• Clean Technology
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• v.26 no.1
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• pp.1-6
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• 2020

Rapid expansion of supercritical solution (RESS) process was used to make molsidomine (MOL) loaded peracetyl-β-cyclodextrin (PAc-β-CD) nanoparticles, which were collected into the air. The effect of the concentration of the drug PAc-β-CD (0.5 and 1 wt%), extraction temperature (45 ~ 60 ℃), nozzle length (5 ~ 20 mm) and internal diameter (ID) (50 ~ 150 μm) of a capillary, and spray distance on the particle size and morphology of the resulting particles were investigated. The interaction of a drug and PAc-β-CD was confirmed by ¹H-NMR spectroscopy while the particle size was measured by means of a scanning electron microscope. It was found that increasing the temperature from 45 ℃ to 60 ℃ and decreasing the nozzle diameter from 150 μm to 50 μm had an increasing effect on the average particle size, while increasing the spray distance led to a decrease in the average particle size at a constant pressure of 34.5 MPa and temperature of 45 ℃. With 0.5 wt% of PAc-β-CD, the capillary nozzle of short length (5 mm) and small ID (50 μm) gave the smallest size (165 nm). The obtained nanoparticles showed increased dispersity and solubility in oil. The oil suspension of the inclusion complex showed increased sustainability, which can increase the in-vitro controlled release time of the drug.

• Journal of The Korean Association For Science Education
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• v.37 no.6
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• pp.1005-1014
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• 2017

Focusing on the role of the science museum as an institution to improve the scientific literacy of the public, this study investigated public perception and behavior about science museum to know how much science museums affect the public by using social media big data analysis. For this purpose, we extracted texts containing 'science museum' in Naver blogs and Twitter, analyzed them by using network, frequency, co-ocurrence, and semantics analysis and compared them with the results in English speaking countries. As a result, blogs were mainly concerned with science museum among parents who have young children, while in Twitter posts from many students who visited as a group appeared. Therefore, the Korean public used science museum mainly as a space for children's experience, and in this case, programs and exhibitions of science museums are perceived positively. On the other hand, students who visited as a group showed some negative emotions. The result of comparison with the cases of foreign countries in terms of the function of the third generation science museum such as communications with the science museum and the public and the participation of the public in science, the Korean public hardly mentioned the scientific contents, words related to communications such as 'argue', and curators or staff after visiting the science museum. In contrast to many verbs related to meaningful activities such as 'learn', 'participate', 'listen', 'read', 'ask', 'think' appeared in English, only a small number of verbs include 'ask' and 'thin' appeared in Korean. Therefore, science museum need to improve impression, communicating with public, and involving activity with impact and variety after visit.

• Journal of the Korean GEO-environmental Society
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• v.15 no.4
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• pp.61-67
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• 2014

With a view to resolving environmental problems of hazardous cement, this study seeks to identify the unconfined compressive strength and bending strength of the vegetation block designed herein by utilizing high-strength natural soil stabilizer instead of cement. Soil stabilizer is mainly made of mixture of short fiber extracted from natural fiber and lime, etc. Soil stabilizer reinforces the shearing strength of soil to improve block supportive power and durability while preventing flood and frost damages. For the unconfined compressive strength test, test pieces were prepared by mixing soil stabilizer and weathered soil in different ratios of 6 %, 12 % and 18 %. Experiments were carried out according to curing periods of 5th, 7th, 14th and 28th of the day. For bending strength test, blocks were made in the same mixture ratios as for the unconfined compressive test and tested for each stage. Also, to evaluate for the field applicability, proposed optimum water content considering the characteristics of the soil stabilizer. Permeability test result for the vegetation block, satisfied by the KS F 4419 quality standards.

• The Journal of the Acoustical Society of Korea
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• v.37 no.5
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• pp.369-377
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• 2018

This study investigated the effect of noise and reverberation on subjective measure of speech transmission performance for elderly person with hearing loss in residential space through listening test. Floor impact, road traffic, airborne, and drainage noise were employed as the residential noise, and several impulse responses were obtained through room acoustical computer simulation for an apartment building. Sound sources for the listening test consisted of residential noises and speech sounds for boh the young (the original sound) and the aged (the sound filtered out by filters with frequency responses of hearing loss of 65 years elderly person). In the listening test, subjects evaluated speech intelligibility and listening difficulty for the presented word ($L_{Aeq}$ 55 dB) at three noise levels ($L_{Aeq}$ 30, 40, 50 dB) and three reverberation times (0.5, 1.0, 1.5 s). Results showed that the residential space with noise level lower than equal to 50 dB ($L_{i,Fmax,AW}$) for jumping noise and 40 dB ($L_{Aeq}$) for road traffic, airborne, and drainage noise had speech intelligibility of 90 % and over and listening difficulty of 30 % and below. Speech intelligibility and listening difficulty for the aged sound source was shown to be 0 % ~ 5 % lower and 2 % ~ 20 % higher than those for the young sound source, respectively.

• Journal of the Korean association of regional geographers
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• v.16 no.6
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• pp.706-723
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• 2010

The impervious surface was frequently employed as a proxy of the total environmental burden in the urban area. The impervious surface was extracted from a satellite image and the GIS (Geographical Information System) database for childhood asthma hospitalizations was generated for a total of 62,136 children using the National Health Insurance database of South Korea. Children living in an impervious environment do result in almost twice as many hospitalizations (26.58%) for asthma, as compared to the sub-urban pervious living (15.82%). Furthermore, the risk zones with persistently high hospitalizations for three years were specifically identified over the impervious sub-district alone. The impervious zone showed a small inter-year variation of hospitalizations (r: 0.937) while the sub-urban pervious fringe was found to display a yearly variation(r: 0.371). The strong temporal autocorrelation means that the impervious areas have frequent long-lived hospitalizations for asthma, thus children living in impervious areas were likely to have had more chronic asthma attacks than those living in pervious areas. These experimental results indicate that an impervious surface as thematic parameter of analysis is a crucial explanatory variable for asthma hospitalizations and its longer persistence among children.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.1-6
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• 2015

The objectives of this study were to calculate the radius of influence (ROI) of well for an air-sparging (AS)/soil vapor extraction (SVE) system and to evaluate the applicability of the system applied for the remediation of the petroleum contaminated rail site. For air permeability test, three monitoring wells were installed at a location of 1.3 m, 2.3 m, 3.0 m from the extraction well. And the pressure of each monitoring well was measured by extracting air from the extraction well with the pressure and flow of $(-)2,600mmH_2O$ and $1.58m^3/min$. The ROI for an extraction well was calculated as 4.31 m. Air was injected into the injection well with the pressure and flow of $3,500mmH_2O$ and $0.6m^3/min$ to estimate the radius of influence for oxygen transfer. Oxygen concentrations of air from three monitoring wells were measured. The ROI of an injection well for oxygen transfer was calculated as 3.46 m. The 28 extraction wells and 19 injection wells were installed according to the ROI calculated. The AS/SVE system was operated eight hours a day for five months. The rail site was contaminated with the petroleum and concentrations of benzene, toluene, and xylene were over the 'Worrisome Standard' of the 'Soil Environment Conservation Act'. The contaminated area was estimated as $732m^2$ and contaminants were dispersed up to (-)3 m from the ground. During the operation period, soil samples were collected from 5 points and analyzed periodically. With the AS/SVE system operation, concentrations of benzene, toluene, and xylene were decreased from 7.5 mg/kg to 2.0 mg/kg, from 32.0 mg/kg to 23.0 mg/kg, from 35.5 mg/kg to 23.0 mg/kg, respectively. The combined AS/SVE system applied to the rail site contaminated with volatile organic compounds (VOCs) exhibited a high applicability. But the concentration of contaminants in soil were fluctuated due to the heterogeneous of soil condition. Also the effect of the remediation mechanisms was not clearly identified.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.194-205
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• 1994

In this research, we attempt to fabricate an excellent CFRC(Carbon Fiber Reinforced Carbon), which has good thermal and mechanical properties, with 8H/satin woven fabric prepreg, high modulus and high strength type continuous carbon fiber and raw coal tar pitch(RCTP) matrix or THF soluble fraction(THFSP) matrix which has good graphitizability. Green bodies were fabricated with hot press molding technique and CFRC samples were made after carbonization, impregnation, recarbonization and graphitization steps. For the purpose of characterization of the physical properties, SEM, polarized light microscope, TGA were observed, and tested flexural strength, modulus and ILSS. After heat treating the THFSP matrix up to $2300^{\circ}C$, the value of $C_0$/2 was 3.380$\AA$, which is analogous to the structure of natural graphite and the value of 2$\theta$ is $26.276^{\circ}$ approached to the Bragg's angle of natural graphite. As a result of TGA to test the high temperature air oxidation, the THFSP matrix, graphitized up to $2300^{\circ}C$, exhibited the best air oxidation resistance. And mechanical properties were increased up to 65~70% as fiber volume fraction increased. Because of the good orientation graphitizability, the fracture surface of THFSP matrix CFRC is very good.

• Annual Conference on Human and Language Technology
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• 1999.10e
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• pp.257-264
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• 1999

자연언어 처리에 있어 문장의 성분 구조를 파악하는 통사적 해석에서는 애매성 있는 결과가 많이 생성된다. 한국어의 경우 어순 등의 통사적 특성뿐 아니라 상황과 의미, 문맥이 문장의 분석에 더 중요한 역할을 하기 때문에 문맥 자유 문법에 의한 접근 방법만으로는 중의적 구조의 해결이 어렵다. 이는 또한 의미 분석시 애매성을 증가시키는 원인이 된다. 이러한 통사적, 의미적 중의성 해결을 위해 용언 중심의 하위범주화 사전을 구축하였다. 본 논문에서는 용언에 따라 제한될 수 있는 하위범주 패턴을 정의하고 패턴에 따라 하위범주 사전을 구축하였다. 하위범주화 사전에는 명사의 시소러스와 정합하여 보어를 선택 제한(Selectional Restriction)할 수 있도록 용언과 명사와의 의미적 연어 관계에 따라 의미마커를 부여했다. 말뭉치를 통해 수집된 용언 12,000여개를 대상으로 25,000여개의 하위범주 패턴을 구축하였고 이렇게 구축한 하위범주화 사전이 120,000여 명사에 대한 의미를 갖고 있는 계층 시소러스 의미 사전과 연동하도록 하였다. 또한 논문에서 구현된 하위범주화 사전이 구문과 어휘의 중의성을 어느 정도 해소하는지 확인하기 위해 반자동적으로 의미 태깅(Sense Tagging)된 2만여 문장의 말뭉치를 통해 검증 작업을 수행하고, 의존관계와 어휘의 의미를 포함하고 있는 말뭉치에 하위범주 패턴이 어느정도 정합되는지를 분석하여, 하위범주 패턴과 말뭉치의 의존관계만 일치하는 경우와 어휘의 의미까지 일치하는 경우에 대해 평가한다. 이 과정에서 하위범주 패턴에 대한 빈도 정보나, 연어 정보를 수집하여 데이터베이스에 포함시키고, 각 의미역과 용언의 통계적 공기 정보 등을 추출하는 방법도 제시하고자 한다.을 입증하였다.적응에 문제점을 가지기도 하였다. 본 연구에서는 그 동안 계속되어 온 한글과 한잔의 사용에 관한 논쟁을 언어심리학적인 연구 방법을 통해 조사하였다. 즉, 글을 읽는 속도, 글의 의미를 얼마나 정확하게 이해했는지, 어느 것이 더 기억에 오래 남는지를 측정하여 어느 쪽의 입장이 옮은 지를 판단하는 것이다. 실험 결과는 문장을 읽는 시간에서는 한글 전용문인 경우에 월등히 빨랐다. 그러나. 내용에 대한 기억 검사에서는 국한 혼용 조건에서 더 우수하였다. 반면에, 이해력 검사에서는 천장 효과(Ceiling effect)로 두 조건간에 차이가 없었다. 따라서, 본 실험 결과에 따르면, 글의 읽기 속도가 중요한 문서에서는 한글 전용이 좋은 반면에 글의 내용 기억이 강조되는 경우에는 한자를 혼용하는 것이 더 효율적이다.이 높은 활성을 보였다. 7. 이상을 종합하여 볼 때 고구마 끝순에는 페놀화합물이 다량 함유되어 있어 높은 항산화 활성을 가지며, 아질산염소거능 및 ACE저해활성과 같은 생리적 효과도 높아 기능성 채소로 이용하기에 충분한 가치가 있다고 판단된다.등의 관련 질환의 예방, 치료용 의약품 개발과 기능성 식품에 효과적으로 이용될 수 있음을 시사한다.tall fescue 23%, Kentucky bluegrass 6%, perennial ryegrass 8%) 및 white clover 23%를 유지하였다. 이상의 결과를 종합할 때, 초종과 파종비율에 따른 혼파초지의 건물수량과 사료가치의 차이를 확인할 수 있었으며, 레드 클로버 + 혼파 초지가 건물수량과 사료가치를 높이는데 효과적이었다.\ell}$ 이었으며 , yeast extract 첨가(添加)하여 배양시(培養時)는 yeast extract

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.53-60
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• 2010

The comprehensive tests on unsaturated weathered granite soils are carried out to obtain the soil-water characteristic curve that is the one of the essential requisites to study the unsaturated soil. The weathered granite soils were obtained at Palgong mountain in Daegu. The existing test results have been carried out without overburden pressures and volume changes. In this study, the volumetric pressure plate extractor is improved to consider two factors such as overburden pressure and volume change. The applied overburden pressures were 0, 25, 50, 75, 100kPa and volume changes were measured at each phase. he results of this study are summarized as follows: As the overburden pressure increases, the volumetric water content decreases at the same matric suction and the air entry value increases and gradient of curve at the transition zone and the size of the hysteresis loops decreases. As the overburden pressure increases, the degree of saturation increases at the same matric suction and degree of saturation of the wetting curve is higher than that of dry curve. The SWCC with volume changes are slightly larger than those without volume changes. The general equation proposed by Fredlund & Xing(1994) to fit the experimental result of the SWCC indicates good agreement. The empirical parameters a, n, m as overburden pressure show similar inclination as the existing results.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.63-73
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• 2017

In contemporary society, it is increasingly common to spend more time indoors. As such, there is a continually growing desire to build comfortable and safe indoor environments. Along with this trend, however, there are some serious indoor-environment challenges, such as the quality of indoor air and Sick House Syndrome. To address these concerns the government implements various systems to supervise and manage indoor environments. For example, green building certification is now compulsory for public buildings. There are three categories of green building certification related to indoor air in Korea: Health-Friendly Housing Construction Standards, Green Standard for Energy & Environmental Design(G-SEED), and Indoor Air Certification. The first two types of certification, Health-Friendly Housing Construction Standards and G-SEED, evaluate data in a drawing plan. In comparison, the Indoor Air Certification evaluates measured data. The certification using data from a drawing requires a considerable amount of time compared to other work. A 2D tool needs to be employed to measure the area manually. Thus, this study proposes an automatic assessment process using a Building Information Modeling(BIM) model based on 3D data. This process, using open source Industry Foundation Classes(IFC), exports data for the certification system, and extracts the data to create an Excel sheet for the certification. This is expected to improve the work process and reduce the workload associated with evaluating indoor air conditions.