• Journal of Korean Society of Forest Science
• /
• v.102 no.3
• /
• pp.407-414
• /
• 2013

This study was conducted to classify forest cover types using the multivariate statistical analysis in the natural forest of western Mt. Jiri. On the basis of the vegetation data by point quarter sampling, the adopted analytical methods were species-area curve (SAC), hierarchical cluster analysis (HCA), indicator species analysis (ISA), and multiple discriminant analysis (MDA). SAC selected the outlier tree species which was likely to have no influence on the classification of forest cover types, excluded from all analytical process. Based on forest vegetative information, HCA classified the study area into 2 to 10 clusters and ISA indicated that the optimal number of clusters were seven. MDA was taken to test the clusters that classified with HCA and ISA. The seven clusters were classified appropriately as overall classification success were 91.3%. The classified forest cover types were named by the ratio of the dominant species in the upper layer of each cluster. They were (1) Quercus mongolica Pure forest, (2) Mixed mesophytic forest, (3) Q. mongolica - Q. serrata forest, (4) Abies koreana - Q. mongolica forest, (5) Fraxinus mandshurica forest, (6) Q. serrata forest, and (7) Carpinus laxiflora forest.

• Environmental Mutagens and Carcinogens
• /
• v.16 no.1
• /
• pp.1-5
• /
• 1996

Fumonisin B$_1$ is hepatotoxic in all species, but liver carcinogenic and nephrotoxic in rat. Our objective was to investigate the effects of multiple iv dose of FB$_1$. Male Sprague-Dawley rats were injected intravenously (iv) with FB$_1$ at 1 mg/kg singly (T1), or daily for 2 (T2) or 3 (T3). T1 rats did not show any cytotoxicity in both liver and kidney. However, the most dramatic change occurred in this group was mitotic figures in liver, which increased 5.5-fold to that of control. Hepatotoxic effects were shown in T3, based on histopathology and serum chemistry. A few scattered single cell deaths occurred primarily in the centrilobular area of the liver in T2. Similar but more lesions in liver and a small number of degenerating cells with hypereosinophilic cytoplasm in outer stripe of medulla of kideny were found in T3 rats. Serum chemical profiles included liver enzymes increased, in which cholesterol was very sensitive. This study suggests that multiple exposure of low dose FB$_1$ cause cytotoxic in the liver earlier time point than kideny. FB$_1$$ also stimulates mitosis in liver that may be associated with carcinogenesis.

• Journal of Korean Society of Forest Science
• /
• v.107 no.2
• /
• pp.218-228
• /
• 2018

This study was carried out to investigate the recognition and requirements of mountain eco-tourism by surveying mountain villages'visitors. As a feasibility study to introduce new eco-tourism policies, the individual interview survey was conducted from June 17, 2015 to September 17, 2015 targeting 439 visitors in 57 mountain villages, where the Korea Forest Service designated them as mountain eco-villages and the Ministry of Agriculture, Food and Rural Affairs has been operating the rural experience and recreation village business. As a result of the major analysis, the respondents'intention to participate in mountain eco-tourism was 3.65 by Likert 5-point-scale and the respondent's most preferred the number of visits was once a year(44.6%) or twice a year(30.1%). Also, the most preferred region was Gangwon-do(44.8%) and the average amount of expense willing to pay was 153,320 won. Lastly, the respondents said they expect development of regional tourism product(M=3.99) and mountain eco-tourism program(M=3.96) by requirements for mountain eco-tourism. This result shows that it is necessary to inspire public awareness regarding the value of mountain eco-tourism and to develop new policies or programs making people more attracted to mountain villages. Thus, it means that mountain eco-tourism can be utilized as a way to steer sustainable mountain village.

• Journal of Broadcast Engineering
• /
• v.13 no.6
• /
• pp.781-795
• /
• 2008

This paper focuses on effects that IPTV will have on domestic broadcasting market in the point of view of customers. The purpose of the paper is to present the future landscape of competitive media market when IPTV is launched, and to research how IPTV will have impact on terrestrial broadcasting, cable TV and satellite broadcasting industry. The paper integrates two known theories, such as the niche-gratification model and the value-expectancy model, to analyze competitive media market. The value expected model makes it possible to overcome the weakness of the niche-gratification model and to forecast competitiveness more accurately. According to this research, competitive power will be in the order of Cable TV, IPTV, and satellite broadcasting. Terrestrial broadcasting does not show strong competitive relationships with others statistically. As a result, Cable TV will be the most competitive medium in the future. IPTV will be stuck in the middle and can rapidly substitute for existing broadcasting services. While IPTV will severely threaten the satellite broadcasting company which has a relatively small number of subscribers, cable TV will be in a superior position to IPTV.

• The Journal of Internal Korean Medicine
• /
• v.37 no.1
• /
• pp.77-89
• /
• 2016

Objectives: The aim of this study was to develop a standard instrument of pattern identification and evaluation for chemotherapy-induced peripheral neuropathy (CIPN).Methods: The advisory committee for this study was organized by 12 professors of traditional Korean medicine from the Korean Association of Traditional Oncology. The items and structure of the instrument were designed based on a review of previous publications. We revised the instrument in consultation with the advisory committee and received additional advice via email.Results: We divided the symptoms and signs of CIPN into four pattern identifications: wind arthralgia (風痺), cold arthralgia (寒痺), dampness arthralgia (濕痺), and arthralgia of the deficiency type (虛痺). We obtained the mean weights to reflect the standard deviations from each symptom of the four pattern identifications, which were scored on a 5-point scale by the advisor committee. After we obtained the answers to discrimination between variable symptoms (變症) and ordinary symptoms (素症) from the 12 experts, we gained the final weight from the combination of the ratio of pattern identification to the number of total answers of the advisory committee and the mean weight.Conclusions: The Instrument on Pattern Identification and Evaluation for CIPN was developed through a discussion between 12 experts. There was a limitation that the validity and reliability of this instrument have not been proven. However, the significance of this study was that it is the first Instrument on Pattern Identification and Evaluation aimed at assessing CIPN in traditional Korean medicine.

• Fire Science and Engineering
• /
• v.33 no.3
• /
• pp.56-62
• /
• 2019

This study examined effects of the operating characteristics of a pump according to the rotational speed of a pump and the change in flow rate when a centrifugal pump operates under the following conditions: regulated flow rate, head, rotational speed, and specific speed of 0.7 m/min, 8 m, 1750 rpm, an 182 (m, ㎥/min, rpm), respectively. The pump in the experiment did not have a guide vane and was connected directly to the rim, so that the rotational speed of the volute pump in a spiral or volute casing increased by 100 rpm from 1350 to 1750 rpm. The result of the relationship between the H-Q, L-Q, and 𝜂-Q characteristics and the dimensionless performance characteristics, such as the head coefficient, power coefficient and efficiency were studied. The change in pump performance could be estimated depending on the increase in the number of revolutions. The maximum efficiency of the pump was 52% with 1450 rpm, 0.165 ㎥/min flux, and 4.73 m of lift. The efficiency reached 50% with a maximum of 1750 rpm, 0.183 ㎥/min of flux, and 6.72 m of lift. The efficiency curve on the performance characteristics of the lift versus flux curve became oval not a curve from a quadratic equation that passes through the starting point according to the similarity law of the pump. Finally, when the flux coefficient increased, the power coefficient increased and the lift coefficient decreased. When the flux coefficient was 0.08, the maximum efficiency was 52%. Therefore, the change in flux affects the driving characteristics.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.2
• /
• pp.103-114
• /
• 2013

This paper suggests a method to reduce the number of performances of Kruskal and Reverse-delete algorithms. Present Kruskal and Reverse-delete algorithms verify whether the cycle occurs within the edges of the graph. For this reason, they have problems of unnecessarily performing extra algorithms from the edges, even though they've already obtained the minimum spanning tree. This paper, first of all, suggests the 1st method which reduces the no. of performances by introducing stop point criteria of algorithm, but at the same time, performs algorithms from all the edges, just like how Kruskal and Reverse-delete algorithms. Next, it suggests the 2nd method which finds the minimum spanning tree from the remaining edges after getting rid of all the unnecessary edges which are considered not to affect the minimum spanning tree. These suggested methods have an effect of terminating algorithm at least 1.4 times and at most 3.86times than Kruskal and Reverse-delete algorithms, when applied to the real graphs. We have found that the 2nd method of the Reverse-delete algorithm has the fastest speed in terminating an algorithm, among 4 algorithms which are results of the 2 suggested methods being applied to 2 algorithms.

• The Journal of Korean Society for School & Community Health Education
• /
• v.1 no.2
• /
• pp.105-125
• /
• 2000

The purpose of this study was to examine the influence of school safety accident on teacher's normal educational activities and to seek some desirable ways to cope with it. The subjects in this study were 351 class teachers randomly selected from Seoul and Kyonggi Province and surveyed from April through July, 2000. The conclusions were as follows; 1. Actual Condition of School Safety Accident 1) Approximately many teachers investigated had had an experience to suffer safety accident. Safety accident occurred most during break or class, but there was a significant difference according to service area. 2) Safety accident took place most in playground, and the most common cause was student's own carelessness, and the most widely occurred accident type was an injury. But there was no significant difference caused by the general characteristics of the teachers. 2. Influence of Safety Accident On Teacher's Educational Activities. 1) The largest reason they offered safety education was to ensure student safety. The greatest number of them had an opinion they would consider changing or giving up a planned normal educational activity if they recognized any possibilities of safety accident. There was a significant difference in this point according to gender and career. 2) They worried about possible safety accident most during field study, but there was a significant difference according to gender or presence or absence of safety accident experience. 3) The general characteristics of teacher produced a significant difference to an experience of avoiding educational activity due to psychological withdrawal, but safety accident experience didn't make any difference. 3. Minimization of Teacher Damage or Loss from Safety Accident. 1) The dominant opinion about teacher's small mistake for any occurrence of safety accident was that the responsibility should be escaped to maintain teacher's authority. For severe mistake, however, there were two different opinions at the same percentage: one was being exempted and the other was taking civil liability. 2) Establishing teacher insurance was preferred as a way to minimize teacher's economic loss from safety accident, but there was a significant difference according to gender. 3) The dominant opinion about the payment of insurance premium for safety accident was that it should be paid from school operating expenses.

• Journal of Korean Society of Forest Science
• /
• v.96 no.1
• /
• pp.107-114
• /
• 2007

Establishments of the seedlings inside the natural forest from adjacent artificial forests would be an important factor in forest stand dynamics. This study was conducted to see the invasion of Korean pine (Pinus koraiensis) seedlings which is not native in this region, into the natural deciduous broad-leaved forest in Gwangneung, Korea. There is no mother tree at the I ha study site while the number of naturally regenerated P. koraiensis seedlings was 345 trees and 56% of them were clumped with more than two seedlings at each point. Applying the image segmentation method to IKONOS satellite image of January, 2003, the distance from the center of 1 ha study site to the nearest mother tree and plantation of Korean pine were 200 m and 270 m, respectively. The average height and root-collar diameter of the seedlings were 34 em and 7 mm, respectively and the age of 207 seedlings (60%) were below 5 years old. Most abundant range of soil moisture gradient and LAl (leaf area index) were from 16 to 20% and those of LAI were from 3.1 to 3.5. To understand the dynamics and seed dispersal pattern of Korean pine in the Gwangneung natural deciduous broad-leaved forests, additional studies not only long-term monitoring of growth and mortality of naturally regenerated Korean pine seedlings but also application of stable isotope analysis and molecular genetic techniques was recommended.

• Journal of the Korean Geographical Society
• /
• v.40 no.6 s.111
• /
• pp.770-788
• /
• 2005

In this article, major research trends are examined mainly from articles published in Journal of the Korean Geography, academic society journals of sub-fields in geography and Ph.D. dissertations in geography of universities in Korea. Based on the research trends up to current point, issues and research directions in order to raise the status of Korean Geography in the twenty first century are prospected. Sixty years of Korean Geography can be divided into 4 periods such as before 1970s, during the 1980s, during the 1990s, and the period after the 2001. Each period of time revealed distinct aspects of development both quantitatively and qualitatively. For the last 60 years, the study of Korean Geography has gone through enormous changes in the number of articles with dynamics and variety in contents and methodology, breathing with the changes of the Korean society. Experiencing urbanization and industrialization along with rapid economical growth, the study of Korean Geography has progressed by analyzing the issues and problems of national space and conducting various researches from the case studies for problem-solving to the theoretical and policy oriented studies. The key-words such as 'knowledge based information society', 'aged society', and 'the era of globalization' will be realized in the twenty flit century. And environment-friendly policies for sustainable development will be more stressed in a globalized world. In order to provide research methods and alternatives suitable for newly transformed global society and for utilizing the essence of Geography in the future, the studies on Korean Geography should actively focus on integrative studies between physical and human geography, on interdisciplinary studies, on regional studies related to foreign countries and North Korea, and on the establishment of Korean geographical theory and model.