• Journal of ILASS-Korea
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• v.23 no.1
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• pp.1-8
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• 2018

In this study, the effects of variation in cam phasing and valve lift of exhaust valves by using Cam-in-Cam system on combustion and emission characteristics for diesel engine were investigated under GT-POWER simulation environment. This paper showed analytic result of combustion characteristics and diesel exhaust valve's control with GT-Power 1-D detail model. As a result, it was found that volumetric efficiency and IMEP were decreased as the exhaust valve opening and closing timing is advanced due to its internal EGR effects. Also, it was found that NOx emission were decreased as EVC timing was retarded. These show that the retarding the exhaust valve closing and opening while keeping the duration at constant can be effective for controlling AFR and mixing rate in diffusion combustion of diesel engine.

• Journal of the Korea Safety Management & Science
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• v.3 no.1
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• pp.93-105
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• 2001

Many production management systems for increasing productivity, minimizing inventory, keeping due dates and maximizing use of resources have been proposed, and GT, MRP and JIT are frequently used among these systems. The three systems have merits and demerits through comparing with each other. Because each system has mutual dependence, a hybrid production system Is necessary for using their merits maximally. In this study, a hybrid production system is designed by combining GT, MRP and JIT, which is suitable in the domestic production system and it is presented as followings. -. Basic research works for G7, MRP and JIT. -. Comparison and analysis are carried out for each system.- . The hybrid production system is designed. -. The hybrid production system is developed.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.523-523
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• 2016

본 연구에서는 두 지역의 실제 상수관망에 대해서 부정류해석을 수행하였고 각각의 상수관망에 필요한 부정류피해 최소화방안을 제시하였다. 본 연구에서는 실제 도시 상수관망인 광탄 GT1-1 소블럭 상수관망을 대상으로 부정류해석을 수행하였고 신뢰성해석을 통하여 구역별 파괴 확률을 산정하였다. 또한 상수관망의 운영인자로써 물 사용량지수와 급수전지수, 사용연수지수, 수압지수, 사고이력지수를 개발하여 광탄 GT1-1 소블럭 상수관망의 운영지수에 의한 구역별 위험도를 분석하여 상대적으로 안전에 취약한 구역을 선정할 수 있었다. 광탄 GT1-1 소블럭 상수관망을 7개 구역으로 나누어서 신뢰성해석과 운영지수에 따른 위험도 분석을 수행하였고 상대적으로 수격압으로 인한 관로파괴에 취약한 구역을 선정할 수 있었다. 또한 광탄 GT1-1 소블럭 상수관망에서는 구역별 파괴확률과 운영지수에 따른 위험도 순위가 같게 나타났다. 본 연구에서 개발된 상수 관망의 신뢰성해석모형과 운영지수를 운영관리에 적용한다면 향후 개량이나 교체가 필요한 상수 관로의 우선순위 선정에 유용하게 사용될 것으로 판단된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.8-12
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• 2019

Combined Cycle Unit(CC) generates the primary power from the Gas Turbine(GT) and supplies the remaining heat of the GT to the Steam Turbine(ST) to generate the secondary power from the ST. It plays a major role in terms of energy efficiency and Load Frequency Control(LFC). Incremental Heat Rate(IHR) curves of economic dispatch(ED) of CC is applied differently by GT/ST combination. But It is practically difficult because of performance test by all combinations. This paper suggests a reasonable method for estimating IHR curves for partial combinations(1:1~(N-1):1) using IHR curves when operating with GT alone(1:0) and with all(N:1) combinations of CC.

• Journal of ILASS-Korea
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• v.28 no.3
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• pp.119-125
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• 2023

In this research, a network model was developed to predict combustion instability in an annular gas turbine combustor (GT24) for power generation. The model consisted of various acoustic elements such as several ducts and area changes which could represent a real combustor with a complex geometry, applied mass, momentum, and energy equations to each element. In addition, a one-dimensional network model through a cylindrical coordinate system has been proposed to predict various acoustic modes. As a result of the analysis, the key resonant frequencies such as longitudinal, circumferential, and complex modes were derived from the EV combustor of GT24, and the reliability of the current model was verified through comparison with the 3D Helmholtz solver.

• Journal of Oral Medicine and Pain
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• v.48 no.4
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• pp.137-143
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• 2023

Purpose: To assess Google Trends (GT) search behavior regarding orofacial pain (OFP) and headaches. Methods: GT scores for OFP and headache specialists between February 2013 and December 2022 were analyzed. Statistical tests such as Poisson regression analyses, mean differences, and Cohen's D were used to assess the score change over time. Results: The top three search words for OFP specialists were "temporomandibular joint (TMJ) specialist," "TMJ doctor," and "TMJ dentist," whereas the top three search words for headache specialists were "Headache specialist," "Headache doctor," and "Migraine specialist." Here, TMJ is temporomandibular joint. The GT scores for OFP specialists increased significantly (p<0.05) for all years except 2017, with the highest mean difference in 2020. The scores for headache specialists showed similar trends but gradually. Conclusions: The interest in OFP and headache specialists expressed by Google searches has increased over the years. More awareness is needed regarding the OFP scope of practice, and the use of GT may serve as an indicator.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.1
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• pp.8-15
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• 2005

It is well known that intaking alcohol chronically and heavily causes many formsof physical systemic distress including serious chronic alcoholic liver disease such as alcoholic hepatitis, fatty liver, liver cirrhosis and hepatoma. Carbohydrate-deficient transferrin (CDT) is known as a specific marker in detecting and monitoring alcohol associated disease. Weanalyzed various alcohol-associated parameters to evaluate the clinical usefulness of CDT. The first patient group consisted of fifty patients, who had been diagnosed with alcoholic liver disease from January 2003 to June 2004 at Chungnam National University Hospital. The second group consisted of 12 patients with non-alcoholic liver disease. The third group consisted of 19 teetotalerswho had visited the hospital for the purpose of routine healthcare checks. Various hepatic parameters such as CDT, $\small{\Gamma}$-GT (gamma-glutamyl transferase), AST (aspartate aminotransferase) and ALT (alanine aminotransferase) were compared in the three groups. CDT and AST increased in direct proportion to the amount and duration of alcohol consumption with high significance, but $\small{\Gamma}$-GT and ALT showed arbitrary patterns with no statistical significance. The sensitivities of CDT, $\small{\Gamma}$-GT, AST and ALT were 74 %, 96 %, 68 % and 58 %, respectively and the specificities were 95 %, 74 %, 68 % and 79 % in order respectively. The correlation study of CDT with $\small{\Gamma}$-GT, AST and ALT showed a very low value of correlation coefficients, implying that CDT could be taken as an independent parameter in evaluating alcohol liver disease compared to $\small{\Gamma}$-GT, AST and ALT. This present study suggested that CDT coud be one of the most useful parameters in reflecting the amount and duration of alcohol consumption as well as being another independent parameter in assessing and following up patients with alcoholic liver disease. Moreover we recommend it is the best method of measuring both CDT and $\small{\Gamma}$-GT in patients with alcoholic liver disease.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.113-117
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• 1997

Simple sequence repeats (SSR) are widely dispersed throughout eukaryotic genomes, highly polymorphic, and easily typed using polymerase chain reaction (PCR). The objective of this study was to determine the polymorphism of different Chlamydomonas reinhartdtii strains and to determine the mode of inheritance of the SSR locus in Chlamydomonas. A genomic DNA library of C. reinhardtii was constructed and screened with a radiolabeled $(AC)_{11}$ probe for the selection of (CA/GT)n repeat clone. Selected clone was seqeuenced, and PCR primer set flanking (CA/GT)n sequence was constructed. PCR was used to specifically amplify the SSR locus from multiple isolates of C. reinhardtii. The locus was polymorphic in some of the C. reinhardtii isolates. However, the locus was amplified only 4 of 6 isolates of C. reinhardtii, not in other 2 isolates of C. reinhardtii, suggesting that this locus is not extensively conserved. A simple Mendelian inheritance pattern was found, which showed 2:2 segregation in the tetrads resulting from a cross between C. reinhardtii and C. smithii. Our results suggest that this simple sequence repeat DNA polymorphism will be useful for identity testing, population studies, linkage analysis, and genome mapping in Chlamydomonas.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.205-210
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• 2011

Genistein (GT), a major isoflavone found in soybeans, has a potent antioxidant effect that protects the skin from UV-induced damages and malignant melanoma. In order to enhance the cellular uptake of GT, liposome/Tat complexes were prepared by an electrostatic interaction of anionic liposome (DMPC/DCP, 9:1 in molar ratio) with Tat peptide (0.02 to 0.08 mole), one of the well-known cell penetrating peptide (CPP). As the amount of Tat increased, the size increased but the zeta potential decreased. In vitro release study with dialysis membrane elicited GT release from liposomal preparations in a controlled manner. The addition of Tat increased GT release, especially for the initial period. In the cellular uptake study by incubating B16 melanoma cells with various liposomal preparations containing GT, B16 melanoma cells demonstrated a time-dependent increase of drug accumulation. Compared to the aqueous GT suspension, intracellular uptake was substantially enhanced by anionic liposomal formulation and further increased by the complex formulation. Therefore, liposome/ Tat complex might be a good candidate for facilitating intracellular drug delivery.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.459-466
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• 2020

The physicochemical and antioxidant properties of cookies prepared using powders of barley sprout (BS), lemon balm (LB), and green tea (GT) were studied. The same dough density was maintained in all the sample groups. The experimental group to which the natural ingredients containing antioxidants were added did not show any significant change in the appearance of cookies compared to the control. LB and GT cookies showed significantly lower hardness compared to the control (p<0.05). Control showed the lowest antioxidant effect when assessed with 2,2-diphenyl-1-picrylhydrazyl. (DPPH) and this gradually increased in the order of BS, LB, and GT. The antioxidant activity of GT was 7 times higher as compared to the control (p<0.05). The antioxidant activity assessed using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) also showed results similar to that seen with DPPH. GT showed a significantly higher total phenol content, about 2-3 times higher compared to the control (p<0.05). GT had significantly higher total flavonoid content than that of the control (p<0.05). Thus, the addition of natural antioxidant ingredients such as sprout barley, lemon balm and specifically green tea, in the preparation of cookies, resulted in excellent antioxidant activity with similar physicochemical quality characteristics. The study suggests that it is possible to develop cookies that are competitive in terms of nutritional and physiologically active functions.