• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.81-89
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• 2010

Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget.

• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.7-19
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• 2019

In this study, a model was developed for estimating deliverability considering the pressure dependent permeability and predicting production profile with Material Balance Equation(MBE) for Coalbed Methane(CBM) fields. The estimated deliverability was compared with the conventional deliverability based on CBM well testing data with coefficient of determination($R^2$). As a result, the former was 0.76 and the latter was 0.69. It was confirmed that the deliverability which consider the pressure dependent permeability is more adoptable when representing the productivity of CBM fields. Through this process, in order to calculate pressure dependent permeability when well testing data exist, a method to infer reservoir pressure within the radius of investigation was proposed. The production profile of 31 gas wells was predicted for 15 years, using the estimated deliverability and the MBE. After that, the results was compared with simulation results of the literature. The simulation results did not account the pressure dependent permeability and the developed model results considered that. As the applied field permeability rised 1.17 times, field production rate was increased approximately 15% than the literature results. According to other researches, the permeability of CBM fields can be rise 6 ~ 25 times. For these cases, the production profiles may have significant difference with conventional gas fields.

• Fire Science and Engineering
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• v.30 no.2
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• pp.75-80
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• 2016

In the wake of expanding and overpopulating urban areas, traffic congestion has been worsening increasingly, causing huge economic losses. In a bid to effectively use the space of metropolitan areas, the construction and operation of a double deck tunnel has been on the rise. On the other hand, a lower height of a double deck tunnel is expected to generate more smoke and soot in a fire than other usual tunnels. Therefore, it is undesirable to apply the standard for fire intensity or smoke generation, which were designed for existing road tunnels. A part of an effort to propose a design fire curve that is useful for double deck tunnel, is intended to obtain and analyze the fire characteristics in a double deck tunnel through a real scale fire test. The test was conducted according to the fire scenario with one passenger car and two passenger cars; the monitored fire intensity was a maximum of 2.4 MW and 3.5 MW, respectively.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.44-51
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• 2002

This paper describes the performance evaluation and analysis of an Orthogonal Frequency-Division Multiplexing (OFDM) system having the least Inter Symbol Interference (ISI) in a multi-path fading channel environment. Wireless Local Area Network (W-LAN) in accordance with IEEE 802.11a and IEEE 802.11b provides high-speed transmission to universities, businesses and other various places. In addition, service providers can offer a public W-LAN service on restricted areas such as a subway. The proliferation of W-LAN has led to greater W-LAN service demands, but problems are also on the rise in offering a good W-LAN service. In particular, urban areas with high radio wave interference and many buildings are vulnerable to deteriorated QoS including disconnected data and errors. For example, when high-speed data is transmitted in such areas, the relatively high frequency generates ISI between Access Points (AP) and Mobile Terminals (such as a notebook computer), leading to a frequency selective fading channel environment. Consequently, it is difficult to expect a goodW-LAN service. The simulation proves that the OFDM system enables W-LAN to implement QoS in high-speed data transmission in a multi-path fading channel environment. The enhanced OFDM performance with 52 sub-carriers is verified via data modulation methods such as BPSK, QPSK and 16QAM based on IEEE 802.11a and punched convolutional codes with code rate of 1/2 and 3/4 and constraint length of 7. Especially, the simulation finds that the OFDM system has better performance and there is no data disconnection even in a mobile environment by applying a single tap equalizer and a decision feedback equalizer to a mobile channel environment with heavy fading influence. Given the above result, the OFDM system is an ideal solution to guarantee QoS of the W-LAN service in a high-speed mobile environment.

• Fire Science and Engineering
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• v.30 no.4
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• pp.27-38
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• 2016

The paper reports the development of a distributed temperature sensing (DTS) system, which is a fire detection system using optical sensor linear detectors that depends on foreign and domestic technologies. This study accordingly analyzed the electrical signal patterns of Raman scattering light mainly used for temperature sensing among back-scattered light generated in optical fiber by using an oscilloscope. Through the measurement results, it could be verified that the Stokes signal patterns had little change by the temperature increase, but the temperature-sensitive anti-Stokes patterns had relative increase of the changes. This study developed a K-DTS system, which is an optical sensor linear fire detection system composed of an optical repeater and a receiver that can detect fires using Raman scattering light. It could be verified that the developed K-DTS system satisfied the type approval standards through the sensitivity tests using the rate of rise type and fixed temperature type sensitivity testers. In addition, performance experiments have been performed for performance evaluation of the K-DTS system developed in comparison with S-DTS system which has been imported from abroad and widely used in Korea. It can be confirmed from the results of the performance experiments using model tunnels that comparable performances can be obtained in fire detection locations and the measurements of fire temperatures.

• Food Science and Preservation
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• v.15 no.4
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• pp.542-549
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• 2008

The effects of Angelica gigas nakai powder(AP) addition on bread dough were investigated by preparing dough with 0-10%(w/v) powder. Dough raising power, gluten levels, rapid visco properties, and falling number, were investigated. The rheological properties of dough as measured by mixography, farinography, alveography, color assessment, and with scanning electron microscopy, were examined. Increase in AP concentration resulted in a linear decrease in gluten content. Dough raising power and extensibility were decreased by water absorption rate, and resistance increased. Dough stability and rose when AP was present at 1-2%(w/v). Water absorption, dough stability, and dough valorimeter values also rose when AP was present at 1-2%(w/v), but AP induced weakness in the dough, as revealed through farinography, and also resulted in a lowering of initial pasting temperature and the temperature at peak viscosity. A decrease in viscosity at the peak point, and(as revealed by RVA), a decrease in extensibility, an increased resistance to extension, and a rise in the energy required for extension, were also seen when AP powder was added, as was an increase in the R/E ratio. Overall, the addition of AP to dough to levels of 1% or 2%(both w/v) is thought to be useful in the preparation of a functional white pan bread, and results in quality improvements.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.183-190
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• 2021

The purpose of this study was to determine the change trend of emergency department visits among elderly patients with chronic diseases. Using the National Emergency Department Information System data, from January 1, 2014 to December 31, 2019, the selected patient data were evaluated for the emergency department discharge main diagnosis codes for eight chronic diseases. The incidence of elderly chronic diseases, emergency department visits, and admission rates were analyzed. Since 2014, there has been a consistent increase in the number of elderly patients visiting the emergency department, especially among those aged over 85 years. The number of emergency department visits among the elderly chronically ill patients also increased, with a significant increase in ischemic heart disease and arthrosis cases. Furthermore, there was a significant difference in the number of chronically ill patients in each year from 2014-2019 (P<0.001). With respect to the trend of admission rates to the emergency department by chronic disease, most diseases showed an increasing trend (P<0.001). however, hyperlipidemia showed a continuous decreasing trend in all age groups since 2014 (P<0.001). Among the elderly chronically ill patients, a greater increase in the admission rate following emergency department visits was noted in those over 85 years of age, with a significant difference in all diseases, except for hyperlipidemia, hypertension, and tuberculosis (P<0.001). As the aging population grows, the emergency department admission rates among the elderly chronically ill patients will rise rapidly. This could create issues with respect to the use and consumption of emergency medical resources. Hence, it is necessary to manage chronic diseases effectively in the elderly.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.147-157
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• 2020

Mass change in the Antarctic Ice Sheet(AIS) is the most important indicator of changes in Earth's climate system including global mean sea level rise that are largely affected by ongoing global warming. In this study, AIS mass variations are examined with satellite gravity data and outputs from a regional climate model. The analysis of gravity data shows that along the coastal region the Western AIS has experienced a continuous and significant ice loss while a slight increasing in the Eastern AIS during the study period (2002.08-2016.08). The temporal and spatial variations in ice mass changes are recovered by a regional climate model, but the recovered amplitudes are much smaller than those of observations. This under-estimation is remarkably resolved by modifying a base flow field for the ice discharge. The recovered estimates based on the ice-flow field can explain about 97% of the rate of mass change in observations before 2009. This implies that changes in ice flow dynamics along the coast line plays a pivotal role in regulating long-term budget of ice mass in AIS.

• Cartoon and Animation Studies
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• s.42
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• pp.105-123
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• 2016

The webtoon market has been consisently developing in the digital market. Under such circumstances, The Korea webtoon market is rapidly growing and leading of them. This is the time to prepare the base of a stable environment for the webtoon market which shows a swift rise. The Korean webtoon is surely aiming at the global market as well as the domestic one. As the Korean webtoon companies spread out to the world briskly, The leading publication cartoon market, Japan tries to break into the Korean digital market. The domestic market that has the good-quality cartoons through exportation and importation to make people of all ages enjoy them. and also the Korean webtoon is in the center of the global webtoon markert. The early model of Korean webtoon, line-webtoon is translated in English, Chinese, Thai language and Indonesian language to use on the mobile applications and web. Nevertheless, It is just the stating point. With Eradicating of the Achilles heel of the digital contents, illegal distribution and finding materials for cultural discount rate minimized cartoon, The Korean webtoon can become the highest in the global market and hold it. Moreover, not only webtoon but also published cartoons are existing together to have a long run. Beyond the existing cartoon books printed on paper, we should reach toward the digital books with portability and economic feasibility to make the contents stay out longer.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.32-42
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• 1995

Cultivation using rain shelter is very popular in summer because rain shelter has a simple structure using less materials than any other regular greenhouse. Although it has a main advantage of easy construction in terms of labour, time and cost, it has some disadvantage of poor ventilation and rain fall inflow. Therefore, the rain shelters being able to overcome the problems, to some extent, are necessary to propagate for practical purpose. Three characteristic types of rain shelter were analyzed using measured and simulated environment data. Type 1 was a conventional type with an arched roof, and Type 2 and Type 3 were improved ones which were designed to have three arched roofs and three sawtooth like roofs with the openings for ventilation, respectively. The distribution of inside temperature measured was relatively uniform in Type 2 and 3 by the natural ventilation through the openings of the roof compared to Type 1 which had no openings. The relative light transmittance measured in Type 2 and 3 showed lower than that in Type 1, which suppressed the rise of inside temperature, For more accurate comparison, the differences between inside and outside temperatures to various wind speeds were calculated by the model. The difference in Type 1 was the greatest at lower wind speed below 1 ㎧, that is, the highest in inside temperature, but decreased rapidly as wind speed increased above 1 ㎧. Measured temperatures generally showed the same trends as calculated ones by the model. As a whole, the improved rain shelters(Type 2 and 3) showed better performance than the conventional one in ventilation as well as inside temperature.