• Journal of Life Science
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• v.14 no.1
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• pp.32-37
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• 2004

A portion of ribosomal internal transcribed spacer (ITS) 2 was sequenced from the samples of Pseudo nitzschia (P. deticatissima, P. multiseries, P. pungens and P. subfraudulenta) to investigate the genetic characteristics by measuring tile magnitude of genetic diversity and the degree of similarity coefficient using random amplified polymorphic DNAs (RAPD)-PCR patterns. The phylogenetic trees inferred from the genetic distance analyses showed the placement of P. delicatissima formed a quite long distance from p. P. multiseries, P. pungens, and even P. subfraudulenta. The phylogenetic tree from RAPD patterns showed that P. multiseries and P. pungens had dissimilarity coefficient of 0.31, while P. delicatissima and three species of Pseudo-nitzschia had that of 0.81. It is likely thought that the genetic position of P. delicatissima formed far from P. multiseries, P. punges, and P. subfraudulenta. These results imply that ITS2 region is expected to support a useful molecular characters for recognizing at the species level and for even discriminating P. multiseries from P. pungens. RAPD method also will be used to differentiate the species of Pseudo-nitzschia in a short time.

• Journal of Korean Society for Quality Management
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• v.43 no.3
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• pp.409-420
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• 2015

Purpose: This study is to estimate the life of elevator wire rope by using the accelerated degradation test with two accelerating variables of applied load and corrosion. Methods: Linear regression method is used to find the pseudo life of elevator wire rope at each combination of accelerating variables and the median life of elevator wire rope at use condition is estimated under the assumption that the life of elevator wire rope follows lognormal distribution. Results: The particular case study demonstrated that the results of the elevator wire life estimation by using the proposed method can provide the better solutions than existing methods. Conclusion: It can be economical to use accelerated degradation model for estimating the life of elevator wire rope.

• Neonatal Medicine
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• v.15 no.2
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• pp.196-199
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• 2008

The interstitial cells of Cajal are the pacemakers in the gastrointestinal tract that modulate gastrointestinal motility. A case of a neonate with intestinal pseudo-obstruction caused by a decreased number of the interstitial cells of Cajal is presented. A premature male infant born at 32 weeks of gestation showed progressive abdominal distention beginning 3 days after initiation of enteral feeding at 15 days of life. No etiologic factors were identified on radiologic studies, a gastrographin enema, and an intestinal biopsy other than a markedly decreased number of the intestinal cells of Cajal. An ileostomy, followed by repair of the ileostomy was done, which resulted in but a limited improvement of the abdominal gas pattern. Respiratory distress, pancytopenia, and abdominal distention persisted, and the infant expired on 142 days of life.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.118-123
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• 2001

Most structures of automobile are composed of many substructures connected to one another by various types of mechanical joints. In automotive engineering, it is important to study these connected structures under various dynamic farces for the evaluations of fatigue life and stress concentration exactly. It is rarely obtained the accurate load history of specified positions because of the errors such as modeling, measurement, and etc. In the beginning of design, exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. In this paper, the procedure of practical dynamic load determination is developed by the combination of the principal stresses of F.E. analysis and experiment. Inverse problem and least square pseudo inverse matrix are adopted to obtain an inverse matrix of analyzed stresses matrix. Pseudo-Practical dynamic load was calculated for Lab. Test of sub-structure. GUI program(PLODAS) was developed for whole of above procedure. This proposed method could be extended to any geometric shape of structure.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.433-440
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• 1995

The constituents and proportions of non-protein free amino acids including canavanine were measured in roots and leaves of legumes, Robinia pseudo-acacia L., Wistaria floribunda L., and Canavalia lineata L. by using high performance liquid chromatography during dormant and fertilizing seasons. in all the three plant species, asparagine was the most abundant amino acid occurring 30％ of total free amino acids, and canavanine was the second most abundant amino acid contributing 10％ of total free amino acids throughout dormant and fertilizing seasons. In dormant season, roots contained 2 to 3 folds of free amino acids including canavanine and asparagine compared to those in fertilizing season. When proportions of asparagine and canavanine to total gree amino acids in various parts of C. lineata were examined in fertilizinng season, the level of asparagine was the highest in roots while that of canavanine was in seeds. On the basis of these results, it is assumed that canavanine appears and functions as a nitrogen-storing compound in roots and leaves throughout the whole life cycle of the investigated plants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.200-209
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• 2019

When forecasting future values, a model estimated after minimizing training errors can yield test errors higher than the training errors. This result is the over-fitting problem caused by an increase in model complexity when the model is focused only on a given dataset. Some regularization and resampling methods have been introduced to reduce test errors by alleviating this problem but have been designed for use with only a given dataset. In this paper, we propose a new optimization approach to reduce test errors by transforming a test error minimization problem into a training error minimization problem. To carry out this transformation, we needed additional data for the given dataset, termed pseudo data. To make proper use of pseudo data, we used three types of missing data imputation techniques. As an optimization tool, we chose the least squares method and combined it with an extra pseudo data instance. Furthermore, we present the numerical results supporting our proposed approach, which resulted in less test errors than the ordinary least squares method.

• Molecules and Cells
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• v.19 no.1
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• pp.39-45
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• 2005

RPK118 is a sphingosine kinase-1-binding protein that has been implicated in sphingosine 1 phosphate-mediated signaling. It contains a PX (phox homology) domain and two pseudo-kinase domains, and co-localizes with sphingosine kinase-1 on early endosomes. In this study we identified a novel RPK118-binding protein, PRDX3 (peroxiredoxin-3), by yeast two-hybrid screening. The interaction between these proteins was confirmed by pull-down assays and co-immunoprecipitation experiments. Deletion studies showed that RPK118 interacted with PRDX3 through its pseudokinase domains, and with early endosomes through its PX domain. Double immunofluorescence experiments demonstrated that PRDX3 co-localized with RPK118 on early endosomes in COS7 cells. PRDX3 is a member of the antioxidant family of proteins synthesized in the cytoplasm and functioning in mitochondria. Our findings indicate that RPK118 is a PRDX3-binding protein that may be involved in transporting PRDX3 from the cytoplasm to its mitochondrial site of function or to other membrane structures via endosome trafficking.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.10
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• pp.997-1004
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• 2017

The life of elevator wire ropes is one of the most important characteristics of an elevator, which is closely related to the safety of users and its maintenance policy. It is not cost effective to measure the lifetime of elevator wire ropes during their use. In this study, the life estimation of elevator wire ropes (8x19W-IWRC) is considered using accelerated degradation test data. A bending fatigue tester is used to perform the accelerated degradation tests, incorporating the acceleration factor of tensile force. Assuming that the life of wire ropes is log-normally distributed, two life estimation methods are suggested and their results are compared. The first method estimates the life of wire ropes utilizing the accelerated life model with pseudo lives obtained from a linear regression model. The second method estimates the life using a logistic model based on failure probability.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1856-1863
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• 2004

In the last 50 years, lead-contained solder materials have been the most popular interconnect materials used in the electronics industry. Recently, lead-free solders are about to replace lead-contained solders for preventing environmental pollutions. However, the reliability of lead-free solders is not yet satisfactory. Several researchers reported that lead-contained solders have a good fatigue property. The others published that the lead-free solders have a longer thermal fatigue life. In this paper, the reason for the contradictory results published on the estimation of fatigue life of lead-free solder is investigated. In the present study, fatigue behavior of 63Sn37Pb, and two types of lead-free solder joints were compared using pseudo-power cycling testing method, which provides more realistic load cycling than chamber cycling method does. Pseudo-power cycling test was performed in various temperature ranges to evaluating the shear strain effect. A nonlinear finite element model was used to simulate the thermally induced visco-plastic deformation of solder ball joint in BGA packages. It was found that lead-free solder joints have a good fatigue property in the small temperature range condition. That condition induce small strain amplitude. However in the large temperature range condition, lead-contained solder joints have a longer fatigue life.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1740-1743
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• 2007

In this study, two types of fatigue tests were conducted. First, cyclic bending tests were performed using the micro-bending tester. A four-point bending test method was adopted, because it induces uniform stress fields within a loading span. Second, thermal fatigue tests were conducted using a pseudo power cycling machine which was newly developed for a realistic testing condition. The pseudo-power cycling method makes up for the weak points in a power cycling and a chamber cycling method. Two compositions of solder are tested in all test condition, one is lead-free solder (95.5Sn4.0Ag0.5Cu) and the other is eutectic lead-contained solder (63Sn37Pb). In the cyclic bending test, the solder that exhibits a good reliability can be reversed depending on the load conditions. The lead-contained solders have a longer fatigue life in the region where the applied load is high. On the contrary, the lead-free solder sustained more cyclic loads in the small load region. A similar trend was detected at the thermal cycling test. A three-dimensional finite element analysis model was constructed. A finite element analysis using ABAQUS was performed to extract the applied stress and strain in the solder joints. A constitutive model which includes both creep and plasticity was employed. Thermal fatigue was occurred due to the creep. And plastic deformation is main damage for bending failure. From the inelastic energy dissipation per cycle versus fatigue life curve, it can be found that the bending fatigue life is longer than the thermal fatigue life.