kind of wavelength converter can provide the widely tunable wavelength conversion of the high speed data above 10 Gbps. We also investigated the effect of input optical power and the bias current on the characteristics of the device such as extinction ration and eye diagram. The modeling results show very similar trend to the experimental reports.

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A New Calibration Method for the Characterization of Microwave Devices (마이크로파 소자 특성화를 위한 새로운 보정 방법)

  • 신헌철;유영길;정의붕;이종악
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.3
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    • pp.10-16
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    • 1991
  • The error networks due to the measuring systems and the test fixture must be previously calibrated in order to characterize the microwave devices. In this paper, it is presented a new method to characterize the error networks in which only two different microstrip lines are used for the calibration. Once each length of two calibrat- ing microstrip lines is accurately defined, the calibrated data can be easily obtained without acknowledgement for the propagation constant. The end effect is not considered when fabricated the microstrip lines used to calibration. The ATF13736 GaAs MESFET is characterized by means of the calibrating procedure with this method. The range of measuring frequency is 2 to 18 GHz, and the bias voltage and current are $V_{DS}$ =2.5V, $I_{DS}$ =20mA, respectively. Compared the calibrated data with data sheet, it is showed that the magnitude is nearly agreed with each other and the phase is deviated by 0.1 to 12 degrees in lower frequencies.

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13.56~915 MHz CMOS Rectifier Using Bootstrapping and Active Body Biasing (부트스트래핑과 능동 몸체 바이어싱을 이용한 13.56~915 MHz용 CMOS 정류기)

  • Jin, Ho Jeong;Cho, Choon Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.10
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    • pp.932-935
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    • 2015
  • This paper proposes a rectifier using bootstrapping and active body biasing in $0.11{\mu}m$ RF CMOS process. The proposed rectifier employs the full-wave rectifying structure with cross coupling and increases the power conversion efficiency by reducing the threshold voltage and leakage current using bootstrapping and active bias biasing. Also, it has been designed to be applied to a wide range of applications from 13.56 MHz used in wireless power transmission to 915 MHz used in RFID. As a measured result, 80 % of power conversion efficiency is obtained when the input power is 0 dBm at $10k{\Omega}$ load resistance and 13.56 MHz. Also 40 % of power conversion efficiency is shown in 915 MHz.

Evidence based practice within the complementary medicine context

  • McLean, Lisa;Micalos, Peter Steve;McClean, Rhett;Pak, Sok Cheon
    • CELLMED
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    • v.6 no.3
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    • pp.15.1-15.4
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    • 2016
  • Evidence based practice (EBP) is a system of applying the most current and valid high quality evidence to support clinical decision making in a healthcare setting. In the twenty five years since its inception, EBP has become the accepted benchmark for excellence in healthcare. Although the system emerged within the biomedical sciences, in the years since EBP has become normative across all healthcare modalities from dentistry, allied health to complementary and alternative medicine (CAM). Practicing evidence based medicine within any modality potentially offers the patient the best available care based on high quality evidence. Yet it is the nature of the evidence that provokes some questions about the suitability of EBP across all modalities of healthcare. The meta analysis of randomized controlled trial (RCT) stands at the pinnacle of the hierarchy of evidence in EBP. This forms a challenge to CAM due to the difficulty in reducing the elementals of a holistic naturopathic assessment of a patient into an answerable question to be tested within a RCT. On one level this makes EBP paradigmatically incompatible with CAM, yet on another level it presents the opportunity to redefine the parameters of what is considered high level evidence. EBP has become a tool, and at times a weapon wielded by governments and health insurance companies to direct healthcare funding and policy. The implications of the nature of accepted evidence are becoming far reaching. The pursuit of the best available healthcare for each individual is the focus of EBP. However, the injudicious use of this system to direct health policy is fraught with biomedical bias and dominance. This issue raises the challenge to CAM to present high level evidence according to the rules of evidence, or face the annihilation of centuries of empirical knowledge.