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Determination of Electron Spin Relaxation Time of the Gadolinium-Chealted MRI Contrast Agents by Using an X-band EPR Technique (EPR을 통한 상자성 자기공명 조영제의 전자스핀 이완시간의 결정)

  • Sung-wook Hong;Yongmin Chang;Moon-jung Hwang;Il-su Rhee;Duk-Sik Kang
    • Investigative Magnetic Resonance Imaging
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    • v.4 no.1
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    • pp.27-33
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    • 2000
  • Purpose: To determine the electronic spin relaxation times, $T_{le}$, of three commercially available Gd-chelated MR contrast agents, Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA, using Electron Paramagnetic Resonance(EPR) technique. Material and Methods: The paramagnetic MR contrast agents, Gd-DTFA(Magnevist) , Gd-DTFA-BMA(OMNISCAN) and Gd-DOTA(Dotarem), were used for this study, The EPR spectra of these contrast agents, which were prepared 2:1 methanol/water solution, were obtained at low temperatures, from $-160^{\circ}C~20^{\circ}C$. The glassy-state EPR spectra for these contrast agents were then fitted by the simulation spectra generated with different zero-field splitting (ZFS) parameters by a computer simulation program 'GEN', which generates the EPR powder spectrum using a given ZFS in $3{\times}3$ tensor. Finally, the spin relaxation times of the contrast agents were then determined from the $T_{2e}$, D, and E values of the best simulation spectra using the McLachlan's theory of average relaxation rate. Results: The electronic transverse spin relaxation times, $T_{2e}'s$, of Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA were 0.113ns, 0.147ns and 1.81ns respectively. The g-values were 1.9737, 1.9735 and 1.9830 and the electronic spin relaxation times, $T_{1e}'s$, were 18.70ns, 33.40ns and $1.66{\mu}s$, respectively. Conclusion: The results of these studies reconfirm that the paramagnetic MR contrast agents with larger ZFS parameters should have shorter $T_{1e}'s$. Among three contrast agents used for this study, Gd-DOTA chelated with cyclic ligand structure shows better electronic property then the others with linear structure. Thus, it is concluded that the exact determination of ZFS parameters is the important factor in evaluating relaxation enhancement effect of the agents and in developing new contrast agents.

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The Principles of Total Quality Management(TQM) and Its Implementation. (총체적 질관리(Total Quality Management)의 이론적 배경과 그 적용실태)

  • Kang, So-Young
    • Journal of Korean Academy of Nursing Administration
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    • v.1 no.2
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    • pp.388-407
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    • 1995
  • This study is (a) to describe the history of Total Quality Management (TQM) generated in the industry, health care service, and nursing society ; (b) to define the concept, total quality management including the definition of quality ; (C) to explain the each principle of TQM theory developed by main theorists, E. Deming, J. Juran, and B. Crosby ; (d) to give the examples related to TQM implementation at the health care organization ; and (e) to mention the extent to which the health care organizations are able to evaluate their cultural organization toward TQM and have had the way to measure the effect of TQM implementation. TQM referred to Continuous Quality Improvement(CQI), Quality Improvement(QI), and Total Quality Improvement(TQI), was not recognized by experts in the United States industry, but by economists in Japan until the end of the 1970's. However, the United States' government led to introduce the principles of TQM to general industry as well as health care service area so that TQM became a main philosophy to manage the organizations in health care service. TQM is a structured, systematic process for creating organization-wide participation in planning and implementing continuous improvement in quality. E. Deming established the "Chain reaction in Quality" and the fourteen point of TQM. The Chain reaction in quality is to describe the relationship among the reduction of waste, rework, and delay, quality improvement, customer satisfaction, and productivity. There are fourteen points to explain the principles of TQM by E. Deming. Juran defined the "Quality Trilogy" to improve the level of quality in any organization. Quality Trilogy has three steps such as quality planning, quality control, and quality improvement for implementing the TQM projects. Crosby describes his TQM theory by establishing "Four Absolutes" and "Fourteen steps in TQM" implementation. Until now, most healthcare organizations have made efforts to organize the TQM task team and to implement TQM principles with various issues. There are three priorities to select the TQM issues : High-volume, High-risk, and Problem-prone. However, there is no absolute, credible measurement yet to evaluate the effects of TQM implementation in health care organization regardless of the classification of health care organizations, geographical background, and social influence. Thus, developing the evaluation way in terms of TQM is the foremost task in health service area. The most important thing for TQM implementation in the organization is to settle up the concept, cultural transformation from traditional management toward quality.

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Variation of Discharge in Length of Hard Micro-path of Drip Hose (점적 호스의 경질 미로 길이에 대한 유량의 변화)

  • Kim, J.H.;Woo, M.H.;Song, N.S.;Kim, D.E.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.57-57
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    • 2017
  • Water line은 UV 처리된 호스의 내부에 압력보상 기능이 첨부된 경질의 미로 튜브를 끼워 사용하도록 제작되어 있다. 점적 호스의 외경은 15.8mm이며 대부분 0.5~2.5bar 사이의 압력에 1.5~3.0 L/hr의 유량을 공급한다. 따라서 전적 호스의 내부에 위치한 경질 미로 튜브의 설계는 유량의 압력보상에 밀접한 관계가 있다. 본 연구에서는 경질 미로 튜브를 통과하는 작은 돌기의 수가 압력과 유량에 어떤 영향을 미치는지에 대한 기초적인 실험을 수행하였으며 경질 미로의 압력과 유량 특성에 따른 이론적 해석과의 비교분석을 통하여 새로운 미로의 형상 설계에 활용할 기초적 연구를 수행하고자 하였다. 점적 호스의 성능은 길이(보통 300~400m)에 대한 유량의 균등성을 유지하는 것이며 균등성은 압력보상에 의해 이루어진다. 원통형 미로는 점적 호스의 내부에 삽입되어 원통 부분에 형성된 미로의 길이에 따른 유량의 균등성을 유지하도록 설계되어 있다. 점적 호스의 원통 주변에는 8개의 미로로 구성되어 있으며 미로의 길이를 금속 평면으로 금형 제작하여 투명판에서 미로의 형상을 보이게 하였다. 또한 입구부분에 물을 공급하고 미로의 각 위치별 배출구를 설치하여 압력에 따른 유출량을 전자저울에 측정하여 압력별 유량의 균등성에 대한 데이터를 측정하였다. 유입구의 압력을 0.5, 1.5, 2.5, 3.0bar로 각각 공급하였으며 유출량은 미로의 8개 구간에 따라 측정하였다. 경질 미로의 유출량은 미로의 길이가 짧을수록, 압력이 커질수록 유출량이 높게 나타났다. 또한 미로의 길이가 짧을 경우에는 유출량의 차이가 비교적 크게 나타났으나 미로의 길이가 길수록 압력에 대한 유출량에 대한 차이가 크지 않음을 알 수 있었다. 따라서 경질 미로에서 미로의 길이를 길게 할 경우에는 유출량을 비교적 균일하게 할 수 있음을 보여주고 있다. 반면에 미로의 길이가 길어질수록 압력변화에 따른 유출량이 지수적으로 감소함을 나타내고 있다. 미로의 길이가 7번과 8번에서는 상당히 균일한 성능을 보여주므로 경질 미로의 배출구를 전체적으로 모두 활용함으로써 압력보상을 비교적 균일하게 할 수 있음을 보여주고 있다. 압력보상은 탄성을 가진 실리콘과 미로로 구성될 경우에 가장 큰 효과를 나타내지만 점적 호스와 같이 경질 미로만으로 압력보상을 해야 할 경우에는 경질 미로의 길이가 매우 중요하다.

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An Analysis of Inquiry Activities in the Chemistry Parts of Middle School Science Textbook Based on the Sixth Curriculum (제 6차 교육과정에 따른 중학교 과학(화학부분) 교과서의 탐구활동 분석)

  • Moon, Seong Bae;Jun, Sung Ae;Kim, Yun Hi
    • Journal of the Korean Chemical Society
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    • v.45 no.2
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    • pp.162-176
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    • 2001
  • This study was covered with the analysis of five kinds of the middle school science text books(chemistry part) based on the oth curriculum. Particularly, inquiry activities part was analyzed by the three dimension framework which consists of inquiry content dimension, inquiry process dimension and inquiry context dimension and the results are as follows;1. In the analysis of the contents in the middle school science textbooks(chemistry part), the average number of total pages was 197.6. The illustration and picture were contained 0.66 in number per a page, and the average number of further readings was 5.8.2. In the analysis of the inquiry content dimension of inquiry activities, the total number of themes in five kinds of textbooks was 222. And the number of imquiry activities in five kinds of textbooks was siverse : A textbook had 51, B texbook 49, C textbook 37 and E textbook 35.3. For the analysis of inquiry process dimension. it follows in the order of 'interpreing data and formulating generalizations (42.4%)','observation and measuring (38.1%)','seeing a problem and seeking ways to solve it (7.8%)' and 'building, testing and revising the theoretical model(11.7%)'.4. As for the analysis of the inquiry context dimension, the scientific context occupied 94.2%, the individual context 0.4%, the social context 2.7% and the technical context 2.7%. It shows that the proportion of STS(Science-Technology-Society) related contents in inquiry activities was only 5.8%.

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The Effect of Creativity of Executives on Innovative Performance of Firms: Focusing on the Mediating Effects of Entrepreneurial Orientation and Technological Innovation Orientation of Research Organization (경영자의 개인창의성이 기업 혁신성과에 미치는 영향: 연구조직의 기업가지향성과 기술혁신지향성의 매개효과를 중심으로)

  • Shin, Ju Hoon;Cho, Keun Tae;Park, Sang Hyeok
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.13 no.1
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    • pp.73-87
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    • 2018
  • Creativity, entrepreneurship, and technological innovation orientation are key factors for technological innovation. The main driver of technological innovation in the enterprise is the executives of the firm. According to the Upper Echelons Theory of D.C. Hambrick(2007), the creativity of the managerial individual will be put into various aspects within the organization's innovation system. The organizational innovation system is positively influenced by the creativity of the executives, and is achieved by manifesting innovation orientation and technological innovation orientation with innovative performances. The purpose of this study is to investigate using Structural Equation Modeling(SEM), whether individual creativity of executives of 132 companies with research organizations among domestic semiconductor companies in Korea influences innovation performance of firms through entrepreneurship orientation and technology innovation orientation. We applied the personal creativity level measurement index, the entrepreneurial orientation measurement factor, and the technology innovation orientation measurement factor identified in the previous research literature. The results of the Structural Equation Modeling analysis show that the creativity of executives have a positive (+) relationship with the innovation performance of firms when they are only mediated by technological innovation orientation, and entrepreneurial orientation. On the other hand, the results of the SEM shows the direct effects between the creativity of executives and innovation performance are not statistically valid. As a result, the individual creativity of executives who lead the innovation of the firm, entrepreneurial orientation, and technological innovation orientation of the researcher organization are very important factors and an inseparable relationship for the successful innovation of the firms.

Transient Torsional Vibration Analysis of Ice-class Propulsion Shafting System Driven by Electric Motor (전기 모터 구동 대빙급 추진 시스템의 과도 비틀림 진동 분석)

  • Barro, Ronald D.;Lee, Don Chool
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.9
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    • pp.667-674
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    • 2014
  • A ship's propulsion shafting system is subjected to varying magnitudes of intermittent loadings that pose great risks such as failure. Consequently, the dynamic characteristic of a propulsion shafting system must be designed to withstand the resonance that occurs during operation. This resonance results from hydrodynamic interaction between the propeller and fluid. For ice-class vessels, this interaction takes place between the propeller and ice. Producing load- and resonance-induced stresses, the propeller-ice interaction is the primary source of excitation, making it a major focus in the design requirements of propulsion shafting systems. This paper examines the transient torsional vibration response of the propulsion shafting system of an ice-class research vessel. The propulsion train is composed of an electric motor, flexible coupling, spherical gears, and a propeller configuration. In this paper, the theoretical analysis of transient torsional vibration and propeller-ice interaction loading is first discussed, followed by an explanation of the actual transient torsional vibration measurements. Measurement data for the analysis were compared with an applied estimation factor for the propulsion shafting design torque limit, and they were evaluated using an existing international standard. Addressing the transient torsional vibration of a propulsion shafting system with an electric motor, this paper also illustrates the influence of flexible coupling stiffness design on resulting resonance. Lastly, the paper concludes with a proposal to further study the existence of negative torque on a gear train and its overall effect on propulsion shafting systems.

A Comparative Study on the Traditional Medicine Policies between Korea and China: Focused on the Second Korean Medicine Development Plan and the 12.5 Traditional Chinese Medicine Development Plan (한국과 중국의 전통의학 정책 비교: 제2차 한의약육성발전계획 및 중의약사업발전 12.5규획 중심)

  • Ko, Chang-Ryong;Ku, Nam-Pyong;Seol, Sung-Soo
    • Journal of Korea Technology Innovation Society
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    • v.17 no.2
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    • pp.421-447
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    • 2014
  • Traditional medicine has been integrated into the national health system in many countries such as Korea, China, Taiwan, etc. Korea and China are most representative among them. The purpose of this study is to compare the policies on traditional medicine in Korea and China focusing on where it came from and where it is headed. In this regard, the study suggested the first analysis tool in the world for analyzing the policy of traditional medicine. The results of the study are as follows: First of all, the development process of Korean Medicine (KM) and Traditional Chinese Medicine (TCM) shows the same pattern, that is, both are influenced by its own national policies. Secondly, the difference between the two countries is due to the gap in the development status or the different aspects in national heath system. TCM is more vitalized in health system and has larger category, and stays ahead in globalization compared to KM. TCM covers Chinese medicine, integrative medicine and ethno-medicine. Korea emphasizes the role of KM in the declining birthrate and aging society, and promotes the overseas patient invitation strategy. China, on the other hand, establishes the medical system for emergency medical treatment and preventive treatment of major diseases and promotes overseas expansion of TCM service. In addition, Korea stressed the safety and distribution of herbal medicine, and China emphasizes production technologies. Korea has a strong medical device industry along with the government's fostering policy; however, in China, medical devices are in the R&D stage yet. Even though both countries promotes the drug development from natural products, Korea focuses on developing herbal cosmetics in application industry, but China shows weakness in policies on application industry. China shores up the foundation for culture and theory of traditional medicine, while Korea doesn't have related policy. Korea places emphasis on promoting collaboration with international organizations and medical volunteer programs, whereas China is more interested in mutual cooperation and real trade with other countries.

Two-Stage Evolutionary Algorithm for Path-Controllable Virtual Creatures (경로 제어가 가능한 가상생명체를 위한 2단계 진화 알고리즘)

  • Shim Yoon-Sik;Kim Chang-Hun
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.11_12
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    • pp.682-691
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    • 2005
  • We present a two-step evolution system that produces controllable virtual creatures in physically simulated 3D environment. Previous evolutionary methods for virtual creatures did not allow any user intervention during evolution process, because they generated a creature's shape, locomotion, and high-level behaviors such as target-following and obstacle avoidance simultaneously by one-time evolution process. In this work, we divide a single system into manageable two sub-systems, and this more likely allowsuser interaction. In the first stage, a body structure and low-level motor controllers of a creature for straight movement are generated by an evolutionary algorithm. Next, a high-level control to follow a given path is achieved by a neural network. The connection weights of the neural network are optimized by a genetic algorithm. The evolved controller could follow any given path fairly well. Moreover, users can choose or abort creatures according to their taste before the entire evolution process is finished. This paper also presents a new sinusoidal controller and a simplified hydrodynamics model for a capped-cylinder, which is the basic body primitive of a creature.

Foreign Stock Investment and Firms's Dividend Policy in Korea (외국인 투자자가 국내 유가증권시장 상장기업의 배당 행태에 미치는 영향에 대한 연구 : 다양한 계량경제모형의 적용)

  • Kim, Young-Hwan;Jung, Sung-Chang;Chun, Sun-Eae
    • The Korean Journal of Financial Management
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    • v.26 no.1
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    • pp.1-29
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    • 2009
  • As foreign investors' share holdings in Korean firms have dramatically increased since 1998 following the financial deregulation on the limit of foreign stock investment, the concern over the negative impacts the foreign investors would bring on the firms' financial policy has been growing too. Foreign investors were perceived to require the firms of excessive payments of cash dividends sometimes with threat of hostile takeover trials detering the firm from investing its cash flow in the physical facilities and RandD eroding their potential growth capabilities. We examine the impact of foreign investment on the firms' dividend policy using 234 listed firms' panel data over the sample periods of 1998 to 2005 employing various panel regression methodology. Foreign shareholders are found not to be related or even negatively related to the payout ratio(dividend/net income), but positively and statistically significantly related to the ratio of cash dividends to book of asset, negatively to the dividend yields. Considering the payout ratio is the most appropriate measure for the dividend payment, we can not support the arguments that the foreign investors' holdings have induced the excessive dividend level in Korean firms.

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A Study on the Torsional Vibration Characteristics of Super Large Two Stroke Low Speed Diesel Engines with Tuning Damper (튜닝댐퍼를 갖는 초대형 저속 2행정 디젤엔진의 비틀림진동 특성에 관한 연구)

  • Lee, Don-Chool;Barro, Ronald D.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.64-75
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    • 2009
  • The shipbuilder's requirement for a higher power output rating has led to the development of a super large two stroke low speed diesel engines. Usually a large-sized bore engine ranging from $8{\sim}14$ cylinders, this engine group is capable of delivering power output of more than 100,000 bhp at maximum continuous rating(mcr). Other positive aspects of this engine type include higher thermal efficiency, reliability, durability and mobility. This plays a vital role in meeting the propulsion requirement of vessels, specifically for large container ships, of which speed is a primary concern to become more competitive. Consequently, this also resulted in the modification of engine parameters and new component designs to meet the consequential higher mean effective pressure and higher maximum combustion pressure. Even though the fundamental excitation mechanisms unchanged, torsional vibration stresses in the propulsion shafting are subsequently perceived to be higher. As such, one important viewpoint in the initial engine design is the resulting vibration characteristic expected to prevail on the propulsion shafting system(PSS). This paper investigated the torsional vibration characteristics of these super large engines. For the two node torsional vibration with a nodal point on the crankshaft, a tuning damper is necessary to reduce the torsional stresses on the crankshaft. Hence, the tuning torsional vibration damper design and compatibility to the shafting system was similarly reviewed and analyzed.