• ETRI Journal
• /
• v.39 no.3
• /
• pp.364-372
• /
• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• Journal of Information Technology Services
• /
• v.10 no.1
• /
• pp.89-103
• /
• 2011

ITS (Intelligent Transportation System) has been more popular but ITS project managements remain complex because of diverse stakeholders and multidisciplinary processes of ITS. The multidisciplinary process enforces specialized competencies on ITS project managers comparing to other system integration project managers. In this paper, we derived core competencies of ITS projects from previous researches, built the hierarchy of the competencies, and employed AHP (Analytic Hierarchy Process) surveying ITS project managers and auditors with the hierarchy. Finally, we analyzed the difference of evaluation model on ITS project manager between project managers and auditors using Mann-Whitney U test. Additionally we suggest a method of building MECE (Mutually Exclusive and Collectively Exhaustive) structure for AHP using the HoQ (House of Quality). We expect our model to give some inspirations for raising capable ITS project managers and selecting a proper project manager for an ITS project.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.1380-1382
• /
• 1996

In this paper, a motion estimation module is made with ADSP-21020 based on MPEG-2 which is an international standard for moving picture compression. And, the block matching algorithm used as motion estimation method is easy for an hardware implementation. The ADSP-21020 of Analog Device is used for a main control processor. We used three block matching method (exhaustive search method, 2D-logarithmic search method, three step search method) for software simulation and implemented the three step search method to hardware. For the test of the estimation module, we used ping pong image sequences and mobile and calendar image sequences.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.1
• /
• pp.18-29
• /
• 2015

State Estimation (SE) is the basis of a variety of advanced applications used in most modern power systems. An SE problem formed with enough phasor measurement units (PMUs) data is simply a linear weighted least squares problem requiring no iterations. Thus, designing a minimum-cost placement of PMUs that guarantees observability of a power system becomes a worthy challenge. This paper proposes an equivalent integer linear programming method for substation-oriented optimal PMU placement (SOOPP). The proposed method uses an exhaustive search to determine a globally optimal solution representing the best PMU placement for that particular power system. To obtain a more comprehensive model, contingencies and the limitation of the number of PMU measurement channels are considered and embodied in the model as changes to the original constraints and as additional constraints. The proposed method is examined for applicability using the IEEE 14-bus, 118-bus and 300-bus test systems. The comparison between SOOPP results and results obtained by other methods reveals the excellence of SOOPP. Furthermore, practical large-scale power systems are also successfully analyzed using SOOPP.

• The Korean Journal of Applied Statistics
• /
• v.17 no.3
• /
• pp.459-473
• /
• 2004

It has well known that an exhaustive search algorithm suggested by Breiman et. a1.(1984) has a trend to select the variable having relatively many possible splits as an splitting rule. We propose an algorithm to overcome this variable selection bias problem and then construct unbiased regression trees based on the algorithm. The proposed algorithm runs two steps of selecting a split variable and determining a split rule for binary split based on the split variable. Simulation studies were performed to compare the proposed algorithm with Breiman et a1.(1984)'s CART(Classification and Regression Tree) in terms of degree of variable selection bias, variable selection power, and MSE(Mean Squared Error). Also, we illustrate the proposed algorithm with real data sets.

• Journal of Korean Medicine Rehabilitation
• /
• v.30 no.2
• /
• pp.37-46
• /
• 2020

Objectives In this study, we analyzed the effect of Dioscoreae Rhizoma on exercise practice ability and blood fatigue variable factor in the forced swimming test. Methods Male mice were divided into four group. Mice were administrated with saline, Discorae Rhizoma extracted by water (DRW), Discorae Rhizoma extracted by 30% ethanol (DRE), red ginseng (RG), orally once per day, for 1 week. Exercise performance was evaluated by exhaustive swimming time and weights. Glycogen contents of liver and soleus muscle were measured at the end of the experiment. In addition, the biochemical parameters such as asparate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen, creatine, lactate dehydrogenase (LDH), ammonia, triglycerides (TG), total cholesterol (TC) and free fatty acid (FFA) were analyzed. Results Both DRW and DRE showed an improvement of swimming endurance compared with control group. Levels of ALT, ammonia, TG, TC and FFA were significantly decreased in both DRW and DRE compared with control group. Levels of AST, Creatine were significantly reduced in DRE group compared with control group. Moreover LDH showed only a tendency to increase in the DRW and DRE groups. Conclusions In summary, the present study showed that Dioscoreae Rhizoma improved in physical fatigue and exercise practice ability and DRE improved the superior than those of DRW.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.7
• /
• pp.49-55
• /
• 2016

In digital forensic images, there is a serious problem that is distributed with various image types. For the problem solution, this paper proposes a classification algorithm of the forensic image types. The proposed algorithm extracts the 21-dim. feature vector with the contrast and energy from GLCM (Gray Level Co-occurrence Matrix), and the entropy of each image type. The classification test of the forensic images is performed with an exhaustive combination of the image types. Through the experiments, TP (True Positive) and FN (False Negative) is detected respectively. While it is confirmed that performed class evaluation of the proposed algorithm is rated as 'Excellent(A)' because of the AUROC (Area Under Receiver Operating Characteristic Curve) is 0.9980 by the sensitivity and the 1-specificity. Also, the minimum average decision error is 0.1349. Also, at the minimum average decision error is 0.0179, the whole forensic image types which are involved then, our classification effectiveness is high.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.9 no.2
• /
• pp.77-80
• /
• 2011

Purpose: The purpose of this study was to investigate the relationship between patients with a neuropsychiatric history and features of their suicide attempt, in order to analyze the risk associated with psychiatrist prescribed drugs Methods: We retrospectively investigated cases of intentional overdose drug ingestion in patients greater than 14 years of age who visited OO emergency medical center between January 1, 2008 and July 31, 2010. We evaluated patient medical records to ascertain their age, sex, neuropsychiatric history, and components of ingested intoxicant. Information regarding any suicide reattempt was obtained after discharge through follow up telephone survey. SPSS version 13.0 was used for statistical analysis. Fisher's exact test was performed with p<0.05 considered statistically significant. Results: Ninety-six of 209 patients (46%) had a past history of psychological problems. Among those 96 patients with a history of psychological problems, 46(48%) used an overdose of the medicine prescribed by their psychologist in order to attempt suicide. However, for patients without a history of psychological problems, intoxication by neuropsychiatric drugs was insignificant. Neuropsychiatric patients required greater follow up care after discharge and exhibited significantly more suicide reattempts. Conclusion: This study revealed that patients sometimes use the medicine prescribed by their psychologist to attempt suicide. Therefore, an exhaustive plan to control the medicines prescribed to psychiatric patients should be established.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.12C
• /
• pp.1231-1238
• /
• 2005

This paper presents a new fast encoding algorithm for image vector quantization that incorporates the partial distances of multiple features with a multidimensional look-up table (LUT). Although the methods which were proposed earlier use the multiple features, they handles the multiple features step by step in terms of searching order and calculating process. On the other hand, the proposed algorithm utilizes these features simultaneously with the LUT. This paper completely describes how to build the LUT with considering the boundary effect for feasible memory cost and how to terminate the current search by utilizing partial distances of the LUT Simulation results confirm the effectiveness of the proposed algorithm. When the codebook size is 256, the computational complexity of the proposed algorithm can be reduced by up to the $70\%$ of the operations required by the recently proposed alternatives such as the ordered Hadamard transform partial distance search (OHTPDS), the modified $L_2-norm$ pyramid ($M-L_2NP$), etc. With feasible preprocessing time and memory cost, the proposed algorithm reduces the computational complexity to below the $2.2\%$ of those required for the exhaustive full search (EFS) algorithm while preserving the same encoding quality as that of the EFS algorithm.

• The Korean Journal of Physiology
• /
• v.5 no.2
• /
• pp.15-27
• /
• 1971

Physiological analysis of the physical exercise was made on 9 subjects performing mountain climbing. The course between two points (256 and 516 meters altitude) was 1,300 meters in distance and difference of vertical height was 260 meters making the mean grade of 20%. In the field, the heart rates during uphill or downhill walk were recorded by EKG radio-telemetry. In the laboratory, oxygen consumption was obtained by the recorded heart rates, using individual heart rate vs oxygen consumption diagram obtained by treadmill test. the following results were obtained. 1. Uphill walk time was 36.5 minutes, and during this period the mean heart rate was 149.0 heats/min and peak heart rate was 169.2 beats/min. The total heart beats during the uphill walk was 5.433 beats. 2. The ratio of individual mean heart rate during the uphill walk to the maximal heart rate distributed between 66.6% and 98.3%, and the mean of the total group was 83.1%. The ratio of peak heart rate of uphill walk to the maximal heart rate was 94.5% in the group. Thus uphill walk of a 20% grade mountain course was an exhaustive exercise. 3. Oxygen consumption during uphill walk was 2.22 l/min (ranged between 1.79 and 2.70 l/min) and the ratio of this to the resting oxygen consumption was 8.31. The peak value of oxygen consumption during uphill walk was 2.73 l/min and the ratio of this to the resting oxygen consumption was 10.39. 4. Energy expenditure during uphill walk showed a mean of 11.1 kcal/min and the peak expenditure rate was 13.6 kcal/min. The total energy expenditure during 36.5 minutes of uphill walk was 396 kcal. 5. In downhill walk, the time was 31.7 minutes, mean heart rate was 118.4 (ranged between 100.1 and 142.7) beats/min, and the peak heart rate was only 129.4 beats/min. The ratio of mean heart rate to the maximal heart rate was 66.3%. Total heart beats during downhill walk was 3,710 beats. The ratio of downhill oxygen consumption to the resting consumption was 5.70. The rate of energy expenditure was 7.5 kcal/min, and the total onery expenditure during the 31.7 minutes of downhill walk was 228 kcal. 6. The effect of training was manifest in the uphill walk and not in the downhill walk. After training in mountain course walk, i) the uphill time was shortened, ii) mean heart rate increased, iii) time vs heart rate curve became smooth and showed less frequent zig-zag, i.e., the depth of trough on the curve decreased and the magnitude was less than 10 beats. In non-trained subject the depth of trough on the curve was greater than 50 beats and appeared more frequently. 7. Mountain climbing is a good health promotion exercise. For the promotion of health the reasonable amount of uphill mountain walk exercise in a 20% grade course is a walk for 40 or 50 minutes duration once a week.