• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.715-725
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• 2000

As a link composition of a double link type level luffing jib crane was determinated through the link composition design, the design to be considered will be computations of the luffing trajectory deviation at the fly jib tip and the required luffing device capacity. This paper is a study regarding the static and dynamic analysis for a mechanism of the crane. The objective of the static analysis is to determinate the capacity and the dimension of luffing device when the crane selfload, rated hoisting load, wind load and inertia force are applied on the crane. The objective of dynamic analysis is to compute the luffing trajectory deviation, velocity and inertia force due to luffing acceleration for each link. All analyses are performed by computer programs. The reliability of the program was checked by results from analyses of the related commercial package. It is expected that the productivity and reliability of the design can be improved by this program which can rapidly and exactly deal with static and dynamic analysis for a given link composition of the crane.

• Korean Journal of Oriental Medicine
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• v.14 no.2
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• pp.11-19
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• 2008

In order to unravel the implication on the Hwang Jahu's, a well-known medical doctor, critique of "HyangYakJibSungBang(鄕藥集成方)"(Compendium of Prescriptions from the Countryside)'s publication, this essay calls for an investigation of socio-economical situations and systematic support for the development of native herbal drugs of that time. In the period of King SeJong various systematic aspects supporting the development and utilization of native herbal drugs were created. In this ambient, Hwang Jahu also dedicated his life in the application of native herbal drugs. Though Hwang strongly recommended the use of native herbal herbs while importing insufficient resources from China. He gave a critique of "HyangYakJibSungBang(鄕藥集成方)"'s publication. Hwang's critique didn't lie on the book itself but on the practicality of this large volume from the public. He insisted more on the necessities of practical and easy accessible books for emergency situations. Throughout the emphasis on wide distribution of compact medical books and the utilization of acupuncture and moxibustion, in part reveals his pragmatic stand.

• Journal for History of Mathematics
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• v.19 no.2
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• pp.1-24
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• 2006

We study the theory of finite series in Chosun Dynasty Mathematics. We divide it into two parts by the publication of Lee Sang Hyuk(李尙爀, 1810-?)'s Ik San(翼算, 1868) and then investigate their history. The first part is examined by Gyung Sun Jing(慶善徵, 1616-?)'s Muk Sa Jib San Bub(默思集算法), Choi Suk Jung(崔錫鼎)'s Gu Su Ryak(九數略), Hong Jung Ha(洪正夏)'s Gu Il Jib(九一集), Cho Tae Gu(趙泰耉)'s Ju Su Gwan Gyun(籌書管見), Hwang Yun Suk(黃胤錫)'s San Hak Ib Mun(算學入門), Bae Sang Sul(裵相設)'s Su Gye Soe Rok and Nam Byung Gil(南秉吉), 1820-1869)'s San Hak Jung Ei(算學正義, 1867), and then conclude that the theory of finite series in the period is rather stable. Lee Sang Hyuk obtained the most creative results on the theory in his Ik San if not in whole mathematics in Chosun Dynasty. He introduced a new problem of truncated series(截積). By a new method, called the partition method(分積法), he completely solved the problem and further obtained the complete structure of finite series.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.64-73
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• 2007

Turbulent flows around yacht sails were calculated to access the applicability of CFD for yacht design. Multi-block grid system was generated by using Gridgen package and Fluent was used to calculate flows around two sail system. A 30ft class sailing yacht designed and tested by KRISO was chosen. The interference effect between main and jib sails was analyzed. Pressure distribution on the sails was obtained and the center of effort was estimated. It was found that the jib angle affects the flow phenomena around a main sail due to the change of inflow angle. The location of center of effort is much different from the empirical formula based on a simple geometrical consideration. The calculated results are compared with the previous numerical and experimental results. Both CFD results are similar, but there are some discrepancies with experimental data. However, it is certain that CFD can be a very useful tool for yacht design.

• Journal for History of Mathematics
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• v.22 no.4
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• pp.15-28
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• 2009

In this paper, we study the 17th Century Chosun's mathematics book ${\ll}$Muk Sa Jib San Beob${\gg}$ written by Chosun's mathematician Kyeong Seon Jing. Our study of thebook shows the ${\ll}$Muk Sa Jip San Beop${\gg}$ as an important 17th Century mathematics book and also as a historical data showing the mathematical environment of 17th Century Chosun.

• Korean Architects
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• s.473
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• pp.20-21
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• 2008

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1993.10a
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• pp.3-13
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• 1993

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.42-47
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• 2004

This paper describes basic structural design for the large floating crane barge of fixed undulation type. Structural analysis is performed to divide two parts because crane barge is composed two parts, crane part of jib boom back stay and back tower and barge part to support crane part. The structural strength for jib boom structure members are in compliance with JIS B 8821 and scantling of all barge structural members are in compliance with the requirement of KR (Korean Register of Shipping) Steel Barges and Rules for Classification of Steel Ships. For the structural analysis of large floating crane, MSC/NASTRAN & MSC/PATRAN software is used.

• Journal for History of Mathematics
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• v.27 no.1
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• pp.1-12
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• 2014

From the mid 17th century, Joseon mathematics had a new beginning and developed along two directions, namely the traditional mathematics and one influenced by western mathematics. A great Joseon mathematician if not the greatest, Hong JeongHa was able to complete the Song-Yuan mathematics in his book GuIlJib based on his studies of merely Suanxue Qimeng, YangHui Suanfa and Suanfa Tongzong. Although Hong JeongHa did not deal with the systems of equations of higher degrees and general systems of linear congruences, he had the more advanced theories of right triangles and equations together with the number theory. The purpose of this paper is to show that Hong was able to realize the completion through his perfect understanding of mathematical structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.433-437
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• 2004

A provision crane is generally installed on the upper deck to the rear of the accommodation of the ship in order to load and unload engine part or something heavy. There are two types of provision cranes: one is jib-type and the other is monorail-type. So the natural frequency of the jib-type crane equipment is low, therefore, there are some possibility of resonance between crane structure and the main excitation sources of the ship in normal operating range. This study describe a vibration reduction technique for provision crane by applying a proper countermeasure through finite element analysis and modal test. In order to find out weak point in design of provision crane, a sensitive analysis has been performed.