• Title/Summary/Keyword: direct RP

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Accuracy Enhancement in Direct & Adaptive Slicing of a Rotational Surface (회전곡면의 직접ㆍ적응 단면화에 있어서 정밀도 향상)

  • 박정환;신양호
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.1
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    • pp.185-191
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    • 2000
  • Direct & adaptive slicing of sculptured surfaces in RP improves, quality & accuracy of the final product, compared to the slicing with uniform layer thickness or the slicing of facets (ie, STL). Present D&A slicing procedures adaptively compute the next layer thickness based on the surface information of current sliced contour, which assumes constant normal curvature values. In some cases, however. such assumption leads to intolerable slicing result which cannot correctly consider the entire local feature shape. We propose improved adaptive slicing algorithms which can determine near-optimal layer thickness, including illustrated examples.

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Analysis on the practicality and manufacture by DMLS and NC Multiple machines (DMLS와 NC복합가공기의 실용성 검토)

  • Moon, Dae-Young
    • Design & Manufacturing
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    • v.9 no.3
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    • pp.34-40
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    • 2015
  • In the study, Three-dimensional drawing parts for conformal cooling circuit cavity & core and their 3D Metal parts using DMLS(Direct MetalLaser Sintering) and NC integrated machining center were showned. For conformal cooling circuit cavity and core parts, I discussed its practicality to DMLS multiple machinins process introducing general manufacturing process and comparing with them.

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Development of Automatic Filling Process using Low-Melting Point Metal for Rapid Manufacturing with Machining Process (절삭가공과 저융점금속에 의한 쾌속제작용 자동충진공정 개발)

  • Shin, Bo-Seong;Yang, Dong-Yeol;Choi, Du-Seon;Kim, Ki-Don;Lee, Eung-Suk;Je, Tae-Jin;Hwang, Kyeong-Hyeon
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.88-94
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    • 2002
  • Recently, the life cycle and the lead-time of a product are to be shortened in order to satisfy consumer's demand. It is thus important to reduce the time and cost in manufacturing trial products. Several technique have been developed and successfully commercialized in the market of RPM(Rapid Prototyping and Manufacturing). However, most commercial systems currently use resins or waxes as the raw materials. So, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome these problems, high-speed machining technology is being investigated worldwide for rapid manufacturing and even for direct rapid tooling application. In this paper, some fundamental experiments and analyses are carried out to obtain the filling time, materials, method, and process parameters for HisRP(High-Speed RP) process. HisRP is a new RP process that is combined high-speed machining with automatic filling. In filling process, Bi58-Sn alloy is chosen as filling material because of the properties of low-melting point, low coefficient of thermal expansion and no harm to environment. Also the use of filling wire it if advantage since it needs simple and flexible mechanism. Then the rapid product, for example a skull, is manufactured for aluminum material by HisRP process with an automatic set-up device thor 4-faces machining.

Mutation Analysis in β2-Adrenergic Receptor Gene by Denaturing High Performance Liquid Chromatography (DHPLC) (DHPLC를 이용한 β2-교감신경수용체 유전자에서의 돌연변이 분석)

  • Park, Sang-Bum;Oh, Chung-Hun;Kim, Jong-Wan;Jang, Won-Cheoul
    • Analytical Science and Technology
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    • v.15 no.3
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    • pp.190-195
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    • 2002
  • We analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed-phase high performance liquid chromatography (IP-RP-HPLC). We extracted genomic DNA from 50 asthma patients, amplified DNA using PCR, and analysed PCR product by DHPLC. As a result, we obtained that mutation frequency was 15 (30%) among 50 cases. Consequently DHPLC mutation detection was confirmed that the result of direct sequencing was coincide exactly.

Antimutagenic Effects of Juices from the Peppers in Salmonella Assay System

  • Park, Kun-Young;Kweon, Young-Mi;Rhee, Sook-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.3
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    • pp.440-445
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    • 1995
  • The antimutagenic effects of juices from green pepper(GP), red pepper leaf(RPL), red pepper(RP) and sweet pepper(SP) were examined by the Ames method using Salmonella typhimurium TA100. The juice supernatants of GP, RPL and RP showed antimutagenic activities against afltoxin B1(AFB1) in Salmonella typhimurium TA 100. The juice supermatants of GP and RPL also exhibited the inhibitory effects(p<0.05) to the mutagenicities induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitro-quinoline-1-oxide(4-NQO). The juice of RP showed antimutagenic activities against indirect mutagen of AFB1, however, the activity was reduced at higher concentration(5.0%), furthermore, as the adding concentration of sample increased to 5.0%, it exhibited slight comutagenicith on direct mutagen of MNNG. Theantimutagenic activities of GP and RPL juices were reduced significantly after heating at 100℃ for 20min, supposing that the antimutagenic compound(s) in the juices were heat labile.

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A Study on methodology of physical Fabrication & reorganization of Epidermis in Space Design - Focused on reorganization of Epidermis, Fabrication - (공간디자인에서 디지털 표피 재 조직화, 물리적 구현 방법 연구 - 표피 재 조직화, 가공 중심으로 -)

  • Park, Jeong-Joo
    • Korean Institute of Interior Design Journal
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    • v.17 no.2
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    • pp.150-161
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    • 2008
  • It requires more close cooperation process and mediator for smooth communication in this industry structure where design and engineers are separated. The database of design integrates separate system and helps connection between organizations. The application category is utilized variously from formation to operation. Architectures addressed in this content as Frank Gehry and Nox are making differentiated design on the base of 3d digital methodology and using it widely from generation to fabrication. Especially they got to be free from the generative limit as it became available to analyse, digital surface organization, and realize the complex system form. Now more integrated and delicate works got to be affordable owing to various kinds of improved CNC, RP(rapid-prototype) machines, and architecture hardwares. With a linkage of software now at their disposal, architects can create a digital model of a building and all of its design elements, and in turn use this 3d information to construct actual building components using machines driven by CNC and other advanced manufacturing techniques. Digital technologies are enabling a direct correlation between what design and construction, thus bringing to the forefront the issue of the significance of information, the production, communication, application, and control of digital information in the industrial system. The central requirement is the clear, reliable, and consistent exchange of information among all parties involved in creating a given project.

Using Disaggregate Behavioral Analyze to Measure the Effects of Telecommuting on Transportation (개별행태분석을 통한 통신업무(Telecommuting)의 교통대체효과 추정)

  • 김형철;박규영;김흥준
    • Journal of Korean Society of Transportation
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    • v.17 no.2
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    • pp.7-19
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    • 1999
  • The Purpose of this study is to analyze the impact of telecommuting-the use of telecommunications technology to perform work from remote sites- on the transportation system. It examined the effects of telecommuting on commuter travel. After reviewing case studies of foreign countries and their telecommuting characteristic, two types of survey, RP(Revealed Preference) and SP (Stated Preference), were carried out in order to analyze the impact of telecommuting on traffic. The RP survey examined respondents'attitudes toward information technology and the characteristics of their work. The SP survey asked respondents what conditions would make them want to become a telecommuter. It was found that higher salaries and communication subsidies would induce more people to telecommute. Overall, it was found that if telecommuting were to be executed in Seoul, 49.1% of workers would become telecommuters, which would result in a 14,407 billion won reduction in direct and indirect transport costs per year. This research proves that traffic congestion can be reduced effectively by instituting telecommuting as an option for workers.

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Weed Occurrence, Rice Growth, and Soil Temperature as Affected by Different Biodegradable Mulching Materials in Wet Seeded Rice

  • Yang, Woon-Ho;Kim, Jae-Hyun;Kim, Je-Kyu;Han, Hee-Suk;Shin, Jeong-Ju
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.1
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    • pp.1-7
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    • 2003
  • In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30${\times}$14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 $\mu\textrm{m}$+RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 $\mu\textrm{m}$+RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.

Fucoidan Increases Porcine Neutrophil Extracellular Trap Formation through TNF-α from Peripheral Blood Mononuclear Cells

  • Changwoo Nahm;Yoonhoi Koo;Taesik Yun;Hakhyun Kim;Byeong-Teck Kang;Mhan-Pyo Yang
    • Journal of Veterinary Clinics
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    • v.40 no.3
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    • pp.175-181
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    • 2023
  • Fucoidan extracted from brown seaweed has a variety of biological activities. Neutrophil extracellular traps (NETs) formation is an immune response for the invasion of pathogens. Neutrophils release granule protein and chromatin that form extracellular fibers that bind microbes. These NETs degrade virulence factors and kill bacteria. The aim of this study was to investigate the effect of fucoidan on NET formation of porcine peripheral blood polymorphonuclear cells (PMNs). The NET formation was determined by fluorescence emission of propidium iodide (PI) in PMNs by a fluorescence microplate reader. The production of tumor necrosis factor (TNF)-α from peripheral blood mononuclear cells (PBMCs) was measured by ELISA method. Fucoidan itself did not show any direct effect on NET formation. However, NET formation of PMNs was increased by the culture supernatant from PBMCs treated with fucoidan. The NET formation of PMNs were also enhanced by treatment with recombinant porcine (rp) TNF-α. The ability of culture supernatant from PBMCs treated with fucoidan to increase the NET formation of PMNs was inhibited by addition of goat anti-rp TNF-α polyclonal antibody (pAb) (IgG) prior to the culture. The increase of NET formation by rp TNF-α was also inhibited by goat anti-rp TNF-α pAb (IgG). The level of TNF-α in culture supernatant from PBMCs was increased by treatment with fucoidan. These results suggest that fucoidan increases porcine NET formation, which is mediated by TNF-α produced from PBMCs.

A Study on the Effective Scattering Center Analysis for Radar Cross Section Reduction of Complex Structures (복합구조물의 RCS 저감을 위한 효율적 산란중심 해석에 관한 연구)

  • Kim, Kook-Hyun;Kim, Jin-Hyeong;Cho, Dae-Seung
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.4 s.142
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    • pp.421-426
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    • 2005
  • Scattering center extraction schemes for radar cross section reduction of large complex targets, like warships, was developed, which are an 1-D radar image method(range profile), and a direct analysis based on an object precision method. The analysis result of partial dihedral model shows that the presented direct analysis method is more efficient than the 1-D radar image method for scattering center extraction of interested targets, in terms of radar cross section reduction design, not signal processing. In order to verify the accuracy of the direct analysis method, a scattering center analysis of an naval weapon system was carried out, and the result was coincident with that of another well-known RCS analysis program. Finally, an analysis result of RCS and its scattering center of an 120m class warship-like model presented that the direct analysis method can be an efficient and powerful tools for radar cross section reduction of large complex targets.