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A Mathematical Approach to Allocate the Contributions by Applying UPFCs to Transmission System Usage

  • Sedaghati, Alireza
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.158-163
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    • 2005
  • Competitive electricity markets necessitate equitable methods for allocating transmission usage in order to set transmission usage charges and congestion charges in an unbiased and an open-accessed basis. So in competitive markets it is usually necessary to trace the contribution of each participant to line usage, congestion charges and transmission losses, and then to calculate charges based on these contributions. A UPFC offers flexible power system control, and has the powerful advantage of providing, simultaneously and independently, real-time control of voltage, impedance and phase angle, which are the basic power system parameters on which sys-tem performance depends. Therefore, UPFC can be used efficiently and flexibly to optimize line utilization and increase system capability and to enhance transmission stability and dampen system oscillations. In this paper, a mathematical approach to allocate the contributions of system users and UPFCs to transmission system usage is presented. The paper uses a dc-based load flow modeling of UPFC-inserted transmission lines in which the injection model of the UPFC is used. The relationships presented in the paper showed modified distribution factors that modeled impact of utilizing UPFCs on line flows and system usage. The derived relationships show how bus voltage angles are attributed to each of changes in generation, injections of UPFC, and changes in admittance matrix caused by inserting UPFCs in lines. The relationships derived are applied to two test systems. The results illustrate how transmission usage would be affected when UPFC is utilized. The relationships derived can be adopted for the purpose of allocating usage and payments to users of transmission network and owners of UPFCs used in the network. The relationships can be modified or extended for other control devices.

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In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment

  • Cordasco, Giancarlo;Giudice, Antonino Lo;Militi, Angela;Nucera, Riccardo;Triolo, Giuseppe;Matarese, Giovanni
    • 대한치과교정학회지
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    • 제42권4호
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    • pp.218-224
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    • 2012
  • Objective: To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods: Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at $36^{\circ}C$ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. Results: The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Conclusions: Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when lowstiffness alignment wires are used.

한.중 FTA 추진에 따른 농산물교역의 과제와 대응방안 (Prospect of FTA and Trade of Agricultural Products between Korea and China)

  • 배기형;조성제
    • 통상정보연구
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    • 제12권3호
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    • pp.167-195
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    • 2010
  • The global financial crisis, the instability of the global economy since the beginning of the growing economic interests of the countries to adjust to establish a new economic system was set up on occasion. Meanwhile, standing in the international trade environment, multilateral system of international trade for the country as the cumulative fatigue of open markets and trade liberalization as an alternative to lead the free trade agreements between countries. Currently in Korea and China, in addition to the geographical proximity in all areas, including economic exchanges and mutually dependent relationship that is deepening the world's No. 1 exporter in China and overseas investors have become partners. FTA with China by promoting the growth of emerging economies in the Chinese market by securing a stable economic growth of China as a driver of economic growth in the country to utilize the plan is being promoted from. This study is currently being promoted, in a discussion of the FTA's agricultural trade measures to address the challenges and poems. Agricultural trade with other goods to be different from the specificity of the discussion of market opening and liberalization of trade has been recognized in the main essentially nothing. We promote an FTA, according to one review and discuss the background and trends of the agricultural trade in a market, through the analysis of the status and trends and present problems for future bilateral trade negotiations with Korea for agricultural markets and propose countermeasures for. Agricultural trade, during a discussion of the FTA is essentially nothing in the review is expected to expand the bilateral trade in agricultural products, while protecting its agricultural markets to be trying to policy implications.

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지역 전수교육관의 문화융합을 위한 공간 개선 연구 (A Study of Improve Space for Culture Convergence of Local intangible cultural heritage teaching hall)

  • 이상희;전칠수
    • 한국융합학회논문지
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    • 제8권11호
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    • pp.299-306
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    • 2017
  • 본 연구는 전수교육관의 대형화와 복합화 추세에 있어, 교육 외에도 방문객을 위한 차별화된 프로그램의 개발, 다양한 문화생활 지원을 위한 복합화의 방법, 그리고 지역주민들의 참여가 가능한 무형문화재 전수시설로서 공공성 증진을 위한 방안을 모색하고자 하는 것이다. 많은 중소도시의 경우 무형문화재전수시설은 전반적으로 복합화와 공공성을 수용하기 위해서는 공간이 미비한 상태여서, 전수교육관의 활성화를 위해 개선이 더욱 절실하다. 따라서 본 연구는 전수교육관의 활성화 방안을 모색하기 위한 기초연구로, 수도권 및 광역권 등의 대도시를 제외한 지역에 3곳의 전수교육관에 대한 방문조사를 통해 사용자 관점의 활성화 방안을 모색하기 위해 건립과 운영 실태를 파악하였다. 본 연구를 토대로 전수교육관이 본래의 기능과 더불어 공공성을 갖춘 복합문화공간으로 거듭나도록 기초연구자료로 활용되길 기대한다.

온실 난방을 위한 모세관형 태양열 집열기의 성능에 미치는 유량의 효과에 관한 연구 (The Effects of Water Flow Rates on the Performance of a Capillary Tube Solar Collector for Greenhouse Heating)

  • 유영선;장유섭;홍성기;윤진하;정두호;강영덕
    • 생물환경조절학회지
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    • 제5권1호
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    • pp.57-64
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    • 1996
  • To use effectively the solar energy in greenhouse heating, a high performance solar collector should be developed. And then the size of the solar collector and thermal storage tank should be determined through the calculation of heating load. The solar collector must be set in the optimum tilt angle and direction to take daily solar radiation maximally, and the flow rate of heat transfer fluid through the solar collector should be kept in the optimum range. In this research, the performance tests of a capillary tube solar collector were performed to determine the optimum water flow rate and the results summarized as follows. 1. The regressive equations for efficiency estimations of the capillary tube solar collector in the open loop were modeled in the water flow rate of 700-l,000 $\ell$/hr. 2. The optimum water flow rate of the solar collector was estimated by the second order polynomial regression and the maximum efficiency was 80% at the water flow rate of 850 $\ell$/hr. 3. The solar thermal storage system consisted of a capillary tube solar collector and a water storage tank was tested at the water flow rate of 850 $\ell$/hr in the closed loop, and obtained the solar thermal storage efficiency of 55.2%. 4. As the capillary tube solar collector engaged in this experiment was made of non-corrosive polyolefin tubes, its weight was as light as 1/30 of the flat plate solar collector made of copper tubes. Therefore it was considered to be suitable for the greenhouse heating system.

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오리엔탈리즘을 응용한 유니폼 디자인 연구 - 한국·일본·중국의 전통의상을 중심으로 - (A Study on Uniform Design Applied Orientalism)

  • 진경옥;이민정
    • 한국의류산업학회지
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    • 제5권5호
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    • pp.443-452
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    • 2003
  • People have been getting interested in the Orientalism and it has come up in various areas due to scientific progress. I designed uniforms, which was simple and western, to show its symbolic meanings in the Orientalism. And I have been trying to generalize uniforms with originality and beauty. I have studied the process of the Orientalism and its changes and transitions, concepts and origins in history. And I applied the styles of Korean, Japanese and Chineses costume on it. I also referred to characters of uniforms, which already had images of Korea, Japan and China. Firstly, Korean styles have a contrast in colors by application of Taegeuk. And they gave lines with dark colors in black one-piece dress. This makes people who are wearing looking slimmer. White ramie top looks fresh and Korean traditional tie called Maedeup is set up for button. Secondly, Japanese styles were mainly Kimono style, one piece. They changed into two pieces designed to be active. So, it has emphasized the image of Kimono with Obi at the waist. Thirdly, Chinese styles basically are Chipao style, which has a Chinese collar and a long skirt, which has opening. But they gradually changed into short skirts and more open in the chest. For one of them, they gave lines in the side of chest, sleeves and skirt to be more natural. The costumes have kept their positions as a part of mass society that grows and changes with speed. And oriental uniforms are not just uniforms any longer only for work. It is quite symbolic like a 'second face' as it represents images for their countries and enterprises.

Comparing Compliance and Efficacy of Isocaloric Oral Nutritional Supplementation Using 1.5 kcal/mL or 1 kcal/mL Sip Feeds in Mildly to Moderately Malnourished Indonesian Children: A Randomized Controlled Trial

  • Devaera, Yoga;Syaharutsa, Danny Maesadatu;Jatmiko, Herwasto Kuncoroyakti;Sjarif, Damayanti Rusli
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제21권4호
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    • pp.315-320
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    • 2018
  • Purpose: This study set out to evaluate the compliance to, and efficacy of oral supplementation, using a 1.5 kcal/mL or 1 kcal/mL sip feed, in children with mild to moderate malnutrition. Methods: This was a parallel, randomized, controlled open-label trial in children aged 3 to 6 years with a weight for height Z (WHZ) score <-1 and ${\geq}-3$, who were randomized to receive a total of 600 kcal/day from either a 1.5 kcal/mL or a 1.0 kcal/mL pediatric sip feed for 28 days. Assessments included daily study product intake, body weight, tolerance and dietary intake from solid food. Results: Of 110 children recruited, 98 ($mean{\pm}standard$ deviation of age $49{\pm}7months$) completed the study. Both sip feeds were well tolerated, with high compliance ($80{\pm}24%$ and $81{\pm}22%$ of prescribed volume in 1.5 kcal/mL and 1.0 kcal/mL groups respectively, p=0.79). Both study groups gained similar weight during the 28 days intervention period ($0.42{\pm}0.40kg$ in 1.5 kcal/mL group vs. $0.49{\pm}0.49kg$ in 1.0 kcal/mL group, p=0.43). There were no significant differences between the groups in weight gain and in the change in WHZ score over the intervention period. Dietary analysis at the end of the study did not show replacement of solid food by the oral nutritional supplements. Conclusion: In children with mild to moderate malnutrition, both 1.5 kcal/mL and 1 kcal/mL pediatric sip feeds had high compliance and were well tolerated, and were equally effective in promoting weight gain in the 28 days study period.

Determination of Chemical Composition of Gallbladder Stones and their Association with Induction of Cholangiocarcinoma

  • Hussain, Saad Muhmood;Al-Jashamy, Karim Alwan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6257-6260
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    • 2013
  • Gallstone disease is a major surgical problem in many populations; it is probably related to diet, especially excessive consumption of meat. The objective of this study was to determine the chemical composition of gallstones and their association with neoplastic changes including cholangiocarcinomas in cholecystectomised patients. The chemical composition of gallstones from 40 patients (8 males and 32 females) was analyzed. This is a prospective study performed in Baquba teaching hospital in the period from 1/10/2012 to 1/1/2013 in which we collected the gallstones for the patients who underwent cholecystectomy, whether open or laparoscopic. The stones were classified according to their chemical composition as a mixed stones (MS), and examined using a stone analysis set (chemical qualitative method) for calcium, magnesium, phosphate, uric acid and oxalate which was used reagent for qualitative determination of main individual components of stones. The results of this study showed the highest incidence of gallstones in the age group 40-49 was 13 cases followed by 11, 8 and 4 cases for age groups 30-39, 50-59, 20-29 and 60 and above, respectively. The chemical analysis showed the majority of gallstones were mixed, 38 containing calcium followed by 37 cases with uric acid, 28 with magnesium, and 25 and 22 stones with oxalate and phosphate, respectively. Microscopically, we confirmed neoplastic changes (17.5%) as cholangiocarcinomas (CCCs) (7.55%) and dysplastic cells of carcinoma in situ in 4 (10%), 31 (77.5%) cases were chronic cholecystitis and 2 (5%) cases were acute cholecystitis with empyema out of bile duct disorders patients. In conclusion, majority of cases had mixed gallstones that involved five and four of inorganic chemicals of calcium, magnesium and phosphate, the highest incidence of gallstones in age group 40-49 years old was 13 cases, and neoplastic changes were confirmed (17.5%) including CCCs, (7.5%) and dysplastic cells of carcinoma in situ (10%), while 31 (77.5%) cases were chronic cholecystitis.

유체기계에 있어서 부의 음원 임피던스의 원인에 관한 고찰 (A Review of the Possible Causes of Negative Source Impedance in Fluid Machines)

  • 이정권
    • 한국음향학회지
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    • 제20권3호
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    • pp.76-82
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    • 2001
  • 대부분의 유체기계는 일정 조건하에서는 주기적인 소음 원들로 간주될 수 있으며, 소음원 및 관련 덕트의 음향계를 주파수영역으로 표현이 가능하게 되는데, 음원은 주파수의 함수인 음원강도와 음원 임피던스로 표현된다. 이들 변수를 알아내기 위하여는 다양한 이론적, 실험적 방법이 있으나, 고속, 고온, 고강도의 유체 기계와 같은 단일 연결구를 갖는 음원에 대하여는 다양한 길이의 많은 관들을 부하로 사용하는 다부하법만이 적용 가능하다. 문제는 이 다부하법을 적용했을 때, 음원 임피던스의 실수부가 부의 값을 갖는 경우가 많다는 점이다. 본 논문에서는 이 문제의 명확한 원인분석을 위한 일환으로서, 다양한 이론적 실험적 결과에 대한 분석을 바탕으로 하여 가능한 여러 가지 원인에 대한 물리적 조사 결과를 보이고, 분석 결과에 대한 새로운 해석을 통해 기본 가정의 위배와 함께 다부하법 자체의 문제점을 제시한다 유체 기계 덕트에서는 다른 무엇보다도 음원의 시변성이 부의 음원저항을 낳는데 가장 큰 영향을 미치게 되며, 부하 임피던스가 최종 결과에 지대한 영향을 미치게 된다.

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O.P.E.N Triad: The Future Success for Individuals, Institutes, and Industries

  • Kim, Hae-Jung;Forney, Judith;Crowley, Ruth
    • 한국의류학회지
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    • 제34권12호
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    • pp.1980-1991
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    • 2010
  • This study proposes the O P E N Triad framework as a future set of tools and perspectives for individual members and institutes to further their professional and academic potential as well as prospect and vitalize the future of the Korean Clothing and Textiles discipline through a global perspective. The millennial generation desires On-demand, Personal, Engaging, and Networked (O P E N) experiences effecting cultural change for creative and influential interaction in transactions, communication, and education. O P E N Individuals offers a WebSphere model as a holistic learning system that has a synergizing value of education across academic courses, industries, and cultures. Through a digitalized and virtualized class, it complements relevant technologies already familiar to the student population. By employing environmental scanning approaches, the most influential and viable future global issues related to the clothing and textiles discipline are identified and dialogued within O P E N Institutes. For future clothing and textiles institutes, this scanning allows them to be open to new ideas, to focus on inter-engagements, to collaborate among individuals, to associate as a part of web of people, organizations, and ideas, to personalize an institutes curricula, and to dialogue generative knowledge. O P E N Industries reveals three dominant future issues that cross academia and industry, sustainability, supply chain management, and social networking. In-depth interviews with U.S. industry experts identified interdependent gaps in global consumer experience practices and suggested the following gaps as future research areas: a standardized business model to the entrepreneurial model, strategic management to a sustainable competitive advantage, standardized to differentiated products, services and operations, market segmentation to global consumer clusters, business-driven marketplaces to consumer-engaged marketspaces, and excellent services to optimal experience. This O P E N Triad framework empowers millennial students, universities, and industries to anticipate and prepare for a radically changing world.