• Women's Health Nursing
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• v.1 no.1
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• pp.28-43
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• 1995

The relationship between perceived social support and adaptation to maternal role for first-time mothers was investigated in this descriptive correlational study. A nonprobable sample of 90 first-time mothers were selected, who had uncomplicated perinatal experiences and delivered healthy and term newborns as well. The data was collected during a home interview at 4-6weeks postpartum. The outcome of adaptations was defined as the level of sensitivity in parent-infant interactions and of the self confidence in infant care. The perception of social support in the primiparous was assessed by the NSSQ during the postpartum. The results obtained from this study are summarized as follows : 1. The mean score of the perceived total functional support was $116.6{\pm}37.5$ points (affective : 38.1 affirmative : 39.3, aid : 39.3), and the score of the total network support was $45.2{\pm}13.9$ points (size : 4.9, duration :19.8 frequency : 20.4). These scores tended to be slightly low. 2. The mean score of the self confidence on the infant care activity as the subjective aspect of the maternal role adaptation (MRA) was 56.5 points (86.9%), whereas that of the sensitivity of the mother-infant interaction of the MRA was 78.9 points (63.2%). 3. The subjective aspect of the MRA has showed a positive relation ship with the aid dimension of the functional support. And the objective aspect of the MRA also showed a positive relationship with the total functional support and the total network support. However the correlating degrees were slightly low. In conclusion, the primiparous mothers perceived that they had received a small amount of social support during the postpartum period, suggesting the need of various kinds of social support to promote the MRA for the primiparous.

• Journal of the Korean Institute of Navigation
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• v.13 no.2
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• pp.23-36
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• 1989

Marine casualities in the high sea are mainly classified into the breakage of hull and capsize , of which the latter occurs frequently to a small craft and container vessels by extreme rolling. The aim of this study is to develop shiphandling techniques for the prevention of ship's large rolling by way of evaluating dangerous degree of rolling in heavy weather. In this study, rolling motion is analized by using statistical method as follow : (1) 8 sample ships is presented for calculation. (2) Analized sea state are Beaufort scale 7 and 10 (wind velocity 30kts and 50kts respectively) and significant wave height is put as 5.2m and 11.2m. (3) The formula recommended by International Towing Tank Conference (ITTC) is used to calculated the wave spectrum. The results of this study are as follow : The results of this study are as follow : (1) Most of the vessels with beam of 20 meters or less was found to be capized in the waves abeam under the sea condition of Bearfort scale7(30kts). (2) For the vessels range 20m to 30m was found safe under the sea conditions of Bearfort scale 7(30kts) and imminent danger under the sea condition of Beaufort scale 11(50kts). (3) It is proved that any vessel could be capsized by heavy rolling regardless of vessel's size whenever the motion is synchronized with waves abeam. This study concludes that the navigator, especially at night , must anticipate the exact wave direction, referring to the wether report and coastaline, not to lay the vessel in the serial wave abeam.

• Ocean and Polar Research
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• v.28 no.3
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• pp.225-236
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• 2006

Seagrass meadows are considered as critical habitats for a wide variety of marine organisms in coastal and estuarine ecosystems. In many cases, studies on the spatial/temporal distribution of seagrass have depended on direct observations using SCUBA diving. As an alternative method fur studying seagrass distribution, an application of hydroacoustic technique has been assessed for mapping seagrass distribution in Dongdae Bay, on the south coast of Korea, in September 2005. Data were collected using high frequency transducer (420 kHz split-beam), which was installed with towed body system. The system was linked to DGPS to make goo-referenced data. Additionally, in situ seagrass distribution has been observed using underwater cameras and SCUBA diving at four stations in order to compare with acoustic data. Acoustic survey was conducted along 23 transects with 3-4 blot ship speed. Seagrass beds were vertically limited to depths less than 3.5m and seagrass height ranged between 55 and 90cm at the study sites. Dense seagmss beds were mainly found at the entrance of the bay and at a flat area around the center of the bay. Although the study area was a relatively small, the vertical and spatial distributions of the seagrass were highly variable with bathymetry and region. Considering dominant species, Zostera marina L., preliminary estimation of seagrass biomass with acoustic and direct sampling data was approximately $56.55g/m^2$, and total biomass of 104 tones (coefficient variation: 25.77%) was estimated at the study area. Hydroacoustic method provided valuable information to understand distribution pattern and to estimate seagrass biomass.

• Journal of Welding and Joining
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• v.28 no.1
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• pp.34-40
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• 2010

In Friction Stir Lap Welding(FSLW), the movement of material within the weld was more important than the microstructure, due to the interface present between the sheets. Thus, The soundness of free defect, Effective Sheet Thickness(EST) and width of joint were most important factor of mechanical properties. Specimens by lap joint types that were 'A-type' and 'R-type' were made in this study. A-type tensile specimen was loaded at advancing side and R-type tensile specimen was loaded at retreating side. Macro-, micro-structural observation and mechanical properties of FSLW A5052-H112 alloy ware investigated under varying rotating and welding speed. The results were as follows: Material hook formed decreasing after sharply increasing was appeared at the end interface of joint area in advanced side, and material hook formed decreasing after smoothly increasing was observed at that in retreated side. Tensile load had no relation with defects. As rotating speed was higher, tensile strength was increasing and EST was decreasing regardless of joint types. joint efficiency was over 70%. In a result of fractography, fracture in A-type was partially occurred by dimple in SZ, and fracture in R-type was generally occurred by dimple in HAZ.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.159.2-159.2
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• 2011

Hyundai Heavy Industries has developed a tidal current energy converter utilizing the accumulated technology as the world largest constructor for ship and offshore structures. The model has two sets of turbines in both ends in order to utilize the bi-directional current flows in flood and ebb tide. The torque produced by turbine in tidal current is directly delivered to generator along the horizontal axis, in which the turbine, gear, generator, gear and turbine are connected successively. The manufactured model for field test has the turbine diameter of 5 meters to produce the maximum power of 500kW at maximum current speed of 5m/s. The technical verification of tidal power converter was performed by means of small scale model test in towing tank as well as field test at the Strait of Uldolmok located in Jindo of Jeollanamdo province. Field test was performed by mounting the tidal current converter on the SEP(Self Elevating Platform) which could lower the 4 vertical legs on the seabed and could elevate platform over the water surface using the hydraulic power for itself. The field test performed for a month shows that power output is similar or larger compared with the expected one in design stage. This paper presents the development of tidal current energy converter and real sea field test by Hyundai Heavy Industries. This project has finished successfully and provided the technical advance toward commercial services for tidal current power generation in the south-west region in Korea.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.617-622
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• 2006

Gamcheon Harbor was developed to cope with increased freight demand of Busan port and supplement function of the north port. Because container wharf is opened to 1997 as well as general wharf, present maximum 50,000DWT class containerships have been incoming and outgoing. However, In Gamcheon port, small size ships such as fishing boats, miscellaneous boats account for 50 percent of the traffic and a public marine products wholesale market that is building on the north wharf will open in 2008. Therefore, it needs to grasp future year traffic volume before establishing operation plan for port management. Also, analysis on crossing situation risk is required because the breakwater entrance in Gamcheon Harbor is narrow and the crossed passing of ship is ever-present at breakwater front. Thus the traffic volume in the future was presumed and quantitative analysis was achieved on crossing situation though simulations with the traffic volume.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.2
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• pp.125-131
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• 1996

In order to investigate the relation between the environmental properties and the catch fluctuation of set net fishing grounds located in the coastal waters of Yosu, oceanographic observations on the fishing grounds were carried out by the training ship ofYosu Fisheries University from January, 1990 to September, 1992, and the data obtained were compared with the catch data from the joint market ofYosu fisheries cooperative society from 1984 to 1993. The resuItes obtained are summerized as follows : 1. The ranges of water temperature and salinity in the fishing ground was 7.0 to $27^{\circ}C.$and 26.6 to 33.2${\textperthousand}$, and water temperature increased from March to August and decreased from September to February of following year. 2. The salinity in the fishing grounds was relatively high without significant changes from November to June of the following year. From July, however, the salinity decreased to continue a low value till September and then increased. The salinity in the fishing ground was dominated mainly by the precipitation and its variation was large at the north entrance of set net fishing ground, influenced greatly by the land waters from the river of Somjin, but small in the offshore of the fishing grounds. 3. The fishes caught by the set nets were arranged in order of catch as follows; Spanish mackerel> Horse mackerel > Sardine > Anchovy > Hair tail. The catches of Anchovy and Sardine were high in April to May and those of Hair tail in June to July, but Spanish mackerel and Horse mackerel were caught for whole period of fishing. Spanish mackerel was caught most in September and least in April and their means were largest in August and smallest in June. 4. The ranges of optimum water temperature for fishing by the set nets was 13.5 to $25^{\circ}C.$, and in the ranges the catches increased with increasing temperature. The ranges of optimum salinity for fishing varied between 25.0 and 32.0${\textperthousand}$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.29-33
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• 2004

Design of general steel structure had applied to achieve elastic designing concept so far. Because elastic design supposes that whole structure complies with elasticity formula so that achieve via allowable stress of material. It is concept that calculate stress distribution of construction about action external load and estimate load when the maximum stress reaches equally with allowable stress that is established by maximum safety load of the structure. But, absence that compose actuality structure by deal with external load increase small success surrender and structure hardness falls and structure in limited state finally on the whole as showing complicated process by interference between collapse and buckling under compression. Applied ANSYS (elasto-plasticity large deformation finite element method) to be mediocrity finite element program for analysis method and analysis control used in Newton-Raphson method & Arc-length method.

• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.49-54
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• 2003

Recently, mega-float offshore structure is studied as of the effective utilization of the ocean space. And mega-float structure are now being considered for various applications such as floating airports. container yard, offshore cities and so on. This mega-float structure is relatively flexible compared with floating structures like large ship. When we estimate dynamic responses of these structures in waves, the elastic deformation is important, because vertical dimension is small compare with horizontal. the analysis of the dynamic reponses as it receive regular wave is studied. The finite element method is used in the analysis of structural section of this model. And the analysis is carried out using the boundary element method in the fluid division. In oder to know the characteristics of the dynamic response of the mega-float structures, effects of wavelength, water depth, and wave direction on the dynamic response of the floating structure are studied by use of numerical calculation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.941-944
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• 2015

In this paper study for VSAT(very small aperture terminal) LNB(low noise block). ship LNB was demanded high stability and low noise figure. We designed FEM(Front-End Module) that was operated multi-band. FEM designed was constructed in a multi-band low noise receiver amplifier, a frequency converter, IF amplifier, Voltage Control Oscillator signal generating circuit four circuit using. To convert the multi-band 2.05GHz band, it generates four local oscillator signals, the four(band1, band2, band3, band4) designed to output an IF signal developed conversion apparatus, the conversion gain 64dB, noise figure 1dB or less, output P1dB 15dBm or more, phase noise showed -73dBc@100Hz.