• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.353-356
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• 2009

OWL 온톨로지의 확장 가능한(scalable) 추론(reasoning)에 대한 접근 방법으로 SQL로 구축된 논리 규칙을 관계형 데이터베이스에 저장되어있는 개체(individual)에 대한 사실(facts)과 공리(axioms)들에 적용하는 것이다. 예로서 미네르바(Minerva)는 서술 논리 프로그램(Description Logic Program, DLP)을 적용함으로써 ABox 추론을 수행한다. 본 연구에서는 관계형 데이터베이스를 기반으로 추론을 시도하며, 대규모 논리 규칙 집합을 사용한 추론을 시도한다. 뿐만 아니라, 특정 클래스에 속한 익명(anonymous)의 개체들과 개체들의 묵시적(implicit)인 관계성 추론을 시도하며, 필요한 경우 새로운 개체를 생성함으로써 명시화하여 추론을 시도한다. 더욱이, 추론의 논리 패러다임(paradigm)에서부터 데이터베이스 패러다임에 이르기까지 변화 시켜가면서 카디널리티(cardinality) 제약을 만족하는 개체들에 대한 제약적인 추정 추론을 시도하며, 벤치마크 테스트 결과 향상된 추론 능력을 얻을 수 있음을 보인다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.4
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• pp.441-448
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• 2010

This paper estimates the tree height using Airborne LiDAR that is obtained for each season to analyze its influence based on a canopyclosure and data fusion. The tree height was estimated by extracting the First Return (RF) from the tree and the Last Return (LR) from the surface of earth to assume each tree via image segmentation and to obtain the height of each tree. Each data on tree height that is collected from seasonal data and the result of tree height acquired from the data fusion were compared. A tree height measuring device was used to measure on site and its accuracy was compared. Also, its applicability on the result of fused data that is obtained through the Airborne LiDAR is examined. As a result of the experiment, the result of image segmentation for an individual tree was closer to the result of site study for 1 meter interval when compared to the 0.5 meter interval of point cloud. In case of the tree height, the application of fused data enables a closer site measurement result than the application of data for each season.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.5
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• pp.725-731
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• 2013

In This paper, through simulation, proposes a system which makes it possible for freely moving multiple agents with ultrasonic receivers to estimate their own position by themselves using the ultrasonic signals sequentially emitted from multiple ultrasonic transmitters. This system possesses an advantage that there is no limit in the number of agents existing in the space covered by more than three transmitters fixed at proper locations. Hence, the proposed system can be utilized effectively in position tracking control of multiple robotic agents system and motion capturing system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.195-203
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• 1974

The individual production rate of Plecoglossus altivelis was studied from the 18th of June to the 25th of September (99 days) 1973, when the fish grow best at Gangjeong Stream, Jeju Do, as one of the ways to find out the reasons why the size of P. altivelis of Jeju Island is smaller than that of other places. The results obtained are as follows : 1) The indivudual production rate of the fish in the Gangjeong Stream during the summer 1973, was estimated as shown in Table 6. 2) The individual production rate of the fish and standing crop of algae on stones in the Gang-jeon Stream were no more than $7.2\%$ and $6.2\%$ respectively, when compared with those of the Ukawa River (which is located in Japan), thus the individual production rate of the fish at Gang-jeong Stream being very poor. 3) Population density was 5.2 individuals average per square meter during the research period. This is beyond the estimated density limit, i. e., 4.8 individuals per square meter, for the standing crop of algae on stones. 4) The period that the individual production rate of the fish was the most brisk during the summer in this stream was from August to September in 1973. 5) The poor individual production rate is primarily regarded due to insufficient gross ingestion. The reasons seemed to be insufficeient productivity of algae on the bottom stones, over-population density of the fish, and the lowered activity of ingestion due to low water temperature in daytime as compared with other places. Thus, the production rate of Plecoglossus altivelis in the Gangjeong Stream during the summer was greatly influenced by these factors.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.246-248
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• 2009

기존의 항공사진 및 위성사진을 활용한 원격탐사방법은 기상조건에 따른 제약과 3차원적 수직구조 관한 정보 수집에 한계가 있다. 따라서 보다 정확하고 신속한 산림자원 정보를 획득하기 위해서는 새로운 기술적 접근이 필요하다. 3차원 측정이 가능한 LiDAR의 특성을 이용하면 기존 방법의 부정확성과 비효율성을 상당부분 극복 할 수 있다. 본 연구에서는 지상 Laser Scanner 와 항공 LiDAR를 이용하여 개체목의 3차원 구조를 예측하여 수고, 지하고, 수관면적, 수관체적을 추정하고 결과를 비교하였다. 지상 Laser Scanner에 의한 측정치를 참조자료로 하여 항공 LiDAR의 개체목 측정 정확성을 향상 시킬 수 있는 보정식을 최종적으로 개발하였다.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.121-127
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• 2013

In this study, growth-line analysis was carried out on the hard clam (Meretrix petechialis) collected from the Neolithic shell middens in Daejuk-ri, Seosan, Korea, to reconstruct palaeoenvironment. Growth increments of 206 specimens of the clam were examined. The ages of the specimens were determined from the rings on the shells. The relationship between shell length and ring radius in each ring group was expressed as a regression line, indicating a correspondence in each ring formation. Growth pattern of the midden specimens was compared to that of modern ones collected from Gimje, Jeonbuk. Growth curves for shell length fitted to the von Berta anffy's growth curve were expressed respectively as follows: $SL_t=102.9025[1-e^{-0.18657(t+1.0906)}]$ in the shell midden specimens, $SL_t=104.2583[1-e^{-0.2277(t+0.7499)}]$ in the modern ones. The relationship between shell length (SL; mm) and shell height (SH; mm) was expressed by the following equations: SH = 0.7791 SL + 3.6636 ($R^2$ = 0.946) in the midden specimens, SH = 0.8103 SL + 0.5145 ($R^2$ = 0.991) in the modern ones. The results of the tests regarding the differences between regression coefficients and elevations of growth curves of these two populations demonstrate that the slopes were not significantly different (p < 0.05), but the elevations were (p > 0.05). However, overall growth curves of the midden and modern populations were not significantly different, indicating that shell growth environments of the two areas are similar. Therefore, it is likely that sea temperature near the midden area could be similar to that of present Gimje area, and thus temperature during the period of the midden formation could be higher than presently known.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.407-410
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• 2004

우리나라 연근해 해역에서 발생하는 적조 현상은 매년 특정 시기에 끊임없이 나타나고, 그 피해액은 해를 거듭해갈 수록 증가하고 있다. 이러한 적조 발생을 조기에 탐지할 수 있는 것만으로도 그 피해는 상당히 줄어들 것이라고 여겨진다. 본 논문에서는 우리나라 연근해 해역에서 발생하는 적조의 우점종 플랑크톤인 Cochlodinium polykrikoides를 탐지하기 위한 방법으로 C. polykrikoides 의 개체수 변화에 따른 후방산란신호를 획득하여 그 상관관계에 관한 실험을 실시하였다. 실험에 사용된 주파수는 5MHz, 10MHz 이고, 적조 주의보와 적조 경보에 해당하는 개체수인 300cell/mL, 1000cell/mL 을 중심으로 개체수를 변화하였다. 필터링 후의 해수와 Cochlodinium 이 있는 해수의 체적산란 패턴 변화뿐만 아니라 Cochlodinium 의 개체수 변화에 따른 산란 패턴의 변화를 볼 수 있었다.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.689-694
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• 2003

Weight records of Hanwoo cows from birth to 36 months of age collected in Daekwanryeong branch, National Livestock Research Institute(NLRI) were fitted to Gompertz, von Bertalanffy and Logistic functions. For the growth curve parameters fitted on individual records using Gompertz model, the mean estimates of mature weight(A), growth ratio(b) and growth rate(k) were 383.42 ${\pm}$ 97.29kg, 2.374 ${\pm}$ 0.340 and 0.0037 ${\pm}$ 0.0012, respectively, and mean estimates of body weight, age and daily gain rate at inflection were 141.05 ${\pm}$ 35.79kg, 255.63 ${\pm}$ 109.09 day and 0.500 ${\pm}$ 0.123kg, respectively. For von BertalanfTy model, the mean estimates of A, b and k were 410.47 ${\pm}$ 117.98kg, 0.575${\pm}$0.057 and 0.003 ${\pm}$ 0.001, and mean estimates of body weight, age and daily gain at inflection were 121.62 ${\pm}$ 34.94kg, 211.02 ${\pm}$ 105.53 and 0.504 ${\pm}$ O.l24kg. For Logistic model, the mean estimates of A, b and k were 347.64 ${\pm}$ 97.29kg, 6.73 ${\pm}$ 0.34 and 0.006 ${\pm}$ 0.0018, and mean estimates of body weight, age and daily gain at inflection were 173.82 ${\pm}$ 37.25kg, 324.47 ${\pm}$ 126.85 and 0.508 ${\pm}$ 0.131kg. Coefficients of variation for the A, b and k parameter estimates were 25.3%, 14.3% and 32.4%, respectively, for Gompertz model, 28.70/0, 9.9% and 33.3% for von Bertalanffy model, and 27.9°/0, 5.0% and 30.0% for Logistic model.

• The Korean Journal of Applied Statistics
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• v.31 no.1
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• pp.123-137
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• 2018

A nonlinear mixed effects model is mainly used to analyze repeated measurement data in various fields. A nonlinear mixed effects model consists of two stages: the first-stage individual-level model considers intra-individual variation and the second-stage population model considers inter-individual variation. The individual-level model, which is the first stage of the nonlinear mixed effects model, estimates the parameters of the nonlinear regression model. It is the same as the general nonlinear regression model, and usually estimates parameters using the least squares estimation method. However, the least squares estimation method may have a problem that the estimated value of the parameters and standard errors become extremely large if the assumed nonlinear function is not explicitly revealed by the data. In this paper, a new estimation method is proposed to solve this problem by introducing the ridge regression method recently proposed in the nonlinear regression model into the first-stage individual-level model of the nonlinear mixed effects model. The performance of the proposed estimator is compared with the performance with the standard estimator through a simulation study. The proposed methodology is also illustrated using quantitative high throughput screening data obtained from the US National Toxicology Program.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.74-81
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• 1998

The estimates of genetic diversity based on 7 polymorphic loci coding for 6 isozymes were compared between the tolerant and the sensitive trees in an air polluted Prunus sargentii stand located on Ulsan industrial area. Although we could not observe statistically significant differences in allele and genotype frequencies between the two groups except the gene locus Got-2, the unique alleles and genotypes were observed in the tolerant group. All the genetic parameters such as genetic multiplicity, genetic diversity, and heterozygosity revealed that a greater amount of genetic variations existed in the tolerant group.