• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.347-355
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• 2020

An Isolation-with-Migration (IM) model is used to estimate extant population sizes, the splitting time of populations split away from their common ancestral populations, and migration rates between the extant populations. An evolutionary model such as IM models is estimated by analyzing DNA sequences sampled from the extant populations in the model. When a true model includes an unsampled 'ghost' population without data, the unsampled population is often ignored from the evolutionary model to infer. In this paper, we conduct a simulation study to investigate the effect of an unsampled population on the estimation of the size of the sampled population. When there exists an unsampled population that shares migrations with the sampled population, the size estimation of the sampled population was biased. However, the size estimation was improved if an evolutionary model, including the unsampled population, was estimated.

• The Korean Journal of Applied Statistics
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• v.33 no.3
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• pp.269-280
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• 2020

Time course gene expression data is a large amount of data observed over time in microarray experiments. This data can also simultaneously identify the level of gene expression. However, the experiment process is complex, resulting in frequent missing values due to various causes. In this paper, we propose a pattern consistency index adaptive nearest neighbors as a method of missing value imputation. This method combines the adaptive nearest neighbors (ANN) method that reflects local characteristics and the pattern consistency index that considers consistent degree for gene expression between observations over time points. We conducted a Monte Carlo simulation study to evaluate the usefulness of proposed the pattern consistency index adaptive nearest neighbors (PANN) method for two yeast time course data.

• Journal of Korean Society of Steel Construction
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• v.23 no.6
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• pp.763-775
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• 2011

The wake galloping phenomenon is evaluated for two cylinders via two-dimensional wind tunnel tests. The two cylinders are deployed parallel to the inclination of the vertical plane, which simulates the inclined stay cables of a cable-stayed bridge. The upstream and downstream displacements of the cylinder are observed with varying center distances between the two cylinders. The effect of structural damping on the mitigation of wake galloping is also investigated. The amplitude of the vibration is very sensitive to center distance between the two cylinders. The maximum amplitudes exceededthe allowable limit of the design guidelines for small center distances of less than or equal to six times the diameter of the cylinder. The overall results conformedto the conventional design practice for the wake galloping of parallel cables. It was found, however, that the increase in the damping was not effective in reducing the amplitude of the vibration in the wake galloping phenomenon.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.83-93
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• 2007

Pedestrians and vehicle users should be treated with equal importance in urban street design. However, current street design suggests that the design criteria for sidewalks is based on the functional hierarchy of the vehicles, therefore it is necessary to develop sidewalk design standards that give more weight to pedestrians rather than vehicles. For this, this study suggests that the level of service of pedestrians should be considered in the process of designing sidewalks. Currently, level of service (LOS) criteria for pedestrians in the Korean Highway Capacity Manual are based on pedestrian volume, but the volume of pedestrians is seldomly estimated in practice. So, the current LOS criteria has limitations in terms of practical use. Also, the study assumes that the pedestrian flow rate is hardly the dominant factor that could affect the LOS of pedestrians at most urban sidewalks. In this context, the study considers a new LOS for sidewalk design based on the comfort of pedestrians while passing pedestrians coming from the opposite direction. Then the study attempts to link the new LOS criteria to the land use patterns using data of pedestrian traffic characteristics acquired from the field. In addition to this, the scope in which the suggested criteria can be applied is suggested.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.129-137
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• 2009

Operation of intelligent transport systems technologies in transportation networks and more detailed analysis give rise to necessity of dynamic traffic analysis model. Existing static models describe network state in average. on the contrary, dynamic traffic analysis model can describe the time-dependent network state. In this study, a dynamic traffic model for the expressway system using FTMS data is developed. Time-dependent origin-destination trip tables for nationwide expressway network are constructed using TCS data. Computation complexity is critical issue in modeling nationwide network for dynamic simulation. A subarea analysis model is developed which converts the nationwide O-D trip tables into subarea O-D trip tables. The applicability of the proposed model is tested under various scenario. This study can be viewed as a starting point of developing deployable dynamic traffic analysis model. The proposed model needs to be expanded to include arterial as well without critical computation burden.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.211-214
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• 2004

In the present study, the effect of SIDT (Strain Induced Dynamic Transformation) on the microstructure of medium carbon steels was investigated to develop spheroidized annealing-free steel wire rods. When $0.45\%C$ steels were hot-deformed under the conditions of heavy reduction at low temperatures, a microstructure quite different from conventional ferrite-pearlite structure was obtained. It was considered that this ferrite-cementite microstructure was obtained because very small retained austenite grains existing between fine SIDT ferrites prefer to transform to cementite and ferrite instead of pearlite during cooling. Through the present study, $0.45\%C$ steels containing ferrite-cementite (FC) structure instead of ferrite-pearlite structure was obtained in as-rolled state by introducing SIDT. The specimen containing the FC structure was much softer than that containing conventional ferrite-pearlite structure. Therefore, it is concluded that deforming medium carbon steels under the conditions of SIDT is a very powerful method to obtain soft steel wire rods which could be cold-forged without softening heat-treatment

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.370-377
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• 1998

본 연구는 황색포도상구균의 병원성 인자인 alpha-toxin, casular polysaccharides (CPS)와 fibronectin-binding protein (FnBP)을 이용해 실험동물인 토끼에서의 항체가 형성 능과 공격접종 후 방어능에 관한 연구를 위하여 수행되었으며 향후 젖소 유방염 아단위 항원 을 이용한 백신개발 가능성을 탐색하고자 수행되어졌다. 황색포도상구균의 alpha-toxin, capsu18r polysaccharides (CPS)91 fibronectin-binding protein (FnBP) 항원을 이통재 효소면 역측정법을 통한 혈중 IgG 항체가수준을 측정하였으며 alpha-toxin, capsular polysaccharides (CPS)와 fibronectin-binding protein (FnBP)으로 면역시킨 토끼에서 대조군의 토끼보다 혈 중 항체가 수준이 1차 면역 이후 유의성 있게 높았다 (p<0.05). 백신에 사용된 alpha-toxin, capsular polysaccharides (CPS)와 fibronectin-binding protein (FnBP) 항원중 capsular polysaccharides (CPS)가 다른 alpha toxin과 fibronectin-binding protein (FnBP)의 혈중항 체가 수준과 비교하여 볼 때 비교적 낮은 수준이었다. 세균을 혈중으로 공격접종한 후 대조군 과 백신접종군의 혈중내 세균제거율에 있어 대조군에 비해 백신접종군에서 유의성 있게 낮은 균수를 보였다 (p<0.05). 또한 장기내 균수측정실험결과 대조군의 장기보다 백신접종군에서 유의성 있게 세균수가 낮게 출현하였다 (p<0.05). 결론적으로 본 연구결과 황색포도상구균의 3가지 항훤 alpha-toxin, capsular polysaccharide와 재조합 fibronectin binding protein을 이 퐁한 실험동물에서 안단위 유방염 백신은 방어능이 있다고 생각된다.

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.58-62
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• 2012

To protect aquatic animal health of importing countries from the potential risks associated with exotic diseases introduced through international trade of live aquatic animals, inspection of designated commodities at ports of entry is a critical component of the safeguarding system. The only way to be 100% confident that no fishes in a shipment are infected with a specific agent is to test every fish in the commodity imported with a perfect diagnostic test. For the majority of cases, this is unrealistic since the group of interest may very large particularly for aquatic animals, or imperfect tests are often available. It is, therefore, more common to test a fixed proportion of a group by preplanned sampling schemes. However, decision making based on results of testing the sample can provide quite a chance that infected groups may be misclassified as uninfected, depending on sampling strategy employed. The objective of this study was to determine the possibility that one or more fishes in the group imported being infected but tests negative after inspecting samples. This question is critical to government authorities to examine whether sampling plan is sufficient to achieve the purpose intended for. At fixed population size, the maximum number of infected fishes when all tests negative was decreased as the sampling fraction increased. The probability of including at least one undetected but infected fish in a group for negative tests increased with the number of fish tested or true prevalence. The risk was much lesser where high sensitivity test was assumed; when increasing test sensitivity from 0.9 to 0.99, this risk was dramatically reduced to about a tenth or a fourth for prevalence ranges from 2 to 10%, given sample size ranges from 10 to 200. Based on the preliminary analysis, the author concluded that current sampling plan testing 4-8% of the import proposal for human consumption still can yield high false negative results. Therefore, from the quarantine inspection point of view, an enforced commodity-specific sampling design that accounts for the cost of testing with an imperfect test at the specified design prevalence is urgent.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.322-322
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• 2009

국내산 밀을 유기농 재배하여 친환경 농산물 인증을 받으려면 파종에 필요한 종자도 유기농으로 생산된 것(유기종자)을 사용해야한다. 국립식량과학원에서는 유기종자 생산용 밀 품종 선발을 위한 연구를 수행하고 있으며, 관련 시험으로서 유기질 비료 시비가 밀의 농업형질 및 종자의 아미노산 함량에 미치는 영향을 검토하였다. 무비, 화학비료 및 유기질 비료를 시비한 시험구에 금강밀 등 24개 밀 품종을 파종하여 시험 구별로 출수기 등 농업형질과 수확된 종자의 아미노산 함량을 분석하였다. 밀의 출수기는 시비 조건에 따른 영향을 받지 않았으나 성숙기는 유기질 비료 시비조건에서 화학비료 및 무비보다 1일과 2일 지연되었다. 밀의 간장, 수장, 수수, 수당립수 및 L중은 시비의 종류에 따른 차이를 나타내지 않았다. 한편, 유기질 비료 시비에 따른 밀 종실수량(368.4kg/10a)은 무비 및 화학비료보다 각각 25%와 8% 유의하게 증가하였다. 밀 종자의 전체 아미노산 함량은 무비<화학비료<유기질비료 순으로 유의하게 증가하였다. 각각의 아미노산별로 시비조건에 따른 함량차이를 조사한 결과, Glutamate 등 13종의 아미노산은 시비조건에서 5~16% 증가하였다. Alanine 함량의 경우 무비조건에 비하여 유기질 비료 시비조건에서 38% 증가하였으나 화학비료 시비조건에서는 12% 감소하였다. 한편, tyrosine, phenylalanine 및 proline은 유기질 비료 시비조건에서 11~29% 감소하였으나, 화학비료 시비조건에서 9~36% 증가하였다.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.319-319
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• 2009

관행재배 농산물에 대한 유기재배 농산물의 우수성이 구전되고 있으나 객관적인 과학적 데이터가 부족한 실정이다. 그래서 본 연구에서는 한국인이 주식으로 하고 있는 쌀(동진 1호)을 대상으로 생산이력이 분명한 유기 및 관행재배 시료를 이용하여 독자적으로 확립한 분석법을 이용해 유기 및 관행재배 쌀에 함유된 생리활성성분의 함량 비교를 행하였다. 생리활성성분 분석은 $\gamma$-oryzanol, $\beta$-sitosterol 및 tocopherol류를 대상으로 행하였다. 쌀에 함유된 주요 4종의 $\gamma$-oryzanol류의 동정을 위해 그 4종 화합물들을 ESI-MS 및 NMR 분석을 행한 결과, ODS 컬럼 상에서 cycloartenyl ferulate, 24-methylene cycloartenyl ferulate, campesteryl ferulate 및 $\beta$-sitosteryl ferulate 순으로 용출됨을 확인하였다. 동정된 각 성분들을 HPLC로 분석한 결과, cycloartenyl ferulate와 $\beta$-sitosteryl ferulate의 함량은관행보다 유기재배 쌀에서 유의(p<0.05)하게 높은 값을 보였다. 또한 $\gamma$-oryzanol 중 24-methylene cycloartenyl ferulate와 campesteryl ferulate의 함량은 유의차는 인정되지 않았으나 관행보다 유기재배 쌀에서 더 높은 경향을 보였다. 그리고 $\beta$-sitosterol 함량에 있어서는 유의차가 인정되지 않았으나 관행보다 유기재배 쌀에서 더 높은 경향을 나타냈다. 관행재배와 유기재배 쌀의 tocopherol류의 함량을 분석한 결과, $\alpha$-tocopherol의 함량에 있어서는 관행과 유기재배 쌀 간의 유의차가 관찰되지 않았고, $\beta$- and/or $\gamma$-tocopherols의 함량에 있어서는 유기재배 쌀에서 더 높은 경향이 관찰되었다. 이처럼 쌀에 함유된 생리활성 성분과 그로 인해 발휘되는 기능성 측면에 있어서 유기농산물의 우수성은 유기농산물 재배 농가의 수익 창출에 도움이 되는 홍보자료 제공 및 식품 기능학적 측면에 있어 중요한 기초자료로 활용될 수 있으리라 기대된다. 그러나 본 결과는 본 실험에서 대상으로 한 시료에 한정될 수 있으며, 유기재배 방법과 재배환경 및 조건에 따라 다양한 결과가 얻어질 수 있음에 주의가 요구된다.