• 한국수자원학회논문집
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• 제46권6호
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• pp.613-627
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• 2013

본 연구에서는 지속기간별(1-, 3-, 6-, 12-, 24개월)로 가장 가뭄이 심한 해의 5월 건조현상을 지역별로 분석하기 위해 1973년부터 2006년까지 우리나라 53개 기후관측지점에서 관측된 월별 기후자료를 이용하여 FAO Penman-Monteith 기준잠재증발산량(RET)을 산정하였다. 그리고 강수량(P)에 대한 RET의 비(P/RET)를 이용하여 건조지수(aridity index)와 P/RET의 변동지수(variation index, VI)를 산정하고, 표준강수지수(standard precipitation index, SPI)와 비교하였다. 우리나라 지역별 건조현상을 파악하기 위해 53개 기후관측지점을 20개 연구지역으로 구분하여 분석하였다. 또한 지역별 건조지수의 추세분석을 위해 Mann-Kendall 추세분석, Spearman rank test 그리고 Sen's slope을 적용하였다. 분석 결과에 의하면 각 지속기간별로 P/RET의 변동지수(VI)와 표준강수지수사이에 양호한 상관관계를 보였다. 또한 우리나라 전역에 걸쳐서 지속기간이 단기화 될수록 5월 기후가 더욱 건조한 것으로 나타났다. 3개월이나 6개월 지속기간의 경우 대부분 지역에서 유의하거나 혹은 유의하지 않은 수준에서 건조지수의 감소추세를 보였다. 반면에 12개월 및 24개월 지속기간의 경우 유의한 건조지수의 감소추세를 보이는 지역은 없는 것으로 나타났다.

• Smart Structures and Systems
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• 제19권2호
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• pp.151-161
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• 2017

A new method is developed to estimate road profile in order to estimate IRI based on the ASTM standard. This method utilizes an accelerometer and a Dynamic Tire Pressure Sensor (DTPS) to estimate road roughness. The accelerometer measures the vertical axle acceleration. The DTPS, which is mounted on the tire's valve stem, measures dynamic pressure inside the tire while driving. Calibrated transfer functions are used to estimate road profile using the signals from the two sensors. A field test was conducted on roads with different quality conditions in the city of Brockton, MA. The IRI values estimated with this new method match the actual road conditions measured with Pavement Condition Index (PCI) based on the ASTM standard, images taken from an onboard camera and passengers' perceptions. IRI has negative correlation with PCI in general since they have overlapping features. Compared to the current method of IRI measurement, the advantage of this method is that a) the cost is reduced; b) more space is saved; c) more time is saved; and d) mounting the two sensors are universally compatible to most cars and vans. Therefore, this method has the potential to provide continuous and global monitoring the health of roadways.

• 한국CDE학회논문집
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• 제18권5호
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• pp.359-366
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• 2013

In the lower arm design process, a tolerance optimization of the variance of design variables should be preceded before manufacturing process, since it is very cost-effective compared to a strict management of tolerance of products. In this study, a design of experiment (DOE) based on response surface model (RSM) was carried out to find optimized design variables of the lower arm, which can meet a given requirement of probability constraint for the process capability index (Cpk) of the weight and maximum stress. Then, the design space was explored by using the central composite design method, in which the 2nd order Taylor expansion was applied to predict a standard deviation of the responses. The optimal solutions satisfying the probability constraint of the Cpk were found by considering both of the mean value and the standard deviation of the design variables.

• 대한토목학회논문집
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• 제34권6호
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• pp.1831-1836
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• 2014

공학적 측면에서 확률론적 액상화 재해 작성법이 점차 요구됨에 따라, 본 연구에서는 실제 액상화 피해 현장의 액상화 가능 지수(Liquefaction Potential Index, LPI)를 이용한 로지스틱 회귀분석으로 액상화 피해 확률을 예측하였다. 또한 이 분석을 바탕으로 광역지역의 액상화 재해도 기법을 제시하였다. 사례 연구로서 미국 세인트루이스 지역 홍수평야의 표준관입시험(273 곳) 결과를 대상으로 LPI를 산정하였고 최대지반가속도를 코크리깅의 이차변수로 적용하여 보간하였다. 연구결과, 일부 구역에서 연약지반과 얕은 지하수위로 인해 LPI 값이 5이상으로 나타나, 액상화로 인한 지반 피해 확률이 0.5 이상으로 예측되었다.

• Journal of Welding and Joining
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• 제16권3호
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• pp.95-101
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• 1998

Waveforms of $CO_2$ gas shielded arc welding in short circuit transfer mode was studied with the waveform analysis program, which can calculate various waveform factors such as number of short circuit event, mean and standard deviation of short circuit time and arc time. The calculated values of these factors were correlated independently or in combination with the spatter generation rate to figure out the most reliable index for evaluating spatter generation and further for arc stability. As a result this study, it was confirmed that the spatter generation tends to decrease with the increase of short circuit frequency. Further to this, it was also found that as the short circuit frequency increases the short circuit event becomes more uniform resulting in the decrease of standard deviations ($\sigma$values) of short circuit time and arc time. This result demonstrated that these factors are strongly correlated with each other and thus any one of these factors can be used for the evaluation index. In the discussion, however, short circuit frequency was proposed for the most practical index in evaluating the arc stability of short circuit transfer mode since it is the one which could be monitored in-process condition without any complex caculation process.

• 한국안전학회지
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• 제30권4호
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• pp.174-180
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• 2015

This study developed a Safety Culture Impact Assessment Model (SCIAM) which consists of a safety culture assessment methodology and a safety culture impact quantification methodology. The SCIAM uses safety culture impact index (SCII) to monitor the status of safety culture of the NPPs periodically and it uses relative core damage frequency (RCDF) to present the impact of safety culture on the safety of the NPPs. As a result of applying SCIAM to the reference plant (Kori 3), the standard for the healthy safety culture of the reference plant is suggested. SCIAM might contribute to improve the safety of the NPPs (Nuclear Power Plants) by monitoring the status of safety culture periodically and presenting the standard of healthy safety culture.

• 교육녹색환경연구
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• 제9권2호
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• pp.30-37
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• 2010

This study purposed realization and a phase reduction of school building $CO_2$ emissions. Accordingly selected standard school buildings and evaluated life cycle environmental load($CO_2$). This study proposed Green building technology which separated design sector, energy sector, afforestation sector for carbon-neutral city school buildings realization of M-city. As a result, elementary, middle and high schools of M-city built in the year 2013 were required that design sector was Energy Performance Index(EPI) 75 point and energy sector was solar installations more than 25% of the power usage, Solar systems installed more than 10% of total gas consumption and the area of afforesting more than 35% of the ecological area to achieve 30% $CO_2$ reduction compared to the Respectively standard school buildings.

• 한국건축시공학회지
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• 제13권1호
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• pp.90-100
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• 2013

Deck-plates are widely used on construction sites, and have the advantage of enabling contractors to achieve a relatively uniform quality. But nevertheless, quality deviation in deck-plate construction can occur as the result of differences in site conditions and the experience of crew workers. In this study, the authors present a site quality evaluation prototype for building deck-plate construction. Through analyses of case studies and interviews with experts, standard quality check sheets and a quality management index were developed by estimating the importance of quality check items based on a Failure Mode and Effects Analysis (FMEA) method. The applicability and effectiveness of the prototype was evaluated through a case study and interviews with case participants. It was found that the prototype promoted an active quality management as a way of continuously improving quality management in deck-plate construction instead of passive quality inspection practice.

• 대한한의학회지
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• 제45권1호
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• pp.225-232
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• 2024

Objectives: The purpose of this case study was to report the effect of Chuna therapy include Space Spinal Conduction Exercise and Manipulation Treatment for Functional dyspepsia patients. Methods: A 32-years-old male patients with functional dyspepsia visited the clinic ten times from March 17th 2023 to April 22th 2023. To assess the treatment outcomes, we used the Standard tool for pattern identification of Functional dyspepsia and Nepean Dyspepsia Index-Korean version (NDI-K) symptom score. Result: After treatment, Standard tool for pattern identification of Functional dyspepsia and Nepean Dyspepsia Index-Korean version (NDI-K) score decreased. Conclusion: Chuna therapy include Space Spinal Conduction Exercise and Manipulation Treatment was effective in the treatment of patient with Functional dyspepsia.

• Journal of Biosystems Engineering
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• 제32권6호
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• pp.416-421
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• 2007

Physical damage to fruits and vegetables caused by shock degrades the value of product in the fresh market. In order to design a product/packaging system to protect the product, the G-factor to the product that causes shock damage needs to be determined. The shock fragility of organisms such as fruits with a concept correspondent to the G-factor of industrial products was calculated and we defined the allowable bio-shock fragility index as the value divided peak acceleration that was generated in safe drop height by standard acceleration of gravity. We did modeling for safe drop hight that would prevent fruits from damage by drop tests and tried to estimate the allowable bio-shock fragility index of pears and apples for optimum packaging design. The bio-shock fragility index of pears was in the range of $0.74{\sim}2.29\;G$, while apples had a slightly higher value than that of pears, of $0.51{\sim}2.98\;G$. This result shows accordance with the general fact that apples have a firmer structure and get less damage from the same impact. Based on this result, it is possible to create an optimum packaging design by providing a damage standard by impact.