• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.748-757
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• 2007

This paper is intended to solve the technical problem that fails in large-capacity induction motor starting due to serious voltage drop during starting period. One induction motor that is established already can reach in steady-state using reactor starting method but the voltage magnitude of PCC (point of common coupling) has dropped down a little. When the same capacity induction motor is installed additionally in the PCC, where the existing induction motor is operating, voltage drop becomes more serious by starting of additional induction motor. As a result, the additional induction motor fails in starting. Therefore, voltage compensation method is proposed so that all of two induction motors can be started completely. First, modeling technique is described in order to implement starting characteristics of large induction motor. And then, this paper proposes strategic starting scheme by proper voltage compensation that use no-load transformer tap control (NLTC) and step voltage regulator (SVR) for starting of two large induction motors successfully and improving the feeding network voltage profile during the starting period. The induction motor discussed in this paper is the pumped induction motor of 2500kVA capacity that is operating by KOWACO (Korea Water Resources Corporation). Modeling and simulation is conducted using PSCAD/EMTDC software.

• Journal of Intelligence and Information Systems
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• v.28 no.3
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• pp.185-207
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• 2022

Recently, with the development of deep learning technology, researches to apply a deep learning algorithm to analyze unstructured data such as text and images are being actively conducted. Text classification has been studied for a long time in academia and industry, and various attempts are being performed to utilize data characteristics to improve classification performance. In particular, a hierarchical relationship of labels has been utilized for hierarchical classification. However, the top-down approach mainly used for hierarchical classification has a limitation that misclassification at a higher level blocks the opportunity for correct classification at a lower level. Therefore, in this study, we propose a methodology for classifying hierarchical data using the autoencoder-based deeply supervised network that high-level classification does not block the low-level classification while considering the hierarchical relationship of labels. The proposed methodology adds a main classifier that predicts a low-level label to the autoencoder's latent variable and an auxiliary classifier that predicts a high-level label to the hidden layer of the autoencoder. As a result of experiments on 22,512 academic papers to evaluate the performance of the proposed methodology, it was confirmed that the proposed model showed superior classification accuracy and F1-score compared to the traditional supervised autoencoder and DNN model.

• International Area Studies Review
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• v.13 no.1
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• pp.391-416
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• 2009

The purpose of this paper is to provide an ideal agreement proposal for the satisfactory settlement of FTA origin criteria negotiations, which will be the most severe issue in both inter-governmental FTA negotiations to begin in the near future. Towards this end, we, the authors, based on our nine FTA related agreements already concluded with other countries, researched the concrete origin criteria in the previous origin agreements, analyzed the characteristics of these agreements, and derived the ideal origin rule. As a result, we came to the conclusion that in consideration of Korea and China's FTA's substantial transformation test, it's better to choose any one criterion from the following. Criterion 1: CTH (Change of Heading) and Criterion 2: Value Added Criteria by 40% within region. In addition, we also did that in calculating the ratio of value added, the calculation method and price criteria should be more simple and standardized. It led to the conclusion that the objective deduction method should be used mainly and that CIF or FOB should be used as the price criterion.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.3
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• pp.147-155
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• 2010

This study was conducted to investigate the benzene exposure levels in coal chemical and petrochemical refining industries during BTX turnaround (TA) processes where benzene was being produced. Three companies producing benzene were selected, one coal chemical and two petrochemical industries. TA processes were classified into three stages: shut down, maintenance, and start up. Data was analyzed by classifying the refining method into 2 groups (Petrochemistry, Coal chemistry) for 823 workers. Comparing the data from petrochemical industries with data from a coal chemical refining industry, while benzene concentration levels of long-term samples during TA were not statistically different (p> 0.05), those levels of short-term samples were significantly different (p< 0.001). About 4.79 % of data in petrochemical industries exceed the occupational exposure limits (OELs) of benzene, 1 ppm. In a coal refining methods, about 15.7% exceeded the benzene OELs. The benzene concentrations in maintenance and start up stage of TA for petrochemical refineries were higher than those in a coal chemical refinery (p <0.01). These findings suggest that the coal chemical refining site requires more stringent work practice controls compare to petrochemical refining sites during TA processes. Personal protective equipments including organic respirators should be used by TA workers to protect them from benzene overexposure.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.95-109
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• 2014

The variety show has expanded as a contemporary genre of popular culture since it first appeared as the Industrial Revolution allowed the public to enjoy their leisure time. In Korea, it has developed itself in similar ways, but it also has been criticized as low-brow. Recently, however, the real variety show has caught great attention as one of the social phenomena and is winning fervent responses from general publics as it is not consumed as a kind of entertainment show but is establishing its form and style as Korean real variety show. On the basis of these features, this paper focuses on the characteristics of real variety show as openness and expandability which can be found in the pre-modern Korea's traditional theatrical performances. Quite different from the cases in the Western culture, the Korean traditional theatrical performances used to set a stage up around the living space, attract audience to willingly approach the stage and participate in the theatre, and let them enjoy their participation. At the same time, however, The perfection of the shows had not been missed. And in comparison with the traditional theatrical performances, the present real variety show reveals the anticipation that the real variety show will not settle down just as a certain format or a genre, but accumulate its abundant contents and continue its new attempts and changes.

• Ocean and Polar Research
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• v.23 no.2
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• pp.77-95
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• 2001

Temperature, salinity, nutrients, chlorophyll-a, and primary production were measured within the upper 200 m water column in the area around the South Shetland Islands in January, 2000. Surface temperature was relatively high in the Drake Passage north of the South Shetland Islands and low in the northeastern area of the Antarctic Peninsula. In contrast, surface salinity was low in the Drake Passage and increased toward the Antarctic Peninsula, reaching the maximum value in the northeastern area of the Antarctic Peninsula. Surface nutrients were low in the Drake Passage and high in the area near the South Shetland Islands. Surface chlorophyll-a was also low in the Drake Passage and near the Antarctic Peninsula and high in the area of the northern King George Island. The study area could be classified as four geographical zones based on the characteristic shape of the T/S diagrams;the Drake Passage, the Bransfield Strait, the mixed zone, and the Weddell Sea. Each geographical zone showed apparently different physical, chemical, and biological characteristics. Phytoplankton biomass was relatively low in the Drake Passage and the Weddell Sea and high in the Bransfield Strait and the mixed zone. The low phytoplankton biomass in the Weddell Sea could be explained by the low water temperature and deep surface mixing down to 200 m. The high grazing pressure and low availability of iron could be responsible for the low phytoplankton biomass in the Drake Passage.

• Fire Science and Engineering
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• v.31 no.6
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• pp.16-22
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• 2017

In Korea, performance-based fire safety designs are being discussed to deal with the various risks of fire in complex and diverse types of structure. However, performance-based fire safety designs are not actively employed because it is difficult to estimate the fire characteristics related to the various factors in buildings. In this study, real scale fire tests were conducted based on fire severity levels and fire loads provided in He New Zealand Building Code, in order to use the results as guidelines and fundamental data for performance-based designs. In the real scale fire tests conducted in a 10MW full-scale calorimeter, wood cribs were placed in a $2.4(L){\times}3.6(W){\times}2.4(H)m$ mock-up of a compartment which had one $0.8(L){\times}2.0(H)$ opening for different fire loads and heating was continued until all of the wood cribs were burned down. The heat release rate started to increase rapidly 90 seconds after the wood cribs caught fire. In the test with a fire load level 1, the maximum heat release rate of 4743.4 kW was reached at 244 second. In the test with fire load level 2, a maximum heat release rate of 5050.9 kW was reached at 497 second. In the test with fire load level 3, a maximum heat release rate of 4446.9 kW was reached at 677 second.

• Journal of the Korean association of regional geographers
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• v.21 no.2
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• pp.364-378
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• 2015

As safety Issue becomes one of the hot topics, practical researches and feasible policies are in needs not only for central government but also local officers. The previous studies focused on organizational or institutional approaches and on functional efficiencies, especially how to integrate disaster data at every stage of disaster from preparedness to recovery. Physical and social environments differ from among others, top-down disaster management plan cannot work, and therefore more practical statistics and survey is required to prepare the safety management plan for local government. We aim to suggest a safety environment survey framework and to apply it to two guns (Muan and Goheung). We considered main factors of the framework based on legal requirement for safety index and four stages of disaster progress. Two guns are located in remote area and have a population who are weak to disaster. Action items were drawn from the survey and analysis from the framework respectively. We expect this framework to be expanded to include more urbanized and complex areas.

• The Journal of the Acoustical Society of Korea
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• v.30 no.2
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• pp.92-99
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• 2011

In Japan, bang machine has been considered to have problems about not only the impact force and frequency response which are different from the real impact sources such as children's jumping and running, but also damage in the wooden structure housing. Therefore, a new impactor for lower impact force to prevent demage in wooden structure housing was developed. The impact ball was adopted as the second standard impact source in JIS A 1418-2 and ISO 140-11. In the present study, floor impact sounds generated by impact ball with drop heights in four floors of mock-up building of Building Research Institute (BRI) similar to typical Japanese wooden structure housing were investigated and also compared to jumping sound. The results show that Impact ball sound dropped at 10 cm to 30 cm was most similar to jumping sound. And The impact sound levels at 250 and 500 Hz were more sensitive to drop height than other lower frequencies. The error that may occur from the difference of height of 10 cm up and down based on the standard drop height caused by the impact ball operated by human hands was approx. 1 dB or less only in its value of characteristic, but it must be carefully taken into Impact ball in the Korea Standard.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.110-113
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• 1994

This experiment was carried out to establish the optimum planting density for producing high tuber yield of Liriope platyphylla WANG and TANG using the recommended variety 'Maekmoondong 1'. Different planting distances such as $20cm\;/rows{\times}10cm\;/hill,\;30{\times}10,\;30{\times}30$ and different plant numbers like 2 plants /hill, 4,6 were combined to make different planting densities. Upper growth state was better by further spacing in case of leaf size, tiller number, fresh leaf weight per each hill. But unlike upper growth state tuber number and. its yield were highest at 372kg /10a and 43No. /hill. respectively with the planting density, $30cm{\times}10cm$, 6 plants per hill. Over growth of vegetative parts cut down the tuber yield. Correlations among leaf size, tiller number, leaf weight and root weight were positive. Tuber number was positively correlated with all characteristics except root weight.