• Title/Summary/Keyword: Lam Dong

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Optic Module for Laser Integrated Machine (레이저 복합가공기용 광학모듈의 제작)

  • Shin, Dong-Sig;Lee, Jae-Hoon;Suh, Jeong
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1475-1480
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    • 2007
  • In the last few years, lasers have found new applications in production engineering as tools for surface treatment, cutting, welding, drilling and marking. So far, the laser has mainly been used in special laser processing machines ('laser-only') directly integrated into a production line or serving as stand-alone stations in the workshop. By combining conventional metal cutting technologies with laser processes in one machine, complete processing of a workpiece with different technologies in one setting can be realized. The main advantages are a reduction of the material flow between the production machines, which leads to a reduction in processing time and logistics, and an enhancement of manufacturing quality due to the processing in one setting. In addition to this approach new processing technologies such as laser-assisted machining are possible.

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Development of Information System for Maintenance of Urban Transit using Wireless LAN (무선랜을 이용한 전동차 유지보수 정보화시스템 구현에 대한 연구)

  • Ahn Tae-Ki;Park Ki-Jun;Lee Ho-Yong;Kim Gil Dong;Han Seok-Yun
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.542-547
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    • 2003
  • This paper proposes the method to develop information system for maintenance of urban transit using wireless LAM. Wireless LAN communication provides very useful method to maintain urban transit vehicle. We will use wireless LAN to transmit driving data, operational data and trace data from vehicle to wayside. And also we will use wireless LAN to refer various information concerning to work in real time. Proposed method may prevent loss of maintenance manpower and provide effective maintenance process.

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New Components from the Thorns of Gleditsia sinensis and Their Antimutagenic Activities

  • Lim, Jae-Chul;Park, Jong-Hee;Lee, Dong-Ung
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.204.3-205
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    • 2003
  • Antimutagenic activity-guided fractionation of an extract prepared from the thorns of Gleditsia sinensis Lam. (Leguminosae), which is a perennial shrub widely distributed throughout China (called "Zao Jiao Ci" ) and in Gyeongju city area in Korea (called "Jo Gak Ja" ) and has been used in traditional medicine for the treatment of swelling, suppuration, carbuncle and skin diseases, led to the isolation of one triterpenoid and four steroids, which were identified as D:C-friedours-7-en-3-one (1), stigmastane-3,6-dione (2), ${\beta}$-sitosterol (3), sigmasterol (4), and stigmast-4-en-3,6-dione (5). (omitted)

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A New Record for Invasive Alien Plant: Melilotus dentatus (Waldst. & Kit.) Desf. (Fabaceae) in Korea

  • Se Ryeong Lee;Eun Su Kang;Hyeon Jin Jeong;Dong Chan Son
    • Korean Journal of Plant Resources
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    • v.36 no.3
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    • pp.219-224
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    • 2023
  • Melilotus dentatus (Waldst. & Kit.) Desf. is an invasive plant native to Europe, Russia, Uzbekistan, Mongolia and China. It was introduced to North America to create grazing areas for livestock; its growth has since become uncontrollable. Melilotus dentatus is now found in Namyang-eup, Hwaseong-si, Gyeonggi-do, South Korea as an alien plant. This species is morphologically similar to Melilotus suaveolens Ledeb. and Melilotus officinalis (L.) Lam. M. dentatus differs from other species based on its oblong leaflets, distinct teeth, two ovules, surface of the legume that is minutely reticulate-nerved or smooth, and seeds that are dark green to greenish brown. Here, we have provided a detailed description and photographs of the alien species M. dentatus as well as an updated key to five Melilotus taxa studied, which will help prepare a continuous monitoring and management plan.

Study on Angle Calculation of Two-axis Manipulator for Laser Assisted Machining (레이저 보조 가공을 위한 2-축 틸팅의 회전각에 대한 연구)

  • Kim, Dong Hong;Jung, Dong Won;Lee, Choon Man
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.2
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    • pp.113-117
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    • 2014
  • Laser Assisted Machining (LAM) was often used in process of difficulty-to-cut materials. In previous study, Laser assisted machining was a straight path processing using 1-axis manipulator in laser module. But 1-axis manipulator in laser module was able to process only straight path. So, in this study, laser module in laser assisted machining equipped to 2-axis manipulator. 2-axis manipulator has two motors. First motor is machining direction motor and second motor is Vertical Motor. Machining direction motor rotates in the direction of machining and vertical motor rotates vertical direction in the direction of machining. Machining path of laser assisted machining was considered diagonal path and curved path of laser heat source. This study calculated the 2-axis manipulator's rotation angle in diagonal path and curved path.

A basic study on the historical description for the cityscape identity ; The image of cheongju in the archaic texts of geography

  • 홍형순;장태현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.3
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    • pp.52-65
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    • 1998
  • It has been recognized that the cityscate identity is a very important factor in a modern city. It is necessary to have a variable view to urban comunities for understanding the cityscape identity. We have investigated the contents of archaic texts such as the geography for tracing a cityscape identity to its origin in a city. Because it has been written about politics, economics and culture of a specific area in the geography based on deep interest to the city, we can look into the early image of the cityscape closely after searching of archaic texts. It is also significant to stdy with archaic texts of geography since these studies have a correlatio to the understand of an area and the keeping of historical conscious which are fundamental of cityscape identity. We have studieds on the area of Cheongju from the middle of Chosun dynasty to the end of this kingdom, since that many geographies were described those days. It was selected "Go-Reo-Sa" and "Se-Jong-Sil-Lok" Geography, "Sin-Jeung-Dong-Guk-Y대-Ji-Seung-Lam" "Dae-Dong-Ji-Ji" "Dong-Guk- Yeo-Ji-Ji", "Jeug-Bo-Mun-Heon-Bi-Go Yeo-Ji-Go", and "Taek-Li-Ji", as archaic texts of geography because these texts described in detail about city and gave a clue to speculate an image of city. The major results are as follows; 1) It was described about the cityscape in those archaic texts are metaphysical image, existing and usable elements of cityscape, lost resources of cityscape. 2) The metaphysical images are neither objective nor consistent in the each archaic texts. But the metaphysical image of old city suggests good insight for the application to the modern city image. 3) It is necessary to the careful onsideration about the existing elements. 4) There are variable programs about the lost resources of the cityscape, in accordance with the possibility of the restoraton. 5) The physical and visible factors and non-physical and invisible factors are equally important elements of the cityscape identity. Our research suggests that it is necessary to understand in detail how those factors of cityscape identity have changed with the changes of the times, and how those factors affect the modern cityscape identity.

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Understanding the Growth Kinetics of Graphene on Cu and Fe2O3 Using Inductively-Coupled Plasma Chemical Vapor Deposition

  • Van Nang, Lam;Kim, Dong-Ok;Trung, Tran Nam;Arepalli, Vinaya Kumar;Kim, Eui-Tae
    • Applied Microscopy
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    • v.47 no.1
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    • pp.13-18
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    • 2017
  • High-quality graphene was synthesized on Cu foil and $Fe_2O_3$ film using $CH_4$ gas via inductively-coupled plasma chemical vapor deposition (ICPCVD). The graphene film was formed on $Fe_2O_3$ at a temperature as low as $700^{\circ}C$. Few-layer graphene was formed within a few seconds and 1 min on Cu and $Fe_2O_3$, respectively. With increasing growth time and plasma power, the graphene thickness was controllably reduced and ultimately self-limited to a single layer. Moreover, the crystal quality of graphene was constantly enhanced. Understanding the ICPCVD growth kinetics that are critically affected by ICP is useful for the controllable synthesis of high-quality graphene on metals and oxides for various electronic applications.

Improvement of Predictive and Corrective Inspection Methods to Control Nosema bombycis Infection in the Silkworm, Bombyx mori

  • Nguyen, Mau-Tuan;Jon
    • Journal of Sericultural and Entomological Science
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    • v.39 no.2
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    • pp.146-153
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    • 1997
  • The microsporidian infection with Nosema bombycis, reconfirmed its high virulence and transovarial tranmissibility, however, the characteristic symptom of the spots like pepper grains on the diseased larval skin was no more recognized by present varieties of the silkworm. Transovarial transmission rate detected from moth was above 90% in dead eggs or dead larvae in the rearing by mulberry leaves, 80% in the newly hatched larvae starved to death. Transovarially transmitted N. bombycis was easily observed from dead eggs and larvae, and were suggested an individual inspection of a few of dead eggs for detection of the pathogenic spores. The progeny population provided indicative factors on the sampling of predictive and corrective inspection. The higher concentration of N. bombycis spores included in the hindabdormal part of infected moth, applicative on the simple method of indivisual moth inspection. For the predictive inspection of growned 5th-instar larvae, N. bombycis infection was detectable without microscopic observation by the unique symptom of turbid milky-white spots on the silk gland. Inspection of the meconia artificially discharged from silkworm moth, was also succesful of microscopic observation before crossing, without killing or homogenize the moths. The results provided a basis of rational methods for the inspection of N. bombycis infection of the silkworm.

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Establishment of Simplistic Moth Inspection System to Prevent Nosema Bombycis Infection of the Silkworm, Bombyx mori

  • Han, Myung-Sae;Mau
    • Journal of Sericultural and Entomological Science
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    • v.39 no.2
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    • pp.154-160
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    • 1997
  • Present experiment designed for the review of theoretical basis for the inspection system of infected insects by Nosema bombycis. A microporidian N. bombycis, known as the high virulence, produced at the average of 7$\times$108 spores per female moth of the silkworm, Bombyx mori, enabled transovarial tranmission. Detectability of N. bombycis spores in the mass inspection was varied by dillution level, the higher limit of dillution with healthy moths was 1:140 for 100% detection, 1:160 for 99.5%, 1:200 for 99.0%. For an efficient inspection under the microscopic observation (600$\times$), the lower limit of spore concentration was determined as 1, 000, 000 spores/ml, 60-80 moths could be applicable for a maximum sample unit of a lot. Following the present inspection unit conditioned 35 to 40 moths for a lot. N. bombycis spores were easily detectable from the preparation of crude homogenate with 2% KOH, even the step of contrifuge was omitted. The results suggested a new basis of rational mass inspection system of silkworm female moths to save the facilities, labor, and time.

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Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae): A new record to the flora of Vietnam

  • TRAN, Binh Duc;TRAN, Bach The;DO, Van Hai;BUI, Quang Hong;DOAN, Son Hoang;LE, Han Ngoc;NGUYEN, Thuy Thu;EUM, Sangmi
    • Korean Journal of Plant Taxonomy
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    • v.50 no.3
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    • pp.351-355
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    • 2020
  • Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae) is newly recorded in Vietnam. It is similar to A. mekongensis Gagnep & Courch in having a white campanulate corolla but differs from that species by having whitish surface of the abaxial leaf, narrowly lanceolate or linear-oblong, curly, rolled up the bract with a longer length of the petiole and a shorter pedicel. It was previously known only in Thailand, but was recently found in Lam Dong Province, Vietnam, for the first time. The present study provides a detailed description, colorful photos and the distribution of the species. Furthermore, a comparison of the diagnostic characters between this species and a related species in Vietnam, A. mekongensis Gagnep & Courch, is provided.