• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.53-64
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• 2012

Deep and narrow welds can be produced by laser welding at high welding speeds with a narrow heat-affected zone (HAZ) and little distortion of the workpiece. This study aims to evaluate the usefulness of laser welding at automobile component manufacture. Microstructure observation, hardness test, tensile test and fatigue life test are performed by using the fiber laser welded SPFC590 steel sheets which is used widely in the manufacture of automotive seat frame. Three kinds of specimens are only a SPFC590 steel plate, quasi-butt joint plate and lap joint plate by laser welding. The following results that will be helpful to understand the static strength, fatigue crack initiation and growth mechanism were obtained. (1) The tensile strength of quasi butt joint specimens nearly equal to base metal specimens, but lap joint specimens fractured in shear area of weld metal. (2) The fatigue strength of quasi-butt joint specimen was approximately 8 percent lower than that of the base metal specimens. Furthermore, the lap joint specimens were less than 86 percent of the base metal specimens. (3) The lap joint fatigue specimens fractured at shear area in high level stress amplitude, while fractured at normal area in low level stress amplitude. From these results, the applicability of the laser welding to the automobile component is discussed.

• Journal of the Korea Furniture Society
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• v.27 no.2
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• pp.111-121
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• 2016

In the structure of modern houses, a living room is the space most frequently used by family members. In a living room, they rest, talk together, watch TV, study, read books and enjoy hobbies. A living room is furnished with a TV cabinet, a storage closet, a sofa, a bookshelf, a desk and etc. depending on the purposes of activities in it, which can be different in each house. Furniture is the required tool for indoor architectural space and humans to lead a life. In most families, a man and a woman marry each other and become man and wife, go through the honeymoon phase, give birth to one or two children and become a family with three or four members. According to the children's growth cycle from birth to infancy, early childhood, childhood, adolescence, youth and adulthood, furniture layout and kinds of furniture in a living room change. Depending on the family life cycle, most parents of young children try to help their children to form good habits of reading books and studying for their future. As for the environmental elements interrupting reading and studying, watching TV and using smart phones excessively are being regarded as problems. As the number of two-income families is increasing in this era when many women are participating in the social activities with the government's encouragement, children are having more time.

• Korean Journal of Veterinary Service
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• v.41 no.1
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• pp.57-61
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• 2018

Canine peripheral nerve sheath tumors (PNSTs) are spindle cell tumors that arise from Schwann cells, perineural cells, fibroblasts or all of them. Based on the morphology and biologic behavior, PNSTs are divided into benign PNST (BPNST) and malignant PNST (MPNST) forms. The aim of this study is to diagnose the two cases of neoplastic tissue samples with features of PNSTs by the histopathology and immunohistochemistry. The study was performed using two specimens from small animal clinic. The first case, A was a mass, 3~4 cm in diameter, extruded from vaginal mucosa of 10-year-old spayed female mixed-breed dog. And the second case, B was a subcutaneous mass, 1.5 cm in diameter, which is originated from right hind leg of 9-year-old castrated male mixed-breed dog. Two cases were stained with hematoxylin and eosin (H&E) for histopathological examination. And also immunohistochemistry (IHC) was performed by the avidin-biotin peroxidase complex (ABC) method with antibodies specific for the following proteins: S-100 protein, smooth muscle actin (SMA) and epidermal growth factor receptor (EGFR). In results, Antoni B schwannoma pattern characterized by pleomorphic, round and fusiform polygonal cells was seen in A. In B, Antoni A pattern, densely packed spindle cells arranged in interlacing bundles was seen in addition to Antoni B pattern. In IHC, cytoplasms of neoplastic cells were diffusely labeled for S-100 expression in A and B. For SMA, both A and B show negative expression. And for EGFR, A shows negative expression but B shows partially positive expression in areas of Antoni B schwannoma pattern. The histopathologic features of two cases coupled with the S-100 immunoreactivity led to a diagnosis of PNST. For SMA, both A and B show negative expression. The diagnosis of A will be a BPNST with the negative result and B will be a MPNST with the positive result for EGFR.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.621-627
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• 2017

The understanding of the mechanical properties of amyloid fibers, which induce various neurodegenerative diseases, is directly related to the amyloid growth mechanism. Diverse studies have been performed on amyloid fibers from the viewpoint of disease epidemiology. Recently, attempts have been made to use amyloid fibers as new materials because of their notable mechanical properties and self-aggregation abilities. In this study, the mechanical properties of transthyretin (TTR105-115), which induces cardiovascular disease, were evaluated using a molecular dynamics (MD) simulation. In particular, the effect of the end-terminal capping on the structural stability of TTR105-115 was evaluated. The mechanical behavior and properties of TTR105-115 were measured by steered molecular dynamics (SMD). We clarified the factors affecting the mechanical properties of these materials and suggested the possibility of utilizing them as nature inspired materials.

• Health Policy and Management
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• v.8 no.1
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• pp.232-265
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• 1998

Taiwan has experienced rapid economic growth during the past two decades. As a result, the demand for health care in Taiwan has increased rapidly. To meet the rising demand, Taiwan implemented a National Health Insurance (NHI) program on March 1, 1995. This program now covers more than 96 percent of Taiwan's citizens. Implementation of the NHI in 1995 represents fulfillment of a primary social and health policy goals of Taiwan. The goals of the NHI program is to eliminate financial barriers of health care for the citizens, to improve the quality of care. To achieve these goals, the NHI was designed on the following principles: 1. All Taiwan citizens are compul내교 joined the NHI program by law; 2. The NHI program provides comprehensive services; 3. The NHI is run by one single govt' subsidy; 5. The NHI adopt fee-for-services scheme to pay medical expenses and copayment to avoid abouse of medical services. However, the scheme did not bring in the efficient use of health care C. National Health Council, 1986 NARC, Aging in Japan, International Publication Series 1991;2 Kahana EF. Kiyak HA. Attitude and behavior of staff in facilities for the aged, 1984 Naoki I, John CC. Health polic report japan's medical care system, New England Joumal of Medicine 1995; 333(19) National Economic Research Associates, The Health CAre System in Japan, NERA, 1993. National Federation of health Insurance Societies (KEMPOREM), Health Insurance and Health Insurance Societies in Japan, 1995. Owe Ahlund, Aging and housing in sweden, Paper presented at the International Symposium, Long term Care Facility, 1993. Statisitics Jahrbuch, Statistisches Bundesamt, 1992. Stein S. Linn, MIW. and Stein EM. Patient's anticipation of stress in nursing home care, 1985. U. S. Senate Special Committee on Aging, A Report of the special Committee on Aging, Washing D. C, 1992. U.S. Bureau of the Census, 1994.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.937-946
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• 1986

In this paper, the plane stress fracture toughness of low carbon steel with 3mm thickness is investigated for various specimen widths and crack ratios using the J integral. The experiments is carried out for the compact tension(CT) specimen on an Instron machine. For materials that may be approximated by the Ramberg and Osgood stress strain law, the relevant crack parameter like the J integral and load line displacement are approximately normalized. Crack driving forces in terms of J integral is computed using the above estimation scheme. Abtained results are summarized as follows. (1) The plane stress fracture toughness, J$_{c}$, is almost constant in the range 50-70mm of width. Hence J$_{c}$ can be obtained by using smaller specimen than ASTM standard. (2) Yoon's and Simpson's formular which considers crack growth in obtaining J integral show more consevative J than Rice's and Merkle's (3) J$_{c}$ is almost constant in the range 0.499-0.701 crack ratios tested. J$_{c}$ obtained by using Kumar's formular is 28.14kgf/mm for base metal specimen and 32.51kgf/mm for annealed. (4) Comparison of the prediction with actual experimental measurements by Yoon's formular show good agreement for several different-size specimens.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.1
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• pp.60-65
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• 2014

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disease caused by a defect in cholesterol biosynthesis. This mutation encodes 7-dehydrocholesterol reductase (DHCR7), which is located on chromosome 11q13. It is characterized by typical facial appearances, microcephaly, small up-turned nose, cleft palate, syndactyly, and is correlated with cardiac, gastrointestinal and genital malformations. There may also be mental retardation, behavioral problems and growth retardation. It causes a broad spectrum of effects, ranging from a mild disorder of learning and behavior to a lethal malformation. There are four reports of Smith-Lemli-Opitz syndrome in Korean children. Here, we describe a two months old female with microcephaly, toe syndactyly and a cleft soft palate who was diagnosed as SLOS with c. 1054 C>T (p.R352W) and c.907G>A (p. G303R) mutations.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.4
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• pp.164-171
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• 1988

Recently with the rapid development in marine and shipbuilding industries such as marine structures, ships and chemical plants, it takes much interest in the study of corrosion fatigue characteristics that was close up an important role in mechanical design. In this study, characteristics of corner crack propagation on the base metal and heat affected zone of 5086 Al-Alloy was tested by using of a rotary bending fatigue tester and was investigated under the environments of specific resistance, $\rho$=25$\Omega$ cm and air. The corrosion fatigue crack initiation and corrosion fatigue life sensitivity were quantitatively inspected for 5086 Al-Alloy in the specific resistance, $\rho$=25$\Omega$ cm. Main results obtained are as follows: (1) The corrosion sensitivity of heat affected zone under specific resistance, $\rho$=25$\Omega$cm shows approximately 1.69~2.22 and corrosion sensitivity of base metal is more susceptible than that of heat affected zone. (2) The corrosion fatigue life sensitivity on heat affected zone decreases eminently than that of initial corrosion fatigue crack. (3) The characteristics of quarter elliptical corner crack propagation shows that depth crack is more grown than surface crack at crack initiation, but the surface crack is more propagated than depth crack as the crack propagation is increased. (4) The surface crack and depth crack growth on heat affected zone by softness show delayed phenomenon than that of base metal.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.85-94
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• 2010

In vitro shoot regeneration of gladiolus in three different culture systems, viz., semi-solid agar (AS), membrane raft (MR), and duroplast foam liquid (DF) cultures was evaluated following the kinetics of shoot multiplication and hyperhydricity at optimized growth regulator combinations. Compared to the AS system, matrixsupported liquid cultures enhanced shoot multiplication. The peak of shoot multiplication rate was attained at 18 days of incubation in the MR and DF systems, whereas the maximum rate in the AS system was attained at 21 days. An early decline in acceleration trend was observed in liquid cultures than the AS culture. The hyperhydric status of the regenerated shoots in the different culture systems was assessed in terms of stomatal attributes and antioxidative status. Stomatal behavior appeared to be normal in the AS and MR systems. However, structural anomaly of stomata such as large, round shaped guard cells with damage in bordering regions of stomatal pores was pronounced in the DF system along with a relatively higher $K^+$ ion concentration than in the AS and MR systems. Antioxidative status of regenerated shoots was comparable in the AS and MR systems, while a higher incidence of oxidative damages of lipid membrane as evidenced from malondialdehyde and ascorbate content was observed in the DF system. Higher oxidative stress in the DF system was also apparent by elevated activities of superoxide dismutase, ascorbate peroxidase, and catalase. Among the three culture systems, liquid culture with MR resulted in maximum shoot multiplication with little or no symptoms of hyperhydricity. Shoots in the DF system were more prone to hyperhydricity than those in the AS and MR systems. The use of matrix support such as membrane raft as an interface between liquid medium and propagating tissue could be an effective means for rapid and efficient mass propagation with little or no symptoms of hyperhydricity.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.298-304
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• 2007

We have studied the effect of $N_2$ flow rate on the structural and optical properties of GaN nanorods grown on (111) Si substrates by radio-frequency plasma-assisted molecular-beam epitaxy. The hexagonal shape nanorods with lateral diameters from 80 to 190 nm with increasing $N_2$ flow rate from 1.1 to 2.0 sccm are obtained. However, the ratio of length (thickness) and compact region increases with increasing $N_2$ flow rate up to 1.7 sccm and then saturate. From the photoluminescence, free exciton transition is clearly observed for GaN nanorods with low $N_2$ flow rate. And the PL peak energies are blue-shifted with decreasing diameter of the GaN nanorods due to size effect. Temperature-dependent photoluminescence spectra for the nanorods with $N_2$ flow rate of 1.7 sccm show an abnormal behavior like "S-shape" with increasing temperature.