• Journal of Navigation and Port Research
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• v.30 no.4
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• pp.291-294
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• 2006

Corrosion is never avoided in the use rf materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP(Impressed Current Cathodic Protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. This thesis is about the ICCP control and monitoring system, which brings protection against the corrosion of the ship's hull in the sea environments. The test system for ICCP is composed of a power supply, anode, reference electrode and controller. The test system is composed power supply, anode, ref electrode, shunt and etc. The protection current is sent to the protection area though anode. Reference electrode senses whether or not the detected potential is within a range of protection of test equipment and then it is automatically controlled to increase or decrease the amount of protective current to be sent to the anode by controller. The monitoring system with LabView is also detected in order to check the normal state of the system at operation period, because an operator does not always watch over this system and thus the system cannot operate well because rf his or her negligent management. This paper was studied the variation of potential and current density with environment factors, velocity and time, and the experimental results will be explained Also, It is suggested that this system can accommodate a ship's automation for SCMS(Ship Control and Management System) and will be very useful.

• The Journal of Natural Sciences
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• v.7
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• pp.165-167
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• 1995

3'-Methylamino pyrimidine 3 was prepared from deoxy pyrimidine via the following 8 step reaction sequences; silyl protection, mesylation, cyclization, azide substitution, hydrogenation, t-Boc protection, methylation, and deprotection in 23% overall yield as a potential anti-AIDS agents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.100-105
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• 2007

Signalling equipments at railroad sites are widely exposed to high voltage lightning surges. This paper presents a lightning protection system for the signalling equipments at subway car depots. The main features of the system are as follows : (1)the common grounding system between power system grounds and the signaling system grounds, (2)physical and chemical methods to reduce grounding resistivity, (3)rearrangement of lightning rods based on the rolling bal1 theory, (4)equi-potential bonding networks to minimize the potential differences between the equipments grounds. The system has been constructed at six subway car depots in Seoul metropolitan area and it is measured that the grounding resistivity are reduced to 0.266 ohms and the potential differences between devices are reduced to a negligible quantity. After the construction of the systems, it has not been reported the break-down of the signalling equipments caused by lighting surges.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.717-721
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• 2013

In order to analyze the effect of environmental protection on wind energy dissemination quantitatively, the onshore wind resource potential is estimated using Environmental Conservation Value Assessment Map and Korea Wind Resource Map. The onshore wind resource potential of 11 GW is calculated if wind farm development is prohibited within Class 1 area of Environmental Conservation Value Assessment plus 500 m buffer area. Therefore it is worried that environmental protection would be a practical barrier of accomplishing 4,155 thousand TOE target of wind energy dissemination until 2030.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.228-235
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• 2021

Backgroud: Ginsenoside compound K (GK) is a major metabolite of protopanaxadiol-type ginsenosides and has remarkable anticancer activities in vitro and in vivo. This work used an ionic cross-linking method to entrap GK within O-carboxymethyl chitosan (OCMC) nanoparticles (Nps) to form GK-loaded OCMC Nps (GK-OCMC Nps), which enhance the aqueous solubility and stability of GK. Methods: The GK-OCMC Nps were characterized using several physicochemical techniques, including x-ray diffraction, transmission electron microscopy, zeta potential analysis, and particle size analysis via dynamic light scattering. GK was released from GK-OCMC Nps and was conducted using the dialysis bag diffusion method. The effects of GK and GK-OCMC Nps on PC3 cell viability were measured by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Fluorescent technology based on Cy5.5-labeled probes was used to explore the cellular uptake of GK-OCMC Nps. Results: The GK-OCMC NPs had a suitable particle size and zeta potential; they were spherical with good dispersion. In vitro drug release from GK-OCMC NPs was pH dependent. Moreover, the in vitro cytotoxicity study and cellular uptake assays indicated that the GK-OCMC Nps significantly enhanced the cytotoxicity and cellular uptake of GK toward the PC3 cells. GK-OCMC Nps also significantly promoted the activities of both caspase-3 and caspase-9. Conclusion: GK-OCMC Nps are potential nanocarriers for delivering hydrophobic drugs, thereby enhancing water solubility and permeability and improving the antiproliferative effects of GK.

• Imaging Science in Dentistry
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• v.37 no.3
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• pp.117-126
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• 2007

Although the diagnostic information provided by radiographs may be of definite benefit to the patients, the radiographic examination does carry the potential for harm from exposure to ionizing radiation. Therefore we should try to expose radiation as low as reasonably achievable and to give diagnostic information to patients as much as possible. All of dentists should have competence in radiation protection. I wish to deal with what we should do for the optimization of radiation protection in dental clinic.

• The Korean Society of Law and Medicine
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• v.10 no.1
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• pp.39-75
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• 2009

The development of the biomedical science and technology has extended an argument about a status in constitutional law of unborn human life and a protection of the potential human life to that of an embryo and a gamete beyond a fetus. This argument has been focused on whether we should provide unborn or potential human life with human dignity and the right to life that are guaranteed by the constitutional law altogether or separately. If the right to life is given to unborn or potential human life, on what grounds can we restrict this right. Those who argue for the unity of the right to life with human dignity and the inseparability of those two claims that the right to life in itself should be guaranteed absolutely. According to the constitutional law, however, any constitutional right of the human person within the protection of essential part of the right can be compared with each other and restricted with some valid reasons from the legal perspective. This measure is unavoidable in reality because one right can come into conflict with another right frequently. Since fetus and embryo are in a process of developing into the human person, it is difficult to think that they are the same with the human person. For that reason, it is hard to consider that the right to life of fetus or embryo is the same with that of the human person. However, since a fetus has a special status as a potential human person, and an embryo also has a special value as a potential fetus upon an implantation, the right to life of fetus or embryo should be judged differently according to the stage of their development. A study on a constitutional status and protection of a fetus and an embryo is essential because unborn or potential human life is the origin of human person. Therefore, we have to make much account of their right to life and seek the legal respect for their inherent value.

• 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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.8-14
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• 2002

A modern lightning protection system is required to eliminate the risks such as electrical shocks and damages of structures, electrical and electronic equipments due to lightning. However, the conventional lightning protection systems play and important role in protecting persons and structures only. Thus an effective lightning protection system is indispensable today in computer, information and communication facilities and etc. The mafor objective of this paper is to develop the technology to protect electronics and computerized facilities against lightning-caused overvoltages. The study is oriented on the control of the potential rise of down conductors with the type and installation method of down conductors. As a result, to reduce side flashes and hazards caused by the potential rise of down conductor due to lightning current, the coaxial cable with a low characteristic impedance and high insulation level is suitable for a down conductor. In particular it is extremely effective to bond down conductors to the steel supporter, metal raceways and steel frame of structures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1441-1451
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• 2000

There are two types of protection switching : a) automatic switching and b) forced switching. The switching mechanism is generally realised by OAM functions, therefore, the required OAM information field should be reserved in the PLOAM cells. This paper proposes an unidirectional and a bidirectional protection switching method and potential advantages. The unidirectional protection switching method can be faster than the bidirectional method because the unidirectional method does not require an APS protocol for protection switching. The bidirectional protection switching method uses APS K1 byte and K2 byte, which is included in octets of a PST message through downstream or upstream PLOAM cells, for protection switching. As making comparisons between the unidirectional and the bidirectional protection. switching method, this paper proposes an effective constructing method for ATM-PON network.