• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.53-58
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• 2009

A SMT mounter is a kind of equipment that mounts SMD parts quickly on the printed circuit board. By using linear motors, it is controlled with high speed and precision, which is similar to semi-conductor and display process equipment. It is necessarily used in an assembly process of an electronic device. Mobile devices such as a mobile phone and PDA are required to reduce mount areas due to the demands for high performance and small size. Hence, super small sized and complex mobile devices have been developed. To improve the productivity of the corresponding equipment, designs with large sized, high speed, and multidisciplinary functions have been consistently performed. Meanwhile, a design trend of large size and light-weight on SMT mounter causes a low natural frequency of systems and vibration problems at the high speed operation. In this paper, the dynamic characteristics of the SMD mounter system were investigated through a modal test and transmissibility test, and verified by finite element method. Also, various design improvement was performed to avoid the resonance phenomena.

• The Journal of Korean Academic Society of Nursing Education
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• v.23 no.1
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• pp.15-26
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• 2017

Purpose: This study evaluated the efficacy of a communication ability enhancement program for nursing students in Korea through a systematic review of literature and meta-analysis. Methods: The researchers searched data-bases, including the Data Base Periodical Information Academic, Research Information Sharing Service, National Digital Science Library and National Assembly Library. The key words used included 'communication' and 'nursing student'. The researchers evaluated articles published up to July 2016. Out of 381 selected articles, 20 clinical trial studies were meta-analyzed. Each article was evaluated in accordance with the Checklist of Scottish Intercollegiate Guideline Network. The effect size of communication ability, self-efficacy and interpersonal relations were synthesized by a random effects model from analysis software (R 3.2.3). The heterogeneity of effect size was analyzed by exploratory and confirmatory moderator analysis. Results: The overall effect size of the program was of a moderate level (SMD=0.78, 95% CI: 0.49~1.07) along with each outcome of self-efficacy (SMD=0.80, 95% CI: 0.23~1.37), and interpersonal relations (SMD=0.47, 95% CI: 0.14~0.80). For heterogeneity, moderator analysis was performed, by grade, and a statistically significant moderator was found. Conclusion: It is evident that a communication ability enhancement program for nursing students is moderately effective in improving communication ability, self-efficacy and interpersonal relations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.95-99
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• 2006

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and to inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens, LED illumination systems, and a frame grabber inside the PC. This system loads up to six feeders at a time and inspects them automatically and sequentially. The inspection software was implemented using Visual C++ on Windows with easily usable GUI. Using this system, we can automatically measure and inspect the quality of ail feeders in production process by analyzing the measurement results statistically.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.98.4-98
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• 2001

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens ...

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.1-8
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• 1993

Electrical or electronic products have been becoming smaller and high integrated recently, with printed circuit boards(PCB's) being the key components for these products. The introduction of new technology of surface mounted devices(SMD) opens new ways towards high integration on the PCB. Many plants in eletronical industry which produce high variety of PCB's to meet the demands of customer orders require flexibility in PCB's production lines. This survey paper describes the related optimization problems and solution methods to the automated surface mount technology(SMT) assembly lines, and provides with the research direction for improving flexibility.

• Journal of the KSME
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• v.34 no.2
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• pp.112-117
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• 1994

최근의 전자기기는 반도체 기술의 급속한 발전에 따라 소형화, 고기능화 및 다양화 뿐만 아니라 경박단소화되는 추세에 있다. 이러한 시장의 요구에 대응하여 표면실장용 전자부품이 등장하여 그 사용이 점차증가하고 있고 여기에 발맞춰 국내 . 외 전자기기 제조업체가 제품내의 PCB를 SMD화하는 추세에 있다. 따라서 표면실장 부품의 조립을 위한 고밀도, 고정도의 실장기술의 개발이 요구되고 있다. 또한 부품 자동삽입 등 기존의 방법들로 조립된, 전자기기 내부에 사용 되는 PCB의 조립상태 및 각 부품의 특성들을 검사하기 위한 In-circuit Tester의 기술도 빠른 속도로 발전하여 자동화되어가고 있는 추세에 있다. 이에 따라 본 연구소에서는 '90년에 능 Mounter GCA-M2000 모델을 개발 완료하였고 현재 관련 사업부에서 양산중에 있으며, 아날로그 방식 및 디지털 방식의 In-circuit Tester 모델도 개발 완료하여 현재 양산 중에 있다. 이 지면을 빌어 소개할 기회를 갖고자 한다.

• Journal of Korean Critical Care Nursing
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• v.14 no.3
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• pp.141-156
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• 2021

Purpose : This study aimed to systematically review the preventive interventions for delirium in Korean intensive care unit (ICU) patients and evaluate their efficacy. Methods : For this systematic review and meta-analysis, we searched the literature and selected studies from data sources that included the RISS, KISS, National Central Library, National Assembly Library, DBpia, Science on, MEDLINE, and Cochrane Library. We used Cochrane's revised tool for risk of bias in randomized trials and non-randomized studies of intervention tools to assess the quality of the selected studies. The effect size of the intervention was calculated as odds ratio (OR) and standardized mean difference (SMD). Results : Preventive interventions reported in 23 studies with a total of 4,799 ICU patients were effective in reducing the occurrence of delirium (OR=0.64, 95% CI : 0.49~0.91, p=.011), but not the duration (SMD=-0.22, 95% CI : -0.51~0.08, p=.148). As a result of a subgroup analysis, non-pharmacological interventions were effective in reducing the occurrence of delirium (OR=0.66, 95% CI : 0.47~0.94, p=.020), while pharmacological interventions had no effect (OR=0.68, 95% CI : 0.33~1.40, p=.295). Among the non-pharmacological interventions, multi-component intervention had the largest effect size (OR=0.38, 95% CI : 0.26~0.55, p<.001). Conclusion : Non-pharmacological interventions were effective in reducing the occurrence of delirium. We recommend the development and application of multi-component interventions to prevent delirium in the Korean ICU patients.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.573-577
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• 2002

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens, LED illumination systems, and a frame grabber inside the PC. This system loads up to six feeders at a time and inspects them automatically and sequentially. The inspection software was implemented using Visual C++on Windows NT with easily usable GUI. Using this system, we can automatically measure and inspect the quality of all feeders in production process by analyzing the measurement results statistically.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.2
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• pp.29-36
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• 2002

Experiments have been performed to investigate the effect of secondary venturi tip angle on flow and spray characteristics in gas turbine combustor with a swirl cup assembly. Three variations of secondary venturi tip angle are made: converging, straight and diverging angles. It is found that the variation of venturi tip angle results in the significant changes of flow and spray characteristics in gas turbine combustors, such as the size and location of recirculation zones. drop size and mass distribution affecting combustion efficiency and NOx emissions. In diverge case, central toroidal recirculation zone(CTRZ) exists near the exit, which is known to be beneficial for flame stability. But in converge case, the finest SMD distribution and uniform mass distribution are found and CTRZ is longer than other cases. Consequently, high combustion efficiency and low pollutant emission are expected in converge case.