• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.96-99
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• 1997

This paper proposes a very fast preprocessor for isolated word recognition. The proposed preprocessor has a small computational cost for extracting candidate words. In the preprocessor, we used a feature sorting algorithm instead of vector quantization to reduce the computational cost. In order to show the effectiveness of our preprocessor, we compared it to a speech recognition system based on semi-continuous hidden Markov Model and a VQ-based preprocessor by computing their recognition performances of a speaker independent isolated word recognition. For the experiments, we used the speech database consisting of 244 words which were uttered by 40 male speakers. The set of speech data uttered by 20 male speakers was used for training, and the other set for testing. As the results, the accuracy of the proposed preprocessor was 99.9% with 90% reduction rate for the speech database.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.266-272
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• 1999

Aboveground biomass and nutrient contents of a 31-year-old pitch pine(Pinus rigida) and a 31-year-old Japanese larch(Larix leptolepis) plantations were measured in the Chungbu Forest Experiment Station, Kyunggi Province. Aboveground biomass was 170.2ton/ha in the pitch pine and 87.2ton/ha in the Japanese larch plantations. Aboveground biomass difference between both plantations was due to the difference of stand density. Aboveground biomass in both plantations was allocated as follows : stemwood>branch>stembark>needle. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in the Japanese larch needle than in the pitch pine because of high nutrient uptake characteristics of larch compared with pine tree species. The nutrient concentration in different tree tissues in both tree species decreased in the order of needle>branch>stembark>stemwood. Nutrient contents of aboveground biomass were : N, 335.9 ; P, 40.4 ; K, 121.4 ; Ca, 188.6 ; Mg, 93.8kg/ha in the pitch pine plantation, while nutrient contents in the Japanese larch plantation were : N, 226 ; P, 11.5 ; K, 72.9 ; Ca, 75.7 ; Mg, 37.1kg/ha. The nitrogen use efficiency calculated as the biomass produced by one unit of nitrogen was higher in the pitch pine than in the Japanese larch plantations. This result suggests that pine with high nitrogen use efficiency could be adapted in lower site productivity area compared with larch tree species.

• Annual Conference on Human and Language Technology
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• 1999.10e
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• pp.128-134
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• 1999

기계번역이나 정보검색 등에 적용되는 자연언어처리기술에 있어서 구문분석은 매우 중요한 위치를 차지한다. 하지만, 문장의 길이가 증가함에 따라 구문분석의 복잡도는 크게 증가하게 된다. 이를 해결하기 위한 많은 노력 중에서 전처리기의 지원을 통해 구문분석기의 부담을 줄이려는 방법이 있다. 본 논문에서는 구문분석의 애매성과 복잡성을 감소시키기 위해 유한상태 변환기 (Finite-State-Transducer FSI)를 이용한 전처리기를 제안한다. 유한상태 변환기는 사전표현, 단어분할, 품사태깅 등에 널리 사용되어 왔는데, 본 논문에서는 유한상태 변환기를 이용하여 형태소 분석된 문장에서 시간표현 등의 제한된 표현들을 구문요소화하는 전처리기를 설계 및 구현하였다. 본 논문에서는 기계번역기에서의 구문분석기 뿐만 아니라 변환지식의 모듈화를 지원하기 위해 유한상태 변환기를 이용하여 시간표현 등의 부분적인 표현들을 번역하는 방법을 제안한다. 또한 유한상태 변환기의 편리한 작성을 위하여 유한상태 변환기 작성 지원도구를 구현하였다. 본 논문에서는 전처리기의 적용을 통해 구문분석기의 부담을 덜어 주며 기계번역기의 변환부분의 일부를 성공적으로 담당할 수 있음을 보여 준다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.334-335
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• 2003

우리나라에서 자생하는 소나무속의 침엽수 중 가장 대표적인 수종은 소나무이며, 리기다소나무가 그 뒤를 잇는다. 이 두 수종을 대상으로 테르펜의 배출속도와 물질별 구성비율을 비교하여 본 결과, 소나무와 리기다의 유사점은 $\alpha$-pinene, myrcene, $\beta$-phellandrene이 주요하게 나타났다. 리기다소나무의 경우에는 소나무에서 보다 $\beta$-pinene이 다소 크게 나타났으나, 지역별로는 테르펜의 구성비 차이가 거의 없었다. 삼림으로부터 방출되는 테르펜의 배출특성을 연구하기 위해서는 보다 많은 수종에 대한 광범위한 연구가 필요할 것으로 사료된다.

• Journal of Korean Society of Forest Science
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• v.72 no.1
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• pp.16-26
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• 1986

Allozyme study on a small pitch pine stand originating and expanded rather rapidly from a few founder trees indicated that the colonization of the pitch pine population was made progressively from the place where the founder trees located to another by moving in cohorts of seeds from a limited number of family or genetically closely related family groups in line with the succeeding generations. This pattern of migration and colonization resulted marked differences in allelic and genotypic frequencies at many of the allozyme loci between the initially colonized subpopulation on the south-facing slope and the lately colonized subpopulation on north-facing slope of a hill. It appeared that gene fixation due to inbreeding and genetic drift occurred at some loci in the pitch pine population or subpopulations. However, even in t 1e inbreeding small pitch pine population or subpopulations, a comparatively large amount of genetic diversity or heterozygosity was maintained due to the high levels of gene recombination at many of the gene loci and natural selections favoring for heterozygotes.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.15-20
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• 2011

The objective of this study was to develop allometric equations and stem density and biomass expansion factor for Pinus rigida stands in Muju region. The coefficient of determination of the allometric equations in independent variable (dbh) and dependent variable (biomass) was more than 95% with the exception of leaf (78%) and branch(83%). The total biomass was $102Mg\;ha^{-1}$ ($65.9 Mg\;ha^{-1}$ from stem wood, $9.5Mg\;ha^{-1}$ from stem bark, $19.6Mg\;ha^{-1}$ from branch and $7.0Mg\;ha^{-1}$ from leaf). Biomass distribution ratio of Pinus rigida stands showed the highest in stem wood with 64.6%, followed by the branch with 19.2%, stem bark with 9.3% and the leaf with 6.9%. The results indicated that the stem density $(g/cm^{3})$ and the biomass expansion factor were 0.453 and 1.344, respectively.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.406-411
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• 2012

Structure and dynamics for three type forests of Quercus acuta, Quercus acutissima and Pinus rigida forests were studied in Wando island, Korea. Quercus acuta and Quercus acutissima forests were natural forest and Pinus rigida forest was a about 30-year-old plantation. Density of tree layers of Quercus acuta, Quercus acutissima and Pinus rigida forests was 2,250 trees/ha, 760 trees/ha, and 1,560 trees/ha, respectively. Mean DBH of tree layers of Quercus acuta, Quercus acutissima and Pinus rigida forests was 12.1 cm, 14.3 cm, and 14.1 cm, respectively. Total basal area of tree layer and subtree layer was $37.1m^2/ha$ for Quercus acuta forest, $19.0m^2/ha$ for Quercus acutissima forest, and $29.2m^2/ha$ for Pinus rigida forest, respectively. According to importance percentage, Camellia japonica was the first dominant species in subtree and shrub layers of all of Quercus acuta, Quercus acutissima and Pinus rigida forests. Species diversity(H') of forest total was 0.814 for Quercus acuta forest, 0.956 for Quercus acutissima forest, and 0.866 for Pinus rigida forest, respectively. According to diameter distribution, Quercus acuta forest was supposed to remain unchanged for a long time. Quercus acutissima forest was changing to Camellia japomica forest and Pinus rigida forest was changing to Quercus acuta-Camellia japonica forest.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.416-425
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• 1996

Aboveground biomass, distribution of N and P in tree components, forest floor and the top 20cm of mineral soil, and litterfall were determined in adjacent 37-year-old plantations of Pinus rigida Mill. and Larix leptolepis Gord. on a sandy clay loam soil in Yangpyeong, Kyonggi Province. Total above-ground tree biomass for P. rigida and L. leptolepis were 138.2 and 127.2 t/ha, respectively, and did not differ between the two species. Nitrogen concentrations in stembark and foliage were all greater in L. leptolepis. Understory biomass contributed less than 2.0% of the total aboveground biomass but contributed up to 12.0% of the aboveground nutrient contents. Soil below L. leptolepis had higher concentrations of N and P. Total ecosystem N content (kg/ha) was greater for L. leptolepis (5,579) than P. rigida (4,147). Litterfall dry mass (kg/ha/yr) was greater for P. rigida (6,020) than L. leptolepis (4,191) whereas N contents in leaf litterfall (kg/ha/yr) was almost twice as large in L. leptolepis (28) than P. rigida (16). This common garden experiment suggests a strong influence of tree species on nutrient distribution and cycling in a forest ecosystem.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.291-295
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• 2015

The insect community structures between a plantation of Pinus rigida and a secondary forest of Quercus monglica were compared to find out one of the ecological roles of a forest planted in 1960s in a suburban area of Seoul, Korea. We collected the insect samples biweekly from September to November in 2014 by using 5 pitfall traps in both forests. The results of analyzing the community structure index of insects in both forests of P. rigida and Q. Mongolica showed that the species richness was a little higher and species evenness was a little lower in P. rigida plantation, and species diversity and dominance were similar in the two forests. The analysis results of insect community structure at the two forests did not show any significant difference. We conclude that the plantation of P. rigida over 40-50 years could sufficiently perform an ecological function as an insect habitat.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.205-212
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• 2006

Effects of nitrogen and phosphorus fertilization on nutrient dynamics and litterfall production were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeongggi Province. Litterfall production were significantly different among sampling dates and between the tree species, whereas it was not significantly different among the treatments. Total annual litterfall production was 6,377 kg/ha for P. rigida and 4,778 kg/ha for L. kaempferi, respectively. Litterfall nutrient concentrations of L. kaempferi were higher than those of P. rigida. For both tree species, litterfall nutrient concentrations were highest in summer when the least litterfall production occurred, and lowest in late-autumn when the greatest litterfall production occurred, except for Ca in the L. kaempferi stand. The amount of total organic matter in the forest floor of P. rigida and L. kaempferi plantations were 24,296 kg/ha and 10,763 kg/ha, respectively. Forest floor N and P contents were 126, 10 kg/ha for P. rigida and 102, 8 kg/ha for L. kaempferi, respectively.