• 응용통계연구
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• 제21권3호
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• pp.361-375
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• 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.

• 한국환경과학회지
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• 제26권11호
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• pp.1247-1253
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• 2017

The Fuji variety of apple, introduced in Japan, has excellent storage quality and good taste, such that it is the most commonly cultivated apple variety in Gunwi County, North Gyeongsang Province, Korean Peninsula. Accurate prediction of harvest maturity allows farmers to more efficiently manage their farm in important aspects such as working time, fruit storage, market shipment, and labor distribution. Temperature is one of the most important factors that determine plant growth, development, and yield. This paper reports on the beta distribution (function) model that can be used to simulate the the phenological response of plants to temperature. The beta function, commonly used as a skewed probability density in statistics, was introduced to estimate apple harvest maturity as a function of temperature in this study. The model parameters were daily maximum temperature, daily optimum temperature, and maximum growth rate. They were estimated from the input data of daily maximum and minimum temperature and apple harvest maturity. The difference in observed and predicted maturity day from 2009 to 2012, with optimal parameters, was from two days earlier to one day later.

• 농업과학연구
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• 제45권4호
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• pp.839-845
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• 2018

As a solution to the rural shortage of labor, mechanization crop production is necessary, but in some cases, the mechanization can cause problems such as a decrease in products due to the expansion of the necessary moderate workspace. The purpose of this study was to compare the yields of pepper by the planting-density for the mechanization of pepper cultivation. Experiments were done with three planting-density levels of $900{\times}300mm^2$(A-T), $1200{\times}450mm^2$(B-T), and $1500{\times}600mm^2$(C-T). In the analysis of growth, the highest values in plant height and thickness and the number of branches were observed with the B-T. C-T showed the highest values in the number of green-pepper and red-pepper and weight of the green-pepper and red-pepper, followed by B-T and A-T. In the analysis of growth, it was concluded that the proportion of the pepper body to the total length increased as the planting-density decreased. C-T had the biggest maximum diameter of the body, followed by B-T and A-T. On the other hand, A-T had the biggest minimum diameter of the body, followed by B-T and C-T. It was judged that the larger the planting-density was, the shorter the length was and the thicker the form was. As a result of measuring the chromaticity, there was no significant statistical difference in quality. Based on the experiment results, the ranking in total yields was in the order of C-T, B-T, and A-T. The reduced planting-density seemed to increase the productivity, while the labor intensity and time were reduced due to the improvement of the working environment.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 1997년도 추계학술대회논문집 기업경쟁력 향상을 위한 정보통신 기술의 활용
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• pp.113-125
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• 1997

The objective of this research is to construct and build a software platform to enable collaboration among enterprise headquarters, product designers, software engineers, manufacturing plants, and suppliers which are located at different remote locations via internet. In specific, agent technology is adopted as a software vehicle to automate demand as a software vehicle to automate demand and supply process in the internet environment. Agents are programs that act an behalf of their human users to perform laborious tasks such as information locating, accessing, filtering, integrating, adapting and resolving inconsistencies. Global competition is forcing the present day industry to produce high quality product more fast and inexpensively. In Korea, most labor-intensive industries have moved to China and other Asian countries for cost reduction. The need for fast information exchange has increased among the remote locations for the cooperation and coordination. In this research, a virtual global manufacturing system will be constructed that distributes production schedule among remote places, acts as a bridge between the headquarters and manufacturing plants, distributes tasks and collates different solutions between demand and supply using agent. The external communication protocol takes HTML format, internal message handling requires SGML for document exchange, and KQML for agent implementation. The expected benefits will be : reduced cost of real-time information exchange, realization of global manufacturing environment, the maximum utilization of internet for the enterprise data exchange.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.154-160
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• 1997

Present experiment designed for the review of theoretical basis for the inspection system of infected insects by Nosema bombycis. A microporidian N. bombycis, known as the high virulence, produced at the average of 7$\times$108 spores per female moth of the silkworm, Bombyx mori, enabled transovarial tranmission. Detectability of N. bombycis spores in the mass inspection was varied by dillution level, the higher limit of dillution with healthy moths was 1:140 for 100% detection, 1:160 for 99.5%, 1:200 for 99.0%. For an efficient inspection under the microscopic observation (600$\times$), the lower limit of spore concentration was determined as 1, 000, 000 spores/ml, 60-80 moths could be applicable for a maximum sample unit of a lot. Following the present inspection unit conditioned 35 to 40 moths for a lot. N. bombycis spores were easily detectable from the preparation of crude homogenate with 2% KOH, even the step of contrifuge was omitted. The results suggested a new basis of rational mass inspection system of silkworm female moths to save the facilities, labor, and time.

• 한국정보시스템학회지:정보시스템연구
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• 제6권2호
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• pp.85-105
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• 1997

The objective of this research is to construct and build a software platform to enable collaboration among enterprise headquarters, product designers, software engineers, manufacturing plants, and suppliers which are locate at different remote locations via internet. In specific, agent technology is adopted as a software vehicle to automate demand and supply process in the internet environment. Agents are programs that act on behalf of their human users to perform laborious tasks such as information locating, accessing, filtering, integrating, adapting and resolving inconsistencies. Global competion is forcing the present day industry to produce high quality product more fast and inexpensively. In Korea, most labor-intensive industries have moved to China and other Asian countries for cost reduction. The need for fast information exchange has increased among the remote locations for the cooperation and coordination. In this research, a virtual global purchasing and ordering system will be constructured that distributes production schedule among remote places, acts as a bridge between the headquarters and manufacturing plants, distributes tasks and collates different solutions between demand and supply using agent. The external communication protocol takes HTML format, internal message handling requires SGML for document exchange, and KQML for agent implementation. The expected benefits will be : reduced cost of real-time information exchange, realization of global manufacturing environment, the maximum utilization of internet for the enterprise data exchange.

• 대한화학회지
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• 제14권3호
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• pp.207-212
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• 1970

A large variety of weed killers, insecticides, and bactericiedes on the market today are of almost infinite variety, but their pharmacological effects are different from each other according to the objects to cope with. Therefore, it is hoped that some chemical substance which serves as weed killer, an insecticide, and a bactericede at a same time, should be synthesized, in order to save expense and labor. I anticipated that the desire would be met by introducing to a molecule the radical which has the three effects. Here, I made an attempt of introducing $Cl_2$ gas to aniline considering the following respects: 1. Introduction velocity of $Cl_2$ gas under the varied temeratures and velocities of $Cl_2$ gas 2. The effect of reaction period under the condition which gives the most satisfactory yield. 3. The actions of catalysts, $SbCl_3$, $FeCl_3$, and $MoCl_5$, and their proportions when a mixture of the three catalysts is used in producing 2,6-dichloro-aniline. After consideration of above phenomena, the maximum production rate of 79.5% of 2.6-compound was obtained. With the compound I synthesized 2.6-dichloro-4-nitroaniline-mercuric acetate. Investigations of the effects of the compound as weed killer, an insecticide, and a bactericide showed that the compound, 2,6-dichloro-4-Nitro Aniline mercuric acetate has a satisfactory herbi-insecti-bactericidal effect.

• 한국BIM학회 논문집
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• 제9권2호
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• pp.1-10
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• 2019

In this research, schedule optimization is defined as balancing the number of workers while keeping the demand and needs of the project resources, creating the perfect schedule for each activity. Therefore, when one optimizes a schedule, multiple potentials of schedule changes are assessed to get an instant view of changes that avoid any over and under staffing while maximizing productivity levels for the available labor cost. Optimizing the number of workers in the scheduling process is not a simple task since it usually involves many different factors to be considered such as the development of quantity take-offs, cost estimating, scheduling, direct/indirect costs, and borrowing costs in cash flow while each factor affecting the others simultaneously. That is why the optimization process usually requires complex computational simulations/modeling. This research attempts to find an optimal selection of daily maximum workers in a project while considering the impacts of other factors at the same time through OPEN BIM based multiple computer simulations in resource leveling. This paper integrates several different processes such as quantity take-offs, cost estimating, and scheduling processes through computer aided simulations and prediction in generating/comparing different outcomes of each process. To achieve interoperability among different simulation processes, this research utilized data exchanges supported by building SMART-IFC effort in automating the data extraction and retrieval. Numerous computer simulations were run, which included necessary aspects of construction scheduling, to produce sufficient alternatives for a given project.

• Smart Structures and Systems
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• 제29권2호
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• pp.287-299
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• 2022

Rather than using smartphones as seismometers with designated locations and orientations, this study proposes to employ crowds' smartphones in buildings to perform fast safety assessment of buildings. The principal advantage of using crowds' smartphones is the potential to monitor the safety of millions of buildings without hardware costs, installation labor, and long-term maintenance. This study's goal is to measure the maximum interstory drift ratios during earthquake excitation using crowds' smartphones. Beacons inside the building are required to provide the location and relevant building information for the smartphones via Bluetooth. Wi-Fi Direct is employed between nearby smartphones to conduct peer-to-peer time synchronization and exchange the acceleration data measured. An algorithm to align the orientation between nearby smartphones is proposed, and the performance of the orientation alignment, interstory drift measurement, and damage level estimation are studied numerically. Finally, the proposed approach's performance is verified using large-scale shaking table tests of a scaled steel building. The results presented in this study illustrate the potential to use crowds' smartphones with the proposed approach to record building motions during earthquakes and use those data to estimate buildings' safety based on the interstory drift ratios measured.

• Journal of Radiation Protection and Research
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• 제43권1호
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• pp.10-19
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• 2018

Background: Monte Carlo (MC) simulation is the most accurate for calculating radiation dose distribution and determining patient dose. In MC simulations of the therapeutic accelerator, the characteristics of the initial electron must be precisely determined in order to achieve accurate simulations. However, It has been computation-, labor-, and time-intensive to predict the beam characteristics through predominantly empirical approach. The aim of this study was to analyze the relationships between electron beam parameters and dose distribution, with the goal of simplifying the MC commissioning process. Materials and Methods: The Varian Clinac 2300 IX machine was modeled with the Geant4 MC-toolkit. The percent depth dose (PDD) and lateral beam profiles were assessed according to initial electron beam parameters of mean energy, radial intensity distribution, and energy distribution. Results and Discussion: The PDD values increased on average by 4.36% when the mean energy increased from 5.6 MeV to 6.4 MeV. The PDD was also increased by 2.77% when the energy spread increased from 0 MeV to 1.019 MeV. In the lateral dose profile, increasing the beam radial width from 0 mm to 4 mm at the full width at half maximum resulted in a dose decrease of 8.42% on the average. The profile also decreased by 4.81% when the mean energy was increased from 5.6 MeV to 6.4 MeV. Of all tested parameters, electron mean energy had the greatest influence on dose distribution. The PDD and profile were calculated using parameters optimized and compared with the golden beam data. The maximum dose difference was assessed as less than 2%. Conclusion: The relationship between the initial electron and treatment beam quality investigated in this study can be used in Monte Carlo commissioning of medical linear accelerator model.