• KIEAE Journal
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• v.11 no.2
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• pp.105-111
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• 2011

Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.111-114
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• 1999

Electroluminescence(EL) devices based on organic thin films have been attracted lots of interests in large-area light-emitting display. In this stuffy, an emissive layer was fabricated using Langmuir-Blodgett(LB) technique in organic light-emitting (OLEDs). This emissive organic material was synthesized and named PECCP[poly(3.6-N-2-ethylhexyl carbazolyl cyanoterephthalidene)] which has a strong electron donor group and an electron acceptor group in main chain repeated unit. This material has good solubility in common organic solvents such as chloroform. THF, etc, and has a good stability in air. The Langmuir-Blodgett(LB) technique has the advantage of precise control of the thickness down to the molecular scale, In particular, by varying the film thickness it is possible to investigate the metal/polymer interface. Optimum conditions for the LB film deposition are usually determined by investigating a relationship between a surface pressure $\pi$ and an effective are A occupied by one molecule on the subphase. The LB films were deposited on an indium-tin-oxide(ITO) glass at a surface pressure of 10 mN/m and dipping speed of 12 mm/min after spreading PECCP solution on distilled water surphase at room temperature, Cell structure was ITO/PECCP LB film/Alq$_3$/Al. We considered PECCP as a hole -transport layer inserted between the emissive layer and ITO. We also used Alq$_3$ as an emissive layer and an electron transport layer. We measured current-voltage(I-V) characteristics, UV/visible absorption, PL spectrum and EL spectrum of the OLEDs.

• Archives of design research
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• v.18 no.3 s.61
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• pp.35-44
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• 2005

Songjung beach located in Busan has been developed without design concept or any specific plans for its characteristics. This study attempts to suggest design ideas with specific plans and 3D perspectives in order to develop Songjung beach based on the characteristics and needs of the visitors and provide its own identity. The research was performed in three steps: First, the researcher visited the beach and explored how the beach facilities were used. Second, the satisfaction level and needs on the beach were investigated by questionnaire. Third, the specific plans were suggested based on the above results, which included 5 poly units with restroom, shower room, snack bar, fast-food restaurant, internet Cafe and cafeteria, etc. The form and color of the poly units were decided to show Korean traditional roof image and provide unique image to Songjung beach. This study will show a good example of beach design project reflecting visitors' specific needs through the research.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.4
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• pp.77-84
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• 2017

Purpose: In terms of the flexibility in hospital architecture, there are fixed elements of hospital architecture: mechanical, electrical, aeration rooms and shafts, which are the main utility spaces. Thus, it is necessary to recognize the utility space as a system that helps internal functions and flexible internal changes. This study analyzes the notion of the main utility space in hospital architecture and the architectural planning features of the main utility spaces as the system in the design process of the recently built hospitals. Methods: The design factors are extracted comparing two hospitals' plans in each stage and the systematic characteristics of utility spaces are analyzed accordingly. The opinions gathered from interviews of practitioners, architects and facility planning experts directly involved in the architecture design process are analyzed and reflected in the results. Results: Planning for utility spaces should be accompanied by the architectural plan from the basic design process, and proceeded with recognizing utility spaces as a system, which is a fixed element. Utility spaces are highly organically connected. Horizontal and vertical distribution of air chambers can reduce the length and number of ducts, and thus save story height, and reduce the number of shafts, the vertical connection passage. This is advantageous in securing the variable area, which is the ultimate objective of the system-centered hospital architecture plan. Implications: Thereby aims to provide fundamental data on systematic utility space planning in the hospital architecture planning.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.167-173
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• 2004

The heterodyne He-Ne laser interferometer is the most widely used sensing unit to measure the position error. It measures the positioning error from the displacement of a moving reflector in terms of the wave length. But, the wave length is affected by the variation of atmospheric temperature. Temperature variation of 1$^\circ C$ results in the measuring error of 1ppm. In this paper, for measuring more accurately the position error of the ultra precision stage, the refractive index compensation method is introduced. The wave length of the laser interferometer is compensated using the simultaneously measured room temperature variations in the method. In order to investigate the limit of compensation, the stationary test against two fixed reflectors mounted on the zerodur$\circledR$ plate is performed firstly. From the experiment, it is confirmed that the measuring error of the laser interferometer can be improved from 0.34${\mu}m$ to 0.11${\mu}m$ by the application of the method. Secondly, for the verification of the compensating effect, it is applied to estimate the positioning accuracy of an ultra precision aerostatic stage. Two times of the refractive index compensation are performed to acquire the positioning error of the stage from the initially measured data, that is, to the initially measured positioning error and to the measured positioning error profile after the NC compensation. Although the positioning error of an aerostatic stage cannot be clarified perfectly, it is known that by the compensation method, the measuring error by the laser interferometer can be improved to within 0.1${\mu}m$.

• Journal of Korean Clinical Nursing Research
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• v.25 no.3
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• pp.333-341
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• 2019

Purpose: The purpose of this study was to determine the most appropriate shelf life for sterilized products according to their packaging material. Methods: Samples were prepared to target six nursing units in one general hospital in Seoul. After steam and E.O gas sterilization, sterilized product, samples were supplied to wards. Data collection was conducted for 3 months, after the expiration date of 3 months had passed for samples packaged with crepe paper and nonwoven wraps. For samples packaged with paper-plastic pouches, data collection conducted for 3 months when the expiration date of 9 months had passed. The sterilized products were collected and tested for microbial contamination. Identification of the storage environment was done as samples were collected. Results: This study confirmed that the storage environment met international standards such as CDC, except for temperature. For steam sterilized crepe paper packaging samples and steam and E.O gas sterilized for nonwoven packaging samples no contamination in all products was found for 3 months past the expiration date. However, in the E.O gas sterilized paper-plastic pouch packaging sterile samples, Gram-positive bacilli were detected in one sample from a surgical intensive care unit at 45 weeks and another sample from an operating room at 47 weeks. Furthermore, the results did not show any microorganisms for up to 52 weeks in all products. Conclusion: According to the results of this study, sterilized product packaging made with crepe paper and nonwoven wraps is better able an extended shelf life from 3 months to 6 months, reducing unnecessary costs.

• Bulletin of the Korean Chemical Society
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• v.21 no.9
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• pp.867-874
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• 2000

Two new azobenzene crown ether calix[4]arenes, 10 and 11, were synthesized by two pathways. In the first pathway,two ethoxy nitrobenzene groups were attached to t-butylcalix[4]arenes in a 1,3 position. Subsequent reduction ofthe nitrobenzene group s by metallic zinc in an alkaline solution afforded 10 and 11 in8% and 12%,respectively. In the second pathway,an azobenzene containing two glycolic units was prepared prior connect-ing to t-butylcalix[4]arenes. The yields from the second approach (5%, 8% for 10 and 11, respectively) were lower than those from the former approach. Single crystals of 10 suitable for X-ray crystallography was ob-tained by recrystallization in methanol.Both the X-ray structure and the 1H-NMR spectrum of 10 indicated that the stereoisomer of the azobenzene moiety was trans and the calixarene platform was in cone conformation. 1H NMR spectroscopy suggested that 10 underwent an observable cis-trans isomerization in CDCl3 under room light and upon UV irradiation with cis:trans ratios of 33:67 and 36:64,respectively. Compound 6 which was the precursor of 11showed fluxional behavior and was found to have mixed conformations ofcone and partial cone with a ratio of 47:53 at -30 $^{\circ}C.$ 1H NMR spectrum of 11 suggested that 11 was initially isolated as cis azobenzene with calix[4]arene in cone conformation and underwent conformational interconversion through calix[4]arene annulas in a similar fashion to 6 upon exposing to light. The complexation studies of 10 with picrate salts of Na+ and K+ using 1H NMR spectroscopysuggested that Na+ preferred to bind the cis form of 10 while K+ preferred to bind the trans form. The stereoisomer of the azobenzene unit in 11 changed partially from cis to trans upon complexing with K+.

• Design & Manufacturing
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• v.12 no.3
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• pp.25-30
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• 2018

Recently The automotive industry is trying to increase the energy efficiency by reducing the weight of the car body and engine components as a way to achieve high energy efficiency. In particular, the reduction of the weight of the vehicle through the weight reduction of the vehicle body has the advantage that the fuel consumption and the output can be improved. But at the same time, there is the disadvantage that the strength becomes weak due to the reduction of the material thickness. Therefore, in order to overcome these disadvantages, materials with high strength according to the unit thickness have been actively developed, and researches for applying them have also been increasing. In this study, we will investigate the application of cold rolled steel sheet, which is a lightweight material, to a horn bracket that secures a installed in an automobile engine room. The horn bracket secures the horn on the car engine and is bolted to the outer wall of the engine. The momentum is acted on the bracket due to the distance between the bolt fastening part and the car horn installed on the bracket end side. Therefore, the body part of the bracket is more likely to be destroyed by the influence of the continuous stress. In this paper, design optimization for weight reduction and strength enhancement was performed to solve this problem, and possibility of applying the rolled steel sheet material as lightweight material by tensile test and fabrication was confirmed.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.26 no.1
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• pp.91-101
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• 2019

Purpose: The purpose of this study was to identify factors associated with stress related to home mechanical ventilator (HMV) care in general ward nurses. Methods: The study participants were 110 general ward nurses. Data on participant characteristics, level of knowledge, education needs, coping ability in emergency situations, confidence, and stress were collected from August 1 to 30, 2018 using a structured questionnaire by web-based surveys. Data were analyzed using SPSS/WIN 20.0 for descriptive statistics and independent t-test, one-way analysis of variance, Pearson's correlation coefficient, and multiple regression analysis. Results: Significant factors associated with stress related to HMV care were ward career, intensive care unit (ICU) career, intensive care room (ICR) career, education experience, and satisfaction level of HMV education. Stress had negative correlations with confidence and positive correlations with education needs. The determining factors affecting stress related to HMV care in the general ward were confidence (${\beta}=-.31$, p=.004), ICR career (${\beta}=-.27$, p<.001), education needs (${\beta}=.24$, p=.005), education frequency (${\beta}=-.18$, p=.040), and ICU career (${\beta}=-.18$, p=.025); their explanation power was about 41.8%. Conclusions: It is necessary to develop HMV care training manuals and guidelines and consider ICU or ICR careers for patient safety.

• Quality Improvement in Health Care
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• v.24 no.2
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• pp.2-14
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• 2018

Purpose: The objective of this study was to report the incidence of falls in hospitals and analyze the risk factors for falls. Methods: This study used data on 1,216 patients who experienced falls from 2015 to 2017 during their hospitalization. The data was collected from the falls incident reports and patient' electronic medical record of hospital. Data were analyzed with descriptive statistics using Chi-square test, Fisher's exact test and multiple Poisson regression analysis with the SAS 9.4 Results: The incidence of falls was 1.38 per 1,000 patients days (2015), 1.81 per 1,000patients days (2016) and 1.99 per 1,000patients days (2017). The incidence of injury caused by falls (level III~V) was 0.05 per 1,000patients days (2015), 0.04 per 1,000patients days (2016) and 0.06 per 1,000patients days (2017). The largest number of falls occurred during night shift (42.5%), specifically in the patients' room (70.8%), and medical unit (66.0%). Average age of fallers was 69.1 years and 61.7% of them were older than 71 years. CCI and the patient's department have statistically significant differences in injury or injury levels from falls, but the integrated nursing care services had no significant difference in injury or injury levels from falls. Conclusion: The result of this study can be used as a reference for establishing a fall prevention strategy for hospitalized patients by presenting index values such as the fall rate.