• Journal of Chest Surgery
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• 제49권4호
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• pp.273-279
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• 2016

Background: The use of extracorporeal life support (ECLS) in the setting of cardiopulmonary resuscitation (CPR) has shown improved outcomes compared with conventional CPR. The aim of this study was to determine factors predictive of survival in extracorporeal CPR (E-CPR). Methods: Consecutive 85 adult patients (median age, 59 years; range, 18 to 85 years; 56 males) who underwent E-CPR from May 2005 to December 2012 were evaluated. Results: Causes of arrest were cardiogenic in 62 patients (72.9%), septic in 18 patients (21.2%), and hypovolemic in 3 patients (3.5%), while the etiology was not specified in 2 patients (2.4%). The survival rate in patients with septic etiology was significantly poorer compared with those with another etiology (0% vs. 24.6%, p=0.008). Septic etiology (hazard ratio [HR], 2.84; 95% confidence interval [CI], 1.49 to 5.44; p=0.002) and the interval between arrest and ECLS initiation (HR, 1.05 by 10 minutes increment; 95% CI, 1.02 to 1.09; p=0.005) were independent risk factors for mortality. When the predictive value of the E-CPR timing for in-hospital mortality was assessed using the receiver operating characteristic curve method, the greatest accuracy was obtained at a cutoff of 60.5 minutes (area under the curve, 0.67; 95% CI, 0.54 to 0.80; p=0.032) with 47.8% sensitivity and 88.9% specificity. The survival rate was significantly different according to the cutoff of 60.5 minutes (p=0.001). Conclusion: These results indicate that efforts should be made to minimize the time between arrest and ECLS application, optimally within 60 minutes. In addition, E-CPR in patients with septic etiology showed grave outcomes, suggesting it to be of questionable benefit in these patients.

• Journal of Korean Society of Water and Wastewater
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• 제27권4호
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• pp.429-438
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• 2013

This study was to develop effective water quality management measures using LDC (Load Duration Curve) curves for TMDL (Total Maximum Daily Loads) unit watershed. Using LDC curves, major factors for BOD and T-P concentration loads generation (i.e. point source or non-point source) in the case study area (Geumho river basin) were found for different hydrologic conditions. Different measures to deal with the pollutant loads were suggested to establish BMPs (Best Management Practices). It was found that the target area has urgent T-P management methods especially at moist and midrange hydrologic conditions because of point source pollutants occurred in developed areas. One example measure for this could be establishment of advanced treatment facility. This study proved that the use of LDC was a useful way to achieve TWQ (Target Water Quality) on the target watershed considered. It was also expected that the methodology applied in this study could have a wider application on the establishment of watershed water management measures.

• Journal of Gastric Cancer
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• 제18권2호
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• pp.172-181
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• 2018

Purpose: This study aimed to evaluate the surgical outcomes and investigate the feasibility of reduced-port laparoscopic gastrectomy using learning curve analysis in a small-volume center. Materials and Methods: We reviewed 269 patients who underwent laparoscopic distal gastrectomy (LDG) for gastric carcinoma between 2012 and 2017. Among them, 159 patients underwent reduced-port laparoscopic gastrectomy. The cumulative sum technique was used for quantitative assessment of the learning curve. Results: There were no statistically significant differences in the baseline characteristics of patients who underwent conventional and reduced-port LDG, and the operative time did not significantly differ between the groups. However, the amount of intraoperative bleeding was significantly lower in the reduced-port laparoscopic gastrectomy group (56.3 vs. 48.2 mL; P<0.001). There were no significant differences between the groups in terms of the first flatus time or length of hospital stay. Neither the incidence nor the severity of the complications significantly differed between the groups. The slope of the cumulative sum curve indicates the trend of learning performance. After 33 operations, the slope gently stabilized, which was regarded as the breakpoint of the learning curve. Conclusions: The surgical outcomes of reduced-port laparoscopic gastrectomy were comparable to those of conventional laparoscopic gastrectomy, suggesting that transition from conventional to reduced-port laparoscopic gastrectomy is feasible and safe, with a relatively short learning curve, in a small-volume center.

• Structural Engineering and Mechanics
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• 제49권1호
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• pp.95-110
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• 2014

The study deals with physical modeling of space frame-pile foundation and soil system using finite element models. The superstructure frame is analyzed using complete three-dimensional finite element method where the component of the frame such as slab, beam and columns are descretized using 20 node isoparametric continuum elements. Initially, the frame is analyzed assuming the fixed column bases. Later the pile foundation is worked out separately wherein the simplified models of finite elements such as beam and plate element are used for pile and pile cap, respectively. The non-linear behaviour of soil mass is incorporated by idealizing the soil as non-linear springs using p-y curve along the lines similar to that by Georgiadis et al. (1992). For analysis of pile foundation, the non-linearity of soil via p-y curve approach is incorporated using the incremental approach. The interaction analysis is conducted for the parametric study. The non-linearity of soil is further incorporated using iterative approach, i.e., secant modulus approach, in the interaction analysis. The effect the various parameters of the pile foundation such as spacing in a group and configuration of the pile group is evaluated on the response of superstructure owing to non-linearity of the soil. The response included the displacement at the top of the frame and bending moment in columns. The non-linearity of soil increases the top displacement in the range of 7.8%-16.7%. However, its effect is found very marginal on the absolute maximum moment in columns. The hogging moment decreases by 0.005% while sagging moment increases by 0.02%.

• Journal of Korean Ophthalmic Optics Society
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• 제8권2호
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• pp.163-168
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• 2003

The eye sensitivity in the difference conditions of a light source intensity consists of two functions by the receptor of cone and rod according to a wavelength. We derived a distribution function of $P{\lambda}=A{\cdot}e^{-({\lambda}-{\lambda}_u)^2/2W^2}$ using a respond probability of the receptor of cone-rod for a photon. It was well applied for a CIE eye's sensitivity curve of a wavelength. When there is lens In front of eye, luminous efficiency should be corrected. Transmission light which permeate to depends on absorption wavelength, and relationship of final luminous efficiency's estimation method is expressed by multiplication of luminous efficiency and transmittance intensity of lens. $$Pf({\lambda})=T({\lambda}){\cdot}P({\lambda})$$. The theory was applied to photopic and scopic vision with brown color lens.

• Journal of Power System Engineering
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• 제9권2호
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• pp.93-98
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• 2005

The performance of cooling tower is dependent on the thermal performance of the packings. It's assessed by heat transfer rate and fan power. In this study, new packing was developed for application in compact type cross-flow cooling tower. The packing characteristic curve and the pressure drop curve were obtained by measuring packing characteristic values and pressure drops of small sized filler in comparison to existing mid-large sized filler. The heat transfer characteristics on small sized filler are about 66% higher than existing mid-large sized filler. The pressure drop characteristics on small sized filler are about two times of the pressure drop characteristics on existing mid-large sized filler.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.573-578
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• 1998

In this paper, we propose a new technique of codification. The purpose of this method is to take in consideration the natural language nuances and the fuzziness that characterizes the human reasoning. So, we warranted a means of more flexible encoding that translates as well the linguistic descriptions. Its principle is simple and intuitive. It consists simply in replacing in ambiguous cases, a unique number by an interval. The introduction of the new codification necessitates the elaboration of metric or similarity in order to compare two intervals. This comparison must take in consideration the difference of their size, the remoteness of their center and the width of their intersection. In consequence, we defined three new fuzzy concepts : "fuzzy inclusion degree", "fuzzy resemblance degree," and " fuzzy curve".

• Asian-Australasian Journal of Animal Sciences
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• 제11권1호
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• pp.84-88
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• 1998

The aim of this study was to describe growth patterns of mice using Gompertz model. Two distinct types of mice, laboratory mouse $CF_{\sharp1}$ (Mus musculus domesticus) and Yonakuni wild mouse (Yk, Mus musculus molossinus yonakuni) were used. From all possible crosses, there were two parental types and two reciprocal $F_1$ crosses obtained. Individual body weights were measured weekly from birth to ten weeks of age on 321 mice. Standardization to six mice was conducted and only first litters were used. Growth curve parameters were estimated to fit growth data. The results showed that growth among genetic groups were significantly different (p < 0.05) for both sexes, in which parental type of $CF_{\sharp1}$ and Yk had the highest and the smallest values, respectively. Meanwhile, reciprocal $F_1$ crosses were intermediate between parental types. It was concluded that Gompertz model provided and excellent fit for the growth data with a high coefficient determination $(R^2 = 0.999)$.

• Electrical & Electronic Materials
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• 제7권2호
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• pp.107-116
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• 1994

In the manufacturing of VLSI circuits, variations of device characteristics due to the slight differences in process parameters drastically aggravate the performances of fabricated devices. Therefore, it is very important to establish optimal process conditions in order to minimize deviations of device characteristics. In this paper, we used one-dimensional process simulator, SUPREM-II, and two dimensional device simulator, MINIMOS 4.0 in order to extract optimal process parameter which can minimize changes of the device characteristics caused by process parameter variation in the case of short channel nMOSFET and pMOSFET device. From this simulation, we have derived the dependence relations between process parameters and device characteristics. Here, we have suggested a method to extract process parameters from design trend curve(DTC) obtained by these dependence relations. And we have discussed short channel effects and device limitations by scaling down MOSFET dimensions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.585-588
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• 2005

The dissolution characteristic of metal shows the different tendency according to the applied electrical potential, the kind of electrolyte and pH value, etc. In the micro electrochemical machining (ECM), unfavorable oxide/passive layer formation and overall corrosion of electrodes must be prevented. The anodic polarization curve of nickel has distinct three dissolution regions, i.e. two active regions and the transpassive dissolution region. In this paper, the stable electrode potentials of workpiece and tool were determined in sulfuric acid and hydrochloric acid solution, respectively. In each solution, different machining property was shown and possible electrochemical reactions were discussed. On the basis of this experiment, the methodology to obtain the proper electrode potential was suggested.