• Journal of the Korean Institute of Gas
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• v.8 no.4 s.25
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• pp.62-69
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• 2004

It is necessary to eliminate the electric static for the prevention of disasters by electric static discharge, the improvement of production efficiency, the protection of a sensitive electronic devices in the variable manufacturing processes. Then it is handled for elimination of electric static in the painting plant, the film manufacturing plant, the producing semi-conductor factory. This study described on the ideal condition of electric static elimination efficiency by changing of the length of voltage input type eliminator's bar, the length of copper pipe and the gap of electrode and the existence of explosion by inflammable gas with that conditions. As the result, the electric static elimination efficiency has the most ideal value at the 8-11(mm) gap of the earth electrode and needle type electrode each elimination bar and there is not explode at the explosive experiment of inflammable gas with the ideal elimination bar. We can consider that there are some data which are needed for elimination efficiency and it will be able to protect the occurrence of explosion accident inflammable nas in the industrial fields.

• Korean Journal of Legislative Studies
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• v.27 no.2
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• pp.71-109
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• 2021

The purpose of this study is to find out what factors influence lawmakers' voting decisions in the plenary session. In particular, the study examines causes and characteristics of waffling and strategic waffling, which express opposition or abstention in a discharge petition or a vote at the plenary session despite participating in a bill sponsorship. The study on waffling is meaningful because it has not been covered in previous literatures. To this end, the Gadeokdo New Airport Special Act, which the National Assembly passed in February 2021, was set as an analysis target. The study examined the factors that affected legislators' voting decisions and participation in bill sponsorship and who were related with waffling. Statistical results showed that the age variable influenced the motion of the bill while seniority and party affiliation had an effect on the participation of the bill. Likewise, the study found that party affiliation and district had an influence on the approval of the bill. In addition, the analysis of waffling showed that lawmakers with higher seniority tended not to participate in the vote. It could be interpreted that lawmakers with more legislative experience judged that they would benefit from strategic waffling. There is a limit to understanding lawmakers' decision-making and waffling through a limited analysis of the Gadeokdo New Airport bill. However, given that lawmakers tend to choose avoidance strategies in ambiguous situations, and given the high intelligence of lawmakers who know better than anyone about the future impact of a new bill, the decision-making shown by lawmakers in each stage of the situation is a prudent judgment gained from their experience. It indicates that it is necessary to research the legislative activities of lawmakers in various ways.

• Korea Journal of Hospital Management
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• v.23 no.1
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• pp.87-106
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• 2018

Objective: The objective of this study is to examine the association between process quality of inpatient care and risk-adjusted, thirty-day potentially preventable hospital readmission (PPR) rates. Data Sources/Study Setting: This was an observational cross-sectional study of nonfederal acute-care hospitals located in two states California and Florida, discharging Medicare patients with a principal discharge diagnosis of heart failure, acute myocardial infarction, or pneumonia January through December 31, 2007. Data were obtained from the Healthcare Cost and Utilization Project State Inpatient Database of the Agency for Healthcare Research and Quality, Centers for Medicare and Medicaid Services Hospital Compare database, and the American Hospital Association Annual Survey of Hospitals. Study Design: The dependent variable of this study is condition-specific, risk-adjusted, thirty-day potentially preventable hospital readmission (PPR). 3M's PPR software was utilized to determine whether a readmission was potentially preventable. The independent variable of this study is hospital performance for process quality of inpatient care, measured by hospital adherence to recommended processes of care. We used multivariate hierarchical logistic models, clustered by hospitals, to examine the relationship between condition-specific, risk-adjusted, thirty-day PPR rates and process quality of inpatient care, after taking clinical and socio-demographic characteristics of patients and structural and operational characteristics of hospitals into account. Findings: Better performance on the process quality metrics was associated with better patient outcome (i.e., low thirty-day PPR rates) in pneumonia, but not generally in two cardiovascular conditions (i.e., heart failure and acute myocardial infarction). Practical Implication: Adherence to the process quality metrics currently in use by CMS is associated with risk-adjusted, thirty-day PPR rates for patients with pneumonia, but not with cardiovascular conditions. More evidence-based process quality metrics closely linked to 30-day PPR rates, particularly for cardiovascular conditions, need to be developed to serve as a guideline to reduce potentially preventable readmissions.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1115-1124
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• 2022

The impact of climate change on water resources was evaluated for Chungju Dam and Soyang-gang Dam basins by constructing an integrated modeling framework consisting of a dam inflow prediction model based on the Variable Infiltration Capacity (VIC) model, a distributed hydrologic model, and an LSTM based dam outflow prediction model. Considering the uncertainty of future climate data, four models of CMIP6 GCM were used as input data of VIC model for future period (2021-2100). As a result of applying future climate data, the average inflow for period increased as the future progressed, and the inflow in the far future (2070-2100) increased by up to 22% compared to that of the observation period (1986-2020). The minimum value of dam discharge lasting 4~50 days was significantly lower than the observed value. This indicates that droughts may occur over a longer period than observed in the past, meaning that citizens of Seoul metropolitan areas may experience severe water shortages due to future droughts. In addition, compared to the near and middle futures, the change in water storage has occurred rapidly in the far future, suggesting that the difficulties of water resource management may increase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.155-158
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• 2000

Influence of sustain pulse-width on electro-luminous efficiency is experimentally investigated for surface discharge of AC-PDP. A square pulse with variable duty ratio and rising time of 300 ns has been used in the experiment. It is found that the firing voltage is decreased as the pulse-width is increased from 2 ${\mu}s$ to 8 ${\mu}s$ with sweeping frequency range of 10 kHz to 50 kHz. It has been found that the optimal sustain pulse-width is in the range of $3{\sim}4{\mu}s$ under driving frequency range of 30 kHz and 50 kHz, based on observation of memory coefficient, wall charge, and wall voltage as well as luminous efficiency.

• Water for future
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• v.28 no.5
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• pp.151-162
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• 1995

A two-dimensional stream tube dispersion model is developed to simulate accurately transverse dispersion processes of pollutants in natural channels. Two distinct features of the stream tube dispersion model derived herein are that it employs the transverse cumulative discharge as an independent variable replacing the transverse distance and that it is developed in a natural coordinate system which follows the general direction of the channel flow. In the model studied, Eulerian-Lagrangian method is used to solve the stream tube dispersion equation. The stream tube dispersion equation is decoupled into two components by the operator-splitting approach; one is governing advection and the other is governing dispersion. The advection equation has been solved using the method of characteristics and the results are interpolated onto Eulerian grid on which the dispersion equation is solved by centered difference method. In solving the advection equation, cubic spline interpolating polynomials is used. In the present study, the results of the application of this model to a natural channel are compared with a steady-state flow measurements. Simulation results are in good accordance with measured data.

• Journal of Korea Water Resources Association
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• v.41 no.1
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• pp.17-25
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• 2008

Whether rating curves are used in practice or new ones are derived, the characteristics of regression analysis are often neglected. For example, a discharge rating curve, which is established from a regression of observed water levels (H) on observed flowrates(Q), is sometimes used for estimating a design water level corresponding to a simulated design flood runoff. However, if independent and dependent variables are changed with each other, the regression equation is changed in existing regression analysis, which is derived from vertical errors between observed data and regression line. Thus, regression equations should not be applied inversely. To avoid this problem, A new two-way variable least-squares regression analysis is proposed. The new method was applied to the rating curves of five water level stations on main stream of Nakdong River. The three kinds of regression models, which are respectively regression of Q versus H (model 1), H versus Q (model 2) and two-way (model 3), showed that the new method can reduce inadvertent mistakes when applied in practice.

• Journal of Korea Water Resources Association
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• v.42 no.4
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• pp.297-307
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• 2009

For reliable water quality simulation by semi distributed model, accurate daily runoff simulation should have preceded. In this study, newly developed channel routing method which is nonlinear storage method is combination of Muskingum routing method and variable storage routing method and temporally weighted average curve number method were applied for effect analysis of water quality simulation. Developed modules, which are added in SWAT models and simulation, were conducted for the Chungju dam watershed. The simulation result by each module applied effect. As a result of analysis contribute water quality modeling, nonlinear storage method is more effective than temporally weighted average curve number method. Nutrient loading discharge was affected by development of runoff delaying from improvement of channel routing, because of characteristics of nonpoint source pollution.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.133-140
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• 2016

Most small weir installed in Korea is concrete solidated weir. Fixed weir causes stagnant flow, which leads to deposit sediment just upstream of weir. As time goes on, it would induce reduction of water storage capacity and invoke the serious water quality issues. Therefore, there has been a growing interest in movable weir. Especially, the flexible rubber weir is easy to install and possible to operate in extreme environments. However, even though this type can be flatable, it is also not free from sediment deposition problem. Thus, to enhance the ability of releasing deposition the bypass pipe was constructed underneath it. In this study the performance of its ability was examined with hydraulic model test. This bypass pipe was designed with 3 different dimensions to connect between each bottom of upstream and downstream of a weir, such as Type A, B, and C. The efficiency of drainage of deposition upstream was studied under two water of upstream and sediment heights. In addition, the ability of sediment emission through the bypass pipe after the pipe was blocked by debris like soil, vegetation et al. was examined by video monitoring. From this study, it was suggested a dimensionless equation which show the relationship of variable parameters and amount of emission sediment through bypass pipe. And it was found that the most significant factors on efficiency of releasing were elbow angle and discharge, and the ability of emission when the pipe was blocked was most highly influenced in tilting length.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.361-364
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• 2009

Purpose: Sebaceous carcinoma is a rare malignant tumor derived from the adnexal epithelium of sebaceous glands. This tumor usually occurs on the eyelids, but uncommonly it may occur on the extraocular sites. It is characterized by a tendency of local recurrence and occasional metastasis. Surgical excision is appropriate treatment for patients with sebaceous carcinoma. Because this kind of case is rare, we report two cases of sebaceous carcinoma developed on scalp. Methods: Case 1 was a 69 - year - old woman. She visited the hospital with a $1.5{\times}2.5cm$ sized reddish yellow - colored, slowly growing mass on left parietal scalp. The mass began at birth and started growing at 5 years ago. Case 2 was a 67 - year - old woman. She had $2.5{\times}3.0cm$ sized yellow - colored mass on right parietal scalp. It occured at birth and started growing at 3 years ago. And the masses had erythematous ulcer with sanguineous discharge. In the beginning, the masses were miliary nodule. Results: CT scan and fine needle biopsy were done. Case 1 and 2 were diagnosed as sebaceous carcinoma. Wide excision with safety margin of 10 mm and split thickness skin graft was done. Histological examination revealed well demarcated, irregular, variable sized tumor lobules. Each lobule was composed of sebaceous and undifferentiated cells. Postoperatively, the patients did well and the lesion had not recurred. Conclusion: Sebaceous carcinoma is an aggressive malignant tumor. It often can be mistaken for other skin tumors. Authors experienced two rare cases of sebaceous carcinoma developed on scalp. We recommend early wide excision with enough safety margin as treatment of sebaceous carcinoma.