• 한국산림과학회지
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• 제6권1호
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• pp.1-5
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• 1967

We studied on the bark Percentage of red pine (Pinus denssiflora S & Z) and tarch (Larix Kaemdferi sargent) and obtained the results as follows: (1) For diameter classes from 8 to 38 cm in red pine. the linear equation adopts the relation of the bark percentage to the diameter more accurately than the logarithmic equation. (2) The difference between the regression equation of the bark percentage between red pine and Larch is significant and the correlation cofficient in red Pine is high so that standard error of red Pine is lower than its value of Larch. We established, therefore the tables of bark percentage for each species by applying the following regression equations. red Pine Y=10.08205-0.08794x Larch Y=10.3527-0.17071x.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.849-856
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• 2017

Objective: The net energy requirement for the maintenance ($NE_m$) of broilers was determined using regression models by the indirect calorimetry method (ICM) or the comparative slaughter method (CSM). Methods: A $2{\times}4$ factorial arrangement of treatments including the evaluation method (ICM or CSM) and feed intake (25%, 50%, 75%, or 100% of ad libitum recommended) was employed in this experiment. In the ICM, 96 male Arbor Acres (AA) birds aged d 15 were used with 4 birds per replicate and 6 replicates in each treatment. In the CSM, 116 male AA birds aged d 15 were used. Among these 116 birds, 20 were selected as for initial data and 96 were assigned to 4 treatments with 6 replicate cages and 4 birds each. The linear regression between retained energy (RE) and metabolizable energy intake (MEI) or the logarithmic regression between heat production (HP) and MEI were used to calculate the metabolizable or net energy requirement for maintenance ($ME_m$) or $NE_m$, respectively. Results: The evaluation method did not detect any differences in the metabolizable energy (ME), net energy (NE), and NE:ME of diet, and in the MEI, HP, and RE of broilers. The MEI, HP, and RE of broilers decreased (p<0.01) as the feed intake decreased. No evaluation method${\times}$feed intake interaction was observed on these parameters. The $ME_m$ and $NE_m$ estimated from the linear relationship were 594 and 386 kJ/kg of body weight $(BW)^{0.75}/d$ in the ICM, and 618 and 404 kJ/kg of $BW^{0.75}/d$ in the CSM, respectively. The $ME_m$ and $NE_m$ estimated by logarithmic regression were 607 and 448 kJ/kg of $BW^{0.75}/d$ in the ICM, and were 619 and 462 kJ/kg of $BW^{0.75}/d$ in the CSM, respectively. Conclusion: The NEm values obtained in this study provide references for estimating the NE values of broiler diets.

• 한국해안·해양공학회논문집
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• 제29권6호
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• pp.279-285
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• 2017

일반적으로 멱법칙과 대수함수 프로파일은 유속 연직 프로파일 모델로 많이 사용된다. 그러나 해역특성에 따라 모델별 매개변수의 값들이 상이하므로 실제 관측치를 통해 이들 값을 추정할 필요가 있다. 본 연구에서는 울돌목 해역에서 관측한 30분 평균 유속자료를 이용하여 창 낙조 시 멱법칙의 고도분포지수(n) 값과 대수함수 프로파일의 마찰속도($u^*$)와 조도길이($z_0$)를 추정하였다. 또한, 수심평균유속과 매개변수간의 상관관계를 분석하였으며, 관측치와의 오차분석을 수행하였다. 그 결과, power law의 고도분포지수(n)는 창조 시에는 평균 10.75, 낙조 시에는 평균 9.3의 고도분포지수 값을 가지는 것으로 나타났다. 한편, 대수함수 프로파일의 $u^*$는 창 낙조 시, 0.084 m/s와 0.105 m/s로 각각 추정되었으며, $z_0$는 0.004 m, 0.006 m로 각각 추정되었다.

• Steel and Composite Structures
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• 제21권1호
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• pp.93-107
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• 2016

Seismic fragility analysis is a probabilistic decision-making framework which is widely implemented for evaluating vulnerability of a building under earthquake loading. It requires ingredient named probabilistic model and commonly developed using statistics requiring collecting data in large quantities. Preparation of such a data-base is often costly and time-consuming. Therefore, in this paper, by developing generic seismic drift demand model for regular-multi-story steel moment resisting frames is tried to present a novel application of the probabilistic decision-making analysis to practical purposes. To this end, a demand model which is a linear function of intensity measure in logarithmic space is developed to predict overall maximum inter-story drift. Next, the model is coupled with a set of regression-based equations which are capable of directly estimating unknown statistical characteristics of the model parameters.To explicitly address uncertainties arise from randomness and lack of knowledge, the Bayesian regression inference is employed, when these relations are developed. The developed demand model is then employed in a Seismic Fragility Analysis (SFA) for two designed building. The accuracy of the results is also assessed by comparison with the results directly obtained from Incremental Dynamic analysis.

• 대한토목학회논문집
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• 제36권3호
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• pp.427-437
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• 2016

본 연구에서는 지형 및 기상학적 인자만으로 미계측 유역의 저유량부 유황곡선을 추정할 수 있는 지역회귀모형을 개발하고자 하였다. 이를 위해서 16개 유역의 계측 자료로부터 저유량 영역(지속일수 185일에서 365일)에 대한 유황곡선을 작성하고, 이를 토대로 로그형태의 이변수 회귀모형을 구축하였다. 이 회귀모형을 미계측 유역에 적용할 수 있도록 유역면적, 유역경사, 수계밀도, 연평균강수량, 연평균유출량, 유출곡선지수 등의 유역특성인자를 이용하여 모형의 매개변수를 지역화 하였다. 개발한 지역회귀모형으로 평균갈수량, 평균저수량, 평균평수량을 추정하여 관측값과 비교한 결과, 유역면적, 유출곡선지수, 연평균강수량 조합으로 구성된 지역회귀모형이 가장 우수한 것으로 분석되었다.

• 한국산림과학회지
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• 제78권2호
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• pp.143-150
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• 1989

본(本) 연구(硏究)는 무기적(無機的) 환경요인(環境要因)이 잣나무 유묘(幼苗)의 생육(生育)에 마치는 영향(影響)에 관(關)한 연구(硏究)의 일환(一環)으로 이식상(移植床)에서 상대광도(相對光度)와 식재밀도(植栽密度)를 달리하여 생육(生育)시킨 잣나무 묘(苗)의 엽(葉) 중량생장(重量生長)과 타(他) 기관(器官) 생장간(生長間)의 관계(關係)를 조사(調査) 것으로 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 상대광도별(相對光度別)에 있어서 엽건중(葉乾重)과 타(他) 생장(生長)(지상부(地上部) 건중(乾重), 지하부(地下部) 건중(乾重), 묘(苗) 건중(乾重), 묘경(苗徑)) 간(間)에는 정(正)의 상관관계(相關關係)에 있었고, 또 이들 간(間)에는 1차회귀(次回歸) 관계(關係)도 인정(認定)할 수 있었다. 그러나 엽(葉) 건중(乾重)과 묘장(苗長) 간(間)에는 2차(次) 곡선회귀(曲線回歸) 관계(關係)에 있었다. 식재밀도(植栽密度) 별(別)에 있어서는 엽건중(葉乾重)과 지상부(地上部) 건중(乾重) 및 묘장(苗長) 간(間)에는 2차(次) 곡선회귀관계(曲線回歸關係)에 있었고, 지하부(地下部) 건중(乾重) 및 묘건중(苗乾重) 간(間)에는 1차회귀(次回歸) 관계(關係)에 있었다. 그러나 묘경(苗徑) 간(間)에는 상관(相關)을 인정(認定)할 수 없었다. 2. 상대광도(相對光度) 별(別)에 있어서 엽면적(葉面積)과 지상부(地上部) 건중(乾重) 및 묘(苗) 건중(乾重) 간(間)에는 1차회귀(次回歸) 관계(關係)에 있었고, 지하부(地下部) 건중(乾重) 간(重)과는 지수곡선(指數曲線) 관계(關係), 그리고 엽면적(葉面積)과 묘장(苗長) 간(間)에는 2차곡선(次曲線) 관계(關係)에 있음을 알 수 있었다. 그러나 묘경(苗徑) 간(間)에는 대수(代數) 곡선적(曲線的) 경향(傾向)이었다. 식재밀도(植栽密度) 별(別)에 있어서는 엽면적(葉面積)과 지상부(地上部) 건중(乾重) 간(間)에는 대수곡선(代數曲線) 회귀관계(回歸關係)에 있었고, 지하부(地下部) 건중(乾重) 및 묘(苗) 건중(乾重) 간(間)에는 직선회귀(直線回歸) 관계(關係)에 그리고 엽면적(葉面積)과 묘장(苗長) 및 묘경(苗徑) 간(間)에는 2차곡선(次曲線) 회귀(回歸) 관계(關係)에 있었다.

• 한국안전학회지
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• 제17권4호
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• pp.19-24
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• 2002

User-friendly-web-based database system for searching creep property data was developed. This system includes about 38000 creep data for 270 different materials including low carbon steel, stainless steel and alloy steel. Data on creep rupture, creep deformation, creep crack growth and creeping materials can be searched through this system. Retrieved data is displayed in numeric form and also presented in graphical form for visualizing the data. Furthermore, the creep rupture data is designed to be fitted to a regression equation of logarithmic stress using time-temperature parameter(TTP). The degree of the regression equation, orthogonal polynomials, was determined using analysis of variance.

• 한국측량학회지
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• 제35권1호
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• pp.31-39
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• 2017

The goal of this study was to efficiently analyze the relationships of the number of thefts with related factors, considering the spatial patterns of theft crimes. Theft crime data for a 5-year period (2009-2013) were collected from Haeundae Police Station. A logarithmic transformation was performed to ensure an effective statistical analysis and the number of theft crimes was used as the dependent variable. Related factors were selected through a literature review and divided into social, environmental, and defensive factors. Seven factors, were selected as independent variables: the numbers of foreigners, aged persons, single households, companies, entertainment venues, community security centers, and CCTV (Closed-Circuit Television) systems. OLS (Ordinary Least Squares) and GWR (Geographically Weighted Regression) were used to analyze the relationship between the dependent variable and independent variables. In the GWR results, each independent variable had regression coefficients that differed by location over the study area. The GWR model calculated local values for, and could explain the relationships between, variables more efficiently than the OLS model. Additionally, the adjusted R square value of the GWR model was 10% higher than that of the OLS model, and the GWR model produced a AICc (Corrected Akaike Information Criterion) value that was lower by 230, as well as lower Moran's I values. From these results, it was concluded that the GWR model was more robust in explaining the relationship between the number of thefts and the factors related to theft crime.

• Journal of Forest and Environmental Science
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• 제30권4호
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• pp.351-361
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• 2014

Leaf area ($A_0$) and leaf biomass ($M_0$) estimation are significant prerequisites to studying tree physiological processes and modeling in the forest ecosystem. The objective of this study was to develop allometric models for estimating $A_0$ and $M_0$ of Swietenia mahagoni L. from different tree parameters such as DBH and tree height of mahogany plantations in the northeastern region of Bangladesh. A total of 850 healthy and well formed trees were selected randomly for sampling in the five study sites. Then, twenty two models were developed based on different statistical criteria that propose reliable and accurate models for estimating the $A_0$ and $M_0$ using non-destructive measurements. The results exposed that model iv and xv were selected on a single predictor of DBH and showed more statistically accuracy than other models. The selected models were also validated with an additional test data set on the basis of linear regression and t-test for mean difference between observed and predicted values. After that, a comparison between the best logarithmic and non-linear allometric model shows that the non-linear model produces systematic biases and underestimates $A_0$ and $M_0$ for larger trees. As a result, it showed that the bias-corrected logarithmic model iv and xv can be used to help quantify forest structure and functions, particularly valuable in future research for estimating $A_0$ and $M_0$ of S. mahagoni in this region.

• 한국식품과학회지
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• 제17권6호
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• pp.460-468
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• 1985

츄잉검의 저장중 물성변화를 파악키 위해 성분 및 제조조건을 다르게 시료를 제조하여 저장중 수분함량의 변화, 기계적 물성 및 관능적 물성값을 측정하였다. 저장중 수분함량의 변화는 RH32, 43%의 낮은 상대습도에서는 물엿함량이 적을수록, 물엿의 DE가 낮을수록 탈습(脫濕) 심하게 일어났고, RH65, 85%에서는 반대로 물엿이 함량이 많을수록, DE가 높을수록 흡습(吸濕)이 심하였다. 전반적으로 기계적 물성값의 변화는 낮은 상대습도에서는 급격히 증가하였고, RH65%에서는 평형, RH85%에서는 약간 감소하였다. 이러한 변화는 수분함량의 변화 및 물엿의 DE값에 크게 영향을 받았으며 반면에 물엿의 함량, 제조조건 및 저장온도에 대한 영향은 크지 않았다. 수분함량과 각 기계적 물성값은 대수함수 관계로 나타낼 수 있었으며, 이들간에는 모두 0.1%의 유의 수준에서 상관관계가 있었다. 또한 관능적 물성과 기계적 물성간에는 모두 0.1% 유의수준에서 상관관계가 있었으며, 희귀식으로부터 각 물성의 최적값을 추정하였다.