• Aerospace Engineering and Technology
• /
• v.10 no.2
• /
• pp.56-64
• /
• 2011

In this paper, the characteristics of LCL set-up parameters for the satellite load distribution are analyzed under the electrical system environment, implemented the LCL circuits and evaluated the performance and its behaviour. Recently, it is implemented the load distribution circuit by latching current limiter(LCL) rather than conventional fuse and relay for the protection of the satellite power system from a fault load. The LCL circuit is composed of the electrical components, not mechanical parts with the fuse and relay. When detected the over current on a fault load, it is activated to maintain the trip-off level for set-up time and then cut-off the load power by the active control. It is more flexible and provided a chance to reuse of the load in case of temporarily event, but the fuse and relay can't be used again after activating due to the physical disconnection. However, for implementation of LCL circuit, it should be carefully considered the behavior of the LCL circuit under the worst electrical system environment and applied it to define the set-up parameters related with over-current inhibition.

• Journal of Magnetics
• /
• v.21 no.2
• /
• pp.266-272
• /
• 2016

Transcranial magnetic stimulation devices has been used mainly for diagnostic purposes by measuring the functions of the nervous system rather than for treatment purposes, and has a problem of considerable energy fluctuations per repeated pulse. The majority of strokes are caused by ischemia and result in brain tissue damage, leading to problems of the central nervous system including hemiparesis, dysfunction of language and consciousness, and dysfunction of perception. Control is difficult and the size is large due to the difficulty of digitalizing the energy stored in a capacitor, and there are many heavy devices. In addition, there are many constraints when it is used for a range of purposes such as head and neck diagnosis, treatment and rehabilitation of nerve palsy, muscle strengthening, treatment of urinary incontinence etc. Output stabilization and minimization of the energy variation rate are required as the level of the transcranial magnetic stimulation device is dramatically improved and the demand for therapeutic purposes increases. This study developed a compact, low cost transcranial magnetic stimulation device with minimal energy variation of a high repeated pulse and output stabilization using a real time capacitor charge discharge voltage. Ischemia was induced in male SD rats by closing off the common carotid artery for 5 minutes, after which the blood was re-perfused. In the cerebrum, the number of PARP reactive cells after 24 hours significantly decreased (p < 0.05) in the TMS group compared to the GI group. As a result, TMS showed the greatest effect on necrosis-related PARP immuno-reactive cells 24 hours after ischemia, indicating necrosis inhibition, blocking of neural cell death, and protection of neural cells.

• Archives of Pharmacal Research
• /
• v.19 no.6
• /
• pp.480-485
• /
• 1996

Brain GABA transaminase is inactivated by preincubation with antidepressant/antipanic drug pheneizine (${\beta}$ethylphenylhydrazine) (mixing molar ratio 10:1) at pH 7.4. The reaction of enzyme with phenelzine was monitored by absorption and fluorescence spectroscopic methods. The inactive enzyme was fully reconstituted by addition of cofactor pyridoxal-5-phosphate. This result implies that the blocking of 1 mol of pyridoxal-5-phosphate per enzyme dimer is needed for inactivation of the enzyme. The time course of the reaction is significantly affected by the substrate .alpha.-ketoglutarate, which afforded complete protection against the loss of catalytic activity. The kinetic studies shows that phenelzine reacts with the cofactor of enzyme with a second-order rate constant of $2.1{\times}10^3M^{-1}s^{-1}$. It is postulated that the antidepressant/antipanic drug phenelzine is able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on GABA degradative enzyme GABA transaminase.

• Fire Science and Engineering
• /
• v.34 no.3
• /
• pp.58-66
• /
• 2020

Households are categorized as exceptions in the Fire Services Act; oftentimes, the 'Golden Time' is missed at the early stages of a fire, resulting in loss of life. As such, due to the high number of deaths caused by household fires, the Korean government amended the Fire Services Act to make it mandatory for all detached houses to be equipped with a fire extinguisher from 2017 onwards. Only 34.8% of households were properly equipped with a fire extinguisher, according to the 2018 factual survey on fire extinguishing facilities in households conducted by the Fire Department. Fire extinguishers are crucial in case of fire but many households avoid them because they are red and have a rough aesthetic, which does not suit the household environment. There is now a need for diverse simple fire extinguisher designs so that they can be used as interior décor in the household in the day-to-day while being available for putting out a fire when necessary. If fire extinguishers have designs that go well with any household space like other decorative ornaments, this will greatly increase consumers' motivation to purchase them. It is greatly anticipated that various companies will work on developing designs for fire extinguishers to commercialize them for households in the future.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.1
• /
• pp.59-65
• /
• 2018

Radon gas is a colorless, odorless, tasteless gas that occurs when uranium, a natural radioactive material in rocks and soils, collapses. 85% of the annual radiation exposure of the human body is due to natural radiation, of which 50% is radon. According to the US Environmental Protection Agency (EPA) survey, 62 out of 1,000 smokers and 7 out of 1,000 nonsmokers are exposed to lung cancer when exposed to radon gas for a long time. In order to reduce the risk of radon gas, activate carbon was used to fabricate matrix, and the pore properties and radon reduction properties were investigated. When the activate carbon was used, the radon gas concentration was drastically reduced and the graph was changed as the measurement period became longer. The pore distribution and microporous properties, which are one of the material properties of activate carbon, can be grasped.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.3
• /
• pp.359-368
• /
• 1998

One of the topics concerning the electromagnetic compatibility of modern electronic circuits is to take protection from transient overvoltages caused by not only cloud-to-ground lightnings but also induced lightning discharges. In this paper, the vertical electric and horizontal magnetic fields from cloud-to-ground lightnings were measured and analyzed. The electric and magnetic fields waveforms associated with cloud-to-ground lightnings have several subsidiary peaks which decrease with time. There were not much differences between the electric and magnetic field due to long distance cloud-to-ground discharges. Average values of 10~90% rise times of electric fields are $4.65mutextrm{s}$ for the positive cloud-to-ground lightning and $3.29mutextrm{s}$ for the negative cloud-to-ground lightning, respectively. Also, in the positive and negative cloud-to-ground lightning discharges, the zero-to-zero crossing times in the wave tail of magnetic fields are significantly longer than those of the electric fields.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.4
• /
• pp.687-694
• /
• 2020

SDN and NFV are next-generation network technologies, and cloud, such as data centers, campuses, and large companies, has been established, or is actively applied by service-oriented communication companies. In particular, the Defense Integrated Data Center will be a prime example for military applications. In order for the Defense Integrated Data Center (DIDC) to become an intelligent center, it is accelerating the promotion of the "Smart Defense Integrated Data Center", which applied the latest information and communication technology (ICT). At the time of the establishment of DIDC, it plans to start building infrastructure such as cloud services at around 30% level, and expand D-Cloud to 75% through 'Cloud First'. In addition, the introduction of SDN/NFV will reduce the operation cost and manpower of DIDC, strengthen the ability to efficiently use information resources and cyber information protection systems, and increase flexibility and agility in using each system to improve efficiency in defense management in the future. Therefore, we will discuss the justification and expected effects of SDN/NFV introduction, focusing on DIDC.

• Journal of the Korean Home Economics Association
• /
• v.42 no.3
• /
• pp.105-118
• /
• 2004

Cable TV Home Shopping is one of the popular distribution channels in modem society because of purchasing convenience and saving in shopping time. However, in spite of these advantages, there are some problems because of marketing strategies of many Cable TV shopping companies which stimulate impulse purchases. This study is aimed to find the relationship between buying experience and reaction to impulsive buying stimulus. This study can give a valuable insight in consumer education regarding impulsive purchase behavior in Cable TV home shopping. Study results can also give useful information on the direction of consumer campaign and consumer protection policies. The data was collected by using a questionnaire and the final 496 cases were analyzed by SPSS Win 10.0 program. The major finding were that: 1. Younger, more educated and unmarried consumers tend to response more to impulsive purchasing stimulus. 2. consumers with higher response to impulsive purchasing stimulus had more buying experience, higher shopping frequencies and spent more money in Cable TV home shopping than consumers with lower response. These study results showed that there are some relationship between impulse purchasing stimulus and buying experience in Cable TV home shopping. Therefore, Cable TV Home Shopping companies should provide correct information to the consumers, so they can make resonable decisions. And the consumers should also try to restrain themselves from purchasing impulsively. A law that will regulate all false or exaggerated ads should be provided. To reach righteous and beneficial home shopping culture for both consumer and companies, all these means should be cooperated.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.2
• /
• pp.173-180
• /
• 2010

The research of the preserving privacy of sensitive information has been popular recently. Many researches about the techniques of generalizing records under k-anonymity rules have been done. Considering that data anonymity requires a lot of time and resources, it would be important to decide whether a table is vulnerable to privacy attacks before being opened in terms of the improvement of data utilization as well as the privacy protection. It is also important to check to which attack the table is vulnerable and which of anonymity methods should be applied in the table. This paper describe two possible privacy attacks based upon related references. Also, we suggest the technique to check whether data table is vulnerable to any attack of them and describe what kind of anonymity methods should be done in the table. The technique we suggest in this paper can also be applied for checking the safety of anonymity tables in which insert or delete operations occurred as well from privacy attacks.

• Journal of the Korean Institute of Gas
• /
• v.19 no.4
• /
• pp.15-21
• /
• 2015

Looking at the large and small fire, explosion, or release accidents that occurred recently, we can see that the accident of subcontractor workers has been increased in the contractor workplace while a harmful or dangerous maintenance works. In this study, the actual status of subcontractor's safety management was examined by using the questionnaire to the contractor who submitted the process safety report. In order to improve the safety management of subcontractors, the responsibility and rational role-sharing between the contractors and subcontractors were reviewed. Also, Providing safety and health information and worker protection measures during maintenance were investigated. The results of this study can be used to help strengthen and improvement safety management of the subcontractor at the time of a hazardous or dangerous works. In addition, it will be utilized to reduce industrial accidents and to build mutual cooperation relationship between contractor and subcontractor.