• 대한기계학회논문집A
• /
• 제29권12권
• /
• pp.1645-1652
• /
• 2005

Pick-and-place systems using suction cups have been being widely used and continuously developed in production automation. There are, however, some drawbacks in constructing such systems. One of them is that it generates high level noise due to air compressors. And the system must have complex constitutions of mechanical component such as air compressors, air tubes, air valves, etc. Moreover, it needs continuous air supply to maintain vacuum in suction cups. If there is a failure in any suction cup, the total suction system may fail owing to air leakage. To overcome these drawbacks, we propose PMS (Permanent Magnet Suction) mechanism which has permanent magnets for vacuuming suction cups with no air compressor. The basic concept of PMS mechanism is to rotate permanent magnets with fixed angle. Simple rotation of permanent magnets changes the direction of the magnetic force applied at the suction cups. Since each suction cup has no direct connection with any of the others, the air leakage at one suction cup is not critical. The proposed suction mechanism was designed and fabricated. With some experiments, the feasibility and performance of the PMS mechanism was shown. The strong points of the PMS mechanism are in its simple structure, generating low noise, high energy efficiency, and no need of continuous energy supply.

• 대한산업공학회지
• /
• 제41권3호
• /
• pp.253-258
• /
• 2015

The 3D printing is any of various processes for making a three dimensional object of almost any shape from a 3D model. Recently, a rapidly expanding hobbyist and home-use market has become established with the inauguration of the open-source RepRap and Fab@Home projects. However, this causes problems regarding copyright protection and usage of illegal 3D data. In this paper, we developed a 3D printing open-market system, which guarantees copyright protection using the remote 3D printing without direct distribution of 3D design data. Because most of the home-use 3D printers are FFF (Fused Filament Fabrication) based on NC code system, open-market system uses FFF 3D printers. Also, open-market system inspects the uploaded 3D model data, so the system can prevent distribution of illegal model data such as weapons, etc.

• 한국가금학회지
• /
• 제26권2호
• /
• pp.131-144
• /
• 1999

Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria seriously impairs the growth and feed utilization of livestock and poultry. Due to complex life cycle of organism and intricate host immune responses to Elmeria, coccidia vaccine development has been difficult. Understanding of basic imunobiology of pertinent host-parasite interactions is necessary for the development of novel control strategy. Although chickens infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions, antibody mediated responses play a minor role in protection gainst coccidiosis. Rather, increasing evidence show that cell-mediated immunity plays a major role in resistance to coccidiosis. T-lymphocytes appear to respond to coccidiosis both through cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T-cells eliminate the parasites, however, remain to be investigated. Since it is crucial to understand the intestinal immune system in order to develop an immunological control strategy against any intestinal immune system in order to develop an immunological control strategy against any intestinal diseases, this presentation will summarize our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria, to provide a conceptual overview of the complex molecular and cellular events involved in intestinal immune responses to enteric pathogens.

• Biomolecules & Therapeutics
• /
• 제11권3호
• /
• pp.183-189
• /
• 2003

General phannacological properties of IH-901, a new pharmacological composition as an intestinal metabolite formed from ginseng protopanaxadiol saponins, were investigated in experimental animals administered orally and in vitro test system. IH-901 had no effects on general behavior, pentobarbital sleeping time, spontaneous motor activity, motor coordination of mice, normal body temperature, chemoshock produced by pentylenetetrazole and writhing syndromes induced by 0.8％ acetic acid at the dose of 25 and 250 mg/kg. Gastric secretion of rats and intestinal motility in mice were not also influenced by the administration of IH-901 at doses of 25 and 250 mg/kg. IH-901 (25 and 250 mg/kg) did not change the mean arterial blood pressure and heart rate in conscious rats. IH-901 had no effect on the respiratory rate at the same doses when it was given to anesthetized rats. In in vitro experiments, IH-90l at the concentration of 25$\mu\textrm{g}$/L did not show any direct effect and inhibitory or augmentative action on the histamine-or acetylcholine-induced contractions in the isolated ileum of guinea-pig. Based on these results, it was concluded that IH-901 did not induce any adverse effects in experimental animals.

• Journal of Astronomy and Space Sciences
• /
• 제11권1호
• /
• pp.41-52
• /
• 1994

Currently, the CCDs are widely used in astronomical observations either in direct imaging use or spectroscopic mode. However according to the recent technical advances, new large format CCDs are rapidly developed which have better performances with higher quantum efficiency and sensitivity. In many cases, some microprocessors have been adopted to deal with necessary digital logic for a CCD imaging system. This could often lack the flexibility of a system for a user for to upgrade with new devices, especially if it is a commercial product. A new design concept has been explored which could provide the opportunity to deal with any format of devices from any manufactures effectively for as tronomical purposes. Recently available PLD (Programmable Logic Devices)technology makes it possible to develop such digital circuit design, which can be integrated into a single component, instead of using micrprocessors. The design concept could dramatically increase the efficiency and flexibility of a CCD imaging system, particularly when new or large format devices are available and to upgrade the performance of a system. Some variable system control parameters can be selected by a user with a wider range of choice. The software can support such functional requirements very conveniently. This approach can be applied not only to astronomical purpose, but also to some related fields, such as remote sensing and industrial applications.

• Bulletin of the Korean Chemical Society
• /
• 제32권8호
• /
• pp.2677-2682
• /
• 2011

Direct nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane (DPT) is a feasible way to synthesize HMX, and it has multiple practical applications. In this paper, a new nitrolysis process involving the use of an $N_2O_5-HNO_3$ system catalyzed by acidic ionic liquids (AILs) was developed. The results show that [$Et_3NH$]TsO was the best catalyst among the 28 AILs used and that HMX was formed at a higher yield of 61%, compared to 45% without any AIL. Moreover, with the addition of $N_2O_5$, the yield was further increased to a maximum value of 69%. The AILs were also efficiently recovered by simple extractions without any apparent loss of catalytic activity, even after five runs.

• 천문학회지
• /
• 제29권spc1호
• /
• pp.389-390
• /
• 1996

The CCDs are widely used in astronomical observations either in direct imaging use or spectroscopic mode. However, the areas of available sensors are too small for large imaging format. One possibility to obtain large detection area is to assemble mosaics of CCD, and drive them simultaneously. Parallel driving of many CCDs together rules out the possibility of individual tuning; however, such optimisation is very important, when the ultimate low light level performance is required, particularly for new, or mixed devices. In this work, a new concept is explored for an entirely novel approach, where the drive waveforms are multiplexed and interleaved. This simultaneously reduces the number of leadout connections and permits individual optimisation efficiently. The digital controller can be designed within a single EPLD (Erasable Programmable Logic Device) chip produced by a CAD software package, where most of the digital controller circuits are integrated. This method can minimise the component. count., and improve the system efficiency greatly, based on earlier works by Han et a1. (1996, 1994). The system software has an open architecture to permit convenient modification by the user, to fit their specific purposes. Some variable system control parameters can be selected by a user with a wider range of choice. The digital controller design concept allows great flexibility of system parameters by the software, specifically for the compatibility to deal with any number of mixed CCDs, and in any format, within the practical limit.

• Architectural research
• /
• 제16권4호
• /
• pp.193-202
• /
• 2014

This research started from the premise that Jacques Perret, "Savoyard gentleman" of the 17th century - whose only legacy consists of Des fortifications et artifices, a book of fortified town designs - is still an elusive figure in the history of architecture and deserves to be further investigated. In particular, attention needs to be paid to the lack of any attempt by scholars to define his actual professional status and cultural background: was he an architect, an engineer, a professional or an amateur? The intention of this paper is therefore to shed some light on this question by examining selected contents of his book describing five projects of fortified towns. Plates and descriptions are carefully analyzed related to the engineering (defensive structures) and architectural (city layouts, buildings) content. The figure that emerges is that of an articulate personality who does not fit either in the architectural or in the military engineering professional world. In the field of engineering, he simultaneously demonstrated the competence of a professional and the na$\ddot{i}$vety of an immature technician, while in the field of architecture he showed an advanced creativity alongside several technical and theoretical misunderstandings. From the analysis in this study, the assumption is formulated that Jacques Perret was a connoisseur, i.e. an erudite without any direct involvement in real professional activity. This work is intended to provide a hypothesis for further researches that, hopefully, will deepen our understanding of several other aspects of Perret's complex identity and work.

• 한국임상수의학회지
• /
• 제19권4호
• /
• pp.450-454
• /
• 2002

A five-year-old, female Great Dane dog with edema, localized trauma, mild pain, and lameness of the right hind limb was referred to the Veterinary Medical Teaching Hospital of Chungbuk National University. This dog had a history of mammary tumor excisions 6 months ago. Abnormal changes were not seen in the values of complete blood count and serum biochemical tests. But pedal direct lymphangiography using aqueous-based radiographic agent showed the obstructed lymph flow in right popliteal lymph node. Based on these observations, the dog was suspected as lymphedema resulted from lymph drainage flilure without any other possibilities of inflammation or other causes. Although recommended chemotherapy and physiotherapy had been applied for resolvinr presented problems for one month, there was no improvement on edema of damaged region and any other clinical signs. Therefore, the necropsy was performed after euthanasia under agreement of the owner of patient. In histopatholofical examination, the most characteristic lesions in the mass of femoral region were diffuse edema fibrosis and neoplastic cells in the lymphatics. Also, the neoplastic cells were very similar to those found in the tumor mass of mammary gland, which had diagnosed as fibrosing carcinoma. These facts suggested that the cause of obstructed lymph flow was the neoplasia in lymphatics of the right hind limb. With these results, a diagnosis of malignant lymphedema was made in this dog.

• 콘크리트학회논문집
• /
• 제11권4호
• /
• pp.43-54
• /
• 1999

Shear tests are performed on four full-scale 12.5 m proto-type models, "least depth double tee," which are resulted from the optimization process. Domestic superimposed live load regulation, domestic material properties which is available to product. Korean building code requirements, construction environments and economy are considered as the main factors to establish the process. All of the specimens tested fully comply with the shear strength requirements as specified by ACI 318-95. The research has shown following results. 1) The development length requirement of ACI 318-95 does not seem a good predictor for the estimation of bond failure in a beam with the strands below the supports. 2) The load required for the first initial coner cracking in the dap end and first web shear cracking does not seem to have any relation with the dimension and shear strength of the section in the test beams. 3) The strand slip has a direct relationship with the web shear cracking. However, the coner cracking in the dap end does not give any help for the slip in anchorage. 4) Use of whole area for bearing steel at the bottom of dap end is desired for safe bearing pressure design in the precast prestressed double tee beams. 5) The deflection of beam influences directly on the amount of strand slip at the anchorage after initiation of it, and relationship between them are very linear.