• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.139-144
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• 2019

For recent decades, Non-volatile Memory (NVM) technologies have been drawing a high attention both in industry and academia due to its high density and short latency comparable to that of DRAM. However, NVM devices has write endurance problem and thus the current data structures that have been built around DRAM-specific features including unlimited program cycles is inadequate for NVM, reducing the device lifetime significantly. In this paper, we revisit a red-black tree extensively adopted for data indexing across a wide range of applications, and make it to better fit for NVM. Specifically, we observe that the conventional red-black tree wears out the specific location of memory because of its rebalancing operation to ensure fast access time over a whole dataset. However, this rebalancing operation frequently updates the long-lived nodes, which leads to the skewed wear out across the NVM cells. To resolve this problem, we present a new swapping wear-leveling red-black tree that periodically moves data in the worn-out node into the young node. The performance study with real-world traces demonstrates the proposed red-black tree reduces the standard deviation of the write count across nodes by up to 12.5%.

• Journal of The Korean Dental Society of Anesthesiology
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• v.3 no.1 s.4
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• pp.34-37
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• 2003

Postoperative stroke is uncommon even in elderly patients, who have a higher incidence of all types of postoperative complications. The mechanism of postoperative stroke is not certain, but can be explained by intravascular clottings originated from thrombus or embolus or by intracranial hemorrhage. In a 66-year-old male patient with current hypertension medication, who underwent both neck dissection for malignancy metastasis under general anesthesia, the left hemiparesis and delayed emergency were found postoperatively. After transferred to intensive care unit, he got the thrombolytic therapy and then the therapies to decrease the swelling of the brain on the diagnosis of cerebral infarction in the vascular distribution of the middle cerebral artery. A brain MRI definitely showed the midline deviation to the left of the right brain hemisphere due to the progressing edematous changes. As he got worse, the emergency neurosurgical operation was proposed but rejected by his family. He died at postoperative 3 days. In this hypertensive patient. perioperative stroke could be originated from the surgical stimuli on major vessels, which were inevitable in neck dissection during the operation. We report this case of the postoperative stroke, which could be highly possible to be associated with extensive head and neck surgery.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2313-2321
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• 2014

A concentration meter is widely used at purification plants, sewage treatment plants and waste water treatment plants to sort and transfer high concentration sludge and to control the amount of chemical input. This study has been prepared for improving efficiency of operation on sludge processes and to establish a basic for factory automation by accuracy improvement and problem solution of sludge concentration meter. The concentration meter's accuracy and stability is improved by applying multi-beam sensors and minimum deviation linear average filtering. Furthermore maintenance without cut-off of water in sludge operation is possible by detachable sensors. The performance of multi-beam concentration meter has been variously verified by the pilot plant experiment.

• Journal of the Korea Computer Industry Society
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• v.6 no.3
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• pp.495-508
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• 2005

Moving objects are spatiotemporal data that change their location or shape continuously over time. Their location coordinates are periodically measured and stored i3l the application systems. The linear function is mainly used to estimate the location information that is not in the system at the query time point. However, a new method is needed to improve uncertainties of the location representation, because the location estimation by linear function induces the estimation error. This paper proposes an application method of the cubic spline interpolation in order to reduce deviation of the location estimation by linear function. First, we define location information of the moving object on the two-dimensional space. Next, we apply the cubic spline interpolation to location estimation of the proposed data model and describe algorithm of the estimation operation. Finally, the precision of this estimation operation model is experimented. The experimentation comes out more accurate results than the method by linear function.

• Journal of Korean Clinical Nursing Research
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• v.17 no.3
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• pp.455-466
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• 2011

Purpose: The purpose of this study was to investigate the effects of a structured preoperative PCA education on the knowledge and attitude regarding PCA usage, level of pain, and the consumption of analgesics after operation for colorectal surgery patients. Methods: This study was conducted from 18 Feb to 2 May, 2008. Participants were 80 colorectal cancer patients who would use the IV-PCA after colorectal surgery in a cancer hospital in Gyeonggi-do, Korea. Two groups, experimental and control were consisted of 40 patients each. The 20-minute structured education regarding PCA usage was applied to each patient individually in the experimental group but only the routine anesthetic consultation was given to each patient in the control group the day before the surgery. The SPSS/PC 10.0 program was introduced to analyze the collected data on frequency, percentage, mean, standard deviation, $x^2$-test, t-test and paired t-test. Results: The experimental group with the structured preoperative PCA education showed higher knowledge and more positive attitudes regarding the PCA usage than the control group. Also the experimental group showed better pain control and lower consumption of analgesics at 4, 8 and 24 hours after than the control group. Conclusion: The structured preoperative PCA education is an effective nursing intervention for improving the knowledge and attitude of the colorectal surgery patients on the PCA usage, and enabling the patient to take the analgesic more effectively with lower consumption, while reducing the patients' pain after operation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.181-186
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• 2018

With progress in industrialization, facilities for generating, delivering, and receiving high levels of electric power are in great demand. The scale of electric power equipment is increasing in both size and complexity. This has contributed to the development of our modern, high-tech and information-based society. However, if the generation of electric power is suspended due to unexpected accidents at power facilities or power stations, a range of equipment the operations of which are dependent on electric power can be damaged, causing substantial socioeconomic losses in an industrial society. A great deal of time and money would be expended to repair damaged facilities at a power station, causing enormous economic loss. In order to detect the deterioration processes of power cables, and to prevent the destruction of power cables, the operation status of power cables should be monitored on a regular basis. We studied the method in order to improve accuracy and reliability for diagnosising the junction where accident occurs frequently. We present the method of data acquisition and statistical processing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.173-180
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• 2022

The operation and transportation environment for an unmanned aerial vehicle will be completely different from those for the conventional air and ground transportation. The requirement for a traffic management system for its safe operation has been emerging. Accordingly, investigation is being conducted to analyze the danger that unmanned aerial vehicle may encounter during the flight and to provide the countermeasure by the simulation. When the drones operate in an urban environment, they may be affected by the wind around the building. Thus it is essential to predict the influence of the gust and analyze the resulting risk. In this paper, a method for evaluating the safety for a flight mission under the gust is suggested. By using the precise 6-degree-of-freedom flight simulation that is capable of simulating the gust condition, possible deviation from the pre-planned flight path in terms of the attitude orientation will be predicted. A method of quantifying the probability of the flight mission failure will also be presented.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.44-54
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• 2023

In this study, the second-order Nomoto's nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto's nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.

• Korean Journal of Radiology
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• v.23 no.8
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• pp.803-810
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• 2022

Objective: To investigate the clinical application of differential subsampling with Cartesian ordering (DISCO) contrast-enhanced (CE) magnetic resonance angiography for anterolateral thigh (ALT) flap transplantation, using operative findings as a reference. Materials and Methods: Thirty patients (21 males and nine females; mean age ± standard deviation, 45.5 ± 15.6 years) who were scheduled to undergo reconstruction with ALT flaps between June 2020 and June 2021 were included in the prospective study. Before ALT flap transplantation, patients were scanned using CE-DISCO imaging. All acquired DISCO images of the 60 lower limbs (both sides from each patient) were analyzed using maximum intensity projection and volume rendering methods. Two experienced radiologists were employed to examine the patterns of the lateral circumflex femoral artery (LCFA), its branches, and perforators and their skin termini, which were compared with the operative findings. Results: Using CE-DISCO, the patterns of the LCFA and its branches were clearly identified in all patients. Four different origins of the LCFA were found among the 60 blood vessels: type I (44/60, 73.3%), type II (6/60, 10.0%), type III (8/60, 13.3%), and type IV (2/60, 3.3%). Owing to a lack of perforators entering the skin, two patients did not undergo ALT flap transplantation. For the remaining 28 patients, the ALT flaps in 26 patients were successfully operated without flap reselection during the operation, while the remaining two patients underwent other surgical procedures due to the thin diameter of the perforator or injury of the perforator during the operation. The success rate of flap transplantation was 92.8% (26/28). All transplanted flaps exhibited good blood supply and achieved primary healing without infection or delayed healing. Conclusion: CE-DISCO imaging can be an effective method for preoperative perforator imaging before ALT flap transplantation.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.308-319
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• 2018

This study is intended to develop evaluation indicators for the improvement and operation of R&D project management process. To achieve this, an empirical survey was carried out to small companies specializing in technology-centered R&D. First, 12 evaluation indicators showed that there was a deviation of more than 2 times from the highest score of 60.77 to the lowest score of 30 in integrated management, which the R&D project management process needs to be selectively used for the improvement and operation. Second, the difference in industry showed that the biotech industry was the highest, while the chemical, electrical and electronic industries were the lowest. Third, the difference in the number of employees showed that companies with 50~100 employees were relatively high, while small companies with more than 100 employees were somewhat low. Fourth, the difference in career showed that 5~7-year career was relatively high, while 7~10-year career was somewhat high. Overall, evaluation indicators for the improvement and operation of R&D project management processor showed that integrated management was the most important, followed by communication management, risk management, and time management. This implies that small companies specializing in technology-centered R&D need to concentrate on the importance of efficient integrated management and rapid decision-making and risk management among individual participation subjects.