• East Asian mathematical journal
• /
• v.34 no.2
• /
• pp.219-238
• /
• 2018

The purpose of this paper is to reinterpret and visualize Pappus' methods for trisecting the angle by utilizing the Nicomedes' conchoid and Apollonius' symptom of a hyperbola. In particular, we reinterpret the Pappus' three results which are the methods of hyperbola and circle, the trisection of the arc and focus and directrix of the hyperbola by 3 steps(analysis, construction, and proof) in the current middle school curriculum of Mathematics. Moreover, we visualize the construction of an hyperbola which is represented by means of an eccentricity.

• Journal for History of Mathematics
• /
• v.19 no.4
• /
• pp.81-96
• /
• 2006

This paper aims to review Leibniz's analytic ideas in his philosophy, logics, and mathematics. History of analysis in mathematics ascend its origin to Greek period. Analysis was used to prove geometrical theorems since Pythagoras. Pappus took foundation in analysis more systematically. Descartes tried to find the value of analysis as a heuristics and found analytic geometry. And Descartes and Leibniz thought that analysis was played most important role in investigating studies and inventing new truths including mathematics. Among these discussions about analysis, this paper investigate Leibniz's analysis focusing to his ideas over the whole of his studies.

• Asian Journal of Turfgrass Science
• /
• v.18 no.1
• /
• pp.29-36
• /
• 2004

The efficient refinement of seed is required to reduce the cost and labor input in artificial propagation of wild plant. This study was carried out to develop methods for collecting and refining tiny seeds from wild plants. For obtaining Phragmites communis seeds, the inflorescence was cut into small fragments using a Straw Cutter and subsequently detached pappus hairs from seed coat by Hammer Mill. The primary refined seeds were passed 1.0 mm sieve. The screened seeds were subjected to Seed Blower with wind speed of 0.25 mㆍsec-1 to collected intact and well-ripen seeds. The seeds of Imperata cylindrica were refined as follows. Inflorescences were cut using a Straw Cutter first. The pappus was removed from cut fragments using a Hammer Mill and subsequently subjected to Seed Scarifier at 500rpm for 60 sec. for further separation. The separated seeds were passed 1.0 mm screen and collected after blowing with Seed Blower of wind speed of 0.15 mㆍsec-1. When the amount of seed was too little to refine with Seed Scarifier and Blower, the procedure was slightly modified from the procedure described above. The crude seed mixture obtained from Hammer Mill step was hand-refined roughly and then immersed into cone. (95%) sulfuric acid for 2 min. and collected floating portion after dilution of sulfuric acid solution 100 times with tap water. The collected seeds were dried and passed 0.149 mm sieve. During seed refining process using mechanical or sulfuric acid treatments, a small portion of damaged seed were evolved, however, the amount was not noticeable as compared to the total amount of collected seeds. Because the germination percentages between hand-refined seeds and seeds refined by above methods were not statistically different, the developed procedures for refining tiny seed of wild plants are helpful to reduce the cost and labor input in artificial propagation of two species.

• Korean Journal of Plant Taxonomy
• /
• v.44 no.3
• /
• pp.188-190
• /
• 2014

The unrecorded plant, Aster hispidus var. leptocladus (Compositae), was reported from Mt. Palgong-san, Daegu-si, Korea and was named as 'Gin-ssuk-bu-jaeng-i' after its slender leaves. It is distinguished from var. hispidus by having glabrous linear cauline leaves with acute apex, small heads and involucre, short pappus in disc florets. It had been considered as Japanese endemic plant especially adapted to serpentine area.

• The Korean Journal of Ecology
• /
• v.13 no.4
• /
• pp.331-342
• /
• 1990

Analysis of vegetation on the pavements and under the trees of streets in Seoul city were investigated from July to November 1989. All of the vascular herbs were 9 orders, 13 families, 30 genera, 37 species and 1 forma. Species diversity and evenness index were higher on the pavements than under the trees of streets. Eragrostis multicaulis with C-4 pathway was a dominant species, and next orders of importace values were Eleusine indica(C-4), Digitaria sanguinalis(C-4), Taraxacum officinale(C-3) and Erigeron annus(C-3). On the pavements and under the trees of streets, light intensity and surface temperature were very high, Also, these sites were affected by many kinds of human interferences. Therefore, it was an example of adaptation to specific ecological environments that C-4 plats were more dominant than C-3, growth forms of C-3 plants were rosette or prostrate, and annual or biennial plants were distributed in these studied sites. Generally, fruits types were grains, achens and capsules. Seeds were very small and some had appendages such as pappus.

• Plant Resources
• /
• v.8 no.1
• /
• pp.36-43
• /
• 2005

This study were focused on the genetic relationship using RAPDs and some morphological characteristics among eleven taxa Aster collected in Korea. Twenty random primers were selected, a total 216 DNA bands were generated and 213 bands were shown polymorphism among species. The collected eleven taxa were clustered into five groups at 0.609 similarity index. The first group was A. glehni, A. ageratoides, A. maackii and A. scaber was clustered at 0.713 of genetic distance. The second group was A. tataricus and A. koraiensis and the third group was A. spathulifolius, the forth group was A. yomena, A. hayatae and A. hispidus and the fifth was A. tripolium.

• Journal of Applied Biological Chemistry
• /
• v.59 no.2
• /
• pp.107-112
• /
• 2016

Pectolinarin was isolated from the ethyl acetate fraction of Cirsium setidens using open column chromatography and was analyzed using spectrometry. Pectolinarin content in Cirsium spp. was determined using HPLC/UV. Pectolinarin content in the aerial part of Cirsium spp. was higher than that in the root and pappus. Pectolinarin content was highest in the aerial part of C. chlorolepis (110.65mg/g extract). Consequently, the aerial part of C. chlorolepis has potential for use in new natural medicinal products, health supplements, and beverages.

• Journal for History of Mathematics
• /
• v.20 no.3
• /
• pp.167-180
• /
• 2007

In this study, we explored the role of analysis in the algebra development. For this, we classified ancient geometric analysis into an analysis by reduction and a Pappusian problematic analysis. this shows that both analyses have the function of reduction. Pappus' analysis consists of four steps; transformation, resolution, construction, demonstration. The transformation, by which conditions of given problem is transformed into other conditions which suggest a problem-solving, seems to be a kind of reduction. Mathematicians created new problems as a result of the reductional function of analysis, and became to see mathematics in the different view. An analytical thinking was a background at the birth of symbolic algebra, the reductional function of analysis played an important role in the development of symbolic algebra.

• Korean Journal of Plant Taxonomy
• /
• v.38 no.4
• /
• pp.509-522
• /
• 2008

한국산 가막사리속(Bidens L.)에 포함된 10분류군(8종 2변종)의 수과형태를 연구하기 위하여 입체현미경과 주사전자현미경을 이용하여 관찰하였다. 연구된 가막사리속에서 까끄라기를 제외한 수과의 크기는 $3.0-19.5{\times}0.7-2.6 mm$이다. 관모는2-4개의 까끄라기로 구성되어 있고, 까끄라기의 길이는 2.2-5.6 mm이다. 강모의 배열은 1-3열이었다. 수과의 다형화가 6개의 분류군(B. bipinnata, B. biternata, B. frondosa, B. parviflora, B. pilosa var. pilosa, B. tripartita var. tripartita)에서 확인되었다. 수과의 형태와 까끄라기의 수에 의해 4가지 유형으로 구분되었다. - Type A: 장타원형이고, 까끄라기 수는 2개(B. parviflora); Type B: 장타원형이고, 까끄라기 수는 3개 이상(B. bipinnata, B. biternata, B. pilosa var. pilosa, B. pilosa var. minor) Type C: 도란형이고, 까끄라기의 수는 2개(B. frondosa, B. radiata var. radiata, B. radiata var. pinnatifida, B. tripartita var. tripartita); Type D: 도란형이고, 까끄라기의 수는 3개 이상(B. cernua). 까끄라기의 강모 표면무늬는 3가지 즉 나선상, 평활상, 불규칙한 직선형으로 나타났다. 수과의 표면은 각피층이 발달한 다각형, 평활상 그리고 굴곡형으로 나타났다. 수과형질의 분류학적 적용에 대하여 간략하게 토의하였다. 수과형질을 바탕으로 한국산 가막사리속 분류군에 대한 검색표를 제시하였다.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.12 no.1
• /
• pp.63-73
• /
• 2006

The first packaging of Korean market milk dates back to July 1937 when Seoul Dairy Co-operative (Kyung Seong Dairy Co-operative in those days) used 1 hob (180 ml) glass bottles with either paper caps or cork caps. During 1945-1972, 2 hob (360 ml) glass bottles were produced, and iron caps and egret-shaped plastic film replaced the previously used caps. When there were insufficient numbers of milk bottles, other glass bottles such as soda drink bottles and beer bottles were used instead. Seoul Dairy Co-operative was the only dairy company existing in Korea until Nam Yang Dairy Co. Ltd was founded in March 1964, followed by Hae Tae Dairy Co. Ltd(Tae Han Food Public Corporation in those days) in 1969 and Mae-il Dairy Co. Ltd (Korea Dairy Company in those days) in May 1971. As many other dairy companies along with the above-mentioned companies were established, a variety of dairy products were packaged and marketed. In 1971 Seoul Dairy Co-operative first used triangular-shaped polyethylene film wrappers, and in 1972 Nam Yang Diary was the first company importing sterilized Tetra pak for the packaging of milk. Since 1974 rectangular shaped polyethylene film wrappers and plastic bottles were used. In 1977 the gable top carton pack made of paper was first introduced by Seo Joo Industry Co. Ltd, and its market share increased rapidly with gradual increase in its volume, from 180ml to 200ml, to 250ml, to 500ml and finally to 1,000ml, causing change in the volume of milk consumption. And in Sep. 1987 Pasteur market milk Co. Ltd. first used round type high density polyethylene bottle(body) with low density polyethylene cap of 245g, 490g and 980g volumes respectively.