• Journal of Energy Engineering
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• v.12 no.1
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• pp.1-10
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• 2003

Pressurized fluidized bed combustion unit is operated at pressures of 1~1.5 MPa with combustion temperatures of 850~87$0^{\circ}C$. The pressurized coal combustion system heats steam, in conventional heat transfer tubing, and produces a hot gas supplied to a gas turbine. Gas cleaning is a vital aspect of the system, as is the ability of the turbine to cope with some residual solids. The need to pressurize the feed coal, limestone and combustion air, and to depressurize the flue gases and the ash removal system introduces some significant operating complications. The proportion of power coming from the steam : gas turbines is approximately 80:20%. Pressurized fluidized bed combustion and generation by the combined cycle route involves unique control considerations, as the combustor and gas turbine have to be properly matched through the whole operating range. The gas turbines are rather special, in that the maximum gas temperature available from the FBC is limited by ash fusion characteristics. As no ash softening should take place, the maximum gas temperature is around 90$0^{\circ}C$. As a result a high pressure ratio gas turbine with compression intercooling is used. This is to offset the effects of the relatively low temperature at the turbine inlet.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.55-59
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• 2015

Novel low-volume solder-on-pad (SoP) process is proposed for a fine pitch Cu pillar bump interconnection. A novel solder bumping material (SBM) has been developed for the $60{\mu}m$ pitch SoP using screen printing process. SBM, which is composed of ternary Sn-3.0Ag-0.5Cu (SAC305) solder powder and a polymer resin, is a paste material to perform a fine-pitch SoP in place of the electroplating process. By optimizing the volumetric ratio of the resin, deoxidizing agent, and SAC305 solder powder; the oxide layers on the solder powder and Cu pads are successfully removed during the bumping process without additional treatment or equipment. The Si chip and substrate with daisy-chain pattern are fabricated to develop the fine pitch SoP process and evaluate the fine-pitch interconnection. The fabricated Si substrate has 6724 under bump metallization (UBM) with a $45{\mu}m$ diameter and $60{\mu}m$ pitch. The Si chip with Cu pillar bump is flip chip bonded with the SoP formed substrate using an underfill material with fluxing features. Using the fluxing underfill material is advantageous since it eliminates the flux cleaning process and capillary flow process of underfill. The optimized interconnection process has been validated by the electrical characterization of the daisy-chain pattern. This work is the first report on a successful operation of a fine-pitch SoP and micro bump interconnection using a screen printing process.

• Conservation Science in Museum
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• v.11
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• pp.31-42
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• 2010

Here is an introduction of the conservation and making process of Seodae(Rank Belt with A Rhinoceros' Horn) of the Chuncheon National Museum. The seodae has a structure composed of wrapping fabric around a leather frame and decorated with ttidon(an ornament) made of a rhinoceros' horn and a metal frame. The adhesion between leather was weak and separation was taking place, parts of the horn were missing and the fabric was discoloring. Also the metal frame and the metal wire attaching ttidon were severly corroded. Nondestructive analysis was carried out by using a portable x-ray fluorescence spectroscopy to analyze the components of the metal parts. Conservation was carried out by dismantling parts and carrying out conservation process of each one according to material, then the parts were put back together.

• The Journal of Sustainable Design and Educational Environment Research
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• v.6 no.2
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• pp.66-90
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• 2007

The purpose of this study is to measure and analyze primary causes of indoor air pollution, including carbon dioxide, minute dust, and total volatile organic compounds, for each room before the beginning of a class through the time of discharge after the end of the class in general classrooms, computer rooms, and science rooms of three newly-established schools that opened in 2006, examine properties of indoor air environment in each room by educational activities at school, and determine effective management schemes; the results of this study can be summarized as follows: 1) As for implications for each item found in the mean for each place, since minute dust (PM10) was more likely to occur in time slots full of students' activities, such as a traveling class and a recess, than in the middle of a class and could be expected fully, it is necessary to make a scheme for cleaning in order to reduce minute dust within a room, for example, by usually using a vacuum cleaner indoors. 2) While carbon dioxide was expected to vary with the differences in the amount of breath between higher-graders and lower-graders in a general classroom but showed insignificant difference by grades, showing differences in pollution by four times at a maximum according to the opening of a window as expected, it is necessary to implement artificial or natural ventilation and take a positive measure, for example, by presenting a concrete ventilation scheme, in order to improve indoor air pollution at a room practice. 3) Total volatile organic compounds were found to exceed the standard by more than twice in general classrooms, science rooms, and computer rooms of the schools because of building materials, furnitures including desks and chairs, panels and boards for environment beautification, and items which could be detected even from students' clothes; while a field directly-reading tool was used, obtaining high reliability for the results, it is necessary to apply an analytical method based on process test separately for actual correct measurement if a significantly great amount of total volatile organic compounds appear as compared with other schools due to measuring expenses and consecutive measurements. 4) Since formaldehyde (HCHO) was generally found to exceed the standard in general classrooms, science rooms, and computer rooms, it is necessary to establish and operate a ventilator during a class in a computer room which requires airtightness and a science room in which an organic compound should be used for a class.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.199-212
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• 1998

The ultimate goal of this study can be summed up as follows: First, the utility of Time-Lapse that observes and records people's behavior will be shown and its merits and demerits will be discussed through comparing with other data-collecting methods such as the naked- eye observation, and the specific way in which Time-Lapse can be put to use will be suggested. Second, analysis of use behavior boserved in the plaza of Chungryangri station by Time-Lapse will be made, on the basis of which suggestions will be made concerning planing, designing, layout, and management of the station plaza. Time-Lapse can observe and records the plaza of Chungryangri Staton through 6 different ways of recording in Time-Lapse: 30 seconds, every minute, every two minutes, second every five minutes, every one tenth of a second, and every one fifth of a second, and these different ways of recording were analyzed through comparison from one to each other to check their respective utilities. And also analysis of tracks of pedestrians, density, and use behavior of users were made, according to which the way in which Time-Lapse can be utilized was examined. Several useful results obtained from this study are shown as follows. First, Time-Lapse made it possible to continuously observe for a long time using minimu efforts, and a single tape which is able to cover from 12 hours up to 25 days is useful for observing variation of behavior in space with the passage of time and seasons. Second, among six ways of recording, the recording every one tenth of a second and every one fifth of a second are useful for finding the tracks of pedestrians, the number of users, the member compositions, the time spent in one place, and manner of use. And besides the moving direction and its purpose can be recognized in a short time, which makes it possile to see where crossings of moving directions occur. Third, the recording every thirty seconds, every minute, every two minutes, and every five minutes are useful for analyzing the density in space as well as for finding the number of users and frequency of facilities use. In particular the recording every thirty seconds made it possible to keep the track of pedestrians' walking, and to observe even slowly moving motions such as cleaning. But when the recording interval exceeds one minute, this was not possible. Fourth, time-lapse has advantages over the naked eye observation in several respects. Time-lapse can measure observed behavior and density in terms of number, and locate the position of users. Time-Lapse, if accompanied by other methods such as interviewing and question that can examine psychological aspects like satisfaction or the purpose of use and be a useful device for space studies.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.155-163
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• 2017

Membrane filtration has become more popular in drinking water treatment recently, since the filtration can control not only particulate matters but also pathogenic microorganisms such as giardia and cryptosporidium very effectively. Pilot-scale ($120m^3/d$ of treatment capacity) and test-bed ($25,000m^3/d$ of treatment capacity) microfiltration experiments were conducted to find optimum operating mode and the critical flux. Optimum operating mode of pilot-test was assessed as inflow 1.0 min, filtration 36.5 min, air backwash 0.9 min, backwash 1.0 min and outflow 1.0 min with 50 LMH ($L/min{\cdot}m3^$) of critical flux. Critical Flux was calculated to be $50L/m^2-h$ (within TMP 0.5 bar) based on the increase formula of the transmembrane pressure difference according to the change of time at Flux 20, 40, 56 and 62 LMH in pilot operation. Chemical cleaning was first acid washed twice, and alkali washing was performed secondarily, and a recovery rate of 95% was obtained in the test-bed plant. The results of operating under these appropriate conditions are as follows. Turbidity of treated water were 0.028, 0.024, 0.026 and 0.028 NTU in spring, summer, autumn and winter time, respectively. Microfiltration has superior treatment capability and performance characteristics in removing suspended solids and colloidal materials, which are the main cause of turbidity and important carrier of metal elements, and it has shown great potential in being an economically substitute to traditional processes (sand filtration).

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.179-188
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• 2021

Biodiversity informatics applies information technology methods in organizing, accessing, visualizing, and analyzing primary biodiversity data and quantitative data management through the scientific names of accepted names and synonyms. We reviewed the GBIF data published by China, Japan, Taiwan, and internal institutes, such as NIBR, NIE, and KNA of the Republic of Korea, and assessed data in diverse aspects of data quality using BRAHMS software. Most data from four Asian countries have quality problems with the lack of data consistency and missing information on georeferenced data, collectors, collection date, and place names (gazetteers) or other invalid data forms. The major problem is that biodiversity management institutions in East Asia are using unstructured databases and simple spreadsheet-type data. Owing to the nature of the biodiversity information, if data relationships are not structured, it would be impossible to secure the data integrity of scientific names, human names, geographical names, literature, and ecological information. For data quality, it is essential to build data integrity for database management and training systems for taxonomists who are continuous data managers to correct errors. Thus, publishers in East Asia play an essential role not only in using specialized software to manage biodiversity data but also in developing structured databases and ensuring their integration and value within biodiversity publishing platforms.

• Korean Journal of Childcare and Education
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• v.8 no.1
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• pp.85-107
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• 2012

The movie WALL-E shows the Earth which has been overrun with garbage and devoid of plant and animal life, and humans who try to restore the ecosystem. The aim of this study is to find the implications of children's education with a detailed analysis of the movie's theme. The analysis method is the interpretive analysis model that is one of the qualitative methods of data analysis based on the concept of Wolcott. First, the Earth is an abandoned planet covered in trash: the Axiom is a haven for morbidly obese and indolent people. The main area of the earth's destruction, and the captain's cabin is the place to find a clue to awakening and change. Second, with the lapse of time, the Axiom becomes a ship allowing their return to earth. The Earth, recognized as their homeland, turns in to the land of hope when people return. Third, the cleaning robot Wall-E, as a main agent of change, has changed humans as well as itself. The results showed that we found nature-friendly development, destruction of nature, the criticism of modern civilization, the sanctity of life, ecological consciousness, coexistence, symbiosis and a win-win principle in our research.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.173-179
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• 2020

The purpose of this study was to examine whether chicken-rearing activity is effective on the character, emotion and self-esteem of middle school students, as a pilot study for the development of an animal-assisted education program based on chicken-rearing activity. School was selected as the place where students have experience with raising animals before and no poultry farms were located near the school. The experimental group consisted of 11 students as the chicken-rearing group. The conducted activities were greeting chickens, cleaning henhouse, feeding them, and picking eggs up for five months. Character, emotion and self-esteem scales were used as test tools, and pre-testing and post-testing were conducted to verify the effectiveness of the study. Data collected were analyzed by using SPSS Win 25.0 statistical program. As a result, the character, emotional stability and self-esteem of middle school students who participated in chicken-rearing activity were improved. This study is meaningful in that the chicken-rearing activity proved to be effective for the character, emotion and self-esteem of middle school students and prepared an experimental case study for developing an animal-assisted education program based on chicken-rearing activity. It is expected to be useful as basic data of animal-assisted education for adolescents in school.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.316-325
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• 2012

In this study, we suggested adequate control technology by analyzing emission process and main chemical of VOC/HAPs generated from four paint factories in Busan area. And we estimated whether Kapok fiber, which is a natural material, can be commercially used for an absorbent by testing adsorption ability. As a result of this sturdy, above 60% of VOC/HAPs was volatilized and dispersed inside the working place without conducting control system of facilities during manufacturing paints. Concentration profile of VOC/HAPs, which is volatile naturally outside the factories, is surveyed above 70% at Toluene, Ethylbenzene, and Xylene. And a result of evaluation of odor attribution level about the component whose Odor Threshold is known, it is estimated that major cause material of A, B, C factories is Toluene and that of D factory is m/p-Xylene. And that result presented design arguments such as facilities specifications, activated carbon filling volume, and replace cycle of activated carbon as control technology. Also, that result presented emission process improvement such as adsorption of central-controlled ventilation device, installation of inlet flenge, and potable cleaning process. The rate of pollutant adsorption of Kapok fiber, which is natural material, is indicated about 91.9%, 66.7%. That result validated the possibility as replacement of activated carbon.