• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.1
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• pp.17-22
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• 2000

A quaternary alloy film of $CoCr_{16.2}Pt_{10.8}Ta_4$was investigated for its magnetic properties and c-axis orientation with and without Ti underlayer. Additional elements such as Ta, Pt have been frequently introduced in CoCr alloy film for perpendicular recording as a means of improving magnetic performance. It has been reported that the addition of Pt and Ta in CoCr increase the coercivity and the magnetic isolation of columnar grains, respectively. However, CoCrPtTa perpendicular magnetic layer should be more increased its perpendicular magnetic anisotropy than at present for the application of ultrahigh recording density. The improvement of underlayers and substrate materials is one of the promised schemes to intensify the perpendicular magnetic anisotropy. In this study, the insertion of Ti underlayer shows the remarkable improvement of c-axis orientation compare with the direct deposition on the bare glass. The mechanism about this effect of Ti underlayer on CoCrPtTa is not to be clarified yet. Meanwhile, it is found that the magnetic domain of CoCrPtTa on 20 nm Ti underlayer has the continuous stripe pattern but the one of CoCrPtTa on 90 nm Ti underlayer shows the discrete mass type from the results of MFM investigation. This phenomenon is to be a distinct evidence that the improvement of perpendicular anisotropy by the adoption of Ti underlayer is originated from the reinforcement of the grain boundary segregation in CoCrPtTa alloy. Moreover, the transition of the M-H hysteresis pattern with the thickness of Ti underlayer indicates that the major contribution of Ti underlayer is not the magnetocrystalline anisotropy but the shape anisotropy due to the formation of uniform columnar grains by the nonmagnetic alloy segregation.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1129-1135
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• 2015

The stow net is a stationary gear made from netting, usually in shape like trawl net without wings. The nets are fixed by means of anchors, placed according to the direction and strength of the current. And the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard factors analysis for the fishermen's safety of offshore stow nets vessel was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2012 to 2014 (n=1,144). As a result, the average occupational accident occurrence rate of this fishery was 206.9‰ in all industries 36.9 times the rate of that. In addition, average death and missing rate was found to have a very serious level management to 50.4‰ in all industries of death of 42.0 times. The accident occurred in 84.5 to 94.6% was happened at sea. The struck by object, slipping, contact with machinery, contact by object or gear and others occurred more frequently in order on the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore stow nets vessel.

• The Korean Journal of Zoology
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• v.8 no.1
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• pp.1-7
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• 1965

The short-necked clam is distributed widely in Korean tidal flats and it is a much an important bivalve quantitatively as to control the production of the tidal flat. The shell of this clam tends to show remarkable morphological variations depending on the habitat. Under a seemingly favorable condition for the growth , the color pattern of shell of the clam is clear and obvious and having less weight and elongated shape, the ratios of shell length to both height and width are small . On the contrary , when the environment appears to be an unfavorable one, the shell is found to be heavy and stunted with smudgy color pattern. If this correlation between could be a basis for the judgement in suitability of growth environment for the clam. In the Ikawazu Bay, Japan, it is revealed that the elongated shell is produced from the coast outside of the Bay (1) , the stunted from the esturay (2) and the intermediate from the floodgate area (3) and the middle of the Bay (4). Followings are the results obtained from the morphological investigation of the claim in this Bay. 1. Relationship between the shell length and the largest shell rib length is linear and between the shell length and the shell width is also linear but with a critical point at the shell length of 17-20 mm. The ratio between the width and the largest rib length at a given shell length increases with the order of 1, 3, 4, and 2. 2. A gradual decreases of the ratio of the shell length to the largest rib length is observed when the former is less than 17-18 mm, and this ratio increases with the shell of longer. Also there is a different range of this ratio in each different location ; the greatest range in 2, the smallest in 1 and 4 being in between. 3. A similar biometric finding is apparent with the ratio between the length and width of the shell and the order in value is 2, 4, 1 and 3. 4. The ratios between the length and the largest rib length of elongated and stunted shell are 0.84-0.86 and 0.89-0.92, respectively , and those between the length and width are 0.40-0.51 and 0.49-0.58, respectively. 5. Generally , the elongated short necked clam shells are products of the tidal flat of good circulation of sea water with high salinity and smaller fluctuations of salinity and temperature within a day. The stunted shells are produced for tidal flats of opposite of above conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.1034-1037
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• 2005

The variation of shapes and related properties of ZnO nanostructures grown on the metal pattern and Si substrate have been investigated. Ni, Cr metal patterns were formed on Si (111) substrates by e-beam evaporation, and ZnO nanostructures were fabricated on it by using thermal evaporation of Zn powder in air. Growth temperature was controlled from 500 $^{\circ}$C to 700 $^{\circ}$C. When the growth temperature was relatively low, no considerable effect was found. However, UV emission intensity decreased, and Green-emission intensity, which is regarded as originated from the defect state in the ZnO nanostructure, increased as growth temperature increase. Also, the variation of nanostructure shape at high temperature (700 $^{\circ}$C) is understood in terms of the enhanced incorporation of metal vapor during the nanostructure formation.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.3_4
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• pp.407-417
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• 2003

The purpose of this study is to develop designs and patterns of a functional brassiere. For this purpose, women who have protruding and drooping breasts with 75B for their brassiere size were sampled. The fitting test for the fitness and function of test brassiere and control brassiere were carried out twice and compared the results from the both in terms of front, rear and side looks. The results of this study can be summarized as follows; 1. The results from measuring the level of sag and spread, and volume and protrusion of breasts shows that there are some distinctive differences in the measurements before and after wearing the test brassiere and the test brassiere is proved to be very effective in correcting breasts' shapes. 2. Front look: Since the two front cutting lines of the test brassiere served to have the curved main part pressing against the breasts, it could support breasts to more than satisfactory level. In addition, upperline panel and side panels of the test brassiere were found to have the upperline of the upper cup pressed against the breasts and at the same time it pressed and gathered the flab around upper part of the breasts and armpits that helped to rearrange the shape of the breasts. It is also proved that the two-pieced test brassier was found to be more functional in supporting the lower cup of the breasts. 3. Rear look: The test brassier was made up of two wide U-shaped wings with 2.5cm tape on its lower sides. Each wing has 4 lines and 3 hems (5.5cm). For this reason, the test brassiere was tighter and better fitted on its back. 4. Side look and entire look: The wings of the test brassiere might look wider than that of the control brassier which has conventional straight-shaped wings, but it was analyzed that the test brassiere held the upper and lower sides of the wings more effectively to be more pressed against the breast. Therefore, the test brassiere scored higher in terms of adjusting to body movements, while the control brassiere looked better in overall terms. 5. The functional brassier fur protruding and drooping breasts developed from the experiments of this study is a full side stretch brassiere which covers the entire breasts satisfactorily. The pattern drafting methods are suggested in to .

• Polymer(Korea)
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• v.26 no.5
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• pp.691-700
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• 2002

Interstitial therapy using biodegradable polymeric device loaded with anticancer agent can deliver the drug to the tumor site at high concentration, resulting in an increase of therapeutic efficacy. 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) is most commonly used as chemotherapeutic agent for brain tumors. The design of implantable device is regarded as an important factor lot the efficient delivery of antitumor agent to targeting site. In order to control the release profile of drug, the release pattern of BCNU with the changes of various dimension and additives was investigated. The PLGA wafers containing 3.85, 10, 20 and 30% of BCNU were prepared in various shape (diameter of 3, 5 and 10 mm, thickness of 0.5, 1 and 2 mm) by direct compression method. In vitro drug release profile of BCNU-loaded PLGA wafers could be controlled by changing the dimension of wafers such as initial drug content, weight, diameter, thickness, volume and surface area of wafers, as well as PLGA molecular weight and additives. Drug release from BCNU-loaded PLGA wafers was facilitated with an increase of BCNU-loading amount or presence of poly(N-vinylpyrrolidone)(PVP) or sodium chloride (NaCl). The effects of various geometric factors and additives on the BCNU release pattern were confirmed by the investigation of mass loss and morphology of BCNU-loaded PLGA wafers.

• Korean Journal of Remote Sensing
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• v.23 no.2
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• pp.131-135
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• 2007

The tidal channel is influenced by sediment type, grain size, grain composition and tidal currents in tidal flat. The development of tidal channel including density, shape and order can be used to analyze the characteristics of tidal channel. The quantitative investigation to the tidal channel is insufficiency. In this paper, we represented the fractal analysis method according to the quantitatively analysis in tidal channel and compared with the different intertidal channel patterns. The tidal channel was extracted from the IKONOS image of the southern part of the Kanghwa-do. We used the Box-counting method to estimate fractal dimensions for each tidal channel. As a result, the fractal dimension values (D) were 1.31 in the southern Kanghwa-Do. Linear pattern and less dense channel development area had low D values (from 1.0563 to 1.0672). Dendritic pattern and dense channel development area had high D values (from 1.2550 to 1.3016). In other words, fractal dimension values had difference about 0.2 values according to the characteristic of tidal channel development. We concluded that fractal analysis can be able to quantitatively classification in tidal channel.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.151-159
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• 2021

Since January 2019, insurance coverage for caries treatment of permanent teeth using composite resin in children aged 12 and under has started in South Korea. The purpose of this study was to compare the pattern of permanent molar composite resin restoration aged 12 and under before and after the insurance coverage from January 2009 to March 2020 in the Department of Pediatric Dentistry at Kyung Hee University Dental Hospital at Gangdong. Since the insurance coverage was started in 2019, the frequency of permanent molar composite resin restoration aged 12 and under has increased more than twice. There was a significant change in frequency of resin restoration by shape of cavity comparing before and after the insurance coverage, whereas there was no significant difference in changes by patient age, gender and position of tooth. As accessibility to the permanent tooth composite resin restoration is increased by the insurance coverage, which shows a fair survival rate, it is expected that it could be able to secure oral health in the early permanent dentition aged 12 and under.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.403-412
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• 2021

Despite strengthening requirements for fire retardancy and applied buildings of insulation panels, the number of fires and influence of damage have increased. In this study, the thermal effects were evaluated as the separation distances, and three types of EPS panel, glass wool panel, and gypsum board panel were then selected. Temperature sensors on the panels were installed vertically from the ground. The fire source on the lamination layer of lumber was ignited by changes in the separation distances (0 cm, 25 cm, 50 cm) from the panels. The test results suggested that the maximum temperature was 349 ℃ in the EPS panel. The inside/outside shape changes were limited by the height of the low and middle positions until the critical point of a 25 cm separation distance. Furthermore, the combustion marks appeared after 500 s on average, and then the EPS panel with a high fire strength showed a broad "U type" pattern, glass wool panel, and gypsum board panel showed medium or narrow "V type" pattern. Therefore, the acquired data can provide valuable information for evaluating the fire risks and verifying fire investigation from buildings composed of these insulation panels.

• Geomechanics and Engineering
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• v.17 no.4
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• pp.333-342
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• 2019

Geological dynamic hazards during coal mining can be caused by the failure of a composite system consisting of roof rock and coal layers, subject to different loading rates due to different advancing velocities in the working face. In this paper, the uniaxial compression test simulations on the composite rock-coal layers were performed using $PFC^{2D}$ software and especially the effects of loading rate on the stress-strain behavior, strength characteristics and crack nucleation, propagation and coalescence in a composite layer were analyzed. In addition, considering the composite layer, the mechanisms for the advanced bore decompression in coal to prevent the geological dynamic hazards at a rapid advancing velocity of working face were explored. The uniaxial compressive strength and peak strain are found to increase with the increase of loading rate. After post-peak point, the stress-strain curve shows a steep stepped drop at a low loading rate, while the stress-strain curve exhibits a slowly progressive decrease at a high loading rate. The cracking mainly occurs within coal, and no apparent cracking is observed for rock. While at a high loading rate, the rock near the bedding plane is damaged by rapid crack propagation in coal. The cracking pattern is not a single shear zone, but exhibits as two simultaneously propagating shear zones in a "X" shape. Following this, the coal breaks into many pieces and the fragment size and number increase with loading rate. Whereas a low loading rate promotes the development of tensile crack, the failure pattern shows a V-shaped hybrid shear and tensile failure. The shear failure becomes dominant with an increasing loading rate. Meanwhile, with the increase of loading rate, the width of the main shear failure zone increases. Moreover, the advanced bore decompression changes the physical property and energy accumulation conditions of the composite layer, which increases the strain energy dissipation, and the occurrence possibility of geological dynamic hazards is reduced at a rapid advancing velocity of working face.