• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.2
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• pp.63-69
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• 1999

The frequency-dependent characteristics of the finline have previously been analyzed using several frequency domain approaches. But the time domain TLM method presented in this paper is another independent approaches for obtaining frequency domain results for finline. The structure analysed with this algorithm is unilateral finline in WR-62 waveguide enclosures and the symmetrical condensed node based on the properties of Huygen's scattering model is used. From the TLM results, the frequency-dependent scattering parameters of a unilateral finline have been calculated by Fourier transform of the time domain data. The numerical results are in good agreements with other paper, thus demonstrating the validity and usefulness of the proposed method.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.825-827
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• 2000

자성체를 포함하는 자기 시스템을 해석하는데 있어 비선형과 히스테리시스(Hysteresis)는 매우 중요한 역할을 한다. 특히 재질의 히스테리시스 특성을 유한요소법(FEM)을 이용하여 계산하기 위해서 많은 방법들이 소개되었다. 단순 반복법이나 Fixed Point Technique(FPT), M-iteration 법. 뉴튼 랍슨 (Newton-Raphson) 법 등이 그 예이다. 이 방법들 중에서 뉴튼 랍슨법은 빠른 수렴 특성으로 가장 많이 사용되고 있다. 하지만 뉴튼-랍슨법을 이용하여 히스테리시스 재질을 해석할 때는 매 반복 계산 때마다 계 계수행렬(System Stiffness matrix)이 변화하기 때문에 요소의 수가 매우 많을 경우 역행렬을 계산하기 위한 시간이 많이 소요되는 단점이 있다. 특히 히스테리시스 해석의 경우에는 주로 time-step법을 이용하여 계산하므로 가장 시간이 많이 소요되는 행렬 계산 시간을 단축함으로써 전체 계산 시간을 크게 줄일 수 있다. 최근 비선형 해석에서 TLM(Transmission Line Modeling)법이 도입되어 비선형 해석 시의 계산 시간을 크게 단축할 수 있게 되었다. 본 논문에서는 비선형 해석에 적용된 TLM법을 히스테리시스 해석에 적용하는 방법을 새로 제안한다. TLM법은 뉴튼-랍슨법과 달리 각 반복 계산 때마다 계수행렬식이 변화하지 않고 단지 구동항만 변하기 때문에 행렬의 LU를 한 번 저장해 두면 forward와 backward substitution만 시행하면 된다. 따라서 요소의 수가 증가할 경우 TLM법을 사용하면 뉴튼-랍슨법에 비해 매우 큰 계산 이득을 얻을 수 있다. 본 논문에서는 TLM법을 히스테리시스에 적용하는 방법을 기술하고 간단한 모델에 이 방법을 적용하여 뉴튼-랍슨법과의 비교를 통해 TLM법의 효용성을 보인다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.349-349
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• 2010

Great performance of many semiconductor devices requirs the use of low-resistance ohmic contact. Typically, transmission line method (TLM) patterns are used to measure the specific contact resistance between silicon and metal. In this works, we investigate contact resistance for metal dependent (Cr/Ag, Ni) using TLM pattern based on silicon-on-insulator (SOI) wafer. The electrode with Ni linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in accumulation part, but non-linearly increase in inversion part. In additional, the electrode with Cr/Ag linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in inversion part, but non-linearly increase in accumulation part.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.121-125
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• 1974

Polyclads (Stylochus ijimai and Pseudostylochus obscurus) which damage oyster were treated with calcium hypochlorite to determine the TLm concentration. In this experiment the TLm and the extermination density as well as the growth of the oyster after the treatment were checked with following results: The higher the temperature and the longer the period of the treatment is, the lower the TLm is. The greater the concentration of sea water is, the higher TLm is because of the weakened action of calcium hypochlorite. When the oyster is treated by calcium hypochlorite at the oyster farm, its extermination concentration is 2.4-7.1 times higher than that of TLm in fresh water. The growth rate was not affected after the treatment.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.212-212
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• 2013

본 연구에서는 최근 다양한 전자 소자로써의 연구가 진행되고 있는 그라핀을 실리콘 기판위에 전자빔 식각(Electron-Beam Lithography)을 이용하여 TLM (Transfer Length Method) 패턴을 형성하고 가스 유입이 가능한 진공 챔버를 가지는 Probe Station을 이용하여 I-V 변화를 측정함으로써, 그라핀을 가스 센서 소자로서의 가능성을 연구하였다. 우리는 기존의 광식각을 이용한 TLM 패턴 형성과 더불어 전자빔 식각(E-Beam Lithography: EBL)을 이용한 TLM 패턴을 형성하여 I-V를 측정하였는데, 전자빔을 이용한 TLM 패턴의 형성은 광식각을 이용한 방법에 비해 더 세밀하고 미세한 패턴을 형성하는 것이 가능하다. 이렇게 형성된 그라핀의 TLM패턴은 가스 유량 조절이 가능한 진공 챔버를 가지는 Probe Station을 이용하여 측정하게 되는데, 이 때 저진공 상태의 챔버 내로 N2, H2 두 종류의 가스를 각각 유량을 변화시키며 주입하고 그 변화를 측정하였다. 유입된 가스는 그라핀의 Dangling Bond에 결합됨으로써 그라핀의 전도도를 변화시키게 되고, 변화된 그라핀의 전도도에 따른 I-V 결과의 변화를 측정하여 이를 가스 센서로 사용할 수 있는지를 측정하였다. 또한 유입되는 가스의 유량 변화에 따른 I-V 결과의 변화량을 통하여 가스 센서의 민감도 또한 측정하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.662-664
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• 1998

본 논문에서는 다목적 실용위성인 아리랑위성(KOMPSAT-I)에서 지상과의통신을 위해 사용하는 CCSDS(Consultative Committee for Space Data Systems)표준 Command/Telemetry(CMD/TLM)시스템과 KOMPSAT-I의 목적에 맞게 이를 적용한 CMD/TLM 시스템을 소개한다. 현재 한국항공우주 연구소는 Observer 회원 자격으로 CCSDS 에 가입되어 있으며 국내 위성 개발에서 CMD/TLM 시스템에 CCSDS프로토콜을 사용한 것은 처음이다.

• Structural Engineering and Mechanics
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• v.65 no.1
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• pp.91-98
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• 2018

Three structure-dependent integration methods with no numerical dissipation have been successfully developed for time integration. Although these three integration methods generally have the same numerical properties, such as unconditional stability, second-order accuracy, explicit formulation, no overshoot and no numerical damping, there still exist some different numerical properties. It is found that TLM can only have unconditional stability for linear elastic and stiffness softening systems for zero viscous damping while for nonzero viscous damping it only has unconditional stability for linear elastic systems. Whereas, both CEM and CRM can have unconditional stability for linear elastic and stiffness softening systems for both zero and nonzero viscous damping. However, the most significantly different property among the three integration methods is a weak instability. In fact, both CRM and TLM have a weak instability, which will lead to an adverse overshoot or even a numerical instability in the high frequency responses to nonzero initial conditions. Whereas, CEM possesses no such an adverse weak instability. As a result, the performance of CEM is much better than for CRM and TLM. Notice that a weak instability property of CRM and TLM might severely limit its practical applications.

• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.29-34
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• 2011

Traditionally, the main strategy of treatment of the head and neck cancer was en bloc resection including adjacent normal tissues through wide incision. However, the procedures may leave severe functional deficit such as swallowing difficulty, aspiration, and wide neck scar. Therefore, many attempts have been made up to minimize these morbidities. Of them, the minimal invasive approach such as transoral laser microsurgery (TLM) and transoral robot surgery (TORS) have been spolighted as a sensible strategy for organ preservation of the head and neck cancer patients. Results of TLM are equivalent to those obtained by conventional surgery, with considerably less morbidity, less hospital time and better postoperative function. Oncologic results of TLM are equivalent to conventional surgery. TORS are safe, feasible, and promising but oncologic safety is not yet verified. This article covers to current application of TLM and TORS, their advantages and limitations, and future direction.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.10
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• pp.523-529
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• 1999

In the case of the large power transformer, the grain-oriented material is usually used. So, to obtain more accurate results, anisotropy and non-linearity of the material must be considered. The Newton-Raphson(NR) method is generally used for analyzing these non-linear properties, but it consumes so much time, especially when the number of nodes is large or the shape of the model is complex. The transmission line modeling (TLM) method is successfully adopted to the analysis of non-linear properties with FEM, but it has not been adopted to the analysis of the anisotropic material. In this paper, the formulation of the TLM method considering anisotropy is developed and the adoption to the 3-phase transformer is presented.

• Medical Lasers
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• v.9 no.2
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• pp.103-109
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• 2020

Transoral microsurgery has come a long way as a go-to surgical intervention technique for head and neck cancers. This minimally invasive procedure had gained acceptance through comparative clinical studies against radical neck surgical procedures, radiotherapy, and chemotherapy. Laser technology has vastly improved the oncological outcomes of this procedure and brought about an appreciation of transoral laser surgery (TLM) as a mainstay for re-sectioning malignant tumors along the throat. As an established procedure, TLM has undergone several upgrades regarding the different energy devices used for cutting, ablation, and hemostasis. Continued advances in automation have eventually led to surgical robotics, resulting in the emergence of transoral robotic surgery (TORS) as a viable advanced alternative for TLM. Similarly, expansions and enhancements (image-based guidance, fluorescence spectroscopy, and advanced robotic system) have also been investigated as potential upgrades for TORS. This paper reviews a selection of publications on the significant technological advancements to TLM and TORS over the past five years.