• Journal of Environmental Science International
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• v.10 no.1
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• pp.41-45
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• 2001

This study was carried out to investigate phytoplankton community structure in the Naktong river from January to December in 1999. In water quality, average value of pH were 8.1, BOD 2.5mg/$\ell$, COD 5.0mg/$\ell$, Chl-a 41$\mu\textrm{g}$/$\ell$, and $NH_4^+-N$ 0.08mg/$\ell$, respectively. Phytoplankton were identified 42 genera 76 species. Among these, diatoms were 39 species(51.3%), green algae 25 species(32.9%), cyanobacteria 4 species(5.3%), dinoflagellates 4 repectively. The highest standing crops were 33,023 cells/$m\ell$ in February at the Mulgum and the lowest 79 cells/$m\ell$ in March at the Goryung. Also, Standing crops were increased with proceeding from middle part to lower part. Seasonal succession of phytoplankton represented that Stephanodiscus hantzschii was dominant species in winter, Cyclotella menaghiniana and Synedra acus in spring, C. meneghiniana, S. acus, Aulacoseira granulata var. angustissima in summer, and A. granulata var. angustissima and C. meneghiniana in autumn. Ecological important species were 4 species, that are Stephanodiscus hantzschii, Cyclotella meneghiniana, Synedra acus, and Aulacoseira granulata var. angustissima. In the community analysis, dominance indices ranged from 0.434(August, Namji) to 0.999(January, February, Mulgum) and diversity indices from 0.026(February, Mulgum) to 3.073(September, Namji). According to the similarity index among the stations, it was generally defind as two areas such as middle(Goryung, Namji and Samryangjin) and lower part(Mulgum).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1385-1390
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• 2011

A coaxial-conical-radial transmission line conversion circuits have been investigated to realize a low loss high performance microwave power divider/combiner. In order to optimize the characteristics of the device, the power divider/combiner was designed separately with two parts-the inner part and the outer part. Utilizing the rectangular approximation of the outer part, we can design the low loss device which is not affected by the partition number N of the outer part. The small return loss which is lower than 20dB was obtained on the frequency range of 5.15GHz(7.45~12.60GHz). A conical connector was employed for smooth connection between the central coaxial line and the outer radial line. Making use of the $47^{\circ}$ and $90^{\circ}$ 2-stage conical connector, the return loss lower than 30dB was obtained on the operating frequency range of 5GHz. The total return loss of the designed divider/combiner was lower than 20dB on the frequency range of 5GHz for the partition number N=11, N=12 and N=16.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.408-420
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• 2010

It is important to forecast the final deformation of a tunnel during construction for evaluating its mechanical stability. In this study, the final deformation of a tunnel is forecasted by fitting tunnel deformations measured while excavating to a displacement function and exterpolating it. The tunnel for the study was built in two stages divided into an upper and a lower part. During the lower part construction of the tunnel, the displacement function forecasts the final incremental displacement well compared to the increment measured after completion of the tunnel. It is because the critical initial displacement occurred on passing the measurement pins can be adequately measured during excavating the lower part, which can not be measured during the upper part excavation of the tunnel.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.347-354
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• 2014

PURPOSE: This study was to examine changes in muscle activity of lower extremity shoes sole form (high heels, shoes with curved out sole, house shoes). METHODS: The subjects of this study were 12 women in their twenties. They put three kinds of shoes (high heels, shoes with curved out sole, house shoes) and walked 5m. The muscles activities of lower extremity muscles (rectus femoris, vastus medialis, tibialis anterior, gastrocnemius medial part) were measured using a wireless electromyogram (EMG). Rectus femoris was attached to 1/2 position at the distance between ASIS and knee bone and vastus medials was attached to 2cm from upper inside of knee bone. Tibialis anterior was attached to 75% position above line connecting knee joint and ankle joint and gastrocnemius medial part was attached to 3 5% position above knee joint and ankle. RESULTS: It was found that there were significant differences in changes of muscles activities of lower extremity muscles (rectus femoris, vastus medialis, tibialis anterior, gastrocnemius medial part) on shoes sole forms (p<.05). All lower extremity muscles were showed high muscles activities, when high heels wear (p<.05). Wearing shoes with curved out sole was showed high muscle activity of tibialis anterior and lower muscle activity of gastrocnemius medial part compared with wearing house shoes (p<.05). CONCLUSION: Shoes sole form should be considered when patients with knee and ankle joint problems choose shoes because muscles were showed different activities according to shoes sole forms.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.3
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• pp.36-40
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• 2008

This study is analyzed by the simulation of automotive steering system. The maximum equivalent stress of $2.2418{\times}109Pa$ and the maximum total displacement of 0.014929m are shown at the universal joint and its lower part respectively. As the minimum cycle of 34.047 is shown at the universal joint in case of fatigue analysis, it is possible to have greatest damage at this part. In case of natural frequency analysis at vibration, its frequency of 47 to 59Hz is occurred generally. The maximum total displacement of 0.5m is shown at handle on the natural frequency of 57 to 58Hz. And the displacement over 2m is shown at the lower part of universal joint on the natural frequency of 58 to 59Hz. As the basis of the simulation analysis of steering system, passenger's comfort of car body can be improved in the design of practical part and the design effect necessary to safe driving can be promoted.

• Development and Reproduction
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• v.21 no.1
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• pp.63-69
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• 2017

On the 15 days after hatching, the larvae was 4.24-5.10 mm (mean $4.66{\pm}2.18mm$) in total length, and the fins of the membrane started to develop into a fan shape and the melanophore was deposited upper the alimentary canal of the abdomen and on the bladder. At 35 days after hatching, the post-larvae formed a branch-shaped melanophore on the head part with a total length of 6.98-12.5 (mean $9.35{\pm}1.71$) mm, formed on the upper and lower parts of the caudal part, formed on the upper and lower parts of the caudal part, and deposited under the head part and abdomen. At 40 days after hatching, the juvenile was 11.3-18.1 (mean $14.9{\pm}1.53$) mm in total length.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.157-160
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• 2003

In this paper, we describe how to represent lower case hand-written English alphabets by a sequence of two to seven fuzzy sets. Each fuzzy set represents an arc segment of the character and each arc segment is assumed to be a part of an ellipse. The part of an ellipse is defined by five quantities; its short and long radii, its orientation angle, whether it is a part of the lower half or the upper half, and whether it is the full half or a part of a half. Hence, we use the Cartesian product of five fuzzy sets to represent each arc segment. We show that this representation is a translation, rotation, and scaling invariant and that it can be used to generate the hand-written English alphabets. The representation we describe is different from the one proposed earlier by the author and when compared with the previous representation, the one described in this paper simulates more closely the behavior of how one writes English characters.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.92-98
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• 2001

We determined the transfer coefficient through the analysis of three dimensional temperature distribution in comparison with the measured temperature on the piston in the turbocharged diesel engine. And we analyzed the thermal stress and the thermal deformation with that heat transfer coefficient by using finite element method. According to this results, we found that maximum tempetature range of the piston appeared at the upper part of the piston crown and that the heat transfer coefficient of the upper part of the piston is smaller than that of the lower one. It showed that the maximum thermal deformation is shown at the edge of the upper part of piston and that the maximum thermal stress was shown on the lower part of the piston crown. Finally, we defined the method of determination of a piston heat transfer analysis by using measured temperature on the piston and analyzed temperature with finite element method.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.202-205
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• 2006

Recently, high vacuum pumps are widely used in the semi-conduction and liquid-crystal display ( LCD ) process. The composite-type high vacuum pumps are widely used in the various processes. In this study, the pumping performance of composite-type molecular pumps has been investigated experimentally. The experimented pumps are a compound molecular pump ( CMP ) and hybrid molecular pump ( HMP ). The CMP consists with helical-type drag pump, at lower part, and with turbomolecular pump ( TMP ), at upper part. The HMP consists with disk-type drag pump, at lower part, and with TMP, at upper part. The experiments are performed in the outlet pressure of $0.2\;{\sim}\;533\;Pa$. We have measured the ultimate pressure, compression ratio, and pumping speed

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.265-267
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• 2013

Tire labeling is an important issue to reduce $CO_2$ and to secure the safety of tire/vehicle on wet road. A basic study on the effects of tire basic stiffness design on tire labeling performance has been done through experimental test. The pass-by noise is affected by tire structural design. The tire with lower side part stiffness and lower tread part stiffness has the lowest PBN level and the best wet grip. And the tire with higher tread part stiffness and higher side part stiffness has the better RR performance. Also it is observed that the trade-off between RR and wet grip exists for various tire stiffness design.