• Journal of the Korean Statistical Society
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• v.28 no.4
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• pp.399-413
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.445-450
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• 1997

Self-Powered Neutron Detectors(SPNDs) are currently used to estimate the power generation distribution and fuel burn-up in several nuclear power reactors in Korea. In this paper, Monte Carlo simulation is accomplished to calculate the escape probability of beta particle as a function of their birth position fur the typical geometry of rhodium-based SPNDs. Also, a simple numerical method calculates the initial generation rate of beta particles and the change of generation rate due to rhodium burn-up. Using the simulation and the numerical method, the burn-up profile of rhodium density and the neutron sensitivity are calculated as a function of burn-up time in the reactor. The sensitivity of the SPNDs decreases non-linearly due to the high absorption cross-section and the non-uniform burn-up of rhodium in the emitter rod. In addition, for improvement of some properties of rhodium-based SPNDs which are currently used, this paper presents a new material. The method used here can be applied to the analysis of other types of SPNDs and will be useful in the optimum design of new SPNDs for long term usage.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.273-281
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• 2007

The decision of how long performing system burn-in must be answered with a probabilistic model of a system lifetime at which infant mortality failures created during assembly processes are quantified. In this paper, we propose such a model which is modified from previous results. Using the system model, we derived system reliability in terms of component and system burn-in times for the two cases of minimal repair at system failure and of component replacement and connection repair at their failure times. The procedure is illustrated with a bridge system and the optimal system burn-in times are obtained for maximizing system reliability. The result suggests that an assumption of minimal repair at system failure may underestimate the optimal burn-in time in practice.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.62
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• pp.1-10
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• 2001

The electronics industry is fast growing segment of manufacturing and service industries. It is important that the manufacturer develops a product with adequate life cycle, high quality, and low failure rate in the specified time period. Environmental Stress Screening(ESS) and burn-in are widely used in the electronic industry to assist in the elimination of early failure. In this research, we construct optimal cost model of combined ESS and burn-in under various warranty policy and establish optimal testing times for given environments. Also we conduct sensitivity analysis on various parameter. The results of this study are summarized as follows. Comparing free warranty policy to rebate warranty policy, optimal ESS time is longer under free warranty policy, and optimal burn-in time is longer under rebate warranty policy. Free warranty policy higher than rebate warranty policy in total cost.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3127-3132
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• 2021

Feasibility study of burn-up analysis and monitoring using delayed fast neutrons was investigated at Missouri University of Science and Technology Reactor (MSTR). Burnt and fresh fuel elements were used to collect delayed fast neutron data for different power levels. Total reactivity varied depending on the burn-up rate of fuel elements for each core configuration. The regulating rod worth was 2.07E-04 𝚫k/k/in and 1.95E-04 𝚫k/k/in for T121 and T122 core configurations at 11 inch, respectively. Delayed fast neutron spectrum of F1 (burnt) and F16 (fresh) fuel elements were analyzed further, and a strong correlation was observed between delayed fast neutron emission and burn-up. According to the analyzed peaks in burnt and fresh fuels, reactor power dependency was observed and it was determined that delayed neutron provided more reliable results at reactor powers of 50 kW and above.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.121-124
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• 2023

With the continuous incorporation of new technologies and advancements in surgical technique, microsurgical procedures around the world have generated a higher success rate and innovative procedures are now possible. In this setting, limitations regarding accessibility and acquisition of medical resources and equipment for these types of operations may be difficult in developing countries. We believe the dexterities of surgeons go beyond the surgical technique, meaning that we are able to use everyday materials to re-create affordable solutions that can be used during surgery in a safe way. This manuscript presents our experience with different surgical instruments and gadgets, developed out of necessity, to improve microsurgical interventions in developing countries.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.121-124
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• 2010

Thermal burn occurred in the anesthetized dog as a result of using hot pack to treat hypothermia. After hospital discharge, thermal burn leaded to secondary infection due to dog bites of the other dog in the house. After secondary infection, the treatment was performed with medication and bandaging. Because of the pain and infection from the wound, carprofen (2 mg/kg bid) and amoxicillin (20 mg/kg bid) were administrated orally for 40 days. And for 35 days, wet-to-dry gauze dressing was used to absorb purulent exudate. During this period, the burn eschar was removed completely from the burn site. After 35 days, the hydrophilic polyurethane foam ($Medifoam^{(R)}$, Ildong Pharm, Co., Korea) was admitted to the burn site for 30 days. $Medifoam^{(R)}$ made healing rate of the wound faster because the inner layer did not adhered to the wound, and newly formed tissue was protected. The second layer, hydrophilic absorptive layer absorbed excessive fluid and kept the wound surface moist. After 65 days after thermal burn, the wound was healed completely.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.22-31
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• 2018

In this study, numerical simulations were performed to determine the dynamic characteristics of a pintle nozzle, with changes to the chamber boundary conditions. To apply movement, to the pintle, the nozzle and pintle were created separately by an auto-grid generation program using an overset grid method. The chamber boundary conditions were selected between a constant mass-flow rate condition and a propellant burn-back condition. The pressure and thrust characteristics of the constant mass-flow rate condition were determined by changing the ratio of the mass-flow rate in the inlet. The propellant burn-back condition was considered by formulation of the combustion rate. The burn-back conditions represented nonlinear phenomena, unlike the constant mass flow rate, and a small flow rate resulted in a large change in the chamber pressure.

• Tuberculosis and Respiratory Diseases
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• v.62 no.6
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• pp.506-515
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• 2007

Background: Nosocomial pneumonia in an intensive care unit (ICU) is associated with a high mortality rate. Diagnosing a respiratory tract infection in critically ill patients is still difficult but detailed information for the pathogens is needed to establish an adequate antimicrobial treatment. This study examined the causative organisms and their antimicrobial resistance using bronchoalveolar lavage (BAL) from patients suspected of having pneumonia in the ICU. Methods: From January 2004 to June 2006, ICU patients with diffuse lung infiltration were prospectively enrolled. The BAL was used to diagnose the respiratory infection, with 104 > or = organisms considered a positive result. The most common organisms and their antimicrobial resistances were analyzed from the quantitative BAL cultures in the burn ICU and non-burn ICU. Results: A total 72 patients were included, 35 (M 29, F 6) in the burn ICU and 37 (M 26, F 11) in the non-burn ICU. 27 patients (77.1%) in the burn ICU and 22 patients (59.5%) in the non-burn ICU met the criteria for a positive BAL culture. The major pathogens were Staphylococcus aureus, Acinetobacter species and Pseudomonas aeruginosa. All strains (100%) of Staphylococcus aureus isolated from BAL (9 cases) were methicillin-resistant (MRSA) in the burn ICU, but 5 strains (71.4%, 7 cases) were MRSA in the non-burn ICU. Regarding Pseudomonas aeruginosa, the rate of resistance to amikacin, ciprofloxacin, cefepime, imipenem, ceftazidime, piperacillin/tazobactam in the burn and non-burn ICU ranged from 45.5% to 90% and 25% to 50%, respectively. In addition, the rate of resistance of Acinetobacter species to the above drugs in the burn and non-burn ICU ranged from 81.8% to 100% and 62.5% to 100%, respectively. Conclusions: These results are expected to provide useful guidelines for choosing the effective empirical antimicrobial therapy in patients with lung infiltrations in the burn and non-burn ICU.

• Korean Journal of Clinical Pharmacy
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• v.12 no.2
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• pp.55-64
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• 2002

Infection is one of the main causes of death in severe burn cases. Treatment of burn patient includes fluid therapy, wound care, complication care and antibiotic therapy for infection. The objective of this study was to evaluate the characteristics of burn patients, the type of isolated microorganisms and their susceptibility, and the systemic antibiotics used. This is a retrospective study of 126 burn patients treated in the Hanil General Hospital from January to December 2001. Total 126 patients were assessed with 103 males and 23 females (4.5:1). The average age was $34.8\pm17.6$ years and extent of burn $(TBSA\;\%)\;was\;24.5\pm18.5\%$. The burn was caused by electric accident $(47.6\%),\;flame\;(29.4\%),\;scalding\;(21.4\%),\;and\;chemical\;accident\;(1.6\%)$. The overall mortality rate was $7.14\%$ (9/126) and all expired patients were males. The average age (n=9) was $48.8\pm15.6$ yrs and the extent of burn was $65.0\pm19.0\%$. The causes of death were due to flame burns $(13.5\%)$ and electric burns $(6.7\%)$. The culture sites of the isolated microorganisms were wound $(85.3\%),\;sputum\;(9.3\%),\;urine\;(2.7\%),\;blood\;(1.3\%)\;and\;catheter\;tip\;(1.3\%)$. Pseudomonas aeruginosa was the most commonly isolated organism $(35\%)$, followed by Staphylococcus aureus $(30.1\%)$, Acinetobacter baumannii $(21.4\%)$, and Enterococcus spp. $(3.9\%)$. The number of systemic antibiotics administered was 4.5. The classes of the antibiotics were cephalosporines $(38.5\%)$, aminoglycosides $(31\%)$, quinolones $(13.3\%)$, penicillins $(12.4\%)$, carbapenems $(2.4\%)$, glycopeptides $(1.9\%)$ and others $(0.6\%)$. In conclusion, most of burn patients had wound infection and Pseudomonas aeruginosa was the most commonly isolated organism. Cephalosporins were administered the most frequently among antibiotics.