• 한국환경복원기술학회지
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• 제13권5호
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• pp.146-153
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• 2010

Urban development typically results in many species being confined to small, isolated and degraded habitat fragments. Fragment size and isolation underpin many studies of modified landscape to prevent biodiversity loss. However, habitat characteristics such as vegetation structure and edge effects are less frequently incorporated in planning. The relative influence of biogeographic (e.g. size, isolation) and vegetation parameters on assemblages is poorly understood, but critical for conservation management. In this study, the relative importance of biogeographic and vegetation parameters in explaining the diversity of forest-interior dwelling birds in forest fragments in Chungcheong Province Area. Fragment size and vegetation characteristics were consistently important predictors of bird diversity. Forestinterior bird richness was influenced by fragment size (0.437), wood age (0.332), wood diameter (0.068), and patch shape (-0.079). To preserve bird diversity of Chungcheong Province Area, it is important to consider differing responses of bird diversity to landscape change, move beyond a focus primarily on spatial attributes (size, isolation) to recognize that landscape change also has profound effects on habitat composition and quality. The result is very useful for long-term aspect of biodiversity conservation plan in regional scale.

• 한국산업보건학회지
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• 제32권1호
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• pp.21-30
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• 2022

Objectives: The purpose of this study is to suggest an optimal method by comparing the analysis methods of work environment measurement datasets including left-censored data where one or more measurements are below the limit of detection (LOD). Methods: A computer program was used to generate left-censored datasets for various combinations of censoring rate (1% to 90%) and sample size (30 to 300). For the analysis of the censored data, the simple substitution method (LOD/2), β-substitution method, maximum likelihood estimation (MLE) method, Bayesian method, and regression on order statistics (ROS)were all compared. Each method was used to estimate four parameters of the log-normal distribution: (1) geometric mean (GM), (2) geometric standard deviation (GSD), (3) 95th percentile (X95), and (4) arithmetic mean (AM) for the censored dataset. The performance of each method was evaluated using relative bias and relative root mean squared error (rMSE). Results: In the case of the largest sample size (n=300), when the censoring rate was less than 40%, the relative bias and rMSE were small for all five methods. When the censoring rate was large (70%, 90%), the simple substitution method was inappropriate because the relative bias was the largest, regardless of the sample size. When the sample size was small and the censoring rate was large, the Bayesian method, the β-substitution method, and the MLE method showed the smallest relative bias. Conclusions: The accuracy and precision of all methods tended to increase as the sample size was larger and the censoring rate was smaller. The simple substitution method was inappropriate when the censoring rate was high, and the β-substitution method, MLE method, and Bayesian method can be widely applied.

• Journal of applied mathematics & informatics
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• 제3권1호
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• pp.101-115
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• 1996

In this paper we extend the best choice of subsample size m in the 2-stage sampling which suggested by Mohammad(1986) to the 3-stage sampling in cases of known and of unknown cost and variance ratio. We find the subsample size m.k which ensures more than the relative efficiency 90% Also we see that the choice of 3-stage subsample size depends on the design parameters using in 2-stage sampling.

• Journal of Forest and Environmental Science
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• 제39권2호
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• pp.73-80
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• 2023

Little is known of the life history of Garcinia kola; the objective of this study, therefore, was to assess the fruiting age and tree size of the species in a coastal humid tropical climate plantation condition. A total 103 trees were used in the study viz; 80 ten-year-old trees at reproductive maturity onset and 13 thirty-year-old trees with several cycles of reproduction that constitute two independent variables. Data collected were age of onset of flowering and size at reproductive maturity onset. Relative size at reproductive maturity onset (RSOM) was estimated as size at reproductive maturity onset (SOM) divided by asymptotic maximal size (AMS). Data analysis was conducted using pairwise t-test and principal component analysis (PCA). Reproductive maturity onset (flowering) was recorded in the ten-year-old stand eight (8) years after planting. Mean size at reproductive maturity onset (SOM) was height 5.32±1.7 m, dbh 0.11±0.03 m, total number of branches was 29.6±7.3, crown depth 5.24±1.05 m, crown diameter was 4.78±0.7 m, branch diameter 0.098±0.01 m, leaf length 0.13±0.02 m, leaf breadth 0.37±0.01 m, twig length 0.35±0.11 m and leaf per twig 6±0.84 and asymptotic maximal size (AMS) was height 19.85±0.76 m, dbh 0.95±0.09 m, total number of branches 62±5, crown depth 18.83±0.7 m, crown diameter 12.5±1.64 m, branch diameter 0.5±1.6 m, leaf length 0.16±0.023 m, leaf breadth 0.45±0.12 m, twig length 0.37±0.11 m and leaf per twig 19±7.5. Pairwise t-test analysis showed there was significant differences between SOM and AMS in all growth factors except leaf length, leaf breadth, and twig length. Highest relative size at reproductive maturity onset (RSOM) was recorded in leaf length 0.82, twig length 0.82, and leaf breadth 0.80, while, the lowest was branch diameter 0.11. Four components out of the total of eleven were extracted to explain the relationship in RSOM: Principal component one (PC1) explained 37.23%; PC2 26.4%, PC3 22.73%, and PC4 13.64%.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1994년도 가을 학술발표회 논문집
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• pp.265-272
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• 1994

The relative density seems to be important as a factor of controlling the physical properties in the case of cohesionless soil ground as sand. Therefore, the study is more important about the method for reappearing the same relative density when the specimen of shearing test is to be produced or the model test of ground is to be made. In this study, the apparatus making use of the multiple sieving pluviation method - one of the reappearance of relative density - could be made. Using this apparatus, tests were practiced varying the factors such as the size of sieve mesh and the number of sieve, the amount of falling discharge, the falling height etc. about the standard sand in Jumunjin and Hadong sand. When laboratory test is performed by the cohensionless soil , it presents the method for reappearing of the relative density in field.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.276-279
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• 2005

As the Ubiquitous generation approaches, the importance of the sensor data processing is growing. The data approximation scheme, one of the data processing methods, can be the key of sensor data processing, for it is related not only to the lifetime of sensors but also to the size of the storage. In this paper, we propose the Harmonic Wavelet transform which can minimize the relative error for given sensor data. Harmonic Wavelets use the harmonic mean as a representative which is the minimum point of the maximum relative error between two data values. In addition, Harmonic Wavelets retain the relative errors as wavelet coefficients so we can select proper wavelet coefficients that reduce the relative error more easily. We also adapt the greedy algorithm for local optimization to reduce the time complexity. Experimental results show the performance and the scalability of Harmonic Wavelets for sensor data.

• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.836-842
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• 2015

In this paper, the target size and model based target size estimator (TMBE) algorithm is presented for iimaging infrared (IIR) seeker. At the imaging seeker, target size information is important factor for accurate tracking. The model based target size estimator filter (MBEF) algorithm was proposed to estimate target size at imaging infrared seeker. But, the model based target size estimator filter algorithm need to know relative distance from the target. In order to overcome the problem, we propose target size and model based target size estimator filter (TMBEF) algorithm which based on the target size. The performance of proposed algorithm is tested at target intercept scenario. The experiment results show that the proposed algorithm has the accurate target size estimating performance.

• 한국인구학
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• 제11권2호
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• pp.11-21
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• 1988

• 한국의류학회지
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• 제37권4호
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• pp.598-617
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• 2013

This study analyzes the body sizes of young boys in order to categorize a sizing system for middle and high school uniforms. The study was based on the $6^{th}$ National Anthropometric Survey (Size Korea 2010) data. The sample size consisted of 2,317 boys between the ages of 13 and 18 years. Most measurement items increased significantly relative to age and there was rapid growth between the ages of 13 and 14 years. The growth for the chest and hip was more than the waist. The drop value 1 (difference between chest circumference and waist circumference) and the drop value 2 (difference between hip circumference and waist circumference) increased remarkably from the age of 13 to the age of 15. Therefore, the waist size decreased and chest and hip became wider relative to the age increase. Middle school students had a smaller chest and hip circumference than high school students in the comparative body measurement results for middle school students (13-15 years) and high school students (16-18 years) of the same height group. The somatotype of high school students showed a long trunk length, broad chest and shoulder.

• 한국수산과학회지
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• 제44권4호
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• pp.390-396
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• 2011

Southern rough shrimp Trachysalambria curvirostris is exploited mainly by small shrimp beam trawl in coastal regions of Korea. To determine the size selectivity of a shrimp beam trawl for this species, a series of comparative fishing experiments was conducted in the sea adjacent to Geoje Island off the southern cost of Korea in June and November, 2010, using codends with four different mesh sizes(14.2, 17.8, 25.5, and 35.3 mm). The extended Share Each Length's Catch Total(SELECT) analysis method, based on a multinomial distribution, was applied to the fishing data to obtain a master selection curve. The model with the estimated split parameters fit the catch data best. The master selection curve was estimated to be: s(R)=exp(15.183R-7.872)/[1+exp(15.183R-7.872)], where the relative carapace length, R, is the ratio of carapace length to mesh size. The relative carapace length for 50% retention was 0.518, and the selection range was 0.145. The results suggest that codends with a larger mesh size allow more small-sized shrimps to escape.