• Title/Summary/Keyword: ClusterAnalysis

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Distributional Patterns of Understory Vegetation at Mt. Geumdae's Protected Area for Forest Genetic Resources (금대봉 산림유전자원보호림의 하층식생 분포양상)

  • Chun, Seung-Hoon;Lee, Hyung-Sook;Lim, Jong-Hwan
    • Journal of Korean Society of Forest Science
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    • v.98 no.3
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    • pp.339-350
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    • 2009
  • This study was carried out to investigate distributional condition of rare plants and useful plant resources, and to verify distributional patterns of understory vegetation associated with the upper layer's vegetation structure. Total 59 families, 160 genera, 218 kinds of vascular plants were identified at the study site including 6 rare plants designated by Korea Forest Service (Lloydia triflora Bak., Trillium kamtschaticum Pall., Lilium distichum Nakai, Anemone koraiensis Nakai, Iris odaesanensis Y.N. Lee, Viola diamantica Nakai). Twenty three species of useful plant resources were also identified at the site; 8 of them showed clustered distributions and the others were prone to scatter. Actual vegetation of this study area consisted of one natural community dominated by Quercus mongolica Fisch. and three disturbed communities of Larix kaempferi (Lamb.) Carriere, Abies holophylla Max. and/or a herbaceous vegetation resulting from forest removal and strong wind of mountain top. This classification was strongly supported by cluster analysis based on the surveyed plot data. Distributional patterns of understory vegetation within forest stand were somewhat related to overstory vegetation structure, but showed a different tendency according to site condition, species composition, and competitive pressure among understory vegetation. Therefore, in order to protect the important understory components as forest genetic resources, forest treatments such as density control of overstory should be implanted based on understanding of impact on understory's dynamics and growing condition.

Risk Factors Influencing Stroke : using data from the 7th(2016-2018) Korea National Health and Nutrition Examination Survey (뇌졸중에 영향을 미치는 위험요인 : 국민건강영양조사 제7기(2016-2018) 자료를 활용하여)

  • Chung, Myung Sill;Seomun, GyeongAe
    • Journal of Digital Convergence
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    • v.18 no.9
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    • pp.277-283
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    • 2020
  • The purpose of this study was to identify the risk factors influencing stroke. The research method was used two-stage stratified cluster sampling using data from the National Health and Nutrition Survey (2016-2018). This study subjects performed a complex sample logistic regression analysis on adults aged 19 or older. Risk factors affecting stroke were shown as follows: in age groups, odds ratio were conformed when people are in their 70s, the rate is 8.861 times higher; when they are in their subjective health conditions, the odds ratio are 4.501 times higher in the bad groups; odds ratio was 3.158 times higher in the group diagnosed with hypertension and 1.598 times higher in the group diagnosed with diabetes. The result of this study found that chronic diseases such as high blood pressure and diabetes and the management of senior citizens are important because stroke is dangerous and can be managed through prevention.

The New Finding on BOLD Response of Motor Acupoint KI6(照海) by fMRI (fMRI를 이용하여 수지굴신운동(手指屈伸運動)과 조해(照海)(KI6) 자침(刺鍼)에 의(依)한 대뇌운동피질(大腦運動皮質)의 활성변화(活性變化)에 관(關)한 비교(比較) 연구(硏究))

  • Kwon, Cheol-hyeon;Lee, Jun-beom;Hwang, Min-seob;Yoon, Jong-hwa
    • Journal of Acupuncture Research
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    • v.21 no.6
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    • pp.177-186
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    • 2004
  • Introduction : Recent studies Suggested that there is a strong correlation between acupuncture stimulation and its related cortical activation. Anther study showed that either positive or negative BOLD effects could be observed depending on anatomical structure in acupuncture stimulation. In ttis study, we investigated a new acupoint $KI_6$ (照海), which was known as motor-related acupoint and obtained an evidence that the stimulation of $KI_6$ resulted in either negative or positive BOLD response to stimulation. Methods & Results : 1. Subjects and paradigms : Two separate stimulation paradigms were performed on five healthy (aged 22-23 yrs) in this study. First, the paradigm of acupuncture stimulation was that the acupuncture needle was inserted in acupoints $KI_6$, which is located in lateral side of the foot and then continuously twisted(補瀉를 除外한 捻轉法) for 70 seconds for 10 cycles of activation. During rest period (70 seconds), the needle was completed removed from acupoint. Total 60 cycles were performed and 10 images were obtained per cycle. Second, nonacupoint was randomly selected and the same paradigm was performed as acupoint stimulation. The stimulation protocol comprised 10 cycles of alternating. activation and rest (10 images per cycle). Total 60 cycles were performed and each cycle take about 1.5 sec for motor task. Subjects take an at least 15 minutes break before starting anther paradigm. 2. fMRI mapping : Multi-slice functional images were obtained on a 1.5T Magnetom Vision MRI scanner (Simens Medical, Erlangen, Germany) equipped with high performance whole-body gradients. The BOLD T2 * - weighted images were acquired with acho planar imaging sequence (TR = 1.2 sec, TE = 60 msec, and flip angle = $90_{\circ}$). The other sequence parameter are : FOV = 210 mm, matrix=$64{\times}128$ or $64{\times}64$, slice number=10 and slice thickness = 5 or 8 mm. the anatomic images were obtained with Spin-echo T1-weighted images. The resulting images were then anaiyzed with STIMULATE (CMRR, U. of Minnesota) to generate functional maps using a student T-test (p < 0.005) and cluster analysis. Both positive and negative response were evaluated. Conclusions : We have observed the activation of the motor cortex by stimulating motor-related acupoint ($KI_6$). Among five subjects, negative BOLD response was shown in four and positive response in one. All subjects showed positive response to conventional finger flexion-extension task. To understand the detailed mechanisms of correlation between acupuncture stimulation and BOLD fMRI changes and two typs of response, further study strongly required.

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Association between Periodontitis and Coronary heart disease in Korea : Inflammatory markers and IL-1 gene polymorphism (한국인에서 치주질환과 관상동맥질환의 관련성에 대한 염증표지자와 IL-1 유전자 다변성의 영향)

  • Jeong, Ha-Na;Chung, Hyun-Ju;Kim, Ok-Su;Kim, Young-Joon;Kim, Ju-Han;Koh, Jung-Tae
    • Journal of Periodontal and Implant Science
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    • v.34 no.3
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    • pp.607-622
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    • 2004
  • Recently epidemiologic studies have indicated that the patients with periodontitis may have increased risk of ischemic cardiovascular events, and have suggested the important roles of blood cytokines and acute reactant proteins in the systemic infection and inflammatory response. Periodontitis and coronary heart disease (CHD) may share the common risk factors and the genetic mechanism associated with interleukin(IL)-1A, B and RA genotype may be involved in the production of IL-1. This study was aimed to investigate the relationship between angiographically defined CHD and periodontitis as chronic Gram-negative bacterial infection and to determine whether the IL-1 gene polymorphism is associated in both diseases. Patients under the age of 60 who had undergone diagnostic coronary angiography were enrolled in this study. Subjects were classified as positive CHD (+CHD, n=37) with coronary artery stenosis more than 50% in at least one of major epicardial arteries, and negative CHD (-CHD, n=30) without significant stenosis. After recording the number of missing teeth, periodontal disease severity was measured by means of plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), and radiographic bone loss around all remaining teeth. Gingival crevicular fluid (GCF) was collected from the 4 deepest periodontal pockets and assessed for cytokine ($IL-1{\beta}$, IL-6, IL-1ra, tumor necrosis $factor-{\alpha}$, and prostaglandin $E_2$). Additionally, blood CHD markers, lipid profile, and blood cytokines were analyzed. IL-1 gene cluster genotyping was performed by polymerase chain reaction and enzyme restriction using genomic DNA from buccal swab, and allele 2 frequencies of IL-1A(+4845), IL-1B(+3954), IL-B(-511), and IL-1RA(intron 2) were compared between groups. Even though there was no significant difference in the periodontal parameters between 2 groups, GCF level of $PGE_2$ was significantly higher in the +CHD group(p<0.05). Correlation analysis showed the positive relationship among PD, CAL and coronary artery stenosis(%) and blood $PGE_2$. There was also significant positive relationship between the periodontal parameters (PI, PD, CAL) and the blood CHD markers (leukocyte count, C-reactive protein, and lactic dehyrogenase). IL-1 gene genotyping showed that IL-1A(+3954) allele 2 frequency was significantly higher in the +CHD group compared with the -CHD group (15% vs. 3.3%, OR 5.118,p=0.043). These results suggested that periodontal inflammation is related to systemic blood cytokine and CHD markers, and contributes to cardiovascular disease via systemic inflammatory reaction. IL-1 gene polymorphism might have an influence on periodontal and coronary heart diseases in Korean patients.

Sleep Habits and Insomnia-Associated Factors in Korean Adult Population: A Cross-sectional Survey of Three Rural Communities (한국 성인의 수면습관 및 불면증 관련 요인 : 3개 농촌지역주민을 대상으로 한 단시적 연구)

  • Jeong, Do-Un;Sohn, Chang-Ho;Sung, Joo-Hon;Chang, Song-Hun;Lee, Kun-Sei;Lee, Won-Jin;Shin, Hai-Rim;Lee, Bu-Ok;Cho, Soo-Hun
    • Sleep Medicine and Psychophysiology
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    • v.4 no.2
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    • pp.201-212
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    • 1997
  • Objectives: We attempted to study sleep habits and insomnia-associated factors in Korean rural adult population. Methods : In 1,441 adult subjects of three rural communities selected by cluster sampling, we administered an epidemiologic survey using questionnaire methods from July 14, 1996 to July 28, 1996. Results : 1) Mean sleep latency and mean time to sleep again after awakening during nocturnal sleep were longer in females than in males. Females suffered more frequently from insomnia symptom, awakening during nocturnal sleep. morning headache, dysphoric mood in the morning, and the feeling of 'not refreshed' on waking-up than males. 2) The older age group (defined as those older than 65 years) was found to have earlier bed-time, longer sleep latency, more frequent nocturia, longer time to sleep again after awakening during nocturnal sleep, and more frequent insomnia symptom. 3) The presence of insomnia symptom more than once a week was significantly associated with suffering from physical illness, being divorced-separated-widowed, frequently feeling depressed, nocturia, or low education level. 4) In multiple logistic regression analysis, old age, being female, low education level, frequently feeling depressed, and nocturia were independently associated with the presence of insomnia symptom more than once a week. Conclusion : We conclude that, in a Korean rural adult population, insomnia symptom increases with age and females usually suffer more from insomnia symptom than males. In addition, low education level, feeling depressed mood frequently, and nocturia are found to be significantly associated independently with the presence of insomnia symptom more than once a week.

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An Effect of Consumers' Types of Buying Behavior Values and Types of Price Discount on Product Attitude (소비자들의 구매행위 가치관 유형과 제품의 가격할인 유형이 제품태도에 미치는 영향)

  • Kim, Eun Hee;Kim, Hwa Dong
    • Journal of Digital Convergence
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    • v.12 no.10
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    • pp.135-144
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    • 2014
  • This study examined whether there is difference in consumers' product attitude according to the type of buying behavior values and the type of price discount among their lifestyle. First, the factors of values comprising consumers' buying behavior were derived as frugal buying, impulse buying, quality buying, and principle buying. Cluster analysis showed that the types of buying behavior value included high quality impulse buying, reasonable buying and practical buying. Second, it was found that there were differences in product attitude according to the type of consumers' buying behavior values. Third, interaction effect was found between the type of price discount and consumers' product attitude according to the type of buying behavior values. Fourth, among the factors of value comprising consumers' buying behavior, frugal buying factor has an effect on the product attitude with price discount of 50% and quality buying and impulse buying factors have an effect on the product attitude with bundle price discount (1+1). The above mentioned result of study suggests that when a company establishes a strategy of price discount, it should consider sales promotion strategy taking account of consumers' buying behavior values and type of product price discount.

Vegetation Structure of Mountain Ridge from Miwangjae to Cheonwhangbong in Weolchulsan National Park (월출산국립공원 미왕재-천황봉 구간의 능선부 식생구조)

  • Choo Gab-Cheul;Kim Gab-Tae;Cho Hyun-Seo
    • Korean Journal of Environment and Ecology
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    • v.20 no.2
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    • pp.114-121
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    • 2006
  • To investigate the vegetation structure of mountain ridge from Miwangjae to Cheonwhangbong, 11 plots($2000m^2$) set up with random sampling method were surveyed. Three groups of Quercus mongolica community, Quercus mongolica-Styrax japonica community, Q. mongolica-Pinus densiflora community were classified by cluster analysis. Quercus mongolica was a major woody plant species in the ridge area from Miwangjae to Cheonwhangbong, and Styrax japonica and Pinus densiflora was partly occupied. High positive correlations was proved between Prunus sargentii and Euonymus alatus for. ciliato-dentatus; Quercus serrata and Euonymus alatus; Sorbus alnifolia and Euonymus alatus, Magnolia sieboldii; Acer pseudo-sieboldianum and Euonymus alatus for. ciliato-dentatus; Rhododendron schlippenbachii and Euonymus alatus for. ciliato-dentatandus; Euonymus alatus and Lindera obtusiloba, Castanea crenata, Lindera erythrocarpa; Lespedeza bicolor and Rhododendron schlippenbachii; Castanea crenata and Magnolia sieboldii; Magnolia sieboldii and Lindera erythrocarpa, and relatively high negative correlations was proved between Rhododendron schlippenbachii and Euonymus alatus; Lespedeza bicolor and Castanea crenata; Stephanandra incisa and Magnolia sieboldii; Rhododendron yedoense var. poukhanense and Lindera erythrocarpa; Euonymus alatus for. ciliato-dentatus and Magnolia sieboldii; Fraxinus sieboldiana and Sapium japonicum; Prunus sargentii and Lespedeza maximowiczii; Lespedeza maximowiczii and Lindera erythrocarpa. Species diversity(H') of investigated groups was ranged $2.3225{\sim}2.7721$, and it was relatively low value compared to that of mountain ridge area of other national parks.

Vegetation Structure of Mountain the Region from Wolgagsan to Dogabjae in Weolchulsan National Park Korea (월출산국립공원 월각산-도갑재 지역의 산림 능선부 식생구조)

  • Kim Gab-Tae;Choo Gab-Cheul;Kim Jung-Oh
    • Korean Journal of Environment and Ecology
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    • v.20 no.2
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    • pp.122-129
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    • 2006
  • To investigate the vegetation structure of mountain region from Wolgagsan to Dogabjae, 14 plots($2000m^2$) set up with random sampling method were surveyed. Two groups of Quercus variabilis-Pinus densiflora community, Quercus mongolica-Quercus acutissima community were classified by cluster analysis. Quercus variabilis, Pinus densiflora, Quercus mongolica, Quercus acutissima, Quercus dentata and Quercus serrata were found as a major woody plant species in Weolchulsan National Park region. In this area, Quercus variabilis and Pinus densiflora were dominated partially. In the future, the importance percentage of Pinus densiflora might be decreased, but those of Quercus variabilis, Quercus mongolica, Quercus acutissima and Quercus dentata might be increased. High positive correlations was proved between Quercus variabilis and Pinus rigida; Styrax japonica and Quercus dentata, Quercus acutissima; Pinus rigida and Lindera erythrocarpa, Pinus densiflora; Lindera obtusiloba and Rhododendron mucronulatum; Albizzia julibrissin and Styrax obassia, and relatively high negative correlations was proved between Diospyros kaki and Quercus dentata; Platycarya strobilacea and Lindera erythrocarpa; Symplocos chinensis for. pilosa and Quercus acutissima; Styrax japonica and Styrax obassia; Pinus rigida and Lindera obtusiloba, Fraxinus sieboldiana, Rhododendron mucronulatum; Quercus mongolica and Albizzia julibrissin. Species diversity(H') of investigated groups was ranged $1.2430{\sim}1.2892$.

Vegetation Structure of Mountain Ridge from Songchu to Dobong in the Bukhansan National Park, Korea (북한산국립공원 도봉산 송추-도봉 구간의 능선부 식생구조)

  • Um, Tae-Won;Kim, Gab-Tae
    • Korean Journal of Environment and Ecology
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    • v.22 no.2
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    • pp.106-112
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    • 2008
  • To investigate the vegetation structure of the mountain ridges ranging from Songchu to Dobong, this research set up 22 plots$(400m^2)$ as survey target areas. As a result of the analysis of woody plant cluster, it was classified as two groups-Quercus mongolica community and Quercus mongolica-Pinus densiflora community. Quercus mongolica was found as a mostly dominant woody plant species in the ridge areas from Songchu to Dobong, while Pinus densiflora, Quercus serrata and Quercus acutissima were mixed up partly in low altitudes. High negative correlations were shown between Quercus mongolica and Quercus serrata, Quercus serrata and Acer pseudosieboldianum, Pinus densiflora and Acer pseudosieboldianum, and relatively high positive correlations were found to exist between Quercus acutissima and Quercus serrata; Quercus mongolica and Rhododendron mucronulatum; Pinus rigid a and Rhododendron schlippenbachii; Sorbus alnifolia and Rhododendron mucronulatum; Pinus rigida and Pinus densiflora; Pinus densiflora and Robinia pseudoacacia; Acer pseudosieboldianum and Styrax obassia; Magnolia sieboldii and Symplocos chinensis. Species diversity index(H') by community at the surveyed areas stayed in the scope of $0.997\sim1.160$, which indexes showed nothing different from the vegetation structure of other national parks.

Promoting Technology Convergence in Industrial Clusters through Intellectual Property Service Center (산업클러스터 기술융합 활성화를 위한 효율적인 지식재산서비스 지원 방안 연구)

  • So, Byeong-Woo;Gong, Byeong-Yeong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.6 no.1
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    • pp.133-158
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    • 2011
  • In 2030s, as we enter in to the era of BT (Bio-Technology) market opening up, technologies in all areas such as IT, data analysis, IC and biochemistry are necessitated. New development in technology will be based on "Convergence", especially between IT and BT. In order to have synergy effects from the convergence, those related industries and universities should be physically inter-related in an appropriate location. Until 2009, 819 industrial clusters where many Korean industries and firms are concentrated have been constructed in Korea. They have had supports from various institutions and facilities. However, few systems designed to assist "intellectual property (IP) service" for technology convergence are found in Korea. Thus, by analyzing current problems and challenges of the Korean industrial clusters, this paper suggests a possible answer to maximize the synergy from technology convergence through organic cooperation among companies in industrial clusters. This paper finds that the Korean industrial clusters need to establish IP service supporting center while suggesting its function and concept on organization structure, and work flow, which help firms to develop IP strategies. In addition, the paper provides a direction for current IP system and policies implemented by the Korean government to be more effective to small-and-medium-sized companies located in the industrial clusters.

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