• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.130-149
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• 2017

The subalpine zone which is vulnerable to climate change could be functioning as a habitat for northern plant species especially in the Korean peninsula. In this study, classification of phytosociological community type and investigation on flora of vascular plants of Daecheongbong area in Mt. Seorak were carried out in order to provide a basic information for an ecological restoration and management of the vegetation through community ecological approach. Vegetation data were collected from 31 of quadrates from May to October, 2016. We analyzed vegetation types with phytosociological method, importance value with Curtis & McIntosh method, CCA using PC-ORD program tool, and flora of vascular plants. As a result, the forest vegetation was classified into Abies nephrolepis community. The community was divided 3 groups such as Pinus pumila group, Rhododendron brachycarpum group and Angelica decursiva group. Therefore, the vegetation had 3 kinds of units. The differential species group, it was classified into total of 7 species group units including Thuja koraiensis and Smilacina bicolor differential species group. The mean importance percentage (MIP) in VU 1 was shown Pinus koraiensis (24.1), A. nephrolepis (23.6) and Betula ermanii (10.5), and in VU 2, it was P. koraiensis (26.2), A. nephrolepis (20.8) and B. ermanii (10.5), and in VU 3, it was P. koraiensis (22.2), A. nephrolepis (16.4), B. ermanii (13.5) in the order, respectively. As for importance values of P. koraiensis and A. nephrolepis representative competition species, were different at each layers. The former (46.7) was higher than the latter (26.1) in tree layer, but the latter was higher than the former in subtree and, shrub and herb layers of VU 1. VU 2 and VU 3 also indicated the same tendency. P. pumila group and A. decursiva group were shown to have positive correlation with altitude and present species, respectively. The designated as the endemic plant was 11 taxa and, as the rare plant 24 taxa and 62.5% of vascular plant was northern plant species. It is necessary to continue further long-term monitoring of 3 vegetation units, IV of main competition species (P. koraiensis and A. nephrolepis) with stratum and main specific species (rare plants and endemic plants) considering vegetation science and, population and community ecology approaches.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.117-131
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• 2017

This study was conducted to draw vegetation landscape elements in the ancient literature, investigate plant community structure, understand vegetation structure, and suggest reasonal conservation management methods. As a result of analyzing ancient literature, geomorphological landscapes in Guryong valley were canyon landscape and valley surrounded in Mt. Chiak. Plant landscape factors were as followed. Rhododendron spp. spread around valley. Also, Pinus densiflora communities were distributed in Guryong valley around. Especially, the entrance zones of Guryong valley were described as covered with Pinus densiflora and Whangchangkumpyo(黃腸禁標). Therefore, it was estimated that entry of Guryong valley was covered with Pinus densiflora community landscape. As for current vegetation result, the main vegetation was divided into mixed deciduous broad-leaved trees community and Pinus densiflora community. As a result of analysis by TWINSPAN for community classification, five communities(Deciduous broadleaved trees, Pinus densiflora, Pinus densiflora-Abies holophylla, Abies holophylla, and Pinus koraiensis community) were classified. To maintain historic plant landscape and conserve crucial resources, Pinus densiflora community was classified as concentrated conservation management area($105,472m^2$). To maintain Pinus densiflora landscape which has high historical and cultural value of Guryong valley, it was considered that active density control of lower layer vegetation would be necessary. Accordingly, to conserve P. densiflora landscape, Whangchangkumpyo(?腸禁標), that area was separated into Pinus densiflora lower layer forest management area($84,029m^2$) and Pinus densiflora seedling conservation management area($21,443m^2$). In understory of Pinus densiflora lower layer flora, the target tree species for elimination and management were Quercus serrata and Quercus mongolica. They were $4{\sim}6trees/100m^2$ and their average diameter was 7.1cm. To preserve Pinus densiflora seedlings, areas with Sasa borealis, the ground vegetation of Pinus densiflora community, rate of 80% or more should be selected as priority management areas and concentrated elimination and management of Sasa borealis should be implemented. Likewise, traditional Pinus densiflora forest is a historically cultural heritage to preserve with sustainable interest and survey. Efficient management method through systematic monitoring system should be made.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2037-2042
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• 2013

Background: Different methods of diagnosis have been found to be inefficient in terms of screening and early diagnosis of lung cancer. Cancer cells produce proteins whose serum levels may be elevated during the early stages of cancer development. Therefore, those proteins may be recognized as potential cancer markers. The aim of this study was to differentiate healthy individuals and lung cancer cases by analyzing their serum protein profiles and evaluate the efficacy of this method in the early diagnosis of lung cancer. Materials and Methods: 170 patients with lung cancer, 53 under high risk of lung cancer, and 47 healthy people were included in our study. Proteomic analysis of the samples was performed with the SELDI-TOF-MS approach. Results: The most discriminatory peak of the high risk group was 8141. When tree classification analysis was performed between lung cancer and the healthy control group, 11547 was determined as the most discriminatory peak, with a sensitivity of 85.5%, a specificity of 89.4%, a positive predictive value (PPV) of 96.7% and a negative predictive value (NPV) of 62.7%. Conclusions: We determined three different protein peaks 11480, 11547 and 11679 were only present in the lung cancer group. The 8141 peak was found in the high-risk group, but not in the lung cancer and control groups. These peaks may prove to be markers of lung cancer which suggests that they may be used in the early diagnosis of lung cancer.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.1
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• pp.41-48
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• 2008

Enhanced machine reliability has dramatically reduced the rate and number of railway accidents but for further reduction human error should be considered together that accounts for about 20% of the accidents. Therefore, the objective of this study was to suggest a new taxonomy of performance shaping factors (PSFs) that could be utilized to identify the causes of a human error associated with railway accidents. Four categories of human factor, task factor, environment factor, and organization factor and 14 sub-categories of physical state, psychological state, knowledge/experience/ability, information/communication, regulation/procedure, specific character of task, infrastructure, device/MMI, working environment, external environment, education, direction/management, system/atmosphere, and welfare/opportunity along with 131 specific factors was suggested by carefully reviewing 8 representative published taxonomy of Casualty Analysis Methodology for Maritime Operations (CASMET), Cognitive Reliability and Error Analysis Method (CREAM), Human Factors Analysis and Classification System (HFACS), Integrated Safety Investigation Methodology (ISIM), Korea-Human Performance Enhancement System (K-HPES), Rail safety and Standards Board (RSSB), $TapRoot^{(R)}$, and Technique for Retrospective and Predictive Analysis of Cognitive Errors (TRACEr). Then these were applied to the case of the railway accident occurred between Komo and Kyungsan stations in 2003 for verification. Both cause decision chart and why-because tree were developed and modified to aid the analyst to find causal factors from the suggested taxonomy. The taxonomy was well suited so that eight causes were found to explain the driver's error in the accident. The taxonomy of PSFs suggested in this study could cover from latent factors to direct causes of human errors related with railway accidents with systematic categorization.

• The Journal of Information Systems
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• v.27 no.1
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• pp.171-191
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• 2018

Purpose Corporate technology leakage is not only monetary loss, but also has a negative impact on the corporate image and further deteriorates sustainable growth. In particular, since SMEs are highly dependent on core technologies compared to large corporations, loss of technology leakage threatens corporate survival. Therefore, it is important for SMEs to "prevent and protect technology leakage". With the recent development of data analysis technology and the opening of public data, it has become possible to discover and proactively detect companies with a high probability of technology leakage based on actual company data. In this study, we try to construct profiles of enterprises with and without technology leakage experience through profiling analysis using data mining techniques. Furthermore, based on this, we propose a classification model that distinguishes companies that are likely to leak technology. Design/methodology/approach This study tries to develop the empirical model for prevention and protection of technology leakage through profiling method which analyzes each SME from the viewpoint of individual. Based on the previous research, we tried to classify many characteristics of SMEs into six categories and to identify the factors influencing the technology leakage of SMEs from the enterprise point of view. Specifically, we divided the 29 SME characteristics into the following six categories: 'firm characteristics', 'organizational characteristics', 'technical characteristics', 'relational characteristics', 'financial characteristics', and 'enterprise core competencies'. Each characteristic was extracted from the questionnaire data of 'Survey of Small and Medium Enterprises Technology' carried out annually by the Government of the Republic of Korea. Since the number of SMEs with experience of technology leakage in questionnaire data was significantly smaller than the other, we made a 1: 1 correspondence with each sample through mixed sampling. We conducted profiling of companies with and without technology leakage experience using decision-tree technique for research data, and derived meaningful variables that can distinguish the two. Then, empirical model for prevention and protection of technology leakage was developed through discriminant analysis and logistic regression analysis. Findings Profiling analysis shows that technology novelty, enterprise technology group, number of intellectual property registrations, product life cycle, technology development infrastructure level(absence of dedicated organization), enterprise core competency(design) and enterprise core competency(process design) help us find SME's technology leakage. We developed the two empirical model for prevention and protection of technology leakage in SMEs using discriminant analysis and logistic regression analysis, and each hit ratio is 65%(discriminant analysis) and 67%(logistic regression analysis).

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.185-202
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• 2018

Many ecological studies regarding forest succession, which is the process of arriving at climax forest through ecological changes, have suggested that Carpinus laxiflora is the leading tree type of the climax forest of temperate zone in South Korea. However, most of these studies on C. laxiflora forest have focused on vegetation structure and succession process in specific areas or regional physiognomical forest communities, and thus some may question whether it is rational to consider C. laxiflora forest as the climax forest in South Korea's temperate forest zone. The purpose of this study was to analyze the vegetation classification, species composition, and stratum structure and to investigate the succession tendency with the vegetation data collected from C. laxiflora forests in 75 quadrates in 17 mountains between 2014 and 2017. We used the phytosociological method to analyze the vegetation structure and the importance value to analyze the stratum structure. The results showed the floristic composition of 6 vegetation units and 9 species groups. The hierarchy of the C. laxiflora community group was represented by the Ulmus laciniata community, Corylus heterophylla community (subdivided Quercus aliena group and Corylus heterophylla typical group), and Rhododendron schlippenbachii community (subdivided Fraxinus chiisanensis group, Carpinus tschonoskii group, and Rhododendron schlippenbachii typical group). Successional tendency of C. laxiflora forest based on the importance of each layer is predicted to be the total of three types such as to maintain the stand (vegetation units 2, 3, and 6), to success the Carpinus cordata forest (vegetation units 1 and 4), and to success Quercus acuta forest (vegetation unit 5).

• Journal of Plant Biology
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• v.28 no.2
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• pp.165-175
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• 1985

The natural forest vegetation of the Piagol, Mt. Chiri, was classified into five major communities, i.e. Quercus mongolica, Carpinus laxiflora, C. tschonoskii, Q. serrata and Fraxinus mandshurica community. C. tschonoskii, C. laxiflora and Q. mongolica characteristically were dominated in the range of 500∼700 m, 700∼900 m and 900∼1,400 m in altitude, respectively. Abies nephrolepis and Rhododendron schlippenbachii in the ridge of Nogodan-Nalnaribong, and F. mandshurica and Q. serrata in the Yongsuam ravine were found as the dominant species. The transition between C. tschonoskii and C. laxiflora communities was relatively wide. The boundary between F. mandshurica, in the conglomerated zone, and the other communities surrounding its community was fairly abrupt. In Q. mongolica community, the canopy was relatively opened and the oak young tree of undergrowth was fairly dense. In the community of C. laxiflora and C. tschonoskii, the species composed of their understory was rich while their coverage was lower than that of Q. mongolica community. Shannon's diversity index was decreased in order of C. tschonoskii, C. laxiflora and Q. mongolica community, while their Simpson's dominance index increased conversely. Judging by the DBH-class distribution showing the negative exponential curve, these communities were considered as the climax forest. In Polar Ordination used samples (quadrats), the vegetation of the Piagol was divided into five groups, which was coincided with five communities classified by Braun-Blanquet system. In the ordination, the first axis and the second axis may be considered soil conditions and thermal conditions, respectively. It seems that two different methods, phytosociological method in macro level and ordination techniques in micro level, are useful for the vegetation classification.

• Journal of the Korea Society for Simulation
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• v.23 no.1
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• pp.21-31
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• 2014

In this article, data mining simulation is applied to find a proper approach and results of analysis for study of variables related to organization. Also, turnover intention and organizational commitment are used as target (dependent) variables in this simulation. Classification and regression tree (CART) with ensemble methods are used in this study for simulation. Human capital corporate panel data of Korea Research Institute for Vocation Education & Training (KRIVET) is used. The panel data is collected in 2005, 2007, and 2009. Organizational commitment variables are analyzed with combined measure variables which are created after investigation of reliability and single dimensionality for multiple-item measurement details. The results of this study are as follows. First, major determinants of turnover intention are trust, communication, and talent management-oriented trend. Second, the main determining factors for organizational commitment are trust, the number of years worked, innovation, communication. CART with ensemble methods has two ensemble CART methods which are CART with Bagging and CART with Arcing. Comparing two methods, CART with Arcing (Arc-x4) extracted scenarios with very high coefficients of determination. In this study, a scenario with maximum coefficient of determinant and minimum error is obtained and practical implications are presented. Using one of data mining methods, CART with ensemble method. Also, the limitation and future research are discussed.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.245-251
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• 1994

Ten strains of 7 species from the genus Ganoderma, G. lucidum ATCC 64251, FP-103561-T, and ES70701, G. applanatum ATCC 44053 and FP-57035-T. G. lobatum ATCC 42985, G. resinaceum ATCC 52416, G. subamboinense var. laevisporum ATCC 52420, G. meredithae ATCC 64492, and G. microsporum ATCC 76024, were studied to discuss their phylogenetic relationships by utilizing restriction fragment length polymorphisms (RFLPs) of mitochondrial DNAs (mtDNAs). Six restriction enzymes, BamHI, BglII, EcoRI, HindIII, PvuII, and XbaI which digested mtDNAs into adequate numbers of restriction fragments for cluster analysis, were used in this study. Restriction profiles of strains for each restriction enzyme were treated as analysis characters to calculate similarity coefficients, which were converted into nucleotide sequence divergence values whose mean values were then arranged in a matrix table. This table was utilized for a phylogenetic analysis using the Neighborjoining method of the PHYLIP package to construct phylogenetic tree. Three strains of G. lucidum and two strains of G. applanatum exhibited different lineages each but one of G. applanatum strains showed a close relationship with G. lobatum, which reflected the species complexity of these species whose strains were phenotypically indistinguishable but genetically distinct. The present results suggest that the natural classification of Ganoderma needs to be considered from the viewpoints of molecular biology-based systematics as well as morphological classifications and cultural identifications for better phylogenetic conclusions.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.275-285
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• 2020

Background: In Korea, Symplocos prunifolia Siebold. & Zucc. is only found on Jeju Island. Conservation of the species is difficult because little is known about its distribution and natural habitat. The lack of research and survey data on the characteristics of native vegetation and distribution of this species means that there is insufficient information to guide the management and conservation of this species and related vegetation. Therefore, this study aims to identify the distribution and vegetation associated with S. prunifolia. Results: As a result of field investigations, it was confirmed that the native S. prunifolia communities were distributed in 4 areas located on the southern side of Mt. Halla and within the evergreen broad-leaved forest zones. Furthermore, these evergreen broad-leaved forest zones are themselves located in the warm temperate zone which are distributed along the valley sides at elevations between 318 and 461 m. S. prunifolia was only found on the south side of Mt. Halla, and mainly on south-facing slopes; however, small communities were found to be growing on northwest-facing slopes. It has been confirmed that S. prunifolia trees are rare but an important constituent species in the evergreen broad-leaved forest of Jeju. The mean importance percentage of S. prunifolia community was 48.84 for Castanopsis sieboldii, 17.79 for Quercus acuta, and 12.12 for Pinus thunbergii; S. prunifolia was the ninth most important species (2.6). Conclusions: S. prunifolia can be found growing along the natural streams of Jeju, where there is little anthropogenic influence and where the streams have caused soil disturbance through natural processes of erosion and deposition of sediments. Currently, the native area of S. prunifolia is about 3300 ㎡, which contains a confirmed population of 180 individual plants. As a result of these low population sizes, it places it in the category of an extremely endangered plant in Korea. In some native sites, the canopy of evergreen broad-leaved forest formed, but the frequency and coverage of species were not high. Negative factors that contributed to the low distribution of this species were factors such as lacking in shade tolerance, low fruiting rates, small native areas, and special habitats as well as requiring adequate stream disturbance. Presently, due to changes in climate, it is unclear whether this species will see an increase in its population and habitat area or whether it will remain as an endangered species within Korea. What is clear, however, is that the preservation of the present native habitats and population is extremely important if the population is to be maintained and expanded. It is also meaningful in terms of the stable conservation of biodiversity in Korea. Therefore, based on the results of this study, it is judged that a systematic evaluation for the preservation and conservation of the habitat and vegetation management method of S. prunifolia should be conducted.