• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3787-3800
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• 2023

Reactivity Initiated Accident (RIA) scenarios require special attention using advanced simulation techniques due to their complexity and importance for nuclear power plant (NPP) safety. While the conservative approach has traditionally been used for safety analysis, it may lead to unrealistic results which calls for the use of best estimate plus uncertainty (BEPU) approach, especially with the current advances in computational power which makes the BEPU analysis feasible. In this work an Uncontrolled Control Element Assembly (CEA) Withdrawal at Full Power accident scenario is analyzed using the BEPU approach by loosely coupling the thermal hydraulics best-estimate system code (RELAP5/SCDAPSIM/MOD3.4) to the statistical analysis software (DAKOTA) using a Python interface. Results from the BEPU analysis indicate that a realistic treatment of the accident scenario yields a larger safety margin and is therefore encouraged for accident analysis as it may enable more economic and flexible operation.

• Journal of Korean Neurosurgical Society
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• 제37권3호
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• pp.173-178
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• 2005

Objective: The goal of this study is to provide the clinical data of patients with brainstem cavernous hemangiomas after treatment with microsurgery or radiosurgery after conducting a retrospective analysis of 21 patients at one institution. Methods: Twenty one patients with brainstem cavernous hemangiomas were treated at the authors' institution between 1995 and 2004 and clinical analysis was performed by retrospective review of medical records and neuroimaging examinations. Thirteen patients underwent microsurgical resection and radiosurgery was performed as an initial treatment in 9 patients. Results: Radical excision was achieved in 12 among 13 patients and transitory neurological deterioration or new neurological deficit developed during the immediate postoperative period in 7 (54%). The final outcomes at 5 - 70 months after surgery were improved in 11 patients (85%) and worsened in 2 patients (15%) compared with the preoperative state. Radiosurgery was performed in 9 patients. During the follow up period from 5 to 70 months there was neurological improvement in 3 patients, no significant change in 3 and deterioration in 3 patients. Two patients developed rebleeding at 5 months, 60 months respectively after radiosurgery. Conclusion: Microsurgery for symptomatic cavernous hemangioma of brainstem can be performed with acceptable morbidity. Fatal complication is rare with careful selection of the optimal operative approach in well selected patients. Radiosurgery is an effective alternative for the lesions which are not accessible by surgical approach, however, there is still a possibility of rebleeding over a long period after radiosurgical treatment and microsurgery should be considered as a treatment with priority for the majority of cases.

• Membrane and Water Treatment
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• 제10권1호
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• pp.75-82
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• 2019

In a highly urbanized area, land availability is limited for the installation of space consuming stormwater systems for best management practices (BMPs), leading to the consideration of underground stormwater treatment devices connected to the stormwater pipe system. The configuration of a stormwater pipe network determines the hydrological and pollutant transport characteristics of the stormwater discharged through the pipe network, and thus should be an important design consideration for effective management of stormwater quantity and quality. This article presents a multi-objective optimization approach for designing a stormwater pipe network with on-line stormwater treatment devices to achieve an optimal trade-off between the total installation cost and the annual removal efficiency of total suspended solids (TSS). The Non-dominated Sorted Genetic Algorithm-II (NSGA-II) was adapted to solve the multi-objective optimization problem. The study site used to demonstrate the developed approach was a commercial area that has an existing pipe network with eight outfalls into an adjacent stream in Yongin City, South Korea. The stormwater management model (SWMM) was calibrated based on the data obtained from a subcatchment within the study area and was further used to simulate the flow rates and TSS discharge rates through a given pipe network for the entire study area. In the simulation, an underground stormwater treatment device was assumed to be installed at each outfall and sized proportional to the average flow rate at the outfall. The total installation cost for the pipes and underground devices was estimated based on empirical formulas using the flow rates and TSS discharge rates simulated by the SWMM. In the demonstration example, the installation cost could be reduced by up to 9% while the annual TSS removal efficiency could be increased by 4% compared to the original pipe network configuration. The annual TSS removal efficiency was relatively insensitive to the total installation cost in the Pareto-optimal solutions of the pipe network design. The results suggested that the installation cost of the pipes and stormwater treatment devices can be substantially reduced without significantly compromising the pollutant removal efficiency when the pipe network is optimally designed.

• 한국정밀공학회지
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• 제15권4호
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• pp.58-67
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• 1998

A sectional analysis of sheet metal forming process with an arbitrary tool shape is proposed in the present work. To improve the numerical convergence in the conventional membrane sectional analysis, the Bending Energy Augmented Membrane (BEAM) elements had been developed. The BEAM elements particularly improve the stability and convergence of the finite element method for the case of deep drawing. In this work, the FERGUBON spline (C$^2$-continuous) was used to fit the deformed mesh to smooth the given curves and calculate the local curvature of the deformed sheet. The fittings of the deformed sheet and tool surface profile ensure the stability and the convergence of the finite element analysis of highly nonlinear stamping processes. A center floor section and front fender section are analyzed to show the accuracy and robustness of the approach. The results obtained by the proposed approach are compared with the available experimental data.

• 상하수도학회지
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• 제26권4호
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• pp.535-545
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• 2012

Recently, drinking water quality has significantly improved with the progress of water treatment technologies, however, customer's trust on tap water is still relatively low. Low trust on water quality is mainly due to vague anxiety. Therefore, to improve customer's trust on drinking water quality new strategy such as water safety plan(WSP) which recommended by WHO and IWA should be introduced. WSP can be defined as an approach which uses comprehensive risk assessment and risk management approach that encompasses all steps in water supply from catchment to consumer to ensure the safety of a drinking water supply. In this study, cases on WSP introduction in other countries as well as strategy for the introduction of WSP in Korea were investigated. In addition, recommendations on the improvement of the current water contamination response manual was suggested based on the analysis of the existing manual at a full scale water treatment plant.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2017년도 춘계 종합학술대회 논문집
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• pp.33-34
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• 2017

In 2015, Ministry of Health and Welfare of Korea announced a research and development plan of using Korean healthcare data to support decision making, reduce cost and enhance a better treatment. This project relies on the adoption of BigData technology such as Apache Hadoop, Apache Spark to store and process HealthCare Data from various institution. Here we present an approach a design and implementation of OLAP server in Korean HealthCare BigData platform. This approach is used to establish a basis for promoting personalized healthcare research for decision making, forecasting disease and developing customized diagnosis and treatment.

• 대한구순구개열학회지
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• 제8권2호
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• pp.95-105
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• 2005

Cleft lip and palate is a congenital deformity which needs a professional and consistent management from the birth and along with the physical growth of patients. The patients with cleft lip and palate can have general speech problems with resonance disorders, voice disorders and articulation disorders after the successful primary surgical management and the physical growth. Speech problems of Cleft lip and palate are characterized hypernasality, nasal air emission, increased nasal air flow, and aberrant speech marks which decrease intelligibility. These speech problems of cleft lip and palate can be treated with the secondary surgical procedure, the application of temporary prosthesis and the effective and well-timed speech therapy. The speech and language problems of cleft lip and palate, the general procedures and schedules of the speech assessment and therapy based on the multidisciplinary approach are introduced for the patients with cleft lip and palate, their family and the other members of the cleft palate treatment team.

• 대한기관식도과학회지
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• 제3권2호
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• pp.270-276
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• 1997

The records of 18 patients with squamous cell carcinoma of the tongue and floor of mouth treated surgically were reviewed. Surgical approaches, staging, treatment modalities, recurrence and vital status were evaluated. The distrubutions of involved sites were tongue(9 cases) and mouth floor(9 cases). Patients were treated by surgery primarily, combined chemotherapy and radiation, and by surgical salvage in the failure cases of radiation and chemotherapy. All ipsilateral necks of mouth floor cancer and advanced tongue cancer were treated with neck dissection. Cases of early tongue cancer could be excised with transoral route, and advanced cases needed transmandibular approach. Whereas, majorites of mouth floor cancer needed transmandibular approach, and other cases could be excised transoral and pull-through approaches. In the recontructions, we used primary closure, pectoralis major myocutaneous flap, forearm free flap, fibular osteocutaneous flap and skin graft. One year survival rate was 93% and 2 year survival rate was 60%.

• The Korean Journal of Pain
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• 제26권1호
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• pp.98-101
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• 2013

Postherpetic neuralgia (PHN) is a debilitating complication of herpes zoster, especially in elderly and comorbid patients. Unfortunately, the currently available treatments have shown limited efficacy and some adverse events that are poorly tolerated in elderly patients. Scrambler Therapy, proposed as an alternative treatment for chronic neuropathic pain recently, is a noninvasive approach to relieve pain by changing pain perception at the brain level. Here, we report our clinical experiences on the effect of Scrambler Therapy for three patients with PHN refractory to conventional treatment.

• Environmental Engineering Research
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• 제23권3호
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• pp.282-287
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• 2018

Three different methods of bacterial viability monitoring were compared to detect chemically or thermally inactivated Escherichia coli. Direct colony enumeration, live/dead bacterial cell staining with a fluorescent dye, and the dehydrogenase activity assay were compared with respect to their ease of use and time required to perform the three different tests. The green (live cell)/red (dead cell) ratio obtained from the fluorescent bacterial cell staining approach showed a linear relationship with the colony forming units; the result obtained with dehydrogenase was similar to those. The sensitivity of the monitoring methods to detect bacterial deactivation varied with different disinfection conditions. After thermal treatment, the sensitivity of the staining approach was lower, while that of the dehydrogenase activity assay was the highest. After chemical treatment, the sensitivity of detection for both methods was similar.