• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.207-215
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• 2002

This study is focusing on mixing the foamed concrete incorporated by waste expanded polystyrene(W-EPS), investigating the physical properties and offering a proper quality control method to the field engineers. Two types of W-EPS (type A and type B) were studied. Type A (B) had globular (crushed) shape and diameter of 3-5 (1-2) mm. The results show that the flow was suddenly reduced with increasing mixing quantity of two types, but it satisfies KS F 4039 until 60 ％ of mixing rate. In general, the absorption rate was suddenly reduced with increased mixing quantity of two types especially, in type A. Apparent specific gravity was 0.36∼0.53 and reduced with increasing mixing quantify of type A. But it increased in case of type B. Compressive strength and heat conduction rate increased with mixing with W-EPS than non-mixing W-EPS but reduced with mixing too much W-EPS. Based ong the results, it is believed that mixing with W-EPS can improve the recycle of industrial wastes and produce the high quality foamed concrete.

• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.47-53
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• 2020

In this study, the optimization design data was presented by analyzing the performance and durability of the cooling fan by one-way fluid-structure interaction analysis of the cooling fan shape used in the engine generator. For this purpose, a steady-state analysis was performed on the flow field inside the cooling fan, and the durability was analyzed by using the steady-state calculation results as input data for structural analysis. Six types were modeled for fluid analysis by changing the blade and sweep angle of the cooling fan, and the ratio of mass flow rate and torque was best in A type, but B type with relatively large mass flow rate was the best. It was judged to have flow performance. As a result of examining the structural analysis by setting the four blade thickness of the B type selected through the fluid analysis, it was judged that B Type-3 is the most suitable when considering the fatigue safety factor.

• Journal of Plant Biology
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• v.36 no.4
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• pp.337-343
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• 1993

Tracheid structure of aerial system in five species of Ophioglossaceae and one species of Osmundaceae was examined with light and scanning electron microscopy. The species were Botrichium multifidum var. robustrum, B. ternatum, strictum, B. virginianum, Ophioglossum vulgatum, and Osmunda japonica. Three types of tracheids could be recognized by the pattern of secondary wall thickening; helical, irregular reticulate and circular bordered pitted tracheids. Among them, the appearance of circular bordered pitted tracheids supported that ophioglossaceous plants might have phylogenetic relationship with progymnosperm-seed plant line. Circular and elliptical bordered pits in shape were observed in five ophioglossaceous species; the former was subdivided into large and small types in size. In conclusion, three types of bordered pits were found: (1) large circular type- O. vulgatum, (2) small circular type- B. multifidum var. robustrum, B. ternatum and (3) elliptical type-B. strictum, B. virginianum. B. strictum and B. virginianum belong to subgenus Osmundopteris had the elliptical bordered pits. Therefore, this group might be interpreted as the most primitive in this family; however, such suggestion did subgenus Osmundopteris was classified into the most advanced group.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.91-100
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• 1980

A formula for calculation of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes with axial symmetry has been developed and the magnetic moments for these complexes are calculated, using the experimental values of the distortion parameters$({\delta})$, spin-orbit coupling constants and orbital reduction factors. The calculated magnetic moments for axially distorted octahedral $[Ti(III)A_3B_3]$ type complexes are in resonable agreement with the experimental valuest It is found that the calculated magnetic moments decrease as the extent of axial distortion increases and the orbital reduction factor decreases. A calculation method of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes which are in a ligand field of lower than axial symmetry has also been developed and the structure of distorted octahedral $[Ti(III)A_3B_3]$ type complexes are discussed on the basis of the of the calculated magnetic moments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.8
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• pp.1172-1179
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• 2022

This paper describes a design of point scalar multiplier for public-key cryptography based on binary Edwards curves (BEdC). For efficient implementation of point addition (PA) and point doubling (PD) on BEdC, projective coordinate was adopted for finite field arithmetic, and computational performance was improved because only one inversion was involved in point scalar multiplication (PSM). By applying optimizations to hardware design, the storage and arithmetic steps for finite field arithmetic in PA and PD were reduced by approximately 40%. We designed two types of point scalar multipliers for BEdC, Type-I uses one 257-b×257-b binary multiplier and Type-II uses eight 32-b×32-b binary multipliers. Type-II design uses 65% less LUTs compared to Type-I, but it was evaluated that it took about 3.5 times the PSM computation time when operating with 240 MHz. Therefore, the BEdC crypto core of Type-I is suitable for applications requiring high-performance, and Type-II structure is suitable for applications with limited resources.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.497-509
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• 1988

Current therapy of aortic dissections remains unstandardized because of the relative rarity of these catastrophic events and conflicting reported results of various therapeutic strategies. Hence, we reviewed our current results and planned to purify our method of interpretation of results and so, to standardize therapeutic managements. This study comprised unselected, consecutive 27 patients with aortic dissections who were operated at Seoul National University Hospital from Jan 1983 to March 1988. The results from analysis of their preoperative, operative and postoperative finding were as follows: 1] 7 patients had acute type A, 14 had chronic type A, 4 had acute type B, and 2 had chronic type B. 2] The causes of dissections were unclear, but 8 patients had Marfan`s syndromes, 2 had previous operative histories on cardiovascular systems and 2 had congenital heart diseases. 3] Multiple preoperative variables were found to correlate significantly with operative mortality and complications. The prevalences of such preoperative major complicating factors were significantly more frequent in acute than chronic [P < 0.05] and type A than type B [P < 0.01]. 4] Operations were performed according to the type of the dissections and whether it was acute or chronic. Usually dacron tube graft replacements were performed[25/26]. Intraluminal sutureless graft replacement was performed in 11 patients. Of the 14 patients with combined aortic regurgitation, concomitant aortic valve resuspension in 4, seperative aortic valve replacement in 1, and aortic valve replacement with coronary reimplantation were performed in 9 patients. 2 patients had concomitant arch vessel managements. 5] Over-all operative mortality rate was 33% and 54% for acute type A, 25% for acute type B, 29% for chronic type A, 0% for chronic type B respectively. The main causes of operative mortality were cardiovascular complications [mainly CPB-weaning failure] in acute cases and hemorrhagic complications in chronic cases.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.33-40
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• 1991

This study was performed to obtain the basic data applied to use of synthetic lightweight aggregate concrete affected by alkali silica reaction. The results obtained were summarized as follows; 1. The compressive strength of type A concrete was increased with increase of curing age. At the curing age 28 days, the highest compressive strength was showed at type Band C concrete, respectively. But, it was gradually decreased with increase of curing age at those concrete. 2. The flexural strength of type A concrete was increased with increase of curing age. At the curing age 14 days, the highest flexural strength was showed at type Band C concrete, respectively. But, it was gradually decreased with increase of curing age at those concrete. 3. The correlation between compressive and flexural strength of the sample was shown highly significant only at type A concrete. 4. It was shown that the water absorptions of the type Band C were 7.0-7.8 times higher than the type A concrete. It was significantly higher at the early stage of immersed time at all sample. 5. The correlation between compressive strength and water absorption of the sample was significant only at the type A concrete.

• Korean Journal of Veterinary Research
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• v.58 no.2
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• pp.95-98
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• 2018

Brucellosis is one of the common zoonoses caused by Brucella abortus (B. abortus). However, little has been reported on factors affecting invasion of B. abortus into host cells. To investigate cell-type dependent invasion of B. abortus, phagocytic RAW 264.7 and THP-1 cells and non-phagocytic HeLa cells were infected with wild-type and mutant B. abortus, and their invasion efficiencies were compared. The invasion efficiencies of the strains were cell-type dependent. Wild-type B. abortus invasion efficiency was greater in phagocytic cells than in epithelial cells. The results also indicated that there are different factors involved in the invasion of B. abortus into phagocytic cells.

• The Journal of Internal Korean Medicine
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• v.29 no.3
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• pp.810-818
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• 2008

Objective : The aim of this case report is to drive further studies evaluating the effectiveness of Korean oriental medicine on extranodal marginal zone B cells of MALT (mucosa-associated lymphoid tissue) type lymphoma. Methods : This case report is about a patient who was diagnosed with extranodal marginal zone B cell of MALT type lymphoma, who refused chemotherapy and preferred to be treated with Korean oriental medicine. Neck, chest abdomen & pelvis with enhanced computed tomography (CT) and positron emission tomography computed tomography (PET-CT) were performed to evaluate the anticancer effect of Hangam-dan (HAD). Results : The patient diagnosed with MALT showed partial response after receiving 17 months of Korean oriental medical treatment. Neck, chest, abdomen & pelvic CT and PET-CT show decrease in size. Conclusion : This case report shows a possibility that Korean oriental treatment could offer potential benefits for patients with extranodal marginal zone B cell of MALT type lymphoma.

• Journal of Magnetics
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• v.3 no.1
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• pp.9-14
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• 1998

A non-coercive cast Nd-Fe-B-type material can be easily converted into a coercive one by employing HDDR process. Applying the conventional HDDR process to the Nd-Fe-B-type material generally leads to a powder-like material. HDDR treated material in a solid form can, however, be realised if the process is properly modified (solid-HDDR). In the present study, the change of rigidity (compressive strength) of the Nd-Fe-B-type material during the solid-HDDR has been investigated using a homogeneous sintered magnet with composition $Nd_{13.8}Dy_{0.7}Fe_{78.25}Si_{0.15}Mn_{0.6}B_{6.5}.$ It has been found that the low strength of the hydrided material was improved by the subsequent disproportionation. The restoration of the strength was explained by the eutectoid-like disproportionation structure containing fine neodymium hydride rod embedded in tough iron matrix. The high strength of disproportionated material was reduced radically in earlier stage of recombination, and this wes explained by the reduction of the disproportionated phase. The reduced strength was, however, recovered by further recombination, and this was explained by the fact that as the recombination continues the recombined grains adhere together. The optimally HDDR processed material has a comparable or even higher strength with respect to the initial sintered material prior to the solid-HDDR. The present study suggested that the rigidity of Nd-Fe-B-type material could be retained even after the solid-HDDR.