• 한국정보과학회논문지:소프트웨어및응용
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• 제28권4호
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• pp.369-379
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• 2001

본 논문은 부영역 분할과 코드워드 인텍스의 캐시 개념을 이용하여 벡터 양자화를 위한 고속코드북 생성 및 부호화 방법을 제안한다. 제안한 방법은 인접한 입력 벡터는 대개 코드북내 특정 코드워드에 의해 나타내어지는 국부성에 바탕을 두고 있다. 초기에 모든 학습 벡터가 거리에 기반한 근접성을 이용하여 정해진 수의 부영역으로 분할된다. 각 부영역에 하나의 코드워드 인덱스 캐시가 할당되는데 이 캐시는 학습 초기에는 전체 코드북 크기에 대응하는 코드워드 인덱스를 갖는다. 학습이 진행되면서 입력 벡터가 갖는 국부성 때문에 각 부영역내 캐시중 사용되지 않는 코드워드 인덱스가 점차 발생하게 되므로 이들은 LRU(Least Recently Used) 삭제 알고리즘에 의해 제거된다. 학습이 진행됨에 따라 부영역 캐시에는 주어진 입력 벡터에 의해 참조되는 코드워드 인덱스만이 남게 되므로 한 학습 주기 동한 필요한 학습 시간이 점차 짧아지게 되어 전체적으로 코드북 생성 시간을 크게 줄일 수 있게 된다. 제안한 방법은 매 학습주기마다, 코드워드 인덱스 삭제 후보 중 주어진 부영역 중심으로부터 거리에 의해 멀리 떨어진 것부터 반만을 제거함에 따라. 복원된 영상의 화질 열화가 거의 없다. 시뮬레이션 결과 제안한 방법은 기존의 LBG 방법에 비해 화질 열화는 거의 없지만 코드북 생성 (또는 부호화) 속도를 2.6-5.4배 (또는3.7-18.8배) 향상시킨다.

• 한국통신학회논문지
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• 제21권7호
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• pp.1685-1695
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• 1996

The postprocessing of compressed images based on the projections onto convex sets and the constrained minimization imposes several constraints on the procesed data. The quantization constraint has been commonly used in various algorithms. Quantization is many-to-one mapping, by which all the dat in a quantization region are mapped to the corresponding representative level. The basic idea behind the projection onto the QCS(quantization constraint set) is to prevent the processed data from diverging from the original quantization region in order to redue the artifacts caused by filtering in postprocessing. However, there have been few efforts to analye the POQCS(projection onto the QCS). This paper analyzed mathematically the POQCS of filtered data from the viewpoint of minimizing the mean square error. Our analysis shows that a proper filtering technique followed by the POQCS can reduce the quantization distortion. In the conventional POQCS, the outside data of each quantization region are mapped into the corresponding boundary. Our analysis also shows that mappingthe outside data to the boundary of a subregion of the quantization region yields lower distortion than does the mapping to the boundary of the original region. In addition, several examples and discussions on the theory are introduced.

• 산업공학
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• 제22권2호
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• pp.126-134
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• 2009

As product quality and yield are essential factors in semiconductor manufacturing, monitoring the main manufacturing steps is a critical task. For the purpose, FDC(Fault detection and classification) is used for diagnosing fault states in the processes by monitoring data stream collected by equipment sensors. This paper proposes an FDC model based on decision tree which provides if-then classification rules for causal analysis of the processing results. Unlike previous decision tree approaches, we reflect the structural aspect of the data stream to FDC. For this, we segment the data stream into multiple subregions, define structural features for each subregion, and select the features which have high relevance to results of the process and low redundancy to other features. As the result, we can construct simple, but highly accurate FDC model. Experiments using the data stream collected from etching process show that the proposed method is able to classify normal/abnormal states with high accuracy.

• Journal of Forest and Environmental Science
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• 제34권6호
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• pp.419-428
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• 2018

Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

• 한국과학교육학회지
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• 제40권2호
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• pp.227-236
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• 2020

이 연구는 디지털 리터러시를 강조한 과학 수업을 통해 학생의 과학에 대한 태도 변화와 핵심역량의 성장을 알아보았다. 이를 위해 C 지역의 C 중학교 1학년 116명을 대상으로 연구를 진행하였으며, 총 35차시의 디지털 리터러시를 강조한 과학 수업을 투입하였다. 첫째로, 과학 태도에 미치는 영향을 알아본 결과 통계적으로 유의미한 변화가 있었다(p<.05). 하위영역별 효과 크기는 0.67~1.52로 중간이상의 효과 크기를 보였다. 둘째로, 디지털 리터러시를 강조한 수업의 유형에 따라서 성장 인식의 전체 빈도 차이는 크게 없었다. 하지만 핵심역량에 따른 분석에서는 Web 기반 수업은 핵심역량별로 빈도의 차이가 크지 않는 반면, 첨단기술 수업은 핵심역량별로 다소 차이가 큼을 확인할 수 있었다. 이는 과학교육에 주는 시사점으로 디지털 리터러시를 강조한 과학 수업의 활용을 높일 필요가 있다.

• 대기
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• 제29권4호
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• pp.391-401
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• 2019

This study first investigates the changes of the mean and extreme temperatures and precipitation in East Asia (EA) under stabilized 1.5℃ and 2℃ warming conditions above preindustrial levels provided by HAPPI project. Here, five model with 925 members for 10-year historical period (2006~2015) and 1.5/2.0℃ future warming scenarios (2091~2100) have been used and monthly based data have been analyzed. The results show that the spatial distribution fields over EA and domain averaged variables in HAPPI 1.5/2.0℃ hindcast simulations are comparable to observations. It is found that the magnitude of mean temperature warming in EA and Korea is similar to the global mean, but for extreme temperatures local higher warming trend for minimum temperature is significant. In terms of precipitation, most subregion in EA will see more increased precipitation under 1.5/2.0℃ warming compared to the global mean. These attribute for probability density function of analyzed variables to get wider with increasing mean values in 1.5/2.0℃ warming conditions. As the result of vulnerability of 0.5℃ additional warming from 1.5 to 2.0℃, 0.5℃ additional warming contributes to the increases in extreme events and especially the impact over South Korea is slightly larger than EA. Therefore, limiting global warming by 0.5℃ can help avoid the increases in extreme temperature and precipitation events in terms of intensity and frequency.

• Parasites, Hosts and Diseases
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• 제56권2호
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• pp.153-165
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• 2018

Development of an effective vaccine is critically needed for the prevention of malaria. One of the key antigens for malaria vaccines is the apical membrane antigen 1 (AMA-1) of the human malaria parasite Plasmodium falciparum, the surface protein for erythrocyte invasion of the parasite. The gene encoding AMA-1 has been sequenced from populations of P. falciparum worldwide, but the haplotype diversity of the gene in P. falciparum populations in the Greater Mekong Subregion (GMS), including Thailand, remains to be characterized. In the present study, the AMA-1 gene was PCR amplified and sequenced from the genomic DNA of 65 P. falciparum isolates from 5 endemic areas in Thailand. The nearly full-length 1,848 nucleotide sequence of AMA-1 was subjected to molecular analyses, including nucleotide sequence diversity, haplotype diversity and deduced amino acid sequence diversity and neutrality tests. Phylogenetic analysis and pair-wise population differentiation ($F_{st}$ indices) were performed to infer the population structure. The analyses identified 60 single nucleotide polymorphic loci, predominately located in domain I of AMA-1. A total of 31 unique AMA-1 haplotypes were identified, which included 11 novel ones. The phylogenetic tree of the AMA-1 haplotypes revealed multiple clades of AMA-1, each of which contained parasites of multiple geographical origins, consistent with the $F_{st}$ indices indicating genetic homogeneity or gene flow among geographically distinct populations of P. falciparum in Thailand's borders with Myanmar, Laos and Cambodia. In summary, the study revealed novel haplotypes and population structure needed for the further advancement of AMA-1-based malaria vaccines in the GMS.

• 한국통신학회논문지
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• 제17권12호
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• pp.1437-1450
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• 1992

본 논문에서는 손바닥의 interdigital영역으로 부터 특징패턴을 추출하는 과정과 이 특징패턴과 관련된 자료를 이용한 개인식별 방법을 제안하였다. 처리과정은 interdigital영역을 일정한 크기로 분할하고 각 분할된 영역에 대하여 융선의 분포에 따른 4방향의 방향 코드를 부여한후 이것을 분석하는 것에 의해 특징패턴의 존재 유무와 1차 중심점을 검출하였다. 검출된 1차 중심점의 주변 제한된 영역에 대해서만 세선화와 융선 추적을 통하여 특징패턴의 종류와 2차 중심점(core)을 구하였다. 2차 중심점들을 연결하는 특징패턴 좌표계를 설정하고 각 중심점에 대한 상대적 거리와 방향정보 특징 패턴의 종류등에 대한 특징 파라미터를 구하였다. 식별실험은 각 특징패턴의 종류와 수, 존재위치에 의하여 판단하거나 특징 파라미터를 비교, 분석하는 것에 의해 수행하였다.

• 한국통신학회논문지
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• 제19권12호
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• pp.2364-2375
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• 1994

효율적인 인쇄체 한글 인식을 위하여 다중 최소평균 상관 에너지 필터를 제안하였다. 제안된 방법은 기존의 나무구조 알고리듬의 단점인 인식시스템의 방대함과 인식방법의 복잡함을 해결하였다. 오직 하나의 자음 MMACE 필터와 모음 MMACE 필터를 사용하여 완전한 한글을 인식하였다. 각 MMACE 필터는 24개의 자모음으로 합성된 4개의 K-tuple MACE 필터를 이용하여 다중화시켰다. 따라서 제안된 MMACE 필터의 필터평면과 상관분포 평면은 4개의 부평면으로 나누어 진다. 각 상관분포 부평면으로 한글 인식을 위한 코드를 얻었다. 얻어진 코드와 컴퓨터에 내장된 자모음을 인식하기 위한 진리표와 비교하였다. 일치하는 코드의 해당자모음을 찾아 출력상관평면상의 상관첨두 위치에 치환하면 완전한 한글을 인식할 수 있다. 컴퓨터 시뮬레이션과 광 실험을 통하여 제안된 MMACE 필터를 이용한 한글 인식 시스템의 높은 변별력을 확인하였다.

• 한국패류학회지
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• 제10권1호
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• pp.38-48
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• 1994

Gonadal developmint, age and growth of Ruditapes philippinarum were investigated using samples from the intertidal zone of Simpo on the coast of Kimje, Korea, which were collected onthly for one year from Februaty 1993 to January 1994.Ruditapes philippinarum is diecious in sex. The gonads are located between the subregion of the midintestinal glands and reticular connective tissue of the foot. The ovary is composed of a number of ovarian sacs, and the testis is composed of numerous seminiferous tubules. The clam spawns once a year from early June to darly October, and the main spawning occurred between July and August when the water temperature went above 23$^{\circ}C$. Ripe oocytes are about 65-70${\mu}{\textrm}{m}$ in diameter. Gonadal phases of this species can be divided into five successive stages; multiplicative(February to March), growing (April to May), mature(Aprilto Septimber), spent(June to October), and degenerative and resting(july to March). Spawning is closely related to the sea water temperature. Based on the monthly variations of marginal index (MI')of the shell, it was suggested that the annual ring mark formation occurred in March once a year and took approximately 8 months (0.67 year) for first ring to be formed on the shell. The relationship between the shell length(SL) and the total weight (TW) was represented by nonlinear equation; TW=1.208 x 10/ sup -4/ S $L^{3.158}$, and also in the relationship be-tweenthe shell length (SL) and the shell height(SH), the shell length and the shell width (SW) were represented by the linear equations; SH=0.726 SL-0.483, SW=0.542 SL-0.803.Growth curves for shell length and total weight fitted to von Bertalanffs equation were expressed as: S $L_{t}$ =68.34(1- $e^{0.221}$(t+0.418)) T $W_{t}$ =75.16(1- $e^{0.221}$(t=0.418))$^{3.158/3.158}$