• Title/Summary/Keyword: Stress Pattern

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Comparison of Hsp90 and CYP1A Expression Patterns by Water Temperature Stress in Atlantic Salmon (Salmo salar) (대서양 연어(Salmo salar)의 수온 스트레스에 의한 Hsp90 및 CYP1A 발현 양상 비교)

  • Kang, Han Seung;Song, Jae-Hee;Kang, Hee Woong
    • Journal of Marine Life Science
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    • v.3 no.2
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    • pp.51-58
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    • 2018
  • Variations in water temperature are known to affect almost every part of fish physiology. The rise in water temperature due to climate change can physically damage fish. This study was conducted to evaluate the health status of the Atlantic salmon (Salmo salar) at high water temperature (20℃) than the optimum water temperature (15℃). Liver tissue exerts important metabolic functions in thermal adaptation. Therefore, liver tissue was used in this study. The evaluation method is to develop the biomarker gene using NGS RNAseq analysis and to examine the expression pattern using RT-qPCR analysis. The NGS RNAseq analysis revealed 1,366 differentially expressed genes, among which 880 genes were increase expressed and 486 genes were decrease expressed. The biomarker genes are such as heat shock protein 90 alpha (Hsp90α), heat shock protein 90 beta (Hsp90β) and cytochrome P450 1A (CYP1A). The selected genes are sensitive to changes in water temperature through NGS RNAseq analysis. Expression patterns of these genes through RT-qPCR were similar to those of NGS RNAseq analysis. The results of this study can be applied to other fish species and it is considered to be useful industrially.

Three-Dimensional Numerical Simulations of Open-Channel Flows with Alternate Vegetated Zones (교행식생 영역을 갖는 개수로 흐름에서의 3차원 수치모의)

  • Kang, Hyeongsik;Kim, Kyu-Ho;Im, Dongkyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.247-257
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    • 2009
  • In the present paper, turbulent open-channel flows with alternate vegetated zones are numerically simulated using threedimensional model. The Reynolds-averaged Navier-Stokes Equations are solved with the ${\kappa}-{\varepsilon}$ model. The CFD code developed by Olsen(2004) is used for the present study. For model validation, the partly vegetated channel flows are simulated, and the computed depth-averaged mean velocity and Reynolds stress are compared with measured data in the literature. Comparisons reveal that the present model successfully predicts the mean flow and turbulent structures in vegetated open-channel. However, it is found that the ${\kappa}-{\varepsilon}$ model cannot accurately predict the momentum transfer at the interface between the vegetated zone and the non-vegetated zone. It is because the ${\kappa}-{\varepsilon}$ model is the isotropic turbulence model. Next, the open channel flows with alternate vegetated zones are simulated. The computed mean velocities are compared well with the previously reported measured data. Good agreement between the simulated results and the experimental data was found. Also, the turbulent flows are computed for different densities of vegetation. It is found that the vegetation curves the flow and the meandering flow pattern becomes more obvious with increasing vegetation density. When the vegetation density is 9.97%, the recirculation flows occur at the locations opposite to the vegetation zones. The impacts of vegetation on the flow velocity and the water surface elevation are also investigated.

Development of the Large-Capacity Mooring Fittings according to MEG4(Mooring Equipment Guideline 4) (MEG4(Mooring Equipment Guideline 4) 적용에 따른 대용량 무어링 피팅 개발)

  • Myung-Su Yi;Kwang-Cheol Seo;Joo-Shin Park
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.950-957
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    • 2023
  • For safe mooring and towing between the ship and port, the equipment must be designed in accordance with the relevant international regulations. However, some small shipyards and engineering companies often do not fully comprehend the core contents. Therefore, the international regulations regarding towing and mooring equipment are reviewed and the bollard and chock are newly developed based on the Mooring Equipment Guideline 4 (MEG4) standards. A bollard is a mooring equipment used to fix a mooring rope to the hull. It has two columns and is mostly used in a figure eight pattern knots under the mooring condition. The chock, which is used to change the mooring rope direction coming into the ship from outside, is manufactured using a casting with curvature. The two mooring equipment are widely used in the stern, bow, and mid-side. Owing to the increase in the size of container vessels and LNG ships, the mooring rope load has increased and the safe working load of the mooring equipment must be revised. This study summarizes and examines the results of the allowable stress method obtained using finite element analysis modelling. To consider the mesh size effect, a reasonable criteria was suggested by referring the existing class guidance. Additionally, the safe working load was verified through nonlinear collapse analysis, and the elastic region against load increments was confirmed. Furthermore, the proposed evaluation method can be used to develop similar equipment in the near future.

A Study of Home Care Needs of Patients at Discharge and Effects of Home Care -Centered on Patients Discharged from a Rural General Hospilal- (퇴원환자의 가정간호요구와 가정간호사업의 효과 분석 - 일 종합병원을 중심으로)

  • Choi, Yun Soon;Kim, Dai Hyun;Storey, Margaret;Kim, Cho Ja;Kang, Kyu Sook
    • The Korean Nurse
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    • v.31 no.4
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    • pp.77-99
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    • 1992
  • The study was carried out at W. hospital, an affiliated hospital of Y university, involved a total of 163 patients who were discharged from the hospital between May 1990 und March 199J. Data collection was twice, just prior to discharge and a minimum of three months post discharge. Thirty patients who lived within a hour travel time of the hospital received home care during the three months post discharge. Nursing diagnoses and nursing interventions For these patients were analyzed in this study. The results of the study are summarized as follows : 1. Discharge needs for the subjects of the study were analyzed using Gordon's eleven Functional categories and it was found that 48.3% of the total sample had identified nursing needs. Of these, the needs most frequently identified were in the categories of sexuality, 79.3 %, health perception, 68.2 % self concept, 62.5 %, and sleep and rest 62.5 %. Looking ut j he nursing diagnosis that were made for the 30 patients receiving home care, the following diagnoses were the most frequently given; alteration in sexual pattern 79.3%, alterations in health maintenance, 72.6%, alteration in comfort, 68.0%, depression, 64.0%, noncompliance with diet therapy, 6.3.7%, alteration in self concept, 55.6%, and alteration in sleep pattern, 53%. 2. In looking at the effects of home nursing care as demonstrated by changes in the functional categories over the three month period, it was Found that of the 11 functional categories, the need level for health perception, nutrition, activity and self concept decreased slightly over the three month period. On the average sleep patterns improved, but restfulness was slightly less and bowel elimination patterns improved but satisfaction with urinary elimination was slightly less. On the other hand, role enactment, sexuality, stress management and spirituality decreased slightly. The only results that were statistically significant at the 0.05 level were improvement. in digestion and decrease in pain. No statistically significant changes were found in ability related to ADL, the total ADL Score at discharge was $19.78{\pm}8.234, and after 3 months $19.01{\pm}8.12$. Considering that a majority of the patients were over 60 years of age and that many had brain or spinal cord injuries, the fact that their ADL ability did nor deteriorate after discharge can be interpreted as related to a positive impact by the home health care nurses. Similarly there was a slight be not statistically significant decrease in the quality of life scores between the two lest times(l47.83 at discharge and 113.02 at the three month period). Again, when the chronic nature of thee problems facing these patients is considered this maintenance of quality of life can be interpreted as a positive impact by the home health care nurses. 3. One of the home care nursing activities was diagnosis. For this activity it was found that for nine functional health categories(sexuality and spirituality excepted) there were 20 nursing diagnoses. The most frequent were noncompliance, alteration in skin integrity both actual and potential, and impaired physical mobility in that order. 4. Delivery of home health care by the home health nurses included the following nursing activities; assessment, patient education, demonstration of care activities, counselling, direct care to the patient and referrals. Direct care included changing dressings, bladder irrigations, changing Foley catheters, measurement of residual urine, perineal care, position change, back care, oral hygiene, exercise and massage of motion exercises, cleansing enemas, tracheostomy suctioning and tracheostomy care, care of dentures, applications of heat and other similar nursing activities. In conclusion almost 50% of (he sample indicated a need for continued nursing care at the time of discharge and for the patients in the sample who received home care there was a slight decrease in nursing needs but while the patients had chronic and debilitation problems there was ill decrease in ADL abilities or in quality of life. Further study needs Lo be done La increase the reliability and validity of the tool that was used to measure home health care needs. It is also recommended that study by done using a randomized sampling with a control group to compare patients who receive home care with those who do not.

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A Study on the Factors Affecting Health Promoting Lifestyles of Some Workers (일부 직업인의 건강증진생활양식에 영향을 미치는 요인 연구)

  • Lee Eun-Kyoung;An Byung-Sang;Yu Taek-Su;Kim Seoung-Cheon;Jeung Jea-Yeal;Park Young-Shin;Jahng Doo-Sub;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.4 no.2
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    • pp.119-141
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    • 2000
  • The current industrial health service is shifting to health improvement business with 1st primary prevention-focused service from secondary and tertiary prevention-focused business, and Oriental medicine can provide such primary prevention-focused service due to the characteristics of its science. In particular, the advanced concept of health improvement can match the science of health care of Oriental medicine. Notably, what is most important in health improvement is our lifestyle, This does not underestimate the socio-environmental factors, which have lessened their importance due to modernism. The approach of Oriental medicine weighs more individuals' lifestyle and health care through self-cultivation. This matches the new model of advanced health business. Oriental medicine is less systemized than Western medicine, but it can provide ample contents that enhance health. If we conceive health-improvement program based on the advantages provided by these two medical systems, this will influence workers to the benefit of their health. Also, health Program needs to define factors that determine individual lives, and to provide information and technologies essential to our lives. The Oriental medicine approach puts more stress on a subject's capabilities than it does on the effect his surrounding environment can have. This needs to be supported theoretically by not only defining the relations between an individual's health state and his lifestyle, but also identifying the degree to which an individual in the industrial work place practices health improvement lifestyle . This is the first step toward initiating health-improvement business . In order to do this, this researcher conducted a survey by taking random samplings from workers, and can draw the following conclusions from it. 1 The sampled group is categorized into', by sender, female 6.6%, and male 93.4%, with males dominant; by marriage status , unmarried 43.9% and married 55.6%, with both similar percentage, and, by age, below 30, 48.4%, between 30 and 39, 27.4%, between 40 and 49, 18.2%, and over 50, 6.0%. The group further is categorized into; by education, middle school or under 1.7%, high school 30.5%, and junior college or higher 65.8% with high school and higher dominant: and by income, below 1.7 million won 24.2%, below 2.4 million won 14.8%, and above 2.4 million 6.3% Still, the group by job is categorized into collegians with 23.9%, office worker with 10.3%, and professionals with 65.8% , and this group does not include workers engaged in production that are needed for this research, but mostly office workers . 2. The subjects selected for this survey show their degree of practicing health-improvement lifestyle at an average of 2.63, health management pattern at 2.64, and health-related awareness at 2.62 The sub-divisions of health-improvement lifestyle show social emotion (2.87), food (2.66). favorite food (2.59), and leisure activities (2.52), in this order for higher points. It further shows health awareness (2.47) and safety awareness (2.40), lower points than those in health management pattern . 3. In the area of using leisure time for health-improvement, males, older people, married, and people with higher income earn higher marks. And, in the area of food management, the older and married earn higher marks . In the area of favorite food management, females, lower-income bracket, and lower-educated show higher degree of practice , while in the area of social emotion management, the older. married, and higher-income bracket show higher marks. In addition, in the area of health awareness, the older, married, and people with higher-income show higher degree of practice. 4. To look at correlation by overall and divisional health-improvement practice degree , this researcher has analyzed the data using Person's correlation coefficient. The lifestyle shows significant correlation with its six sub-divisions, and use of leisure time, food, and health awareness all show significant correlation with their sub-divisions. And. the social emotion and safety awareness show significant correlation with all sub-divisions except favorite food management.

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한국 청소년의 약물남용과 비행행위

  • 김성이
    • Korea journal of population studies
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    • v.11 no.2
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    • pp.54-66
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    • 1988
  • I. Introduction Since the 1970's drug abuse among young people has increasingly become a social problem in Korea. In the 1980's, drug abuse, especially glue sniffing, has become the cause of many unfortunated incidents resulting in harm to others as well as the abusers themselves. Taking into consideration of the seriousness of this problem, the Republic of Korea National Red Cross initiated a nation-wide research programme, to understand the present situation and to raise the level of public awareness. The goal of this research was to begin a nation - wide campaign against drug abuse. The research team was composed of the Advisary Committee members and the staff of the Youth Department of the Republic of Korea National Red Cross. The data were collected in February 1988 with the collaboration of the staff and volunteers in the local Chapters. The respondents were allocated nation-wide by the quota sampling method. The questionnaires were distributed to the respondents in three groups :2, 700 to junior and senior high school students, 605 to working youths, and 916 to delinquent youths. A total of 4, 221 questionnaires were collected. II. Characteristics of the Respondents The respondents in each group were selected evenly from rural and urban areas. The general characteristics of the respondents can be described as follow: in case of students, the proportions between male and female respondents, and between senior high school and junior high school students were almost evenly distributed. In case of working youths, the proportion of females (80.5%) was higher than those of the students and the delinquents groups. Delinquent youths were defined as those currently being under custody of the centers for juvenile delinquents. Of this number, 38.8% and 68.2% were junior and senior high school drop-outs respectively. The majority of them (92.6%) were male. As for the family background of the respondents, the proportion of those residing in poverty - stricken areas, and the proportion of those from broken families were higher in case of working youths and delinquent youths than those in case of students. III. Present Patterns of Drug Abuse The following summarizes the presents of drug abuse, as tabulated from the results of the survey. 1. Smoking The percentage of youths who smoke was 36% in the student group, 32% m the working youths group, and 94.4% in the delinquent youths group. 2. Alcohol 50.3% of students, 71.6% of working youths, and 93.3% of delinquent youths has experienced drinking alcohol beverages. 3. Tonic: non - alcoholic, caffeinated beverages popular in Korea and Japan The percentage of those who have used tonic at least once was over 90% in all of the three groups. 4. Sedative About 70% of each group has used sedative with the proportion of working youths use higher than those in other groups. 5. Stimulants Those who have used stimulants comprised around 15% in each group. 6. Tranquilizers Somewhat less than 5% of students and working youths, and 28% of delinquent youths, have used tranquilizers. 7. Hypnotics The users of hypnotics amounted to 0.4% of students, 2.6% of working youths and 7.1% of delinquent youths. 8. Marihuana Those who have used marihuana indicated 0.7% of students, 0.8% of working youths, and 13% of delinquent youths. 9. Glue-sniffing The percentage of glue-sniffing was 3.7%, 5% in the students group and in the youths group respectively, but the proportion was unusually high, at 40.7% in the delinquent youths group. From the results of the survey the present situation of drug abuse in Korea can be summarized as follows: 1. A high percentage of Korean youths have experienced smoking cigarettes and drinking alcoholic beverages. 2. Tonics (non - alcoholic, caffeinated beverages), antipyretic analgesics and stimulants quite regularly used. 3. Tranquilizers, hypnotics, marihuana and glue-sniffing are more widely used among delinquent youths than the other youths. From this fact, there exists a correlation between drug abuse and juvenile delinquency. IV. Time-series Analysis of the First Experience of Drug Abuse and Deviant Behaviour The respoundents were asked when they were first exposed to drugs and when they committed deviant acts. By calculating the average age of each experience, the following pattern was found (See Figure 1). Youths are first exposed to drugs by abuse of tonic(non - alcoholic, caffeinated beverages). At the age of 13, they amoke cigarettes, the use of antipyretic analgesics begins at 14 year old, while at the age of 15, they use tranquilizers, and at 16 hynotics. The period of drug abuse which starts from drinking caffeinated beverages and smoking cigarettes and ends in the use of hypnotics takes about three years. During this period, other delinquent behaviours begin to surface, that is, at the age of 13 when smoking cigarettes begins, the delinquent behaviour pattern starts with truancy. Next, they start taking money from others by using physical force. Prior to the age of 15, they are suspended from school, become hostile to adults, begin running away from home, and start using stimulants and alcohol. Soon they become involved even in glue-sniffing and in the use of marihuana. At the age of 15, they begin to see adult videos and carry weapons. Sexual promiscuity and usage of tranquilizers follows the viewing of adult videos. Consequently, by the time they reach the age of 16, they visit drinking establishments, and are picked up by police for committing delinquent acts. And finally, they come to use hypnotic - type drugs. From the above descriptions, drug abuse can be assumed to have a close correlation with delinquent behaviour. V. Social Factors Related to Drug Abuse As for the Korean youths, glue-sniffing is found to he related to aggressive delinquency, in such cases as run - aways, being picked up by the police, and taking money by force. Smoking cigarettes and drinking alcohol is found to be related to seeing adult videos and visiting drinking establishments. Hypnotics and marihuana were found to be representive of drugs which are related to degenerational delinquency, irrespective of social delinquency. The social factors connected with these drug abuse are as follows: 1. Individual factors Male students were more heavily involved in the usage of drug than females. Youths who do not attend church were more likely to be involved in drugs than those who attend. 2. Family factors The youths who were displeased with their mothers smoking and those who thought their parents did not love each other, or those whose parents had used drugs without prescription, were more likely to he drug users. 3. School factors Those youths who found school life boring, were unsuccessful in their studies, spend most of their time with friends, feel their teachers smoke too much, those who had a positive perception of their teachers smoking were likely to he drug users. To sum up, drug abusers depend on the influence of their parents, teachers and peers. IV. Reasons for Drug Abuse Korean students have mainly used drugs to release stress (42.8%), to stay awake (19.7%), and because of the easy accessibility of drugs( 16.6%). Other reasons are due to their ignorance of the side effects of the drugs (3.6%), natural curiosity (4.2%), and to increase strength(3.O%). From the above facts, the major reasons for drug abuse among Korean youths are to release stress and to stay awake in order to prepare exams. Furthermore, since drugs are readily available, we can conclude that drug abuse is caused by the school system(such as entrance exams) in Korea. VII. Conclusion Drug usage among Korean youths are relatively less common than those of western youths. In some cases, such as, glue-sniffing and use of stimulants, the pattern of drug abuse is found. Moreover, early drug abuse is evident, and it has a close connection with deviant behaviour, resulting in juvenile delinquency. Drug abuse cannot be attributed to any one social factor. Specifically, drug abuse depends on parents, peers, teachers and other members of the community, and also is influenced by social institutions such as the entrance exam system. Every person and organization concerned with youth must participate collectively in restraining drug abuse. Finally, it is suggested that social agencial working for youth welfare should make every effort to tackle this serious problem confronted by the Korean youths today.

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Analyzing Contextual Polarity of Unstructured Data for Measuring Subjective Well-Being (주관적 웰빙 상태 측정을 위한 비정형 데이터의 상황기반 긍부정성 분석 방법)

  • Choi, Sukjae;Song, Yeongeun;Kwon, Ohbyung
    • Journal of Intelligence and Information Systems
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    • v.22 no.1
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    • pp.83-105
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    • 2016
  • Measuring an individual's subjective wellbeing in an accurate, unobtrusive, and cost-effective manner is a core success factor of the wellbeing support system, which is a type of medical IT service. However, measurements with a self-report questionnaire and wearable sensors are cost-intensive and obtrusive when the wellbeing support system should be running in real-time, despite being very accurate. Recently, reasoning the state of subjective wellbeing with conventional sentiment analysis and unstructured data has been proposed as an alternative to resolve the drawbacks of the self-report questionnaire and wearable sensors. However, this approach does not consider contextual polarity, which results in lower measurement accuracy. Moreover, there is no sentimental word net or ontology for the subjective wellbeing area. Hence, this paper proposes a method to extract keywords and their contextual polarity representing the subjective wellbeing state from the unstructured text in online websites in order to improve the reasoning accuracy of the sentiment analysis. The proposed method is as follows. First, a set of general sentimental words is proposed. SentiWordNet was adopted; this is the most widely used dictionary and contains about 100,000 words such as nouns, verbs, adjectives, and adverbs with polarities from -1.0 (extremely negative) to 1.0 (extremely positive). Second, corpora on subjective wellbeing (SWB corpora) were obtained by crawling online text. A survey was conducted to prepare a learning dataset that includes an individual's opinion and the level of self-report wellness, such as stress and depression. The participants were asked to respond with their feelings about online news on two topics. Next, three data sources were extracted from the SWB corpora: demographic information, psychographic information, and the structural characteristics of the text (e.g., the number of words used in the text, simple statistics on the special characters used). These were considered to adjust the level of a specific SWB. Finally, a set of reasoning rules was generated for each wellbeing factor to estimate the SWB of an individual based on the text written by the individual. The experimental results suggested that using contextual polarity for each SWB factor (e.g., stress, depression) significantly improved the estimation accuracy compared to conventional sentiment analysis methods incorporating SentiWordNet. Even though literature is available on Korean sentiment analysis, such studies only used only a limited set of sentimental words. Due to the small number of words, many sentences are overlooked and ignored when estimating the level of sentiment. However, the proposed method can identify multiple sentiment-neutral words as sentiment words in the context of a specific SWB factor. The results also suggest that a specific type of senti-word dictionary containing contextual polarity needs to be constructed along with a dictionary based on common sense such as SenticNet. These efforts will enrich and enlarge the application area of sentic computing. The study is helpful to practitioners and managers of wellness services in that a couple of characteristics of unstructured text have been identified for improving SWB. Consistent with the literature, the results showed that the gender and age affect the SWB state when the individual is exposed to an identical queue from the online text. In addition, the length of the textual response and usage pattern of special characters were found to indicate the individual's SWB. These imply that better SWB measurement should involve collecting the textual structure and the individual's demographic conditions. In the future, the proposed method should be improved by automated identification of the contextual polarity in order to enlarge the vocabulary in a cost-effective manner.

Mechanical Anisotropy of Pocheon Granite under Uniaxial Compression (일축압축하에서 포천화강암의 역학적 이방성)

  • Park Deok-Won
    • The Journal of Engineering Geology
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    • v.15 no.3
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    • pp.337-348
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    • 2005
  • Jurassic granite from Pocheon area were tested to investigate the effect of microcracks on mechanical properties of the granite. Three oriented core specimens were used for uniaxial compressive tests and each core specimen are perpendicular to the axes'R'(rift plane),'c'(grain plane) and'H'(hardway plane), respectively Among vacious elastic constants, the variation of Poisson's ratio as function of the directions was examined. From the related chart between ratio of failure strength and Poisson's ratio, H-specimen shows the highest range in Poisson's ratio and Poisson's ratio decreases in the order of C-specimen and R-specimen. The curve pattern is nearly linear in stage $I\simIII$ but the slope increases abruptly in stage H-3. As shown in the related chart, diverging point of a curve is formed when ratio of failure strength is $0.92\sim0.96$ Stage IV -3 is out of elastic region. The behaviour of rock in the four fracturing stages was analyzed in term of the stress-volumetric strain me. From the stress increment-volumetric strain equations governing the behaviour of rock, characteristic material constants, a, n, Q, m and $\varepsilon_v^{mcf}$, were determined. Among these, inherent microcrack porosity$(a, 10^{-3})$ and compaction exponent(n) in the microcrack closure region(stage I ) show an order of $a^R(3.82)>a^G(3.38)>a^H(2.32)\;and\;n^R(3.69)>n^G(2.79)>n^H(1.99)4, respectively. Especially, critical volumetric microcrack strain($\varepsilon_v^{mcf}$) in the stage W is highest in the H-specimen, normal to the hardway plane. These results indicate a strong correlation between two major sets of microcracks and mechanical properties such as Poisson's ratio and material constants. Correlation of strength anisotropy with microcrack orientation can have important application in rock fracture studies.

Temporal and Spatial Characteristics of Surface Winds over the Adjacent Seas of the Korean Peninsula (한국 주변해역에서의 해상풍의 시공간적 특성)

  • Han, Sang-Kyu;Lee, Heung-Jae;Na, Jung-Yul
    • 한국해양학회지
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    • v.30 no.6
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    • pp.550-564
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    • 1995
  • The temporal and spatial characteristics of wind fields over the neighbouring seas of the Korean peninsula are investigated using 10-years daily wind data during 1978${\sim}$1987 which have been spatially smoothed and low-pass filtered. Long term annual and monthly means are examined for synoptic patterns and spectral analyses are made for temporal variability and spatial coherence. Spatial patterns of the annual mean wind stress and curl have a strong resemblance with those of monthly means during the winter season. Two outstanding periodicities are observed at 1 and 2 cycles per year. The synoptic winds over the study area are highly coherent at both the annual and semi-annual periodicities. However, each basin has its own characteristic spatial pattern. For instance, the prevailing wind during the winter season is northerIy over the northern East Sea (ES), Yellow Sea (YS), and northern East China Sea (ECS), while it is northwesterly over the southern ES and northesterly over the northern ES and southern ECS. At the same time, the wind stress curl is positive over the northern ES and southern ECS, while it is negative over the southern ES, YS and northern ECS. On the other hand, the wind field during the summer season, with its strength being much reduced, is completely different from that during the winter season, and frequent passage of tropical storms provokes large temporal variability over ECS. One remarkable point is that the annual cycle, dominated by the Siberian High, tends to propagate from northeast to southwest, i.e., from northern 25 toward southern ES, YS and ECS, while the semi-annual cycle propagates in the opposite direction, from southwest to northeast. The semi-annual periodicity may reflect development of extratropical cyclones in spring and fall which frequently cross the Korean peninsula. In higher frequencies, there are no dominant periodicities, but local winds over YS and ES are highly correlated for frequencies larger than 0.1 cycles per day and phase difference increases linearly with frequency. This linear increase of phase corresponds to phase speed of 550 and 730 km/d at 0.1 and 0.3 cpd, respectively, The phase speed is apparently coincident with moving speed of extratropical cyclones across the Korean peninsula in the west-east direction.

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A FEM comparison study about the force, displacement and initial stress distribution on the maxillary first molars by the application of Asymmetric Head-Gears with the different traction forces (Asymmetric Head-Gear의 견인력의 차이에 따른 상악 제 1 대구치에 나타나는 힘과 변위 및 초기 응력분포에 관한 유한요소법적 비교 연구)

  • Cha, Kyung-Suk
    • The korean journal of orthodontics
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    • v.31 no.3 s.86
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    • pp.311-323
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    • 2001
  • One of the various mechanics used to treat unilateral Class II malocclusion is head gear with asymmetric face bow. We made the finite element models of unilateral Class II maxillary dental arch and power arm asymmetric face bow. We designed this experiment to observe stress distribution of periodontal ligament, reaction force, and displacement and to understand force system, so to predict the therapeutic effect. On the basis of computerized tomograph of maxillary dental arch of 25 years old male with normal occlusion without extraction and orthodontic treatment history, we made finite element models of maxillary dental arch and periodontal ligament. Then we modified that model to unilateral maxillary Class II malocclusion model of which maxillary left molar displaced mesially. Also, We made finite element model of asymmetric face bow of which right outer bow shorter than left by 25mm(RMO, Penta-FormTM/Medium size, 0.045 inch iner bow, 0.072 inch outer bow). After that, retraction force of 250g, 300b, 350g were applied to maxillary first molar. We concluded as follow. 1. The Net force that both maxillary first molars were received increased as the retraction force increased. Mesially positioned tooth received more force than normally positioned tooth. But, both tooth were received distal force, so distal movement occured. 2. Both tooth received buccal lateral force. In analysis of force element, as the retraction force were increased, force of X-axis at mesially positioned tooth decreased, and force of X-axis at normally positioned tooth increased. so lateral force component moved to the side received less force from more force. 3. There were rotation, tipping with distal movement in maxillary first molar. As retraction force were increased, rotation and tipping also increased. More tipping and rotation occured at the side received more force, that is, mesially positioned tooth. Though it Is small change, displacement of same pattern occur in normally positioned tooth

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