• Journal of Ecology and Environment
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• 제38권4호
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• pp.397-403
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• 2015

Rice (Oryza sativa L.) is an important feeding crop in Asia, and utilization of genetically modified (GM) rice is highly demanding. For co-existence of GM rice and non-GM rice, the proper confinement measures should be provided. Thus, we surveyed gene flow from herbicide resistant GM rice to the conventional rice cultivars in the field tests. Gene flow frequency decreased with increasing distance between the pollen donor and recipients and did not exceed more than 1% even at the nearest distance. In single recipient model plot, a maximum gene flow frequency was observed at the shortest distance and hybrid was detected up to 12 m from the pollen donor. The direction of gene was coincided with the dominant wind direction. Gene flow assessment to multiple recipient plots was conducted under the high raining season by chance, and abrupt decline of gene flow frequency and maximum distance were resulted. According to the survey results, current regulation for isolation distance is reasonable for environmental safety or for general crop production. However, we suggest an alternative measure for GM rice cultivation that should be supplemented to overcome the out of estimation and in the environment asking higher security levels.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.629-635
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• 2021

In the spring, 2020, the pandemic caused quarantine and all educational institutions switched to distance learning, which led to significant changes in the field of education around the world. It has become necessary to build its capacity to provide distance learning to protect education and create opportunities for more individualized approaches to teaching and learning not only during future pandemics but also during other possible issues, such as natural disasters, when a developed flexible curricula could be taught face-to-face or online. The article presents an analysis of distance education in the world during a pandemic, analyzes significant changes, and implements measures in the field of education in Ukraine and around the world. The role of public and international organizations in the implementation of quarantine in the conditions of COVID-19, which partially took over the functions of state and local authorities, is emphasized. The closure of schools under COVID-19 has led to a de facto deterioration in learning outcomes, so we have analyzed the effects of distance learning and digital inequality in the world. It is shown how the COVID-19 pandemic affected access to public services in Ukraine.

• 한국경제지리학회지
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• 제17권1호
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• pp.98-113
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• 2014

본 연구의 목적은 2000년대 이후 수도권 광역철도망 확충에 따른 서울 대도시권 접근성의 변화를 분석하는 것이다. 이를 위하여 수도권 광역철도망과 같이 노선의 신설이나 확충으로 지속적으로 변화하는 비고정성 교통망의 세 가지 거리비용을 중심으로 하는 접근도 산출모형을 제시한다. 특히 도시민의 통행에서 중요하게 작용하지만 자료 구득의 한계로 제한되었던 시간거리 접근도를 산출하기 위하여 교통카드 통행거래 빅데이터를 이용하여 역과 역 사이의 시간거리(time distance)산출 알고리즘을 제시한다. 수도권 지역에서 교통카드가 본격적으로 도입된 이후의 두 시점 2005년과 2011년의 동일한 조건을 가진 주중 평일 하루치 교통카드 통행자료를 이용하여 수도권 광역철도체계의 세 가지 거리비용 접근성을 산출하고 그 결과를 비교분석한다.

• Communications for Statistical Applications and Methods
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• 제26권6호
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• pp.623-633
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• 2019

This paper proposes two distance measures between two cumulative hazard functions that can be obtained by comparing their difference and ratio, respectively. Then we estimate the measures and present goodness of t test statistics. Since the proposed test statistics are expressed in terms of the cumulative hazard functions, we can easily give more weights on earlier (or later) departures in cumulative hazards if we like to place an emphasis on earlier (or later) departures. We also show that these test statistics present comparable performances with other well-known test statistics based on the empirical distribution function for an exponential null distribution. The proposed test statistic is an omnibus test which is applicable to other lots of distributions than an exponential distribution.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2002년도 춘계학술대회논문집
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• pp.33-41
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• 2002

This paper deals with the development of simulation model for the container terminal consisting of 3 berths, 8 container cranes, 16 yard blocks with each yard cranes and 90 yard trucks in order to evaluate the various operational rules. The proposed operational rules are 3 ship dispatching rules, 3 berth allocation rules, 2 crane allocation rules, 2 yard allocation rules and 2 yard truck allocation rules and 4 performance measures like ship time in the terminal, ship time in the port, the number of ships processed and the number of containers handled are considered. The simulation result are as follows. 1) no difference among 3 ship dispatching rules, 2) berth allocation rules depends on performance measures 3) dynamic crane allocation is better than fixed policy 4) pooling yard allocation is better than short distance yard allocation rules and 5) fixed yard truck allocation by berth is a little better than pooling policy.

• 한국항만경제학회지
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• 제18권1호
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• pp.27-41
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• 2002

This paper deals with the development of a simulation model for the container terminal, which consists of 3 berths, 8 container cranes, and 16 yard blocks with each yard crane and 90 yard trucks in order to evaluate the various operational rules. The proposed operational rules are 3 ship-dispatching rules, 3 berth allocation rules, 2 crane allocation rules, 2 yard allocation rules, and 2 yard truck allocation rules. These rules are simulated using 4 performance measures, such as ship time in the terminal, ship time in the port, the number of ships processed, and the number of containers handled. The simulation result is as follows: 1) there is no difference among 3 ship-dispatching rules, 2) berth allocation rules depend on performance measures, 3) dynamic crane allocation is better than fixed policy, 4) pooling yard allocation is better than short distance yard allocation rules, and 5) fixed yard truck allocation by berth is a little better than pooling policy.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1090-1095
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• 2008

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, which determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from the characteristics of measuring device. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolley. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is EM-120, measures versine with 10m of symmetrical chord length.

• Structural Engineering and Mechanics
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• 제49권3호
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• pp.311-327
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• 2014

The safety relating to leakage of water and pitch instability of ship chambers of the full balanced hoist vertical shiplifts has been the focus of adoption of the type of vertical shiplifts. This paper aims to remove the doubts through theoretical and engineering researches. The leakage and pitch stability of ship chambers of full balanced hoist vertical ship lifts are investigated on the basis of theoretical analysis and exploration of engineering measures. Regarding the issue of leakage of ship chambers, a mathematical model on leaking process is built and corresponding formula and coping measures are obtained which can be applied in control program of ship lifts by linking with monitoring. The concept of safety grade is put forward to seek the best technical and economic index and the corresponding technical measures are for different grades of ship lift is suggested. For the issue of pitch instability, a methodology of combining theoretical deduction and summary of achievements of design and operation of the type of the full balanced hoist shiplifts is adopted, and the formula for design about pitch stability of ship chambers is derived.

• 한국정밀공학회지
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• 제16권10호
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• pp.80-86
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• 1999

Since the quality of the coated wires is in various applications dependant on the coating depth, accuracy of hole size of dies used for coating wires must be maintained precisely, in general within one micron. This paper proposes a new vision system which measures automatically the size and shape of small holes having diameters less than 1mm within an error limit of 1 micron. To quickly obtain the focused image, this paper proposes an estimation method of the camera position using only a couple of defocused hole images. It measures the distributions of light intensity around the image boundary and decides the direction and distance of a camera motion. The proposed system measures the size, shape distortion, inclination of the hole against the axis of the dies structure, to decides the acceptability of the dies for use. The proposed algorithm has been implemented using a cheap 640${\times}$480 image system and has shown an average size error of 1micron when measuring the dieses having 0.1mm to 1.0mm diameters. It can be applied to the inspection of the size and position of holes in PCB, too.

• 한국정보통신학회논문지
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• 제20권3호
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• pp.471-476
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• 2016

본 논문에서는 음성 특성 지표를 이용한 음성 인식 성능 예측 실험의 내용을 소개한다. 선행 실험에서 효과적인 음성 인식 성능 예측을 위해 대표적인 음성 인식 성능 지표인 단어 오인식률과 상관도가 높은 여러 가지 특성 지표들을 조합하여 새로운 성능 지표를 제안하였다. 제안한 지표는 각 음성 특성 지표를 단독으로 사용할 때 보다 단어 오인식률과 높은 상관도를 나타내 음성 인식 성능을 예측하는데 효과적임을 보였다. 본 실험에서는 이 결과를 근거하여 조합에 사용된 음성 특성 지표를 채택하여 4차원 특징 벡터를 생성하고 GMM 기반의 음성 인식 성능 예측기를 구축한다. 가우시안 요소를 증가시키며 실험한 결과 제안된 시스템은 babble 잡음, 자동차 잡음에서 모두 SNR이 낮을수록 단어 오인식률을 높은 확률로 예측함을 확인하였다.