• The Journal of Korean Philosophical History
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• no.32
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• pp.161-183
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• 2011

Lee Ik(李瀷) had put emphasis on the achievements by self-regulated academic learning through doubts, and at the same time that it was all-embracing. His academic attitude had set an example among the members of Seongho school(星湖學派), and his disciples had strived to emulate his style. The greatness of Seongho(星湖)'s study had been revealed by development of Seongho school(星湖學派) right after his death. He had argued that the six strokes of I-Ching should be read having it divided into inward and outward divine signs. He had stated his view clearly that the divine signs ranging from one stroke to six strokes were not connected, same as Shao yong(邵雍)'s method, but, the three strokes of inward divine sign as well as the three strokes of outward divine signs were independent from each other. Seongho(星湖) also had raised many questions about Shifa(筮法), and Bianyao(變爻) and Zhuzi(朱子)'s Shifa(筮法), or Yixueqimeng("易學啓蒙") "Kaobianzhan("考變占")". In view of the Shifa(筮法), Seongho(星湖) had helped Dasan(茶山) to present 'Shiguafa(蓍卦法)' by proposing different divination rule from Zhuzi(朱子)'s Method of Divination by Shiyi("筮儀"). Seongho(星湖) had not professed something significantly different from Zhuzi(朱子) in his I-xue. His study on I-xue had been accomplished under his goal of achievements by self-regulated academic learning through doubts. "Shiguakao("蓍卦攷")" is also same. I-xue of Seongho(星湖) had made a great contribution to form Dasan(茶山)'s I-xue in the later years.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1022-1035
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• 2016

A double-tube once-through steam generator (DOTSG) consisting of an outer straight tube and an inner helical tube is studied in this work. First, the structure of the DOTSG is optimized by considering two different objective functions. The tube length and the total pressure drop are considered as the first and second objective functions, respectively. Because the DOTSG is divided into the subcooled, boiling, and superheated sections according to the different secondary fluid states, the pitches in the three sections are defined as the optimization variables. A multi-objective optimization model is established and solved by particle swarm optimization. The optimization pitch is small in the subcooled region and superheated region, and large in the boiling region. Considering the availability of the optimum structure at power levels below 100% full power, we propose a new operating scheme that can fix the boundaries between the three heat-transfer sections. The operation scheme is proposed on the basis of data for full power, and the operation parameters are calculated at low power level. The primary inlet and outlet temperatures, as well as flow rate and secondary outlet temperature are changed according to the operation procedure.