• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.361-368
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• 2016

A ship's rolling motion can make crew and passengers sick and/or apply forces to the structure that cause damage.. Therefore bilge keels are equipped in most ships for anti-rolling. In special cases, anti-rolling tanks (ARTs), fin stabilizers, or gyroscopes can be installed. However, ARTs require a large area to install, and fin stabilizers and gyroscopes are costly to install and expensive to operate. This paper suggests a Anti-rolling pendulum (ARP) to reduce roll motion. ARPs acts like ARTs. However, the ARP has a circular shaped guidance arc instead of the string or wire of a simple pendulum. The device suggested has about 1/ 8 the weight and 1/ 6 the volume of a ART and is more effective. This study derives the nonlinear and linear differential equations of system motion.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.39-44
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• 2016

Due to the dazzling development of IT in this IT-oriented era, information delivering technology among objects, between objects and humans, and among humans has been actively performed. As information delivery technology has been actively performed, IoT became closely related to our daily lives and ubiquitous at any time and place. Therefore, IoT has become a part of our daily lives. CoAp, a web-based protocol, is mostly used in IoT environment. CoAp protocol is mostly used in the network where transmission speed is low along with the huge loss. Therefore, it is mostly used in IoT environment. However, there is a weakness on IoT that it is weak in security. If security issue occurs in IoT environment, there is a possibility for secret information of individuals or companies to be disclosed. If attackers infect the targeted device, and infected device accesses to the wireless frequently used in public areas, the relevant device sends arp spoofing to other devices in the network. Afterward, infected devices receive the packet sent by other devices in the network after occupying the packet flow in the internal network and send them to the designated hacker's server. This study suggests counter-attacks on this issues and a method of coping with them.

• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.27-44
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• 2001

In this study, I investigate the drinking behavior and related factors among white collar workers in seoul. Examination was executed with questionnaire to 520 white collar workers. Drinking behavior involves frequency of drinking, amount of alcohol consumption in a drinking situation and alcohol-related problem. Related factors involves the general characteristics, the knowledge about alcohol, the allowable attitude about drinking, work stress and stress copying. This was analyzed with percentage, mean, standard deviation, t-test, ANOV A and pearson's correlation. The results are as follows: Data shows that about 96.3% of the respondents drink at least during the last year and 89.8% of the respondents drink at least during the last month. 59.4% male respondents drink 3-8 times a month, 44.8% female respondents drink 1-2 times a month. High prevalence rates were found in male, married person and those with low-religious spirit in a usual amount of drinking(p〈0.05), male in the latest amount of drinking(p〈0.05), male, forties, married person and those with the highest monthly family income and those with low-religious spirit in frequency of drinking during the latest month(p〈0.05). The score of alcohol-related problem(ARP) was as follows: male workers-2.61, female workers-1.61 out of 35. The score of ARP was statistically significantly different according to sex(p〈0.05). A positive correlation was observed between amount of drinking, frequency of drinking and ARP(p〈0.01). The score of knowledge about alcohol was 3.6 and any correlation and statistically significant difference were not observed between the knowledge about alcohol and drinking behavior. The score of allowable attitude about drinking was statistically significantly different according to sex(p〈0.05), age(p〈0.05). A positive correlation was observed between attitude about drinking and amount of drinking, frequency of drinking, ARP(p〈0.01). The work stress and stress copying had no significant relations with drinking behavior. Most respondents do not drink at stress situation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.1
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• pp.12-27
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• 2007

This fundamental studies on for the productivity improvement and laborsaving of purse seine fishery. Given the difficulty posed from the distortion of net shape caused by the external forces, such as tide, at the time of shooting and pursing, we set the 4 steps of 0, 2, 4 and 6cm/sec in flow velocity in the flume tank for the experiment in order to examine those characteristics. We used two model seines designed on the scale of 1 to 180 based on the power block seine, which is the mackerel purse seine generally used in the near sea of Jeju Island and triplex seine, which is the mackerel purse seine of one boat system fishing expected in the future, for the experiment, and interpreted the characteristics of several motion in water, such as the shape of seine, the change in tension and area during pursing and its the analysis results are as follows. Though the experiment could be conducted up to 6cm/sec of flow velocity that was defined, the experiment could not go on because of the severe distortion in the seine at the flow velocity in excess of 6cm/sec. As for the depth of leadline and reduction rate of side area of seine when the pursing is connected, P seine turned out to be slightly higher than T seine, and the hauling speed and reduction rate of upper area of seine were found similar to each other. The correlation between the hauling time (Ht) and depth of lead line (Dhp, Dht) of P seine and T seine can be expressed by the equation, that is, Dhp=(0.99Pt-7.63)Pt+69.01, Dht=(1.03Pt-7.73)Pt+66.74. The correlation between the hauling time and hauling velocity (Hpp, Hpt) can be expressed by the equation, that is, $Hpp=-0.06Ht^2+0.88Ht+0.78,\;Hpt=-0.05Ht^2+0.81Ht+0.98$ here, Pt is pursing time. And the correlation between the pursing time and the reduction rate of side area (sArp, sArt) can be expressed by the equation, that is, $sArp=-0.48Pt^2+14.79Pt-16.74,\;sArt=-0.45Pt^2+14.56Pt-16.48$. The reduction rate of upper area of seine (tArp, tArt) can be expressed by the equation, that is, $tArp=0.34Pt^2-0.66Pt-0.74,\;tArt=0.34Pt^2-0.27Pt-1.80$. In addition, the correlation between the pursing time and tension of purse line (Tep, Tet) can be expressed by the equation, that is, $Tep=2.79Pt^2+2.26Pt-0.60,\;Tet=2.14Pt^2+8.08Pt-27.50$.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1790-1792
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• 2004

This paper deals with the lightning test methods on aircraft. It shows lightning current and voltage test waveforms referred to SAE ARP 5412. According to this standard, to test lightning effects, mixes appropriately 5 waves for current and 4 waves for voltage depend on structure and comparison information.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.562-564
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• 2011

본 논문에서는 리눅스 운영체제를 기반으로 오픈 소스 침입탐지 시스템인 Snort 등울 LSM(Linux Security Module) 구조의 hooking 부분에 구현시켜 보안 관리자가 의도하는 포트 스캔, DDOS 공격, ARP/IP 위장, 서명 탐지 등이 가능하도록 시스템을 구현하는 방법을 제시하고자 한다.

• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.182-183
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• 2011

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.238-238
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• 2005

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.587-588
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• 2013

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.301-302
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• 2005