• The Korean Journal of Zoology
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• v.26 no.4
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• pp.271-282
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• 1983

The authors observed the ultrastructure of the pigment cells of the frog, Rana nigromaculata Hallowell, during the hibernation. The specimens from the skin were fixed in 2.5% glutaraldehyde-paraform-aldehyde fixative in phosphate buffer at pH 7.2 prior to fixation in 2% osimium tetroxide, dehydrated in graded ethanol and acetone, embedded in Epon 812 mixture, and sectioned with LKB-ultramicrotome. the ultrathin sections were contrasted with uranyl acetate and lead citrate and observed with a JEOL-100B electron microscope. The results were as follows. In hibernating phase, pigment cells of the frog were consisted of the three kinds of chromatophores (xanthophore, iridophore and melanophore) in their dorsal skin. The traits of these cells were as follows. 1. Xanthophores A. Xanthophores were filled with pterinosomes and carotenoid vesicles. Many ribosomes, a few mitochondria and glycogen particles were dispersed in the cytoplasm. B. Pterinosomes were spherical or ellipsoidal in shape. They were divided into 6 types (type I, type II, type III, type IV, type V, type VI pterinosomes) by the their inner structure and especially, type I, type II, type III pterinosomes were well developed.

• Korean Journal of Veterinary Research
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• v.16 no.1
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• pp.11-25
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• 1976

Studies on pathogenicities and developmental stages of Nosema apis (Zander, 1909) were carried out through artificial infection to Nosema free honey bees with various levels of spores isolated from local honey bee colony. The results obtained were summarized as follows: 1. The clinical symptoms were observed as dysentery, enteritis of mid-gut (enlargement and decoloration), crawling posture and shortening of the longevity of worker bees in the rearing honey bee colony inoculated with the spores. 2. Number of spores harvested from laboratory rearing honey bees were progresively increased to 4 weeks after inoculation. The regression equations and coefficients of correlations to various spore levels were as follows in each treatment colony. Colony 1. ($$1,000{\times}10^4spores/ml$$) $$y_{c1}=471{\times}10^{4}x+454{\times}10^4(r=0.65^*$$) Colony 2. ($$500{\times}10^4spores/ml$$) $$y_{c2}=340{\times}10^{4}x+207.8{\times}10^4(r=0.99^{**}$$) Colony 3. ($$100{\times}10^4spores/ml$$) $$y_{c3}=150{\times}10^{4}x+84.2{\times}10^4(r=0.99^{**}$$) Colony 4. ($$10{\times}10^4spores/ml$$) $$y_{c4}=13.8{\times}10^{4}x+13{\times}10^4(r=0.98^{**}$$) 3. Average longevity of worker bees artificially infected with Nosema apis was shortened as 21.7~43.8% compare to the control. (p<.05, p<.01) 4. The spores which were isolated from honey bee colony infected with Nosema disease were ovoid or spherical form, and measured, as a rule, from $4.7{\mu}m$ to $6.1{\mu}m$ (mean $5.3{\mu}m$) in length and from $2.4{\mu}m$ to $3.2{\mu}m$ (mean $2.9{\mu}m$) in width. 5. In the mid-gut of honey bees, the spore was progresively germinated and became trophozoite stage. The trophozoites were grown to meronts and their binary fission were begun. The divided two sporoblasts were developed to the spores which had elastic membrane. The new spores were shed in excreta of honey bees 10~15 day after inoculation at $25{\pm}2$ centigrade. 6. The ultrastructure of spore membrane consisted of three layers, such as, outer, middle and inner layer. The sporoplasm consisting lamellar structure occupied only anterior part of the spore and was often extended to posterior direction where definite vacuoles and a polar filament was able to detect.

• Membrane Journal
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• v.15 no.2
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• pp.147-156
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• 2005

It is well-known that polyethersulfone (PES) has high $CO_2$ selectivity over $N_2\;(or\;CH_4)$ and excellent pressure resistance of $CO_2$ plasticization among muy commercialized engineering plastics[1-4]. Asymmetric PES hollow fiber membranes for flue gas separation were developed by dry-wet spinning technique. The dope solution consists of PES, NMP and acetone. Water and water/NMP mixtures are used in outer and inner coagulants, respectively. Gas permeation rate (i.e., permeance) and $CO_2/N_2$ selectivity were measured with pure gas, respectively and the micro-structure of hollow fiber membranes was characterized by scanning electron microscopy. The effects of polymer concentration, ratio of NMP to acetone, length of air gap, evaporation condition and silicone coating were investigated on the $CO_2/N_2$ separation properties of the hollow fibers. Optimized PES hollow fiber membranes exhibited high permeance of $25\~50$ GPU and $CO_2/N_2$ selectivity of $30\~40$ at room temperature and have the apparent skin layer thickness of about $0.1\;{\mu}m$. The developed PES hollow fiber membranes, would be a good candidate suitable for the flue gas separation process.

• Membrane Journal
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• v.15 no.2
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• pp.157-164
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• 2005

In this study, composite hollow fiber membranes were developed for the recovery of olefin monomers in polyolefin industry off-gases. Polyetherimide (PEI) hollow fiber support membranes were fabricated from spinning solutions containing PEI, NMP and polyethylene glycol (PEG). The influence of dope solution and inner coagulant composition on the permeation properties and structure of hollow fiber supports was examined. PDMS was used as a selective layer and coated on PEI hollow fiber support. The thickness of active layer was controlled by changing coating solution concentration. The permeation properties of hollow fiber supports and composite membranes were characterized with a pure gas permeation test. The optimized composite hollow fiber membrane has $10\;{\mu}m$ selective layer and shows excellent separation performance; the ideal selectivity of olefins over nitrogen is in the following order: 1-butylene (6.4) > propylene (17) > ethylene (97), which selectivity data are similar to the intrinsic olefin/nitrogen selectivities of PDMS. This confirms that the new composite hollow fiber membranes suitable for olefin off-gas recovery has developed successfully.

• Journal of architectural history
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• v.5 no.2 s.10
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• pp.25-39
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• 1996

Architectural researches on the traditional houses of Korea have been studied mainly based on the data collected in the field survey. From explosively incresed real mesurements and drawings in the field, plenty of data have been collected. Those have been the basic data for verifing and developing the theories on the traditional house. But after Korean war the researchers in South-Korea were not able to approach to the field in North Korea, so the new data of North Korea were not added any more. The poverty of real data have caused regional unbalance in the researches. This paper aims at collecting new data of traditional house in North Korea. But still being prohibited for the researchers of South Korea to approach to the field, I had to depend on the memories and experiences of the immigrants from North Korea who are now living in Kyon-Nam and Pusan Province. Through the questionnaire and drawings, they described vivid memory of their old houses. I was able to collect the data of 71 cases, which are significant and valuable as much as those of the real field are. The data include the address and site condition, family structure, economic condition, construction period of each house, The drawings by themselves show the building forms and plans, the plans of each building, and the included spaces. Although the quantity of those data is not enough for statistical analysis, it shows general tendency for analizing regional charateristics, the differnces among economical classes, and the periodical change. It opens the way for verfying the existing theory. Analizing the data, I have some conclusions as followings: a. Most of researchers have classified the dominant housing type of Hamkyong-Do as 'the double fold' type. In this study, all cases of Hamkyongbuk-do also show 'the double fold plan with Chongju-kan'. But in Hamkyongnam-do some cases show 'the double fold plan without Chongju-kan, or projecting the stable into the yard, which seem to be different type from 'the double fold plan with Chongju-kan' b. Existing theories classified the dominant housing type of Pyongahn-do as 'two buildings with pararell arrangement'. This classification is verified with the plentiful cases in this study. Futhermore, I found new tendency, that is, getting higher econnomic condition, they construct annex buildings between the main buildings. Finally their houses show 'scattered ㅁ shape'. The houses included in this two types has narrow and closed inner yard, which is different from the houses of the same shape in the south region of Korea. c. Existing theories classified the dominant housing type of Hwanghae-do as 'ㅁ sape with Daechong' type. I found many cases of 'ㅁ shape', but only two cases show 'Daechong'. 'The doble fold' type was also founded. Unfortunately very few cases were sent from Hwanghae-do, it is not enough for finding general tendency.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.195-202
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• 2006

Thin-walled structures are efficiently utilized an automobiles, aircraft, satellite and ship as well as needed light weight simultaneously. This paper presents new shape of automobile hood reinforcement that rotating parts as engine, transmission are protected by thin-walled structures. The automobile hood is concerned about the resonance occurs due to the frequency of the rotating parts. The hood must be designed by supporting the stiffness of design loads and considering the natural frequencies. Hence, it is sustained the stiffness and considered the vibration by resonance. It is deep related to ride. Therefore, the topology, shape and size optimization methods are used to design the automobile hood. Topology technique is applied to determine the layout of a structural component optimum size with maximized natural frequency by volume reduction. In this research, The optimal structure layout of an inner reinforcement of an automobile hood for the natural frequency of a designated mode is obtained by using topology optimization method. The optimum size and the optimum shape are determined by PLBA(Pshenichny-Lim-Belegundu-Arora) algorithm.

• Journal of the Korean earth science society
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• v.28 no.4
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• pp.393-404
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• 2007

The purpose of this study was to identity scientific models included in the Earth domain of the $10^{th}$ grade science textbooks. Three earth science-related chapters in each of 11 trade books were analyzed. A framework was developed and used to classify a scientific model from three different perspectives: medium of representation, method of representation, and mobility of a model. Results showed that the science textbooks utilized domain-specific models in which the nature of sub-areas of earth science was embedded. That is, the unit of 'Change of the Earth' included many iconic models that represented the inaccessible inner structure of the earth and the movement of the tectonic plates. These were also two-dimensional pictorial and static models. In the chapter of 'Atmosphere and Oceans', symbolic and diagrammatic models were dominant in use, which included weather maps and contour line graphs of sea surface temperature and salinity. The unit of 'Solar System and Galaxies' showed the highly frequent use of iconic and analogical models for the large-scale celestial objects and their movements. Implications for earth science education and relevant research were discussed.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.203-211
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• 2008

Minimizing damage to anatomical structure is a prerequisite for skeletal anchorage system to install a miniscrew. This research has focused on evaluating the stability and safety of installation in the maxillary molar buccal area, in which most miniscrews are installed clinically and initial fixation is weak. CT (computerized tomography)images were taken for surveying the possibility of damaging to adjucent teeth in accordance with installation angle. If we install a mini-screw($1.2{\times}6.0mm$) in the maxillary molar buccal area, it would be located generally in the 5~8mm upper of CEJ and 3~5mm inner of the cortical bone surface. We has measured the space between roots And comparison has been made for gender and the space between roots in accordance with the 3 different angles of installation(30 degree, 40 degree, 60 degree) in 3 categories. Category 1 : between 1st molar and 2nd molar Category 2 : between 1st molar and 2nd premolar Category 3 : between 1st premolar and 2nd premolar The result are as follow; 1. The space for category 1 was significantly small. 2. For the installation angle, it was safer to install with steeper angle in category 1 and category 2, but not in category 3. According to these results, the installation a miniscrew in category 2, 3 is safer than in category 1. And it is safer to install with steeper angle in category 1 and category 2.

• Journal of the Korean Society of Costume
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• v.58 no.7
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• pp.76-91
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• 2008

The purpose of this study is to prescribe formative perspectives as a framework where the aesthetic taste and demands of a certain period are embodied and to develop new analytical tools to examine the beauty of dress in terms of form. First, the theoretical tools selected for this study are Heinrich Wolfflin's formative perspective theory derived from art and Marilyn R. DeLong's framework for visual analysis of dress. Second, several issues that limited the development of a new framework for analyzing the form of dress were identified and addressed. Third, the selected aspects of dress form to be analyzed are specified. They are: silhouette, inner form, structure form, materials and patterns based upon the relationship between the body, dress and space in order to develop new formative perspectives. Based upon these theories a new framework for analyzing dress aesthetics in terms of form is developed. This reconstructed framework consists of three sets of antagonistic representational styles: closed form/open form, linear form/painterly form and multiplicity/unity. Closed form/open form represented in dress can be classified by the clear or obscure silhouette shown not only in the relationship between the dress and space around the dress, but also from changeability or invariability of dress in relation to the body. The material, pattern and various design elements are used as the central criteria to determine the linear/painterly characteristics in dress representations. Finally, the multiplicity/unity can be found in the relationship between the whole and the parts. Multiplicity is represented in dress when the parts have a visual priority over the whole, whereas unity is represented when a dress as a whole has visual priority over the parts. A dress represented with closed form, linear characteristic and multiplicity is perceived as a clear form. In contrast, a dress with open form, painterly characteristic and unity is understood to be an obscure form. It can be said that this study is the first attempt to establish the formative perspectives for analyzing the form of dress in various periods, cultures and races for the future studies.

• Composites Research
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• v.29 no.5
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• pp.282-287
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• 2016

p-DCPD (poly dicyclopentadiene) is the resin that the versatile mechanical properties can be changeable via the control of inner monomer and catalysts. In this work, to improve the strength of composites, surface treated MGF (milled glass fiber) was used as an reinforcement in p-DCPD by molybdenum (Mo) catalyst matrix. The optimum concentration of surface treatment was obtained and the cohesion of MGF themselves increased with concentration. In case of 0.2 wt% silane concentration, the maximized mechanical properties of MGF/p-DCPD composite exhibited because of minimized MGF cohesion. When butyl silane showing minimizing cohesion was used as the optimized alkyl length, high tensile and flexure strength exhibited due to the steric hindrance effect among MGFs. Mechanical and their fractured surfaces of MGF/p-DCPD composites was compared for 4 different chemical functional groups. Norbornene functional groups containing similar chemical structure to DCPD matrix exhibited higher interfacial adhesion between MGFs and DCPD matrix.