• Child Health Nursing Research
• /
• v.13 no.2
• /
• pp.147-156
• /
• 2007

Purpose: The purpose of this study was to investigate the sleep/activity patterns of premature babies. Method: The subjects were 55 premature babies who were hospitalized in the Neonatal Intensive Care Unit (NICU) of one University Hospital in Daejeon from September 1, 2004 to March 31, 2006. The sleep/activity patterns of the premature babies were observed for 24 hours a day for 7 days. The observations were made and recorded by the researcher and 5 trained research assistants using NCASA records developed by Barnard et al. (1979). For statistical analysis, frequency, average, t-test, and Pearson correlation coefficients were used. Results: The infants slept more and had less awake periods during daytime than full-term infants. As the hospital stay of the premature babies increased, the amount of daytime sleep and total daily sleep decreased, and the amount of daytime awake periods increased. Conclusions: The findings suggest that the level of physical and physiological maturity of premature babies is one of the major variables that affect their sleep/activity patterns. Furthermore, the findings of this study will provide information about the sleep/activity patterns of premature babies, and present baseline data to develop the nursing intervention programs which support optimum development for the premature babies.

• Fibers and Polymers
• /
• v.6 no.1
• /
• pp.13-18
• /
• 2005

PLA/LPCL/HPCL blend fibers composed of poly (lactic acid) (PLA), low molecular weight poly ($\varepsilon$-caprolactone) (LPCL), and high molecular weight poly ($\varepsilon$-caprolactone) (HPCL) were prepared by melt blending and spinning for bioab­sorbable filament sutures. The effects of blending time and blend composition on the X-ray diffraction patterns and tensile properties of PLA/LPCL/HPCL blend fibers were characterized by WAXD and UTM. In addition, the effect of in vitro degra­dation on the weight loss and tensile properties of the blend fibers hydrolyzed during immersion in a phosphate buffer solu­tion at pH 7.4 and 37$^{\circ}C$ for 1-8 weeks was investigated. The peak intensities of PLA/LPCL/HPCL blend fibers in X-ray diffraction patterns decreased with an increase of blending time and LPCL contents in the blend fibers. The weight loss of PLA/LPCL/HPCL blend fibers increased with an increase of blending time, LPCL contents, and hydrolysis time while the tensile strength and modulus of the blend fibers decreased. The tensile strength and modulus of the blend fibers were also found to be increased with an increase of HPCL contents in the blend fibers. The optimum conditions to prepare PLA/LPCL/HPCL blend fibers for bioabsorbable sutures are LPCL contents of $5 wt\%, HPCL contents of $35 wt\%, and blending time of 30 min. The strength retention of the PLA/LPCL/HPCL blend fiber prepared under optimum conditions was about $93.5\% even at hydrolysis time of 2 weeks.

• Journal of the Semiconductor & Display Technology
• /
• v.10 no.4
• /
• pp.65-70
• /
• 2011

These days, printed electronics attract attention from electronics industry. In this paper, the fabrication of the fine patterns by Near Field Electro Spinning (NFES) was studied by using Ag ink on silicon wafer (substrate). Two types of ink, the high viscous ink Ag-200 and low viscous ink Ag-15, were used. The fine and uniform patterns were easily fabricated by using Ag-200 because jet breakup is less occurred in high viscosity solution. As increasing flow rate of solution, aspect ratio of Ag pattern decreased. And there was optimum applied voltage for fine pattern. In case of Ag-200, the optimum applied voltage was about 2.02KV. When pattern was fabricated by NFES, the pattern width and height were affected by many factors such as viscosity, flow rate of solution, applied voltage etc.

• Proceedings of the Korean Institute of Interior Design Conference
• /
• 2001.05a
• /
• pp.117-120
• /
• 2001

This study is a preliminary research to develop design principles for environmentally friendly housing. The purposes of study are to investigate the literatures related passive design for summer and theory of ventilation, to analyze the indoor airflow patterns in traditional Korean house during summer, and to propose the design factors for effective passive cooling system. The analysis for airflow patterns was focused on the ‘An bang’and the ‘Dae Chung’in the ‘An Chae’of a traditional house located in Seoul. Field measurements of air temperature and air velocity were carried out at 30 different measuring points with 8 different window-opening conditions. The measurements were taken on the hottest summer days in August 2000. It is concluded that from an environmentally friendly standpoint design factors to control indoor thermal environment by a passive cooling system during the summer are as follows; ceiling structure has thermal performance like a time-lag effect, optimum height and length of eaves which can prevent sunlight and divert airflow toward the sitting level, building arrangement acceptable the prevailing wind, strategic window arrangement which makes cross ventilation possible (especially north-south) at the sitting level, window opening condition which is possible to intersect two cross-ventilation stream at the main living areas, northward windows remaining in shade to create the air pressure difference, and planning building shape like a bracket that has optimum width and depth.

• Journal of information and communication convergence engineering
• /
• v.13 no.2
• /
• pp.123-131
• /
• 2015

Training neural networks is a complex task with great importance in the field of supervised learning. In the training process, a set of input-output patterns is repeated to an artificial neural network (ANN). From those patterns weights of all the interconnections between neurons are adjusted until the specified input yields the desired output. In this paper, a new hybrid algorithm is proposed for global optimization of connection weights in an ANN. Dynamic swarms are shown to converge rapidly during the initial stages of a global search, but around the global optimum, the search process becomes very slow. In contrast, the gradient descent method can achieve faster convergence speed around the global optimum, and at the same time, the convergence accuracy can be relatively high. Therefore, the proposed hybrid algorithm combines the dynamic particle swarm optimization (DPSO) algorithm with the backpropagation (BP) algorithm, also referred to as the DPSO-BP algorithm, to train the weights of an ANN. In this paper, we intend to show the superiority (time performance and quality of solution) of the proposed hybrid algorithm (DPSO-BP) over other more standard algorithms in neural network training. The algorithms are compared using two different datasets, and the results are simulated.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.698-701
• /
• 2005

We have investigated experimentally a nano patterning using electron beam lithography for the nickel stamper fabrication. Recently, DVD and Blu-ray disk(BD) have nano-scale patterns in order to increase the storage density. Specially, BD has 100nm-scale patterns which are generally fabricated by electron beam lithography. In this paper, we found optimum condition of electron-beam lithography for 100nm-scale patterning. We controlled various conditions of EHP(acceleration voltage), beam current, dose and aperture size in order to obtain optimum conditions. We used 100nm-thick PMMA layer on a silicon wafer as photoresist. We found that EHP was the most dominant factor in electron-beam lithography.

• Journal of Nutrition and Health
• /
• v.17 no.4
• /
• pp.262-272
• /
• 1984

A study on the balance of essential amino acids in Korean diet and further investigation on quality of protein through optimum combination of foods using the least square method based on FAO/WHO (1973) provisional score patterns were carried out The results of the optimum gross combination are summarized as follows: 1) The first limiting amino acids of the Korean diet was found to be methionine and cysteine based on both whole egg and FAO/WHO (1973) provisional score patterns. 2) Weight ratios between rice and beef, chicken, pork, rabbit meat are 7 : 3, 4 : 1, 4 : 1, and 3 : 1. The amino acid score and the least amino acid are 100(phe+tyr), 99(thr), 111(trp), and 109(leu) for each combination. This result indicates that pork and rabbit meat can be high quality protein sources for the rice eating people. 3) Weight ratios between rice and anchovy, saury, ark shell, pollack, cuttle fish, tuna and herring are 2 : 1, 5 : 1, 3 : 2, 3 : 1, 3 : 1, 4 : 1, and 3 : 1. 4) Weight ratios between potato and rice, wheat flour are 8 : 1 and 24 : 1. Lysine, the limiting amino acid of rice and wheat flour can be complemented by combining these with potato. 5) It is possible to apply this idea on typical Korean dishes. For example, in case of soybean-sprout rice the optimum combinations of rice : soybean-sprout : pork and rice : soybean-sprout : beef are 4 : 1 : 1 and 11 : 1 : 5. It is of utmost importance to pursue further more desirable combinations with more complex food items and transform the result obtained by the computer analysis into more practical terms for practical use.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2000.11a
• /
• pp.28-45
• /
• 2000

It was unusual crop weather for 1998 and 1999 compared with normal in Korea. The consecutive days of the optimum ripening period for rice plant that had daily mean temperature 21-23C for 40 days after heading, increased with long anomalies in 1998-99. The air temperature during ripening period was much higher than the optimum temperature and lower sunshine hour than normal in the local adaptability tests of newly developed rice lines during those years. In response of rice cultivation to warming and cloudy weather during crop season, the yield shall be decreased. Most scientists agree that the rate of heating is accelerating and temperature change could become increasingly disruptive. Weather patterns should also become more erratic. Agrometeorologists could be analyzed yearly variations of temperature, sunshine hour and rainfall pattern focused on transient agroclimate change for last a decade. Rice agronomists could be established taking advantage of real time agricultural meteorology information system for fertilization, irrigation, pest control and harvest. Also they could be analyzed the characteristics of flowering response of the recommended and newly bred rice cultivars for suitable cropping plan such as cultural patterns and sowing or transplanting date. Rice breeders should be deeply considered introducing the characteristics of basic vegetative type of flowering response like Tonsil rices as prospective rice cultivars corresponding to global warming because of the rices needed higher temperature at ripening stage than Japonica rices, photoperiod sensitive and thermo-sensitive ecotypes

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.10
• /
• pp.76-82
• /
• 1998

As the minimum feature size of a semiconductor chip gets smaller, the inevitable distortion of patterned image by optical lithography becomes the limiting factor in the mass production of VLSI. The optical proximity correction (OPC), which corrects pattern distortion that originates from the resolution limit of optical lithography, is becoming indispensable technology. In this paper, we describe a program that corrects optical proximity effect and thus finds the optimum mask pattern with a Monte-Carlo method. The program was applied to real memory cell patterns to produce mask patterns that generate image patterns closer to object images than original mask patterns, and increase of process margin is expected, as well.

• YAKHAK HOEJI
• /
• v.42 no.2
• /
• pp.153-158
• /
• 1998

Calcium hydrogen phosphate was synthesized by reacting calcium chloride and sodium hydrogen phosphate solution in this study. It is well known that the particle size and yield o f calcium hydrogen phosphate produced is greatly affected by the synthetic conditions such as the reactant concentration, reaction temperature, reacting fine, mole ratio and drying temperature, etc. The purpose of this study is to investigate the optimum synthesis condition from the viewpoint of yield and sedimentation volume of the prepared calcium hydrogen phosphate powder according to a randomized complete block design proposed by G.E.P. Box and K.B. Wilson. It was found that the optimum synthetic conditions of calcium hydrogen phosphate were as follows: It was found that optirnum temperature range of reactant solutions was $28-38^{\circ}C$ and $32-42^{\circ}C$ respectively, on the viewpoint of yield and sedimentation volume. The optimum concentration range of reactant solutions was 5.5-10.0% and 6.9-7.4% respectively, on the viewpoint of yield and sedimentation volume. The optimum mole ratio of $CaCl_2$ to $Na_2HPO_4$ was in the range of 1.2-2.0 and the optimum reacting time range was 8.5-11.0 minutes. The optimum drying temperature range was $39-41^{\circ}C$ from the viewpoint of yield, but it was $39-43^{\circ}C$ on the basis of sedimentation volume. Crystallographic analysis to X-ray diffraction patterns of commercially available ecalcium hydrogen phosphate and calcium hydrogen phosphate samples prepared in this study suggested that all samples tested belonged to monoclinic crystal system characteristic of $CaHP0_4{\cdot}2H_20$ crystals.