• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.157-164
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• 2017

A parallel slide gate valve (PSGV) is located between the heat recovery steam generator (HRSG) and the steam turbine in a combined cycle power plant (CCPP). It is used to control the flow of steam and runs with repetitive operations such as startups, load changes, and shutdowns during its operation period. Therefore, it is necessary to evaluate the fatigue damage and the structural integrity under a large compressive thermal stress due to the temperature difference through the valve wall thickness during the startup operations. In this paper, the thermal-structural analysis and the fatigue life evaluation of a 16-inch PSGV, which is installed on the HP steam line, is performed according to the fatigue life assessment method described in the ASME B&PVC VIII-2; the method uses the equivalent stress from the elastic stress analysis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.87-91
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• 1997

Ecological stability of the Lake Shihwa, artificially made by the construction of the Shihwa Dike, was evaluated by the species composition and variation in biomass of zooplankton. Species composition and seasonal variation in biomass in the seaside stations were similar to those observed in nearby bays and coastal zone. However, those in the lake sites showed very different patterns. The brackish water copepod, Sinocaianus tenellus, held the first rank in every season (with more than 66% in spring, 98% in summer and fall, and 80% in winter). The species composition was very simple and the biomass (in terms of total individuals $m^{-3}$) varied markedly with season up to the order of $10^4$ magnitude. These results imply that the lake ecosystem made by the construction of Sihwa dike is in very unstable stage probably due to the input of industrial wastes as well as unpredictable variation in salt content caused by irregular control of the watergate of the dike and resultant irregular flow direction of the water through the gate.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.747-752
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• 1993

A curd yogurt was prepared from milk added with skim milk powder or four kinds of starch such as rice starch, wheat starch, corn starch and potato starch. The effects of starch addition at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effects of starch addition on quality of curd yogurt in terms of apparent viscosity, sensory property and volatile aroma compounds were also examined. Addition of starch markedly stimulated the acid production by lactic acid bacteria. Among four organisms tested, Lactobacillus jugurti produced the highest amount of acid. Apparent viscosity of curd yogurt added with starch was significantly higher than that of control. Curd yogurt fermented with L. jugurti showed pseudoplastic and thixotropic characteristics. Sensory property of curd yogurt added with corn starch or rice starch was evaluated as slightly better than reference sample, but that with potato starch was evaluated as the worst among all samples. Acetaldehyde, acetone, ethanol and butanol were detected by gas chromatographic analysis.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.207-213
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• 2006

The effects of gellan gum (from S. paucimobilis), EPS-CB (exopolysaccharide from S. chungbukensis), and a series of commercial gums (arabic gum, xanthan gum, guar gum, deacyl gellan gum), on the swelling, rheological, and pasting properties of non-waxy rice flour dispersions were investigated. The swelling properties of rice flours in gellan or guar gum dispersion after heating were found to have increased with increasing gum concentrations, but the swelling properties of rice flour/other gum systems decreased with increasing concentrations. The rice flour/gum mixtures showed high shear-thinning flow behavior (n=0.14-0.32), and consistency index (K) was higher in guar gum than other gum dispersions. The initial pasting temperatures and peak times increased along with increasing gum concentration. The peak viscosity of rice flour increased in guar gum and deacyl gellan dispersions, and the breakdown and setback viscosity of the rice flour paste was lowest in the xanthan gum system, but remained higher than those of the control. The apparent viscosities of the rice flour/gellan gum mixture pastes were the highest among the tested combinations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.315-318
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• 2007

A dynamic simulation of a turbo-shaft engine was performed for analysis of transient-state and engine-starting characteristics using the MATLAB/SIMULINKTM. The turbo-shaft engine was modelled based on thermodynamic and rotor dynamic relations. The analysis of engine starting characteristics was performed by monitoring the rate of the pressure, temperature and mechanical torque changes along the engine stations by the torque input generated from the accessary power unit and transmitted to the power turbine. The simulation of the transient-state characteristics of the engine was performed under fuel flow rate increase from the steady-state condition. For the future study, engine control unit will be added to the basic turbo-shaft engine model to enhance capability of engine performance simulation.

• Computers and Concrete
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• v.19 no.5
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• pp.489-499
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• 2017

Self-Compacting Concrete (SCC) is a new technology capable to flow without segregation or any addition of energy which leads to efficient construction and cost savings. In this study, the effect of replacing the Ordinary Portland Cement (OPC) with Fly Ash (FA) on the strength, durability of the concrete was investigated experimentally, and carbon footprint and cost were also assessed. Four different replacement FA ratios (0%, 20%, 40% and 60%) were used to create four SCC mixes. Standard test methods were used to determine the workability, strength, and durability of the SCC mixes including resist chloride ion penetration, water permeability, water absorption, and initial surface absorption. The axial cube compressive strength tests were performed on the SCC mixes at 1, 7, 14, 28 and 35 days. Replacing the OPC with FA had a significant positive impact on chloride iron penetration resistance and water absorption but had a considerable negative impact on the compressive strength. The SCC mix with 60% FA had 36.7% and 15.8% enhancement in the resistance to chloride ion penetration and water absorption, respectively. Evaluation of the carbon footprint and the cost of each SCC mixes showed the $CO_2$ emissions mixes 1, 2, 3 and 4 were significantly reduced by increasing the FA content from 0% to 60%. Compared with the control mix, the cost of all mixes increased when the FA content increased, but no significant differences were seen between the estimated costs of all four mixes.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6605-6608
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• 2015

Background: Colorectal cancer is a major cause of morbidity and mortality throughout the world. Colorectal cancer screening is an optimal way for reducing of morbidity and mortality and a clinical decision support system (CDSS) plays an important role in predicting success of screening processes. DSS is a computer-based information system that improves the delivery of preventive care services. The aim of this article was to detail engineering of information requirements and work flow design of CDSS for a colorectal cancer screening program. Materials and Methods: In the first stage a screening minimum data set was determined. Developed and developing countries were analyzed for identifying this data set. Then information deficiencies and gaps were determined by check list. The second stage was a qualitative survey with a semi-structured interview as the study tool. A total of 15 users and stakeholders' perspectives about workflow of CDSS were studied. Finally workflow of DSS of control program was designed by standard clinical practice guidelines and perspectives. Results: Screening minimum data set of national colorectal cancer screening program was defined in five sections, including colonoscopy data set, surgery, pathology, genetics and pedigree data set. Deficiencies and information gaps were analyzed. Then we designed a work process standard of screening. Finally workflow of DSS and entry stage were determined. Conclusions: A CDSS facilitates complex decision making for screening and has key roles in designing optimal interactions between colonoscopy, pathology and laboratory departments. Also workflow analysis is useful to identify data reconciliation strategies to address documentation gaps. Following recommendations of CDSS should improve quality of colorectal cancer screening.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6047-6053
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• 2012

Bracken fern [Pteridium aquilinem (L.) kuhn (Dennstaedtiaceae)] is one of the most common species on the planet. It has been consumed by humans and animals for centuries. Use by some human groups is because they believe bracken fern is good for health as plant medicine. However, it is also one of the few known plants that can cause tumors in farm animals. Many interested groups have focused their attention on bracken fern because of these interesting features. In order to evaluate the biological effects of exposure to this plant in cellular level, human cancer cell lines were treated with the fern dichloromethane extracts and the genotoxic and cytotoxic effects were studied. Anti-proliferative/cytotoxic effects were evaluated by cell count, MTT assay and flow cytometry methods with three different cancer cell lines, TCC, NTERA2, and MCF-7, and two normal cells, HDF1 and HFF3. Pro-apoptotic effects of the extracts were determined by DAPI staining and comet assay, on TCC cancer cells compared to the normal control cell lines. Cellular morphology was examined by light microscopy. Our present study showed that the extract caused DNA damage and apoptosis at high concentrations ($200{\mu}g/mL$) and also it may induce cell cycle arrest (G2/M phase) at mild concentrations (50 and $30{\mu}g/mL$) depending on the cell type and tumor origin. These results indicate that bracken fern extract is a potent source of anticancer compounds that could be utilized pharmaceutically.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1377-1382
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• 2012

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-${\kappa}B$ using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-${\kappa}B$ were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-${\kappa}B$.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.4
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• pp.193-204
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• 2017

Various 3D-stacked DRAMs have been proposed to overcome the memory wall problem. Hybrid Memory Cube (HMC) is a true 3D-stacked DRAM with stacked DRAM layers on top of a logic layer. The logic die is mainly used to implement a memory controller for HMC, and it is connected through a high speed serial link called SerDes with a host that is either a processor or another HMC. In HMC, the serial link is crucial for both performance and power consumption. Therefore, it is important that the link is configured properly so that the required performance should be satisfied while the power consumption is minimized. In this paper, we propose a HMC system model included the high speed serial link to estimate performance accurately. Since the link modeling strictly follows the link flow control mechanism defined in the HMC spec, the actual HMC performance can be estimated accurately with respect to each link configuration. Various simulations are conducted in order to deduce the correlation between the HMC performance and the link configuration with regard to memory utilization. It is confirmed that there is a strong correlation between the achievable maximum performance of HMC and the link configuration in terms of both bandwidth and latency. Therefore, it is possible to find the best link configuration when the required HMC performance is known in advance, and finding the best configuration will lead to significant power saving while the performance requirement is satisfied.