• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.157-169
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• 2019

Pseudotachylytes, produced by frictional heating during seismic slip, provide information that is critical to understanding the physics of earthquakes. We report the results of occurrence, structural characteristics, scanning electron microscopic observation and geochemical analysis of pseudotachylytes, which is presumed to have formed after the Late Cretaceous in outcrops of the Paleoproterozoic granitic gneiss on the Bulil waterfall of the Jirisan area, Yeongnam massif, Korea. Fault rocks, which are the products of brittle deformation under the same shear stress regime in the study area, are classified as pseudotachylyte and foliated cataclasite. The occurrences of pseudotachylyte identified on the basis of thickness and morphology are fault vein-type and injection vein-type pseudotachylyte. A number of fault vein-type pseudotachylytes occur as thin (as thick as 2 cm) layers generated on the fault plane, and are cutting general foliation and sheared foliation developed in granitic gneiss. Smaller injection vein-type pseudotachylytes are found along the fault vein-type pseudotachylytes, and appear in a variety of shapes based on field occurrence and vein geometry. At a first glance fault vein-type seudotachylyte looks like a mafic vein, but it has a chemical composition almost identical to the wall rock of granitic gneiss. Also, it has many subrounded clasts which consist predominantly of quartz, feldspar, biotite and secondary minerals including clay minerals, calcite and glassy materials. Embayed clasts, phenocryst with reaction rim, oxide droplets, amygdules, and flow structures are also observed. All of these evidences indicate the pseudotachylyte formed due to frictional melting of the wall rock minerals during fault slip related to strong seismic faulting events in the shallow depth of low temperature-low pressure. Further studies will be conducted to determine the age and mechanical aspect of the pseudotachylyte formation.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.47-55
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• 2009

This study was carried out to investigate the effects of spider-derived protease [Arazyme (AZ)] supplementation on egg production, egg quality, cecal microflora and viscosity of intestinal contents in laying hens at the late production. A total of two hundred, 59-wks-old, Hy-Line Brown layers were divided into four groups, placed into 5 replicates per group (50 birds per group) and fed one of four diets containing 0.05, 0.075 or 0.1% AZ or control for 5 wks. The results showed that egg weight in group fed the diet containing 0.05% AZ was significantly higher than those of other groups (P<0.05). There were no significant differences in egg interior and eggshell qualities among the groups. The serum parameters such as total cholesterol, the levels of GOT and GPT were not influenced by AZ feeding. There were no significant differences in the cecal number of total microbes, Coliforms and lactic acid bacteria among the groups. The viscosity and ammonia concentration of intestinal contents in the groups fed AZ were significantly reduced compared to those of the control (P<0.05). In conclusion, laying hens fed AZ supplemented diet improved egg weight as compared with that of control. In addition, the AZ supplemented diet reduced the viscosity and ammonia concentration of intestinal contents, reflecting a significant feed enzyme effect.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.153-162
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• 2008

This experiment was conducted to evaluate the dietary effects of mixture of probiotics and colistin on laying performance, intestinal microflora and egg yolk cholesterol in laying hens. One hundred sixty 50-wk-old Hy-Line Brown layers were divided into four treatments and fed a commercial diet (Control) or experimental diets containing 0.2% mixture of probiotics or probiotics and colistin mixture (T1, Bacillus subtilis + Aspergillus oryzae + Lactobacillus plantarum; T2, Bacillus subtilis + Aspergillus oryzae; T3, Bacillus subtilis + Aspergillus oryzae+colistin) for 8 wk. No significant differences were found in laying performance and liver weight among the groups. The Haugh unit of treated groups were significantly improved (P<0.05) compared to that of control, but eggshell qualities were not changed by the treatments. The cecal ammonia concentration was significantly decreased in both T1 and T3 groups. The number of coli forms in cecal content and feces were significantly reduced in all treated groups compared to that of Control (P<0.05). The egg yolk cholesterol contents in the groups fed the diet containing mixture of probiotics and colistin were reduced in comparison with that of Control. In conclusion, dietary supplementation of mixture of probiotics and colistin improved quality of egg albumen, and reduced the egg cholesterol contents. They also reduced intestinal coli forms without harmful effects on overall productive and physiological responses in laying hens.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.469-477
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• 2008

Purpose: The goal of this paper is to present the design and performance of a position encoding circuit for $16{\times}16$ array of position sensitive multi-anode photomultiplier tube for small animal PET scanners. This circuit which reduces the number of readout channels from 256 to 4 channels is based on a charge division method utilizing a resistor array. Materials and Methods: The position encoding circuit was simulated with PSpice before fabrication. The position encoding circuit reads out the signals from H9500 flat panel PMTs (Hamamatsu Photonics K.K., Japan) on which $1.5{\times}1.5{\times}7.0\;mm^3$ $L_{0.9}GSO$ ($Lu_{1.8}Gd_{0.2}SiO_{5}:Ce$) crystals were mounted. For coincidence detection, two different PET modules were used. One PET module consisted of a $29{\times}29\;L_{0.9}GSO$ crystal layer, and the other PET module two $28{\times}28$ and $29{\times}29\;L_{0.9}GSO$ crystal layers which have relative offsets by half a crystal pitch in x- and y-directions. The crystal mapping algorithm was also developed to identify crystals. Results: Each crystal was clearly visible in flood images. The crystal identification capability was enhanced further by changing the values of resistors near the edge of the resistor array. Energy resolutions of individual crystal were about 11.6%(SD 1.6). The flood images were segmented well with the proposed crystal mapping algorithm. Conclusion: The position encoding circuit resulted in a clear separation of crystals and sufficient energy resolutions with H9500 flat-panel PMT and $L_{0.9}GSO$ crystals. This circuit is good enough for use in small animal PET scanners.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.334-344
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• 1983

This study was conducted to investigate the variables affecting the performance of hammer mills by the theoretical and dimensional analysis, and evaluate the power requirements of hammer mills for farm use in Korea. From the theoretical analysis, 16 variables affecting the performance of hammer mills were defined. In order to develop the mathematical relationships among the variables, the dimensional analysis was made for power requirements and $12{\pi}$ parameters were obtained. For the evaluation of the power requirements of hammer mills, approximate rates of grinding for 1HP, 3HP, 5HP, 6HP, 8HP, and 10HP were analyzed. Then, the fineness of grinding recommendation and average feeding rate of grain for livestock which is native cattle, dairy cattle, beef cattle, swine, broilers, and layers, were estimated. Finally number of livestock feeding shelled corn and barley were estimated from the above for one hour's hammer mill operation having the various power requirements. From this study it is known that 5HP is considered as an enough power for feed grinding of any kinds of livestock of Korean farm, as far as the grinding capacity is concerned.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.241-250
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• 1982

The structure of gonads, gametogenesis and reproductive cycle of the cockle, Fulvia mutice, were studied mainly by histological observation. The materials were monthly sampled in the southern area of Yeosu from October 1980 to September 1981. F. mutica was monoecious. The gonads were situated between the liver tissues and the outer fibronuscular layers compacted by the connective tissue fibers and muscle fibers beneath the outermost layer of simple cuboidal epithelium. The gonad was composed of a number of the ovarian sacs and the testicular tubules which form the tubular structure. Testicular tubules in the mature stage sometimes contained 'testis-ova' The undifferentiated mesenchymal tissues and the eosinophilic cells were abundantly distributed on the germinal epithelium in the early development stage. With the further development of the ovary and testis, these tissues and cells gradually disapprared. The undifferentiated mesenchymal tissues and the eosinophilic cells are related to the growing of the oocytes and spermatocytes . Early multiplicating oogonium was about $10{\mu}m$ in diameter. As the oocytes grow to $27-34\times50-58{\mu}m$ by increasing cytoplasm, the oocytes connected to the basement membrane by their egg-stalks. The ripe eggs were about $60{\mu}m$ in diameter and they were surrounded by gelatinous membrane. Most male germ cells in mature stage were transformed into the spermatozoa and they formed the sperm bundles. After spawning, undischarged ripe eggs and spermatozoa remained in the ovarian sac and the testicular tubule respectively for some time, then they finally degenerated. Especially the early spent ovarian sacs in May did not contract significantly and then they took part in the secondary maturation within two or three months during the summer season. The monthly changes of the fatness well agreed with the reproductive cycle. The reproductive cycle of F. mutica could be classified into six successive stages : multiplicative, growing, mature, spent, degenerative and recovery stage. It seems that the spawning season is closely rotated to the water temperature, and the spawning occurs from May to October at about $20^{\circ}C$ in water temperature. The peak spawning seasons appeared twice a year between June and July and in September. Acknowledgement The authors wish to express their gratitude to Dr. Kim, In Bae, Dr. Chun, Seh Kyu and Dr. Yoo, Sung Kyoo of National Fisheries University of Busan and Mr. Min, Byoung Seo of National fisheries Research and Development Agency for their critical reading of the manu script.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1078-1086
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• 1996

The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using $2g/10mL(W-IPA/H_2O)$ sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layers dried at the temperature of $65{\sim}70^{\circ}C$ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of $230{\sim}240^{\circ}C$ for 30min. A linear rotation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had $60{\AA}$ after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical characteristic of the $ITO/WO_3$ thin film electrode were confirmed by the cyclic voltammetry and the cathodic Tafel polaization method. The coloring bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in $H_2SO_4$ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.151-164
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• 2022

According to the records of historical and instrumental earthquakes, the southeastern part of the Korean Peninsula is considered the highest seismic activity area. Owing to recent reports of numerous Quaternary faults along the Yangsan and Ulsan fault zones, paleoseismological studies are being actively conducted in these areas. The study area is located in the central part of the Ulsan fault zone, where the largest number of active faults have been reported. Based on lineament and geomorphic analysis using LiDAR images and aerial photographs, fault-related landforms showing topographic relief were observed and a trench survey was conducted. The trench length 20 m, width 5 m, depth 5 m is located approximately 300 m away to the northeast from the previously reported Malbang fault. From the trench section, we interpreted the geometric and kinematic characteristics of the fault based on the deformed features of the Quaternary sedimentary layers. The attitude of the reverse fault, N26°W/33°NE, is similar to those of the reported faults distributed along the Ulsan fault zone. Although a single apparent displacement of approximately 40 cm has been observed, the true displacement could not be calculated due to the absence of the slickenline on the fault plane. Based on the geochronological results of the cryogenic structure proposed in a previous study, the most recent faulting event has been estimated as being earlier than the late Wurm glaciation. We interpreted the thrust fault system of the study area as an imbrication structure based on the previous studies and the fault geometry obtained in this additional trench. Although several previous investigations including many trench surveys have been conducted, they found limited success in obtaining the information on fault parameters, which could be due to complex characteristics of the reverse fault system. Additional paleoseismic studies will contribute to solving the mentioned problems and the comprehensive fault evolution.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.207-221
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• 2023

This study suggests deep neural network models for estimating air temperature with Level 1B (L1B) datasets of GEO-KOMPSAT-2A (GK-2A). The temperature at 1.5 m above the ground impact not only daily life but also weather warnings such as cold and heat waves. There are many studies to assume the air temperature from the land surface temperature (LST) retrieved from satellites because the air temperature has a strong relationship with the LST. However, an algorithm of the LST, Level 2 output of GK-2A, works only clear sky pixels. To overcome the cloud effects, we apply a deep neural network (DNN) model to assume the air temperature with L1B calibrated for radiometric and geometrics from raw satellite data and compare the model with a linear regression model between LST and air temperature. The root mean square errors (RMSE) of the air temperature for model outputs are used to evaluate the model. The number of 95 in-situ air temperature data was 2,496,634 and the ratio of datasets paired with LST and L1B show 42.1% and 98.4%. The training years are 2020 and 2021 and 2022 is used to validate. The DNN model is designed with an input layer taking 16 channels and four hidden fully connected layers to assume an air temperature. As a result of the model using 16 bands of L1B, the DNN with RMSE 2.22℃ showed great performance than the baseline model with RMSE 3.55℃ on clear sky conditions and the total RMSE including overcast samples was 3.33℃. It is suggested that the DNN is able to overcome cloud effects. However, it showed different characteristics in seasonal and hourly analysis and needed to append solar information as inputs to make a general DNN model because the summer and winter seasons showed a low coefficient of determinations with high standard deviations.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.95-107
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• 2017

In this study, a preliminary study was undertaken for development of a tunnel incident automatic detection system based on a machine learning algorithm which is to detect a number of incidents taking place in tunnel in real time and also to be able to identify the type of incident. Two road sites where CCTVs are operating have been selected and a part of CCTV images are treated to produce sets of training data. The data sets are composed of position and time information of moving objects on CCTV screen which are extracted by initially detecting and tracking of incoming objects into CCTV screen by using a conventional image processing technique available in this study. And the data sets are matched with 6 categories of events such as lane change, stoping, etc which are also involved in the training data sets. The training data are learnt by a resilience neural network where two hidden layers are applied and 9 architectural models are set up for parametric studies, from which the architectural model, 300(first hidden layer)-150(second hidden layer) is found to be optimum in highest accuracy with respect to training data as well as testing data not used for training. From this study, it was shown that the highly variable and complex traffic and incident features could be well identified without any definition of feature regulation by using a concept of machine learning. In addition, detection capability and accuracy of the machine learning based system will be automatically enhanced as much as big data of CCTV images in tunnel becomes rich.