• The Journal of the Petrological Society of Korea
• /
• v.27 no.1
• /
• pp.1-15
• /
• 2018

The characteristics of the rock cleavage of Jurassic Geochang granite were analysed using the distribution of microcrack lengths and spacings. The length and spacing-cumulative diagrams for the six directions of rock cleavages were arranged in increasing order ($H2{\rightarrow}R1$) on the density (${\rho}$) of microcrack length. The various parameters were extracted through the combination of above two types of diagrams. The evaluation for the six directions of rock cleavages was performed using the four groups (I~IV) of parameters such as (I) intersection angle (${\alpha}-{\beta}$), exponent difference (${\lambda}_S-{\lambda}_L$), length of line (ol and ll'), length ratio (ol/os and ll'/sl'), mean length ((ss'+ll')/2), area of right-angled triangle (${\Delta}oaa_a^{\prime}$ and ${\Delta}obb_a^{\prime}$) and area difference (${\Delta}obb^{\prime}-{\Delta}oaa^{\prime}$ and ${\Delta}obb_a^{\prime}-{\Delta}oaa_a^{\prime}$), (II) length of line (oa and os) and area (${\Delta}oaa^{\prime}$), (III) length of line (sl') and length ratio (ss'/ll') and (IV) length of line (ob, ss' and ls') and area (${\Delta}obb^{\prime}$, ${\Delta}ll^{\prime}s^{\prime}$, ${\Delta}ss^{\prime}l^{\prime}$ and ⏢ll'ss'). The results of correlation analysis between the values of parameters for three rock cleavages and those for three planes are as follows. The values of parameters for three rock cleavages are in orders of (I) H(hardway, (H1 + H2)/2) < G(grain, (G1 + G2)/2) < R(rift, (R1 + R2)/2), (II) R < G < H, (III) G < H < R and (IV) H < G < R. On the contrary, the values of parameters for three planes are in orders of (I) R' < G' < H', (II) H' < G' < R' and (III and IV) R' < H' < G'. Especially the values of parameters belonging to group I and group II show mutual reverse orders. In conclusion, this type of correlation analysis is useful for discriminating three quarrying planes.

• Fire Science and Engineering
• /
• v.17 no.1
• /
• pp.8-20
• /
• 2003

Natural gas has been supplied through underground pipelines and valve stations as a new city gas in Seoul. In contrast to its handiness the natural gas has very substantial hazards due to fires and explosions occurring from careless treatments or malfunctions of the transporting system. The main objectives of this study are to identify major hazards and to perform risk assessments after assessing reliabilities of the composing units in dealing with typical pipeline networks. there-fore two method, fault tree analysis ;1nd event tree analysis, are used here. Random valve stations are selected and considered its situation in location. The value of small leakage, large rupture, and no supply of liquefied natural gas is estimated as that of top event. By this calculation the values of small leakage are 3.29 in I)C valve station, 1.41 in DS valve station, those of large rup-lure are $1.90Times10_{-2}$ in DC valve station, $2.32$\times$10^{-2}$ in DS valve station, and those of no supply of LNG to civil gas company are $2.33$\times$10 ^{-2}$ , $2.89$\times$10^{-2}$ in each valve station. And through minimal cut set we can find the parts that is important and should be more important in overall system. In DC valve station one line must be added between basic event 26,27 because the potential hazard of these parts is the highest value. If it is added the failure rate of no supply of LNG is reduced to one fourth. In DS valve station the failure rate of basic event 4 is 92eye of no supply of LNG. Therefore if the portion of this part is reduced (one line added) the total failure rate can be decreased to one tenth. This analytical study on the risk assessment is very useful to prepare emergency actions or procedures in case of gas accidents around underground pipeline networks and to establish a resolute gas safety management system for loss prevention in Seoul metropolitan area.

• Korean Journal of Microbiology
• /
• v.41 no.1
• /
• pp.24-37
• /
• 2005

This study was conducted to analyze the molecular epidemiological properties and to select the most efficient and reliable PCR method on 116 of Staphylococcus aureus (S. aureus) isolates from Korean cattle, black goat, pig, dog, chicken, mouse and also human clinical cases from hospital. The distribution patterns of SSG [species specific genes; coagulase (coa), protein A (spa), nuclease (nuc) and aroA (RsaI) gene] were analyzed by PCR method. Among the SSGs, the nuc-gene was found in all strains $(100\%)$ tested and followed by coa-gene $(87.9\%)$, spa-gene $(91.4\%)$ and aroA-gene $(26.7\%)$, in order. The genetic subtyping by RFLP method was performed on the coa [AluI] and aroA-gene [RsaI] PCR products. The mecA-gene PCR and PCR-RFLP techniques were chosen to detect and verify of MRSA strains. Only the human strains $(12.1\%)$ were detected the positive mecA-gene products (533 bp), which were divided into two specific bands [201 & 332 bp] by HhaI enzyme digestion. On coa-gene and spa-gene typing, coa-gene was typed with ten kinds of genotype and coa-3 type were determined as the most predominant genotype, while spa-gene was divided into eleven kinds of genotype and also spa-7 type were selected the most prevalent genotype based on their genetic variations. On the aroA and coa-gene subtyping by PCR-RFLP, aroA-gene products were discriminated with only seven types of genotype, while coa-gene products were further divided into an eleven genotype, respectively. In comparison of SID values of five PCR based typing methods, the coa-PCR-RFLP (SID0.894) was evaluated the most efficient and reliable tools and followed by coa-PCR (SID0.883) and aroA-PCR-RFLP (SID0.462), in order. In conclusion, we could determined that the coa-PCR-RFLP method was the most suitable genetic analysis tool for S. aureus and MRSA strains from domestic animals and humans.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.3
• /
• pp.366-373
• /
• 2005

This study was carried out to investigate the self-reported health and eating habit of the elite female adolescent athletes in Incheon. The subjects were 102 elite female athletes of middle and high schools located in Inchon. A self-administered Questionnaire was used for this cross-sectional survey. Statistical analysis by two-way ANOVA was performed to discriminate between the main effects of age (as middle and high school athletes) and sports type, and their interaction. As use of nutritional supplements, 35.8% of the total subjects took vitamin and iron supplements and 62.5% of field and track athletes took vitamin and iron supplements. While mental stress related to exercise was much in fencing ＆gt; shooting ＆gt; field and track ＆gt; swimming athletes, physical burden during training was higher in swimming ＆gt; field and track ＆gt; fencing ＆gt; shooting athletes. More than half of the subjects showed irregular menstrual cycle. As the most severe problem of eating habit, they reported skipping meal ＆gt; overeating ＆gt; prejudiced meal ＆gt; preference to salty and spicy foods. More than half of the subjects skipped meal over three times per week. Fencing and shooting athletes showed very significantly higher frequency of skipping meal and more irregular breakfast time compared to those of other sport types. As for snack, they ate cookies, carbonated drink, chocolate, candy ＆gt; milk, yogurt, ice cream ＆gt; cake, bread, rice cake ＆gt; fried noodle ＆gt; hamburger, pizza. Therefore, nutritional counseling and education by sport type are necessary for health and good eating habit of these elite female adolescent athletes.

• Journal of Korean Society of Forest Science
• /
• v.86 no.4
• /
• pp.489-501
• /
• 1997

This research was conducted to analyze the influence of the environmental factors on water quality such as pH, dissolved oxygen, and electrical conductivity of rainfall, throughfall, soil water(A and B layer), and stream water quality at a small forested watershed. Rainfall, throughfall, soil water(A and B layer), and stream water were sampled at the study sites in Kwanak Arboretum, Seoul National University in Mt. Kwanak for 14 months(Jul. 1, 1996~Aug. 31, 1997). Average rainfall pH value was 6.06(ranged from 5.02 to 6.60). Acid rain frequency(less than pH 5.6) was 16.7%. The lowest rainfall pH value was 5.02. Average of pH values in hydrological processes were decreasing in the following order, stream water>soil water [Prunus serrulata var, spontanea(B layer>A layer)]>throughfall(Prunus serrulata var. spontanea)>soil water [Carpinus laxiflora(B layer >A layer)]>throughfall(Carpinus laxiflora)>rainfall>soil water [Pinus rigida(B layer>A layer)]>throughfall(Pinus rigida). pH values of throughfall in Prunes serrulata var. spontanea and Carpinus laxiflora were higher in Pines rigida. Average of dissolved oxygen values in hydrological processes were decreasing in the order, stream water>throughfall(Carpinus laxiflora>Prunus serrulata var, spontanea>Pines rigida)>rainfall>soil water [Prunes serrulata var. spontanea(A layer)>Pines rigida(A layer)>Carpinus laxiflora(A layer)>Prunes serrulata var. spontanea(B layer)>Pines rigida(B layer)>Carpinus laxiflora(B layer)]. And average electrical conductivity values in hydrological processes were decreasing in the order, soil water (B layer>A layer)>throughfall(Pinus rigida>Prunes serrulata var, spontanea>Carpinus laxiflora)>stream water>rainfall. Multiple regression equations of electrical conductivity and $Mg^{2+}$, $Na^+$, total amount of cation, total amount of ion, and no. of before non-rain days in rainfall, throughfall, soil and stream water shows high significance(Multi R; 0.84).

• Journal of agricultural medicine and community health
• /
• v.42 no.3
• /
• pp.132-144
• /
• 2017

Objectives: The purpose of this study was to identify the association between satisfaction with assistive technology devices and psychosocial impact among some mentally or physically disabled children. Methods: The study subjects were 120 disabled children and their primary caregivers who were using rental assistive technology devices in Gwangju and Jeollanam-Do. Data were collected by structured questionnaire composed of general characteristics of subjects, characteristics related with using assistive devices. Quebec User Evaluation of Satisfaction with assistive Technology 2.0 (QUEST 2.0) and Psychosocial Impact of Assistive Device Scale (PIADS). The statistical analysis were performed by descriptive statistics, t-test, ANOVA and Pearson's correlational analysis. Results: The total mean score for QUEST 2.0 was $4.08{\pm}0.66$ (satisfaction with devices, $4.01{\pm}0.70$; satisfaction with the assistive devices service, $4.14{\pm}0.90$) and the mean of PIADS was $1.00{\pm}0.75$ (ability, $0.99{\pm}0.78$; adaptability, $1.04{\pm}0.86$; self-respect, $0.99{\pm}0.74$). The scores of PIADS was statistically significant difference according to usage time of assistive devices. The PIADS was significantly positive correlated with QUEST 2.0 Conclusions: The mentally or physically disabled children reported that the higher level of satisfaction and the more positive impact of psychosocial aspect with assistive technology devices. It would be necessary to perform further studies for addressing the effects of assistive technology devices.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.6
• /
• pp.836-842
• /
• 1999

Background: Mixed obstructive and restrictive pattern of spirometry can not be concluded in the presence of true restrictive disorders because pure obstructive disorders can also show reduced vital capacity. However, it is not known how many patients with mixed spirometric pattern really have restrictive disorders in Korea whose pattern of pulmonary diseases is somewhat different from foreign countries. To answer this question, I performed this study and tried to answer it according to diseases in addition. Method: Test results from 413 patients who undergone both spirometry and lung volume measurements on the same visit from August 1, 1998 to July 31, 1999 were included. Spirometry data were classified as mixed obstructive-restrictive pattern when spirometry showed '$FEV_1/FVC$<70% (<65% if age$\geq$60)' and FVC<80% of predicted value'. TLC by the method of nitrogen washout was considered as gold standard to diagnose restrictive disorders in which TLC is less than 80% of predicted value. Results: Out of 404 patients who could be evaluated, 58 had mixed pattern of spirometry. 58 patients were suffered from airway diseases(39 patients) such as COPD(22 patients, 38%), asthma(11, 19%), bronchiectasis (6,10%), and sequelae of pulmonary tuberculosis(15, 26%) or other diseases(4,7%). Only 18 out of 58(31%) were confirmed to have true restrictive disorders by TLC. The proportion of true restrictive disorders was different according to diseases, 20.5%(8/39patients) in patients with airway diseases and 53.3%(8/15) with sequelae of pulmonary tuberculosis(p<0.05). Conclusion: Many patients whose spirometry showed mixed pattern didn't have restrictive disorders but had pure obstructive disorders. This was true for more patients with airway diseases. Therefore it would be prudent that lung volume be tested to diagnose restrictive disorders in patients with mixed spirometric pattern.

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.2
• /
• pp.169-178
• /
• 2000

Background : Usually fever subsides within one week in over 90% of pulmonary tuberculosis (TBp) patients after the start of short-course anti-tuberculosis therapy, but occasionally it persists over two weeks after treatment. When the fever persists, drug resistance, combined infection, or drug fever, and so on, are considered as an etiology and, in some cases, drugs are changed. But inadvertent discontinuation of a short-course regimen inevitably will extend the duration of treatment, and the treatment completion may be delayed. This study was performed to investigate the causes of prolonged fever (PF) and to identify the predictors of PF in drug-susceptible TBp patients in Korea. Method : Five hundred-ninety-eight patients, who were admitted to Asan Medical Center from January 1996 to March 1999, diagnosed with TBp and prescribed short-course, anti-tuberculosis treatment, were reviewed. PF was defined as having fever over two weeks despite treatment. The causes of PF were analyzed. Drug-sus-ceptible TBp patients who presented no causes for PF, except turberculosis itself, were selected(n=22), and they were compared with those who had no fever at diagnosis (n=22) and those who had fever at diagnosis, which had subsided within two weeks after treatment (n=22). Clinical, laboratory, and radiological parameters were compared among the three groups. Results : Twenty-eight (4.8%) of 598 patients showed PF over two weeks despite short-course treatment. The causes of PF were drug fever (n=2), multi-drug resistant tuberculosis (n=3), disseminated Mycobacterium kansasii infection (n=1), and drug-susceptible tuberculosis itself (n=22). The patients with PF had more risk factors for tuberculosis, long duration of symptoms before treatment, night sweats, weight long, numerous acid fast bacilli on sputum smear, anemia, hyponatremia, hypoalbuminemia, over three lung cavity numbers and extensive infiltration, indicating that they had prolonged and extensive lung diseases. Conclusion : The main cause of PF in TBp despite short-course regimen seems to be drug-susceptible but extensive disease in Korea. Any changes to the drug regiment provided for TBp patients with prolonged fever despite treatment should be carefully considered.

• Journal of Korean Home Economics Education Association
• /
• v.19 no.2
• /
• pp.1-12
• /
• 2007

This study analyzed the recognition and utilization regarding teacher's guidebook for middle school technology-home economics class in the 7th Educational Curriculum. The data were collected via e-mail to teachers teaching home economics in middle schools. These e-mail addresses were acquired from middle school web pages registered on the Educational Board. The 355 data were analyzed using the SPSS program. The results were as follows: First, teachers recognized highly the necessity of teacher's guidebook. However, as the actual guidebook was not adequately helpful, the overall degree of satisfaction was relatively low. Teachers utilizing guidebook had more positive recognition on teacher's guidebook than teachers who did not. And teachers majored in technology education thought teacher's guidebook more helpful compared with teachers majored in home economics education. Second, teachers referenced teacher's guidebook mostly for field practice guidance. Third, teachers who did not utilize teacher's guidebook used other reference materials such as Internet Web sites and audiovisual materials. They were most commonly used for the reason that the contents were ample and easy to access. Fourth, the followings were suggested to improve teacher's guidebook. The provision of learning contents that can be practically used in class, the various samples of teaching-learning method, the specified methods of planning and criteria for performance assessment, the adequate supplementations regarding textbook contents, and the improvement of the outward layout format of the guidebook.

• Journal of Intelligence and Information Systems
• /
• v.19 no.4
• /
• pp.97-121
• /
• 2013

With the growing importance of knowledge for sustainable competitive advantages and innovation in a volatile environment, many researches on knowledge sharing have been conducted. However, previous researches have mostly relied on the questionnaire survey which has inherent perceptive errors of respondents. The current research has drawn the relationship among primary participant behaviors towards the participation level in knowledge sharing, basically from online user behaviors on Wikipedia, a representative community for online knowledge collaboration. Without users' participation in knowledge sharing, knowledge collaboration for creating knowledge cannot be successful. By the way, the editing patterns of Wikipedia users are diverse, resulting in different revisiting periods for the same number of edits, and thus varying results of shared knowledge. Therefore, we illuminated the participation level of knowledge sharing from two different angles of number of edits and revisiting period. The behavioral dimensions affecting the level of participation in knowledge sharing includes the article talk for public discussion and user talk for private messaging, and community registration, which are observable on Wiki platform. Public discussion is being progressed on article talk pages arranged for exchanging ideas about each article topic. An article talk page is often divided into several sections which mainly address specific type of issues raised during the article development procedure. From the diverse opinions about the relatively trivial things such as what text, link, or images should be added or removed and how they should be restructured to the profound professional insights are shared, negotiated, and improved over the course of discussion. Wikipedia also provides personal user talk pages as a private messaging tool. On these pages, diverse personal messages such as casual greetings, stories about activities on Wikipedia, and ordinary affairs of life are exchanged. If anyone wants to communicate with another person, he or she visits the person's user talk page and leaves a message. Wikipedia articles are assessed according to seven quality grades, of which the featured article level is the highest. The dataset includes participants' behavioral data related with 2,978 articles, which have reached the featured article level, with editing histories of articles, their article talk histories, and user talk histories extracted from user talk pages for each article. The time period for analysis is from the initiation of articles until their promotion to the featured article level. The number of edits represents the total number of participation in the editing of an article, and the revisiting period is the time difference between the first and last edits. At first, the participation levels of each user category classified according to behavioral dimensions have been analyzed and compared. And then, robust regressions have been conducted on the relationships among independent variables reflecting the degree of behavioral characteristics and the dependent variable representing the participation level. Especially, through adopting a motivational theory adequate for online environment in setting up research hypotheses, this work suggests a theoretical framework for the participation level of online knowledge sharing. Consequently, this work reached the following practical behavioral results besides some theoretical implications. First, both public discussion and private messaging positively affect the participation level in knowledge sharing. Second, public discussion exerts greater influence than private messaging on the participation level. Third, a synergy effect of public discussion and private messaging on the number of edits was found, whereas a pretty weak negative interaction effect of them on the revisiting period was observed. Fourth, community registration has a significant impact on the revisiting period, whereas being insignificant on the number of edits. Fifth, when it comes to the relation generated from private messaging, the frequency or depth of relation is shown to be more critical than the scope of relation for the participation level.