• 한국전기전자재료학회논문지
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• 제31권5호
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• pp.320-323
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• 2018

SiGe thin films were deposited by remote plasma enhanced chemical vapor deposition (RPE-CVD) at $400^{\circ}C$ using $SiH_4$ or $SiCl_4$ and $GeCl_4$ as the source of Si and Ge, respectively. The growth rate and the degree of crystallinity of the fabricated films were characterized by scanning electron microscopy and Raman analysis, respectively. The optical and electrical properties of SiGe films fabricated using $SiCl_4$ and $SiH_4$ source were comparatively studied. SiGe films deposited using $SiCl_4$ source showed a lower growth rate and higher crystallinity than those deposited using $SiH_4$ source. Ultraviolet and visible spectroscopy measurement showed that the optical band gap of SiGe is in the range of 0.88~1.22 eV.

• 한국분무공학회지
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• 제20권2호
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• pp.82-87
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• 2015

A nozzle with vortex generator was used to develop the low pressure nozzle with high atomization performance and the nozzle atomized the liquid by centrifugal shear forces. In order to analyze the atomization characteristics, a shadowgraphy method was used and the measurement of droplet size was performed by using laser diffraction analyzer. The liquid injection pressure was fixed as 0.03 bar which is very low pressure and the gas injection pressures were changed from 0 bar to 2.0 bar. As a result, the breakup was achieved at the air injection pressure of 0.25 bar and over. The nozzle with the orifice diameter of 0.4 mm and the orifice gap of 0.25 mm presented small droplet diameters under 50 at the air injection pressure of 0.75 bar.

• 디지털산업정보학회논문지
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• 제13권1호
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• pp.37-48
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• 2017

As the risk of technical leakage is increasing, technology protection support systems for small and medium-sized businesses have gained attention. This paper analyzed the perception gap of the user and policy-maker regarding technology protection support systems. First, to identify key elements of technology protection support systems and construct measurement factors, interviews with experts are conducted. Then, surveys are conducted to analyze the perception differences between the users and policy-makers. Factor analysis and ANOVA have been utilized to analyze survey results. The result shows that the perception gaps exist in the following areas: management system, cost reduction, copyright protection, customer satisfaction, leakage prevention, and awareness. To enhance the effectiveness of technology protection support systems, this paper suggests technology protection support systems should be customized in terms of the company's size and type of busines.

• 한국자동차공학회논문집
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• 제11권6호
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• pp.134-140
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• 2003

The film sensor is used for measuring pressure distribution at planar area, especially at a small space or gap. The present paper deals with the development of film type sensors and system for pressure distribution measuring. The developed system is consist of (1)film sensor with 40/sup */40 array, (2)PCI interface card with maximum sampling rate of 100㎐, and (3)software for data processing and real-time display. The contact pressure test of wiper blade and front glass of vehicle was performed with wiper blade by 40cm. Generally spring force of wiper arm is designed at 0.7∼1kN. Test results of total force was 9.4N and 7.1N in each driver and passenger toward. The paper suggested possibility for base definition in wiper design. A windshield wiper blade experiment revealed that the system successfully measured the contact force distribution during static state, showing the usefulness of the developed system.

• 품질경영학회지
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• 제42권2호
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• pp.189-197
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• 2014

Purpose: To reinforce the product competitiveness of Korean small and medium-sized business in the world market. Methods: By clarifying the definition of a masterpiece, developing global masterpiece quality index(MQI) equipped with checklists, surveying several companies and customers, and analyzing the results of the survey via the MQ zone diagram. Results: The results of the survey show the gap between Korean small and medium-sized business and global masterpiece companies in terms of MQI. From this analysis, in order for the surveyed Korean companies to be the world-class ones, the managerial aspects to be improved could be clearly pointed out through the measurement indices. Conclusion: This research would provide Korean small and medium-sized companies, which wish to get on the global masterpiece level, with an objective guideline.

• 한국유체기계학회 논문집
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• 제14권1호
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• pp.5-10
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• 2011

MTG(Micro turbine generator) operating at 400,000 rpm is under development and the impact test rig to measure the dynamic stiffness and damping coefficient of air foil bearing for high speed rotor is presented in this study. The stiffness and damping coefficient of air foil bearing depending on the rotational speed can be measured easily and effectively by using the simple configuration of impact test rig which is composed of air gun, gap sensors and high speed motor. The estimation results of stiffness and dampling coefficient using least square estimation method is presented as well.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2000년도 추계학술대회 및 정기총회
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• pp.189-189
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• 2000

본 연구에서는 기업의 성과측정시스템을 평가하고 성과측정관행의 성숙도를 진단하는 방법을 제시하고 이를 토대로 우리나라 서비스 기업 두 곳을 선정하여 적용 연구를 수행하였다. 구체적으로 K병원과 A항공사의 경영층과의 면담을 통하여 각 기업에 적합한 성과측정시스템의 틀(framework)을 균형성과표(balanced scorecard)를 기초로 구현하고 다양한 성과차원의 주요성과지표들(KPIs: key performance indicators)을 기업이 추구하는 전략과 부합할 수 있도록 인과관계로 연계하였다. 그리고 구성원들을 대상으로 실시한 구조화된 설문조사를 통하여 각 사례기업의 성과측정시스템의 적합도를 alignment analysis, congruence analysis, consensus analysis, confusion analysis 등 네 가지 차원의 차이분석(gap analyses)을 이용하여 평가하고, 그들의 현행 성과측정관행의 성숙도를 진단하였다.

• 대한기계학회논문집B
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• 제23권9호
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• pp.1192-1200
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• 1999

The present study investigates flow characteristics in a cavity with one rotating disk and co-rotating disks for application to HDD. The experiments are conducted for rotating Reynolds numbers of $5.5{\times}104$ to $1.10{\times}105$ and for gap ratios of 0.059 to 0.175 in a single rotating and 0.047 to 0.094 in co-rotating disk. Time-resolved velocity components and turbulence intensity on the rotating disks are obtained by using LDA measurements. Detailed Knowledge of the flow characteristics is essential to analyze flow vibration and heat transfer and to design head-arm assembly and hub height in HDD. The results indicate that the velocity field in HDD is changed largely by the rotating Reynolds numbers and hub height of the disk.

• 소음진동
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• 제9권4호
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• pp.822-827
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• 1999

The reduction of booming noise level and improvement of sound quality in the vehicle interior have been major fields of vehicle NVH for many years. In order to reduce the booming noise this paper proposed a system variable, which takes account of mode shapes and natural frequencies of the structural-acoustic system, measurement points and excitation frequency. By simplifying the system variable, the major contributors of panels inculding roof, roof lining, wind shield glasses, doors and floor to booming noise at a specific frequency was experimentally found. Also the relationships between structural modes of roof lining, one of the major contributors, and acoustic modes of compartment cavity were investigated from the viewpoint fo structure-borne noise. In addition, the roof lining was modified structurally by applying marble sponge to the gap between roof and roof lining. Asthe result of structural modification, the booming noise was reduce at target frequency.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.887-890
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• 2007

The low frequency noise, including infra-sound is known to affect human physiology and psychology. Guidelines and measurement method of low frequency noise has been introduced in several countries in order to evaluate low frequency noise. In this work, low frequency characteristics of Daejeon subway was investigated in terms of the noise level and spectrum in the interior of running subway car and the subway station. The interior sound pressure level of the passenger car was between 60 and 102 dB in the frequency range of $1{\sim}250$ Hz.