• Korean Journal of Microbiology
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• v.32 no.3
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• pp.202-207
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• 1994

A mutant strain PRM1 defective in light-activated heterotrophic growth was isolated from Synechocystis sp. PCC 6803. PRM1 could be grown at growth rate equivalent to Synechocystis 6803 under mixotrophic growth conditions. However, PRM1 could not be grown under light-activated heterotrophic conditions, in which a daily pulse of light for 5 min was given. These results suggest that PRM1 is not defective in heterotrophic metabolism, but in the transduction pathway of light signal essential to the growth. Plasmid patterns, absorption spectra of whole cells, and the exterior and interior structures of PRM1 were similar to those of Synechocystis 6803, except that PRM1 could not produce amorphous slime holding cells together.

• The Journal of the Acoustical Society of Korea
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• v.13 no.3
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• pp.5-15
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• 1994

In order to examine the propagation loss associated with water depth and bottom sediment type, an acoustic experiment was conducted in the Southeast Sea of Korea. A sound source was towed along the pre-defined tracks in about 5kts and the signal was simultaneously received at three bottom-moored hydrophones. The propagation loss of sound wave traveling along the isodepth was compared with that crossing the isodepth. The former case shows, in general, less loss than the latter. This trend is stronger as the distance between a source and a receiver increases. When sound wave propagates across the isodepth, we also find that the propagation loss is influenced by the upsloping and downslopoing conditions of wave propagtion. In general, the propagation loss under downsloping condition is smaller than that of upsloping condition, and the differences are as large as 10dB in some cases. However, little difference are found in the propagation loss depending on the bottom types : gravelly sand and sand-silt-clay. Meanwhile, the optimum propagation frequencies are found within range of 130-255Hz.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.130-135
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• 1991

The effects of a herbicide butachlor[2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide] on the growth of the purple non-sulfur bacteria were investigated. The butachlor inhibited the growth of all species tested by 18-51%, except Rhodospirillum rubrum at concentrations of M, which would be field capacity. The photosynthetic growth rate of the species in the presence of butachlor was influenced by the nitrogen source. Cultures supplied with (NH&S04 showed a somewhat higher growth rate than those fixing dinitrogen, but they were more susceptible to butachlor (26-51%). On the contrary, butachlor enhanced the growth rate of Rhodospirillum rubrum in nitrogen gas conditions. When the culture was performed in medium with butachlor as the carbon source, the cells of fixing dinitrogen showed a higher exhaustion of butachlor than those supplemented with (N&)2S04, which exhaustion was examined by a decrease of the major absorbance at 213 nm and 260 nm. The exhaustion of butachlor as the carbon source had relation with the growth of the cells. The alkalization of culture supplemented with nitrogen gas was found in the cells treated with butachlor or untreated. The butachlor affected the carotenoid region but bacteriochlorophyll remained unaffected.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.19-24
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• 2004

To illuminate the physiological response to salinity, barnyard grass (Echinochloa hispidula) was germinated with high concentration of NaCl and KCL. Duration and promptness of seed germination were observed. Under salt stress, lipid peroxidation and polyamine biosynthesis were also analyzed. It appeared that high salt treatments per se did not provoke an inhibition of germination although the process of germination was significantly delayed. In context of lipid peroxidation and polyamine biosynthesis, we would imply that barnyard grass is tolerant to salinity. The increase in lipid peroxidation and putrescine content was prolonged only for 1 day after saline treatment. It could be concluded that these early acciimulation of putrescine and production of lipid peroxide seems to be associated with salt tolerance in the short-term. The physiological interest of these responses was discussed.

• Journal of Korean Library and Information Science Society
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• v.44 no.4
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• pp.209-231
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• 2013

This study is a comparative analysis of R&D performance and research collaboration relationship among ten ocean research institutes in the Republic of Korea and foreign nations through analyzing SCI publications from 2008 to 2012. The result indicated that SIO, WHOI, and NOC had the highest number of publications, while research institutes in East Asian nations including NFRDI, KIOST, IOCAS, and JAMSTEC had the notable growth in publication. In terms of number of publication per researcher, SIO, WHOI, and NOC had relatively high number. In terms of publication per research budget (1 billion KRW), number of publication was high in the order of IOCAS, NOC, GEOMAR, SIO. The number of Citations Per Publications (CPP) was high among WHOI, SIO, NOC, GEOMAR, JAMSTEC, and IFREMER, which are North American, European and Japanese institutes. The average Impact Factor (IF) of journal submission per publication for IFREMER, KIOST and JAMSTEC was relatively increasing, while the number was fluctuating in other institutes. The analysis of research collaboration among institutes around the globe showed that the collaboration in Asia was relatively closed, whereas it was more open in Europe. In the case of Europe and Asia, higher number of research collaboration among nations also increased the quality of submitted articles.

• KIISE Transactions on Computing Practices
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• v.23 no.5
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• pp.299-303
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• 2017

By piling up hidden layers in artificial neural networks, deep learning is delivering outstanding performances for high-level abstraction problems such as object/speech recognition and natural language processing. Alternatively, deep-learning users often struggle with the tremendous amounts of time and resources that are required to train deep neural networks. To alleviate this computational challenge, many approaches have been proposed in a diversity of areas. In this work, two of the existing Apache Spark-based acceleration frameworks for deep learning (SparkNet and DeepSpark) are compared and analyzed in terms of the training accuracy and the time demands. In the authors' experiments with the CIFAR-10 and CIFAR-100 benchmark datasets, SparkNet showed a more stable convergence behavior than DeepSpark; but in terms of the training accuracy, DeepSpark delivered a higher classification accuracy of approximately 15%. For some of the cases, DeepSpark also outperformed the sequential implementation running on a single machine in terms of both the accuracy and the running time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.517-524
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• 2010

Recently, the size of online texts and textual information is increasing explosively, and the automated classification has a great potential for handling data such as news materials and images. Text classification system is based on supervised learning which needs laborous work by human expert. The main goal of this paper is to reduce the manual intervention, required for the task. The other goal is to increase accuracy to be high. Most of the documents have high complexity in contents and the high similarities in their described style. So, the classification results are not satisfactory. This paper shows the implementation of classification system based on ETOM+RPost algorithm and classification progress using SPAM data. In experiments, we verified our system with right-training documents and wrong-training documents. The experimental results show that our system has high accuracy and stability in all situation as 16% improvement in accuracy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.29-37
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• 2011

PIV measurements of the velocity field, pressure field, vorticity, and turbulent intensity in the rear of curved section of an oil fence with current speed showed that the flow directions in the rear of flow boundary area were similar to those in the front of it. As the current speed increased, the patterns of pressure distribution were changed, and the turbulent flow became more irregular. CFD simulations under the same conditions as the PIV tests showed that the flow patterns of the wake were similar to those by PIV tests in speed of 0.3 m/s and less, but were distinctively deviated from those in 0.4 m/s due to the flexibility of the oil fence, which was not properly taken care of in CFD modeling.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.138-141
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• 1999

Purpose : This study was to evaluate the effectiveness of arthroscopic management for septic elbows. Materials and Methods : The subjects were 7 patients ranged in age from 6 to 32 years. All patients were diagnosed as having septic arthritis of the elbow after arthrocentesis. Emergency arthroscopic lavage, debridement, and selective synovectomy for infective and necrotic tissue were performed. All patients had a follow-up period of more than 12 months by checking leukocyte count, ESR, CRP and range of motion. Results : For children, we found a return to normal of laboratory tests for infection after an average of 8.4 days while for adults, it required 12.3 days. After 12 months all patients showed normal elbow function as well as normal blood tests. Conclusion : We found arthroscopic management for septic arthritis of the elbows made it possible to visualize the pathologic findings directly and protect further articular damage. In conclusion, arthroscopic management is one of the efficient methods for controlling the joint infection.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.547-556
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• 2000

A study have been conducted for the adsorption and desorption characteristics of Cu ion using manganese nodule as adsorbent. For 100 ppm Cu ion solution, the adsorbed amount of Cu ion was more than 90 % at equilibrium state. Adsorption was equilibrated in 42 hours the adsorption reaction was shown to be first order reaction. For the desorption reaction of Cu ion in the region of solution pH 3.5~9.5, the desorption was completed in the acidic region, but it has been decreased as the pH was raised. Also, the desorption rate was higher in the acidic region compared with alkaline region. The desorbed amount was decreased as the reaction temperature increased, therefore, the desorption reaction was thought to be exothermic. Also, several thermodynamic properties were calculated based on experimental results and compared with theoretically driven values. To see the effect of complexing agent on the desorption of Cu ion, EDTA was introduced and the des orbed amount increased in the presence of EDTA.