• 한국수정란이식학회지
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• 제15권2호
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• pp.175-180
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• 2000

The possible use of micromanipulative biopsy and PCR of the biopsied embryonic cells was tested to produce sexed bovine embryos in practical terms. By micromanipulation and PCR techniques, higher survival rate and accurate sexing of demi-embryos were btained. Bovine oocytes matured and fertilized in vitro were co-cultured with bovine oviductal epithelial cell (BOEC) monolayer in USU-6 medium supplemented with 15% FBS, and the embryos of 37% (327/885) were developed to blastocysts. Among 111 blastocysts produced by invitro, only 7 (6.3%) embryos were found unable to determine their sex, probably due to the loss of cells, since no PCR product was found from those cells. All the remaining 104 (93.7%) demi-embryos survived micromanipulation and demonstrated male-specific product or bovine-specific product alone suggesting that correct sexing of the sample. Forty-three point one percent(25/58) of manipulated and cryopreserved demi-embryos after thawing were survived. Final verification of the sexed embryos is necessary to make sure the same sex in fetus and newborn calf upon embryo transfer. The established sexing method on a large number of bovine embryos from previous and this study suggests that this a could be used practically in the field.

• Nuclear Engineering and Technology
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• 제44권4호
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• pp.355-362
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• 2012

The aim of this study was to develop a bundle position-wise linear model (BPLM) to predict Pressure Tube (PT) diametral creep employing the previously measured PT diameters and operating conditions. There are twelve bundles in a fuel channel, and for each bundle a linear model was developed by using the dependent variables, such as the fast neutron fluences and the bundle coolant temperatures. The training data set was selected using the subtractive clustering method. The data of 39 channels that consist of 80 percent of a total of 49 measured channels from Units 2, 3, and 4 of the Wolsung nuclear plant in Korea were used to develop the BPLM. The data from the remaining 10 channels were used to test the developed BPLM. The BPLM was optimized by the maximum likelihood estimation method. The developed BPLM to predict PT diametral creep was verified using the operating data gathered from Units 2, 3, and 4. Two error components for the BPLM, which are the epistemic error and the aleatory error, were generated. The diametral creep prediction and two error components will be used for the generation of the regional overpower trip setpoint at the corresponding effective full power days. The root mean square (RMS) errors were also generated and compared to those from the current prediction method. The RMS errors were found to be less than the previous errors.

• 한국정보시스템학회지:정보시스템연구
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• 제21권1호
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• pp.93-116
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• 2012

Internet users' desire to share shopping experiences has resulted in the appearance of the paradigm shift called social commerce, which combines social media with commerce. However, while foreign market realizes social commerce in a various way, current domestic social commerce market still seems to be highly filled with social shopping sites offering 50 percent discount, thus causing concerns about market distortion from a cutthroat competition. In order to overcome the limitations of social commerce remaining in the early stage, and to enhance the communication among consumers, this study conducted an empirical study on the social-commerce business models design based on context. The results of the study brought the imaginary, optimal combination model by conjoint analysis, using the segmented group through cluster analysis. To overcome the uniformity of social commerce and to enhance communication among consumers, the context-based optimal combination model should be proposed as the alternative social commerce business model in the domestic market which remains as a simple group-purchase function. Furthermore, this study will be used as an informative reference designing customer oriented service model for social commerce business.

• 공업화학
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• 제32권5호
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• pp.581-588
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• 2021

In this study, soil slurry bioreactors were used to treat soils containing 16 polycyclic aromatic hydrocarbons (PAHs) for 35 days. Five different soil samples were taken from manufactured gas plant (MGP) and coal tar disposal sites. Soil properties, such as carbon content and particle distribution, were measured. These properties were significantly correlated with percent biodegradation and degradation rate. The cumulative amount of PAH degraded (P), degradation rate (K_m), and lag phase (𝜆) constants of PAHs in different MGP soils for 16 PAHs were successfully obtained from nonlinear regression analysis using the Gompertz equation, but only those of naphthalene, anthracene, acenaphthene, fluoranthene, chrysene, benzo[k]fluoranthene, benzo(a)pyrene, and benzo(g,h,i)perylene are presented in this study. A comparison between total non-carcinogenic and carcinogenic PAHs indicated higher maximum amounts of PAH degraded in the former than that in the latter owing to lower partition coefficients and higher water solubilities (S). The degradation rates of total non-carcinogenic compounds for all soils were more than four times higher than those of total carcinogenic compounds. Carcinogenic PAHs have the highest partitioning coefficients (K_oc), resulting in lower bioavailability as the molecular weight (MW) increases. Good linear relationships of K_m, 𝜆, and P with the octanol-water partitioning coefficient (K_ow), MW, and S were used to estimate PAH remaining, lag time, and biodegradation rate for other PAHs.

• 산업융합연구
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• 제7권1호
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• pp.63-82
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• 2009

Many The purpose of this paper is to revisit the existence of monthly effect in the Korea Stock Market. We conducted additory test about KOSPI200 from January 1990 to December 2002 and about KOSDAQ from January 2002 to December 2006. The other main focus is examine Size Effect in Korean Stock Market. We also indicate Information hypothesis throught our findig. Data used in this paper are monthly returns of KOSPI and KOSDAQ from 1980 to 2006. As a result, Evidence is provided that monthly abnormal returns in January have large means relative to the remaining eleven months. The relation between abnormal returns and size is always negative and more pronounced in January than in any other month-even in years. More than fifty percent of the January premium is attributable to large abnormal returns during the first week of trading in the year particularly on the first trading day. This finding is highly significant in the mall sized capital stock of KOSPI market. We found January effect and Size Effect in the KOSPI market, but we didn't find January effect and Size Effect in the KOSDAQ market and KOSPI200.

• 한국과학교육학회지
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• 제39권6호
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• pp.767-775
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• 2019

본 연구는 2015 개정 교육과정에 따른 과학교과서를 대상으로 교과서에 수록된 과학용어의 명시적, 암시적 교육 사례를 분석하여 과학용어 교육 측면에서 현행 교과서가 가지는 문제점들을 짚어보고 개선 방안을 제안하고자 실시하였다. 2015 개정 교육과정에 따른 초등학교 3학년과 6학년, 중학교 1학년, 고등학교 1학년의 과학교과서 8권으로 부터 사용된 과학용어들을 추출하고, 명시적 및 암시적으로 사용된 사례를 수집 및 분석하였다. 연구 결과를 간략하게 정리하면 다음과 같다. 첫째, 2015 개정 과학교과서의 초, 중, 고 과학교과서에는 교과서에 포함된 전체 어휘 대비 약 15~30% 정도의 비율로 과학용어가 사용되고 있었는데, 이는 페이지당 수록 과학용어 개수를 기준으로 외국의 경우와 비교했을 때 평균적으로 5배 이상의 많은 분량에 해당한다. 둘째, 과학교과서에 사용된 과학용어들 가운데 명시적 방법을 통해 의미 교육이 이루어지는 과학용어의 비율은 9.7~18.8%로 20%가 되지 않았으며, 자연적으로 나머지 80% 이상의 과학용어들은 암시적 교육 형태로 제시되어 있음을 의미한다. 셋째, 저학년일수록 명시적 용어 교육의 비율이 높아야 함에도 불구하고 오히려 초등학교의 명시적 용어 교육의 비율이 가장 낮았으며, 6학년의 경우는 10%가 되지 않는 것으로 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.268-268
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• 2017

Common sowing method of italian ryegrass (IRG) has been using the backpack seed sprayer (BSS) in Korea. It has weak point including a hard work and a little sowing area. This study was conducted to find out the effects of sowing IRG using unmanned helicopter (UH) under the established rice field. We checked the labour saving of sowing IRG and the growth and yield of rice after using IRG as forage crop. Two sowing implements(using by UH and backpack seed sprayer (BSS)) were tested for the ability of sowing IRG. For proper pretreatment of IRG seeds for aerial sowing using with UH, we tested one-day soaking seeds, iron-coated seeds, coated seeds sold in stores and untreated seeds. Aerial sowing of IRG seeds using UH was tested under the speed 10 km/h and flying altitude 3~4m. We tried to confirm the effects on rice growth in a paddy field after IRG had been used as forage in mid May. In 6 hours of seeding per day, UH had a seeding area of 21.8 hectares, three times wider than BSS. UH had a decrease of about 63 percent of sowing-seed cost in comparison with BSS. In the IRG aerial sowing using UH, coating seeds had the wider sowing width of 5~6 meter than 3~4 meter untreated seeds. Residual dry matter of IRG after using forage had 4.5 ton per hectare and 20 percent of top dry matter. The amount of nitrogen remaining in residual IRG in the soil was 12 kg per hectare, and the other nutrients such as calcium and potassium was incorporated into the soil with less than 10 kg/ha. The rice yield after the harvesting IRG was 5 percent higher than that of rice single cropping. Consequently, IRG sowing using UH was effective in reducing sowing time and sowing cost compared with conventional methods and, it is considered that there is a positive effect on the rice cultivation compared to rice single cropping.

• 인지과학
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• 제4권1호
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• pp.213-242
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• 1993

그동안 자동색인 기법에 대해서는 단일어 색인,구색인,시소러스 기반 색인 등의 연구가 이루어져 왔는데,단일어 색인 기법이 단일어에 기초한 단순한 색인 방법 임에도 불구하고 다른 두가지 기법보다 일반적으로 우수하다고 알려져왔다. 시소러스 기반 색인은 이중에서도 검색효율이 낮은 것으로 알려져 왔는데,이는 일반적으로 시소러스가 포함하고 있는 색인용어들이 한정되어 있어 색인하려는 자료들이 이색인 용어에 부합(match)되지 않을 경우 색인 자체가 이루어 지지 않기 때문이다. 본 연구에서는 시소러스 기반 색인이 지금까지 기법으로는 검색효율이 좋지 않지만 실제 전문 색인들이 하는 색인과 매우 유사하다는 장범에 기초하여,입력 자료를 구문분석하고,분석된 자료들과 색인용어들을 정확부합(exact match)이 아닌 부분부합(partial match)을 통하여 색인 함으로써 검색효율이 우수한 시소러스기반 자동 색인 시스템을 개발하고자 한다. 본 연구에서 개발된 색인 시스템이 THINS는 우선 시소러스를 트리형태로 구성하고 입력자료들을 KAIST에서 개발한 언어번역기 MATES/EK를 통하여 구문분석한 후 명사구들만 뽑아낸다.그다음 명사구에 있는 용어들중 불용어를 제거하고 스테밍작업을 진행한후 생기는 형태를 색인 용어들과 부분부합 과정을 반복하여,유사한 색인 용어들과 가능하면 색인이 되도록 한다. 본 연구에서는 CACM 데이타 집합을 가지고 본 시소러스 기반 색인 시스템과 단일어 색인방식을 혼성지식기반 시스템인 HYKIS에서 성능을 평가하였다.이 성능평가에서 시소러스를 기반으로 하는 색인 시스템이 단일어 색인방식보다 회상도에서는 8-9%떨어지지만 정확도에서는 10%정도 높은 결과를 나타내었다.그러나 이는 기존의 시소러스 기반시스템이 단일어 색인 방식보다 정확도가 25%-30%정도 떨어진다는 것을 비추어 볼때 기존의 방식보다 우수한 것이라 평가된다.또한 CACM 에서 제공하는 시소러스인 CRCS 가 1000여개의 색인어밖에 포함하고 있어 매우 불완전한 것이라는 것을 고려하면,THINS가 최근에 개발되고 있는 시소러스와 접속된다면 매우 우수한 검색효율을 내리라 사료된다.

• 한국인구학
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• 제16권2호
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• pp.125-139
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• 1993

Korea has successfully achieved a lowered fertility level owing to the strong population control policy and effective family planning program. Along with fertility decline and decreased number of children in family, average number of household members has decreased and nontraditional households such as one person household and households composed of unrelated individuals have prolifirated, even though the absolute number of them are found minimal in Korea. However in recent years several data and survey results suggest that one person households are gradually in the increasing trend. The study aimed at investigating the real state of one person households in Korea and next analyzing the proportional distribution of one person households by a few socioeconomic characteristics, thus providing basic for eatablishing far-singhted population and social welfare policy in the future. Korea has experienced high growth rate of economy through government-led development plans starting from the 1960s. During the past three decades, Korea has shifted from the agricultural state to the industrialized one. In compliance with the economic growth, urbanization and industrialization have brought about rural-to-urban migration and a great bulk of young population migrated to urban areas, who are seeking for educational and job opportunities. Korean society has also been under drastic change in every aspect of life involving norms, tradition, and attitude, etc. Therefore, in spite of the prejudice on 'living alone' still remaining, young people gradually leave parents and home, and further form nontraditional households in urban areas. Current increase in the number of one person households is partly attributable to the increase in high female educational attainment and female participation in economic activities. As the industrial structure in Korea changes from primary into secondary and tertiary industries, job opportunities for service/sales and manufacturing are opened to young female labor force in the process of industrialization. Contrary to the formation of one person households by young people, the aged single households are composed when children in family leave one by one because of marriage, education, employment. In particular, a higher proportion of aged female single households occur in rural areas due to the mortality difference by sex. Based on the data released form the 1990 Population and Housing Census and National Fertility and Family Health Survey in 1985 and 1991, the study tried to examine the state of one person households in Korea. According to Census data, the number of one person households increased to 1, 021, 000 in 1990, comprising 9.0 percent of total households. And the survey reveal that among total 11, 540 households, 8.0 percent, 923 households, are composed of one person households. Generally, the proportion of female single households is greater than that of male ones, and a big proportion of one person households is concentrated in the 25-34 age bracket in urban areas and 65 years and more in rural areas. It is shown than one person householders in urban areas have higher educational attainment with 59.2 percent high schooling and over in 1991, Job seeking proved to be the main reason for leaving home and forming one person households. The number of young female single households with higher education and economic self-reliance are found nil and the study did not allow to analyze the causal realtionship between female education and employment and one person household formation. However more research and deep analysis on the causal facors on one person household formation using statistical method are believed to be necessary.

• 광물과 암석
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• 제37권1호
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• pp.1-11
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• 2024

2021년 세계 석재 생산은 162,500천 톤으로 전년도 155,000천 톤과 비교하여 7,500천톤, 4.8% 증가했다. 석재 생산 순위는 중국, 인도, 튀르키예, 브라질, 이란 및 이탈리아 순서로 나타났으며 상위 6개 국가에서 전 세계 석재 생산량의 72.8%를 생산했다. 석재 수출은 전년도 19,370백만 USD와 비교해 2,310백만 USD 증가한 21,680백만 USD로 나타났다. 원료 및 가공석재 무역은 전년도 51,430천 톤과 비교하여 2,975천 톤 증가한 54,405천 톤으로 나타났다. 골재 수출액은 전년도 천연석 19,370백만 달러, 인공석 10,930백만 USD와 비교하여 천연석은 2,310백만 USD 증가하고, 인공석은 2,660백만 USD 증가해 각각 21,680백만 USD, 13,590백만 USD로 나타났다. 석재(Code: 68.02) 평균 가격은 전년도 2020년 729.62 USD/ton과 비교하여 65.2 USD/ton 증가한 794.82 USD/ton로 나타났다. 또한 건축 재료로 많이 사용되는 가공석재 가격은 전년도 39.44 USD/m²와 비교하여 3.52 USD/m² 증가한 42.96 USD/m²로 나타났다. 총채석량은 333,500천 톤(100%), 완제품은 96,000천 톤(28.8%), 석재채취 및 가공공정에서 발생하는 폐기물이 237,500천 톤(71.2%)으로 석재폐기물에 대한 재활용 문제가 꾸준히 발생하였다. 우리나라 석재 수출액은 전년도 3,195천 USD와 비교하여 38.3% 감소한 1,972천 USD로 나타났다. 반면에 수입액은 전년도 698,496천 USD와 비교하여 8.6% 증가한 758,868천 USD로 나타났다. 2025년 세계 석재 무역량은 66,100천 톤까지 상승할 것으로 전망되고, 석재 사용량은 108,920천 톤, 20억 m²에 도달할 것으로 전망된다.