• Animal cells and systems
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• v.1 no.2
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• pp.351-354
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• 1997

The distributions of G to A substitution ($G^{-75}{\rightarrow}A$) mutation in the human apolipoprotein A1 (APOAI) gene promoter region and glutathione S-tran-sferase Mu1 (GSTM1) gene deletion were examined in subjects with Korean population. The $G^{-75}{\rightarrow}A$ mutation of APOA1 was genotyped by the polymerase chain reaction (PCR) and subsequent digestion of the PCR product using either Mspl or Mval (n=206). The observed numbers of GG, GA and AA genotypes were 132, 63 and 11, respectively. The allele frequencies of G and A were 0.794 and 0.206, respectively. The GSTM1 gene deletion was simply examined by the PCR amplification (n=106). The observed numbers of null type ($GSTM1^*0/GSTM1^*0$) and positive type were 55 and 51, respectively. The allele frequency of $GSTM1^*0$ was 0.720.

• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.108-114
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• 2017

Background: The study was conducted to investigate the distributions of faecal bacteria in commercial oriental medicine herb products. Methods and Results: A survey was conducted on the microbial contamination levels and antimicrobial specificity of Bacillus cereus and other microbes using 106 oriental medicine herb products on sale in Seoul. Pouring and isolation methods such as standard plate counts were used to identify the bacteria. The isolated bacterias included coliforms, Bacillus spp., Enterococcus spp., Staphylococcus spp., Listeria spp.were identified by using gram staining and an API (analytical profile index) kit. Antimicrobial drugs discs were determined by CLSI (clinical and laboratory standards institute). Conclusions: The bacterial isolates present in the herbal medicines included 98 coliforms, 45 Bacillus spp., 29 Enterococcus spp., and 2 Listeria spp. Among these, there were nine Bacillus cereus strains, one Enterococcus faecium strain, and one Enterococcus faecalis strain present. The 9 Bacillus cereus strains were tested for susceptibility to 36 types of antibiotics products by the disc diffusion method. The strains showed resistance to 13 of these antibiotic products and semi-resistance to 5 antibiotic products. On the basis of these results, any oriental medicine herb product can be assumed to be contain resistant or semi-resistant bacterial strains. Therefore, we suggest prescribing guidelines and special management for the use of antibiotics in farms producing oriental medicine herb products.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.159-164
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• 1998

Polycarbosilane(PCS) as a SiC precursor was synthesized from the rearrangement reaction of polydimethysilane(PDMS) in an autoclave, which prepared by dehalocoupling reaction of dichlorodimethylsilane. After fractional precipitation into three fractions in n-hexane-methanol mixture, they were characterized by FT-IR, NMR, GPC, TGA/DSC and XRD, and compared with the commercial product. We found that the molecular weight distributions of the PCS depended on the reaction pressures, temperatures and the reaction times, and affected thermal property and ceramic yield of the polymer. The monodispersed PCS containing less amount of oligomers and nonsoluble products was prepared by reaction of PDMS at $420^{\circ}C$ for 10 hrs, and it also gave the greatest amount of medium molecular weight($M_n=4,000$) fraction.

• Polymer(Korea)
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• v.32 no.6
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• pp.501-508
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• 2008

Small injection molded articles such as lens and mobile product parts are usually molded in multi-cavity mold. The problem occurring in multi-cavity molding is flow unbalance among the cavities. The flow unbalance affects the dimensions and physical properties of molded articles. First of all, the origin of flow unbalance is geometrical unbalance of the delivery system. However, even the geometry of the delivery system is well balanced, cavity unbalance occurs. This comes from the temperature distributions in the cross-section of runner. Temperature distribution depends upon injection speed because heat generation near runner wall is high at high injection speed. Among the operational conditions, injection speed is the most significant process variable affecting the filling unbalances in multi-cavity injection molding. In this study, experimental study of flow unbalance has been conducted for various injection speeds and materials. Also, the filling unbalances were compared with CAE results. The dimensions and weights of multi-cavity molded parts were examined. The results showed that the filling unbalances vary according to the injection speeds and resins. Subsequently, the unbalanced filling and pressure distribution in the multi-cavity affect the dimensions and physical states of molded parts.

• Archives of design research
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• v.3 no.1
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• pp.17-33
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• 1990

Evaluation plays an essential role in design activity. Many theorist have agreed that designing involves problem solving or decision making. In evaluation, designers attempt to determine the value of a particular proposal arrived at by synthesis. And the results of designing, the product, is evaluated twice, objectively and subjectively.Alternatives in $$\mu$ti-objective decision problems generally possess numerous attributes by which they can be described and compared. The evaluation factors include all attributes that have levels specified by quantitative and qualitative objectives. However since qualitiative factors are difficult to quantify as $$\mu$eral estmates, these factors have tended to be ignored without regard for their importance to human content. Therefore we need some study that convert qualitative attributes into quantitative scale values. Following to Thurstone' s Psychological scaling methods (The method of successive intervals), attribute values of TV set are assigned by rating scale methods. The method of successive intervals, like the method of equal-appearing intervals, requires but a single judgement from each subject for each statement to be scaled. It is, therefore, a convinient method to use when the number of to be scaled is large. We make the assumtion that those cu$$\mu$ative proportion distributions are normal for each statement when they are projected on the unknown psychological continuum. In this study, we have determined the scale values of 42 statements of TV set by the method of successive intervals. Then we can apply a test of internal consistency similar to that used with the method of paired comparisons. We have as our absolute average deviation, -1.748/252= -0.0069. We have reason to believe that our scale values are consistent with the empirical data, because these discrepanicies are very small.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.4
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• pp.247-255
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• 2005

Although heat treatment is a process of great technological importance in order to obtain desired mechanical properties such as hardness, the process was required a tedious and expensive experimentation to specify the process parameters. Consequently, the availability of reliable and efficient numerical simulation program would enable easy specification of process parameters to achieve desired microstructure and mechanical properties without defects like crack and distortion. In present work, the developed numerical simulation program could predict distributions of microstructure and thermal stress in steels under different cooling conditions. The computer program is based on the finite difference method for temperature analysis and microstructural changes and the finite element method for thermal stress analysis. Multi-phase decomposition model was used for description of diffusional austenite decompositions in low alloy steels during cooling after austenitization. The model predicts the progress of ferrite, pearlite, and bainite transformations simultaneously during quenching and estimates the amount of martensite also by using Koistinen and Marburger equation. To verify the developed program, the calculated results are compared with experimental ones of casting product. Based on these results, newly designed heat treatment process is proposed and it was proved to be effective for industry.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.279-291
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• 2020

The seismic design of conventional frame structures is meant to enhance plastic deformations at beam ends and prevent yielding in columns. To this end, columns are made stronger than beams. Yet yielding in columns cannot be avoided with the column-to-beam strength ratios (about 1.3) prescribed by seismic codes. Preventing plastic deformations in columns calls for ratios close to 4, which is not feasible for economic reasons. Furthermore, material properties and the rearrangement of geometric shapes inevitably make the distribution of damage among stories uneven. Damage in the i-th story can be characterized as the accumulated plastic strain energy (W_pi) normalized by the product of the story shear force (Q_yi) and drift (δ_yi) at yielding. Past studies showed that the distribution of the plastic strain energy dissipation demand, W_pi/ΣW_pj, can be evaluated from the deviation of Q_yi with respect to an "optimum value" that would make the ratio W_pi/(Q_yiδ_yi) -i.e. the damage- equal in all stories. This paper investigates how the soil type and ductility demand affect the optimum lateral strength distribution. New optimum lateral strength distributions are put forth and compared with others proposed in the literature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1691-1696
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• 2010

The efforts of reflecting the system's uncertainties in design step have been made and robust optimization or reliabilitybased design optimization are examples of the most famous methodologies. The statistical moments of a performance function and the constraints corresponding to probability conditions are involved in the formulation of these methodologies. Therefore, it is essential to effectively and accurately calculate them. The sensitivities of these methodologies have to be determined when nonlinear programming is utilized during the optimization process. The sensitivity of statistical moments and probability constraints is expressed in the integral form and limited to the normal random variable; we aim to expand the sensitivity formulation to nonnormal variables. Additional functional calculation will not be required when statistical moments and failure or satisfaction probabilities are already obtained at a design point. On the other hand, the accuracy of the sensitivity results could be worse than that of the moments because the target function is expressed as a product of the performance function and the explicit functions derived from probability density functions.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.457-461
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• 2007

Laser slide marking systems are being considered by the staffs of clinical laboratories in hospitals as the main potential substituent for the conventional manual processes of the laboratory works. Many of the processes in domestic hospitals such as operations of test equipments in clinical laboratories and physical distributions in hospitals are being computerized due to the recent development of information technologies. The clinical laboratories in charge of inspection processes are putting their efforts on the computerization and automation of the test equipments, which increases the demand for the usage of laser marking slide systems which is the main component of the inspection works. The domestic market size of the laser slide marking systems is expected to be 250 million won in 2008, which is believed to increase to 1.75 billion won in 2012. The laser slide marking system was first introduced to domestic hospitals in 2005. It's product life cycle is currently on the early stage, and it is believed to have a very high growth potential in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.457-460
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• 2000

Injection molding is the most widely used process for the industrial forming of plastic articles. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation·orientation and infection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of welding parts in injection-molded products is assessed. And the effects of fiber content and injection mold shapes on the fiber orientation in case of fiber reinforced polymeric composites are studied. experimentally.