• East Asian mathematical journal
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• v.28 no.2
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• pp.159-172
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• 2012

In all Mathematics I Textbooks(Kim, S. H., 2010; Kim, H. K., 2010; Yang, S. K., 2010; Woo, M. H., 2010; Woo, J. H., 2010; You, H. C., 2010; Youn, J. H., 2010; Lee, K. S., 2010; Lee, D. W., 2010; Lee, M. K., 2010; Lee, J. Y., 2010; Jung, S. K., 2010; Choi, Y. J., 2010; Huang, S. K., 2010; Huang, S. W., 2010) in high schools in Korea these days, it is written and taught that for a positive real number $a$, $a^{\frac{m}{n}}$ is defined as $a^{\frac{m}{n}}={^n}\sqrt{a^m}$, where $m{\in}\mathbb{Z}$ and $n{\in}\mathbb{N}$ have common prime factors. For that situation, the author shows his opinion that the definition is not well-defined and $a^{\frac{m}{n}}$ must be defined as $a^{\frac{m}{n}}=({^n}\sqrt{a})^m$, whenever $^n\sqrt{a}$ is defined, based on the field axiom of the real number system including rational number system and natural number system. And he shows that the following laws of exponents for reals: $$\{a^{r+s}=a^r{\cdot}a^s\\(a^r)^s=a^{rs}\\(ab)^r=a^rb^r$$ for $a$, $b$>0 and $s{\in}\mathbb{R}$ hold by the completeness axiom of the real number system and the laws of exponents for natural numbers, integers, rational numbers and real numbers are logically equivalent.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.667-674
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• 2004

This thesis is about the Impressed Current Cathodic Protection (ICCP) control and monitoring system. which brings protection against the corrosion of the ship's hull in the sea environments. The ICCP system is composed of a power supply. anode. reference electrode and controller. AC sources from the ship's generator are converted to DC sources in terms of power supply, and a protection current is sent to ship's hull though anode. The controller fully senses whether or not the detected potential is within a range of protection of ship's hull and then it is automatically controlled to increase or decrease the amount of protective current to be sent to the anode. The monitoring system with RS 232/485 communication is also studied in order to check the normal state of the system at a long period. because an operator does not always watch over this system and thus the system cannot operate well because of his or her negligent management. Since the vessel always navigates in the sea. an characteristics experiment of the ICCP system is conducted by introducing various corrosive environmental factors such as velocity, resistivity, dissolved oxygen, PH, temperature and contamination degree. These results must be referred to when the ICCP system is set up. In short. the ICCP is a multi-system for use on ships and on land structures because it includes a safety device. It is suggested that this system can accomodate a ship's automation and will be very useful.

• International Journal of Computer Science & Network Security
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• v.23 no.8
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• pp.1-8
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• 2023

The artificial intelligence of robot is the weakness of digital intelligence of a person who able to train, self-realize and to develop competences, creative, professional and behavioral skills. A new methodology proposed for managing robots inside the mines using an electronic system designed for driving robots to injured people in seas, mines or wells who can not be reached by human force. This paper also explains the concept of managing and remote-controlling the process of searching and helping the injured. The user controls the robot through an application that receives all the reports that the robot sends from the injured person. The robot's tasks are to take a sample of the blood of the injured person, examine it, and measure the percentage of oxygen underground and send it to the user who directs the robot to pump a specific percentage of oxygen to the injured person. The user can also communicate with the person The patient and determine his condition through the camera connected to the robot equipped with headphones to communicate with the injured and the user can direct the camera of the robot and take x-rays from the injured.

• Korean journal of applied entomology
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• v.7
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• pp.39-51
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• 1969

The study involved determination of resistance levels of spider mites ta argano-phosphates using topical application and slide dip techniques; laboratory serening tests of alternative acaricides using an O/P resistant strain and a field trial of the screened materials. 1. Strains of Tetranychus were from Timaru(TR), Havelock Narth (HNR), Lincaln (LN). Germany (GR, GN). Comparisons of the resistant strains and normal strains at the LD50 and LC50 levels were as follows : (a) Using the topical application tochnique; with Parathian. resistant levels of the GR. TR and HNR strains of T. urticae were respeativuly, 1035. 484 and 452 times as resistant' as the LN strain. (b) Using the slide dip technique; with Phosdrin, resistant of GR, TR and HNR strains of T. urticae were 635, 274 and 266 times greater respeativuly, than the GN strain. 2. The laboratory sereaning tests were carried out far their contact plus stomach and residual effect to assess the toxicities of eleven alternative materials which would be used far control of O/P resistant strain of T. urticae. The acaricide groups represented were 3 organo-chlorines (Spidex, Kelthane and C 8514), 2 nitrophenyls (UC 19786 and Morocide), 2 cyclic carbonates(Eradex and Morestan). I carbamate (UC2004 7A), 1 mixture of carbamate and orano-chlorine and 2 other chemicals (C 8677 and M2527). From all acaricide tested. Kelthane and Morocide were the most effective, folowed by Spidex and M2527. Morestan, C8514. C8677 and RS 143 were intermediate, but Eradex, UC 19786 and UC 20046A were poor. 3, The number of sapmles required for estimation of the population in the field evaluation of acaricidal effects was one giving the highest practical precision. It was decided, after preliminary sampling trials. to use samples of 30 leaves per replicate which gave a $5.7\%$ standard error. 4. In the field trials, Morocide applied at the $0.05\%\;and\; 0.04\%$ a. i. conc. to black currant trees gave excellent control of O/P resistant population of T. urticae for about 12 days, but Morocide 0.025 and Kel thane $0.02\%$ a. i. cone. gave efficient control for about 6 days. In other words. first applications of Kel thane ane Moroeide gave very high degrees of control of O/P resistant population of the two-spotted spider mite. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage of black Currants and strawberries by either acaricides at the concentrations used. Acknowledgment ... The authors are grateful to: Dr. R. P. pottinger, Senior Lecturer in Agricultural Zoology. Lincoln college. New Zealand. for his helpful assistance in aiding with the organization of thd field work. Department of agriculture officers for mite colonies. Mr. D. A. Slade, Technical Advisor. Fruitgrowers' Federation (now at Massey University) for his assistance and provision of mites for testing. Mr T. McRae of Timaru for permission to use his crops for field tests. The following chemical companies and I or their New Zealand agents for so readily supplying samples of acarides; Ivan Watkins-Dow Limited. Fruitgrowers Chemical Company Limited. Henry H. York & company (New Zealand). Shell Oil (New Zealand) Limited.

• Korean Journal of Remote Sensing
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• v.30 no.1
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• pp.61-73
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• 2014

This study reviewed an application of water quality estimation using an Airborne Hyperspectral Imagery (A-HSI) and tested a part of Han River water quality (especially suspended solid) estimation with available in-situ data. The estimation of water quality was processed two methods. One is using observation data as downwelling radiance to water surface and as scattering and reflectance into water body. Other is linear regression analysis with water quality in-situ measurement and upwelling data as at-sensor radiance (or reflectance). Both methods drive meaningful results of RS estimation. However it has more effects on the auxiliary dataset as water quality in-situ measurement and water body scattering measurement. The test processed a part of Han River located Paldang-dam downstream. We applied linear regression analysis with AISA eagle hyperspectral sensor data and water quality measurement in-situ data. The result of linear regression for a meaningful band combination shows $-24.847+0.013L_{560}$ as 560 nm in radiance (L) with 0.985 R-square. To comparison with Multispectral Imagery (MSI) case, we make simulated Landsat TM by spectral resampling. The regression using MSI shows -55.932 + 33.881 (TM1/TM3) as radiance with 0.968 R-square. Suspended Solid (SS) concentration was about 3.75 mg/l at in-situ data and estimated SS concentration by A-HIS was about 3.65 mg/l, and about 5.85mg/l with MSI with same location. It shows overestimation trends case of estimating using MSI. In order to upgrade value for practical use and to estimate more precisely, it needs that minimizing sun glint effect into whole image, constructing elaborate flight plan considering solar altitude angle, and making good pre-processing and calibration system. We found some limitations and restrictions such as precise atmospheric correction, sample count of water quality measurement, retrieve spectral bands into A-HSI, adequate linear regression model selection, and quantitative calibration/validation method through the literature review and test adopted general methods.