• 식물병연구
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• 제17권1호
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• pp.95-98
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• 2011

국내 당근 유기재배를 위한 저항성 품종 선발을 목적으로 한 실험에서는 당근 유전자원 32품종을 이용하여 병저항성(흰가루병, 검은무늬병, 검은잎마름병) 검정, 내충성 및 추대 정도를 조사하였다. 흰가루병 스크리닝 결과 'PI 223360'이 저항성이었으며, 'Oxheart Carrot Heirloom'를 포함한 10개의 품종이 중도저항성이었고 'Long Impeator #58'을 포함한 22품종이 감수성인 것으로 나타났다. 당근 검은무늬병과 검은잎마름병의 스크리닝 결과 모든 품종이 저항성을 나타내진 않았지만, 몇몇 품종이 중도저항성을 가진 것으로 확인되었다. 내충성을 조사한 결과 'Oxheart Carrot Heirloom'를 포함한 13품종이 내충성인 것으로 조사되었으며, 'Nantes Coreless Carrot'을 포함한 11개의 품종들이 중간정도를 나타냈으며 'SA 102'와 'Scarlet Keeper Carrot Rare'은 감수성인 것으로 조사되었다. 추대조사 결과에서는 'Hongsim Ouchon Carrot'을 포함한 6개의 품종이 이른 추대를 보였으며, 'Japanese Imperial Long Carrot'를 포함한 4개 품종이 중간 추대를 나머지는 만추대성인 것을 확인하였다. 이상의 결과를 근거로 'Oxheart Carrot Heirloom'이 조사한 32개 당근 유전자원 중 유기재배를 위한 품종으로 선발되었다.

• 산업경영시스템학회지
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• 제40권2호
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• pp.145-149
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• 2017

One of the challenges facing precision manufacturers is the increasing feature complexity of tight tolerance parts. All engineering drawings must account for the size, form, orientation, and location of all features to ensure manufacturability, measurability, and design intent. Geometric controls per ASME Y14.5 are typically applied to specify dimensional tolerances on engineering drawings and define size, form, orientation, and location of features. Many engineering drawings lack the necessary geometric dimensioning and tolerancing to allow for timely and accurate inspection and verification. Plus-minus tolerancing is typically ambiguous and requires extra time by engineering, programming, machining, and inspection functions to debate and agree on a single conclusion. Complex geometry can result in long inspection and verification times and put even the most sophisticated measurement equipment and processes to the test. In addition, design, manufacturing and quality engineers are often frustrated by communication errors over these features. However, an approach called profile tolerancing offers optimal definition of design intent by explicitly defining uniform boundaries around the physical geometry. It is an efficient and effective method for measurement and quality control. There are several advantages for product designers who use position and profile tolerancing instead of linear dimensioning. When design intent is conveyed unambiguously, manufacturers don't have to field multiple question from suppliers as they design and build a process for manufacturing and inspection. Profile tolerancing, when it is applied correctly, provides manufacturing and inspection functions with unambiguously defined tolerancing. Those data are manufacturable and measurable. Customers can see cost and lead time reductions with parts that consistently meet the design intent. Components can function properly-eliminating costly rework, redesign, and missed market opportunities. However a supplier that is poised to embrace profile tolerancing will no doubt run into resistance from those who would prefer the way things have always been done. It is not just internal naysayers, but also suppliers that might fight the change. In addition, the investment for suppliers can be steep in terms of training, equipment, and software.

• Design & Manufacturing
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• 제15권2호
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• pp.42-48
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• 2021

In this paper, when manufacturing large/multi-mold parts (more than 30 core parts),A mold manufacturing (tolerance) management system was established through design-processing linkage.The mold manufacturing (tolerance) management system is a design-based measurement shape/measurement position determination system, M/C processing-linked measurement drive system,It is composed of four parts: CAD-linked measurement result analysis system and manager mold part quality management system.In addition, the constructed system was applied to the field and the effect of system construction was evaluated by comparing it with the existing process.As a result of the evaluation, the measurement precision is within 0.02mm, and the time it takes to measure after the end of processing is shorter than that of the existing process.(12 hours → 2 hours) It was shortened to 16.7%.In addition, it was confirmed that the time required for reprocessing after measurement was reduced by 25% (4 hours → 1 hour) compared to the existing process.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.83-93
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• 2019

이 연구는 IPP 일학습 병행 훈련에 참여한 훈련생들과 참여기업 현장교사의 개인특성이 훈련생의 고용가능성에 미치는 영향에 관한 연구를 통하여 IPP 일학습 훈련의 효과 및 효율성 향상에 기여할 수 있는 시사점을 제시하고자 한다. 본 연구는 IPP 일학습 훈련에 참여하고 있는 9개 대학의 훈련생(학습근로자) 200명을 대상으로 설문지를 배포하여 회수된 설문지(157부)를 바탕으로 요인 간 인과관계를 검증한 결과 다음과 같은 결론을 도출하였다. 첫째, IPP 훈련생의 고용가능성을 높이기 위해서는 먼저 훈련생을 선발할 때 훈련생 개개인이 갖고 있는 개인특성을 검증하여 핵심역량과 실패내성이 강한 훈련생을 선발할 필요가 있다. 둘째, 기업에서는 교수역량 뿐만 아니라 진성리더십이 강한 선임사원을 기업현장교사로 선임하고, 기업현장교사 연수기관에서는 그들의 리더십 향상을 위한 연수를 강화하여야 한다. 셋째, 일학습 기업은 사회적 통합과 흡수역량이 높은 기업으로 선정하고, 참여기업은 신기술을 습득하고 학습하는 조직문화를 구축하기 위해 노력하여야 한다. 본 연구 결과는 앞으로 훈련생 및 참여기업 선발 기준을 체계화하고 기업과 기업현장교사의 훈련 역량을 높일 수 있는 훈련시스템 구축을 통하여 일학습 훈련의 효과를 높이는 데 기여할 수 있을 것으로 사료된다.

• 전기학회논문지
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• 제57권7호
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• pp.1213-1217
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• 2008

Poling is an important process in fabricating PZT ceramic devices such as filters and resonators and activates piezoelectricity to sintered PZT ceramics. Tolerance of the operating frequency of these devices is tightly required in applications. And a factor to attribute the tolerance is the temperature dependence of the resonance frequency of PZT ceramics. In this paper the relationship of poling strength and temperature dependence of resonance frequency of PZT specimens was studied. The $Pb(Zr_{0.53}Ti_{0.47})O_3$ ceramics were fabricated and the poling strengths were chosen to be 0.5, 1.5, 2.5 and 3.5 [kV/mm]. The dielectric constant of the specimen poled in poling strength 0.5 [kV/mm] was less than that of unpoled specimen and the specimen poled in higher electric field had the higher dielectric constant. (002) peak in X-ray diffraction patterns of the specimens increased as poling strength increased. And the change of resonance frequency of the specimens according to the variation of temperature was measured. Resonance frequency of all specimens increased as the temperature increased. The specimen poled in higher electric field had the smaller positive temperature coefficient of resonance frequency. The effect that temperature coefficient of resonance frequency becomes smaller is obtained when Zr mole in PZT composition equation increase. Controlling the poling strength is believed to be a method to adjust the temperature stability of resonance frequency of the PZT ceramic devices.

• 아시안잔디학회지
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• 제7권1호
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• pp.19-30
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• 1993

Experiments were conducted to investigate propagation, shade tolerance, cold resistance and growth rate of evergreen ground cover plants ; Vinca minor K , Ajuga reptans L., Ophiopogon japonicus ker. f nanus hort , and Hedera helix.. The results were as follows : 1.It is convenient to use the growing case for rice seed to grow and transplant Vinca minor seed-ling. The most proper density of transplanting Vinea was 180 plants per 1m$^2$. At the end of growing season, the coverage came up to 90% The rooting ability of Hedera helix was best to cut from April to May (temperature 15~23˚C). The seedling length of Parthenocissus quinguefohlia were irregular and ranged from 5 cm of 200cm. 2. Ajuga reptans L., Ophiopogon j. and Vinca minor L. grew better under 50% light intensity than full sunlight. Particularly, under full sunlight and aestival high temperature, there were a few withering plants in Ajuga reptans L. , and V Vilica minor L. 3. Of Vinca minor K., Ajuga reptans L. , Ophiopogon japonicus ker. f. nanus hort. and Hedera helix. acclimatized in open field, where temperature was from -7~8˚C. There were few plants had damage in low temperature incubator to -16˚C after field acclimatization. 4.Tendrils of Parthenocissus quinguefolia strongly clung to the wire netting stone fence but intruded into the gap and cranny of the precast concrete fence and so clung to, so that it needed to install the bending net on the precast concrete fence.

• 대한방사선기술학회지:방사선기술과학
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• 제45권6호
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• pp.491-502
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• 2022

The purpose of this study was to retrospectively investigate the upper and lower control limits of treatment planning parameters using EBT film based delivery quality assurance (DQA) results and to analyze the results of statistical process control (SPC) in helical tomotherapy (HT). A total of 152 patients who passed or failed DQA results were retrospectively included in this study. Prostate (n = 66), rectal (n = 51), and large-field cancer patients, including lymph nodes (n = 35), were randomly selected. The absolute point dose difference (DD) and global gamma passing rate (GPR) were analyzed for all patients. Control charts were used to evaluate the upper and lower control limits (UCL and LCL) for all the assessed treatment planning parameters. Treatment planning parameters such as gantry period, leaf open time (LOT), pitch, field width, actual and planning modulation factor, treatment time, couch speed, and couch travel were analyzed to provide the optimal range using the DQA results. The classification and regression tree (CART) was used to predict the relative importance of variables in the DQA results from various treatment planning parameters. We confirmed that the proportion of patients with an LOT below 100 ms in the failure group was relatively higher than that in the passing group. SPC can detect QA failure prior to over dosimetric QA tolerance levels. The acceptable tolerance range of each planning parameter may assist in the prediction of DQA failures using the SPC tool in the future.

• 한국환경농학회지
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• 제24권1호
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• pp.45-55
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• 2005

This study was undertaken to find out necessary measures to improve the tolerance setting system of pesticide residues on food crops in Korea which is scientifically reasonable and harmonizable with international standards. Information on tolerance setting systems of pesticide residues by Codex Alimentarius Commission, Joint FAO/WHO Meeting of Experts on Pesticide Residues, USA, EU, Japan and Taiwan was collected and analyzed. On the basis of information in the above countries, necessary actions to be taken by the Korean regulatory authorities were recommended with respect to priority setting, maximum residue limits (MRLs) setting based on field residue data, group MRLs, minor crop problems, quantitation limit and dietary intake assessment.

• 천문학회보
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• 제40권2호
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• pp.56.4-57
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• 2015

We present the optical design and a sensitivity analysis for a wide field of view (FOV) instrument operating at UV and IR wavelengths. The ongoing investigation is performed in collaboration with Omnisys Instruments (Sweden) and focuses on a telluric-limb-viewing instrument that will fly in a low Earth orbit to study mesospheric wave structures over a wide range of horizontal scales in the altitude range 80 - 100 km. The instrument has six wavelength channels which consist of 4 channels of IR and 2 of UV. We are proposing an optical design based on three mirror aplanatic off-axis reflective system. The entrance pupil diameter and effective focal length are 45 mm and 270 mm, respectively. The FOV is $5.5^{\circ}{\times}1^{\circ}$ and the secondary mirror is set for stop. The optical specification is required to have an encircled energy of at least 80 % within a diameter of 21 um. We performed sensitivity analysis for the longest wavelength of 772 nm in consideration of the diffraction limit of system. The results show that tolerance limits for positions and angles of the mirrors are not very sensitive compared with typical error budgets of manufacturing and assembling process. The secondary mirror has the most sensitive tolerance for surface figure of 250 nm in root-mean-square.

• 식물조직배양학회지
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• 제27권4호
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• pp.325-337
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• 2000

All living organisms depend on soil and water for their sustained growth and development. In recent years, sustenance of life in these growth matrices has been adversely affected by the cumulative increase in environmental pollutants resulting from increasing population, growing economies and resource-use. This review provides a glimpse into the problem of global environmental pollution, the traditional technologies available for remediation and the scope of emerging‘plant-based remediation’technologies. Phytoremediation, the use of plants to effectively remove or stabilize contaminants from the growth substrate, is a low cost and ecologically friendly alternative to the common‘dig and dump’technologies. The field of phytoremediation has been driven by the intrinsic need for identification of ideal candidate plant species. To date, there are only a very few identified plants which satisfy all of the prerequisites for use in phytoremediation. The review focuses on one such plant species, the common horticultural plant scented geranium (Pelargonium sp.), with demonstrated potential to remediate metal / salt contaminated soils / aqueous systems. The characterization of tolerance and metal / salt accumulation potential of Pelargonium sp. and its efficacy in remediating complex contaminated sites are described. The unique ability of scented geraniums to tolerate excessive amounts of multi-metals, hydrocarbon and salt mixtures, and at the same time to accumulate significant amounts of metal and salt ions in the biomass, renders this plant species as one of the ideal candidates for remediation.