• 한국정밀공학회지
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• 제29권1호
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• pp.41-47
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• 2012

The LDS(Laser Direct Structuring) is one of the new direct writing methods to fabricate conductive patterns by energy beam. It uses thermoplastic polymers with an additive compound that serves as plating seed after the activation by laser. The advantages of LDS include the miniaturization of electrical components, design flexibility, and a reduced number of production steps. The purpose of this study is to investigate the fundamental mechanism for LDS and the characteristics of conductive patterns by laser parameters. These results were studied by SEM, EDX, and XPS analysis. We have used a 20W pulse-modulated fiber laser and copper electroless plating to fabricate conductive patterns on polymer. The result showed that electroless copper plating seed caused the laser cracking of additive compound. In particular, the additive compound contained in copper metal oxides atoms will be changed to copper metal elements. Also, the characteristics of conductive patterns were dependent on laser parameter, especially laser fluence.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.34-34
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• 2018

레이저를 통한 플라스틱 일체형 회로형성 기술은 레이저 직접 성형 (Laser Direct Structuring, LDS) 기술과 도금기술을 이용하여 기판 표면에 전도성 회로 패턴을 형성하고 소자를 집적하여 부품을 제작하는 기술이다. 종래에는 PCB 기반의 평면기판을 기반으로 하여 제작된 소자와 부품이 전자제품의 주를 이루었으나, 최근 소자의 집적화와 제품 디자인의 유연화(flexible)로 굽힘(bendable) 형태의 스마트 시계와 같은 웨어러블(wearable) 전자 제품이 출시되었으며, 레이저를 통한 플라스틱 일체형 회로형성 기술은 미래 사회의 주를 이룰 웨어러블 형태의 제품의 상용화를 가능하게 할 뿐만 아니라 회로 집적이 가능하여 제품 혁신을 주도할 기술로 주목 받고 있다. 본 연구에서는 LDS 부품의 미세 회로 구현을 위한 공정 기술 개발에 있어서 고생산성 무전해 동도금액 및 부품 실장을 위한 표면처리 기술 개발에 대한 결과를 보고한다. 미세 회로 패터닝 기술의 상용화를 위해서는 도금액의 안정성뿐만 아니라 고속 공정기술이 필요하다, 현재 국내 무전해 동 도금의 석출 속도는 시간 당 $4{\sim}5{\mu}m$ 내외이기 때문에, 생산성을 향상시키기 위해서는 시간 당 $10{\mu}m$ 정도의 고속 무전해 동 도금 공정 개발 필요하다.

• Transactions on Electrical and Electronic Materials
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• 제8권6호
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• pp.246-249
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• 2007

A triple-band antenna was developed and fabricated by LDS(Laser Direct Structuring) process. The effects of the plating rate and heat treatment condition were investigated and the gains of fabricated antennas were measured at various frequencies. The laser irradiated surface shows clearly that there are prominence and depression. It shows anchoring effect between a plating material and ablation surface. The plating rate was decreased when the plating material is exhausted in the solution. This solution needs to refreshed by the new aid solution. The copper plating thickness is decreased with the increase of heat treatment temperature in the same time but it does not change other condition. The gain of LDS antenna showed higher than the generally processed antenna. This result was related with practical use of the dimension and effective dielectric constant.

• Journal of Chest Surgery
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• 제48권4호
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• pp.272-276
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• 2015

Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder that is characterized by aggressive arterial and aortic disease, often involving the formation of aortic aneurysms. We describe the cases of two children with LDS who were diagnosed with aortic root aneurysms and successfully treated by valve-sparing aortic root replacement (VSRR) with a Valsalva graft. VSRR is a safe and suitable operation for children that avoids prosthetic valve replacement.

• 전자공학회논문지A
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• 제32A권8호
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• pp.119-125
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• 1995

Strained multiple quantum well(SMQW) PBH-DFB-LDs emitting at 1.55$\mu$m wavelength has been fabricated using OMVPE and LPE crystal growth tecnique. Using the SMQW active layer, a linewidty enhancement factor of 2.65 was obtained at lasing wavelength and consequnently, packaged 42 modules showed a very low average chirp of 0.44nm at 2.5Gbps NRZ direct modulation. The 77 devices showed average threshold current of 8.72mA and average slope efficiency of 0.181 mW/mA, and single longitudinal mode operation with SMSR larger than 30dB up to 5mW. Among the 77 devices, standard deviation of lasing wavelength of 3.57nm was obtained owing to a good crystal growth uniformity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.249-251
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• 2007

The proposed LDS(Link-status Dependent Scheduling) algorithm in HR-WPAN up to now aims at doing only throughput elevation of the whole network, when the crucial DEV(Device) is connected with worst-link relatively, throughput of this DEV becomes aggravation, The proposed the WGS(Worst-case Guaranteed Scheduling) _algorithm in this paper guarantees throughput of the DEV which is connected with worst-link in a certain degree as maintaining throughput of all DEVs identically even if a link-status changes, decreases delay of the whole network more than current LDS algorithm Therefore proposed WGS algorithm in this paper will be useful in case of guaranteeing throughput of a DEV which is connected worst-link in a certain degree in a design of HR-WPAN hereafter.

• 대한상한금궤의학회지
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• 제9권1호
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• pp.47-58
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• 2017

Objective : The purpose of this paper is to report the adverse drug reactions of patient with cervical spondylotic myelopathy(CSM) treated by herb medicine, Soshiho-tang. Methods : The patient was prescribed Soshiho-tang herbal medicine for 9days. The patient complained of dizziness, difficulty of concentration and elevation of blood pressure on the 6th day. The doctor made the patient stop to take the herbal medicine and every symptoms and abnormal blood pressure are normalized after 6 days. The abnormal responses were assessed by WHO-UMC Causality Categories and LDS scale. Results : The WHO-UMC Causality is 'probable/likely' and LDS scale is 5, it means 'moderate' severity. Conclusions : The herbal medicine, Soshiho-tang is relevant to abnormal responses of the patient with CSM. This is a first case report of hypertension induced by herbal medicine, Soshiho-tang in Korea.

• 한국결정성장학회지
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• 제12권1호
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• pp.11-20
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• 2002

The world at the end of the $20^{th}$ Century has become "blue" Indeed, this past decade has witnessed a "blue rush" towards the development of violet-blue-green light emitting diodes (LEDs) and laser diodes (LDs) based on wide bandgap III-Nitride semiconductors. And the hard work has culminated with, first, the demonstration of commercial high brightness blue and green LEDs and of commercial violet LDs, at the very end of this decade. Thanks to their extraordinary properties, these semiconductor materials have generated a plethora of activity in semiconductor science and technology. Novel approaches are explored daily to improve the current optoelectronics state-of-the-art. Such improvements will extend the usage and the efficiency of new light sources (e.g. white LEDs), support the rising information technology age (e.g. high density optical data storage), and enhance the environmental awareness capabilities of humans (ultraviolet and visible photon detectors and sensors). Such opportunities and many others will be reviewed in this presentation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2615-2617
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• 2003

The Kalman filter is a recursive Linear Estimator for the linear dynamic systems(LDS) affected by two different noises called process noise and measurement noise both of which are uncorrelated white. The Expectation Maximization(EM) algorithm is employed in this paper as a preprocessor to reinforce the effectiveness of Kalman estimator. Particularly, we focus on the relation between Kalman filter and EM algorithm in the LDS. In this paper, we propose a new algorithm to improve the performance on the parameter estimation via EM algorithm, which improves the overall process of Kalman filtering. Since Kalman filter algorithm not only needs the system parameters but also is very sensitive the initial state conditions, the initial conditions decided through EM turns out to be very effective. In experiments, the computer simulation results ate provided to demonstrate the superiority of the proposed algorithm.

• 한국멀티미디어학회논문지
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• 제11권6호
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• pp.729-736
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• 2008

Using video synthesis to depict flowing water is useful in virtual reality, computer games, digital movies and scientific computing. This paper presents a novel algorithm for synthesizing dynamic water scenes through a sample video based on a dynamic texture model. In the paper, we treat the video sample as a 2-D texture image. In order to obtain textons, we analyze the video sample automatically based on dynamic texture model. Then, we utilize a linear dynamic system (LDS) to describe the characteristics of each texton. Using these textons, we synthesize a new video for dynamic flowing water which is prolonged and non-fuzzy in vision. Compared with other classical methods, our method was tested to demonstrate the effectiveness and efficiency with several video samples.