• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.202-208
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• 2007

Recently, a lot of research have been studied to apply wireless sensor networks to USN applications. The characteristics of USN applications is that they are varied according to the sort of sensors and sensing objects. They includes military applications, water pollusion monitoring, intelligent traffic system, farm, logistics, location position applications, and so on. There is no traditional method to classify these applications. In this paper, we propose a taxonomy scheme to classify USN applications. The criteria is based on 3 properties, the criticalness of services, the mobility of sensing entity, and the mobility of sensed objects, to classify them into 8 groups. We also describe the technical issues and related works in them. Our taxonomy can make USN applications to be easily understood and memorized.

• Journal of Korean Library and Information Science Society
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• v.32 no.2
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• pp.323-347
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• 2001

This study is to suggest a classification system to classify the military information resources on the internet. In the first part, it compares LCC\`s Class U(military Science) and Class V(Naval Science) with Yahoo! Korea\`s web site classification system(Home/Government/Military). The second part compares the classes of Yahoo! Korea with those of Simmani search engine and Yahoo! US. Based on this comparative analysis, it proposes a classificatory system for the military information resources on the internet.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.13-17
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• 2009

고해상도 위성영상의 분류 기술은 최근 가장 활발히 연구되고 있는 분야 중 하나로 텍스쳐(texture), NDVI, PCA 영상 등 다양한 전처리 정보들을 추출하고 이를 멀티스펙트럴 밴드와 조합하여 분류 정확도를 높이는 기술을 개발하는 연구들이 주를 이루고 있다. 고해상도 위성영상에서 건물의 그림자와 옆벽면의 폐색 지역은 개체 추출 및 분류를 방해하는 주된 요인이 되며, 다양한 형태와 분광특성을 갖는 개개의 건물은 자동 분류 과정을 통해 제대로 식별되지 않는다는 한계를 갖는다. 이에 본 연구에서는 KOMPSAT-2 단영상으로부터 효율적으로 건물 정보 및 토지피복을 분류하기 위하여, 추출된 건물 정보를 바탕으로 건물의 그림자와 폐색지역을 보정한 후 비건물 지역에 대한 분류를 수행하여 분류 정확도를 높이고자 하였다. 우선 삼각벡터구조 기반의 반자동 인터페이스를 이용하여 건물의 3차원 모델 및 그림자 영역을 추출하고 이로부터 추출된 그림자 영역을 효과적으로 보정하기 위해 반복 선형회귀 연산을 이용한 그림자 보정을 수행한 후 inpainting 기법을 건물 폐색영역 복원에 적용하여 영상의 품질을 향상시켰다. 이러한 과정을 통해 도심 지역의 영상 분석에 있어 가장 큰 오차를 일으키는 인공물의 그림자와 폐색에 의한 오차를 최소화한 후 분류에 적용하여 이를 보정 전 영상을 이용한 분류 결과와 비교하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.148-151
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• 2010

분류 기법은 데이터 마이닝 기술 중 가장 잘 알려진 방법으로서, Decision tree, SVM(Support Vector Machine), ANN(Artificial Neural Network) 등 기법을 포함한다. 분류 기법은 이미 알려진 상호 배반적인 몇 개 그룹에 속하는 다변량 관측치로부터 각각의 그룹이 어떤 특징을 가지고 있는지 분류 모델을 만들고, 소속 그룹이 알려지지 않은 새로운 관측치가 어떤 그룹에 분류될 것인가를 결정하는 분석 방법이다. 분류기법을 수행할 때에 기본적으로 특징 공간이 잘 표현되어 있다고 가정한다. 그러나 실제 응용에서는 단일 특징으로 구성된 특징공간이 분명하지 않기 때문에 분류를 잘 수행하지 못하는 문제점이 있다. 본 논문에서는 이 문제에 대한 해결방안으로써 많은 정보를 포함하면서 빈발패턴에 대한 정보의 순실이 없는 닫힌 빈발패턴 기반 분류에 대한 연구를 진행하였다. 본 실험에서는 ${\chi}^2$(Chi-square)과 정보이득(Information Gain) 속성 선택 척도를 사용하여 의미있는 특징 선택을 수행하였다. 그 결과, 이 연구에서 제시한 척도를 사용하여 특징 선택을 수행한 경우, C4.5, SVM 과 같은 분류기법보다 더 향상된 분류 성능을 보였다.

• Journal of Environmental Impact Assessment
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• v.25 no.2
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• pp.103-123
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• 2016

This study is a comparison of the flora and case studies distributed in Gulup-do Ongjingun, Incheon. The numbers of vascular plants were summarized as 282 taxa including 81 families, 201 genera, 252 species, 3 subspecies, 22 varieties and 5 forms. The Raunkiaer life forms are analyzed in hemicryptophytes were 66 taxa (23.4%) in dormancy form, non-clonal growth ($R_5$) were 160 taxa (56.7%) in propagation form of radicoid form, having no special modification for dissemination ($D_4$) were 197 taxa (48.6%) in propagation form of disseminule form, erect form (e) were 117 taxa (41.5%) in growth form. The halophytes were 23 taxa including Salsola collina, Asparagus oligoclonos and so on. The rare plants were 7 taxa including Pyrrosia hastata (VU), Senecio nemorensis (VU) and so on. The Korean endemic plants were 5 taxa including Hepatica insularis, Lespedeza maritima and so on. In the specific plants by floristic region were 38 taxa, a degree I were 23 taxa (Dictamnus dasycarpus, Vitex rotundifolia and so on), 6 taxa of a degree II (Morus cathayana, Euphorbia esula and so on), 8 taxa of a degree III (Pyrrosia hastata, Rhodotypos scandens and so on), Senecio nemorensis of a degree V and degree IV were not found. The naturalized plants were 17 taxa including Robinia pseudoacacia, Bromus tectorumand so on. Of those Ambrosia artemisiifolia is a invasive alien plants. Naturalization rate (NR) was 6.0% of all 282 taxa of vascular plants and urbanization index (UI) was 5.3% of all 321 taxa of naturalized plants. Gulup-do and adjacent Baega-do were locally investigated field work and it summarizes the results of a total of 41 islands literature in Ongjin-gun and Ganghwa-gun, Incheon including uninhabited islands, Baengnyeong-do, Daecheong-do and so on. The average number of species were each analyzed in about 89 taxa, rare plants are about 2 taxa, endemic plants are about 1 taxa, naturalized plants are about 4 taxa. This study was the comparison of the flora and literature distribution case that the Gulup-do maintain the naturalness and continuously conducted to explore the future conservation measures the adjacent islands.

• Korean Journal of Cognitive Science
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• v.11 no.1
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• pp.47-65
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• 2000

Categorization systems of homepages in search engines are likely to be constructed considering system's efficiency only but not user-centered. This study I investigated user's mental model of superordinate and subordinate categories using category terms of major Korean search engines. From this result, we constructed two kinds of categorization system; redundant system and singular system. In the redundant system, for example, a subordinate category can belong to a number of superordinate categories, but in the singular system to only one superordinate category Three prototype categorization systems, with 'Simmani', were designed and search performances of each system were observed repetitively Overall results, with frequency of correct a answers, number of steps and time taken in solution taken into account, showed the redundant system was superior to the other two systems. This indicates that categorization search could be improved with appropriate categorizaton system. However. l in recognition test score in singular system was the best, which indicates that search performance and recognition memory of categorization reveal different aspects of categorization system learning. Issues of category organization. ways of interface, prior knowledge, exploratory learning, and application areas are discussed further.

• Journal of the Korean Geotechnical Society
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• v.39 no.6
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• pp.5-12
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• 2023

Proactive assessment of landslide susceptibility is necessary for minimizing casualties. This study proposes a methodology for classifying the landslide safety factor using a classification algorithm based on machine learning techniques. The high-risk area model is adopted to perform the classification and eight geotechnical parameters are adopted as inputs. Four classification algorithms-namely decision tree, k-nearest neighbor, logistic regression, and random forest-are employed for comparing classification accuracy for the safety factors ranging between 1.2 and 2.0. Notably, a high accuracy is demonstrated in the safety factor range of 1.2~1.7, but a relatively low accuracy is obtained in the range of 1.8~2.0. To overcome this issue, the synthetic minority over-sampling technique (SMOTE) is adopted to generate additional data. The application of SMOTE improves the average accuracy by ~250% in the safety factor range of 1.8~2.0. The results demonstrate that SMOTE algorithm improves the accuracy of classification algorithms when applied to geotechnical data.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.144-154
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• 2019

The flora of naturalized plants in historic sites, urban parks and stream of Gyeongju-si, South Korea were summarized as 84 taxa including 21 families, 59 genera, 78 species, 1 subspecies, and 5 varieties. Direct investigation was conducted in a historic site with 68 taxa, a neighborhood park with 43 taxa, a stream with 59 taxa and a small park with 42 taxa at 86 sites. Among them, 31.0% (Naturalized Degree (ND) 3) was common but not abundant, 29.8% (ND 5) was common and an abundant plant, 20.2% (ND 2) was local and not an abundant plant. 7 taxa such as Lactuca scariola, Symphyotrichum pilosum, Rumex acetosella were invasive alien species. Lactuca scariola was the most abundant with 41.9%, Symphyotrichum pilosum was more abundant around stream with 34.9%, and Rumex acetosella was abundant on historic sites or small park with 25.6% in all the surveyed sites. To prevent spread of invasive alien species, monitoring may be required, especially, in early settlement stage. A proper management plan needs to be incorporated through physical removal of those plants, substitution of soil and so on.

• Korean Journal of Plant Taxonomy
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• v.39 no.3
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• pp.220-228
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• 2009

C-banded karyotypes of eight taxa of Korean Allium sect. Sacculiferum were examined by means of Giemsa techniques. Each of the taxa had their own characteristic bands. Most of the bands on the somatic metaphase chromosomes were mainly located on the short arm, intercalary region and medium sized chromosomes. In addition, the heterochromatic bands were usually facultative, recognized as two spots, and all investigated taxa had a pair of satellites of heterochromatin. The similarities of total length and number of bands revealed that three varieties of A. thunbergii G. Don have a closer cytological relationship than the others. The C-banding patterns of A. longistylum and A. linearifolium were examined for the first time in this study, and the former was clearly distinguished from the others by the distribution and number of its bands. The proportion of heterochromatic bands suggested that A. thunbergii var. thunbergii is the most primitive, and A. sacculiferum the most advonced, within the section.

• Korean Journal of Plant Taxonomy
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• v.37 no.2
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• pp.155-196
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• 2007

This study was carried out to elucidate floristic data of Chirisan National Park by performing practical field investigation for 1 year and literatures survey simultaneously in 2004. The data from field study were yielded based on voucher specimens. Total number and components of flora of Chirisan National Park is revealed as 1,825 taxa. Among 1,825 taxa, 708 taxa were identified in this field study, and these were comprised 37 orders, 109 families, 382 genera, 590 species 3 subspecies 95 varities 20 forms. Unconfirmed taxa in field but recorded previous literatures were 1,117 taxa, which consist of 41 orders 130 families 500 genera 901 species 9 subspecies 140 varities 67 forms. In conclusion, there may be provisionally 1,825 (708+1,117) taxa in Chirisan National Park. The 43 taxa were firstly found out in this field study. In the floristic data from field study, the number of Korean endemic plants were 31 taxa, the rare and endangered plants which was designated by Korea Forest Service were 21 taxa, the taxa that is more than the third degree among the floristic regional indicator plants which was designated by Korean Ministry of Environment were 40 taxa, and naturalized alien plants to Korea were 27 taxa respectively. Among 1,117 taxa which were not found in this study but recorded in 22 previous literatures, the number of Korean endemic plants were 45 taxa, the rare and endangered plants which was designated by Korea Forest Service were 45 taxa, the taxa that is more than the third degree among the floristic regional indicator plants which was designated by Ministry of Environment were 121 taxa, and naturalized alien plants to Korea were 31 taxa. It can be inferred that the vegetation of Chirisan National Park was changing by some factors and valuable plant resources were tend to diminishing by such as human interference and developments.