• 운동영양학회지
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• 제25권1호
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• pp.35-41
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• 2021

[Purpose] This pilot study aimed to develop a regression model to estimate the excess post-exercise oxygen consumption (EPOC) of Korean adults using various easy-to-measure dependent variables. [Methods] The EPOC and dependent variables for its estimation (e.g., sex, age, height, weight, body mass index, fat-free mass [FFM], fat mass, % body fat, and heart rate_sum [HR_sum]) were measured in 75 healthy adults (31 males, 44 females). Statistical analysis was performed to develop an EPOC estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and HR_sum were important variables in the EPOC regression models of various exercise types. The explanatory power and standard errors of estimates (SEE) for EPOC of each exercise type were as follows: the continuous exercise (CEx) regression model was 86.3% (R²) and 85.9% (adjusted R²), and the mean SEE was 11.73 kcal, interval exercise (IEx) regression model was 83.1% (R²) and 82.6% (adjusted R²), while the mean SEE was 13.68 kcal, and the accumulation of short-duration exercise (AEx) regression models was 91.3% (R²) and 91.0% (adjusted R²), while the mean SEE was 27.71 kcal. There was no significant difference between the measured EPOC using a metabolic gas analyzer and the predicted EPOC for each exercise type. [Conclusion] This pilot study developed a regression model to estimate EPOC in healthy Korean adults. The regression model was as follows: CEx = -37.128 + 1.003 × (FFM) + 0.016 × (HR_sum), IEx = -49.265 + 1.442 × (FFM) + 0.013 × (HR_sum), and AEx = -100.942 + 2.209 × (FFM) + 0.020 × (HR_sum).

• 해양환경안전학회지
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• 제28권2호
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• pp.354-360
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• 2022

해양플랜트 상구구조물의 중량 절감을 위한 알루미늄 핸드레일 적용을 위하여, 소재의 항복강도 향상 및 관련 국제기준에 부합한 강도평가를 통하여 설계가 이루어지고 있다. 기존에 해양프로젝트에 설치된 알루미늄 핸드레일은 플랫폼에 설치 시 소켓에 볼트 연결되며, 소켓의 설계 정도에 따라서 핸드레일 처짐 량이 크게 좌우된다. 그러나 국제기준에서는 소켓에 대한 중요성 언급이 없으며, 별도의 평가 절차나 기준도 모호하다. 따라서 본 연구를 통해서 핸드레일 소켓 설계 시 고려해야 하는 주요 인자들에 대한 강도 해석을 수행하고, 최적의 치수를 도출하였다. 개발모델의 구조 안전성을 확보하기 위하여, 실험을 통한 검증을 수행하였고, 국제기준에서 요구하는 허용 처짐 이내에서 모두 만족함을 확인하였다. 개발된 국산화 모델은 기존 외국 제조사와 비교하여 가볍고, 생산성이 향상되어 향후 많은 분야에서 사용이 될 것으로 판단된다.

• 한국토양비료학회지
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• 제50권5호
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• pp.422-433
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• 2017

Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we developed for estimating garlic growth at field scale model in major cultivation regions. We used the $NDVI_{UAV}$ that reflects the crop conditions, and seven meteorological elements for 3 major cultivation regions from 2015 to 2017. For this study, UAV imagery was taken at Taean, Changnyeong, and Hapcheon regions nine times from early February to late June during the garlic growing season. Four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.), and fresh weight (F.W.) were measured for twenty plants per plot for each field campaign. The multiple linear regression models were suggested by using backward elimination and stepwise selection in the extraction of independent variables. As a result, model of cold type explain 82.1%, 65.9%, 64.5%, and 61.7% of the P.H., F.W., L.N., P.D. with a root mean square error (RMSE) of 7.98 cm, 5.91 g, 1.05, and 3.43 cm. Especially, model of warm type explain 92.9%, 88.6%, 62.8%, 54.6% of the P.H., P.D., L.N., F.W. with a root mean square error (RMSE) of 16.41 cm, 9.08 cm, 1.12, 19.51 g. The spatial distribution map of garlic growth was in strong agreement with the field measurements in terms of field variation and relative numerical values when $NDVI_{UAV}$ was applied to multiple linear regression models. These results will also be useful for determining the UAV multi-spectral imagery necessary to estimate growth parameters of garlic.

• 한국수산과학회지
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• 제35권4호
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• pp.327-335
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• 2002

Effects of available food on growth of commercially cultured Pacific oysters, Crassostrea gigas in Goseong Bay on the south coast were studied using a numerical model. levels of total protein, carbohydrate and lipid in particulate organic matter in the water column as well as chlorophyll a concentration were determined for estimating total available food for oyster growth. Environmental parameters including water temperature, salinity and total suspended solid were also monitored for the model. Oyster growth was also monitored by means of measuring shell length and tissue wet weight increase on a monthly basis. Simulation results from the numerical model indicated that chlorophyll a is not a good representative of available food for the oysters in Goseong Bay. In contrast, available food in the water column measured by filtration of the organic particles and analyzed in terms of total lipids, carbohydrates and protein was well matched with simulated oyster growth in the Bay which is similar to observed growth. The model also suggested that oysters have relatively low retention efficiency of $50\%$ or less. This result indicates that oysters in the bay utilize only a part of food particle available in the water column, as reported in other studies.

• 시스템엔지니어링학술지
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• 제18권2호
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• pp.108-116
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• 2022

Accurately predicting wartime resources requirements and preparing war supplies in peacetime is an important task that can determine the outcome of the war by guaranteeing the duration of the operation. The wartime warship damage rate is a measure of estimating the battle damage of our warships in the process of performing battles to achieve the war goal. In the previously studied wartime warship damage rate estimation method, when damage occurs, long-term repair is required due to the complexity and specificity of the ship structure. Only the case of a complete defeat at the level of sinking was defined as a damage, and even if it was impossible to perform a maritime operation mission, it was not estimated as a damage if the level of sinking was not reached. Therefore, in order to improve the reliability of the wartime warship damage rate, the equipment damage assessment level can be estimated based on the warhead weight of the threat weapon system, the vulnerability rate of the warship's equipment, and the warship's hull. In the future, it is expected that the estimation methodology proposed in this study will be used as a simulation logic when developing a model for analyzing the wartime resources requirements for the warship's equipment and hull.

• 한국수자원학회논문집
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• 제52권3호
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• pp.187-194
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• 2019

한국의 수자원 총량중 이용량은 26.3%로 강으로부터의 취수 비율은 3%에 불과하며, 중국, 인도, 이탈리아, 남아공 등과 함께 물 스트레스 기준 중~고에 해당한다. 따라서 본 연구에서는 댐 수자원 확보를 위한 적지선정과 관련하여 연구하였다. 미국, 일본 및 한국의 댐 건설절차에 대한 조사 결과, 정량적인 기준 및 계산 방법 또는 공식이 부재하였다. 댐 적지선정의 정량적 기준 제시를 위하여 먼저 기후 변화 시나리오를 조사, 분석하였으며, IPCC제 5 차 평가 보고서에 제시된 12.5 km 격자 해상도의 RCP 4.5 및 8.5를 SWAT와 HEC-ResSim를 이용하여 유역 연구에 적용하였다. 댐 시뮬레이션 결과를 토대로 홍수 및 가뭄의 감소 효과를 정량적으로 제시하였다. 그리고 댐 적지 선정 지표 결정과, AHP 기법을 이용하여 평가지표에 대한 전문가 설문을 실시하여 가중치를 부여하였으며, 이를 통해 댐 적지 선정 함수식(FSDS)을 제안하였다. 함수식의 경우 4곳의 기 설치된 유역에 대하여 보정 및 검증 하였으며, FSDS와 GIS의 'Model builder'를 사용하여 댐 적지선정 자동화 모델을 개발하였다.

• 대한토목학회논문집
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• 제42권5호
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• pp.599-606
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• 2022

공용 중 강교량의 피로 평가에 활용할 수 있는 현장계측 데이터에는 대표적으로 변형률 계측과 Brigde Weight-In-motion (BWIM)이 있다. AASHTO The Manual For Bridge Evaluation에 따라, 대상 교량에서 계측된 데이터로부터 피로 상세에 가해지는 유효응력범위 및 반복응력 횟수를 추정할 수 있다. 추정된 유효응력범위와 반복응력 횟수를 통해 피로 손상 누적에 의한 신뢰도분석을 수행할 수 있다. 하지만 현장계측 데이터로부터 유효응력범위 및 응력범위 반복횟수를 추정하는 절차가 평가규정에 구체적으로 제시되어 있지 않고, 계측 데이터의 종류 또는 처리방법에 따른 피로 평가결과의 차이를 정량적으로 비교한 연구는 아직 미비한 실정이다. 본 연구에서는 공용 중 교량에서 동시에 계측한 변형률계 및 BWIM 데이터를 활용하여 피로 신뢰도평가를 수행하여, 활용되는 현장계측 데이터의 종류에 따른 평가결과의 차이에 대해 정량적으로 검토하였다. 이때, BWIM 데이터를 활용한 피로 신뢰도평가 시 구조해석모델의 정밀성이 평가결과에 미치는 영향을 검토하기 위해 평가 대상 교량의 뼈대요소 해석모델과 Shell-Solid 해석모델을 구축하였다. 또한, BWIM 데이터로부터 유효응력범위와 반복응력 횟수를 추정하기 위한 두 종류의 데이터 처리 방법을 정의하였으며, 이로 인한 피로 신뢰도 차이 역시 검토하였다.

• 한국수산과학회지
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• 제53권1호
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• pp.50-56
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• 2020

Determination of the precise size at sexual maturity is very important for science-based stock assessment and fisheries resource management. In this study, two different models, (1) a visual method and (2) a gonadosomatic index (GSI) method, were employed to estimate length at sexual maturity of the small yellow croaker Larimichthys polyactis in the Yellow Sea of Korea. The visual method is a common qualitative method using visual gonadal identification. Conversely, the GSI method is a quantitative method using the GSI, which can be easily and precisely collected. We compared results from these methods to determine the best approach, and to examine the practicality of the GSI method. Logistic regression of the maturity ogive was conducted using a general linear model (GLM) with the R statistics program. Also, the bootstrapped 95% confidence intervals of all estimates were calculated. The best-fit model was the visual method (R_Mc²=0.805, AUC=0.989, L₅₀=15.1). Among models using the GSI method, the model computing GSI_ref=0.94 was the best-fit model (R_Mc²=0.792, AUC=0.989, L₅₀=15.2). There was no significant difference between the two models, evidencing the effectiveness and accuracy of the GSI method.

• 한국조경학회지
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• 제29권1호
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• pp.161-167
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• 2001

The purpose of this study is to find out the difference of Zoysia matrella's evaporation in between 100 percent soil and mixed soil with 50 percent of perlite to create green spaces on the artificial ground. It is believed that the weight against the artificial ground will be reduced, provided the vegetation is possible in the circumstance of the mixed sol with 50 percent of perlite. The study employed a modified Makkink's model by Iwasa who had developed the model for estimating Zoysia matrella's evaporation in the natural ground using the Makkink's formula in 1997 at Chiba University, Japan. The parameter of Makkink's formula is the solar radiation. For that reason, the Makkink's formula is simple and easy to measure the parameter and has a high utility. If the outcomes from mixed soil are close to modified Makkinks formula, the modified Makkink's formula will be applied to estimate in the artificial ground with mixed soil with 50 percent of perlite. Weather observation and actual amount of evaporation of Zoysia matrella have been measured, and the relation between weather condition and actual amount of evaporation had been also investigated. In line with this, we found out that there is a relevant relationship between daily average temperature, the modified Makkink's model by Iwasa, and the actual amount of evaporation. As the results of the experiment, the outcomes from mixed soil with 50 percent of perlite have very high relation to 100 percent soil. In addition, mixed soil has more adhesion with water than natural soil. However, it needs to be adequately maintained in terms of fertilization and damage from disease and harmful insects until the gras fastens its roots into the soil. By using mixed soil with 50 percent of perlite, the load from soil on the artificial ground can be reduced. The study on the growth of the grass throughout the plant vegetation and the actual amount of evaporation in the mixed soil with 50 percent of perlite should be performed in the future.

• 상하수도학회지
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• 제35권6호
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• pp.389-403
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• 2021

In this study, dual drainage system based runoff model was established for W-drainage area in G-si, and considering the various rainfall characteristics determined using Huff and Mononobe methods, the degree of flooding in the target area was analyzed and the risk was compared and analyzed through the risk matrix method. As a result, the Monobe method compared to the Huff method was analyzed to be suitable analysis for flooding of recent heavy rain, and the validity of the dynamic risk assessment considering the weight of the occurrence probability as the return period was verified through the risk matrix-based analysis. However, since the definition and estimating criteria of the flood risk matrix proposed in this study are based on the return period for extreme rainfall and the depth of flooding according to the results of applying the dual drainage model, there is a limitation in that it is difficult to consider the main factors which are direct impact on inland flooding such as city maintenance and life protection functions. In the future, if various factors affecting inland flood damage are reflected in addition to the amount of flood damage, the flood risk matrix concept proposed in this study can be used as basic information for preparation and prevention of inland flooding, as well as it is judged that it can be considered as a major evaluation item in the selection of the priority management area for sewage maintenance for countermeasures against inland flooding.