• Title/Summary/Keyword: Life History Method

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Egg Development and Early Life History of the Natural Monument Species Hemibarbus mylodon (Pisces: Cyprinidae) in Korea (천연기념물 어름치 Hemibarbus mylodon (Pisces: Cyprinidae)의 난 발생 및 초기생활사)

  • Ko, Myeong-Hun;Kim, Hae-Rim;Park, Sang-Yong;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.29 no.2
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    • pp.101-108
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    • 2017
  • Egg development and early life history of the Korean natural monument fish Hemibarbus mylodon (Pisces: Cyprinidae) were investigated to provide basic data on biological characteristics and ecological recovery. Adult fish were collected from nature and transferred to the laboratory. For the first time, artificial maturation of females and males succeeded after 15 months of indoor culture. Mature eggs and sperm were obtained using Ovaprim injections (0.5 mL/kg) and then the eggs were fertilized using the dry method in the laboratory. The mature eggs were adhesive, turbid, and greyish; they averaged $2.21{\pm}0.06mm$ (n=30) in diameter. The embryos began to hatch about 78 h after fertilization at a water temperature $20{\pm}1^{\circ}C$, and the newly-hatched larvae were $6.6{\pm}0.75mm$ in total length (TL). At 14 days after hatching, the post-larval individuals were $13.5{\pm}0.23mm$ (TL), and their yolk sacs were completely absorbed. Twenty one days after hatching, they entered the juvenile stage and reached $13.5{\pm}0.23mm$ (TL). At 100 days after hatching, their band patterns, external form, and a pair of barbels were similar to those of adults, and they averaged $33.0{\pm}4.25mm$ (TL). The breeding technology and characteristics of early life history obtained in this study will be very helpful for conservation of H. mylodon in nature.

Fatigue life estimation using the multi-axial multi-point Load Counting method under Variable Amplitude Loading (가변진폭하중에서 다축-다점 하중 Counting method를 이용한 피로수명평가)

  • 이원석;이현우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.913-920
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    • 1996
  • In this study, the counting method for multi-axial and multi-point load states was proposed. Using this counting method, the load spectrum is generated from the service load history which is measured for boom structure of excavator. Loading state for loading points of boom structure is described as a multi-dimensional state space. From this load spectrum, the stress spectrum was generated by FEM analysis using the superposition of the unit load. The cumulated damage at the severe damage point of In nm structure by the failure example is calculated by Palmgren-Miner's rule. As a result of this study, the fatigue life estimation using the multi-axial and multi-point load counting method is useful.

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Learning Experience Study of Problem Based Learning on War history (문제중심학습(PBL) 경험연구 -군사학과 전쟁사 강좌 사례를 중심으로-)

  • Kim, Sung Woo
    • Convergence Security Journal
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    • v.13 no.2
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    • pp.101-109
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    • 2013
  • Problem Based Learning(PBL) is one of effective teaching-learning strategy for enhancing military students' motivation, comparing with the other study method. After monitoring military student classes, we conclude that PBL can enhance the effectiveness of learning in War history case study education and finds merits; PBL assists students to play a more active role in the class, induces students to solve problems independently, and makes the learning military situation real case study. The case study is common in social sciences and life sciences. Case studies may be descriptive or explanatory. It is good for War history education. The demerit of PBL is a costly method as students should spend more time and institutions should provide more manpower and materials. This study suggests that more empirical researches on alternative teaching methods, including PBL, to a lecture in War history education.

A bibliographical analysis on the studies of history of Korean women (우리나라 여성사연구의 서지적 고찰)

  • 유소영
    • Journal of Korean Library and Information Science Society
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    • v.35 no.2
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    • pp.115-133
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    • 2004
  • The literature on Km women's history from ancient times to the end of the Japanese occupation is collected and analyzed The total number of documents treated in this paper is 369. The documents, all written by 2003 include books, theses for master's and Ph. D. degrees, journal articles, and digital papers on the Internet home pages. The results shows that the favored themes of the researchers were women's status, education, and arts. Other subjects include women's activities, daily life, biographies, and religion. The most preferred period was the Chosun Dynasty and the least preferred period was the Koryo Dynasty. The usual method of these documents is narrative. There are few attempts to compare women's history of Korea with that of other countries.

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Dynamic Stress Analysis of joint by Practical Dynamic Load History (실하중 이력에 의한 조인트의 동적강도해석)

  • ;;;Akira Simamoto
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.5
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    • pp.118-123
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    • 2001
  • Most structures of automobile are composed of many substructures connected to one another by various types of mechanical joints. In automotive engineering, it is important to study these connected structures under various dynamic farces for the evaluations of fatigue life and stress concentration exactly. It is rarely obtained the accurate load history of specified positions because of the errors such as modeling, measurement, and etc. In the beginning of design, exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. In this paper, the procedure of practical dynamic load determination is developed by the combination of the principal stresses of F.E. analysis and experiment. Inverse problem and least square pseudo inverse matrix are adopted to obtain an inverse matrix of analyzed stresses matrix. Pseudo-Practical dynamic load was calculated for Lab. Test of sub-structure. GUI program(PLODAS) was developed for whole of above procedure. This proposed method could be extended to any geometric shape of structure.

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A Study on the Characteristics of the 8th grade Textbooks about Probability (중학교 2학년 확률 내용에 대한 고찰)

  • Byun, Hee-Hyun
    • Journal for History of Mathematics
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    • v.22 no.2
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    • pp.81-98
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    • 2009
  • Probability plays a very important role in modern society as an essential tool for solving various kinds of problems from our real life or scientific province. However, most of precedent studies on probability pointed out that many students had difficulties in understanding the nature of it, and that probability teaching method in the classroom is easily led only to calculation system, which is isolated from practical applications. In this paper, I make a close study further onto these themes, by analyzing the 8th grade textbooks through these following questions; how do the textbooks deal with calculation of probability that certain two events occur at the same time? On the practical basis, how do they make use of probability as a problem-solving instrument in both actual life and scientific fields? After these, I try to extract some features and issues of probability teaching method in current Korean textbooks.

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Fatigue life prediction of horizontally curved thin walled box girder steel bridges

  • Nallasivam, K.;Talukdar, Sudip;Dutta, Anjan
    • Structural Engineering and Mechanics
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    • v.28 no.4
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    • pp.387-410
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    • 2008
  • The fatigue damage accumulation rates of horizontally curved thin walled box-girder bridge have been estimated from vehicle-induced dynamic stress history using rain flow cycle counting method in the time domain approach. The curved box-girder bridge has been numerically modeled using computationally efficient thin walled box-beam finite elements, which take into account the important structural actions like torsional warping, distortion and distortional warping in addition to the conventional displacement and rotational degrees of freedom. Vehicle model includes heave-pitch-roll degrees of freedom with longitudinal and transverse input to the wheels. The bridge deck unevenness, which is taken as inputs to the vehicle wheels, has been assumed to be a realization of homogeneous random process specified by a power spectral density (PSD) function. The linear damage accumulation theory has been applied to calculate fatigue life. The fatigue life estimated by cycle counting method in time domain has been compared with those found by estimating the PSD of response in frequency domain. The frequency domain method uses an analytical expression involving spectral moment characteristics of stress process. The effects of some of the important parameters on fatigue life of the curved box bridge have been studied.

History of nursing and medicine as phenomena of knowledge/power (지식/권력의 현상으로 본 간호와 의학사)

  • Kim, Nam-Sun;Hong, Yoon-Mi;Lee, Kyu-Eun
    • Journal of Korean Academy of Nursing Administration
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    • v.8 no.3
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    • pp.373-380
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    • 2002
  • Purpose : The purpose of this study is to analyze the history of nursing and medicine as phenomena of knowledge/power from the viewpoint of Foucault. Method : The present study adopts the genealogical method by Foucault, which tries to unite languages and knowledge. Foucault who attempted to show that the basic ideas which people normally take to be permanent truths about human nature and society change in the course of history. Results : It has been emphasized that the development of modern health care has been due to the progressive efforts of medicine and to medical discoveries. Foucault examines the institutionalization of knowledge and the power exerted thereby, with special reference to the devices of social regulation and their function over the madness, the disease, the crime, and the sexuality. The concept of power is that it is exerted spontaneously in verbal behaviors of individuals through knowledge of everyday life such as definition of body or mind. Therefore as to the problem of knowledge/power, this study tries to understand the meaning of history of nursing and medicine through an analysis of the formation of text of history. In order to have authority in a power relation, the medical professional asserts that medical discourse is the most scientific knowledge. Conclusion : According to the above findings, it can be concluded that the body is also directly invested in a political field: power relations have an immediate hold upon it; they invest it, mark it, train it, torture it, force it to carry out tasks, to perform ceremonies, to emit signs. Therefore the devaluation of nursing care is reinforced by the medicine which has the legitimate authority through use of the political skills about the body.

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A Study on Dynamic Analysis and Fatigue Life of the Belt in the OHT Vehicle (OHT 차량 벨트 동특성 및 피로 수명에 관한 연구)

  • Jung Il-Ho;Kim Chang-Su;Cho Dong-Hyeob;Park Joong-Kyung;Park Tae-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.8 s.239
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    • pp.1085-1092
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    • 2005
  • The OHT(Over Head Transportation) Vehicle transports heavy products quickly and repeatedly at the industrial workplace. The belt in the OHT vehicle is used to support the weight of the OHT Cage. The fatigue of the belt is caused by the dynamic load during the operation time. Since the fatigue fracture of the belt affects the safety at the workplace, the correct prediction of the dynamic load is necessary to calculate the fatigue life of the belt on the design step. In this paper a computer aided analysis method is proposed for the belt in the early design stage using dynamic analysis, stress analysis, belt tensile test, belt fatigue test and fatigue lift prediction method. From the dynamic load time histories and the stress of the belt FE model, a dynamic stress time history is produced. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The method developed in this paper is used to reduce the time and cost for designing the OHT belt in different environment and condition.

Establishment and Application of the Guideline for Hypertension by Delphi Method in the Field of Primary Medical Care (Delphi방법을 이용한 일차의료 고혈압 진료지침 개발 및 적용)

  • Yang, Yun-Jun;Hong, Myung-Ho
    • Quality Improvement in Health Care
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    • v.2 no.1
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    • pp.68-84
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    • 1995
  • Background: Guideline for practice is useful because it can be the standard for assessment and way to improve quality. We need to take account of expert opinion and consensus as well as scientific evidences to develope practice guideline because it should be practical. Delphi method has been developed to gather opinions from experts fairly. This study was designed to develop practice guideline and apply it to practices as a method to improve quality in primary medical care. Methods: Hypertension(in adults over 18 years old) was selected as a target problem. Self questionnaires about management of hypertensive patients were developed by a researcher with advice of 11 experts. The questionnaires were designed to response as a 5 pont scale. The results of previous questionary were given to respondents in second and third questionnaires. If needed, the questionnaires were changed on the previous responses. The items with medium greater than or equal to 4 point in 1st and 2nd responses were accepted in guideline. The items with medium lesser than or equal to 3 point were questioned again about whether they can be excluded or not. The criteria for assessment was made with reference to guideline and applied to 85 hypertensive patients of 9 family practitioners. At 3 months after practice guideline had been given to family practitioners, performance of same practitioners was assessed with 36 new hypertensive patients. Results: 23 professors in family medicine, 22 family practitioners and 6 cardiologists, responded among 50, 50, 15 respectively. Practice guideline with 33 items was developed as a result of 3 times questionaires. The difference of responses between professors in family medicine, family practitioners and cardiologists was not significant. Performance of practice was improved in diagnosis, history taking about 6 fields, laboratory examination and decision making about time of pharmaceutical prescription. It was not improved in physical examination, life style modification, method of pharmaceutical prescription, choice of initial antihypertensives and history taking about duration of disease and diet habit. It was decreased in history taking about psychosocial factors. The assessment scores were low in history taking, physical examination and life style modification before and after use of practice guideline. Conclusion: Practice guideline for hypertension could be developed by Delphi method. Performance of practice improved partially after use of guideline.

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