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        검색결과 17

        1.
        2023.11 구독 인증기관·개인회원 무료
        To evaluate the inventory of radionuclides for the disposal of waste generated from nuclear power plants, indirect assessment methods such as the scaling factor method or average radioactivity concentration method can be applied. A scaling factor represents the average concentration ratio between key radionuclides and difficult-to-measure (DTM) radionuclides, while the average radioactivity concentration refers to the average concentration of DTM radionuclides, regardless of the concentration of key radionuclides or within specific ranges of key radionuclide concentrations. These indirect assessment methods can be statistically derived through the analysis of representative drums. This study will address how to apply these scaling factors and average radioactivity concentrations. Firstly, the concentration of gamma-emitting radionuclides will be analyzed using a drum radionuclide analyzer, and the concentration of DTM radionuclides will be determined by applying scaling factors specific to each DTM radionuclide. In the case of using the average radioactivity concentration method, the average concentration of DTM radionuclides will be applied independently of the concentration of gamma-emitting radionuclides. It is crucial to perform radioactive decay correction based on the date of generation or disposal when applying scaling factors or average radioactivity concentration. Additionally, for repackaged 320 L drums, determining which drum among the two 200 L drums inside should serve as the reference is of utmost importance
        2.
        2023.11 구독 인증기관·개인회원 무료
        To effectively assess the inventory of radionuclides generated from nuclear power plants using a consistent evaluation method across diverse groups, it is imperative to analyze the similarity in radioactive distribution between these groups. Various methodologies exist for evaluating this similarity, and the application of statistical approaches allows us to establish similarity at a specific confidence level while accounting for the dataset size (degrees of freedom). Initially, if the variance characteristics of the two groups are similar, a t-test for equal variances can be employed. However, if the variance characteristics differ, methods for unequal variances should be applied. This study delineates the approach for assessing the similarity in radioactive distribution based on the analytical characteristics of the two groups. Furthermore, it delves into the results obtained through two case studies to offer insights into the assessment process.
        3.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The prolonged and heavy East Asian summer precipitation in 2020 may have been caused by an enhanced Madden-Julian Oscillation (MJO), which requires evaluation using forecast models. We examined the performance of GloSea6, an operational forecast model, in predicting the East Asian summer precipitation during July 2020, and investigated the role of MJO in the extreme rainfall event. Two experiments, CON and EXP, were conducted using different convection schemes, 6A and 5A, respectively to simulate various aspects of MJO. The EXP runs yielded stronger forecasts of East Asian precipitation for July 2020 than the CON runs, probably due to the prominent MJO realization in the former experiment. The stronger MJO created stronger moist southerly winds associated with the western North Pacific subtropical high, which led to increased precipitation. The strengthening of the MJO was found to improve the prediction accuracy of East Asian summer precipitation. However, it is important to note that this study does not discuss the impact of changes in the convection scheme on the modulation of MJO. Further research is needed to understand other factors that could strengthen the MJO and improve the forecast.
        4,200원
        11.
        2019.04 구독 인증기관·개인회원 무료
        고위험해충에 대한 국내 유입/발생 여부를 상시 조사하고, 조기 대응하는 전국 민·관·학 예찰협력 네트워크 구성을 위하여, 고위험해충 11종(Bactrocera dorsalis, Solenopsis invicta, Cydia pomonella, Drosophila suzukii, Bactrocera depressa, Lobesia botrana, Proeulia sp., Aceria diospyri, Stephaitis takeyai, Bactrocera minax, Bactrocera tsuneonis)에 대하여 7개 대학(경상대학교, 군산대학교, 서울대학교, 순천대학교, 안동대학교, 제주대학교, 충북대학교)이 참여한 전국 권역별 예찰조사를 2018년 6월부터 10월까지 실시하였다. 조사결과, B. dorsalis, S. invicta, C. pomonella은 발견되지 않았으며, D. suzukii (3,584개체), B. depressa (21개체) 채집되었다. 포도, 단감, 감귤의 유입우려해충(L. botrana, P. sp., A. diospyri, S. takeyai, B. minax, B. tsuneonis)은 발견되지 않았다. 본 조사연구를 통하여, 고위험해충을 조기 탐색할 수 있는 7개 대학을 통한 전국단위의 감시체계를 구축하였고, 수출단지 상대국우려병해충 및 수출품목에 대한 정밀 예찰과 관리를 통한 수출지원, 국경 이후 병해충 예찰․관리를 위한 거점 확보의 성과를 이루었다.
        13.
        2017.04 구독 인증기관·개인회원 무료
        The bean bug, Riptortus pedestris, is a pest of leguminous crops. Recent studies have revealed an interesting relationship between R. pedestris and a gut symbiont Burkholderia sp.. R. pedestris mainly acquires Burkholderia sp. during 2nd instar period, which leads to enhancement of growth and reproductive rate of the host. Nevertheless, how R. pedestris acquires its symbiont is not yet clearly described. Therefore, we investigated whether 2nd instar nymphs have preference on Burkholderia sp. compared to untreated control in laboratory settings. In the choice test, no significant difference was found in the preference by R. pedestris between the two treatments. To further investigate single individual’s behaviors (its first choice, approaching frequency to each treatment, and residence time on the treatment). We video-recorded single individuals in the choice setting for 12 hours. Again, there was no significant difference in any of the behavioral traits recorded. Further choice tests will be conducted in the Y-tube olfactometer systems and semi-field conditions.
        14.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        농촌체험의 관심과 체험이 증가되는 상황에서 농촌체험의 지속성과 경쟁력의 확보 차원으로 서비스품질이 중요해지고 있다. 이 연구는 농촌체험을 경험한 서울지역 소비자를 대상으로 서비스품질과 고객만족, 고객만족과 추천의도 간의 관계를 분석하였다. 설문분석은 총 234부이며, 빈도분석, 신뢰도분석, 확인적 요인분석, 가설검정을 하였다. 분석결과는 다음과 같다. 첫째, 신뢰도의 크론바흐 알파값은 0.6 이상, 타당도의 요인적재량은 0.7 이상, 평균분산추출은 0.5 이상이 었다. 둘째, 확인적 요인분석의 모형적합도는, CMIN/DF, GFI, TLI, CFI, RMSEA이 전반적으로 적합하였다. 셋째, 가설검정의 결과, H1의 H1-2(유형성)와 H1-3(응답성)을 제외한 H1-1(신뢰성), H1-4(확신성), H1-5(공감성)는 고객만족 에 긍정적인 영향을 주었고, H2는 고객만족이 추천의도에 긍정적인 영향을 주었다. 따라서 농촌체험의 서비스를 이용자와 제공자 간의 상호작용으로 볼 때, 서비스품질에 대한 지속적인 개선이 필요할 것이다.
        4,000원
        15.
        2014.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Using a cosmological CDM simulation, we analyze the differences between the widely-used spin pa- rameters suggested by Peebles and Bullock. The dimensionless spin parameter λ proposed by Peebles is theoretically well-justified but includes an annoying term, the potential energy, which cannot be directly obtained from observations and is computationally expensive to calculate in numerical simulations. The Bullock’s spin parameter λ′ avoids this problem assuming the isothermal density profile of a virialized halo in the Newtonian potential model. However, we find that there exists a substantial discrepancy between λ and λ′ depending on the adopted potential model (Newtonian or Plummer) to calculate the halo total energy and that their redshift evolutions differ to each other significantly. Therefore, we introduce a new spin parameter, λ′′, which is simply designed to roughly recover the value of λ but to use the same halo quantities as used in λ′. If the Plummer potential is adopted, the λ′′ is related to the Bullock’s definition as λ′′ = 0.80 × (1 + z)−1/12λ′. Hence, the new spin parameter λ′′ distribution becomes consistent with a log-normal distribution frequently seen for the λ′ while its mean value is much closer to that of λ. On the other hand, in case of the Newtonian potential model, we obtain the relation of λ′′ = (1 + z)−1/8λ′; there is no significant difference at z = 0 as found by others but λ′ becomes more overestimated than λ or λ′′ at higher redshifts. We also investigate the dependence of halo spin parameters on halo mass and redshift. We clearly show that although the λ′ for small-mass halos with Mh < 2× 1012M⊙ seems redshift independent after z = 1, all the spin parameters explored, on the whole, show a stronger correlation with the increasing halo mass at higher redshifts.
        4,000원
        17.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Bioremediation in situ is heavily dependent on the oxygenic environment which would privide the dwelling microorganism with sufficient oxygen. The situation could be easily resolved with supply of an Oxygen Releasing Compound (ORC). In this paper we prepared that sort of material out of oyster shell powder (mostly calcium carbonate) that prevails every shore areas of the country. We used two different oxidizing methods in the first step of the whole manufacturing process–conventional heating in a furnace and an ultrasound generator to obtain calcium oxide. Then that calcium oxide was further oxidized into calcium peroxide which may release oxygen under a moisturized condition. The oxygen releasing experiments were run to test the performance of our products, and to determine the gas kinetics during the experiments. Interestingly, calcium peroxide derived from ultrasound treatment was much more energy-effective as ORC than that from furnace heating although the heat derived process was better than that of ultrasound in terms of oxygen content and its releasing rate. We also found that most of the data collected from the gas releasing experiments fairly supported an ordinary 1st order kinetics to oxygen concentration, which shaped a sharp discharge of oxygen at the very early moment of each test.