• Journal of the Society of Naval Architects of Korea
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• v.45 no.3
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• pp.329-336
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• 2008

Basic performances of wireless sensor network (WSN) and power line communication (PLC) confirmed in the test bed ashore are investigated in the 3000-ton class training ship of Korea Maritime University. The ubiquitous technologies can be considered for the provision of safety and convenience in a ship. We employed WSN and PLC, as the ubiquitous technologies, at the two areas within the training ship to estimate the realization of the ubiquitous environments in a ship. The experiments show rather good results in terms of data transfer rate. However, more detailed studies concerning the connection between WSN and PLC, noises induced to power line and fading effects are required to improve the quality and the stability of the communication for the ubiquitous environments.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1740-1751
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• 2018

This paper proposes a novel fault tolerant tracking control (FTTC) scheme for a class of nonlinear systems with actuator failures based on the policy iteration (PI) algorithm and the adaptive fault observer. The estimated actuator failure from an adaptive fault observer is utilized to construct an improved performance index function that reflects the failure, regulation and control simultaneously. With the help of the proper performance index function, the FTTC problem can be transformed into an optimal control problem. The fault tolerant tracking controller is composed of the desired controller and the approximated optimal feedback one. The desired controller is developed to maintain the desired tracking performance at the steady-state, and the approximated optimal feedback controller is designed to stabilize the tracking error dynamics in an optimal manner. By establishing a critic neural network, the PI algorithm is utilized to solve the Hamilton-Jacobi-Bellman equation, and then the approximated optimal feedback controller can be derived. Based on Lyapunov technique, the uniform ultimate boundedness of the closed-loop system is proven. The proposed FTTC scheme is applied to reconfigurable manipulators with two degree of freedoms in order to test the effectiveness via numerical simulation.

• KIEE International Transactions on Power Engineering
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• v.3A no.2
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• pp.63-69
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• 2003

The necessity of compact high temperature superconducting cables is more keenly felt in densely populated metropolitan areas. Because the compact high-temperature superconducting cables can be installed in ducts and tunnels, thereby reducing construction costs and making the use of underground space more effective, the effect of introducing it to the power system will be huge. Seoul, Korea, is selected as a review model for this paper. The loads are estimated by scenario based on a survey and analysis of 345kV and 154kV power supply networks in this area. Based on this, the following elements for an urban transmission system are examined. (1) A method of constructing a model system to introduce high-temperature superconducting cables to metropolitan areas is presented. (2) A case study is conducted through the analysis of power demand scenarios, and the amount of high-temperature superconducting cable to be introduced by scenario is examined. (3) The economy involved in expanding existing cables and introducing high-temperature superconducting cables(ducts or tunnels) following load increase in urban areas is examined and compared., and standards for current cable ducts are calculated. (4) The voltage level that can be accommodated by existing ducts is examined.

• IE interfaces
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• v.23 no.1
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• pp.48-57
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• 2010

A tryout is one of the most important process in development and production of dies. For automotive press dies, it takes 3 to 4 months during the vehicle development process. Moreover, useful information and knowledge from tryout process is very important to design and production planning of dies. In this paper, we developed a new supporting system for making and managing tryout reports of an automotive press die. The CBDTS(Case-Based reasoning for Die Tryout report System) was developed and applied using case-based reasoning method in order to reduce time and manage knowledge of tryout. It consists of "Class Retrieval Wizard", "Case Cleansing Module", and "Case Viewer." Also, this CBDTS could be a channel to integrate field information with enterprise-wide information management systems as well. The CBDTS was applied to a Korean automotive press die shop, and the results were very satisfied in both quantitative and qualitative manners.

• Toxicological Research
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• v.30 no.3
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• pp.179-184
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• 2014

Xenobiotics causing a variety of toxicity in biological systems could be classified as two types, inorganic and organic chemicals. It is estimated that the organic xenobiotics are responsible for approximately 80~90% of chemical-induced toxicity in human population. In the class for toxicology, we have encountered some difficulties in explaining the mechanisms of toxicity caused especially by organic chemicals. Here, a simple flowchart was introduced for explaining the mechanism of toxicity caused by organic xenobiotics, as the central dogma of molecular biology. This flowchart, referred to as a central dogma, was described based on a view of various aspects as follows: direct-acting chemicals vs. indirect-acting chemicals, cytochrome P450-dependent vs. cytochrome P450-independent biotransformation, reactive intermediates, reactivation, toxicokinetics vs. toxicodynamics, and reversibility vs. irreversibility. Thus, the primary objective of this flowchart is to help better understanding of the organic xenobiotics-induced toxic mechanisms, providing a major pathway for toxicity occurring in biological systems.

• Journal of The Korean Astronomical Society
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• v.35 no.3
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• pp.151-157
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• 2002

From the data of solar wind observation by ACE spacecraft orbiting the Earth-Sun Lagrangian point, we selected 48 forward interplanetary shocks(IPSs) occurred in 2000, maximum solar activity period. Examining the profiles of solar wind parameters, the IPSs are classified by their shock drivers. The significant shock drivers are the interplanetary coronal mass ejection(ICME) and the high speed stream(HSS). The IPSs driven by the ICMEs are classified into shocks driven by magnetic clouds and by ejectas based on the existence of magnetic flux rope structure and magnetic field strength. Some IPSs could be formed as the blast wave by the smaller energy and shorter duration of shock drivers such as type II radio burst. Out of selected 48 forward IPSs, $56.2\%$ of the IPSs are driven by ICME, $16.7\%$ by HSS, and $16.7\%$ of the shocks are classified into blast-wave type shocks. However, the shock drivers of remaining $10\%$ of the IPSs are unidentified. The classification of the IPSs by their driver is a first step toward investigating the critical magnitudes of the IPS drivers commencing the magnetic storms in each class.

• Korean Journal of Veterinary Service
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• v.44 no.3
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• pp.125-131
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• 2021

Benzimidazole is an widely used anthelmintics in livestock clinics. The aim of present study was to investigate benzimidazole residues in the meat in Sejong City. A total of 338 samples of meat(beef 287, pork 37, chicken 14) were selected from the laboratory meat(Korean beef genetic test, hygiene test) supplied to school in Sejong City. Representative benzimidazole class drug such as thiabendazole, 2-amino albendazole sulfone, fenbendazole, oxfendazole, and oxfendazole sulfone were monitored in samples by using lc-ms/ms and the analysis was preformed based on the Korea Food Code guideline. Limit of quantitation (LOQ) was ranged from 0.56 to 3.02 ppb for target drugs and the accuracy was within the acceptance criteria. Among the sample analyzed only one case, the pork meat was found to have drug levels that exceed LOQ. However, the overall residue concentration was 2.17 ppb, which was lower than the maximum residue levels (100 ppb).

• Journal of Interdisciplinary Genomics
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• v.1 no.1
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• pp.10-13
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• 2019

A 10-year and 5 month-old girl with developmental delay, intellectual disability, attention deficit hyperactivity disorder, poor weight gain, and microcephaly was transferred to our pediatric clinic for genetic evaluation. Her height was within the 5-10th percentile, and her weight was under the 3rd percentile. On the social maturity scale, her developmental status was scored as 3 years 9 months for social age, and the social quotient was 35.98. A chromosomal microarray analysis was performed and the microduplication at chromosome 16p was observed: arr[GRCh37] 16p11.2 (29580020_30190029)${\times}3$. Currently, the patient is diagnosed with Grade 2 intellectual disability and is attending a computerized cognitive rehabilitation class twice weekly. In addition, nutritional support and growth follow up are also ensured in the Pediatric Gastrointestinal and Endocrinology clinic.

• Steel and Composite Structures
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• v.30 no.2
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• pp.123-140
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• 2019

This paper presents experimental study on effects of width-to-thickness ratio and loading history on cyclic rotational capacity of H-shaped steel beams subjected to pure bending. Eight Class 3 and 4 H-shaped beams with large width-to-thickness ratios were tested under four different loading histories. The coupling effect of local buckling and cracking on cyclic rotational capacity of the specimens was investigated. It was found that loss of the load-carrying capacity was mainly induced by local buckling, and ductile cracking was a secondary factor. The width-to-thickness ratio plays a dominant effect on the cyclic rotational capacity, and the loading history also plays an important role. The cyclic rotational capacity can decrease significantly due to premature elasto-plastic local buckling induced by a number of preceding plastic reversals with relative small strain amplitudes. This result is mainly correlated with the decreasing tangent modulus of the structural steel under cyclic plastic loading. In addition, a theoretical approach to evaluate the cyclic rotational capacity of H-shaped beams with different width-to-thickness ratios was also proposed, which compares well with the experimental results.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.473-481
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• 2019

Statins are a class of lipid-lowering drugs commonly used in the prevention of cardiovascular diseases. However, statin therapy presents many limitations, which have led to an increased interest in non-drug therapies, such as probiotics, to improve blood cholesterol levels. Indeed, probiotic strains such as Lactobacillus acidophilus have been found to improve blood lipid profiles, especially in reducing total cholesterol and LDL-C levels. In this study, we established a high-cholesterol rat model and studied the effect of Lactobacillus acidophilus administration alone or in combination with rosuvastatin. We were able to show that Lactobacillus exerts a cholesterol-lowering effect. Additionally, we observed that when administered together, rosuvastin and Lactobacillus exert a combined cholesterol-lowering effect. Altogether, our data advocate for the possibility of establishing probiotics as non-drug supplements for the treatment of hypercholesterolemia.