• Title/Summary/Keyword: critical means

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Fabrication of SmBCO superconducting coated conductor using 100m class batch-type co-evaporation method (100m 급 batch-type co-evaporation 증착장치를 이용한 SmBCO 초전도테이프 제조)

  • Kim, H.S.;Oh, S.S.;Ha, H.S.;Yang, J.S.;Kim, T.H.;Lee, N.J.;Jeong, Y.H.;Ko, R.K.;Song, K.J.;Ha, D.W.;Youm, D.J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.24-25
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    • 2006
  • SmBCO coated conductors were successfully fabricated using EDDC (Evaporation using Drum in Dual Chambers) deposition system that is a bath type co-evaporation system for fabrication of superconducting tape and divided into two chambers named evaporation chamber and reaction chamber. To obtain long and high quality superconducting coated conductor, it is very important to secure the uniformity of all the deposition parameters m the deposition system such as deposition temperature, oxygen partial pressure, compositional ratios and so on. Therefore, we investigated the distribution of the parameters along the axis of the drum m EDDC on which tapes were wound helically. When the temperature on the middle point of deposition zone was $700^{\circ}C$, that on the edge of deposition zone was $675^{\circ}C$. When the thickness of SmBCO layer on the middle point of deposition zone was 1063 nm, that on the edge of deposition zone was 899 nm. The partial pressure of oxygen was 5 mTorr in the reaction chamber while that was $7{\times}10^{-5}$Torr in the evaporation chamber. The composition ratio of Sm:Ba:Cu, that was measured by EDX, was very uniform along the axis of the drum. Under these deposition conditions, critical current distribution along the drum axis was 175 A/cm, 190A/cm, 217.5 A/cm, 182.5 A/cm, 175 A/cm with the interval of 9 cm between samples. It means that the EDDC system has the potential of fabricating (100m, 200A) class coated conductor.

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An analysis of determinants of purchase intension of individual pension using structural equation model (구조방정식모형을 이용한 개인연금 가입의향의 결정요인 분석)

  • Lee, Chanhee;Jung, Hongjoo
    • The Korean Journal of Applied Statistics
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    • v.29 no.3
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    • pp.409-424
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    • 2016
  • This study analyzed the causal relationship among factors that influence the purchase intensions for individual pensions which have a growing importance as a financial means after retirement. For this purpose, structural equation modeling based on the survey data (N = 928) was conducted to analyze psychological factors and financial factors comprehensively. According to empirical results of the structural equation, in the case of non-subscribers of individual pensions, potential longevity and coping efficacy influenced the purchase intensions for individual pensions fully mediated by fear and worry about longevity. Trust in insurers and risk tolerance directly influenced the purchase intensions for individual pensions. These show that trust in insurers is the most important factor in purchase intensions for individual pensions. Also, only trust in insurers give a direct impact on individual pensions in the case of individual pension subscribers. Longevity-related emotional side is expected to help in marketing activities that target potential customers signing individual pensions. In addition, trust in insurers has the greatest impact on new and additional subscriptions that represent critical efforts to improve trust in insurers.

Halotolerant Plant Growth Promoting Bacteria Mediated Salinity Stress Amelioration in Plants

  • Shin, Wansik;Siddikee, Md. Ashaduzzaman;Joe, Manoharan Melvin;Benson, Abitha;Kim, Kiyoon;Selvakumar, Gopal;Kang, Yeongyeong;Jeon, Seonyoung;Samaddar, Sandipan;Chatterjee, Poulami;Walitang, Denver;Chanratana, Mak;Sa, Tongmin
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.4
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    • pp.355-367
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    • 2016
  • Soil salinization refers to the buildup of salts in soil to a level toxic to plants. The major factors that contribute to soil salinity are the quality, the amount and the type of irrigation water used. The presented review discusses the different sources and causes of soil salinity. The effect of soil salinity on biological processes of plants is also discussed in detail. This is followed by a debate on the influence of salt on the nutrient uptake and growth of plants. Salinity decreases the soil osmotic potential and hinders water uptake by the plants. Soil salinity affects the plants K uptake, which plays a critical role in plant metabolism due to the high concentration of soluble sodium ($Na^+$) ions. Visual symptoms that appear in the plants as a result of salinity include stunted plant growth, marginal leaf necrosis and fruit distortions. Different strategies to ameliorate salt stress globally include breeding of salt tolerant cultivars, irrigation to leach excessive salt to improve soil physical and chemical properties. As part of an ecofriendly means to alleviate salt stress and an increasing considerable attention on this area, the review then focuses on the different plant growth promoting bacteria (PGPB) mediated mechanisms with a special emphasis on ACC deaminase producing bacteria. The various strategies adopted by PGPB to alleviate various stresses in plants include the production of different osmolytes, stress related phytohormones and production of molecules related to stress signaling such as bacterial 1-aminocyclopropane-1-carboxylate (ACC) derivatives. The use of PGPB with ACC deaminase producing trait could be effective in promoting plant growth in agricultural areas affected by different stresses including salt stress. Finally, the review ends with a discussion on the various PGPB activities and the potentiality of facultative halophilic/halotolerant PGPB in alleviating salt stress.

Rotordynamic Analysis of a Dual-Spool Turbofan Engine with Focus on Blade Defect Events (블레이드 손상에 따른 이축식 터보팬 엔진의 동적 안정성 해석)

  • Kim, Sitae;Jung, Kihyun;Lee, Junho;Park, Kihyun;Yang, Kwangjin
    • Tribology and Lubricants
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    • v.36 no.2
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    • pp.105-115
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    • 2020
  • This paper presents a numerical study on the rotordynamic analysis of a dual-spool turbofan engine in the context of blade defect events. The blades of an axial-type aeroengine are typically well aligned during the compressor and turbine stages. However, they are sometimes exposed to damage, partially or entirely, for several operational reasons, such as cracks due to foreign objects, burns from the combustion gas, and corrosion due to oxygen in the air. Herein, we designed a dual-spool rotor using the commercial 3D modeling software CATIA to simulate blade defects in the turbofan engine. We utilized the rotordynamic parameters to create two finite element Euler-Bernoulli beam models connected by means of an inter-rotor bearing. We then applied the unbalanced forces induced by the mass eccentricities of the blades to the following selected scenarios: 1) fully balanced, 2) crack in the low-pressure compressor (LPC) and high pressure compressor (HPC), 3) burn on the high-pressure turbine (HPT) and low pressure compressor, 4) corrosion of the LPC, and 5) corrosion of the HPC. Additionally, we obtained the transient and steady-state responses of the overall rotor nodes using the Runge-Kutta numerical integration method, and employed model reduction techniques such as component mode synthesis to enhance the computational efficiency of the process. The simulation results indicate that the high-vibration status of the rotor commences beyond 10,000 rpm, which is identified as the first critical speed of the lower speed rotor. Moreover, we monitored the unbalanced stages near the inter-rotor bearing, which prominently influences the overall rotordynamic status, and the corrosion of the HPC to prevent further instability. The high-speed range operation (>13,000 rpm) coupled with HPC/HPT blade defects possibly presents a rotor-case contact problem that can lead to catastrophic failure.

Safety of the Herbicide Fluazifop-butyl application on the Korean Ginseng(Panax ginseng C.A. Meyer) (고려인삼(高麗人蔘)에 대한 제초제(除草劑) Fluazifob-butyl의 안전성(安全性))

  • Jo, Jae-Seong;Won, Jun-Yeon
    • Korean Journal of Medicinal Crop Science
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    • v.3 no.2
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    • pp.146-150
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    • 1995
  • Weed control in the Korean ginseng(Panax ginseng C.A. Meyer) garden is more difficult than in other crops because the ginseng is a perennial crop and has to be cultivated under the artificial shading. As hand weeding is the only practical means to control weed after crop establishment, a selective herbicide would greatly simplify the control of weed in ginseng garden. In an exploratory experiment, the hervicide Fluazifop-butyl was found to be selectively safe for the Korean ginseng plants. Various rates of Fluazifop-butyl were sprayed on 2-, 3-, and 4-years old ginseng plants as a foliar spray to detect crop injury and to difine their critical concentration. No apparent injury to the ginseng plant was noticable even the doubled application rate of Fluazifop-butyl the based on recommended dosage. Neither abnormal foliar change nor any inhibition in leaf and stem growth was resulted for 2-, 3-, and 4-years old ginseng plants treated with Fluazifop-butyl tripled the recommended usage. The foliar treatments of Fluazifop-butyl did not influence the photosynthesis ability but inhibited the respiration of the ginseng leaf.

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A Study on the development of leadership training program for first-line nurse managers (일선 간호관리자를 위한 리더십 훈련 프로그램 개발)

  • Koh, Myung-Suk;Han, Sung-Suk
    • Journal of Korean Academy of Nursing Administration
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    • v.6 no.3
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    • pp.333-345
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    • 2000
  • The health care environment becomes more competitive every day. It has fallen to nurse managers - from vice presidents of patient care to nurse managers and their assistants - to recruit and develop a workforce that successfully meets the needs of both patients and the organization. This means employees who demonstrate advanced critical thinking skills, creative problem solving, and sound decision making skills combined with clinical skills and patient advocacy. The environment which nurse managers create and the way they relate to their workforce, are pivotal to organizational viability. Especially leadership of first -line nurse managers contributes to the success of their organizations. First-line nurse managers are deserved to be one of the most administrative supervisors through the middle stratum in a hospital organization as being a manager in the field service if assessed from the overall aspects of hospital, as being an interim managers in the nursing department as well as being a supreme supervisor in a unit in terms of an organizational structure in the hospital. Similarly, as a compete leader, the first-line nurse managers have not only a professional which is qualified to perform a role of appropriate coordination with medical staff and key personnel but also hold an important key position a being responsible for performing his or her given role. The first-line nurse manager is expected to manage human and fiscal resources in ways not required before. While an identified need for well-prepared first-line nurse manager continues to plague the profession, first-line nurse managers often have difficulty providing the leadership required. The need leadership training to function effectively in their positions. But we hardly find a useful leadership training program for first-line nurse managers, therefore the purpose of this study was to developed the leadership training program for them. The steps of leadership program development were below: 1st step, 2 studies were done before develop a leadership program. One was done to ask to first-line nurse managers what they want to learn through leadership training, the other one was to ask the staff nurses what their opinions are for their first-line nurse managers leadership. 2nd step was searching other leadership programs contents. The results of this study were below: The total amount of hours is 24. Leadership training program contents are : Future of nursing profession (210min), understanding basic factor's of leadership and leadership theories(310 min), self understanding as first- line nurse managers(320 min), basic principle and practice of interpersonal relationship(210 min), assertiveness training, conflict management (180min), and group study(210min). This is challenging time to be a leader, especially in nursing. As nurse managers look toward the new millennium, it seems as through the same struggles are ahead that are behind. So nurse managers need to embrace change with a positive attitude. They need to demonstrate risk taking and support it in their staffs. All these things are possible that after they participate the leadership training program.

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A Content Analysis of the test of the National Examination for Registration Nurses in Korea over 3 years (간호사 국가고시문제의 내용분석)

  • 서문자;윤순녕;유지수;송지호;최경숙
    • Journal of Korean Academy of Nursing
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    • v.26 no.1
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    • pp.73-93
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    • 1996
  • This study aimed to analyse the test contents of the national examination for the registered nurses (NERN) over 3 years from 1991 to 1993 in Korea. In recent years in Korea, the MCQ(multiple choice question) has been showing to be a highly recognized method for assessing the qualification of registered nurses. Unfortunately, nursing faculties have found NERN had some bad MCQs through having evaluation workshop for Some MCQs often provide so many unwriting clues which become a bias of the results, and some items fell into the category of the lower level of educational taxonomy such as isolated recall a fact or data. Frequently the stems of the questions are ambigous, unclear, disputable, esoterical or trivial. Considering those fallacies of the national examination, it is very critical to review the test items to see whether it is of high quality, is more fair, reliable and objective in depth. Therefore, this study was done to provide data for the improvement of the test contents as well as the teachers's assessment skill. For this study, the ad hoc committee was composed of 16 members, including 5 education board members of Korean Academic Nurses Association and 11 nursing faculty members. This committee had one day panel discussion and filled the checklist for this study. The process of analysing data was held over 10 times during 1992-1994. The analysis focussed on educational taxonomy such as cognitive domain(knowledge), psychmotor domain (skill), affective domain(attitude) and the level of learning such as recall, understanding, problems solving, and learning area of theory and practice, and the learning content categorised by nursing process and disease process. The test analysed using difficulty index and the structure of the test items was analysed. The conclusions and suggestion as follows : 1. In learning area, the average ratio of the theory and practice was 1 : 1.1 which was less than 1 : 2 suggested by Korean National Health Institute, and the ratio was different by the 8 leaning subjects of nursing. 2. In category of the educational taxonomy, the knowledge domain was emphasized mostly(79. 7%), the skill domain was 14.9%, and the attitude domain was 5.4% only. 3. In the level of learning, generally, the test items of the level of recall(45.5%) and the understanding(46.3%) were covered almost and the problem solving was 8.1%. 4. In the learning contents, generally, the test items related to nursing process was 67.2% and that of disease process was 32.8%. However, this proportion was different by the 8 leaning subjects. Even though the nursing diagnosis has been emphasized in nursing curricula recently, the test items of this was identified very few. 5. In the structure of the test item, some were not clear, incorrect grammar, unclear description and some have clues to answer. 6. In the item analysis, the non-acceptable level of the difficulty index (means too easy) was 65.7%, and the acceptable level was 33.9%. Considering the results we would like to suggest the followings, 1. Since the test items of knowledge domain was dominant, the test items of the practice domain and attitude domain should be emphasized more. 2. The regular review and analysis of NERN should be arranged in order to improve the quality of the test items which will give influence to the nursing education positively.

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A Critical Study on Arthur C. Danto's' Philosophizing Art' (단토의 '철학하는 예술' 개념에 대한 비판적 고찰)

  • Kim, Baik-Gyun
    • The Journal of Art Theory & Practice
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    • no.10
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    • pp.183-202
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    • 2010
  • The term "philosophizing art" was coined by Arthur Danto, who tried to define new forms of art, especially Andy Warhol's pop art appeared in New York after 1960's, which could not be explained by traditional concept of "representation". As Danto said "the term 'philosophizing art' is unclear, whether art discusses philosophical issues or art is the object of philosophic discussions", it does not seem like Danto himself had a specific idea when he used this term. The background for Danto coining this term derives from the fact that the old art concept such as denotation and connotation could not fully explain phenomenalistic aspects of concept art which appeared frequently at that time. Many articles in his book "philosophizing art", in which many of his criticism are included, mainly say that art begins philosophizing by dealing with not mimesis or representation but concepts. According to his argument, the history of western art, which has been consisted of mimesis and representation, has come to end when art is about physically embodied with meaning. Of course, as Danto say so, what goes to end is not art itself, but the narrative of art. It means master narrative saying art should be shown different from nature or artificial daily product is over. Danto could not find principals of mimesis and representation which had been main logic in the western art history, when he saw Andy Warhol's Brillo Boxes at Stable Gallery, New York in 1964. Danto questioned "if we can not distinguish Brillo box's artistic aspects visually from other factory-made products, how can we distinguish art from non-art", By answering those questions, he discovered two facts which made him realize the end of Art: One is there is no special way in which works of art have to be shown or has to exist. Therefore, art history has proven that commercial boxes, trashes and files of underwear can be a work of art. The other is we have fully recognized it at the end of 20thcentury. Danto confessed that through Brillo Boxes, he realized the works of art are decided by something can not be seen by eyes, not by distinguished differences by looking at it. This thesis is trying to show personal understanding about art, philosophy and discourses surrounding them and to figure out how Dante opened a new world to art criticism by using new definitions such as 'end of art' and 'philosophizing art' which Danto used to explain inner aspects of art.

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A Study of the Scope and the Electronization of Electronic Letter of Credit in the Practitioner's Perspective (전자신용장의 활용범위와 '전자화' 정도에 대한 연구: 실무자적 관점을 중심으로)

  • Chung, Yong-Kyun;Jeong, Jae-Yeon
    • International Commerce and Information Review
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    • v.15 no.2
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    • pp.429-455
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    • 2013
  • This paper investigates the extent and scope of electronization of Letter of Credit and examines the obstacles in the course of electronization of Letter of Credit. For this purpose, this paper adopts two track methodologies. First, we study the electronization of Letter of Credit in the macro perspective. It means that we analyze the scope and the extent of electronization of electronic Letter of Credit in the national economy as a whole. Second, we utilize the case study approach to examine the electronization of Letter of Credit in micro perspective. In other words we examine individual commercial banks in Korea. For this purpose, we analyze the data from two commercial banks out of four largest domestic banks in Korea. For example, we select two commercial banks in Korea and ask current status of electronization of Letter of Credit, i.e, the utilization of EDI L/C, e-L/C, and e-B/L. A major finding of our study is that the extent of electronization is not negligible in micro perspective as well as in macro perspective. In micro perspective, two commercial banks utilize EDI letter of credit in a critical sense. On the other hand, they seldom uses e-L/C and e-B/L in international transaction. This study shows that major bottlenecks for the electronization of Letter of Credit are pessimistic perception of SME entrepreneurs toward the electronization of Letter of Credit and the high costs of system building. We conclude that unlike superficial perception, there is a considerable progress toward the electronization of Letter of Credit in micro perspective.

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A New Upper Layer Decoding Algorithm for a Hybrid Satellite and Terrestrial Delivery System (혼합된 위성 및 지상 전송 시스템에서 새로운 상위 계층 복호 알고리즘)

  • Kim, Min-Hyuk;Park, Tae-Doo;Kim, Nam-Soo;Kim, Chul-Seung;Jung, Ji-Won;Chun, Seung-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.9
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    • pp.835-842
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    • 2009
  • DVB-SSP is a new broadcasting system for hybrid satellite communications, which supports mobile handheld systems and fixed terrestrial systems. However, a critical factor must be considered in upper layer decoding which including erasure Reed-Solomon error correction combined with cyclic redundancy check. If there is only one bit error in an IP packet, the entire IP packet is considered as unreliable bytes, even if it contains correct bytes. IF, for example, there is one real byte error, in an If packet of 512 bytes, 511 correct bytes are erased from the frame. Therefore, this paper proposed two kinds of upper layer decoding methods; LLR-based decoding and hybrid decoding. By means of simulation we show that the performance of the proposed decoding algorithm is superior to that of the conventional one.