• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.197-202
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• 2014

In order to operate multiple UAVs for multiple tasks efficiently, we need a task allocation algorithm with minimum cost, i.e.,total moving distance required to accomplish the whole mission. In this paper, we have proposed the MCBAA (Modified Consensus Based Auction Algorithm) which can be suitably applied to the operation of multiple UAVs. The key idea of proposed algorithm is to minimize sum of distance from current location of agents to location of tasks based on the conventional CBAA. Several simulation test performed on three UAV agents with multiple tasks demonstrates the overall efficiency both in time and total distance.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.502-504
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• 1995

In video image compression, it is important to extract the exact notion information from image sequence in order to perform the data compression, the field rate conversion, and the motion compensated interpolation effectively. It is well known that the location of the smallest sum of absolute difference(SAD) does not always give the true motion vector(MV) since the MV obtained via full block search is often corrupted by noise. In this paper, we first classifies the input blocks into 3 categories : the background, the shade-motion, and the edge-motion. According to the characteristics of the classified blocks, multiple locations of relatively small SAD are searched with an adaptive search window by using the proposed method. The proposed method picks MVs among those candidates by using temporal correlation. Since temporal correlation reveals the noise level in a particular region of the video image sequence, we are able to reduce the search are very effectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.100-106
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• 2009

A novel 8 V DC power source with an external series-parallel connection of 50 Dye-sensitized Solar Cells (DSCs) has been proposed. One DSC has the optimized length to width ratio of $5.2{\times}2.6\;cm$ and an active area $8\;cm^2$ ($4.62{\times}1.73\;cm$) which attained a conversion efficiency of 4.02%. From the electrochemical impedance spectroscopic analysis, it was found that the resistance elements related to the Pt electrode and electrolyte interface behave like that of diode and the series resistance corresponds to the sum of the other resistance elements. Surface morphology and sheet resistance of Pt counter electrode did not degrade the performance of the cell. This novel 8V-0.33A DC power source shows stable performance with an energy conversion efficiency of 4.24% under 1 sun illumination (AM 1.5, Pin of $100\;mW/cm^2$).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.761-766
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• 2008

This paper describes a compensation algorithm for a measurement voltage transformer (VT) based on the hysteresis characteristics of the core. The error of the VT is caused by the voltages across the primary and secondary windings. The latter depends on the secondary current whilst the former depends on the primary current, i.e. the sum of the exciting current and the secondary current. The proposed algorithm calculates the voltages across the primary and secondary windings and add them to the measured secondary voltage for compensation. To do this, the primary and secondary currents should be estimated. The secondary current is obtained directly from the secondary voltage and used to calculate the voltage across the secondary winding. For the primary current, in this paper, the exciting current is decomposed into the two currents, i.e. the core-loss current and the magnetizing current. The core-loss current is obtained by dividing the primary induced voltage by the core-loss resistance. The magnetizing current is obtained by inserting the flux into the flux-magnetizing current curve. The calculated voltages across the primary and secondary windings are added to the measured secondary current for compensation. The proposed compensation algorithm improves the error of the VT significantly.

• IE interfaces
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• v.21 no.3
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• pp.274-282
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• 2008

This paper considers a transporter scheduling problem under dynamic block transportation environment in shipbuilding. In dynamic situations, there exist the addition or cancellation of block transportation requirements, sudden breakdowns and maintenance of transporters. The transportation of the blocks in the shipyard has some distinct characteristics. Some blocks are available to be picked up at a specific time during the planning horizon while some other blocks need to be delivered before a specific time. These requirements cause two penalty times : 1) delay times incurred when a block is picked up after a required start time, and 2) tardy times incurred when a block shipment is completed after the required delivery time. The blocks are located at different areas in the shipyard and transported by transporters. The objective of this paper is to propose heuristic algorithms which minimize the weighted sum of empty transporter travel times, delay times, and tardy times. Four heuristic algorithms for transporter scheduling are proposed and their performance is evaluated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.628-634
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• 2016

We investigated the characteristics and rate of development of allotriploid embryos derived from a cross between female olive flounder Paralichthys olivaceus and male starry flounder Platichthys stellatus. The allotriploidy was induced by cold shocking fertilized eggs three minutes post-fertilization at 3°C for 45 minutes. The average cellular DNA content of the allotriploid embryos was 2.06±0.03 pg/cell, which is equal to the sum of the cellular DNA content of a diploid olive flounder (1.42 pg/cell) and a haploid starry flounder (0.66 pg/haploid cell). The first cleavage, midblastula, gastrula and Kupffer's vesicle appearance stages of the allotriploid eggs began at 1.5, 8, 13 and 26 hours after cold shocking at 18°C, respectively. The developmental rate of allotriploid eggs was equivalent to that of diploid and triploid olive flounder eggs at 10, 14 and 18°C. However, the hatching times of allotriploid eggs, 7 h at 10°C, 5 h at 14°C and 4 h at 18°C, were earlier than those of diploid and triploid olive flounder.

• Journal of The Korean Association of Information Education
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• v.7 no.2
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• pp.219-226
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• 2003

It takes a lot of time to classify official documents in schools and educational institutions. In order to reduce the overhead, we propose an automatic document classification method using word information of the titles of documents in this paper. At first, meaningful words are extracted from titles of existing documents and Inverse Document Frequency(IDF) weights of words are calculated against each category. Then we build a word weight dictionary. Documents are automatically classified into the appropriate category of which the sum of weights of words of the title is the highest by using the word weight dictionary. We also evaluate the performance of the proposed method using a real dataset of a middle school.

• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.686-694
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• 2010

Purpose: This study was done to examine the effects of moxibustion on physiological indices, such as 24-hr blood pressure, pulse pressure, and pulse rate, and autonomic nervous symptoms among adults with prehypertension. Methods: Participants were adults whose systolic and diastolic blood pressures were in the prehypertension stage and were not under treatment for the condition. Both experimental and control group consisted of 13 participants who were taking classes on acupuncture and moxibustion at a private institute. The experimental group received moxibustion once a day for 15 min, at least 5 days a week for 8 weeks. The results were analyzed using $x^2$-test, t-test, Fisher's exact test, Wilcoxon rank sum test and repeated measures ANOVA with the SAS program. Bonferroni correction method was adopted for multiple comparisons. Results: No significant change was observed in the 24-hr systolic and diastolic blood pressure between the two groups. Differences in the 24-hr pulse pressure and pulse rate were also not significant. However, significant decreases in headache, symptoms of flushing and fatigue were observed in the experimental group. Conclusion: The results suggest that moxibustion contributes to alleviating symptoms such as headache, flushing and fatigue associated with the autonomic nervous system among adults with prehypertension.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.316-321
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• 2000

In this study, heat collecting performance was study of flat plate solar collector by the angle. A method of study on were made turn out artificial sun by the angle of 0, 15, 30 degrees. The heat performances were measured the tube array surface temperature by thermo-couple. The winter season natural condition for 4 times on the angles of various general and emboss glass at optimum distance(0.68m) calculated of between sun and solar collector. To sum up temperature rise is appear more or less that emboss glass is all the better for general glass. The temperature variable at below of 30 degree was appear very less. The maximum performance of this system at that it is tilt angle of 30 with general glass is appear Q:11.54(kcal/min) and ${\Delta}T=18.9^{\circ}C$.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.3
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• pp.59-66
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• 2008

This study was performed to ascertain how HyangGyos based on national ideology were built in Jeju Island and what their detailed styles are. In Jeju-HyangGyo, unique architectural characteristics are shown as they have been built in an island independent from the mainland. Also up-down system was well reflected in detailed architectural styles. The main temple of Jeju-HyangGyo was built in the type of one-Chulmok(a subsidiary material of Gongpo and a piece of wood to support the eaves) of which ancon supports a purline from the center of a pillar and two-Ikgong(a piece of wood engraved to put on an ancon), but in the case of the lecture hall, its Gongpo(a piece of wood to support the eaves) was inferior in quality. In the case of Jeju abutments were used in main temples and fire walls were mostly used. In particular, their abutments are difficult to be observed in HyangGyo in the mainland. It is presumed that the abutment and the fire wall used in Jeju Island might be the best solution to protect structures from rain and moisture. To sum up, local characteristics and traditional rules were thoroughly reflected in Jeju-HyangGyos built in Jeju Island from the aspect of arrangement and detailed style. In conclusion, it is significant that architectural styles, not to mention the other aspects of Jeju culture, were suitably adapted to Jeju Island.