• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.667-675
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• 2013

This paper presents vision-based techniques for underwater landmark detection, map-based localization, and SLAM (Simultaneous Localization and Mapping) in structured underwater environments. A variety of underwater tasks require an underwater robot to be able to successfully perform autonomous navigation, but the available sensors for accurate localization are limited. A vision sensor among the available sensors is very useful for performing short range tasks, in spite of harsh underwater conditions including low visibility, noise, and large areas of featureless topography. To overcome these problems and to a utilize vision sensor for underwater localization, we propose a novel vision-based object detection technique to be applied to MCL (Monte Carlo Localization) and EKF (Extended Kalman Filter)-based SLAM algorithms. In the image processing step, a weighted correlation coefficient-based template matching and color-based image segmentation method are proposed to improve the conventional approach. In the localization step, in order to apply the landmark detection results to MCL and EKF-SLAM, dead-reckoning information and landmark detection results are used for prediction and update phases, respectively. The performance of the proposed technique is evaluated by experiments with an underwater robot platform in an indoor water tank and the results are discussed.

• Membrane and Water Treatment
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• 제9권5호
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• pp.373-383
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• 2018

Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

• 한국식품과학회지
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• 제5권2호
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• pp.119-128
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• 1973

마늘은 강장(强壯), 강정(强精) 식품으로 인정되어 왔으나 그 원인은 아직 미지이다. 여기에는 비타민 E와 밀접한 연관성이 있는 Se 함유아미노산에 기인됨을 가정하고 병아리에 비타민 E, Se 및 마늘을 투여하여 각 장기에 대한 Se 의 함량을 조사하였다. 마늘을 투여한 동물은 Se 및 비타민 E와 Se 투여군보다 Se 함량이 많으며 특히 정소에는 수배이나 축적됨으로 정력제로 될수 있는 요인이 된다고 본다. 쥐에 Se를 $2\;{\mu}g/ml\;(Na_2SeO_3\;Na_2SeO_4)$ 투여하여 성장 및 생존에 미치는 영향을 조사하였다. Se 투여군에서 숫쥐는 성장 및 치사에 영향이 없지만 암쥐는 성장이 훨씬 저하되었다. 본 실험결과 마늘이 정력제에 작용을 하는 것은 Se 함유 아미노산 함량이 풍부함으로 이것이 비타민 E의 작용과 같이 불임(不姙)을 막고 노쇠한 모세혈관을 회복시키는 역할을 상승시켜 주는 것으로 간주된다. 여기서는 Se, 비타민 E, 마늘에 대한 동물의 기능에 영향을 관찰 한 것을 보고 한다.

• ALGAE
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• 제27권4호
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• pp.303-313
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• 2012

Cyanobacteria are well known for their production of a multitude of highly toxic and / or allelopathic compounds. Among the photosynthetic microorganisms, cyanobacteria, belonging to the genus Nostoc are regarded as good candidate for producing biologically active secondary metabolites which are highly toxic to humans and other animals. Since so many reports have been published on the poisoning of different animals from drinking water contaminated with cyanobacteria toxins, it might be assumed that bioactive compounds are found only in aquatic species causes toxicity. However, the discovery of several dead dogs, mice, ducks, and fish around paddy fields, prompted us to study the toxic compounds in a strain of Nostoc which is most abundant in the paddy fields of Iran, using polymerase chain reaction and liquid chromatography coupled with a diode array detector and mass spectrophotometer. Results of molecular analysis demonstrated that the ASN_M strain contains the nosF gene. Also, the result of ion chromatograms and $MS^2$ fragmentation patterns showed that while there were three different peptidic compound classes (anabaenopeptin, cryptophycin, and nostocyclopeptides), there were no signs of the presence of anatoxin-a, homoanatoxin-a, hassallidin or microcystins. Moreover, a remarkable antifungal activity was identified in the methanolic extracts. Based on the results, this study suggests that three diverse groups of potentially bioactive compounds might account for the death of these animals. This case is the first documented incident of toxicity from aquatic cyanobacteria related intoxication in dogs, mice, and aquatic organisms in Iran.

• 한국수산과학회지
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• 제32권3호
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• pp.310-316
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• 1999

염분변화에 따른 생리적 반응과 성장 및 생존율에 관한 기초자료를 얻고자, 해수와 담수에서 광염성 어류로 알려진 숭어와 틸라피아를 재료로 급격한 염분변화 조건에서 어체의 생리적 변화를 조사하였다. 숭어의 코티졸 농도와 글루코스 농도는 해수사육과 담수사육에 유의한 차이를 보이지 않았다. 틸라피아는 해수사육에 따른 증가하는 경향을 나타냈다. 숭어의 $Na^+,\;Cl^-$ 및 $K^+$ 농도는 실험개시시와 차이를 나타내지 않았다. 그러나 틸라피아는 해수사육에 따른 유의한 증가를 보였다. 숭어의 삼투질농도는 293.5$\~$335mOsm/kg 범위를 보였다. 틸라피아는 해수사육 3일째 유의한 증가를 보였다. 생존율에 있어 숭어는 $96.5\%$를 보였고, 틸라피아는 해수사육 3일만에 전량 폐사하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제26권2호
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• pp.49-56
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• 2003

초음파 Q/A팬텀은 조직등가물질(TMM)과 표적물질로 구성한다. 표적물질은 데드존, 거리분해능, 측분해능, 수직과 수평거리 정확성 등을 평가하는 모노필라멘트로 TMM과 조화를 이뤄 선명하게 나타나야 한다. 본 연구의 목적은 금속성 모노필라멘트와 나일론 모노필라멘트를 이용하여 TMM 내에서 최적의 해상력을 표현할 수 있는 선 표적물질을 얻기 위해 탈기수와 C15 g TMM을 합성하여 모노필라멘트를 설치하고 SONOACE 6000C $3.5{\sim}7.5\;MHz$를 주사하여 다음과 같은 결론을 얻었다. 1. 0.1 mm 금속성 모노필라멘트와 0.12 mm, 180데너아 나일론 모노필라멘트에서 점상의 선명한 에코양상을 관찰할 수 있었다. 2. 0.2 mm 금속성과 나일론 모노필라멘트는 다중반사에 의한 혜성꼬리음영이 관찰되었다. 3. 데드존과 거리분해능은 0.1 mm 나일론 모노필라멘트가 유용한 것으로 나타났다. 4. 나일론 모노필라멘트는 금속성 모노필라멘트에 비해 견고성과 수축성이 우수하여 팬텀제작에 유리한 것으로 나타났다. 5. TMM의 경도 차가 모노필라멘트의 에코 양상에 많이 관여하지 않는 것으로 나타났다.

• 한국습지학회지
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• 제19권4호
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• pp.451-458
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• 2017

본 연구에서는 비용효율적인 인공습지의 설계를 위하여 초기 침강지 내 다양한 도류벽형태에 따른 인공습지의 사수역 및 입자상 물질의 제거효율을 전산유체역학(Computational Fluid Dynamics, CFD)을 통해 연구하였다. 그 결과, 초기 침강지에서 도류벽의 형태는 유입 유속에 영향을 미치며, 침전률에도 큰 영향을 미치는 것으로 분석되었다. $2{\mu}m$ 와 $5{\mu}m$와 같은 미세한 입자에서는 수평으로 설치한 도류벽에서 침전률이 높았으며, $10{\mu}m$와 $20{\mu}m$ 크기의 큰 입자는 수직형 도류벽에서도 높은 침전률을 나타내었다. 또한, 수직형 도류벽의 경우 좁은 면적에 침전이 집중적으로 이루어지기에 다른 형태에 비해 유지관리가 효율적일 것으로 판단되었다. 이에 인공습지의 설계 목적에 따라 가장 적절한 도류벽의 형태를 선정하여 설계해야 할 것으로 보여진다.

• 한국수산과학회지
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• 제38권4호
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.

• Fisheries and Aquatic Sciences
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• 제12권4호
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• pp.350-353
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• 2009

As a result of human industrial development, carbon dioxide ($CO_2$) is currently accumulating in the atmosphere and dissolving into the oceans. Sequestration into the deep sea has been proposed as a possible solution to this increasing atmospheric $CO_2$, although the impact of such a program on marine ecosystems is unknown. We examined the effects of increased $CO_2$ levels on the growth of the olive flounder, Paralichthys olivaceus. Juvenile olive flounder 40 days post hatching were exposed to two levels of $CO_2$ (3.60-7.55 and 4.05-11.46 kPa) in running seawater for 26 days. During the exposure period, the pH and $CO_2$ levels of the water were measured, and the numbers of dead individuals were counted in each aquarium. Following the exposure period, the total lengths (mm) and body weights (mg) of the juvenile fish were measured. Both $CO_2$ treatments significantly increased fish mortality compared to controls ($19.87\pm4.53%$ vs. 7.14% and $75.96\pm1.36%$ vs. 7.14% for high and low doses, respectively). After the high $CO_2$ treatment, total length ($14.98\pm6.58$ mm vs. $19.52\pm1.83$ mm) and body weight ($28.92\pm13.85$ mg vs. $67.35\pm18.32$ mg) of the exposed flounder were reduced compared to the control fish; however, no significant differences in these values were observed after the low $CO_2$ dose. These results suggested that $CO_2$ exposure inhibits growth in the juvenile stage and that $CO_2$-enriched seawater is toxic in the early life stages of olive flounder.

• 대한한의학방제학회지
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• 제13권1호
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• pp.123-143
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• 2005

Objective : This study was carried out to evaluate the liver toxicities of Wild Aconiti Tuber decoction. Methods : The amounts of aconitine in the methanol extract of Wild Aconiti Tuber was measured by HPLC. Safeties was studied by LD50 in mice. Liver toxicities were evaluated histologically and by CBC, blood chemistry after 2 weeks of 0.4g/kg/day clinical dosage oral administrations in rat. Results : 1. The amounts of aconitine in the methanol extract of Wild Aconiti Tuber is $1.697{\pm}0.052mg/g$. But aconitine was not detected in the water decoction of Wild Aconiti Tuber. 2. To evaluate LD50 and safeties of Wild Aconiti Tuber decoction, ICR mice were given high dose of 2, 5, 10g/kg for single time and were observed for 2 weeks. There were no dead animal and abnormal clinical sign and no abnormalities at the autopsy. So, LD50 was admitted to higher than 10g/kg. 3. After 2 weeks of 0.4g/kg/day clinical dosage oral administrations in rat, there was no significant change in the CBC and blood chemistry. 4. In the liver tissues of clinical dosage, mitotic figures, apoptosis and individual cell death were observed, but clear liver toxicities like fatty liver or necrosis were not observed. the liver tissues of high dose in mice, hydropic changes were getting severe as dose grows. Conclusions : According to the results, though aconitine was not detected in the Wild Aconiti Tuber decoction, 0.4g/kg/day 2 weeks p. o (clinical dosage) group showed weak changes in the liver tissues and high dose group showed liver toxicities like hydropic changes.