• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.970-979
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• 2012

The purpose of study was to analyze the ecological health of the Namcheon Stream using Index of Biotic Integrity(IBI) Qualitative Habitate Evaluation Index(QHEI) and Water quality condition. Diatom samples were collected from ten sampling sites in the stream at total four times in 2006 and 2007. To assess ecological health of the stream, it was used modify metrics proposed by USEPA(1999). IBI values of the stream averaged 23 which was judged as a "fair". Physical habitate evaluation analysis showed that QHEI values in the stream averaged 57 indicating a "poor" condition. Water quality condition in the stream averaged "II" indicating a "a little good" condition In conclusion, ecological health of the Namcheon Stream was "fair" condition that means habitate minimally disturb in the aquatic environment and relatively good water quality. Especially, St. 6 St. 7, St. 8, and St. 9 showed that QHEI values in the stream averaged 47 indicating a "poor" condition. St. 6 exists mostly to interfere with the flow of the river piers and artificial beams around. They are also serious disturbance at riverbed structure in aquatic ecosystems. St. 10 was good about habitate condition however, it was disturbance of aquatic ecosystems due to nutrient. It is suggest that St. 10 needs to be managed for nutrient inflows.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.224-228
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• 2012

A new $Saxifraga$ $fortunei$ cultivar 'Crystal' was bred by crossing 'Dotaerang' with light pink and light Green (RP 58D) colored petals and 'Rocksun' with light pink and light green white (RP62A + GW157A) colored petals. The selection and flower characterization were conducted from 2004 to 2007 in a greenhouse of the National Institute of Highland Agriculture. The flowering of 'Crystal' occurred from September 21 for 31 days. The number of flowers per plant was 279.0 with many flowering habit. The flower coloration was mixed light pink and green white (RP62D + GW157B) at the opening. The number of petals were 7.0, with a width of 2.1 cm and length of 1.8 cm. The plant height was 15.3 cm and number of leaves was 133.7. 'Crystal' cultivar can be used for pot flower. Fifty percent shading is a good cultural practice against direct sunlight and soft rot disease would occurs usually by over-irrigation. 'Crystal' cultivar was registered as a new variety with No. 3466 at Korea Seed and Variety Service in April of 2011 year.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.859-877
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• 2012

In this study, Echo-sounder($E_s$) monitoring methodology was applied to test environmental impacts of artificial weirs(SCW and JSW) in the Yeongsan River on fish community and habitat structures at first time, and was compared with conventional fish sampling methodologies($C_s$). For the Es monitoring in the fields, parallel transect methods was employed in determining the survey distance interval with every 125 m within the upper-lower 2 km of the weirs. Four different fish sampling gears such as casting nets, kick nets, fyke nets, and gill nets were used for applications of $C_s$ monitoring methodology. According to the Echo-sounder monitoring, fish density, expressed as a number of individuals per square meter, along the longitudinal axis of the weir was significantly greater(JSW, t = 3.506, n = 30, p < 0.001) in the down-river reach of the weir than in the up-river reach. Also, fish density along the vertical water column was highest at mid-depths of Seungchon weir, which has simple habitat substrates, while fish density was highest at hypolimnetic depth of Juksan weir. According to fish sampling by the $C_s$ methodology, the fish compositions decreased as the river goes upward, and significant differences(JSW, t = 0.248, n = 30, p < 0.05) in the compositions of fish species occurred between up-reach and down-reach of the weirs. The dominant species near the two weirs were Opsarichthys uncirostris amurensis, Hemiculter eigenmanni and Coilia nasus. Overall, our fish and habitat data, based on $E_s$ and $C_s$ monitoring methodologies, suggest that the weirs disturbed the rivers due to initial habitat disturbances by the weir constructions as well as the barrier roles of weirs on fish passage and migrations. More long-term scientific and systematic fish impact monitoring and assessments($E_s$ and $C_s$) are required in the future to predict changes of ecological structures and functions on the constructions of the weirs.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.275-281
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• 2004

Socket weldment used to change the flow direction of fluid nay have flaws such as lack of fusion and cracks. Liquid penetrant testing or Radiography testing have been applied as NDT methods for flaw detection of the socket weldment. But it is difficult to detect the flaw inside of the socket weldment with these methods. In order to inspect the flaws inside the socket weldment, a ultrasonic testing method is established and a ultrasonic transducer and automated ultrasonic testing system are developed for the inspection. The automated ultrasonic testing system is based on the portable personal computer and operated by the program based Windows 98 or 2000. The system has a pulser/receiver, 100MHz high speed A/D board, and basic functions of ultrasonic flaw detector using the program. For the automated testing, motion controller board of ISA interface type is developed to control the 4-axis scanner and a real time iC-scan image of the automated testing is displayed on the monitor. A flaws with the size of less than 1mm in depth are evaluated smaller than its actual site in the testing, but the flaws larger than 1mm appear larger than its actual size on the contrary. This tendency is shown to be increasing as the flaw size increases. h reliable and objective testing results are obtained with the developed system, so that it is expected that it can contribute to safety management and detection of repair position of pipe lines of nuclear power plants and chemical plants.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.4
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• pp.164-172
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• 2004

Water temperature, salinity, the phytoplankton community and population of a marine photosynthetic ciliate, Mesodinium rubrum (=Myrionecta rubra), were monitored every 0.5-2 weeks in Gomso Bay and the Geum River Estuary from September 1999 to December 2000. Patterns of temporal variation of the M. rubrum population and phytoplankton community were compared with each other in relation to the differences in temporal fluctuation patterns of the water temperature and salinity in the two study areas. Higher population densities and more frequent blooms of M. rub rum in the Geum River Estuary than those in Gomso Bay could be due to the relatively higher nutrient input by freshwater influx in the Geum River Estuary. In the Geum River Estuary which experience more abrupt and irregular fluctuations of salinity, M. rubrum with its greater tolerance to salinity change exhibited increased dominance while neritic diatoms such as Skeletonema costatum, Asterionellopsis glacialis, A. kariana, Chaetoceros debilis, Eucampia zodiacus, Paralia sulcata, Thalassiosira pacifica, T. nordenskioeldii showed decreased dominance compared with those in Gomso Bay. Thus, it is possible that M. rubrum replaces the dominant diatom species in coastal waters where artificial modification of coast lines as in the case of Saemankeum Reclamation Project should increase the frequency as well as the absolute scale of freshwater discharges.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.189-195
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• 2003

The objective of this study is to improve the optical sensitivity of laser fluorescence for detection of incipient enamel caries. An incipient carious lesion was formed in various stages by placing an enamel specimen of a bovine tooth in STPP demineralization solution. After measuring the optical density of the lesion surface by laser fluorescence induced by argon laser and various alter of yellow(500-520nm), amber(520-540nm), orange(540-560nm), and red(560-580nm), the specimen was cut vertically to measure the depth of the lesion using a polarizing microscope. SAS statistical program was used to analyze the relationship between the optical density of the lesion suface and the depth of the lesion. The results were as follows: 1. The optical density of early carious lesion, measured by laser fluorescence with amber and orange filter, and lesion depth observed by polarizing microscope, were increased as demineralization time increased. 2. The correlation coefficient between optical density of the lesion surface and the histological depth of the lesion was the highest in orange filter(r=0.49), followed by amber(r=0.32), yellow(r=0.13) and red(0.01). 3. Regression analysis showed that the most linear relationship between the optical density and the lesion depth was existed in orange filter group. In regard above results, laser fluorescence could be considered to be reliable for optical diagnosis of dental caries.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.415-422
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• 2013

The contents development for the Internet and cyber tour has been attempted in a number of areas. 3D topography of the spatial environment, land planning and land information contents as a 3D tour of the future ubiquitous city safe for tourism due to the implementation of information made available major area. Domestic service, and in urban areas of the country where land and precise spatial information in order to shoot satellites and aircraft in the area you want to mount the camera on a variety of photo images taken by conducting 3D spatial that is required is able to obtain the information. Geo spatial information in a variety of direct or indirect acquisition of the initial spatial data into a database for accurate collection, storage, editing, manipulation and application technology changes in the future by establishing a database of 3D spatial by securing content organization ubiquitous tourist to take advantage of new tourism industry was greatly. As a result of this study for future tourism using geo spatial information and analysis of 3D modeling by intelligent land information indirectly, with quite a few stereo site experience and a variety of tourist spatial acquisition and utilization of information could prove.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.202-210
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• 2017

Shear stress is one of the most important mechanical factors used in various fields and is important for the design of artificial channels. Current shear stresses have been used in the past, but there are factors that are difficult to actually measure or calculate, such as bed shear stress and energy slope in the equation used. In particular, the energy slope is a very difficult factor to estimate, and it is difficult to estimate the slope and flow velocity of the boundary layer although the energy slope can be used to obtain the shear stress distribution. In addition, the bed shear stress among the shear stress distribution is very difficult to measure directly, and the research is somewhat slower than the velocity. In this study, we have studied the simple calculation of the average flow velocity and the shear stress distribution using entropy M without reflecting the energy gradient, and we used existing laboratory data to demonstrate the utility of the applied equation. The stress distribution in the graphs was comparatively analyzed. In the case of the uniform flow and the non-uniform flow, the correlation coefficient was almost identical to 0.930-0.998.

• Journal of Korean Society of Forest Science
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• v.69 no.1
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• pp.19-27
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• 1985

Introgressive hybridization of Pinus densiflora in Korea was investigated by examining the position of resin ducts in 4,992 trees from 67 populations. Judging that P. densiflora has only external resin ducts, P. thunbergii only medial resin ducts, and any tree which has even one needle with external and medial resin ducts is hybrid, hybrids are found at all populations investigated. As variation in position of resin ducts was found among needles on a tree, the number of needles investigated from a tree affects judgment of the tree's hybridity. Therefore, hybridity seems to be judged by many traits rather than by the single trait, position of resin ducts. Seed production by artificial pollination between P. densiflora and P. thunbergii was very poor, i.e. one full seed from five female flowers or from two mature cones. This poor seed production, in addition to the low hybrid vigor, if any, seems to make the artificial pollination between the two species for mass-production of seeds for planting impractical.

• Journal of Satellite, Information and Communications
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• v.3 no.2
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• pp.13-17
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• 2008

The conventional telemetry system of Korean low-earth orbiting satellites has certain limitations in accommodating various missions. As the payload becomes complex, it requires very complicated operational concepts in terms of telemetry. With the current design, the telemetry formats have to be rebuilt whenever new payloads or operation concepts are involved, and many constraints in operation shall be produced due to the lacks of its flexibility. As the capability and performance of a satellite have been improved, the communication structure of the satellite should be improved to gather more telemetry data. For the efficiency of data handling, it is necessary to change the grid based telemetry system in which the downlink interval and types for telemetry was limited. Comparing the fixed data map such as grid type, the packet based telemetry system can be operated as flexible and various types of packet can be designed such as the dump packet and the event packet. The sequence of the packets can be modified or newly defined to manage the massive satellite state of health data. In this paper, a new strategy for the telemetry development partially derived from PUS (Packet Utilization Standard) of European Space Agency, which provides enhanced features for the accommodation of payloads & operational requirements, is presented.