• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.113-121
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• 1999

We have analyzed 251 data of the daily sunspot observations during the period of January 3 to December 31 in 1998 and present the daily relative sunspot numbers. During the 1998, the prehmmary annual average of the relative sunspot numbers is found to be 84.8 based on 26.6 distinct spots in a single group for 4.6 spot groups. According to the appearance of 286 spot groups, our analysis shows that the mean life time of spot group is about 4 day and 23.6 hours.

• Journal of the Korean Magnetics Society
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• v.18 no.2
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• pp.71-74
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• 2008

In this paper, we have measured the effect of the optical spot size, incident upon the quadrant photodetector, on the optical displacement sensitivity of the optical beam deflection technique. We have built an optical displacement detection system based on the optical beam deflection method using 3 mW He-Ne laser and measured the displacement sensitivity with changing the optical spot size on the quadrant photodetector. We have also calculated the changes in the optical displacement sensitivity as a function of the incident laser spot size by modeling a circular optical spot with constant laser intensity. Our experimental and theoretical studies show that the optical displacement sensitivity increases with the decrease in the optical spot size. This suggests that in the design of the optical motion detection systems with sub-nanometer sensitivity, the displacement sensitivity can be optimized by reducing the size of the incident optical spot on the detector.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.618-624
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• 1990

The antimutagenic effects of apple enzymatic browning reaction products(AEBRP) which resulted from the reaction of catechol, hydroquinone, homocatechol, hydroxyhydroquinone and pyrogallol with polyphenol oxidase extracted from apple(Jona gold) were investigated. Test strain used in SOS spot test and SOS chromotest was E. coli PQ 37/plasmid pKM 101. In SOS spot test, all of five AEBRPs showed strong antimutagenic effects on mytomycin C(MMC), 4-nitroquinoline-1-oxide(4NQO), N-me-thyl-N'-nitro-N-nitrosoguanidlne(MNNG) as increasing concentrations of AEBRP solution. In SOS chromotest, most of AEBRPs also showed strong antimutagenic effects on MMC, MNNG, 4NQO and 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1), as increasing concentration of AEBRP solution.

• Journal of fish pathology
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• v.35 no.2
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• pp.241-246
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• 2022

White spot syndrome virus (WSSV) is a prevalent and virulent pathogen affecting cultured whiteleg shrimp (Litopenaeus vannamei) in Korea. In this study, seven monoclonal antibodies (mAbs) (10A12, 16C3, 17G4, 21G5, 22C4, 23B6 and 24G6) were produced by using purified WSSV. The reactivity of these mAbs was analysed by Western blot (WB), indirect immunofluorescence (IIF), and lateral flow immunochromatographic assay (LFIA). WB analysis demonstrated that three mAbs (17G4, 22C4, and 23B6) reacted specifically to VP28 with an approximate molecular weight of 24 kDa, mAb 16C3 reacted with approximately 17 kDa. IIF analysis demonstrated specific fluorescence signals on gill tissues of WSSV-infected shrimp, with five mAbs (10A12, 16C3, 22C4, 23B6, and 24G6), pleopods from WSSV-infected shrimp were used for LFIA, where, two mAbs (21G5 and 22C4) exhibited positive reaction. In conclusion, it can be inferred that the mAbs usage and specificity depends on the nature of assay used for diagnosis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.200-210
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• 2000

objective to ascertain whether the concept of the therapeutic side is associated with changes in the blind sport mapping that represents the brain function. design Physiological blind spot maps were used as an integer of brain activity before and after acupuncture needling on the meridian point Hapkok(合谷) and Techung(太衝) in the unilateral side decided by double-blind controlled study(20 subjects). setting outpatient clinic participants: adult volunteers intervention twenty subjects were divided into two comparative groups and underwent specific acupuncture therapy on the unilateral side. Blinded examiners obtained reproducible pre and post-acupuncture cortical maps, which were subjected to statistical analysis. main outcome measures Brain activity was demonstrated by reproducible circumferential measurements of cortical hemispheric blind spot maps before and after acupuncture on the unilateral side. in case of acupuncture needling on the ipsilateral side of an enlarged side of bilnd spot, there were reduction of blind spot in 7 cases of 10 subjects, and enlargement in 3 cases. in case of acupuncture needling on the contralateral side of the enlarged side of blind spot, there were enlargement of blind spot in 6 cases of 10 subjects, and reduction in 4 cases. results the significant changes in the blind spots before and after acupuncture were observed Acupuncture needlings on the ipsilateral or contralateral side of an enlarged cortical map were associated with the concept of the therapeutic side traditionally accepted in the oriental medical society. Acupuncture needling on the ipsilateral side of an enlarged blind spot map is associated with the reduction of map, and increaed contralateral cortical activity. Acupuncture needling on the side opposite an enlarged blind spot map is associated with the enlargement of map, and decreased cortical activity. conclusion Reproducible maps of cortical responses can be used to measure the neurological consequences of acupuncture needling. Acupuncture can affect the somatic sensory informations that reach to the contralateral thalamus, and so affect thalamic integration. we found that acupuncture therapy may be associated with an increase or a decrease in brain function depending on the side of acupuncture needling. thus, the traditional concept of the contralateral therapeutic theory in acupuncture approach has the clinical significance in the view of brain function.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.213-222
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• 2001

In the study, the fatigue strength improvement and mechanism have been estimated by the Spot-Heating treatment on welded bead toes. For this, web-gusset specimens were made without residual stresses and the others with residual stresses imposed by Spot-Heating. The 4-point bending tests were performed in order to estimate the effect of spot-heating on fatigue strength and fatigue characteristics quantitatively for non load-carrying fillet welded joints subjected to pure bending. As a result of fatigue test, fatigue strength of As-Welded specimen for non load-carrying fillet welded joints subjected to pure bending has satisfied the grade of fatigue prescribed in specifications of korea, AASHTO and JSSC. As compare with As-Welded specimen and Spot-Heating specimen have increased about 20% for the fatigue strength at $7.7{\times}10^6$ cycles. The Spot-Heating by reformation of the residual stress on welded bead toes has greatly affected the fatigue crack propagation life, but has slightly affected the fatigue crack initiation life.

• Journal of Welding and Joining
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• v.15 no.4
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• pp.42-62
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• 1997

Resistance spot welding has been widely used in the sheet metal joining processes because of its high productivity and convenience. Recently, automobile industries are trying to replace partly steel sheets with aluminum alloy sheets. Among currently produced aluminum alloys, Al alloy sheets of Al-Mg-Si(6000 series) are being tested. Especially, 6000 series are the most probable substitute in view of strength and weldability. In this paper, an attempt was made to apply resistance spot welding to joining of dissimilar sheet metals (KS6383+SCPZn or KS6383+SHCP). An effort was made to balance heating rate in the Al alloy with that in the steel sheets by increasing electrode tip diameter. Although resistance spot welding of Al alloy sheet and sheet metals does not produce desirable nugget, it proved to have reasonable strength if optimal weld condition is found by tensile-shear strength and fatigue life test. Since spot weld joints in automobile are always experiencing repeated load, spot welding methodology proposed in this paper is found to be not suitable to automobile body manufacturing.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.98-104
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• 2006

In this paper, for the purpose of investigation the acoustic emission(AE) behaviors during resistance spot welding process and tension test of spec steels. As the results present the resistance spot welding method that can get suitable welding qualities or structural integrity estimating method. The resistance spot welding process consists of several stages: set-down of the electrodes; squeeze; current flow; forging; hold time; and lift-off. Various types of AE signals are produced during each of these stages. For tensile-shear test and cross tensile test in resistance spot welded specimens, fracture pa 야 ems are produced: tear fracture; shear fracture; and plug fracture. Tensile-shear specimens strength appeared higher than cross tensile specimens one. In case of tensile-shear specimen happened tear fracture that crack happens in most lower plate. Also, in case of cross tensile specimens, upper plate and lower plate are detached perfect fracture was exposed increases a little as acting force is lower than ordinary welding condition. Therefore, the structure which is combined by resistance spot welding confirmed that welding design must attain so that shear stress may can interact mainly.

• Mycobiology
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• v.40 no.4
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• pp.268-271
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• 2012

In June 2012, leaf spot and stem rot were observed on Wilford Swallowwort plants grown in Cheonan, Korea. Three fungal isolates obtained from the diseased leaves and stems were identified as Stemphylium lycopersici, based on morphological, cultural, and molecular characteristics and pathogenicity. This is the first report of leaf spot and stem rot on Wilford Swallowwort caused by S. lycopersici.

• Journal of fish pathology
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• v.13 no.1
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• pp.15-20
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• 2000

Infection rates with white spot baculovirus(WSBV) in wild-caught shrimp spawners appeared to be 52% in Penaeus chinensis and 20% in Penaeus japonicus when diagnosed by polymerase chain reaction (PCR). Infection rates of WSBV from inhabitant organisms in shrimp farm showed 37% in Upogebia major and 29% in Calliamassa japonica. The viruses maintained their survivorship in seawater at $4^{\circ}C$, but lost it at $25^{\circ}C$.