• 한국신뢰성학회지:신뢰성응용연구
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• 제3권2호
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• pp.93-101
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• 2003

Life time data analysis requires some time-to-failure data to an extent. Some life tests result in few or no failure. In such cases, it is difficult to access reliability with traditional life tests that record only time to failure. Furthermore, with short product development time, reliability tests must be conducted with severe time constraints. For some devices, it is possible to obtain degradation measurements over time, and these measurements may contain useful information about product reliability. This article describes degradation reliability analysis methods to do inferences and predictions about a failure-time distribution by using software. In addition, the possibility of extension to CBM (Condition Based Maintenance) is suggested as an example of applied degradation data analysis.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2010년도 심포지엄 및 추계학술발표회
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• pp.497-498
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• 2010

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.73-80
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• 2004

The speed up of conventional lines feel strongly the necessity of it, for fully realizing a role of transportation system, for human life style is high, and increasing of time value. Especially curved lines zone have crucial effects on the speed of train. In this study, the extension method of transition curve is evaluated, based on the alignment of Jang-Hang line, investigated field conditions of the sections where the curves exist. The result of this research is very applicable to the condition where it is difficult to over-all alignment improvements.

• 화훼연구
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• 제18권3호
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• pp.211-215
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• 2010

'Maigic' 품종은 경남농업기술원 화훼연구소에서 복색 홑꽃인 'Artist Pink'를 모본, 복색 홑꽃인 'SP0347'을 부본으로 인공교배를 실시하여 2003년에서 2007년에 걸쳐서 파종과 계통선발을 통해 육성하였다. 품종의 특성검정은 2005년부터 2007년까지 봄 촉성재배와 가을 억제재배 조건아래서 3회에 걸쳐 조사하였다. 'Maigic' 품종의 자연개화기는 10월26일경이며, 일장조절에 의해 주년재배가 가능하다. 꽃 크기가 6.1 cm인 중륜화로 꽃 하나의 꽃잎수가 31.6개정도이고 착화수는 14개 정도이다. 화색은 복색(백색/자주색)이며, 녹색화심을 가졌다. 봄의 단일상태에서 'Maigic' 품종의 개화소요일수는 43일 정도로 개화가 빠르며, 가을의 절화수명은 20.6일로 나타났다.

• 농촌지도와개발
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• 제7권2호
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• pp.257-277
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• 2000

The objectives of this study are to investigate the relationship between the growth of the horticultural sector and horticultural research and extension and to examine the socioeconomic returns to investment on research and extension in Korean horticulture. Data for horticultural production values, producer price indices and research and extension budgets for horticultural sector from 1965 to 1998 are collected from various sources. Multi-variate time series analysis technique with vector auto-regression model and Akino-Hayami Formula were employed for the analysis. This study finds (1) horticultural production responds about seven years later to the horticultural research investment shock. the magnitude of the impacts increases to a peak in seventeen years from the initial expenditures and then declines slowly thereafter until twenty years. and this peak gives a tip that horticultural research impact lasts much longer than grain's or agriculture's: (2) the social surplus from research investment benefits more to the consumer rather than to the horticultural producer: (3) B/C ratios in horticultural research are quite high with the range of 9 to 55 from 1965 to 1998. but these have been decreased since the early 1990s: (4) the socioeconomic returns to horticultural research is quite high with 56 percents of internal rate of return. It remains to be analyzed returns to investment on extension in horticulture because of no statistic significance in this study.

• 한국환경농학회지
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• 제40권1호
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• pp.40-48
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• 2021

BACKGROUND: Although the calcined oyster shell can be used as a calcium-rich adsorbent for phosphate removal, information about it is limited. The purpose of this study was to evaluate the phosphate adsorption characteristics and its mechanism using calcined oyster shells. METHODS AND RESULTS: In this study, calcined oyster shell (C-OS600) was prepared by calcining oyster shells (P-OS) at 600℃ for 20 min. Phosphate adsorption by C-OS600 was performed under various environmental conditions. Phosphate adsorption by C-OS600 occurred rapidly at the beginning of the reaction, and the time to reach equilibrium was less than 1 h. The optimal isotherm and kinetic models for predicting the adsorption of phosphate by C-OS600 were the Langmuir isotherm and pseudo-second order kinetic model, respectively, and the maximum adsorption capacity derived from the Langmuir isotherm was 68.0 mg/g. The adsorption properties of phosphate by C-OS600 were dominantly influenced by the initial pH and C-OS600 dose. In addition, SEM-EDS and FTIR analysis clearly showed a difference in C-OS600 before and after phosphate adsorption, which proved that phosphate was adsorbed on the surface of C-OS600. CONCLUSION: Overall, the calcined oyster shell can be considered as an useful and effective adsorbent to treat wastewater containing phosphate.

• 한국도로학회논문집
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• 제19권5호
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• pp.153-162
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• 2017

PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.

• 한국항공우주학회지
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• 제49권7호
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• pp.565-572
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• 2021

본 연구에서는 국방 분야에서 분리장치로 사용되고 있는 파이로 장치 중 장기간 보관된 폭발볼트의 성능 및 노화에 관한 연구를 수행하였다. 연구를 위해 약 10년간 무기체계에 탑재되어 있던 폭발볼트를 확보하였으며, AIAA Standard 및 MIL-STD를 기반으로 성능 및 수명 평가 절차를 수립하였다. 성능 평가를 위해 먼저 비기능 검사를 수행하여 외적인 변화나 고장이 발생하였는지 확인하였으며, 내부 회로 및 구조에 이상이 없는지 회로검사와 X-ray 검사를 수행하였다. 비기능 검사가 통과된 시료에 대해서 작동 확인을 위한 성능 시험을 실시하였다. 성능 시험을 통해 폭발볼트의 분리 여부 및 분리시간을 측정하였으며, 일부 시료의 경우 잔여 수명 및 연장 가능성을 확인하기 위해 고온저장시험 후 성능 시험을 실시하였다. 마지막으로 시험 결과와 아레니우스 모델을 바탕으로 잔여 수명 및 신뢰도를 예측하였으며, 수명에 따른 신뢰도를 확인하였다.

• 원예과학기술지
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• 제31권1호
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• pp.123-127
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• 2013

'Blue Hope' 품종은 경남농업기술원 화훼연구소에서 2009년에 육성한 스프레이 국화 신품종으로 2005년도에 백색 아네모네형의 스프레이 국화 'Ford' 품종을 모본, 백색 아네모네형 스프레이 국화 'Chopin' 품종을 부본으로 교배하여 육성하였다. 이 품종은 백색 꽃잎을 가진 아네모네형이다. 2007에서 2009년까지 춘계 억제재배와 하계 촉성재배를 포함하는 특성검정을 통해 최종적으로 'Blue Hope'를 육성하였다. 'Blue Hope' 품종의 자연개화기는 10월 24일이며, 전조와 차광처리에 의한 일장조절에 의해 주년재배가 가능하다. 성장세가 매우 좋고 개화반응주기는 6.5주이다. 가을재배에 있어서 화경은 4.9cm, 본당 착화수가 19.1개이고, 절화수명은 23.8일이었다. 춘계 차광재배에서의 단일처리 후 개화소요일수가 45일이었다. 이 품종은 흰녹병에 중도저항성을 나타내고 있으며, 대조품종에 비해 기호도도 높았다.

• 한국CDE학회논문집
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• 제16권4호
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• pp.268-276
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• 2011

The product-level carbon footprint (PCF) is a comprehensive and widely accepted metric for sustainable product development. However, since a full PCF study in general is time and cost intensive, it is not feasible for the product development team to synchronize the activity to the main product development process. In addition, the current dedicated life cycle assessment (LCA) tools for calculating PCF, separated from the main product data management systems, have limitations to provide timely PCF information for design decision makings and collaborations between design and environment engineers. This paper examines the possibility of the extension of the current product data model that can support the PCF calculation with PDM (Product Data Management) databases. The product data model can represent not only the content of products but also context or system information of the products. The product data model can be implemented as a PDM database that can satisfy the needs for handy and timely PCF calculations from the consistent product data for dynamic design decision makings and engineering collaborations.