• 분석과학
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• 제35권1호
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• pp.32-40
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• 2022

The concentrations of radon in the atmosphere were measured at the Gosan site of Jeju Island during 2017-2018, in order to investigate the time-series variation characteristics and the dependency of airflow transport pathways. The mean ²²²Rn concentration was 2,480 mBq m^-3, and its monthly concentration in November was 3,262 mBq m^-3, more than twice as that in July (1,459 mBq m^-3). The diurnal radon concentrations increased throughout the nighttime to the maximum (2,862 mBq m^-3) at around 7 a.m., then gradually decreased throughout the daytime by the minimum (1,997 mBq m^-3) at around 3 p.m. The seasonal and monthly variations of CO, NO₂, O₃ showed a roughly similar pattern to that of radon for the same period, as high in winter and low in summer. The cluster back trajectory analysis described that about 60 % of overall airflow pathways was influenced by the airflow from China. The concentrations of radon and gaseous pollutants were relatively high as the airflow was influenced by China continent, but comparatively much lower as influenced by the northern Pacific Ocean.

• The Plant Pathology Journal
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• 제38권2호
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.

• 산업경영시스템학회지
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• 제45권3호
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• pp.197-203
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• 2022

Urban space expansion is an important symbol of the urbanization process and has always been an important topic in urban studies. In addition, for sustainable city management, it is important to identify factors that can influence, such as the driving force and direction of urban space expansion, from the stage of establishing an urban development plan. To understand these factors, by observing the expansion process of a specific city, it is possible to sufficiently observe how the urban spatial dimension changes. Through a series of processes, the spatial growth characteristics of the city are analyzed, and the influence and results of important factors are analyzed. For this purpose, this paper examines the changes in the city's outer boundary and land use structure through monitoring data on urban areas of 14 cities in Hunan Province, China from 2000 to 2016. Temporal and spatial regularity according to the urban space expansion of these cities were analyzed, and a preliminary assessment was made on whether the urban space expansion is coordinated with the urban population growth. The assessment result showed: (1) The urban space of most cities has been extended rapidly in 2000-2015 however, the rate and the intensity of urban space expanding has been declining. (2) The construction of the industrial park is the core driving force of the urban space expanding, and the change of the urban space structure is manifested as enclave city expansion because that the industrial park is usually far away from the city center. (3) The population agglomeration is another driving force of the urban space expanding. At this time, the urban space expanding is like boundary extension. (4) Except Changsha city, all of the cities has a high urbanization-area-growth elastic coefficient. It means that most of the cities should enhance the land use degree.

• 농업과학연구
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• 제49권1호
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• pp.61-75
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• 2022

The first purpose of this study is to evaluate the usefulness of pork traceability data, which is monthly time-series data, and to draw implications with regard to its usefulness. The second purpose is to construct a dynamic ecological equation model (DEEM) that reflects the biological characteristics at each growth stage, such as pregnancy, birth and growth, and the slaughter of pigs, using traceability data. With the monthly pig model devised in this study, it is expected that the number of slaughtered animals (supply) that can be shipped in the future is predictable and that policy simulations are possible. However, this study was limited to traceability data and focused only on building a supply-side model. As a result of verifying the traceability data, it was found that approximately 6% of farms produce by mixing great grand parent (GGP), grand parent (GP), parent stock (PS), and artificial insemination (AI), meaning that it is necessary to separate them by business type. However, the analysis also showed that the coefficient values estimated by constructing an equation for each growth stage were consistent with the pig growth outcomes. Also, the model predictive power test was excellent. For this reason, it is judged that the model design and traceability data constructed with the cohort and the dynamic ecological equation model system considering biological growth and shipment times are excellent. Finally, the model constructed in this study is expected to be used as basic data to inform producers in their decision-making activities and to help with governmental policy directions with regard to supply and demand. Research on the demand side is left for future researchers.

• Journal of Forest and Environmental Science
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• 제39권3호
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• pp.167-179
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• 2023

The extent of change in the Land use/Land cover (LULC) of Okomu National Park (ONP) and fringe communities was evaluated. High resolution Landsat imagery was used to identify the major vegetation cover/land use systems and changes around the national park and fringe communities while field visits/ground truthing, involving the collection of coordinates of the locations was carried out to ascertain the various land cover/land use types identified on the images, and the extent of change over three-time series (2000, 2010 and 2020). The change detection was analyzed using area calculation, change detection by nature and normalized difference vegetation index (NDVI). The result of the classification and analysis of the LULC Change of ONP and fringe communities revealed an alarming rate of encroachment into the protected area. All the classification features analyzed had notable changes from 2000-2020. The forest, which was the dominant LULC feature in 2000, covering about 66.19% of the area reduced drastically to 36.12% in 2020. Agricultural land increased from 6.14% in 2000 to 34.06% in 2020 while vegetation (degraded land) increased from 27.18% in 2000 to 38.89% in 2020. The magnitude of the change in ONP and surroundings showed the forest lost -247.136 km² (50.01%) to other land cover classes with annual rate change of 10%, implying that 10% of forest land was lost annually in the area for 20 years. The NDVI classification values of 2020 indicate that the increase in medium (399.62 km² ) and secondary high (210.17 km² ) vegetation classes which drastically reduced the size of the high (38.07 km² ) vegetation class. Consequent disappearance of the high forests of Okomu is inevitable if this trend of exploitation is not checked. It is pertinent to explore other forest management strategies involving community participation.

• 사회복지연구
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• 제42권1호
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• pp.433-461
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• 2011

이 연구는 복지국가 재편기에 공적연금의 급여 관대성과 지출의 변화추이 및 결정요인을 밝히고자 하였다. 특히 공적연금 제도에서의 경로의존성을 밝힌 방대한 질적 연구들의 심층적 논의를 계량적 비교국가연구의 흐름에 통합하여 공적연금제도의 변화에 영향을 미치는 중요한 요인으로서 공적연금제도의 구조(structure)에 주목하였다. 한편, 복지국가 발달을 설명했던 산업화 이론과 권력자원 이론이 복지국가 재편기 공적연금정책의 변화를 설명하는 데에도 유용한가를 검증하고자 하였다. 1980-2007년까지 서구 복지국가 13개국을 대상으로 분석한 결과는 다음과 같다. 첫째, 공적연금제도의 구조에 따라 연금급여 관대성과 지출수준에 상이한 변화 추이가 확인되었다. 둘째, 결합시계열 회귀분석 결과, 연금구조는 제도 관대성과 지출에 영향을 미치는 가장 중요한 요인임이 밝혀졌다. 셋째, 고령화의 영향력은 연금급여 관대성을 통제한 상태에서도 유의미하게 나타나, 고령화가 연금지출을 증가시키는 요인으로 나타났다. 다만 신사회적 위험 정도가 높을수록 노인에 대한 현금지출 집중도는 낮아졌다. 넷째, 권력자원 이론은 재편기의 연금정책 국면에서는 설명력이 통계적으로 입증되지 않았다.

• 한국지반공학회논문집
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• 제26권6호
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• pp.21-28
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• 2010

화강풍화토는 가장 일반적인 흙의 종류이다. 비등방성 화강풍화토의 응력-변형-강도를 측정하는 것은 사면, 옹벽, 굴착의 변형과 안정을 위하여 매우 중요하다. 불포화 강도특성을 알기 위하여 일련의 불포화 배수삼축압축시험을 시행하였다. 시험시료는 다짐방향에 각각 0, 45, 90도의 축방향각을 갖도록 하였다. 등방압축을 받는 시료의 축변형률은 다짐방향에 의하여 크게 영향을 받으며 이차압축과정에는 시간의존성은 다짐방향과 관계가 거의 없다. 삼축압축강도와 변형에 미치는 다짐방향의 영향은 저구속압과 포화토에서 더 확연한것으로 나타났다. 다짐방향과의 각도를 고려하는 불포화화강풍화토의 강도를 추정하는 방법을 제안하였다.

• 디자인융복합연구
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• 제15권2호
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• pp.223-236
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• 2016

근대화의 발전과 함께 성장해온 서울의 대중교통의 인프라는 국내외로 성공적인 평가를 받고 있으며 현재 가장 높은 수송 분담률을 가지고 있다. 그럼에도 불구하고 서비스 고도화 단계에 진입한 서울시의 대중교통은 아직도 부족한 부분이 많으며 특히 교통약자에 대한 이동성이 보장되지 않고 있다. 고령화 및 다문화 등의 사회적 변화에 맞춰 특정 계층의 대중교통 이용에 지원이 필요한 시점이다. 본 연구에서는 대중교통의 현황 및 이용자의 현황을 살펴보고 고령자 및 외국인을 주 조사 대상으로 선정하여 관찰조사를 진행하고 행태를 분석하였다. 또한 심층 인터뷰를 통해 대중교통 서비스 상세한 평가를 진행하여 대중교통수단과 이용단계 별 불편요소를 발굴하였다. 이를 토대로 아이디어 워크숍을 통해 개선요소를 정의하고 컨셉 디자인을 하여 향후 대중교통에 적용할 수 있는 개선안을 제시하여 추후 대중교통 서비스를 개선하는데 일조하고자 하였다.

• 아태비즈니스연구
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• 제14권1호
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• pp.149-169
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• 2023

Purpose - The main purpose of this study is to develop the stress test model for Korean banks by exploring the optimal Monte Carlo simulation and BIS forecasting model. Design/methodology/approach - This study selects 15 Korean banks as sample financial firms and collects relevant 76 quarterly data for the period between year 2000 and 2018 from KRX(Korea Excange), Bank of Korea, and FnGuide. The Regression analysis, Unit-root test, and Monte Carlo simulation are hired to analyze the data. Findings - First, most of the sample banks failed to keep 8% BIS ratio for the adverse and severely Adverse Scenarios, implying that Korean banks must make every effort to realize better BIS ratios under adverse market conditions. Second, we suggest the better Monte Carlo simulation model for the Korean banks by finding that the more appropriate volatility should be different depending on variables rather than simple two-sigma which has been used in the previous studies. Third, we find that the stepwise regression model is better fitted than simple regression model in forecasting macro-economic variables for the BIS variables. Fourth, we find that, for the more robust and significant statistical results in designing stress tests, Korean banks are required to construct more valid time-series and cross-sectional data-base. Research implications or Originality - The above results all together show that the optimal volatility in designing optimal Monte Carlo simulation varies depending on the country, and many Korean banks fail to pass sress test under the adverse and severely adverse scenarios, implying that Korean banks need to make improvement in the BIS ratio.

• 한국빅데이터학회지
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• 제6권2호
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• pp.169-179
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• 2021

소비자의 식품소비행동은 소비자 패널 데이터와 같은 정형 데이터 뿐 아니라 매스미디어와 소셜미디어(SNS) 등 비정형 데이터로부터 영향을 받을 가능성이 높아지고 있다. 본 연구에서는 식품소비 관련된 정형 데이터와 비정형 데이터를 연계한 융합데이터 셋에 대하여 딥러닝 기반의 소비예측 모델을 생성하고 이를 검증한다. 연구의 결과는 정형 데이터와 비정형 데이터를 결합할 때 모델 정확도가 향상되었음을 보여주었다. 또한 비정형 데이터가 모델 예측 가능성을 향상시키는 것으로 나타났다. 변수들의 중요도를 식별하기 위해 SHAP 기법을 사용한 결과 블로그 및 비디오 데이터 관련 변수가 상위 목록에 있었고, 파프리카 구매 금액과 양의 상관관계가 있음을 알 수 있었다. 또한 실험 결과에 따르면 머신러닝 모델이 딥러닝 모델보다 높은 정확도를 보였고, 기존의 시계열 분석 모델링에 대한 효율적인 대안이 될 수 있음을 확인하였다.