• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.500-506
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• 1999

We designed and fabricated a bidirectional optical transceiver module for low cost access network. An integrated chip forming a pin-PD on an 1.3 urn FP-LD was assembled by flip-chip bonding on a Si optical bench, a single mode fiber with an angled end facet was aligned passively with the integrated chip on V-groove of Si-optical bench. Gaussian beam theory was applied to evaluate the coupling coefficients as a function of some parameters such as alignment distance, angle of fiber end facet, vertical alignment error. The theory is also used to search the bottle-neck between transmittance and receiving coupling efficiency in the bi-directional optical system. Tn this paper, we confirmed that reduction of coupling efficiency by the vertical alignment error between laser beam and fiber core axis can be compensated by controlling the fiber facet angle. In the fabrication of sub-module, a'||'&'||' we made such that the fiber facet have a corn shape with an angled facet only core part, the reflection of transmitted laser beam from the fiber facet could be minimized below -35 dE in alignment distance of 2: 30 /J.m. In the same condition, transmitted output power of -12.1 dEm and responsivity of 0.2. AIW were obtained.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.131-143
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• 1994

For maintenance of exposed implant in healthy state, it is necessary to treat the surface of implant fixture and provide the surface adjustable to surrounding tissues. Variable techniques have been introduced such as citric acid and air-abrasive system to treat the failed implant. Although when the rough surface of HA coated implant was exposed to oral environment, the surface treatment method with citric acid or air-abrasive system is effective for removal of bacterial endotoxin, it is unsuccessful to prevent plaque deposition due to difficulty in removal of rough surface of HA coated implant. Thus, in this study the method that removes bacterial endotoxin and makes smooch surface without alteration of surface characteristics was studied. HA coated disc manufactured by IMZ Co. Was treated with high speed diamond bur, low speed diamond bur, stone bur, rubber point, jetpolisher. And then its surface state was examined with profilometer and SEM to evaluate the surface smoothness, and its surface component was analyzed with EDX to evaluate wheter the surface characteristics were altered or not. As a result, following results were obtained. When the surface roughness of each implant disc was measured by profilometer, the group I showed a $R_{max}\;2.11{\mu}m$ and the group II, III, IV, V showed a $R_{max2}\;4.17{\mu}m$, $7.28{\mu}m$, $8.61{\mu}m$ and $39.44{\mu}m$ respectively. That is, surface smoothness was highest in the group I and it has been gradually decreased in the group II, III, IV and V. Under the SEM examination, the group I showed relatively smooth surface and the group II showed slightly rougher surface than the group I due to partially remaining HA particles while most HA particle was removed. The group III and IV showed rough topography due to HA particles that was not grinded, and HA coated surface in group V showed very irregular surface with deep groove and prominence. In cross-sectional view, the group I showed uniform surface, and the group III, IV showed rough surface due to remaining HA particles but the thickness of HA coating was remarkably reduced. The group II has similar pattern in group I, and the group V showed about $40{\mu}m$ thickness although it was not constant. By analysis of surface component with EDX, the group II in which the grinding was effective showed a small quantity of calcium and phosphorous and the group III, IV, in which the grinding was incomplete showed calcium and phosphorus peak. In all experimental group, no other than titanium, aluminum, calcium, phosphorus was observed.

• Journal of fish pathology
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• v.9 no.2
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• pp.113-118
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• 1996

During a study to document more fully the parasitic ciliates of Korean freshwater fishes, we found numerous small ciliates in the gills and skin of crucian carp, Carassius carassius. Cursory examination indicated that the ciliate were very similar with Chilodonella sp. In this study, we described the morphometrics of this ciliate in detail and compared with other species of Chilodonella in the world. Numerous small ciliates were observed in the body surface, fins and gills of infected fish and excessive mucus production were seen in those fish. Sometimes ulcer was observed in the body of moribund fish. From the scrutinized observation of the parasite, it was identified as Chilodonella hexasticha. The parasite was dorsoventrally flattened body, without a notch in the posterior margin, and it measured 30-$45{\mu}m$ long and 15-$30{\mu}m$ wide. In number of kineties, the right band ciliature was 3-5 and the left band ciliature was 3-5. The right ventral ciliary band shaped arch and was longer than the left, straight band. It had a single oval macronucleus, 8-$15{\mu}m$ in diameter, a single micronucleus, 2-$4{\mu}m$ in diameter. The cytopharynx was reinforced by 10-16 conspicuous nematodesmata, which shaped like a tube and curved at its inner end. Two contractile vacuoles, one anteriorly at right and the second posteriorly at left were observed in wet mounts. This parasite reproduced by a simple division at $22{\pm}1^{\circ}C$.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.255-258
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• 2000

본 연구는 육성돈에 있어 인분해효소인 phytase의 첨가가 환경친화성사료개발을 위한 기초자료로 사용하기 위해 영양소 이용률을 측정하였다. 대조구는 옥수수-대두박의 육성돈 사료이고, 처리구는 대조구 사료에 Phytase의 첨가 수준을 500 unit 및 1,000 unit을 첨가한 구로 3×3 Latin Square 방법으로 실시하였다. 건물과 질소에 대한 소화율에서는 각 처리구간에 유의적인 차이가 없었다(P>0.05). 회분, 칼슘 및 인의 소화율의 경우 phytase 첨가구가 대조구에 비해 높은 수준을 보였다(P<0.05). 돼지가 섭취한 인의 양은 phytase 첨가구가 대조구에 비해 증가하였다. 또한 인의 흡수량에서 phytase 첨가구가 대조구에 비해 높았다(P<0.05) 분과 뇨의 총 인 배설량은 유의적인 차이를 나타내지 않았다. 칼슘의 섭취량은 처리구가 대조구에 비해 높았다. 칼슘의 분 배설량은 각 처리구간에 별 다른 차이를 보이지 않았으나(P>0.05), 뇨의 배설량은 처리구가 대조구보다 적은 양이 배설되었다. 소화된 아미노산 중 cystine, isoleucine, tyrosine, phenylalanine은 처리구가 대조구에 비해 소화율이 현저히 증가된 것을 알 수 있었다(P<0.05). Asparagine, threonine, serine, methionine, leucine의 경우 phytase를 500 unit 첨가한 구가 높은 소화율을 나타내었다(P<0.05). 한편 lysine, histidine, arginine 등의 다른 아미노산은 처리구가 대조구보다 약간의 소화율 증가를 보였으나 통계적 유의차는 나타나지 않았다(P>0.05). 결론적으로 인분해효소 phytase를 사료내 첨가하므로서 분중 영양소를 줄일 수 있는 환경친화성 사료를 개발 가능하다고 사료된다. 체결홈이 형성된 체결부를 갖는 안경집과 이것에 결합되는 체결구가 마련되어 개폐되는 커버가 형성된 케이스로 구성된다.로 금형설계 및 제작기간을 단축하고자 한다.ere demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-dif

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.1059-1075
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• 2017

The objective of this study was to evaluate the freezing and thawing resistance of the existing drainage system for leakage treatment of underground concrete structures operating in cold regions. The freezing and thawing test was conducted on 4 types of drainage system specimens to evaluate the freezing and thawing resistance of the drainage system. The freezing and thawing resistance was evaluated on 4 types of Hotty-gel, as a waterproofing material, connection methods and on two methods to fix the drainage board with Hotty-gel on the surface of cement concrete specimen. One cycle of the freeze-thaw testing was 48 hours (24 hours of freezing and 24 hours of thawing), and the temperatures of freezing and thawing were at $-18^{\circ}C$ and $10^{\circ}C$, respectively. Among the 4 types of Hotty-gel connection methods, leakage occurred after 28 cycles (8 weeks) of freeze-thawing only in the Hotty-gel connection method with the 'V' groove applied to the corner of the drainage board. No leakage occurred in the 3 types of Hotty-gel connection methods. In two fixing methods, leakage occurred in the method of fixing the drainage board on the cement concrete specimen using the washer, screw and plastic wall plug. Leakage occurred at one point after 10 cycles (3 weeks) of freezing and thawing. After 28 cycles (8 weeks) of freezing and thawing, leakage point increased to 5 points. As time passed, the leak point was not increased, but the amount of leakage was increased at each leak point. The Hotty-gel connection method with cross-sectional diagonal shape was evaluated to be the highest in the production efficiency considering the production time and manufacturing method of the Hotty-gel connection shape. In the construction efficiency considering the construction time and construction method, the fixing method of air nailer, fixed nail and washer was superior to that of the washer, screw and plastic wall plug.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.203-216
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• 2023

Purpose: This study examines the weight control behavior depending on university students' motives of using social media. Methods: The participants were 447 university students in the Jeonbuk area. Collected data were analyzed using factor analysis, cluster analysis, analysis of variance, and χ² tests with SPSS v. 26.0. Considering the motives of using social media, we investigated the usage of social media, dietary behavior related to social media, and weight control behavior. Results: Using the K-clustering method, the motives to use social media were categorized into three clusters: cluster 1 was the interest-centered group, cluster 2 was the multipurpose information-seeking group, and cluster 3 was the relationship-centered group. Among the various social media sites, YouTube (86.8%), Instagram (76.1%), and Facebook (61.1%) were the most visited by the subjects. The dietary behavior related to social media in cluster 2 was significantly higher than clusters 1 and 3 (p < 0.001). Clusters 1 and 2 showed a significantly higher dissatisfaction with one's weight (p < 0.05) and consequent interest in weight control than cluster 3 (p < 0.001). Cluster 2 used weight control-related information from social media significantly more than other clusters (p < 0.05). Weight control experiences in cluster 1 and 2 were significantly higher than in cluster 3 (p < 0.001). Conclusion: Differences in dietary behavior related to social media and weight control behavior were observed between cluster types of motivation to use social media. Based on the usage motives of university students and their behaviors, we propose that educational programs should be conducted for weight control using social media.