• 응용통계연구
• /
• 제21권3호
• /
• pp.361-375
• /
• 2008

본 논문에서는 패널의 일부를 규칙적으로 교체하는 4-8-4 교체표본설계에서 발생할 수 있는 항목 무응답을 대체하는 방법에 대하여 연구하였다. 특히 소득이나 취업과 같이 민감한 질문에 대하여 발생할 수 있는 무응답에 대하여 무시할 수 없는 무응답(nonignorable nonresponse) 체계하에서 발생하는 무응답을 가정하였다. 무응답들의 대체방법으로 모형에 기반한 대체방법을 고려하였으며 베이지안 방법을 이용하여 사후확률밀도함수를 최대화하는 최대사후우도추정량(maximum posterior likelihood estimator)을 구하였다. 그리고 대체된 자료를 이용하여 면접시점이 달라질 때 발생하는 편향을 추정하였으며 추정된 편향을 제거한 후 연속적인 두 조사기간에서의 각 칸의 확률과 고정된 시점에서의 주변확률을 계산하였다. 모의실험을 통해 최종적으로 도출된 결과를 평균제곱오차와 편향의 관점에서 비교하였다.

• 한국물환경학회지
• /
• 제37권4호
• /
• pp.275-285
• /
• 2021

Algal bloom is an important issue in maintaining the safety of the drinking water supply system. Fast detection and classification of algae images are essential for the management of algal blooms. Conventional visual identification using a microscope is a labor-intensive and time-consuming method that often requires several hours to several days in order to obtain analysis results from field water samples. In recent decades, various deep learning algorithms have been developed and widely used in object detection studies. YOLO is a state-of-the-art deep learning algorithm. In this study the third version of the YOLO algorithm, namely, YOLOv3, was used to develop an algae image detection model. YOLOv3 is one of the most representative one-stage object detection algorithms with faster inference time, which is an important benefit of YOLO. A total of 1,114 algae images for 30 genera collected by microscope were used to develop the YOLOv3 algae image detection model. The algae images were divided into four groups with five, 10, 20, and 30 genera for training and testing the model. The mean average precision (mAP) was 81, 70, 52, and 41 for data sets with five, 10, 20, and 30 genera, respectively. The precision was higher than 0.8 for all four image groups. These results show the practical applicability of the deep learning algorithm, YOLOv3, for algae image detection.

• 한국수자원학회논문집
• /
• 제45권8호
• /
• pp.783-794
• /
• 2012

시간에 따른 하도의 수위 및 유량 변화에 영향을 많이 받는 수리구조물의 설계에 있어서 부정류 흐름 해석은 반드시 필요하다. 일반적으로 부정류 흐름 해석에는 수치모형이 많이 활용되고 있으나 수치모형의 검 보정을 위한 현장 자료의 획득이 어려운 경우가 많다. 또한 자료구축이 가능하더라도 인력과 비용이 많이 소모되며, 측정 정확도를 신뢰하기 어려운 경우가 많다. 이러한 경우 수치모형의 검 보정을 위해 부정류 수리실험을 통해 획득되는 자료를 활용하는 것이 대안이 될 수 있다. 따라서 본 연구에서는 다양한 형태의 부정류 수문곡선을 실험에서 재현할 수 있는 유량공급장치를 개발하고자하며, 개발된 부정류 유량공급장치를 이용하여 수리실험 수로에서 재현되는 수문곡선과 목표 수문곡선을 비교 분석함으로써 재현 정확도를 정량적으로 평가하고자 한다. 본 연구에서는 유량이 급격하게 증가 또는 감소하는 사각형 형태, 첨두유량 발생 시간이 짧은 삼각형 형태 및 일반적인 홍수 수문곡선 형태의 종(bell) 형태 수문곡선을 대상으로 재현 오차 및 Root Mean Square Error (RMSE)를 분석하였다. 재현 정확도 분석 결과, 사각형 형태의 수문곡선 재현 오차는 약 59% 정도로 가장 크게 나타났으며, 삼각형 형태의 수문곡선은 단일첨두와 이중첨두 형태 모두 약 10% 정도의 재현 오차가 나타났지만 홍수 수문곡선 형태인 종 모양의 수문곡선의 재현 오차는 최대 2% 이내인 것으로 나타났다.

• 한국잠사곤충학회지
• /
• 제3권
• /
• pp.61-67
• /
• 1963

본보의 목적은 현재 우리나라에서 장려품종으로 지정된 잠품종 3종과 시험도중에 있는 잠품종 2종을 재료로 하여 그 견계섬도의 변이가 생계섬도편차에 미치는 영향을 조사하여 생계제조전에 원료견만으로서 생계섬도편차를 평가하여 운영계획에 과학성을 유지하게 하는데 있고 다음과 같은 결론을 얻었다. 1. 교잡종견의 견계섬도변이는 정립조건으로 볼때 P$_{k}$ $\times$ S$_{n}$은 21 중용견으로 가장 적합하다. 그러나 입촌수가 8립으로 되기 때문에 능률에는 지장이 있을 것이고 생계촉감면으로는 다른 품종보다우수하다. 2. 백두$\times$금강 및 묘향$\times$청천은 21 중용견으로서 능률위주의 원료견이다. 3. 설악$\times$소양은 14중, 및 28 중용견으로서 적합하다. 4. 묘향$\times$청천은 생계섬도편차입장으로 볼 때 이용가치가 희박하다. 5. 원료견의 평균견계섬도와 종합견계섬도표준편차간에는 소야씨의 실험을 재확인하는 동시에 밀접한 상관관계가 있었다. 6. 우리나라 산견의 원료견 평균섬도조사만으로 생계섬도편차를 중수별로 도표에 의해 추정할 수 있는 도표를 작성하였다. 7. 동시에 목적섬도에 따라 획득할 수 있는 최고등급표도 작성하였다. 8. 본보고에 사용한 견품종별 견사섬도변이가 생계섬도 및 등급에 미치는 영향은 제오표와 같다. 9. 현재 한국생계 21 중의 섬도편차성적은 평균 1.25D인 바 상기 표의 평균치와 합치하고 있다. 단지 그편차분포를 향상시킬 필요가 있다.다.

• 대한의생명과학회지
• /
• 제24권4호
• /
• pp.430-434
• /
• 2018

Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was $97.8%{\pm}2.9$ and $99.7%{\pm}0.46$, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

• 농업과학연구
• /
• 제49권3호
• /
• pp.483-493
• /
• 2022

It is important to improve the efficiency of plant breeding and crop yield to fulfill increasing food demands. In plant phenotyping studies, the capability to correlate morphological traits such as plant height, stem diameter, leaf length, leaf width, leaf angle and size of panicle of the plants has an important role. However, manual phenotyping of plants is prone to human errors and is labor intensive and time-consuming. Hence, it is important to develop techniques that measure plant phenotypic traits accurately and rapidly. The aim of this study was to determine the feasibility of point cloud data based on a 3D light detection and ranging (LiDAR) system for plant phenotyping. The obtained results were then verified through manually acquired data from the sorghum samples. This study measured the plant height, plant crown diameter and the panicle height and diameter. The R² of each trait was 0.83, 0.94, 0.90, and 0.90, and the root mean square error (RMSE) was 6.8 cm, 1.82 cm, 5.7 mm, and 7.8 mm, respectively. The results showed good correlation between the point cloud data and manually acquired data for plant phenotyping. The results indicate that the 3D LiDAR system has potential to measure the phenotypes of sorghum in a rapid and accurate way.

• 농업과학연구
• /
• 제49권2호
• /
• pp.269-284
• /
• 2022

The development of radish collectors has the potential to increase radish yields while decreasing the time and dependence on human labor in a variety of field activities. Stress and fatigue analyses are essential to ensure the optimal design and machine life of any agricultural machinery. The objectives of this research were to analyze the stress and fatigue of major components of a tractor-mounted radish collector under dynamic load conditions in an effort to increase the design dependability and dimensions of the materials. An experiment was conducted to measure the shaft torque of stem-cutting and transferring conveyor motors using rotary torque sensors at different tractor ground speeds with and without a load. The Smith-Watson-Topper mean stress equation and the rain-flow counting technique were utilized to determine the required shear stress with the distribution of the fatigue life cycle. The severity of the operation was assessed using Miner's theory. All running conditions produced more than 10⁷ of high cycle fatigue strength. Furthermore, the highest severity levels for motor shafts used for stem cutting and transferring and for transportation joints and cutting blades were 2.20, 4.24, 2.07, and 1.07, and 1.97, 3.81, 1.73, and 1.07, respectively, with and without a load condition, except for 5.24 for a winch motor shaft under a load. The stress and fatigue analysis presented in this study can aid in the selection of the most appropriate design parameters and material sizes for the successful construction of a tractor-mounted radish collector, which is currently under development.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.132-132
• /
• 2022

The application of direct seeding cultivation reduces time, labor, and cost. However, this application often has poor seedling establishment and leads to lower yield as compared to transplanting system. The tolerance to anaerobic and low temperature germination is important to improve seedling establishment and the wide-spread application of direct seeding method. This study was carried out to evaluate the responses of three japonica cultivars to different temperatures (15℃, 18℃, 21℃, 24℃, and 27℃) and different flooding levels (1 cm, 4 cm, 7 cm, 10 cm) during germination and seedling development. The mean survival percentage significantly increased (P<0.05) when the flooding level decreased and when temperature increased. There were significant effects of the interaction between temperature and water depth on survival percentage and seedling height. When temperature decreased from 27℃ to 15℃, the germination duration significantly increased from 6.4 days to 16.3 days while the germination speed, survival percentage, and seedling height decreased from 5.3 seeds day^-1, 61.9% and 190.6 cm to 2.2 seeds day^-1, 33.2%, and 47 cm, respectively. The increase in temperature under submergence condition was associated with the increased expression of Amy3D and ALDH2a but the decreased expression of ADH1 and PDC1. The results of this research would be used for further studies and breeding programs to improve rice seedling establishment and the application of direct seeding cultivation.

• Journal of Information Science Theory and Practice
• /
• 제11권4호
• /
• pp.51-81
• /
• 2023

This study aimed to study its required performance requirements and proposes a competency framework necessary for the digital workforce of the Provincial Offices in Thailand. The specific primary informants were determined as 17 people. The collecting process was performed using the Delphi technique and the electronic Delphi technique in two phases, totaling four rounds. In the first time, a structured interview was used to conduct online interviews for 15 people. Content validation was performed to determine issues of the competency framework essential for the digital workforce with 7-level scaled questionnaires, and then online reviews were collected between 10-15 people (2nd to 4th times). A consensus was found and confirmed four times with descriptive statistics, namely frequency, mean, standard deviation, mode, median, and the absolute value of the difference between mode and median, interquartile range, and application of the conceptual framework. The research findings revealed that the essential competency requirements for the digital workforce were covered in digital literacy (six aspects), digital skills (four aspects), and digital characteristics (four aspects). Consensus was confirmed for 84 issues. Therefore, it was concluded that 61 points for building an essential competency framework for the digital workforce made them effective in using digital technology as a labor-saving instrument, as well as for expanding the breadth of development of digital expertise to include members of the organization's digital practitioner network. This development will benefit government agencies and the private sector, both national and international, in the future.

• 원예과학기술지
• /
• 제28권4호
• /
• pp.580-584
• /
• 2010

가을철(9-10월) 무가온 하우스에서 돌나물($Sedum$ $samentosum$)의 4지역 수집종을 재료로 순환식 NFT 수경재배 방식을 이용하여 수량 및 품질에 미치는 재식거리의 영향을 조사하였다. 배양 40일째에 초장은 15.0-18.9cm 범위였으며, 평균 초장은 $10{\times}10$>$2.5{\times}2.5$>$5{\times}5cm$ 순으로 길었다. 재식거리에 관계없이 '포항'과 '완도' 수집종이 '군산'과 '완주' 수집종에 비하여 빠른 생장을 보였으며, 마디수, 줄기 직경, 개체당 생체중 및 건물중은 밀식할수록 감소하였다. 반면 단위면적 당 생체수량은 밀식할수록 크게 증가하여$2.5{\times}2.5cm$에서 4지역 수집종 평균 $14.9kg{\cdot}m^{-2}$이었으며, 수집종간에는 '포항' 수집종이 $17.6kg{\cdot}m^{-2}$으로 가장 높았다. 초장생육에 근거한 1차 수확적기는 30-40일경이었으며, 밀식할수록 줄기 경도를 나타내는 압착강도가 낮았으며, 쓴맛이 감소하였다. 그러나 밀식에 따른 삽식노력이 과중한 점은 개선해야 할 필요가 있었다.