• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.26-32
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• 2012

Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafers. This study will report the characteristic of wafer according to processing time, machining speed and pressure which have major influence on the abrasion of Si wafer polishing. It is possible to evaluation of wafer abrasion by load cell and infrared temperature sensor. The characteristic of wafer surface according to processing condition is selected to use a result data that measure a pressure, machining speed, and the processing time. This result is appeared by the characteristic of wafer surface in machining condition. Through that, the study cans evaluation a wafer characteristic in variable machining condition. It is important to obtain optimal condition. Thus the optimum condition selection of ultra precision Si wafer polishing using load cell and infrared temperature sensor. To evaluate each machining factor, use a data through each sensor. That evaluation of abrasion according to variety condition is selected to use a result data that measure a pressure, machining speed, and the processing time. And optimum condition is selected by this result.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.65-75
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• 2003

Objectives: To investigate the role of TGF (Transforming growth factor-$\beta$) involved in the paracrinic communication during decidualization between UEC (uterine epithelial cells) and USC (uterine stromal cells), we have employed a co-culture system composed of human endometrial epithelial and stromal cells in defined hormonal conditions. Design: In the co-culture, endometrial epithelial cells cultured in the matrigel-coated cell culture insert are seeded on top of the endometrial stromal cells cultured within a collagen gel. The co-culture was maintained for 48 hours under the following hormonal conditions: progesterone dominant condition (100 nM P4 and 1 nM E2) or estrogen-dominant condition (100 nM E2 and 1 nM P4). 10 ng/ ml HGF and/or 10 ng/ml TGF-$\beta$1 are added. Methods: RT-PCR is utilized to detect mRNAs quantitatively. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining are utilized to detect proteins in the tissue. Results: Prolactin mRNA is expressed in the co-cultured stromal cells under the progesterone dominant condition. TGF-$\beta$1 and its receptors are expressed in both the co-cultured epithelial and stromal cells irrespective of the steroid present, which is in contrast with no or negligible expression of TGF-$\beta$1 or its receptor in cells separately cultured. Both estrogen and progesterone significantly elevate the concentration of hepatocyte growth factor (HGF) in the conditioned medium of the co-culture with the value of 4, 325 pg/ml in E2-dominant and 2, 000 pg/ml in P4-dominant condition compare to 150 pg/ml in no hormone. In separately cultured stromal cells, administration of HGF induces the expression of TGF receptor 1 in both hormonal conditions, but induction of TGF receptor 2 is only manifest in the P4-dominant condition. Administration of TGF-$\beta$ and HGF directly induce the decidualization marker prolactin mRNA in separately cultured stromal cells. Conclusion: It is likely that steroid hormones induces prolactin mRNA indirectly by promoting the cell to cell communication between the stromal and the epithelial cells. TGF-$\beta$ and HGF are two possible paracrine mediators in the human endometrial decidualization.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.306-312
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• 2017

Changes in the cell growth and lipid accumulation of marine microalga Dunaliella tertiolecta were investigated in response to the combination of different stress factors including the variation of iron supply as a primary stress factor and different options in light irradiation and $CO_2$ supply as a secondary stress factor. High or limited Fe conditions could act as a stress for lipid synthesis. As a secondary stress factor, non-$CO_2$ condition was good for lipid accumulation, but the overall cell growth was sacrificed significantly after a long-time cultivation. Dark condition as a secondary stress factor also favored lipid accumulation and the extent of cell density reduction at the early period in the dark was small compared to other stress conditions. The two-stage cultivation strategy was necessary to maximize lipid production because tendencies of the cell growth and lipid content were not identical under the chosen stress condition. The first stage was for preparing a high cell density under the normal growth-favoring condition and the second stage was the stress condition to induce lipid accumulation in a short time. The short-term (12 h) incubation under the 5X Fe (3.25 mg/L) and dark conditions resulted in the best lipid productivity of 1.44 g/L/d providing 2 g/L inoculum at the second stage.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.747-763
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• 2000

through a literal study upon Arrhythmia between east and west medicine, the results were as follows 1. Arrhythmia is not only irregular cardiac beat but disorder of cardiac impulse making and conduction disturbance. it means almost irregularity of interval between two beat 2. In the east medicine, arrhythmia is represented various category as palpitation, continuous palpitation, dizziness, consumption which give the first consideration by the accompanied symptoms. A separate way in a diagnostics it become a base of diagnosis of diseases and decision of prognosis by the examination of pulse 3. In the west medicine, Arrhythmia is classified as disorder of heart rate, rhythm, conduction disturbance or tachycardia, bradycardia and it is concomitant with fatigue, palpitation, dyspnoea, syncope, chest discomfort 4. The diagnostic study of pulse condition which represent arrhythmia was started from $\mathbb{<}$Nae-Kyung$\mathbb{>}$ and it was revealed as pulse condition of rapid pulse, slow pulse, swift pulse, running pulse, knotted pulse, intermittent pulse etc. Out of them running pulse, knotted pulse, intermittent pulse which obviously are concomitant with irregularity of interval are clinically meaningful in a conditions of disease and decision of prognosis. and the significance of these pulse condition are transformed through the changes of the times 5. According to cause of disease it is classified by Arrhythmia(running pulse, knotted pulse, intermittent pulse) due to heat, cold, phlegm, deficiency(or insufficiency) and There are three categories of etiological factor that is, endogenous, exogenous and non-exo-endogenous factor. the endogenous factor is insufficiency of the heart Ki, deficiency of both Ki and blood, intemal stagnation of phlegm and fluid, stagnation of seven emotions. the exogenous factor is caused by stagnation of Ki and blood by six exogenous pathogenic factor and the non-exo-endgenous factors are improper diet, overstrain, traumatic injury. A cause of arrhythmia in western medicine are a organic and pathological change of the heart itself and malfunction of the autonomic nervous system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.9
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• pp.2792-2799
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• 1996

It was shown in the previous study that the numerically derived elastic work factor for CLS specimen was independent of fiber direction for a unidirectional case. Also, it was proposed the elastic work factor could be used to determine energy release rate from a single test record. In the present study, elastic work factor was derived from a simple beam theory to investigate its dependence on material property and geometric condition. Also, the elastic work factor of CLS specimen was applied experimentally to determine critical energy release rate in order to prove its validity determining critical energy release rate from a single specimen. For this purpose, critical energy release rate determined using the elastic work factor was compared with that determined by the compliance method. The results showed that while elastic work factor is affected by $t_2/t_1$ and $L_2/L_1$ it is independent of fiber angle for a unidirectional case. It was also found that critical energy release rates determined by both methods are comparable each other, thus elastic work factor approach can be used to determine energy release rate from a single test specimen.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.33-42
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• 2003

Since the cut slope has been big concern due to frequent failures, the government decided to include cut slopes in the“Act for Safety Control of Public Structures”. Based on the Act, the cut slope whose height is over 50m and length is over 200m should be inspected on the regular basis. According to the Act, KISTEC developed the objective evaluation method for the condition of cut slope. The evaluation method is divided into two categories: evaluation for damaged condition and evaluation for failure affecting factor. Based on the evaluation results, the cut slope is graded from A to E. In this study, the process to evaluate the cut slope condition and the evaluation criteria to divide the grade of cut slope are introduced.

• Water Engineering Research
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• v.5 no.1
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• pp.1-16
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• 2004

The purpose of this study is to understand the characteristics of hourly PET(Potential Evapo Transpiration) variation estimated using Penman ET model. The estimated PET using Penman model was compared with measured ET. For this study, two subwatersheds were selected, and fluxes, meteorological data and soil moisture data were measured during the summer and winter days. During the winter days, the aerodynamic term of Penman ET is much greater than that of energy term of Penman ET for dry soil condition. The opposite phenomena appeared fer wet soil condition. During the summer days, energy term is much more important factor for ET estimation compared with aerodynamic term regardless of soil moisture condition. Penman ET, measured ET, and energy term show the similar hourly variation pattern mainly because the influence of net radiation on the estimation of Penman ET is much more significant compared with other variables. Even though there are much more soil moisture in the soil during the wet days, the estimated hourly ET from Penman model and measured hourly ET have smaller values compared with those of dry days, indicating the effect of cloudy weather condition.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.185-190
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• 2003

The most shortcoming of metalhalide lamps is what the instant restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition. Therefore it takes about five minutes to restart the metalhalide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 20kV at the both sides of lamp. The proposed electronic ballast is consist of a electromagnetic interference (EMI) filter, a power factor correction (PFC) circuit, a flyback converter, a half-bridge inverter, and a high voltage igniter circuit. By this composition we can restart the lamp with the voltage 20kV, even if the lamp is in the hot condition.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.85-92
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• 2003

Hysteretic behaviors of a seismic isolator are identified by using the regularized output error estimator (OEE) based on the secant stiffness model. A proper regularity condition of tangent stiffness for the current OEE is proposed considering the regularity condition of Duhem hysteretic operator. The proposed regularity condition is defined by 12-norm of the tangent stiffness with respect to time. The secant stiffness model for the OEE is obtained by approximating the tangent stiffness under the proposed regularity condition by the secant stiffness at each time step. A least square method is employed to minimize the difference between the calculated response and measured response for the OEE. The regularity condition of the secant stiffness is utilized to alleviate ill-posedness of the OEE and to yield numerically stable solutions through the regularization technique. An optimal regularization factor determined by geometric mean scheme (GMS) is used to yield appropriate regularization effects on the OEE.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.113-129
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• 2010

Proper pre-safety training is one of core mandatory in order to reduce injuries at the construction fields. In this study, we investigate the employee's opinions of safety training, safety recognition, the actual conditions of safety through survey. As a result of study, incident factors are roughly divided into technical factor, managerial factor, and educational factor. We confirmed that the educational factor led by deficiency of safety awareness and knowledge was the major factor. It needs to be resettled or revised properly to match with the incident trends and the safety training curriculum should also be improved and drastically revised with special quality. The managerial workers' safety recognition is lower than the site ones regarding the correct understanding of the importance of the training.. It suggest that the education method and system in construction fields might have fundamental problems.