• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.325-333
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• 1995

Laparoscopic cholecystectomy was introduced into Korea in 1990 and has been rapidly replacing open cholecystectomy when the indications were met. In this study a medical utilization and technology was assessed on the selected hospitalized patients with cholelithiasis who underwent open or laparoscopic cholecystectomy from April 1, 1991 to March 31, 1994. The results are as follows. Despite the low reimbursement rate by the health insurance, the number of laparoscopic cases have been steadily increased. The post-operative days before health insurance coverage were significantly shortened from 8.4 days to 4.6 days. The preoperative days before health insurance coverage were significantly shorted from 8.4 days to 4.0 days. The total length-of-stays in the hospital were also significantly shortened from 15.2 days to 10.7 and 9.8 days in laparoscopic cholecystectomy. The laparoscopic cholecystectomy showed low expenses in all aspects expect the average hospital charges per day. For the hospital to have cost containment, it is more effective if length-of-stay is shorter because of high daily inpatient hospital charge. The laparoscopic cholecystectomy also showed shortened anesthesia time and operation time compared with open cholecystectomy that were statistically significant. The mean anesthesia and operation time for open cholecystectomy were 113.2 and 90.2 minutes but those of laparoscopic cholecystectomy were 105.7 and 68.6 minutes. According to this study the laparoscopic cholecystectomy has reduced the medical expenditure and we recommend this procedure over open cholecystectomy. The further discussion on the different morbidity rate between two types of procedure is essential in providing quality medical care, and to educate specialist.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.6
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• pp.78-84
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• 1984

We propose a new algorithm which detects stuck-open faults in CMOS circuits without being affected by time skews not using additional circuits. That is, the Domino CMOS circuit structure is used as circuit configurations and the clocking gate in this circuit is modeled as one branch, then test sequence is generated by using the transition test. Also, it is verified by applying this algorithm implemented in VAX II/780 to arbitrary CMOS circuits that all of stuck-open faults which were not detected because of time skews in conventional methods is detected.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.5-12
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• 2008

This paper presents the features of an impact angle constrained open-loop optimal trajectory which is given by a function of initial conditions and optimal guidance gains. Using missile motion described by linearized kinematic equations and a proper form of performance index, an inverse optimal problem is suggested to investigate the gains related to the performance index. The flight trajectory and time-to-go can be shaped in terms of the optimal guidance gains. The results are evaluated by 3-DOF simulation.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.79-87
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• 2017

The retractable roof structure is used in various fields and it is classified for steel retractable system and soft retractable system. For the domestic industry, it is in the initial phase now and the demand of the retractable roof structure is expected to increase in the future. Therefore, this paper is classified for steel retractable system and soft retractable system from the retractable roof structures in overseas to survey and analyze the cases of wind velocity on retractable roof structure in Japan that uses the same wind velocity criteria like Korea regarding the open-close time and average open-close time for retractable roof area.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.1-7
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• 2019

Previously, parallel computing was mainly used in areas requiring high computing performance, but nowadays, multicore CPUs and GPUs have become widespread, and parallel programming advantages can be obtained even in a PC environment. Various parallel programming frameworks using multicore CPUs such as OpenMP and PPL have been announced. Nvidia and AMD have developed parallel programming platforms and APIs for program developers to take advantage of multicore GPUs on their graphics cards. In this paper, we develop digital image transformation programs that runs on each of the major parallel programming frameworks, and measure the execution time. We analyze the characteristics of each framework through the execution time comparison. Also a constant K indicating the ratio of program execution time between different parallel computing environments is presented. Using this, it is possible to predict rough execution time without implementing a parallel program.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.49-60
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• 2017

Recently, the use of mashup that integrates real-time data with spatial data such as tiled map and satellite imagery has been increased significantly. As the use of mashup has been extended to various fields of O2O, LBS, Smart City, and Autonomous Driving, the performance of mashup has become more important. Therefore, this study aims to compare and analyze the performance of various map platforms, when large amounts of real-time data are integrated with spatial data. Specifically, we compare the performance of most popular map platforms available in Korea, such as Google Maps, OpenStreetMap, Daum Map, Naver Map, olleh Map, and VWorld. We also compare the performance using most common web browsers of Chrome, Firefox and Internet Explorer. In the performance analysis, we measured and compared the initialization time of basic map and the mashup time of real-time data for the above map platforms. From analysis results, we could find that Google Maps, OpenStreetMap, VWorld, and olleh Map platforms showed a better performance than the others.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.559-571
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• 2008

Platform Screen Door(PSD) has been installed and operated at seoul subway line $1\sim4$ in the manual train operation mode(ATS/ATC) by SeoulMetro since 2005. SeoulMetro uses the wireless (RF) communication system and the train door detection system for the link between the train and PSD doors opening/closing motion in the manual train operation mode. For the convenience and safety of passengers, the train doors and the PSD doors opening/closing shall be synchronized as much as possible. In ATO(Automatic Train Operation) mode which provides the interface between train control system and PSD system, ATO signaling system makes the train doors and PSD doors open/close command signals systematically, so PSD doors can be opened/closed almost simultaneously with the train doors. But, in the manual train control(ATS/ATC) mode, PSD system needs to detect the train doors open/close operation and make PSD open/close command signals to actuate PSD doors. These PSD open/close commanding process cause time delay of PSD doors opening/closing motion in response to the train doors opening/closing motion. Sometimes the response delay time can be over 1 second, which is not proper to operate PSD, and need to be reduced This paper presents the reduction method of the PSD response delay time to improve the convenience and safety of passengers.

• Journal of Korean Library and Information Science Society
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• v.41 no.2
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• pp.229-250
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• 2010

Open access policies are very important for the successful open access projects in any institutions. This study aims to propose elements to consider for establishing open access policies of universities. The 3 university institutional repositories' open access policies in Korea and foreign universities' policies registered in the ROARMAP are analyzed. The major categories proposed in the study are materials, time of deposition, depositors, copyright, level of requirement, exemption, usage, options for open access, and support.

• Research in Mathematical Education
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• v.3 no.1
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• pp.9-21
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• 1999

In mid 1980s, open education arrived in Korea. It was influenced by the educational reforms implemented in American primary schools. Currently, the Ministry of Education is appealing to teachers for their active involvement in educational reform by using open education methodology. Often teachers in Korea complain that they do not know what to do or how to change in order to practice the open education. It is time to review the state of open education in Korea and the United States. This paper contains the following segments: 0) Introduction, 1) Beginning of open education, 2) A brief history of open education in Korea, 3) The current status of open education in the United States, 4) A glance at open mathematics classroom in Korea, 5) Lessons from the review, and 6) Conclusion.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.486-490
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• 1999

In this study, to improve the required properties of tile cement mortar such as excellent water retention capacity (WRC), workability, open time, sag resistance, and tile adhesive strength, tile cement mortars containing the several additives with different ratio were compared and analyzed. By adding small amount of synthesized starch to hydroxypropyl methylcellulose (HPMC) which is used for improving WRC, the decrease of moisture evacuation from mortar surface was observed and the workability of mortar was improved with long open time. Polyacrylamide (PAAm) and ethylencvinyl acetate (EVAc) were also added in order to increase the adhesion of tile. As a results, the saggings of mortar itself and tile were decreased and the adhesive strength of mortar between base and tile was enhanced. By adding melment, the workability was improved by increasing the fluidity of mortar. It is postulated that the properties of tile cement mortar was improved by adding 0.80~1.20% of HPMC, 0.10~0.15% of starch, 0.001~0.015% of PAAm, 0.05~0.10% of EVAc and 0.003~0.005% of melment to the cement mortar.