• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.128-134
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• 2004

This paper presents a result of sound transmitting system with power line communication technique. Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detecting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirmed the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.790-796
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• 2010

This paper designed the horn of half-wave needed for Ultrasonic meta) welding. The horn has to be designed and manufactured accurately, because measurements such as the shape, length, mass and etc. have effects on the resonant frequency and the vibration mode. Designed horn of half-wave has the feature of 40,000Hz of nature frequency, and maximizes vibration range in the Tip by resonance in the frequency of ultrasonic wave machine. In this study, we calculated and analyzed the natural frequency to find the optimal design of the horn that amplified the amplitude about double by the modal analysis and harmonic analysis using ANSYS. And we did FFT analysis of the manufactured horn.

• Journal of Korean Clinical Health Science
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• v.4 no.2
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• pp.593-602
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• 2016

Purpose. The purpose of this study was to investigate knowledge, stress and nursing performance about care for delirium in geriatric hospital nurses. Methods. For this study, data were collected from 242 nurses employed at geriatric hospitals with the capacity of more than 100 beds which were located in A, P and Y cites. Frequency analysis, t-test and one-way ANOVA were utilized to analyze the data and Scheffe test was used to conduct post-hoc tests. Results. Nurses showed significant differences in the level of Knowledge, as well as terminal care performance by marital status, nursing experience. A significant relationship was found between knowledge, stress and Delirium care performance. Conclusion. This study found nurses perform delirium care with a high level of stress but with insuffiecient understanding, and thus, showed great needs for related training. Such findings can be useful to develop educational programs to improve knowledge on delirium and plans to reduce stress from delirium for geriatric hospital nurses.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.66-72
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• 2012

Ultrasonic metal welder is consisted of power supply, transducer, booster, and horn. Precise designing is required since each part's shape, length and mass can affect driving frequency and vibration mode. This paper gives a description of an experimental study of the ultrasonic welding of metals. A horn suitable for 40,000Hz was attached to the ultrasonic metal welder in order to weld Cu sheet. The Cu sheet welding was done with different amplitude, pressure and welding time, and its maximum tension was measured. Maximum tension of 177.99N was obtained when the pressure was 2.5bar, amplitude was 80%, and welding time was 0.34sec. Therefore, excessive welding condition negatively influences maximum tension measurement result.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.14-19
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• 2009

Micro fluid channels are machined on quartz glass using powder blasting, and the machining characteristics of the channels are experimentally evaluated. The powder blasting process parameters such as injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns affect machining results. In this study, the influence of the number of nozzle scanning, abrasive particle size, and blasting pressure on the formation of micro channels is investigated. Machined shapes and surface roughness are measured, and the results are discussed. Through the experiments and analysis, LOC are ettectinely machined on quartz glass using powder blasting.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.219-219
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• 2011

최근 지방자치단체에서는 농업용 취수보를 이용한 소수력발전에 관심을 가지고 지자체내의 유휴자원인 하천유수를 이용하여 소수력발전을 함으로써 환경친화적인 에너지를 생산하여 석유 등 에너지 수입대체 효과와 전력수요 급증시의 부하평준화에 기여하고자 하고 있다. 이는 정부의 "저탄소 녹색성장의 에너지정책"에 부응하는 것이며, 또한 하천에 소규모 인공호수를 조성함으로써 소수력발전소 인근지역의 경관개선과 관광자원화에 기여함은 물론 농업용수 공급과 하천유지수를 조정하여 안전한 하천으로서 그 기능을 하도록 계획한 것이다. 이와 병행하여 소수력발전소에서 발생한 무공해 청정에너지를 생산함으로써 전 세계적으로 관심이 높아지고 있는 '온실가스 배출 감축' 노력에 동참함으로써 선진형 기후변화 대응체계에 적응할 수 있다. 본 연구에서는 농업용 취수보를 대상으로 소수력 발전시설의 성능분석 기법을 이용하여 소수력발전시설적용 타당성을 조사 분석하였다. 그림 1은 농업용 취수보인 북평보의 유역면적도를 나타내고, 그림 2는 북평보에 소수력발전시설을 적용할 경우의 부하특성을 나타낸다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.554-557
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• 2001

Indium Tin Oxide(ITO) thin films have been fabricated by the dc magnetron sputtering technique with a target of a mixture $In_{2}O_{3}$(90mol%) and $SnO_{2}$(10mol%). We prepared ITO thin films with substrate temperature 200 to $400^{\circ}C$ and annealing temperature 200 to $500^{\circ}C$. Good polycrystalline-structured ITO films with a low electrical resistivity of $3.4{\times}10^{-4}\Omega{\cdot}cm$ have been obtained. The visible light transmittance of all obtained films was over 80 %.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.117-121
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• 2002

In this paper, the proper manufacturing method to the use of Illite with many application was studied. We confirmed merit of manufacturing and forming according as respective temperature. The variety of crystallization and surface was confirmed by X-ray diffraction(XRD) analysis and SEM. Then, we performed the experiments such as a antibiosis, a heavy metal adsorption and a gas deodorizaton to confirm the function of Illite. As a result, the adsorption of gas decreased according as the heat treatment of Illite, but the ability of antibiosis wasn't changed.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.191-198
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• 2005

The effective stiffness-based optimal technique to control quantitatively lateral drift for shear wall-Frame structure system using composit member subject to lateral loads is presented. Also, displacement sensitivity depending on behavior characteristics of structure system is established and approximation concept that preserves the generality of the mathematical programming is introduced. Finally, the resizing technique of shear wall, frame and composite member is developed and the example of 20 story framework is presented to illustrate the features of the quantitative lateral drift control technique.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.41-42
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• 2001

울산지역의 고정배출원 및 이동배출원과 같은 각종 배출원에서 발생되는 대기오염물은 건물, 도로, 토양 각종 식물 및 수목, 강, 호수, 바다 등과 같은 아주 다양한 수용체로 침적되고 있다. 최근의 연구에 의하면 대단위 산업공단을 가지고 있는 대형산업도시인 울산지역 대기중의 중금속 농도는 타 지역에 비하여 매우 높으며, 또 상당한 정도의 산성비도 내리고 있는 것으로 나타났다. 본 연구는 울산지역의 수목의 잎에 침적되어 있는 중금속을 울산 지역의 산성비 수준의 pH로 조절한 산성용액으로 용출하여 그 성분을 분석하여 각종 대기 오염물이 나무를 비롯한 식물에 침적되는 정도를 각 특성지역과 계절(봄, 여름)별로 비교ㆍ분석하였다. (중략)