• Journal of Korean Neurosurgical Society
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• v.41 no.2
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• pp.82-87
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• 2007

Objective : Pontine hemorrhages usually result in a much higher morbidity and mortality than any other intracranial vascular lesion. The purpose of this study was to evaluate survival and the contributing factors for patients with pontine hemorrhage. Methods : Of the 41 patients who were admitted to our hospital with their first acute pontine hemorrhage from 1997 to 2005, 35 patients were included in this study. Medical records were reviewed to confirm the accuracy of diagnosis and collect demographic, clinical and radiological data. The patients were divided into two groups, survivors and deceased patients; then the survivors were divided again into a group of patient with good results and those with poor results. The location of the hematoma, maximum anteroposterior [AP] diameter, maximum transverse diameter, hematoma volume, ventricular extension, extension into the midbrain, hydrocephalus and initial Glasgow coma scale [GCS] were evaluated. Results : The two year survival rate was 58.5%. The survival of patients with pontine hemorrhage was affected by initial GCS score and transverse hematoma dimeter. Functional outcome of patients who survived was affected by initial GCS, maximum transverse diameter, maximum AP diameter and hematoma volume. Conclusion : The rate of survival after pontine hemorrhage is associated with the transverse diameter of the hematoma and more importantly the initial GCS. Long-term outcome of survivors is influenced by the initial GCS, transverse diameter, AP diameter and volume. Through the multivariate analysis, initial GCS is the only significant factor on survival. Strictly speaking, initial GCS is not modifiable. However, surgical reduction may be considered to amend theses decisive factors. Additional study for indication, timing and method of surgical management is needed.

• Bulletin of the Society of Naval Architects of Korea
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• v.9 no.2
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• pp.43-48
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• 1972

Inertia friction welding, a relatively recent innovation in the art of joining materials, is a forge-welding process that releases kinetic energy stored in the flywheel as frictional heat when two parts are rubbed together under the right conditions. In a comparatively short time, the process has become a reliable method for joining ferrous, and dissimilar metals. The process is based on thrusting one part, attached to a flywheel and rotating at a relatively high speed, against a stationary part. The contacting surfaces, heated to plastic temperatures, are forged together to produce a reliable, high-strength weld. Welds are made with little or no workpiece preparation and without filler metal or fluxes. However, In order to obtain a good weld, the determination of the optimum weld parameters is an important problem. Especially, because the amount of the flywheel mass will be determined according to the initial rotating velocity values at the constant thrust load, the initial rotating velocity is an important factor to affect a weld character of the inertia-welded IN713C-SAE8630, which is used for the wheel-shafts of turbine rotors or turbochargers, exhausting valves, etc. In this paper, the effects of initial rotational velocity on a weld character of inertia-welded IN713C-SAE8630 was studied through considerations of weld parameters determination, micro-structural observations and tensile tests. The results are as the following: 1) As initial rotating velocity was reduced to 267 FPM, cracks and carbide stringers were completely eliminated in the micro-structure of welded zone. 2) As initial rotating velocity was reduced and flywheel mass was increased correspondingly, the maximum welding temperatures were decreased and the plastic working in the weld zone was increased. 3) As initial rotating velocity was progressively decreased and carbides were decreased, the tensile strengths were increased. 4) And also the fracture location moved out of the weld zone and the tensile tests produced, the failures only in the cast superalloy IN713C which do not extend into the weld area. 5) The proper initial rotating velocity could be determined as about 250 thru 350 FPM for the better weld character.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.439-448
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• 2019

There are various factors affecting the success and failure of an apartment building project. However, after the unit sale price has been determined and the sale has started, the most important factor affecting on the project is the initial sales ratio for one month after the sale. Generally, developers predict an initial sales ratio by various data such as economic situation, the trend of the housing market, and the house price near the business place. However, it is very difficult for these factors to be calculated quantitatively in connection with the initial sales ratio. Therefore, the purpose of this study is to develop a regression model for forecasting the initial sales ratio of apartment building projects. For this study, pre-sales data collection, correlation analysis between influencing factors, and regression model development are performed sequentially. The results of this study are used as basic data for predicting the initial sales ratio in the feasibility analysis of apartment building projects and are used as key data for the development of the risk management model.

• KIEAE Journal
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• v.14 no.6
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• pp.105-110
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• 2014

The basic factors determining the amount of energy used in hospital buildings are weather conditions and building factors. But the real energy consumer is central plant equipment such as boilers and chillers that produce thermal energy for heating and cooling. Inaccurate decision of the primary equipment's size can cause a high initial-cost, an excessive equipment space, a wasted energy by low operation-efficiency and shortening of the machine's life. In this reason, the decision of optimal size for central plant equipment is very important. There are several factors for the decision such as an operation factor, a factor (equipment factor), piping losses and a simultaneous usage factor applied in the sizing process except a basic cooling load. But there is no standard method for applying those factors. Usually, factors are applied individually by an experience or custom of each engineer. In this study, the authors emphasize the meaning and the problem of those factors, examine them by analyzing factors which were applied to actual practices, and propose the recommendation value of safety, load, operation factors and application methods.

• Journal of the Korean Society of Safety
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• v.5 no.1
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• pp.19-29
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• 1990

The objective of this paper is to investigate the effect of residual stresses on the $\Delta$K$\sub$th/ and fatigue crack growth behavior of butt weldments. For this purpose, transverse butt sutmerged arc welding was performed on SM50A steel plate and CT(compact tension) specimens which loading direction is perpendicular to weld bead were selected. Welding residual stresses distribution on the specimen was determined by hole drilling method. The case of crack located parallel to weld bead, the states of as weld and PWHT, $\Delta$K$\sub$th/ of specimens(HAZ, weld zone) was higher than that of the base metal probably because of the compressive residual stresses of crack tip. In low $\Delta$K region, it is estimated that the effects of residual stresses for da/dN are great. In region II, the da/dN of weldments in as weld state was lower than that of the base metal. Though da/dN of Weldments in PWHT state was similar to that of the base metal. The constant of power law, m in two states consisted with the base metal. Therefore , it is estimated that the value of m is not affected by residual stresses. Fatigue crack growth behavior of weldments consisted with the base metal considering the effective stress intensity factor range($\Delta$K$\sub$eff/) included the effect of initial residual stress(Kres). Thus, we can predict the fatigue crack growth behavior of weldment by knowing the distribution of initial residual stress at the crack tip.

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.791-795
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• 2002

We studied the physical properties of $Co_3$$O_4$-added Ni-Zn ferrite which were sintered at 1050~110$0^{\circ}C$ for 2 hours. X-ray diffraction showed a spinel structure, and optical microscopy showed grain sizes of 5 to 10 $\mu\textrm{m}$. As the sintering temperature was increased from $1050^{\circ}C$ to $1070^{\circ}C$, the initial permeability and magnetic induction increased, and both of the loss factor and the coercive force decreased. The Curie temperatures were about $^234~245{\circ}C$ with added $Co_3$$O_4$. The initial permeability was 350 to 420 and maximum magnetic induction density and coercive force 4870G to 4980G and 0.15 Oe to 0.21 Oe, respectively which were similar to those of Ni-Zn ferrite synthesized in the conventional process. The frequency of specimen was in the range of 1MHz to 300MHz. In the plot of initial permeability vs. frequencies, a $180^{\circ}C$ rotation of the magnetic domain could be perceived in a broad band of microwave before and after the resonance frequency.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.162-162
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• 2012

ZnPc and CuPc molecules stacked similar way in the film, but showed different growth modes in thermal evaporation. The distribution of CuPc crystals did not change by the film thickness, whereas the distribution of ZnPc became random as the increase of the film thickness. The disc type nanograins of CuPc were quite regularly distributed at the initial growth regime and the regular distribution of nanograins was kept during the film growth. On the other hand, ZnPc consisted in ellipsoid shaped nanograins and the distribution of nanograins was not regular in the initial growth regime. The irregular distribution of nanograins changed to the regular mode at the later growth regime by showing structure factor in GISAXS measurement. The different initial nanograin distribution in ZnPc and CuPc was related to the different nanostructure in the mixed layer with C60 to form the bulk heterojunction.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.274-278
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• 2003

Plackette-Burman method, one of the statistical experimental methods, was used for the screening of main factor for the enhanced production of hGM-CSF. A nine-runs Plackette-Burman design including one center point was the screening design selected for the initial set of experiments. The analysis of the data from the Plackette-Burman experiments showed main effect. Sucrose, nitrogen and temperature were determined to be main factors to enhance the production of hGM-CSF because the absolute values of main effect of sucrose, nitrogen and temperature were higher than the other factors. The production of hGM-CSF was improved when initial sucrose concentration was 50 g/L, initial nitrogen concentration was 90 mM and initial temperature was $20^{\circ}C$.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1006-1011
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• 2010

This study was focused on the reactivity of furnace slag against cadmium to design the vertical drain method with reactive column for improving contaminated sea shore sediment. The removal capacity of furnace slag was analyzed using pseudo-second-order model. And the effective parameters of removal test were initial concentration and initial pH. According to equilibrium removal amount and reactive constant calculated by pseudo-second-order model, the removal capacity was analyzed. Equilibrium removal amount of furnace slag was linearly increased as increasing intial cadmium concentration. Because the pH was around 11, the removal mechanism of furnace slag could be both sorption and precipitation. Therefore the removal amount was increased due to initial concentration. pH was increased to around 11 in the case of "No treat", but the pH were 3.8 in the case of "HAc added" and 0.7 in the case of "HCl added". The removal amount was different 4.8, 1.19 and 0.27 mg/g. This results show the pH was major factor to remove cadmium using furnace slag.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.385-390
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• 2014

Abalone immortal cell lines can be used to study the physiological properties and disease mechanisms of abalone at the cellular and molecular level. As a first step for the final goal to establish abalone immortal cell lines, we examined various initial culture conditions for primary cell populations derived from Haliotis discus hannai radula tissue. The survival rate after cell isolation procedures using the enzymatic method was as low as $9.95{\pm}2.37%$. Based on three different experimental conditions for H. discus hannai radula-derived cell culture, we found that the salinity of the media and the presence of growth-promoting factors were important to support radula-derived primary cell populations during the initial culture. The growth factor-containing media adjusted to 35 psu salinity could induce 100% (8 out of 8 trials) initial cell attachment, and the rate of cell attachment reached 50-70%. The data obtained from this study will provide useful information for developing immortal cell lines from abalone species.