• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.71-78
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• 2001

In GMA(Gas Metal Arc)Welding, the weld size that is a locally melted area of a workpiece is one of the most important considerations in determining the strength of a welded structure. Variations in the weld power and the welding heat flux may affect the weld pool formation and ultimately the size of the weld. Therefore, an accurate prediction of the weld size requires a precise analysis of the weld thermal cycle. In this study, a model which can estimate the weld bead geometry and a method for thermal analysis, including the model, are suggested. In order to analyze the weld bead geometry, a mathematical model was developed with transformed coordinates to apply to the horizontal fillet joints. A heat flow analysis was performed with a two dimensional finite element model that was adopted for computing the base metal melting zone. The reliability of the proposed model and the thermal analysis was evaluated through experiments, and the results showed that the proposed model was very effective for predicting the weld bead shape and good correspondence in melting zone of the base metal.

• Corrosion Science and Technology
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• v.18 no.4
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• pp.121-128
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• 2019

Electrochemical Impedance Spectroscopy (EIS) was used to predict corrosion behaviour of metallic Cultural Heritage assets in two monitoring campaigns: 1) an iron bar chain exposed indoor from over 500 years in the Notre Dame Cathedral in Amiens (France); and 2) a large weathering steel sculpture exposed outdoor from tens of years in Ferrara (Italy). The EIS portable instrument employed was battery operated. In situ EIS measurements on the iron chain could be used to investigate the phenomena involved in the electrochemical interfaces among various corrosion products and assess and predict their corrosion behaviour in different areas of the Cathedral. Meanwhile, the sculpture of weathering steel, like most outdoor artefacts, showed rust layers of different chemical composition and colour depending on the orientation of metal plates. The EIS monitoring campaign was carried out on different areas of the artefact surface, allowing assessment of their protective effectiveness. Results of EIS measurements evidenced how employing a simple test that could be performed in situ without damaging the artefacts surface is possible to quickly gain knowledge of the conservation state of an artefact and highlight potential danger conditions.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.858-863
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• 2004

The thermoelectric power, dc conductivity and magnetic properties of the cubic L $a_{2}$ 3/Ti $O_{2.84}$ were investigated. The thermoelectric power was negative below 350 K. The measured thermoelectric power of L $a_{2}$ 3/Ti $O_{2.84}$ increased linearly with temperature, in agreement with model proposed by Emin and Wood, and was represented by A+BT. Temperature dependence indicates that the charge carrier in this material is a small polaron. L $a_{2}$ 3/Ti $O_{2.84}$ exhibited a cross over from variable range hopping to small polaron hopping conduction at a characteristic temperature well below room temperature. The low temperature do conduction mechanism in L $a_{2}$ 3/Ti $O_{2.84}$ was analyzed using Mott's approach. Mott parameter analysis gave values for the density of state at Fermi level [N( $E_{F}$)] = 3.18${\times}$10$^{20}$ c $m^{-3}$ e $V^{-1}$ . The disorder energy ( $W_{d}$) was found to be 0.93 eV, However, it was noted that the value of the disorder energy was much higher than the high temperature activation energy. The exist linear relation between log($\sigma$T)와 1/T in the range of 200 to 300 K, the activation energy for small polaron hopping was 0.15 eV.

• Water for future
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• v.14 no.4
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• pp.53-72
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• 1981

In this study, South Korea is divided into 5 zones and is studied about the analysis of time-regional distribution of previpitation frequency and rainfall intensity in Korea. In the previpitation frequency analysis, the basic data groups of 39 stations were selected. The diagram of previpitation frequency was drawn, and the time-regional distribution of precipitation frequency was analized. In the rainfall intensity analysis, the basic data groups of 36 stations were selected. The probable rainfall, I-D-F curve, and regression equation between 24hr. and 10min.-18hr. areal depth were obtained. The results of this study are following; 1) The precipitation class of max. recurrence probability in every season except summer was commonly (1) 1-5mm, (2) 0.1-1mm, (3) 5-10mm in order. 2) The zone of max. recurrence frequency owing to the precipitation class was zone II in precipitation frequency of below 20mm, zone IV in precipitation frequency of 30-40mm, zone I in precipitation frequency of above 70mm for a year. 3) The recurrence probability of precipitation in Korea can be represented to the equation of exponential function; $$W(x)=e^{\alpha+\beta}$$ 4) The first and third zones were expected heavy rain for the short and long duration. 5) The I.D.F. curves were drawn, and established that the time interval for the least deviation of I.D.F curve is 10~40min., 40min. -4hr., 4~24hr. 6) The regression equations of areal mean depth between 24hr. and 10min.-18hr. for each zone were obtained. 7)The probable rainfall of 36 points were calculated.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.72-82
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• 2005

The objective of this paper is to describe the optimization of design parameters in a large-sized commercial bus heater system by using CFD(computational fluid dynamics) analysis and Taguchi method. In order to obtain the best combination of each control factor which results in a desired performance of heater system, the parameter design of the Taguchi method is adopted for the robust design considering the dynamic characteristic. The research activity may be divided into four phases. The first one is analyzing the problem, i.e., ascertaining the influential factors. In the second phase the levels were set in such a way that their variation would significantly influence the response. In the third phase the experimental runs were designed. In the final phase the planned runs were carried out numerically to evaluate the optimal combination of factors which is able to provide the best response. In this study, eight factors were considered for the analysis: one with two level and seven with three level combinations comprising the $L_{18}(2^1{\times}3^7)$ orthogonal array. The results of this study can be summarized as follows ; (i)The optimum condition of control factor is a set of <$A_2\;B_1\;C_3\;D_3\;E_1\;F_2\;G_3\;H_2$> where A is shape of the outer fin, B is pitch of the outer fin, C is height of the outer fin, D is the inner fin number, E is the inner fin height, F is length of the flame guide, G is diameter of the heating element and H is clearance between air guide and heating element. (ii)The heat capacity of heated discharge air under the optimum condition satisfies the equation y=0.6M w here M is a signal factor. (iii)The warm-up rate improves about three times, more largely as com pared with the current condition, which results in about 9.2minutes reduction.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.61.1-61.1
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• 2011

We report on a detailed study on gap-state distribution in thin amorphous silicon layers(a-Si:H) with film thickness between 5 nm and 20 nm c-Si wafers performed by UV excited photoelectron spectroscopy(UV-PES). We measured how the work function, the gap state density, the position of the Fermi-level and the Urbch-energy depend on the layer thickness and the doping level of the ultra thin a-Si:H(n) layer. It was found, that for phosphorous doping the position of the Fermi level saturates at $E_F-E_V$=1.47 eV. This is achieved at a gas phase concentration of 10000 ppm $PH_3$ in the $SiH_4/H_2$ mixture which was used for the PECVD deposition process. The variation of the doping level from 0 to 20000 ppm $PH_3$ addition results in an increase of the Urbach energy from 65 meV to 101 meV and in an increase of the gap state density at midgap($E_i-E_V$=0.86eV) from $3{\times}10^{18}$ to $2{\times}1019cm^{-3}eV^{-1}$.

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.11-21
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• 1977

Many in nursing look back on Nursing Research history and proudly point to the fact that emphasis in nursing research has changed from studying the nurse to studying nursing practice. In recent years, much emphasis has been placed on seeking a method of evaluating the quality of nursing care. In spite of these attempts, however, an instrument for evaluating the quality of nursing care that is actually applicable in the clinical area has not been found. The Purposes of this study are as follows: 1) To develop the instrument to be used in evaluating the quality of nursing care provided in the Neuro - Surgery Constant Care Unit of Severance Hospital 2) To evaluate the quality of nursing care in the clinical area. 3) To provide the necessary information for improvement of quality of nursing care. The instrument for evaluating the quality of nursing care, developed by the investigator, was composed of 7 nursing goals and divided into 65 standards of nursing performance. The 7 nursing goal are as follows : 1) Maintenance of airway 2) Maintenance of fluid at electrolyte balance 3) Maintenance of elimination 4) Personal hygiene 5) Optimum activity 6) Prevention of accidents 7) Emotional care The study population defined was composed of all the case (51) who were admitted in the Neuro- Surgery Constant Care Unit of Severance Hospital from May 7-13, 1976. The observation method was used and the data was subjected to the %, X²-test, T-test, F-test and Correlation. The results of tile study were as follows : 1. Levels of nursing performance regarding nursing goals. Seven different nursing care indices were constructed in terms of nursing goals. The index scores were grouped arbitrarily into ,j categories such as "excellent", "good", "moderate", "incomplete", and "poor"based upon the investigator′s personal judgement. a. The nursing index of maintaining airway showed that 78% of the patients fell within the "excellent" and 22% of the patients, fell within the "good" category. b. The nursing index of maintaining fluid & electrolyte balance showed that 95% of the patients fell within the "excellent" and 5 % of the patients fell within the "good" category. c. The nursing index of maintaining elimination showed that 100% of the patients fell within the "excellent" category. d. The nursing index of personal hygiene revealed that 49% of the patients fell within the "excellent" and 51% of the patients fell within the "good" category. e. The nursing index of optimum activity showed that 63% of the patients fell within the "excellent" and 32% of the patients fell within tile "good" and 5% of patients fell within the "moderate" category. f. The nursing index of prevention of accidents showed that 100% of the patients foil within the "excellent" category. g. The nursing index of emotional cart revealed that 27% of the patients fell within the "excellent", 24 % of the patients fell within tile "good", 29 % of the patients fell within the "incomplete" category. From these findings it is disclosed that the quality of nursing care provided in the Neuro- Surgery Constant Care Unit of Severance Hospital was excellent. h. There were statistically significant differences between the nursing index of physical care and emotional care. (t=8.73, D. F. =100. p<0.01) It is revealed that more physical care then emotional care was carried out by nurses. 2. Levels of nursing performance regarding general characteristics of the patients. No significant differences were observed statistically with the nursing indices of nursing goals according to the sex (t=0.084, D. F. =12, p>0.05). Age (F=0.1251, D. F. : 3.18. p 〉0.05), absence or presence of operating experiences (t=0.6032, D. F. =12, p〉0.05, levels of consciousness (F=0.31, D. F. :3. 18, p >0.05) 3. Relationship between the levels of consciousness and the nursing index of each nursing goal. There was negative correlation between the levels of consciousness and the nursing index of maintaining airway (r=-0. 5449, p<0.01) and personal hygiene (r= -0.4075, p<0.01) There was positive correlation between the levels of consciousness and the nursing index of optimum activity (r=0.3936, p <0.01) and emotional care (r=0.7819, p〈0.01). There was slight correlation between the levels of consciousness and the nursing index of maintaining fluid & electrolyte balance (r=-0.3418, 0.010.05) and preventing accidents (r=0.1441, p>0.05.

• Journal of the Korean Society of Food Culture
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• v.30 no.6
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• pp.790-796
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• 2015

The objective of this study was to investigate the physicochemical properties and antioxidant activities of seven (A, B, C, D, E, F, G) commercial ketchups marketed in Korea. The 70% ethanol extracts were prepared and evaluated for total phenolic content, DPPH and ABTS radical scavenging activities, and metal chelating effect. pH ranged from 3.64 to 3.94, and soluble solid and reducing sugar contents of samples were 2.21~3.51oBrix and 4.78~13.45%, respectively. Salinity of samples was in the range of 1.79 to 3.21%, and sample G showed the lowest salinity. The lightness, redness, and yellowness of the Hunter color system of samples were 15.42~19.94, 18.55~23.98, and 20.87~24.34, respectively. The phenolic contents ranged from 1.37 to 2.60 mg GAE (gallic acid equivalents)/g, with samples F and G exhibiting the highest contents. Antioxidant activity determined based on DPPH and ABTS radical scavenging activities, and metal chelating effects were 45.10~90.87, 55.35~92.53, and 71.10~92.20%, respectively, at a concentration of 200 mg/mL. Samples A and G showed higher antioxidant activity than other samples. There were positive correlations between phenolic contents and antioxidant activity, suggesting that phenolic compounds are the major contributors to antioxidant activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.290-296
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• 2017

Purpose: The purpose of this study was to compare the effects of CPR training according to the mannequin used for CPR training using Little $Anne^{(R)}$, $BRAYDEN^{(R)}$, and $HeartiSense^{(R)}$. Method: Research subjects were 90 firefighters who were not paramedics. They were divided into three groups, A, B, and C. Theoretical education was conducted for 50 minutes, and practical education was conducted in groups of three for 50 minutes, using Little $Anne^{(R)}$ for 30 people in Group A; $BRAYDEN^{(R)}$ for 30 people in Group B; and $HeartiSense^{(R)}$ for 30 people in Group C. The results of CPR were printed out using Resusci Anne $SkillReporter^{(R)}$, and the subjects were asked to fill in a questionnaire. Results: The following significant differences were noted: satisfaction index according to the mannequin, $x^2=81.050$, p<.000; reason for satisfaction, $x^2=91.050$, p<.000; ratio of accurate chest compression, F=5.087, p<.004; and ratio of accurate ventilation, F=10.54, p<.000. Conclusion: For the subjects who require accurate and efficient CPR training, it is judged that a mannequin that provides information to allow corrections in real-time would be effective, and have a high educational effect.

• Research in Community and Public Health Nursing
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• v.6 no.1
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• pp.55-73
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• 1995

An Effect of Muscle Strength Training Program on Muscle Strength, Muscle Endurance, Instrumental Activities of Daily Living and Quality of Life in the Institutionalized Elderly Recent statistics shows that the aged are the fastest growing segment of our population by increasing life span. The age group of over 60 shows multiple health problems and the most serious handicapping problem of these. are related to the changes in muscular skeletal system. With aging, people lose. their muscle mass and muscle strength resulting from biological changes and physical inactivity. Studies documented a 30-50% loss of muscle mass in an advanced age and thus, ordinary life activities can be seriously affected due to weakened muscle strength. Preservation of muscle strength of lower limb is especially important in the aged. Since it is readily affected from reduced physical activity in old age, sometimes to the detriment of moving or walking. So muscle strength exercise program designed for the elderly to improve leg muscle strength and leg muscle endurance. The research design used was nonequivalent control group pretest - protest design. The purposes of this study were to test the effect of muscle strength exercise program utilizing Leg Press on muscle strength, muscle endurance, instrumental activities of daily living(IADL), cognitive perceptual variables and quality of life. Forty nine subjects participating in this study consisted of twenty four male and twenty five female. Twenty four experimental group subjects were selected from C-institution in Chung Buk province, and twenty five control group subjects were selected from O-institution in Chung Nam province. The mean age of subjects was 72.8 years. Muscle strength training program utilizing Leg Press for the experimental group was carried out three times a week for 9 weeks. The data was collected from August, 1993 to October, 1993. Data were analyzed with $X^2-test$, t-test, ANCOVA test, Kruskal Wallis 1-Way ANOVA test using SPSS PC program. Results were obtained as follows : 1) The experimental group showed significantly higher scores on muscle strength (leg lift strength, back lift strength and grip strength) and muscle endurance than control group after the experiment $\ulcorner$F=52.35(p=.001), F=54.07(p=.001), F=6.97(p=.011), F=18.17(p=.001)$\lrcorner$ 2) Experimental group were significantly higher scores on IADL than control group(F=7.51, p=.009). 3) Experimental group showed significantly higher scores on economical state and self esteem aspects of the quality of life scale than control group $\ulcorner$F=10.59(p=.002), F=6.97(p=.011)$\lrcorner$. But there were no differences in emotional state, physical and functional state and relationship with reatives in the quality of life between groups. 4) Scores on IADL showed a significant difference with the level of muscle strength and muscle endurance $\ulcornerx^2=7.73(p=.025),\;x^2=8.86\;(p=.011)\lrcorner$ 5) Scores on self esteem and physical and functional state aspects of the quality of life scale showed a significant difference with the level of IADL $\ulcornerx^2=11.39(p=.003),\;x^2=9.02(p=.011)\lrcorner$. 6) Scores of experimental group after the experiment in cognitive perceptual variables (perceived benefit on exercise, perceived health status, self efficacy, emotion on exercise) were significantly higher than those of control group $\ulcorner$F=32.09(p=.001), F=5.07(p=.029), F=20.63 (p=.001), F=30.38(p=.001)$\lrcorner$. As a result of this study, the effect of strength training exercise program with Leg. Press had improved muscle strength, muscle endurance, IADL, and the perception of self esteem, physical and funtional state, and economical state. Thus strength training program could be beneficially applied for the prevention of disablity and promotion of health and wellbeing in the aged easily and safely. The subjects in the experimental group have maintained their exercises till six months after the cessation of the experiment. This seem to illustrate that changes in cognitive perceptual variables and the improvement in health status have reinforced motivation for the continuation of voluntary exercises. A further study is necessary to determine the factors affecting maintainance of muscle strength exercise and to assess the effect of weight training program on bone density.