• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.307-309
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• 2011

최근 출시되는 고사양의 Hand-phone 적용되어진 Camera Module은 대부분 Auto Focusing기능이 탑재되어 있으며 Camera Module의 화소수가 높아지면서 좀 더 정밀하고 안정적인 AF구동제품이 소비자에 의해 요구되고 있다. 본 논문은 현재 출시되고 있는 Camera Module적용 VCM(Actuator)의 문제점인 Auto Focusing시 Lens 초점위치 및 Module 자세에 따른 해상도편차 발생으로 해상도 보증 및 안정된 Actuator 구동을 위해 개선된 구조의 Hybrid VCM을 제안한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.616-619
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• 2003

This work presents the design, fabrication and microwave performance of distributed analog phase shifter (DAPS) fabricated on $(Ba,\;Sr)TiO_3$ (BST) thin films for X-band applications. Ferroelectric BST thin films were deposited on MgO substrates by pulsed laser deposition. The DAPS consists of high impedance coplanar waveguide (CPW) and periodically loaded tunable BST interdigitated capacitors (IDC). In order to reduce the insertion loss of DAPS and to remove the alteration of unloaded CPW properties according to an applied dc bias voltage, BST layer under transmission lines were removed by photolithography and RF-ion milling. The measured results are in good agreement with the simulated results at the frequencies of interest. The measured differential phase shift based on BST thin films was $24^{\circ}$ and the insertion loss decreased from 1.1 dB to 0.7 dB with increasing the bias voltage from 0 to 40V at 10 GHz.

• 한국간호교육학회지
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• 제14권1호
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• pp.88-97
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• 2008

Purpose: This study was done to develop strategies for better education and career adaptation of nursing students by investigating the recognition and intentions of nursing students and graduates on the nursing and a future career. Method: Data was collected from a survey conducted between the 1st of October and 5th of December, 2007. Participants were 113 students and 37 graduates of one nursing college. Result: The majority of participants thought that atmosphere and relationships were important criteria to choose a job. Most of them selected nursing major not because their aptitude but because of its professionalism and job stability. Most wanted to go to graduate school and were interested in a nurse specialist program, especially for critical and emergency care. The preferred nursing role changed from recovery care to health promotion as they advanced in their studies. They thought work overload and fatigue from three shift as barriers for a longer stay as a clinical nurse. Conclusion: This study is meaningful in a way that it suggests some strategies for promoting nursing professionalism and adaptation to working field. In order to generalize the results of this study, replicate studies need to be conducted with nation-wide samples.

• 대한전자공학회논문지TC
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• 제42권1호`
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• pp.29-37
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• 2005

다중반송파 변조방식의 주요한 문제점중의 하나는 도플러 천이에 의한 주파수 옵셋에 민감하다는 점이다. 주파수 옵셋은 다중반송파 변조된 신호의 주파수 중첩으로 인한 반송파간의 간섭을 야기시킨다. 그러나 채널변화에 따른 도플러 천이는 또 다른 다이버시티 이득을 제공할 수 있는 요소가 될 수 있다. 본 논문에서는 변형된 다중반송파 코드분할 다중접속(multicarrier CDMA) 시스템을 제안함으로써 다중경로 다이버시티외에 도플러 다이버시티를 이용할 수 있게 하였다. 이를 위하여 이동 무선채널을 독립적인 시간 및 주파수 페이딩 채널로 분해하고 시간 다이버시티를 이용하는 레이크 수신기를 주파수영역으로 확장하므로써 다중경로 및 도플러 다이버시티 이득을 동시에 얻을 수 있도록 하였다.

• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.408-417
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• 2000

The design and simulation of meshing of a single enveloping worm-gear drive with modified surfaces is presented. Generally worm-gear is generated by the hob which is identical to the worm. This process guarantees the conjugation between the worm and the gear but results in a line contact at every instant which is very sensitive to misalignment. The localization of bearing contact is necessary to reduce the sensitivity of the worm-gear drive to misalignment. Practically this localization is achieved by application of an oversized worm type hob to cut the worm-gear. The oversized hob approach is very practical and effective to localize bearing contact but can not provide the conjugation between the worm and the modified worm-gear. This work proposes an analytical procedure to make the worm surface conjugate to the worm-gear which is cut by the oversized hob. The developed computer program allows the investigation of the influence of misalignment on the shift of the bearing contact and the determination of the transmission errors, the contact ratio and the principle curvatures. The developed approach has been applied for ZK type of single-enveloping worm-gear drives and the developed theory is illustrated with a numerical example.

• 산업경영시스템학회지
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• 제35권2호
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• pp.204-211
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• 2012

In this study, appropriate preventive measures are suggested as follows by analyzing industrial accident cases occurred for five years of company J and workers' survey. First, personnel management including meticulous shift work and rotation task for older workers should be made strictly in terms of safety and health management. Second, Industrial disasters occurred more in spring than in other seasons, so safety management will have to be enhanced in spring. That is, to reduce industrial disaster various occupational safety and health activities to prevent spring fatigue are needed. Third, to improve safety consciousness of workers, penalties for those who have not received safety training and for people without protective equipment are required. Also, hazard prediction training such as Tool Box Meeting shall be proceeded. Fourth, building of proactive safety culture that the workers themselves handle risk factors is urgent. Fifth, the company-wide safety and health programs including safety awards and cases presentation are needed to be planned.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.109-118
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• 2004

No.2 PCM (Pickling and tandem cold rolling mill) at Pohang works was revamped in 2003. The purpose of this project is to produce carbon and stainless steel using conventional carbon production process, rolling and annealing. This paper introduces the applied facilities and technologies of PCM which are used in production of carbon and stainless steel. To realize the main purpose of this project, POSCO have developed laser weld technology in normal carbon and special steel (stainless, high carbon and high silicon). And this report describes the method which is developed to get down the surface defect of stainless 400 series. After revamping, No.2 PCM can have competitive power in this field and can supply the special steel using carbon rolling process.

• Advances in aircraft and spacecraft science
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• 제6권6호
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• pp.479-495
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• 2019

Periodic cellular core structures included in sandwich panels possess good stiffness while saving weight and only lately their potential to act as passive vibration filters is increasingly being studied. Classical homogeneous honeycombs show poor vibracoustic performance and only by varying certain geometrical features, a shift and/or variation in bandgap frequency range occurs. This work aims to investigate the vibration filtering properties of the AUXHEX "hybrid" core, which is a cellular structure containing cells of different shapes. Numerical simulations are carried out using two different approaches. The first technique used is the harmonic analysis with commercially available software, and the second one, which has been proved to be computationally more efficient, consists in the Wave Finite Element Method (WFEM), which still makes use of finite elements (FEM) packages, but instead of working with large models, it exploits the periodicity of the structure by analysing only the unit cell, thanks to the Floquet-Bloch theorem. Both techniques allow to produce graphs such as frequency response plots (FRF's) and dispersion curves, which are powerful tools used to identify the spectral bandgap signature of the considered structure. The hybrid cellular core pattern AUXHEX is analysed and results are discussed, focusing the investigation on the possible spectral bandgap signature heritage that a hybrid core experiences from their "parents" homogeneous cell cores.

• 한국의류산업학회지
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• 제11권2호
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• pp.231-241
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• 2009

Embroidery is one of the oldest methods of textiles surface decoration. The masterpiece "Tapisserie de Bayeux," is one of the earliest Medieval embroideries. Embroidery was popular on a broad scale with introduction of what was called Opus Anglicanum("English work") in the 13th century. France had been producing sophisticated embroideries since the 16th century. England was the country producing the greatest quantity of embroideries of the best quality in the 17th century. Until the 17th century, the Church was the most important patron of needlework. Then a shift in emphasis occurred towards the domestic embroidery. English 17th century domestic embroidery reached a high point of technical brilliance and charm. In France, embroidery was produced on hangings as well as costume. 18th century interest in embellishing the domestic environment, embroideries became much more finely detailed than those of the 17th century with the use of finer wool and silk threads. French silk were the finest in the world, and their embroidery was arguably equally fine both in furnishing textiles and on costumes. "Art Needlework" was the major movement in embroidery in the late 19th century. The Royal School of Needlework was founded in 1872, followed by similar institutions around Britan. Splendid fashion embroidery of French haut-couture that was represented to Lesage atelier in 20th century.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.204.2-204.2
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• 2014

Among various metal oxides, ZrO2 is of particular interests and has received widespread attention thanks to its ideal mechanical and chemical stability. As a cheap metal, Ag nanoparticles are also widely used as catalysts in ethylene epoxidation and methanol oxidation. However, the nature of Ag-ZrO2 interfaces is still unknown. In this work, the growth, interfacial interaction and thermal stability of Ag nanoparticles on ZrO2(111) film surfaces were studied by low-energy electron diffraction (LEED), synchrotron radiation photoemission spectroscopy (SRPES), and X-ray photoelectron spectroscopy (XPS). The ZrO2(111) films were epitaxially grown on Pt(111). Three-dimensional (3D) growth model of Ag on the ZrO2(111) surface at 300 K was observed with a density of ${\sim}2.0{\times}1012particles/cm2$. The binding energy of Ag 3d shifts to low BE from very low to high Ag coverages by 0.5 eV. The Auger parameters shows the primary contribution to the Ag core level BE shift is final state effect, indicating a very weak interaction between Ag clusters and ZrO2(111) film. Thermal stability experiments demonstrate that Ag particles underwent serious sintering before they desorb from the zirconia film surface. In addition, large Ag particles have stronger ability of inhibiting sintering.