• Membrane Journal
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• v.19 no.3
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• pp.194-202
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• 2009

In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in advanced water treatment by tubular ceramic ultrafiltration membrane for Gongji stream in Chuncheon city. The back-flushing period (FT, filtration time) 2 min with periodic water-back-flushing of 15 sec showed the highest value of dimensionless permeate flux (permeate flux vs. initial permeate flux), and the lowest value of resistance of membrane fouling. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of resistance of membrane fouling and the highest value of dimensionless permeate flux, and we could be obtained the highest total permeate volume of 107.3 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment, which was the exactly same results of our previous tubular alumina microfiltration. Then the average rejection rates of pollutants by our tubular ceramic UF system were 97.0% for turbidity, 32.1 % for chemical oxygen demand by manganese method, 28.8% for ammoniac nitrogen and 54.4% for T-P.

• Nuclear Engineering and Technology
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• v.16 no.1
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• pp.11-17
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• 1984

Sample calculations were done for KORI-1 to develop a better understanding of what happens after very small LOCA ($\leq$0.05 ft$^2$). For a water-side break with the break size larger than 0.006 ft$^2$, fluid-loss through break exceeds the makeup. If the break size is larger than 0.008ft$^2$, decay heat can be completely removed through break. Based on these results, it was concluded that KORI-1 is fairly safe for the whole spectrum of sizes in very small LOCA. However, for the reactor with 900 MWe or 1200 MWe, a certain spectrum of sizes in very small LOCA should be carefully considered. In the accident sequence the transition from natural circulation to pool boiling or from pool boiling to natural circulation may be troublesome to the operator or in the safety analysis. Operator's intervention was discussed; primary pump shutoff, HPI pump shutoff, break isolation, and opening relief valve. It was proved that continuous operation of HPI pumps after shutdown will not threaten the integrity of the primary system.

• Analytical Science and Technology
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• v.17 no.1
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• pp.45-52
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• 2004

Determination of some PAHs in sediments at Ulsan bay has been carried out by extraction of the components into n-hexane followed by synchronous spectrofluorimetric technique. 11 PAHs, such as acenaphthene (Ace), anthracene (Anth), benz(a)anthracene (BaA), benzo(b)fluoranthene (BbFt), benzo(k)fluoranthene (BkFt) benzo(a)pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthene(Ft), perlyrene (Per), and pyrene (Pyr) in sediment samples were able to determine separately by synchronous spectrofluorimetry. Calibration curves for those components were linear for the concentration range of 0.15~166 ppb PAHs with the correlation factor of 0.9985~0.9999. The total amount of PAHs in sediments varied from 68.8 to 324.4 ng/g. The PAHs concentration was shown a tendency to increase from the outer bay to the inner basin as well the predominant contributors to the aromatic ring groups of the PAHs was 4-ring group.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.335-365
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• 2012

Fission-track (FT) thermochronological records from SE Korean Cretaceous-Paleogene granitic plutons in different fault-bounded blocks reveal contrasting cooling and later thermal histories. Overall cooling patterns are represented by a monotonous (J-shaped) curve in most plutons except some Cretaceous granites retaining a complicated (N-shaped) path due to post-reset re-cooling. Discriminative cooling rates over different temperature ranges can be explained for individual plutons with respect to relative pluton sizes, differences in initial heat loss depending on country rocks, and the presence and proximity of later igneous activity. Even within a single batholith, cooling times for different isotherms were roughly contemporaneous with respect to positions. Insignificant deviations in cooling ages from two different plutons in succession across the Yangsan fault may suggest their contemporaneity before major horizontal fault movement. The extent of later thermal rise recorded locally along the Yangsan and Dongnae fault zones were reached the Apatite Partial Stability Zone ($70-125^{\circ}C$), but did not exceed $200^{\circ}C$. Thermal alteration from fractured zones in the Yangsan-Ulsan fault junction may suggest a thermal reset above $290^{\circ}C$ resulting a complete reset in FT sphene age (31 Ma), caused by a tectonic subsidence in Early Oligocene. A consistency in FT zircon/apatite ages (24 Ma) may imply a sudden rapid cooling over $200-105^{\circ}C$, plausibly related to the abrupt tectonic uplift of the Pohang-Gampo Block including the fault junction in Late Oligocene. A remarkable trend of lower cooling ages for $300-200-100^{\circ}C$ isotherms (i.e., 19% for FT sphene and K-Ar biotite; 20% for FT zircon; 27% for FT apatite) from the east of the Ulsan fault (Pohang-Gampo Block) comparing to the west of the fault may be attributed to retarded cooling times from the Paleogene granites and also reflected by their partially-reduced apatite ages due to later thermal effects.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.83-115
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• 2013

Erroneous fission-track (FT) ages caused by an inappropriate calibration in the initial stage of FT dating were redefined by re-experiments and zeta calibration using duplicate samples. Revised FT zircon ages newly define the formation ages of Yucheon Group rhyolitic-dacitic tuffs as Late Cretaceous to Early Paleocene ($78{\pm}4$ Ma to $65{\pm}2$ Ma) and Gokgangdong rhyolitic tuff as Early Eocene ($52.1{\pm}2.3$ Ma). In case of the Early Miocene volcanics, FT zircon ages from a dacitic tuff of the upper Hyodongri Volcanics ($21.6{\pm}1.4$ Ma) and a dacitic lava of the uppermost Beomgokri Volcanics ($21.3{\pm}2.0$ Ma) define chronostratigraphies of the upper Beomgokri Group, respectively in the southern Eoil Basin and in the Waeup Basin. A FT zircon age ($19.8{\pm}1.6$ Ma) from the Geumori dacitic tuff defines the time of later dacitic eruption in the Janggi Basin. Based on FT zircon ages for dacitic rocks and previous age data (mostly K-Ar whole-rock, partly Ar-Ar) for basaltic-andesitic rocks, reference ages are recommended as guides for stratigraphic correlations of the Miocene volcanics and basements in SE Korea. The times of accumulation of basin-fill sediments are also deduced from ages of related volcanics. Recommended reference ages are well matched to the whole stratigraphic sequences despite complicated basin structures and a relative short time-span. The Beomgokri Group evidently predates the Janggi Group in the Eoil-Waeup basins, while it is placed at an overlapped time-level along with the earlier Janggi Group in the Janggi Basin. Therefore, the two groups cannot be uniformly defined in a sequential order. The Janggi Group of the Janggi Basin can be evidently subdivided by ca. 20 Ma-basis into two parts, i.e., the earlier (23-20 Ma) andesitic-dacitic and later (20-18 Ma) basaltic strata.

• Journal of Korea Water Resources Association
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• v.57 no.7
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• pp.437-449
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• 2024

Rainfall-runoff prediction studies using deep learning while considering catchment attributes have been gaining attention. In this study, we selected two models: the Transformer model, which is suitable for large-scale data training through the self-attention mechanism, and the LSTM-based multi-state-vector sequence-to-sequence (LSTM-MSV-S2S) model with an encoder-decoder structure. These models were constructed to incorporate catchment attributes and predict the inflow of 10 multi-purpose dam watersheds in South Korea. The experimental design consisted of three training methods: Single-basin Training (ST), Pretraining (PT), and Pretraining-Finetuning (PT-FT). The input data for the models included 10 selected watershed attributes along with meteorological data. The inflow prediction performance was compared based on the training methods. The results showed that the Transformer model outperformed the LSTM-MSV-S2S model when using the PT and PT-FT methods, with the PT-FT method yielding the highest performance. The LSTM-MSV-S2S model showed better performance than the Transformer when using the ST method; however, it showed lower performance when using the PT and PT-FT methods. Additionally, the embedding layer activation vectors and raw catchment attributes were used to cluster watersheds and analyze whether the models learned the similarities between them. The Transformer model demonstrated improved performance among watersheds with similar activation vectors, proving that utilizing information from other pre-trained watersheds enhances the prediction performance. This study compared the suitable models and training methods for each multi-purpose dam and highlighted the necessity of constructing deep learning models using PT and PT-FT methods for domestic watersheds. Furthermore, the results confirmed that the Transformer model outperforms the LSTM-MSV-S2S model when applying PT and PT-FT methods.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1257-1257
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• 2001

Fourier transform near infrared (FT-NIR) spectroscopy was used as a rapid method to measure the $^{o}Brix$ content and to discriminate between different must samples in terms of their fee amino nitrogen (FAN) values. FT-NIR spectroscopy was also used as a rapid method to discriminate between Chardonnay wine samples in terms of the status of the male-lactic fermentation (MLF). This was done by monitoring the conversion of malic to lactic acid and thereby determining whether MLF has started, is underway or has been completed followed by classification of the samples. Furthermore, FT-NIR spectroscopy was applied as a rapid method to discriminate between table wine samples in terms of the ethyl carbamate (EC) content. EC in wine can pose a health threat and need to be monitored by determining the EC content in relation to the regulatory limits set by the authorities. For each of the above mentioned parameters, $QUANT+^{TM}$ methods were built and calibrations derived and it was found that a very strong correlation existed in the sample set for the FT-NIR spectroscopic predictions of $^{o}Brix$ (r = 0.99, SECV = 0.306), but the correlations for the FAN (r = 0.61, SECV = 272.1), malic acid (r = 0.58, SECV = 1.06), lactic acid (r = 0.51, SECV = 1.14) and EC predictions (r = 0.47, SECV = 3.67) were not as good. Soft Independent Modeling by Class Analogy (SIMCA) diagnostics and validation was applied as a sophisticated discrimination method. The must samples could be classified in terms of their FAN values when SIMCA was applied, obtaining results with recognition rates exceeding 80%. When SIMCA diagnostics and validation were applied to determine the progress of conversion of malic to lactic acid and the EC content, again results with recognition rates exceeding 80% were obtained. The evaluation of the applicability of FT-NIR spectroscopy measurement of FAN, $^{o}Brix$ values, malic acid, lactic acid and EC content in must and wine shows considerable promise. FT-NIR spectroscopy has the potential to reduce the analytical times considerably in a range of measurements commonly used during the wine making process. Where conventional FT-NIR calibrations are not effective, SIMCA methods can be used as a discriminative method for rapid classification of samples. SIMCA can replace expensive, time-consuming, quantitative analytical methods, if not completely, at least to some extent, because in many processes it is only needed to know whether a specific cut off point has been reach or not or whether a sample belongs to a certain class or not.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.1-12
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• 2006

This study was carried out to compile year 2001 forest resource statistics for the State of Virginia. USA. Virginia has 15.8 million acres (6.4 million ha) of forested 1and, accounting for 62% of the landcover with non-industrial private forest landowners owning 77% of the forested area. Deciduous forests make up 78% of Virginia's forests. Total tree volume is 26.5 billion cubic ft, of which average volume per acre is $1.677ft^3/ac(117m^3/ha)$. The overall annual volume of roundwood output is $543\;million\;ft^3$. Tree growth exceeds removals by $271\;million\;ft^3$ each year for all species statewide. Average net forest land loss in Virginia is 20,000 acre (8,094 ha) per year. In 1999, the forest products industry contributed over $25.4 billion to Virginia's economy while providing over 248,000 jobs. Among forest industries logging contributes to the economy at over $863 million/yr; timber accounts for the greatest amount (28%) of the total market value of Virginia's agricultural crops. Revenue received from stumpage by landowners exceeded $345 million/yr. In their entirety. Virginia's forests provide over $30.5 billion in annual return. including $3 billion for recreation and $1.9 billion for carbon sequestation and pollution control.

• Journal of Korean Physical Therapy Science
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• v.11 no.1
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• pp.14-19
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• 2004

Objective : This study obtained normative values for variable parameters of lumbar function with the isoinertial triaxial dynamometer in patients with chronic low back pain. Subjects and Methods : 30 patients(male 15, female 15) with chronic low back pain in this study. Variable parameters that were measured with the Isostation B-200 were lumbar range of motion, isometric maximum torques, and maximum velocities in three axis. Results : In patient male group mean R.O.M. was $82.9{\pm}12.5$ degrees in lumbar rotation, $76.5{\pm}17.1$ degrees in lumbar flexion/extension, and $64.3{\pm}14.5$ degrees in lumbar lateral flexion. In patient female group mean R.O.M. was $78.4{\pm}18.5$ degrees in lumbar rotation, $71.7{\pm}20.4$ degrees in lumbar flexion/extension, and $63.2{\pm}14.4$ degrees in lumbar lateral flexion. In patient male group mean isometric maximum torques was $64.7{\pm}23.8ft-lbs$ in lumbar rotation, $81.1{\pm}42.0ft-lbs$ in lumbar flexion, $122.2{\pm}43.6ft-lbs$ in lumbar extension, and $101.0{\pm}37.0ft-lbs$ in lumbar lateral flexion. In patient female group mean isometric maximum torques was $41.9{\pm}9.2ft-lbs$ in lumbar rotation, $49.9{\pm}23.9ft-lbs$ in lumbar flexion, $90.1{\pm}26.8ft-lbs$ in lumbar extension, and $62.0{\pm}16.7ft-lbs$ in lumbar lateral flexion. In patient male group mean maximum velocity of isoinertial exercise with low (25%) resistance was $102.4{\pm}28.8deg/sec$ in lumbar rotation, $108.9{\pm}32.2deg/sec$ in lumbar flexion/extension, and $103.5{\pm}30.4deg/sec$ in lumbar lateral flexion. In patient female group mean maximum velocity of isoinertial exercise with low (25%) resistance was $84.1{\pm}24.4deg/sec$ in lumbar rotation, $93.2{\pm}32.9deg/sec$ in lumbar flexion/extension, and $98.5{\pm}33.7deg/sec$ in lumbar lateral flexion. In patient male group mean maximum velocity of isoinertial exercise with high (50%) resistance was $74.0{\pm}20.9deg/sec$ in lumbar rotation, $98.7{\pm}32.8deg/sec$ in lumbar flexion/extension, and $85.0{\pm}25.8deg/sec$ in lumbar lateral flexion. In patient female group mean maximum velocity of isoinertial exercise with high (50%) resistance was $67.3{\pm}26.4deg/sec$ in lumbar rotation, $82.5{\pm}31.0deg/sec$ in lumbar flexion/extension, and $79.7{\pm}23.9deg/sec$ in lumbar lateral flexion. Conclusion : Maximum isoinertial velocities were more reliable and more significant than isometric maximum torque for the objective assessment of chronic low hack pain.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.383-390
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• 2016

To determine whether FT-IR spectral analysis based on multivariate analysis could be used to discriminate Chinese cabbage breeding line at metabolic level, whole cell extracts of nine different breeding lines (three paternal, three maternal and three $F_1$ lines) were subjected to Fourier transform infrared spectroscopy (FT-IR). FT-IR spectral data of Chinese cabbage plants were analyzed by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and hierarchical clustering analysis (HCA). The hierarchical dendrograms based on PLS-DA from two of three cross combinations showed that paternal, maternal, and their progeny $F_1$ lines samples were perfectly separated into three branches in breeding line dependent manner. However, a cross combination failed to fully discriminate them into three branches. Thus, hierarchical dendrograms based on PLS-DA of FT-IR spectral data of Chinese cabbage breeding lines could be used to represent the most probable chemotaxonomical relationship among maternal, paternal, and $F_1$ plants. Furthermore, these metabolic discrimination systems could be applied for rapid selection and classification of useful Chinese cabbage cultivars.