• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.29-32
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• 1999

Korea Multi-Purpose SATellite(KOMPSAT) is scheduled to be launched by TAURUS launch vehicle in November, 1999. Tracking, Telemetry and Command(TT&C) operation and the flight dynamics support should be performed for the successful Launch and Early Orbit Phase(LEOP) operation. After the first contact of the KOMPSAT spacecraft, initial orbit determination using ground based tracking data should be performed for the acquisition of the orbit. Although the KOMPSAT is planned to be directly inserted into the Sun- synchronous orbit of 685 km altitude, the orbit maneuvers are required fur the correction of the launch vehicle dispersion. Flight dynamics support such as orbit determination and maneuver planning will be performed by using KOMPSAT Mission Analysis and Planning Subsystem(MAPS) in KOMPSAT Mission Control Element(MCE). The KOMPSAT MAPS have been jointly developed by Electronics and Telecommunications Research Institute(ETRI) and Hyundai Space & Aircraft Company(HYSA). The KOMPSAT MCE was installed in Korea Aerospace Research Institute(KARI) site for the KOMPSAT operation. In this paper, the orbit determination and maneuver planning are introduced and simulated for the KOMPSAT spacecraft in LEOP operation. Initial orbit determination using short arc tracking data and definitive orbit determination using multiple passes tracking data are performed. Orbit maneuvers for the altitude correction and inclination correction are planned for achieving the final mission orbit of the KOMPSAT.

• Journal of Chest Surgery
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• v.23 no.6
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• pp.1174-1179
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• 1990

Forty-five patients with double-outlet right ventricle[DORV] underwent complete intracardiac repair between July, 1983 and June, 1989. Patients with complete atrioventricular canal, atrioventricular discordance and uni-ventricular heart were excluded. The 32 male and 13 female patients ranged in age from 3 months to 15 years[mean 4 years]. Thirty-two patients had pulmonary stenosis. The early mortality was 11.ltd[5 /45] None of 27 died after a completely intraventricular repair. The mortality was 20%[1/5] for repair using transannular patch, 20% [1/5] for REV operation, 33.3%[1/3] for repair including extracardiac valved conduit, and 50% [1/2] for Jatene operation, respectively. Two modified Fontan procedures were performed without mortality. One died after Senning operation. Causes of early deaths included high residual right ventricular pressure[one patient] small left atrial and left ventricular volume[one patient], persisting severe pulmonary hypertension [one patient] and low cardiac output of unknown cause [two patients]. Complete heart block developed in one patient. Two late deaths occurred among the 40 operative survivors [5.0Po] from persisting severe pulmonary hypertension and bleeding at reoperation. Our results indicate that significant defects can be repaired with low mortality and morbidity.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.32-41
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• 1989

We scrutinized the 64 cases of TGA and Taussig-Bing anomaly who underwent Senning and Mustard operations from Jan. 1981 to May 1988. The ratio of male to female was 45; 19, and the age at operation varied from 2 months to 18 years [mean 18.9*32.9 months]. The in-hospital mortality was in 24 cases [37.5%] and the major causes were myocardial failure and congestive heart failure associated with arrhythmias. The risk factors for hospital mortality were complex TGA, prolonged bypass time and high postoperative CVP. In addition, mortality increased during the first year the procedure was used. Late mortality occurred in 6 cases and the major causes was congestive heart failure, and there was not any significant risk factor noted in late mortality. Early arrhythmia developed in 37.5%, all of which were transient and self limited and 7 cases of early mortality were related to the arrhythmias. Late arrhythmias developed in 8 cases, but 7 cases were transient. One case died with junctional tachycardia. Of significance the one case that died late by arrhythmia had a similar junctional tachycardia in the early postoperative period. The survival rate in all cases disregarding initial in-hospital mortality 1YSR 89.8% and 5YSR 84.3%, but because of short duration of follow up this is not significant. We concluded that early hospital mortality could be decreased by operating at an earlier age and by adjusting the appropriate operation method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.467-474
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• 2017

The objective of this study is to analyze teachers' experience in the operation of outdoor play in an early childhood educational institute. For this purpose, the experience obtained in planning/operating the outdoor play in early childhood educational institutes, as well as the difficulties experienced in their operational process, were examined. The data was collected through interviews with eight early childhood teachers. In the results of the study, first, the teachers' perception of outdoor play was analyzed. The teachers considered outdoor play as meaningful in that the children could develop gross/fine-motor skills, have the chance to develop their sociality, relieve their stress, and also commune with nature through outdoor play. Second, regarding the plan/operation of the outdoor play activities, even though they aimed to provide the children with meaningful outdoor play activities through various materials and methods, most of the teachers could not put their original plans into practice, because of the numerous variables in the actual site. The teachers' difficulties included insufficient time, spatial limitations, and insufficient qualifications for play instruction.

• Journal of Astronomy and Space Sciences
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• v.41 no.1
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• pp.43-60
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• 2024

Korea Pathfinder Lunar Orbiter (KPLO) is South Korea's first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft's initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.

• Journal of architectural history
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• v.29 no.3
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• pp.67-78
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• 2020

This study examines the transitional situation that can be seen from the palace operation in early Joseon Dynasty. The first decades of Joseon after the nation was founded differ from the Joseon Dynasty as a whole, but rather similar with the Goryeo Dynasty. By examining "The History of Goryeo(高麗史)," it showed that palace operation during the Goryeo Dynasy was marked by the fact that a separate palace was built and resided in despite the existence of the Bongweol(本闕, main palace) as the central palace. The separation of the parent's generation and the children's generation was shown through the establishment of one's own palace. Such trait of Goryeo affected palace construction directly after the founding of Joseon. This can be shown from the characteristic of palace operation by generation. The construction of the Changdeokgung Palace(昌德宮) of King Taejong, as his own palace, is an example. Afterwards, the palace system of Joseon was established, and the space of the king and the crown prince was merged through ritual reform during the reign of King Sejong. However, the space for the parents of the king were considered separate, and this influence continued to the reign of King Seongjong. The construction of Changgyeonggung Palace(昌慶宮) during the reign of King Seongjong is an event where the king proclaimed the separation with his mother and grandmother.

• Journal of Chest Surgery
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• v.22 no.6
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• pp.1036-1043
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• 1989

Seventy eight patients underwent operation for combined multiple valve disease, with an overall early mortality of 14.1 % from January, 1983 to September, 1988 in the department of thoracic and cardiovascular surgery of Pusan National University Hospital. All of the above cases had combined multiple valve procedures. There were 33 mitral valve replacements and tricuspid annuloplasties, 33 aortic and mitral valve replacements, 5 aortic and mitral valve replacements with tricuspid annuloplasties, 3 aortic valve replacements and mitral annuloplasties, 1 open mitral commissurotomy and tricuspid annuloplasty and, 1 mitral valve replacement and primary closure of tricuspid valve cleft, 1 mitral valve replacement and aortic commissurotomy, 1 mitral, aortic and tricuspid valve replacement were done. 44 were male and 34 were female and the age distribution was from 14 to 57 with mean 38 year old. According to NYHA[New York Heart Association] classification, 49 patients were class I, 19 patients were class Il and 10 were class IV. Average perfusion time was 205.3 minutes. The live patients perfusion time was 178.7 minutes while that of dead ones was 272.0 minutes. Early deaths within 30 days from operation were 11 cases, 6 of which were due to low cardiac output, 3 were acute renal failure and 2 were cardiac rupture. The 65 patients were followed up from 2 to 30 months for a total 20.6 patient years. 1 patient committed suicide because of postoperative depression 1 year after operation. All of the survivors were enjoying their daily life and their NYHA class was superior to the preoperative ones.

• Korean Journal of Childcare and Education
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• v.12 no.4
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• pp.151-181
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• 2016

This study examined professional development systems in America, England, and Australia, and devised ways to enhance early childhood teachers' professional development in Korea. To suggest effective ways to improve current professional development system and its operation, this research aimed to investigate first, advanced professional development systems and policies in three countries, America, England, and Australia, second, the process of teacher qualification and requirements for acquiring teacher credential and its maintenance, and lastly, the effort of quality control for professional development, its operation, and evaluation systems in three countries. Based on the analysis of the three country's systems, five solutions for effective professional development are suggested. First, it is necessary to differentiate requirements for teachers by the level of teacher credentials. Second, an incessant training process for professional development is required. Third, an individualized professional development plan should be set for an individual teacher for the best outcomes in professional competence. Fourth, instructors for professional development trainings are needed to ensure the quality of training. Lastly, individuals, organizations, and policy and its operation systems need to be considered holistically as a whole in the perspective of convergence in policy making and its operation for effective professional development.

• Journal of Chest Surgery
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• v.23 no.1
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• pp.22-32
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• 1990

Postoperative cardiac performance of cyanotic congenital heart disease is somewhat different from that of other cardiac diseases. For the evaluation of postoperative cardiac performance in the cyanotic congenital heart disease we measured cardiac output by thermodilution technique at 1, 4, 8, 12, 16, 20, 24, 36, 48 postoperative hours in 14 patients operated from Feb. 1989 to Nov. 1989 in The Department of Thoracic and Cardiovascular Surgery, Seoul National University Children`s Hospital. At the same time, we checked left atrial pressure [LAP], central venous pressure [CUP], and mixed venous oxygen saturation [SvO2] to detect correlation between them. Immediate postoperative cardiac index was 3.585 $\pm$ 0.945 L/min/m2, and it decreased maximally to 3.322$\pm$1.007 L/min/m2 at postoperative 16 hours. After then it increased and stabilized from 36 hours after operation, and its value was 4.426$\pm$1.358 L/min/m2. There were no correlations between cardiac index and left atrial pressure or central venous pressure. Between mixed venous oxygen saturation and cardiac index, there was no correlation in the early postoperative period but after postoperative 16 hours, there was significant correlation between them and correlation coefficients were 0.573 [16hrs], 0.743 [20hrs], 0.436 [24hrs], 0.560 [36hrs], 0.636 [48hrs], respectively. From these results, we concluded that in the corrective surgery of cyanotic congenital heart disease, cardiac performance was depressed in the early postoperative period. It improved from postoperative 16 hours, and stabilized from 36 hours after operation. During early postoperative period, mixed venous oxygen saturation should not be used as a predictor of cardiac performance but it could be used as a predictor of cardiac performance from 16 hours after operation.

• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.429-430
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• 2014