• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.710-713
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• 2005

Many impact or drop test researches of home appliances are published, but those of toys cannot be found easily. External impacts are the primary causes of fracture of toys. For impact proof design, the finished product should pass an impact test after molding design. There are several international toy safety standards or requirements such as US CPSC(Consumer Product Safety Commission), ASTM F963-96a, EN71 and so on. The puppy robot which patrols around the house, namely, the watchdog was selected to investigate toy safety because it has considerable weight and outer panels are made of plastics. First the model of watchdog robot was obtained by 3 dimensional scan. Surface data can be generated from 3D polygon data of the watchdog. A reliable drop simulation method for the watchdog was established using Pam-crash program according to Korean toy safety standards. When there is a low impact allowance value, the molding design should be reinforced or changed. It was found that the maximum impact stress reaches the ultimate stress of panel material.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.394-398
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• 2001

Because of the great concern over the possibility of contamination from the rod-shaped nuclear virus (PRDV) from Japan and white spot virus (WSSV) from Taiwan, most eggs used in Korean shrimp farms are currently obtained from local broodstock. In addition, the screening of imported broodstock for any viral presence at the National Fisheries Research and Development Institute is also mandatory. Nonetheless, massive mortality from white spot syndrome continues in Korea. In the present study, we present an improved PCR method to use tissue-extracted DNA instead of viral DNA extracted from a purified virus based on a sucrose density gradient, and produced results within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected only with PRDV, while Fenneropenaeus chinensis were infected with both PRDV and WSSV. In 1999, PRDV and WSSV were detected in F. chinensis with signs of infection, but not with WSSV alone.

• 대한수의학회지
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• 제38권2호
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• pp.336-344
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• 1998

Eight monoclonal antibodies(MAbs) against the transmissible gastroenteritis virus (TGEV) were produced and characterized. Four of the MAbs were produced against a reference TGEV, Purdue strain(P115) and the others were produced against the Korean vaccine virus, Pyungtaek strain. Only one MAb(5C8) produced against P115 had neutralizing activity and was found to be E2 protein-specific. The other seven MAbs(4E2, 4G8, 5H6, 1F8, 2C6, 5H5, and 3A6) had specificity of nucleocapsid protein and no neutralizing activity. All MAbs reacted with different strains of TGEV, but none of the MAbs was reactive with porcine enteropathogenic viruses such as rotavirus, epidemic diarrhea virus and enterovirus by fluorescence antibody(FA) test.

• Steel and Composite Structures
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• 제13권1호
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• pp.71-89
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• 2012

The paper investigates beam lateral buckling stability according to linear and non-linear models. Closed form solutions for single-symmetric cross sections are first derived according to a non-linear model considering flexural-torsional coupling and pre-buckling deformation effects. The closed form solutions are compared to a beam finite element developed in large torsion. Effects of pre-buckling deflection and gradient moment on beam stability are not well known in the literature. The strength of singly symmetric I-beams under gradient moments is particularly investigated. Beams with T and I cross-sections are considered in the study. It is concluded that pre-buckling deflections effects are important for I-section with large flanges and analytical solutions are possible. For beams with T-sections, lateral buckling resistance depends not only on pre-buckling deflection but also on cross section shape, load distribution and buckling modes. Effects of pre-buckling deflections are important only when the largest flange is under compressive stresses and positive gradient moments. For negative gradient moments, all available solutions fail and overestimate the beam strength. Numerical solutions are more powerful. Other load cases are investigated as the stability of continuous beams. Under arbitrary loads, all available solutions fail, and recourse to finite element simulation is more efficient.

• 복식
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• 제1권
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• pp.59-65
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• 1977

Les modes des costumes naitonaux de $cor{\acute{e}}e$ est plus simple que celle du Occident. mais les facons, sur les quelles les mesures fondamentalement agissent, ont des $varit{\acute{e}}s$ selon les personnes qui se les habillent: masculines, $f{\acute{e}}m$ nines, jeunes, vieilles. Le but de cette ${\acute{e}}tude$ est, par l'anayse statistique des mesures, $d'{\acute{e}}tablir$ comment sont les $vari{\acute{e}}t{\acute{e}}s$. Les $r{\acute{e}}sultats$ de ce travail peuveut $\hat{e}tre$ $r{\acute{e}}sum{\acute{e}}s$ ainsi: 1. Plus $\grave{a}g{\acute{e}}s$ sont les personnes, plue larges et longues les Cheo-go-ri (vestes). 2. A propos des longeur des vestes, on les $g{\acute{e}}n{\acute{e}}ralement$ $consid{\acute{e}}re$ comme les $donn{\acute{e}}es$ principalement $subondonn{\acute{e}}es$ aux tailles des personnes $habill{\acute{e}}es$. mais a mon travail, le tour do poitrine peut-$\hat{e}tre$ le plus relatis en ce problemes. [parce que le coefficient $conr{\acute{e}}ratif$ ayant rapponts au tour de poitrine (r=0.512) est plus haut que celui qui est relatif a la taille (r=0.436).

• Advances in aircraft and spacecraft science
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• 제7권6호
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• pp.495-516
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• 2020

Nonlinear state estimation is a desirable and required technique for many situations in engineering (e.g., aircraft/spacecraft tracking, space situational awareness, collision warning, radar tracking, etc.). Due to high standards on performance in these applications, in the last few decades, there was an increasing demand for methods that are able to provide more accurate results. However, because of the mathematical complexity introduced by the nonlinearities of the models, the nonlinear state estimation uses techniques that, in practice, are not so well-established which, leads to sub-optimal results. It is important to take into account that each method will have advantages and limitations when facing specific environments. The main objective of this paper is to provide a comprehensive overview and interpretation of the most well-known methods for nonlinear state estimation with Gaussian priors. In particular, the Kalman filtering methods: EKF (Extended Kalman Filter), UKF (Unscented Kalman Filter), CKF (Cubature Kalman Filter) and EnKF (Ensemble Kalman Filter) with an aerospace perspective.

• Nuclear Engineering and Technology
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• 제33권2호
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• pp.225-230
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• 2001

The aim of this study is to describe a usefulness of nuclear analytical technique in assessing and comparing the concentration levels through the analysis of uranium using human hair sample in the field of environment. A fission track detection technique was applied to determine the uranium concentration in human hair. Hair samples were collected from two groups of people - a) workers not dealing with uranium directly, and b) workers possibly contaminated with uranium. The concentration of $^{235}$ U for the first group varied from <1 to 39 ng/g and the second group can be estimated up to the level of $\mu$g/g. Radiographs of heavy-duty work samples contained high dense “hot spots” along a single hair. After washing in acetone and distilled water, external contamination was not totally removed. Insoluble uranium compounds were not completely washed out. The (n, f)- radiography technique, having high sensitivity, and capable of getting information on uranium content at each point of a single hair, is an excellent tool for environmental monitoring.

• 한국동물학회지
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• 제35권2호
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• pp.219-225
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• 1992

The genetic variation in mitochondrial DNA (mtDNA) was analysed within and between two species of tree frogs. Hyla japonica and H. suweonensis from South Korea. Purified mtDNAs were digested with each of 11 restriction enLvmes which cleave at six base recognition sequences. The genome size of H. iaponica revealed ho types (20.0 $\pm$ 0.3 and 19.6 $\pm$ 0.3 kb) and this difference is explained by either addition or deletion of about 0.4 kb fragment. On the other hand, the genome sire of H. suueonensis was about 19.0 $\pm$ 0.4 kb only. For the analysis, level of fragment homology (F) and nucleotide sequence divergence (p) were estimated from comparisons of digestion profiles. Among four populations of H. iaponica, substantial mean sequence divergence was 0.017 (range 0.001-0.026); between identical types, 0.001 IslilaRl type) and 0.004 (Large type) respectively; between different ones, 0.024 (range 0.023-0.026). The level of sequence divergence between he species was 0.142 (range 0.131-0.146). This result suggested that he species ㅂwere distinctly differentiated species. The divergence time between ko species was estimated 7.1 million years.

• 한국전기전자재료학회논문지
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• 제22권1호
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• pp.81-85
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• 2009

We has been analysed optical properties of OLED(organic light emitting diode) and characteristics of ITO(Indium Tin Oxide) in terms of $O_2$ plasma treatment for manufacturing high efficiency OLED, RF power of $O_2$ plasma was changed 25, 50, 100, 200 W. $O_2$ gas flow, gas pressure and treatment time were fixed. Sheet resistance and surface roughness of ITO were measured by Hall-effect measurement system and AFM, respectively. The ranges of sheet resistance and surface roughness were $5.5{\sim}6,06\;{\Omega}$ and $2.438{\sim}3.506\;nm$ changing of RF power, respectively, PM(Passive Matrix)OLED was fabricated with the structure of ITO(plasm treatment)/TPD($400\;{\AA}$)/$Alq_3(600\;{\AA})$/LiF($5\;{\AA}$)/Al($1200\;{\AA}$). Turn-on voltage of PMOLED was 7 V and luminance was $7,371\;cd/m^2$ at the RF power of 25 W, $O_2$ plasma treatment of ITO surface was result in lowering the operating voltage and improving luminance of PMOLED.

• Steel and Composite Structures
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• 제48권3호
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• pp.251-262
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• 2023

There are many examples of steel structures subjected to severe environmental conditions with bolted connections directly exposed to extreme climatic agents such as freeze-thaw cycles or low temperatures. Some examples are: steel bridges, mining transfer towers, wind towers... These service conditions neither are included in Eurocode 3 or EN1090-2, nor there are references in other international standards. In this experimental research, 46 specimens of non-slip joints with HV M20 bolts and four different types of contact surfaces have been studied. Half of the specimens were subjected to fourteen twelve-hours freeze-thaw cycles, with periodic immersion in water and temperature oscillation. Subsequently, half of the connections were subjected to a slip test under monotonic load at temperature of -20 ± 0.5 ℃ and the other half at room temperature. The results were compared with others equal joints not subjected to freeze-thaw cycles and kept at room temperature for the same time. This finally resulted in 4 sets of joints by combining the freeze-thaw degradation or not with the low-temperature conditions or not in the slip testing. Therefore, a total of 16 different conditions were studied by also considering 4 different contact surfaces between the joined plates in each set. The results obtained show influence of environmental conditions on the slip resistant capacity of these joints.