• Journal of Welding and Joining
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• 제18권3호
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• pp.83-88
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• 2000

Laser cladding processing allows rapid transfer of heat to the material being processed with minimum conduction into base metal, resulting in low total heat input. The effects of Nd:YAG laser cladding with wire feeding on the mechanical properties of Inconel alloy were investigated. inconel alloy is used as the material of nuclear steam generator tubing because of its mechanical properties and corrosion resistance properties. The device for Nd:YAG laser cladding with wire feeding was designed. It consists of the wire feeding system, the wire cladding system and the shielding gas system which prevents the clad layer from being oxidized. Experimental as results indicated that the wire feeding direction and position were important for laser cladding with wire feeding. The wire feeding speed should be adapted according to cladding speed for good shaping of clad layer. The effect of heat on the HAZ size can be limited and the growth of grain size of HAZ size was not serious. The hardness of clad layer and heat affected zone increased with increasing of cladding speed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.65-69
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• 2002

In order to practicalize high precision centerless grinder for machining the ferrule, its feeding system is designed and tested. For satisfying the desired diametric tolerance and cylindricity of the ferrule, the feeding system is designed to have relatively high axial stiffness of 600 N/$\mu\textrm{m}$, high angular motion accuracy of 0.5 arcsec/mm in yaw direction and minimum resolution of 0.05 $\mu\textrm{m}$. A prototype of feeding system is built up with hydrostatic guideway and ballscrew. A linear scale with 0.05 $\mu\textrm{m}$ of resolution is used for position feedback. Experimental results show that the feeding system has the infinity of axial stiffness within the range of 1000 N and 0.3 arcsec/mm of yawing error. Also the feeding system shows obvious step response against 0.05 $\mu\textrm{m}$/step command without the lost motion or backlash. Although the vertical stiffness is reduced to 440 N/$\mu\textrm{m}$ by the elastic deformation of rail, it is good enough to use for machining the ferrule. From above, it is confirmed that the feeding system is applicable to centerless grinder for machining the ferrule.

• 대한간호학회지
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• 제5권1호
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• pp.133-143
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• 1975

Most of mothers place their babies in either supine or prone position without change of position. Studies comparing supine and prone position of the newborn infants -have already been performed with the result that the prone position is relatively better than the supine position. However, one kind of position recommended to the mothers is not sufficient for the good rearing practice of children, because the same position placed for period long of time may bring out physical, mental tension and fatigue, and deformities of the skull and the thorax. For this reason nurses have to find out other position which has identical or more advantages than prone position so as to perform the position change for the babies. Main purpose of this study is to identify the differences of vital signs, the number of urination, defecation, diaper rash, crying and amount of feeding of the newborn infants with prone position or lateral position during the first three days of life. Sixty two newborn infants who were delivered at Seoul National University Hospital during the period from July 1 to September 5, 1974 were chosen as subjects for this study. The criteria for the choice of subjects were the babies born with vaginal delivery; body weight 2.5kg or over at birth; Apgar score Seven or over; and gestation period between thirty-eight months ana forty- two months. Of these subjects, by random sampling, thirty-one newborn infants were placed in the prone position and the other thirty-one in the lateral position. The results of this study reviewed in a statistical analysis of the t-test to obtain the following findings : 1. The heart rates of babies in the prone position were the mean heart rates of 135.03 and those in the lateral position 135.98 without any statistically significant difference. 2. There was no significant difference of respiration rate between two groups : a group in the prone position showed the mean respiration rates of 45,57 and the other in the lateral position 46.49. 3. There was no significant difference of body temperature between two groups: the mean body temperature of a group placed in the prone position was 98$^{\circ}$18'F(36$^{\circ}$77'C) and that of the other group 98$^{\circ}$20'F(36$^{\circ}$78'C). 4. One baby showed diaper rash only in a group of infants in the prone position. 5. The number of crying of the babies in the prone position were 23.70 and those in the lateral position 30.00 with a statistical difference at 5 percent level. 6, There was no difference of frequency of urination between two groups: the mean frequency of a group placed in tile prone position was 5.44 and that of the other group 5.06, 7. There was no significant difference of frequency of defecation between two groups : the mean frequency of a group placed in the prone position was 4.20 and that of tile other group 4.21, 8. There was no significant difference of feeding amount between two groups : the average amount of a group in the prone position showed 325.03 and that of the other group in the lateral position 291.51. All the above results mean that we may substitute tile lateral position for the Prone position or utilize both position for tile rearing practice of the babies.

• 한국수산과학회지
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• 제28권6호
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• pp.793-804
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• 1995

Polychaetous community survey in Tomioka Bay was carried out 5 times seasonally from May 1991 to March 1992 by quantitative grab sampling (0.05m2) at 11 stations. Based on the granulometric composition and environmental factors, a homogeneous soft bottom was found in St.5-10. The species of the polychaete were classified into three feeding groups using the Fauchald and Jumars' feeding guild system. According to polychaetous community composition data, deposit feeders predominate in sandy silt area where the silt-clay content is $60-69.3\%.$ These deposit feeders were subdivided into surface deposit feeders and subsurface deposit feeders by their living position and mode. Also, suspension feeding group comes as the third dominant group. Seasonal changes of each feeding group were described in terms of numerical density and biomass. Feeding layer and types of dominant species (Lumbrineris longifolia: surface deposit feeder; Praxillella pacifica: subsurface deposit feeder; Chone duneri; suspension filter feeder, etc.) were examined in the intact sediment core samples. Also, longterm density change among the three dominant species during 10 years was disussed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.75-78
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• 2004

In an optical disk drive, a feeding system which is used to move the optical pick-up system to the target position and the proper control scheme of it are important in random access performance. Since the effect of control is directly affected by the modeling precision of the real system, the precise modeling to the real system should be acquired. Although a simple linear order modeling to the feeding system of an optical disk drive is useful in understanding of the overall dynamic characteristics, the dynamic characteristics which are belongs to the nonlinear area cannot be predicted correctly. Furthermore, the feeding system of an optical disk drive has many nonlinear characteristics such as a nonlinear friction and backlash. For this reason, the understanding of the nonlinear properties in the feeding system is very important. In this paper, the nonlinear items of the feeding system, friction and backlash, are introduced and the effect of it are investigated. Finally, the mathematical model considering the nonlinear properties is compared to the real system, and some comments of it are given.

• Child Health Nursing Research
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• 제5권3호
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• pp.281-291
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• 1999

The purpose of this study was to compare the sleep characteristics between the prone and the supine position in healthy newborns. The 48 newborns were observed in the prone position and the supine position respectively on the 2nd day after birth. The data were collected from January to May, 1999. The state of a newborn was classified and categorized to 6 states (deep sleep. light sleep, drowsy, quiet alert, active alert, crying) by Barnard. The movements of eyes, face and extremities, pulse and arterial oxygen were observed and recorded continuously from the start of sleep after feeding until the time of being woken for the next feeding by a trained nurse The data was analyzed by using paired t-test. The results of this study were as follows; 1. There was no significant difference in the length of sleeping time between the prone and the supine position. 2. There was no significant difference in the length and frequencies of each states(deep sleep, light sleep, drowsy, quiet alert, active alert, crying) between the prone and the supine position But the frequency of light sleep in the supine position was significantly higher than that of the prone position. 3 There was no significant difference In the numbers or eyes movements between the prone and the supine sleep position. But the amount of facial and extremity movement in the supine position was significantly higher than those in the prone position 4. There was no significant difference in the arterial oxygen content between the prone and the supine sleep position. 5. There was no significant difference in the heart rates between the prone and the supine sleep position. The above results indicated that the newborns in the prone Position moved less and slept deeper than those in the supine position. though there was no difference in the length of sleep or arterial oxygen content between the prone and the supine sleep Position. But. Nurses and mothers should consider the relationship between the sleep Position and SIDS suggested by previous researches. The infant's 'awakening' during sleep is a normal process and rather valuable because it can provide an opportunity to promote a stronger relationship between mother and baby. So, It is suggested that the supine sleep position is better than the prone sleep position for infants.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.792-795
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• 1996

In TIG welding of pipe, back bead size monitoring is important for weld quality assurance. Many researches have been performed on estimation of the back bead size by heat conduction analysis. However numerical conduction model based on many uncertain thermal parameters causes remarkable errors and thermomechanical phenomena in molten pool can not be considered. In this paper, filler wire feeding force in addition to weld current, wire feedrate, torch travel speed and orbital position angle is monitored to estimate back bead size in orbital TIG welding. Monitored welding process variables are fed into an artificial neural network estimator which has been trained with the monitored process variables (input patterns) and actual back bead size (output patterns). Experimental verification of the proposed estimation method was performed. The predicted results are in a good agreement with the actual back bead shape. The results are quite promising in that estimation of invisible back bead shape can be achieved by analyzing the welding parameters without any conventional NDT of welds.

• 한국정밀공학회지
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• 제23권7호
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• pp.59-66
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• 2006

In laser welding, automatic seam tracking is important to adjust the laser head position in real time as it moves along the seam. Also if the joint gap is occurred, filling the missing material into the joint gap is necessary to prevent welding defects and bad welding quality. In general, the joint gap width is not constant along the seam due to a variety of reason. So it is essential to control the filler wire speed into the joint gap to acquire good welding quality. This paper describes an intelligent filler wire feeding device which can control 3-dimensional seam tracking and the filler wire speed by measuring the gap position and the joint gap width in laser welding. We call this device as Smart Micro Control system(SMC). To achieve this objective, we assessed weld quality in 2mm sheets of A16061 which had various gap width by using the developed device. From the experimental results, It was found the possibility that the developed device could be used in welding various 3-dimensional structures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.950-955
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• 2005

This paper describes an intelligent filler wire feeding device which can control 3- dimensional seam tracking and the filler wire speed by measuring the gap position and the joint gap width in laser welding. By means of visual sensor controlled filling the missing material into the joint gap and 3 dimensional seam tracking, lineup errors from manufacturing tolerances and the repeatability of lineup jigs and weld robot can be balanced and at an even seam quality which avoids weld defects. In this paper, we assessed weld quality in 2mm sheets of A16061 which had various gap width by using the intelligent filler wire feeding device.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제4권1호
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• pp.1-9
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• 2001

목 적: 위식도 역류는 위내용물이 불수의적으로 식도로 넘어가는 것으로, 신생아 및 영유아에서 하부식도 괄약근의 발달이 해부학적으로 미숙하기 때문에, 하부식도 괄약근의 수축력이 낮아 잘 일어난다. 식도는 15개월이 되어야 기능이 성숙하게 되므로 그 동안 위배출시간을 단축시킬 수 있다면 위식도 역류를 감소시킬 수 있을 것이며, 위배출시 간은 수유의 종류와 자세에 따라 영향을 받을 것이다. 방 법: 저자는 수유종류에 따른 위식도 역류 빈도의 차이를 알아보고자 1996년 8월부터 1999년 6월까지 순천향대학병원에 잦은 올려냄으로 내원한 6개월 미만의 영아 16명(모유 수유군 7례, 분유 수유군 9례)을 대상으로 위식도 역류증에 대한 검사를 시행하였다. 각 수유군을 24시간 식도 pH 검사를 통하여 역류 횟수, 역류율, 가장 긴 역류 시간, 5분 이상 지속된 역류 횟수, 직립위시 가장 긴 역류 시간, 앙와위시 가장 긴 역류 시간 등의 6가지 역류지수로 비교하였고 통계처리는 Mann- Whitney 검정을 통하여 분석하였다. 결 과: 1) 연구 대상은 모유 수유군 7례, 분유 수유군 9례 총 16례였으며 평균 월령은 모유 수유군이 2.1개월, 분유수유군이 2.6개월로 차이가 없었다. 2) 역류 횟수는 모유 수유군이 $244{\pm}151$회/일, 분유 수유군이 $275{\pm}155$회/일로 차이가 없었다. 3) 역류율은 모유 수유군이 $14{\pm}15%$, 분유 수유군이 $28{\pm}22%$로 모유수유군이 낮았다. 4) 가장 긴 역류 시간은 모유 수유군이 $20{\pm}28$분, 분유 수유군이 $58{\pm}66$분으로 분유 수유군이 길었다. 5) 5분 이상 지속된 역류 횟수는 각각 $5{\pm}6$회와 $9{\pm}3$회로 차이가 없었다. 6) 직립위시 가장 긴 역류 시간은 각각 $10{\pm}8$분과 $40{\pm}47$분으로 모유 수유군이 의미있게 짧았다. 7) 앙와위시 가장 긴 역류 시간은 각각 $18{\pm}29$분과 $52{\pm}66$분으로 모유 수유군이 의미있게 짧았다. 결 론: 이상의 결과로 보아 식도의 기능이 미숙하고 위의 연동운동이 아직 발달 중에 있는 영아들은 모유 수유를 하는 것이 위식도 역류증을 줄일 수 있는 방법이며 이는 모유 수유의 또 하나의 장점이라고 할 수 있겠다.