• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4773-4779
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• 2012

In this paper we propose two types of reconfigurable 3-D beam steering antenna for intelligent or smart antenna system. Proposed antennas are composed of triangular(structure1.) or circuler(structure2.) loop structure and bended dipole antenna structure. This antenna can steer beam pattern of 6 direction at xy-plane state (0, 1, 2) and xz-plane state (3, 4, 5) by 4 switch motion with one antenna element. Antenna structure1. is symmetric equilibrium structures based on feeding point. There is no grounding point. As a result, designed antenna's gain is similar to dipole antenna. Also, As unbalanced structure by using CPWG in the form of a semicircular, structure2. is enhanced directivity. The operation frequency of antenna are 2.5 GHz(Structure1.) and 2.55 GHz(Structure2.), maximum gain is 1.04 ~ 2.06 dBi(Structure1. : Omni-directional beam), 1.6 ~ 4 dBi(structure2. : Directional beam). The overall HPBW is about over $160^{\circ}$ in the both of the xy-plane and xz-plane at structure1. and over $125^{\circ}$ at structure2.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.197-206
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• 2014

This research intends to explore services, programs or policies for supporting married immigrant women to qualify themselves for being employed from the professional point of view on the assumption that their desire to get a job is high. To achieve this purpose, a delphi survey was conducted with a panel of 13 experts related to multi cultural family support in three sessions from December 20, 2013 to June 5, 2014. To analyze the collected data, descriptive statistics, including frequency, percentage, the mean, and standard deviation, were implemented, and Kendall's W for the internal reliability test on the survey instrument was carried out for statistical processing. The results are as follows : from the first session, services, programs, and policies in the level of married immigrant women themselves, children, parents in law and/or husband, organizations, and government were suggested. The highest item in average is systematization of levelwise Korean teaching program. The next higher items in average are daycare service during job training, parents in law and/or husband's consideration, parenting support services, program development of the organizations, linkage and integration system among the government ministries. As a result of the Kendall's W performed for the internal reliability test of the Delphi research, it has been concluded that the professionals' view on the supportive measures' important contents was statistically identical. According to the results of the Delphi research, systematization of levelwise Korean teaching program most required for the furtherance of the married immigrant women's entering the workforce, followed by provision of the services to draw family support, a grounding teaching of Korean corporate culture, and reconsideration of the policies.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.137-142
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• 1994

Myrosinase in leaf mustard was purified and characterized to furnish a grounding information for utilizing the pungent taste and the potential antimicrobial capability of Dolsan leaf mustard to enhance the taste and storage life of kimchi. When myrosinase was purified from leaf mustard through a series of DEAE Sephadex, chromatofocusing and Con A Sepharose column chromatography, specific activity of the enzyme increased 7107-fold compared with that of crude enzyme preparation, and 18.8% yield was obtained. The purified myrosinase showed the optimum pH of 5.9, isoelectric point of 4.6, molecular weight of 129 kD, Km of 0.206 mM, and Vmax of $2.039\;{\mu}M{\cdot}min^{-1}{\cdot}mg\;protein^{-1}$, respectively. The optimum concentration of L-ascorbic for the maximum activity of the enzyme was 0.6 mM, and the enzyme activity decreased at a higher concentration of L-ascorbic acid than 0.6 mM, showing almost no enzyme activity at a L-ascorbic acid concentration of higher than 2.0 mM. Myrosinase activity in leaf mustard kimchi immediately after the kimchi was formulated was shown to be about 70 nmol/min/mg protein which decreased rapidly after 3 days of storage at $20^{\circ}C$, showing that less than half and almost none of the enzyme activity was retained in 4 and 10 days of storage, respectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.201-207
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• 2010

Recently, about 600 cases of marine accidents occur annually in Korea. According to many studies and analyses on occurrence of marine accidents, 70~80% of marine accidents were caused by human factors. Among the human factors, navigation officers' fatigue is very important factor. Although navigation officers' fatigue serves as an important role in marine accidents, there is no method to exactly examine the degree of officers' fatigue. Accordingly, this study analyzed human factors according to types of marine accidents and extracted important five factors affecting navigation officers' fatigue through the questionnaire survey by means of literatures and 5-point scale. In addition, evaluation factors of marine accident risks caused by fatigue factors were divided and structured by using ISM. Lastly, it found out the importance of each fatigue factor drawn by AHP and decided marine accidents that were most highly caused by navigation officers' fatigue in order. At the result, weights were high as sleep time 0.385, stress 0.302, health condition 0.139, rest time 0.099, alcohol and drug 0.074 in fatigue factors, and death and injury 0.328, collision 0.308, grounding 0.195, sinking 0.094, fire accident 0.075 in evaluation factors of marine accident risks. Therefore, the control plan to lower marine accident risks should be prepared on the basis of high weight factors.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.259-262
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• 2005

Ground resistance measurement is an elementary technique for the evaluation of grounding system. There are main environmental factors to consider for correct measurement but the problem is that it is practically most cases to measure ground resistance unable to know the factors. This paper presents a methodology toward true value of resistance in the unknown circumstances, utilizing the defined term 'variation rate' of potential difference curve appearing in the distance to a current probe as in the three point fall-of-potential method which comprises the characteristics of environmental factors. This methodology is a induced result from the previous demostrated studies.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.37-45
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• 2019

The characteristic of fire and explosion related to electrostatic discharge is that it is difficult to reproduce the electrostatic charge and discharge phenomenon in addition to the large human and material damage. Therefore, in order to prevent accidents and disasters related to electrostatic in fire and explosion hazard areas, it is important to manage the level of electrostatic in a safe manner from the perspective of system between industrial facilities and human bodies. Rule 325 of the Occupational Safety and Health Regulations, "Prevention of Fire / Explosion due to Electrostatic", requires the use of grounding, conductive materials, humidification and electrification in order to prevent the risk of disaster caused by static explosion and electrostatic in the production process. In order to comply with these measures, related technologies, standards and systems are needed from the viewpoint of preventive measures related to electrostatic in fire and explosion hazard areas, but in Korea, it is still insufficient. Therefore, technical, institutional and managerial measures are needed as a precautionary measure to improve the level of ESD safety in fire and explosion hazard areas and prevent electrostatic related injury. In Korea, we analyzed the current status and characteristics of electrostatic related disaster by using the statistics of industrial accident and fire statistics of the Ministry of Employment and Labor. We also analyzed the current status and characteristics of electrostatic related disasters in Japan using JNIOSH accidents and disasters investigation cases and JNIOSH fire accident data of Japan Fire Bureau. The purpose of this study is to compare and analyze the current status of electrostatic related accidents and disasters in Korea and Japan in order to improve the safety management of electrostatic in fire and explosion hazard areas. In order to prevent accidents and disasters in the industrial field, The technical, institutional, and managerial measures to manage the level of electrostatic in a safe state were derived from the system point of view.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.3
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• pp.1-7
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• 2021

In this paper, by embedding a bare-die chip-type drive amplifier into the PCB composed of ABF and FR-4, it implements an embedded active device that can be applied in 28 GHz band modules. The ABF has a dielectric constant of 3.2 and a dielectric loss of 0.016. The FR-4 where the drive amplifier is embedded has a dielectric constant of 3.5 and a dielectric loss of 0.02. The proposed embedded module is processed into two structures, and S-parameter properties are confirmed with measurements. The two process structures are an embedding structure of face-up and an embedding structure of face-down. The fabricated module is measured on a designed test board using Taconic's TLY-5A(dielectric constant : 2.17, dielectric loss : 0.0002). The PCB which embedded into the face-down expected better gain performance due to shorter interconnection-line from the RF pad of the Bear-die chip to the pattern of formed layer. But it is verified that the ground at the bottom of the bear-die chip is grounded Through via, resulting in an oscillation. On the other hand, the face-up structure has a stable gain characteristic of more than 10 dB from 25 GHz to 30 GHz, with a gain of 12.32 dB at the center frequency of 28 GHz. The output characteristics of module embedded into the face-up structure are measured using signal generator and spectrum analyzer. When the input power (P_in) of the signal generator was applied from -10 dBm to 20 dBm, the gain compression point (P_1dB) of the embedded module was 20.38 dB. Ultimately, the bare-die chip used in this paper was verified through measurement that the oscillation is improved according to the grounding methods when embedding in a PCB. Thus, the module embedded into the face-up structure will be able to be properly used for communication modules in millimeter wave bands.