• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.327-343
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• 2001

This is a survey article on finite element a posteriori error estimates with an emphasize on gradient recovery type error estimators. As an example, the error estimator based on the ZZ patch recovery technique will be discussed in some detail.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.4
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• pp.281-290
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• 2013

The IT asset is a core part that supports the management objective of an organization, and the fast settlement of the IT asset fault is very important. In this study, a fault recovery prediction technique is proposed, which uses the existing fault data to address the IT asset fault. The proposed fault recovery prediction technique is as follows. First, the existing fault recovery data were pre-processed and classified by fault recovery type; second, a rule was established for the keyword mapping of the classified fault recovery types and reported data; and third, a machine learning process that allows the prediction of the fault recovery method based on the established rule was presented. To verify the effectiveness of the proposed machine learning process, company A's 33,000 computer fault data for the duration of six months were tested. The hit rate for fault recovery prediction was approximately 72%, and it increased to 81% via continuous machine learning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2067-2080
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• 1994

Recently, joint blind equalization and carrier recovery for digital mobile transmission system is of growing interest. In this paper, we describe new receiver structure of joint godard blind equalizer and various recovery loop for QAM modulated signal. After a brief review of Godard blind equalizer and MAP estimation Costas loop, Generalized Costas loop, Leclert loop, Angular form loop, we present two kinds of receiver structures for joint blind equalization and carrier recovery. Using a Monto Carlo simulation technique, we can confirm that two kinds of receiver structures operate very well in the steady state.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1752-1758
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• 2018

In a low-voltage distribution system, the molded case circuit breaker (MCCB) is a widely used device to protect loads by interrupting over-current; however the hot gas generated from the arc discharge in the interrupting process depletes the dielectric recovery strength between electrodes and leads to re-ignition after current-zero. Even though the circuit breaker is ordinarily tripped and successfully interrupts the over-current, the re-ignition causes the over-current to flow to the load again, which carries over the failure interruption. Therefore, it is necessary to understand the dielectric recovery process and the dielectric recovery voltage of the MCCB. To determine these characteristics, a measuring system comprised of the experimental circuit and source is implemented to apply controllable recovery voltage and over-current. By changing the controllable recovery voltage, in this work, re-ignition is driven repeatedly to obtain the dielectric recovery voltage V-t curve, which is used to analyze the dielectric recovery strength of the MCCB. A measuring system and an evaluation technique for the dielectric recovery strength of the MCCB are described. By using this system and method, the measurement to find out the dielectric recovery characteristics after current-zero for ready-made products is done and it is confirmed that which internal structure of the MCCB affects the dielectric recovery characteristics.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1438-1448
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• 2019

We present a new technique, called VED (very effective debugging), for detecting and correcting division by zero errors for all types of .NET application. We use applications written in C# because C# applications are distributed through the internet and its executable format is used extensively. A tool called Immunity Debugger is used to reverse engineer executable code to get binaries of source code. With this technique, we demonstrate integer division by zero errors, the location of the error causing assembly language code, as well as error recovery done according to user preference. This technique can be extended to work for other programming languages in addition to C#. VED can work on different platforms such as Linux. This technique is simple to implement and economical because all the software used here are open source. Our aims are to simplify the maintenance process and to reduce the cost of the software development life cycle.

• Parasites, Hosts and Diseases
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• v.47 no.4
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• pp.353-357
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• 2009

Cryptosporidium can cause gastrointestinal diseases worldwide, consequently posing public health problems and economic burden. Effective techniques for detecting contaminated oocysts in water are important to prevent and control the contamination. Immunomagnetic separation (IMS) method has been widely employed recently due to its efficiency, but, it is costly. Sucrose floatation technique is generally used for separating organisms by using their different specific gravity. It is effective and cheap but time consuming as well as requiring highly skilled personnel. Water turbidity and parasite load in water sample are additional factors affecting to the recovery rate of those 2 methods. We compared the efficiency of IMS and sucrose floatation methods to recover the spiked Cryptosporidium oocysts in various turbidity water samples. Cryptosporidium oocysts concentration at 1, $10^1$, $10^2$, and $10^3$ per $10{\mu}l$ were spiked into 3 sets of 10 ml-water turbidity (5, 50, and 500 NTU). The recovery rate of the 2 methods was not different. Oocyst load at the concentration < $10^2$ per 10 ml yielded unreliable results. Water turbidity at 500 NTU decreased the recovery rate of both techniques. The combination of sucrose floatation and immunofluorescense assay techniques (SF-FA) showed higher recovery rate than IMS and immunofluorescense assay (IMS-FA). We used this SF-FA to detect Cryptosporidium and Giardia from the river water samples and found 9 and 19 out of 30 (30% and 63.3%) positive, respectively. Our results favored sucrose floatation technique enhanced with immunofluorescense assay for detecting contaminated protozoa in water samples in general laboratories and in the real practical setting.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.677-687
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• 2006

Kriging interpolation is one of the generally used interpolation techniques in Geostatistics field. This technique includes the experimental and theoretical variograms and the formulation of kriging interpolation. In contrast to the conventional least square method for stress recovery, kriging interpolation is based on the weighted least square method to obtain the estimated exact solution from the stress data at the Gauss points. The weight factor is determined by variogram modeling for interpolation of stress data apart from the conventional interpolation methods that use an equal weight factor. In addition to this, the p-level is increased non-uniformly or selectively through a posteriori error estimation based on SPR (superconvergent patch recovery) technique, proposed by Zienkiewicz and Zhu, by auto mesh p-refinement. The cut-out plate problem under tension has been tested to validate this approach. It also provides validity of kriging interpolation through comparing to existing least square method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.1
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• pp.31-37
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• 2017

In this paper, computation results of reducible modeling, stress recovery and energy release rate were compared with the results of VABS, Virtual Crack Closure Technique. The result of stress recovery analysis for 1-D model including the stiffness matrix is compared with stress results of three-dimensional 3-D FEM. Energy release rate of composite beam with longitudinal cracks is calculated and compare verifications of numerical analysis results of 3-D FEM and VABS. The procedure of calculating energy release rate through dimensional reduction and stress recovery is intended to be efficient and be utilized in the life-cycle of high-altitude uav's wing, wind blades and tilt rotor blade.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1867-1879
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• 1997

DREAM-S is a distributed main-memory database system for the real-time processing of shared operational datra in ATM switching systems. DREAM-S has a client-server architecture in which only the server has the diskstorage, and provides the T-Tree index structure for efficient accesses to the data. We propose a recovery technique for the T-Tree index structre in DREAM-S. Although main-memory database system offer efficient access performance, the database int he main-memory may be broken when system failure such as database transaction failure or power failure occurs. Therfore, a recovery technique that recovers the database (including index structures) is essential for fault tolerant ATM switching systems. Proposed recovery technique relieves the bottleneck of the server processors disk operations by maintaining the T-Tree index structure only in the main-memory. In addition, fast recovery is guaranteed even in large number of client systems since the T-Tree index structure(s) in each system can be recovered cncurrently.

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.344-349
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• 2019

Background Lymphaticovenous anastomosis is an important surgical treatment for lymphedema, with lymphaticovenous side-to-end anastomosis (LVSEA) and lymphaticovenous end-to-end anastomosis being the most frequently performed procedures. However, LVSEA can cause lymphatic flow obstruction because of regurgitation and tension in the anastomosis. In this study, we introduce a novel and simple procedure to overcome this problem. Methods Thirty-five female patients with lower extremity lymphedema who underwent lymphaticovenous anastomosis at our hospital were included in this study. Eighty-five LVSEA procedures were performed, of which 12 resulted in insufficient venous blood flow. For these 12 anastomoses, the proximal lymphatic vessel underwent clipping after the anastomotic procedure and the venous inflow was monitored. Subsequently, the proximal ligation after side-to-end anastomosis recovery (PLASTER) technique, which involves ligating the proximal side of the lymphatic vessel, was applied. A postoperative evaluation was performed using indocyanine green 6 months after surgery. Results Despite the clipping procedure, three of the 12 anastomoses still showed poor venous inflow. Therefore, it was not possible to apply the PLASTER technique in those cases. Among the nine remaining anastomoses in which the PLASTER technique was applied, three (33%) were patent. Conclusions Our findings show that achieving patent anastomosis is challenging when postoperative venous inflow is poor. We achieved good results by performing proximal ligation after LVSEA. Thus, the PLASTER technique is a particularly useful recovery technique when LVSEA does not result in good run-off.